ceph: make ceph_msg_new return NULL on failure; clean up, fix callers

Returning ERR_PTR(-ENOMEM) is useless extra work.  Return NULL on failure
instead, and fix up the callers (about half of which were wrong anyway).

Signed-off-by: Sage Weil <sage@newdream.net>

7 files changed, 48 insertions, 80 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 51fd39da1470..8755e2d83d4c 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -939,8 +939,8 @@ static int send_cap_msg(struct ceph_mds_session *session,
 	     xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0);
 
 	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), 0, 0, NULL);
-	if (IS_ERR(msg))
-		return PTR_ERR(msg);
+	if (!msg)
+		return -ENOMEM;
 
 	msg->hdr.tid = cpu_to_le64(flush_tid);
 
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 834d2b83834a..b0426090e8c3 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -649,8 +649,8 @@ more:
 				    do_sync,
 				    ci->i_truncate_seq, ci->i_truncate_size,
 				    &mtime, false, 2);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
+	if (!req)
+		return -ENOMEM;
 
 	num_pages = calc_pages_for(pos, len);
 
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index d549ab3adfda..7e89c185d38d 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -666,9 +666,9 @@ static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 	struct ceph_mds_session_head *h;
 
 	msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), 0, 0, NULL);
-	if (IS_ERR(msg)) {
+	if (!msg) {
 		pr_err("create_session_msg ENOMEM creating msg\n");
-		return ERR_PTR(PTR_ERR(msg));
+		return NULL;
 	}
 	h = msg->front.iov_base;
 	h->op = cpu_to_le32(op);
@@ -687,7 +687,6 @@ static int __open_session(struct ceph_mds_client *mdsc,
 	struct ceph_msg *msg;
 	int mstate;
 	int mds = session->s_mds;
-	int err = 0;
 
 	/* wait for mds to go active? */
 	mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
@@ -698,13 +697,9 @@ static int __open_session(struct ceph_mds_client *mdsc,
 
 	/* send connect message */
 	msg = create_session_msg(CEPH_SESSION_REQUEST_OPEN, session->s_seq);
-	if (IS_ERR(msg)) {
-		err = PTR_ERR(msg);
-		goto out;
-	}
+	if (!msg)
+		return -ENOMEM;
 	ceph_con_send(&session->s_con, msg);
-
-out:
 	return 0;
 }
 
@@ -883,8 +878,8 @@ static int send_renew_caps(struct ceph_mds_client *mdsc,
 		ceph_mds_state_name(state));
 	msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
 				 ++session->s_renew_seq);
-	if (IS_ERR(msg))
-		return PTR_ERR(msg);
+	if (!msg)
+		return -ENOMEM;
 	ceph_con_send(&session->s_con, msg);
 	return 0;
 }
@@ -931,17 +926,15 @@ static int request_close_session(struct ceph_mds_client *mdsc,
 				 struct ceph_mds_session *session)
 {
 	struct ceph_msg *msg;
-	int err = 0;
 
 	dout("request_close_session mds%d state %s seq %lld\n",
 	     session->s_mds, session_state_name(session->s_state),
 	     session->s_seq);
 	msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
-	if (IS_ERR(msg))
-		err = PTR_ERR(msg);
-	else
-		ceph_con_send(&session->s_con, msg);
-	return err;
+	if (!msg)
+		return -ENOMEM;
+	ceph_con_send(&session->s_con, msg);
+	return 0;
 }
 
 /*
@@ -1426,8 +1419,10 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
 		len += req->r_old_dentry->d_name.len;
 
 	msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, 0, 0, NULL);
-	if (IS_ERR(msg))
+	if (!msg) {
+		msg = ERR_PTR(-ENOMEM);
 		goto out_free2;
+	}
 
 	msg->hdr.tid = cpu_to_le64(req->r_tid);
 
@@ -1518,7 +1513,7 @@ static int __prepare_send_request(struct ceph_mds_client *mdsc,
 	if (IS_ERR(msg)) {
 		req->r_err = PTR_ERR(msg);
 		complete_request(mdsc, req);
-		return -PTR_ERR(msg);
+		return PTR_ERR(msg);
 	}
 	req->r_request = msg;
 
@@ -2158,11 +2153,10 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds)
 		goto fail_nopagelist;
 	ceph_pagelist_init(pagelist);
 
+	err = -ENOMEM;
 	reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, 0, 0, NULL);
-	if (IS_ERR(reply)) {
-		err = PTR_ERR(reply);
+	if (!reply)
 		goto fail_nomsg;
-	}
 
 	/* find session */
 	session = __ceph_lookup_mds_session(mdsc, mds);
@@ -2469,7 +2463,7 @@ void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 	len += dnamelen;
 
 	msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, 0, 0, NULL);
-	if (IS_ERR(msg))
+	if (!msg)
 		return;
 	lease = msg->front.iov_base;
 	lease->action = action;
diff --git a/fs/ceph/messenger.c b/fs/ceph/messenger.c
index af3b143fbf02..fe7d0c52ae3c 100644
--- a/fs/ceph/messenger.c
+++ b/fs/ceph/messenger.c
@@ -1402,19 +1402,17 @@ static int read_partial_message(struct ceph_connection *con)
 		con->in_msg = ceph_alloc_msg(con, &con->in_hdr, &skip);
 		if (skip) {
 			/* skip this message */
-			dout("alloc_msg returned NULL, skipping message\n");
+			dout("alloc_msg said skip message\n");
 			con->in_base_pos = -front_len - middle_len - data_len -
 				sizeof(m->footer);
 			con->in_tag = CEPH_MSGR_TAG_READY;
 			con->in_seq++;
 			return 0;
 		}
-		if (IS_ERR(con->in_msg)) {
-			ret = PTR_ERR(con->in_msg);
-			con->in_msg = NULL;
+		if (!con->in_msg) {
 			con->error_msg =
 				"error allocating memory for incoming message";
-			return ret;
+			return -ENOMEM;
 		}
 		m = con->in_msg;
 		m->front.iov_len = 0;    /* haven't read it yet */
@@ -2147,7 +2145,7 @@ out2:
 	ceph_msg_put(m);
 out:
 	pr_err("msg_new can't create type %d len %d\n", type, front_len);
-	return ERR_PTR(-ENOMEM);
+	return NULL;
 }
 
 /*
@@ -2190,10 +2188,7 @@ static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
 		mutex_unlock(&con->mutex);
 		msg = con->ops->alloc_msg(con, hdr, skip);
 		mutex_lock(&con->mutex);
-		if (IS_ERR(msg))
-			return msg;
-
-		if (*skip)
+		if (!msg || *skip)
 			return NULL;
 	}
 	if (!msg) {
@@ -2202,17 +2197,16 @@ static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
 		if (!msg) {
 			pr_err("unable to allocate msg type %d len %d\n",
 			       type, front_len);
-			return ERR_PTR(-ENOMEM);
+			return NULL;
 		}
 	}
 	memcpy(&msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
 
 	if (middle_len) {
 		ret = ceph_alloc_middle(con, msg);
-
 		if (ret < 0) {
 			ceph_msg_put(msg);
-			return msg;
+			return NULL;
 		}
 	}
 
diff --git a/fs/ceph/mon_client.c b/fs/ceph/mon_client.c
index 5bee9250bf2a..35f593e7e364 100644
--- a/fs/ceph/mon_client.c
+++ b/fs/ceph/mon_client.c
@@ -490,16 +490,13 @@ int ceph_monc_do_statfs(struct ceph_mon_client *monc, struct ceph_statfs *buf)
 	req->buf = buf;
 	init_completion(&req->completion);
 
+	err = -ENOMEM;
 	req->request = ceph_msg_new(CEPH_MSG_STATFS, sizeof(*h), 0, 0, NULL);
-	if (IS_ERR(req->request)) {
-		err = PTR_ERR(req->request);
+	if (!req->request)
 		goto out;
-	}
 	req->reply = ceph_msg_new(CEPH_MSG_STATFS_REPLY, 1024, 0, 0, NULL);
-	if (IS_ERR(req->reply)) {
-		err = PTR_ERR(req->reply);
+	if (!req->reply)
 		goto out;
-	}
 
 	/* fill out request */
 	h = req->request->front.iov_base;
@@ -634,30 +631,22 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
 		CEPH_ENTITY_TYPE_OSD | CEPH_ENTITY_TYPE_MDS;
 
 	/* msg pools */
+	err = -ENOMEM;
 	monc->m_subscribe_ack = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE_ACK,
 				     sizeof(struct ceph_mon_subscribe_ack),
 				     0, 0, NULL);
-	if (IS_ERR(monc->m_subscribe_ack)) {
-		err = PTR_ERR(monc->m_subscribe_ack);
-		monc->m_subscribe_ack = NULL;
+	if (!monc->m_subscribe_ack)
 		goto out_monmap;
-	}
 
 	monc->m_auth_reply = ceph_msg_new(CEPH_MSG_AUTH_REPLY, 4096, 0, 0,
 					  NULL);
-	if (IS_ERR(monc->m_auth_reply)) {
-		err = PTR_ERR(monc->m_auth_reply);
-		monc->m_auth_reply = NULL;
+	if (!monc->m_auth_reply)
 		goto out_subscribe_ack;
-	}
 
