Commit b8b1e2db authored by Alex Elder's avatar Alex Elder
Browse files

rbd: get snapshot name for a v2 image 



Define rbd_dev_v2_snap_name() to fetch the name for a particular
snapshot in a format 2 rbd image.

Define rbd_dev_v2_snap_info() to to be a wrapper for getting the
name, size, and features for a particular snapshot, using an
interface that matches the equivalent function for version 1 images.

Define rbd_dev_snap_info() wrapper function and use it to call the
appropriate function for getting the snapshot name, size, and
features, dependent on the rbd image format.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 35d489f9

drivers/block/rbd.c

+79 −2
Original line number Diff line number Diff line
@@ -2319,6 +2319,83 @@ out: 
	return 0;

}



static char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev, u32 which)

{

	size_t size;

	void *reply_buf;

	__le64 snap_id;

	int ret;

	void *p;

	void *end;

	size_t snap_name_len;

	char *snap_name;



	size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;

	reply_buf = kmalloc(size, GFP_KERNEL);

	if (!reply_buf)

		return ERR_PTR(-ENOMEM);



	snap_id = cpu_to_le64(rbd_dev->header.snapc->snaps[which]);

	ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name,

				"rbd", "get_snapshot_name",

				(char *) &snap_id, sizeof (snap_id),

				reply_buf, size,

				CEPH_OSD_FLAG_READ, NULL);

	dout("%s: rbd_req_sync_exec returned %d\n", __func__, ret);

	if (ret < 0)

		goto out;



	p = reply_buf;

	end = (char *) reply_buf + size;

	snap_name_len = 0;

	snap_name = ceph_extract_encoded_string(&p, end, &snap_name_len,

				GFP_KERNEL);

	if (IS_ERR(snap_name)) {

		ret = PTR_ERR(snap_name);

		goto out;

	} else {

		dout("  snap_id 0x%016llx snap_name = %s\n",

			(unsigned long long) le64_to_cpu(snap_id), snap_name);

	}

	kfree(reply_buf);



	return snap_name;

out:

	kfree(reply_buf);



	return ERR_PTR(ret);

}



static char *rbd_dev_v2_snap_info(struct rbd_device *rbd_dev, u32 which,

		u64 *snap_size, u64 *snap_features)

{

	__le64 snap_id;

	u8 order;

	int ret;



	snap_id = rbd_dev->header.snapc->snaps[which];

	ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, &order, snap_size);

	if (ret)

		return ERR_PTR(ret);

	ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, snap_features);

	if (ret)

		return ERR_PTR(ret);



	return rbd_dev_v2_snap_name(rbd_dev, which);

}



static char *rbd_dev_snap_info(struct rbd_device *rbd_dev, u32 which,

		u64 *snap_size, u64 *snap_features)

{

	if (rbd_dev->image_format == 1)

		return rbd_dev_v1_snap_info(rbd_dev, which,

					snap_size, snap_features);

	if (rbd_dev->image_format == 2)

		return rbd_dev_v2_snap_info(rbd_dev, which,

					snap_size, snap_features);

	return ERR_PTR(-EINVAL);

}



/*

 * Scan the rbd device's current snapshot list and compare it to the

 * newly-received snapshot context.  Remove any existing snapshots
@@ -2372,7 +2449,7 @@ static int rbd_dev_snaps_update(struct rbd_device *rbd_dev) 
			continue;

		}



		snap_name = rbd_dev_v1_snap_info(rbd_dev, index,

		snap_name = rbd_dev_snap_info(rbd_dev, index,

					&snap_size, &snap_features);

		if (IS_ERR(snap_name))

			return PTR_ERR(snap_name);

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