[PATCH 4/4] dm: introduce a new DM_MAPIO_KILL return value

[Christoph Hellwig]

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 <h...@lst.de>
---
 drivers/md/dm-rq.c            | 12 +++++-------
 drivers/md/dm-target.c        |  2 +-
 include/linux/device-mapper.h |  1 +
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 769f04f83ca2..ea4fdf68a0ed 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 5bafe3af27cc..0dc4d9cce128 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -590,6 +590,7 @@ 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)( \
 { \
-- 
2.11.0