NULL dereference fixes in code base after running with 'clang'

* 212 logical (NULL deref/divide by zero) errors reduced to 28
  (27 of them in contrib/ and lex part of codebase, 1 is invalid)
* 11 API errors reduced to 0

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 966 (NULL check for avoiding NULL dereferencing of pointers..)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=966

4 files changed, 30 insertions, 22 deletions

diff --git a/xlators/protocol/legacy/client/src/client-protocol.c b/xlators/protocol/legacy/client/src/client-protocol.c
index dae31dcb356..0dc5bee5d56 100644
--- a/xlators/protocol/legacy/client/src/client-protocol.c
+++ b/xlators/protocol/legacy/client/src/client-protocol.c
@@ -302,6 +302,8 @@ call_bail (void *data)
                         gf_ops = gf_cbks;
                         gf_op_list = gf_cbk_list;
                         break;
+                default:
+                        goto out;
                 }
 
                 localtime_r (&trav->saved_at.tv_sec, &frame_sent_tm);
@@ -3255,6 +3257,9 @@ client_lookup (call_frame_t *frame, xlator_t *this, loc_t *loc,
         client_local_t      *local = NULL;
         char                *buf = NULL;
 
+        GF_VALIDATE_OR_GOTO (this->name, loc, unwind);
+        GF_VALIDATE_OR_GOTO (this->name, loc->path, unwind);
+
         local = GF_CALLOC (1, sizeof (*local), gf_client_mt_client_local_t);
         GF_VALIDATE_OR_GOTO (this->name, local, unwind);
 
@@ -3262,9 +3267,6 @@ client_lookup (call_frame_t *frame, xlator_t *this, loc_t *loc,
 
         frame->local = local;
 
-        GF_VALIDATE_OR_GOTO (this->name, loc, unwind);
-        GF_VALIDATE_OR_GOTO (this->name, loc->path, unwind);
-
         if (loc->ino != 1 && loc->parent) {
                 ret = inode_ctx_get2 (loc->parent, this, &par, &gen);
                 if (loc->parent->ino && ret < 0) {
@@ -3319,7 +3321,7 @@ client_lookup (call_frame_t *frame, xlator_t *this, loc_t *loc,
         return ret;
 
 unwind:
-        STACK_UNWIND (frame, op_ret, op_errno, loc->inode, NULL, NULL);
+        STACK_UNWIND (frame, op_ret, op_errno, (loc)?loc->inode:NULL, NULL, NULL);
         return ret;
 }
 
diff --git a/xlators/protocol/legacy/server/src/server-helpers.c b/xlators/protocol/legacy/server/src/server-helpers.c
index 7ab2ce88531..595916a3656 100644
--- a/xlators/protocol/legacy/server/src/server-helpers.c
+++ b/xlators/protocol/legacy/server/src/server-helpers.c
@@ -427,15 +427,17 @@ server_connection_destroy (xlator_t *this, server_connection_t *conn)
                 INIT_LIST_HEAD (&file_lockers);
                 INIT_LIST_HEAD (&dir_lockers);
 
-                LOCK (&ltable->lock);
-                {
-                        list_splice_init (&ltable->file_lockers,
-                                          &file_lockers);
+                if (ltable) {
+                        LOCK (&ltable->lock);
+                        {
+                                list_splice_init (&ltable->file_lockers,
+                                                  &file_lockers);
 
