From: Olaf Kirch <okir@suse.de>
[PATCH] Fix miscompare in __posix_lock_file
If an application requests the same lock twice, the
kernel should just leave the existing lock in place.
Currently, it will install a second lock of the same type.
Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/locks.c b/fs/locks.c
index f7daa5f..7eb1d77 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -829,12 +829,16 @@
/* Detect adjacent or overlapping regions (if same lock type)
*/
if (request->fl_type == fl->fl_type) {
+ /* In all comparisons of start vs end, use
+ * "start - 1" rather than "end + 1". If end
+ * is OFFSET_MAX, end + 1 will become negative.
+ */
if (fl->fl_end < request->fl_start - 1)
goto next_lock;
/* If the next lock in the list has entirely bigger
* addresses than the new one, insert the lock here.
*/
- if (fl->fl_start > request->fl_end + 1)
+ if (fl->fl_start - 1 > request->fl_end)
break;
/* If we come here, the new and old lock are of the