[dm-devel] Write protected devices, unexpected dm-multipath queueing

[Hannes Reinecke]

On 01/06/2012 11:32 PM, Mike Snitzer wrote:
> On Fri, Jan 06 2012 at  2:30pm -0500,
> Christophe Varoqui <christophe.varoqui at gmail.com> wrote:
> 
>> Hannes, list,
>>
>> reading your kernel path there
>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=63583cca745f440167bf27877182dc13e19d4bcf
>> I wonder if this is expected that a write io on a write protected device
>> is returned to the queue ? I would have guessed it qualified as
>> TARGET_ERROR, hence not retryable (and not causing path invalidation).
>>
>> In the following log the sense code is clearly seen as 
>> Sense Key : Data Protect [current]
>> Add. Sense: Write protected
>>
>> The log is grabbed from a el6 kernel rev. 131 which include the
>> mentioned patch (since rev. 110 iirc).
>>
>> Care to confirm something is fishy there ?
> 
> scsi_check_sense() needs to be trained to return TARGET_ERROR for this
> case.
> 
> The commit you referenced wasn't meant to have covered _every_ possible
> TARGET_ERROR case.  For example, I posted a patch for other TARGET_ERROR
> cases here:
> http://www.spinics.net/lists/linux-scsi/msg55792.html
> 
Yes, that's correct. We'll need to check for this case, too.

I'll be sending a patch.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
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