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Commit Graph

39 Commits

Author SHA1 Message Date
David Teigland
71933d3496 devices file: recommend removing filter
When the devices file is enabled and the filter is set,
recommand that the user remove the filter from lvm.conf
since it's ignored.
2021-05-05 13:59:42 -05:00
David Teigland
e9d10f3711 filters: better message for excluding LV
Make the generic "device is not usable" message from filter-usable
more specific in case the device is not usable because it's an LV.
(i.e. when scan_lvs=0)
2021-03-03 12:07:57 -06:00
David Teigland
83fe6e720f device usage based on devices file
The LVM devices file lists devices that lvm can use.  The default
file is /etc/lvm/devices/system.devices, and the lvmdevices(8)
command is used to add or remove device entries.  If the file
does not exist, or if lvm.conf includes use_devicesfile=0, then
lvm will not use a devices file.  When the devices file is in use,
the regex filter is not used, and the filter settings in lvm.conf
or on the command line are ignored.

LVM records devices in the devices file using hardware-specific
IDs, such as the WWID, and attempts to use subsystem-specific
IDs for virtual device types.  These device IDs are also written
in the VG metadata.  When no hardware or virtual ID is available,
lvm falls back using the unstable device name as the device ID.
When devnames are used, lvm performs extra scanning to find
devices if their devname changes, e.g. after reboot.

When proper device IDs are used, an lvm command will not look
at devices outside the devices file, but when devnames are used
as a fallback, lvm will scan devices outside the devices file
to locate PVs on renamed devices.  A config setting
search_for_devnames can be used to control the scanning for
renamed devname entries.

Related to the devices file, the new command option
--devices <devnames> allows a list of devices to be specified for
the command to use, overriding the devices file.  The listed
devices act as a sort of devices file in terms of limiting which
devices lvm will see and use.  Devices that are not listed will
appear to be missing to the lvm command.

Multiple devices files can be kept in /etc/lvm/devices, which
allows lvm to be used with different sets of devices, e.g.
system devices do not need to be exposed to a specific application,
and the application can use lvm on its own set of devices that are
not exposed to the system.  The option --devicesfile <filename> is
used to select the devices file to use with the command.  Without
the option set, the default system devices file is used.

Setting --devicesfile "" causes lvm to not use a devices file.

An existing, empty devices file means lvm will see no devices.

The new command vgimportdevices adds PVs from a VG to the devices
file and updates the VG metadata to include the device IDs.
vgimportdevices -a will import all VGs into the system devices file.

LVM commands run by dmeventd not use a devices file by default,
and will look at all devices on the system.  A devices file can
be created for dmeventd (/etc/lvm/devices/dmeventd.devices)  If
this file exists, lvm commands run by dmeventd will use it.

Internal implementaion:

- device_ids_read - read the devices file
  . add struct dev_use (du) to cmd->use_devices for each devices file entry
- dev_cache_scan - get /dev entries
  . add struct device (dev) to dev_cache for each device on the system
- device_ids_match - match devices file entries to /dev entries
  . match each du on cmd->use_devices to a dev in dev_cache, using device ID
  . on match, set du->dev, dev->id, dev->flags MATCHED_USE_ID
- label_scan - read lvm headers and metadata from devices
  . filters are applied, those that do not need data from the device
  . filter-deviceid skips devs without MATCHED_USE_ID, i.e.
    skips /dev entries that are not listed in the devices file
  . read lvm label from dev
  . filters are applied, those that use data from the device
  . read lvm metadata from dev
  . add info/vginfo structs for PVs/VGs (info is "lvmcache")
- device_ids_find_renamed_devs - handle devices with unstable devname ID
  where devname changed
  . this step only needed when devs do not have proper device IDs,
    and their dev names change, e.g. after reboot sdb becomes sdc.
  . detect incorrect match because PVID in the devices file entry
    does not match the PVID found when the device was read above
  . undo incorrect match between du and dev above
  . search system devices for new location of PVID
  . update devices file with new devnames for PVIDs on renamed devices
  . label_scan the renamed devs
- continue with command processing
2021-02-23 16:43:32 -06:00
David Teigland
450f272b31 devices: support printing the filter that rejects a device
Use of this new message function needs to be added
to various commands to improve the output.
2020-10-01 12:00:09 -05:00
David Teigland
bfcecbbce1 filter: add config setting to skip scanning LVs
devices/scan_lvs (default 1) determines whether lvm
will scan LVs for layered PVs.  The lvm behavior has
always been to scan LVs, but it's rare for LVs to have
layered PVs, and much more common for there to be many
LVs that substantially slow down scanning with no benefit.

This is implemented in the usable filter, and has the
same effect as listing all LVs in the global_filter.
2018-08-30 09:59:50 -05:00
David Teigland
22c5467add filters: remove cache file in persistent filter
It creates problems because it's not always correct,
and it doesn't actually help much.
2018-06-13 14:00:47 -05:00
Joe Thornber
7f97c7ea9a build: Don't generate symlinks in include/ dir
As we start refactoring the code to break dependencies (see doc/refactoring.txt),
I want us to use full paths in the includes (eg, #include "base/data-struct/list.h").
This makes it more obvious when we're breaking abstraction boundaries, eg, including a file in
metadata/ from base/
2018-05-14 10:30:20 +01:00
David Teigland
57bb46c5e7 filter: use bcache for filter reads
Filters are still applied before any device reading or
the label scan, but any filter checks that want to read
the device are skipped and the device is flagged.

