Fix getting names for MD member disks with MD properties (#1727180)

[vojtechtrefny]

Some MD member disks have the 'MD_*' properties in UDev database
which confuses our 'udev.device_get_name' function.

---

The result is three devices with same name (two disks and the array). This doesn't happen for all arrays, I was able to reproduce this with a raid1 created directly on top of the disks (without partitions).

$ udevadm info /dev/vdc
P: /devices/pci0000:00/0000:00:0c.0/virtio6/block/vdc
N: vdc
L: 0
S: disk/by-path/pci-0000:00:0c.0
S: disk/by-path/virtio-pci-0000:00:0c.0
E: DEVPATH=/devices/pci0000:00/0000:00:0c.0/virtio6/block/vdc
E: DEVNAME=/dev/vdc
E: DEVTYPE=disk
E: MAJOR=252
E: MINOR=32
E: SUBSYSTEM=block
E: USEC_INITIALIZED=9888220
E: ID_PATH=pci-0000:00:0c.0
E: ID_PATH_TAG=pci-0000_00_0c_0
E: ID_FS_UUID=8a9a5a4a-bfa8-b1c7-2366-bcbde5ef324e
E: ID_FS_UUID_ENC=8a9a5a4a-bfa8-b1c7-2366-bcbde5ef324e
E: ID_FS_UUID_SUB=cae91f65-006e-ef11-b512-95331d445ea6
E: ID_FS_UUID_SUB_ENC=cae91f65-006e-ef11-b512-95331d445ea6
E: ID_FS_LABEL=localhost.localdomain:127
E: ID_FS_LABEL_ENC=localhost.localdomain:127
E: ID_FS_VERSION=1.2
E: ID_FS_TYPE=linux_raid_member
E: ID_FS_USAGE=raid
E: MD_DEVICE=md127
E: MD_DEVNAME=127
E: MD_FOREIGN=no
E: MD_STARTED=unsafe
E: SYSTEMD_WANTS=mdadm-last-resort@md127.timer
E: UDISKS_MD_MEMBER_LEVEL=raid1
E: UDISKS_MD_MEMBER_DEVICES=2
E: UDISKS_MD_MEMBER_NAME=localhost.localdomain:127
E: UDISKS_MD_MEMBER_ARRAY_SIZE=1071.64MB
E: UDISKS_MD_MEMBER_UUID=8a9a5a4a:bfa8b1c7:2366bcbd:e5ef324e
E: UDISKS_MD_MEMBER_UPDATE_TIME=1564873206
E: UDISKS_MD_MEMBER_DEV_UUID=cae91f65:006eef11:b5129533:1d445ea6
E: UDISKS_MD_MEMBER_EVENTS=20
E: DEVLINKS=/dev/disk/by-path/pci-0000:00:0c.0 /dev/disk/by-path/virtio-pci-0000:00:0c.0
E: TAGS=:systemd:

[vojtechtrefny]

The rawhie test fail is unrelated, it's just new version of pylint discovering new issues, I'll address this in a separate PR.

[vpodzime]

Looks good to me.

[dwlehman]

See b4e9cee for an alternative solution to this which covers partitions as well.

[vojtechtrefny]

Interesting. This fixes the crash, the array is added correctly to the tree, but not the partitions on it. In my case the name of the array is actually 127, so we need to try to add partitions with name 127p1 because md127p1` doesn't work with parted:

DEBUG:blivet: looking up parted Partition: /dev/md/md127p1
ERROR:blivet: Failed to instantiate PartitionDevice: ('cannot find parted partition instance', 'md127p1')
DEBUG:blivet: no device obtained for md127p1

But from the bug mentioned in your patch it looks like the problem there was completely opposite -- we were trying to add partition /dev/10p3 instead of /dev/md/10p3 or /dev/md10p3.

[vojtechtrefny]

Closing, see #827