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>

3 files changed, 7 insertions, 8 deletions

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 920e854caba9..a48130b90157 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 43d3445b121d..6264ff00dcf0 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 5a02fc0ff311..78ad0624cdae 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)( \
 { \