Merge tag 'dm-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - fix a 4.6-rc1 bio-based DM 'struct dm_target_io' leak in an error
   path

 - stable@ fix for DM cache metadata's READ_LOCK macros that were
   incorrectly returning error if the block manager was in read-only
   mode; also cleanup multi-statement macros to use do {} while(0)

* tag 'dm-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros
  dm: fix dm_target_io leak if clone_bio() returns an error

2 files changed, 43 insertions, 25 deletions

diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 27f2ef300f8b..65ce6985f87a 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -867,39 +867,55 @@ static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
 	return 0;
 }
 
-#define WRITE_LOCK(cmd)	\
-	down_write(&cmd->root_lock); \
-	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
-		up_write(&cmd->root_lock); \
-		return -EINVAL; \
+static bool cmd_write_lock(struct dm_cache_metadata *cmd)
+{
+	down_write(&cmd->root_lock);
+	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
+		up_write(&cmd->root_lock);
+		return false;
 	}
+	return true;
+}
 
-#define WRITE_LOCK_VOID(cmd) \
-	down_write(&cmd->root_lock); \
-	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
-		up_write(&cmd->root_lock); \
-		return; \
-	}
+#define WRITE_LOCK(cmd)				\
+	do {					\
+		if (!cmd_write_lock((cmd)))	\
+			return -EINVAL;		\
+	} while(0)
+
+#define WRITE_LOCK_VOID(cmd)			\
+	do {					\
+		if (!cmd_write_lock((cmd)))	\
+			return;			\
+	} while(0)
 
 #define WRITE_UNLOCK(cmd) \
-	up_write(&cmd->root_lock)
+	up_write(&(cmd)->root_lock)
 
-#define READ_LOCK(cmd) \
-	down_read(&cmd->root_lock); \
-	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
-		up_read(&cmd->root_lock); \
-		return -EINVAL; \
+static bool cmd_read_lock(struct dm_cache_metadata *cmd)
+{
+	down_write(&cmd->root_lock);
+	if (cmd->fail_io) {
+		up_write(&cmd->root_lock);
+		return false;
 	}
+	return true;
+}
 
-#define READ_LOCK_VOID(cmd)	\
-	down_read(&cmd->root_lock); \
-	if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
-		up_read(&cmd->root_lock); \
-		return; \
-	}
+#define READ_LOCK(cmd)				\
+	do {					\
+		if (!cmd_read_lock((cmd)))	\
+			return -EINVAL;		\
+	} while(0)
+
+#define READ_LOCK_VOID(cmd)			\
+	do {					\
+		if (!cmd_read_lock((cmd)))	\
+			return;			\
+	} while(0)
 
 #define READ_UNLOCK(cmd) \
-	up_read(&cmd->root_lock)
+	up_read(&(cmd)->root_lock)
 
 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
 {
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index be4905769a45..3d3ac13287a4 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1662,8 +1662,10 @@ static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
 		tio = alloc_tio(ci, ti, target_bio_nr);
 		tio->len_ptr = len;
 		r = clone_bio(tio, bio, sector, *len);
-		if (r < 0)
+		if (r < 0) {
+			free_tio(ci->md, tio);
 			break;
+		}
 		__map_bio(tio);
 	}