block: unify request timeout handling

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index f25eb9786d94..d768a8ddc173 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -110,6 +110,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
         memset(rq, 0, sizeof(*rq));
 
         INIT_LIST_HEAD(&rq->queuelist);
+        INIT_LIST_HEAD(&rq->timeout_list);
         rq->cpu = -1;
         rq->q = q;
         rq->sector = rq->hard_sector = (sector_t) -1;
@@ -490,6 +491,8 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
         }
 
         init_timer(&q->unplug_timer);
+        setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
+        INIT_LIST_HEAD(&q->timeout_list);
 
         kobject_init(&q->kobj, &blk_queue_ktype);
 
@@ -897,6 +900,8 @@ EXPORT_SYMBOL(blk_start_queueing);
  */
 void blk_requeue_request(struct request_queue *q, struct request *rq)
 {
+        blk_delete_timer(rq);
+        blk_clear_rq_complete(rq);
         blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
 
         if (blk_rq_tagged(rq))
@@ -1650,6 +1655,8 @@ static void end_that_request_last(struct request *req, int error)
 {
         struct gendisk *disk = req->rq_disk;
 
+        blk_delete_timer(req);
+
         if (blk_rq_tagged(req))
                 blk_queue_end_tag(req->q, req);