[libvirt] [PATCH 1/3] networkStateInitialize: Don't lock network driver

Michal Privoznik mprivozn at redhat.com
Mon Mar 16 16:41:58 UTC 2015


There's no need to lock the network driver, as network driver
initialization is done prior accepting any client. There's nobody
to hop in and do something over partially initialized driver. Nor
qemu driver is doing that.

==30532== Observed (incorrect) order is: acquisition of lock at 0x1439EF50
==30532==    at 0x4C31A26: pthread_mutex_lock (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0x5324895: virMutexLock (virthread.c:88)
==30532==    by 0x5307E86: virObjectLock (virobject.c:323)
==30532==    by 0x5396440: virNetworkObjListForEach (network_conf.c:4511)
==30532==    by 0x19B29308: networkStateInitialize (bridge_driver.c:686)
==30532==    by 0x53E1CCC: virStateInitialize (libvirt.c:777)
==30532==    by 0x11DEB7: daemonRunStateInit (libvirtd.c:906)
==30532==    by 0x5324B6A: virThreadHelper (virthread.c:197)
==30532==    by 0x4C30456: ??? (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0xA1EC1F2: start_thread (in /lib64/libpthread-2.19.so)
==30532==    by 0xA4EDC8C: clone (in /lib64/libc-2.19.so)
==30532==
==30532==  followed by a later acquisition of lock at 0x1439CD60
==30532==    at 0x4C31A26: pthread_mutex_lock (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0x5324895: virMutexLock (virthread.c:88)
==30532==    by 0x19B27B2C: networkDriverLock (bridge_driver.c:102)
==30532==    by 0x19B27B60: networkGetDnsmasqCaps (bridge_driver.c:113)
==30532==    by 0x19B2856A: networkUpdateState (bridge_driver.c:389)
==30532==    by 0x53963E9: virNetworkObjListForEachHelper (network_conf.c:4488)
==30532==    by 0x52E2224: virHashForEach (virhash.c:521)
==30532==    by 0x539645B: virNetworkObjListForEach (network_conf.c:4512)
==30532==    by 0x19B29308: networkStateInitialize (bridge_driver.c:686)
==30532==    by 0x53E1CCC: virStateInitialize (libvirt.c:777)
==30532==    by 0x11DEB7: daemonRunStateInit (libvirtd.c:906)
==30532==    by 0x5324B6A: virThreadHelper (virthread.c:197)
==30532==
==30532== Required order was established by acquisition of lock at 0x1439CD60
==30532==    at 0x4C31A26: pthread_mutex_lock (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0x5324895: virMutexLock (virthread.c:88)
==30532==    by 0x19B27B2C: networkDriverLock (bridge_driver.c:102)
==30532==    by 0x19B28DF9: networkStateInitialize (bridge_driver.c:609)
==30532==    by 0x53E1CCC: virStateInitialize (libvirt.c:777)
==30532==    by 0x11DEB7: daemonRunStateInit (libvirtd.c:906)
==30532==    by 0x5324B6A: virThreadHelper (virthread.c:197)
==30532==    by 0x4C30456: ??? (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0xA1EC1F2: start_thread (in /lib64/libpthread-2.19.so)
==30532==    by 0xA4EDC8C: clone (in /lib64/libc-2.19.so)
==30532==
==30532==  followed by a later acquisition of lock at 0x1439EF50
==30532==    at 0x4C31A26: pthread_mutex_lock (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0x5324895: virMutexLock (virthread.c:88)
==30532==    by 0x5307E86: virObjectLock (virobject.c:323)
==30532==    by 0x538A09C: virNetworkAssignDef (network_conf.c:527)
==30532==    by 0x5391EB2: virNetworkLoadState (network_conf.c:3008)
==30532==    by 0x53922D4: virNetworkLoadAllState (network_conf.c:3128)
==30532==    by 0x19B2929A: networkStateInitialize (bridge_driver.c:671)
==30532==    by 0x53E1CCC: virStateInitialize (libvirt.c:777)
==30532==    by 0x11DEB7: daemonRunStateInit (libvirtd.c:906)
==30532==    by 0x5324B6A: virThreadHelper (virthread.c:197)
==30532==    by 0x4C30456: ??? (in /usr/lib64/valgrind/vgpreload_helgrind-amd64-linux.so)
==30532==    by 0xA1EC1F2: start_thread (in /lib64/libpthread-2.19.so)

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/network/bridge_driver.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index a007388..b3dcadc 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -606,7 +606,6 @@ networkStateInitialize(bool privileged,
         VIR_FREE(network_driver);
         goto error;
     }
-    networkDriverLock(network_driver);
 
     /* configuration/state paths are one of
      * ~/.config/libvirt/... (session/unprivileged)
@@ -677,8 +676,6 @@ networkStateInitialize(bool privileged,
                                  network_driver->networkAutostartDir) < 0)
         goto error;
 
-    networkDriverUnlock(network_driver);
-
     /* Update the internal status of all allegedly active
      * networks according to external conditions on the host
      * (i.e. anything that isn't stored directly in each
-- 
2.0.5




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