ceph: reuse mon subscribe message instead of allocated anew

Use the same message, allocated during startup.  No need to reallocate a
new one each time around (and potentially ENOMEM).

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

2 files changed, 14 insertions, 10 deletions

diff --git a/fs/ceph/mon_client.c b/fs/ceph/mon_client.c
index 12d94f24ee97..f6510a476e7e 100644
--- a/fs/ceph/mon_client.c
+++ b/fs/ceph/mon_client.c
@@ -188,16 +188,12 @@ static void __send_subscribe(struct ceph_mon_client *monc)
              monc->want_next_osdmap);
         if ((__sub_expired(monc) && !monc->sub_sent) ||
             monc->want_next_osdmap == 1) {
-                struct ceph_msg *msg;
+                struct ceph_msg *msg = monc->m_subscribe;
                 struct ceph_mon_subscribe_item *i;
                 void *p, *end;
 
-                msg = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 96, GFP_NOFS);
-                if (!msg)
-                        return;
-
                 p = msg->front.iov_base;
-                end = p + msg->front.iov_len;
+                end = p + msg->front_max;
 
                 dout("__send_subscribe to 'mdsmap' %u+\n",
                      (unsigned)monc->have_mdsmap);
@@ -227,7 +223,8 @@ static void __send_subscribe(struct ceph_mon_client *monc)
 
                 msg->front.iov_len = p - msg->front.iov_base;
                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
-                ceph_con_send(monc->con, msg);
+                ceph_con_revoke(monc->con, msg);
+                ceph_con_send(monc->con, ceph_msg_get(msg));
 
                 monc->sub_sent = jiffies | 1;  /* never 0 */
         }
@@ -631,7 +628,7 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
                 CEPH_ENTITY_TYPE_AUTH | CEPH_ENTITY_TYPE_MON |
                 CEPH_ENTITY_TYPE_OSD | CEPH_ENTITY_TYPE_MDS;
 
-        /* msg pools */
+        /* msgs */
         err = -ENOMEM;
         monc->m_subscribe_ack = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE_ACK,
                                      sizeof(struct ceph_mon_subscribe_ack),
@@ -639,9 +636,13 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
         if (!monc->m_subscribe_ack)
                 goto out_monmap;
 
+        monc->m_subscribe = ceph_msg_new(CEPH_MSG_MON_SUBSCRIBE, 96, GFP_NOFS);
+        if (!monc->m_subscribe)
+                goto out_subscribe_ack;
+
         monc->m_auth_reply = ceph_msg_new(CEPH_MSG_AUTH_REPLY, 4096, GFP_NOFS);
         if (!monc->m_auth_reply)
-                goto out_subscribe_ack;
+                goto out_subscribe;
 
         monc->m_auth = ceph_msg_new(CEPH_MSG_AUTH, 4096, GFP_NOFS);
         monc->pending_auth = 0;
@@ -665,6 +666,8 @@ int ceph_monc_init(struct ceph_mon_client *monc, struct ceph_client *cl)
 
 out_auth_reply:
         ceph_msg_put(monc->m_auth_reply);
+out_subscribe:
+        ceph_msg_put(monc->m_subscribe);
 out_subscribe_ack:
         ceph_msg_put(monc->m_subscribe_ack);
 out_monmap:
@@ -691,6 +694,7 @@ void ceph_monc_stop(struct ceph_mon_client *monc)
 
         ceph_msg_put(monc->m_auth);
         ceph_msg_put(monc->m_auth_reply);
+        ceph_msg_put(monc->m_subscribe);
         ceph_msg_put(monc->m_subscribe_ack);
 
         kfree(monc->monmap);
diff --git a/fs/ceph/mon_client.h b/fs/ceph/mon_client.h
index 76887785a4d7..174d794321d0 100644
--- a/fs/ceph/mon_client.h
+++ b/fs/ceph/mon_client.h
@@ -63,7 +63,7 @@ struct ceph_mon_client {
         struct delayed_work delayed_work;
 
         struct ceph_auth_client *auth;
-        struct ceph_msg *m_auth, *m_auth_reply, *m_subscribe_ack;
+        struct ceph_msg *m_auth, *m_auth_reply, *m_subscribe, *m_subscribe_ack;
         int pending_auth;
 
         bool hunting;