* [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
@ 2016-12-23 9:30 Chandan Rajendra
2016-12-23 10:27 ` Chandan Rajendra
2017-01-06 11:45 ` Filipe Manana
0 siblings, 2 replies; 8+ messages in thread
From: Chandan Rajendra @ 2016-12-23 9:30 UTC (permalink / raw)
To: linux-btrfs; +Cc: Chandan Rajendra, fdmanana, dsterba
The following deadlock is seen when executing generic/113 test,
---------------------------------------------------------+----------------------------------------------------
Direct I/O task Fast fsync task
---------------------------------------------------------+----------------------------------------------------
btrfs_direct_IO
__blockdev_direct_IO
do_blockdev_direct_IO
do_direct_IO
btrfs_get_blocks_direct
while (blocks needs to written)
get_more_blocks (first iteration)
btrfs_get_blocks_direct
btrfs_create_dio_extent
down_read(&BTRFS_I(inode) >dio_sem)
Create and add extent map and ordered extent
up_read(&BTRFS_I(inode) >dio_sem)
btrfs_sync_file
btrfs_log_dentry_safe
btrfs_log_inode_parent
btrfs_log_inode
btrfs_log_changed_extents
down_write(&BTRFS_I(inode) >dio_sem)
Collect new extent maps and ordered extents
wait for ordered extent completion
get_more_blocks (second iteration)
btrfs_get_blocks_direct
btrfs_create_dio_extent
down_read(&BTRFS_I(inode) >dio_sem)
--------------------------------------------------------------------------------------------------------------
In the above description, Btrfs direct I/O code path has not yet started
submitting bios for file range covered by the initial ordered
extent. Meanwhile, The fast fsync task obtains the write semaphore and
waits for I/O on the ordered extent to get completed. However, the
Direct I/O task is now blocked on obtaining the read semaphore.
To resolve the deadlock, this commit modifies the Direct I/O code path
to obtain the read semaphore before invoking
__blockdev_direct_IO(). The semaphore is then given up after
__blockdev_direct_IO() returns. This allows the Direct I/O code to
complete I/O on all the ordered extents it creates.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
---
fs/btrfs/inode.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5ca88f0..f796037 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7325,7 +7325,6 @@ static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
struct extent_map *em = NULL;
int ret;
- down_read(&BTRFS_I(inode)->dio_sem);
if (type != BTRFS_ORDERED_NOCOW) {
em = create_pinned_em(inode, start, len, orig_start,
block_start, block_len, orig_block_len,
@@ -7344,7 +7343,6 @@ static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
em = ERR_PTR(ret);
}
out:
- up_read(&BTRFS_I(inode)->dio_sem);
return em;
}
@@ -8800,6 +8798,7 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
dio_data.unsubmitted_oe_range_start = (u64)offset;
dio_data.unsubmitted_oe_range_end = (u64)offset;
current->journal_info = &dio_data;
+ down_read(&BTRFS_I(inode)->dio_sem);
} else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
&BTRFS_I(inode)->runtime_flags)) {
inode_dio_end(inode);
@@ -8812,6 +8811,7 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
iter, btrfs_get_blocks_direct, NULL,
btrfs_submit_direct, flags);
if (iov_iter_rw(iter) == WRITE) {
+ up_read(&BTRFS_I(inode)->dio_sem);
current->journal_info = NULL;
if (ret < 0 && ret != -EIOCBQUEUED) {
if (dio_data.reserve)
--
2.5.5
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2016-12-23 9:30 [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync Chandan Rajendra
@ 2016-12-23 10:27 ` Chandan Rajendra
2016-12-23 11:57 ` Chandan Rajendra
2017-01-06 11:45 ` Filipe Manana
1 sibling, 1 reply; 8+ messages in thread
From: Chandan Rajendra @ 2016-12-23 10:27 UTC (permalink / raw)
To: linux-btrfs; +Cc: fdmanana, dsterba
On Friday, December 23, 2016 03:00:18 PM Chandan Rajendra wrote:
> The following deadlock is seen when executing generic/113 test,
>
> ---------------------------------------------------------+----------------------------------------------------
> Direct I/O task Fast fsync task
> ---------------------------------------------------------+----------------------------------------------------
> btrfs_direct_IO
> __blockdev_direct_IO
> do_blockdev_direct_IO
> do_direct_IO
> btrfs_get_blocks_direct
> while (blocks needs to written)
> get_more_blocks (first iteration)
> btrfs_get_blocks_direct
> btrfs_create_dio_extent
> down_read(&BTRFS_I(inode) >dio_sem)
> Create and add extent map and ordered extent
> up_read(&BTRFS_I(inode) >dio_sem)
> btrfs_sync_file
> btrfs_log_dentry_safe
> btrfs_log_inode_parent
> btrfs_log_inode
> btrfs_log_changed_extents
> down_write(&BTRFS_I(inode) >dio_sem)
> Collect new extent maps and ordered extents
> wait for ordered extent completion
> get_more_blocks (second iteration)
> btrfs_get_blocks_direct
> btrfs_create_dio_extent
> down_read(&BTRFS_I(inode) >dio_sem)
> --------------------------------------------------------------------------------------------------------------
>
> In the above description, Btrfs direct I/O code path has not yet started
> submitting bios for file range covered by the initial ordered
> extent. Meanwhile, The fast fsync task obtains the write semaphore and
> waits for I/O on the ordered extent to get completed. However, the
> Direct I/O task is now blocked on obtaining the read semaphore.
