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;