mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-28 06:23:42 -04:00
Code Issues Packages Projects Releases Wiki Activity

virtio_balloon: warn on failed buffer add in stats_handle_request()

Browse Source 
Like tell_host(), stats_handle_request() ignores the return value of
virtqueue_add_outbuf() and kicks the queue regardless. The same "we
should always be able to add one buffer to an empty queue" assumption
does not hold once the virtqueue has been broken (e.g. on device
shutdown), where the add fails with -EIO. Unlike tell_host() it does
not wait_event() afterwards so it cannot hang, but it still kicks a
queue with nothing queued.

Warn and bail out on failure, mirroring tell_host() and
virtballoon_free_page_report().

Suggested-by: David Hildenbrand <david@kernel.org>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20260624154001.2733242-1-den@openvz.org>
This commit is contained in:
Denis V. Lunev
2026-06-24 17:40:01 +02:00
committed by Michael S. Tsirkin
parent 198eda3950
commit d62fb5cc8a
1 changed files with 4 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/virtio/virtio_balloon.c
View File

@@ -446,6 +446,7 @@ static void stats_handle_request(struct virtio_balloon *vb)
struct virtqueue *vq;
struct scatterlist sg;
unsigned int len, num_stats;
int err;
num_stats = update_balloon_stats(vb);
@@ -453,7 +454,9 @@ static void stats_handle_request(struct virtio_balloon *vb)
if (!virtqueue_get_buf(vq, &len))
return;
sg_init_one(&sg, vb->stats, sizeof(vb->stats[0]) * num_stats);
virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
err = virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
if (WARN_ON_ONCE(err))
return;
virtqueue_kick(vq);
}