[v4,4/6] dm: add add_disk() error handling

Commit Message

Luis Chamberlain Sept. 27, 2021, 9:59 p.m. UTC

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 <[e-mail]>
Signed-off-by: Luis Chamberlain <[e-mail]>
---
 drivers/md/dm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Mike Snitzer Oct. 6, 2021, 1:17 p.m. UTC | #1

On Mon, Sep 27 2021 at  5:59P -0400,
Luis Chamberlain <[e-mail]> wrote:

> 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 <[e-mail]>
> Signed-off-by: Luis Chamberlain <[e-mail]>

Reviewed-by: Mike Snitzer <[e-mail]>

Patch

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index a011d09cb0fa..b83aab8507c2 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2083,7 +2083,9 @@  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) {