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437 Commits

Author SHA1 Message Date
Zdenek Kabelac
b2885b7103 activation: use cmd pending mem for pending_delete
Since we need to preserve allocated strings across 2 separate
activation calls of '_tree_action()' we need to use other mem
pool them dm->mem - but since cmd->mem is released between
individual lvm2 locking calls, we rather introduce a new separate
mem pool just for pending deletes with easy to see life-span.
(not using 'libmem' as it would basicaly keep allocations over
the whole lifetime of clvmd)

This patch is fixing previous commmit where the memory was
improperly used after pool release.
2019-08-27 15:54:42 +02:00
Zdenek Kabelac
7833c45fbe activation: extend handling of pending_delete
With previous patch 30a98e4d67 we
started to put devices one pending_delete list instead
of directly scheduling their removal.

However we have operations like 'snapshot merge' where we are
resuming device tree in 2 subsequent activation calls - so
1st such call will still have suspened devices and no chance
to push 'remove' ioctl.

Since we curently cannot easily solve this by doing just single
activation call (which would be preferred solution) - we introduce
a preservation of pending_delete via command structure and
then restore it on next activation call.

This way we keep to remove devices later - although it might be
not the best moment - this may need futher tunning.

Also we don't keep the list of operation in 1 trasaction
(unless we do verify udev symlinks) - this could probably
also make it more correct in terms of which 'remove' can
be combined we already running 'resume'.
2019-08-26 15:16:38 +02:00
David Teigland
0404539edb vgcreate/vgextend: restrict PVs with mixed block sizes
Avoid having PVs with different logical block sizes in the same VG.
This prevents LVs from having mixed block sizes, which can produce
file system errors.

The new config setting devices/allow_mixed_block_sizes (default 0)
can be changed to 1 to return to the unrestricted mode.
2019-08-01 10:06:47 -05:00
David Teigland
b4402bd821 exported vg handling
The exported VG checking/enforcement was scattered and
inconsistent.  This centralizes it and makes it consistent,
following the existing approach for foreign and shared
VGs/PVs, which are very similar to exported VGs/PVs.

The access policy that now applies to foreign/shared/exported
VGs/PVs, is that if a foreign/shared/exported VG/PV is named
on the command line (i.e. explicitly requested by the user),
and the command is not permitted to operate on it because it
is foreign/shared/exported, then an access error is reported
and the command exits with an error.  But, if the command is
processing all VGs/PVs, and happens to come across a
foreign/shared/exported VG/PV (that is not explicitly named on
the command line), then the command silently skips it and does
not produce an error.

A command using tags or --select handles inaccessible VGs/PVs
the same way as a command processing all VGs/PVs, and will
not report/return errors if these inaccessible VGs/PVs exist.

The new policy fixes the exit codes on a somewhat random set of
commands that previously exited with an error if they were
looking at all VGs/PVs and an exported VG existed on the system.

There should be no change to which commands are allowed/disallowed
on exported VGs/PVs.

Certain LV commands (lvs/lvdisplay/lvscan) would previously not
display LVs from an exported VG (for unknown reasons).  This has
not changed.  The lvm fullreport command would previously report
info about an exported VG but not about the LVs in it.  This
has changed to include all info from the exported VG.
2019-06-25 15:39:08 -05:00
David Teigland
ab61a6d85d move wipe_outdated_pvs to vg_write
and implement it based on a device, not based
on a pv struct (which is not available when the
device is not a part of the vg.)

currently only the vgremove command wipes outdated
pvs until more advanced recovery is added in a
subsequent commit
2019-06-07 15:54:04 -05:00
David Teigland
db98a6e362 Additional MD component checking
If udev info is missing for a device, (which would indicate
if it's an MD component), then do an end-of-device read to
check if a PV is an MD component.  (This is skipped when
using hints since we already know devs in hints are good.)

A new config setting md_component_checks can be used to
disable the additional end-of-device MD checks, or to
always enable end-of-device MD checks.

