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Commit Graph

13 Commits

Author SHA1 Message Date
Peter Rajnoha
7fa7632dc7 Set DM_UDEV_DISABLE_OTHER_RULES_FLAG for suspended DM devices in udev rules.
This is to avoid any scanning and processing of DM devices while they are in
suspended state (e.g. a rename while the device is suspended - a CHANGE event
is generated!). Otherwise, any scanning in the rules could end up with locking
the calling process until the device is resumed and so we don't receive a
notification about udev rules completion until then (and that effectively
locks out the process awaiting the notification!).

However, we still keep 'disk' and any 'subsystem' related udev rules running.
We trust these and these should check themselves whether a device is suspended
or not, not trying to run any scanning if it is.
2011-01-28 11:41:51 +00:00
Peter Rajnoha
a6a66e7c83 Fix udev rules to support udev database content generated by older rules.
This can happen with older rules (without support for synthesized events)
that are still part of initrd while using new udev rules in the system itself.

The consequence was that new udev rules incorrectly assumed that not having
DM_UDEV_PRIMARY_SOURCE_FLAG set always means the uevent is synthesized and
inappropriate (device is still not properly activated) and so it should be
ignored. However, initrd is not updated automatically while updating the
libdevmapper/udev rules in the system and so we end up with the rules not
detecting and setting crucial parts in the initrd environment and the rules
in the system that rely on the information that should have been stored in
udev db (which is incorrect in this configuration, of course).

The overall consequence is that the update of libdevmapper/lvm2 without
regenerating the initrd could end up with a boot failure! Ignoring the event
means removing any existing symlinks in /dev!

To fix this, increase udev rules version to make a difference. So from now on,
mark rules without proper support for synthesized events as
DM_UDEV_RULES_VSN="1" and 2 (or higher) if that support is included.
2010-08-12 13:41:18 +00:00
Peter Rajnoha
b045f4fe9a Reinstate detection of inappropriate uevent with DISK_RO set and suppress it.
We still need to detect this one! We're not so strict with CHANGE events as
with the ADD events while applying filters in the rules so this one would
pass and it would process the rules prematurely (because it appears *before*
the actual CHANGE event used when resuming a DM device while setting read-only
state at the same time).
2010-08-12 13:07:08 +00:00
Peter Rajnoha
02adb0cd9d Use "nowatch" udev rule for known inappropriate devices.
For now, this is just a precaution. Normally, all the other (non-dm) rules
should check DM_UDEV_DISABLE_OTHER_RULES_FLAG and therefore avoid setting
any inotify watches as well. But let's make sure.

Support for final assignment of the "nowatch" rule (the use of ":=") will
appear in next udev release, v160. This should also work in previous udev
versions but the setting won't be sealed so any further OPTIONS="watch" will
always prevail there.

We may want to add more specific "nowatch" rules later if needed.
2010-07-07 11:22:46 +00:00
Peter Rajnoha
acc70bce86 Fix udev rules to handle spurious events properly.
We can use DM_UDEV_PRIMARY_SOURCE_FLAG to identify the spurious events
and use it as an indication that the device has already been activated before
(and hence we can find this property in udev database).

WARNING: This change requires udev startup script to preserve udev database
from initrd. All the information stored there during activation of devices
is important for the initial "udevadm trigger --action=add" call that is
used in udev startup script. If not done this way, udev startup script needs
to define DM_UDEV_PRIMARY_SOURCE_FLAG=1 property for any ADD events it uses.
2010-06-23 17:00:32 +00:00
Peter Rajnoha
942d6ef29f Add support for new IMPORT{db} udev rule.
This rule appeared in udev v152 and it helps us to support spurious events
where we didn't have any flags set (events originated in udevadm trigger
or the watch rule). These flags are important to direct the rule application.
Now, with the help of this rule, we can regenerate old udev db content.
To implement this correctly, we need to flag all proper DM udev events with
DM_UDEV_PRIMARY_SOURCE_FLAG. That happens automatically for all ioctls
generating events originated in libdevmapper.
2010-04-28 13:37:36 +00:00
Peter Rajnoha
0d408f0c43 Disable udev rules on change event with DISK_RO=1.
There's a new change udev event generated since kernel 2.6.32 that
notifies userspace about a change in read-only attribute for block
devices (with DISK_RO=1 environment variable set).

