ID_PATH isn't set correctly for multiple devices

[Hajo Möller]

We're running a server similar to BackBlaze's StoragePod, in which three SATA-PCI-Cards (SiI 3124) each connect to three 5-port SATA PMP backplanes (SiI 3726).

Each disk connected via one of those controllers and backplanes should have a unique ID_PATH, which it had on Debian Squeeze.

After changing the host OS to Ubuntu 12.04.2 today I found /dev/disk/by-path/ not to be filled by the expected symlinks.
It seems udev doesn't resolve ID_PATH correctly but tries to overwrite the old links:

root@ubuntu:~# udevadm test-builtin path_id /sys/block/sda
ID_PATH=pci-0000:02:04.0-scsi-0:0:0:0
ID_PATH_TAG=pci-0000_02_04_0-scsi-0_0_0_0

root@ubuntu:~# udevadm test-builtin path_id /sys/block/sde
ID_PATH=pci-0000:02:04.0-scsi-0:0:0:0
ID_PATH_TAG=pci-0000_02_04_0-scsi-0_0_0_0

root@ubuntu:~# udevadm test /sys/block/sda/
run_command: calling: test
adm_test: version 175
[...]
udev_device_update_db: created db file '/run/udev/data/b8:0' for '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:04.0/ata1/host0/target0:0:0/0:0:0:0/block/sda'
ACTION=add
DEVLINKS=/dev/disk/by-id/ata-SAMSUNG_HD204UI_S2H7J90B804735 /dev/disk/by-id/scsi-SATA_SAMSUNG_HD204UIS2H7J90B804735 /dev/disk/by-id/wwn-0x50024e9205d4ea30 /dev/disk/by-path/pci-0000:02:04.0-scsi-0:0:0:0 /dev/disk/zpool/v0d5
DEVNAME=/dev/sda
DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:04.0/ata1/host0/target0:0:0/0:0:0:0/block/sda
DEVTYPE=disk
[...]
ID_PATH=pci-0000:02:04.0-scsi-0:0:0:0
ID_PATH_TAG=pci-0000_02_04_0-scsi-0_0_0_0
[...]

root@ubuntu:~# udevadm test /sys/block/sde/
[...]
udev_device_update_db: created db file '/run/udev/data/b8:64' for '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:04.0/ata3/host2/target2:0:0/2:0:0:0/block/sde'
ACTION=add
DEVLINKS=/dev/disk/by-id/ata-SAMSUNG_HD204UI_S2H7J90B804734 /dev/disk/by-id/scsi-SATA_SAMSUNG_HD204UIS2H7J90B804734 /dev/disk/by-id/wwn-0x50024e9205d4ea2f /dev/disk/by-path/pci-0000:02:04.0-scsi-0:0:0:0 /dev/disk/zpool/v0d5
DEVNAME=/dev/sde
DEVPATH=/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:04.0/ata3/host2/target2:0:0/2:0:0:0/block/sde
DEVTYPE=disk
[...]
ID_PATH=pci-0000:02:04.0-scsi-0:0:0:0
ID_PATH_TAG=pci-0000_02_04_0-scsi-0_0_0_0
[...]

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.