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35 Commits

Author SHA1 Message Date
David Teigland
96b777167c cov: clean up pvid and vgid usage
pvid and vgid are sometimes a null-terminated string, and
other times a 'struct id', and the two types were often
cast between each other.  When a struct id was cast to a char
pointer, the resulting string would not necessarily be null
terminated.  Casting a null-terminated string id to a
struct id is fine, but is still avoided when possible.

A struct id is:  int8_t uuid[ID_LEN]
A string id is:  char pvid[ID_LEN + 1]

A convention is introduced to help distinguish them:

- variables and struct fields named "pvid" or "vgid"
  should be null-terminated strings.

- variables and struct fields named "pv_id" or "vg_id"
  should be struct id's.

- examples:
  char pvid[ID_LEN + 1];
  char vgid[ID_LEN + 1];
  struct id pv_id;
  struct id vg_id;

Function names also attempt to follow this convention.

Avoid casting between the two types as much as possible,
with limited exceptions when known to be safe and clearly
commented.

Avoid using variations of strcpy and strcmp, and instead
use memcpy/memcmp with ID_LEN (with similar limited
exceptions possible.)
2021-08-16 11:31:15 -05:00
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
677833ce6f lvmcache: renaming functions and variables
related to duplicates, no functional changes.
2019-08-16 13:26:11 -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
01156de6f7 lvmcache: add optional dev arg to lvmcache_info_from_pvid
A number of places are working on a specific dev when they
call lvmcache_info_from_pvid() to look up an info struct
based on a pvid.  In those cases, pass the dev being used
to lvmcache_info_from_pvid().  When a dev is specified,
lvmcache_info_from_pvid() will verify that the cached
info it's using matches the dev being processed before
returning the info.  Calling code will not mistakenly
get info for the wrong dev when duplicate devs exist.

This confusion was happening when scanning labels when
duplicate devs existed.  label_read for the first dev
would add an info struct to lvmcache for that dev/pvid.
label_read for the second dev would see the pvid in
lvmcache from first dev, and mistakenly conclude that
the label_read from the second dev can be skipped
because it's already been done.  By verifying that the
dev for the cached pvid matches the dev being read,
this mismatch is avoided and the label is actually read
from the second duplicate.
2016-06-07 15:15:47 -05:00
David Teigland
d4e434d1e6 pvs: new attr and field for unchosen duplicate device
When there are duplicate devices for a PV, one device
is preferred and chosen to exist in the VG.  The other
devices are not used by lvm, but are displayed by pvs
with a new PV attr "d", indicating that they are
unchosen duplicate PVs.

The "duplicate" reporting field is set to "duplicate"
when the PV is an unchosen duplicate, and that field
is blank for the chosen PV.
2016-05-06 09:00:00 -05:00
Alasdair G Kergon
9898126596 report: Shift (u)sed pv_attr under (a)llocatable.
Showing 'u' in the pv_attr reporting field is mostly unnecessary because
most PVs are allocatable, and being allocatable implies it is (u)sed,
and this is already obvious from other fields in the default 'pvs'
output like the VG name.

So move the new (u)sed pv_attr from character position 4 to 1, and only
show it in those rare cases when the PV is not (a)llocatable or the
relevant metadata is missing.

(Scripts should not be using pv_attr, but rather pv_allocatable,
pv_exported, pv_missing, pv_in_use etc.)
2016-02-26 15:46:37 +00:00
Peter Rajnoha
45be3c875f pv: use pv->fmt to check for fake PVs, not pv->vg
pv->vg is not set yet during pvcreate processing. Use pv->fmt instead to
check for these fake PVs (all normal PVs have format defined, devices
which are not PVs don't have this set).

This fixes commit 0000db7f98.
2016-02-15 15:52:13 +01:00
Peter Rajnoha
0000db7f98 pv: mark fake PVs as not used
Some of the PVs are not even orphan PVs - they're fake PVs - this can
happen if we're listing all devices with "pvs -a". Such PV must not
be marked as used.
2016-02-15 14:46:31 +01:00
Peter Rajnoha
08de88535e report: identify used PVs in pv_attr field with 'u' char 2016-02-15 12:44:46 +01:00
Peter Rajnoha
4cbaaa5c98 pv: add is_used_pv fn 2016-02-15 12:44:46 +01:00
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
f01b7afa19 pv: add 'mem' arg for pv_uuid_dup and pv_name_dup 2015-09-21 14:21:42 +02:00
Zdenek Kabelac
506091be70 pv_vg_name: do not expose internal orphans to lvm2 users
Check for orphan VG name and return just empty string,
Use internally pv->vg_name if the real orphan name is needed.
2014-03-19 00:57:59 +01:00
Alasdair G Kergon
aa21e79991 pre-release 2014-01-20 19:22:56 +00:00
Alasdair G Kergon
5a450eab6a pvs: fix segfaults with orphans
Several fields used to display 0 if undefined.  Recent changes
to the way the fields are reported threw away some tests for
valid pointers, leading to segfaults with 'pvs -o all'.

