glusterd: Handle rpc_connect failure in the event handler

Currently rpc_connect calls the notification function on failure in the
same thread, glusterd notification holds the big_lock and
hence big_lock is released before rpc_connect

In snapshot creation, releasing the big-lock before completeing
operation can cause problem like deadlock or memory corruption.

Bricks are started as part of snapshot created operation.
brick_start releases the big_lock when doing brick_connect and this
might cause glusterd crash.
There is a similar issue in bug# 1088355.

Solution is let the event handler handle the failure than doing it in
the rpc_connect.

Change-Id: I088d44092ce845a07516c1d67abd02b220e08b38
BUG: 1101507
Signed-off-by: Vijaikumar M <vmallika@redhat.com>
Reviewed-on: http://review.gluster.org/7843
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Tested-by: Raghavendra G <rgowdapp@redhat.com>

3 files changed, 169 insertions, 90 deletions

diff --git a/rpc/rpc-transport/socket/src/Makefile.am b/rpc/rpc-transport/socket/src/Makefile.am
index 71e6ed6ff4a..5e909aceac8 100644
--- a/rpc/rpc-transport/socket/src/Makefile.am
+++ b/rpc/rpc-transport/socket/src/Makefile.am
@@ -1,4 +1,4 @@
-noinst_HEADERS = socket.h name.h
+noinst_HEADERS = socket.h name.h socket-mem-types.h
 
 rpctransport_LTLIBRARIES = socket.la
 rpctransportdir = $(libdir)/glusterfs/$(PACKAGE_VERSION)/rpc-transport
diff --git a/rpc/rpc-transport/socket/src/socket-mem-types.h b/rpc/rpc-transport/socket/src/socket-mem-types.h
new file mode 100644
index 00000000000..e5553b172a2
--- /dev/null
+++ b/rpc/rpc-transport/socket/src/socket-mem-types.h
@@ -0,0 +1,21 @@
+/*
+  Copyright (c) 2008-2014 Red Hat, Inc. <http://www.redhat.com>
+  This file is part of GlusterFS.
+
+  This file is licensed to you under your choice of the GNU Lesser
+  General Public License, version 3 or any later version (LGPLv3 or
+  later), or the GNU General Public License, version 2 (GPLv2), in all
+  cases as published by the Free Software Foundation.
+*/
+
+#ifndef __SOCKET_MEM_TYPES_H__
+#define __SOCKET_MEM_TYPES_H__
+
+#include "mem-types.h"
+
+typedef enum gf_sock_mem_types_ {
+        gf_sock_connect_error_state_t     = gf_common_mt_end + 1,
+        gf_sock_mt_end
+} gf_sock_mem_types_t;
+
+#endif
diff --git a/rpc/rpc-transport/socket/src/socket.c b/rpc/rpc-transport/socket/src/socket.c
index 6f566e49345..6d4a862aa8d 100644
--- a/rpc/rpc-transport/socket/src/socket.c
+++ b/rpc/rpc-transport/socket/src/socket.c
@@ -23,7 +23,7 @@
 #include "byte-order.h"
 #include "common-utils.h"
 #include "compat-errno.h"
-
+#include "socket-mem-types.h"
 
 /* ugly #includes below */
 #include "protocol-common.h"
@@ -152,6 +152,13 @@ typedef int SSL_trinary_func (SSL *, void *, int);
                 __socket_proto_update_priv_after_read (priv, ret, bytes_read); \
         }
 
+struct socket_connect_error_state_ {
+        xlator_t            *this;
+        rpc_transport_t     *trans;
+        gf_boolean_t         refd;
+};
+typedef struct socket_connect_error_state_ socket_connect_error_state_t;
+
 static int socket_init (rpc_transport_t *this);
 
 static void
@@ -2652,19 +2659,41 @@ out:
         return ret;
 }
 
+void*
+socket_connect_error_cbk (void *opaque)
+{
+        socket_connect_error_state_t *arg;
+
+        GF_ASSERT (opaque);
+
+        arg = opaque;
+        THIS = arg->this;
+
+        rpc_transport_notify (arg->trans, RPC_TRANSPORT_DISCONNECT, arg->trans);
+
+        if (arg->refd)
+                rpc_transport_unref (arg->trans);
+
+        GF_FREE (opaque);
+        return NULL;
+}
 
 static int
 socket_connect (rpc_transport_t *this, int port)
 {
-        int                      ret = -1;
-        int                      sock = -1;
-        socket_private_t        *priv = NULL;
-        socklen_t                sockaddr_len = 0;
-        glusterfs_ctx_t         *ctx = NULL;
-        sa_family_t              sa_family = {0, };
-        char                    *local_addr   = NULL;
-        union gf_sock_union      sock_union;
-        struct sockaddr_in      *addr         = NULL;
+        int                            ret             = -1;
+        int                            th_ret          = -1;
+        int                            sock            = -1;
+        socket_private_t              *priv            = NULL;
+        socklen_t                      sockaddr_len    = 0;
+        glusterfs_ctx_t               *ctx             = NULL;
+        sa_family_t                    sa_family       = {0, };
+        char                          *local_addr      = NULL;
+        union gf_sock_union            sock_union;
+        struct sockaddr_in            *addr            = NULL;
+        gf_boolean_t                   refd      = _gf_false;
+        socket_connect_error_state_t  *arg             = NULL;
+        pthread_t                      th_id           = {0, };
 