After bcache is populated, but before lvm looks for
devices (i.e. before label scan), the filters are
reapplied to the devices that were flagged above.
The filters will then find the data they need in
bcache.
2018-05-10 16:03:19 -05:00
David Teigland
24e7745d7a devices: ignore lvm1 and pool devices 2018-05-01 15:18:47 -05:00
Joe Thornber
00f1b208a1 [io paths] Unpick agk's aio stuff 2018-04-20 11:03:58 -05:00
Alasdair G Kergon
22b6c482ec config: Split config buffer processing into new fn.
Wrap its parameters into struct process_config_file_params allocated
from a mempool now passed into the config_file_read* fns.
2018-01-02 21:10:46 +00:00
David Teigland
ebd2758dab vgimportclone: add native command
This is cleaner and more efficient than the script.
The args and usage are unchanged.
2016-06-22 13:13:10 -05:00
Zdenek Kabelac
fcbef05aae doc: change fsf address
Hmm rpmlint suggest fsf is using a different address these days,
so lets keep it up-to-date
2016-01-21 12:11:37 +01:00
Peter Rajnoha
1c7a509bed filters: add firmware RAID filter
Just like MD filtering that detects components of software RAID (md),
add detection for firmware RAID.

We're not adding any native code to detect this - there are lots of
firmware RAIDs out there which is just out of LVM scope. However,
with current changes with which we're able to get device info from
external sources (e.g. external_device_info_source="udev"), we can
do this easily if the external device status source has this kind
of information - which is the case of "udev" source where the results
of blkid scans are stored.

This detection should cover all firmware RAIDs that blkid can detect and
which are identified as:
  ID_FS_TYPE = {adaptec,ddf,hpt45x,hpt37x,isw,jmicron,lsi_mega,nvidia,promise_fasttrack,silicon_medley,via}_raid_member
2015-01-30 13:17:12 +01:00
Peter Rajnoha
c50a90c9e6 filter-composite: add external device info hooks
Composite filter is a filter that can put several filters in one set.
This patch adds a switch when creating the composite filter which will
enable or disable external device info handles for all the filters
the composite filter encompasses.

We want to use this external device info for majority of the filters
which are in the "lvmetad filter chain" (or the respective part if
we're not using lvmetad).

Following patches will use the enabled external device handle in
concrete filters from the composite filter...
2015-01-30 13:01:12 +01:00
Peter Rajnoha
8a843d0d97 filters: add "usable device" filter
Usable device filter is responsible for filtering out unusable DM devices.
The filter has 3 modes of operation:

  - FILTER_MODE_NO_LVMETAD:
    When this mode is used, we check DM device usability by looking:
      - whether device is empty
      - whether device is blocked
      - whether device is suspended (only on devices/ignore_suspended_devices=1)
      - whether device uses an error target
      - whether device name/uuid is reserved

  - FILTER_MODE_PRE_LVMETAD:
    When this mode is used, we check DM device usability by looking:
      - whether device is empty
      - whether device is suspended (only on devices/ignore_suspended_devices=1)
      - whether device uses an error target
      - whether device name/uuid is reserved

  - FILTER_MODE_POST_LVMETAD:
    When this mode is used, we check DM device usability by looking:
      - whether device is blocked
      - whether device is suspended (only on devices/ignore_suspended_devices=1)

These modes will be used by subsequent patch to create different
instances of this filter, depending on lvmetad use.
2014-09-30 13:11:58 +02:00
Alasdair G Kergon
80bcdb93ff filters: check for mpath before opening devs
Split out the partitioned device filter that needs to open the device
and move the multipath filter in front of it.

When a device is multipathed, sending I/O to the underlying paths may
cause problems, the most obvious being I/O errors visible to lvm if a
path is down.

Revert the incorrect <backtrace> messages added when a device doesn't
pass a filter.

Log each filter initialisation to show sequence.

Avoid duplicate 'Using $device' debug messages.
2013-08-13 23:26:58 +01:00
Peter Rajnoha
c6f48b7c1a refactor: make device type recognition code common for general use
Changes:

- move device type registration out of "type filter" (filter.c)
to a separate and new dev-type.[ch] for common use throughout the code

- the structure for keeping the major numbers detected for available
device types and available partitioning available is stored in
"dev_types" structure now

- move common partitioning detection code to dev-type.[ch] as well
together with other device-related functions bound to dev_types
(see dev-type.h for the interface)

The dev-type interface contains all common functions used to detect
subsystems/device types, signature/superblock recognition code,
type-specific device properties and other common device properties
(bound to dev_types), including partitioning support.

