dm error: add DAX support

Allow the error target to replace an existing DAX-enabled target.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

2 files changed, 10 insertions, 2 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index ee6f37eafbc3..3e407a9cde1f 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -922,7 +922,8 @@ static int dm_table_determine_type(struct dm_table *t)
         if (bio_based) {
                 /* We must use this table as bio-based */
                 t->type = DM_TYPE_BIO_BASED;
-                if (dm_table_supports_dax(t))
+                if (dm_table_supports_dax(t) ||
+                    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED))
                         t->type = DM_TYPE_DAX_BIO_BASED;
                 return 0;
         }
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
index 5c826b450aad..6eecd6b36f76 100644
--- a/drivers/md/dm-target.c
+++ b/drivers/md/dm-target.c
@@ -148,9 +148,15 @@ static void io_err_release_clone_rq(struct request *clone)
 {
 }
 
+static long io_err_direct_access(struct dm_target *ti, sector_t sector,
+                                 void __pmem **kaddr, pfn_t *pfn, long size)
+{
+        return -EIO;
+}
+
 static struct target_type error_target = {
         .name = "error",
-        .version = {1, 4, 0},
+        .version = {1, 5, 0},
         .features = DM_TARGET_WILDCARD,
         .ctr  = io_err_ctr,
         .dtr  = io_err_dtr,
@@ -158,6 +164,7 @@ static struct target_type error_target = {
         .map_rq = io_err_map_rq,
         .clone_and_map_rq = io_err_clone_and_map_rq,
         .release_clone_rq = io_err_release_clone_rq,
+        .direct_access = io_err_direct_access,
 };
 
 int __init dm_target_init(void)