nntpd+imapd: detect unlinked msgmap

While it's even less common to experience a replaced
msgmap.sqlite3 file, BOFHs may do the darndest things.  This is
another step towards reducing the number of needless wakeups
we need to do in long-lived read-only daemons.

diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index 02186dac717fa329b6fb508d8eeab2c18919bca0..3d9754dce54824f6007d52e98f3ce7c4da5b9b5a 100644 (file)
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -31,7 +31,7 @@ sub cleanup_task () {
        for my $ibx (values %$CLEANUP) {
                my $again;
                if ($have_devel_peek) {
-                       foreach my $f (qw(mm search)) {
+                       foreach my $f (qw(search)) {
                                # we bump refcnt by assigning tmp, here:
                                my $tmp = $ibx->{$f} or next;
                                next if Devel::Peek::SvREFCNT($tmp) > 2;
@@ -47,7 +47,7 @@ sub cleanup_task () {
                }
                check_inodes($ibx);
                if ($have_devel_peek) {
-                       $again ||= !!($ibx->{mm} || $ibx->{search});
+                       $again ||= !!$ibx->{search};
                }
                $next->{"$ibx"} = $ibx if $again;
        }
@@ -182,7 +182,6 @@ sub mm {
        my ($self) = @_;
        $self->{mm} ||= eval {
                require PublicInbox::Msgmap;
-               _cleanup_later($self);
                my $dir = $self->{inboxdir};
                if ($self->version >= 2) {
                        PublicInbox::Msgmap->new_file("$dir/msgmap.sqlite3");
@@ -409,7 +408,7 @@ sub unsubscribe_unlock {
 
 sub check_inodes ($) {
        my ($self) = @_;
-       for (qw(over)) { # TODO: search, mm
+       for (qw(over mm)) { # TODO: search
                $self->{$_}->check_inodes if $self->{$_};
        }
 }

diff --git a/lib/PublicInbox/Msgmap.pm b/lib/PublicInbox/Msgmap.pm
index aa07e344c6a9d75a9b376af5a6fbbd5911481198..e86fb8541bb3e6c0e534317d9058c2809a7473da 100644 (file)
--- a/lib/PublicInbox/Msgmap.pm
+++ b/lib/PublicInbox/Msgmap.pm
@@ -13,6 +13,7 @@ use warnings;
 use DBI;
 use DBD::SQLite;
 use File::Temp qw(tempfile);
+use PublicInbox::Over;
 
 sub new {
        my ($class, $git_dir, $writable) = @_;
@@ -24,29 +25,13 @@ sub new {
        new_file($class, "$d/msgmap.sqlite3", $writable);
 }
 
-sub dbh_new {
-       my ($f, $writable) = @_;
-       if ($writable && !-f $f) { # SQLite defaults mode to 0644, we want 0666
-               open my $fh, '+>>', $f or die "failed to open $f: $!";
-       }
-       my $dbh = DBI->connect("dbi:SQLite:dbname=$f",'','', {
-               AutoCommit => 1,
-               RaiseError => 1,
-               PrintError => 0,
-               ReadOnly => !$writable,
-               sqlite_use_immediate_transaction => 1,
-       });
-       $dbh;
-}
-
 sub new_file {
-       my ($class, $f, $writable) = @_;
-       return if !$writable && !-r $f;
+       my ($class, $f, $rw) = @_;
+       return if !$rw && !-r $f;
 
-       my $dbh = dbh_new($f, $writable);
-       my $self = bless { dbh => $dbh }, $class;
-
-       if ($writable) {
+       my $self = bless { filename => $f }, $class;
+       my $dbh = $self->{dbh} = PublicInbox::Over::dbh_new($self, $rw);
+       if ($rw) {
                create_tables($dbh);
 
