Commit 6e40b3bf authored Jun 17, 2015 by Alexander Yarygin Committed by Stefan Hajnoczi Jun 23, 2015

virtio-blk: Use blk_drain() to drain IO requests



Each call of the virtio_blk_reset() function calls blk_drain_all(),
which works for all existing BlockDriverStates, while draining only
one is needed.

This patch replaces blk_drain_all() by blk_drain() in
virtio_blk_reset(). virtio_blk_data_plane_stop() should be called
after draining because it restores vblk->complete_request.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Message-id: 1434537440-28236-3-git-send-email-yarygin@linux.vnet.ibm.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

parent 97b0385a

hw/block/virtio-blk.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -651,16 +651,21 @@ static void virtio_blk_dma_restart_cb(void *opaque, int running,
		static void virtio_blk_reset(VirtIODevice *vdev)
		{
		VirtIOBlock *s = VIRTIO_BLK(vdev);

		if (s->dataplane) {
		virtio_blk_data_plane_stop(s->dataplane);
		}
		AioContext *ctx;

		/*
		* This should cancel pending requests, but can't do nicely until there
		* are per-device request lists.
		*/
		blk_drain_all();
		ctx = blk_get_aio_context(s->blk);
		aio_context_acquire(ctx);
		blk_drain(s->blk);

		if (s->dataplane) {
		virtio_blk_data_plane_stop(s->dataplane);
		}
		aio_context_release(ctx);

		blk_set_enable_write_cache(s->blk, s->original_wce);
		}