rbd: ask for a weaker incompat mask for read-only mappings (196e2d6d) · Commits · 戴 / test

For a read-only mapping, ask for a set of features that make the image only unwritable rather than both unreadable and unwritable by a client that doesn't understand them. As of today, the difference between them for krbd is journaling (JOURNALING) and live migration (MIGRATING). get_features method supports read_only parameter since hammer, ceph.git commit 6176ec5fde2a ("librbd: differentiate between R/O vs R/W RBD features"). Signed-off-by:

Ilya Dryomov <idryomov@gmail.com> Reviewed-by:

Jason Dillaman <dillaman@redhat.com> Reviewed-by:

Dongsheng Yang <dongsheng.yang@easystack.cn>

drivers/block/rbd.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -5669,9 +5669,12 @@ out:
		}

		static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
		u64 *snap_features)
		bool read_only, u64 *snap_features)
		{
		__le64 snapid = cpu_to_le64(snap_id);
		struct {
		__le64 snap_id;
		u8 read_only;
		} features_in;
		struct {
		__le64 features;
		__le64 incompat;
		@@ -5679,9 +5682,12 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
		u64 unsup;
		int ret;

		features_in.snap_id = cpu_to_le64(snap_id);
		features_in.read_only = read_only;

		ret = rbd_obj_method_sync(rbd_dev, &rbd_dev->header_oid,
		&rbd_dev->header_oloc, "get_features",
		&snapid, sizeof(snapid),
		&features_in, sizeof(features_in),
		&features_buf, sizeof(features_buf));
		dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
		if (ret < 0)
		@@ -5709,6 +5715,7 @@ static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
		static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
		{
		return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
		rbd_is_ro(rbd_dev),
		&rbd_dev->header.features);
		}

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