From: Christoph Hellwig <hch@lst.de>
Date: Wed, 26 Apr 2017 07:40:39 +0000 (+0200)
Subject: dm: introduce a new DM_MAPIO_KILL return value
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=412445ac;p=linux.git

dm: introduce a new DM_MAPIO_KILL return value

This untangles the DM_MAPIO_* values returned from ->clone_and_map_rq
from the error codes used by the block layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 920e854caba98..a48130b90157c 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -504,14 +504,12 @@ static int map_request(struct dm_rq_target_io *tio)
 		/* The target wants to requeue the I/O after a delay */
 		dm_requeue_original_request(tio, true);
 		break;
-	default:
-		if (r > 0) {
-			DMWARN("unimplemented target map return value: %d", r);
-			BUG();
-		}
-
+	case DM_MAPIO_KILL:
 		/* The target wants to complete the I/O */
-		dm_kill_unmapped_request(rq, r);
+		dm_kill_unmapped_request(rq, -EIO);
+	default:
+		DMWARN("unimplemented target map return value: %d", r);
+		BUG();
 	}
 
 	return r;
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
index 43d3445b121d7..6264ff00dcf0e 100644
--- a/drivers/md/dm-target.c
+++ b/drivers/md/dm-target.c
@@ -135,7 +135,7 @@ static int io_err_clone_and_map_rq(struct dm_target *ti, struct request *rq,
 				   union map_info *map_context,
 				   struct request **clone)
 {
-	return -EIO;
+	return DM_MAPIO_KILL;
 }
 
 static void io_err_release_clone_rq(struct request *clone)
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 5a02fc0ff311d..78ad0624cdaed 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -604,6 +604,7 @@ extern struct ratelimit_state dm_ratelimit_state;
 #define DM_MAPIO_REMAPPED	1
 #define DM_MAPIO_REQUEUE	DM_ENDIO_REQUEUE
 #define DM_MAPIO_DELAY_REQUEUE	3
+#define DM_MAPIO_KILL		4
 
 #define dm_sector_div64(x, y)( \
 { \