* [PATCH 0/18 v6] dax, ext4, xfs: Synchronous page faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Hello,
here is the sixth version of my patches to implement synchronous page faults
for DAX mappings to make flushing of DAX mappings possible from userspace so
that they can be flushed on finer than page granularity and also avoid the
overhead of a syscall.
I think we are ready to get this merged - I've talked to Dan and he said he
could take the patches through his tree. It would just be nice to get final
ack from Christoph for the first patch implementing MAP_VALIDATE and someone
from XFS folks to check patch 17 (make xfs_filemap_pfn_mkwrite use
__xfs_filemap_fault()).
---
We use a new mmap flag MAP_SYNC to indicate that page faults for the mapping
should be synchronous. The guarantee provided by this flag is: While a block
is writeably mapped into page tables of this mapping, it is guaranteed to be
visible in the file at that offset also after a crash.
How I implement this is that ->iomap_begin() indicates by a flag that inode
block mapping metadata is unstable and may need flushing (use the same test as
whether fdatasync() has metadata to write). If yes, DAX fault handler refrains
from inserting / write-enabling the page table entry and returns special flag
VM_FAULT_NEEDDSYNC together with a PFN to map to the filesystem fault handler.
The handler then calls fdatasync() (vfs_fsync_range()) for the affected range
and after that calls DAX code to update the page table entry appropriately.
I did some basic performance testing on the patches over ramdisk - timed
latency of page faults when faulting 512 pages. I did several tests: with file
preallocated / with file empty, with background file copying going on / without
it, with / without MAP_SYNC (so that we get comparison). The results are
(numbers are in microseconds):
File preallocated, no background load no MAP_SYNC:
min=9 avg=10 max=46
8 - 15 us: 508
16 - 31 us: 3
32 - 63 us: 1
File preallocated, no background load, MAP_SYNC:
min=9 avg=10 max=47
8 - 15 us: 508
16 - 31 us: 2
32 - 63 us: 2
File empty, no background load, no MAP_SYNC:
min=21 avg=22 max=70
16 - 31 us: 506
32 - 63 us: 5
64 - 127 us: 1
File empty, no background load, MAP_SYNC:
min=40 avg=124 max=242
32 - 63 us: 1
64 - 127 us: 333
128 - 255 us: 178
File empty, background load, no MAP_SYNC:
min=21 avg=23 max=67
16 - 31 us: 507
32 - 63 us: 4
64 - 127 us: 1
File empty, background load, MAP_SYNC:
min=94 avg=112 max=181
64 - 127 us: 489
128 - 255 us: 23
So here we can see the difference between MAP_SYNC vs non MAP_SYNC is about
100-200 us when we need to wait for transaction commit in this setup.
Changes since v5:
* really updated the manpage
* improved comment describing IOMAP_F_DIRTY
* fixed XFS handling of VM_FAULT_NEEDSYNC in xfs_filemap_pfn_mkwrite()
Changes since v4:
* fixed couple of minor things in the manpage
* make legacy mmap flags always supported, remove them from mask declared
to be supported by ext4 and xfs
Changes since v3:
* updated some changelogs
* folded fs support for VM_SYNC flag into patches implementing the
functionality
* removed ->mmap_validate, use ->mmap_supported_flags instead
* added some Reviewed-by tags
* added manpage patch
Changes since v2:
* avoid unnecessary flushing of faulted page (Ross) - I've realized it makes no
sense to remeasure my benchmark results (after actually doing that and seeing
no difference, sigh) since I use ramdisk and not real PMEM HW and so flushes
are ignored.
* handle nojournal mode of ext4
* other smaller cleanups & fixes (Ross)
* factor larger part of finishing of synchronous fault into a helper (Christoph)
* reorder pfnp argument of dax_iomap_fault() (Christoph)
* add XFS support from Christoph
* use proper MAP_SYNC support in mmap(2)
* rebased on top of 4.14-rc4
Changes since v1:
* switched to using mmap flag MAP_SYNC
* cleaned up fault handlers to avoid passing pfn in vmf->orig_pte
* switched to not touching page tables before we are ready to insert final
entry as it was unnecessary and not really simplifying anything
* renamed fault flag to VM_FAULT_NEEDDSYNC
* other smaller fixes found by reviewers
Honza
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* [PATCH 0/18 v6] dax, ext4, xfs: Synchronous page faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Hello,
here is the sixth version of my patches to implement synchronous page faults
for DAX mappings to make flushing of DAX mappings possible from userspace so
that they can be flushed on finer than page granularity and also avoid the
overhead of a syscall.
I think we are ready to get this merged - I've talked to Dan and he said he
could take the patches through his tree. It would just be nice to get final
ack from Christoph for the first patch implementing MAP_VALIDATE and someone
from XFS folks to check patch 17 (make xfs_filemap_pfn_mkwrite use
__xfs_filemap_fault()).
---
We use a new mmap flag MAP_SYNC to indicate that page faults for the mapping
should be synchronous. The guarantee provided by this flag is: While a block
is writeably mapped into page tables of this mapping, it is guaranteed to be
visible in the file at that offset also after a crash.
How I implement this is that ->iomap_begin() indicates by a flag that inode
block mapping metadata is unstable and may need flushing (use the same test as
whether fdatasync() has metadata to write). If yes, DAX fault handler refrains
from inserting / write-enabling the page table entry and returns special flag
VM_FAULT_NEEDDSYNC together with a PFN to map to the filesystem fault handler.
The handler then calls fdatasync() (vfs_fsync_range()) for the affected range
and after that calls DAX code to update the page table entry appropriately.
I did some basic performance testing on the patches over ramdisk - timed
latency of page faults when faulting 512 pages. I did several tests: with file
preallocated / with file empty, with background file copying going on / without
it, with / without MAP_SYNC (so that we get comparison). The results are
(numbers are in microseconds):
File preallocated, no background load no MAP_SYNC:
min=9 avg=10 max=46
8 - 15 us: 508
16 - 31 us: 3
32 - 63 us: 1
File preallocated, no background load, MAP_SYNC:
min=9 avg=10 max=47
8 - 15 us: 508
16 - 31 us: 2
32 - 63 us: 2
File empty, no background load, no MAP_SYNC:
min=21 avg=22 max=70
16 - 31 us: 506
32 - 63 us: 5
64 - 127 us: 1
File empty, no background load, MAP_SYNC:
min=40 avg=124 max=242
32 - 63 us: 1
64 - 127 us: 333
128 - 255 us: 178
File empty, background load, no MAP_SYNC:
min=21 avg=23 max=67
16 - 31 us: 507
32 - 63 us: 4
64 - 127 us: 1
File empty, background load, MAP_SYNC:
min=94 avg=112 max=181
64 - 127 us: 489
128 - 255 us: 23
So here we can see the difference between MAP_SYNC vs non MAP_SYNC is about
100-200 us when we need to wait for transaction commit in this setup.
Changes since v5:
* really updated the manpage
* improved comment describing IOMAP_F_DIRTY
* fixed XFS handling of VM_FAULT_NEEDSYNC in xfs_filemap_pfn_mkwrite()
Changes since v4:
* fixed couple of minor things in the manpage
* make legacy mmap flags always supported, remove them from mask declared
to be supported by ext4 and xfs
Changes since v3:
* updated some changelogs
* folded fs support for VM_SYNC flag into patches implementing the
functionality
* removed ->mmap_validate, use ->mmap_supported_flags instead
* added some Reviewed-by tags
* added manpage patch
Changes since v2:
* avoid unnecessary flushing of faulted page (Ross) - I've realized it makes no
sense to remeasure my benchmark results (after actually doing that and seeing
no difference, sigh) since I use ramdisk and not real PMEM HW and so flushes
are ignored.
* handle nojournal mode of ext4
* other smaller cleanups & fixes (Ross)
* factor larger part of finishing of synchronous fault into a helper (Christoph)
* reorder pfnp argument of dax_iomap_fault() (Christoph)
* add XFS support from Christoph
* use proper MAP_SYNC support in mmap(2)
* rebased on top of 4.14-rc4
Changes since v1:
* switched to using mmap flag MAP_SYNC
* cleaned up fault handlers to avoid passing pfn in vmf->orig_pte
* switched to not touching page tables before we are ready to insert final
entry as it was unnecessary and not really simplifying anything
* renamed fault flag to VM_FAULT_NEEDDSYNC
* other smaller fixes found by reviewers
Honza
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* [PATCH 0/18 v6] dax, ext4, xfs: Synchronous page faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Hello,
here is the sixth version of my patches to implement synchronous page faults
for DAX mappings to make flushing of DAX mappings possible from userspace so
that they can be flushed on finer than page granularity and also avoid the
overhead of a syscall.
I think we are ready to get this merged - I've talked to Dan and he said he
could take the patches through his tree. It would just be nice to get final
ack from Christoph for the first patch implementing MAP_VALIDATE and someone
from XFS folks to check patch 17 (make xfs_filemap_pfn_mkwrite use
__xfs_filemap_fault()).
---
We use a new mmap flag MAP_SYNC to indicate that page faults for the mapping
should be synchronous. The guarantee provided by this flag is: While a block
is writeably mapped into page tables of this mapping, it is guaranteed to be
visible in the file at that offset also after a crash.
How I implement this is that ->iomap_begin() indicates by a flag that inode
block mapping metadata is unstable and may need flushing (use the same test as
whether fdatasync() has metadata to write). If yes, DAX fault handler refrains
from inserting / write-enabling the page table entry and returns special flag
VM_FAULT_NEEDDSYNC together with a PFN to map to the filesystem fault handler.
The handler then calls fdatasync() (vfs_fsync_range()) for the affected range
and after that calls DAX code to update the page table entry appropriately.
I did some basic performance testing on the patches over ramdisk - timed
latency of page faults when faulting 512 pages. I did several tests: with file
preallocated / with file empty, with background file copying going on / without
it, with / without MAP_SYNC (so that we get comparison). The results are
(numbers are in microseconds):
File preallocated, no background load no MAP_SYNC:
min=9 avg=10 max=46
8 - 15 us: 508
16 - 31 us: 3
32 - 63 us: 1
File preallocated, no background load, MAP_SYNC:
min=9 avg=10 max=47
8 - 15 us: 508
16 - 31 us: 2
32 - 63 us: 2
File empty, no background load, no MAP_SYNC:
min=21 avg=22 max=70
16 - 31 us: 506
32 - 63 us: 5
64 - 127 us: 1
File empty, no background load, MAP_SYNC:
min=40 avg=124 max=242
32 - 63 us: 1
64 - 127 us: 333
128 - 255 us: 178
File empty, background load, no MAP_SYNC:
min=21 avg=23 max=67
16 - 31 us: 507
32 - 63 us: 4
64 - 127 us: 1
File empty, background load, MAP_SYNC:
min=94 avg=112 max=181
64 - 127 us: 489
128 - 255 us: 23
So here we can see the difference between MAP_SYNC vs non MAP_SYNC is about
100-200 us when we need to wait for transaction commit in this setup.
Changes since v5:
* really updated the manpage
* improved comment describing IOMAP_F_DIRTY
* fixed XFS handling of VM_FAULT_NEEDSYNC in xfs_filemap_pfn_mkwrite()
Changes since v4:
* fixed couple of minor things in the manpage
* make legacy mmap flags always supported, remove them from mask declared
to be supported by ext4 and xfs
Changes since v3:
* updated some changelogs
* folded fs support for VM_SYNC flag into patches implementing the
functionality
* removed ->mmap_validate, use ->mmap_supported_flags instead
* added some Reviewed-by tags
* added manpage patch
Changes since v2:
* avoid unnecessary flushing of faulted page (Ross) - I've realized it makes no
sense to remeasure my benchmark results (after actually doing that and seeing
no difference, sigh) since I use ramdisk and not real PMEM HW and so flushes
are ignored.
* handle nojournal mode of ext4
* other smaller cleanups & fixes (Ross)
* factor larger part of finishing of synchronous fault into a helper (Christoph)
* reorder pfnp argument of dax_iomap_fault() (Christoph)
* add XFS support from Christoph
* use proper MAP_SYNC support in mmap(2)
* rebased on top of 4.14-rc4
Changes since v1:
* switched to using mmap flag MAP_SYNC
* cleaned up fault handlers to avoid passing pfn in vmf->orig_pte
* switched to not touching page tables before we are ready to insert final
entry as it was unnecessary and not really simplifying anything
* renamed fault flag to VM_FAULT_NEEDDSYNC
* other smaller fixes found by reviewers
Honza
^ permalink raw reply [flat|nested] 132+ messages in thread
* [PATCH 0/18 v6] dax, ext4, xfs: Synchronous page faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Hello,
here is the sixth version of my patches to implement synchronous page faults
for DAX mappings to make flushing of DAX mappings possible from userspace so
that they can be flushed on finer than page granularity and also avoid the
overhead of a syscall.
I think we are ready to get this merged - I've talked to Dan and he said he
could take the patches through his tree. It would just be nice to get final
ack from Christoph for the first patch implementing MAP_VALIDATE and someone
from XFS folks to check patch 17 (make xfs_filemap_pfn_mkwrite use
__xfs_filemap_fault()).
---
We use a new mmap flag MAP_SYNC to indicate that page faults for the mapping
should be synchronous. The guarantee provided by this flag is: While a block
is writeably mapped into page tables of this mapping, it is guaranteed to be
visible in the file at that offset also after a crash.
How I implement this is that ->iomap_begin() indicates by a flag that inode
block mapping metadata is unstable and may need flushing (use the same test as
whether fdatasync() has metadata to write). If yes, DAX fault handler refrains
from inserting / write-enabling the page table entry and returns special flag
VM_FAULT_NEEDDSYNC together with a PFN to map to the filesystem fault handler.
The handler then calls fdatasync() (vfs_fsync_range()) for the affected range
and after that calls DAX code to update the page table entry appropriately.
I did some basic performance testing on the patches over ramdisk - timed
latency of page faults when faulting 512 pages. I did several tests: with file
preallocated / with file empty, with background file copying going on / without
it, with / without MAP_SYNC (so that we get comparison). The results are
(numbers are in microseconds):
File preallocated, no background load no MAP_SYNC:
min=9 avg=10 max=46
8 - 15 us: 508
16 - 31 us: 3
32 - 63 us: 1
File preallocated, no background load, MAP_SYNC:
min=9 avg=10 max=47
8 - 15 us: 508
16 - 31 us: 2
32 - 63 us: 2
File empty, no background load, no MAP_SYNC:
min=21 avg=22 max=70
16 - 31 us: 506
32 - 63 us: 5
64 - 127 us: 1
File empty, no background load, MAP_SYNC:
min=40 avg=124 max=242
32 - 63 us: 1
64 - 127 us: 333
128 - 255 us: 178
File empty, background load, no MAP_SYNC:
min=21 avg=23 max=67
16 - 31 us: 507
32 - 63 us: 4
64 - 127 us: 1
File empty, background load, MAP_SYNC:
min=94 avg=112 max=181
64 - 127 us: 489
128 - 255 us: 23
So here we can see the difference between MAP_SYNC vs non MAP_SYNC is about
100-200 us when we need to wait for transaction commit in this setup.
Changes since v5:
* really updated the manpage
* improved comment describing IOMAP_F_DIRTY
* fixed XFS handling of VM_FAULT_NEEDSYNC in xfs_filemap_pfn_mkwrite()
Changes since v4:
* fixed couple of minor things in the manpage
* make legacy mmap flags always supported, remove them from mask declared
to be supported by ext4 and xfs
Changes since v3:
* updated some changelogs
* folded fs support for VM_SYNC flag into patches implementing the
functionality
* removed ->mmap_validate, use ->mmap_supported_flags instead
* added some Reviewed-by tags
* added manpage patch
Changes since v2:
* avoid unnecessary flushing of faulted page (Ross) - I've realized it makes no
sense to remeasure my benchmark results (after actually doing that and seeing
no difference, sigh) since I use ramdisk and not real PMEM HW and so flushes
are ignored.
* handle nojournal mode of ext4
* other smaller cleanups & fixes (Ross)
* factor larger part of finishing of synchronous fault into a helper (Christoph)
* reorder pfnp argument of dax_iomap_fault() (Christoph)
* add XFS support from Christoph
* use proper MAP_SYNC support in mmap(2)
* rebased on top of 4.14-rc4
Changes since v1:
* switched to using mmap flag MAP_SYNC
* cleaned up fault handlers to avoid passing pfn in vmf->orig_pte
* switched to not touching page tables before we are ready to insert final
entry as it was unnecessary and not really simplifying anything
* renamed fault flag to VM_FAULT_NEEDDSYNC
* other smaller fixes found by reviewers
Honza
^ permalink raw reply [flat|nested] 132+ messages in thread
* [PATCH 0/18 v6] dax, ext4, xfs: Synchronous page faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Hello,
here is the sixth version of my patches to implement synchronous page faults
for DAX mappings to make flushing of DAX mappings possible from userspace so
that they can be flushed on finer than page granularity and also avoid the
overhead of a syscall.
I think we are ready to get this merged - I've talked to Dan and he said he
could take the patches through his tree. It would just be nice to get final
ack from Christoph for the first patch implementing MAP_VALIDATE and someone
from XFS folks to check patch 17 (make xfs_filemap_pfn_mkwrite use
__xfs_filemap_fault()).
---
We use a new mmap flag MAP_SYNC to indicate that page faults for the mapping
should be synchronous. The guarantee provided by this flag is: While a block
is writeably mapped into page tables of this mapping, it is guaranteed to be
visible in the file at that offset also after a crash.
How I implement this is that ->iomap_begin() indicates by a flag that inode
block mapping metadata is unstable and may need flushing (use the same test as
whether fdatasync() has metadata to write). If yes, DAX fault handler refrains
from inserting / write-enabling the page table entry and returns special flag
VM_FAULT_NEEDDSYNC together with a PFN to map to the filesystem fault handler.
The handler then calls fdatasync() (vfs_fsync_range()) for the affected range
and after that calls DAX code to update the page table entry appropriately.
I did some basic performance testing on the patches over ramdisk - timed
latency of page faults when faulting 512 pages. I did several tests: with file
preallocated / with file empty, with background file copying going on / without
it, with / without MAP_SYNC (so that we get comparison). The results are
(numbers are in microseconds):
File preallocated, no background load no MAP_SYNC:
min=9 avg=10 max=46
8 - 15 us: 508
16 - 31 us: 3
32 - 63 us: 1
File preallocated, no background load, MAP_SYNC:
min=9 avg=10 max=47
8 - 15 us: 508
16 - 31 us: 2
32 - 63 us: 2
File empty, no background load, no MAP_SYNC:
min=21 avg=22 max=70
16 - 31 us: 506
32 - 63 us: 5
64 - 127 us: 1
File empty, no background load, MAP_SYNC:
min=40 avg=124 max=242
32 - 63 us: 1
64 - 127 us: 333
128 - 255 us: 178
File empty, background load, no MAP_SYNC:
min=21 avg=23 max=67
16 - 31 us: 507
32 - 63 us: 4
64 - 127 us: 1
File empty, background load, MAP_SYNC:
min=94 avg=112 max=181
64 - 127 us: 489
128 - 255 us: 23
So here we can see the difference between MAP_SYNC vs non MAP_SYNC is about
100-200 us when we need to wait for transaction commit in this setup.
Changes since v5:
* really updated the manpage
* improved comment describing IOMAP_F_DIRTY
* fixed XFS handling of VM_FAULT_NEEDSYNC in xfs_filemap_pfn_mkwrite()
Changes since v4:
* fixed couple of minor things in the manpage
* make legacy mmap flags always supported, remove them from mask declared
to be supported by ext4 and xfs
Changes since v3:
* updated some changelogs
* folded fs support for VM_SYNC flag into patches implementing the
functionality
* removed ->mmap_validate, use ->mmap_supported_flags instead
* added some Reviewed-by tags
* added manpage patch
Changes since v2:
* avoid unnecessary flushing of faulted page (Ross) - I've realized it makes no
sense to remeasure my benchmark results (after actually doing that and seeing
no difference, sigh) since I use ramdisk and not real PMEM HW and so flushes
are ignored.
* handle nojournal mode of ext4
* other smaller cleanups & fixes (Ross)
* factor larger part of finishing of synchronous fault into a helper (Christoph)
* reorder pfnp argument of dax_iomap_fault() (Christoph)
* add XFS support from Christoph
* use proper MAP_SYNC support in mmap(2)
* rebased on top of 4.14-rc4
Changes since v1:
* switched to using mmap flag MAP_SYNC
* cleaned up fault handlers to avoid passing pfn in vmf->orig_pte
* switched to not touching page tables before we are ready to insert final
entry as it was unnecessary and not really simplifying anything
* renamed fault flag to VM_FAULT_NEEDDSYNC
* other smaller fixes found by reviewers
Honza
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, Arnd Bergmann, linux-nvdimm, linux-api,
Darrick J . Wong, Christoph Hellwig, linux-mm, Andy Lutomirski,
linux-fsdevel, linux-ext4, Andrew Morton
From: Dan Williams <dan.j.williams@intel.com>
The mmap(2) syscall suffers from the ABI anti-pattern of not validating
unknown flags. However, proposals like MAP_SYNC need a mechanism to
define new behavior that is known to fail on older kernels without the
support. Define a new MAP_SHARED_VALIDATE flag pattern that is
guaranteed to fail on all legacy mmap implementations.
It is worth noting that the original proposal was for a standalone
MAP_VALIDATE flag. However, when that could not be supported by all
archs Linus observed:
I see why you *think* you want a bitmap. You think you want
a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
etc, so that people can do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
| MAP_SYNC, fd, 0);
and "know" that MAP_SYNC actually takes.
And I'm saying that whole wish is bogus. You're fundamentally
depending on special semantics, just make it explicit. It's already
not portable, so don't try to make it so.
Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
of 0x3, and make people do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
| MAP_SYNC, fd, 0);
and then the kernel side is easier too (none of that random garbage
playing games with looking at the "MAP_VALIDATE bit", but just another
case statement in that map type thing.
Boom. Done.
Similar to ->fallocate() we also want the ability to validate the
support for new flags on a per ->mmap() 'struct file_operations'
instance basis. Towards that end arrange for flags to be generically
validated against a mmap_supported_flags exported by 'struct
file_operations'. By default all existing flags are implicitly
supported, but new flags require MAP_SHARED_VALIDATE and
per-instance-opt-in.
Cc: Jan Kara <jack@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
arch/alpha/include/uapi/asm/mman.h | 1 +
arch/mips/include/uapi/asm/mman.h | 1 +
arch/parisc/include/uapi/asm/mman.h | 1 +
arch/xtensa/include/uapi/asm/mman.h | 1 +
include/linux/fs.h | 1 +
include/linux/mman.h | 39 ++++++++++++++++++++++++++++
include/uapi/asm-generic/mman-common.h | 1 +
mm/mmap.c | 15 +++++++++++
tools/include/uapi/asm-generic/mman-common.h | 1 +
9 files changed, 61 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 3b26cc62dadb..f6d118aaedb9 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
#define MAP_FIXED 0x100 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index da3216007fe0..93268e4cd3c7 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -28,6 +28,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 775b5d5e41a1..bca652aa1677 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x03 /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index b15b278aa314..9ab426374714 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -35,6 +35,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab191a23e..57added3201d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1701,6 +1701,7 @@ struct file_operations {
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
+ unsigned long mmap_supported_flags;
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mman.h b/include/linux/mman.h
index c8367041fafd..94b63b4d71ff 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -7,6 +7,45 @@
#include <linux/atomic.h>
#include <uapi/linux/mman.h>
+/*
+ * Arrange for legacy / undefined architecture specific flags to be
+ * ignored by default in LEGACY_MAP_MASK.
+ */
+#ifndef MAP_32BIT
+#define MAP_32BIT 0
+#endif
+#ifndef MAP_HUGE_2MB
+#define MAP_HUGE_2MB 0
+#endif
+#ifndef MAP_HUGE_1GB
+#define MAP_HUGE_1GB 0
+#endif
+#ifndef MAP_UNINITIALIZED
+#define MAP_UNINITIALIZED 0
+#endif
+
+/*
+ * The historical set of flags that all mmap implementations implicitly
+ * support when a ->mmap_validate() op is not provided in file_operations.
+ */
+#define LEGACY_MAP_MASK (MAP_SHARED \
+ | MAP_PRIVATE \
+ | MAP_FIXED \
+ | MAP_ANONYMOUS \
+ | MAP_DENYWRITE \
+ | MAP_EXECUTABLE \
+ | MAP_UNINITIALIZED \
+ | MAP_GROWSDOWN \
+ | MAP_LOCKED \
+ | MAP_NORESERVE \
+ | MAP_POPULATE \
+ | MAP_NONBLOCK \
+ | MAP_STACK \
+ | MAP_HUGETLB \
+ | MAP_32BIT \
+ | MAP_HUGE_2MB \
+ | MAP_HUGE_1GB)
+
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern unsigned long sysctl_overcommit_kbytes;
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
diff --git a/mm/mmap.c b/mm/mmap.c
index 680506faceae..924839fac0e6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (file) {
struct inode *inode = file_inode(file);
+ unsigned long flags_mask;
+
+ flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
switch (flags & MAP_TYPE) {
case MAP_SHARED:
+ /*
+ * Force use of MAP_SHARED_VALIDATE with non-legacy
+ * flags. E.g. MAP_SYNC is dangerous to use with
+ * MAP_SHARED as you don't know which consistency model
+ * you will get. We silently ignore unsupported flags
+ * with MAP_SHARED to preserve backward compatibility.
+ */
+ flags &= LEGACY_MAP_MASK;
+ /* fall through */
+ case MAP_SHARED_VALIDATE:
+ if (flags & ~flags_mask)
+ return -EOPNOTSUPP;
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
return -EACCES;
diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/tools/include/uapi/asm-generic/mman-common.h
+++ b/tools/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara, Arnd Bergmann, Andy Lutomirski, Andrew Morton
From: Dan Williams <dan.j.williams@intel.com>
The mmap(2) syscall suffers from the ABI anti-pattern of not validating
unknown flags. However, proposals like MAP_SYNC need a mechanism to
define new behavior that is known to fail on older kernels without the
support. Define a new MAP_SHARED_VALIDATE flag pattern that is
guaranteed to fail on all legacy mmap implementations.
It is worth noting that the original proposal was for a standalone
MAP_VALIDATE flag. However, when that could not be supported by all
archs Linus observed:
I see why you *think* you want a bitmap. You think you want
a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
etc, so that people can do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
| MAP_SYNC, fd, 0);
and "know" that MAP_SYNC actually takes.
And I'm saying that whole wish is bogus. You're fundamentally
depending on special semantics, just make it explicit. It's already
not portable, so don't try to make it so.
Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
of 0x3, and make people do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
| MAP_SYNC, fd, 0);
and then the kernel side is easier too (none of that random garbage
playing games with looking at the "MAP_VALIDATE bit", but just another
case statement in that map type thing.
Boom. Done.
Similar to ->fallocate() we also want the ability to validate the
support for new flags on a per ->mmap() 'struct file_operations'
instance basis. Towards that end arrange for flags to be generically
validated against a mmap_supported_flags exported by 'struct
file_operations'. By default all existing flags are implicitly
supported, but new flags require MAP_SHARED_VALIDATE and
per-instance-opt-in.
Cc: Jan Kara <jack@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
arch/alpha/include/uapi/asm/mman.h | 1 +
arch/mips/include/uapi/asm/mman.h | 1 +
arch/parisc/include/uapi/asm/mman.h | 1 +
arch/xtensa/include/uapi/asm/mman.h | 1 +
include/linux/fs.h | 1 +
include/linux/mman.h | 39 ++++++++++++++++++++++++++++
include/uapi/asm-generic/mman-common.h | 1 +
mm/mmap.c | 15 +++++++++++
tools/include/uapi/asm-generic/mman-common.h | 1 +
9 files changed, 61 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 3b26cc62dadb..f6d118aaedb9 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
#define MAP_FIXED 0x100 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index da3216007fe0..93268e4cd3c7 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -28,6 +28,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 775b5d5e41a1..bca652aa1677 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x03 /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index b15b278aa314..9ab426374714 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -35,6 +35,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab191a23e..57added3201d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1701,6 +1701,7 @@ struct file_operations {
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
+ unsigned long mmap_supported_flags;
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mman.h b/include/linux/mman.h
index c8367041fafd..94b63b4d71ff 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -7,6 +7,45 @@
#include <linux/atomic.h>
#include <uapi/linux/mman.h>
+/*
+ * Arrange for legacy / undefined architecture specific flags to be
+ * ignored by default in LEGACY_MAP_MASK.
+ */
+#ifndef MAP_32BIT
+#define MAP_32BIT 0
+#endif
+#ifndef MAP_HUGE_2MB
+#define MAP_HUGE_2MB 0
+#endif
+#ifndef MAP_HUGE_1GB
+#define MAP_HUGE_1GB 0
+#endif
+#ifndef MAP_UNINITIALIZED
+#define MAP_UNINITIALIZED 0
+#endif
+
+/*
+ * The historical set of flags that all mmap implementations implicitly
+ * support when a ->mmap_validate() op is not provided in file_operations.
+ */
+#define LEGACY_MAP_MASK (MAP_SHARED \
+ | MAP_PRIVATE \
+ | MAP_FIXED \
+ | MAP_ANONYMOUS \
+ | MAP_DENYWRITE \
+ | MAP_EXECUTABLE \
+ | MAP_UNINITIALIZED \
+ | MAP_GROWSDOWN \
+ | MAP_LOCKED \
+ | MAP_NORESERVE \
+ | MAP_POPULATE \
+ | MAP_NONBLOCK \
+ | MAP_STACK \
+ | MAP_HUGETLB \
+ | MAP_32BIT \
+ | MAP_HUGE_2MB \
+ | MAP_HUGE_1GB)
+
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern unsigned long sysctl_overcommit_kbytes;
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
diff --git a/mm/mmap.c b/mm/mmap.c
index 680506faceae..924839fac0e6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (file) {
struct inode *inode = file_inode(file);
+ unsigned long flags_mask;
+
+ flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
switch (flags & MAP_TYPE) {
case MAP_SHARED:
+ /*
+ * Force use of MAP_SHARED_VALIDATE with non-legacy
+ * flags. E.g. MAP_SYNC is dangerous to use with
+ * MAP_SHARED as you don't know which consistency model
+ * you will get. We silently ignore unsupported flags
+ * with MAP_SHARED to preserve backward compatibility.
+ */
+ flags &= LEGACY_MAP_MASK;
+ /* fall through */
+ case MAP_SHARED_VALIDATE:
+ if (flags & ~flags_mask)
+ return -EOPNOTSUPP;
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
return -EACCES;
diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/tools/include/uapi/asm-generic/mman-common.h
+++ b/tools/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara, Arnd Bergmann,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
Andy Lutomirski, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA, Andrew Morton
From: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
The mmap(2) syscall suffers from the ABI anti-pattern of not validating
unknown flags. However, proposals like MAP_SYNC need a mechanism to
define new behavior that is known to fail on older kernels without the
support. Define a new MAP_SHARED_VALIDATE flag pattern that is
guaranteed to fail on all legacy mmap implementations.
It is worth noting that the original proposal was for a standalone
MAP_VALIDATE flag. However, when that could not be supported by all
archs Linus observed:
I see why you *think* you want a bitmap. You think you want
a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
etc, so that people can do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
| MAP_SYNC, fd, 0);
and "know" that MAP_SYNC actually takes.
And I'm saying that whole wish is bogus. You're fundamentally
depending on special semantics, just make it explicit. It's already
not portable, so don't try to make it so.
Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
of 0x3, and make people do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
| MAP_SYNC, fd, 0);
and then the kernel side is easier too (none of that random garbage
playing games with looking at the "MAP_VALIDATE bit", but just another
case statement in that map type thing.
Boom. Done.
Similar to ->fallocate() we also want the ability to validate the
support for new flags on a per ->mmap() 'struct file_operations'
instance basis. Towards that end arrange for flags to be generically
validated against a mmap_supported_flags exported by 'struct
file_operations'. By default all existing flags are implicitly
supported, but new flags require MAP_SHARED_VALIDATE and
per-instance-opt-in.
Cc: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
Cc: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
Cc: Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Suggested-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Suggested-by: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
arch/alpha/include/uapi/asm/mman.h | 1 +
arch/mips/include/uapi/asm/mman.h | 1 +
arch/parisc/include/uapi/asm/mman.h | 1 +
arch/xtensa/include/uapi/asm/mman.h | 1 +
include/linux/fs.h | 1 +
include/linux/mman.h | 39 ++++++++++++++++++++++++++++
include/uapi/asm-generic/mman-common.h | 1 +
mm/mmap.c | 15 +++++++++++
tools/include/uapi/asm-generic/mman-common.h | 1 +
9 files changed, 61 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 3b26cc62dadb..f6d118aaedb9 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
#define MAP_FIXED 0x100 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index da3216007fe0..93268e4cd3c7 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -28,6 +28,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 775b5d5e41a1..bca652aa1677 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x03 /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index b15b278aa314..9ab426374714 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -35,6 +35,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab191a23e..57added3201d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1701,6 +1701,7 @@ struct file_operations {
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
+ unsigned long mmap_supported_flags;
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mman.h b/include/linux/mman.h
index c8367041fafd..94b63b4d71ff 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -7,6 +7,45 @@
#include <linux/atomic.h>
#include <uapi/linux/mman.h>
+/*
+ * Arrange for legacy / undefined architecture specific flags to be
+ * ignored by default in LEGACY_MAP_MASK.
+ */
+#ifndef MAP_32BIT
+#define MAP_32BIT 0
+#endif
+#ifndef MAP_HUGE_2MB
+#define MAP_HUGE_2MB 0
+#endif
+#ifndef MAP_HUGE_1GB
+#define MAP_HUGE_1GB 0
+#endif
+#ifndef MAP_UNINITIALIZED
+#define MAP_UNINITIALIZED 0
+#endif
+
+/*
+ * The historical set of flags that all mmap implementations implicitly
+ * support when a ->mmap_validate() op is not provided in file_operations.
+ */
+#define LEGACY_MAP_MASK (MAP_SHARED \
+ | MAP_PRIVATE \
+ | MAP_FIXED \
+ | MAP_ANONYMOUS \
+ | MAP_DENYWRITE \
+ | MAP_EXECUTABLE \
+ | MAP_UNINITIALIZED \
+ | MAP_GROWSDOWN \
+ | MAP_LOCKED \
+ | MAP_NORESERVE \
+ | MAP_POPULATE \
+ | MAP_NONBLOCK \
+ | MAP_STACK \
+ | MAP_HUGETLB \
+ | MAP_32BIT \
+ | MAP_HUGE_2MB \
+ | MAP_HUGE_1GB)
+
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern unsigned long sysctl_overcommit_kbytes;
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
diff --git a/mm/mmap.c b/mm/mmap.c
index 680506faceae..924839fac0e6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (file) {
struct inode *inode = file_inode(file);
+ unsigned long flags_mask;
+
+ flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
switch (flags & MAP_TYPE) {
case MAP_SHARED:
+ /*
+ * Force use of MAP_SHARED_VALIDATE with non-legacy
+ * flags. E.g. MAP_SYNC is dangerous to use with
+ * MAP_SHARED as you don't know which consistency model
+ * you will get. We silently ignore unsupported flags
+ * with MAP_SHARED to preserve backward compatibility.
+ */
+ flags &= LEGACY_MAP_MASK;
+ /* fall through */
+ case MAP_SHARED_VALIDATE:
+ if (flags & ~flags_mask)
+ return -EOPNOTSUPP;
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
return -EACCES;
diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/tools/include/uapi/asm-generic/mman-common.h
+++ b/tools/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara, Arnd Bergmann, Andy Lutomirski, Andrew Morton
From: Dan Williams <dan.j.williams@intel.com>
The mmap(2) syscall suffers from the ABI anti-pattern of not validating
unknown flags. However, proposals like MAP_SYNC need a mechanism to
define new behavior that is known to fail on older kernels without the
support. Define a new MAP_SHARED_VALIDATE flag pattern that is
guaranteed to fail on all legacy mmap implementations.
It is worth noting that the original proposal was for a standalone
MAP_VALIDATE flag. However, when that could not be supported by all
archs Linus observed:
I see why you *think* you want a bitmap. You think you want
a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
etc, so that people can do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
| MAP_SYNC, fd, 0);
and "know" that MAP_SYNC actually takes.
And I'm saying that whole wish is bogus. You're fundamentally
depending on special semantics, just make it explicit. It's already
not portable, so don't try to make it so.
Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
of 0x3, and make people do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
| MAP_SYNC, fd, 0);
and then the kernel side is easier too (none of that random garbage
playing games with looking at the "MAP_VALIDATE bit", but just another
case statement in that map type thing.
Boom. Done.
Similar to ->fallocate() we also want the ability to validate the
support for new flags on a per ->mmap() 'struct file_operations'
instance basis. Towards that end arrange for flags to be generically
validated against a mmap_supported_flags exported by 'struct
file_operations'. By default all existing flags are implicitly
supported, but new flags require MAP_SHARED_VALIDATE and
per-instance-opt-in.
Cc: Jan Kara <jack@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
arch/alpha/include/uapi/asm/mman.h | 1 +
arch/mips/include/uapi/asm/mman.h | 1 +
arch/parisc/include/uapi/asm/mman.h | 1 +
arch/xtensa/include/uapi/asm/mman.h | 1 +
include/linux/fs.h | 1 +
include/linux/mman.h | 39 ++++++++++++++++++++++++++++
include/uapi/asm-generic/mman-common.h | 1 +
mm/mmap.c | 15 +++++++++++
tools/include/uapi/asm-generic/mman-common.h | 1 +
9 files changed, 61 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 3b26cc62dadb..f6d118aaedb9 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
#define MAP_FIXED 0x100 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index da3216007fe0..93268e4cd3c7 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -28,6 +28,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 775b5d5e41a1..bca652aa1677 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x03 /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index b15b278aa314..9ab426374714 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -35,6 +35,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab191a23e..57added3201d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1701,6 +1701,7 @@ struct file_operations {
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
+ unsigned long mmap_supported_flags;
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mman.h b/include/linux/mman.h
index c8367041fafd..94b63b4d71ff 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -7,6 +7,45 @@
#include <linux/atomic.h>
#include <uapi/linux/mman.h>
+/*
+ * Arrange for legacy / undefined architecture specific flags to be
+ * ignored by default in LEGACY_MAP_MASK.
+ */
+#ifndef MAP_32BIT
+#define MAP_32BIT 0
+#endif
+#ifndef MAP_HUGE_2MB
+#define MAP_HUGE_2MB 0
+#endif
+#ifndef MAP_HUGE_1GB
+#define MAP_HUGE_1GB 0
+#endif
+#ifndef MAP_UNINITIALIZED
+#define MAP_UNINITIALIZED 0
+#endif
+
+/*
+ * The historical set of flags that all mmap implementations implicitly
+ * support when a ->mmap_validate() op is not provided in file_operations.
+ */
+#define LEGACY_MAP_MASK (MAP_SHARED \
+ | MAP_PRIVATE \
+ | MAP_FIXED \
+ | MAP_ANONYMOUS \
+ | MAP_DENYWRITE \
+ | MAP_EXECUTABLE \
+ | MAP_UNINITIALIZED \
+ | MAP_GROWSDOWN \
+ | MAP_LOCKED \
+ | MAP_NORESERVE \
+ | MAP_POPULATE \
+ | MAP_NONBLOCK \
+ | MAP_STACK \
+ | MAP_HUGETLB \
+ | MAP_32BIT \
+ | MAP_HUGE_2MB \
+ | MAP_HUGE_1GB)
+
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern unsigned long sysctl_overcommit_kbytes;
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
diff --git a/mm/mmap.c b/mm/mmap.c
index 680506faceae..924839fac0e6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (file) {
struct inode *inode = file_inode(file);
+ unsigned long flags_mask;
+
+ flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
switch (flags & MAP_TYPE) {
case MAP_SHARED:
+ /*
+ * Force use of MAP_SHARED_VALIDATE with non-legacy
+ * flags. E.g. MAP_SYNC is dangerous to use with
+ * MAP_SHARED as you don't know which consistency model
+ * you will get. We silently ignore unsupported flags
+ * with MAP_SHARED to preserve backward compatibility.
+ */
+ flags &= LEGACY_MAP_MASK;
+ /* fall through */
+ case MAP_SHARED_VALIDATE:
+ if (flags & ~flags_mask)
+ return -EOPNOTSUPP;
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
return -EACCES;
diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/tools/include/uapi/asm-generic/mman-common.h
+++ b/tools/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara, Arnd Bergmann, Andy Lutomirski, Andrew Morton
From: Dan Williams <dan.j.williams@intel.com>
The mmap(2) syscall suffers from the ABI anti-pattern of not validating
unknown flags. However, proposals like MAP_SYNC need a mechanism to
define new behavior that is known to fail on older kernels without the
support. Define a new MAP_SHARED_VALIDATE flag pattern that is
guaranteed to fail on all legacy mmap implementations.
It is worth noting that the original proposal was for a standalone
MAP_VALIDATE flag. However, when that could not be supported by all
archs Linus observed:
I see why you *think* you want a bitmap. You think you want
a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
etc, so that people can do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
| MAP_SYNC, fd, 0);
and "know" that MAP_SYNC actually takes.
And I'm saying that whole wish is bogus. You're fundamentally
depending on special semantics, just make it explicit. It's already
not portable, so don't try to make it so.
Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
of 0x3, and make people do
ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
| MAP_SYNC, fd, 0);
and then the kernel side is easier too (none of that random garbage
playing games with looking at the "MAP_VALIDATE bit", but just another
case statement in that map type thing.
Boom. Done.
Similar to ->fallocate() we also want the ability to validate the
support for new flags on a per ->mmap() 'struct file_operations'
instance basis. Towards that end arrange for flags to be generically
validated against a mmap_supported_flags exported by 'struct
file_operations'. By default all existing flags are implicitly
supported, but new flags require MAP_SHARED_VALIDATE and
per-instance-opt-in.
Cc: Jan Kara <jack@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
arch/alpha/include/uapi/asm/mman.h | 1 +
arch/mips/include/uapi/asm/mman.h | 1 +
arch/parisc/include/uapi/asm/mman.h | 1 +
arch/xtensa/include/uapi/asm/mman.h | 1 +
include/linux/fs.h | 1 +
include/linux/mman.h | 39 ++++++++++++++++++++++++++++
include/uapi/asm-generic/mman-common.h | 1 +
mm/mmap.c | 15 +++++++++++
tools/include/uapi/asm-generic/mman-common.h | 1 +
9 files changed, 61 insertions(+)
diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
index 3b26cc62dadb..f6d118aaedb9 100644
--- a/arch/alpha/include/uapi/asm/mman.h
+++ b/arch/alpha/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
#define MAP_FIXED 0x100 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
index da3216007fe0..93268e4cd3c7 100644
--- a/arch/mips/include/uapi/asm/mman.h
+++ b/arch/mips/include/uapi/asm/mman.h
@@ -28,6 +28,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
index 775b5d5e41a1..bca652aa1677 100644
--- a/arch/parisc/include/uapi/asm/mman.h
+++ b/arch/parisc/include/uapi/asm/mman.h
@@ -11,6 +11,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x03 /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
index b15b278aa314..9ab426374714 100644
--- a/arch/xtensa/include/uapi/asm/mman.h
+++ b/arch/xtensa/include/uapi/asm/mman.h
@@ -35,6 +35,7 @@
*/
#define MAP_SHARED 0x001 /* Share changes */
#define MAP_PRIVATE 0x002 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
#define MAP_TYPE 0x00f /* Mask for type of mapping */
#define MAP_FIXED 0x010 /* Interpret addr exactly */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab191a23e..57added3201d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1701,6 +1701,7 @@ struct file_operations {
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
+ unsigned long mmap_supported_flags;
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
diff --git a/include/linux/mman.h b/include/linux/mman.h
index c8367041fafd..94b63b4d71ff 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -7,6 +7,45 @@
#include <linux/atomic.h>
#include <uapi/linux/mman.h>
+/*
+ * Arrange for legacy / undefined architecture specific flags to be
+ * ignored by default in LEGACY_MAP_MASK.
+ */
+#ifndef MAP_32BIT
+#define MAP_32BIT 0
+#endif
+#ifndef MAP_HUGE_2MB
+#define MAP_HUGE_2MB 0
+#endif
+#ifndef MAP_HUGE_1GB
+#define MAP_HUGE_1GB 0
+#endif
+#ifndef MAP_UNINITIALIZED
+#define MAP_UNINITIALIZED 0
+#endif
+
+/*
+ * The historical set of flags that all mmap implementations implicitly
+ * support when a ->mmap_validate() op is not provided in file_operations.
+ */
+#define LEGACY_MAP_MASK (MAP_SHARED \
+ | MAP_PRIVATE \
+ | MAP_FIXED \
+ | MAP_ANONYMOUS \
+ | MAP_DENYWRITE \
+ | MAP_EXECUTABLE \
+ | MAP_UNINITIALIZED \
+ | MAP_GROWSDOWN \
+ | MAP_LOCKED \
+ | MAP_NORESERVE \
+ | MAP_POPULATE \
+ | MAP_NONBLOCK \
+ | MAP_STACK \
+ | MAP_HUGETLB \
+ | MAP_32BIT \
+ | MAP_HUGE_2MB \
+ | MAP_HUGE_1GB)
+
extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern unsigned long sysctl_overcommit_kbytes;
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
diff --git a/mm/mmap.c b/mm/mmap.c
index 680506faceae..924839fac0e6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (file) {
struct inode *inode = file_inode(file);
+ unsigned long flags_mask;
+
+ flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
switch (flags & MAP_TYPE) {
case MAP_SHARED:
+ /*
+ * Force use of MAP_SHARED_VALIDATE with non-legacy
+ * flags. E.g. MAP_SYNC is dangerous to use with
+ * MAP_SHARED as you don't know which consistency model
+ * you will get. We silently ignore unsupported flags
+ * with MAP_SHARED to preserve backward compatibility.
+ */
+ flags &= LEGACY_MAP_MASK;
+ /* fall through */
+ case MAP_SHARED_VALIDATE:
+ if (flags & ~flags_mask)
+ return -EOPNOTSUPP;
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
return -EACCES;
diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
index 203268f9231e..8ce7f5a0800f 100644
--- a/tools/include/uapi/asm-generic/mman-common.h
+++ b/tools/include/uapi/asm-generic/mman-common.h
@@ -16,6 +16,7 @@
#define MAP_SHARED 0x01 /* Share changes */
#define MAP_PRIVATE 0x02 /* Changes are private */
+#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
#define MAP_TYPE 0x0f /* Mask for type of mapping */
#define MAP_FIXED 0x10 /* Interpret addr exactly */
#define MAP_ANONYMOUS 0x20 /* don't use a file */
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 02/18] mm: Remove VM_FAULT_HWPOISON_LARGE_MASK
2017-11-01 15:36 ` Jan Kara
(?)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
It is unused.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/mm.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 065d99deb847..ca72b67153d5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,8 +1182,6 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
-#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
-
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
VM_FAULT_FALLBACK)
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 02/18] mm: Remove VM_FAULT_HWPOISON_LARGE_MASK
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
It is unused.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/mm.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 065d99deb847..ca72b67153d5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,8 +1182,6 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
-#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
-
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
VM_FAULT_FALLBACK)
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 02/18] mm: Remove VM_FAULT_HWPOISON_LARGE_MASK
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
It is unused.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/mm.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 065d99deb847..ca72b67153d5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,8 +1182,6 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
-#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
-
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
VM_FAULT_FALLBACK)
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 02/18] mm: Remove VM_FAULT_HWPOISON_LARGE_MASK
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
It is unused.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
include/linux/mm.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 065d99deb847..ca72b67153d5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,8 +1182,6 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
-#define VM_FAULT_HWPOISON_LARGE_MASK 0xf000 /* encodes hpage index for large hwpoison */
-
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
VM_FAULT_FALLBACK)
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 03/18] dax: Simplify arguments of dax_insert_mapping()
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
dax_insert_mapping() has lots of arguments and a lot of them is actuall
duplicated by passing vm_fault structure as well. Change the function to
take the same arguments as dax_pmd_insert_mapping().
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index f001d8c72a06..0bc42ac294ca 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -820,23 +820,30 @@ int dax_writeback_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);
-static int dax_insert_mapping(struct address_space *mapping,
- struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, size_t size, void *entry,
- struct vm_area_struct *vma, struct vm_fault *vmf)
+static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
+{
+ return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long vaddr = vmf->address;
void *ret, *kaddr;
pgoff_t pgoff;
int id, rc;
pfn_t pfn;
- rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
if (rc)
return rc;
id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
+ rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
+ &kaddr, &pfn);
if (rc < 0) {
dax_read_unlock(id);
return rc;
@@ -936,11 +943,6 @@ int __dax_zero_page_range(struct block_device *bdev,
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
-static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
-{
- return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
-}
-
static loff_t
dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@@ -1087,7 +1089,6 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
- sector_t sector;
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
@@ -1140,9 +1141,9 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto error_finish_iomap;
}
- sector = dax_iomap_sector(&iomap, pos);
-
if (vmf->cow_page) {
+ sector_t sector = dax_iomap_sector(&iomap, pos);
+
switch (iomap.type) {
case IOMAP_HOLE:
case IOMAP_UNWRITTEN:
@@ -1175,8 +1176,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev,
- sector, PAGE_SIZE, entry, vmf->vma, vmf);
+ error = dax_insert_mapping(vmf, &iomap, pos, entry);
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 03/18] dax: Simplify arguments of dax_insert_mapping()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_insert_mapping() has lots of arguments and a lot of them is actuall
duplicated by passing vm_fault structure as well. Change the function to
take the same arguments as dax_pmd_insert_mapping().
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index f001d8c72a06..0bc42ac294ca 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -820,23 +820,30 @@ int dax_writeback_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);
-static int dax_insert_mapping(struct address_space *mapping,
- struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, size_t size, void *entry,
- struct vm_area_struct *vma, struct vm_fault *vmf)
+static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
+{
+ return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long vaddr = vmf->address;
void *ret, *kaddr;
pgoff_t pgoff;
int id, rc;
pfn_t pfn;
- rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
if (rc)
return rc;
id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
+ rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
+ &kaddr, &pfn);
if (rc < 0) {
dax_read_unlock(id);
return rc;
@@ -936,11 +943,6 @@ int __dax_zero_page_range(struct block_device *bdev,
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
-static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
-{
- return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
-}
-
static loff_t
dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@@ -1087,7 +1089,6 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
- sector_t sector;
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
@@ -1140,9 +1141,9 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto error_finish_iomap;
}
- sector = dax_iomap_sector(&iomap, pos);
-
if (vmf->cow_page) {
+ sector_t sector = dax_iomap_sector(&iomap, pos);
+
switch (iomap.type) {
case IOMAP_HOLE:
case IOMAP_UNWRITTEN:
@@ -1175,8 +1176,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev,
- sector, PAGE_SIZE, entry, vmf->vma, vmf);
+ error = dax_insert_mapping(vmf, &iomap, pos, entry);
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 03/18] dax: Simplify arguments of dax_insert_mapping()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
dax_insert_mapping() has lots of arguments and a lot of them is actuall
duplicated by passing vm_fault structure as well. Change the function to
take the same arguments as dax_pmd_insert_mapping().
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index f001d8c72a06..0bc42ac294ca 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -820,23 +820,30 @@ int dax_writeback_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);
-static int dax_insert_mapping(struct address_space *mapping,
- struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, size_t size, void *entry,
- struct vm_area_struct *vma, struct vm_fault *vmf)
+static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
+{
+ return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long vaddr = vmf->address;
void *ret, *kaddr;
pgoff_t pgoff;
int id, rc;
pfn_t pfn;
- rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
if (rc)
return rc;
id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
+ rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
+ &kaddr, &pfn);
if (rc < 0) {
dax_read_unlock(id);
return rc;
@@ -936,11 +943,6 @@ int __dax_zero_page_range(struct block_device *bdev,
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
-static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
-{
- return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
-}
-
static loff_t
dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@@ -1087,7 +1089,6 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
- sector_t sector;
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
@@ -1140,9 +1141,9 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto error_finish_iomap;
}
- sector = dax_iomap_sector(&iomap, pos);
-
if (vmf->cow_page) {
+ sector_t sector = dax_iomap_sector(&iomap, pos);
+
switch (iomap.type) {
case IOMAP_HOLE:
case IOMAP_UNWRITTEN:
@@ -1175,8 +1176,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev,
- sector, PAGE_SIZE, entry, vmf->vma, vmf);
+ error = dax_insert_mapping(vmf, &iomap, pos, entry);
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 03/18] dax: Simplify arguments of dax_insert_mapping()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_insert_mapping() has lots of arguments and a lot of them is actuall
duplicated by passing vm_fault structure as well. Change the function to
take the same arguments as dax_pmd_insert_mapping().
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index f001d8c72a06..0bc42ac294ca 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -820,23 +820,30 @@ int dax_writeback_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);
-static int dax_insert_mapping(struct address_space *mapping,
- struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, size_t size, void *entry,
- struct vm_area_struct *vma, struct vm_fault *vmf)
+static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
+{
+ return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long vaddr = vmf->address;
void *ret, *kaddr;
pgoff_t pgoff;
int id, rc;
pfn_t pfn;
- rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
if (rc)
return rc;
id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
+ rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
+ &kaddr, &pfn);
if (rc < 0) {
dax_read_unlock(id);
return rc;
@@ -936,11 +943,6 @@ int __dax_zero_page_range(struct block_device *bdev,
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
-static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
-{
- return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
-}
-
static loff_t
dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@@ -1087,7 +1089,6 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
- sector_t sector;
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
@@ -1140,9 +1141,9 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto error_finish_iomap;
}
- sector = dax_iomap_sector(&iomap, pos);
-
if (vmf->cow_page) {
+ sector_t sector = dax_iomap_sector(&iomap, pos);
+
switch (iomap.type) {
case IOMAP_HOLE:
case IOMAP_UNWRITTEN:
@@ -1175,8 +1176,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev,
- sector, PAGE_SIZE, entry, vmf->vma, vmf);
+ error = dax_insert_mapping(vmf, &iomap, pos, entry);
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 03/18] dax: Simplify arguments of dax_insert_mapping()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_insert_mapping() has lots of arguments and a lot of them is actuall
duplicated by passing vm_fault structure as well. Change the function to
take the same arguments as dax_pmd_insert_mapping().
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index f001d8c72a06..0bc42ac294ca 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -820,23 +820,30 @@ int dax_writeback_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL_GPL(dax_writeback_mapping_range);
-static int dax_insert_mapping(struct address_space *mapping,
- struct block_device *bdev, struct dax_device *dax_dev,
- sector_t sector, size_t size, void *entry,
- struct vm_area_struct *vma, struct vm_fault *vmf)
+static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
+{
+ return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long vaddr = vmf->address;
void *ret, *kaddr;
pgoff_t pgoff;
int id, rc;
pfn_t pfn;
- rc = bdev_dax_pgoff(bdev, sector, size, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
if (rc)
return rc;
id = dax_read_lock();
- rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
+ rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
+ &kaddr, &pfn);
if (rc < 0) {
dax_read_unlock(id);
return rc;
@@ -936,11 +943,6 @@ int __dax_zero_page_range(struct block_device *bdev,
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
-static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
-{
- return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
-}
-
static loff_t
dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@@ -1087,7 +1089,6 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
- sector_t sector;
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
@@ -1140,9 +1141,9 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto error_finish_iomap;
}
- sector = dax_iomap_sector(&iomap, pos);
-
if (vmf->cow_page) {
+ sector_t sector = dax_iomap_sector(&iomap, pos);
+
switch (iomap.type) {
case IOMAP_HOLE:
case IOMAP_UNWRITTEN:
@@ -1175,8 +1176,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev,
- sector, PAGE_SIZE, entry, vmf->vma, vmf);
+ error = dax_insert_mapping(vmf, &iomap, pos, entry);
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 04/18] dax: Factor out getting of pfn out of iomap
2017-11-01 15:36 ` Jan Kara
(?)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Factor out code to get pfn out of iomap that is shared between PTE and
PMD fault path.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++-------------------------------
1 file changed, 43 insertions(+), 40 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 0bc42ac294ca..116eef8d6c69 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -825,30 +825,53 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
+static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
+ pfn_t *pfnp)
{
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret, *kaddr;
pgoff_t pgoff;
+ void *kaddr;
int id, rc;
- pfn_t pfn;
+ long length;
- rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, size, &pgoff);
if (rc)
return rc;
-
id = dax_read_lock();
- rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
- &kaddr, &pfn);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
+ length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
+ &kaddr, pfnp);
+ if (length < 0) {
+ rc = length;
+ goto out;
}
+ rc = -EINVAL;
+ if (PFN_PHYS(length) < size)
+ goto out;
+ if (pfn_t_to_pfn(*pfnp) & (PHYS_PFN(size)-1))
+ goto out;
+ /* For larger pages we need devmap */
+ if (length > 1 && !pfn_t_devmap(*pfnp))
+ goto out;
+ rc = 0;
+out:
dax_read_unlock(id);
+ return rc;
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
+{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ unsigned long vaddr = vmf->address;
+ void *ret;
+ int rc;
+ pfn_t pfn;
+
+ rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
+ if (rc < 0)
+ return rc;
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
if (IS_ERR(ret))
@@ -1223,46 +1246,26 @@ static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct dax_device *dax_dev = iomap->dax_dev;
- struct block_device *bdev = iomap->bdev;
struct inode *inode = mapping->host;
- const size_t size = PMD_SIZE;
- void *ret = NULL, *kaddr;
- long length = 0;
- pgoff_t pgoff;
+ void *ret = NULL;
pfn_t pfn = {};
- int id;
+ int rc;
- if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
+ rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
+ if (rc < 0)
goto fallback;
- id = dax_read_lock();
- length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
- if (length < 0)
- goto unlock_fallback;
- length = PFN_PHYS(length);
-
- if (length < size)
- goto unlock_fallback;
- if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR)
- goto unlock_fallback;
- if (!pfn_t_devmap(pfn))
- goto unlock_fallback;
- dax_read_unlock(id);
-
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
RADIX_DAX_PMD);
if (IS_ERR(ret))
goto fallback;
- trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
pfn, vmf->flags & FAULT_FLAG_WRITE);
-unlock_fallback:
- dax_read_unlock(id);
fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
return VM_FAULT_FALLBACK;
}
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 04/18] dax: Factor out getting of pfn out of iomap
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Factor out code to get pfn out of iomap that is shared between PTE and
PMD fault path.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++-------------------------------
1 file changed, 43 insertions(+), 40 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 0bc42ac294ca..116eef8d6c69 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -825,30 +825,53 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
+static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
+ pfn_t *pfnp)
{
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret, *kaddr;
pgoff_t pgoff;
+ void *kaddr;
int id, rc;
- pfn_t pfn;
+ long length;
- rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, size, &pgoff);
if (rc)
return rc;
-
id = dax_read_lock();
- rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
- &kaddr, &pfn);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
+ length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
+ &kaddr, pfnp);
+ if (length < 0) {
+ rc = length;
+ goto out;
}
+ rc = -EINVAL;
+ if (PFN_PHYS(length) < size)
+ goto out;
+ if (pfn_t_to_pfn(*pfnp) & (PHYS_PFN(size)-1))
+ goto out;
+ /* For larger pages we need devmap */
+ if (length > 1 && !pfn_t_devmap(*pfnp))
+ goto out;
+ rc = 0;
+out:
dax_read_unlock(id);
+ return rc;
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
+{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ unsigned long vaddr = vmf->address;
+ void *ret;
+ int rc;
+ pfn_t pfn;
+
+ rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
+ if (rc < 0)
+ return rc;
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
if (IS_ERR(ret))
@@ -1223,46 +1246,26 @@ static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct dax_device *dax_dev = iomap->dax_dev;
- struct block_device *bdev = iomap->bdev;
struct inode *inode = mapping->host;
- const size_t size = PMD_SIZE;
- void *ret = NULL, *kaddr;
- long length = 0;
- pgoff_t pgoff;
+ void *ret = NULL;
pfn_t pfn = {};
- int id;
+ int rc;
- if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
+ rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
+ if (rc < 0)
goto fallback;
- id = dax_read_lock();
- length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
- if (length < 0)
- goto unlock_fallback;
- length = PFN_PHYS(length);
-
- if (length < size)
- goto unlock_fallback;
- if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR)
- goto unlock_fallback;
- if (!pfn_t_devmap(pfn))
- goto unlock_fallback;
- dax_read_unlock(id);
-
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
RADIX_DAX_PMD);
if (IS_ERR(ret))
goto fallback;
- trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
pfn, vmf->flags & FAULT_FLAG_WRITE);
-unlock_fallback:
- dax_read_unlock(id);
fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
return VM_FAULT_FALLBACK;
}
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 04/18] dax: Factor out getting of pfn out of iomap
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Factor out code to get pfn out of iomap that is shared between PTE and
PMD fault path.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++-------------------------------
1 file changed, 43 insertions(+), 40 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 0bc42ac294ca..116eef8d6c69 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -825,30 +825,53 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
+static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
+ pfn_t *pfnp)
{
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret, *kaddr;
pgoff_t pgoff;
+ void *kaddr;
int id, rc;
- pfn_t pfn;
+ long length;
- rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, size, &pgoff);
if (rc)
return rc;
-
id = dax_read_lock();
- rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
- &kaddr, &pfn);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
+ length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
+ &kaddr, pfnp);
+ if (length < 0) {
+ rc = length;
+ goto out;
}
+ rc = -EINVAL;
+ if (PFN_PHYS(length) < size)
+ goto out;
+ if (pfn_t_to_pfn(*pfnp) & (PHYS_PFN(size)-1))
+ goto out;
+ /* For larger pages we need devmap */
+ if (length > 1 && !pfn_t_devmap(*pfnp))
+ goto out;
+ rc = 0;
+out:
dax_read_unlock(id);
+ return rc;
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
+{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ unsigned long vaddr = vmf->address;
+ void *ret;
+ int rc;
+ pfn_t pfn;
+
+ rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
+ if (rc < 0)
+ return rc;
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
if (IS_ERR(ret))
@@ -1223,46 +1246,26 @@ static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct dax_device *dax_dev = iomap->dax_dev;
- struct block_device *bdev = iomap->bdev;
struct inode *inode = mapping->host;
- const size_t size = PMD_SIZE;
- void *ret = NULL, *kaddr;
- long length = 0;
- pgoff_t pgoff;
+ void *ret = NULL;
pfn_t pfn = {};
- int id;
+ int rc;
- if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
+ rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
+ if (rc < 0)
goto fallback;
- id = dax_read_lock();
- length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
- if (length < 0)
- goto unlock_fallback;
- length = PFN_PHYS(length);
-
- if (length < size)
- goto unlock_fallback;
- if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR)
- goto unlock_fallback;
- if (!pfn_t_devmap(pfn))
- goto unlock_fallback;
- dax_read_unlock(id);
-
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
RADIX_DAX_PMD);
if (IS_ERR(ret))
goto fallback;
- trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
pfn, vmf->flags & FAULT_FLAG_WRITE);
-unlock_fallback:
- dax_read_unlock(id);
fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
return VM_FAULT_FALLBACK;
}
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 04/18] dax: Factor out getting of pfn out of iomap
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Factor out code to get pfn out of iomap that is shared between PTE and
PMD fault path.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++-------------------------------
1 file changed, 43 insertions(+), 40 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 0bc42ac294ca..116eef8d6c69 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -825,30 +825,53 @@ static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
+static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
+ pfn_t *pfnp)
{
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret, *kaddr;
pgoff_t pgoff;
+ void *kaddr;
int id, rc;
- pfn_t pfn;
+ long length;
- rc = bdev_dax_pgoff(iomap->bdev, sector, PAGE_SIZE, &pgoff);
+ rc = bdev_dax_pgoff(iomap->bdev, sector, size, &pgoff);
if (rc)
return rc;
-
id = dax_read_lock();
- rc = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(PAGE_SIZE),
- &kaddr, &pfn);
- if (rc < 0) {
- dax_read_unlock(id);
- return rc;
+ length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size),
+ &kaddr, pfnp);
+ if (length < 0) {
+ rc = length;
+ goto out;
}
+ rc = -EINVAL;
+ if (PFN_PHYS(length) < size)
+ goto out;
+ if (pfn_t_to_pfn(*pfnp) & (PHYS_PFN(size)-1))
+ goto out;
+ /* For larger pages we need devmap */
+ if (length > 1 && !pfn_t_devmap(*pfnp))
+ goto out;
+ rc = 0;
+out:
dax_read_unlock(id);
+ return rc;
+}
+
+static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
+ loff_t pos, void *entry)
+{
+ const sector_t sector = dax_iomap_sector(iomap, pos);
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ unsigned long vaddr = vmf->address;
+ void *ret;
+ int rc;
+ pfn_t pfn;
+
+ rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
+ if (rc < 0)
+ return rc;
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
if (IS_ERR(ret))
@@ -1223,46 +1246,26 @@ static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
const sector_t sector = dax_iomap_sector(iomap, pos);
- struct dax_device *dax_dev = iomap->dax_dev;
- struct block_device *bdev = iomap->bdev;
struct inode *inode = mapping->host;
- const size_t size = PMD_SIZE;
- void *ret = NULL, *kaddr;
- long length = 0;
- pgoff_t pgoff;
+ void *ret = NULL;
pfn_t pfn = {};
- int id;
+ int rc;
- if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0)
+ rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
+ if (rc < 0)
goto fallback;
- id = dax_read_lock();
- length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn);
- if (length < 0)
- goto unlock_fallback;
- length = PFN_PHYS(length);
-
- if (length < size)
- goto unlock_fallback;
- if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR)
- goto unlock_fallback;
- if (!pfn_t_devmap(pfn))
- goto unlock_fallback;
- dax_read_unlock(id);
-
ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
RADIX_DAX_PMD);
if (IS_ERR(ret))
goto fallback;
- trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
pfn, vmf->flags & FAULT_FLAG_WRITE);
-unlock_fallback:
- dax_read_unlock(id);
fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret);
+ trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
return VM_FAULT_FALLBACK;
}
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 05/18] dax: Create local variable for VMA in dax_iomap_pte_fault()
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 116eef8d6c69..c09465884bbe 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1108,7 +1108,8 @@ static int dax_fault_return(int error)
static int dax_iomap_pte_fault(struct vm_fault *vmf,
const struct iomap_ops *ops)
{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
@@ -1196,7 +1197,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
count_vm_event(PGMAJFAULT);
- count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
+ count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
error = dax_insert_mapping(vmf, &iomap, pos, entry);
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 05/18] dax: Create local variable for VMA in dax_iomap_pte_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 116eef8d6c69..c09465884bbe 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1108,7 +1108,8 @@ static int dax_fault_return(int error)
static int dax_iomap_pte_fault(struct vm_fault *vmf,
const struct iomap_ops *ops)
{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
@@ -1196,7 +1197,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
count_vm_event(PGMAJFAULT);
- count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
+ count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
error = dax_insert_mapping(vmf, &iomap, pos, entry);
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 05/18] dax: Create local variable for VMA in dax_iomap_pte_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 116eef8d6c69..c09465884bbe 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1108,7 +1108,8 @@ static int dax_fault_return(int error)
static int dax_iomap_pte_fault(struct vm_fault *vmf,
const struct iomap_ops *ops)
{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
@@ -1196,7 +1197,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
count_vm_event(PGMAJFAULT);
- count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
+ count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
error = dax_insert_mapping(vmf, &iomap, pos, entry);
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 05/18] dax: Create local variable for VMA in dax_iomap_pte_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 116eef8d6c69..c09465884bbe 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1108,7 +1108,8 @@ static int dax_fault_return(int error)
static int dax_iomap_pte_fault(struct vm_fault *vmf,
const struct iomap_ops *ops)
{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
@@ -1196,7 +1197,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
count_vm_event(PGMAJFAULT);
- count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
+ count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
error = dax_insert_mapping(vmf, &iomap, pos, entry);
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 05/18] dax: Create local variable for VMA in dax_iomap_pte_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 116eef8d6c69..c09465884bbe 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1108,7 +1108,8 @@ static int dax_fault_return(int error)
static int dax_iomap_pte_fault(struct vm_fault *vmf,
const struct iomap_ops *ops)
{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ struct vm_area_struct *vma = vmf->vma;
+ struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
unsigned long vaddr = vmf->address;
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
@@ -1196,7 +1197,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
count_vm_event(PGMAJFAULT);
- count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
+ count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
error = dax_insert_mapping(vmf, &iomap, pos, entry);
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 06/18] dax: Create local variable for vmf->flags & FAULT_FLAG_WRITE test
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index c09465884bbe..5ea71381dba0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1116,6 +1116,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
+ bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
@@ -1130,7 +1131,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto out;
}
- if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page)
+ if (write && !vmf->cow_page)
flags |= IOMAP_WRITE;
entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
@@ -1207,7 +1208,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
- if (!(vmf->flags & FAULT_FLAG_WRITE)) {
+ if (!write) {
vmf_ret = dax_load_hole(mapping, entry, vmf);
goto finish_iomap;
}
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 06/18] dax: Create local variable for vmf->flags & FAULT_FLAG_WRITE test
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index c09465884bbe..5ea71381dba0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1116,6 +1116,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
+ bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
@@ -1130,7 +1131,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto out;
}
- if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page)
+ if (write && !vmf->cow_page)
flags |= IOMAP_WRITE;
entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
@@ -1207,7 +1208,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
- if (!(vmf->flags & FAULT_FLAG_WRITE)) {
+ if (!write) {
vmf_ret = dax_load_hole(mapping, entry, vmf);
goto finish_iomap;
}
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 06/18] dax: Create local variable for vmf->flags & FAULT_FLAG_WRITE test
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index c09465884bbe..5ea71381dba0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1116,6 +1116,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
+ bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
@@ -1130,7 +1131,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto out;
}
- if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page)
+ if (write && !vmf->cow_page)
flags |= IOMAP_WRITE;
entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
@@ -1207,7 +1208,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
- if (!(vmf->flags & FAULT_FLAG_WRITE)) {
+ if (!write) {
vmf_ret = dax_load_hole(mapping, entry, vmf);
goto finish_iomap;
}
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 06/18] dax: Create local variable for vmf->flags & FAULT_FLAG_WRITE test
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index c09465884bbe..5ea71381dba0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1116,6 +1116,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
+ bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
@@ -1130,7 +1131,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto out;
}
- if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page)
+ if (write && !vmf->cow_page)
flags |= IOMAP_WRITE;
entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
@@ -1207,7 +1208,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
- if (!(vmf->flags & FAULT_FLAG_WRITE)) {
+ if (!write) {
vmf_ret = dax_load_hole(mapping, entry, vmf);
goto finish_iomap;
}
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 06/18] dax: Create local variable for vmf->flags & FAULT_FLAG_WRITE test
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
There are already two users and more are coming.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index c09465884bbe..5ea71381dba0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1116,6 +1116,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
struct iomap iomap = { 0 };
unsigned flags = IOMAP_FAULT;
int error, major = 0;
+ bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
@@ -1130,7 +1131,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
goto out;
}
- if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page)
+ if (write && !vmf->cow_page)
flags |= IOMAP_WRITE;
entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
@@ -1207,7 +1208,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
- if (!(vmf->flags & FAULT_FLAG_WRITE)) {
+ if (!write) {
vmf_ret = dax_load_hole(mapping, entry, vmf);
goto finish_iomap;
}
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 07/18] dax: Inline dax_insert_mapping() into the callsite
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
dax_insert_mapping() has only one callsite and we will need to further
fine tune what it does for synchronous faults. Just inline it into the
callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ea71381dba0..5b20c6456926 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -858,32 +858,6 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
return rc;
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret;
- int rc;
- pfn_t pfn;
-
- rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
- if (rc < 0)
- return rc;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
- if (IS_ERR(ret))
- return PTR_ERR(ret);
-
- trace_dax_insert_mapping(mapping->host, vmf, ret);
- if (vmf->flags & FAULT_FLAG_WRITE)
- return vm_insert_mixed_mkwrite(vma, vaddr, pfn);
- else
- return vm_insert_mixed(vma, vaddr, pfn);
-}
-
/*
* The user has performed a load from a hole in the file. Allocating a new
* page in the file would cause excessive storage usage for workloads with
@@ -1119,6 +1093,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
+ pfn_t pfn;
trace_dax_pte_fault(inode, vmf, vmf_ret);
/*
@@ -1201,7 +1176,24 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn);
+ if (error < 0)
+ goto error_finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ 0);
+ if (IS_ERR(entry)) {
+ error = PTR_ERR(entry);
+ goto error_finish_iomap;
+ }
+
+ trace_dax_insert_mapping(inode, vmf, entry);
+ if (write)
+ error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
+ else
+ error = vm_insert_mixed(vma, vaddr, pfn);
+
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 07/18] dax: Inline dax_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_insert_mapping() has only one callsite and we will need to further
fine tune what it does for synchronous faults. Just inline it into the
callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ea71381dba0..5b20c6456926 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -858,32 +858,6 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
return rc;
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret;
- int rc;
- pfn_t pfn;
-
- rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
- if (rc < 0)
- return rc;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
- if (IS_ERR(ret))
- return PTR_ERR(ret);
-
- trace_dax_insert_mapping(mapping->host, vmf, ret);
- if (vmf->flags & FAULT_FLAG_WRITE)
- return vm_insert_mixed_mkwrite(vma, vaddr, pfn);
- else
- return vm_insert_mixed(vma, vaddr, pfn);
-}
-
/*
* The user has performed a load from a hole in the file. Allocating a new
* page in the file would cause excessive storage usage for workloads with
@@ -1119,6 +1093,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
+ pfn_t pfn;
trace_dax_pte_fault(inode, vmf, vmf_ret);
/*
@@ -1201,7 +1176,24 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn);
+ if (error < 0)
+ goto error_finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ 0);
+ if (IS_ERR(entry)) {
+ error = PTR_ERR(entry);
+ goto error_finish_iomap;
+ }
+
+ trace_dax_insert_mapping(inode, vmf, entry);
+ if (write)
+ error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
+ else
+ error = vm_insert_mixed(vma, vaddr, pfn);
+
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 07/18] dax: Inline dax_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
dax_insert_mapping() has only one callsite and we will need to further
fine tune what it does for synchronous faults. Just inline it into the
callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ea71381dba0..5b20c6456926 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -858,32 +858,6 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
return rc;
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret;
- int rc;
- pfn_t pfn;
-
- rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
- if (rc < 0)
- return rc;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
- if (IS_ERR(ret))
- return PTR_ERR(ret);
-
- trace_dax_insert_mapping(mapping->host, vmf, ret);
- if (vmf->flags & FAULT_FLAG_WRITE)
- return vm_insert_mixed_mkwrite(vma, vaddr, pfn);
- else
- return vm_insert_mixed(vma, vaddr, pfn);
-}
-
/*
* The user has performed a load from a hole in the file. Allocating a new
* page in the file would cause excessive storage usage for workloads with
@@ -1119,6 +1093,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
+ pfn_t pfn;
trace_dax_pte_fault(inode, vmf, vmf_ret);
/*
@@ -1201,7 +1176,24 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn);
+ if (error < 0)
+ goto error_finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ 0);
+ if (IS_ERR(entry)) {
+ error = PTR_ERR(entry);
+ goto error_finish_iomap;
+ }
+
+ trace_dax_insert_mapping(inode, vmf, entry);
+ if (write)
+ error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
+ else
+ error = vm_insert_mixed(vma, vaddr, pfn);
+
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 07/18] dax: Inline dax_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_insert_mapping() has only one callsite and we will need to further
fine tune what it does for synchronous faults. Just inline it into the
callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ea71381dba0..5b20c6456926 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -858,32 +858,6 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
return rc;
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret;
- int rc;
- pfn_t pfn;
-
- rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
- if (rc < 0)
- return rc;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
- if (IS_ERR(ret))
- return PTR_ERR(ret);
-
- trace_dax_insert_mapping(mapping->host, vmf, ret);
- if (vmf->flags & FAULT_FLAG_WRITE)
- return vm_insert_mixed_mkwrite(vma, vaddr, pfn);
- else
- return vm_insert_mixed(vma, vaddr, pfn);
-}
-
/*
* The user has performed a load from a hole in the file. Allocating a new
* page in the file would cause excessive storage usage for workloads with
@@ -1119,6 +1093,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
+ pfn_t pfn;
trace_dax_pte_fault(inode, vmf, vmf_ret);
/*
@@ -1201,7 +1176,24 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn);
+ if (error < 0)
+ goto error_finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ 0);
+ if (IS_ERR(entry)) {
+ error = PTR_ERR(entry);
+ goto error_finish_iomap;
+ }
+
+ trace_dax_insert_mapping(inode, vmf, entry);
+ if (write)
+ error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
+ else
+ error = vm_insert_mixed(vma, vaddr, pfn);
+
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 07/18] dax: Inline dax_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_insert_mapping() has only one callsite and we will need to further
fine tune what it does for synchronous faults. Just inline it into the
callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ea71381dba0..5b20c6456926 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -858,32 +858,6 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
return rc;
}
-static int dax_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct vm_area_struct *vma = vmf->vma;
- struct address_space *mapping = vma->vm_file->f_mapping;
- unsigned long vaddr = vmf->address;
- void *ret;
- int rc;
- pfn_t pfn;
-
- rc = dax_iomap_pfn(iomap, pos, PAGE_SIZE, &pfn);
- if (rc < 0)
- return rc;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0);
- if (IS_ERR(ret))
- return PTR_ERR(ret);
-
- trace_dax_insert_mapping(mapping->host, vmf, ret);
- if (vmf->flags & FAULT_FLAG_WRITE)
- return vm_insert_mixed_mkwrite(vma, vaddr, pfn);
- else
- return vm_insert_mixed(vma, vaddr, pfn);
-}
-
/*
* The user has performed a load from a hole in the file. Allocating a new
* page in the file would cause excessive storage usage for workloads with
@@ -1119,6 +1093,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
bool write = vmf->flags & FAULT_FLAG_WRITE;
int vmf_ret = 0;
void *entry;
+ pfn_t pfn;
trace_dax_pte_fault(inode, vmf, vmf_ret);
/*
@@ -1201,7 +1176,24 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn);
+ if (error < 0)
+ goto error_finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ 0);
+ if (IS_ERR(entry)) {
+ error = PTR_ERR(entry);
+ goto error_finish_iomap;
+ }
+
+ trace_dax_insert_mapping(inode, vmf, entry);
+ if (write)
+ error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
+ else
+ error = vm_insert_mixed(vma, vaddr, pfn);
+
/* -EBUSY is fine, somebody else faulted on the same PTE */
if (error == -EBUSY)
error = 0;
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 08/18] dax: Inline dax_pmd_insert_mapping() into the callsite
2017-11-01 15:36 ` Jan Kara
(?)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
dax_pmd_insert_mapping() has only one callsite and we will need to
further fine tune what it does for synchronous faults. Just inline it
into the callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 47 +++++++++++++++++--------------------------
include/trace/events/fs_dax.h | 1 -
2 files changed, 19 insertions(+), 29 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5b20c6456926..675fab8ec41f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1235,33 +1235,11 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
}
#ifdef CONFIG_FS_DAX_PMD
-static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct inode *inode = mapping->host;
- void *ret = NULL;
- pfn_t pfn = {};
- int rc;
-
- rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
- if (rc < 0)
- goto fallback;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
- RADIX_DAX_PMD);
- if (IS_ERR(ret))
- goto fallback;
-
- trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
- return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
- pfn, vmf->flags & FAULT_FLAG_WRITE);
-
-fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
- return VM_FAULT_FALLBACK;
-}
+/*
+ * The 'colour' (ie low bits) within a PMD of a page offset. This comes up
+ * more often than one might expect in the below functions.
