Re: [PATCH 05/11] block: drop custom queue draining used by scsi_transport_{iscsi|fc}

[Mike Christie <michaelc-hcNo3dDEHLuVc3sceRu5cw@public.gmane.org>]

On 04/26/2012 04:59 PM, Tejun Heo wrote:
> iscsi_remove_host() uses bsg_remove_queue() which implements custom
> queue draining.  fc_bsg_remove() open-codes mostly identical logic.
> 
> The draining logic isn't correct in that blk_stop_queue() doesn't
> prevent new requests from being queued - it just stops processing, so
> nothing prevents new requests to be queued after the logic determines
> that the queue is drained.
> 
> blk_cleanup_queue() now implements proper queue draining and these
> custom draining logics aren't necessary.  Drop them and use
> bsg_unregister_queue() + blk_cleanup_queue() instead.
> 
> Signed-off-by: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> Cc: James Bottomley <James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>
> Cc: Mike Christie <michaelc-hcNo3dDEHLuVc3sceRu5cw@public.gmane.org>
> Cc: James Smart <james.smart-laKkSmNT4hbQT0dZR+AlfA@public.gmane.org>
> ---
>  block/bsg-lib.c                     |   53 -----------------------------------
>  drivers/scsi/scsi_transport_fc.c    |   38 -------------------------
>  drivers/scsi/scsi_transport_iscsi.c |    2 +-

iSCSI changes worked ok for me. I replicated the problem that the old
code was supposed to fix and verified the new code worked ok. I also
tested the FC code briefly (I do not have a proper setup to really
stress it), and it worked ok.

Thanks for killing that code for us.

Reviewed-by: Mike Christie <michaelc@.cs.wisc.edu>