rbd: don't retry setting up header watch (c0430647) · Commits · 戴 / test

When an rbd image is initially mapped a watch event is registered so we can do something if the header object changes. The code that does this currently loops if initiating the watch request results in an ERANGE error. The osds will never return ERANGE, so there's no reason to do this loop, so get rid of it. This resolves: http://tracker.newdream.net/issues/3860 Note that the problem this loop was intended to solve is a race between collecting image header information and setting up the watch on the header object. The real fix for that problem is described here: http://tracker.newdream.net/issues/3871 Signed-off-by:

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

Josh Durgin <josh.durgin@inktank.com>

drivers/block/rbd.c

+4 −19

Original line number	Diff line number	Diff line
		@@ -1474,6 +1474,9 @@ static int rbd_req_sync_watch(struct rbd_device *rbd_dev, int start)
		struct ceph_osd_req_op *op;
		int ret = 0;

		rbd_assert(start ^ !!rbd_dev->watch_event);
		rbd_assert(start ^ !!rbd_dev->watch_request);

		if (start) {
		struct ceph_osd_client *osdc;

		@@ -1482,8 +1485,6 @@ static int rbd_req_sync_watch(struct rbd_device *rbd_dev, int start)
		&rbd_dev->watch_event);
		if (ret < 0)
		return ret;
		} else {
		rbd_assert(rbd_dev->watch_request != NULL);
		}

		op = rbd_osd_req_op_create(CEPH_OSD_OP_WATCH,
		@@ -3023,22 +3024,6 @@ static void rbd_bus_del_dev(struct rbd_device *rbd_dev)
		device_unregister(&rbd_dev->dev);
		}

		static int rbd_init_watch_dev(struct rbd_device *rbd_dev)
		{
		int ret, rc;

		do {
		ret = rbd_req_sync_watch(rbd_dev, 1);
		if (ret == -ERANGE) {
		rc = rbd_dev_refresh(rbd_dev, NULL);
		if (rc < 0)
		return rc;
		}
		} while (ret == -ERANGE);

		return ret;
		}

		static atomic64_t rbd_dev_id_max = ATOMIC64_INIT(0);

		/*
		@@ -3584,7 +3569,7 @@ static int rbd_dev_probe_finish(struct rbd_device *rbd_dev)
		if (ret)
		goto err_out_bus;

		ret = rbd_init_watch_dev(rbd_dev);
		ret = rbd_req_sync_watch(rbd_dev, 1);
		if (ret)
		goto err_out_bus;

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