libceph: pass reply buffer length through ceph_osdc_call()

To spare checking for "this reply fits into a page, but does it fit
into my buffer?" in some callers, osd_req_op_cls_response_data_pages()
needs to know how big it is.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/net/ceph/cls_lock_client.c b/net/ceph/cls_lock_client.c
index 50f040fdb2a97f4278fce4130a0cf4bbe3c87052..f13a1ea874594eca8596d3ec741c7830501e0f5d 100644 (file)
--- a/net/ceph/cls_lock_client.c
+++ b/net/ceph/cls_lock_client.c
@@ -278,7 +278,7 @@ int ceph_cls_lock_info(struct ceph_osd_client *osdc,
        int get_info_op_buf_size;
        int name_len = strlen(lock_name);
        struct page *get_info_op_page, *reply_page;
-       size_t reply_len;
+       size_t reply_len = PAGE_SIZE;
        void *p, *end;
        int ret;
 

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 3a2417bb6ff061ff1fc61f56849c870339591d9f..ac4753421d0ca80ab84749b371d0f37c82542bb1 100644 (file)
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -4023,7 +4023,7 @@ EXPORT_SYMBOL(ceph_osdc_maybe_request_map);
  * Execute an OSD class method on an object.
  *
  * @flags: CEPH_OSD_FLAG_*
- * @resp_len: out param for reply length
+ * @resp_len: in/out param for reply length
  */
 int ceph_osdc_call(struct ceph_osd_client *osdc,
                   struct ceph_object_id *oid,
@@ -4036,6 +4036,9 @@ int ceph_osdc_call(struct ceph_osd_client *osdc,
        struct ceph_osd_request *req;
        int ret;
 
+       if (req_len > PAGE_SIZE || (resp_page && *resp_len > PAGE_SIZE))
+               return -E2BIG;
+
        req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
        if (!req)
                return -ENOMEM;
@@ -4054,7 +4057,7 @@ int ceph_osdc_call(struct ceph_osd_client *osdc,
                                                  0, false, false);
        if (resp_page)
                osd_req_op_cls_response_data_pages(req, 0, &resp_page,
-                                                  PAGE_SIZE, 0, false, false);
+                                                  *resp_len, 0, false, false);
 
        ceph_osdc_start_request(osdc, req, false);
        ret = ceph_osdc_wait_request(osdc, req);