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: 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 93369a1..c259b40 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -1889,7 +1889,8 @@
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 @@
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 @@
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 @@
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 @@
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,