ceph: break up send_cap_msg

Push the allocation of the msg and the send into the caller. Rename
the function to encode_cap_msg and make it void return.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/caps.c

@@ -1222,36 +1222,27 @@ struct cap_msg_args {
 };
 
 /*
- * Build and send a cap message to the given MDS.
- *
- * Caller should be holding s_mutex.
+ * cap struct size + flock buffer size + inline version + inline data size +
+ * osd_epoch_barrier + oldest_flush_tid
  */
-static int send_cap_msg(struct cap_msg_args *arg)
+#define CAP_MSG_SIZE (sizeof(struct ceph_mds_caps) + \
+		      4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4)
+
+/* Marshal up the cap msg to the MDS */
+static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
 {
 	struct ceph_mds_caps *fc;
-	struct ceph_msg *msg;
 	void *p;
-	size_t extra_len;
 	struct ceph_osd_client *osdc = &arg->session->s_mdsc->fsc->client->osdc;
 
-	dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
-	     " seq %u/%u tid %llu/%llu mseq %u follows %lld size %llu/%llu"
-	     " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(arg->op),
-	     arg->cid, arg->ino, ceph_cap_string(arg->caps),
-	     ceph_cap_string(arg->wanted), ceph_cap_string(arg->dirty),
-	     arg->seq, arg->issue_seq, arg->flush_tid, arg->oldest_flush_tid,
-	     arg->mseq, arg->follows, arg->size, arg->max_size,
-	     arg->xattr_version,
+	dout("%s %s %llx %llx caps %s wanted %s dirty %s seq %u/%u tid %llu/%llu mseq %u follows %lld size %llu/%llu xattr_ver %llu xattr_len %d\n",
+	     __func__, ceph_cap_op_name(arg->op), arg->cid, arg->ino,
+	     ceph_cap_string(arg->caps), ceph_cap_string(arg->wanted),
+	     ceph_cap_string(arg->dirty), arg->seq, arg->issue_seq,
+	     arg->flush_tid, arg->oldest_flush_tid, arg->mseq, arg->follows,
+	     arg->size, arg->max_size, arg->xattr_version,
 	     arg->xattr_buf ? (int)arg->xattr_buf->vec.iov_len : 0);
 
-	/* flock buffer size + inline version + inline data size +
-	 * osd_epoch_barrier + oldest_flush_tid */
-	extra_len = 4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4;
-	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc) + extra_len,
-			   GFP_NOFS, false);
-	if (!msg)
-		return -ENOMEM;
-
 	msg->hdr.version = cpu_to_le16(10);
 	msg->hdr.tid = cpu_to_le64(arg->flush_tid);
 
@@ -1323,9 +1314,6 @@ static int send_cap_msg(struct cap_msg_args *arg)
 
 	/* Advisory flags (version 10) */
 	ceph_encode_32(&p, arg->flags);
-
-	ceph_con_send(&arg->session->s_con, msg);
-	return 0;
 }
 
 /*
@@ -1456,22 +1444,23 @@ static void __prep_cap(struct cap_msg_args *arg, struct ceph_cap *cap,
  */
 static void __send_cap(struct cap_msg_args *arg, struct ceph_inode_info *ci)
 {
+	struct ceph_msg *msg;
 	struct inode *inode = &ci->vfs_inode;
-	int ret;
 
-	ret = send_cap_msg(arg);
-	if (ret < 0) {
-		pr_err("error sending cap msg, ino (%llx.%llx) "
-		       "flushing %s tid %llu, requeue\n",
+	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, CAP_MSG_SIZE, GFP_NOFS, false);
+	if (!msg) {
+		pr_err("error allocating cap msg: ino (%llx.%llx) flushing %s tid %llu, requeuing cap.\n",
 		       ceph_vinop(inode), ceph_cap_string(arg->dirty),
 		       arg->flush_tid);
 		spin_lock(&ci->i_ceph_lock);
 		__cap_delay_requeue(arg->session->s_mdsc, ci);
 		spin_unlock(&ci->i_ceph_lock);
+		return;
 	}
 
+	encode_cap_msg(msg, arg);
+	ceph_con_send(&arg->session->s_con, msg);
 	ceph_buffer_put(arg->old_xattr_buf);
-
 	if (arg->wake)
 		wake_up_all(&ci->i_cap_wq);
 }
@@ -1482,6 +1471,11 @@ static inline int __send_flush_snap(struct inode *inode,
 				    u32 mseq, u64 oldest_flush_tid)
 {
 	struct cap_msg_args	arg;
+	struct ceph_msg		*msg;
+
+	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, CAP_MSG_SIZE, GFP_NOFS, false);
+	if (!msg)
+		return -ENOMEM;
 
 	arg.session = session;
 	arg.ino = ceph_vino(inode).ino;
@@ -1520,7 +1514,9 @@ static inline int __send_flush_snap(struct inode *inode,
 	arg.flags = 0;
 	arg.wake = false;
 
-	return send_cap_msg(&arg);
+	encode_cap_msg(msg, &arg);
+	ceph_con_send(&arg.session->s_con, msg);
+	return 0;
 }
 
 /*