use strict;
-# What we do is this:
+# DGIT-REPOS-DIR contains:
+# git tree (or other object) lock (in acquisition order, outer first)
+#
+# _tmp/PACKAGE_prospective ! } SAME.lock, held during receive-pack
+#
+# _tmp/PACKAGE_incoming$$ ! } SAME.lock, held during receive-pack
+# _tmp/PACKAGE_incoming$$_fresh ! }
+#
+# PACKAGE.git } PACKAGE.git.lock
+# PACKAGE_garbage } (also covers executions of
+# PACKAGE_garbage-old } policy hook script for PACKAGE)
+# PACKAGE_garbage-tmp }
+# policy* } (for policy hook script, covered by
+# } lock only when invoked for a package)
+#
+# leaf locks, held during brief operaton only:
+#
+# _empty } SAME.lock
+# _empty.new }
+#
+# _template } SAME.lock
+#
+# locks marked ! may be held during client data transfer
+
+# What we do on push is this:
# - extract the destination repo name
# - make a hardlink clone of the destination repo
# - provide the destination with a stunt pre-receive hook
# + verify the signature on the signed tag
# and if necessary check that the keyid and package are listed in dm.txt
# + check various correspondences:
-# * the suite is one of those permitted
# * the signed tag must refer to a commit
# * the signed tag commit must be the refs/dgit value
# * the name in the signed tag must correspond to its ref name
# * the tag name must be debian/<version> (massaged as needed)
+# * the suite is one of those permitted
# * the signed tag has a suitable name
-# * the commit is a fast forward
+# * run the "push" policy hook
+# * replay prevention for --deliberately-not-fast-forward
+# * check the commit is a fast forward
+# * handle a request from the policy hook for a fresh repo
# + push the signed tag and new dgit branch to the actual repo
#
# If the destination repo does not already exist, we need to make
# of _template
# - we use the prospective new destination repo instead of the
# actual new destination repo (since the latter doesn't exist)
-# - we set up a post-receive hook as well, which
-# + touches a stamp file
# - after git-receive-pack exits, we
# + check that the prospective repo contains a tag and head
# + rename the prospective destination repo into place
# the corresponding temporary tree, as the lockfile is also
# a stampfile whose presence indicates that there may be
# cleanup to do
+#
+# Policy hook script is invoked like this:
+# POLICY-HOOK-SCRIPT DISTRO DGIT-REPOS-DIR ACTION...
+# ie.
+# POLICY-HOOK-SCRIPT ... check-list [...]
+# POLICY-HOOK-SCRIPT ... check-package PACKAGE [...]
+# POLICY-HOOK-SCRIPT ... push|push-confirm PACKAGE \
+# VERSION SUITE TAGNAME DELIBERATELIES [...]
+#
+# Exit status is a bitmask. Bit weight constants are defined in Dgit.pm.
+# NOFFCHECK (2)
+# suppress dgit-repos-server's fast-forward check ("push" only)
+# FRESHREPO (4)
+# blow away repo right away (ie, as if before push or fetch)
+# ("check-package" and "push" only)
+# any unexpected bits mean failure, and then known set bits are ignored
+# if no unexpected bits set, operation continues (subject to meaning
+# of any expected bits set). So, eg, exit 0 means "continue normally"
+# and would be appropriate for an unknown action.
+#
+# cwd for push and push-confirm is a temporary repo where the
+# to-be-pushed objects have been received; TAGNAME is the
+# version-based tag
+#
+# if push requested FRESHREPO, push-confirm happens in said fresh repo
+#
+# policy hook for a particular package will be invoked only once at
+# a time - (see comments about DGIT-REPOS-DIR, above)
+
use POSIX;
use Fcntl qw(:flock);
return $fh;
}
-sub acquiretree ($$) {
+sub acquirermtree ($$) {
my ($tree, $must) = @_;
my $fh = acquirelock("$tree.lock", $must);
if ($fh) {
return $fh;
}
+sub locksometree ($) {
+ my ($tree) = @_;
+ acquirelock("$tree.lock", 1);
+}
+
+sub lockrealtree () {
+ locksometree($realdestrepo);
+}
+
sub mkrepotmp () {
my $tmpdir = "$dgitrepos/_tmp";
return if mkdir $tmpdir;
sub policyhook {
my ($policyallowbits, @polargs) = @_;
- # => ($exitstatuspolicybitmap, $policylockfh);
+ # => ($exitstatuspolicybitmap);
die if $policyallowbits & ~0x3e;
my @cmd = ($policyhook,$distro,$repos,@polargs);
debugcmd @_;
sub mkrepo_fromtemplate ($) {
my ($dir) = @_;
my $template = "$dgitrepos/_template";
- debug "copy tempalate $template -> $dir";
+ locksometree($template);
+ debug "copy template $template -> $dir";
my $r = system qw(cp -a --), $template, $dir;
!$r or die "create new repo $dir failed: $r $!";
}
sub movetogarbage () {
+ # $realdestrepo must have been locked
my $garbagerepo = "$dgitrepos/${package}_garbage";
- my $lfh =acquiretree($garbagerepo,1);
# We arrange to always keep at least one old tree, for anti-rewind
# purposes (and, I guess, recovery from mistakes). This is either
# $garbage or $garbage-old.
rename $realdestrepo, $garbagerepo
or $! == ENOENT
or die "$garbagerepo $!";
- close $lfh;
}
sub onwardpush () {
sub fixmissing__git_receive_pack () {
mkrepotmp();
$destrepo = "$dgitrepos/_tmp/${package}_prospective";
- acquiretree($destrepo, 1);
+ acquirermtree($destrepo, 1);
mkrepo_fromtemplate($destrepo);
}
sub makeworkingclone () {
mkrepotmp();
$workrepo = "$dgitrepos/_tmp/${package}_incoming$$";
- acquiretree($workrepo, 1);
+ acquirermtree($workrepo, 1);
+ my $lfh = lockrealtree();
runcmd qw(git clone -l -q --mirror), $destrepo, $workrepo;
+ close $lfh;
rmtree "${workrepo}_fresh";
}
die Dumper(\%got)." -- missing refs in new repo"
if grep { !$_ } values %got;
- movetogarbage; # in case of FRESHREPO
+ lockrealtree();
+
+ if ($destrepo eq "${workrepo}_fresh") {
+ movetogarbage;
+ }
debug "install $destrepo => $realdestrepo";
rename $destrepo, $realdestrepo or die $!;
return unless $policy & (FRESHREPO|NOFFCHECK);
my $garbagerepo = "$dgitrepos/${package}_garbage";
- acquiretree($garbagerepo,1);
+ lockrealtree();
local $ENV{GIT_DIR};
foreach my $garb ("$garbagerepo", "$garbagerepo-old") {
debug "translated version $v";
$tagname eq "debian/$v" or die;
- $policy = policyhook(NOFFCHECK|FRESHREPO, 'push',$package,
- $version,$suite,$tagname,
- join(",",@delberatelies));
+ lockrealtree();
+
+ my @policy_args = ($package,$version,$suite,$tagname,
+ join(",",@delberatelies));
+ $policy = policyhook(NOFFCHECK|FRESHREPO, 'push', @policy_args);
checktagnoreplay();
checksuite();
$destrepo = "${workrepo}_fresh"; # workrepo lock covers
mkrepo_fromtemplate $destrepo;
}
+
+ policyhook(0, 'push-confirm', @policy_args);
}
sub stunthook () {
sub fixmissing__git_upload_pack () {
$destrepo = "$dgitrepos/_empty";
- my $lfh = acquiretree($destrepo,1);
+ my $lfh = locksometree($destrepo);
return if stat_exists $destrepo;
rmtree "$destrepo.new";
mkemptyrepo "$destrepo.new", "0644";
}
sub main__git_upload_pack () {
- runcmd qw(git upload-pack), $destrepo;
+ my $lfh = locksometree($destrepo);
+ chdir $destrepo or die "$destrepo: $!";
+ close $lfh;
+ runcmd qw(git upload-pack), ".";
}
#----- arg parsing and main program -----
reject "unknown method" unless $mainfunc;
- my ($policy, $pollock) = policyhook(FRESHREPO,'check-package',$package);
+ my $lfh = lockrealtree();
+
+ $policy = policyhook(FRESHREPO,'check-package',$package);
if ($policy & FRESHREPO) {
movetogarbage;
}
- close $pollock or die $!;
+
+ close $lfh;
if (stat_exists $realdestrepo) {
$destrepo = $realdestrepo;
foreach my $lf (<*.lock>) {
my $tree = $lf;
$tree =~ s/\.lock$//;
- next unless acquiretree($tree, 0);
+ next unless acquirermtree($tree, 0);
remove $lf or warn $!;
unlockall();
}