         GF_VALIDATE_OR_GOTO ("socket", this, err);
         GF_VALIDATE_OR_GOTO ("socket", this->private, err);
@@ -2680,52 +2709,43 @@ socket_connect (rpc_transport_t *this, int port)
 
         pthread_mutex_lock (&priv->lock);
         {
-                sock = priv->sock;
-        }
-        pthread_mutex_unlock (&priv->lock);
-
-        if (sock != -1) {
-                gf_log_callingfn (this->name, GF_LOG_TRACE,
-                                  "connect () called on transport already connected");
-                errno = EINPROGRESS;
-                ret = -1;
-                goto err;
-        }
+                if (priv->sock != -1) {
+                        gf_log_callingfn (this->name, GF_LOG_TRACE,
+                                          "connect () called on transport "
+                                          "already connected");
+                        errno = EINPROGRESS;
+                        ret = -1;
+                        goto unlock;
+                }
 
-        gf_log (this->name, GF_LOG_TRACE,
-                "connecting %p, state=%u gen=%u sock=%d", this,
-                priv->ot_state, priv->ot_gen, priv->sock);
+                gf_log (this->name, GF_LOG_TRACE,
+                        "connecting %p, state=%u gen=%u sock=%d", this,
+                        priv->ot_state, priv->ot_gen, priv->sock);
 
-        ret = socket_client_get_remote_sockaddr (this, &sock_union.sa,
-                                                 &sockaddr_len, &sa_family);
-        if (ret == -1) {
-                /* logged inside client_get_remote_sockaddr */
-                goto err;
-        }
+                ret = socket_client_get_remote_sockaddr (this, &sock_union.sa,
+                                                     &sockaddr_len, &sa_family);
+                if (ret == -1) {
+                        /* logged inside client_get_remote_sockaddr */
+                        goto unlock;
+                }
 
-        if (port > 0) {
-                sock_union.sin.sin_port = htons (port);
-        }
-        if (ntohs(sock_union.sin.sin_port) == GF_DEFAULT_SOCKET_LISTEN_PORT) {
-                if (priv->use_ssl) {
-                        gf_log(this->name,GF_LOG_DEBUG,
-                               "disabling SSL for portmapper connection");
-                        priv->use_ssl = _gf_false;
+                if (port > 0) {
+                        sock_union.sin.sin_port = htons (port);
                 }
-        }
-        else {
-                if (priv->ssl_enabled && !priv->use_ssl) {
-                        gf_log(this->name,GF_LOG_DEBUG,
-                               "re-enabling SSL for I/O connection");
-                        priv->use_ssl = _gf_true;
+                if (ntohs(sock_union.sin.sin_port) ==
+                    GF_DEFAULT_SOCKET_LISTEN_PORT) {
+                        if (priv->use_ssl) {
+                                gf_log(this->name,GF_LOG_DEBUG,
+                                "disabling SSL for portmapper connection");
+                                priv->use_ssl = _gf_false;
+                        }
                 }
-        }
-        pthread_mutex_lock (&priv->lock);
-        {
-                if (priv->sock != -1) {
-                        gf_log (this->name, GF_LOG_TRACE,
-                                "connect() -- already connected");
-                        goto unlock;
+                else {
+                        if (priv->ssl_enabled && !priv->use_ssl) {
+                                gf_log(this->name,GF_LOG_DEBUG,
+                                       "re-enabling SSL for I/O connection");
+                                priv->use_ssl = _gf_true;
+                        }
                 }
 
                 memcpy (&this->peerinfo.sockaddr, &sock_union.storage,
@@ -2737,6 +2757,7 @@ socket_connect (rpc_transport_t *this, int port)
                         gf_log (this->name, GF_LOG_ERROR,
                                 "socket creation failed (%s)",
                                 strerror (errno));
+                        ret = -1;
                         goto unlock;
                 }
 
@@ -2795,7 +2816,8 @@ socket_connect (rpc_transport_t *this, int port)
                                     &local_addr);
                 if (!ret && SA (&this->myinfo.sockaddr)->sa_family == AF_INET) {
                         addr = (struct sockaddr_in *)(&this->myinfo.sockaddr);
-                        ret = inet_pton (AF_INET, local_addr, &(addr->sin_addr.s_addr));
+                        ret = inet_pton (AF_INET, local_addr,
+                                         &(addr->sin_addr.s_addr));
                 }
 
                 ret = client_bind (this, SA (&this->myinfo.sockaddr),
@@ -2803,9 +2825,7 @@ socket_connect (rpc_transport_t *this, int port)
                 if (ret == -1) {
                         gf_log (this->name, GF_LOG_WARNING,
                                 "client bind failed: %s", strerror (errno));
-                        close (priv->sock);
-                        priv->sock = -1;
-                        goto unlock;
+                        goto handler;
                 }
 
                 if (!priv->use_ssl && !priv->bio && !priv->own_thread) {
@@ -2814,9 +2834,7 @@ socket_connect (rpc_transport_t *this, int port)
                                 gf_log (this->name, GF_LOG_ERROR,
                                         "NBIO on %d failed (%s)",
                                         priv->sock, strerror (errno));
-                                close (priv->sock);
-                                priv->sock = -1;
-                                goto unlock;
+                                goto handler;
                         }
                 }
 
