This is a more sane solution, than ignoring subsequent "change" events.
The only danger is that we could loop, if a lvm scan triggers a broken
md partition, which triggers a broken PV and so on.
Better fix the scanning tools, not to emit change events for devices,
if no action was taken.
Since different distros may or may not use vol_id in udev, and blkid
is generally replacing vol_id, abstract them out into a function which
tries to use vol_id first and blkid second, on the assumption that
blkid can take over for vol_id if vol_id is no longer there.
LVM
rd_NO_LVM
disable LVM detection
rd_LVM_VG=<volume group name>
only activate the volume groups with the given name
crypto LUKS
rd_NO_LUKS
disable crypto LUKS detection
rd_LUKS_UUID=<luks uuid>
only activate the LUKS partitions with the given UUID
MD
rd_NO_MD
disable MD RAID detection
rd_MD_UUID=<md uuid>
only activate the raid sets with the given UUID
DMRAID
rd_NO_DM
disable DM RAID detection
rd_DM_UUID=<dmraid uuid>
only activate the raid sets with the given UUID
Intel BIOS raid is being shifted from dmraid to mdraid because mdraid offers
more features. So if an imsm metadata capable mdadm is present use mdraid
instead of dmraid for isw_raid_member's
This patch also adds code to mdraid_start.sh so that the raidsets
inside the imsm containers get started once udev is done probing
(doing this earlier leads to potentially degraded use of the sets and
an unwanted resync).
init now has the following points to inject scripts:
/cmdline/*.sh
scripts for command line parsing
/pre-udev/*.sh
scripts to run before udev is started
/pre-trigger/*.sh
scripts to run before the main udev trigger is pulled
/initqueue/*.sh
runs in parallel to the udev trigger
Udev events can add scripts here with /sbin/initqueue.
If /sbin/initqueue is called with the "--onetime" option, the script
will be removed after it was run.
If /initqueue/work is created and udev >= 143 then this loop can
process the jobs in parallel to the udevtrigger.
If the udev queue is empty and no root device is found or no root
filesystem was mounted, the user will be dropped to a shell after
a timeout.
Scripts can remove themselves from the initqueue by "rm $job".
/pre-mount/*.sh
scripts to run before the root filesystem is mounted
NFS is an exception, because it has no device node to be created
and mounts in the udev events
/mount/*.sh
scripts to mount the root filesystem
NFS is an exception, because it has no device node to be created
and mounts in the udev events
If the udev queue is empty and no root device is found or no root
filesystem was mounted, the user will be dropped to a shell after
a timeout.
/pre-pivot/*.sh
scripts to run before the real init is executed and the initramfs
disappears
All processes started before should be killed here.
The behaviour of the dmraid module demonstrates how to use the new
mechanism. If it detects a device which is part of a raidmember from a
udev rule, it installs a job to scan for dmraid devices, if the udev
queue is empty. After a scan, it removes itsself from the queue.
Harald Hoyer