* [PATCH 01/13] mm: Add AOP_UPDATED_PAGE return value
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 22:03 ` Matthew Wilcox
2020-09-17 15:10 ` [PATCH 02/13] 9p: Tell the VFS that readpage was synchronous Matthew Wilcox (Oracle)
` (11 subsequent siblings)
12 siblings, 1 reply; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
Allow synchronous ->readpage implementations to execute more
efficiently by skipping the re-locking of the page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
Documentation/filesystems/locking.rst | 7 ++++---
Documentation/filesystems/vfs.rst | 21 ++++++++++++++-------
include/linux/fs.h | 5 +++++
mm/filemap.c | 12 ++++++++++--
4 files changed, 33 insertions(+), 12 deletions(-)
diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index 64f94a18d97e..06a7a8bf2362 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -269,7 +269,7 @@ locking rules:
ops PageLocked(page) i_rwsem
====================== ======================== =========
writepage: yes, unlocks (see below)
-readpage: yes, unlocks
+readpage: yes, may unlock
writepages:
set_page_dirty no
readahead: yes, unlocks
@@ -294,8 +294,9 @@ swap_deactivate: no
->write_begin(), ->write_end() and ->readpage() may be called from
the request handler (/dev/loop).
-->readpage() unlocks the page, either synchronously or via I/O
-completion.
+->readpage() may return AOP_UPDATED_PAGE if the page is now Uptodate
+or 0 if the page will be unlocked asynchronously by I/O completion.
+If it returns -errno, it should unlock the page.
->readahead() unlocks the pages that I/O is attempted on like ->readpage().
diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index ca52c82e5bb5..16248c299aaa 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -643,7 +643,7 @@ set_page_dirty to write data into the address_space, and writepage and
writepages to writeback data to storage.
Adding and removing pages to/from an address_space is protected by the
-inode's i_mutex.
+inode's i_rwsem held exclusively.
When data is written to a page, the PG_Dirty flag should be set. It
typically remains set until writepage asks for it to be written. This
@@ -757,12 +757,19 @@ cache in your filesystem. The following members are defined:
``readpage``
called by the VM to read a page from backing store. The page
- will be Locked when readpage is called, and should be unlocked
- and marked uptodate once the read completes. If ->readpage
- discovers that it needs to unlock the page for some reason, it
- can do so, and then return AOP_TRUNCATED_PAGE. In this case,
- the page will be relocated, relocked and if that all succeeds,
- ->readpage will be called again.
+ will be Locked and !Uptodate when readpage is called. Ideally,
+ the filesystem will bring the page Uptodate and return
+ AOP_UPDATED_PAGE. If the filesystem encounters an error, it
+ should unlock the page and return a negative errno without marking
+ the page Uptodate. It does not need to mark the page as Error.
+ If the filesystem returns 0, this means the page will be unlocked
+ asynchronously by I/O completion. The VFS will wait for the
+ page to be unlocked, so there is no advantage to executing this
+ operation asynchronously.
+
+ The filesystem can also return AOP_TRUNCATED_PAGE to indicate
+ that it had to unlock the page to avoid a deadlock. The caller
+ will re-check the page cache and call ->readpage again.
``writepages``
called by the VM to write out pages associated with the
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e019ea2f1347..6fc650050d20 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -273,6 +273,10 @@ struct iattr {
* reference, it should drop it before retrying. Returned
* by readpage().
*
+ * @AOP_UPDATED_PAGE: The readpage method has brought the page Uptodate
+ * without releasing the page lock. This is suitable for synchronous
+ * implementations of readpage.
+ *
* address_space_operation functions return these large constants to indicate
* special semantics to the caller. These are much larger than the bytes in a
* page to allow for functions that return the number of bytes operated on in a
@@ -282,6 +286,7 @@ struct iattr {
enum positive_aop_returns {
AOP_WRITEPAGE_ACTIVATE = 0x80000,
AOP_TRUNCATED_PAGE = 0x80001,
+ AOP_UPDATED_PAGE = 0x80002,
};
#define AOP_FLAG_CONT_EXPAND 0x0001 /* called from cont_expand */
diff --git a/mm/filemap.c b/mm/filemap.c
index 1aaea26556cc..131a2aaa1537 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2254,8 +2254,10 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
* PG_error will be set again if readpage fails.
