Re: [PATCH] sd_zbc: Write unlock zone from sd_uninit_cmnd()

[Bart Van Assche <Bart.VanAssche@wdc.com>]

On Tue, 2017-08-08 at 13:17 +0900, Damien Le Moal wrote:
> Releasing the write lock of a zone when the write commnand that
                                                    ^^^^^^^^
                                                    command?
> acquired the lock completes can cause deadlocks with scsi-mq due to
> potential queue reordering if the lock owning request is requeued and
> not executed.

Please note that even with scsi-sq requeueing can cause request reordering.

> Since sd_uninit_cmnd() is always called when a request is requeued,
> call sd_zbc_write_unlock_zone() from that function for write requests
> that acquired a zone lock. Acquisition of a zone lock by a write command
> is indicated using the new command flag SCMD_ZONE_WRITE_LOCK.

Hello Damien,

Since this patch differs slightly from the version that was posted a few
days ago, should a "v2" label have been added to the subject and should a
changelog have been included? Anyway:

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>