[PATCH] mptsas: fixed hot-removal processing

[PATCH] mptsas: fixed hot-removal processing

[Kei Tokunaga]

Hi Kashyap,

This patch fixes mptsas disk hot-removal processing.  The
hot-removal processing doesn't complete because of this condition.

  drivers/message/fusion/mptsas.c:
  mptsas_taskmgmt_complete()

  if ((mptsas_find_vtarget(ioc, channel, id)) && !ioc->fw_events_off)
    mptsas_queue_device_delete(...);

mptsas_queue_device_delete(), which must be called for
hot-removal, never gets called because mptsas_find_vtarget()
always returns 0 here.  At that time, the vtarget has already
been freed in mptsas_target_destroy(), and also the scsi_device
has been marked as SDEV_DEL.

As a result of the issue, port deletion functions won't get
called and the device ends up being in an incomplete state.
(Some data structures and sysfs entries, which should be
removed in hot-removal, remain.)  One side effect of this is
that a hot-addition of the device (bringing the device back
on) fails.

This patch just removes mptsas_find_vtarget() from the if-state
condition.

This applies to 2.6.34-rc3.

Thanks,
Kei


Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
---

 linux-2.6.34-rc3-kei/drivers/message/fusion/mptsas.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN drivers/message/fusion/mptsas.c~fix-mptsas_hot_removal drivers/message/fusion/mptsas.c
--- linux-2.6.34-rc3/drivers/message/fusion/mptsas.c~fix-mptsas_hot_removal	2010-04-07 16:47:36.000000000 +0900
+++ linux-2.6.34-rc3-kei/drivers/message/fusion/mptsas.c	2010-04-07 16:48:17.000000000 +0900
@@ -1221,7 +1221,7 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *io
 	 * enable work queue to remove device from upper layers
 	 */
 	list_del(&target_reset_list->list);
-	if ((mptsas_find_vtarget(ioc, channel, id)) && !ioc->fw_events_off)
+	if (!ioc->fw_events_off)
 		mptsas_queue_device_delete(ioc,
 			&target_reset_list->sas_event_data);
 

_

Re: [PATCH] mptsas: fixed hot-removal processing

[Kei Tokunaga]

Kei Tokunaga wrote:
> Hi Kashyap,
> 
> This patch fixes mptsas disk hot-removal processing.  The
> hot-removal processing doesn't complete because of this condition.
> 
>   drivers/message/fusion/mptsas.c:
>   mptsas_taskmgmt_complete()
> 
>   if ((mptsas_find_vtarget(ioc, channel, id)) && !ioc->fw_events_off)
>     mptsas_queue_device_delete(...);
> 
> mptsas_queue_device_delete(), which must be called for
> hot-removal, never gets called because mptsas_find_vtarget()
> always returns 0 here.  At that time, the vtarget has already
> been freed in mptsas_target_destroy(), and also the scsi_device
> has been marked as SDEV_DEL.
> 
> As a result of the issue, port deletion functions won't get
> called and the device ends up being in an incomplete state.
> (Some data structures and sysfs entries, which should be
> removed in hot-removal, remain.)  One side effect of this is
> that a hot-addition of the device (bringing the device back
> on) fails.
> 
> This patch just removes mptsas_find_vtarget() from the if-state
> condition.
> 
> This applies to 2.6.34-rc3.

Kashyap, can you please give it an ACK?  I confirmed it still
applies to the latest git tree (scsi-misc-2.6).

Thanks,
Kei


> Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
> ---
> 
>  linux-2.6.34-rc3-kei/drivers/message/fusion/mptsas.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff -puN drivers/message/fusion/mptsas.c~fix-mptsas_hot_removal drivers/message/fusion/mptsas.c
> --- linux-2.6.34-rc3/drivers/message/fusion/mptsas.c~fix-mptsas_hot_removal	2010-04-07 16:47:36.000000000 +0900
> +++ linux-2.6.34-rc3-kei/drivers/message/fusion/mptsas.c	2010-04-07 16:48:17.000000000 +0900
> @@ -1221,7 +1221,7 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *io
>  	 * enable work queue to remove device from upper layers
>  	 */
>  	list_del(&target_reset_list->list);
> -	if ((mptsas_find_vtarget(ioc, channel, id)) && !ioc->fw_events_off)
> +	if (!ioc->fw_events_off)
>  		mptsas_queue_device_delete(ioc,
>  			&target_reset_list->sas_event_data);
>  
> 
> _
> 
> 
> 
> 
> 

RE: [PATCH] mptsas: fixed hot-removal processing

[Desai, Kashyap]

> -----Original Message-----
> From: Kei Tokunaga [mailto:tokunaga.keiich@jp.fujitsu.com]
> Sent: Tuesday, July 20, 2010 6:00 AM
> To: Desai, Kashyap
> Cc: linux-scsi; Kei Tokunaga
> Subject: Re: [PATCH] mptsas: fixed hot-removal processing
> 
> Kei Tokunaga wrote:
> > Hi Kashyap,
> >
> > This patch fixes mptsas disk hot-removal processing.  The
> > hot-removal processing doesn't complete because of this condition.
> >
> >   drivers/message/fusion/mptsas.c:
> >   mptsas_taskmgmt_complete()
> >
> >   if ((mptsas_find_vtarget(ioc, channel, id)) && !ioc->fw_events_off)
> >     mptsas_queue_device_delete(...);
> >
> > mptsas_queue_device_delete(), which must be called for
> > hot-removal, never gets called because mptsas_find_vtarget()
> > always returns 0 here.  At that time, the vtarget has already
> > been freed in mptsas_target_destroy(), and also the scsi_device
> > has been marked as SDEV_DEL.
> >
> > As a result of the issue, port deletion functions won't get
> > called and the device ends up being in an incomplete state.
> > (Some data structures and sysfs entries, which should be
> > removed in hot-removal, remain.)  One side effect of this is
> > that a hot-addition of the device (bringing the device back
> > on) fails.
> >
> > This patch just removes mptsas_find_vtarget() from the if-state
> > condition.
> >
> > This applies to 2.6.34-rc3.
> 
> Kashyap, can you please give it an ACK?  I confirmed it still
> applies to the latest git tree (scsi-misc-2.6).

Kei,
This patch has valid code change. I have also validated patch works fine for your explained case.
Please consider this patch as ACKed.

James, Can we have this patch committed in next merge window?

~Kashyap
> 
> Thanks,
> Kei
> 
> 
> > Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
> > ---
> >
> >  linux-2.6.34-rc3-kei/drivers/message/fusion/mptsas.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff -puN drivers/message/fusion/mptsas.c~fix-mptsas_hot_removal
> drivers/message/fusion/mptsas.c
> > --- linux-2.6.34-rc3/drivers/message/fusion/mptsas.c~fix-
> mptsas_hot_removal	2010-04-07 16:47:36.000000000 +0900
> > +++ linux-2.6.34-rc3-kei/drivers/message/fusion/mptsas.c	2010-04-07
> 16:48:17.000000000 +0900
> > @@ -1221,7 +1221,7 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *io
> >  	 * enable work queue to remove device from upper layers
> >  	 */
> >  	list_del(&target_reset_list->list);
> > -	if ((mptsas_find_vtarget(ioc, channel, id)) && !ioc-
> >fw_events_off)
> > +	if (!ioc->fw_events_off)
> >  		mptsas_queue_device_delete(ioc,
> >  			&target_reset_list->sas_event_data);
> >
> >
> > _
> >
> >
> >
> >
> >