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| author | Sachin Prabhu <sprabhu@redhat.com> | 2010-03-13 09:03:55 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-26 07:41:29 -0700 |
| commit | 56d704107153877ba124c9fafb31fb54a86a0f84 (patch) | |
| tree | bafa807937aaf4547b85363bec059c740e91c776 | |
| parent | 26ec941a150774814a0416b28c7e8d22bfb777f8 (diff) | |
| download | linux-stable-56d704107153877ba124c9fafb31fb54a86a0f84.tar.gz linux-stable-56d704107153877ba124c9fafb31fb54a86a0f84.tar.bz2 linux-stable-56d704107153877ba124c9fafb31fb54a86a0f84.zip | |
9p: Skip check for mandatory locks when unlocking
commit f78233dd44a110c574fe760ad6f9c1e8741a0d00 upstream.
While investigating a bug, I came across a possible bug in v9fs. The
problem is similar to the one reported for NFS by ASANO Masahiro in
http://lkml.org/lkml/2005/12/21/334.
v9fs_file_lock() will skip locks on file which has mode set to 02666.
This is a problem in cases where the mode of the file is changed after
a process has obtained a lock on the file. Such a lock will be skipped
during unlock and the machine will end up with a BUG in
locks_remove_flock().
v9fs_file_lock() should skip the check for mandatory locks when
unlocking a file.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Cc: maximilian attems <max@stro.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/9p/vfs_file.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 3902bf43a088..5fb43bd19688 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -114,7 +114,7 @@ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) P9_DPRINTK(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); /* No mandatory locks */ - if (__mandatory_lock(inode)) + if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) return -ENOLCK; if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { |