From f02b9ac35a47dff745c7637fbc095f01cc03646e Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 19 Nov 2013 18:57:24 -0700 Subject: [PATCH] virtio-blk: virtqueue_kick() must be ordered with other virtqueue operations It isn't safe to call it without holding the vblk->vq_lock. Reported-by: Dave Chinner Signed-off-by: Shaohua Li Fixed another condition of virtqueue_kick() not holding the lock. Signed-off-by: Jens Axboe --- drivers/block/virtio_blk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 588479d58f52..6a680d4de7f1 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -199,15 +199,16 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) spin_lock_irqsave(&vblk->vq_lock, flags); if (__virtblk_add_req(vblk->vq, vbr, vbr->sg, num) < 0) { + virtqueue_kick(vblk->vq); spin_unlock_irqrestore(&vblk->vq_lock, flags); blk_mq_stop_hw_queue(hctx); - virtqueue_kick(vblk->vq); return BLK_MQ_RQ_QUEUE_BUSY; } - spin_unlock_irqrestore(&vblk->vq_lock, flags); if (last) virtqueue_kick(vblk->vq); + + spin_unlock_irqrestore(&vblk->vq_lock, flags); return BLK_MQ_RQ_QUEUE_OK; } -- 2.20.1