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pugmajereLinus Torvalds
pugmajere
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Linus Torvalds
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[PATCH] Add git-relink-script to fix up missing hardlinks
This will scan 2 or more object repositories and look for common objects, check if they are hardlinked, and replace one with a hardlink to the other if not. This version warns when skipping files because of size differences, and handle more than 2 repositories automatically. Signed-off-by: Ryan Anderson <ryan@michonline.com> Cheered-on-by: Jeff Garzik <jgarzik@pobox.com> Acked-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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‎Makefile‎

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@@ -25,7 +25,7 @@ SCRIPTS=git git-apply-patch-script git-merge-one-file-script git-prune-script \
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git-deltafy-script git-fetch-script git-status-script git-commit-script \
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git-log-script git-shortlog git-cvsimport-script git-diff-script \
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git-reset-script git-add-script git-checkout-script git-clone-script \
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gitk git-cherry git-rebase-script
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gitk git-cherry git-rebase-script git-relink-script
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PROG= git-update-cache git-diff-files git-init-db git-write-tree \
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git-read-tree git-commit-tree git-cat-file git-fsck-cache \

‎git-relink-script‎

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#!/usr/bin/env perl
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# Copyright 2005, Ryan Anderson <ryan@michonline.com>
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# Distribution permitted under the GPL v2, as distributed
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# by the Free Software Foundation.
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# Later versions of the GPL at the discretion of Linus Torvalds
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#
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# Scan two git object-trees, and hardlink any common objects between them.
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use 5.006;
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use strict;
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use warnings;
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use Getopt::Long;
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sub get_canonical_form($);
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sub do_scan_directory($$$);
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sub compare_two_files($$);
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sub usage();
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sub link_two_files($$);
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# stats
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my $total_linked = 0;
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my $total_already = 0;
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my ($linked,$already);
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my $fail_on_different_sizes = 0;
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my $help = 0;
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GetOptions("safe" => \$fail_on_different_sizes,
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"help" => \$help);
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usage() if $help;
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my (@dirs) = @ARGV;
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usage() if (!defined $dirs[0] || !defined $dirs[1]);
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$_ = get_canonical_form($_) foreach (@dirs);
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my $master_dir = pop @dirs;
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opendir(D,$master_dir . "objects/")
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or die "Failed to open $master_dir/objects/ : $!";
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my @hashdirs = grep !/^\.{1,2}$/, readdir(D);
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foreach my $repo (@dirs) {
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$linked = 0;
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$already = 0;
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printf("Searching '%s' and '%s' for common objects and hardlinking them...\n",
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$master_dir,$repo);
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foreach my $hashdir (@hashdirs) {
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do_scan_directory($master_dir, $hashdir, $repo);
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}
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printf("Linked %d files, %d were already linked.\n",$linked, $already);
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$total_linked += $linked;
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$total_already += $already;
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}
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printf("Totals: Linked %d files, %d were already linked.\n",
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$total_linked, $total_already);
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sub do_scan_directory($$$) {
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my ($srcdir, $subdir, $dstdir) = @_;
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my $sfulldir = sprintf("%sobjects/%s/",$srcdir,$subdir);
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my $dfulldir = sprintf("%sobjects/%s/",$dstdir,$subdir);
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opendir(S,$sfulldir)
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or die "Failed to opendir $sfulldir: $!";
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foreach my $file (grep(!/\.{1,2}$/, readdir(S))) {
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my $sfilename = $sfulldir . $file;
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my $dfilename = $dfulldir . $file;
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compare_two_files($sfilename,$dfilename);
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}
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closedir(S);
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}
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sub compare_two_files($$) {
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my ($sfilename, $dfilename) = @_;
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# Perl's stat returns relevant information as follows:
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# 0 = dev number
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# 1 = inode number
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# 7 = size
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my @sstatinfo = stat($sfilename);
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my @dstatinfo = stat($dfilename);
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if (@sstatinfo == 0 && @dstatinfo == 0) {
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die sprintf("Stat of both %s and %s failed: %s\n",$sfilename, $dfilename, $!);
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} elsif (@dstatinfo == 0) {
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return;
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}
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if ( ($sstatinfo[0] == $dstatinfo[0]) &&
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($sstatinfo[1] != $dstatinfo[1])) {
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if ($sstatinfo[7] == $dstatinfo[7]) {
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link_two_files($sfilename, $dfilename);
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} else {
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my $err = sprintf("ERROR: File sizes are not the same, cannot relink %s to %s.\n",
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$sfilename, $dfilename);
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if ($fail_on_different_sizes) {
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die $err;
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} else {
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warn $err;
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}
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}
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} elsif ( ($sstatinfo[0] == $dstatinfo[0]) &&
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($sstatinfo[1] == $dstatinfo[1])) {
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$already++;
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}
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}
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sub get_canonical_form($) {
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my $dir = shift;
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my $original = $dir;
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die "$dir is not a directory." unless -d $dir;
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$dir .= "/" unless $dir =~ m#/$#;
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$dir .= ".git/" unless $dir =~ m#\.git/$#;
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die "$original does not have a .git/ subdirectory.\n" unless -d $dir;
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return $dir;
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}
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sub link_two_files($$) {
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my ($sfilename, $dfilename) = @_;
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my $tmpdname = sprintf("%s.old",$dfilename);
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rename($dfilename,$tmpdname)
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or die sprintf("Failure renaming %s to %s: %s",
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$dfilename, $tmpdname, $!);
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if (! link($sfilename,$dfilename)) {
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my $failtxt = "";
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unless (rename($tmpdname,$dfilename)) {
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$failtxt = sprintf(
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"Git Repository containing %s is probably corrupted, " .
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"please copy '%s' to '%s' to fix.\n",
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$tmpdname, $dfilename);
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}
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die sprintf("Failed to link %s to %s: %s\n%s" .
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$sfilename, $dfilename,
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$!, $dfilename, $failtxt);
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}
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unlink($tmpdname)
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or die sprintf("Unlink of %s failed: %s\n",
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$dfilename, $!);
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$linked++;
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}
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sub usage() {
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print("Usage: $0 [--safe] <dir> [<dir> ...] <master_dir> \n");
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print("All directories should contain a .git/objects/ subdirectory.\n");
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print("Options\n");
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print("\t--safe\t" .
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"Stops if two objects with the same hash exist but " .
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"have different sizes. Default is to warn and continue.\n");
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exit(1);
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}

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