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| author |   Jeff Layton <jlayton@poochiereds.net> | 2014-06-10 12:24:40 -0400 |
|---|---|---|
| committer | Jeff Layton <jlayton@poochiereds.net> | 2014-06-10 12:24:40 -0400 |
| commit | 962bd40bc30e412828e091bfda041b7547e779c8 (patch) | |
| tree | dc5afa02febd54262708784552b497f11bd0c080 /include/linux/fs.h | |
| parent | Merge tag 'for-f2fs-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs (diff) | |
| download | linux-dev-962bd40bc30e412828e091bfda041b7547e779c8.tar.xz linux-dev-962bd40bc30e412828e091bfda041b7547e779c8.zip | |
locks: add missing memory barrier in break_deleg
break_deleg is subject to the same potential race as break_lease. Add
a memory barrier to prevent it.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index c3f46e499dd0..22ae79650b82 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1914,6 +1914,12 @@ static inline int break_lease(struct inode *inode, unsigned int mode) static inline int break_deleg(struct inode *inode, unsigned int mode) { + /* + * Since this check is lockless, we must ensure that any refcounts + * taken are done before checking inode->i_flock. Otherwise, we could + * end up racing with tasks trying to set a new lease on this file. + */ + smp_mb(); if (inode->i_flock) return __break_lease(inode, mode, FL_DELEG); return 0; |