glusterd: perform rcu_read_lock/unlock() under cleanup_lock mutex

Problem: glusterd should not try to acquire locks on any resources,
when it already received a SIGTERM and cleanup is started. Otherwise
we might hit segfault, since the thread which is going through
cleanup path will be freeing up the resouces and some other thread
might be trying to acquire locks on freed resources.

Solution: perform rcu_read_lock/unlock() under cleanup_lock mutex.

fixes: bz#1654270
Change-Id: I87a97cfe4f272f74f246d688660934638911ce54
Signed-off-by: Sanju Rakonde <srakonde@redhat.com>

1 files changed, 32 insertions, 32 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-sm.c b/xlators/mgmt/glusterd/src/glusterd-sm.c
index 35bc71455d2..f9b044fae47 100644
--- a/xlators/mgmt/glusterd/src/glusterd-sm.c
+++ b/xlators/mgmt/glusterd/src/glusterd-sm.c
@@ -163,7 +163,7 @@ glusterd_broadcast_friend_delete(char *hostname, uuid_t uuid)
     if (ret)
         goto out;
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
     cds_list_for_each_entry_rcu(peerinfo, &priv->peers, uuid_list)
     {
         if (!peerinfo->connected || !peerinfo->peer)
@@ -186,7 +186,7 @@ glusterd_broadcast_friend_delete(char *hostname, uuid_t uuid)
         }
     }
 unlock:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     gf_msg_debug("glusterd", 0, "Returning with %d", ret);
 
@@ -229,7 +229,7 @@ glusterd_ac_reverse_probe_begin(glusterd_friend_sm_event_t *event, void *ctx)
     GF_ASSERT(event);
     GF_ASSERT(ctx);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
 
     peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!peerinfo) {
@@ -274,7 +274,7 @@ glusterd_ac_reverse_probe_begin(glusterd_friend_sm_event_t *event, void *ctx)
     }
 
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     if (ret) {
         if (new_event)
@@ -305,7 +305,7 @@ glusterd_ac_friend_add(glusterd_friend_sm_event_t *event, void *ctx)
 
     GF_ASSERT(conf);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
 
     peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!peerinfo) {
@@ -328,7 +328,7 @@ glusterd_ac_friend_add(glusterd_friend_sm_event_t *event, void *ctx)
     }
 
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     if (ret && frame)
         STACK_DESTROY(frame->root);
@@ -361,7 +361,7 @@ glusterd_ac_friend_probe(glusterd_friend_sm_event_t *event, void *ctx)
 
     GF_ASSERT(conf);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
     peerinfo = glusterd_peerinfo_find(NULL, probe_ctx->hostname);
     if (peerinfo == NULL) {
         // We should not reach this state ideally
@@ -407,7 +407,7 @@ glusterd_ac_friend_probe(glusterd_friend_sm_event_t *event, void *ctx)
     }
 
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     if (dict)
         dict_unref(dict);
@@ -440,7 +440,7 @@ glusterd_ac_send_friend_remove_req(glusterd_friend_sm_event_t *event,
 
     GF_ASSERT(conf);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
 
     peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!peerinfo) {
@@ -487,7 +487,7 @@ glusterd_ac_send_friend_remove_req(glusterd_friend_sm_event_t *event,
     }
 
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     gf_msg_debug("glusterd", 0, "Returning with %d", ret);
 
@@ -534,7 +534,7 @@ glusterd_ac_send_friend_update(glusterd_friend_sm_event_t *event, void *ctx)
 
     GF_ASSERT(priv);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
 
     cur_peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!cur_peerinfo) {
@@ -597,7 +597,7 @@ glusterd_ac_send_friend_update(glusterd_friend_sm_event_t *event, void *ctx)
     gf_msg_debug("glusterd", 0, "Returning with %d", ret);
 
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     if (friends)
         dict_unref(friends);
@@ -632,7 +632,7 @@ glusterd_ac_update_friend(glusterd_friend_sm_event_t *event, void *ctx)
 
     GF_ASSERT(priv);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
 
     cur_peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!cur_peerinfo) {
@@ -694,7 +694,7 @@ glusterd_ac_update_friend(glusterd_friend_sm_event_t *event, void *ctx)
     gf_msg_debug(this->name, 0, "Returning with %d", ret);
 
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     if (friends)
         dict_unref(friends);
@@ -801,13 +801,13 @@ glusterd_ac_handle_friend_remove_req(glusterd_friend_sm_event_t *event,
     ret = glusterd_xfer_friend_remove_resp(ev_ctx->req, ev_ctx->hostname,
                                            ev_ctx->port);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
     cds_list_for_each_entry_rcu(peerinfo, &priv->peers, uuid_list)
     {
         ret = glusterd_friend_sm_new_event(GD_FRIEND_EVENT_REMOVE_FRIEND,
                                            &new_event);
         if (ret) {
-            rcu_read_unlock();
+            RCU_READ_UNLOCK;
             goto out;
         }
 
