[RFC PATCH v2 2/3] dm mpath: propagate target errors immediately

[Mike Snitzer <snitzer@redhat.com>]

DM now has more information about the nature of the underlying storage
failure.  Path failure is avoided if a request failed due to a target
error.  Instead the target error is immediately passed up the stack.

Discard requests that fail due to non-target errors may now be retried.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
 drivers/md/dm-mpath.c |   11 +----------
 1 files changed, 1 insertions(+), 10 deletions(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 487ecda..071529a 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1270,16 +1270,7 @@ static int do_end_io(struct multipath *m, struct request *clone,
 	if (!error && !clone->errors)
 		return 0;	/* I/O complete */
 
-	if (error == -EOPNOTSUPP)
-		return error;
-
-	if (clone->cmd_flags & REQ_DISCARD)
-		/*
-		 * Pass all discard request failures up.
-		 * FIXME: only fail_path if the discard failed due to a
-		 * transport problem.  This requires precise understanding
-		 * of the underlying failure (e.g. the SCSI sense).
-		 */
+	if (error == -EOPNOTSUPP || error == -EREMOTEIO)
 		return error;
 
 	if (mpio->pgpath)
-- 
1.7.2.3