diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 51fcd46be265..e1929bcc4e53 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2638,6 +2638,32 @@ static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) return 0; } +void scsi_start_queue(struct scsi_device *sdev) +{ + if (cmpxchg(&sdev->queue_stopped, 1, 0)) + blk_mq_unquiesce_queue(sdev->request_queue); +} + +static void scsi_stop_queue(struct scsi_device *sdev, bool nowait) +{ + /* + * The atomic variable of ->queue_stopped covers that + * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue. + * + * However, we still need to wait until quiesce is done + * in case that queue has been stopped. + */ + if (!cmpxchg(&sdev->queue_stopped, 0, 1)) { + if (nowait) + blk_mq_quiesce_queue_nowait(sdev->request_queue); + else + blk_mq_quiesce_queue(sdev->request_queue); + } else { + if (!nowait) + blk_mq_wait_quiesce_done(sdev->request_queue); + } +} + /** * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state * @sdev: device to block @@ -2662,7 +2688,7 @@ int scsi_internal_device_block_nowait(struct scsi_device *sdev) * request queue. */ if (!ret) - blk_mq_quiesce_queue_nowait(sdev->request_queue); + scsi_stop_queue(sdev, true); return ret; } EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); @@ -2689,19 +2715,12 @@ static int scsi_internal_device_block(struct scsi_device *sdev) mutex_lock(&sdev->state_mutex); err = __scsi_internal_device_block_nowait(sdev); if (err == 0) - blk_mq_quiesce_queue(sdev->request_queue); + scsi_stop_queue(sdev, false); mutex_unlock(&sdev->state_mutex); return err; } -void scsi_start_queue(struct scsi_device *sdev) -{ - struct request_queue *q = sdev->request_queue; - - blk_mq_unquiesce_queue(q); -} - /** * scsi_internal_device_unblock_nowait - resume a device after a block request * @sdev: device to resume |