scsi: Avoid that SCSI queues get stuck
authorBart Van Assche <bart.vanassche@sandisk.com>
Fri, 7 Apr 2017 18:16:53 +0000 (11:16 -0700)
committerJens Axboe <axboe@fb.com>
Fri, 7 Apr 2017 18:27:08 +0000 (12:27 -0600)
commit36e3cf273977da34a760d513e1bef8431a9abaa0
tree945fe3f10fb8ea94e77e81b39c036e34354c81b7
parent7587a5ae7eef0439f7be31f1b5959af062bbc5ec
scsi: Avoid that SCSI queues get stuck

If a .queue_rq() function returns BLK_MQ_RQ_QUEUE_BUSY then the block
driver that implements that function is responsible for rerunning the
hardware queue once requests can be queued again successfully.

commit 52d7f1b5c2f3 ("blk-mq: Avoid that requeueing starts stopped
queues") removed the blk_mq_stop_hw_queue() call from scsi_queue_rq()
for the BLK_MQ_RQ_QUEUE_BUSY case. Hence change all calls to functions
that are intended to rerun a busy queue such that these examine all
hardware queues instead of only stopped queues.

Since no other functions than scsi_internal_device_block() and
scsi_internal_device_unblock() should ever stop or restart a SCSI
queue, change the blk_mq_delay_queue() call into a
blk_mq_delay_run_hw_queue() call.

Fixes: commit 52d7f1b5c2f3 ("blk-mq: Avoid that requeueing starts stopped queues")
Fixes: commit 7e79dadce222 ("blk-mq: stop hardware queue in blk_mq_delay_queue()")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Long Li <longli@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/scsi/scsi_lib.c