From: Dave Jiang <dave.jiang@intel.com>
To: tytso@mit.edu, darrick.wong@oracle.com, jack@suse.cz, zwisler@kernel.org
Cc: linux-nvdimm@lists.01.org, david@fromorbit.com,
linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
lczerner@redhat.com, linux-ext4@vger.kernel.org, hch@lst.de
Subject: [PATCH v2 2/2] [PATCH] xfs: Close race between direct IO and xfs_break_layouts()
Date: Wed, 08 Aug 2018 10:26:36 -0700 [thread overview]
Message-ID: <153374915981.40645.3350205963852459041.stgit@djiang5-desk3.ch.intel.com> (raw)
In-Reply-To: <153374910694.40645.17166196534680658204.stgit@djiang5-desk3.ch.intel.com>
This patch is the duplicate of ross's fix for ext4 for xfs.
If the refcount of a page is lowered between the time that it is returned
by dax_busy_page() and when the refcount is again checked in
xfs_break_layouts() => ___wait_var_event(), the waiting function
xfs_wait_dax_page() will never be called. This means that
xfs_break_layouts() will still have 'retry' set to false, so we'll stop
looping and never check the refcount of other pages in this inode.
Instead, always continue looping as long as dax_layout_busy_page() gives us
a page which it found with an elevated refcount.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v2:
- Rename parameter from did_unlock to retry (Jan)
fs/xfs/xfs_file.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index a3e7767a5715..cd6f0d8c4922 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -721,12 +721,10 @@ xfs_file_write_iter(
static void
xfs_wait_dax_page(
- struct inode *inode,
- bool *did_unlock)
+ struct inode *inode)
{
struct xfs_inode *ip = XFS_I(inode);
- *did_unlock = true;
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
schedule();
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
@@ -736,7 +734,7 @@ static int
xfs_break_dax_layouts(
struct inode *inode,
uint iolock,
- bool *did_unlock)
+ bool *retry)
{
struct page *page;
@@ -746,9 +744,10 @@ xfs_break_dax_layouts(
if (!page)
return 0;
+ *retry = true;
return ___wait_var_event(&page->_refcount,
atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
- 0, 0, xfs_wait_dax_page(inode, did_unlock));
+ 0, 0, xfs_wait_dax_page(inode));
}
int
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next prev parent reply other threads:[~2018-08-08 17:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-08 17:25 [PATCH v2 1/2] ext4: Close race between direct IO and ext4_break_layouts() Dave Jiang
2018-08-08 17:26 ` Dave Jiang [this message]
2018-08-09 8:57 ` [PATCH v2 2/2] [PATCH] xfs: Close race between direct IO and xfs_break_layouts() Jan Kara
2018-08-09 16:21 ` Dave Jiang
2018-09-10 16:23 ` [PATCH v2 1/2] ext4: Close race between direct IO and ext4_break_layouts() Eric Sandeen
2018-09-11 15:26 ` Jan Kara
2018-08-08 17:31 [PATCH v2 2/2] [PATCH] xfs: Close race between direct IO and xfs_break_layouts() Dave Jiang
2018-08-10 15:48 ` Darrick J. Wong
2018-08-10 15:54 ` Dave Jiang
2018-08-10 16:02 ` Darrick J. Wong
2018-08-10 16:05 ` Dave Jiang
2018-08-10 18:31 ` Eric Sandeen
2018-08-10 19:23 ` Dave Jiang
2018-08-10 19:24 ` Ross Zwisler
2018-08-10 19:26 ` Eric Sandeen
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