                # TRUNCATE reduces I/O compared to the default (DELETE)
@@ -70,7 +55,6 @@ sub tmp_clone {
        my $tmp = ref($self)->new_file($fn, 1);
        $tmp->{dbh}->do('PRAGMA synchronous = OFF');
        $tmp->{dbh}->do('PRAGMA journal_mode = MEMORY');
-       $tmp->{tmp_name} = $fn; # SQLite won't work if unlinked, apparently
        $tmp->{pid} = $$;
        close $fh or die "failed to close $fn: $!";
        $tmp;
@@ -246,28 +230,28 @@ sub mid_set {
 sub DESTROY {
        my ($self) = @_;
        delete $self->{dbh};
-       my $f = delete $self->{tmp_name};
-       if (defined $f && $self->{pid} == $$) {
+       my $f = $self->{filename};
+       if (($self->{pid} // 0) == $$) {
                unlink $f or warn "failed to unlink $f: $!\n";
        }
 }
 
 sub atfork_parent {
        my ($self) = @_;
-       my $f = $self->{tmp_name} or die "not a temporary clone\n";
+       $self->{pid} or die "not a temporary clone\n";
        delete $self->{dbh} and die "tmp_clone dbh not prepared for parent";
-       my $dbh = $self->{dbh} = dbh_new($f, 1);
+       my $dbh = $self->{dbh} = PublicInbox::Over::dbh_new($self, 1);
        $dbh->do('PRAGMA synchronous = OFF');
 }
 
 sub atfork_prepare {
        my ($self) = @_;
-       my $f = $self->{tmp_name} or die "not a temporary clone\n";
+       $self->{pid} or die "not a temporary clone\n";
        $self->{pid} == $$ or
                die "BUG: atfork_prepare not called from $self->{pid}\n";
        $self->{dbh} or die "temporary clone not open\n";
        # must clobber prepared statements
-       %$self = (tmp_name => $f, pid => $$);
+       %$self = (filename => $self->{filename}, pid => $$);
 }
 
 sub skip_artnum {
@@ -296,4 +280,23 @@ sub skip_artnum {
        }
 }
 
+sub check_inodes {
+       my ($self) = @_;
+       # no filename if in-:memory:
+       my $f = $self->{dbh}->sqlite_db_filename // return;
+       if (my @st = stat($f)) { # did st_dev, st_ino change?
+               my $st = pack('dd', $st[0], $st[1]);
+               if ($st ne ($self->{st} // $st)) {
+                       my $tmp = eval { ref($self)->new_file($f) };
+                       if ($@) {
+                               warn "E: DBI->connect($f): $@\n";
+                       } else {
+                               %$self = %$tmp;
+                       }
+               }
+       } else {
+               warn "W: stat $f: $!\n";
+       }
+}
+
 1;

diff --git a/t/nntpd.t b/t/nntpd.t
index 28008ec15f763d8b787b1770d78daaae2cee0020..954e6e75430a7203324162d91a7bfff7b74b1e45 100644 (file)
--- a/t/nntpd.t
+++ b/t/nntpd.t
@@ -14,6 +14,7 @@ use Net::NNTP;
 use Sys::Hostname;
 use POSIX qw(_exit);
 use Digest::SHA;
+use_ok 'PublicInbox::Msgmap';
 
 # FIXME: make easier to test both versions
 my $version = $ENV{PI_TEST_VERSION} || 1;
@@ -341,6 +342,13 @@ Date: Fri, 02 Oct 1993 00:00:00 +0000
                        'article did not exist');
                $im->add($ex);
                $im->done;
+               {
+                       my $f = $ibx->mm->{filename};
+                       my $tmp = "$tmpdir/tmp.sqlite3";
+                       $ibx->mm->{dbh}->sqlite_backup_to_file($tmp);
+                       delete $ibx->{mm};
+                       rename($tmp, $f) or BAIL_OUT "rename($tmp, $f): $!";
+               }
                ok(run_script([qw(-index --reindex -c), $ibx->{inboxdir}],
                                undef, $noerr), '-compacted');
                select(undef, undef, undef, $fast_idle ? 0.1 : 2.1);