When both hints and udev info are disabled/unavailable,
the end of PVs will now be scanned by default.  If md
devices with end-of-device superblocks are not being
used, the extra I/O overhead can be avoided by setting
md_component_checks="start".
2019-06-07 13:27:16 -05:00
David Teigland
2bcd43c683 lvmcache: remove unused_duplicate_devs list from cmd
Save the previous duplicate PVs in a global list instead
of a list on the cmd struct.  dmeventd reuses the cmd struct
for multiple commands, and the list entries between commands
were being freed (apparently), causing a segfault in dmeventd
when it tried to use items in cmd->unused_duplicate_devs
that had been saved there by the previous command.
2019-06-07 10:14:33 -05:00
David Teigland
c3e385c108 hints: skip hint flock if nolocking option is set 2019-04-29 13:01:15 -05:00
David Teigland
8c87dda195 locking: unify global lock for flock and lockd
There have been two file locks used to protect lvm
"global state": "ORPHANS" and "GLOBAL".

Commands that used the ORPHAN flock in exclusive mode:
  pvcreate, pvremove, vgcreate, vgextend, vgremove,
  vgcfgrestore

Commands that used the ORPHAN flock in shared mode:
  vgimportclone, pvs, pvscan, pvresize, pvmove,
  pvdisplay, pvchange, fullreport

Commands that used the GLOBAL flock in exclusive mode:
  pvchange, pvscan, vgimportclone, vgscan

Commands that used the GLOBAL flock in shared mode:
  pvscan --cache, pvs

The ORPHAN lock covers the important cases of serializing
the use of orphan PVs.  It also partially covers the
reporting of orphan PVs (although not correctly as
explained below.)

The GLOBAL lock doesn't seem to have a clear purpose
(it may have eroded over time.)

Neither lock correctly protects the VG namespace, or
orphan PV properties.

To simplify and correct these issues, the two separate
flocks are combined into the one GLOBAL flock, and this flock
is used from the locking sites that are in place for the
lvmlockd global lock.

The logic behind the lvmlockd (distributed) global lock is
that any command that changes "global state" needs to take
the global lock in ex mode.  Global state in lvm is: the list
of VG names, the set of orphan PVs, and any properties of
orphan PVs.  Reading this global state can use the global lock
in sh mode to ensure it doesn't change while being reported.

The locking of global state now looks like:

lockd_global()
  previously named lockd_gl(), acquires the distributed
  global lock through lvmlockd.  This is unchanged.
  It serializes distributed lvm commands that are changing
  global state.  This is a no-op when lvmlockd is not in use.

lockf_global()
  acquires an flock on a local file.  It serializes local lvm
  commands that are changing global state.

lock_global()
  first calls lockf_global() to acquire the local flock for
  global state, and if this succeeds, it calls lockd_global()
  to acquire the distributed lock for global state.

Replace instances of lockd_gl() with lock_global(), so that the
existing sites for lvmlockd global state locking are now also
used for local file locking of global state.  Remove the previous
file locking calls lock_vol(GLOBAL) and lock_vol(ORPHAN).

The following commands which change global state are now
serialized with the exclusive global flock:

pvchange (of orphan), pvresize (of orphan), pvcreate, pvremove,
vgcreate, vgextend, vgremove, vgreduce, vgrename,
vgcfgrestore, vgimportclone, vgmerge, vgsplit

Commands that use a shared flock to read global state (and will
be serialized against the prior list) are those that use
process_each functions that are based on processing a list of
all VG names, or all PVs.  The list of all VGs or all PVs is
global state and the shared lock prevents those lists from
changing while the command is processing them.