>
> To resolve the deadlock, this commit modifies the Direct I/O code path
> to obtain the read semaphore before invoking
> __blockdev_direct_IO(). The semaphore is then given up after
> __blockdev_direct_IO() returns. This allows the Direct I/O code to
> complete I/O on all the ordered extents it creates.
>
Btw, I was able to reproduce the issue on kdave/for-next branch with "Merge
branch 'for-next-next-4.9-20161125' into for-next-20161125" as the topmost
commit. The issue cannot be reproduced yet on latest code available from
kdave/for-next branch.
--
chandan
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2016-12-23 10:27 ` Chandan Rajendra
@ 2016-12-23 11:57 ` Chandan Rajendra
2016-12-24 0:18 ` Liu Bo
0 siblings, 1 reply; 8+ messages in thread
From: Chandan Rajendra @ 2016-12-23 11:57 UTC (permalink / raw)
To: linux-btrfs; +Cc: fdmanana, dsterba
On Friday, December 23, 2016 03:57:40 PM Chandan Rajendra wrote:
> On Friday, December 23, 2016 03:00:18 PM Chandan Rajendra wrote:
> > The following deadlock is seen when executing generic/113 test,
> >
> > ---------------------------------------------------------+----------------------------------------------------
> > Direct I/O task Fast fsync task
> > ---------------------------------------------------------+----------------------------------------------------
> > btrfs_direct_IO
> > __blockdev_direct_IO
> > do_blockdev_direct_IO
> > do_direct_IO
> > btrfs_get_blocks_direct
> > while (blocks needs to written)
> > get_more_blocks (first iteration)
> > btrfs_get_blocks_direct
> > btrfs_create_dio_extent
> > down_read(&BTRFS_I(inode) >dio_sem)
> > Create and add extent map and ordered extent
> > up_read(&BTRFS_I(inode) >dio_sem)
> > btrfs_sync_file
> > btrfs_log_dentry_safe
> > btrfs_log_inode_parent
> > btrfs_log_inode
> > btrfs_log_changed_extents
> > down_write(&BTRFS_I(inode) >dio_sem)
> > Collect new extent maps and ordered extents
> > wait for ordered extent completion
> > get_more_blocks (second iteration)
> > btrfs_get_blocks_direct
> > btrfs_create_dio_extent
> > down_read(&BTRFS_I(inode) >dio_sem)
> > --------------------------------------------------------------------------------------------------------------
> >
> > In the above description, Btrfs direct I/O code path has not yet started
> > submitting bios for file range covered by the initial ordered
> > extent. Meanwhile, The fast fsync task obtains the write semaphore and
> > waits for I/O on the ordered extent to get completed. However, the
> > Direct I/O task is now blocked on obtaining the read semaphore.
> >
> > To resolve the deadlock, this commit modifies the Direct I/O code path
> > to obtain the read semaphore before invoking
> > __blockdev_direct_IO(). The semaphore is then given up after
> > __blockdev_direct_IO() returns. This allows the Direct I/O code to
> > complete I/O on all the ordered extents it creates.
> >
>
> Btw, I was able to reproduce the issue on kdave/for-next branch with "Merge
> branch 'for-next-next-4.9-20161125' into for-next-20161125" as the topmost
> commit. The issue cannot be reproduced yet on latest code available from
> kdave/for-next branch.
>
>
Maybe changes in upstream might have masked the issue in the recent
kdave/for-next branch. I say that because 'git bisect' resulted in the
following commit ...
e3597e6090ddf40904dce6d0a5a404e2c490cac6
Author: Chris Mason <clm@fb.com>
AuthorDate: Tue Nov 1 12:54:45 2016 -0700
Commit: Chris Mason <clm@fb.com>
CommitDate: Tue Nov 1 12:54:45 2016 -0700
Parent: 570dd45 btrfs: fix races on root_log_ctx lists
Parent: 9d1032c btrfs: fix WARNING in btrfs_select_ref_head()
Merged: btrfs-next-for-linus-4.8 kdave-master linus-v4.7-rc6 local-v4.7-rc4
Containing: direct-io-fsync-deadlock kdave-for-next
Follows: v4.8-rc8 (57)
Precedes: next-20161219 (30006)
Merge branch 'for-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.9
5 files changed, 29 insertions(+), 9 deletions(-)
fs/btrfs/extent-tree.c | 3 +++
fs/btrfs/extent_io.c | 8 ++++----
fs/btrfs/inode.c | 13 +++++++++----
fs/btrfs/ioctl.c | 5 +++++
fs/btrfs/relocation.c | 9 ++++++++-
--
chandan
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2016-12-23 11:57 ` Chandan Rajendra
@ 2016-12-24 0:18 ` Liu Bo
2016-12-24 3:27 ` Chandan Rajendra
2017-01-02 14:29 ` David Sterba
0 siblings, 2 replies; 8+ messages in thread
From: Liu Bo @ 2016-12-24 0:18 UTC (permalink / raw)
To: Chandan Rajendra; +Cc: linux-btrfs, fdmanana, dsterba
On Fri, Dec 23, 2016 at 05:27:55PM +0530, Chandan Rajendra wrote:
> On Friday, December 23, 2016 03:57:40 PM Chandan Rajendra wrote:
> > On Friday, December 23, 2016 03:00:18 PM Chandan Rajendra wrote:
> > > The following deadlock is seen when executing generic/113 test,
> > >
> > > ---------------------------------------------------------+----------------------------------------------------
> > > Direct I/O task Fast fsync task
> > > ---------------------------------------------------------+----------------------------------------------------
> > > btrfs_direct_IO
> > > __blockdev_direct_IO
> > > do_blockdev_direct_IO
> > > do_direct_IO
> > > btrfs_get_blocks_direct
> > > while (blocks needs to written)
> > > get_more_blocks (first iteration)
> > > btrfs_get_blocks_direct
> > > btrfs_create_dio_extent
> > > down_read(&BTRFS_I(inode) >dio_sem)
> > > Create and add extent map and ordered extent
> > > up_read(&BTRFS_I(inode) >dio_sem)
> > > btrfs_sync_file
> > > btrfs_log_dentry_safe
> > > btrfs_log_inode_parent
> > > btrfs_log_inode
> > > btrfs_log_changed_extents
> > > down_write(&BTRFS_I(inode) >dio_sem)
> > > Collect new extent maps and ordered extents
> > > wait for ordered extent completion
> > > get_more_blocks (second iteration)
> > > btrfs_get_blocks_direct
> > > btrfs_create_dio_extent
> > > down_read(&BTRFS_I(inode) >dio_sem)
> > > --------------------------------------------------------------------------------------------------------------
> > >
> > > In the above description, Btrfs direct I/O code path has not yet started
> > > submitting bios for file range covered by the initial ordered
> > > extent. Meanwhile, The fast fsync task obtains the write semaphore and
> > > waits for I/O on the ordered extent to get completed. However, the
> > > Direct I/O task is now blocked on obtaining the read semaphore.
> > >
> > > To resolve the deadlock, this commit modifies the Direct I/O code path
> > > to obtain the read semaphore before invoking
> > > __blockdev_direct_IO(). The semaphore is then given up after
> > > __blockdev_direct_IO() returns. This allows the Direct I/O code to
> > > complete I/O on all the ordered extents it creates.
> > >
> >
> > Btw, I was able to reproduce the issue on kdave/for-next branch with "Merge
> > branch 'for-next-next-4.9-20161125' into for-next-20161125" as the topmost
> > commit. The issue cannot be reproduced yet on latest code available from
> > kdave/for-next branch.
> >
> >
>
> Maybe changes in upstream might have masked the issue in the recent
> kdave/for-next branch. I say that because 'git bisect' resulted in the
> following commit ...
I guess that the for-next branch didn't revert this patch[1] as upstream
did, so that generic/113 would complain, however, even w/o that patch,
this fix is still required since the deadlock could be reproduced by
running generic/113 with '-ofragment=data' and in fact Filipe has
proposed a almost same fix but not a real patch in this thread [2].
[1]: Btrfs: adjust len of writes if following a preallocated extent
https://patchwork.kernel.org/patch/9413129/
[2]: https://patchwork.kernel.org/patch/9445231/
Thanks,
-liubo
>
> e3597e6090ddf40904dce6d0a5a404e2c490cac6
> Author: Chris Mason <clm@fb.com>
> AuthorDate: Tue Nov 1 12:54:45 2016 -0700
> Commit: Chris Mason <clm@fb.com>
> CommitDate: Tue Nov 1 12:54:45 2016 -0700
>
> Parent: 570dd45 btrfs: fix races on root_log_ctx lists
> Parent: 9d1032c btrfs: fix WARNING in btrfs_select_ref_head()
> Merged: btrfs-next-for-linus-4.8 kdave-master linus-v4.7-rc6 local-v4.7-rc4
> Containing: direct-io-fsync-deadlock kdave-for-next
> Follows: v4.8-rc8 (57)
> Precedes: next-20161219 (30006)
>
> Merge branch 'for-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.9
>
> 5 files changed, 29 insertions(+), 9 deletions(-)
> fs/btrfs/extent-tree.c | 3 +++
> fs/btrfs/extent_io.c | 8 ++++----
> fs/btrfs/inode.c | 13 +++++++++----
> fs/btrfs/ioctl.c | 5 +++++
> fs/btrfs/relocation.c | 9 ++++++++-
>
> --
> chandan
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" 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] 8+ messages in thread
* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2016-12-24 0:18 ` Liu Bo
@ 2016-12-24 3:27 ` Chandan Rajendra
2017-01-02 14:29 ` David Sterba
1 sibling, 0 replies; 8+ messages in thread
From: Chandan Rajendra @ 2016-12-24 3:27 UTC (permalink / raw)
To: bo.li.liu; +Cc: linux-btrfs, fdmanana, dsterba
On Friday, December 23, 2016 04:18:00 PM Liu Bo wrote:
> On Fri, Dec 23, 2016 at 05:27:55PM +0530, Chandan Rajendra wrote:
> > On Friday, December 23, 2016 03:57:40 PM Chandan Rajendra wrote:
> > > On Friday, December 23, 2016 03:00:18 PM Chandan Rajendra wrote:
> > > > The following deadlock is seen when executing generic/113 test,
> > > >
> > > > ---------------------------------------------------------+----------------------------------------------------
> > > > Direct I/O task Fast fsync task
> > > > ---------------------------------------------------------+----------------------------------------------------
> > > > btrfs_direct_IO
> > > > __blockdev_direct_IO
> > > > do_blockdev_direct_IO
> > > > do_direct_IO
> > > > btrfs_get_blocks_direct
> > > > while (blocks needs to written)
> > > > get_more_blocks (first iteration)
> > > > btrfs_get_blocks_direct
> > > > btrfs_create_dio_extent
> > > > down_read(&BTRFS_I(inode) >dio_sem)
> > > > Create and add extent map and ordered extent
> > > > up_read(&BTRFS_I(inode) >dio_sem)
> > > > btrfs_sync_file
> > > > btrfs_log_dentry_safe
> > > > btrfs_log_inode_parent
> > > > btrfs_log_inode
> > > > btrfs_log_changed_extents
> > > > down_write(&BTRFS_I(inode) >dio_sem)
> > > > Collect new extent maps and ordered extents
> > > > wait for ordered extent completion
> > > > get_more_blocks (second iteration)
> > > > btrfs_get_blocks_direct
> > > > btrfs_create_dio_extent
> > > > down_read(&BTRFS_I(inode) >dio_sem)
> > > > --------------------------------------------------------------------------------------------------------------
> > > >
> > > > In the above description, Btrfs direct I/O code path has not yet started
> > > > submitting bios for file range covered by the initial ordered
> > > > extent. Meanwhile, The fast fsync task obtains the write semaphore and
> > > > waits for I/O on the ordered extent to get completed. However, the
> > > > Direct I/O task is now blocked on obtaining the read semaphore.
