[SCSI] Add detailed SCSI I/O errors
Instead of just passing 'EIO' for any I/O error we should be
notifying the upper layers with more details about the cause
of this error.
Update the possible I/O errors to:
- ENOLINK: Link failure between host and target
- EIO: Retryable I/O error
- EREMOTEIO: Non-retryable I/O error
- EBADE: I/O error restricted to the I_T_L nexus
'Retryable' in this context means that an I/O error _might_ be
restricted to the I_T_L nexus (vulgo: path), so retrying on another
nexus / path might succeed.
'Non-retryable' in general refers to a target failure, so this
error will always be generated regardless of the I_T_L nexus
it was send on.
I/O errors restricted to the I_T_L nexus might be retried
on another nexus / path, but they should _not_ be queued
if no paths are available.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 45c7564..991de3c 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -223,7 +223,7 @@
* @scmd: Cmd to have sense checked.
*
* Return value:
- * SUCCESS or FAILED or NEEDS_RETRY
+ * SUCCESS or FAILED or NEEDS_RETRY or TARGET_ERROR
*
* Notes:
* When a deferred error is detected the current command has
@@ -326,17 +326,19 @@
*/
return SUCCESS;
- /* these three are not supported */
+ /* these are not supported */
case COPY_ABORTED:
case VOLUME_OVERFLOW:
case MISCOMPARE:
- return SUCCESS;
+ case BLANK_CHECK:
+ case DATA_PROTECT:
+ return TARGET_ERROR;
case MEDIUM_ERROR:
if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
sshdr.asc == 0x13 || /* AMNF DATA FIELD */
sshdr.asc == 0x14) { /* RECORD NOT FOUND */
- return SUCCESS;
+ return TARGET_ERROR;
}
return NEEDS_RETRY;
@@ -344,11 +346,9 @@
if (scmd->device->retry_hwerror)
return ADD_TO_MLQUEUE;
else
- return SUCCESS;
+ return TARGET_ERROR;
case ILLEGAL_REQUEST:
- case BLANK_CHECK:
- case DATA_PROTECT:
default:
return SUCCESS;
}
@@ -787,6 +787,7 @@
case SUCCESS:
case NEEDS_RETRY:
case FAILED:
+ case TARGET_ERROR:
break;
case ADD_TO_MLQUEUE:
rtn = NEEDS_RETRY;
@@ -1469,6 +1470,14 @@
rtn = scsi_check_sense(scmd);
if (rtn == NEEDS_RETRY)
goto maybe_retry;
+ else if (rtn == TARGET_ERROR) {
+ /*
+ * Need to modify host byte to signal a
+ * permanent target failure
+ */
+ scmd->result |= (DID_TARGET_FAILURE << 16);
+ rtn = SUCCESS;
+ }
/* if rtn == FAILED, we have no sense information;
* returning FAILED will wake the error handler thread
* to collect the sense and redo the decide
@@ -1486,6 +1495,7 @@
case RESERVATION_CONFLICT:
sdev_printk(KERN_INFO, scmd->device,
"reservation conflict\n");
+ scmd->result |= (DID_NEXUS_FAILURE << 16);
return SUCCESS; /* causes immediate i/o error */
default:
return FAILED;
