Re: [libvirt] [PATCH 4/5] Retry veth device creation on failure

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; The veth device creation code run in two steps, first it looks for two free veth device names, then it runs ip link to create the veth pair. There is an obvious race between finding free names and creating them, when guests are started in parallel. Rewrite the code to loop and re-try creation if it fails, to deal with the race condition. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- src/util/virnetdevveth.c | 151 +++++++++++++++++++++++++++++------------------ 1 file changed, 92 insertions(+), 59 deletions(-)

/* Functions */ + +static int virNetDevVethExists(int devNum) +{ + int ret; + char *path = NULL; + if (virAsprintf(&path, "/sys/class/net/veth%d/", devNum) < 0) + return -1; + ret = virFileExists(path) ? 1 : 0;

- if (virAsprintf(veth, "veth%d", devNum) < 0) - return -1; + for (devNum = startDev ; devNum < MAX_DEV_NUM ; devNum++) {