[pve-devel] [RFC qemu-server v2 31/32] blockdev: add support for NBD paths

[Fiona Ebner]

Co-developed-by: Alexandre Derumier <alexandre.derumier at groupe-cyllene.com>
Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---

RFC, still didn't come around to testing it (will be done with
blockdev-mirror).

Changes in v2:
* Also support unix socket NBD paths.

 src/PVE/QemuServer/Blockdev.pm | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/PVE/QemuServer/Blockdev.pm b/src/PVE/QemuServer/Blockdev.pm
index 76a00383..75fe40ec 100644
--- a/src/PVE/QemuServer/Blockdev.pm
+++ b/src/PVE/QemuServer/Blockdev.pm
@@ -12,6 +12,18 @@ use PVE::Storage;
 
 use PVE::QemuServer::Drive qw(drive_is_cdrom);
 
+# gives ($host, $port, $export)
+my $NBD_TCP_PATH_RE_3 = qr/nbd:(\S+):(\d+):exportname=(\S+)/;
+my $NBD_UNIX_PATH_RE_2 = qr/nbd:unix:(\S+):exportname=(\S+)/;
+
+my sub is_nbd {
+    my ($drive) = @_;
+
+    return 1 if $drive->{file} =~ $NBD_TCP_PATH_RE_3;
+    return 1 if $drive->{file} =~ $NBD_UNIX_PATH_RE_2;
+    return 0;
+}
+
 my sub get_node_name {
     my ($type, $drive_id, $volid, $snap) = @_;
 
@@ -98,7 +110,13 @@ sub generate_file_blockdev {
 
     my $drive_id = PVE::QemuServer::Drive::get_drive_id($drive);
 
-    if ($drive->{file} eq 'cdrom') {
+    if ($drive->{file} =~ m/^$NBD_UNIX_PATH_RE_2$/) {
+        my $server = { type => 'unix', path => "$1" };
+        $blockdev = { driver => 'nbd', server => $server, export => "$2" };
+    } elsif ($drive->{file} =~ m/^$NBD_TCP_PATH_RE_3$/) {
+        my $server = { type => 'inet', host => "$1", port => "$2" }; # port is also a string in QAPI
+        $blockdev = { driver => 'nbd', server => $server, export => "$3" };
+    } elsif ($drive->{file} eq 'cdrom') {
         my $path = PVE::QemuServer::Drive::get_iso_path($storecfg, $drive->{file});
         $blockdev = { driver => 'host_cdrom', filename => "$path" };
     } elsif ($drive->{file} =~ m|^/|) {
@@ -155,6 +173,7 @@ sub generate_format_blockdev {
 
     die "generate_format_blockdev called without volid/path\n" if !$drive->{file};
     die "generate_format_blockdev called with 'none'\n" if $drive->{file} eq 'none';
+    die "generate_format_blockdev called with NBD path\n" if is_nbd($drive);
 
     my $scfg;
     my $format;
@@ -199,7 +218,9 @@ sub generate_drive_blockdev {
     die "generate_drive_blockdev called with 'none'\n" if $drive->{file} eq 'none';
 
     my $child = generate_file_blockdev($storecfg, $drive, $options);
-    $child = generate_format_blockdev($storecfg, $drive, $child, $options);
+    if (!is_nbd($drive)) {
+        $child = generate_format_blockdev($storecfg, $drive, $child, $options);
+    }
 
     # this is the top filter entry point, use $drive-drive_id as nodename
     return {
-- 
2.39.5