rbd: preserve snapc->seq in rbd_header_set_snap() (78dc447d) · Commits · 戴 / test

In rbd_header_set_snap(), there is logic to make the snap context's seq field get set to a particular snapshot id, or 0 if there is no snapshot for the rbd image. This seems to be an artifact of how the current snapshot id for an rbd_dev was recorded before the rbd_dev->snap_id field began to be used for that purpose. There's no need to update the value of snapc->seq here any more, so stop doing it. Tidy up a few local variables in that function while we're at it. Signed-off-by:

Alex Elder <elder@inktank.com> Reviewed-by:

Josh Durgin <josh.durgin@inktank.com>

drivers/block/rbd.c

+7 −11

Original line number	Diff line number	Diff line
		@@ -588,29 +588,25 @@ static int snap_by_name(struct rbd_image_header header, const char snap_name,

		static int rbd_header_set_snap(struct rbd_device rbd_dev, u64 size)
		{
		struct rbd_image_header *header = &rbd_dev->header;
		struct ceph_snap_context *snapc = header->snapc;
		int ret = -ENOENT;
		int ret;

		down_write(&rbd_dev->header_rwsem);

		if (!memcmp(rbd_dev->snap_name, RBD_SNAP_HEAD_NAME,
		sizeof (RBD_SNAP_HEAD_NAME))) {
		if (header->total_snaps)
		snapc->seq = header->snap_seq;
		else
		snapc->seq = 0;
		rbd_dev->snap_id = CEPH_NOSNAP;
		rbd_dev->snap_exists = false;
		rbd_dev->read_only = 0;
		if (size)
		*size = header->image_size;
		*size = rbd_dev->header.image_size;
		} else {
		ret = snap_by_name(header, rbd_dev->snap_name,
		&snapc->seq, size);
		u64 snap_id = 0;

		ret = snap_by_name(&rbd_dev->header, rbd_dev->snap_name,
		&snap_id, size);
		if (ret < 0)
		goto done;
		rbd_dev->snap_id = snapc->seq;
		rbd_dev->snap_id = snap_id;
		rbd_dev->snap_exists = true;
		rbd_dev->read_only = 1;
		}

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