The ORPHAN lock previously attempted to produce an accurate
listing of orphan PVs, but it was only acquired at the end of
the command during the fake vg_read of the fake orphan vg.
This is not when orphan PVs were determined; they were
determined by elimination beforehand by processing all real
VGs, and subtracting the PVs in the real VGs from the list
of all PVs that had been identified during the initial scan.
This is fixed by holding the single global lock in shared mode
while processing all VGs to determine the list of orphan PVs.
2019-04-29 13:01:05 -05:00
David Teigland
c33770c02d lvmlockd: do not allow mirror LV to be activated shared
This reverts 518a8e8cfb
  "lvmlockd: activate mirror LVs in shared mode with cmirrord"

because while activating a mirror LV with cmirrord worked,
changes to the active cmirror did not work.
2019-04-04 13:21:38 -05:00
David Teigland
85e68a8333 lvextend: refresh shared LV remotely using dlm/corosync
When lvextend extends an LV that is active with a shared
lock, use this as a signal that other hosts may also have
the LV active, with gfs2 mounted, and should have the LV
refreshed to reflect the new size.  Use the libdlmcontrol
run api, which uses dlm_controld/corosync to run an
lvchange --refresh command on other cluster nodes.
2019-03-21 12:38:20 -05:00
David Teigland
dd8d083795 config: add new setting io_memory_size
which defines the amount of memory that lvm will allocate
for bcache.  Increasing this setting is required if it is
smaller than a single copy of VG metadata.
2019-03-04 11:36:21 -06:00
David Teigland
fb83719d7f logging: remove unused code
Incomplete bits of original code that's unused.
2019-02-28 10:30:54 -06:00
David Teigland
90149c303e logging: new config settings to specify debug fields
For users who do not want all of the fields included
in debug lines, let them specify in lvm.conf which
fields to include.  timestamp, command[pid], and
file:line fields can all be disabled.
2019-02-26 14:42:16 -06:00
David Teigland
9aea6ae956 logging: add command[pid] and timestamp to file and verbose output
Without this, the output from different commands in a single
log file could not be separated.

Change the default "indent" setting to 0 so that the default
debug output does not include variable spaces in the middle
of debug lines.
2019-02-26 10:03:44 -06:00
David Teigland
ebaaff3590 move init_use_aio
it doesn't make sense to call from init_logging
2019-01-16 11:45:53 -06:00
David Teigland
7b5abc3fb1 hints: fix hint flock when using lvm shell
also cmd->use_hints needs to be set for each shell command
2019-01-15 12:23:16 -06:00
David Teigland
6620dc9475 add device hints to reduce scanning
Save the list of PVs in /run/lvm/hints.  These hints
are used to reduce scanning in a number of commands
to only the PVs on the system, or only the PVs in a
requested VG (rather than all devices on the system.)
2019-01-15 10:23:47 -06:00
Zdenek Kabelac
701ecff0ff lvm: drop usage of dl library
Since lvm no longer supports any dlopen-able plugins
(which in practice was never really usable) drop linking
with -ldl.
2018-12-17 10:36:52 +01:00
David Teigland
3d2fd95af7 remove unused full filter
it's the same as cmd->filter
2018-12-04 14:06:46 -06:00
David Teigland
89c11a2b49 remove unused lvmetad filter 2018-12-04 12:44:43 -06:00
David Teigland
ca66d52032 io: use sync io if aio fails
io_setup() for aio may fail if a system has reached the
aio request limit.  In this case, fall back to using
sync io.  Also, lvm use of aio can be disabled entirely
with config setting global/use_aio=0.

The system limit for aio requests can be seen from
  /proc/sys/fs/aio-max-nr

The current usage of aio requests can be seen from
  /proc/sys/fs/aio-nr

The system limit for aio requests can be increased by
setting fs.aio-max-nr using sysctl.

Also add last-byte limit to the sync io code.
2018-11-20 09:13:20 -06:00
David Teigland
3ae5569570 Add dm-writecache support
dm-writecache is used like dm-cache with a standard LV
as the cache.

$ lvcreate -n main -L 128M -an foo /dev/loop0

$ lvcreate -n fast -L 32M -an foo /dev/pmem0

$ lvconvert --type writecache --cachepool fast foo/main

$ lvs -a foo -o+devices
  LV            VG  Attr       LSize   Origin        Devices
  [fast]        foo -wi-------  32.00m               /dev/pmem0(0)
  main          foo Cwi------- 128.00m [main_wcorig] main_wcorig(0)
  [main_wcorig] foo -wi------- 128.00m               /dev/loop0(0)

$ lvchange -ay foo/main

$ dmsetup table
foo-main_wcorig: 0 262144 linear 7:0 2048
foo-main: 0 262144 writecache p 253:4 253:3 4096 0
foo-fast: 0 65536 linear 259:0 2048

$ lvchange -an foo/main

$ lvconvert --splitcache foo/main

$ lvs -a foo -o+devices
  LV   VG  Attr       LSize   Devices
  fast foo -wi-------  32.00m /dev/pmem0(0)
  main foo -wi------- 128.00m /dev/loop0(0)
2018-11-06 14:18:41 -06:00
Zdenek Kabelac
13c49033ed cov: fix failing filter initialization
When persistent_filter_create() fails, the existing passed filter
should be preserved, so it could be properly deleted on
error path - so new pfilter is assigned instead.
2018-10-15 17:49:44 +02:00
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
8a66c81b9b lvconvert: restrict command matching for no option variant
The 'lvconvert LV' command def has caused multiple problems
for command matching because it matches the required options
of any lvconvert command.  Any lvconvert with incorrect options
ends up matching 'lvconvert LV', which then produces an error
about incorrect options being used for 'lvconvert LV'.  This
prevents suggestions from nearest-command partial command matches.

Add a special case for 'lvconvert LV' so that it won't be used
as a partial match for a command that has options specified.
2018-07-23 11:12:38 -05:00
David Teigland
117160b27e Remove lvmetad
Native disk scanning is now both reduced and
async/parallel, which makes it comparable in
performance (and often faster) when compared
to lvm using lvmetad.

Autoactivation now uses local temp files to record
online PVs, and no longer requires lvmetad.

There should be no apparent command-level change
in behavior.
2018-07-11 11:26:42 -05:00
Zdenek Kabelac
a8f84f7801 vdo: introduce segment types and manip functions
Core functionality introducing lvm VDO support.
2018-07-09 15:28:35 +02:00
David Teigland
15826214f9 Remove code for using files as devices
It appears this has not been used in a long time,
and it seems to have no point since loop devices exist.
2018-06-21 09:33:21 -05:00
David Teigland
428514a07f Drop --ignoreskippedcluster option
It's no longer needed.  Clustered VGs are now handled in
the same way as foreign VGs, and as shared VGs that
can't be accessed:

- A command processing all VGs sees a clustered VG,
  prints a message ("Skipping clustered VG foo."),
  skips it, and does not fail.

- A command where the clustered VG is explicitly
  named on the command line, prints a message and fails.
  "Cannot access clustered VG foo, see lvmlockd(8)."

The option is listed in the set of ignored options for
the commands that previously accepted it.  (Removing it
entirely would cause commands/scripts to fail if they
set it.)
2018-06-15 15:59:34 -05:00
David Teigland
328303d4d4 Remove unused device error counting 2018-06-15 14:04:39 -05:00
David Teigland
e53cfc6a88 lvmlockd: update method for changing clustered VG
The previous method for forcibly changing a clustered VG
to a local VG involved using -cn and locking_type 0.
Since those options are deprecated, replace it with
the same command used for other forced lock type changes:
vgchange --locktype none --lockopt force.
2018-06-13 15:30:28 -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
David Teigland
17f5572bc9 Remove independent metadata areas
in which metadata is stored in files on the local fs
instead of on PVs.
2018-06-13 12:25:19 -05:00
David Teigland
9df6f601e0 Remove code for loading other metadata formats
other formats are not used.
2018-06-13 12:03:42 -05:00
Joe Thornber
d5da55ed85 device_mapper: remove dbg_malloc.
I wrote dbg_malloc before we had valgrind.  These days there's just
no need.
2018-06-08 13:40:53 +01:00
David Teigland
e6bb780d24 Rework lock-override options and locking_type settings
The last commit related to this was incomplete:
  "Implement lock-override options without locking type"

This is further reworking and reduction of the locking.[ch]
layer which handled all clustering, but is now only used
for file locking.  The "locking types" that this layer
implemented were removed previously, leaving only the
standard file locking.  (Some cluster-related artifacts
remain to be cleared out later.)

