On 01/21/2011 02:07 AM, Hannes Reinecke wrote:
Consider a scenario where a SCSI EH command like TUR fails with a NOT READY status - MANUAL INTERVENTION REQUIRED (02/04/03). As evident in the ASC/ASCQ description, manual intervention is required in this case i.e. the target wants TUR to fail here so that the host administrator can take corrective action. But this particular ASC/ASCQ is not handled in the scsi_check_sense, which ultimately causes scsi_eh_tur to erroneously report a SUCCESS (device ready) instead of the actual FAILURE state (device not ready). This patch converts scsi_check_sense() to return SOFT_ERROR in cases where an error has been signalled via the sense code, but we should not wake the error handler. This error code will be reverted back to SUCCESS for normal command handling, but scsi_eh_completed_normally() will convert it to FAILED. Reported-by: Martin George<marting@xxxxxxxxxx> Signed-off-by: Hannes Reinecke<hare@xxxxxxx> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 45c7564..e86e62e 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -223,7 +223,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost, * @scmd: Cmd to have sense checked. * * Return value: - * SUCCESS or FAILED or NEEDS_RETRY + * SUCCESS or FAILED or NEEDS_RETRY or SOFT_ERROR * * Notes: * When a deferred error is detected the current command has @@ -278,7 +278,7 @@ static int scsi_check_sense(struct scsi_cmnd *scmd) case ABORTED_COMMAND: if (sshdr.asc == 0x10) /* DIF */ - return SUCCESS; + return SOFT_ERROR; return NEEDS_RETRY; case NOT_READY: @@ -324,19 +324,19 @@ static int scsi_check_sense(struct scsi_cmnd *scmd) * Pass the UA upwards for a determination in the completion * functions. */ - return SUCCESS; + return SOFT_ERROR;
For normal IO execution the UA, not ready, and illegal request handling in scsi_io_completion would determine that some of these are retryable conditions, but with the patch in the scsi_error.cs path we will return soft error and fail. Also a lot of these that were retryable were returned as success in the past, but with the patch are being failed.
Martin made me the same bugzilla :) I was thinking we needed to make check_sense smarter or move some of the scsi_io_completion code to some lib helpers so scsi_error.c could call them.
And does scsi_eh_stu need to be covnerted to check for soft error and failed.
Also if we did this patch, then I think we also have to convert the device handlers.
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