[pve-devel] [PATCH guest-common v13 2/12] add dir mapping section config

[Markus Frank]

Adds a config file for directories by using a 'map' property string for
each node mapping.

Next to node & path, there is the optional announce-submounts parameter
which forces virtiofsd to report a different device number for each
submount it encounters. Without it, duplicates may be created because
inode IDs are only unique on a single filesystem.

example config:
```
some-dir-id
	map node=node1,path=/mnt/share/,announce-submounts=1
	map node=node2,path=/mnt/share/,
```

Signed-off-by: Markus Frank <m.frank at proxmox.com>
---
 src/Makefile           |   1 +
 src/PVE/Mapping/Dir.pm | 185 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 186 insertions(+)
 create mode 100644 src/PVE/Mapping/Dir.pm

diff --git a/src/Makefile b/src/Makefile
index cbc40c1..030e7f7 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,6 +15,7 @@ install: PVE
 	install -m 0644 PVE/StorageTunnel.pm ${PERL5DIR}/PVE/
 	install -m 0644 PVE/Tunnel.pm ${PERL5DIR}/PVE/
 	install -d ${PERL5DIR}/PVE/Mapping
+	install -m 0644 PVE/Mapping/Dir.pm ${PERL5DIR}/PVE/Mapping/
 	install -m 0644 PVE/Mapping/PCI.pm ${PERL5DIR}/PVE/Mapping/
 	install -m 0644 PVE/Mapping/USB.pm ${PERL5DIR}/PVE/Mapping/
 	install -d ${PERL5DIR}/PVE/VZDump
diff --git a/src/PVE/Mapping/Dir.pm b/src/PVE/Mapping/Dir.pm
new file mode 100644
index 0000000..e6e2237
--- /dev/null
+++ b/src/PVE/Mapping/Dir.pm
@@ -0,0 +1,185 @@
+package PVE::Mapping::Dir;
+
+use strict;
+use warnings;
+
+use PVE::Cluster qw(cfs_register_file cfs_read_file cfs_lock_file cfs_write_file);
+use PVE::INotify;
+use PVE::JSONSchema qw(get_standard_option parse_property_string);
+use PVE::SectionConfig;
+
+use base qw(PVE::SectionConfig);
+
+my $FILENAME = 'mapping/dir.cfg';
+
+cfs_register_file($FILENAME,
+    sub { __PACKAGE__->parse_config(@_); },
+    sub { __PACKAGE__->write_config(@_); });
+
+
+# so we don't have to repeat the type every time
+sub parse_section_header {
+    my ($class, $line) = @_;
+
+    if ($line =~ m/^(\S+)\s*$/) {
+	my $id = $1;
+	my $errmsg = undef; # set if you want to skip whole section
+	eval { PVE::JSONSchema::pve_verify_configid($id) };
+	$errmsg = $@ if $@;
+	my $config = {}; # to return additional attributes
+	return ('dir', $id, $errmsg, $config);
+    }
+    return undef;
+}
+
+sub format_section_header {
+    my ($class, $type, $sectionId, $scfg, $done_hash) = @_;
+
+    return "$sectionId\n";
+}
+
+sub type {
+    return 'dir';
+}
+
+my $map_fmt = {
+    node => get_standard_option('pve-node'),
+    path => {
+	description => "Absolute directory path that should be shared with the guest.",
+	type => 'string',
+	format => 'pve-storage-path',
+    },
+    'announce-submounts' => {
+	type => 'boolean',
+	description => "Announce that the directory contains other mounted file systems."
+           ." If this is not set and multiple file systems are mounted, the guest may"
+           ." encounter duplicates due to file system specific inode IDs.",
+	optional => 1,
+	default => 1,
+    },
+    description => {
+	description => "Description of the node specific directory.",
+	type => 'string',
+	optional => 1,
+	maxLength => 4096,
+    },
+};
+
+my $defaultData = {
+    propertyList => {
+	id => {
+	    type => 'string',
+	    description => "The ID of the directory",
+	    format => 'pve-configid',
+	},
+	description => {
+	    type => 'string',
+	    description => "Description of the directory",
+	    optional => 1,
+	    maxLength => 4096,
+	},
+	map => {
+	    type => 'array',
+	    description => 'A list of maps for the cluster nodes.',
+	    optional => 1,
+	    items => {
+		type => 'string',
+		format => $map_fmt,
+	    },
+	},
+    },
+};
+
+sub private {
+    return $defaultData;
+}
+
+sub map_fmt {
+    return $map_fmt;
+}
+
+sub options {
+    return {
+	description => { optional => 1 },
+	map => {},
+    };
+}
+
+sub assert_valid {
+    my ($dir_cfg) = @_;
+
+    my $path = $dir_cfg->{path};
+
+    if (! -e $path) {
+	die "Path $path does not exist\n";
+    } elsif (! -d $path) {
+	die "Path $path exists, but is not a directory\n";
+    }
+
+    return 1;
+};
+
+sub assert_no_duplicate_node {
+    my ($map_list) = @_;
+
+    my %count;
+    for my $map (@$map_list) {
+	my $entry = parse_property_string($map_fmt, $map);
+	$count{$entry->{node}}++;
+    }
+    for my $node (keys %count) {
+	if ($count{$node} > 1) {
+	    die "Node '$node' is specified $count{$node} times.\n";
+	}
+    }
+}
+
+sub config {
+    return cfs_read_file($FILENAME);
+}
+
+sub lock_dir_config {
+    my ($code, $errmsg) = @_;
+
+    cfs_lock_file($FILENAME, undef, $code);
+    if (my $err = $@) {
+	$errmsg ? die "$errmsg: $err" : die $err;
+    }
+}
+
+sub write_dir_config {
+    my ($cfg) = @_;
+
+    cfs_write_file($FILENAME, $cfg);
+}
+
+sub find_on_current_node {
+    my ($id) = @_;
+
+    my $cfg = config();
+    my $node = PVE::INotify::nodename();
+
+    return get_node_mapping($cfg, $id, $node);
+}
+
+sub get_node_mapping {
+    my ($cfg, $id, $nodename) = @_;
+
+    return undef if !defined($cfg->{ids}->{$id});
+
+    my $res = [];
+    my $mapping_list = $cfg->{ids}->{$id}->{map};
+    for my $map (@{$mapping_list}) {
+	my $entry = eval { parse_property_string($map_fmt, $map) };
+	warn $@ if $@;
+	if ($entry && $entry->{node} eq $nodename) {
+	    push $res->@*, $entry;
+	}
+    }
+    return $res;
+}
+
+PVE::Mapping::Dir->register();
+PVE::Mapping::Dir->init();
+
+1;
-- 
2.39.5