Command options to override or modify locking behavior
are reimplemented here without using the locking types.
Also, deprecated locking_type values are recognized,
and implemented as if one of the equivalent override
options was set.

Options that override file locking are:

. --nolocking disables all file locking.

. --readonly grants read lock requests without actually
  taking a file lock, and refuses write lock requests.

. --ignorelockingfailure tries to set up file locks and
  uses them normally if possible.  When not possible, it
  behaves like --readonly, but allows activation.

. --sysinit is the same as ignorelockingfailure.

. global/metadata_read_only acquires actual read file
  locks, and refuses write lock requests.

(Some of these options could probably be deprecated
because they were added as workarounds to various
locking_type behaviors that are now deprecated.)

The locking_type setting now has one valid value: 1 which
refers to standard file locking.  Configs that contain
deprecated values are recognized and still work in
largely the same way:

. 0 disabled all locking, now implemented like --nolocking
  is set.  Allow the nolocking option in all commands.

. 1 is the normal file locking setting and is unchanged.

. 2 was for external locking which was not used, and
  reverts to normal file locking.

. 3 was for cluster/clvm.  This reverts to normal file
  locking, and prints messages about lvmlockd.

. 4 was equivalent to readonly, now implemented like
  --readonly is set.

. 5 disabled all locking, now implemented like
  --nolocking is set.
2018-06-07 16:47:15 -05:00
Heinz Mauelshagen
de66704253 segtype: add linear
Add linear segtype addressing FIXME in preparation
for linear <-> striped convenience conversion support
2018-06-05 16:23:18 +02:00
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
c016b573ee clvmd: separate saved_vg from vginfo
The clvmd saved_vg data is independent from the normal lvm
lvmcache vginfo data, so separate saved_vg from vginfo.
Normal lvm doesn't need to use save_vg at all, and in clvmd,
lvmcache changes on vginfo can be made without worrying
about unwanted effects on saved_vg.
2018-05-03 14:54:48 -05:00
David Teigland
977d0a3613 filters: increase MAX_FILTERS for new filter
The new signature filter was added without increasing this.
2018-05-02 14:10:30 -05:00
David Teigland
24e7745d7a devices: ignore lvm1 and pool devices 2018-05-01 15:18:47 -05:00
David Teigland
c1cd18f21e Remove lvm1 and pool disk formats
There are likely more bits of code that can be removed,
e.g. lvm1/pool-specific bits of code that were identified
using FMT flags.

The vgconvert command can likely be reduced further.

The lvm1-specific config settings should probably have
some other fields set for proper deprecation.
2018-04-30 16:55:02 -05:00
David Teigland
4670e9f698 skip some clvmd-specific code in common cases
This, or something like it, can probably be done
in many other places.
2018-04-25 16:40:08 -05:00
David Teigland
aee27dc7ba scan: skip device rescan in vg_read
For reporting commands (pvs,vgs,lvs,pvdisplay,vgdisplay,lvdisplay)
we do not need to repeat the label scan of devices in vg_read if
they all had matching metadata in the initial label scan.  The
data read by label scan can just be reused for the vg_read.
This cuts the amount of device i/o in half, from two reads of
each device to one.  We have to be careful to avoid repairing
the VG if we've skipped rescanning.  (The VG repair code is very
poor, and will be redone soon.)
2018-04-20 11:23:14 -05:00
David Teigland
c0973e70a5 dev_cache: clean up scan
Pull out all of the twisted logic and simply call dev_cache_scan
at the start of the command prior to label scan.
2018-04-20 11:22:48 -05:00
David Teigland
d9a77e8bb4 lvmcache: simplify metadata cache
The copy of VG metadata stored in lvmcache was not being used
in general.  It pretended to be a generic VG metadata cache,
but was not being used except for clvmd activation.  There
it was used to avoid reading from disk while devices were
suspended, i.e. in resume.

