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| author | Olaf Kirch <okir@suse.de> | 2005-08-25 16:25:35 -0700 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2005-09-23 12:37:59 -0400 |
| commit | 449231d6ddf50ca46b7fb2f76ecf790135222913 (patch) | |
| tree | 0c493d7f4fb68f1f639c56258bcd025d5b904fb0 /fs/locks.c | |
| parent | 20509f1bc553ed7fafa88fa8d01c6212d1876d9f (diff) | |
| download | lwn-449231d6ddf50ca46b7fb2f76ecf790135222913.tar.gz lwn-449231d6ddf50ca46b7fb2f76ecf790135222913.zip | |
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>
Diffstat (limited to 'fs/locks.c')
| -rw-r--r-- | fs/locks.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/locks.c b/fs/locks.c index f7daa5f48949..7eb1d77b9204 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -829,12 +829,16 @@ static int __posix_lock_file(struct inode *inode, struct file_lock *request) /* 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 |