+ */
+#define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1)
static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
void *entry)
@@ -1317,6 +1295,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
void *entry;
loff_t pos;
int error;
+ pfn_t pfn;
/*
* Check whether offset isn't beyond end of file now. Caller is
@@ -1394,7 +1373,19 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
switch (iomap.type) {
case IOMAP_MAPPED:
- result = dax_pmd_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
+ if (error < 0)
+ goto finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ RADIX_DAX_PMD);
+ if (IS_ERR(entry))
+ goto finish_iomap;
+
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
+ result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
+ write);
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index fbc4a06f7310..88a9d19b8ff8 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -148,7 +148,6 @@ DEFINE_EVENT(dax_pmd_insert_mapping_class, name, \
TP_ARGS(inode, vmf, length, pfn, radix_entry))
DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping);
-DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping_fallback);
DECLARE_EVENT_CLASS(dax_pte_fault_class,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, int result),
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 08/18] dax: Inline dax_pmd_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_pmd_insert_mapping() has only one callsite and we will need to
further fine tune what it does for synchronous faults. Just inline it
into the callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 47 +++++++++++++++++--------------------------
include/trace/events/fs_dax.h | 1 -
2 files changed, 19 insertions(+), 29 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5b20c6456926..675fab8ec41f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1235,33 +1235,11 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
}
#ifdef CONFIG_FS_DAX_PMD
-static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct inode *inode = mapping->host;
- void *ret = NULL;
- pfn_t pfn = {};
- int rc;
-
- rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
- if (rc < 0)
- goto fallback;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
- RADIX_DAX_PMD);
- if (IS_ERR(ret))
- goto fallback;
-
- trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
- return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
- pfn, vmf->flags & FAULT_FLAG_WRITE);
-
-fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
- return VM_FAULT_FALLBACK;
-}
+/*
+ * The 'colour' (ie low bits) within a PMD of a page offset. This comes up
+ * more often than one might expect in the below functions.
+ */
+#define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1)
static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
void *entry)
@@ -1317,6 +1295,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
void *entry;
loff_t pos;
int error;
+ pfn_t pfn;
/*
* Check whether offset isn't beyond end of file now. Caller is
@@ -1394,7 +1373,19 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
switch (iomap.type) {
case IOMAP_MAPPED:
- result = dax_pmd_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
+ if (error < 0)
+ goto finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ RADIX_DAX_PMD);
+ if (IS_ERR(entry))
+ goto finish_iomap;
+
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
+ result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
+ write);
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index fbc4a06f7310..88a9d19b8ff8 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -148,7 +148,6 @@ DEFINE_EVENT(dax_pmd_insert_mapping_class, name, \
TP_ARGS(inode, vmf, length, pfn, radix_entry))
DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping);
-DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping_fallback);
DECLARE_EVENT_CLASS(dax_pte_fault_class,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, int result),
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 08/18] dax: Inline dax_pmd_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_pmd_insert_mapping() has only one callsite and we will need to
further fine tune what it does for synchronous faults. Just inline it
into the callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 47 +++++++++++++++++--------------------------
include/trace/events/fs_dax.h | 1 -
2 files changed, 19 insertions(+), 29 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5b20c6456926..675fab8ec41f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1235,33 +1235,11 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
}
#ifdef CONFIG_FS_DAX_PMD
-static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct inode *inode = mapping->host;
- void *ret = NULL;
- pfn_t pfn = {};
- int rc;
-
- rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
- if (rc < 0)
- goto fallback;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
- RADIX_DAX_PMD);
- if (IS_ERR(ret))
- goto fallback;
-
- trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
- return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
- pfn, vmf->flags & FAULT_FLAG_WRITE);
-
-fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
- return VM_FAULT_FALLBACK;
-}
+/*
+ * The 'colour' (ie low bits) within a PMD of a page offset. This comes up
+ * more often than one might expect in the below functions.
+ */
+#define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1)
static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
void *entry)
@@ -1317,6 +1295,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
void *entry;
loff_t pos;
int error;
+ pfn_t pfn;
/*
* Check whether offset isn't beyond end of file now. Caller is
@@ -1394,7 +1373,19 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
switch (iomap.type) {
case IOMAP_MAPPED:
- result = dax_pmd_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
+ if (error < 0)
+ goto finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ RADIX_DAX_PMD);
+ if (IS_ERR(entry))
+ goto finish_iomap;
+
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
+ result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
+ write);
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index fbc4a06f7310..88a9d19b8ff8 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -148,7 +148,6 @@ DEFINE_EVENT(dax_pmd_insert_mapping_class, name, \
TP_ARGS(inode, vmf, length, pfn, radix_entry))
DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping);
-DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping_fallback);
DECLARE_EVENT_CLASS(dax_pte_fault_class,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, int result),
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 08/18] dax: Inline dax_pmd_insert_mapping() into the callsite
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
dax_pmd_insert_mapping() has only one callsite and we will need to
further fine tune what it does for synchronous faults. Just inline it
into the callsite so that we don't have to pass awkward bools around.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 47 +++++++++++++++++--------------------------
include/trace/events/fs_dax.h | 1 -
2 files changed, 19 insertions(+), 29 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5b20c6456926..675fab8ec41f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1235,33 +1235,11 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf,
}
#ifdef CONFIG_FS_DAX_PMD
-static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap,
- loff_t pos, void *entry)
-{
- struct address_space *mapping = vmf->vma->vm_file->f_mapping;
- const sector_t sector = dax_iomap_sector(iomap, pos);
- struct inode *inode = mapping->host;
- void *ret = NULL;
- pfn_t pfn = {};
- int rc;
-
- rc = dax_iomap_pfn(iomap, pos, PMD_SIZE, &pfn);
- if (rc < 0)
- goto fallback;
-
- ret = dax_insert_mapping_entry(mapping, vmf, entry, sector,
- RADIX_DAX_PMD);
- if (IS_ERR(ret))
- goto fallback;
-
- trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, ret);
- return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
- pfn, vmf->flags & FAULT_FLAG_WRITE);
-
-fallback:
- trace_dax_pmd_insert_mapping_fallback(inode, vmf, PMD_SIZE, pfn, ret);
- return VM_FAULT_FALLBACK;
-}
+/*
+ * The 'colour' (ie low bits) within a PMD of a page offset. This comes up
+ * more often than one might expect in the below functions.
+ */
+#define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1)
static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
void *entry)
@@ -1317,6 +1295,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
void *entry;
loff_t pos;
int error;
+ pfn_t pfn;
/*
* Check whether offset isn't beyond end of file now. Caller is
@@ -1394,7 +1373,19 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
switch (iomap.type) {
case IOMAP_MAPPED:
- result = dax_pmd_insert_mapping(vmf, &iomap, pos, entry);
+ error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
+ if (error < 0)
+ goto finish_iomap;
+
+ entry = dax_insert_mapping_entry(mapping, vmf, entry,
+ dax_iomap_sector(&iomap, pos),
+ RADIX_DAX_PMD);
+ if (IS_ERR(entry))
+ goto finish_iomap;
+
+ trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
+ result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
+ write);
break;
case IOMAP_UNWRITTEN:
case IOMAP_HOLE:
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index fbc4a06f7310..88a9d19b8ff8 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -148,7 +148,6 @@ DEFINE_EVENT(dax_pmd_insert_mapping_class, name, \
TP_ARGS(inode, vmf, length, pfn, radix_entry))
DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping);
-DEFINE_PMD_INSERT_MAPPING_EVENT(dax_pmd_insert_mapping_fallback);
DECLARE_EVENT_CLASS(dax_pte_fault_class,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, int result),
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 09/18] dax: Fix comment describing dax_iomap_fault()
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Add missing argument description.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index 675fab8ec41f..5214ed9ba508 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1435,7 +1435,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
/**
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
- * @ops: iomap ops passed from the file system
+ * @pe_size: Size of the page to fault in
+ * @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
* their fault handler for DAX files. dax_iomap_fault() assumes the caller
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 09/18] dax: Fix comment describing dax_iomap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Add missing argument description.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index 675fab8ec41f..5214ed9ba508 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1435,7 +1435,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
/**
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
- * @ops: iomap ops passed from the file system
+ * @pe_size: Size of the page to fault in
+ * @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
* their fault handler for DAX files. dax_iomap_fault() assumes the caller
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 09/18] dax: Fix comment describing dax_iomap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Add missing argument description.
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index 675fab8ec41f..5214ed9ba508 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1435,7 +1435,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
/**
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
- * @ops: iomap ops passed from the file system
+ * @pe_size: Size of the page to fault in
+ * @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
* their fault handler for DAX files. dax_iomap_fault() assumes the caller
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 09/18] dax: Fix comment describing dax_iomap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Add missing argument description.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index 675fab8ec41f..5214ed9ba508 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1435,7 +1435,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
/**
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
- * @ops: iomap ops passed from the file system
+ * @pe_size: Size of the page to fault in
+ * @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
* their fault handler for DAX files. dax_iomap_fault() assumes the caller
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 09/18] dax: Fix comment describing dax_iomap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Add missing argument description.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/dax.c b/fs/dax.c
index 675fab8ec41f..5214ed9ba508 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1435,7 +1435,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
/**
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
- * @ops: iomap ops passed from the file system
+ * @pe_size: Size of the page to fault in
+ * @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
* their fault handler for DAX files. dax_iomap_fault() assumes the caller
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
For synchronous page fault dax_iomap_fault() will need to return PFN
which will then need to be inserted into page tables after fsync()
completes. Add necessary parameter to dax_iomap_fault().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 13 +++++++------
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 2 +-
fs/xfs/xfs_file.c | 4 ++--
include/linux/dax.h | 2 +-
5 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9ba508..5ddf15161390 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1079,7 +1079,7 @@ static int dax_fault_return(int error)
return VM_FAULT_SIGBUS;
}
-static int dax_iomap_pte_fault(struct vm_fault *vmf,
+static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1280,7 +1280,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
return VM_FAULT_FALLBACK;
}
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1425,7 +1425,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
return result;
}
#else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
return VM_FAULT_FALLBACK;
@@ -1436,6 +1436,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
* @pe_size: Size of the page to fault in
+ * @pfnp: PFN to insert for synchronous faults if fsync is required
* @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
@@ -1444,13 +1445,13 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* successfully.
*/
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops)
+ pfn_t *pfnp, const struct iomap_ops *ops)
{
switch (pe_size) {
case PE_SIZE_PTE:
- return dax_iomap_pte_fault(vmf, ops);
+ return dax_iomap_pte_fault(vmf, pfnp, ops);
case PE_SIZE_PMD:
- return dax_iomap_pmd_fault(vmf, ops);
+ return dax_iomap_pmd_fault(vmf, pfnp, ops);
default:
return VM_FAULT_FALLBACK;
}
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index ff3a3636a5ca..d2bb7c96307d 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -99,7 +99,7 @@ static int ext2_dax_fault(struct vm_fault *vmf)
}
down_read(&ei->dax_sem);
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &ext2_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);
up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1da660ac3bc..3cec0b95672f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -306,7 +306,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
}
if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
else
result = VM_FAULT_SIGBUS;
if (write) {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 309e26c9dddb..7c6b8def6eed 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1040,7 +1040,7 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1111,7 +1111,7 @@ xfs_filemap_pfn_mkwrite(
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 122197124b9d..e7fa4b8f45bc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -95,7 +95,7 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev);
ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops);
+ pfn_t *pfnp, const struct iomap_ops *ops);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
For synchronous page fault dax_iomap_fault() will need to return PFN
which will then need to be inserted into page tables after fsync()
completes. Add necessary parameter to dax_iomap_fault().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 13 +++++++------
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 2 +-
fs/xfs/xfs_file.c | 4 ++--
include/linux/dax.h | 2 +-
5 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9ba508..5ddf15161390 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1079,7 +1079,7 @@ static int dax_fault_return(int error)
return VM_FAULT_SIGBUS;
}
-static int dax_iomap_pte_fault(struct vm_fault *vmf,
+static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1280,7 +1280,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
return VM_FAULT_FALLBACK;
}
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1425,7 +1425,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
return result;
}
#else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
return VM_FAULT_FALLBACK;
@@ -1436,6 +1436,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
* @pe_size: Size of the page to fault in
+ * @pfnp: PFN to insert for synchronous faults if fsync is required
* @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
@@ -1444,13 +1445,13 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* successfully.
*/
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops)
+ pfn_t *pfnp, const struct iomap_ops *ops)
{
switch (pe_size) {
case PE_SIZE_PTE:
- return dax_iomap_pte_fault(vmf, ops);
+ return dax_iomap_pte_fault(vmf, pfnp, ops);
case PE_SIZE_PMD:
- return dax_iomap_pmd_fault(vmf, ops);
+ return dax_iomap_pmd_fault(vmf, pfnp, ops);
default:
return VM_FAULT_FALLBACK;
}
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index ff3a3636a5ca..d2bb7c96307d 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -99,7 +99,7 @@ static int ext2_dax_fault(struct vm_fault *vmf)
}
down_read(&ei->dax_sem);
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &ext2_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);
up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1da660ac3bc..3cec0b95672f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -306,7 +306,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
}
if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
else
result = VM_FAULT_SIGBUS;
if (write) {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 309e26c9dddb..7c6b8def6eed 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1040,7 +1040,7 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1111,7 +1111,7 @@ xfs_filemap_pfn_mkwrite(
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 122197124b9d..e7fa4b8f45bc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -95,7 +95,7 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev);
ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops);
+ pfn_t *pfnp, const struct iomap_ops *ops);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
For synchronous page fault dax_iomap_fault() will need to return PFN
which will then need to be inserted into page tables after fsync()
completes. Add necessary parameter to dax_iomap_fault().
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 13 +++++++------
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 2 +-
fs/xfs/xfs_file.c | 4 ++--
include/linux/dax.h | 2 +-
5 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9ba508..5ddf15161390 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1079,7 +1079,7 @@ static int dax_fault_return(int error)
return VM_FAULT_SIGBUS;
}
-static int dax_iomap_pte_fault(struct vm_fault *vmf,
+static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1280,7 +1280,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
return VM_FAULT_FALLBACK;
}
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1425,7 +1425,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
return result;
}
#else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
return VM_FAULT_FALLBACK;
@@ -1436,6 +1436,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
* @pe_size: Size of the page to fault in
+ * @pfnp: PFN to insert for synchronous faults if fsync is required
* @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
@@ -1444,13 +1445,13 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* successfully.
*/
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops)
+ pfn_t *pfnp, const struct iomap_ops *ops)
{
switch (pe_size) {
case PE_SIZE_PTE:
- return dax_iomap_pte_fault(vmf, ops);
+ return dax_iomap_pte_fault(vmf, pfnp, ops);
case PE_SIZE_PMD:
- return dax_iomap_pmd_fault(vmf, ops);
+ return dax_iomap_pmd_fault(vmf, pfnp, ops);
default:
return VM_FAULT_FALLBACK;
}
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index ff3a3636a5ca..d2bb7c96307d 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -99,7 +99,7 @@ static int ext2_dax_fault(struct vm_fault *vmf)
}
down_read(&ei->dax_sem);
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &ext2_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);
up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1da660ac3bc..3cec0b95672f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -306,7 +306,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
}
if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
else
result = VM_FAULT_SIGBUS;
if (write) {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 309e26c9dddb..7c6b8def6eed 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1040,7 +1040,7 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1111,7 +1111,7 @@ xfs_filemap_pfn_mkwrite(
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 122197124b9d..e7fa4b8f45bc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -95,7 +95,7 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev);
ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops);
+ pfn_t *pfnp, const struct iomap_ops *ops);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
For synchronous page fault dax_iomap_fault() will need to return PFN
which will then need to be inserted into page tables after fsync()
completes. Add necessary parameter to dax_iomap_fault().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 13 +++++++------
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 2 +-
fs/xfs/xfs_file.c | 4 ++--
include/linux/dax.h | 2 +-
5 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9ba508..5ddf15161390 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1079,7 +1079,7 @@ static int dax_fault_return(int error)
return VM_FAULT_SIGBUS;
}
-static int dax_iomap_pte_fault(struct vm_fault *vmf,
+static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1280,7 +1280,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
return VM_FAULT_FALLBACK;
}
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1425,7 +1425,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
return result;
}
#else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
return VM_FAULT_FALLBACK;
@@ -1436,6 +1436,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
* @pe_size: Size of the page to fault in
+ * @pfnp: PFN to insert for synchronous faults if fsync is required
* @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
@@ -1444,13 +1445,13 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* successfully.
*/
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops)
+ pfn_t *pfnp, const struct iomap_ops *ops)
{
switch (pe_size) {
case PE_SIZE_PTE:
- return dax_iomap_pte_fault(vmf, ops);
+ return dax_iomap_pte_fault(vmf, pfnp, ops);
case PE_SIZE_PMD:
- return dax_iomap_pmd_fault(vmf, ops);
+ return dax_iomap_pmd_fault(vmf, pfnp, ops);
default:
return VM_FAULT_FALLBACK;
}
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index ff3a3636a5ca..d2bb7c96307d 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -99,7 +99,7 @@ static int ext2_dax_fault(struct vm_fault *vmf)
}
down_read(&ei->dax_sem);
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &ext2_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);
up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1da660ac3bc..3cec0b95672f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -306,7 +306,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
}
if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
else
result = VM_FAULT_SIGBUS;
if (write) {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 309e26c9dddb..7c6b8def6eed 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1040,7 +1040,7 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1111,7 +1111,7 @@ xfs_filemap_pfn_mkwrite(
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 122197124b9d..e7fa4b8f45bc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -95,7 +95,7 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev);
ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops);
+ pfn_t *pfnp, const struct iomap_ops *ops);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
For synchronous page fault dax_iomap_fault() will need to return PFN
which will then need to be inserted into page tables after fsync()
completes. Add necessary parameter to dax_iomap_fault().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 13 +++++++------
fs/ext2/file.c | 2 +-
fs/ext4/file.c | 2 +-
fs/xfs/xfs_file.c | 4 ++--
include/linux/dax.h | 2 +-
5 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5214ed9ba508..5ddf15161390 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1079,7 +1079,7 @@ static int dax_fault_return(int error)
return VM_FAULT_SIGBUS;
}
-static int dax_iomap_pte_fault(struct vm_fault *vmf,
+static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1280,7 +1280,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
return VM_FAULT_FALLBACK;
}
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
struct vm_area_struct *vma = vmf->vma;
@@ -1425,7 +1425,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
return result;
}
#else
-static int dax_iomap_pmd_fault(struct vm_fault *vmf,
+static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
const struct iomap_ops *ops)
{
return VM_FAULT_FALLBACK;
@@ -1436,6 +1436,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* dax_iomap_fault - handle a page fault on a DAX file
* @vmf: The description of the fault
* @pe_size: Size of the page to fault in
+ * @pfnp: PFN to insert for synchronous faults if fsync is required
* @ops: Iomap ops passed from the file system
*
* When a page fault occurs, filesystems may call this helper in
@@ -1444,13 +1445,13 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf,
* successfully.
*/
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops)
+ pfn_t *pfnp, const struct iomap_ops *ops)
{
switch (pe_size) {
case PE_SIZE_PTE:
- return dax_iomap_pte_fault(vmf, ops);
+ return dax_iomap_pte_fault(vmf, pfnp, ops);
case PE_SIZE_PMD:
- return dax_iomap_pmd_fault(vmf, ops);
+ return dax_iomap_pmd_fault(vmf, pfnp, ops);
default:
return VM_FAULT_FALLBACK;
}
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index ff3a3636a5ca..d2bb7c96307d 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -99,7 +99,7 @@ static int ext2_dax_fault(struct vm_fault *vmf)
}
down_read(&ei->dax_sem);
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &ext2_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &ext2_iomap_ops);
up_read(&ei->dax_sem);
if (vmf->flags & FAULT_FLAG_WRITE)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index b1da660ac3bc..3cec0b95672f 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -306,7 +306,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
}
if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
else
result = VM_FAULT_SIGBUS;
if (write) {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 309e26c9dddb..7c6b8def6eed 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1040,7 +1040,7 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1111,7 +1111,7 @@ xfs_filemap_pfn_mkwrite(
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, &xfs_iomap_ops);
+ ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
sb_end_pagefault(inode->i_sb);
return ret;
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 122197124b9d..e7fa4b8f45bc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -95,7 +95,7 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev);
ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
- const struct iomap_ops *ops);
+ pfn_t *pfnp, const struct iomap_ops *ops);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 11/18] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
gets called for a write fault. With synchronous page faults we would
like to insert clean radix tree entry and dirty it only once we call
fdatasync() and update page tables to save some unnecessary cache
flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ddf15161390..efc210ff6665 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -526,13 +526,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
static void *dax_insert_mapping_entry(struct address_space *mapping,
struct vm_fault *vmf,
void *entry, sector_t sector,
- unsigned long flags)
+ unsigned long flags, bool dirty)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
void *new_entry;
pgoff_t index = vmf->pgoff;
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
@@ -569,7 +569,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
entry = new_entry;
}
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&mapping->tree_lock);
@@ -881,7 +881,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
}
entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(entry2)) {
ret = VM_FAULT_SIGBUS;
goto out;
@@ -1182,7 +1182,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0);
+ 0, write);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
@@ -1258,7 +1258,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
goto fallback;
ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(ret))
goto fallback;
@@ -1379,7 +1379,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD);
+ RADIX_DAX_PMD, write);
if (IS_ERR(entry))
goto finish_iomap;
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 11/18] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
gets called for a write fault. With synchronous page faults we would
like to insert clean radix tree entry and dirty it only once we call
fdatasync() and update page tables to save some unnecessary cache
flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ddf15161390..efc210ff6665 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -526,13 +526,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
static void *dax_insert_mapping_entry(struct address_space *mapping,
struct vm_fault *vmf,
void *entry, sector_t sector,
- unsigned long flags)
+ unsigned long flags, bool dirty)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
void *new_entry;
pgoff_t index = vmf->pgoff;
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
@@ -569,7 +569,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
entry = new_entry;
}
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&mapping->tree_lock);
@@ -881,7 +881,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
}
entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(entry2)) {
ret = VM_FAULT_SIGBUS;
goto out;
@@ -1182,7 +1182,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0);
+ 0, write);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
@@ -1258,7 +1258,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
goto fallback;
ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(ret))
goto fallback;
@@ -1379,7 +1379,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD);
+ RADIX_DAX_PMD, write);
if (IS_ERR(entry))
goto finish_iomap;
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 11/18] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
gets called for a write fault. With synchronous page faults we would
like to insert clean radix tree entry and dirty it only once we call
fdatasync() and update page tables to save some unnecessary cache
flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ddf15161390..efc210ff6665 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -526,13 +526,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
static void *dax_insert_mapping_entry(struct address_space *mapping,
struct vm_fault *vmf,
void *entry, sector_t sector,
- unsigned long flags)
+ unsigned long flags, bool dirty)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
void *new_entry;
pgoff_t index = vmf->pgoff;
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
@@ -569,7 +569,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
entry = new_entry;
}
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&mapping->tree_lock);
@@ -881,7 +881,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
}
entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(entry2)) {
ret = VM_FAULT_SIGBUS;
goto out;
@@ -1182,7 +1182,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0);
+ 0, write);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
@@ -1258,7 +1258,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
goto fallback;
ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(ret))
goto fallback;
@@ -1379,7 +1379,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD);
+ RADIX_DAX_PMD, write);
if (IS_ERR(entry))
goto finish_iomap;
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 11/18] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
gets called for a write fault. With synchronous page faults we would
like to insert clean radix tree entry and dirty it only once we call
fdatasync() and update page tables to save some unnecessary cache
flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ddf15161390..efc210ff6665 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -526,13 +526,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
static void *dax_insert_mapping_entry(struct address_space *mapping,
struct vm_fault *vmf,
void *entry, sector_t sector,
- unsigned long flags)
+ unsigned long flags, bool dirty)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
void *new_entry;
pgoff_t index = vmf->pgoff;
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
@@ -569,7 +569,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
entry = new_entry;
}
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&mapping->tree_lock);
@@ -881,7 +881,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
}
entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(entry2)) {
ret = VM_FAULT_SIGBUS;
goto out;
@@ -1182,7 +1182,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0);
+ 0, write);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
@@ -1258,7 +1258,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
goto fallback;
ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(ret))
goto fallback;
@@ -1379,7 +1379,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD);
+ RADIX_DAX_PMD, write);
if (IS_ERR(entry))
goto finish_iomap;
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 11/18] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Currently we dirty radix tree entry whenever dax_insert_mapping_entry()
gets called for a write fault. With synchronous page faults we would
like to insert clean radix tree entry and dirty it only once we call
fdatasync() and update page tables to save some unnecessary cache
flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5ddf15161390..efc210ff6665 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -526,13 +526,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
static void *dax_insert_mapping_entry(struct address_space *mapping,
struct vm_fault *vmf,
void *entry, sector_t sector,
- unsigned long flags)
+ unsigned long flags, bool dirty)
{
struct radix_tree_root *page_tree = &mapping->page_tree;
void *new_entry;
pgoff_t index = vmf->pgoff;
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) {
@@ -569,7 +569,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping,
entry = new_entry;
}
- if (vmf->flags & FAULT_FLAG_WRITE)
+ if (dirty)
radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY);
spin_unlock_irq(&mapping->tree_lock);
@@ -881,7 +881,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry,
}
entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(entry2)) {
ret = VM_FAULT_SIGBUS;
goto out;
@@ -1182,7 +1182,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0);
+ 0, write);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
@@ -1258,7 +1258,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
goto fallback;
ret = dax_insert_mapping_entry(mapping, vmf, entry, 0,
- RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE);
+ RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false);
if (IS_ERR(ret))
goto fallback;
@@ -1379,7 +1379,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD);
+ RADIX_DAX_PMD, write);
if (IS_ERR(entry))
goto finish_iomap;
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the
MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be
refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for
everything else.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 1 +
include/linux/mman.h | 8 ++++++--
include/uapi/asm-generic/mman.h | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5589b4bd4b85..ea78b37deeaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -664,6 +664,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_ACCOUNT)] = "ac",
[ilog2(VM_NORESERVE)] = "nr",
[ilog2(VM_HUGETLB)] = "ht",
+ [ilog2(VM_SYNC)] = "sf",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_WIPEONFORK)] = "wf",
[ilog2(VM_DONTDUMP)] = "dd",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ca72b67153d5..5411cb7442de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -189,6 +189,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
+#define VM_SYNC 0x00800000 /* Synchronous page faults */
#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 94b63b4d71ff..8f7cc87828e6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -9,7 +9,7 @@
/*
* Arrange for legacy / undefined architecture specific flags to be
- * ignored by default in LEGACY_MAP_MASK.
+ * ignored by mmap handling code.
*/
#ifndef MAP_32BIT
#define MAP_32BIT 0
@@ -23,6 +23,9 @@
#ifndef MAP_UNINITIALIZED
#define MAP_UNINITIALIZED 0
#endif
+#ifndef MAP_SYNC
+#define MAP_SYNC 0
+#endif
/*
* The historical set of flags that all mmap implementations implicitly
@@ -125,7 +128,8 @@ calc_vm_flag_bits(unsigned long flags)
{
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
- _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
+ _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
+ _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
}
unsigned long vm_commit_limit(void);
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 7162cd4cca73..00e55627d2df 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h
@@ -12,6 +12,7 @@
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
#define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */
#define MAP_HUGETLB 0x40000 /* create a huge page mapping */
+#define MAP_SYNC 0x80000 /* perform synchronous page faults for the mapping */
/* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the
MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be
refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for
everything else.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 1 +
include/linux/mman.h | 8 ++++++--
include/uapi/asm-generic/mman.h | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5589b4bd4b85..ea78b37deeaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -664,6 +664,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_ACCOUNT)] = "ac",
[ilog2(VM_NORESERVE)] = "nr",
[ilog2(VM_HUGETLB)] = "ht",
+ [ilog2(VM_SYNC)] = "sf",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_WIPEONFORK)] = "wf",
[ilog2(VM_DONTDUMP)] = "dd",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ca72b67153d5..5411cb7442de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -189,6 +189,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
+#define VM_SYNC 0x00800000 /* Synchronous page faults */
#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 94b63b4d71ff..8f7cc87828e6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -9,7 +9,7 @@
/*
* Arrange for legacy / undefined architecture specific flags to be
- * ignored by default in LEGACY_MAP_MASK.
+ * ignored by mmap handling code.
*/
#ifndef MAP_32BIT
#define MAP_32BIT 0
@@ -23,6 +23,9 @@
#ifndef MAP_UNINITIALIZED
#define MAP_UNINITIALIZED 0
#endif
+#ifndef MAP_SYNC
+#define MAP_SYNC 0
+#endif
/*
* The historical set of flags that all mmap implementations implicitly
@@ -125,7 +128,8 @@ calc_vm_flag_bits(unsigned long flags)
{
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
- _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
+ _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
+ _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
}
unsigned long vm_commit_limit(void);
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 7162cd4cca73..00e55627d2df 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h
@@ -12,6 +12,7 @@
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
#define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */
#define MAP_HUGETLB 0x40000 /* create a huge page mapping */
+#define MAP_SYNC 0x80000 /* perform synchronous page faults for the mapping */
/* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the
MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be
refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for
everything else.
