[pve-devel] [PATCH cluster v2 3/3] cfs_lock: save and restore outer alarm

[Thomas Lamprecht]

allow our caller to set alarm on us.

Ensure that the new alarm sub gets assigned before the new alarm gets set.

---
new in v2

maybe there should be even:
 alarm(0)
 local $SIG{ALRM} = sub {...};
 alarm(60);
to ensure we always call the matching alarm sub, but as this is not a
likely nor big problem just keep it this way.

 data/PVE/Cluster.pm | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/data/PVE/Cluster.pm b/data/PVE/Cluster.pm
index f634c84..3da86bc 100644
--- a/data/PVE/Cluster.pm
+++ b/data/PVE/Cluster.pm
@@ -860,6 +860,8 @@ sub cfs_write_file {
 my $cfs_lock = sub {
     my ($lockid, $timeout, $code, @param) = @_;
 
+    my $prev_alarm = alarm(0); # suspend outer alarm early
+
     my $res;
     my $got_lock = 0;
 
@@ -899,8 +901,8 @@ my $cfs_lock = sub {
 
 	# fixed command timeout: cfs locks have a timeout of 120
 	# using 60 gives us another 60 seconds to abort the task
-	alarm(60);
 	local $SIG{ALRM} = sub { die "got lock timeout - aborting command\n"; };
+	alarm(60);
 
 	cfs_update(); # make sure we read latest versions inside code()
 
@@ -911,12 +913,12 @@ my $cfs_lock = sub {
 
     my $err = $@;
 
-    alarm(0);
-
     $err = "$msg: no quorum!\n" if !$got_lock && !check_cfs_quorum(1);
 
     rmdir $filename if $got_lock; # if we held the lock always unlock again
 
+    alarm($prev_alarm);
+
     if ($err) {
         $@ = $err;
         return undef;
-- 
2.11.0