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>
diff --git a/drivers/scsi/ncr53c8xx.c b/drivers/scsi/ncr53c8xx.c
index c57c94c..3b7240e 100644
--- a/drivers/scsi/ncr53c8xx.c
+++ b/drivers/scsi/ncr53c8xx.c
@@ -4170,8 +4170,8 @@
 	**
 	**----------------------------------------------------
 	*/
-	if (np->settle_time && cmd->timeout_per_command >= HZ) {
-		u_long tlimit = jiffies + cmd->timeout_per_command - HZ;
+	if (np->settle_time && cmd->request->timeout >= HZ) {
+		u_long tlimit = jiffies + cmd->request->timeout - HZ;
 		if (time_after(np->settle_time, tlimit))
 			np->settle_time = tlimit;
 	}