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 1 +
include/linux/mman.h | 8 ++++++--
include/uapi/asm-generic/mman.h | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5589b4bd4b85..ea78b37deeaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -664,6 +664,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_ACCOUNT)] = "ac",
[ilog2(VM_NORESERVE)] = "nr",
[ilog2(VM_HUGETLB)] = "ht",
+ [ilog2(VM_SYNC)] = "sf",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_WIPEONFORK)] = "wf",
[ilog2(VM_DONTDUMP)] = "dd",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ca72b67153d5..5411cb7442de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -189,6 +189,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
+#define VM_SYNC 0x00800000 /* Synchronous page faults */
#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 94b63b4d71ff..8f7cc87828e6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -9,7 +9,7 @@
/*
* Arrange for legacy / undefined architecture specific flags to be
- * ignored by default in LEGACY_MAP_MASK.
+ * ignored by mmap handling code.
*/
#ifndef MAP_32BIT
#define MAP_32BIT 0
@@ -23,6 +23,9 @@
#ifndef MAP_UNINITIALIZED
#define MAP_UNINITIALIZED 0
#endif
+#ifndef MAP_SYNC
+#define MAP_SYNC 0
+#endif
/*
* The historical set of flags that all mmap implementations implicitly
@@ -125,7 +128,8 @@ calc_vm_flag_bits(unsigned long flags)
{
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
- _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
+ _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
+ _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
}
unsigned long vm_commit_limit(void);
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 7162cd4cca73..00e55627d2df 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h
@@ -12,6 +12,7 @@
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
#define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */
#define MAP_HUGETLB 0x40000 /* create a huge page mapping */
+#define MAP_SYNC 0x80000 /* perform synchronous page faults for the mapping */
/* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the
MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be
refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for
everything else.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 1 +
include/linux/mman.h | 8 ++++++--
include/uapi/asm-generic/mman.h | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5589b4bd4b85..ea78b37deeaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -664,6 +664,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_ACCOUNT)] = "ac",
[ilog2(VM_NORESERVE)] = "nr",
[ilog2(VM_HUGETLB)] = "ht",
+ [ilog2(VM_SYNC)] = "sf",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_WIPEONFORK)] = "wf",
[ilog2(VM_DONTDUMP)] = "dd",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ca72b67153d5..5411cb7442de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -189,6 +189,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
+#define VM_SYNC 0x00800000 /* Synchronous page faults */
#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 94b63b4d71ff..8f7cc87828e6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -9,7 +9,7 @@
/*
* Arrange for legacy / undefined architecture specific flags to be
- * ignored by default in LEGACY_MAP_MASK.
+ * ignored by mmap handling code.
*/
#ifndef MAP_32BIT
#define MAP_32BIT 0
@@ -23,6 +23,9 @@
#ifndef MAP_UNINITIALIZED
#define MAP_UNINITIALIZED 0
#endif
+#ifndef MAP_SYNC
+#define MAP_SYNC 0
+#endif
/*
* The historical set of flags that all mmap implementations implicitly
@@ -125,7 +128,8 @@ calc_vm_flag_bits(unsigned long flags)
{
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
- _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
+ _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
+ _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
}
unsigned long vm_commit_limit(void);
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 7162cd4cca73..00e55627d2df 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h
@@ -12,6 +12,7 @@
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
#define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */
#define MAP_HUGETLB 0x40000 /* create a huge page mapping */
+#define MAP_SYNC 0x80000 /* perform synchronous page faults for the mapping */
/* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Define new MAP_SYNC flag and corresponding VMA VM_SYNC flag. As the
MAP_SYNC flag is not part of LEGACY_MAP_MASK, currently it will be
refused by all MAP_SHARED_VALIDATE map attempts and silently ignored for
everything else.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 1 +
include/linux/mman.h | 8 ++++++--
include/uapi/asm-generic/mman.h | 1 +
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 5589b4bd4b85..ea78b37deeaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -664,6 +664,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_ACCOUNT)] = "ac",
[ilog2(VM_NORESERVE)] = "nr",
[ilog2(VM_HUGETLB)] = "ht",
+ [ilog2(VM_SYNC)] = "sf",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_WIPEONFORK)] = "wf",
[ilog2(VM_DONTDUMP)] = "dd",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ca72b67153d5..5411cb7442de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -189,6 +189,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
+#define VM_SYNC 0x00800000 /* Synchronous page faults */
#define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
#define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
#define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
diff --git a/include/linux/mman.h b/include/linux/mman.h
index 94b63b4d71ff..8f7cc87828e6 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -9,7 +9,7 @@
/*
* Arrange for legacy / undefined architecture specific flags to be
- * ignored by default in LEGACY_MAP_MASK.
+ * ignored by mmap handling code.
*/
#ifndef MAP_32BIT
#define MAP_32BIT 0
@@ -23,6 +23,9 @@
#ifndef MAP_UNINITIALIZED
#define MAP_UNINITIALIZED 0
#endif
+#ifndef MAP_SYNC
+#define MAP_SYNC 0
+#endif
/*
* The historical set of flags that all mmap implementations implicitly
@@ -125,7 +128,8 @@ calc_vm_flag_bits(unsigned long flags)
{
return _calc_vm_trans(flags, MAP_GROWSDOWN, VM_GROWSDOWN ) |
_calc_vm_trans(flags, MAP_DENYWRITE, VM_DENYWRITE ) |
- _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED );
+ _calc_vm_trans(flags, MAP_LOCKED, VM_LOCKED ) |
+ _calc_vm_trans(flags, MAP_SYNC, VM_SYNC );
}
unsigned long vm_commit_limit(void);
diff --git a/include/uapi/asm-generic/mman.h b/include/uapi/asm-generic/mman.h
index 7162cd4cca73..00e55627d2df 100644
--- a/include/uapi/asm-generic/mman.h
+++ b/include/uapi/asm-generic/mman.h
@@ -12,6 +12,7 @@
#define MAP_NONBLOCK 0x10000 /* do not block on IO */
#define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */
#define MAP_HUGETLB 0x40000 /* create a huge page mapping */
+#define MAP_SYNC 0x80000 /* perform synchronous page faults for the mapping */
/* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 13/18] dax, iomap: Add support for synchronous faults
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Add a flag to iomap interface informing the caller that inode needs
fdstasync(2) for returned extent to become persistent and use it in DAX
fault code so that we don't map such extents into page tables
immediately. Instead we propagate the information that fdatasync(2) is
necessary from dax_iomap_fault() with a new VM_FAULT_NEEDDSYNC flag.
Filesystem fault handler is then responsible for calling fdatasync(2)
and inserting pfn into page tables.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 39 +++++++++++++++++++++++++++++++++++++--
include/linux/iomap.h | 5 +++++
include/linux/mm.h | 6 +++++-
3 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index efc210ff6665..bb9ff907738c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1091,6 +1091,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
unsigned flags = IOMAP_FAULT;
int error, major = 0;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
int vmf_ret = 0;
void *entry;
pfn_t pfn;
@@ -1169,6 +1170,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
goto finish_iomap;
}
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
@@ -1182,12 +1185,27 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0, write);
+ 0, write && !sync);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
}
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PTE into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp)) {
+ error = -EIO;
+ goto error_finish_iomap;
+ }
+ *pfnp = pfn;
+ vmf_ret = VM_FAULT_NEEDDSYNC | major;
+ goto finish_iomap;
+ }
trace_dax_insert_mapping(inode, vmf, entry);
if (write)
error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
@@ -1287,6 +1305,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long pmd_addr = vmf->address & PMD_MASK;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT;
struct inode *inode = mapping->host;
int result = VM_FAULT_FALLBACK;
@@ -1371,6 +1390,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
if (iomap.offset + iomap.length < pos + PMD_SIZE)
goto finish_iomap;
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
@@ -1379,10 +1400,24 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD, write);
+ RADIX_DAX_PMD, write && !sync);
if (IS_ERR(entry))
goto finish_iomap;
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PMD into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp))
+ goto finish_iomap;
+ *pfnp = pfn;
+ result = VM_FAULT_NEEDDSYNC;
+ goto finish_iomap;
+ }
+
trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
write);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f64dc6ce5161..73e3b7085dbe 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -22,6 +22,11 @@ struct vm_fault;
* Flags for all iomap mappings:
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
+/*
+ * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
+ * written data and requires fdatasync to commit them to persistent storage.
+ */
+#define IOMAP_F_DIRTY 0x02
/*
* Flags that only need to be reported for IOMAP_REPORT requests:
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411cb7442de..f57e55782d7d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,6 +1182,9 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
+#define VM_FAULT_NEEDDSYNC 0x2000 /* ->fault did not modify page tables
+ * and needs fsync() to complete (for
+ * synchronous page faults in DAX) */
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
@@ -1199,7 +1202,8 @@ static inline void clear_page_pfmemalloc(struct page *page)
{ VM_FAULT_LOCKED, "LOCKED" }, \
{ VM_FAULT_RETRY, "RETRY" }, \
{ VM_FAULT_FALLBACK, "FALLBACK" }, \
- { VM_FAULT_DONE_COW, "DONE_COW" }
+ { VM_FAULT_DONE_COW, "DONE_COW" }, \
+ { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
/* Encode hstate index for a hwpoisoned large page */
#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 13/18] dax, iomap: Add support for synchronous faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Add a flag to iomap interface informing the caller that inode needs
fdstasync(2) for returned extent to become persistent and use it in DAX
fault code so that we don't map such extents into page tables
immediately. Instead we propagate the information that fdatasync(2) is
necessary from dax_iomap_fault() with a new VM_FAULT_NEEDDSYNC flag.
Filesystem fault handler is then responsible for calling fdatasync(2)
and inserting pfn into page tables.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 39 +++++++++++++++++++++++++++++++++++++--
include/linux/iomap.h | 5 +++++
include/linux/mm.h | 6 +++++-
3 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index efc210ff6665..bb9ff907738c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1091,6 +1091,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
unsigned flags = IOMAP_FAULT;
int error, major = 0;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
int vmf_ret = 0;
void *entry;
pfn_t pfn;
@@ -1169,6 +1170,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
goto finish_iomap;
}
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
@@ -1182,12 +1185,27 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0, write);
+ 0, write && !sync);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
}
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PTE into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp)) {
+ error = -EIO;
+ goto error_finish_iomap;
+ }
+ *pfnp = pfn;
+ vmf_ret = VM_FAULT_NEEDDSYNC | major;
+ goto finish_iomap;
+ }
trace_dax_insert_mapping(inode, vmf, entry);
if (write)
error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
@@ -1287,6 +1305,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long pmd_addr = vmf->address & PMD_MASK;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT;
struct inode *inode = mapping->host;
int result = VM_FAULT_FALLBACK;
@@ -1371,6 +1390,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
if (iomap.offset + iomap.length < pos + PMD_SIZE)
goto finish_iomap;
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
@@ -1379,10 +1400,24 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD, write);
+ RADIX_DAX_PMD, write && !sync);
if (IS_ERR(entry))
goto finish_iomap;
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PMD into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp))
+ goto finish_iomap;
+ *pfnp = pfn;
+ result = VM_FAULT_NEEDDSYNC;
+ goto finish_iomap;
+ }
+
trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
write);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f64dc6ce5161..73e3b7085dbe 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -22,6 +22,11 @@ struct vm_fault;
* Flags for all iomap mappings:
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
+/*
+ * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
+ * written data and requires fdatasync to commit them to persistent storage.
+ */
+#define IOMAP_F_DIRTY 0x02
/*
* Flags that only need to be reported for IOMAP_REPORT requests:
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411cb7442de..f57e55782d7d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,6 +1182,9 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
+#define VM_FAULT_NEEDDSYNC 0x2000 /* ->fault did not modify page tables
+ * and needs fsync() to complete (for
+ * synchronous page faults in DAX) */
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
@@ -1199,7 +1202,8 @@ static inline void clear_page_pfmemalloc(struct page *page)
{ VM_FAULT_LOCKED, "LOCKED" }, \
{ VM_FAULT_RETRY, "RETRY" }, \
{ VM_FAULT_FALLBACK, "FALLBACK" }, \
- { VM_FAULT_DONE_COW, "DONE_COW" }
+ { VM_FAULT_DONE_COW, "DONE_COW" }, \
+ { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
/* Encode hstate index for a hwpoisoned large page */
#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 13/18] dax, iomap: Add support for synchronous faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Add a flag to iomap interface informing the caller that inode needs
fdstasync(2) for returned extent to become persistent and use it in DAX
fault code so that we don't map such extents into page tables
immediately. Instead we propagate the information that fdatasync(2) is
necessary from dax_iomap_fault() with a new VM_FAULT_NEEDDSYNC flag.
Filesystem fault handler is then responsible for calling fdatasync(2)
and inserting pfn into page tables.
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 39 +++++++++++++++++++++++++++++++++++++--
include/linux/iomap.h | 5 +++++
include/linux/mm.h | 6 +++++-
3 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index efc210ff6665..bb9ff907738c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1091,6 +1091,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
unsigned flags = IOMAP_FAULT;
int error, major = 0;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
int vmf_ret = 0;
void *entry;
pfn_t pfn;
@@ -1169,6 +1170,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
goto finish_iomap;
}
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
@@ -1182,12 +1185,27 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0, write);
+ 0, write && !sync);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
}
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PTE into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp)) {
+ error = -EIO;
+ goto error_finish_iomap;
+ }
+ *pfnp = pfn;
+ vmf_ret = VM_FAULT_NEEDDSYNC | major;
+ goto finish_iomap;
+ }
trace_dax_insert_mapping(inode, vmf, entry);
if (write)
error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
@@ -1287,6 +1305,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long pmd_addr = vmf->address & PMD_MASK;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT;
struct inode *inode = mapping->host;
int result = VM_FAULT_FALLBACK;
@@ -1371,6 +1390,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
if (iomap.offset + iomap.length < pos + PMD_SIZE)
goto finish_iomap;
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
@@ -1379,10 +1400,24 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD, write);
+ RADIX_DAX_PMD, write && !sync);
if (IS_ERR(entry))
goto finish_iomap;
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PMD into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp))
+ goto finish_iomap;
+ *pfnp = pfn;
+ result = VM_FAULT_NEEDDSYNC;
+ goto finish_iomap;
+ }
+
trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
write);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f64dc6ce5161..73e3b7085dbe 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -22,6 +22,11 @@ struct vm_fault;
* Flags for all iomap mappings:
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
+/*
+ * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
+ * written data and requires fdatasync to commit them to persistent storage.
+ */
+#define IOMAP_F_DIRTY 0x02
/*
* Flags that only need to be reported for IOMAP_REPORT requests:
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411cb7442de..f57e55782d7d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,6 +1182,9 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
+#define VM_FAULT_NEEDDSYNC 0x2000 /* ->fault did not modify page tables
+ * and needs fsync() to complete (for
+ * synchronous page faults in DAX) */
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
@@ -1199,7 +1202,8 @@ static inline void clear_page_pfmemalloc(struct page *page)
{ VM_FAULT_LOCKED, "LOCKED" }, \
{ VM_FAULT_RETRY, "RETRY" }, \
{ VM_FAULT_FALLBACK, "FALLBACK" }, \
- { VM_FAULT_DONE_COW, "DONE_COW" }
+ { VM_FAULT_DONE_COW, "DONE_COW" }, \
+ { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
/* Encode hstate index for a hwpoisoned large page */
#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 13/18] dax, iomap: Add support for synchronous faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Add a flag to iomap interface informing the caller that inode needs
fdstasync(2) for returned extent to become persistent and use it in DAX
fault code so that we don't map such extents into page tables
immediately. Instead we propagate the information that fdatasync(2) is
necessary from dax_iomap_fault() with a new VM_FAULT_NEEDDSYNC flag.
Filesystem fault handler is then responsible for calling fdatasync(2)
and inserting pfn into page tables.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 39 +++++++++++++++++++++++++++++++++++++--
include/linux/iomap.h | 5 +++++
include/linux/mm.h | 6 +++++-
3 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index efc210ff6665..bb9ff907738c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1091,6 +1091,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
unsigned flags = IOMAP_FAULT;
int error, major = 0;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
int vmf_ret = 0;
void *entry;
pfn_t pfn;
@@ -1169,6 +1170,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
goto finish_iomap;
}
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
@@ -1182,12 +1185,27 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0, write);
+ 0, write && !sync);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
}
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PTE into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp)) {
+ error = -EIO;
+ goto error_finish_iomap;
+ }
+ *pfnp = pfn;
+ vmf_ret = VM_FAULT_NEEDDSYNC | major;
+ goto finish_iomap;
+ }
trace_dax_insert_mapping(inode, vmf, entry);
if (write)
error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
@@ -1287,6 +1305,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long pmd_addr = vmf->address & PMD_MASK;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT;
struct inode *inode = mapping->host;
int result = VM_FAULT_FALLBACK;
@@ -1371,6 +1390,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
if (iomap.offset + iomap.length < pos + PMD_SIZE)
goto finish_iomap;
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
@@ -1379,10 +1400,24 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD, write);
+ RADIX_DAX_PMD, write && !sync);
if (IS_ERR(entry))
goto finish_iomap;
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PMD into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp))
+ goto finish_iomap;
+ *pfnp = pfn;
+ result = VM_FAULT_NEEDDSYNC;
+ goto finish_iomap;
+ }
+
trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
write);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f64dc6ce5161..73e3b7085dbe 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -22,6 +22,11 @@ struct vm_fault;
* Flags for all iomap mappings:
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
+/*
+ * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
+ * written data and requires fdatasync to commit them to persistent storage.
+ */
+#define IOMAP_F_DIRTY 0x02
/*
* Flags that only need to be reported for IOMAP_REPORT requests:
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411cb7442de..f57e55782d7d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,6 +1182,9 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
+#define VM_FAULT_NEEDDSYNC 0x2000 /* ->fault did not modify page tables
+ * and needs fsync() to complete (for
+ * synchronous page faults in DAX) */
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
@@ -1199,7 +1202,8 @@ static inline void clear_page_pfmemalloc(struct page *page)
{ VM_FAULT_LOCKED, "LOCKED" }, \
{ VM_FAULT_RETRY, "RETRY" }, \
{ VM_FAULT_FALLBACK, "FALLBACK" }, \
- { VM_FAULT_DONE_COW, "DONE_COW" }
+ { VM_FAULT_DONE_COW, "DONE_COW" }, \
+ { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
/* Encode hstate index for a hwpoisoned large page */
#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 13/18] dax, iomap: Add support for synchronous faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Add a flag to iomap interface informing the caller that inode needs
fdstasync(2) for returned extent to become persistent and use it in DAX
fault code so that we don't map such extents into page tables
immediately. Instead we propagate the information that fdatasync(2) is
necessary from dax_iomap_fault() with a new VM_FAULT_NEEDDSYNC flag.
Filesystem fault handler is then responsible for calling fdatasync(2)
and inserting pfn into page tables.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 39 +++++++++++++++++++++++++++++++++++++--
include/linux/iomap.h | 5 +++++
include/linux/mm.h | 6 +++++-
3 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index efc210ff6665..bb9ff907738c 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1091,6 +1091,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
unsigned flags = IOMAP_FAULT;
int error, major = 0;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
int vmf_ret = 0;
void *entry;
pfn_t pfn;
@@ -1169,6 +1170,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
goto finish_iomap;
}
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
@@ -1182,12 +1185,27 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- 0, write);
+ 0, write && !sync);
if (IS_ERR(entry)) {
error = PTR_ERR(entry);
goto error_finish_iomap;
}
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PTE into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp)) {
+ error = -EIO;
+ goto error_finish_iomap;
+ }
+ *pfnp = pfn;
+ vmf_ret = VM_FAULT_NEEDDSYNC | major;
+ goto finish_iomap;
+ }
trace_dax_insert_mapping(inode, vmf, entry);
if (write)
error = vm_insert_mixed_mkwrite(vma, vaddr, pfn);
@@ -1287,6 +1305,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
struct address_space *mapping = vma->vm_file->f_mapping;
unsigned long pmd_addr = vmf->address & PMD_MASK;
bool write = vmf->flags & FAULT_FLAG_WRITE;
+ bool sync;
unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT;
struct inode *inode = mapping->host;
int result = VM_FAULT_FALLBACK;
@@ -1371,6 +1390,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
if (iomap.offset + iomap.length < pos + PMD_SIZE)
goto finish_iomap;
+ sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY);
+
switch (iomap.type) {
case IOMAP_MAPPED:
error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn);
@@ -1379,10 +1400,24 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
entry = dax_insert_mapping_entry(mapping, vmf, entry,
dax_iomap_sector(&iomap, pos),
- RADIX_DAX_PMD, write);
+ RADIX_DAX_PMD, write && !sync);
if (IS_ERR(entry))
goto finish_iomap;
+ /*
+ * If we are doing synchronous page fault and inode needs fsync,
+ * we can insert PMD into page tables only after that happens.
+ * Skip insertion for now and return the pfn so that caller can
+ * insert it after fsync is done.
+ */
+ if (sync) {
+ if (WARN_ON_ONCE(!pfnp))
+ goto finish_iomap;
+ *pfnp = pfn;
+ result = VM_FAULT_NEEDDSYNC;
+ goto finish_iomap;
+ }
+
trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry);
result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn,
write);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f64dc6ce5161..73e3b7085dbe 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -22,6 +22,11 @@ struct vm_fault;
* Flags for all iomap mappings:
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
+/*
+ * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
+ * written data and requires fdatasync to commit them to persistent storage.
+ */
+#define IOMAP_F_DIRTY 0x02
/*
* Flags that only need to be reported for IOMAP_REPORT requests:
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5411cb7442de..f57e55782d7d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1182,6 +1182,9 @@ static inline void clear_page_pfmemalloc(struct page *page)
#define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */
#define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */
#define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */
+#define VM_FAULT_NEEDDSYNC 0x2000 /* ->fault did not modify page tables
+ * and needs fsync() to complete (for
+ * synchronous page faults in DAX) */
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \
VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \
@@ -1199,7 +1202,8 @@ static inline void clear_page_pfmemalloc(struct page *page)
{ VM_FAULT_LOCKED, "LOCKED" }, \
{ VM_FAULT_RETRY, "RETRY" }, \
{ VM_FAULT_FALLBACK, "FALLBACK" }, \
- { VM_FAULT_DONE_COW, "DONE_COW" }
+ { VM_FAULT_DONE_COW, "DONE_COW" }, \
+ { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }
/* Encode hstate index for a hwpoisoned large page */
#define VM_FAULT_SET_HINDEX(x) ((x) << 12)
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 14/18] dax: Implement dax_finish_sync_fault()
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Implement a function that filesystems can call to finish handling of
synchronous page faults. It takes care of syncing appropriare file range
and insertion of page table entry.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++++++++++++
include/linux/dax.h | 2 ++
include/trace/events/fs_dax.h | 2 ++
3 files changed, 87 insertions(+)
diff --git a/fs/dax.c b/fs/dax.c
index bb9ff907738c..78233c716757 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1492,3 +1492,86 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
}
}
EXPORT_SYMBOL_GPL(dax_iomap_fault);
+
+/**
+ * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function inserts writeable PTE or PMD entry into page tables for mmaped
+ * DAX file. It takes care of marking corresponding radix tree entry as dirty
+ * as well.
+ */
+static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ void *entry, **slot;
+ pgoff_t index = vmf->pgoff;
+ int vmf_ret, error;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = get_unlocked_mapping_entry(mapping, index, &slot);
+ /* Did we race with someone splitting entry or so? */
+ if (!entry ||
+ (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) ||
+ (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) {
+ put_unlocked_mapping_entry(mapping, index, entry);
+ spin_unlock_irq(&mapping->tree_lock);
+ trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
+ VM_FAULT_NOPAGE);
+ return VM_FAULT_NOPAGE;
+ }
+ radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
+ entry = lock_slot(mapping, slot);
+ spin_unlock_irq(&mapping->tree_lock);
+ switch (pe_size) {
+ case PE_SIZE_PTE:
+ error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
+ vmf_ret = dax_fault_return(error);
+ break;
+#ifdef CONFIG_FS_DAX_PMD
+ case PE_SIZE_PMD:
+ vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
+ pfn, true);
+ break;
+#endif
+ default:
+ vmf_ret = VM_FAULT_FALLBACK;
+ }
+ put_locked_mapping_entry(mapping, index);
+ trace_dax_insert_pfn_mkwrite(mapping->host, vmf, vmf_ret);
+ return vmf_ret;
+}
+
+/**
+ * dax_finish_sync_fault - finish synchronous page fault
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function ensures that the file range touched by the page fault is
+ * stored persistently on the media and handles inserting of appropriate page
+ * table entry.
+ */
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ int err;
+ loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT;
+ size_t len = 0;
+
+ if (pe_size == PE_SIZE_PTE)
+ len = PAGE_SIZE;
+ else if (pe_size == PE_SIZE_PMD)
+ len = PMD_SIZE;
+ else
+ WARN_ON_ONCE(1);
+ err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1);
+ if (err)
+ return VM_FAULT_SIGBUS;
+ return dax_insert_pfn_mkwrite(vmf, pe_size, pfn);
+}
+EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
diff --git a/include/linux/dax.h b/include/linux/dax.h
index e7fa4b8f45bc..d403f78b706c 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -96,6 +96,8 @@ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
pfn_t *pfnp, const struct iomap_ops *ops);
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index 88a9d19b8ff8..7725459fafef 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -190,6 +190,8 @@ DEFINE_EVENT(dax_pte_fault_class, name, \
DEFINE_PTE_FAULT_EVENT(dax_pte_fault);
DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done);
DEFINE_PTE_FAULT_EVENT(dax_load_hole);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite_no_entry);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite);
TRACE_EVENT(dax_insert_mapping,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, void *radix_entry),
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 14/18] dax: Implement dax_finish_sync_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Implement a function that filesystems can call to finish handling of
synchronous page faults. It takes care of syncing appropriare file range
and insertion of page table entry.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++++++++++++
include/linux/dax.h | 2 ++
include/trace/events/fs_dax.h | 2 ++
3 files changed, 87 insertions(+)
diff --git a/fs/dax.c b/fs/dax.c
index bb9ff907738c..78233c716757 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1492,3 +1492,86 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
}
}
EXPORT_SYMBOL_GPL(dax_iomap_fault);
+
+/**
+ * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function inserts writeable PTE or PMD entry into page tables for mmaped
+ * DAX file. It takes care of marking corresponding radix tree entry as dirty
+ * as well.
+ */
+static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ void *entry, **slot;
+ pgoff_t index = vmf->pgoff;
+ int vmf_ret, error;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = get_unlocked_mapping_entry(mapping, index, &slot);
+ /* Did we race with someone splitting entry or so? */
+ if (!entry ||
+ (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) ||
+ (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) {
+ put_unlocked_mapping_entry(mapping, index, entry);
+ spin_unlock_irq(&mapping->tree_lock);
+ trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
+ VM_FAULT_NOPAGE);
+ return VM_FAULT_NOPAGE;
+ }
+ radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
+ entry = lock_slot(mapping, slot);
+ spin_unlock_irq(&mapping->tree_lock);
+ switch (pe_size) {
+ case PE_SIZE_PTE:
+ error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
+ vmf_ret = dax_fault_return(error);
+ break;
+#ifdef CONFIG_FS_DAX_PMD
+ case PE_SIZE_PMD:
+ vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
+ pfn, true);
+ break;
+#endif
+ default:
+ vmf_ret = VM_FAULT_FALLBACK;
+ }
+ put_locked_mapping_entry(mapping, index);
+ trace_dax_insert_pfn_mkwrite(mapping->host, vmf, vmf_ret);
+ return vmf_ret;
+}
+
+/**
+ * dax_finish_sync_fault - finish synchronous page fault
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function ensures that the file range touched by the page fault is
+ * stored persistently on the media and handles inserting of appropriate page
+ * table entry.
+ */
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ int err;
+ loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT;
+ size_t len = 0;
+
+ if (pe_size == PE_SIZE_PTE)
+ len = PAGE_SIZE;
+ else if (pe_size == PE_SIZE_PMD)
+ len = PMD_SIZE;
+ else
+ WARN_ON_ONCE(1);
+ err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1);
+ if (err)
+ return VM_FAULT_SIGBUS;
+ return dax_insert_pfn_mkwrite(vmf, pe_size, pfn);
+}
+EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
diff --git a/include/linux/dax.h b/include/linux/dax.h
index e7fa4b8f45bc..d403f78b706c 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -96,6 +96,8 @@ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
pfn_t *pfnp, const struct iomap_ops *ops);
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index 88a9d19b8ff8..7725459fafef 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -190,6 +190,8 @@ DEFINE_EVENT(dax_pte_fault_class, name, \
DEFINE_PTE_FAULT_EVENT(dax_pte_fault);
DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done);
DEFINE_PTE_FAULT_EVENT(dax_load_hole);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite_no_entry);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite);
TRACE_EVENT(dax_insert_mapping,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, void *radix_entry),
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 14/18] dax: Implement dax_finish_sync_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Implement a function that filesystems can call to finish handling of
synchronous page faults. It takes care of syncing appropriare file range
and insertion of page table entry.
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++++++++++++
include/linux/dax.h | 2 ++
include/trace/events/fs_dax.h | 2 ++
3 files changed, 87 insertions(+)
diff --git a/fs/dax.c b/fs/dax.c
index bb9ff907738c..78233c716757 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1492,3 +1492,86 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
}
}
EXPORT_SYMBOL_GPL(dax_iomap_fault);
+
+/**
+ * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function inserts writeable PTE or PMD entry into page tables for mmaped
+ * DAX file. It takes care of marking corresponding radix tree entry as dirty
+ * as well.
+ */
+static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ void *entry, **slot;
+ pgoff_t index = vmf->pgoff;
+ int vmf_ret, error;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = get_unlocked_mapping_entry(mapping, index, &slot);
+ /* Did we race with someone splitting entry or so? */
+ if (!entry ||
+ (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) ||
+ (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) {
+ put_unlocked_mapping_entry(mapping, index, entry);
+ spin_unlock_irq(&mapping->tree_lock);
+ trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
+ VM_FAULT_NOPAGE);
+ return VM_FAULT_NOPAGE;
+ }
+ radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
+ entry = lock_slot(mapping, slot);
+ spin_unlock_irq(&mapping->tree_lock);
+ switch (pe_size) {
+ case PE_SIZE_PTE:
+ error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
+ vmf_ret = dax_fault_return(error);
+ break;
+#ifdef CONFIG_FS_DAX_PMD
+ case PE_SIZE_PMD:
+ vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
+ pfn, true);
+ break;
+#endif
+ default:
+ vmf_ret = VM_FAULT_FALLBACK;
+ }
+ put_locked_mapping_entry(mapping, index);
+ trace_dax_insert_pfn_mkwrite(mapping->host, vmf, vmf_ret);
+ return vmf_ret;
+}
+
+/**
+ * dax_finish_sync_fault - finish synchronous page fault
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function ensures that the file range touched by the page fault is
+ * stored persistently on the media and handles inserting of appropriate page
+ * table entry.
+ */
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ int err;
+ loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT;
+ size_t len = 0;
+
+ if (pe_size == PE_SIZE_PTE)
+ len = PAGE_SIZE;
+ else if (pe_size == PE_SIZE_PMD)
+ len = PMD_SIZE;
+ else
+ WARN_ON_ONCE(1);
+ err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1);
+ if (err)
+ return VM_FAULT_SIGBUS;
+ return dax_insert_pfn_mkwrite(vmf, pe_size, pfn);
+}
+EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
diff --git a/include/linux/dax.h b/include/linux/dax.h
index e7fa4b8f45bc..d403f78b706c 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -96,6 +96,8 @@ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
pfn_t *pfnp, const struct iomap_ops *ops);
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index 88a9d19b8ff8..7725459fafef 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -190,6 +190,8 @@ DEFINE_EVENT(dax_pte_fault_class, name, \
DEFINE_PTE_FAULT_EVENT(dax_pte_fault);
DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done);
DEFINE_PTE_FAULT_EVENT(dax_load_hole);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite_no_entry);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite);
TRACE_EVENT(dax_insert_mapping,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, void *radix_entry),
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 14/18] dax: Implement dax_finish_sync_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Implement a function that filesystems can call to finish handling of
synchronous page faults. It takes care of syncing appropriare file range
and insertion of page table entry.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++++++++++++
include/linux/dax.h | 2 ++
include/trace/events/fs_dax.h | 2 ++
3 files changed, 87 insertions(+)
diff --git a/fs/dax.c b/fs/dax.c
index bb9ff907738c..78233c716757 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1492,3 +1492,86 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
}
}
EXPORT_SYMBOL_GPL(dax_iomap_fault);
+
+/**
+ * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function inserts writeable PTE or PMD entry into page tables for mmaped
+ * DAX file. It takes care of marking corresponding radix tree entry as dirty
+ * as well.
+ */
+static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ void *entry, **slot;
+ pgoff_t index = vmf->pgoff;
+ int vmf_ret, error;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = get_unlocked_mapping_entry(mapping, index, &slot);
+ /* Did we race with someone splitting entry or so? */
+ if (!entry ||
+ (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) ||
+ (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) {
+ put_unlocked_mapping_entry(mapping, index, entry);
+ spin_unlock_irq(&mapping->tree_lock);
+ trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
+ VM_FAULT_NOPAGE);
+ return VM_FAULT_NOPAGE;
+ }
+ radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
+ entry = lock_slot(mapping, slot);
+ spin_unlock_irq(&mapping->tree_lock);
+ switch (pe_size) {
+ case PE_SIZE_PTE:
+ error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
+ vmf_ret = dax_fault_return(error);
+ break;
+#ifdef CONFIG_FS_DAX_PMD
+ case PE_SIZE_PMD:
+ vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
+ pfn, true);
+ break;
+#endif
+ default:
+ vmf_ret = VM_FAULT_FALLBACK;
+ }
+ put_locked_mapping_entry(mapping, index);
+ trace_dax_insert_pfn_mkwrite(mapping->host, vmf, vmf_ret);
+ return vmf_ret;
+}
+
+/**
+ * dax_finish_sync_fault - finish synchronous page fault
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function ensures that the file range touched by the page fault is
+ * stored persistently on the media and handles inserting of appropriate page
+ * table entry.
+ */
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ int err;
+ loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT;
+ size_t len = 0;
+
+ if (pe_size == PE_SIZE_PTE)
+ len = PAGE_SIZE;
+ else if (pe_size == PE_SIZE_PMD)
+ len = PMD_SIZE;
+ else
+ WARN_ON_ONCE(1);
+ err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1);
+ if (err)
+ return VM_FAULT_SIGBUS;
+ return dax_insert_pfn_mkwrite(vmf, pe_size, pfn);
+}
+EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
diff --git a/include/linux/dax.h b/include/linux/dax.h
index e7fa4b8f45bc..d403f78b706c 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -96,6 +96,8 @@ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
pfn_t *pfnp, const struct iomap_ops *ops);
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index 88a9d19b8ff8..7725459fafef 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -190,6 +190,8 @@ DEFINE_EVENT(dax_pte_fault_class, name, \
DEFINE_PTE_FAULT_EVENT(dax_pte_fault);
DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done);
DEFINE_PTE_FAULT_EVENT(dax_load_hole);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite_no_entry);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite);
TRACE_EVENT(dax_insert_mapping,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, void *radix_entry),
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 14/18] dax: Implement dax_finish_sync_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Implement a function that filesystems can call to finish handling of
synchronous page faults. It takes care of syncing appropriare file range
and insertion of page table entry.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/dax.c | 83 +++++++++++++++++++++++++++++++++++++++++++
include/linux/dax.h | 2 ++
include/trace/events/fs_dax.h | 2 ++
3 files changed, 87 insertions(+)
diff --git a/fs/dax.c b/fs/dax.c
index bb9ff907738c..78233c716757 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1492,3 +1492,86 @@ int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
}
}
EXPORT_SYMBOL_GPL(dax_iomap_fault);
+
+/**
+ * dax_insert_pfn_mkwrite - insert PTE or PMD entry into page tables
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function inserts writeable PTE or PMD entry into page tables for mmaped
+ * DAX file. It takes care of marking corresponding radix tree entry as dirty
+ * as well.
+ */
+static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
+ enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ struct address_space *mapping = vmf->vma->vm_file->f_mapping;
+ void *entry, **slot;
+ pgoff_t index = vmf->pgoff;
+ int vmf_ret, error;
+
+ spin_lock_irq(&mapping->tree_lock);
+ entry = get_unlocked_mapping_entry(mapping, index, &slot);
+ /* Did we race with someone splitting entry or so? */
+ if (!entry ||
+ (pe_size == PE_SIZE_PTE && !dax_is_pte_entry(entry)) ||
+ (pe_size == PE_SIZE_PMD && !dax_is_pmd_entry(entry))) {
+ put_unlocked_mapping_entry(mapping, index, entry);
+ spin_unlock_irq(&mapping->tree_lock);
+ trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
+ VM_FAULT_NOPAGE);
+ return VM_FAULT_NOPAGE;
+ }
+ radix_tree_tag_set(&mapping->page_tree, index, PAGECACHE_TAG_DIRTY);
+ entry = lock_slot(mapping, slot);
+ spin_unlock_irq(&mapping->tree_lock);
+ switch (pe_size) {
+ case PE_SIZE_PTE:
+ error = vm_insert_mixed_mkwrite(vmf->vma, vmf->address, pfn);
+ vmf_ret = dax_fault_return(error);
+ break;
+#ifdef CONFIG_FS_DAX_PMD
+ case PE_SIZE_PMD:
+ vmf_ret = vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd,
+ pfn, true);
+ break;
+#endif
+ default:
+ vmf_ret = VM_FAULT_FALLBACK;
+ }
+ put_locked_mapping_entry(mapping, index);
+ trace_dax_insert_pfn_mkwrite(mapping->host, vmf, vmf_ret);
+ return vmf_ret;
+}
+
+/**
+ * dax_finish_sync_fault - finish synchronous page fault
+ * @vmf: The description of the fault
+ * @pe_size: Size of entry to be inserted
+ * @pfn: PFN to insert
+ *
+ * This function ensures that the file range touched by the page fault is
+ * stored persistently on the media and handles inserting of appropriate page
+ * table entry.
+ */
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn)
+{
+ int err;
+ loff_t start = ((loff_t)vmf->pgoff) << PAGE_SHIFT;
+ size_t len = 0;
+
+ if (pe_size == PE_SIZE_PTE)
+ len = PAGE_SIZE;
+ else if (pe_size == PE_SIZE_PMD)
+ len = PMD_SIZE;
+ else
+ WARN_ON_ONCE(1);
+ err = vfs_fsync_range(vmf->vma->vm_file, start, start + len - 1, 1);
+ if (err)
+ return VM_FAULT_SIGBUS;
+ return dax_insert_pfn_mkwrite(vmf, pe_size, pfn);
+}
+EXPORT_SYMBOL_GPL(dax_finish_sync_fault);
diff --git a/include/linux/dax.h b/include/linux/dax.h
index e7fa4b8f45bc..d403f78b706c 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -96,6 +96,8 @@ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops);
int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
pfn_t *pfnp, const struct iomap_ops *ops);
+int dax_finish_sync_fault(struct vm_fault *vmf, enum page_entry_size pe_size,
+ pfn_t pfn);
int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index);
int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
pgoff_t index);
diff --git a/include/trace/events/fs_dax.h b/include/trace/events/fs_dax.h
index 88a9d19b8ff8..7725459fafef 100644
--- a/include/trace/events/fs_dax.h
+++ b/include/trace/events/fs_dax.h
@@ -190,6 +190,8 @@ DEFINE_EVENT(dax_pte_fault_class, name, \
DEFINE_PTE_FAULT_EVENT(dax_pte_fault);
DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done);
DEFINE_PTE_FAULT_EVENT(dax_load_hole);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite_no_entry);
+DEFINE_PTE_FAULT_EVENT(dax_insert_pfn_mkwrite);
TRACE_EVENT(dax_insert_mapping,
TP_PROTO(struct inode *inode, struct vm_fault *vmf, void *radix_entry),
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 15/18] ext4: Simplify error handling in ext4_dax_huge_fault()
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
If transaction starting fails, just bail out of the function immediately
instead of checking for that condition throughout the function.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 3cec0b95672f..208adfc3e673 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -302,16 +302,17 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
EXT4_DATA_TRANS_BLOCKS(sb));
+ if (IS_ERR(handle)) {
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ sb_end_pagefault(sb);
+ return VM_FAULT_SIGBUS;
+ }
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
- else
- result = VM_FAULT_SIGBUS;
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
+ ext4_journal_stop(handle);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 15/18] ext4: Simplify error handling in ext4_dax_huge_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
If transaction starting fails, just bail out of the function immediately
instead of checking for that condition throughout the function.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 3cec0b95672f..208adfc3e673 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -302,16 +302,17 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
EXT4_DATA_TRANS_BLOCKS(sb));
+ if (IS_ERR(handle)) {
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ sb_end_pagefault(sb);
+ return VM_FAULT_SIGBUS;
+ }
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
- else
- result = VM_FAULT_SIGBUS;
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
+ ext4_journal_stop(handle);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 15/18] ext4: Simplify error handling in ext4_dax_huge_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
If transaction starting fails, just bail out of the function immediately
instead of checking for that condition throughout the function.
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/ext4/file.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 3cec0b95672f..208adfc3e673 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -302,16 +302,17 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
EXT4_DATA_TRANS_BLOCKS(sb));
+ if (IS_ERR(handle)) {
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ sb_end_pagefault(sb);
+ return VM_FAULT_SIGBUS;
+ }
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
- else
- result = VM_FAULT_SIGBUS;
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
+ ext4_journal_stop(handle);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 15/18] ext4: Simplify error handling in ext4_dax_huge_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
If transaction starting fails, just bail out of the function immediately
instead of checking for that condition throughout the function.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 3cec0b95672f..208adfc3e673 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -302,16 +302,17 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
EXT4_DATA_TRANS_BLOCKS(sb));
+ if (IS_ERR(handle)) {
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ sb_end_pagefault(sb);
+ return VM_FAULT_SIGBUS;
+ }
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
- else
- result = VM_FAULT_SIGBUS;
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
+ ext4_journal_stop(handle);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 15/18] ext4: Simplify error handling in ext4_dax_huge_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
If transaction starting fails, just bail out of the function immediately
instead of checking for that condition throughout the function.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 3cec0b95672f..208adfc3e673 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -302,16 +302,17 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
down_read(&EXT4_I(inode)->i_mmap_sem);
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
EXT4_DATA_TRANS_BLOCKS(sb));
+ if (IS_ERR(handle)) {
+ up_read(&EXT4_I(inode)->i_mmap_sem);
+ sb_end_pagefault(sb);
+ return VM_FAULT_SIGBUS;
+ }
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- if (!IS_ERR(handle))
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
- else
- result = VM_FAULT_SIGBUS;
+ result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
if (write) {
- if (!IS_ERR(handle))
- ext4_journal_stop(handle);
+ ext4_journal_stop(handle);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
--
2.12.3
--
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the body to majordomo@kvack.org. For more info on Linux MM,
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 16/18] ext4: Support for synchronous DAX faults
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 15 ++++++++++++++-
fs/ext4/inode.c | 15 +++++++++++++++
fs/jbd2/journal.c | 17 +++++++++++++++++
include/linux/jbd2.h | 1 +
4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 208adfc3e673..08a1d1a33a90 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -26,6 +26,7 @@
#include <linux/quotaops.h>
#include <linux/pagevec.h>
#include <linux/uio.h>
+#include <linux/mman.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
@@ -295,6 +296,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
*/
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
+ pfn_t pfn;
if (write) {
sb_start_pagefault(sb);
@@ -310,9 +312,12 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, &pfn, &ext4_iomap_ops);
if (write) {
ext4_journal_stop(handle);
+ /* Handling synchronous page fault? */
+ if (result & VM_FAULT_NEEDDSYNC)
+ result = dax_finish_sync_fault(vmf, pe_size, pfn);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
@@ -350,6 +355,13 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(file);
if (IS_DAX(file_inode(file))) {
vma->vm_ops = &ext4_dax_vm_ops;
@@ -719,6 +731,7 @@ const struct file_operations ext4_file_operations = {
.compat_ioctl = ext4_compat_ioctl,
#endif
.mmap = ext4_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = ext4_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875bc7a1..13a198924a0f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3394,6 +3394,19 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
}
#ifdef CONFIG_FS_DAX
+static bool ext4_inode_datasync_dirty(struct inode *inode)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal)
+ return !jbd2_transaction_committed(journal,
+ EXT4_I(inode)->i_datasync_tid);
+ /* Any metadata buffers to write? */
+ if (!list_empty(&inode->i_mapping->private_list))
+ return true;
+ return inode->i_state & I_DIRTY_DATASYNC;
+}
+
static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -3466,6 +3479,8 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
}
iomap->flags = 0;
+ if ((flags & IOMAP_WRITE) && ext4_inode_datasync_dirty(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
iomap->bdev = inode->i_sb->s_bdev;
iomap->dax_dev = sbi->s_daxdev;
iomap->offset = first_block << blkbits;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 7d5ef3bf3f3e..fa8cde498b4b 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -738,6 +738,23 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
return err;
}
+/* Return 1 when transaction with given tid has already committed. */
+int jbd2_transaction_committed(journal_t *journal, tid_t tid)
+{
+ int ret = 1;
+
+ read_lock(&journal->j_state_lock);
+ if (journal->j_running_transaction &&
+ journal->j_running_transaction->t_tid == tid)
+ ret = 0;
+ if (journal->j_committing_transaction &&
+ journal->j_committing_transaction->t_tid == tid)
+ ret = 0;
+ read_unlock(&journal->j_state_lock);
+ return ret;
+}
+EXPORT_SYMBOL(jbd2_transaction_committed);
+
/*
* When this function returns the transaction corresponding to tid
* will be completed. If the transaction has currently running, start
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 606b6bce3a5b..296d1e0ea87b 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1367,6 +1367,7 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid);
int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
+int jbd2_transaction_committed(journal_t *journal, tid_t tid);
int jbd2_complete_transaction(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 16/18] ext4: Support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 15 ++++++++++++++-
fs/ext4/inode.c | 15 +++++++++++++++
fs/jbd2/journal.c | 17 +++++++++++++++++
include/linux/jbd2.h | 1 +
4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 208adfc3e673..08a1d1a33a90 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -26,6 +26,7 @@
#include <linux/quotaops.h>
#include <linux/pagevec.h>
#include <linux/uio.h>
+#include <linux/mman.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
@@ -295,6 +296,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
*/
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
+ pfn_t pfn;
if (write) {
sb_start_pagefault(sb);
@@ -310,9 +312,12 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, &pfn, &ext4_iomap_ops);
if (write) {
ext4_journal_stop(handle);
+ /* Handling synchronous page fault? */
+ if (result & VM_FAULT_NEEDDSYNC)
+ result = dax_finish_sync_fault(vmf, pe_size, pfn);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
@@ -350,6 +355,13 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(file);
if (IS_DAX(file_inode(file))) {
vma->vm_ops = &ext4_dax_vm_ops;
@@ -719,6 +731,7 @@ const struct file_operations ext4_file_operations = {
.compat_ioctl = ext4_compat_ioctl,
#endif
.mmap = ext4_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = ext4_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875bc7a1..13a198924a0f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3394,6 +3394,19 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
}
#ifdef CONFIG_FS_DAX
+static bool ext4_inode_datasync_dirty(struct inode *inode)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal)
+ return !jbd2_transaction_committed(journal,
+ EXT4_I(inode)->i_datasync_tid);
+ /* Any metadata buffers to write? */
+ if (!list_empty(&inode->i_mapping->private_list))
+ return true;
+ return inode->i_state & I_DIRTY_DATASYNC;
+}
+
static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -3466,6 +3479,8 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
}
iomap->flags = 0;
+ if ((flags & IOMAP_WRITE) && ext4_inode_datasync_dirty(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
iomap->bdev = inode->i_sb->s_bdev;
iomap->dax_dev = sbi->s_daxdev;
iomap->offset = first_block << blkbits;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 7d5ef3bf3f3e..fa8cde498b4b 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -738,6 +738,23 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
return err;
}
+/* Return 1 when transaction with given tid has already committed. */
+int jbd2_transaction_committed(journal_t *journal, tid_t tid)
+{
+ int ret = 1;
+
+ read_lock(&journal->j_state_lock);
+ if (journal->j_running_transaction &&
+ journal->j_running_transaction->t_tid == tid)
+ ret = 0;
+ if (journal->j_committing_transaction &&
+ journal->j_committing_transaction->t_tid == tid)
+ ret = 0;
+ read_unlock(&journal->j_state_lock);
+ return ret;
+}
+EXPORT_SYMBOL(jbd2_transaction_committed);
+
/*
* When this function returns the transaction corresponding to tid
* will be completed. If the transaction has currently running, start
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 606b6bce3a5b..296d1e0ea87b 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1367,6 +1367,7 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid);
int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
+int jbd2_transaction_committed(journal_t *journal, tid_t tid);
int jbd2_complete_transaction(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 16/18] ext4: Support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/ext4/file.c | 15 ++++++++++++++-
fs/ext4/inode.c | 15 +++++++++++++++
fs/jbd2/journal.c | 17 +++++++++++++++++
include/linux/jbd2.h | 1 +
4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 208adfc3e673..08a1d1a33a90 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -26,6 +26,7 @@
#include <linux/quotaops.h>
#include <linux/pagevec.h>
#include <linux/uio.h>
+#include <linux/mman.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
@@ -295,6 +296,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
*/
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
+ pfn_t pfn;
if (write) {
sb_start_pagefault(sb);
@@ -310,9 +312,12 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, &pfn, &ext4_iomap_ops);
if (write) {
ext4_journal_stop(handle);
+ /* Handling synchronous page fault? */
+ if (result & VM_FAULT_NEEDDSYNC)
+ result = dax_finish_sync_fault(vmf, pe_size, pfn);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
@@ -350,6 +355,13 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(file);
if (IS_DAX(file_inode(file))) {
vma->vm_ops = &ext4_dax_vm_ops;
@@ -719,6 +731,7 @@ const struct file_operations ext4_file_operations = {
.compat_ioctl = ext4_compat_ioctl,
#endif
.mmap = ext4_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = ext4_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875bc7a1..13a198924a0f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3394,6 +3394,19 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
}
#ifdef CONFIG_FS_DAX
+static bool ext4_inode_datasync_dirty(struct inode *inode)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal)
+ return !jbd2_transaction_committed(journal,
+ EXT4_I(inode)->i_datasync_tid);
+ /* Any metadata buffers to write? */
+ if (!list_empty(&inode->i_mapping->private_list))
+ return true;
+ return inode->i_state & I_DIRTY_DATASYNC;
+}
+
static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -3466,6 +3479,8 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
}
iomap->flags = 0;
+ if ((flags & IOMAP_WRITE) && ext4_inode_datasync_dirty(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
iomap->bdev = inode->i_sb->s_bdev;
iomap->dax_dev = sbi->s_daxdev;
iomap->offset = first_block << blkbits;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 7d5ef3bf3f3e..fa8cde498b4b 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -738,6 +738,23 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
return err;
}
+/* Return 1 when transaction with given tid has already committed. */
+int jbd2_transaction_committed(journal_t *journal, tid_t tid)
+{
+ int ret = 1;
+
+ read_lock(&journal->j_state_lock);
+ if (journal->j_running_transaction &&
+ journal->j_running_transaction->t_tid == tid)
+ ret = 0;
+ if (journal->j_committing_transaction &&
+ journal->j_committing_transaction->t_tid == tid)
+ ret = 0;
+ read_unlock(&journal->j_state_lock);
+ return ret;
+}
+EXPORT_SYMBOL(jbd2_transaction_committed);
+
/*
* When this function returns the transaction corresponding to tid
* will be completed. If the transaction has currently running, start
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 606b6bce3a5b..296d1e0ea87b 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1367,6 +1367,7 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid);
int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
+int jbd2_transaction_committed(journal_t *journal, tid_t tid);
int jbd2_complete_transaction(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 16/18] ext4: Support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 15 ++++++++++++++-
fs/ext4/inode.c | 15 +++++++++++++++
fs/jbd2/journal.c | 17 +++++++++++++++++
include/linux/jbd2.h | 1 +
4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 208adfc3e673..08a1d1a33a90 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -26,6 +26,7 @@
#include <linux/quotaops.h>
#include <linux/pagevec.h>
#include <linux/uio.h>
+#include <linux/mman.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
@@ -295,6 +296,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
*/
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
+ pfn_t pfn;
if (write) {
sb_start_pagefault(sb);
@@ -310,9 +312,12 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, &pfn, &ext4_iomap_ops);
if (write) {
ext4_journal_stop(handle);
+ /* Handling synchronous page fault? */
+ if (result & VM_FAULT_NEEDDSYNC)
+ result = dax_finish_sync_fault(vmf, pe_size, pfn);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
@@ -350,6 +355,13 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(file);
if (IS_DAX(file_inode(file))) {
vma->vm_ops = &ext4_dax_vm_ops;
@@ -719,6 +731,7 @@ const struct file_operations ext4_file_operations = {
.compat_ioctl = ext4_compat_ioctl,
#endif
.mmap = ext4_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = ext4_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875bc7a1..13a198924a0f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3394,6 +3394,19 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
}
#ifdef CONFIG_FS_DAX
+static bool ext4_inode_datasync_dirty(struct inode *inode)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal)
+ return !jbd2_transaction_committed(journal,
+ EXT4_I(inode)->i_datasync_tid);
+ /* Any metadata buffers to write? */
+ if (!list_empty(&inode->i_mapping->private_list))
+ return true;
+ return inode->i_state & I_DIRTY_DATASYNC;
+}
+
static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -3466,6 +3479,8 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
}
iomap->flags = 0;
+ if ((flags & IOMAP_WRITE) && ext4_inode_datasync_dirty(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
iomap->bdev = inode->i_sb->s_bdev;
iomap->dax_dev = sbi->s_daxdev;
iomap->offset = first_block << blkbits;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 7d5ef3bf3f3e..fa8cde498b4b 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -738,6 +738,23 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
return err;
}
+/* Return 1 when transaction with given tid has already committed. */
+int jbd2_transaction_committed(journal_t *journal, tid_t tid)
+{
+ int ret = 1;
+
+ read_lock(&journal->j_state_lock);
+ if (journal->j_running_transaction &&
+ journal->j_running_transaction->t_tid == tid)
+ ret = 0;
+ if (journal->j_committing_transaction &&
+ journal->j_committing_transaction->t_tid == tid)
+ ret = 0;
+ read_unlock(&journal->j_state_lock);
+ return ret;
+}
+EXPORT_SYMBOL(jbd2_transaction_committed);
+
/*
* When this function returns the transaction corresponding to tid
* will be completed. If the transaction has currently running, start
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 606b6bce3a5b..296d1e0ea87b 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1367,6 +1367,7 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid);
int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
+int jbd2_transaction_committed(journal_t *journal, tid_t tid);
int jbd2_complete_transaction(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 16/18] ext4: Support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
We return IOMAP_F_DIRTY flag from ext4_iomap_begin() when asked to
prepare blocks for writing and the inode has some uncommitted metadata
changes. In the fault handler ext4_dax_fault() we then detect this case
(through VM_FAULT_NEEDDSYNC return value) and call helper
dax_finish_sync_fault() to flush metadata changes and insert page table
entry. Note that this will also dirty corresponding radix tree entry
which is what we want - fsync(2) will still provide data integrity
guarantees for applications not using userspace flushing. And
applications using userspace flushing can avoid calling fsync(2) and
thus avoid the performance overhead.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 15 ++++++++++++++-
fs/ext4/inode.c | 15 +++++++++++++++
fs/jbd2/journal.c | 17 +++++++++++++++++
include/linux/jbd2.h | 1 +
4 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 208adfc3e673..08a1d1a33a90 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -26,6 +26,7 @@
#include <linux/quotaops.h>
#include <linux/pagevec.h>
#include <linux/uio.h>
+#include <linux/mman.h>
#include "ext4.h"
#include "ext4_jbd2.h"
#include "xattr.h"
@@ -295,6 +296,7 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
*/
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
(vmf->vma->vm_flags & VM_SHARED);
+ pfn_t pfn;
if (write) {
sb_start_pagefault(sb);
@@ -310,9 +312,12 @@ static int ext4_dax_huge_fault(struct vm_fault *vmf,
} else {
down_read(&EXT4_I(inode)->i_mmap_sem);
}
- result = dax_iomap_fault(vmf, pe_size, NULL, &ext4_iomap_ops);
+ result = dax_iomap_fault(vmf, pe_size, &pfn, &ext4_iomap_ops);
if (write) {
ext4_journal_stop(handle);
+ /* Handling synchronous page fault? */
+ if (result & VM_FAULT_NEEDDSYNC)
+ result = dax_finish_sync_fault(vmf, pe_size, pfn);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);
} else {
@@ -350,6 +355,13 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(file);
if (IS_DAX(file_inode(file))) {
vma->vm_ops = &ext4_dax_vm_ops;
@@ -719,6 +731,7 @@ const struct file_operations ext4_file_operations = {
.compat_ioctl = ext4_compat_ioctl,
#endif
.mmap = ext4_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = ext4_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875bc7a1..13a198924a0f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3394,6 +3394,19 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
}
#ifdef CONFIG_FS_DAX
+static bool ext4_inode_datasync_dirty(struct inode *inode)
+{
+ journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
+
+ if (journal)
+ return !jbd2_transaction_committed(journal,
+ EXT4_I(inode)->i_datasync_tid);
+ /* Any metadata buffers to write? */
+ if (!list_empty(&inode->i_mapping->private_list))
+ return true;
+ return inode->i_state & I_DIRTY_DATASYNC;
+}
+
static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned flags, struct iomap *iomap)
{
@@ -3466,6 +3479,8 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
}
iomap->flags = 0;
+ if ((flags & IOMAP_WRITE) && ext4_inode_datasync_dirty(inode))
+ iomap->flags |= IOMAP_F_DIRTY;
iomap->bdev = inode->i_sb->s_bdev;
iomap->dax_dev = sbi->s_daxdev;
iomap->offset = first_block << blkbits;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 7d5ef3bf3f3e..fa8cde498b4b 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -738,6 +738,23 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
return err;
}
+/* Return 1 when transaction with given tid has already committed. */
+int jbd2_transaction_committed(journal_t *journal, tid_t tid)
+{
+ int ret = 1;
+
+ read_lock(&journal->j_state_lock);
+ if (journal->j_running_transaction &&
+ journal->j_running_transaction->t_tid == tid)
+ ret = 0;
+ if (journal->j_committing_transaction &&
+ journal->j_committing_transaction->t_tid == tid)
+ ret = 0;
+ read_unlock(&journal->j_state_lock);
+ return ret;
+}
+EXPORT_SYMBOL(jbd2_transaction_committed);
+
/*
* When this function returns the transaction corresponding to tid
* will be completed. If the transaction has currently running, start
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 606b6bce3a5b..296d1e0ea87b 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1367,6 +1367,7 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid);
int __jbd2_log_start_commit(journal_t *journal, tid_t tid);
int jbd2_journal_start_commit(journal_t *journal, tid_t *tid);
int jbd2_log_wait_commit(journal_t *journal, tid_t tid);
+int jbd2_transaction_committed(journal_t *journal, tid_t tid);
int jbd2_complete_transaction(journal_t *journal, tid_t tid);
int jbd2_log_do_checkpoint(journal_t *journal);
int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid);
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
It will also need to handle flushing for synchronous page faults. So
just make that function use __xfs_filemap_fault().
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 29 ++++-------------------------
fs/xfs/xfs_trace.h | 2 --
2 files changed, 4 insertions(+), 27 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7c6b8def6eed..4496b45678de 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
}
/*
- * pfn_mkwrite was originally inteneded to ensure we capture time stamp
- * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
- * to ensure we serialise the fault barrier in place.
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
*/
static int
xfs_filemap_pfn_mkwrite(
struct vm_fault *vmf)
{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- struct xfs_inode *ip = XFS_I(inode);
- int ret = VM_FAULT_NOPAGE;
- loff_t size;
-
- trace_xfs_filemap_pfn_mkwrite(ip);
-
- sb_start_pagefault(inode->i_sb);
- file_update_time(vmf->vma->vm_file);
-
- /* check if the faulting page hasn't raced with truncate */
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (vmf->pgoff >= size)
- ret = VM_FAULT_SIGBUS;
- else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
- return ret;
-
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}
static const struct vm_operations_struct xfs_file_vm_ops = {
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb5514688d47..6333ad09e0f3 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
-DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
-
TRACE_EVENT(xfs_filemap_fault,
TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
bool write_fault),
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
It will also need to handle flushing for synchronous page faults. So
just make that function use __xfs_filemap_fault().
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 29 ++++-------------------------
fs/xfs/xfs_trace.h | 2 --
2 files changed, 4 insertions(+), 27 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7c6b8def6eed..4496b45678de 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
}
/*
- * pfn_mkwrite was originally inteneded to ensure we capture time stamp
- * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
- * to ensure we serialise the fault barrier in place.
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
*/
static int
xfs_filemap_pfn_mkwrite(
struct vm_fault *vmf)
{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- struct xfs_inode *ip = XFS_I(inode);
- int ret = VM_FAULT_NOPAGE;
- loff_t size;
-
- trace_xfs_filemap_pfn_mkwrite(ip);
-
- sb_start_pagefault(inode->i_sb);
- file_update_time(vmf->vma->vm_file);
-
- /* check if the faulting page hasn't raced with truncate */
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (vmf->pgoff >= size)
- ret = VM_FAULT_SIGBUS;
- else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
- return ret;
-
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}
static const struct vm_operations_struct xfs_file_vm_ops = {
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb5514688d47..6333ad09e0f3 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
-DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
-
TRACE_EVENT(xfs_filemap_fault,
TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
bool write_fault),
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
It will also need to handle flushing for synchronous page faults. So
just make that function use __xfs_filemap_fault().
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/xfs/xfs_file.c | 29 ++++-------------------------
fs/xfs/xfs_trace.h | 2 --
2 files changed, 4 insertions(+), 27 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7c6b8def6eed..4496b45678de 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
}
/*
- * pfn_mkwrite was originally inteneded to ensure we capture time stamp
- * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
- * to ensure we serialise the fault barrier in place.
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
*/
static int
xfs_filemap_pfn_mkwrite(
struct vm_fault *vmf)
{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- struct xfs_inode *ip = XFS_I(inode);
- int ret = VM_FAULT_NOPAGE;
- loff_t size;
-
- trace_xfs_filemap_pfn_mkwrite(ip);
-
- sb_start_pagefault(inode->i_sb);
- file_update_time(vmf->vma->vm_file);
-
- /* check if the faulting page hasn't raced with truncate */
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (vmf->pgoff >= size)
- ret = VM_FAULT_SIGBUS;
- else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
- return ret;
-
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}
static const struct vm_operations_struct xfs_file_vm_ops = {
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb5514688d47..6333ad09e0f3 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
-DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
-
TRACE_EVENT(xfs_filemap_fault,
TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
bool write_fault),
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
It will also need to handle flushing for synchronous page faults. So
just make that function use __xfs_filemap_fault().
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 29 ++++-------------------------
fs/xfs/xfs_trace.h | 2 --
2 files changed, 4 insertions(+), 27 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7c6b8def6eed..4496b45678de 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
}
/*
- * pfn_mkwrite was originally inteneded to ensure we capture time stamp
- * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
- * to ensure we serialise the fault barrier in place.
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
*/
static int
xfs_filemap_pfn_mkwrite(
struct vm_fault *vmf)
{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- struct xfs_inode *ip = XFS_I(inode);
- int ret = VM_FAULT_NOPAGE;
- loff_t size;
-
- trace_xfs_filemap_pfn_mkwrite(ip);
-
- sb_start_pagefault(inode->i_sb);
- file_update_time(vmf->vma->vm_file);
-
- /* check if the faulting page hasn't raced with truncate */
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (vmf->pgoff >= size)
- ret = VM_FAULT_SIGBUS;
- else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
- return ret;
-
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}
static const struct vm_operations_struct xfs_file_vm_ops = {
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb5514688d47..6333ad09e0f3 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
-DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
-
TRACE_EVENT(xfs_filemap_fault,
TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
bool write_fault),
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
It will also need to handle flushing for synchronous page faults. So
just make that function use __xfs_filemap_fault().
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 29 ++++-------------------------
fs/xfs/xfs_trace.h | 2 --
2 files changed, 4 insertions(+), 27 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7c6b8def6eed..4496b45678de 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
}
/*
- * pfn_mkwrite was originally inteneded to ensure we capture time stamp
- * updates on write faults. In reality, it's need to serialise against
- * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
- * to ensure we serialise the fault barrier in place.
+ * pfn_mkwrite was originally intended to ensure we capture time stamp updates
+ * on write faults. In reality, it needs to serialise against truncate and
+ * prepare memory for writing so handle is as standard write fault.
*/
static int
xfs_filemap_pfn_mkwrite(
struct vm_fault *vmf)
{
- struct inode *inode = file_inode(vmf->vma->vm_file);
- struct xfs_inode *ip = XFS_I(inode);
- int ret = VM_FAULT_NOPAGE;
- loff_t size;
-
- trace_xfs_filemap_pfn_mkwrite(ip);
-
- sb_start_pagefault(inode->i_sb);
- file_update_time(vmf->vma->vm_file);
-
- /* check if the faulting page hasn't raced with truncate */
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (vmf->pgoff >= size)
- ret = VM_FAULT_SIGBUS;
- else if (IS_DAX(inode))
- ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
- sb_end_pagefault(inode->i_sb);
- return ret;
-
+ return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
}
static const struct vm_operations_struct xfs_file_vm_ops = {
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index bb5514688d47..6333ad09e0f3 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
-DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
-
TRACE_EVENT(xfs_filemap_fault,
TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
bool write_fault),
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 18/18] xfs: support for synchronous DAX faults
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4,
Christoph Hellwig
From: Christoph Hellwig <hch@lst.de>
Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
blocks for writing and the inode is pinned, and has dirty fields other
than the timestamps. In __xfs_filemap_fault() we then detect this case
and call dax_finish_sync_fault() to make sure all metadata is committed,
and to insert the page table entry.
Note that this will also dirty corresponding radix tree entry which is
what we want - fsync(2) will still provide data integrity guarantees for
applications not using userspace flushing. And applications using
userspace flushing can avoid calling fsync(2) and thus avoid the
performance overhead.
[JK: Added VM_SYNC flag handling]
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 15 ++++++++++++++-
fs/xfs/xfs_iomap.c | 5 +++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4496b45678de..4827e82d5d2c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -44,6 +44,7 @@
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
+#include <linux/mman.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
+ pfn_t pfn;
+
+ ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
+ if (ret & VM_FAULT_NEEDDSYNC)
+ ret = dax_finish_sync_fault(vmf, pe_size, pfn);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1110,6 +1115,13 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(filp);
vma->vm_ops = &xfs_file_vm_ops;
if (IS_DAX(file_inode(filp)))
@@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
.compat_ioctl = xfs_file_compat_ioctl,
#endif
.mmap = xfs_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f179bdf1644d..b43be199fbdf 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -33,6 +33,7 @@
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
+#include "xfs_inode_item.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
@@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
trace_xfs_iomap_found(ip, offset, length, 0, &imap);
}
+ if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
+ iomap->flags |= IOMAP_F_DIRTY;
+
xfs_bmbt_to_iomap(ip, iomap, &imap);
if (shared)
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 18/18] xfs: support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Christoph Hellwig, Jan Kara
From: Christoph Hellwig <hch@lst.de>
Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
blocks for writing and the inode is pinned, and has dirty fields other
than the timestamps. In __xfs_filemap_fault() we then detect this case
and call dax_finish_sync_fault() to make sure all metadata is committed,
and to insert the page table entry.
Note that this will also dirty corresponding radix tree entry which is
what we want - fsync(2) will still provide data integrity guarantees for
applications not using userspace flushing. And applications using
userspace flushing can avoid calling fsync(2) and thus avoid the
performance overhead.
[JK: Added VM_SYNC flag handling]
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 15 ++++++++++++++-
fs/xfs/xfs_iomap.c | 5 +++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4496b45678de..4827e82d5d2c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -44,6 +44,7 @@
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
+#include <linux/mman.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
+ pfn_t pfn;
+
+ ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
+ if (ret & VM_FAULT_NEEDDSYNC)
+ ret = dax_finish_sync_fault(vmf, pe_size, pfn);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1110,6 +1115,13 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(filp);
vma->vm_ops = &xfs_file_vm_ops;
if (IS_DAX(file_inode(filp)))
@@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
.compat_ioctl = xfs_file_compat_ioctl,
#endif
.mmap = xfs_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f179bdf1644d..b43be199fbdf 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -33,6 +33,7 @@
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
+#include "xfs_inode_item.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
@@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
trace_xfs_iomap_found(ip, offset, length, 0, &imap);
}
+ if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
+ iomap->flags |= IOMAP_F_DIRTY;
+
xfs_bmbt_to_iomap(ip, iomap, &imap);
if (shared)
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 18/18] xfs: support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA, Christoph Hellwig
From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
blocks for writing and the inode is pinned, and has dirty fields other
than the timestamps. In __xfs_filemap_fault() we then detect this case
and call dax_finish_sync_fault() to make sure all metadata is committed,
and to insert the page table entry.
Note that this will also dirty corresponding radix tree entry which is
what we want - fsync(2) will still provide data integrity guarantees for
applications not using userspace flushing. And applications using
userspace flushing can avoid calling fsync(2) and thus avoid the
performance overhead.
[JK: Added VM_SYNC flag handling]
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
fs/xfs/xfs_file.c | 15 ++++++++++++++-
fs/xfs/xfs_iomap.c | 5 +++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4496b45678de..4827e82d5d2c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -44,6 +44,7 @@
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
+#include <linux/mman.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
+ pfn_t pfn;
+
+ ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
+ if (ret & VM_FAULT_NEEDDSYNC)
+ ret = dax_finish_sync_fault(vmf, pe_size, pfn);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1110,6 +1115,13 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(filp);
vma->vm_ops = &xfs_file_vm_ops;
if (IS_DAX(file_inode(filp)))
@@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
.compat_ioctl = xfs_file_compat_ioctl,
#endif
.mmap = xfs_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f179bdf1644d..b43be199fbdf 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -33,6 +33,7 @@
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
+#include "xfs_inode_item.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
@@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
trace_xfs_iomap_found(ip, offset, length, 0, &imap);
}
+ if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
+ iomap->flags |= IOMAP_F_DIRTY;
+
xfs_bmbt_to_iomap(ip, iomap, &imap);
if (shared)
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 18/18] xfs: support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Christoph Hellwig, Jan Kara
From: Christoph Hellwig <hch@lst.de>
Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
blocks for writing and the inode is pinned, and has dirty fields other
than the timestamps. In __xfs_filemap_fault() we then detect this case
and call dax_finish_sync_fault() to make sure all metadata is committed,
and to insert the page table entry.
Note that this will also dirty corresponding radix tree entry which is
what we want - fsync(2) will still provide data integrity guarantees for
applications not using userspace flushing. And applications using
userspace flushing can avoid calling fsync(2) and thus avoid the
performance overhead.
[JK: Added VM_SYNC flag handling]
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 15 ++++++++++++++-
fs/xfs/xfs_iomap.c | 5 +++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4496b45678de..4827e82d5d2c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -44,6 +44,7 @@
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
+#include <linux/mman.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
+ pfn_t pfn;
+
+ ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
+ if (ret & VM_FAULT_NEEDDSYNC)
+ ret = dax_finish_sync_fault(vmf, pe_size, pfn);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1110,6 +1115,13 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(filp);
vma->vm_ops = &xfs_file_vm_ops;
if (IS_DAX(file_inode(filp)))
@@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
.compat_ioctl = xfs_file_compat_ioctl,
#endif
.mmap = xfs_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f179bdf1644d..b43be199fbdf 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -33,6 +33,7 @@
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
+#include "xfs_inode_item.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
@@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
trace_xfs_iomap_found(ip, offset, length, 0, &imap);
}
+ if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
+ iomap->flags |= IOMAP_F_DIRTY;
+
xfs_bmbt_to_iomap(ip, iomap, &imap);
if (shared)
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH 18/18] xfs: support for synchronous DAX faults
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Christoph Hellwig, Jan Kara
From: Christoph Hellwig <hch@lst.de>
Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
blocks for writing and the inode is pinned, and has dirty fields other
than the timestamps. In __xfs_filemap_fault() we then detect this case
and call dax_finish_sync_fault() to make sure all metadata is committed,
and to insert the page table entry.
Note that this will also dirty corresponding radix tree entry which is
what we want - fsync(2) will still provide data integrity guarantees for
applications not using userspace flushing. And applications using
userspace flushing can avoid calling fsync(2) and thus avoid the
performance overhead.
[JK: Added VM_SYNC flag handling]
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/xfs/xfs_file.c | 15 ++++++++++++++-
fs/xfs/xfs_iomap.c | 5 +++++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4496b45678de..4827e82d5d2c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -44,6 +44,7 @@
#include <linux/falloc.h>
#include <linux/pagevec.h>
#include <linux/backing-dev.h>
+#include <linux/mman.h>
static const struct vm_operations_struct xfs_file_vm_ops;
@@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
if (IS_DAX(inode)) {
- ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
+ pfn_t pfn;
+
+ ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
+ if (ret & VM_FAULT_NEEDDSYNC)
+ ret = dax_finish_sync_fault(vmf, pe_size, pfn);
} else {
if (write_fault)
ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
@@ -1110,6 +1115,13 @@ xfs_file_mmap(
struct file *filp,
struct vm_area_struct *vma)
{
+ /*
+ * We don't support synchronous mappings for non-DAX files. At least
+ * until someone comes with a sensible use case.
+ */
+ if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
+ return -EOPNOTSUPP;
+
file_accessed(filp);
vma->vm_ops = &xfs_file_vm_ops;
if (IS_DAX(file_inode(filp)))
@@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
.compat_ioctl = xfs_file_compat_ioctl,
#endif
.mmap = xfs_file_mmap,
+ .mmap_supported_flags = MAP_SYNC,
.open = xfs_file_open,
.release = xfs_file_release,
.fsync = xfs_file_fsync,
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f179bdf1644d..b43be199fbdf 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -33,6 +33,7 @@
#include "xfs_error.h"
#include "xfs_trans.h"
#include "xfs_trans_space.h"
+#include "xfs_inode_item.h"
#include "xfs_iomap.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
@@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
trace_xfs_iomap_found(ip, offset, length, 0, &imap);
}
+ if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
+ iomap->flags |= IOMAP_F_DIRTY;
+
xfs_bmbt_to_iomap(ip, iomap, &imap);
if (shared)
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
2017-11-01 15:36 ` Jan Kara
` (2 preceding siblings ...)
(?)
@ 2017-11-01 15:36 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs, Jan Kara, linux-nvdimm, linux-api, Darrick J . Wong,
Christoph Hellwig, linux-mm, linux-fsdevel, linux-ext4
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/man2/mmap.2 b/man2/mmap.2
index 47c3148653be..b38ee6809327 100644
--- a/man2/mmap.2
+++ b/man2/mmap.2
@@ -125,6 +125,21 @@ are carried through to the underlying file.
to the underlying file requires the use of
.BR msync (2).)
.TP
+.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
+The same as
+.B MAP_SHARED
+except that
+.B MAP_SHARED
+mappings ignore unknown flags in
+.IR flags .
+In contrast when creating mapping of
+.B MAP_SHARED_VALIDATE
+mapping type, the kernel verifies all passed flags are known and fails the
+mapping with
+.BR EOPNOTSUPP
+otherwise. This mapping type is also required to be able to use some mapping
+flags.
+.TP
.B MAP_PRIVATE
Create a private copy-on-write mapping.
Updates to the mapping are not visible to other processes
@@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
.BR mmap ()
call are visible in the mapped region.
.PP
-Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
+.B MAP_SHARED
+and
+.B MAP_PRIVATE
+are described in POSIX.1-2001 and POSIX.1-2008.
.PP
In addition, zero or more of the following values can be ORed in
.IR flags :
@@ -352,6 +370,21 @@ option.
Because of the security implications,
that option is normally enabled only on embedded devices
(i.e., devices where one has complete control of the contents of user memory).
+.TP
+.BR MAP_SYNC " (since Linux 4.15)"
+This flags is available only with
+.B MAP_SHARED_VALIDATE
+mapping type. Mappings of
+.B MAP_SHARED
+type will silently ignore this flag.
+This flag is supported only for files supporting DAX (direct mapping of persistent
+memory). For other files, creating mapping with this flag results in
+.B EOPNOTSUPP
+error. Shared file mappings with this flag provide the guarantee that while
+some memory is writeably mapped in the address space of the process, it will
+be visible in the same file at the same offset even after the system crashes or
+is rebooted. This allows users of such mappings to make data modifications
+persistent in a more efficient way using appropriate CPU instructions.
.PP
Of the above flags, only
.B MAP_FIXED
--
2.12.3
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/man2/mmap.2 b/man2/mmap.2
index 47c3148653be..b38ee6809327 100644
--- a/man2/mmap.2
+++ b/man2/mmap.2
@@ -125,6 +125,21 @@ are carried through to the underlying file.
to the underlying file requires the use of
.BR msync (2).)
.TP
+.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
+The same as
+.B MAP_SHARED
+except that
+.B MAP_SHARED
+mappings ignore unknown flags in
+.IR flags .
+In contrast when creating mapping of
+.B MAP_SHARED_VALIDATE
+mapping type, the kernel verifies all passed flags are known and fails the
+mapping with
+.BR EOPNOTSUPP
+otherwise. This mapping type is also required to be able to use some mapping
+flags.
+.TP
.B MAP_PRIVATE
Create a private copy-on-write mapping.
Updates to the mapping are not visible to other processes
@@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
.BR mmap ()
call are visible in the mapped region.
.PP
-Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
+.B MAP_SHARED
+and
+.B MAP_PRIVATE
+are described in POSIX.1-2001 and POSIX.1-2008.
.PP
In addition, zero or more of the following values can be ORed in
.IR flags :
@@ -352,6 +370,21 @@ option.
Because of the security implications,
that option is normally enabled only on embedded devices
(i.e., devices where one has complete control of the contents of user memory).
+.TP
+.BR MAP_SYNC " (since Linux 4.15)"
+This flags is available only with
+.B MAP_SHARED_VALIDATE
+mapping type. Mappings of
+.B MAP_SHARED
+type will silently ignore this flag.
+This flag is supported only for files supporting DAX (direct mapping of persistent
+memory). For other files, creating mapping with this flag results in
+.B EOPNOTSUPP
+error. Shared file mappings with this flag provide the guarantee that while
+some memory is writeably mapped in the address space of the process, it will
+be visible in the same file at the same offset even after the system crashes or
+is rebooted. This allows users of such mappings to make data modifications
+persistent in a more efficient way using appropriate CPU instructions.
.PP
Of the above flags, only
.B MAP_FIXED
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA, Jan Kara,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Christoph Hellwig, linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
---
man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/man2/mmap.2 b/man2/mmap.2
index 47c3148653be..b38ee6809327 100644
--- a/man2/mmap.2
+++ b/man2/mmap.2
@@ -125,6 +125,21 @@ are carried through to the underlying file.
to the underlying file requires the use of
.BR msync (2).)
.TP
+.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
+The same as
+.B MAP_SHARED
+except that
+.B MAP_SHARED
+mappings ignore unknown flags in
+.IR flags .
+In contrast when creating mapping of
+.B MAP_SHARED_VALIDATE
+mapping type, the kernel verifies all passed flags are known and fails the
+mapping with
+.BR EOPNOTSUPP
+otherwise. This mapping type is also required to be able to use some mapping
+flags.
+.TP
.B MAP_PRIVATE
Create a private copy-on-write mapping.
Updates to the mapping are not visible to other processes
@@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
.BR mmap ()
call are visible in the mapped region.
.PP
-Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
+.B MAP_SHARED
+and
+.B MAP_PRIVATE
+are described in POSIX.1-2001 and POSIX.1-2008.
.PP
In addition, zero or more of the following values can be ORed in
.IR flags :
@@ -352,6 +370,21 @@ option.
Because of the security implications,
that option is normally enabled only on embedded devices
(i.e., devices where one has complete control of the contents of user memory).
+.TP
+.BR MAP_SYNC " (since Linux 4.15)"
+This flags is available only with
+.B MAP_SHARED_VALIDATE
+mapping type. Mappings of
+.B MAP_SHARED
+type will silently ignore this flag.
+This flag is supported only for files supporting DAX (direct mapping of persistent
+memory). For other files, creating mapping with this flag results in
+.B EOPNOTSUPP
+error. Shared file mappings with this flag provide the guarantee that while
+some memory is writeably mapped in the address space of the process, it will
+be visible in the same file at the same offset even after the system crashes or
+is rebooted. This allows users of such mappings to make data modifications
+persistent in a more efficient way using appropriate CPU instructions.
.PP
Of the above flags, only
.B MAP_FIXED
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/man2/mmap.2 b/man2/mmap.2
index 47c3148653be..b38ee6809327 100644
--- a/man2/mmap.2
+++ b/man2/mmap.2
@@ -125,6 +125,21 @@ are carried through to the underlying file.
to the underlying file requires the use of
.BR msync (2).)
.TP
+.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
+The same as
+.B MAP_SHARED
+except that
+.B MAP_SHARED
+mappings ignore unknown flags in
+.IR flags .
+In contrast when creating mapping of
+.B MAP_SHARED_VALIDATE
+mapping type, the kernel verifies all passed flags are known and fails the
+mapping with
+.BR EOPNOTSUPP
+otherwise. This mapping type is also required to be able to use some mapping
+flags.
+.TP
.B MAP_PRIVATE
Create a private copy-on-write mapping.
Updates to the mapping are not visible to other processes
@@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
.BR mmap ()
call are visible in the mapped region.
.PP
-Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
+.B MAP_SHARED
+and
+.B MAP_PRIVATE
+are described in POSIX.1-2001 and POSIX.1-2008.
.PP
In addition, zero or more of the following values can be ORed in
.IR flags :
@@ -352,6 +370,21 @@ option.
Because of the security implications,
that option is normally enabled only on embedded devices
(i.e., devices where one has complete control of the contents of user memory).
+.TP
+.BR MAP_SYNC " (since Linux 4.15)"
+This flags is available only with
+.B MAP_SHARED_VALIDATE
+mapping type. Mappings of
+.B MAP_SHARED
+type will silently ignore this flag.
+This flag is supported only for files supporting DAX (direct mapping of persistent
+memory). For other files, creating mapping with this flag results in
+.B EOPNOTSUPP
+error. Shared file mappings with this flag provide the guarantee that while
+some memory is writeably mapped in the address space of the process, it will
+be visible in the same file at the same offset even after the system crashes or
+is rebooted. This allows users of such mappings to make data modifications
+persistent in a more efficient way using appropriate CPU instructions.
.PP
Of the above flags, only
.B MAP_FIXED
--
2.12.3
^ permalink raw reply related [flat|nested] 132+ messages in thread
* [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2017-11-01 15:36 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2017-11-01 15:36 UTC (permalink / raw)
To: Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Jan Kara
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/man2/mmap.2 b/man2/mmap.2
index 47c3148653be..b38ee6809327 100644
--- a/man2/mmap.2
+++ b/man2/mmap.2
@@ -125,6 +125,21 @@ are carried through to the underlying file.
to the underlying file requires the use of
.BR msync (2).)
.TP
+.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
+The same as
+.B MAP_SHARED
+except that
+.B MAP_SHARED
+mappings ignore unknown flags in
+.IR flags .
+In contrast when creating mapping of
+.B MAP_SHARED_VALIDATE
+mapping type, the kernel verifies all passed flags are known and fails the
+mapping with
+.BR EOPNOTSUPP
+otherwise. This mapping type is also required to be able to use some mapping
+flags.
+.TP
.B MAP_PRIVATE
Create a private copy-on-write mapping.
Updates to the mapping are not visible to other processes
@@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
.BR mmap ()
call are visible in the mapped region.
.PP
-Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
+.B MAP_SHARED
+and
+.B MAP_PRIVATE
+are described in POSIX.1-2001 and POSIX.1-2008.
.PP
In addition, zero or more of the following values can be ORed in
.IR flags :
@@ -352,6 +370,21 @@ option.
Because of the security implications,
that option is normally enabled only on embedded devices
(i.e., devices where one has complete control of the contents of user memory).
+.TP
+.BR MAP_SYNC " (since Linux 4.15)"
+This flags is available only with
+.B MAP_SHARED_VALIDATE
+mapping type. Mappings of
+.B MAP_SHARED
+type will silently ignore this flag.
+This flag is supported only for files supporting DAX (direct mapping of persistent
+memory). For other files, creating mapping with this flag results in
+.B EOPNOTSUPP
+error. Shared file mappings with this flag provide the guarantee that while
+some memory is writeably mapped in the address space of the process, it will
+be visible in the same file at the same offset even after the system crashes or
+is rebooted. This allows users of such mappings to make data modifications
+persistent in a more efficient way using appropriate CPU instructions.
.PP
Of the above flags, only
.B MAP_FIXED
--
2.12.3
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 132+ messages in thread
* Re: [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
2017-11-01 15:36 ` Jan Kara
(?)
(?)
@ 2017-11-14 2:19 ` Darrick J. Wong
-1 siblings, 0 replies; 132+ messages in thread
From: Darrick J. Wong @ 2017-11-14 2:19 UTC (permalink / raw)
To: Jan Kara
Cc: linux-xfs, linux-nvdimm, linux-api, Christoph Hellwig, linux-mm,
linux-fsdevel, linux-ext4
On Wed, Nov 01, 2017 at 04:36:46PM +0100, Jan Kara wrote:
> xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
> It will also need to handle flushing for synchronous page faults. So
> just make that function use __xfs_filemap_fault().
>
> Signed-off-by: Jan Kara <jack@suse.cz>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/xfs_file.c | 29 ++++-------------------------
> fs/xfs/xfs_trace.h | 2 --
> 2 files changed, 4 insertions(+), 27 deletions(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 7c6b8def6eed..4496b45678de 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
> }
>
> /*
> - * pfn_mkwrite was originally inteneded to ensure we capture time stamp
> - * updates on write faults. In reality, it's need to serialise against
> - * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
> - * to ensure we serialise the fault barrier in place.
> + * pfn_mkwrite was originally intended to ensure we capture time stamp updates
> + * on write faults. In reality, it needs to serialise against truncate and
> + * prepare memory for writing so handle is as standard write fault.
> */
> static int
> xfs_filemap_pfn_mkwrite(
> struct vm_fault *vmf)
> {
>
> - struct inode *inode = file_inode(vmf->vma->vm_file);
> - struct xfs_inode *ip = XFS_I(inode);
> - int ret = VM_FAULT_NOPAGE;
> - loff_t size;
> -
> - trace_xfs_filemap_pfn_mkwrite(ip);
> -
> - sb_start_pagefault(inode->i_sb);
> - file_update_time(vmf->vma->vm_file);
> -
> - /* check if the faulting page hasn't raced with truncate */
> - xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
> - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - if (vmf->pgoff >= size)
> - ret = VM_FAULT_SIGBUS;
> - else if (IS_DAX(inode))
> - ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
> - xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
> - sb_end_pagefault(inode->i_sb);
> - return ret;
> -
> + return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
> }
>
> static const struct vm_operations_struct xfs_file_vm_ops = {
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index bb5514688d47..6333ad09e0f3 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
>
> -DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
> -
> TRACE_EVENT(xfs_filemap_fault,
> TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
> bool write_fault),
> --
> 2.12.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-14 2:19 ` Darrick J. Wong
0 siblings, 0 replies; 132+ messages in thread
From: Darrick J. Wong @ 2017-11-14 2:19 UTC (permalink / raw)
To: Jan Kara
Cc: Dan Williams, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, linux-mm, linux-api, linux-ext4, linux-xfs
On Wed, Nov 01, 2017 at 04:36:46PM +0100, Jan Kara wrote:
> xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
> It will also need to handle flushing for synchronous page faults. So
> just make that function use __xfs_filemap_fault().
>
> Signed-off-by: Jan Kara <jack@suse.cz>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/xfs_file.c | 29 ++++-------------------------
> fs/xfs/xfs_trace.h | 2 --
> 2 files changed, 4 insertions(+), 27 deletions(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 7c6b8def6eed..4496b45678de 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
> }
>
> /*
> - * pfn_mkwrite was originally inteneded to ensure we capture time stamp
> - * updates on write faults. In reality, it's need to serialise against
> - * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
> - * to ensure we serialise the fault barrier in place.
> + * pfn_mkwrite was originally intended to ensure we capture time stamp updates
> + * on write faults. In reality, it needs to serialise against truncate and
> + * prepare memory for writing so handle is as standard write fault.
> */
> static int
> xfs_filemap_pfn_mkwrite(
> struct vm_fault *vmf)
> {
>
> - struct inode *inode = file_inode(vmf->vma->vm_file);
> - struct xfs_inode *ip = XFS_I(inode);
> - int ret = VM_FAULT_NOPAGE;
> - loff_t size;
> -
> - trace_xfs_filemap_pfn_mkwrite(ip);
> -
> - sb_start_pagefault(inode->i_sb);
> - file_update_time(vmf->vma->vm_file);
> -
> - /* check if the faulting page hasn't raced with truncate */
> - xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
> - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - if (vmf->pgoff >= size)
> - ret = VM_FAULT_SIGBUS;
> - else if (IS_DAX(inode))
> - ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
> - xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
> - sb_end_pagefault(inode->i_sb);
> - return ret;
> -
> + return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
> }
>
> static const struct vm_operations_struct xfs_file_vm_ops = {
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index bb5514688d47..6333ad09e0f3 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
>
> -DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
> -
> TRACE_EVENT(xfs_filemap_fault,
> TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
> bool write_fault),
> --
> 2.12.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
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^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-14 2:19 ` Darrick J. Wong
0 siblings, 0 replies; 132+ messages in thread
From: Darrick J. Wong @ 2017-11-14 2:19 UTC (permalink / raw)
To: Jan Kara
Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-api-u79uwXL29TY76Z2rM5mHXA, Christoph Hellwig,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA
On Wed, Nov 01, 2017 at 04:36:46PM +0100, Jan Kara wrote:
> xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
> It will also need to handle flushing for synchronous page faults. So
> just make that function use __xfs_filemap_fault().
>
> Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
> ---
> fs/xfs/xfs_file.c | 29 ++++-------------------------
> fs/xfs/xfs_trace.h | 2 --
> 2 files changed, 4 insertions(+), 27 deletions(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 7c6b8def6eed..4496b45678de 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
> }
>
> /*
> - * pfn_mkwrite was originally inteneded to ensure we capture time stamp
> - * updates on write faults. In reality, it's need to serialise against
> - * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
> - * to ensure we serialise the fault barrier in place.
> + * pfn_mkwrite was originally intended to ensure we capture time stamp updates
> + * on write faults. In reality, it needs to serialise against truncate and
> + * prepare memory for writing so handle is as standard write fault.
> */
> static int
> xfs_filemap_pfn_mkwrite(
> struct vm_fault *vmf)
> {
>
> - struct inode *inode = file_inode(vmf->vma->vm_file);
> - struct xfs_inode *ip = XFS_I(inode);
> - int ret = VM_FAULT_NOPAGE;
> - loff_t size;
> -
> - trace_xfs_filemap_pfn_mkwrite(ip);
> -
> - sb_start_pagefault(inode->i_sb);
> - file_update_time(vmf->vma->vm_file);
> -
> - /* check if the faulting page hasn't raced with truncate */
> - xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
> - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - if (vmf->pgoff >= size)
> - ret = VM_FAULT_SIGBUS;
> - else if (IS_DAX(inode))
> - ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
> - xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
> - sb_end_pagefault(inode->i_sb);
> - return ret;
> -
> + return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
> }
>
> static const struct vm_operations_struct xfs_file_vm_ops = {
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index bb5514688d47..6333ad09e0f3 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
>
> -DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
> -
> TRACE_EVENT(xfs_filemap_fault,
> TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
> bool write_fault),
> --
> 2.12.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
@ 2017-11-14 2:19 ` Darrick J. Wong
0 siblings, 0 replies; 132+ messages in thread
From: Darrick J. Wong @ 2017-11-14 2:19 UTC (permalink / raw)
To: Jan Kara
Cc: Dan Williams, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, linux-mm, linux-api, linux-ext4, linux-xfs
On Wed, Nov 01, 2017 at 04:36:46PM +0100, Jan Kara wrote:
> xfs_filemap_pfn_mkwrite() duplicates a lot of __xfs_filemap_fault().
> It will also need to handle flushing for synchronous page faults. So
> just make that function use __xfs_filemap_fault().
>
> Signed-off-by: Jan Kara <jack@suse.cz>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/xfs_file.c | 29 ++++-------------------------
> fs/xfs/xfs_trace.h | 2 --
> 2 files changed, 4 insertions(+), 27 deletions(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 7c6b8def6eed..4496b45678de 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1085,37 +1085,16 @@ xfs_filemap_page_mkwrite(
> }
>
> /*
> - * pfn_mkwrite was originally inteneded to ensure we capture time stamp
> - * updates on write faults. In reality, it's need to serialise against
> - * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
> - * to ensure we serialise the fault barrier in place.
> + * pfn_mkwrite was originally intended to ensure we capture time stamp updates
> + * on write faults. In reality, it needs to serialise against truncate and
> + * prepare memory for writing so handle is as standard write fault.
> */
> static int
> xfs_filemap_pfn_mkwrite(
> struct vm_fault *vmf)
> {
>
> - struct inode *inode = file_inode(vmf->vma->vm_file);
> - struct xfs_inode *ip = XFS_I(inode);
> - int ret = VM_FAULT_NOPAGE;
> - loff_t size;
> -
> - trace_xfs_filemap_pfn_mkwrite(ip);
> -
> - sb_start_pagefault(inode->i_sb);
> - file_update_time(vmf->vma->vm_file);
> -
> - /* check if the faulting page hasn't raced with truncate */
> - xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
> - size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
> - if (vmf->pgoff >= size)
> - ret = VM_FAULT_SIGBUS;
> - else if (IS_DAX(inode))
> - ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, &xfs_iomap_ops);
> - xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
> - sb_end_pagefault(inode->i_sb);
> - return ret;
> -
> + return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
> }
>
> static const struct vm_operations_struct xfs_file_vm_ops = {
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index bb5514688d47..6333ad09e0f3 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -688,8 +688,6 @@ DEFINE_INODE_EVENT(xfs_inode_set_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_clear_cowblocks_tag);
> DEFINE_INODE_EVENT(xfs_inode_free_cowblocks_invalid);
>
> -DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
> -
> TRACE_EVENT(xfs_filemap_fault,
> TP_PROTO(struct xfs_inode *ip, enum page_entry_size pe_size,
> bool write_fault),
> --
> 2.12.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 18/18] xfs: support for synchronous DAX faults
2017-11-01 15:36 ` Jan Kara
@ 2017-11-14 2:19 ` Darrick J. Wong
-1 siblings, 0 replies; 132+ messages in thread
From: Darrick J. Wong @ 2017-11-14 2:19 UTC (permalink / raw)
To: Jan Kara
Cc: Dan Williams, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, linux-mm, linux-api, linux-ext4, linux-xfs,
Christoph Hellwig
On Wed, Nov 01, 2017 at 04:36:47PM +0100, Jan Kara wrote:
> From: Christoph Hellwig <hch@lst.de>
>
> Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
> blocks for writing and the inode is pinned, and has dirty fields other
> than the timestamps. In __xfs_filemap_fault() we then detect this case
> and call dax_finish_sync_fault() to make sure all metadata is committed,
> and to insert the page table entry.
>
> Note that this will also dirty corresponding radix tree entry which is
> what we want - fsync(2) will still provide data integrity guarantees for
> applications not using userspace flushing. And applications using
> userspace flushing can avoid calling fsync(2) and thus avoid the
> performance overhead.
>
> [JK: Added VM_SYNC flag handling]
>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Jan Kara <jack@suse.cz>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/xfs_file.c | 15 ++++++++++++++-
> fs/xfs/xfs_iomap.c | 5 +++++
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 4496b45678de..4827e82d5d2c 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -44,6 +44,7 @@
> #include <linux/falloc.h>
> #include <linux/pagevec.h>
> #include <linux/backing-dev.h>
> +#include <linux/mman.h>
>
> static const struct vm_operations_struct xfs_file_vm_ops;
>
> @@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
>
> xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
> if (IS_DAX(inode)) {
> - ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
> + pfn_t pfn;
> +
> + ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
> + if (ret & VM_FAULT_NEEDDSYNC)
> + ret = dax_finish_sync_fault(vmf, pe_size, pfn);
> } else {
> if (write_fault)
> ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
> @@ -1110,6 +1115,13 @@ xfs_file_mmap(
> struct file *filp,
> struct vm_area_struct *vma)
> {
> + /*
> + * We don't support synchronous mappings for non-DAX files. At least
> + * until someone comes with a sensible use case.
> + */
> + if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
> + return -EOPNOTSUPP;
> +
> file_accessed(filp);
> vma->vm_ops = &xfs_file_vm_ops;
> if (IS_DAX(file_inode(filp)))
> @@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
> .compat_ioctl = xfs_file_compat_ioctl,
> #endif
> .mmap = xfs_file_mmap,
> + .mmap_supported_flags = MAP_SYNC,
> .open = xfs_file_open,
> .release = xfs_file_release,
> .fsync = xfs_file_fsync,
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index f179bdf1644d..b43be199fbdf 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -33,6 +33,7 @@
> #include "xfs_error.h"
> #include "xfs_trans.h"
> #include "xfs_trans_space.h"
> +#include "xfs_inode_item.h"
> #include "xfs_iomap.h"
> #include "xfs_trace.h"
> #include "xfs_icache.h"
> @@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
> trace_xfs_iomap_found(ip, offset, length, 0, &imap);
> }
>
> + if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
> + (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
> + iomap->flags |= IOMAP_F_DIRTY;
> +
> xfs_bmbt_to_iomap(ip, iomap, &imap);
>
> if (shared)
> --
> 2.12.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 18/18] xfs: support for synchronous DAX faults
@ 2017-11-14 2:19 ` Darrick J. Wong
0 siblings, 0 replies; 132+ messages in thread
From: Darrick J. Wong @ 2017-11-14 2:19 UTC (permalink / raw)
To: Jan Kara
Cc: Dan Williams, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, linux-mm, linux-api, linux-ext4, linux-xfs,
Christoph Hellwig
On Wed, Nov 01, 2017 at 04:36:47PM +0100, Jan Kara wrote:
> From: Christoph Hellwig <hch@lst.de>
>
> Return IOMAP_F_DIRTY from xfs_file_iomap_begin() when asked to prepare
> blocks for writing and the inode is pinned, and has dirty fields other
> than the timestamps. In __xfs_filemap_fault() we then detect this case
> and call dax_finish_sync_fault() to make sure all metadata is committed,
> and to insert the page table entry.
>
> Note that this will also dirty corresponding radix tree entry which is
> what we want - fsync(2) will still provide data integrity guarantees for
> applications not using userspace flushing. And applications using
> userspace flushing can avoid calling fsync(2) and thus avoid the
> performance overhead.
>
> [JK: Added VM_SYNC flag handling]
>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Jan Kara <jack@suse.cz>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/xfs_file.c | 15 ++++++++++++++-
> fs/xfs/xfs_iomap.c | 5 +++++
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 4496b45678de..4827e82d5d2c 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -44,6 +44,7 @@
> #include <linux/falloc.h>
> #include <linux/pagevec.h>
> #include <linux/backing-dev.h>
> +#include <linux/mman.h>
>
> static const struct vm_operations_struct xfs_file_vm_ops;
>
> @@ -1040,7 +1041,11 @@ __xfs_filemap_fault(
>
> xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
> if (IS_DAX(inode)) {
> - ret = dax_iomap_fault(vmf, pe_size, NULL, &xfs_iomap_ops);
> + pfn_t pfn;
> +
> + ret = dax_iomap_fault(vmf, pe_size, &pfn, &xfs_iomap_ops);
> + if (ret & VM_FAULT_NEEDDSYNC)
> + ret = dax_finish_sync_fault(vmf, pe_size, pfn);
> } else {
> if (write_fault)
> ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
> @@ -1110,6 +1115,13 @@ xfs_file_mmap(
> struct file *filp,
> struct vm_area_struct *vma)
> {
> + /*
> + * We don't support synchronous mappings for non-DAX files. At least
> + * until someone comes with a sensible use case.
> + */
> + if (!IS_DAX(file_inode(filp)) && (vma->vm_flags & VM_SYNC))
> + return -EOPNOTSUPP;
> +
> file_accessed(filp);
> vma->vm_ops = &xfs_file_vm_ops;
> if (IS_DAX(file_inode(filp)))
> @@ -1128,6 +1140,7 @@ const struct file_operations xfs_file_operations = {
> .compat_ioctl = xfs_file_compat_ioctl,
> #endif
> .mmap = xfs_file_mmap,
> + .mmap_supported_flags = MAP_SYNC,
> .open = xfs_file_open,
> .release = xfs_file_release,
> .fsync = xfs_file_fsync,
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index f179bdf1644d..b43be199fbdf 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -33,6 +33,7 @@
> #include "xfs_error.h"
> #include "xfs_trans.h"
> #include "xfs_trans_space.h"
> +#include "xfs_inode_item.h"
> #include "xfs_iomap.h"
> #include "xfs_trace.h"
> #include "xfs_icache.h"
> @@ -1086,6 +1087,10 @@ xfs_file_iomap_begin(
> trace_xfs_iomap_found(ip, offset, length, 0, &imap);
> }
>
> + if ((flags & IOMAP_WRITE) && xfs_ipincount(ip) &&
> + (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
> + iomap->flags |= IOMAP_F_DIRTY;
> +
> xfs_bmbt_to_iomap(ip, iomap, &imap);
>
> if (shared)
> --
> 2.12.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
2017-11-01 15:36 ` Jan Kara
(?)
(?)
@ 2017-11-22 12:02 ` Vlastimil Babka
-1 siblings, 0 replies; 132+ messages in thread
From: Vlastimil Babka @ 2017-11-22 12:02 UTC (permalink / raw)
To: Jan Kara, Dan Williams
Cc: Florian Weimer, linux-xfs, Kees Cook, Arnd Bergmann,
linux-nvdimm, linux-api, Darrick J . Wong, Matthew Wilcox,
Michal Hocko, Christoph Hellwig, linux-mm, Andy Lutomirski,
John Hubbard, linux-fsdevel, linux-ext4, Andrew Morton,
Kirill A. Shutemov
On 11/01/2017 04:36 PM, Jan Kara wrote:
> From: Dan Williams <dan.j.williams@intel.com>
>
> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> define new behavior that is known to fail on older kernels without the
> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> guaranteed to fail on all legacy mmap implementations.
So I'm trying to make sense of this together with Michal's attempt for
MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
instead of flag modifier exactly for the reason of not validating
unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
modifier cannot build on top of this. Wouldn't thus it be really better
long-term to introduce mmap3 at this point? ...
Vlastimil
[1] https://marc.info/?l=linux-arch&m=151083448322336&w=2
> It is worth noting that the original proposal was for a standalone
> MAP_VALIDATE flag. However, when that could not be supported by all
> archs Linus observed:
>
> I see why you *think* you want a bitmap. You think you want
> a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
> etc, so that people can do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
> | MAP_SYNC, fd, 0);
>
> and "know" that MAP_SYNC actually takes.
>
> And I'm saying that whole wish is bogus. You're fundamentally
> depending on special semantics, just make it explicit. It's already
> not portable, so don't try to make it so.
>
> Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
> of 0x3, and make people do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
> | MAP_SYNC, fd, 0);
>
> and then the kernel side is easier too (none of that random garbage
> playing games with looking at the "MAP_VALIDATE bit", but just another
> case statement in that map type thing.
>
> Boom. Done.
>
> Similar to ->fallocate() we also want the ability to validate the
> support for new flags on a per ->mmap() 'struct file_operations'
> instance basis. Towards that end arrange for flags to be generically
> validated against a mmap_supported_flags exported by 'struct
> file_operations'. By default all existing flags are implicitly
> supported, but new flags require MAP_SHARED_VALIDATE and
> per-instance-opt-in.
>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
> arch/alpha/include/uapi/asm/mman.h | 1 +
> arch/mips/include/uapi/asm/mman.h | 1 +
> arch/parisc/include/uapi/asm/mman.h | 1 +
> arch/xtensa/include/uapi/asm/mman.h | 1 +
> include/linux/fs.h | 1 +
> include/linux/mman.h | 39 ++++++++++++++++++++++++++++
> include/uapi/asm-generic/mman-common.h | 1 +
> mm/mmap.c | 15 +++++++++++
> tools/include/uapi/asm-generic/mman-common.h | 1 +
> 9 files changed, 61 insertions(+)
>
> diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
> index 3b26cc62dadb..f6d118aaedb9 100644
> --- a/arch/alpha/include/uapi/asm/mman.h
> +++ b/arch/alpha/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
> #define MAP_FIXED 0x100 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
> index da3216007fe0..93268e4cd3c7 100644
> --- a/arch/mips/include/uapi/asm/mman.h
> +++ b/arch/mips/include/uapi/asm/mman.h
> @@ -28,6 +28,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
> index 775b5d5e41a1..bca652aa1677 100644
> --- a/arch/parisc/include/uapi/asm/mman.h
> +++ b/arch/parisc/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x03 /* Mask for type of mapping */
> #define MAP_FIXED 0x04 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
> index b15b278aa314..9ab426374714 100644
> --- a/arch/xtensa/include/uapi/asm/mman.h
> +++ b/arch/xtensa/include/uapi/asm/mman.h
> @@ -35,6 +35,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 13dab191a23e..57added3201d 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1701,6 +1701,7 @@ struct file_operations {
> long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
> long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
> int (*mmap) (struct file *, struct vm_area_struct *);
> + unsigned long mmap_supported_flags;
> int (*open) (struct inode *, struct file *);
> int (*flush) (struct file *, fl_owner_t id);
> int (*release) (struct inode *, struct file *);
> diff --git a/include/linux/mman.h b/include/linux/mman.h
> index c8367041fafd..94b63b4d71ff 100644
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -7,6 +7,45 @@
> #include <linux/atomic.h>
> #include <uapi/linux/mman.h>
>
> +/*
> + * Arrange for legacy / undefined architecture specific flags to be
> + * ignored by default in LEGACY_MAP_MASK.
> + */
> +#ifndef MAP_32BIT
> +#define MAP_32BIT 0
> +#endif
> +#ifndef MAP_HUGE_2MB
> +#define MAP_HUGE_2MB 0
> +#endif
> +#ifndef MAP_HUGE_1GB
> +#define MAP_HUGE_1GB 0
> +#endif
> +#ifndef MAP_UNINITIALIZED
> +#define MAP_UNINITIALIZED 0
> +#endif
> +
> +/*
> + * The historical set of flags that all mmap implementations implicitly
> + * support when a ->mmap_validate() op is not provided in file_operations.
> + */
> +#define LEGACY_MAP_MASK (MAP_SHARED \
> + | MAP_PRIVATE \
> + | MAP_FIXED \
> + | MAP_ANONYMOUS \
> + | MAP_DENYWRITE \
> + | MAP_EXECUTABLE \
> + | MAP_UNINITIALIZED \
> + | MAP_GROWSDOWN \
> + | MAP_LOCKED \
> + | MAP_NORESERVE \
> + | MAP_POPULATE \
> + | MAP_NONBLOCK \
> + | MAP_STACK \
> + | MAP_HUGETLB \
> + | MAP_32BIT \
> + | MAP_HUGE_2MB \
> + | MAP_HUGE_1GB)
> +
> extern int sysctl_overcommit_memory;
> extern int sysctl_overcommit_ratio;
> extern unsigned long sysctl_overcommit_kbytes;
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 680506faceae..924839fac0e6 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
>
> if (file) {
> struct inode *inode = file_inode(file);
> + unsigned long flags_mask;
> +
> + flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
>
> switch (flags & MAP_TYPE) {
> case MAP_SHARED:
> + /*
> + * Force use of MAP_SHARED_VALIDATE with non-legacy
> + * flags. E.g. MAP_SYNC is dangerous to use with
> + * MAP_SHARED as you don't know which consistency model
> + * you will get. We silently ignore unsupported flags
> + * with MAP_SHARED to preserve backward compatibility.
> + */
> + flags &= LEGACY_MAP_MASK;
> + /* fall through */
> + case MAP_SHARED_VALIDATE:
> + if (flags & ~flags_mask)
> + return -EOPNOTSUPP;
> if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
> return -EACCES;
>
> diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/tools/include/uapi/asm-generic/mman-common.h
> +++ b/tools/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
>
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 12:02 ` Vlastimil Babka
0 siblings, 0 replies; 132+ messages in thread
From: Vlastimil Babka @ 2017-11-22 12:02 UTC (permalink / raw)
To: Jan Kara, Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Arnd Bergmann, Andy Lutomirski, Andrew Morton, Michal Hocko,
Matthew Wilcox, Kees Cook, Florian Weimer, John Hubbard,
Kirill A. Shutemov
On 11/01/2017 04:36 PM, Jan Kara wrote:
> From: Dan Williams <dan.j.williams@intel.com>
>
> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> define new behavior that is known to fail on older kernels without the
> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> guaranteed to fail on all legacy mmap implementations.
