Commit 23ed6e13 authored by Alex Elder's avatar Alex Elder
Browse files

rbd: ignore result of ceph_copy_from_page_vector() 



The result of ceph_copy_from_page_vector() is simply the length
argument it is provided.

This is called by rbd_obj_method_sync(), which returns the result if
it's non-negative.  But we always either ignore or overwrite that
return value.  So explicitly ignore what's returned by the copy
function, and have rbd_obj_method_sync() always return either a
negative errno or 0.

We also return the result of ceph_copy_from_page_vector() in
rbd_obj_read_sync().  There we still want to return the number of
bytes transferred, but we can use the value we already have in hand
rather than what ceph_copy_from_page_vector() provides.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 1ceae7ef

drivers/block/rbd.c

+5 −5
Original line number Diff line number Diff line
@@ -1889,7 +1889,8 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev, 
	ret = obj_request->result;

	if (ret < 0)

		goto out;

	ret = ceph_copy_from_page_vector(pages, inbound, 0,

	ret = 0;

	(void) ceph_copy_from_page_vector(pages, inbound, 0,

					obj_request->xferred);

	if (version)

		*version = obj_request->version;
@@ -2088,7 +2089,9 @@ static int rbd_obj_read_sync(struct rbd_device *rbd_dev, 


	rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);

	size = (size_t) obj_request->xferred;

	ret = ceph_copy_from_page_vector(pages, buf, 0, size);

	(void) ceph_copy_from_page_vector(pages, buf, 0, size);

	rbd_assert(size <= (size_t) INT_MAX);

	ret = (int) size;

	if (version)

		*version = obj_request->version;

out:
@@ -2141,7 +2144,6 @@ rbd_dev_v1_header_read(struct rbd_device *rbd_dev, u64 *version) 
		ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_name,

				       0, size,

				       (char *) ondisk, version);



		if (ret < 0)

			goto out_err;

		if (WARN_ON((size_t) ret < size)) {
@@ -2803,7 +2805,6 @@ static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev) 
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);

	if (ret < 0)

		goto out;

	ret = 0;    /* rbd_obj_method_sync() can return positive */



	p = reply_buf;

	rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
@@ -3742,7 +3743,6 @@ static int rbd_dev_image_id(struct rbd_device *rbd_dev) 
	dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);

	if (ret < 0)

		goto out;

	ret = 0;    /* rbd_obj_method_sync() can return positive */



	p = response;

	rbd_dev->spec->image_id = ceph_extract_encoded_string(&p,

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