[pve-devel] [PATCH v4 1/3] migrate: collect migration tunnel child process

[Thomas Lamprecht]

As we open2 it we also need to collect it to avoid zombies

Wait for 15 seconds if the tunnel is still running then send a
SIGTERM, after another 15 seconds a SIGKILL takes care if it totally
hung up.

As a this stage the tunnel is not used anymore it can safely be
killed, but we wait a little as a gracefull exit is always nicer.

Signed-off-by: Thomas Lamprecht <t.lamprecht at proxmox.com>
---

changes since v3:
* just signal the tunnel once with sigterm and eventually sigkill
* wait 15 seconds for sending a sigterm and another 15 for sending the sigkil



 PVE/QemuMigrate.pm | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index a25efff..8afe099 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -5,6 +5,7 @@ use warnings;
 use PVE::AbstractMigrate;
 use IO::File;
 use IPC::Open2;
+use POSIX qw( WNOHANG );
 use PVE::INotify;
 use PVE::Tools;
 use PVE::Cluster;
@@ -42,7 +43,10 @@ sub fork_command_pipe {
 }
 
 sub finish_command_pipe {
-    my ($self, $cmdpipe, $timeout) = @_;
+    my ($self, $cmdpipe) = @_;
+
+    my $cpid = $cmdpipe->{pid};
+    return undef if !$cpid;
 
     my $writer = $cmdpipe->{writer};
     my $reader = $cmdpipe->{reader};
@@ -50,27 +54,23 @@ sub finish_command_pipe {
     $writer->close();
     $reader->close();
 
-    my $cpid = $cmdpipe->{pid};
+    # collect child process
+    for (my $i = 1; $i <= 30; $i++) {
+	my $waitpid = waitpid($cpid, WNOHANG);
+	last if (defined($waitpid) && ($waitpid == $cpid));
 
-    if ($timeout) {
-	for (my $i = 0; $i < $timeout; $i++) {
-	    return if !PVE::ProcFSTools::check_process_running($cpid);
-	    sleep(1);
+	if ($i == 15) {
+	    $self->log('info', "ssh tunnel still running - terminating now with SIGTERM");
+	    kill(15, $cpid);
+	} elsif ($i == 29) { # kill for sure it and do an other round to collect it
+	    $self->log('info', "ssh tunnel still running - terminating now with SIGKILL");
+	    kill(9, $cpid);
 	}
-    }
-
-    $self->log('info', "ssh tunnel still running - terminating now with SIGTERM\n");
-    kill(15, $cpid);
 
-    # wait again
-    for (my $i = 0; $i < 10; $i++) {
-	return if !PVE::ProcFSTools::check_process_running($cpid);
-	sleep(1);
+	sleep (1);
     }
 
-    $self->log('info', "ssh tunnel still running - terminating now with SIGKILL\n");
-    kill 9, $cpid;
-    sleep 1;
+    delete $cmdpipe->{cpid};
 }
 
 sub fork_tunnel {
@@ -114,7 +114,7 @@ sub finish_tunnel {
     };
     my $err = $@;
 
-    $self->finish_command_pipe($tunnel, 30);
+    $self->finish_command_pipe($tunnel);
 
     die $err if $err;
 }
-- 
2.1.4