udev: Use parent bus id for virtio disk builtin path-id (#5500)

The builtin path id for virtio block devices has been changed
to use the bus id without a prefix "virtio-pci" to be
compatible with all virtio transport types.

In order to not break existing setups, the by-path symlinks for
virtio block devices on the PCI bus are reintroduced by udev rules.
The virtio-pci symlinks are considered to be deprecated and
should be replaced by the native PCI symlinks.

Example output for a virtio disk in PCI slot 7:
 $ ls  /dev/disk/by-path
 pci-0000:00:07.0
 pci-0000:00:07.0-part1
 virtio-pci-0000:00:07.0
 virtio-pci-0000:00:07.0-part1

See also
[1] https://lists.freedesktop.org/archives/systemd-devel/2017-February/038326.html
[2] https://lists.freedesktop.org/archives/systemd-devel/2017-March/038397.html

This reverts f073b1b but keeps the same symlinks for compatibility.

1 files changed, 1 insertions, 4 deletions

diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c
index 527f0bff2d..8cb330dba1 100644
--- a/src/udev/udev-builtin-path_id.c
+++ b/src/udev/udev-builtin-path_id.c
@@ -664,11 +664,8 @@ static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool
                         parent = skip_subsystem(parent, "xen");
                         supported_parent = true;
                 } else if (streq(subsys, "virtio")) {
-                        while (parent && streq_ptr("virtio", udev_device_get_subsystem(parent)))
-                                parent = udev_device_get_parent(parent);
-                        path_prepend(&path, "virtio-pci-%s", udev_device_get_sysname(parent));
+                        parent = skip_subsystem(parent, "virtio");
                         supported_transport = true;
-                        supported_parent = true;
                 } else if (streq(subsys, "scm")) {
                         path_prepend(&path, "scm-%s", udev_device_get_sysname(parent));
                         parent = skip_subsystem(parent, "scm");