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authorSachin Prabhu <sprabhu@redhat.com>2010-03-13 16:03:55 +0100
committerEric Van Hensbergen <ericvh@gmail.com>2010-03-13 16:05:37 +0100
commitf78233dd44a110c574fe760ad6f9c1e8741a0d00 (patch)
tree5b38b76a9f7133cd6e86cecb66673b53fa93d85a
parent9p: Fixes a simple bug enabling writes beyond 2GB. (diff)
downloadlinux-f78233dd44a110c574fe760ad6f9c1e8741a0d00.tar.xz
linux-f78233dd44a110c574fe760ad6f9c1e8741a0d00.zip
9p: Skip check for mandatory locks when unlocking
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>
-rw-r--r--fs/9p/vfs_file.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 019f1cd8750b..df52d488d2a6 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) {