This removes the code that attempted to make this look
like a generic metadata cache, and replaces with with
something narrowly targetted to what it's actually used for.

This is a way of passing the VG from suspend to resume in
clvmd.  Since in the case of clvmd one caller can't simply
pass the same VG to both suspend and resume, suspend needs
to stash the VG somewhere that resume can grab it from.
(resume doesn't want to read it from disk since devices
are suspended.)  The lvmcache vginfo struct is used as a
convenient place to stash the VG to pass it from suspend
to resume, even though it isn't related to the lvmcache
or vginfo.  These suspended_vg* vginfo fields should
not be used or touched anywhere else, they are only to
be used for passing the VG data from suspend to resume
in clvmd.  The VG data being passed between suspend and
resume is never modified, and will only exist in the
brief period between suspend and resume in clvmd.

suspend has both old (current) and new (precommitted)
copies of the VG metadata.  It stashes both of these in
the vginfo prior to suspending devices.  When vg_commit
is successful, it sets a flag in vginfo as before,
signaling the transition from old to new metadata.

resume grabs the VG stashed by suspend.  If the vg_commit
happened, it grabs the new VG, and if the vg_commit didn't
happen it grabs the old VG.  The VG is then used to resume
LVs.

This isolates clvmd-specific code and usage from the
normal lvm vg_read code, making the code simpler and
the behavior easier to verify.

Sequence of operations:

- lv_suspend() has both vg_old and vg_new
  and stashes a copy of each onto the vginfo:
  lvmcache_save_suspended_vg(vg_old);
  lvmcache_save_suspended_vg(vg_new);

- vg_commit() happens, which causes all clvmd
  instances to call lvmcache_commit_metadata(vg).
  A flag is set in the vginfo indicating the
  transition from the old to new VG:
  vginfo->suspended_vg_committed = 1;

- lv_resume() needs either vg_old or vg_new
  to use in resuming LVs.  It doesn't want to
  read the VG from disk since devices are
  suspended, so it gets the VG stashed by
  lv_suspend:
  vg = lvmcache_get_suspended_vg(vgid);

If the vg_commit did not happen, suspended_vg_committed
will not be set, and in this case, lvmcache_get_suspended_vg()
will return the old VG instead of the new VG, and it will
resume LVs based on the old metadata.
2018-04-20 11:22:45 -05:00
David Teigland
e3e5beec74 lvmetad: use new label_scan for update from pvscan
Take advantage of the common implementation with aio
and reduced disk reads.
2018-04-20 11:22:43 -05:00
David Teigland
a7cb76ae94 scan: use bcache for label scan and vg read
New label_scan function populates bcache for each device
on the system.

The two read paths are updated to get data from bcache.

The bcache is not yet used for writing.  bcache blocks
for a device are invalidated when the device is written.
2018-04-20 11:19:24 -05:00
Joe Thornber
00f1b208a1 [io paths] Unpick agk's aio stuff 2018-04-20 11:03:58 -05:00
Zdenek Kabelac
55d83f9f6e mirror: block_on_error only with monitoring
When user configured lvm2 to NOT user monitoring, activated mirror
actually hang upon error and it's quite unusable moment.

So instead Warn those 'brave' non-monitoring users about possible
problem and activation mirror without blocking error handling.

This also makes it a bit simpler for test suite to handle trouble
cases when test is running without  dmeventd.
2018-04-20 12:13:51 +02:00
Zdenek Kabelac
112846ce0b activation: support activation of component LVs
Occasionaly users may need to peek into 'component devices.
Normally lvm2 does not let users activation component.

