[PATCH] Fix get_request nastiness
get_request is now expected to be holding on to queue_lock, with interrupts
disabled, when it returns NULL; but one path forgot that, causing all kinds
of nastiness under swap load - badness backtraces, strange failures, BUGs.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index 1197462..692a5fc 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -1917,10 +1917,9 @@
* limit of requests, otherwise we could have thousands of requests
* allocated with any setting of ->nr_requests
*/
- if (rl->count[rw] >= (3 * q->nr_requests / 2)) {
- spin_unlock_irq(q->queue_lock);
+ if (rl->count[rw] >= (3 * q->nr_requests / 2))
goto out;
- }
+
rl->count[rw]++;
rl->starved[rw] = 0;
if (rl->count[rw] >= queue_congestion_on_threshold(q))