1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index fcdc585278bf..7e3d954c9cac 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1641,6 +1641,87 @@ static void scsi_softirq_done(struct request *rq)
 }
 
 /**
+ * scsi_dispatch_command - Dispatch a command to the low-level driver.
+ * @cmd: command block we are dispatching.
+ *
+ * Return: nonzero return request was rejected and device's queue needs to be
+ * plugged.
+ */
+static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
+{
+        struct Scsi_Host *host = cmd->device->host;
+        int rtn = 0;
+
+        atomic_inc(&cmd->device->iorequest_cnt);
+
+        /* check if the device is still usable */
+        if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
+                /* in SDEV_DEL we error all commands. DID_NO_CONNECT
+                 * returns an immediate error upwards, and signals
+                 * that the device is no longer present */
+                cmd->result = DID_NO_CONNECT << 16;
+                goto done;
+        }
+
+        /* Check to see if the scsi lld made this device blocked. */
+        if (unlikely(scsi_device_blocked(cmd->device))) {
+                /*
+                 * in blocked state, the command is just put back on
+                 * the device queue.  The suspend state has already
+                 * blocked the queue so future requests should not
+                 * occur until the device transitions out of the
+                 * suspend state.
+                 */
+                SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
+                        "queuecommand : device blocked\n"));
+                return SCSI_MLQUEUE_DEVICE_BUSY;
+        }
+
+        /* Store the LUN value in cmnd, if needed. */
+        if (cmd->device->lun_in_cdb)
+                cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
+                               (cmd->device->lun << 5 & 0xe0);
+
+        scsi_log_send(cmd);
+
+        /*
+         * Before we queue this command, check if the command
+         * length exceeds what the host adapter can handle.
+         */
+        if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
+                SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
+                               "queuecommand : command too long. "
+                               "cdb_size=%d host->max_cmd_len=%d\n",
+                               cmd->cmd_len, cmd->device->host->max_cmd_len));
+                cmd->result = (DID_ABORT << 16);
+                goto done;
+        }
+
+        if (unlikely(host->shost_state == SHOST_DEL)) {
+                cmd->result = (DID_NO_CONNECT << 16);
+                goto done;
+
+        }
+
+        trace_scsi_dispatch_cmd_start(cmd);
+        rtn = host->hostt->queuecommand(host, cmd);
+        if (rtn) {
+                trace_scsi_dispatch_cmd_error(cmd, rtn);
+                if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
+                    rtn != SCSI_MLQUEUE_TARGET_BUSY)
+                        rtn = SCSI_MLQUEUE_HOST_BUSY;
+
+                SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
+                        "queuecommand : request rejected\n"));
+        }
+
+        return rtn;
+ done:
+        cmd->scsi_done(cmd);
+        return 0;
+}
+
+/**
  * scsi_done - Invoke completion on finished SCSI command.
  * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
  * ownership back to SCSI Core -- i.e. the LLDD has finished with it.