[PATCH v5 0/14] Fix race conditions related to stopping block layer queues

[Jens Axboe]

On 10/28/2016 06:18 PM, Bart Van Assche wrote:
> Hello Jens,
>
> Multiple block drivers need the functionality to stop a request queue
> and to wait until all ongoing request_fn() / queue_rq() calls have
> finished without waiting until all outstanding requests have finished.
> Hence this patch series that introduces the blk_mq_quiesce_queue()
> function. The dm-mq, SRP and NVMe patches in this patch series are three
> examples of where these functions are useful. These patches have been
> tested on top of kernel v4.9-rc2. The following tests have been run to
> verify this patch series:
> - Mike's mptest suite that stress-tests dm-multipath.
> - My own srp-test suite that stress-tests SRP on top of dm-multipath.
> - fio on top of the NVMeOF host driver that was connected to the NVMeOF
>   target driver on the same host.
> - Laurence verified the previous version (v3) of this patch series by
>   running it through the Red Hat SRP and NVMe test suites.
>
> The changes compared to the third version of this patch series are:
> - Added a blk_mq_stop_hw_queues() call in blk_mq_quiesce_queue() as
>   requested by Ming Lei.
> - Modified scsi_unblock_target() such that it waits until
>   .queuecommand() finished. Unexported scsi_wait_for_queuecommand().
> - Reordered the two NVMe patches.
> - Added a patch that avoids that blk_mq_requeue_work() restarts stopped
>   queues.
> - Added a patch that removes blk_mq_cancel_requeue_work().

Bart, I have applied the series, except patches 11+12. I don't mind
taking them through the block tree, but they can go through the SCSI
tree as well. Let me know what folks think.

-- 
Jens Axboe