[PATCH storage 1/2] add subroutine to classify volume ids

[Thomas Ellmenreich <t.ellmenreich@proxmox.com>]

To enable easier branching on different types of volume id's a new
subroutine classify_volume_id is added. It classifies the passed type
as one of 'volume', 'cdrom', 'none' or 'absolute'. Depending on how
the 'noerr' option is set values that cannot be categorized throw an
error or return undef.

The constants and subroutine are exported by the Storage module

Signed-off-by: Thomas Ellmenreich <t.ellmenreich@proxmox.com>
---
 src/PVE/Storage.pm        | 21 +++++++++++++++++++++
 src/PVE/Storage/Plugin.pm | 25 +++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
index 64ea9da..1401d69 100755
--- a/src/PVE/Storage.pm
+++ b/src/PVE/Storage.pm
@@ -40,6 +40,16 @@ use PVE::Storage::PBSPlugin;
 use PVE::Storage::BTRFSPlugin;
 use PVE::Storage::ESXiPlugin;
 
+use base qw(Exporter);
+
+our @EXPORT_OK = qw(
+    classify_volume_id
+    $VOL_NONE
+    $VOL_CDROM
+    $VOL_ABSOLUTE
+    $VOL_VOLUME
+);
+
 # Storage API version. Increment it on changes in storage API interface.
 use constant APIVER => 15;
 # Age is the number of versions we're backward compatible with.
@@ -131,6 +141,11 @@ our $OVA_CONTENT_RE_1 = qr/${SAFE_CHAR_WITH_WHITESPACE_CLASS_RE}+\.(qcow2|raw|vm
 # FIXME remove with PVE 9.0, add versioned breaks for pve-manager
 our $vztmpl_extension_re = $VZTMPL_EXT_RE_1;
 
+our $VOL_NONE = PVE::Storage::Plugin::VOL_NONE();
+our $VOL_CDROM = PVE::Storage::Plugin::VOL_CDROM();
+our $VOL_ABSOLUTE = PVE::Storage::Plugin::VOL_ABSOLUTE();
+our $VOL_VOLUME = PVE::Storage::Plugin::VOL_VOLUME();
+
 # See the QMP reference documentation.
 my $allowed_qemu_blockdev_options_file = {
     filename => 1,
@@ -615,6 +630,12 @@ sub parse_volume_id {
     return PVE::Storage::Plugin::parse_volume_id($volid, $noerr);
 }
 
+sub classify_volume_id {
+    my ($volid, $noerr) = @_;
+
+    return PVE::Storage::Plugin::classify_volume_id($volid, $noerr);
+}
+
 # test if we have read access to volid
 sub check_volume_access {
     my ($rpcenv, $user, $cfg, $vmid, $volid, $type) = @_;
diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
index 4f69f9b..180ad6c 100644
--- a/src/PVE/Storage/Plugin.pm
+++ b/src/PVE/Storage/Plugin.pm
@@ -27,6 +27,14 @@ use constant COMPRESSOR_RE => join('|', KNOWN_COMPRESSION_FORMATS);
 use constant LOG_EXT => ".log";
 use constant NOTES_EXT => ".notes";
 
+# types of volume ids
+use constant {
+    VOL_NONE => 'none',
+    VOL_CDROM => 'cdrom',
+    VOL_ABSOLUTE => 'absolute',
+    VOL_VOLUME => 'volume',
+};
+
 our @COMMON_TAR_FLAGS = qw(
     --one-file-system
     -p --sparse --numeric-owner --acls
@@ -427,6 +435,23 @@ sub parse_volume_id {
     die "unable to parse volume ID '$volid'\n";
 }
 
+sub classify_volume_id {
+    my ($volid, $noerr) = @_;
+
+    if (!defined($volid) || $volid eq "none") {
+        return VOL_NONE;
+    } elsif ($volid eq 'cdrom') {
+        return VOL_CDROM;
+    } elsif ($volid =~ m|^/|) {
+        return VOL_ABSOLUTE;
+    } elsif (parse_volume_id($volid, 1)) {
+        return VOL_VOLUME;
+    }
+
+    return undef if $noerr;
+    die "unable to classify volume ID '$volid'";
+}
+
 PVE::JSONSchema::register_format('pve-dir-override', \&verify_dir_override);
 
 sub verify_dir_override {
-- 
2.47.3