> > > >
> > > > To resolve the deadlock, this commit modifies the Direct I/O code path
> > > > to obtain the read semaphore before invoking
> > > > __blockdev_direct_IO(). The semaphore is then given up after
> > > > __blockdev_direct_IO() returns. This allows the Direct I/O code to
> > > > complete I/O on all the ordered extents it creates.
> > > >
> > >
> > > Btw, I was able to reproduce the issue on kdave/for-next branch with "Merge
> > > branch 'for-next-next-4.9-20161125' into for-next-20161125" as the topmost
> > > commit. The issue cannot be reproduced yet on latest code available from
> > > kdave/for-next branch.
> > >
> > >
> >
> > Maybe changes in upstream might have masked the issue in the recent
> > kdave/for-next branch. I say that because 'git bisect' resulted in the
> > following commit ...
>
> I guess that the for-next branch didn't revert this patch[1] as upstream
> did, so that generic/113 would complain, however, even w/o that patch,
> this fix is still required since the deadlock could be reproduced by
> running generic/113 with '-ofragment=data' and in fact Filipe has
> proposed a almost same fix but not a real patch in this thread [2].
>
> [1]: Btrfs: adjust len of writes if following a preallocated extent
> https://patchwork.kernel.org/patch/9413129/
> [2]: https://patchwork.kernel.org/patch/9445231/
>
Ah ok. Thanks for pointing it out.
--
chandan
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2016-12-24 0:18 ` Liu Bo
2016-12-24 3:27 ` Chandan Rajendra
@ 2017-01-02 14:29 ` David Sterba
1 sibling, 0 replies; 8+ messages in thread
From: David Sterba @ 2017-01-02 14:29 UTC (permalink / raw)
To: Liu Bo; +Cc: Chandan Rajendra, linux-btrfs, fdmanana, dsterba
On Fri, Dec 23, 2016 at 04:18:00PM -0800, Liu Bo wrote:
> > > Btw, I was able to reproduce the issue on kdave/for-next branch with "Merge
> > > branch 'for-next-next-4.9-20161125' into for-next-20161125" as the topmost
> > > commit. The issue cannot be reproduced yet on latest code available from
> > > kdave/for-next branch.
> >
> > Maybe changes in upstream might have masked the issue in the recent
> > kdave/for-next branch. I say that because 'git bisect' resulted in the
> > following commit ...
>
> I guess that the for-next branch didn't revert this patch[1] as upstream
> did, [...]
> [1]: Btrfs: adjust len of writes if following a preallocated extent
> https://patchwork.kernel.org/patch/9413129/
The revert was present in the for-next-20161219 branch, the for-next
branches sit on top of recent upstream rc tag and are merged from
various dev branches so the patch difference should be minimal in the
end.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2016-12-23 9:30 [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync Chandan Rajendra
2016-12-23 10:27 ` Chandan Rajendra
@ 2017-01-06 11:45 ` Filipe Manana
2017-01-06 12:18 ` David Sterba
1 sibling, 1 reply; 8+ messages in thread
From: Filipe Manana @ 2017-01-06 11:45 UTC (permalink / raw)
To: Chandan Rajendra
Cc: linux-btrfs, Filipe David Borba Manana, David Sterba, Josef Bacik
On Fri, Dec 23, 2016 at 9:30 AM, Chandan Rajendra
<chandan@linux.vnet.ibm.com> wrote:
> The following deadlock is seen when executing generic/113 test,
>
> ---------------------------------------------------------+----------------------------------------------------
> Direct I/O task Fast fsync task
> ---------------------------------------------------------+----------------------------------------------------
> btrfs_direct_IO
> __blockdev_direct_IO
> do_blockdev_direct_IO
> do_direct_IO
> btrfs_get_blocks_direct
> while (blocks needs to written)
> get_more_blocks (first iteration)
> btrfs_get_blocks_direct
> btrfs_create_dio_extent
> down_read(&BTRFS_I(inode) >dio_sem)
> Create and add extent map and ordered extent
> up_read(&BTRFS_I(inode) >dio_sem)
> btrfs_sync_file
> btrfs_log_dentry_safe
> btrfs_log_inode_parent
> btrfs_log_inode
> btrfs_log_changed_extents
> down_write(&BTRFS_I(inode) >dio_sem)
> Collect new extent maps and ordered extents
> wait for ordered extent completion
> get_more_blocks (second iteration)
> btrfs_get_blocks_direct
> btrfs_create_dio_extent
> down_read(&BTRFS_I(inode) >dio_sem)
> --------------------------------------------------------------------------------------------------------------
>
> In the above description, Btrfs direct I/O code path has not yet started
> submitting bios for file range covered by the initial ordered
> extent. Meanwhile, The fast fsync task obtains the write semaphore and
> waits for I/O on the ordered extent to get completed. However, the
> Direct I/O task is now blocked on obtaining the read semaphore.