 	monc->m_auth = ceph_msg_new(CEPH_MSG_AUTH, 4096, 0, 0, NULL);
 	monc->pending_auth = 0;
-	if (IS_ERR(monc->m_auth)) {
-		err = PTR_ERR(monc->m_auth);
-		monc->m_auth = NULL;
+	if (!monc->m_auth)
 		goto out_auth_reply;
-	}
 
 	monc->cur_mon = -1;
 	monc->hunting = true;
diff --git a/fs/ceph/msgpool.c b/fs/ceph/msgpool.c
index ca032223e87b..04fea84890da 100644
--- a/fs/ceph/msgpool.c
+++ b/fs/ceph/msgpool.c
@@ -10,12 +10,8 @@
 static void *alloc_fn(gfp_t gfp_mask, void *arg)
 {
 	struct ceph_msgpool *pool = arg;
-	struct ceph_msg *m;
 
-	m = ceph_msg_new(0, pool->front_len, 0, 0, NULL);
-	if (IS_ERR(m))
-		return NULL;
-	return m;
+	return ceph_msg_new(0, pool->front_len, 0, 0, NULL);
 }
 
 static void free_fn(void *element, void *arg)
@@ -42,17 +38,12 @@ struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool,
 				  int front_len)
 {
 	if (front_len > pool->front_len) {
-		struct ceph_msg *msg;
-
 		pr_err("msgpool_get pool %p need front %d, pool size is %d\n",
 		       pool, front_len, pool->front_len);
 		WARN_ON(1);
 
 		/* try to alloc a fresh message */
-		msg = ceph_msg_new(0, front_len, 0, 0, NULL);
-		if (!IS_ERR(msg))
-			return msg;
-		return NULL;
+		return ceph_msg_new(0, front_len, 0, 0, NULL);
 	}
 
 	return mempool_alloc(pool->pool, GFP_NOFS);
diff --git a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
index 3d2bfbc232dc..a51d0df2af30 100644
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -147,7 +147,7 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
 		req = kzalloc(sizeof(*req), GFP_NOFS);
 	}
 	if (req == NULL)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	req->r_osdc = osdc;
 	req->r_mempool = use_mempool;
@@ -165,9 +165,9 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
 	else
 		msg = ceph_msg_new(CEPH_MSG_OSD_OPREPLY,
 				   OSD_OPREPLY_FRONT_LEN, 0, 0, NULL);
-	if (IS_ERR(msg)) {
+	if (!msg) {
 		ceph_osdc_put_request(req);
-		return ERR_PTR(PTR_ERR(msg));
+		return NULL;
 	}
 	req->r_reply = msg;
 
@@ -179,9 +179,9 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
 		msg = ceph_msgpool_get(&osdc->msgpool_op, 0);
 	else
 		msg = ceph_msg_new(CEPH_MSG_OSD_OP, msg_size, 0, 0, NULL);
-	if (IS_ERR(msg)) {
+	if (!msg) {
 		ceph_osdc_put_request(req);
-		return ERR_PTR(PTR_ERR(msg));
+		return NULL;
 	}
 	msg->hdr.type = cpu_to_le16(CEPH_MSG_OSD_OP);
 	memset(msg->front.iov_base, 0, msg->front.iov_len);
@@ -1263,8 +1263,8 @@ int ceph_osdc_readpages(struct ceph_osd_client *osdc,
 				    CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
 				    NULL, 0, truncate_seq, truncate_size, NULL,
 				    false, 1);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
+	if (!req)
+		return -ENOMEM;
 
 	/* it may be a short read due to an object boundary */
 	req->r_pages = pages;
@@ -1306,8 +1306,8 @@ int ceph_osdc_writepages(struct ceph_osd_client *osdc, struct ceph_vino vino,
 				    snapc, do_sync,
 				    truncate_seq, truncate_size, mtime,
 				    nofail, 1);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
+	if (!req)
+		return -ENOMEM;
 
 	/* it may be a short write due to an object boundary */
 	req->r_pages = pages;
@@ -1393,7 +1393,7 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
 		pr_warning("get_reply front %d > preallocated %d\n",
 			   front, (int)req->r_reply->front.iov_len);
 		m = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, front, 0, 0, NULL);
-		if (IS_ERR(m))
+		if (!m)
 			goto out;
 		ceph_msg_put(req->r_reply);
 		req->r_reply = m;
@@ -1409,7 +1409,7 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
 				   tid, want, m->nr_pages);
 			*skip = 1;
 			ceph_msg_put(m);
-			m = ERR_PTR(-EIO);
+			m = NULL;
 			goto out;
 		}
 		m->pages = req->r_pages;