*/
ClearPageError(page);
- /* Start the actual read. The read will unlock the page. */
+ /* Start the actual read. The read may unlock the page. */
error = mapping->a_ops->readpage(filp, page);
+ if (error == AOP_UPDATED_PAGE)
+ goto page_ok;
if (unlikely(error)) {
if (error == AOP_TRUNCATED_PAGE) {
@@ -2619,7 +2621,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
*/
if (unlikely(!PageUptodate(page)))
goto page_not_uptodate;
-
+page_ok:
/*
* We've made it this far and we had to drop our mmap_lock, now is the
* time to return to the upper layer and have it re-find the vma and
@@ -2654,6 +2656,8 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
ClearPageError(page);
fpin = maybe_unlock_mmap_for_io(vmf, fpin);
error = mapping->a_ops->readpage(file, page);
+ if (error == AOP_UPDATED_PAGE)
+ goto page_ok;
if (!error) {
wait_on_page_locked(page);
if (!PageUptodate(page))
@@ -2867,6 +2871,10 @@ static struct page *do_read_cache_page(struct address_space *mapping,
err = filler(data, page);
else
err = mapping->a_ops->readpage(data, page);
+ if (err == AOP_UPDATED_PAGE) {
+ unlock_page(page);
+ goto out;
+ }
if (err < 0) {
put_page(page);
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 01/13] mm: Add AOP_UPDATED_PAGE return value
2020-09-17 15:10 ` [PATCH 01/13] mm: Add AOP_UPDATED_PAGE return value Matthew Wilcox (Oracle)
@ 2020-09-17 22:03 ` Matthew Wilcox
0 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox @ 2020-09-17 22:03 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
On Thu, Sep 17, 2020 at 04:10:38PM +0100, Matthew Wilcox (Oracle) wrote:
> +++ b/mm/filemap.c
> @@ -2254,8 +2254,10 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
> * PG_error will be set again if readpage fails.
> */
> ClearPageError(page);
> - /* Start the actual read. The read will unlock the page. */
> + /* Start the actual read. The read may unlock the page. */
> error = mapping->a_ops->readpage(filp, page);
> + if (error == AOP_UPDATED_PAGE)
> + goto page_ok;
>
> if (unlikely(error)) {
> if (error == AOP_TRUNCATED_PAGE) {
If anybody wants to actually test this, this hunk is wrong.
+++ b/mm/filemap.c
@@ -2256,8 +2256,11 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
ClearPageError(page);
/* Start the actual read. The read may unlock the page. */
error = mapping->a_ops->readpage(filp, page);
- if (error == AOP_UPDATED_PAGE)
+ if (error == AOP_UPDATED_PAGE) {
+ unlock_page(page);
+ error = 0;
goto page_ok;
+ }
if (unlikely(error)) {
if (error == AOP_TRUNCATED_PAGE) {
> @@ -2619,7 +2621,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
> */
> if (unlikely(!PageUptodate(page)))
> goto page_not_uptodate;
> -
> +page_ok:
> /*
> * We've made it this far and we had to drop our mmap_lock, now is the
> * time to return to the upper layer and have it re-find the vma and
> @@ -2654,6 +2656,8 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
> ClearPageError(page);
> fpin = maybe_unlock_mmap_for_io(vmf, fpin);
> error = mapping->a_ops->readpage(file, page);
> + if (error == AOP_UPDATED_PAGE)
> + goto page_ok;
> if (!error) {
> wait_on_page_locked(page);
> if (!PageUptodate(page))
> @@ -2867,6 +2871,10 @@ static struct page *do_read_cache_page(struct address_space *mapping,
> err = filler(data, page);
> else
> err = mapping->a_ops->readpage(data, page);
> + if (err == AOP_UPDATED_PAGE) {
> + unlock_page(page);
> + goto out;
> + }
>
> if (err < 0) {
> put_page(page);
> --
> 2.28.0
>
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 02/13] 9p: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 01/13] mm: Add AOP_UPDATED_PAGE return value Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
[not found] ` <20200918055919.GA30929@nautica>
2020-09-17 15:10 ` [PATCH 03/13] afs: " Matthew Wilcox (Oracle)
` (10 subsequent siblings)
12 siblings, 1 reply; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The 9p readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/9p/vfs_addr.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index cce9ace651a2..506ca0ba2ec7 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -65,7 +65,7 @@ static int v9fs_fid_readpage(void *data, struct page *page)
SetPageUptodate(page);
v9fs_readpage_to_fscache(inode, page);
- retval = 0;
+ return AOP_UPDATED_PAGE;
done:
unlock_page(page);
@@ -280,6 +280,10 @@ static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
