struct kmem_cache *scsi_sdb_cache;
+/*
+ * When to reinvoke queueing after a resource shortage. It's 3 msecs to
+ * not change behaviour from the previous unplug mechanism, experimentation
+ * may prove this needs changing.
+ */
+#define SCSI_QUEUE_DELAY 3
+
static void scsi_run_queue(struct request_queue *q);
/*
/*
* Requeue this command. It will go before all other commands
* that are already in the queue.
- *
- * NOTE: there is magic here about the way the queue is plugged if
- * we have no outstanding commands.
- *
- * Although we *don't* plug the queue, we call the request
- * function. The SCSI request function detects the blocked condition
- * and plugs the queue appropriately.
- */
+ */
spin_lock_irqsave(q->queue_lock, flags);
blk_requeue_request(q, cmd->request);
spin_unlock_irqrestore(q->queue_lock, flags);
&sdev->request_queue->queue_flags);
if (flagset)
queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
- __blk_run_queue(sdev->request_queue);
+ __blk_run_queue(sdev->request_queue, false);
if (flagset)
queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
spin_unlock(sdev->request_queue->queue_lock);
}
EXPORT_SYMBOL(scsi_release_buffers);
+static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
+{
+ int error = 0;
+
+ switch(host_byte(result)) {
+ case DID_TRANSPORT_FAILFAST:
+ error = -ENOLINK;
+ break;
+ case DID_TARGET_FAILURE:
+ cmd->result |= (DID_OK << 16);
+ error = -EREMOTEIO;
+ break;
+ case DID_NEXUS_FAILURE:
+ cmd->result |= (DID_OK << 16);
+ error = -EBADE;
+ break;
+ default:
+ error = -EIO;
+ break;
+ }
+
+ return error;
+}
+
/*
* Function: scsi_io_completion()
*
req->sense_len = len;
}
if (!sense_deferred)
- error = -EIO;
+ error = __scsi_error_from_host_byte(cmd, result);
}
req->resid_len = scsi_get_resid(cmd);
if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
return;
- error = -EIO;
+ error = __scsi_error_from_host_byte(cmd, result);
if (host_byte(result) == DID_RESET) {
/* Third party bus reset or reset for error recovery
description = "Host Data Integrity Failure";
action = ACTION_FAIL;
error = -EILSEQ;
+ /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
+ } else if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
+ (cmd->cmnd[0] == UNMAP ||
+ cmd->cmnd[0] == WRITE_SAME_16 ||
+ cmd->cmnd[0] == WRITE_SAME)) {
+ description = "Discard failure";
+ action = ACTION_FAIL;
} else
action = ACTION_FAIL;
break;
cmd->request = req;
cmd->cmnd = req->cmd;
+ cmd->prot_op = SCSI_PROT_NORMAL;
return cmd;
}
case BLKPREP_DEFER:
/*
* If we defer, the blk_peek_request() returns NULL, but the
- * queue must be restarted, so we plug here if no returning
- * command will automatically do that.
+ * queue must be restarted, so we schedule a callback to happen
+ * shortly.
*/
if (sdev->device_busy == 0)
- blk_plug_device(q);
+ blk_delay_queue(q, SCSI_QUEUE_DELAY);
break;
default:
req->cmd_flags |= REQ_DONTPREP;
sdev_printk(KERN_INFO, sdev,
"unblocking device at zero depth\n"));
} else {
- blk_plug_device(q);
+ blk_delay_queue(q, SCSI_QUEUE_DELAY);
return 0;
}
}
* the host is no longer able to accept any more requests.
*/
shost = sdev->host;
- while (!blk_queue_plugged(q)) {
+ for (;;) {
int rtn;
/*
* get next queueable request. We do this early to make sure
*/
rtn = scsi_dispatch_cmd(cmd);
spin_lock_irq(q->queue_lock);
- if(rtn) {
- /* we're refusing the command; because of
- * the way locks get dropped, we need to
- * check here if plugging is required */
- if(sdev->device_busy == 0)
- blk_plug_device(q);
-
- break;
- }
+ if (rtn)
+ goto out_delay;
}
goto out;
spin_lock_irq(q->queue_lock);
blk_requeue_request(q, req);
sdev->device_busy--;
- if(sdev->device_busy == 0)
- blk_plug_device(q);
- out:
+out_delay:
+ if (sdev->device_busy == 0)
+ blk_delay_queue(q, SCSI_QUEUE_DELAY);
+out:
/* must be careful here...if we trigger the ->remove() function
* we cannot be holding the q lock */
spin_unlock_irq(q->queue_lock);