Re: [PATCH 1/1] scsi_dh: fix boot oops with EMC Clariion

[Ric Wheeler <rwheeler@redhat.com>]

James Bottomley wrote:
> On Fri, 2008-10-17 at 14:17 -0400, Levy_Jerome@emc.com wrote:
>   
>> The change was the addition of rq->flags = 0; the memset isn't mine.
>> Sorry about the whitespace -- I'm still a bit new at this. 
>>     
>
> That's OK.
>
> Documentation/SubmittingPatches
> Documentation/email-clients.txt
>
> contain useful information.
>
>   
>> As to why it's necessary, I've had boot-time oopses on two completely
>> different hosts -- one iSCSI, one FC -- which both resolved to exactly
>> the same code; bizarre values in rq->flags. The source seems to OR the
>> desired values in but never actually initializes rq->flags (the memset
>> initializes the CDB, not the flags variable), so I added the line to
>> do so. After testing the old module to confirm the oops still occurred
>> regularly, I installed the new code and have since (in over 100
>> reboots) been unable to reproduce the oops. 
>>     
>
> No, my point is that this was fixed by a memset to zero of the request
> in blk_rq_init() in 2.6.26 (so it fixed every other problem, not just
> the one in dm_emc).  I think the kernel you're testing is too old to see
> the generic fix (based on what the diff contained).
>
> James
>   
Of course, if you see this with a vendor specific (older) kernel, you 
can follow up with the vendor and log a bugzilla ticket for that kernel.

Ric