Re: [PATCH v3 59/77] ncr5380: Fix autosense bugs

[Hannes Reinecke]

On 12/22/2015 02:18 AM, Finn Thain wrote:
> NCR5380_information_transfer() may re-queue a command for autosense,
> after calling scsi_eh_prep_cmnd(). This creates several possibilities:
>
> 1. Reselection may intervene before the re-queued command gets processed.
>     If the reconnected command then undergoes autosense, this causes the
>     scsi_eh_save data from the previous command to be overwritten.
>
> 2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(),
>     a new REQUEST SENSE command may arrive. This would be queued ahead
>     of any command already undergoing autosense, which means the
>     scsi_eh_save data might be restored to the wrong command.
>
> 3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(),
>     eh_abort_handler() may abort the command. But the scsi_eh_save data is
>     not discarded, which means the scsi_eh_save data might be incorrectly
>     restored to the next REQUEST SENSE command issued.
>
> This patch adds a new autosense list so that commands that are re-queued
> because of a CHECK CONDITION result can be kept apart from the REQUEST
> SENSE commands that arrive via queuecommand.
>
> This patch also adds a function dedicated to dequeueing and preparing the
> next command for processing. By refactoring the main loop in this way,
> scsi_eh_save takes place when an autosense command is dequeued rather
> than when re-queued.
>
> Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
>
> ---
>   drivers/scsi/NCR5380.c       |  194 +++++++++++++++++++---------------
>   drivers/scsi/NCR5380.h       |    2
>   drivers/scsi/atari_NCR5380.c |  239 ++++++++++++++++++++++++-------------------
>   3 files changed, 249 insertions(+), 186 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke		      zSeries & Storage
hare@xxxxxxx			      +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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