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

Hannes Reinecke
2015-12-22T07:57:44Z

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@telegraphics.com.au>
>
> ---
> 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@suse.com>

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
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