nbd: Always call "close_fn" in nbd_client_new

Rename the parameter "close" to "close_fn" to disambiguous with
close(2).

This unifies error handling paths of NBDClient allocation:
nbd_client_new will shutdown the socket and call the "close_fn" callback
if negotiation failed, so the caller don't need a different path than
the normal close.

The returned pointer is never used, make it void in preparation for the
next patch.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1452760863-25350-2-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

blockdev-nbd.c

@@ -27,9 +27,8 @@ static void nbd_accept(void *opaque)
     socklen_t addr_len = sizeof(addr);
 
     int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
-    if (fd >= 0 && !nbd_client_new(NULL, fd, nbd_client_put)) {
-        shutdown(fd, 2);
-        close(fd);
+    if (fd >= 0) {
+        nbd_client_new(NULL, fd, nbd_client_put);
     }
 }
 

include/block/nbd.h

@@ -98,8 +98,7 @@ NBDExport *nbd_export_find(const char *name);
 void nbd_export_set_name(NBDExport *exp, const char *name);
 void nbd_export_close_all(void);
 
-NBDClient *nbd_client_new(NBDExport *exp, int csock,
-                          void (*close)(NBDClient *));
+void nbd_client_new(NBDExport *exp, int csock, void (*close_fn)(NBDClient *));
 void nbd_client_get(NBDClient *client);
 void nbd_client_put(NBDClient *client);
 

nbd.c

@@ -1475,8 +1475,7 @@ static void nbd_update_can_read(NBDClient *client)
     }
 }
 
-NBDClient *nbd_client_new(NBDExport *exp, int csock,
-                          void (*close)(NBDClient *))
+void nbd_client_new(NBDExport *exp, int csock, void (*close_fn)(NBDClient *))
 {
     NBDClient *client;
     client = g_malloc0(sizeof(NBDClient));
@@ -1485,10 +1484,11 @@ NBDClient *nbd_client_new(NBDExport *exp, int csock,
     client->sock = csock;
     client->can_read = true;
     if (nbd_send_negotiate(client)) {
-        g_free(client);
-        return NULL;
+        shutdown(client->sock, 2);
+        close_fn(client);
+        return;
     }
-    client->close = close;
+    client->close = close_fn;
     qemu_co_mutex_init(&client->send_lock);
     nbd_set_handlers(client);
 
@@ -1496,5 +1496,4 @@ NBDClient *nbd_client_new(NBDExport *exp, int csock,
         QTAILQ_INSERT_TAIL(&exp->clients, client, next);
         nbd_export_get(exp);
     }
-    return client;
 }

qemu-nbd.c

@@ -333,13 +333,9 @@ static void nbd_accept(void *opaque)
         return;
     }
 
-    if (nbd_client_new(exp, fd, nbd_client_closed)) {
-        nb_fds++;
-        nbd_update_server_fd_handler(server_fd);
-    } else {
-        shutdown(fd, 2);
-        close(fd);
-    }
+    nb_fds++;
+    nbd_update_server_fd_handler(server_fd);
+    nbd_client_new(exp, fd, nbd_client_closed);
 }
 
 static void nbd_update_server_fd_handler(int fd)