[SCSI] fix recovered error handling
We have a problem with recovered error handling in that any command
which goes down as BLOCK_PC but which returns a sense code of RECOVERED
ERROR gets completed with -EIO. For actual SG_IO commands, this doesn't
matter at all, since the error return code gets dropped in favour of
req->errors which contain the SCSI completion code.
However, if this command is part of the block system, then it will pay
attention to the returned error code. In particularly if a SYNCHRONIZE
CACHE from a barrier command completes with RECOVERED ERROR, the
resulting -EIO on the barrier causes block to error the request and
return it to the filesystem. Fix this by converting the -EIO for
recovered error to zero, plus remove the printing of this from sd and sr
so the message isn't double printed.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 4b13e36..d1cb64a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -791,7 +791,22 @@
"%d bytes done.\n",
req->nr_sectors, good_bytes));
- /* A number of bytes were successfully read. If there
+ /*
+ * Recovered errors need reporting, but they're always treated
+ * as success, so fiddle the result code here. For BLOCK_PC
+ * we already took a copy of the original into rq->errors which
+ * is what gets returned to the user
+ */
+ if (sense_valid && sshdr.sense_key == RECOVERED_ERROR) {
+ if (!(req->cmd_flags & REQ_QUIET))
+ scsi_print_sense("", cmd);
+ result = 0;
+ /* BLOCK_PC may have set error */
+ error = 0;
+ }
+
+ /*
+ * A number of bytes were successfully read. If there
* are leftovers and there is some kind of error
* (result != 0), retry the rest.
*/
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index aeab5d9..3fcb64b 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1051,12 +1051,6 @@
good_bytes = sd_completed_bytes(SCpnt);
break;
case RECOVERED_ERROR:
- /* Inform the user, but make sure that it's not treated
- * as a hard error.
- */
- scsi_print_sense("sd", SCpnt);
- SCpnt->result = 0;
- memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
good_bytes = scsi_bufflen(SCpnt);
break;
case NO_SENSE:
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index e7fa3ca..0e1a0f2 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -309,15 +309,6 @@
break;
case RECOVERED_ERROR:
-
- /*
- * An error occured, but it recovered. Inform the
- * user, but make sure that it's not treated as a
- * hard error.
- */
- scsi_print_sense("sr", SCpnt);
- SCpnt->result = 0;
- SCpnt->sense_buffer[0] = 0x0;
good_bytes = this_count;
break;