- add dev_types instance to cmd context as cmd->dev_types for common use

- use cmd->dev_types throughout as a central point for providing
information about device types
2013-06-12 12:08:56 +02:00
Zdenek Kabelac
0d3ce181e1 Better structure layout for device_info
Save some relocation entries and use directly char[].
Since we do not need yes more then 127 partitions per device, use just int8_t.
Move lvm_type_filter_destroy into local static function.
2012-03-12 14:40:41 +00:00
Milan Broz
07113beea3 Do not scan device if it is part of active multipath.
Add filter which tries to check if scanned device is part
of active multipath.

Firstly, only SCSI major number devices are handled in filter.

Then it checks if device has exactly one holder (in sysfs) and
if it is device-mapper device and DM-UUID is prefixed by "MPATH-".

If so, this device is filtered out.

The whole filter can be switched off by setting
mpath_component_detection in lvm.conf.

https://bugzilla.redhat.com/show_bug.cgi?id=597010

Signed-off-by: Milan Broz <mbroz@redhat.com>
2011-11-11 15:11:08 +00:00
Petr Rockai
e59e2f7c3c Move the core of the lib/config/config.c functionality into libdevmapper,
leaving behind the LVM-specific parts of the code (convenience wrappers that
handle `struct device` and `struct cmd_context`, basically). A number of
functions have been renamed (in addition to getting a dm_ prefix) -- namely,
all of the config interface now has a dm_config_ prefix.
2011-08-30 14:55:15 +00:00
Alasdair Kergon
9b95a5a939 Always pass unsuspended dm devices through persistent filter to other filters.
Move test for suspended dm devices ahead of other filters.
2010-07-02 02:09:57 +00:00
Milan Broz
4059d2219c Recognise DRBD device part and handle it similar to MD devices.
The DRBD uses underlying device so code should prefer top
device if duplicate is found.

Patch also introduce
        dev_subsystem_part_major and dev_subsytem_name
functions to easily handle all these replication susbystems
and not hardcode md_major call.

See https://bugzilla.redhat.com/show_bug.cgi?id=530881
for full problem description.
2009-10-27 17:00:44 +00:00
Mike Snitzer
3d37e976bf Fix pvcreate on a partition (regressed in 2.02.51).
Eliminate busy loop during pvcreate of a "normal" partition.
_md_sysfs_attribute_snprintf() would busy loop if the device it was
given was not a blkext-based MD partition.

Rather than being cute with a busy-loop prone 'goto check_md_major' in
_md_sysfs_attribute_snprintf(): explicitly check if the provided device
is a blkext-based partition (blkext_major()); and then check that the
get_primary_dev() determined parent is an MD device (md_major()).
2009-08-19 15:34:33 +00:00
Alasdair Kergon
be6845999b Fix inconsistent licence notices: executables are GPLv2; libraries LGPLv2.1. 2007-08-20 20:55:30 +00:00
Alasdair Kergon
352a99b95a Use dm_is_dm_major instead of local copy.
Allow mapped devices to be used as PVs safely.
2005-10-25 19:08:21 +00:00
Alasdair Kergon
68366c99b2 Add is_dm_major() for use in duplicate device detection in lvmcache_add(). 2005-09-16 18:53:01 +00:00
Alasdair Kergon
985ef4617f Detect partition table signature. 2004-11-23 11:44:04 +00:00
Alasdair Kergon
8bad033938 Fix device number handling for 2.6 kernels. 2004-07-01 15:14:29 +00:00
Alasdair Kergon
25579907fc Support tagged config files. 2004-05-04 18:28:15 +00:00
Alasdair Kergon
6606c3ae81 Update copyright notices. 2004-03-30 19:35:44 +00:00
Alasdair Kergon
b896caa19b Improve build robustness. 2003-04-15 13:24:42 +00:00
Alasdair Kergon
26e7f2e0c4 Tidy various pre-processing incl. making libdl optional. 2003-03-24 18:08:53 +00:00
Alasdair Kergon
a648372757 New devices/types config file entry to add new types of block devices. 2002-12-03 16:20:38 +00:00
Alasdair Kergon
25b733809a Merge with text format branch.
Lots of changes/very little testing so far => there'll be bugs!

Use 'vgcreate -M text' to create a volume group with its metadata stored
in text files.  Text format metadata changes should be reasonably atomic,
with a (basic) automatic recovery mechanism if the system crashes while a
change is in progress.

Add a metadata section to lvm.conf to specify multiple directories if
you want (recommended) to keep multiple copies of the metadata (eg on
different filesystems).

e.g. metadata {
        dirs = ["/etc/lvm/metadata1","/usr/local/lvm/metadata2"]
}

Plenty of refinements still in the pipeline.
2002-04-24 18:20:51 +00:00
Patrick Caulfield
c34d34e6a0 Fix prototype. 2002-04-08 13:35:09 +00:00
Alasdair Kergon
ba76e378e9 Ignore all except one PV found with the same UUID. Use one which
has the md major number if there is such.
2002-01-24 13:36:33 +00:00
Alasdair Kergon
20a2b71c9c filter integration into tools 2001-10-23 11:50:49 +00:00
Alasdair Kergon
28f5d16b4f Misc structural changes. 2001-10-01 19:36:06 +00:00