@@ -2645,6 +2645,14 @@ scsi_target_resume(struct scsi_target *starget)
}
EXPORT_SYMBOL(scsi_target_resume);
+static int __scsi_internal_device_block_nowait(struct scsi_device *sdev)
+{
+ if (scsi_device_set_state(sdev, SDEV_BLOCK))
+ return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
+
+ return 0;
+}
+
/**
* scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
* @sdev: device to block
@@ -2661,24 +2669,16 @@ EXPORT_SYMBOL(scsi_target_resume);
*/
int scsi_internal_device_block_nowait(struct scsi_device *sdev)
{
- struct request_queue *q = sdev->request_queue;
- int err = 0;
-
- err = scsi_device_set_state(sdev, SDEV_BLOCK);
- if (err) {
- err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
-
- if (err)
- return err;
- }
+ int ret = __scsi_internal_device_block_nowait(sdev);
/*
* The device has transitioned to SDEV_BLOCK. Stop the
* block layer from calling the midlayer with this device's
* request queue.
*/
- blk_mq_quiesce_queue_nowait(q);
- return 0;
+ if (!ret)
+ blk_mq_quiesce_queue_nowait(sdev->request_queue);
+ return ret;
}
EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
@@ -2699,13 +2699,12 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
*/
static int scsi_internal_device_block(struct scsi_device *sdev)
{
- struct request_queue *q = sdev->request_queue;
int err;
mutex_lock(&sdev->state_mutex);
- err = scsi_internal_device_block_nowait(sdev);
+ err = __scsi_internal_device_block_nowait(sdev);
if (err == 0)
- blk_mq_quiesce_queue(q);
+ blk_mq_quiesce_queue(sdev->request_queue);
mutex_unlock(&sdev->state_mutex);
return err;
For fixing queue quiesce race between driver and block layer(elevator switch, update nr_requests, ...), we need to support concurrent quiesce and unquiesce, which requires the two to be balanced. blk_mq_quiesce_queue() calls blk_mq_quiesce_queue_nowait() for updating quiesce depth and marking the flag, then scsi_internal_device_block() calls blk_mq_quiesce_queue_nowait() two times actually. Fix the double quiesce and keep quiesce and unquiesce balanced. Reported-by: Yi Zhang <yi.zhang@redhat.com> Fixes: e70feb8b3e68 ("blk-mq: support concurrent queue quiesce/unquiesce") Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/scsi/scsi_lib.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-)