@@ -816,13 +816,13 @@ glusterd_ac_handle_friend_remove_req(glusterd_friend_sm_event_t *event,
 
         ret = glusterd_friend_sm_inject_event(new_event);
         if (ret) {
-            rcu_read_unlock();
+            RCU_READ_UNLOCK;
             goto out;
         }
 
         new_event = NULL;
     }
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     glusterd_peer_detach_cleanup(priv);
 out:
@@ -842,14 +842,14 @@ glusterd_ac_friend_remove(glusterd_friend_sm_event_t *event, void *ctx)
 
     GF_ASSERT(event);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
 
     peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!peerinfo) {
         gf_msg(THIS->name, GF_LOG_ERROR, 0, GD_MSG_PEER_NOT_FOUND,
                "Could not find peer %s(%s)", event->peername,
                uuid_utoa(event->peerid));
-        rcu_read_unlock();
+        RCU_READ_UNLOCK;
         goto out;
     }
     ret = glusterd_friend_remove_cleanup_vols(peerinfo->uuid);
@@ -857,7 +857,7 @@ glusterd_ac_friend_remove(glusterd_friend_sm_event_t *event, void *ctx)
         gf_msg(THIS->name, GF_LOG_WARNING, 0, GD_MSG_VOL_CLEANUP_FAIL,
                "Volumes cleanup failed");
 
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
     /* Exiting read critical section as glusterd_peerinfo_cleanup calls
      * synchronize_rcu before freeing the peerinfo
      */
@@ -905,14 +905,14 @@ glusterd_ac_handle_friend_add_req(glusterd_friend_sm_event_t *event, void *ctx)
     ev_ctx = ctx;
     gf_uuid_copy(uuid, ev_ctx->uuid);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
     peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
     if (!peerinfo) {
         gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_PEER_NOT_FOUND,
                "Could not find peer %s(%s)", event->peername,
                uuid_utoa(event->peerid));
         ret = -1;
-        rcu_read_unlock();
+        RCU_READ_UNLOCK;
         goto out;
     }
 
@@ -922,7 +922,7 @@ glusterd_ac_handle_friend_add_req(glusterd_friend_sm_event_t *event, void *ctx)
      */
     gf_uuid_copy(peerinfo->uuid, ev_ctx->uuid);
 
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
 
     conf = this->private;
     GF_ASSERT(conf);
@@ -1047,7 +1047,7 @@ glusterd_friend_sm_transition_state(uuid_t peerid, char *peername,
     GF_ASSERT(state);
     GF_ASSERT(peername);
 
-    rcu_read_lock();
+    RCU_READ_LOCK;
     peerinfo = glusterd_peerinfo_find(peerid, peername);
     if (!peerinfo) {
         goto out;
@@ -1061,7 +1061,7 @@ glusterd_friend_sm_transition_state(uuid_t peerid, char *peername,
 
     ret = 0;
 out:
-    rcu_read_unlock();
+    RCU_READ_UNLOCK;
     return ret;
 }
 
@@ -1413,7 +1413,7 @@ glusterd_friend_sm()
             cds_list_del_init(&event->list);
             event_type = event->event;
 
-            rcu_read_lock();
+            RCU_READ_LOCK;
 
             peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
             if (!peerinfo) {
@@ -1423,7 +1423,7 @@ glusterd_friend_sm()
                        glusterd_friend_sm_event_name_get(event_type));
 
                 GF_FREE(event);
-                rcu_read_unlock();
+                RCU_READ_UNLOCK;
                 continue;
             }
             gf_msg_debug("glusterd", 0, "Dequeued event of type: '%s'",
@@ -1431,7 +1431,7 @@ glusterd_friend_sm()
 
             old_state = peerinfo->state.state;
 
-            rcu_read_unlock();
+            RCU_READ_UNLOCK;
             /* Giving up read-critical section here as we only need
              * the current state to call the handler.
              *
@@ -1489,10 +1489,10 @@ glusterd_friend_sm()
             /* We need to obtain peerinfo reference once again as we
              * had exited the read critical section above.
              */
-            rcu_read_lock();
+            RCU_READ_LOCK;
             peerinfo = glusterd_peerinfo_find(event->peerid, event->peername);
             if (!peerinfo) {
-                rcu_read_unlock();
+                RCU_READ_UNLOCK;
                 /* A peer can only be deleted as a effect of
                  * this state machine, and two such state
                  * machines can never run at the same time.
@@ -1518,7 +1518,7 @@ glusterd_friend_sm()
                 gf_msg(this->name, GF_LOG_ERROR, 0, GD_MSG_PEERINFO_CREATE_FAIL,
                        "Failed to store peerinfo");
             }
-            rcu_read_unlock();
+            RCU_READ_UNLOCK;
 
             glusterd_destroy_friend_event_context(event);
             GF_FREE(event);