[PATCH 09/10] xen-blkfront: add error handling support for add_disk()

From: Luis Chamberlain
Date: Fri Aug 27 2021 - 15:19:36 EST


We never checked for errors on device_add_disk() as this function
returned void. Now that this is fixed, use the shiny new error
handling. The function xlvbd_alloc_gendisk() typically does the
unwinding on error on allocating the disk and creating the tag,
but since all that error handling was stuffed inside
xlvbd_alloc_gendisk() we must repeat the tag free'ing as well.

We set the info->rq to NULL to ensure blkif_free() doesn't crash
on blk_mq_stop_hw_queues() on device_add_disk() error as the queue
will be long gone by then.

Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
drivers/block/xen-blkfront.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 715bfa8aca7f..9fe28af5f6d9 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2343,7 +2343,13 @@ static void blkfront_connect(struct blkfront_info *info)
for_each_rinfo(info, rinfo, i)
kick_pending_request_queues(rinfo);

- device_add_disk(&info->xbdev->dev, info->gd, NULL);
+ err = device_add_disk(&info->xbdev->dev, info->gd, NULL);
+ if (err) {
+ blk_cleanup_disk(info->gd);
+ blk_mq_free_tag_set(&info->tag_set);
+ info->rq = NULL;
+ goto fail;
+ }

info->is_ready = 1;
return;
--
2.30.2