From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=ALL_TRUSTED,BAYES_00 shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id B94321F9FF for ; Wed, 24 Mar 2021 09:23:35 +0000 (UTC) From: Eric Wong To: meta@public-inbox.org Subject: [PATCH 2/9] mbox_lock: dotlock: chdir for relative lock paths Date: Wed, 24 Mar 2021 14:23:28 +0500 Message-Id: <20210324092335.12345-3-e@80x24.org> In-Reply-To: <20210324092335.12345-1-e@80x24.org> References: <20210324092335.12345-1-e@80x24.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: Since lei-daemon will fchdir on every request, we must ensure we're in the correct directory before unlink(2) is called, since we can't use unlinkat(2) from pure Perl. --- lib/PublicInbox/MboxLock.pm | 14 ++++++++++++++ t/mbox_lock.t | 12 ++++++++++++ 2 files changed, 26 insertions(+) diff --git a/lib/PublicInbox/MboxLock.pm b/lib/PublicInbox/MboxLock.pm index bea0e325..856b1e21 100644 --- a/lib/PublicInbox/MboxLock.pm +++ b/lib/PublicInbox/MboxLock.pm @@ -60,6 +60,11 @@ sub acq_dotlock { if (link($tmp, $dot_lock)) { unlink($tmp) or die "unlink($tmp): $!"; $self->{".lock$pid"} = $dot_lock; + if (substr($dot_lock, 0, 1) ne '/') { + opendir(my $dh, '.') or + die "opendir . $!"; + $self->{dh} = $dh; + } return; } unlink($tmp) or die "unlink($tmp): $!"; @@ -111,10 +116,19 @@ sub acq { $self; } +sub _fchdir { chdir($_[0]) } # OnDestroy callback + sub DESTROY { my ($self) = @_; if (my $f = $self->{".lock$$"}) { + my $x; + if (my $dh = delete $self->{dh}) { + opendir my $c, '.' or die "opendir . $!"; + $x = PublicInbox::OnDestroy->new(\&_fchdir, $c); + chdir($dh) or die "chdir (for $f): $!"; + } unlink($f) or die "unlink($f): $! (lock stolen?)"; + undef $x; } } diff --git a/t/mbox_lock.t b/t/mbox_lock.t index 3dc3b449..c2fee0d4 100644 --- a/t/mbox_lock.t +++ b/t/mbox_lock.t @@ -5,6 +5,7 @@ use strict; use v5.10.1; use PublicInbox::TestCommon; use POSIX qw(_exit); use PublicInbox::DS qw(now); use Errno qw(EAGAIN); +use PublicInbox::OnDestroy; use_ok 'PublicInbox::MboxLock'; my ($tmpdir, $for_destroy) = tmpdir(); my $f = "$tmpdir/f"; @@ -15,6 +16,17 @@ ok(!-f "$f.lock", 'dotlock gone'); $mbl = PublicInbox::MboxLock->acq($f, 1, ['none']); ok(!-f "$f.lock", 'no dotlock with none'); undef $mbl; +{ + opendir my $cur, '.' or BAIL_OUT $!; + my $od = PublicInbox::OnDestroy->new(sub { chdir $cur }); + chdir $tmpdir or BAIL_OUT; + my $abs = "$tmpdir/rel.lock"; + my $rel = PublicInbox::MboxLock->acq('rel', 1, ['dotlock']); + chdir '/' or BAIL_OUT; + ok(-f $abs, 'lock with abs path created'); + undef $rel; + ok(!-f $abs, 'lock gone despite being in the wrong dir'); +} eval { PublicInbox::MboxLock->acq($f, 1, ['bogus']);