[pve-devel] [PATCH guest-common v14 2/12] add dir mapping section config
Fabian Grünbichler
f.gruenbichler at proxmox.com
Wed Apr 2 15:14:10 CEST 2025
On March 4, 2025 12:57 pm, Markus Frank wrote:
> 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.
some things about the announce-submounts option that might be worthwhile
to consider:
- does it hurt to set announce-submounts if there are none?
- it sounds like not setting it if there are any is dangerous
why don't we always set it? "announce-submounts" is also a really weird
name if we extend this to managed bind-mounts for containers (which I'd
very much like to do), if we keep it it should be a flag denoting that
this directory contains further mountpoints (which means it
requires/should default to announce-submounts for virtiofsd, and
recursive bind mounting for LXC)?
>
> 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>
> ---
> v14:
> * disallow commas and equal signs in path until the path can be quoted
> in property strings
> * addressed style nits and improved formatting
>
> src/Makefile | 1 +
> src/PVE/Mapping/Dir.pm | 196 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 197 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..581ec39
> --- /dev/null
> +++ b/src/PVE/Mapping/Dir.pm
> @@ -0,0 +1,196 @@
> +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';
> +}
> +
> +# temporary path format that also disallows commas and equal signs
> +# TODO: Remove this when property_string supports quotation of properties
> +PVE::JSONSchema::register_format('pve-storage-path-in-property-string', \&verify_path);
> +sub verify_path {
> + my ($path, $noerr) = @_;
> +
> + if ($path !~ m|^/[^;,=\(\)]+|) {
> + return undef if $noerr;
> + die "Value does not look like a valid absolute path."
> + ." These symbols are currently not allowed in path: ;,=())\n";
stray ')' in the error message
> + }
> + return $path;
> +}
> +
> +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-in-property-string',
> + },
> + '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,
> + },
> +};
> +
> +my $defaultData = {
> + propertyList => {
> + id => {
> + type => 'string',
> + description => "The ID of the directory mapping",
> + format => 'pve-configid',
> + },
> + description => {
> + type => 'string',
> + description => "Description of the directory mapping",
> + 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 $defaultData;
> +}
> +
> +sub options {
> + return {
> + description => { optional => 1 },
> + map => {},
> + };
> +}
> +
> +sub assert_valid {
this is called below in assert_valid_map_list without filtering entries
so that just those for the current node are considered..
> + my ($dir_cfg) = @_;
> +
> + my $path = $dir_cfg->{path};
> +
> + verify_path($path);
> +
> + if (! -e $path) {
> + die "Path $path does not exist\n";
> + } elsif (! -d $path) {
> + die "Path $path exists, but is not a directory\n";
> + }
so these checks don't make sense.. if the directory has to exist on all
nodes, then the per-node mappings could just be dropped entirely ;)
> +
> + return 1;
> +};
> +
> +sub assert_valid_map_list {
> + my ($map_list) = @_;
> +
> + my %count;
> + for my $map (@$map_list) {
> + my $entry = parse_property_string($map_fmt, $map);
> + assert_valid($entry);
> + $count{$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();
> +
> + my $node_mapping = get_node_mapping($cfg, $id, $node);
> + if (@{$node_mapping} > 1) {
> + die "More than than one directory mapping for node $node.\n";
> + }
> + return $node_mapping->[0];
> +}
> +
> +sub get_node_mapping {
> + my ($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
>
>
>
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