goto out;
retval = v9fs_fid_readpage(v9inode->writeback_fid, page);
+ if (retval == AOP_UPDATED_PAGE) {
+ retval = 0;
+ goto out;
+ }
put_page(page);
if (!retval)
goto start;
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 03/13] afs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 01/13] mm: Add AOP_UPDATED_PAGE return value Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 02/13] 9p: Tell the VFS that readpage was synchronous Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 04/13] ceph: " Matthew Wilcox (Oracle)
` (9 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The afs readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/afs/file.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 6f6ed1605cfe..8f15305b6574 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -367,7 +367,8 @@ int afs_page_filler(void *data, struct page *page)
BUG_ON(PageFsCache(page));
}
#endif
- unlock_page(page);
+ _leave(" = AOP_UPDATED_PAGE");
+ return AOP_UPDATED_PAGE;
}
_leave(" = 0");
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 04/13] ceph: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (2 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 03/13] afs: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 16:49 ` Jeff Layton
2020-09-17 15:10 ` [PATCH 05/13] cifs: " Matthew Wilcox (Oracle)
` (8 subsequent siblings)
12 siblings, 1 reply; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The ceph readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/ceph/addr.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 6ea761c84494..b2bf8bf7a312 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -291,10 +291,11 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
static int ceph_readpage(struct file *filp, struct page *page)
{
int r = ceph_do_readpage(filp, page);
- if (r != -EINPROGRESS)
- unlock_page(page);
- else
- r = 0;
+ if (r == -EINPROGRESS)
+ return 0;
+ if (r == 0)
+ return AOP_UPDATED_PAGE;
+ unlock_page(page);
return r;
}
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 04/13] ceph: Tell the VFS that readpage was synchronous
2020-09-17 15:10 ` [PATCH 04/13] ceph: " Matthew Wilcox (Oracle)
@ 2020-09-17 16:49 ` Jeff Layton
0 siblings, 0 replies; 19+ messages in thread
From: Jeff Layton @ 2020-09-17 16:49 UTC (permalink / raw)
To: Matthew Wilcox (Oracle), linux-fsdevel
Cc: linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
On Thu, 2020-09-17 at 16:10 +0100, Matthew Wilcox (Oracle) wrote:
> The ceph readpage implementation was already synchronous, so use
> AOP_UPDATED_PAGE to avoid cycling the page lock.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> fs/ceph/addr.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index 6ea761c84494..b2bf8bf7a312 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -291,10 +291,11 @@ static int ceph_do_readpage(struct file *filp, struct page *page)
> static int ceph_readpage(struct file *filp, struct page *page)
> {
> int r = ceph_do_readpage(filp, page);
> - if (r != -EINPROGRESS)
> - unlock_page(page);
> - else
> - r = 0;
> + if (r == -EINPROGRESS)
> + return 0;
> + if (r == 0)
> + return AOP_UPDATED_PAGE;
> + unlock_page(page);
> return r;
> }
>
Looks good to me. I assume you'll merge all of these as a set since the
early ones are a prerequisite?
Reviewed-by: Jeff Layton <jlayton@kernel.org>
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 05/13] cifs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (3 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 04/13] ceph: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 06/13] cramfs: " Matthew Wilcox (Oracle)
` (7 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The cifs readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/cifs/file.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index be46fab4c96d..533b151a9143 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4537,7 +4537,8 @@ static int cifs_readpage_worker(struct file *file, struct page *page,
/* send this page to the cache */
cifs_readpage_to_fscache(file_inode(file), page);
- rc = 0;
+ kunmap(page);
+ return AOP_UPDATED_PAGE;
io_error:
kunmap(page);
@@ -4677,7 +4678,10 @@ static int cifs_write_begin(struct file *file, struct address_space *mapping,
* an error, we don't need to return it. cifs_write_end will
* do a sync write instead since PG_uptodate isn't set.
*/
- cifs_readpage_worker(file, page, &page_start);
+ int err = cifs_readpage_worker(file, page, &page_start);
+
+ if (err == AOP_UPDATED_PAGE)
+ goto out;
put_page(page);
oncethru = 1;
goto start;
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 06/13] cramfs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (4 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 05/13] cifs: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 07/13] ecryptfs: " Matthew Wilcox (Oracle)
` (6 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The cramfs readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/cramfs/inode.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 912308600d39..7a642146c074 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -916,15 +916,14 @@ static int cramfs_readpage(struct file *file, struct page *page)
flush_dcache_page(page);
kunmap(page);
SetPageUptodate(page);
- unlock_page(page);
- return 0;
+ return AOP_UPDATED_PAGE;
err:
kunmap(page);
ClearPageUptodate(page);
SetPageError(page);
unlock_page(page);
- return 0;
+ return -EIO;
}
static const struct address_space_operations cramfs_aops = {
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 07/13] ecryptfs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (5 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 06/13] cramfs: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 08/13] fuse: " Matthew Wilcox (Oracle)
` (5 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The ecryptfs readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/ecryptfs/mmap.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 019572c6b39a..dee35181d789 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -219,12 +219,13 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
}
}
out:
- if (rc)
- ClearPageUptodate(page);
- else
- SetPageUptodate(page);
- ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
+ ecryptfs_printk(KERN_DEBUG, "Returning page with index = [0x%.16lx]\n",
page->index);
+ if (!rc) {
+ SetPageUptodate(page);
+ return AOP_UPDATED_PAGE;
+ }
+ ClearPageUptodate(page);
unlock_page(page);
return rc;
}
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 08/13] fuse: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (6 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 07/13] ecryptfs: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 09/13] hostfs: " Matthew Wilcox (Oracle)
` (4 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The fuse readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/fuse/file.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 6611ef3269a8..7aa5626bc582 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -850,6 +850,8 @@ static int fuse_readpage(struct file *file, struct page *page)
err = fuse_do_readpage(file, page);
fuse_invalidate_atime(inode);
+ if (!err)
+ return AOP_UPDATED_PAGE;
out:
unlock_page(page);
return err;
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 09/13] hostfs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (7 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 08/13] fuse: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 10/13] jffs2: " Matthew Wilcox (Oracle)
` (3 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The hostfs readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/hostfs/hostfs_kern.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index c070c0d8e3e9..c49221c09c4b 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -455,6 +455,8 @@ static int hostfs_readpage(struct file *file, struct page *page)
out:
flush_dcache_page(page);
kunmap(page);
+ if (!ret)
+ return AOP_UPDATED_PAGE;
unlock_page(page);
return ret;
}
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 10/13] jffs2: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (8 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 09/13] hostfs: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 11/13] ubifs: " Matthew Wilcox (Oracle)
` (2 subsequent siblings)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The jffs2 readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/jffs2/file.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index f8fb89b10227..959a74027041 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -116,15 +116,17 @@ int jffs2_do_readpage_unlock(void *data, struct page *pg)
return ret;
}
-
static int jffs2_readpage (struct file *filp, struct page *pg)
{
struct jffs2_inode_info *f = JFFS2_INODE_INFO(pg->mapping->host);
int ret;
mutex_lock(&f->sem);
- ret = jffs2_do_readpage_unlock(pg->mapping->host, pg);
+ ret = jffs2_do_readpage_nolock(pg->mapping->host, pg);
mutex_unlock(&f->sem);
+ if (!ret)
+ return AOP_UPDATED_PAGE;
+ unlock_page(pg);
return ret;
}
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* [PATCH 11/13] ubifs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (9 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 10/13] jffs2: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-17 20:46 ` Richard Weinberger
2020-09-17 15:10 ` [PATCH 12/13] udf: " Matthew Wilcox (Oracle)
2020-09-17 15:10 ` [PATCH 13/13] vboxsf: " Matthew Wilcox (Oracle)
12 siblings, 1 reply; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The ubifs readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/ubifs/file.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index b77d1637bbbc..82633509c45e 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -772,7 +772,6 @@ static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
