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, 18 insertions, 12 deletions

diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 3a1af551191e..7ab344afb16f 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -101,18 +101,7 @@ static struct notifier_block __cpuinitdata blk_cpu_notifier = {
         .notifier_call  = blk_cpu_notify,
 };
 
-/**
- * blk_complete_request - end I/O on a request
- * @req:      the request being processed
- *
- * Description:
- *     Ends all I/O on a request. It does not handle partial completions,
- *     unless the driver actually implements this in its completion callback
- *     through requeueing. The actual completion happens out-of-order,
- *     through a softirq handler. The user must have registered a completion
- *     callback through blk_queue_softirq_done().
- **/
-void blk_complete_request(struct request *req)
+void __blk_complete_request(struct request *req)
 {
         struct request_queue *q = req->q;
         unsigned long flags;
@@ -151,6 +140,23 @@ do_local:
 
         local_irq_restore(flags);
 }
+
+/**
+ * blk_complete_request - end I/O on a request
+ * @req:      the request being processed
+ *
+ * Description:
+ *     Ends all I/O on a request. It does not handle partial completions,
+ *     unless the driver actually implements this in its completion callback
+ *     through requeueing. The actual completion happens out-of-order,
+ *     through a softirq handler. The user must have registered a completion
+ *     callback through blk_queue_softirq_done().
+ **/
+void blk_complete_request(struct request *req)
+{
+        if (!blk_mark_rq_complete(req))
+                __blk_complete_request(req);
+}
 EXPORT_SYMBOL(blk_complete_request);
 
 __init int blk_softirq_init(void)