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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index ad26502..b895613 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1098,8 +1098,8 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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);