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| author | J. Bruce Fields <bfields@fieldses.org> | 2007-05-10 18:38:43 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-10 20:25:59 -0700 |
| commit | 129a84de2347002f09721cda3155ccfd19fade40 (patch) | |
| tree | 11dabc5695dbcd0eb814935b2c02ddeb01442932 /fs | |
| parent | a9deecba19b8f384d97f82c75379da48bccb2588 (diff) | |
| download | lwn-129a84de2347002f09721cda3155ccfd19fade40.tar.gz lwn-129a84de2347002f09721cda3155ccfd19fade40.zip | |
locks: fix F_GETLK regression (failure to find conflicts)
In 9d6a8c5c213e34c475e72b245a8eb709258e968c we changed posix_test_lock
to modify its single file_lock argument instead of taking separate input
and output arguments. This makes it no longer safe to set the output
lock's fl_type to F_UNLCK before looking for a conflict, since that
means searching for a conflict against a lock with type F_UNLCK.
This fixes a regression which causes F_GETLK to incorrectly report no
conflict on most filesystems (including any filesystem that doesn't do
its own locking).
Also fix posix_lock_to_flock() to copy the lock type. This isn't
strictly necessary, since the caller already does this; but it seems
less likely to cause confusion in the future.
Thanks to Doug Chapman for the bug report.
Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Acked-by: Doug Chapman <doug.chapman@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/locks.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/locks.c b/fs/locks.c index 671a034dc999..8ec16ab5ef74 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -669,7 +669,6 @@ posix_test_lock(struct file *filp, struct file_lock *fl) { struct file_lock *cfl; - fl->fl_type = F_UNLCK; lock_kernel(); for (cfl = filp->f_path.dentry->d_inode->i_flock; cfl; cfl = cfl->fl_next) { if (!IS_POSIX(cfl)) @@ -681,7 +680,8 @@ posix_test_lock(struct file *filp, struct file_lock *fl) __locks_copy_lock(fl, cfl); unlock_kernel(); return 1; - } + } else + fl->fl_type = F_UNLCK; unlock_kernel(); return 0; } @@ -1632,6 +1632,7 @@ static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) flock->l_len = fl->fl_end == OFFSET_MAX ? 0 : fl->fl_end - fl->fl_start + 1; flock->l_whence = 0; + flock->l_type = fl->fl_type; return 0; } |