scsi: centralize command re-queueing in scsi_dispatch_fn

Make sure we only have the logic for requeing commands in one place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

2 files changed, 18 insertions, 26 deletions

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 321f854947b4..2396e89dead0 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -645,9 +645,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
                  * returns an immediate error upwards, and signals
                  * that the device is no longer present */
                 cmd->result = DID_NO_CONNECT << 16;
-                scsi_done(cmd);
-                /* return 0 (because the command has been processed) */
-                goto out;
+                goto done;
         }
 
         /* Check to see if the scsi lld made this device blocked. */
@@ -659,17 +657,9 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
                  * occur until the device transitions out of the
                  * suspend state.
                  */
-
-                scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
-
                 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
                         "queuecommand : device blocked\n"));
-
-                /*
-                 * NOTE: rtn is still zero here because we don't need the
-                 * queue to be plugged on return (it's already stopped)
-                 */
-                goto out;
+                return SCSI_MLQUEUE_DEVICE_BUSY;
         }
 
         /*
@@ -693,20 +683,19 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
                                "cdb_size=%d host->max_cmd_len=%d\n",
                                cmd->cmd_len, cmd->device->host->max_cmd_len));
                 cmd->result = (DID_ABORT << 16);
-
-                scsi_done(cmd);
-                goto out;
+                goto done;
         }
 
         if (unlikely(host->shost_state == SHOST_DEL)) {
                 cmd->result = (DID_NO_CONNECT << 16);
-                scsi_done(cmd);
-        } else {
-                trace_scsi_dispatch_cmd_start(cmd);
-                cmd->scsi_done = scsi_done;
-                rtn = host->hostt->queuecommand(host, cmd);
+                goto done;
+
         }
 
+        trace_scsi_dispatch_cmd_start(cmd);
+
+        cmd->scsi_done = scsi_done;
+        rtn = host->hostt->queuecommand(host, cmd);
         if (rtn) {
                 trace_scsi_dispatch_cmd_error(cmd, rtn);
                 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
@@ -715,12 +704,12 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 
                 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
                         "queuecommand : request rejected\n"));
-
-                scsi_queue_insert(cmd, rtn);
         }
 
- out:
         return rtn;
+ done:
+        scsi_done(cmd);
+        return 0;
 }
 
 /**
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3ac677c48168..bf7342748f32 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1557,9 +1557,12 @@ static void scsi_request_fn(struct request_queue *q)
                  * Dispatch the command to the low-level driver.
                  */
                 rtn = scsi_dispatch_cmd(cmd);
-                spin_lock_irq(q->queue_lock);
-                if (rtn)
+                if (rtn) {
+                        scsi_queue_insert(cmd, rtn);
+                        spin_lock_irq(q->queue_lock);
                         goto out_delay;
+                }
+                spin_lock_irq(q->queue_lock);
         }
 
         return;
@@ -1579,7 +1582,7 @@ static void scsi_request_fn(struct request_queue *q)
         blk_requeue_request(q, req);
         sdev->device_busy--;
 out_delay:
-        if (sdev->device_busy == 0)
+        if (sdev->device_busy == 0 && !scsi_device_blocked(sdev))
                 blk_delay_queue(q, SCSI_QUEUE_DELAY);
 }