if (err)
goto out_warn;
- unlock_page(page1);
ret = 1;
isize = i_size_read(inode);
@@ -892,11 +891,16 @@ static int ubifs_bulk_read(struct page *page)
static int ubifs_readpage(struct file *file, struct page *page)
{
- if (ubifs_bulk_read(page))
- return 0;
- do_readpage(page);
- unlock_page(page);
- return 0;
+ int err;
+
+ err = ubifs_bulk_read(page);
+ if (err == 0)
+ err = do_readpage(page);
+ if (err < 0) {
+ unlock_page(page);
+ return err;
+ }
+ return AOP_UPDATED_PAGE;
}
static int do_writepage(struct page *page, int len)
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 11/13] ubifs: Tell the VFS that readpage was synchronous
2020-09-17 15:10 ` [PATCH 11/13] ubifs: " Matthew Wilcox (Oracle)
@ 2020-09-17 20:46 ` Richard Weinberger
0 siblings, 0 replies; 19+ messages in thread
From: Richard Weinberger @ 2020-09-17 20:46 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-fsdevel, linux-mm, v9fs-developer, linux-kernel, linux-afs,
ceph-devel, linux-cifs, ecryptfs, linux-um, linux-mtd
----- Ursprüngliche Mail -----
> Von: "Matthew Wilcox" <willy@infradead.org>
> An: "linux-fsdevel" <linux-fsdevel@vger.kernel.org>
> CC: "Matthew Wilcox" <willy@infradead.org>, "linux-mm" <linux-mm@kvack.org>, v9fs-developer@lists.sourceforge.net,
> "linux-kernel" <linux-kernel@vger.kernel.org>, linux-afs@lists.infradead.org, "ceph-devel"
> <ceph-devel@vger.kernel.org>, linux-cifs@vger.kernel.org, ecryptfs@vger.kernel.org, "linux-um"
> <linux-um@lists.infradead.org>, "linux-mtd" <linux-mtd@lists.infradead.org>, "richard" <richard@nod.at>
> Gesendet: Donnerstag, 17. September 2020 17:10:48
> Betreff: [PATCH 11/13] ubifs: Tell the VFS that readpage was synchronous
> The ubifs readpage implementation was already synchronous, so use
> AOP_UPDATED_PAGE to avoid cycling the page lock.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
> fs/ubifs/file.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
For ubifs, jffs2 and hostfs:
Acked-by: Richard Weinberger <richard@nod.at>
Thanks,
//richard
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 12/13] udf: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (10 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 11/13] ubifs: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
2020-09-24 9:00 ` Jan Kara
2020-09-17 15:10 ` [PATCH 13/13] vboxsf: " Matthew Wilcox (Oracle)
12 siblings, 1 reply; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The udf inline data readpage implementation was already synchronous,
so use AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/udf/file.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 628941a6b79a..52bbe92d7c43 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -61,9 +61,8 @@ static int udf_adinicb_readpage(struct file *file, struct page *page)
{
BUG_ON(!PageLocked(page));
__udf_adinicb_readpage(page);
- unlock_page(page);
- return 0;
+ return AOP_UPDATED_PAGE;
}
static int udf_adinicb_writepage(struct page *page,
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread
* Re: [PATCH 12/13] udf: Tell the VFS that readpage was synchronous
2020-09-17 15:10 ` [PATCH 12/13] udf: " Matthew Wilcox (Oracle)
@ 2020-09-24 9:00 ` Jan Kara
0 siblings, 0 replies; 19+ messages in thread
From: Jan Kara @ 2020-09-24 9:00 UTC (permalink / raw)
To: Matthew Wilcox (Oracle)
Cc: linux-fsdevel, linux-mm, v9fs-developer, linux-kernel, linux-afs,
ceph-devel, linux-cifs, ecryptfs, linux-um, linux-mtd,
Richard Weinberger
On Thu 17-09-20 16:10:49, Matthew Wilcox (Oracle) wrote:
> The udf inline data readpage implementation was already synchronous,
> so use AOP_UPDATED_PAGE to avoid cycling the page lock.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/udf/file.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/udf/file.c b/fs/udf/file.c
> index 628941a6b79a..52bbe92d7c43 100644
> --- a/fs/udf/file.c
> +++ b/fs/udf/file.c
> @@ -61,9 +61,8 @@ static int udf_adinicb_readpage(struct file *file, struct page *page)
> {
> BUG_ON(!PageLocked(page));
> __udf_adinicb_readpage(page);
> - unlock_page(page);
>
> - return 0;
> + return AOP_UPDATED_PAGE;
> }
>
> static int udf_adinicb_writepage(struct page *page,
> --
> 2.28.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 19+ messages in thread
* [PATCH 13/13] vboxsf: Tell the VFS that readpage was synchronous
2020-09-17 15:10 [PATCH 00/13] Allow readpage to return a locked page Matthew Wilcox (Oracle)
` (11 preceding siblings ...)
2020-09-17 15:10 ` [PATCH 12/13] udf: " Matthew Wilcox (Oracle)
@ 2020-09-17 15:10 ` Matthew Wilcox (Oracle)
12 siblings, 0 replies; 19+ messages in thread
From: Matthew Wilcox (Oracle) @ 2020-09-17 15:10 UTC (permalink / raw)
To: linux-fsdevel
Cc: Matthew Wilcox (Oracle),
linux-mm, v9fs-developer, linux-kernel, linux-afs, ceph-devel,
linux-cifs, ecryptfs, linux-um, linux-mtd, Richard Weinberger
The vboxsf inline data readpage implementation was already synchronous,
so use AOP_UPDATED_PAGE to avoid cycling the page lock.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/vboxsf/file.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/vboxsf/file.c b/fs/vboxsf/file.c
index c4ab5996d97a..c2a144e5cb5a 100644
--- a/fs/vboxsf/file.c
+++ b/fs/vboxsf/file.c
@@ -228,6 +228,8 @@ static int vboxsf_readpage(struct file *file, struct page *page)
}
kunmap(page);
+ if (!err)
+ return AOP_UPDATED_PAGE;
unlock_page(page);
return err;
}
--
2.28.0
^ permalink raw reply related [flat|nested] 19+ messages in thread