[pve-devel] [PATCH guest-common v14 2/12] add dir mapping section config
Markus Frank
m.frank at proxmox.com
Wed Apr 2 17:20:01 CEST 2025
Thanks for the feedback.
On 2025-04-02 15:14, Fabian Grünbichler wrote:
> 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)?
I agree, I think it is best to remove this option altogether and always set it.
>
>>
>> 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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>>
>>
>>
>
>
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