[PATCH] qemu: pre-create the dbus directory in qemuStateInitialize

[Bihong Yu <yubihong@xxxxxxxxxx>]

>From 187323ce736dcd9b1a177d552630b0c6859a4798 Mon Sep 17 00:00:00 2001
From: Bihong Yu <yubihong@xxxxxxxxxx>
Date: Tue, 14 Jul 2020 15:44:05 +0800
Subject: [PATCH] qemu: pre-create the dbus directory in qemuStateInitialize

There are races condiction to make '/run/libvirt/qemu/dbus' directory in
virDirCreateNoFork() while concurrent start VMs, and get "failed to create
directory '/run/libvirt/qemu/dbus': File exists" error message. pre-create the
dbus directory in qemuStateInitialize.

Signed-off-by:Bihong Yu <yubihong@xxxxxxxxxx>
---
 src/qemu/qemu_dbus.c    | 4 +---
 src/qemu/qemu_dbus.h    | 2 +-
 src/qemu/qemu_driver.c  | 4 ++++
 src/qemu/qemu_process.c | 3 ---
 4 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/qemu/qemu_dbus.c b/src/qemu/qemu_dbus.c
index 51f6c94..0e0306a 100644
--- a/src/qemu/qemu_dbus.c
+++ b/src/qemu/qemu_dbus.c
@@ -34,10 +34,8 @@ VIR_LOG_INIT("qemu.dbus");


 int
-qemuDBusPrepareHost(virQEMUDriverPtr driver)
+qemuDBusPreparePath(virQEMUDriverConfigPtr cfg)
 {
-    g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
-
     return virDirCreate(cfg->dbusStateDir, 0770, cfg->user, cfg->group,
                         VIR_DIR_CREATE_ALLOW_EXIST);
 }
diff --git a/src/qemu/qemu_dbus.h b/src/qemu/qemu_dbus.h
index 474eb10..6ce9f7b 100644
--- a/src/qemu/qemu_dbus.h
+++ b/src/qemu/qemu_dbus.h
@@ -21,7 +21,7 @@
 #include "qemu_conf.h"
 #include "qemu_domain.h"

-int qemuDBusPrepareHost(virQEMUDriverPtr driver);
+int qemuDBusPreparePath(virQEMUDriverConfigPtr cfg);

 char *qemuDBusGetAddress(virQEMUDriverPtr driver,
                          virDomainObjPtr vm);
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index d185666..52b68c9 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -50,6 +50,7 @@
 #include "qemu_security.h"
 #include "qemu_checkpoint.h"
 #include "qemu_backup.h"
+#include "qemu_dbus.h"

 #include "virerror.h"
 #include "virlog.h"
@@ -790,6 +791,9 @@ qemuStateInitialize(bool privileged,
                                   cfg->migrationPortMax)) == NULL)
         goto error;

+    if (qemuDBusPreparePath(cfg) < 0)
+        goto error;
+
     if (qemuSecurityInit(qemu_driver) < 0)
         goto error;

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index eba14ed..46620ca 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6449,9 +6449,6 @@ qemuProcessPrepareHost(virQEMUDriverPtr driver,
     qemuDomainObjPrivatePtr priv = vm->privateData;
     g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);

-    if (qemuDBusPrepareHost(driver) < 0)
-        return -1;
-
     if (qemuPrepareNVRAM(cfg, vm) < 0)
         return -1;

-- 
1.8.3.1