This patch adds special mode where user can activate
component LV in a 'read-only' mode i.e.:

lvchange -ay vg/pool_tdata

All devices can be deactivated with:

lvchange -an vg  |  vgchange -an....
2018-03-06 15:42:46 +01:00
Zdenek Kabelac
12fba201be cleanup: detect dmeventd_executable just once
Avoid repeating debug messages about dmeventd executable
and just remember it once for whole cmd lifetime.
2018-02-12 22:14:25 +01:00
Zdenek Kabelac
afdbb28f72 toolcontext: light context missed to set-up mem mempool
If cmd->mem was null, then systemd generator was failing on:

(gdb) bt
dm_pool_alloc_aligned (p=0x0, s=96, alignment=8) at mm/pool-fast.c:95
dm_pool_alloc (p=0x0, s=96) at mm/pool-fast.c:90
dm_pool_zalloc (p=0x0, s=96) at mm/pool.c:74
config_file_read_fd (mem=0x0, cft=0x55f4339dbad0, dev=0x55f4339dfac0, reason=DEV_IO_MDA_CONTENT, offset=0, size=82293, offset2=0, size2=0,
    checksum_fn=0x0, checksum=0, checksum_only=0, no_dup_node_check=0, ioflags=0, config_file_read_fd_callback=0x0, config_file_read_fd_context=0x0) at config/config.c:567
config_file_read (mem=0x0, cft=0x55f4339dbad0) at config/config.c:658
config_file_open_and_read (config_file=0x7f49aef14540 <config_file> "/var/tmp/lvm/etc/lvm/lvm.conf", source=CONFIG_FILE, cmd=0x55f4339d6260)
    at config/config.c:282
_load_config_file (cmd=0x55f4339d6260, tag=0x7f49aeca15da "", local=0) at commands/toolcontext.c:824
_init_lvm_conf (cmd=0x55f4339d6260) at commands/toolcontext.c:853
create_config_context () at commands/toolcontext.c:1814
lvm_config_find_bool (libh=0x0, config_path=0x55f431a884ad "global/use_lvmetad", fail=0) at lvm_base.c:144
main ()
2018-02-12 22:13:53 +01:00
Zdenek Kabelac
83258e3385 toolcontext: do not change stream for pthreaded programs
With pthreaded daemons like 'dmeventd' using  liblvm via plugin,
lvm2 actually should not 'play' with streams at all - as there
could be parallel outputs running.

As a current quick workaround just disable change for pthreaded
program (gettid() != getpid()).

TODO: it's possible the change of buffering actually doesn't serve us
any measurable benefit and could be dropped as whole later...

Meanwhile this patch is fixing this occasional valgrind race report:

