Re: [ V2 PATCH 1/2] scsi: call device handler for failed TUR command

[Hannes Reinecke <hare@suse.de>]

On 11/03/2014 10:28 PM, wenxiong@linux.vnet.ibm.com wrote:
> Multipath devices using the TUR path checker need to see the sense
> code for a failed TUR command in their device handler.  Since commit
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/
> drivers/scsi/scsi_error.c?id=14216561e164671ce147458653b1fea06a
> we always return success for mid layer issued TUR commands before
> calling the device handler, which stopped the TUR path checker from working.
> 
> Move the call to the device handler check sense method before the early
> return for TUR commands to give the device handler a chance to intercept
> them.
> 
> Signed-off-by: Christoph Hellwig <hch@infradead.org>
> Tested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
> ---
>  drivers/scsi/scsi_error.c |   16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> Index: b/drivers/scsi/scsi_error.c
> ===================================================================
> --- a/drivers/scsi/scsi_error.c	2014-10-23 12:54:16.000000000 -0500
> +++ b/drivers/scsi/scsi_error.c	2014-10-23 12:57:44.642078988 -0500
> @@ -459,14 +459,6 @@ static int scsi_check_sense(struct scsi_
>  	if (! scsi_command_normalize_sense(scmd, &sshdr))
>  		return FAILED;	/* no valid sense data */
>  
> -	if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
> -		/*
> -		 * nasty: for mid-layer issued TURs, we need to return the
> -		 * actual sense data without any recovery attempt.  For eh
> -		 * issued ones, we need to try to recover and interpret
> -		 */
> -		return SUCCESS;
> -
>  	scsi_report_sense(sdev, &sshdr);
>  
>  	if (scsi_sense_is_deferred(&sshdr))
> @@ -482,6 +474,14 @@ static int scsi_check_sense(struct scsi_
>  		/* handler does not care. Drop down to default handling */
>  	}
>  
> +	if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
> +		/*
> +		 * nasty: for mid-layer issued TURs, we need to return the
> +		 * actual sense data without any recovery attempt.  For eh
> +		 * issued ones, we need to try to recover and interpret
> +		 */
> +		return SUCCESS;
> +
>  	/*
>  	 * Previous logic looked for FILEMARK, EOM or ILI which are
>  	 * mainly associated with tapes and returned SUCCESS.
> 
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)
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