scsi: Create two versions of scsi_internal_device_unblock()

This will make it easier to serialize SCSI device state changes through
a mutex.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 32 insertions, 14 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index fc8f394eb854..f0eb55744513 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -3023,24 +3023,22 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
 }
  
 /**
- * scsi_internal_device_unblock - resume a device after a block request
+ * scsi_internal_device_unblock_nowait - resume a device after a block request
  * @sdev:	device to resume
- * @new_state:	state to set devices to after unblocking
+ * @new_state:	state to set the device to after unblocking
  *
- * Called by scsi lld's or the midlayer to restart the device queue
- * for the previously suspended scsi device.  Called from interrupt or
- * normal process context.
+ * Restart the device queue for a previously suspended SCSI device. Does not
+ * sleep.
  *
- * Returns zero if successful or error if not.
+ * Returns zero if successful or a negative error code upon failure.
  *
- * Notes:       
- *	This routine transitions the device to the SDEV_RUNNING state
- *	or to one of the offline states (which must be a legal transition)
- *	allowing the midlayer to goose the queue for this device.
+ * Notes:
+ * This routine transitions the device to the SDEV_RUNNING state or to one of
+ * the offline states (which must be a legal transition) allowing the midlayer
+ * to goose the queue for this device.
  */
-int
-scsi_internal_device_unblock(struct scsi_device *sdev,
-			     enum scsi_device_state new_state)
+int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
+					enum scsi_device_state new_state)
 {
 	struct request_queue *q = sdev->request_queue; 
 	unsigned long flags;
@@ -3072,7 +3070,27 @@ scsi_internal_device_unblock(struct scsi_device *sdev,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
+EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
+
+/**
+ * scsi_internal_device_unblock - resume a device after a block request
+ * @sdev:	device to resume
+ * @new_state:	state to set the device to after unblocking
+ *
+ * Restart the device queue for a previously suspended SCSI device. May sleep.
+ *
+ * Returns zero if successful or a negative error code upon failure.
+ *
+ * Notes:
+ * This routine transitions the device to the SDEV_RUNNING state or to one of
+ * the offline states (which must be a legal transition) allowing the midlayer
+ * to goose the queue for this device.
+ */
+static int scsi_internal_device_unblock(struct scsi_device *sdev,
+					enum scsi_device_state new_state)
+{
+	return scsi_internal_device_unblock_nowait(sdev, new_state);
+}
 
 static void
 device_block(struct scsi_device *sdev, void *data)