@@ -2832,21 +2850,20 @@ socket_connect (rpc_transport_t *this, int port)
                                 GF_LOG_DEBUG : GF_LOG_ERROR),
                                 "connection attempt on %s failed, (%s)",
                                 this->peerinfo.identifier, strerror (errno));
-                        close (priv->sock);
-                        priv->sock = -1;
-                        goto unlock;
+                        goto handler;
+                }
+                else {
+                        ret = 0;
                 }
 
-		if (priv->use_ssl && !priv->own_thread) {
-			ret = ssl_setup_connection(this,0);
-			if (ret < 0) {
-				gf_log(this->name,GF_LOG_ERROR,
-					"client setup failed");
-				close(priv->sock);
-				priv->sock = -1;
-				goto unlock;
-			}
-		}
+                if (priv->use_ssl && !priv->own_thread) {
+                        ret = ssl_setup_connection(this,0);
+                        if (ret < 0) {
+                                gf_log(this->name,GF_LOG_ERROR,
+                                       "client setup failed");
+                                goto handler;
+                        }
+                }
 
                 if (!priv->bio && !priv->own_thread) {
                         ret = __socket_nonblock (priv->sock);
@@ -2855,10 +2872,24 @@ socket_connect (rpc_transport_t *this, int port)
                                 gf_log (this->name, GF_LOG_ERROR,
                                         "NBIO on %d failed (%s)",
                                         priv->sock, strerror (errno));
-                                close (priv->sock);
+                                goto handler;
+                        }
+                }
+
+handler:
+                if (ret < 0) {
+                        if (priv->own_thread) {
+                                close(priv->sock);
                                 priv->sock = -1;
                                 goto unlock;
                         }
+                        else {
+                                /* Ignore error from connect. epoll events
+                                   should be handled in the socket handler.
+                                   shutdown(2) will result in EPOLLERR, so
+                                   cleanup is done in socket_event_handler */
+                                shutdown (priv->sock, SHUT_RDWR);
+                        }
                 }
 
                 /*
@@ -2868,31 +2899,58 @@ socket_connect (rpc_transport_t *this, int port)
                 priv->connected = 0;
                 priv->is_server = _gf_false;
                 rpc_transport_ref (this);
+                refd = _gf_true;
 
-		if (priv->own_thread) {
-			if (pipe(priv->pipe) < 0) {
-				gf_log(this->name,GF_LOG_ERROR,
-				       "could not create pipe");
-			}
+                if (priv->own_thread) {
+                        if (pipe(priv->pipe) < 0) {
+                                gf_log(this->name,GF_LOG_ERROR,
+                                "could not create pipe");
+                        }
 
                         this->listener = this;
                         socket_spawn(this);
-		}
-		else {
-			priv->idx = event_register (ctx->event_pool, priv->sock,
-						    socket_event_handler,
-						    this, 1, 1);
-			if (priv->idx == -1) {
-				gf_log ("", GF_LOG_WARNING,
-					"failed to register the event");
-				ret = -1;
-			}
-		}
-        }
+                }
+                else {
+                        priv->idx = event_register (ctx->event_pool, priv->sock,
+                                                    socket_event_handler,
+                                                    this, 1, 1);
+                        if (priv->idx == -1) {
+                                gf_log ("", GF_LOG_WARNING,
+                                        "failed to register the event");
+                                close(priv->sock);
+                                priv->sock = -1;
+                                ret = -1;
+                        }
+                }
+
 unlock:
+                sock = priv->sock;
+        }
         pthread_mutex_unlock (&priv->lock);
 
 err:
+        /* if sock != -1, then cleanup is done from the event handler */
+        if (ret == -1 && sock == -1) {
+                /* Cleaup requires to send notification to upper layer which
+                   intern holds the big_lock. There can be dead-lock situation
+                   if big_lock is already held by the current thread.
+                   So transfer the ownership to seperate thread for cleanup.
+                */
+                arg = GF_CALLOC (1, sizeof (*arg),
+                                 gf_sock_connect_error_state_t);
+                arg->this = THIS;
+                arg->trans = this;
+                arg->refd = refd;
+                th_ret = pthread_create (&th_id, NULL, socket_connect_error_cbk,
+                                         arg);
+                if (th_ret) {
+                       gf_log (this->name, GF_LOG_ERROR, "pthread_create"
+                               "failed: %s", strerror(errno));
+                        GF_FREE (arg);
+                        GF_ASSERT (0);
+                }
+        }
+
         return ret;
 }