Re: scsi_error: do not allow IO errors with certain ILLEGAL_REQUEST sense to be retryable

From: Martin K. Petersen
Date: Mon Feb 13 2012 - 14:16:30 EST


>>>>> "Mike" == Mike Snitzer <snitzer@xxxxxxxxxx> writes:

>> I don't have a fundamental problem with your patch. But since we
>> explicitly handle ILLEGAL REQUEST with 0x20 and 0x24 in sd.c I wonder
>> what's broken? We should disable discard support if the WRITE SAME w/
>> UNMAP fails.

Mike> Yeah, I thought the disabling would be sufficient too. But
Mike> unfortunately multipath doesn't inspect the request it is retrying
Mike> (after it fails the path the request just failed on).

Well, we shouldn't be returning something that multipath should ever act
on.

I think I understand what's going on. Can you try the following patch?

--
Martin K. Petersen Oracle Linux Engineering


diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b2c95db..4e8d0b6 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -879,6 +879,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
cmd->cmnd[0] == WRITE_SAME_16 ||
cmd->cmnd[0] == WRITE_SAME)) {
description = "Discard failure";
+ error = -EREMOTEIO;
action = ACTION_FAIL;
} else
action = ACTION_FAIL;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c691fb5..5f0d383 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -497,6 +497,8 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
max(sdkp->physical_block_size,
sdkp->unmap_granularity * logical_block_size);

+ sdkp->provisioning_mode = mode;
+
switch (mode) {

case SD_LBP_DISABLE:
@@ -524,8 +526,6 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)

q->limits.max_discard_sectors = max_blocks * (logical_block_size >> 9);
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
-
- sdkp->provisioning_mode = mode;
}

/**
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