[PATCH 3/8] set nodatacow on more SQLite files

[Eric Wong <e@80x24.org>]

We'll set nodatacow when detecting existing but empty
files, and also their directories in more cases (for
auxiliary -wal, -journal, -shm files).  Hopefully
this keeps performance reasonable on CoW FSes.
---
 lib/PublicInbox/Over.pm     | 4 +++-
 lib/PublicInbox/SharedKV.pm | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/PublicInbox/Over.pm b/lib/PublicInbox/Over.pm
index 19da056a..98de82c0 100644
--- a/lib/PublicInbox/Over.pm
+++ b/lib/PublicInbox/Over.pm
@@ -16,9 +16,11 @@ use constant DEFAULT_LIMIT => 1000;
 sub dbh_new {
 	my ($self, $rw) = @_;
 	my $f = delete $self->{filename};
-	if (!-f $f) { # SQLite defaults mode to 0644, we want 0666
+	if (!-s $f) { # SQLite defaults mode to 0644, we want 0666
 		if ($rw) {
 			require PublicInbox::Spawn;
+			my ($dir) = ($f =~ m!(.+)/[^/]+\z!);
+			PublicInbox::Spawn::nodatacow_dir($dir);
 			open my $fh, '+>>', $f or die "failed to open $f: $!";
 			PublicInbox::Spawn::nodatacow_fd(fileno($fh));
 		} else {
diff --git a/lib/PublicInbox/SharedKV.pm b/lib/PublicInbox/SharedKV.pm
index 645bb57c..398f4ca8 100644
--- a/lib/PublicInbox/SharedKV.pm
+++ b/lib/PublicInbox/SharedKV.pm
@@ -51,7 +51,8 @@ sub new {
 	$base //= '';
 	my $f = $self->{filename} = "$dir/$base.sqlite3";
 	$self->{lock_path} = $opt->{lock_path} // "$dir/$base.flock";
-	unless (-f $f) {
+	unless (-s $f) {
+		PublicInbox::Spawn::nodatacow_dir($dir); # for journal/shm/wal
 		open my $fh, '+>>', $f or die "failed to open $f: $!";
 		PublicInbox::Spawn::nodatacow_fd(fileno($fh));
 	}