On 5/17/23 18:16, Ming Lei wrote:
On Wed, May 17, 2023 at 04:09:27PM -0700, Bart Van Assche wrote:
@@ -1767,7 +1767,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
break;
case BLK_STS_RESOURCE:
case BLK_STS_ZONE_RESOURCE:
- if (scsi_device_blocked(sdev))
+ if (scsi_device_blocked(sdev) || shost->host_self_blocked)
ret = BLK_STS_DEV_RESOURCE;
What if scsi_unblock_requests() is just called after the above check and
before returning to block layer core? Then this request is invisible to
scsi_run_host_queues()<-scsi_unblock_requests(), and io hang happens.
If returning BLK_STS_DEV_RESOURCE could cause an I/O hang, wouldn't that
be a bug in the block layer core? Isn't the block layer core expected to
rerun the queue after a delay if a block driver returns
BLK_STS_DEV_RESOURCE? See also blk_mq_dispatch_rq_list().
Thanks,
Bart.
