[PATCH] Undo __scsi_kill_request()

[Hannes Reinecke <hare@suse.de>]

[-- Attachment #1: Type: text/plain, Size: 668 bytes --]

Hi all,

the main goal of using FAILFAST is to have requests terminated
early if the link to the target is lost. This is indicated by
the device state SDEV_BLOCK.
So we only have to check for the FAILFAST flag when we check
the queue state in scsi_prep_fn().

This patch reverts parts of the original patch
'Do not requeue requests if REQ_FAILFAST is set'
as the return values of ->queuecommand() should not be affected
by the FAILFAST setting.

James, please apply.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)

[-- Attachment #2: scsi-undo-__kill-request --]
[-- Type: text/plain, Size: 1256 bytes --]

Remove __scsi_kill_request()

We only have to evaluate the FAILFAST flag if the device is in
status SDEV_BLOCK, as this indicates a link failure.
The return status of ->queuecommand() should not be affected by
this, so remove the check there.

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1148c40..6f4862b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1424,17 +1424,6 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
 	return 1;
 }
 
-static void __scsi_kill_request(struct request *req)
-{
-	struct scsi_cmnd *cmd = req->special;
-	struct scsi_device *sdev = cmd->device;
-
-	cmd->result = DID_NO_CONNECT << 16;
-	atomic_inc(&cmd->device->iorequest_cnt);
-	sdev->device_busy--;
-	__scsi_done(cmd);
-}
-
 /*
  * Kill a request for a dead device
  */
@@ -1639,12 +1628,9 @@ static void scsi_request_fn(struct request_queue *q)
 	 * later time.
 	 */
 	spin_lock_irq(q->queue_lock);
-	if (unlikely(req->cmd_flags & REQ_FAILFAST))
-		__scsi_kill_request(req);
-	else {
-		blk_requeue_request(q, req);
-		sdev->device_busy--;
-	}
+	blk_requeue_request(q, req);
+	sdev->device_busy--;
+
 	if(sdev->device_busy == 0)
 		blk_plug_device(q);
  out: