[pve-devel] [PATCH storage 4/4] btrfs: add 'btrfs' import/export format
Wolfgang Bumiller
w.bumiller at proxmox.com
Wed Jun 9 15:18:49 CEST 2021
Signed-off-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
---
PVE/CLI/pvesm.pm | 2 +-
PVE/Storage.pm | 2 +-
PVE/Storage/BTRFSPlugin.pm | 248 +++++++++++++++++++++++++++++++++++--
3 files changed, 240 insertions(+), 12 deletions(-)
diff --git a/PVE/CLI/pvesm.pm b/PVE/CLI/pvesm.pm
index b22f759..ef2f5e6 100755
--- a/PVE/CLI/pvesm.pm
+++ b/PVE/CLI/pvesm.pm
@@ -30,7 +30,7 @@ use PVE::CLIHandler;
use base qw(PVE::CLIHandler);
-my $KNOWN_EXPORT_FORMATS = ['raw+size', 'tar+size', 'qcow2+size', 'vmdk+size', 'zfs'];
+my $KNOWN_EXPORT_FORMATS = ['raw+size', 'tar+size', 'qcow2+size', 'vmdk+size', 'zfs', 'btrfs'];
my $nodename = PVE::INotify::nodename();
diff --git a/PVE/Storage.pm b/PVE/Storage.pm
index 15fcedf..6f5a033 100755
--- a/PVE/Storage.pm
+++ b/PVE/Storage.pm
@@ -692,7 +692,7 @@ sub storage_migrate {
my $migration_snapshot;
if (!defined($snapshot)) {
- if ($scfg->{type} eq 'zfspool') {
+ if ($scfg->{type} eq 'zfspool' || $scfg->{type} eq 'btrfs') {
$migration_snapshot = 1;
$snapshot = '__migration__';
}
diff --git a/PVE/Storage/BTRFSPlugin.pm b/PVE/Storage/BTRFSPlugin.pm
index 733be6e..87e48c7 100644
--- a/PVE/Storage/BTRFSPlugin.pm
+++ b/PVE/Storage/BTRFSPlugin.pm
@@ -9,8 +9,9 @@ use Fcntl qw(S_ISDIR);
use File::Basename qw(dirname);
use File::Path qw(mkpath);
use IO::Dir;
+use POSIX qw(EEXIST);
-use PVE::Tools qw(run_command);
+use PVE::Tools qw(run_command dir_glob_foreach);
use PVE::Storage::DirPlugin;
@@ -594,23 +595,250 @@ sub list_images {
return $res;
}
-# For now we don't implement `btrfs send/recv` as it needs some updates to our import/export API
-# first!
-
sub volume_export_formats {
- return PVE::Storage::DirPlugin::volume_export_formats(@_);
-}
+ my ($class, $scfg, $storeid, $volname, $snapshot, $base_snapshot, $with_snapshots) = @_;
-sub volume_export {
- return PVE::Storage::DirPlugin::volume_export(@_);
+ # We can do whatever `DirPlugin` can do.
+ my @result = PVE::Storage::Plugin::volume_export_formats(@_);
+
+ # `btrfs send` only works on snapshots:
+ return @result if !defined $snapshot;
+
+ # Incremental stream with snapshots is only supported if the snapshots are listed (new api):
+ return @result if defined($base_snapshot) && $with_snapshots && ref($with_snapshots) ne 'ARRAY';
+
+ # Otherwise we do also support `with_snapshots`.
+
+ # Finally, `btrfs send` only works on formats where we actually use btrfs subvolumes:
+ my $format = ($class->parse_volname($volname))[6];
+ return @result if $format ne 'raw' && $format ne 'subvol';
+
+ return ('btrfs', @result);
}
sub volume_import_formats {
- return PVE::Storage::DirPlugin::volume_import_formats(@_);
+ my ($class, $scfg, $storeid, $volname, $base_snapshot, $with_snapshots, $snapshot) = @_;
+
+ # Same as export-formats, beware the parameter order:
+ return volume_export_formats(
+ $class,
+ $scfg,
+ $storeid,
+ $volname,
+ $snapshot,
+ $base_snapshot,
+ $with_snapshots,
+ );
+}
+
+sub volume_export {
+ my (
+ $class,
+ $scfg,
+ $storeid,
+ $fh,
+ $volname,
+ $format,
+ $snapshot,
+ $base_snapshot,
+ $with_snapshots,
+ ) = @_;
+
+ if ($format ne 'btrfs') {
+ return PVE::Storage::Plugin::volume_export(@_);
+ }
+
+ die "format 'btrfs' only works on snapshots\n"
+ if !defined $snapshot;
+
+ die "'btrfs' format in incremental mode requires snapshots to be listed explicitly\n"
+ if defined($base_snapshot) && $with_snapshots && ref($with_snapshots) ne 'ARRAY';
+
+ my $volume_format = ($class->parse_volname($volname))[6];
+
+ die "btrfs-sending volumes of type $volume_format ('$volname') is not supported\n"
+ if $volume_format ne 'raw' && $volume_format ne 'subvol';
+
+ my $path = $class->path($scfg, $volname, $storeid);
+
+ if ($volume_format eq 'raw') {
+ $path = raw_file_to_subvol($path);
+ }
+
+ my $cmd = ['btrfs', '-q', 'send', '-e'];
+ if ($base_snapshot) {
+ my $base = $class->path($scfg, $volname, $storeid, $base_snapshot);
+ if ($volume_format eq 'raw') {
+ $base = raw_file_to_subvol($base);
+ }
+ push @$cmd, '-p', $base;
+ }
+ push @$cmd, '--';
+ if (ref($with_snapshots) eq 'ARRAY') {
+ push @$cmd, (map { "$path\@$_" } ($with_snapshots // [])->@*), $path;
+ } else {
+ dir_glob_foreach(dirname($path), $BTRFS_VOL_REGEX, sub {
+ push @$cmd, "$path\@$_[2]" if !(defined($snapshot) && $_[2] eq $snapshot);
+ });
+ }
+ $path .= "\@$snapshot" if defined($snapshot);
+ push @$cmd, $path;
+
+ run_command($cmd, output => '>&'.fileno($fh));
+ return;
}
sub volume_import {
- return PVE::Storage::DirPlugin::volume_import(@_);
+ my (
+ $class,
+ $scfg,
+ $storeid,
+ $fh,
+ $volname,
+ $format,
+ $base_snapshot,
+ $with_snapshots,
+ $allow_rename,
+ $snapshot,
+ ) = @_;
+
+ if ($format ne 'btrfs') {
+ return PVE::Storage::Plugin::volume_import(@_);
+ }
+
+ die "format 'btrfs' only works on snapshots\n"
+ if !defined $snapshot;
+
+ my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $volume_format) =
+ $class->parse_volname($volname);
+
+ die "btrfs-receiving volumes of type $volume_format ('$volname') is not supported\n"
+ if $volume_format ne 'raw' && $volume_format ne 'subvol';
+
+ if (defined($base_snapshot)) {
+ my $path = $class->path($scfg, $volname, $storeid, $base_snapshot);
+ die "base snapshot '$base_snapshot' not found - no such directory '$path'\n"
+ if !path_is_subvolume($path);
+ }
+
+ my $destination = $class->filesystem_path($scfg, $volname);
+ if ($volume_format eq 'raw') {
+ $destination = raw_file_to_subvol($destination);
+ }
+
+ if (!defined($base_snapshot) && -e $destination) {
+ die "volume $volname already exists\n" if !$allow_rename;
+ $volname = $class->find_free_diskname($storeid, $scfg, $vmid, $volume_format, 1);
+ }
+
+ my $imagedir = $class->get_subdir($scfg, $vtype);
+ $imagedir .= "/$vmid" if $vtype eq 'images';
+
+ my $tmppath = "$imagedir/recv.$vmid.tmp";
+ mkdir($imagedir); # FIXME: if $scfg->{mkdir};
+ if (!mkdir($tmppath)) {
+ die "temp receive directory already exists at '$tmppath', incomplete concurrent import?\n"
+ if $! == EEXIST;
+ die "failed to create temporary receive directory at '$tmppath' - $!\n";
+ }
+
+ my $dh = IO::Dir->new($tmppath)
+ or die "failed to open temporary receive directory '$tmppath' - $!\n";
+ eval {
+ run_command(['btrfs', '-q', 'receive', '-e', '--', $tmppath], input => '<&'.fileno($fh));
+
+ # Analyze the received subvolumes;
+ my ($diskname, $found_snapshot, @snapshots);
+ $dh->rewind;
+ while (defined(my $entry = $dh->read)) {
+ next if $entry eq '.' || $entry eq '..';
+ next if $entry !~ /^$BTRFS_VOL_REGEX$/;
+ my ($cur_diskname, $cur_snapshot) = ($1, $2);
+
+ die "send stream included a non-snapshot subvolume\n"
+ if !defined($cur_snapshot);
+
+ if (!defined($diskname)) {
+ $diskname = $cur_diskname;
+ } else {
+ die "multiple disks contained in stream ('$diskname' vs '$cur_diskname')\n"
+ if $diskname ne $cur_diskname;
+ }
+
+ if ($cur_snapshot eq $snapshot) {
+ $found_snapshot = 1;
+ } else {
+ push @snapshots, $cur_snapshot;
+ }
+ }
+
+ die "send stream did not contain the expected current snapshot '$snapshot'\n"
+ if !$found_snapshot;
+
+ # Rotate the disk into place, first the current state:
+ # Note that read-only subvolumes cannot be moved into different directories, but for the
+ # "current" state we also want a writable copy, so start with that:
+ $class->btrfs_cmd(['property', 'set', "$tmppath/$diskname\@$snapshot", 'ro', 'false']);
+ PVE::Tools::renameat2(
+ -1,
+ "$tmppath/$diskname\@$snapshot",
+ -1,
+ $destination,
+ &PVE::Tools::RENAME_NOREPLACE,
+ ) or die "failed to move received snapshot '$tmppath/$diskname\@$snapshot'"
+ . " into place at '$destination' - $!\n";
+
+ # Now recreate the actual snapshot:
+ $class->btrfs_cmd([
+ 'subvolume',
+ 'snapshot',
+ '-r',
+ '--',
+ $destination,
+ "$destination\@$snapshot",
+ ]);
+
+ # Now go through the remaining snapshots (if any)
+ foreach my $snap (@snapshots) {
+ $class->btrfs_cmd(['property', 'set', "$tmppath/$diskname\@$snap", 'ro', 'false']);
+ PVE::Tools::renameat2(
+ -1,
+ "$tmppath/$diskname\@$snap",
+ -1,
+ "$destination\@$snap",
+ &PVE::Tools::RENAME_NOREPLACE,
+ ) or die "failed to move received snapshot '$tmppath/$diskname\@$snap'"
+ . " into place at '$destination\@$snap' - $!\n";
+ eval { $class->btrfs_cmd(['property', 'set', "$destination\@$snap", 'ro', 'true']) };
+ warn "failed to make $destination\@$snap read-only - $!\n" if $@;
+ }
+ };
+ my $err = $@;
+
+ eval {
+ # Cleanup all the received snapshots we did not move into place, so we can remove the temp
+ # directory.
+ if ($dh) {
+ $dh->rewind;
+ while (defined(my $entry = $dh->read)) {
+ next if $entry eq '.' || $entry eq '..';
+ eval { $class->btrfs_cmd(['subvolume', 'delete', '--', "$tmppath/$entry"]) };
+ warn $@ if $@;
+ }
+ $dh->close; undef $dh;
+ }
+ if (!rmdir($tmppath)) {
+ warn "failed to remove temporary directory '$tmppath' - $!\n"
+ }
+ };
+ warn $@ if $@;
+ if ($err) {
+ # clean up if the directory ended up being empty after an error
+ rmdir($tmppath);
+ die $err;
+ }
+
+ return "$storeid:$volname";
}
1
--
2.30.2
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