From: Eric Wong <e@80x24.org>
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 [thread overview]
Message-ID: <20210324092335.12345-3-e@80x24.org> (raw)
In-Reply-To: <20210324092335.12345-1-e@80x24.org>
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']);
next prev parent reply other threads:[~2021-03-24 9:23 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 9:23 [PATCH 0/9] lei: various corner case leak fixes Eric Wong
2021-03-24 9:23 ` [PATCH 1/9] ds: improve DS->Reset fork-safety Eric Wong
2021-03-24 23:01 ` [SQUASH] " Eric Wong
2021-03-24 9:23 ` Eric Wong [this message]
2021-03-24 9:23 ` [PATCH 3/9] lei: drop circular reference in lei_store process Eric Wong
2021-03-24 9:23 ` [PATCH 4/9] lei: update {3} after -C chdirs Eric Wong
2021-03-24 9:23 ` [PATCH 5/9] lei: clean up pkt_op consumer on exception, too Eric Wong
2021-03-24 9:23 ` [PATCH 6/9] lei_store: give process a better name Eric Wong
2021-03-24 9:23 ` [PATCH 7/9] v2writable: cleanup SQLite handles on --xapian-only Eric Wong
2021-03-24 9:23 ` [PATCH 8/9] lei_mirror: fix circular reference Eric Wong
2021-03-24 9:23 ` [PATCH 9/9] lei-daemon: do not leak FDs on bogus requests Eric Wong
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