This is a note to let you know that I've just added the patch titled
virtio-blk: Ensure no requests in virtqueues before deleting vqs.
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virtio-blk-ensure-no-requests-in-virtqueues-before-d.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 82580ed3a57ccdcabb59aeae29e62cbf3b999f5f
Author: Yi Sun <yi.sun@xxxxxxxxxx>
Date: Mon Jan 29 16:52:50 2024 +0800
virtio-blk: Ensure no requests in virtqueues before deleting vqs.
[ Upstream commit 4ce6e2db00de8103a0687fb0f65fd17124a51aaa ]
Ensure no remaining requests in virtqueues before resetting vdev and
deleting virtqueues. Otherwise these requests will never be completed.
It may cause the system to become unresponsive.
Function blk_mq_quiesce_queue() can ensure that requests have become
in_flight status, but it cannot guarantee that requests have been
processed by the device. Virtqueues should never be deleted before
all requests become complete status.
Function blk_mq_freeze_queue() ensure that all requests in virtqueues
become complete status. And no requests can enter in virtqueues.
Signed-off-by: Yi Sun <yi.sun@xxxxxxxxxx>
Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240129085250.1550594-1-yi.sun@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 9b3ea86c20e5e..3afc07b59477b 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -1063,14 +1063,15 @@ static int virtblk_freeze(struct virtio_device *vdev)
{
struct virtio_blk *vblk = vdev->priv;
+ /* Ensure no requests in virtqueues before deleting vqs. */
+ blk_mq_freeze_queue(vblk->disk->queue);
+
/* Ensure we don't receive any more interrupts */
vdev->config->reset(vdev);
/* Make sure no work handler is accessing the device. */
flush_work(&vblk->config_work);
- blk_mq_quiesce_queue(vblk->disk->queue);
-
vdev->config->del_vqs(vdev);
kfree(vblk->vqs);
@@ -1088,7 +1089,7 @@ static int virtblk_restore(struct virtio_device *vdev)
virtio_device_ready(vdev);
- blk_mq_unquiesce_queue(vblk->disk->queue);
+ blk_mq_unfreeze_queue(vblk->disk->queue);
return 0;
}
#endif