Reinstate the original behaviour.
2014-01-14 03:17:27 +00:00
Petr Rockai
ecc296311f metadata: Do not throw an error in pv_label for missing PVs. 2013-11-17 22:35:16 +01:00
Petr Rockai
67c563ac2b pv_label: NULL result is not always an internal error. 2013-11-17 21:43:06 +01:00
Petr Rockai
dc3a071145 metadata: Add a pv_label accessor (go from a PV to its label). 2013-11-17 21:41:27 +01:00
Petr Rockai
a2034e9a99 metadata: Add lvmcache_info_mda_free as a companion to pv_mda_free. 2013-11-17 21:41:27 +01:00
Peter Rajnoha
732859d21f refactor: rename embedding area -> bootloader area 2013-05-28 12:37:22 +02:00
Peter Rajnoha
9dbe25709e pv_header_extension: add support for reading PV header extension (flags & Embedding Area)
New tools with PV header extension support will read the extension
if it exists and it's not an error if it does not exist (so old PVs
will still work seamlessly with new tools).

Old tools without PV header extension support will just ignore any
extension.

As for the Embedding Area location information (its start and size),
there are actually two places where this is stored:
  - PV header extension
  - VG metadata

The VG metadata contains a copy of what's written in the PV header
extension about the Embedding Area location (NULL value is not copied):

    physical_volumes {
        pv0 {
          id = "AkSSRf-difg-fCCZ-NjAN-qP49-1zzg-S0Fd4T"
          device = "/dev/sda"     # Hint only

          status = ["ALLOCATABLE"]
          flags = []
          dev_size = 262144       # 128 Megabytes
          pe_start = 67584
          pe_count = 23   # 92 Megabytes
          ea_start = 2048
          ea_size = 65536 # 32 Megabytes
        }
    }

The new metadata fields are "ea_start" and "ea_size".
This is mostly useful when restoring the PV by using existing
metadata backups (e.g. pvcreate --restorefile ...).

New tools does not require these two fields to exist in VG metadata,
they're not compulsory. Therefore, reading old VG metadata which doesn't
contain any Embedding Area information will not end up with any kind
of error but only a debug message that the ea_start and ea_size values
were not found.

Old tools just ignore these extra fields in VG metadata.
2013-02-26 11:27:23 +01:00
Peter Rajnoha
722ca363f0 report: fix pvs -o pv_free reporting for PVs with 0 PEs
[0] raw/~ # lsblk -o NAME,SIZE /dev/sda
NAME  SIZE
sda   128M

[0] raw/~ # pvcreate --dataalignment 128m /dev/sda
  Physical volume "/dev/sda" successfully created

[0] raw/~ # vgcreate vg /dev/sda
  Volume group "vg" successfully created

[0] raw/~ # lvcreate -l1 vg
  Volume group "vg" has insufficient free space (0 extents): 1 required.

Before this patch:
[0] raw/~ # pvs -o pv_name,pv_free
  PV         PFree
  /dev/sda   128.00m

After this patch:
[0] raw/~ # pvs -o pv_name,pv_free
  PV         PFree
  /dev/sda      0
2013-02-21 13:28:07 +01:00
Petr Rockai
8e5f7cf3dc Move lvmcache data structures behind an API (making the structures private to
lvmcache.c). No functional change.
2012-02-10 01:28:27 +00:00
Alasdair Kergon
1abaaab1bc Terminate pv_attr field correctly. (2.02.86) 2011-09-07 13:42:00 +00:00
Alasdair Kergon
e189a84f57 Append 'm' attribute to pv_attr for missing PVs. 2011-06-29 14:56:33 +00:00
Peter Rajnoha
9c0035c129 Fix metadata balance code to work with recent changes in metadata handling
interface (with the changes in format_instance).
2011-02-21 12:33:16 +00:00
Dave Wysochanski
0ca1492ca5 Fix copyright dates on new files lib/metadata/{lv|vg|pv}.[ch]. 2010-09-30 20:47:18 +00:00
Dave Wysochanski
b184f791d4 Add pv_name_dup() and pv_fmt_dup() helper functions. 2010-09-30 14:09:22 +00:00
Dave Wysochanski
1cd292af8f Add pv_mda_size, pv_mda_free, and pv_used functions, call from 'disp' functions. 2010-09-30 14:09:10 +00:00
Dave Wysochanski
c508945ca9 Add pv_tags_dup, vg_tags_dup, lv_tags_dup functions that call tags_format_and_copy. 2010-09-30 14:08:19 +00:00
Dave Wysochanski
254d672dcc Add pv_uuid_dup, vg_uuid_dup, and lv_uuid_dup, and call id_format_and_copy.
Add supporting functions for pv_uuid, vg_uuid, and lv_uuid.
Call new function id_format_and_copy.  Use 'const' where appropriate.
Add "_dup" suffix to indicate memory is being allocated.
Call {pv|vg|lv}_uuid_dup from lvm2app uuid functions.
2010-09-30 14:07:47 +00:00
Dave Wysochanski
4bbadbe1cf Simplify logic to create 'attr' strings.
This patch addresses code review request to simplify creation of 'attr'
strings.  The simplification is done in this separate patch to more
easily review and ensure the simplification is done without error.
2010-09-30 14:07:19 +00:00
Dave Wysochanski
14663348d0 Add {pv|vg|lv}_attr_dup() functions and refactor 'disp' functions.
Move the creating of the 'attr' strings into a common function so
they can be called from the 'disp' functions as well as the new
'get' property functions.
Add "_dup" suffix to indicate memory is allocated.
Refactor pvstatus_disp to take pv argument and call pv_attr_dup().
2010-09-30 13:52:55 +00:00
Dave Wysochanski
b88b638d6e Add lib/metadata/pv.[ch] new files.
Apparently git cvsexportcommit does not properly add new files
from a git commit.
2010-09-30 13:15:42 +00:00