So I'm trying to make sense of this together with Michal's attempt for
MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
instead of flag modifier exactly for the reason of not validating
unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
modifier cannot build on top of this. Wouldn't thus it be really better
long-term to introduce mmap3 at this point? ...
Vlastimil
[1] https://marc.info/?l=linux-arch&m=151083448322336&w=2
> It is worth noting that the original proposal was for a standalone
> MAP_VALIDATE flag. However, when that could not be supported by all
> archs Linus observed:
>
> I see why you *think* you want a bitmap. You think you want
> a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
> etc, so that people can do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
> | MAP_SYNC, fd, 0);
>
> and "know" that MAP_SYNC actually takes.
>
> And I'm saying that whole wish is bogus. You're fundamentally
> depending on special semantics, just make it explicit. It's already
> not portable, so don't try to make it so.
>
> Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
> of 0x3, and make people do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
> | MAP_SYNC, fd, 0);
>
> and then the kernel side is easier too (none of that random garbage
> playing games with looking at the "MAP_VALIDATE bit", but just another
> case statement in that map type thing.
>
> Boom. Done.
>
> Similar to ->fallocate() we also want the ability to validate the
> support for new flags on a per ->mmap() 'struct file_operations'
> instance basis. Towards that end arrange for flags to be generically
> validated against a mmap_supported_flags exported by 'struct
> file_operations'. By default all existing flags are implicitly
> supported, but new flags require MAP_SHARED_VALIDATE and
> per-instance-opt-in.
>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
> arch/alpha/include/uapi/asm/mman.h | 1 +
> arch/mips/include/uapi/asm/mman.h | 1 +
> arch/parisc/include/uapi/asm/mman.h | 1 +
> arch/xtensa/include/uapi/asm/mman.h | 1 +
> include/linux/fs.h | 1 +
> include/linux/mman.h | 39 ++++++++++++++++++++++++++++
> include/uapi/asm-generic/mman-common.h | 1 +
> mm/mmap.c | 15 +++++++++++
> tools/include/uapi/asm-generic/mman-common.h | 1 +
> 9 files changed, 61 insertions(+)
>
> diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
> index 3b26cc62dadb..f6d118aaedb9 100644
> --- a/arch/alpha/include/uapi/asm/mman.h
> +++ b/arch/alpha/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
> #define MAP_FIXED 0x100 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
> index da3216007fe0..93268e4cd3c7 100644
> --- a/arch/mips/include/uapi/asm/mman.h
> +++ b/arch/mips/include/uapi/asm/mman.h
> @@ -28,6 +28,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
> index 775b5d5e41a1..bca652aa1677 100644
> --- a/arch/parisc/include/uapi/asm/mman.h
> +++ b/arch/parisc/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x03 /* Mask for type of mapping */
> #define MAP_FIXED 0x04 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
> index b15b278aa314..9ab426374714 100644
> --- a/arch/xtensa/include/uapi/asm/mman.h
> +++ b/arch/xtensa/include/uapi/asm/mman.h
> @@ -35,6 +35,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 13dab191a23e..57added3201d 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1701,6 +1701,7 @@ struct file_operations {
> long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
> long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
> int (*mmap) (struct file *, struct vm_area_struct *);
> + unsigned long mmap_supported_flags;
> int (*open) (struct inode *, struct file *);
> int (*flush) (struct file *, fl_owner_t id);
> int (*release) (struct inode *, struct file *);
> diff --git a/include/linux/mman.h b/include/linux/mman.h
> index c8367041fafd..94b63b4d71ff 100644
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -7,6 +7,45 @@
> #include <linux/atomic.h>
> #include <uapi/linux/mman.h>
>
> +/*
> + * Arrange for legacy / undefined architecture specific flags to be
> + * ignored by default in LEGACY_MAP_MASK.
> + */
> +#ifndef MAP_32BIT
> +#define MAP_32BIT 0
> +#endif
> +#ifndef MAP_HUGE_2MB
> +#define MAP_HUGE_2MB 0
> +#endif
> +#ifndef MAP_HUGE_1GB
> +#define MAP_HUGE_1GB 0
> +#endif
> +#ifndef MAP_UNINITIALIZED
> +#define MAP_UNINITIALIZED 0
> +#endif
> +
> +/*
> + * The historical set of flags that all mmap implementations implicitly
> + * support when a ->mmap_validate() op is not provided in file_operations.
> + */
> +#define LEGACY_MAP_MASK (MAP_SHARED \
> + | MAP_PRIVATE \
> + | MAP_FIXED \
> + | MAP_ANONYMOUS \
> + | MAP_DENYWRITE \
> + | MAP_EXECUTABLE \
> + | MAP_UNINITIALIZED \
> + | MAP_GROWSDOWN \
> + | MAP_LOCKED \
> + | MAP_NORESERVE \
> + | MAP_POPULATE \
> + | MAP_NONBLOCK \
> + | MAP_STACK \
> + | MAP_HUGETLB \
> + | MAP_32BIT \
> + | MAP_HUGE_2MB \
> + | MAP_HUGE_1GB)
> +
> extern int sysctl_overcommit_memory;
> extern int sysctl_overcommit_ratio;
> extern unsigned long sysctl_overcommit_kbytes;
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 680506faceae..924839fac0e6 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
>
> if (file) {
> struct inode *inode = file_inode(file);
> + unsigned long flags_mask;
> +
> + flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
>
> switch (flags & MAP_TYPE) {
> case MAP_SHARED:
> + /*
> + * Force use of MAP_SHARED_VALIDATE with non-legacy
> + * flags. E.g. MAP_SYNC is dangerous to use with
> + * MAP_SHARED as you don't know which consistency model
> + * you will get. We silently ignore unsupported flags
> + * with MAP_SHARED to preserve backward compatibility.
> + */
> + flags &= LEGACY_MAP_MASK;
> + /* fall through */
> + case MAP_SHARED_VALIDATE:
> + if (flags & ~flags_mask)
> + return -EOPNOTSUPP;
> if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
> return -EACCES;
>
> diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/tools/include/uapi/asm-generic/mman-common.h
> +++ b/tools/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 12:02 ` Vlastimil Babka
0 siblings, 0 replies; 132+ messages in thread
From: Vlastimil Babka @ 2017-11-22 12:02 UTC (permalink / raw)
To: Jan Kara, Dan Williams
Cc: Ross Zwisler, Christoph Hellwig,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg,
linux-api-u79uwXL29TY76Z2rM5mHXA,
linux-ext4-u79uwXL29TY76Z2rM5mHXA,
linux-xfs-u79uwXL29TY76Z2rM5mHXA, Darrick J . Wong,
Arnd Bergmann, Andy Lutomirski, Andrew Morton, Michal Hocko,
Matthew Wilcox, Kees Cook, Florian Weimer, John Hubbard,
Kirill A. Shutemov
On 11/01/2017 04:36 PM, Jan Kara wrote:
> From: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>
> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> define new behavior that is known to fail on older kernels without the
> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> guaranteed to fail on all legacy mmap implementations.
So I'm trying to make sense of this together with Michal's attempt for
MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
instead of flag modifier exactly for the reason of not validating
unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
modifier cannot build on top of this. Wouldn't thus it be really better
long-term to introduce mmap3 at this point? ...
Vlastimil
[1] https://marc.info/?l=linux-arch&m=151083448322336&w=2
> It is worth noting that the original proposal was for a standalone
> MAP_VALIDATE flag. However, when that could not be supported by all
> archs Linus observed:
>
> I see why you *think* you want a bitmap. You think you want
> a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
> etc, so that people can do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
> | MAP_SYNC, fd, 0);
>
> and "know" that MAP_SYNC actually takes.
>
> And I'm saying that whole wish is bogus. You're fundamentally
> depending on special semantics, just make it explicit. It's already
> not portable, so don't try to make it so.
>
> Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
> of 0x3, and make people do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
> | MAP_SYNC, fd, 0);
>
> and then the kernel side is easier too (none of that random garbage
> playing games with looking at the "MAP_VALIDATE bit", but just another
> case statement in that map type thing.
>
> Boom. Done.
>
> Similar to ->fallocate() we also want the ability to validate the
> support for new flags on a per ->mmap() 'struct file_operations'
> instance basis. Towards that end arrange for flags to be generically
> validated against a mmap_supported_flags exported by 'struct
> file_operations'. By default all existing flags are implicitly
> supported, but new flags require MAP_SHARED_VALIDATE and
> per-instance-opt-in.
>
> Cc: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
> Cc: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
> Cc: Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
> Suggested-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> Suggested-by: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
> Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Signed-off-by: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
> ---
> arch/alpha/include/uapi/asm/mman.h | 1 +
> arch/mips/include/uapi/asm/mman.h | 1 +
> arch/parisc/include/uapi/asm/mman.h | 1 +
> arch/xtensa/include/uapi/asm/mman.h | 1 +
> include/linux/fs.h | 1 +
> include/linux/mman.h | 39 ++++++++++++++++++++++++++++
> include/uapi/asm-generic/mman-common.h | 1 +
> mm/mmap.c | 15 +++++++++++
> tools/include/uapi/asm-generic/mman-common.h | 1 +
> 9 files changed, 61 insertions(+)
>
> diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
> index 3b26cc62dadb..f6d118aaedb9 100644
> --- a/arch/alpha/include/uapi/asm/mman.h
> +++ b/arch/alpha/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
> #define MAP_FIXED 0x100 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
> index da3216007fe0..93268e4cd3c7 100644
> --- a/arch/mips/include/uapi/asm/mman.h
> +++ b/arch/mips/include/uapi/asm/mman.h
> @@ -28,6 +28,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
> index 775b5d5e41a1..bca652aa1677 100644
> --- a/arch/parisc/include/uapi/asm/mman.h
> +++ b/arch/parisc/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x03 /* Mask for type of mapping */
> #define MAP_FIXED 0x04 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
> index b15b278aa314..9ab426374714 100644
> --- a/arch/xtensa/include/uapi/asm/mman.h
> +++ b/arch/xtensa/include/uapi/asm/mman.h
> @@ -35,6 +35,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 13dab191a23e..57added3201d 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1701,6 +1701,7 @@ struct file_operations {
> long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
> long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
> int (*mmap) (struct file *, struct vm_area_struct *);
> + unsigned long mmap_supported_flags;
> int (*open) (struct inode *, struct file *);
> int (*flush) (struct file *, fl_owner_t id);
> int (*release) (struct inode *, struct file *);
> diff --git a/include/linux/mman.h b/include/linux/mman.h
> index c8367041fafd..94b63b4d71ff 100644
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -7,6 +7,45 @@
> #include <linux/atomic.h>
> #include <uapi/linux/mman.h>
>
> +/*
> + * Arrange for legacy / undefined architecture specific flags to be
> + * ignored by default in LEGACY_MAP_MASK.
> + */
> +#ifndef MAP_32BIT
> +#define MAP_32BIT 0
> +#endif
> +#ifndef MAP_HUGE_2MB
> +#define MAP_HUGE_2MB 0
> +#endif
> +#ifndef MAP_HUGE_1GB
> +#define MAP_HUGE_1GB 0
> +#endif
> +#ifndef MAP_UNINITIALIZED
> +#define MAP_UNINITIALIZED 0
> +#endif
> +
> +/*
> + * The historical set of flags that all mmap implementations implicitly
> + * support when a ->mmap_validate() op is not provided in file_operations.
> + */
> +#define LEGACY_MAP_MASK (MAP_SHARED \
> + | MAP_PRIVATE \
> + | MAP_FIXED \
> + | MAP_ANONYMOUS \
> + | MAP_DENYWRITE \
> + | MAP_EXECUTABLE \
> + | MAP_UNINITIALIZED \
> + | MAP_GROWSDOWN \
> + | MAP_LOCKED \
> + | MAP_NORESERVE \
> + | MAP_POPULATE \
> + | MAP_NONBLOCK \
> + | MAP_STACK \
> + | MAP_HUGETLB \
> + | MAP_32BIT \
> + | MAP_HUGE_2MB \
> + | MAP_HUGE_1GB)
> +
> extern int sysctl_overcommit_memory;
> extern int sysctl_overcommit_ratio;
> extern unsigned long sysctl_overcommit_kbytes;
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 680506faceae..924839fac0e6 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
>
> if (file) {
> struct inode *inode = file_inode(file);
> + unsigned long flags_mask;
> +
> + flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
>
> switch (flags & MAP_TYPE) {
> case MAP_SHARED:
> + /*
> + * Force use of MAP_SHARED_VALIDATE with non-legacy
> + * flags. E.g. MAP_SYNC is dangerous to use with
> + * MAP_SHARED as you don't know which consistency model
> + * you will get. We silently ignore unsupported flags
> + * with MAP_SHARED to preserve backward compatibility.
> + */
> + flags &= LEGACY_MAP_MASK;
> + /* fall through */
> + case MAP_SHARED_VALIDATE:
> + if (flags & ~flags_mask)
> + return -EOPNOTSUPP;
> if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
> return -EACCES;
>
> diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/tools/include/uapi/asm-generic/mman-common.h
> +++ b/tools/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 12:02 ` Vlastimil Babka
0 siblings, 0 replies; 132+ messages in thread
From: Vlastimil Babka @ 2017-11-22 12:02 UTC (permalink / raw)
To: Jan Kara, Dan Williams
Cc: Ross Zwisler, Christoph Hellwig, linux-fsdevel, linux-nvdimm,
linux-mm, linux-api, linux-ext4, linux-xfs, Darrick J . Wong,
Arnd Bergmann, Andy Lutomirski, Andrew Morton, Michal Hocko,
Matthew Wilcox, Kees Cook, Florian Weimer, John Hubbard,
Kirill A. Shutemov
On 11/01/2017 04:36 PM, Jan Kara wrote:
> From: Dan Williams <dan.j.williams@intel.com>
>
> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> define new behavior that is known to fail on older kernels without the
> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> guaranteed to fail on all legacy mmap implementations.
So I'm trying to make sense of this together with Michal's attempt for
MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
instead of flag modifier exactly for the reason of not validating
unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
modifier cannot build on top of this. Wouldn't thus it be really better
long-term to introduce mmap3 at this point? ...
Vlastimil
[1] https://marc.info/?l=linux-arch&m=151083448322336&w=2
> It is worth noting that the original proposal was for a standalone
> MAP_VALIDATE flag. However, when that could not be supported by all
> archs Linus observed:
>
> I see why you *think* you want a bitmap. You think you want
> a bitmap because you want to make MAP_VALIDATE be part of MAP_SYNC
> etc, so that people can do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED
> | MAP_SYNC, fd, 0);
>
> and "know" that MAP_SYNC actually takes.
>
> And I'm saying that whole wish is bogus. You're fundamentally
> depending on special semantics, just make it explicit. It's already
> not portable, so don't try to make it so.
>
> Rename that MAP_VALIDATE as MAP_SHARED_VALIDATE, make it have a value
> of 0x3, and make people do
>
> ret = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED_VALIDATE
> | MAP_SYNC, fd, 0);
>
> and then the kernel side is easier too (none of that random garbage
> playing games with looking at the "MAP_VALIDATE bit", but just another
> case statement in that map type thing.
>
> Boom. Done.
>
> Similar to ->fallocate() we also want the ability to validate the
> support for new flags on a per ->mmap() 'struct file_operations'
> instance basis. Towards that end arrange for flags to be generically
> validated against a mmap_supported_flags exported by 'struct
> file_operations'. By default all existing flags are implicitly
> supported, but new flags require MAP_SHARED_VALIDATE and
> per-instance-opt-in.
>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
> arch/alpha/include/uapi/asm/mman.h | 1 +
> arch/mips/include/uapi/asm/mman.h | 1 +
> arch/parisc/include/uapi/asm/mman.h | 1 +
> arch/xtensa/include/uapi/asm/mman.h | 1 +
> include/linux/fs.h | 1 +
> include/linux/mman.h | 39 ++++++++++++++++++++++++++++
> include/uapi/asm-generic/mman-common.h | 1 +
> mm/mmap.c | 15 +++++++++++
> tools/include/uapi/asm-generic/mman-common.h | 1 +
> 9 files changed, 61 insertions(+)
>
> diff --git a/arch/alpha/include/uapi/asm/mman.h b/arch/alpha/include/uapi/asm/mman.h
> index 3b26cc62dadb..f6d118aaedb9 100644
> --- a/arch/alpha/include/uapi/asm/mman.h
> +++ b/arch/alpha/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping (OSF/1 is _wrong_) */
> #define MAP_FIXED 0x100 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/mips/include/uapi/asm/mman.h b/arch/mips/include/uapi/asm/mman.h
> index da3216007fe0..93268e4cd3c7 100644
> --- a/arch/mips/include/uapi/asm/mman.h
> +++ b/arch/mips/include/uapi/asm/mman.h
> @@ -28,6 +28,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
> index 775b5d5e41a1..bca652aa1677 100644
> --- a/arch/parisc/include/uapi/asm/mman.h
> +++ b/arch/parisc/include/uapi/asm/mman.h
> @@ -11,6 +11,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x03 /* Mask for type of mapping */
> #define MAP_FIXED 0x04 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> diff --git a/arch/xtensa/include/uapi/asm/mman.h b/arch/xtensa/include/uapi/asm/mman.h
> index b15b278aa314..9ab426374714 100644
> --- a/arch/xtensa/include/uapi/asm/mman.h
> +++ b/arch/xtensa/include/uapi/asm/mman.h
> @@ -35,6 +35,7 @@
> */
> #define MAP_SHARED 0x001 /* Share changes */
> #define MAP_PRIVATE 0x002 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x003 /* share + validate extension flags */
> #define MAP_TYPE 0x00f /* Mask for type of mapping */
> #define MAP_FIXED 0x010 /* Interpret addr exactly */
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 13dab191a23e..57added3201d 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1701,6 +1701,7 @@ struct file_operations {
> long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
> long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
> int (*mmap) (struct file *, struct vm_area_struct *);
> + unsigned long mmap_supported_flags;
> int (*open) (struct inode *, struct file *);
> int (*flush) (struct file *, fl_owner_t id);
> int (*release) (struct inode *, struct file *);
> diff --git a/include/linux/mman.h b/include/linux/mman.h
> index c8367041fafd..94b63b4d71ff 100644
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -7,6 +7,45 @@
> #include <linux/atomic.h>
> #include <uapi/linux/mman.h>
>
> +/*
> + * Arrange for legacy / undefined architecture specific flags to be
> + * ignored by default in LEGACY_MAP_MASK.
> + */
> +#ifndef MAP_32BIT
> +#define MAP_32BIT 0
> +#endif
> +#ifndef MAP_HUGE_2MB
> +#define MAP_HUGE_2MB 0
> +#endif
> +#ifndef MAP_HUGE_1GB
> +#define MAP_HUGE_1GB 0
> +#endif
> +#ifndef MAP_UNINITIALIZED
> +#define MAP_UNINITIALIZED 0
> +#endif
> +
> +/*
> + * The historical set of flags that all mmap implementations implicitly
> + * support when a ->mmap_validate() op is not provided in file_operations.
> + */
> +#define LEGACY_MAP_MASK (MAP_SHARED \
> + | MAP_PRIVATE \
> + | MAP_FIXED \
> + | MAP_ANONYMOUS \
> + | MAP_DENYWRITE \
> + | MAP_EXECUTABLE \
> + | MAP_UNINITIALIZED \
> + | MAP_GROWSDOWN \
> + | MAP_LOCKED \
> + | MAP_NORESERVE \
> + | MAP_POPULATE \
> + | MAP_NONBLOCK \
> + | MAP_STACK \
> + | MAP_HUGETLB \
> + | MAP_32BIT \
> + | MAP_HUGE_2MB \
> + | MAP_HUGE_1GB)
> +
> extern int sysctl_overcommit_memory;
> extern int sysctl_overcommit_ratio;
> extern unsigned long sysctl_overcommit_kbytes;
> diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/include/uapi/asm-generic/mman-common.h
> +++ b/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 680506faceae..924839fac0e6 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -1387,9 +1387,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
>
> if (file) {
> struct inode *inode = file_inode(file);
> + unsigned long flags_mask;
> +
> + flags_mask = LEGACY_MAP_MASK | file->f_op->mmap_supported_flags;
>
> switch (flags & MAP_TYPE) {
> case MAP_SHARED:
> + /*
> + * Force use of MAP_SHARED_VALIDATE with non-legacy
> + * flags. E.g. MAP_SYNC is dangerous to use with
> + * MAP_SHARED as you don't know which consistency model
> + * you will get. We silently ignore unsupported flags
> + * with MAP_SHARED to preserve backward compatibility.
> + */
> + flags &= LEGACY_MAP_MASK;
> + /* fall through */
> + case MAP_SHARED_VALIDATE:
> + if (flags & ~flags_mask)
> + return -EOPNOTSUPP;
> if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
> return -EACCES;
>
> diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
> index 203268f9231e..8ce7f5a0800f 100644
> --- a/tools/include/uapi/asm-generic/mman-common.h
> +++ b/tools/include/uapi/asm-generic/mman-common.h
> @@ -16,6 +16,7 @@
>
> #define MAP_SHARED 0x01 /* Share changes */
> #define MAP_PRIVATE 0x02 /* Changes are private */
> +#define MAP_SHARED_VALIDATE 0x03 /* share + validate extension flags */
> #define MAP_TYPE 0x0f /* Mask for type of mapping */
> #define MAP_FIXED 0x10 /* Interpret addr exactly */
> #define MAP_ANONYMOUS 0x20 /* don't use a file */
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
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^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
2017-11-22 12:02 ` Vlastimil Babka
(?)
@ 2017-11-22 16:52 ` Dan Williams
-1 siblings, 0 replies; 132+ messages in thread
From: Dan Williams @ 2017-11-22 16:52 UTC (permalink / raw)
To: Vlastimil Babka
Cc: Florian Weimer, linux-xfs, Jan Kara, Kees Cook, Arnd Bergmann,
linux-nvdimm, Linux API, Darrick J . Wong, Matthew Wilcox,
Michal Hocko, Christoph Hellwig, Linux MM, Andy Lutomirski,
John Hubbard, linux-fsdevel, linux-ext4, Andrew Morton,
Kirill A. Shutemov
On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
> On 11/01/2017 04:36 PM, Jan Kara wrote:
>> From: Dan Williams <dan.j.williams@intel.com>
>>
>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>> define new behavior that is known to fail on older kernels without the
>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>> guaranteed to fail on all legacy mmap implementations.
>
> So I'm trying to make sense of this together with Michal's attempt for
> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> instead of flag modifier exactly for the reason of not validating
> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> modifier cannot build on top of this. Wouldn't thus it be really better
> long-term to introduce mmap3 at this point? ...
We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
else on parisc?
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 16:52 ` Dan Williams
0 siblings, 0 replies; 132+ messages in thread
From: Dan Williams @ 2017-11-22 16:52 UTC (permalink / raw)
To: Vlastimil Babka
Cc: Jan Kara, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, Linux MM, Linux API, linux-ext4, linux-xfs,
Darrick J . Wong, Arnd Bergmann, Andy Lutomirski, Andrew Morton,
Michal Hocko, Matthew Wilcox, Kees Cook, Florian Weimer,
John Hubbard, Kirill A. Shutemov
On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
> On 11/01/2017 04:36 PM, Jan Kara wrote:
>> From: Dan Williams <dan.j.williams@intel.com>
>>
>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>> define new behavior that is known to fail on older kernels without the
>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>> guaranteed to fail on all legacy mmap implementations.
>
> So I'm trying to make sense of this together with Michal's attempt for
> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> instead of flag modifier exactly for the reason of not validating
> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> modifier cannot build on top of this. Wouldn't thus it be really better
> long-term to introduce mmap3 at this point? ...
We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
else on parisc?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 16:52 ` Dan Williams
0 siblings, 0 replies; 132+ messages in thread
From: Dan Williams @ 2017-11-22 16:52 UTC (permalink / raw)
To: Vlastimil Babka
Cc: Jan Kara, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, Linux MM, Linux API, linux-ext4, linux-xfs,
Darrick J . Wong, Arnd Bergmann, Andy Lutomirski, Andrew Morton,
Michal Hocko, Matthew Wilcox, Kees Cook, Florian Weimer,
John Hubbard, Kirill A. Shutemov
On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
> On 11/01/2017 04:36 PM, Jan Kara wrote:
>> From: Dan Williams <dan.j.williams@intel.com>
>>
>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>> define new behavior that is known to fail on older kernels without the
>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>> guaranteed to fail on all legacy mmap implementations.
>
> So I'm trying to make sense of this together with Michal's attempt for
> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> instead of flag modifier exactly for the reason of not validating
> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> modifier cannot build on top of this. Wouldn't thus it be really better
> long-term to introduce mmap3 at this point? ...
We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
else on parisc?
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 19:53 ` Matthew Wilcox
0 siblings, 0 replies; 132+ messages in thread
From: Matthew Wilcox @ 2017-11-22 19:53 UTC (permalink / raw)
To: Dan Williams
Cc: Florian Weimer, linux-xfs, Jan Kara, Kees Cook, Arnd Bergmann,
linux-nvdimm, Linux API, Darrick J . Wong, linux-parisc,
Michal Hocko, Christoph Hellwig, Linux MM, Kirill A. Shutemov,
Andy Lutomirski, John Hubbard, linux-fsdevel, linux-ext4,
Andrew Morton, Vlastimil Babka
On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
> > On 11/01/2017 04:36 PM, Jan Kara wrote:
> >> From: Dan Williams <dan.j.williams@intel.com>
> >>
> >> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> >> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> >> define new behavior that is known to fail on older kernels without the
> >> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> >> guaranteed to fail on all legacy mmap implementations.
> >
> > So I'm trying to make sense of this together with Michal's attempt for
> > MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> > instead of flag modifier exactly for the reason of not validating
> > unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> > implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> > modifier cannot build on top of this. Wouldn't thus it be really better
> > long-term to introduce mmap3 at this point? ...
>
> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
> else on parisc?
It looks like 0x08 should work. But I don't have an HPUX machine around
to check that HP didn't use that bit for something else.
It'd probably help to cc the linux-parisc mailing list when asking
questions about PARISC, eh?
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 19:53 ` Matthew Wilcox
0 siblings, 0 replies; 132+ messages in thread
From: Matthew Wilcox @ 2017-11-22 19:53 UTC (permalink / raw)
To: Dan Williams
Cc: Florian Weimer, linux-xfs, Jan Kara, Kees Cook, Arnd Bergmann,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw, Linux API, Darrick J . Wong,
linux-parisc-u79uwXL29TY76Z2rM5mHXA, Michal Hocko,
Christoph Hellwig, Linux MM, Kirill A. Shutemov, Andy Lutomirski,
John Hubbard, linux-fsdevel, linux-ext4, Andrew Morton,
Vlastimil Babka
On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka-AlSwsSmVLrQ@public.gmane.org> wrote:
> > On 11/01/2017 04:36 PM, Jan Kara wrote:
> >> From: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >>
> >> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> >> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> >> define new behavior that is known to fail on older kernels without the
> >> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> >> guaranteed to fail on all legacy mmap implementations.
> >
> > So I'm trying to make sense of this together with Michal's attempt for
> > MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> > instead of flag modifier exactly for the reason of not validating
> > unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> > implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> > modifier cannot build on top of this. Wouldn't thus it be really better
> > long-term to introduce mmap3 at this point? ...
>
> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
> else on parisc?
It looks like 0x08 should work. But I don't have an HPUX machine around
to check that HP didn't use that bit for something else.
It'd probably help to cc the linux-parisc mailing list when asking
questions about PARISC, eh?
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 19:53 ` Matthew Wilcox
0 siblings, 0 replies; 132+ messages in thread
From: Matthew Wilcox @ 2017-11-22 19:53 UTC (permalink / raw)
To: Dan Williams
Cc: Vlastimil Babka, Jan Kara, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux MM, Linux API, linux-ext4,
linux-xfs, Darrick J . Wong, Arnd Bergmann, Andy Lutomirski,
Andrew Morton, Michal Hocko, Kees Cook, Florian Weimer,
John Hubbard, Kirill A. Shutemov, linux-parisc
On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
> > On 11/01/2017 04:36 PM, Jan Kara wrote:
> >> From: Dan Williams <dan.j.williams@intel.com>
> >>
> >> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> >> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> >> define new behavior that is known to fail on older kernels without the
> >> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> >> guaranteed to fail on all legacy mmap implementations.
> >
> > So I'm trying to make sense of this together with Michal's attempt for
> > MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> > instead of flag modifier exactly for the reason of not validating
> > unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> > implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> > modifier cannot build on top of this. Wouldn't thus it be really better
> > long-term to introduce mmap3 at this point? ...
>
> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
> else on parisc?
It looks like 0x08 should work. But I don't have an HPUX machine around
to check that HP didn't use that bit for something else.
It'd probably help to cc the linux-parisc mailing list when asking
questions about PARISC, eh?
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-22 19:53 ` Matthew Wilcox
0 siblings, 0 replies; 132+ messages in thread
From: Matthew Wilcox @ 2017-11-22 19:53 UTC (permalink / raw)
To: Dan Williams
Cc: Vlastimil Babka, Jan Kara, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux MM, Linux API, linux-ext4,
linux-xfs, Darrick J . Wong, Arnd Bergmann, Andy Lutomirski,
Andrew Morton, Michal Hocko, Kees Cook, Florian Weimer,
John Hubbard, Kirill A. Shutemov, linux-parisc
On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
> > On 11/01/2017 04:36 PM, Jan Kara wrote:
> >> From: Dan Williams <dan.j.williams@intel.com>
> >>
> >> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
> >> unknown flags. However, proposals like MAP_SYNC need a mechanism to
> >> define new behavior that is known to fail on older kernels without the
> >> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
> >> guaranteed to fail on all legacy mmap implementations.
> >
> > So I'm trying to make sense of this together with Michal's attempt for
> > MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
> > instead of flag modifier exactly for the reason of not validating
> > unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
> > implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
> > modifier cannot build on top of this. Wouldn't thus it be really better
> > long-term to introduce mmap3 at this point? ...
>
> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
> else on parisc?
It looks like 0x08 should work. But I don't have an HPUX machine around
to check that HP didn't use that bit for something else.
It'd probably help to cc the linux-parisc mailing list when asking
questions about PARISC, eh?
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
2017-11-22 19:53 ` Matthew Wilcox
@ 2017-11-25 18:45 ` Helge Deller
-1 siblings, 0 replies; 132+ messages in thread
From: Helge Deller @ 2017-11-25 18:45 UTC (permalink / raw)
To: Matthew Wilcox, Dan Williams
Cc: Vlastimil Babka, Jan Kara, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux MM, Linux API, linux-ext4,
linux-xfs, Darrick J . Wong, Arnd Bergmann, Andy Lutomirski,
Andrew Morton, Michal Hocko, Kees Cook, Florian Weimer,
John Hubbard, Kirill A. Shutemov, linux-parisc
On 22.11.2017 20:53, Matthew Wilcox wrote:
> On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
>> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
>>> On 11/01/2017 04:36 PM, Jan Kara wrote:
>>>> From: Dan Williams <dan.j.williams@intel.com>
>>>>
>>>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>>>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>>>> define new behavior that is known to fail on older kernels without the
>>>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>>>> guaranteed to fail on all legacy mmap implementations.
>>>
>>> So I'm trying to make sense of this together with Michal's attempt for
>>> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
>>> instead of flag modifier exactly for the reason of not validating
>>> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
>>> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
>>> modifier cannot build on top of this. Wouldn't thus it be really better
>>> long-term to introduce mmap3 at this point? ...
>>
>> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
>> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
>> else on parisc?
>
> It looks like 0x08 should work.
I posted an RFC to the parisc mailing list for that:
https://patchwork.kernel.org/patch/9970553/
Basically this is (for parisc only):
-#define MAP_TYPE 0x03 /* Mask for type of mapping */
+#define MAP_TYPE (MAP_SHARED|MAP_PRIVATE|MAP_RESRVD1|MAP_RESRVD2) /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
+#define MAP_RESRVD1 0x08 /* reserved for 3rd bit of MAP_TYPE */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
+#define MAP_RESRVD2 0x20 /* reserved for 4th bit of MAP_TYPE */
> But I don't have an HPUX machine around
> to check that HP didn't use that bit for something else.
We completely dropped support for HPUX binaries, so it's not relvant any longer.
> It'd probably help to cc the linux-parisc mailing list when asking
> questions about PARISC, eh?
Yes, please.
Helge
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-25 18:45 ` Helge Deller
0 siblings, 0 replies; 132+ messages in thread
From: Helge Deller @ 2017-11-25 18:45 UTC (permalink / raw)
To: Matthew Wilcox, Dan Williams
Cc: Vlastimil Babka, Jan Kara, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux MM, Linux API, linux-ext4,
linux-xfs, Darrick J . Wong, Arnd Bergmann, Andy Lutomirski,
Andrew Morton, Michal Hocko, Kees Cook, Florian Weimer,
John Hubbard, Kirill A. Shutemov, linux-parisc
On 22.11.2017 20:53, Matthew Wilcox wrote:
> On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
>> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
>>> On 11/01/2017 04:36 PM, Jan Kara wrote:
>>>> From: Dan Williams <dan.j.williams@intel.com>
>>>>
>>>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>>>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>>>> define new behavior that is known to fail on older kernels without the
>>>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>>>> guaranteed to fail on all legacy mmap implementations.
>>>
>>> So I'm trying to make sense of this together with Michal's attempt for
>>> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
>>> instead of flag modifier exactly for the reason of not validating
>>> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
>>> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
>>> modifier cannot build on top of this. Wouldn't thus it be really better
>>> long-term to introduce mmap3 at this point? ...
>>
>> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
>> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
>> else on parisc?
>
> It looks like 0x08 should work.
I posted an RFC to the parisc mailing list for that:
https://patchwork.kernel.org/patch/9970553/
Basically this is (for parisc only):
-#define MAP_TYPE 0x03 /* Mask for type of mapping */
+#define MAP_TYPE (MAP_SHARED|MAP_PRIVATE|MAP_RESRVD1|MAP_RESRVD2) /* Mask for type of mapping */
#define MAP_FIXED 0x04 /* Interpret addr exactly */
+#define MAP_RESRVD1 0x08 /* reserved for 3rd bit of MAP_TYPE */
#define MAP_ANONYMOUS 0x10 /* don't use a file */
+#define MAP_RESRVD2 0x20 /* reserved for 4th bit of MAP_TYPE */
> But I don't have an HPUX machine around
> to check that HP didn't use that bit for something else.
We completely dropped support for HPUX binaries, so it's not relvant any longer.
> It'd probably help to cc the linux-parisc mailing list when asking
> questions about PARISC, eh?
Yes, please.
Helge
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
2017-11-25 18:45 ` Helge Deller
@ 2017-11-27 15:55 ` Vlastimil Babka
-1 siblings, 0 replies; 132+ messages in thread
From: Vlastimil Babka @ 2017-11-27 15:55 UTC (permalink / raw)
To: Helge Deller, Matthew Wilcox, Dan Williams
Cc: Jan Kara, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, Linux MM, Linux API, linux-ext4, linux-xfs,
Darrick J . Wong, Arnd Bergmann, Andy Lutomirski, Andrew Morton,
Michal Hocko, Kees Cook, Florian Weimer, John Hubbard,
Kirill A. Shutemov, linux-parisc
On 11/25/2017 07:45 PM, Helge Deller wrote:
> On 22.11.2017 20:53, Matthew Wilcox wrote:
>> On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
>>> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
>>>> On 11/01/2017 04:36 PM, Jan Kara wrote:
>>>>> From: Dan Williams <dan.j.williams@intel.com>
>>>>>
>>>>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>>>>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>>>>> define new behavior that is known to fail on older kernels without the
>>>>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>>>>> guaranteed to fail on all legacy mmap implementations.
>>>>
>>>> So I'm trying to make sense of this together with Michal's attempt for
>>>> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
>>>> instead of flag modifier exactly for the reason of not validating
>>>> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
>>>> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
>>>> modifier cannot build on top of this. Wouldn't thus it be really better
>>>> long-term to introduce mmap3 at this point? ...
>>>
>>> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
>>> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
>>> else on parisc?