-                        list_splice_init (&ltable->dir_lockers, &dir_lockers);
+                                list_splice_init (&ltable->dir_lockers, &dir_lockers);
+                        }
+                        UNLOCK (&ltable->lock);
+                        GF_FREE (ltable);
                 }
-                UNLOCK (&ltable->lock);
-                GF_FREE (ltable);
 
                 flock.l_type  = F_UNLCK;
                 flock.l_start = 0;
diff --git a/xlators/protocol/legacy/server/src/server-protocol.c b/xlators/protocol/legacy/server/src/server-protocol.c
index 6a48dff390a..da0303019a3 100644
--- a/xlators/protocol/legacy/server/src/server-protocol.c
+++ b/xlators/protocol/legacy/server/src/server-protocol.c
@@ -147,7 +147,7 @@ server_print_params (char *str, int size, server_state_t *state)
                                     "wbflags=%d,", state->wbflags);
         if (state->size)
                 filled += snprintf (str + filled, size - filled,
-                                    "size=%Zu,", state->size);
+                                    "size=%zu,", state->size);
         if (state->offset)
                 filled += snprintf (str + filled, size - filled,
                                     "offset=%"PRId64",", state->offset);
@@ -667,8 +667,8 @@ server_fentrylk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         gf_errno        = gf_errno_to_error (op_errno);
         hdr->rsp.op_errno = hton32 (gf_errno);
 
+        state = CALL_STATE(frame);
         if (op_ret >= 0) {
-                state = CALL_STATE(frame);
                 if (state->cmd == ENTRYLK_UNLOCK)
                         gf_del_locker (conn->ltable, state->volume,
                                        NULL, state->fd, frame->root->pid);
@@ -5656,7 +5656,7 @@ mop_setvolume (call_frame_t *frame, xlator_t *bound_xl,
 fail:
         dict_len = dict_serialized_length (reply);
         if (dict_len < 0) {
-                gf_log (xl->name, GF_LOG_DEBUG,
+                gf_log ("server", GF_LOG_DEBUG,
                         "failed to get serialized length of reply dict");
                 op_ret   = -1;
                 op_errno = EINVAL;
@@ -5670,7 +5670,7 @@ fail:
         if (dict_len) {
                 ret = dict_serialize (reply, rsp->buf);
                 if (ret < 0) {
-                        gf_log (xl->name, GF_LOG_DEBUG,
+                        gf_log ("server", GF_LOG_DEBUG,
                                 "failed to serialize reply dict");
                         op_ret = -1;
                         op_errno = -ret;
@@ -6524,15 +6524,19 @@ int
 notify (xlator_t *this, int32_t event, void *data, ...)
 {
         int          ret = 0;
-        transport_t *trans = data;
+        transport_t *trans = NULL;
         peer_info_t *peerinfo = NULL;
         peer_info_t *myinfo = NULL;
 
-        if (trans != NULL) {
-                peerinfo = &(trans->peerinfo);
-                myinfo = &(trans->myinfo);
+        trans = data;
+        if (!trans) {
+                gf_log (this->name, GF_LOG_ERROR, "!trans");
+                goto out;
         }
 
+        peerinfo = &(trans->peerinfo);
+        myinfo = &(trans->myinfo);
+
         switch (event) {
         case GF_EVENT_POLLIN:
                 ret = protocol_server_pollin (this, trans);
@@ -6576,7 +6580,7 @@ notify (xlator_t *this, int32_t event, void *data, ...)
                 default_notify (this, event, data);
                 break;
         }
-
+out:
         return ret;
 }
 
diff --git a/xlators/protocol/legacy/transport/ib-verbs/src/ib-verbs.c b/xlators/protocol/legacy/transport/ib-verbs/src/ib-verbs.c
index 6714d32e7d8..85228bf4e58 100644
--- a/xlators/protocol/legacy/transport/ib-verbs/src/ib-verbs.c
+++ b/xlators/protocol/legacy/transport/ib-verbs/src/ib-verbs.c
@@ -1718,8 +1718,8 @@ ib_verbs_init (transport_t *this)
 
                 if (!priv->device) {
                         gf_log ("transport/ib-verbs", GF_LOG_ERROR,
-                                "could not create ib_verbs device for %s", 
-                                priv->device->device_name);
+                                "could not create ib_verbs device for %s",
+                                options->device_name);
                         ret = -1;
 			goto cleanup;
                 }