[PATCH UPDATED] block: In blk_execute_rq_nowait, init rq->end_io before checking for dead queue.

[Muthu Kumar <muthu.lkml@xxxxxxxxx>]

Since the queue->lock case is taken care of in the following patch:

(http://www.spinics.net/lists/linux-scsi/msg59845.html [PATCH 1/4]
block: Fix race on request_queue.end_io invocations)

Updated the patch with just the end_io assignment before dead queue check.


-------------
blk-exec.c: In blk_execute_rq_nowait(), if the queue is dead, call to
done() routine is not made. That will result in blk_execute_rq() stuck
in wait_for_completion(). Avoid this by initializing rq->end_io to
done() routine before we check for dead queue.

Signed-off-by: Muthukumar Ratty <muthur@xxxxxxxxx>
CC: Tejun Heo <tj@xxxxxxxxxx>
CC: Jens Axboe <axboe@xxxxxxxxx>
CC: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>

-------------
diff --git a/block/blk-exec.c b/block/blk-exec.c
index fb2cbd5..f8b00c7 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -53,6 +53,9 @@ void blk_execute_rq_nowait(struct request_queue *q,
struct gendisk *bd_disk,
        WARN_ON(irqs_disabled());
        spin_lock_irq(q->queue_lock);

+       rq->rq_disk = bd_disk;
+       rq->end_io = done;
+
        if (unlikely(blk_queue_dead(q))) {
                spin_unlock_irq(q->queue_lock);
                rq->errors = -ENXIO;
@@ -61,8 +64,6 @@ void blk_execute_rq_nowait(struct request_queue *q,
struct gendisk *bd_disk,
                return;
        }

Attachment: blk-exec-assign-endio-before-queue-dead-check.patch
Description: Binary data