Commit f8d4de6e authored by Alex Elder's avatar Alex Elder
Browse files

rbd: support data returned from OSD methods 



An OSD object method call can be made using rbd_req_sync_exec().
Until now this has only been used for creating a new RBD snapshot,
and that has only required sending data out, not receiving anything
back from the OSD.

We will now need to get data back from an OSD on a method call, so
add parameters to rbd_req_sync_exec() that allow a buffer into which
returned data should be placed to be specified, along with its size.

Previously, rbd_req_sync_exec() passed a null pointer and zero
size to rbd_req_sync_op(); change this so the new inbound buffer
information is provided instead.

Rename the "buf" and "len" parameters in rbd_req_sync_op() to
make it more obvious they are describing inbound data.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 3cb4a687

drivers/block/rbd.c

+11 −8
Original line number Diff line number Diff line
@@ -1098,8 +1098,8 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev, 
			   int flags,

			   struct ceph_osd_req_op *ops,

			   const char *object_name,

			   u64 ofs, u64 len,

			   char *buf,

			   u64 ofs, u64 inbound_size,

			   char *inbound,

			   struct ceph_osd_request **linger_req,

			   u64 *ver)

{
@@ -1109,13 +1109,13 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev, 


	rbd_assert(ops != NULL);



	num_pages = calc_pages_for(ofs , len);

	num_pages = calc_pages_for(ofs, inbound_size);

	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);

	if (IS_ERR(pages))

		return PTR_ERR(pages);



	ret = rbd_do_request(NULL, rbd_dev, snapc, snapid,

			  object_name, ofs, len, NULL,

			  object_name, ofs, inbound_size, NULL,

			  pages, num_pages,

			  flags,

			  ops,
@@ -1125,8 +1125,8 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev, 
	if (ret < 0)

		goto done;



	if ((flags & CEPH_OSD_FLAG_READ) && buf)

		ret = ceph_copy_from_page_vector(pages, buf, ofs, ret);

	if ((flags & CEPH_OSD_FLAG_READ) && inbound)

		ret = ceph_copy_from_page_vector(pages, inbound, ofs, ret);



done:

	ceph_release_page_vector(pages, num_pages);
@@ -1445,6 +1445,8 @@ static int rbd_req_sync_exec(struct rbd_device *rbd_dev, 
			     const char *method_name,

			     const char *outbound,

			     size_t outbound_size,

			     char *inbound,

			     size_t inbound_size,

			     int flags,

			     u64 *ver)

{
@@ -1478,7 +1480,8 @@ static int rbd_req_sync_exec(struct rbd_device *rbd_dev, 
	ret = rbd_req_sync_op(rbd_dev, NULL,

			       CEPH_NOSNAP,

			       flags, ops,

			       object_name, 0, 0, NULL, NULL, ver);

			       object_name, 0, inbound_size, inbound,

			       NULL, ver);



	rbd_destroy_ops(ops);
@@ -1789,7 +1792,7 @@ static int rbd_header_add_snap(struct rbd_device *rbd_dev, 


	ret = rbd_req_sync_exec(rbd_dev, rbd_dev->header_name,

				"rbd", "snap_add",

				data, (size_t) (p - data),

				data, (size_t) (p - data), NULL, 0,

				CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,

				NULL);

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