diff options
| author | Konstantin Khlebnikov <khlebnikov@openvz.org> | 2011-04-04 00:15:02 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2011-04-05 23:52:49 +0200 |
| commit | f83e826181f7f8fb152e4190d03854fc3a5dd040 (patch) | |
| tree | 989f440665d529587fcc6365b1968e2b29fb7c94 | |
| parent | a63a5cf84dac7a23a57c800eea5734701e7d3c04 (diff) | |
| download | lwn-f83e826181f7f8fb152e4190d03854fc3a5dd040.tar.gz lwn-f83e826181f7f8fb152e4190d03854fc3a5dd040.zip | |
block: fix request sorting at unplug
Comparison function for list_sort() must be anticommutative,
otherwise it is not sorting in ordinary meaning.
But fortunately list_sort() always check ((*cmp)(priv, a, b) <= 0)
it not distinguish negative and zero, so comparison function can
implement only less-or-equal instead of full three-way comparison.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| -rw-r--r-- | block/blk-core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 4fdf8953efbf..725091d5496d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2665,7 +2665,7 @@ static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) struct request *rqa = container_of(a, struct request, queuelist); struct request *rqb = container_of(b, struct request, queuelist); - return !(rqa->q == rqb->q); + return !(rqa->q <= rqb->q); } static void flush_plug_list(struct blk_plug *plug) |