lei_store: fix locking w.r.t epoch creation

Prior to this change, it was possible for oneshot lei processes
to race on epoch creation/rollover.  lei-daemon normally
prevents the problem by funnelling all writes to a single
socket, but oneshot lei has no such protection.

diff --git a/lib/PublicInbox/ExtSearchIdx.pm b/lib/PublicInbox/ExtSearchIdx.pm
index 9d6b3b9dc99bee09a318fc609373c7dd90f49137..08f2295aa7316fdddf949071ddeb57a18c53cd47 100644 (file)
--- a/lib/PublicInbox/ExtSearchIdx.pm
+++ b/lib/PublicInbox/ExtSearchIdx.pm
@@ -926,7 +926,7 @@ sub update_last_commit { # overrides V2Writable
 
 sub _idx_init { # with_umask callback
        my ($self, $opt) = @_;
-       PublicInbox::V2Writable::_idx_init($self, $opt);
+       PublicInbox::V2Writable::_idx_init($self, $opt); # acquires ei.lock
        $self->{midx} = PublicInbox::MiscIdx->new($self);
 }
 

diff --git a/lib/PublicInbox/LeiStore.pm b/lib/PublicInbox/LeiStore.pm
index fcc9224d4644d7c2c6d97a96a99128155539c329..8af740fdf6e9b3e30ef251764c941354ef5a3785 100644 (file)
--- a/lib/PublicInbox/LeiStore.pm
+++ b/lib/PublicInbox/LeiStore.pm
@@ -88,6 +88,7 @@ sub importer {
                $self->checkpoint;
                $max = $self->git_epoch_max + 1;
        }
+       my (undef, $tl) = eidx_init($self); # acquire lock
        my $pfx = $self->git_pfx;
        $max //= $self->git_epoch_max;
        while (1) {
@@ -97,7 +98,9 @@ sub importer {
                my $git = PublicInbox::Git->new($latest);
                if (!$old) {
                        $git->qx(qw(config core.sharedRepository 0600));
-                       $self->done; # force eidx_init on next round
+                       $self->done; # unlock
+                       # re-acquire lock, update alternates for new epoch
+                       (undef, $tl) = eidx_init($self);
                }
                my $packed_bytes = $git->packed_bytes;
                my $unpacked_bytes = $packed_bytes / $self->packing_factor;
@@ -130,7 +133,7 @@ sub eidx_init {
        my $tl = wantarray && $self->{-err_wr} ?
                        PublicInbox::OnDestroy->new($$, \&_tail_err, $self) :
                        undef;
-       $eidx->idx_init({-private => 1});
+       $eidx->idx_init({-private => 1}); # acquires lock
        wantarray ? ($eidx, $tl) : $eidx;
 }
 
@@ -204,7 +207,7 @@ sub set_sync_info ($$$) {
 sub add_eml {
        my ($self, $eml, $vmd, $xoids) = @_;
        my $im = $self->importer; # may create new epoch
-       my ($eidx, $tl) = eidx_init($self); # updates/writes alternates file
+       my ($eidx, $tl) = eidx_init($self);
        my $oidx = $eidx->{oidx}; # PublicInbox::Import::add checks this
        my $smsg = bless { -oidx => $oidx }, 'PublicInbox::Smsg';
        my $im_mark = $im->add($eml, undef, $smsg);