ceph: have ceph_mdsc_do_request call ceph_mdsc_submit_request

Nothing calls ceph_mdsc_submit_request today, but in later patches we'll
need to be able to call this separately.

Have the helper return an int so we can check the r_err under the mutex,
and have the caller just check the error code from the submit. Also move
the acquisition of CEPH_CAP_PIN references into the same function.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/mds_client.c

@@ -2626,14 +2626,27 @@ static void kick_requests(struct ceph_mds_client *mdsc, int mds)
 	}
 }
 
-void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
+int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
 			      struct ceph_mds_request *req)
 {
-	dout("submit_request on %p\n", req);
+	int err;
+
+	/* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
+	if (req->r_inode)
+		ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
+	if (req->r_parent)
+		ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
+	if (req->r_old_dentry_dir)
+		ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
+				  CEPH_CAP_PIN);
+
+	dout("submit_request on %p for inode %p\n", req, dir);
 	mutex_lock(&mdsc->mutex);
-	__register_request(mdsc, req, NULL);
+	__register_request(mdsc, req, dir);
 	__do_request(mdsc, req);
+	err = req->r_err;
 	mutex_unlock(&mdsc->mutex);
+	return err;
 }
 
 /*
@@ -2648,27 +2661,12 @@ int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 
 	dout("do_request on %p\n", req);
 
-	/* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
-	if (req->r_inode)
-		ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
-	if (req->r_parent)
-		ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
-	if (req->r_old_dentry_dir)
-		ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
-				  CEPH_CAP_PIN);
-
 	/* issue */
-	mutex_lock(&mdsc->mutex);
-	__register_request(mdsc, req, dir);
-	__do_request(mdsc, req);
-
-	if (req->r_err) {
-		err = req->r_err;
+	err = ceph_mdsc_submit_request(mdsc, dir, req);
+	if (err)
 		goto out;
-	}
 
 	/* wait */
-	mutex_unlock(&mdsc->mutex);
 	dout("do_request waiting\n");
 	if (!req->r_timeout && req->r_wait_for_completion) {
 		err = req->r_wait_for_completion(mdsc, req);
@@ -2709,8 +2707,8 @@ int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 		err = req->r_err;
 	}
 
-out:
 	mutex_unlock(&mdsc->mutex);
+out:
 	dout("do_request %p done, result %d\n", req, err);
 	return err;
 }

fs/ceph/mds_client.h

@@ -465,8 +465,9 @@ extern int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
 					   struct inode *dir);
 extern struct ceph_mds_request *
 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode);
-extern void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
-				     struct ceph_mds_request *req);
+extern int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
+				    struct inode *dir,
+				    struct ceph_mds_request *req);
 extern int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
 				struct inode *dir,
 				struct ceph_mds_request *req);