[PATCH 3/9] dm: add add_disk() error handling

[Luis Chamberlain <mcgrof@xxxxxxxxxx>]

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

There are two calls to dm_setup_md_queue() which can fail then,
one on dm_early_create() and we can easily see that the error path
there calls dm_destroy in the error path. The other use case is on
the ioctl table_load case. If that fails userspace needs to call
the DM_DEV_REMOVE_CMD to cleanup the state - similar to any other
failure.

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
 drivers/md/dm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 245fa4153306..6d3265ed37c0 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2086,7 +2086,9 @@ int dm_setup_md_queue(struct mapped_device *md, struct 
dm_table *t)
        if (r)
                return r;
 
-       add_disk(md->disk);
+       r = add_disk(md->disk);
+       if (r)
+               return r;
 
        r = dm_sysfs_init(md);
        if (r) {
-- 
2.30.2