Files
pve-storage/src/PVE/Storage/Common.pm
Alexandre Derumier 933736ad6d plugin: add qemu_img_info
Signed-off-by: Alexandre Derumier <alexandre.derumier@groupe-cyllene.com>
2025-07-16 15:55:28 +02:00

147 lines
3.5 KiB
Perl

package PVE::Storage::Common;
use strict;
use warnings;
use PVE::JSONSchema;
use PVE::Syscall;
use PVE::Tools qw(run_command);
use constant {
FALLOC_FL_KEEP_SIZE => 0x01, # see linux/falloc.h
FALLOC_FL_PUNCH_HOLE => 0x02, # see linux/falloc.h
};
=pod
=head1 NAME
PVE::Storage::Common - Shared functions and utilities for storage plugins and storage operations
=head1 DESCRIPTION
This module contains common subroutines that are mainly to be used by storage
plugins. This module's submodules contain subroutines that are tailored towards
a more specific or related purpose.
Functions concerned with storage-related C<PVE::SectionConfig> things, helpers
for the C<PVE::Storage> API can be found in this module. Functions that can't
be grouped in a submodule can also be found here.
=head1 SUBMODULES
=over
=back
=head1 STANDARD OPTIONS FOR JSON SCHEMA
=over
=back
=head3 pve-storage-image-format
Possible formats a guest image can have.
=cut
# TODO PVE 9 - Note that currently, qemu-server allows more formats for VM images, so third party
# storage plugins might potentially allow more too, but none of the plugins we are aware of do that.
# Those formats should either be allowed here or support for them should be phased out (at least in
# the storage layer). Can still be added again in the future, should any plugin provider request it.
PVE::JSONSchema::register_standard_option(
'pve-storage-image-format',
{
type => 'string',
enum => ['raw', 'qcow2', 'subvol', 'vmdk'],
description => "Format of the image.",
},
);
=pod
=head1 FUNCTIONS
=cut
=pod
=head3 align_size_up
$aligned_size = align_size_up($size, $granularity)
Returns the next size bigger than or equal to C<$size> that is aligned with a
granularity of C<$granularity>. Prints a message if the aligned size is not
equal to the aligned size.
=cut
sub align_size_up : prototype($$) {
my ($size, $granularity) = @_;
my $padding = ($granularity - $size % $granularity) % $granularity;
my $aligned_size = $size + $padding;
print "size $size is not aligned to granularity $granularity, rounding up to $aligned_size\n"
if $aligned_size != $size;
return $aligned_size;
}
=pod
=head3 deallocate
deallocate($file_handle, $offset, $length)
Deallocates the range with C<$length> many bytes starting from offset C<$offset>
for the file associated to the file handle C<$file_handle>. Dies on failure.
=cut
sub deallocate : prototype($$$) {
my ($file_handle, $offset, $length) = @_;
my $mode = FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE;
$offset = int($offset);
$length = int($length);
if (syscall(PVE::Syscall::fallocate, fileno($file_handle), $mode, $offset, $length) != 0) {
die "fallocate: punch hole failed (offset: $offset, length: $length) - $!\n";
}
}
=pod
=head3 run_qemu_img_json
run_qemu_img_json($cmd, $timeout)
Execute qemu_img command C<$cmd> with a timeout C<$timeout>.
Parse the output result and return a json.
=cut
sub run_qemu_img_json {
my ($cmd, $timeout) = @_;
my $json = '';
my $err_output = '';
eval {
run_command(
$cmd,
timeout => $timeout,
outfunc => sub { $json .= shift },
errfunc => sub { $err_output .= shift . "\n" },
);
};
warn $@ if $@;
if ($err_output) {
# if qemu did not output anything to stdout we die with stderr as an error
die $err_output if !$json;
# otherwise we warn about it and try to parse the json
warn $err_output;
}
return $json;
}
1;