Re: [libvirt] [PATCH] cmdMigrate: move vshConnect before vshWatchJob

On 08/08/2014 10:44 AM, Chunyan Liu wrote: > A possible fix to issue: > http://www.redhat.com/archives/libvir-list/2014-August/thread.html#00227 > > While doing migration on KVM host, found problem sometimes: > VM is already running on the target host and disappears from source > host, but 'virsh migrate' command line hangs, cannot exit normally. > If pressing "ENTER" key, it will exit. > > The code hangs at tools/virsh-domain.c: cmdMigrate > ->vshWatchJob->poll(): > poll() is trying to select pipe_fd, which is used to receive message > from doMigrate thread. In debugging, found that doMigrate finishes > and at the end it does call safewrite() to write the retval ('0' or > '1') to pipe_fd, and the write is completed. But cmdMigrate poll() > cannot get the event. If pressing "ENTER" key, poll() can get the > event and select pipe_fd, then command line can exit. > > In current code, authentication thread which is called by vshConnect > will use stdin, and at the same time, in cmdMigrate main process, > poll() is listening to stdin, that probably affect poll() to get > pipe_fd event. Better to move authentication before vshWatchJob. With > this change, above problem does not exist. > > Signed-off-by: Chunyan Liu <cyliu(a)suse.com&gt; > --- > tools/virsh-domain.c | 26 ++++++++++++++++++++------ > tools/virsh.h | 1 + > 2 files changed, 21 insertions(+), 6 deletions(-) ACK > diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c > index f7193cb..2562326 100644 > --- a/tools/virsh-domain.c > +++ b/tools/virsh-domain.c > @@ -8965,6 +8965,7 @@ doMigrate(void *opaque) > virTypedParameterPtr params = NULL; > int nparams = 0; > int maxparams = 0; > + virConnectPtr dconn = data->dconn; > > sigemptyset(&sigmask); > sigaddset(&sigmask, SIGINT); > @@ -9079,18 +9080,12 @@ doMigrate(void *opaque) > ret = '0'; > } else { I'd rather rewrite this condition as: if (dconn) { /* Traditional live migration */ } else { /* peer2peer or direct */ }