Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-26 Thread Hannes Reinecke
On 04/25/2013 05:31 PM, Mike Snitzer wrote: On Thu, Apr 25 2013 at 10:50am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Thu, 25 Apr 2013, Mike Snitzer wrote: On Thu, Apr 25 2013 at 9:48am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Mon, 22 Apr 2013, Mike Snitzer

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-26 Thread Mike Snitzer
On Fri, Apr 26 2013 at 2:05am -0400, Hannes Reinecke h...@suse.de wrote: On 04/25/2013 05:31 PM, Mike Snitzer wrote: On Thu, Apr 25 2013 at 10:50am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Thu, 25 Apr 2013, Mike Snitzer wrote: On Thu, Apr 25 2013 at 9:48am -0400,

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Mikulas Patocka
On Mon, 22 Apr 2013, Mike Snitzer wrote: I spoke with Hannes at LSF, to address the potential crashes in the endio path (e.g. stpg_endio) we'd have to bump the scsi_dh_data kref where appropriate (e.g. for ALUA kref_get in submit_stpg and kref_put in stpg_endio). But that is just the tip

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Mike Snitzer
On Thu, Apr 25 2013 at 9:48am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Mon, 22 Apr 2013, Mike Snitzer wrote: I spoke with Hannes at LSF, to address the potential crashes in the endio path (e.g. stpg_endio) we'd have to bump the scsi_dh_data kref where appropriate (e.g.

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Mikulas Patocka
On Thu, 25 Apr 2013, Mike Snitzer wrote: On Thu, Apr 25 2013 at 9:48am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Mon, 22 Apr 2013, Mike Snitzer wrote: I spoke with Hannes at LSF, to address the potential crashes in the endio path (e.g. stpg_endio) we'd have to

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Bryn M. Reeves
On 04/25/2013 03:50 PM, Mikulas Patocka wrote: On Thu, 25 Apr 2013, Mike Snitzer wrote: The handler that is automatically attached _should_ be the correct handler. We now have the .match() hook for scsi_dh and it has made for reliable scsi_dh attachment of the correct handler. The EMC

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Mike Snitzer
On Thu, Apr 25 2013 at 10:50am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Thu, 25 Apr 2013, Mike Snitzer wrote: On Thu, Apr 25 2013 at 9:48am -0400, Mikulas Patocka mpato...@redhat.com wrote: On Mon, 22 Apr 2013, Mike Snitzer wrote: I spoke with Hannes

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Mike Snitzer
On Thu, Apr 25 2013 at 11:27am -0400, Bryn M. Reeves b...@redhat.com wrote: On 04/25/2013 03:50 PM, Mikulas Patocka wrote: On Thu, 25 Apr 2013, Mike Snitzer wrote: The handler that is automatically attached _should_ be the correct handler. We now have the .match() hook for scsi_dh and it has

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-25 Thread Bryn M. Reeves
On 04/25/2013 04:37 PM, Mike Snitzer wrote: clariion_match does more than check the vendor and product; if tpgs is set (ALUA mode) it returns false. So yes, while there is room for improvement in clariion_match the current code should work just fine with reasoning between emc and alua. Duh,

Re: [PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-22 Thread Mike Snitzer
On Mon, Apr 08 2013 at 5:50pm -0400, Mike Snitzer snit...@redhat.com wrote: Preallocate scsi_dh_data using scsi_dh_alloc_data() during table load but attach the scsi_dh for each path during table resume. This avoids a kernel crash that can happen when changing the scsi_dh during table load.

[PATCH 2/2] dm mpath: attach scsi_dh during table resume

2013-04-08 Thread Mike Snitzer
Preallocate scsi_dh_data using scsi_dh_alloc_data() during table load but attach the scsi_dh for each path during table resume. This avoids a kernel crash that can happen when changing the scsi_dh during table load. When we reload a multipath device, there are two instances of the multipath