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>

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 321f854947b422871afcc7415826e5db54669142..2396e89dead00247c36e4e05880f3f9a3939d439 100644 (file)
--- 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 3ac677c48168678d8ee71c3a44ccb9ba03ad3e10..bf7342748f32ec03546c6408214e81fc2bfd5b88 100644 (file)
--- 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);
 }