>
> To resolve the deadlock, this commit modifies the Direct I/O code path
> to obtain the read semaphore before invoking
> __blockdev_direct_IO(). The semaphore is then given up after
> __blockdev_direct_IO() returns. This allows the Direct I/O code to
> complete I/O on all the ordered extents it creates.
>
> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
As pointed out by Liu Bo, this was known, discussed and with a
proposed fix in another older thread:
https://www.marc.info/?l=linux-btrfs&m=147998603528213&w=2
I was on vacations and waiting for Josef's feedback as well (cc'ed but
never replied) before making a change log and formalizing the proposed
patch in that thread.
>From my point of view, it's ok and you can have:
Reviewed-by: Filipe Manana <fdmanana@suse.com>
thanks
> ---
> fs/btrfs/inode.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 5ca88f0..f796037 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -7325,7 +7325,6 @@ static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
> struct extent_map *em = NULL;
> int ret;
>
> - down_read(&BTRFS_I(inode)->dio_sem);
> if (type != BTRFS_ORDERED_NOCOW) {
> em = create_pinned_em(inode, start, len, orig_start,
> block_start, block_len, orig_block_len,
> @@ -7344,7 +7343,6 @@ static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
> em = ERR_PTR(ret);
> }
> out:
> - up_read(&BTRFS_I(inode)->dio_sem);
>
> return em;
> }
> @@ -8800,6 +8798,7 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
> dio_data.unsubmitted_oe_range_start = (u64)offset;
> dio_data.unsubmitted_oe_range_end = (u64)offset;
> current->journal_info = &dio_data;
> + down_read(&BTRFS_I(inode)->dio_sem);
> } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
> &BTRFS_I(inode)->runtime_flags)) {
> inode_dio_end(inode);
> @@ -8812,6 +8811,7 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
> iter, btrfs_get_blocks_direct, NULL,
> btrfs_submit_direct, flags);
> if (iov_iter_rw(iter) == WRITE) {
> + up_read(&BTRFS_I(inode)->dio_sem);
> current->journal_info = NULL;
> if (ret < 0 && ret != -EIOCBQUEUED) {
> if (dio_data.reserve)
> --
> 2.5.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Filipe David Manana,
"People will forget what you said,
people will forget what you did,
but people will never forget how you made them feel."
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync
2017-01-06 11:45 ` Filipe Manana
@ 2017-01-06 12:18 ` David Sterba
0 siblings, 0 replies; 8+ messages in thread
From: David Sterba @ 2017-01-06 12:18 UTC (permalink / raw)
To: Filipe Manana
Cc: Chandan Rajendra, linux-btrfs, Filipe David Borba Manana,
David Sterba, Josef Bacik
On Fri, Jan 06, 2017 at 11:45:46AM +0000, Filipe Manana wrote:
> >From my point of view, it's ok and you can have:
>
> Reviewed-by: Filipe Manana <fdmanana@suse.com>
Added to next and queued for 4.10, thanks.
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2017-01-06 12:18 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-12-23 9:30 [PATCH] Btrfs: Fix deadlock between direct IO and fast fsync Chandan Rajendra
2016-12-23 10:27 ` Chandan Rajendra
2016-12-23 11:57 ` Chandan Rajendra
2016-12-24 0:18 ` Liu Bo
2016-12-24 3:27 ` Chandan Rajendra
2017-01-02 14:29 ` David Sterba
2017-01-06 11:45 ` Filipe Manana
2017-01-06 12:18 ` David Sterba
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