dm: add add_disk() error handling

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@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211015233028.2167651-4-mcgrof@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7870e6460633f85afcc28175c01e7ee2d48532c2..79d4ac4aab052e19f4f2812ec30f78b91433ed0d 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2078,7 +2078,9 @@ 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) {