>>
>> It looks like 0x08 should work.
>
> I posted an RFC to the parisc mailing list for that:
> https://patchwork.kernel.org/patch/9970553/
Thanks. BTW there doesn't seem to be much interest making MAP_FIXED_SAFE
a flag modifier after all, so MAP_PRIVATE_VALIDATE wouldn't get
immediate users.
> Basically this is (for parisc only):
> -#define MAP_TYPE 0x03 /* Mask for type of mapping */
> +#define MAP_TYPE (MAP_SHARED|MAP_PRIVATE|MAP_RESRVD1|MAP_RESRVD2) /* Mask for type of mapping */
> #define MAP_FIXED 0x04 /* Interpret addr exactly */
> +#define MAP_RESRVD1 0x08 /* reserved for 3rd bit of MAP_TYPE */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> +#define MAP_RESRVD2 0x20 /* reserved for 4th bit of MAP_TYPE */
>
>> But I don't have an HPUX machine around
>> to check that HP didn't use that bit for something else.
>
> We completely dropped support for HPUX binaries, so it's not relvant any longer.
>
>> It'd probably help to cc the linux-parisc mailing list when asking
>> questions about PARISC, eh?
>
> Yes, please.
>
> Helge
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags
@ 2017-11-27 15:55 ` Vlastimil Babka
0 siblings, 0 replies; 132+ messages in thread
From: Vlastimil Babka @ 2017-11-27 15:55 UTC (permalink / raw)
To: Helge Deller, Matthew Wilcox, Dan Williams
Cc: Jan Kara, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, Linux MM, Linux API, linux-ext4, linux-xfs,
Darrick J . Wong, Arnd Bergmann, Andy Lutomirski, Andrew Morton,
Michal Hocko, Kees Cook, Florian Weimer, John Hubbard,
Kirill A. Shutemov, linux-parisc
On 11/25/2017 07:45 PM, Helge Deller wrote:
> On 22.11.2017 20:53, Matthew Wilcox wrote:
>> On Wed, Nov 22, 2017 at 08:52:37AM -0800, Dan Williams wrote:
>>> On Wed, Nov 22, 2017 at 4:02 AM, Vlastimil Babka <vbabka@suse.cz> wrote:
>>>> On 11/01/2017 04:36 PM, Jan Kara wrote:
>>>>> From: Dan Williams <dan.j.williams@intel.com>
>>>>>
>>>>> The mmap(2) syscall suffers from the ABI anti-pattern of not validating
>>>>> unknown flags. However, proposals like MAP_SYNC need a mechanism to
>>>>> define new behavior that is known to fail on older kernels without the
>>>>> support. Define a new MAP_SHARED_VALIDATE flag pattern that is
>>>>> guaranteed to fail on all legacy mmap implementations.
>>>>
>>>> So I'm trying to make sense of this together with Michal's attempt for
>>>> MAP_FIXED_SAFE [1] where he has to introduce a completely new flag
>>>> instead of flag modifier exactly for the reason of not validating
>>>> unknown flags. And my conclusion is that because MAP_SHARED_VALIDATE
>>>> implies MAP_SHARED and excludes MAP_PRIVATE, MAP_FIXED_SAFE as a
>>>> modifier cannot build on top of this. Wouldn't thus it be really better
>>>> long-term to introduce mmap3 at this point? ...
>>>
>>> We have room to define MAP_PRIVATE_VALIDATE in MAP_TYPE on every arch
>>> except parisc. Can we steal an extra bit for MAP_TYPE from somewhere
>>> else on parisc?
>>
>> It looks like 0x08 should work.
>
> I posted an RFC to the parisc mailing list for that:
> https://patchwork.kernel.org/patch/9970553/
Thanks. BTW there doesn't seem to be much interest making MAP_FIXED_SAFE
a flag modifier after all, so MAP_PRIVATE_VALIDATE wouldn't get
immediate users.
> Basically this is (for parisc only):
> -#define MAP_TYPE 0x03 /* Mask for type of mapping */
> +#define MAP_TYPE (MAP_SHARED|MAP_PRIVATE|MAP_RESRVD1|MAP_RESRVD2) /* Mask for type of mapping */
> #define MAP_FIXED 0x04 /* Interpret addr exactly */
> +#define MAP_RESRVD1 0x08 /* reserved for 3rd bit of MAP_TYPE */
> #define MAP_ANONYMOUS 0x10 /* don't use a file */
> +#define MAP_RESRVD2 0x20 /* reserved for 4th bit of MAP_TYPE */
>
>> But I don't have an HPUX machine around
>> to check that HP didn't use that bit for something else.
>
> We completely dropped support for HPUX binaries, so it's not relvant any longer.
>
>> It'd probably help to cc the linux-parisc mailing list when asking
>> questions about PARISC, eh?
>
> Yes, please.
>
> Helge
>
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
2017-11-01 15:36 ` Jan Kara
(?)
@ 2018-04-12 13:00 ` Michael Kerrisk (man-pages)
-1 siblings, 0 replies; 132+ messages in thread
From: Michael Kerrisk (man-pages) @ 2018-04-12 13:00 UTC (permalink / raw)
To: Jan Kara
Cc: xfs, linux-nvdimm, Linux API, Darrick J . Wong,
Christoph Hellwig, Linux-MM, linux-fsdevel, Ext4 Developers List
Hello Jan,
I have applied your patch, and tweaked the text a little, and pushed
the result to the git repo.
On 1 November 2017 at 16:36, Jan Kara <jack@suse.cz> wrote:
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Jan Kara <jack@suse.cz>
I have a question below.
> ---
> man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/man2/mmap.2 b/man2/mmap.2
> index 47c3148653be..b38ee6809327 100644
> --- a/man2/mmap.2
> +++ b/man2/mmap.2
> @@ -125,6 +125,21 @@ are carried through to the underlying file.
> to the underlying file requires the use of
> .BR msync (2).)
> .TP
> +.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
> +The same as
> +.B MAP_SHARED
> +except that
> +.B MAP_SHARED
> +mappings ignore unknown flags in
> +.IR flags .
> +In contrast when creating mapping of
> +.B MAP_SHARED_VALIDATE
> +mapping type, the kernel verifies all passed flags are known and fails the
> +mapping with
> +.BR EOPNOTSUPP
> +otherwise. This mapping type is also required to be able to use some mapping
> +flags.
> +.TP
> .B MAP_PRIVATE
> Create a private copy-on-write mapping.
> Updates to the mapping are not visible to other processes
> @@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
> .BR mmap ()
> call are visible in the mapped region.
> .PP
> -Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
> +.B MAP_SHARED
> +and
> +.B MAP_PRIVATE
> +are described in POSIX.1-2001 and POSIX.1-2008.
> .PP
> In addition, zero or more of the following values can be ORed in
> .IR flags :
> @@ -352,6 +370,21 @@ option.
> Because of the security implications,
> that option is normally enabled only on embedded devices
> (i.e., devices where one has complete control of the contents of user memory).
> +.TP
> +.BR MAP_SYNC " (since Linux 4.15)"
> +This flags is available only with
> +.B MAP_SHARED_VALIDATE
> +mapping type. Mappings of
> +.B MAP_SHARED
> +type will silently ignore this flag.
> +This flag is supported only for files supporting DAX (direct mapping of persistent
> +memory). For other files, creating mapping with this flag results in
> +.B EOPNOTSUPP
> +error. Shared file mappings with this flag provide the guarantee that while
> +some memory is writeably mapped in the address space of the process, it will
> +be visible in the same file at the same offset even after the system crashes or
> +is rebooted. This allows users of such mappings to make data modifications
> +persistent in a more efficient way using appropriate CPU instructions.
It feels like there's a word missing/unclear wording in the previous
line, before "using". Without that word, the sentence feels a bit
ambiguous.
Should it be:
persistent in a more efficient way *through the use of* appropriate
CPU instructions.
or:
persistent in a more efficient way *than using* appropriate CPU instructions.
?
Is suspect the first is correct, but need to check.
Cheers,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 13:00 ` Michael Kerrisk (man-pages)
0 siblings, 0 replies; 132+ messages in thread
From: Michael Kerrisk (man-pages) @ 2018-04-12 13:00 UTC (permalink / raw)
To: Jan Kara
Cc: Dan Williams, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, Linux-MM, Linux API, Ext4 Developers List, xfs,
Darrick J . Wong
Hello Jan,
I have applied your patch, and tweaked the text a little, and pushed
the result to the git repo.
On 1 November 2017 at 16:36, Jan Kara <jack@suse.cz> wrote:
> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> Signed-off-by: Jan Kara <jack@suse.cz>
I have a question below.
> ---
> man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/man2/mmap.2 b/man2/mmap.2
> index 47c3148653be..b38ee6809327 100644
> --- a/man2/mmap.2
> +++ b/man2/mmap.2
> @@ -125,6 +125,21 @@ are carried through to the underlying file.
> to the underlying file requires the use of
> .BR msync (2).)
> .TP
> +.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
> +The same as
> +.B MAP_SHARED
> +except that
> +.B MAP_SHARED
> +mappings ignore unknown flags in
> +.IR flags .
> +In contrast when creating mapping of
> +.B MAP_SHARED_VALIDATE
> +mapping type, the kernel verifies all passed flags are known and fails the
> +mapping with
> +.BR EOPNOTSUPP
> +otherwise. This mapping type is also required to be able to use some mapping
> +flags.
> +.TP
> .B MAP_PRIVATE
> Create a private copy-on-write mapping.
> Updates to the mapping are not visible to other processes
> @@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
> .BR mmap ()
> call are visible in the mapped region.
> .PP
> -Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
> +.B MAP_SHARED
> +and
> +.B MAP_PRIVATE
> +are described in POSIX.1-2001 and POSIX.1-2008.
> .PP
> In addition, zero or more of the following values can be ORed in
> .IR flags :
> @@ -352,6 +370,21 @@ option.
> Because of the security implications,
> that option is normally enabled only on embedded devices
> (i.e., devices where one has complete control of the contents of user memory).
> +.TP
> +.BR MAP_SYNC " (since Linux 4.15)"
> +This flags is available only with
> +.B MAP_SHARED_VALIDATE
> +mapping type. Mappings of
> +.B MAP_SHARED
> +type will silently ignore this flag.
> +This flag is supported only for files supporting DAX (direct mapping of persistent
> +memory). For other files, creating mapping with this flag results in
> +.B EOPNOTSUPP
> +error. Shared file mappings with this flag provide the guarantee that while
> +some memory is writeably mapped in the address space of the process, it will
> +be visible in the same file at the same offset even after the system crashes or
> +is rebooted. This allows users of such mappings to make data modifications
> +persistent in a more efficient way using appropriate CPU instructions.
It feels like there's a word missing/unclear wording in the previous
line, before "using". Without that word, the sentence feels a bit
ambiguous.
Should it be:
persistent in a more efficient way *through the use of* appropriate
CPU instructions.
or:
persistent in a more efficient way *than using* appropriate CPU instructions.
?
Is suspect the first is correct, but need to check.
Cheers,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 13:00 ` Michael Kerrisk (man-pages)
0 siblings, 0 replies; 132+ messages in thread
From: Michael Kerrisk (man-pages) @ 2018-04-12 13:00 UTC (permalink / raw)
To: Jan Kara
Cc: xfs, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw, Linux API,
Darrick J . Wong, Christoph Hellwig, Linux-MM,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Ext4 Developers List
Hello Jan,
I have applied your patch, and tweaked the text a little, and pushed
the result to the git repo.
On 1 November 2017 at 16:36, Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org> wrote:
> Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
I have a question below.
> ---
> man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/man2/mmap.2 b/man2/mmap.2
> index 47c3148653be..b38ee6809327 100644
> --- a/man2/mmap.2
> +++ b/man2/mmap.2
> @@ -125,6 +125,21 @@ are carried through to the underlying file.
> to the underlying file requires the use of
> .BR msync (2).)
> .TP
> +.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
> +The same as
> +.B MAP_SHARED
> +except that
> +.B MAP_SHARED
> +mappings ignore unknown flags in
> +.IR flags .
> +In contrast when creating mapping of
> +.B MAP_SHARED_VALIDATE
> +mapping type, the kernel verifies all passed flags are known and fails the
> +mapping with
> +.BR EOPNOTSUPP
> +otherwise. This mapping type is also required to be able to use some mapping
> +flags.
> +.TP
> .B MAP_PRIVATE
> Create a private copy-on-write mapping.
> Updates to the mapping are not visible to other processes
> @@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
> .BR mmap ()
> call are visible in the mapped region.
> .PP
> -Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
> +.B MAP_SHARED
> +and
> +.B MAP_PRIVATE
> +are described in POSIX.1-2001 and POSIX.1-2008.
> .PP
> In addition, zero or more of the following values can be ORed in
> .IR flags :
> @@ -352,6 +370,21 @@ option.
> Because of the security implications,
> that option is normally enabled only on embedded devices
> (i.e., devices where one has complete control of the contents of user memory).
> +.TP
> +.BR MAP_SYNC " (since Linux 4.15)"
> +This flags is available only with
> +.B MAP_SHARED_VALIDATE
> +mapping type. Mappings of
> +.B MAP_SHARED
> +type will silently ignore this flag.
> +This flag is supported only for files supporting DAX (direct mapping of persistent
> +memory). For other files, creating mapping with this flag results in
> +.B EOPNOTSUPP
> +error. Shared file mappings with this flag provide the guarantee that while
> +some memory is writeably mapped in the address space of the process, it will
> +be visible in the same file at the same offset even after the system crashes or
> +is rebooted. This allows users of such mappings to make data modifications
> +persistent in a more efficient way using appropriate CPU instructions.
It feels like there's a word missing/unclear wording in the previous
line, before "using". Without that word, the sentence feels a bit
ambiguous.
Should it be:
persistent in a more efficient way *through the use of* appropriate
CPU instructions.
or:
persistent in a more efficient way *than using* appropriate CPU instructions.
?
Is suspect the first is correct, but need to check.
Cheers,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 14:00 ` Ross Zwisler
0 siblings, 0 replies; 132+ messages in thread
From: Ross Zwisler @ 2018-04-12 14:00 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: Jan Kara, Dan Williams, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux-MM, Linux API,
Ext4 Developers List, xfs, Darrick J . Wong
On Thu, Apr 12, 2018 at 03:00:49PM +0200, Michael Kerrisk (man-pages) wrote:
> Hello Jan,
>
> I have applied your patch, and tweaked the text a little, and pushed
> the result to the git repo.
>
> On 1 November 2017 at 16:36, Jan Kara <jack@suse.cz> wrote:
> > Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> > Signed-off-by: Jan Kara <jack@suse.cz>
>
> I have a question below.
>
> > ---
> > man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
> > 1 file changed, 34 insertions(+), 1 deletion(-)
> >
> > diff --git a/man2/mmap.2 b/man2/mmap.2
> > index 47c3148653be..b38ee6809327 100644
> > --- a/man2/mmap.2
> > +++ b/man2/mmap.2
> > @@ -125,6 +125,21 @@ are carried through to the underlying file.
> > to the underlying file requires the use of
> > .BR msync (2).)
> > .TP
> > +.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
> > +The same as
> > +.B MAP_SHARED
> > +except that
> > +.B MAP_SHARED
> > +mappings ignore unknown flags in
> > +.IR flags .
> > +In contrast when creating mapping of
> > +.B MAP_SHARED_VALIDATE
> > +mapping type, the kernel verifies all passed flags are known and fails the
> > +mapping with
> > +.BR EOPNOTSUPP
> > +otherwise. This mapping type is also required to be able to use some mapping
> > +flags.
> > +.TP
> > .B MAP_PRIVATE
> > Create a private copy-on-write mapping.
> > Updates to the mapping are not visible to other processes
> > @@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
> > .BR mmap ()
> > call are visible in the mapped region.
> > .PP
> > -Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
> > +.B MAP_SHARED
> > +and
> > +.B MAP_PRIVATE
> > +are described in POSIX.1-2001 and POSIX.1-2008.
> > .PP
> > In addition, zero or more of the following values can be ORed in
> > .IR flags :
> > @@ -352,6 +370,21 @@ option.
> > Because of the security implications,
> > that option is normally enabled only on embedded devices
> > (i.e., devices where one has complete control of the contents of user memory).
> > +.TP
> > +.BR MAP_SYNC " (since Linux 4.15)"
> > +This flags is available only with
> > +.B MAP_SHARED_VALIDATE
> > +mapping type. Mappings of
> > +.B MAP_SHARED
> > +type will silently ignore this flag.
> > +This flag is supported only for files supporting DAX (direct mapping of persistent
> > +memory). For other files, creating mapping with this flag results in
> > +.B EOPNOTSUPP
> > +error. Shared file mappings with this flag provide the guarantee that while
> > +some memory is writeably mapped in the address space of the process, it will
> > +be visible in the same file at the same offset even after the system crashes or
> > +is rebooted. This allows users of such mappings to make data modifications
> > +persistent in a more efficient way using appropriate CPU instructions.
>
> It feels like there's a word missing/unclear wording in the previous
> line, before "using". Without that word, the sentence feels a bit
> ambiguous.
>
> Should it be:
>
> persistent in a more efficient way *through the use of* appropriate
> CPU instructions.
>
> or:
>
> persistent in a more efficient way *than using* appropriate CPU instructions.
>
> ?
>
> Is suspect the first is correct, but need to check.
You're right, the first one is correct.
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 14:00 ` Ross Zwisler
0 siblings, 0 replies; 132+ messages in thread
From: Ross Zwisler @ 2018-04-12 14:00 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: xfs, Jan Kara, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw, Linux API,
Darrick J . Wong, Christoph Hellwig, Linux-MM,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Ext4 Developers List
On Thu, Apr 12, 2018 at 03:00:49PM +0200, Michael Kerrisk (man-pages) wrote:
> Hello Jan,
>
> I have applied your patch, and tweaked the text a little, and pushed
> the result to the git repo.
>
> On 1 November 2017 at 16:36, Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org> wrote:
> > Reviewed-by: Ross Zwisler <ross.zwisler-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> > Signed-off-by: Jan Kara <jack-AlSwsSmVLrQ@public.gmane.org>
>
> I have a question below.
>
> > ---
> > man2/mmap.2 | 35 ++++++++++++++++++++++++++++++++++-
> > 1 file changed, 34 insertions(+), 1 deletion(-)
> >
> > diff --git a/man2/mmap.2 b/man2/mmap.2
> > index 47c3148653be..b38ee6809327 100644
> > --- a/man2/mmap.2
> > +++ b/man2/mmap.2
> > @@ -125,6 +125,21 @@ are carried through to the underlying file.
> > to the underlying file requires the use of
> > .BR msync (2).)
> > .TP
> > +.BR MAP_SHARED_VALIDATE " (since Linux 4.15)"
> > +The same as
> > +.B MAP_SHARED
> > +except that
> > +.B MAP_SHARED
> > +mappings ignore unknown flags in
> > +.IR flags .
> > +In contrast when creating mapping of
> > +.B MAP_SHARED_VALIDATE
> > +mapping type, the kernel verifies all passed flags are known and fails the
> > +mapping with
> > +.BR EOPNOTSUPP
> > +otherwise. This mapping type is also required to be able to use some mapping
> > +flags.
> > +.TP
> > .B MAP_PRIVATE
> > Create a private copy-on-write mapping.
> > Updates to the mapping are not visible to other processes
> > @@ -134,7 +149,10 @@ It is unspecified whether changes made to the file after the
> > .BR mmap ()
> > call are visible in the mapped region.
> > .PP
> > -Both of these flags are described in POSIX.1-2001 and POSIX.1-2008.
> > +.B MAP_SHARED
> > +and
> > +.B MAP_PRIVATE
> > +are described in POSIX.1-2001 and POSIX.1-2008.
> > .PP
> > In addition, zero or more of the following values can be ORed in
> > .IR flags :
> > @@ -352,6 +370,21 @@ option.
> > Because of the security implications,
> > that option is normally enabled only on embedded devices
> > (i.e., devices where one has complete control of the contents of user memory).
> > +.TP
> > +.BR MAP_SYNC " (since Linux 4.15)"
> > +This flags is available only with
> > +.B MAP_SHARED_VALIDATE
> > +mapping type. Mappings of
> > +.B MAP_SHARED
> > +type will silently ignore this flag.
> > +This flag is supported only for files supporting DAX (direct mapping of persistent
> > +memory). For other files, creating mapping with this flag results in
> > +.B EOPNOTSUPP
> > +error. Shared file mappings with this flag provide the guarantee that while
> > +some memory is writeably mapped in the address space of the process, it will
> > +be visible in the same file at the same offset even after the system crashes or
> > +is rebooted. This allows users of such mappings to make data modifications
> > +persistent in a more efficient way using appropriate CPU instructions.
>
> It feels like there's a word missing/unclear wording in the previous
> line, before "using". Without that word, the sentence feels a bit
> ambiguous.
>
> Should it be:
>
> persistent in a more efficient way *through the use of* appropriate
> CPU instructions.
>
> or:
>
> persistent in a more efficient way *than using* appropriate CPU instructions.
>
> ?
>
> Is suspect the first is correct, but need to check.
You're right, the first one is correct.
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
2018-04-12 13:00 ` Michael Kerrisk (man-pages)
(?)
@ 2018-04-12 14:22 ` Jan Kara
-1 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2018-04-12 14:22 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: xfs, Jan Kara, linux-nvdimm, Linux API, Darrick J . Wong,
Christoph Hellwig, Linux-MM, linux-fsdevel, Ext4 Developers List
Hello Michael!
On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
> Hello Jan,
>
> I have applied your patch, and tweaked the text a little, and pushed
> the result to the git repo.
Thanks!
> > +.B MAP_SHARED
> > +type will silently ignore this flag.
> > +This flag is supported only for files supporting DAX (direct mapping of persistent
> > +memory). For other files, creating mapping with this flag results in
> > +.B EOPNOTSUPP
> > +error. Shared file mappings with this flag provide the guarantee that while
> > +some memory is writeably mapped in the address space of the process, it will
> > +be visible in the same file at the same offset even after the system crashes or
> > +is rebooted. This allows users of such mappings to make data modifications
> > +persistent in a more efficient way using appropriate CPU instructions.
>
> It feels like there's a word missing/unclear wording in the previous
> line, before "using". Without that word, the sentence feels a bit
> ambiguous.
>
> Should it be:
>
> persistent in a more efficient way *through the use of* appropriate
> CPU instructions.
>
> or:
>
> persistent in a more efficient way *than using* appropriate CPU instructions.
>
> ?
>
> Is suspect the first is correct, but need to check.
Yes, the first is correct.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 14:22 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2018-04-12 14:22 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: Jan Kara, Dan Williams, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux-MM, Linux API,
Ext4 Developers List, xfs, Darrick J . Wong
Hello Michael!
On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
> Hello Jan,
>
> I have applied your patch, and tweaked the text a little, and pushed
> the result to the git repo.
Thanks!
> > +.B MAP_SHARED
> > +type will silently ignore this flag.
> > +This flag is supported only for files supporting DAX (direct mapping of persistent
> > +memory). For other files, creating mapping with this flag results in
> > +.B EOPNOTSUPP
> > +error. Shared file mappings with this flag provide the guarantee that while
> > +some memory is writeably mapped in the address space of the process, it will
> > +be visible in the same file at the same offset even after the system crashes or
> > +is rebooted. This allows users of such mappings to make data modifications
> > +persistent in a more efficient way using appropriate CPU instructions.
>
> It feels like there's a word missing/unclear wording in the previous
> line, before "using". Without that word, the sentence feels a bit
> ambiguous.
>
> Should it be:
>
> persistent in a more efficient way *through the use of* appropriate
> CPU instructions.
>
> or:
>
> persistent in a more efficient way *than using* appropriate CPU instructions.
>
> ?
>
> Is suspect the first is correct, but need to check.
Yes, the first is correct.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 14:22 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2018-04-12 14:22 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: xfs, Jan Kara, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw, Linux API,
Darrick J . Wong, Christoph Hellwig, Linux-MM,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Ext4 Developers List
Hello Michael!
On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
> Hello Jan,
>
> I have applied your patch, and tweaked the text a little, and pushed
> the result to the git repo.
Thanks!
> > +.B MAP_SHARED
> > +type will silently ignore this flag.
> > +This flag is supported only for files supporting DAX (direct mapping of persistent
> > +memory). For other files, creating mapping with this flag results in
> > +.B EOPNOTSUPP
> > +error. Shared file mappings with this flag provide the guarantee that while
> > +some memory is writeably mapped in the address space of the process, it will
> > +be visible in the same file at the same offset even after the system crashes or
> > +is rebooted. This allows users of such mappings to make data modifications
> > +persistent in a more efficient way using appropriate CPU instructions.
>
> It feels like there's a word missing/unclear wording in the previous
> line, before "using". Without that word, the sentence feels a bit
> ambiguous.
>
> Should it be:
>
> persistent in a more efficient way *through the use of* appropriate
> CPU instructions.
>
> or:
>
> persistent in a more efficient way *than using* appropriate CPU instructions.
>
> ?
>
> Is suspect the first is correct, but need to check.
Yes, the first is correct.
Honza
--
Jan Kara <jack-IBi9RG/b67k@public.gmane.org>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
2018-04-12 14:22 ` Jan Kara
(?)
@ 2018-04-12 18:20 ` Michael Kerrisk (man-pages)
-1 siblings, 0 replies; 132+ messages in thread
From: Michael Kerrisk (man-pages) @ 2018-04-12 18:20 UTC (permalink / raw)
To: Jan Kara
Cc: xfs, linux-nvdimm, Linux API, Darrick J . Wong,
Christoph Hellwig, Linux-MM, linux-fsdevel, Ext4 Developers List
Jan, Ross.
On 12 April 2018 at 16:22, Jan Kara <jack@suse.cz> wrote:
> Hello Michael!
>
> On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
>> Hello Jan,
>>
>> I have applied your patch, and tweaked the text a little, and pushed
>> the result to the git repo.
>
> Thanks!
>
>> > +.B MAP_SHARED
>> > +type will silently ignore this flag.
>> > +This flag is supported only for files supporting DAX (direct mapping of persistent
>> > +memory). For other files, creating mapping with this flag results in
>> > +.B EOPNOTSUPP
>> > +error. Shared file mappings with this flag provide the guarantee that while
>> > +some memory is writeably mapped in the address space of the process, it will
>> > +be visible in the same file at the same offset even after the system crashes or
>> > +is rebooted. This allows users of such mappings to make data modifications
>> > +persistent in a more efficient way using appropriate CPU instructions.
>>
>> It feels like there's a word missing/unclear wording in the previous
>> line, before "using". Without that word, the sentence feels a bit
>> ambiguous.
>>
>> Should it be:
>>
>> persistent in a more efficient way *through the use of* appropriate
>> CPU instructions.
>>
>> or:
>>
>> persistent in a more efficient way *than using* appropriate CPU instructions.
>>
>> ?
>>
>> Is suspect the first is correct, but need to check.
>
> Yes, the first is correct.
Thanks for both checking that phrasing. In the end I decided to reword
the sentence a bot more substantially:
In conjunction with the use of appropriate CPU
instructions, this provides users of such mappings
with a more efficient way of making data modifica‐
tions persistent.
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 18:20 ` Michael Kerrisk (man-pages)
0 siblings, 0 replies; 132+ messages in thread
From: Michael Kerrisk (man-pages) @ 2018-04-12 18:20 UTC (permalink / raw)
To: Jan Kara
Cc: Dan Williams, Ross Zwisler, Christoph Hellwig, linux-fsdevel,
linux-nvdimm, Linux-MM, Linux API, Ext4 Developers List, xfs,
Darrick J . Wong
Jan, Ross.
On 12 April 2018 at 16:22, Jan Kara <jack@suse.cz> wrote:
> Hello Michael!
>
> On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
>> Hello Jan,
>>
>> I have applied your patch, and tweaked the text a little, and pushed
>> the result to the git repo.
>
> Thanks!
>
>> > +.B MAP_SHARED
>> > +type will silently ignore this flag.
>> > +This flag is supported only for files supporting DAX (direct mapping of persistent
>> > +memory). For other files, creating mapping with this flag results in
>> > +.B EOPNOTSUPP
>> > +error. Shared file mappings with this flag provide the guarantee that while
>> > +some memory is writeably mapped in the address space of the process, it will
>> > +be visible in the same file at the same offset even after the system crashes or
>> > +is rebooted. This allows users of such mappings to make data modifications
>> > +persistent in a more efficient way using appropriate CPU instructions.
>>
>> It feels like there's a word missing/unclear wording in the previous
>> line, before "using". Without that word, the sentence feels a bit
>> ambiguous.
>>
>> Should it be:
>>
>> persistent in a more efficient way *through the use of* appropriate
>> CPU instructions.
>>
>> or:
>>
>> persistent in a more efficient way *than using* appropriate CPU instructions.
>>
>> ?
>>
>> Is suspect the first is correct, but need to check.
>
> Yes, the first is correct.
Thanks for both checking that phrasing. In the end I decided to reword
the sentence a bot more substantially:
In conjunction with the use of appropriate CPU
instructions, this provides users of such mappings
with a more efficient way of making data modifica‐
tions persistent.
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-12 18:20 ` Michael Kerrisk (man-pages)
0 siblings, 0 replies; 132+ messages in thread
From: Michael Kerrisk (man-pages) @ 2018-04-12 18:20 UTC (permalink / raw)
To: Jan Kara
Cc: xfs, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw, Linux API,
Darrick J . Wong, Christoph Hellwig, Linux-MM,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Ext4 Developers List
Jan, Ross.
On 12 April 2018 at 16:22, Jan Kara <jack@suse.cz> wrote:
> Hello Michael!
>
> On Thu 12-04-18 15:00:49, Michael Kerrisk (man-pages) wrote:
>> Hello Jan,
>>
>> I have applied your patch, and tweaked the text a little, and pushed
>> the result to the git repo.
>
> Thanks!
>
>> > +.B MAP_SHARED
>> > +type will silently ignore this flag.
>> > +This flag is supported only for files supporting DAX (direct mapping of persistent
>> > +memory). For other files, creating mapping with this flag results in
>> > +.B EOPNOTSUPP
>> > +error. Shared file mappings with this flag provide the guarantee that while
>> > +some memory is writeably mapped in the address space of the process, it will
>> > +be visible in the same file at the same offset even after the system crashes or
>> > +is rebooted. This allows users of such mappings to make data modifications
>> > +persistent in a more efficient way using appropriate CPU instructions.
>>
>> It feels like there's a word missing/unclear wording in the previous
>> line, before "using". Without that word, the sentence feels a bit
>> ambiguous.
>>
>> Should it be:
>>
>> persistent in a more efficient way *through the use of* appropriate
>> CPU instructions.
>>
>> or:
>>
>> persistent in a more efficient way *than using* appropriate CPU instructions.
>>
>> ?
>>
>> Is suspect the first is correct, but need to check.
>
> Yes, the first is correct.
Thanks for both checking that phrasing. In the end I decided to reword
the sentence a bot more substantially:
In conjunction with the use of appropriate CPU
instructions, this provides users of such mappings
with a more efficient way of making data modifica‐
tions persistent.
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-13 11:17 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2018-04-13 11:17 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: Jan Kara, Dan Williams, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux-MM, Linux API,
Ext4 Developers List, xfs, Darrick J . Wong
On Thu 12-04-18 20:20:12, Michael Kerrisk (man-pages) wrote:
>
> Thanks for both checking that phrasing. In the end I decided to reword
> the sentence a bot more substantially:
>
> In conjunction with the use of appropriate CPU
> instructions, this provides users of such mappings
> with a more efficient way of making data modifica‐
> tions persistent.
Great, thanks for the improvement!
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-13 11:17 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2018-04-13 11:17 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: xfs, Jan Kara, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw, Linux API,
Darrick J . Wong, Christoph Hellwig, Linux-MM,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Ext4 Developers List
On Thu 12-04-18 20:20:12, Michael Kerrisk (man-pages) wrote:
>
> Thanks for both checking that phrasing. In the end I decided to reword
> the sentence a bot more substantially:
>
> In conjunction with the use of appropriate CPU
> instructions, this provides users of such mappings
> with a more efficient way of making data modifica‐
> tions persistent.
Great, thanks for the improvement!
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
^ permalink raw reply [flat|nested] 132+ messages in thread
* Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC
@ 2018-04-13 11:17 ` Jan Kara
0 siblings, 0 replies; 132+ messages in thread
From: Jan Kara @ 2018-04-13 11:17 UTC (permalink / raw)
To: Michael Kerrisk (man-pages)
Cc: Jan Kara, Dan Williams, Ross Zwisler, Christoph Hellwig,
linux-fsdevel, linux-nvdimm, Linux-MM, Linux API,
Ext4 Developers List, xfs, Darrick J . Wong
On Thu 12-04-18 20:20:12, Michael Kerrisk (man-pages) wrote:
>
> Thanks for both checking that phrasing. In the end I decided to reword
> the sentence a bot more substantially:
>
> In conjunction with the use of appropriate CPU
> instructions, this provides users of such mappings
> with a more efficient way of making data modificaa??
> tions persistent.
Great, thanks for the improvement!
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 132+ messages in thread
end of thread, other threads:[~2018-04-13 11:17 UTC | newest]
Thread overview: 132+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-11-01 15:36 [PATCH 0/18 v6] dax, ext4, xfs: Synchronous page faults Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 01/18] mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap flags Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-22 12:02 ` Vlastimil Babka
2017-11-22 12:02 ` Vlastimil Babka
2017-11-22 12:02 ` Vlastimil Babka
2017-11-22 12:02 ` Vlastimil Babka
2017-11-22 16:52 ` Dan Williams
2017-11-22 16:52 ` Dan Williams
2017-11-22 16:52 ` Dan Williams
2017-11-22 19:53 ` Matthew Wilcox
2017-11-22 19:53 ` Matthew Wilcox
2017-11-22 19:53 ` Matthew Wilcox
2017-11-22 19:53 ` Matthew Wilcox
2017-11-25 18:45 ` Helge Deller
2017-11-25 18:45 ` Helge Deller
2017-11-27 15:55 ` Vlastimil Babka
2017-11-27 15:55 ` Vlastimil Babka
2017-11-01 15:36 ` [PATCH 02/18] mm: Remove VM_FAULT_HWPOISON_LARGE_MASK Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 03/18] dax: Simplify arguments of dax_insert_mapping() Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 04/18] dax: Factor out getting of pfn out of iomap Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 05/18] dax: Create local variable for VMA in dax_iomap_pte_fault() Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 06/18] dax: Create local variable for vmf->flags & FAULT_FLAG_WRITE test Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 07/18] dax: Inline dax_insert_mapping() into the callsite Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 08/18] dax: Inline dax_pmd_insert_mapping() " Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 09/18] dax: Fix comment describing dax_iomap_fault() Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 10/18] dax: Allow dax_iomap_fault() to return pfn Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 11/18] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 12/18] mm: Define MAP_SYNC and VM_SYNC flags Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 13/18] dax, iomap: Add support for synchronous faults Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 14/18] dax: Implement dax_finish_sync_fault() Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 15/18] ext4: Simplify error handling in ext4_dax_huge_fault() Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 16/18] ext4: Support for synchronous DAX faults Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` [PATCH 17/18] xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault() Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-14 2:19 ` Darrick J. Wong
2017-11-14 2:19 ` Darrick J. Wong
2017-11-14 2:19 ` Darrick J. Wong
2017-11-14 2:19 ` Darrick J. Wong
2017-11-01 15:36 ` [PATCH 18/18] xfs: support for synchronous DAX faults Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-14 2:19 ` Darrick J. Wong
2017-11-14 2:19 ` Darrick J. Wong
2017-11-01 15:36 ` [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2017-11-01 15:36 ` Jan Kara
2018-04-12 13:00 ` Michael Kerrisk (man-pages)
2018-04-12 13:00 ` Michael Kerrisk (man-pages)
2018-04-12 13:00 ` Michael Kerrisk (man-pages)
2018-04-12 14:00 ` Ross Zwisler
2018-04-12 14:00 ` Ross Zwisler
2018-04-12 14:22 ` Jan Kara
2018-04-12 14:22 ` Jan Kara
2018-04-12 14:22 ` Jan Kara
2018-04-12 18:20 ` Michael Kerrisk (man-pages)
2018-04-12 18:20 ` Michael Kerrisk (man-pages)
2018-04-12 18:20 ` Michael Kerrisk (man-pages)
2018-04-13 11:17 ` Jan Kara
2018-04-13 11:17 ` Jan Kara
2018-04-13 11:17 ` Jan Kara
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