We need to detect this and disable the rule application so the
meaning of this change event is not interchanged with the regular
change event used while resuming/renaming DM devices.

If there's anybody awaiting this notification in foreign rules,
he can still check for this env var and do the appropriate actions
separately.
2009-12-07 12:03:47 +00:00
Peter Rajnoha
06f97f3be3 More cleanup in udev rules:
- add copyright notice for 10-dm.rules.in,

 - set DM_UDEV_DISABLE_{DISK, OTHER}_RULES_FLAG in 11-dm-lvm.rules directly
   for inappropriate and non-top-level subdevices in case we use older kernels
   where DM_COOKIE is not used (and therefore there are no flags passed from
   the LVM process itself). This applies for older kernels (version < 2.6.31),

 - remove unnecessary filters in 95-dm-notify.rules - the DM_COOKIE env var
   itself is set for change/remove udev events and for DM devices only so
   there's no need to double-check this.
2009-11-01 18:01:31 +00:00
Peter Rajnoha
421671b1c2 Several changes to udev support code:
- we have these levels when the udev rules are processed:
   10-dm.rules --> [11-dm-<subsystem>.rules] --> [12-dm-permissions.rules] -->
   13-dm-disk.rules --> [...all the other foreign rules...] --> 95-dm-notify.rules

 - each level can be disabled now by
   DM_UDEV_DISABLE_{DM, SUBSYSTEM, DISK, OTHER}_RULES_FLAG

 - add DM_UDEV_DISABLE_DM_RULES_FLAG to disable 10-dm.rules

 - add DM_UDEV_DISABLE_OTHER_RULES_FLAG to disable all the other (non-dm) rules.
   We cutoff these rules by using the 'last_rule', so this one should really be
   used with great care and in well-founded situations. We use this for lvm's
   hidden and layer devices now.

 - add a parameter for add_dev_node, rm_dev_node and rename_dev_node so it's
   possible to switch on/off udev checks

 - use DM_UDEV_DISABLE_DM_RULES_FLAG and DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG
   if there's no cookie set and we have resume, remove and rename ioctl.
   This could happen when someone uses the libdevmapper that is compiled with
   udev_sync but the software does not make use of it. This way we can switch
   off the rules and fallback to libdevmapper node creation so there's no
   udev/libdevmapper race.
2009-10-26 14:29:33 +00:00
Peter Rajnoha
772f7d4188 Use udev flags in the rules and cleanup the rules:
- remove default permissions set in 95-dm-notify.rules (and add a hint in 12-dm-permissions.rules to set it by the user directly)
 - add multipath DM_ACTION=="PATH_FAILED" filter
 - remove unnecessary filters in the headers of the rules (we can simply use DM_UDEV_RULES_VSN instead)
 - fix symlink priorities in /dev/disk/ (snapshot volumes have low priority for FS UUID symlinks so it will not overwrite symlinks for the origin)
2009-10-22 13:11:33 +00:00
Peter Rajnoha
f83332a0d5 Several changes in udev rules:
- add DM_UDEV_RULES_VSN to provide a variable to be checked for in the other
  rules (e.g. to check that DM rules are actually installed, we can alternate
  functionality in the other rules based on this information, also we have
  versioning support for the rules)
- set proper sbin path for dmsetup and blkid, /sbin first, then /usr/sbin.
  This is necessary for anaconda to work properly.
- add 'last_rule' for cryptsetup's temporary devices (symlinks in /dev/mapper
  only)
2009-09-11 16:05:20 +00:00
Peter Rajnoha
83a3c60506 Fix a typo in udev rule (splitname, NOT namesplit) 2009-08-04 08:05:06 +00:00
Alasdair Kergon
252239bdac Add default udev rules.
Update dm-ioctl.h comments.
2009-08-03 18:44:54 +00:00