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	Wed, 29 Jul 2020 11:20:00 +0000 (UTC)
Date: Wed, 29 Jul 2020 11:20:00 +0000
From: Eric Wong <e@yhbt.net>
To: meta@public-inbox.org
Subject: [PATCH 2/1] xapcmd: -xcpdb and -compact disable CoW, too
Message-ID: <20200729112000.GA25039@dcvr>
References: <20200728222158.17457-1-e@yhbt.net>
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In-Reply-To: <20200728222158.17457-1-e@yhbt.net>
List-Id: <meta.public-inbox.org>

This gives an opportunity for users already suffering from CoW
fragmentation to at least get the Xapian DBs off CoW.  Aside
from over.sqlite3 in v1, the SQLite DBs remain untouched; though
VACUUM support may come in the future.
---
 lib/PublicInbox/SearchIdx.pm | 11 ++++++++---
 lib/PublicInbox/Xapcmd.pm    |  5 ++++-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index aa8d8ce3..080aca7c 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -21,7 +21,7 @@ use PublicInbox::OverIdx;
 use PublicInbox::Spawn qw(spawn);
 use PublicInbox::Git qw(git_unquote);
 use PublicInbox::MsgTime qw(msg_timestamp msg_datestamp);
-our @EXPORT_OK = qw(crlf_adjust log2stack is_ancestor check_size);
+our @EXPORT_OK = qw(crlf_adjust log2stack is_ancestor check_size nodatacow_dir);
 my $X = \%PublicInbox::Search::X;
 my ($DB_CREATE_OR_OPEN, $DB_OPEN);
 our $DB_NO_SYNC = 0;
@@ -110,6 +110,12 @@ sub load_xapian_writable () {
 	1;
 }
 
+sub nodatacow_dir ($) {
+	my ($dir) = @_;
+	opendir my $dh, $dir or die "opendir($dir): $!\n";
+	PublicInbox::Spawn::set_nodatacow(fileno($dh));
+}
+
 sub idx_acquire {
 	my ($self) = @_;
 	my $flag;
@@ -128,8 +134,7 @@ sub idx_acquire {
 		if (!-d $dir && (!$is_shard ||
 				($is_shard && need_xapian($self)))) {
 			File::Path::mkpath($dir);
-			opendir my $dh, $dir or die "opendir($dir): $!\n";
-			PublicInbox::Spawn::set_nodatacow(fileno($dh));
+			nodatacow_dir($dir);
 		}
 	}
 	return unless defined $flag;
diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index 3b7a581b..f1c80831 100644
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -5,7 +5,7 @@ use strict;
 use warnings;
 use PublicInbox::Spawn qw(which popen_rd);
 use PublicInbox::Over;
-use PublicInbox::SearchIdx;
+use PublicInbox::SearchIdx qw(nodatacow_dir);
 use File::Temp 0.19 (); # ->newdir
 use File::Path qw(remove_tree);
 use File::Basename qw(dirname);
@@ -187,6 +187,7 @@ sub prepare_run {
 		my $v = PublicInbox::Search::SCHEMA_VERSION();
 		my $wip = File::Temp->newdir("xapian$v-XXXXXXXX", DIR => $dir);
 		$tmp->{$old} = $wip;
+		nodatacow_dir($wip->dirname);
 		push @queue, [ $old, $wip ];
 	} else {
 		opendir my $dh, $old or die "Failed to opendir $old: $!\n";
@@ -217,6 +218,7 @@ sub prepare_run {
 			same_fs_or_die($old, $wip->dirname);
 			my $cur = "$old/$dn";
 			push @queue, [ $src // $cur , $wip ];
+			nodatacow_dir($wip->dirname);
 			$tmp->{$cur} = $wip;
 		}
 		# mark old shards to be unlinked
@@ -406,6 +408,7 @@ sub cpdb ($$) {
 		$ft = File::Temp->newdir("$new.compact-XXXXXX", DIR => $dir);
 		setup_signals();
 		$tmp = $ft->dirname;
+		nodatacow_dir($tmp);
 	} else {
 		$tmp = $new;
 	}