lkml.org 
[lkml]   [2014]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 14/14] fnic: reject device resets without assigned tags for the blk-mq case
On 06/25/2014 06:52 PM, Christoph Hellwig wrote:
> Current the midlayer fakes up a struct request for the explicit reset
> ioctls, and those don't have a tag allocated to them. The fnic driver pokes
> into midlayer structures to paper over this design issue, but that won't
> work for the blk-mq case.
>
> Either someone who can actually test the hardware will have to come up with
> a similar hack for the blk-mq case, or we'll have to bite the bullet and fix
> the way the EH ioctls work for real, but until that happens we fail these
> explicit requests here.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Cc: Hiral Patel <hiralpat@cisco.com>
> Cc: Suma Ramars <sramars@cisco.com>
> Cc: Brian Uchino <buchino@cisco.com>
> ---
> drivers/scsi/fnic/fnic_scsi.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c
> index 3f88f56..961bdf5 100644
> --- a/drivers/scsi/fnic/fnic_scsi.c
> +++ b/drivers/scsi/fnic/fnic_scsi.c
> @@ -2224,6 +2224,22 @@ int fnic_device_reset(struct scsi_cmnd *sc)
>
> tag = sc->request->tag;
> if (unlikely(tag < 0)) {
> + /*
> + * XXX(hch): current the midlayer fakes up a struct
> + * request for the explicit reset ioctls, and those
> + * don't have a tag allocated to them. The below
> + * code pokes into midlayer structures to paper over
> + * this design issue, but that won't work for blk-mq.
> + *
> + * Either someone who can actually test the hardware
> + * will have to come up with a similar hack for the
> + * blk-mq case, or we'll have to bite the bullet and
> + * fix the way the EH ioctls work for real, but until
> + * that happens we fail these explicit requests here.
> + */
> + if (shost_use_blk_mq(sc->device->host))
> + goto fnic_device_reset_end;
> +
> tag = fnic_scsi_host_start_tag(fnic, sc);
> if (unlikely(tag == SCSI_NO_TAG))
> goto fnic_device_reset_end;
>
The correct fix will be part of my EH redesign.
Plan is to allocate a real command/request for EH, which then can be
used to send down EH TMFs and related commands.

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2014-07-11 23:22    [W:0.500 / U:1.660 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site