Re: [libvirt] [PATCH v3 3/9] rpc: set listen backlog on FDs as well as on other sockets

On Wed, Jul 23, 2014 at 04:27:07PM +0200, Martin Kletzander wrote: > Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com&gt; > --- > src/locking/lock_daemon.c | 2 +- > src/rpc/virnetserverservice.c | 5 +++++ > src/rpc/virnetserverservice.h | 1 + > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/src/locking/lock_daemon.c b/src/locking/lock_daemon.c > index e9219d5..02d77e3 100644 > --- a/src/locking/lock_daemon.c > +++ b/src/locking/lock_daemon.c > @@ -614,7 +614,7 @@ virLockDaemonSetupNetworkingSystemD(virNetServerPtr srv) > #if WITH_GNUTLS > NULL, > #endif > - false, 1))) > + false, 0, 1))) > return -1; > > if (virNetServerAddService(srv, svc, NULL) < 0) { > diff --git a/src/rpc/virnetserverservice.c b/src/rpc/virnetserverservice.c > index e85889b..fea05c3 100644 > --- a/src/rpc/virnetserverservice.c > +++ b/src/rpc/virnetserverservice.c > @@ -133,6 +133,7 @@ virNetServerServiceNewFDOrUNIX(const char *path, > tls, > #endif > readonly, > + max_queued_clients, > nrequests_client_max); > } > } > @@ -265,6 +266,7 @@ virNetServerServicePtr virNetServerServiceNewFD(int fd, > virNetTLSContextPtr tls, > #endif > bool readonly, > + size_t max_queued_clients, > size_t nrequests_client_max) > { > virNetServerServicePtr svc; > @@ -292,6 +294,9 @@ virNetServerServicePtr virNetServerServiceNewFD(int fd, > goto error; > > for (i = 0; i < svc->nsocks; i++) { > + if (virNetSocketListen(svc->socks[i], max_queued_clients) < 0) > + goto error; Hmm, systemd should have already called listen() on the socket FD it passes to us. I wonder if it is better than we do the same when auto-spawning libvirtd passing it a listening socket. You kind of need to listen() to avoid a race condition I believe when spawning libvirtd twice. eg if libvirt.so calls listen() and it fails then we know there's another libvirtd in the process of being started on that socket, so we can go back to trying to connect() until it succeeeds.

Regards, Daniel