4.19-stable review patch. If anyone has any objections, please let me know.
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From: Yi Sun yi.sun@unisoc.com
[ 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@unisoc.com Reviewed-by: Stefan Hajnoczi stefanha@redhat.com Link: https://lore.kernel.org/r/20240129085250.1550594-1-yi.sun@unisoc.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/virtio_blk.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 8b3bf11329ba0..8e4c431efc6cc 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -943,14 +943,15 @@ 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);
@@ -968,7 +969,7 @@ 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