Invalid read of size 4
   at 0x571892C: vfprintf (in /usr/lib64/libc-2.26.9000.so)
   by 0x57216B3: fprintf (in /usr/lib64/libc-2.26.9000.so)
   by 0x5042886: dm_event_log (libdevmapper-event.c:925)
   by 0x10B015: _dmeventd_log (dmeventd.c:125)
   by 0x10D289: _unregister_for_event (dmeventd.c:1146)
   by 0x10E52E: _handle_request (dmeventd.c:1583)
   by 0x10E6D7: _do_process_request (dmeventd.c:1631)
   by 0x10E7C6: _process_request (dmeventd.c:1660)
   by 0x1101A4: main (dmeventd.c:2285)
 Address 0x6264d30 is 192 bytes inside a block of size 552 free'd
   at 0x4C2ED68: free (vg_replace_malloc.c:530)
   by 0x573907D: fclose@@GLIBC_2.2.5 (in /usr/lib64/libc-2.26.9000.so)
   by 0x6AC5C00: reopen_standard_stream (log.c:189)
   by 0x6A8E62C: destroy_toolcontext (toolcontext.c:2271)
   by 0x6BA5C22: lvm_fin (lvmcmdline.c:3339)
   by 0x6BD5EF3: lvm2_exit (lvmcmdlib.c:123)
   by 0x6856013: dmeventd_lvm2_exit (dmeventd_lvm.c:103)
   by 0x66535B8: unregister_device (dmeventd_thin.c:432)
   by 0x10CBBC: _do_unregister_device (dmeventd.c:926)
   by 0x10CD74: _monitor_unregister (dmeventd.c:979)
   by 0x10D094: _monitor_thread (dmeventd.c:1066)
   by 0x54B35E0: start_thread (in /usr/lib64/libpthread-2.26.9000.so)
   by 0x57C30EE: clone (in /usr/lib64/libc-2.26.9000.so)
 Block was alloc'd at
   at 0x4C2DBBB: malloc (vg_replace_malloc.c:299)
   by 0x573932B: fdopen@@GLIBC_2.2.5 (in /usr/lib64/libc-2.26.9000.so)
   by 0x6AC5DC2: reopen_standard_stream (log.c:200)
   by 0x6A8D11D: create_toolcontext (toolcontext.c:1898)
   by 0x6BA5B6B: init_lvm (lvmcmdline.c:3319)
   by 0x6BD5BC8: cmdlib_lvm2_init (lvmcmdlib.c:34)
   by 0x6BD5F04: lvm2_init (lvm2cmd.c:20)
   by 0x6855EA7: dmeventd_lvm2_init (dmeventd_lvm.c:67)
   by 0x665305F: register_device (dmeventd_thin.c:352)
   by 0x10CB7A: _do_register_device (dmeventd.c:916)
   by 0x10CEE4: _monitor_thread (dmeventd.c:1006)
   by 0x54B35E0: start_thread (in /usr/lib64/libpthread-2.26.9000.so)
   by 0x57C30EE: clone (in /usr/lib64/libc-2.26.9000.so)
....
Process terminating with default action of signal 6 (SIGABRT): dumping core
   at 0x570016B: raise (in /usr/lib64/libc-2.26.9000.so)
   by 0x5701520: abort (in /usr/lib64/libc-2.26.9000.so)
   by 0x57437D8: __libc_message (in /usr/lib64/libc-2.26.9000.so)
   by 0x5743831: __libc_fatal (in /usr/lib64/libc-2.26.9000.so)
   by 0x5744056: _IO_vtable_check (in /usr/lib64/libc-2.26.9000.so)
   by 0x574751C: __overflow (in /usr/lib64/libc-2.26.9000.so)
   by 0x574191A: fputc (in /usr/lib64/libc-2.26.9000.so)
   by 0x50428E3: dm_event_log (libdevmapper-event.c:934)
   by 0x10B015: _dmeventd_log (dmeventd.c:125)
   by 0x10D289: _unregister_for_event (dmeventd.c:1146)
   by 0x10E52E: _handle_request (dmeventd.c:1583)
   by 0x10E6D7: _do_process_request (dmeventd.c:1631)
   by 0x10E7C6: _process_request (dmeventd.c:1660)
   by 0x1101A4: main (dmeventd.c:2285)
2018-02-09 10:56:40 +01:00
Alasdair G Kergon
8c7bbcfb0f device: Basic config and setup to support async I/O. 2018-02-08 20:15:14 +00:00
Alasdair G Kergon
4b9806ab6f toolcontext: Add paired label_init to refresh_toolcontext.
label_init() and label_exit() should be paired.
2018-01-02 22:00:31 +00:00
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
Zdenek Kabelac
110dac870c cleanup: use existing define with prefix 2017-12-04 15:38:50 +01:00
Alasdair G Kergon
02e9876665 log: Add io debug class 2017-11-15 01:02:15 +00:00
Alasdair G Kergon
f1cc5b12fd tidy: Add missing underscores to statics. 2017-10-18 15:58:13 +01:00
David Teigland
6ac1e04b3a replicator: remove the code
It has not been used in a long time and is not
expected to be used further.
2017-10-13 16:20:42 -05:00
David Teigland
518a8e8cfb lvmlockd: activate mirror LVs in shared mode with cmirrord
Previously lvmlockd disallowed mirror LVs to be activated
in shared mode.
2017-09-20 09:55:34 -05:00
Alasdair G Kergon
3654f478e1 toolcontext: Improve invalid units error message. 2017-07-27 00:51:50 +01:00
David Teigland
013c080756 command struct: remove command name refs
Change run time access to the command_name struct
cmd->cname instead of indirectly through
cmd->command->cname. This removes the two run time
fields from struct command.
2017-02-13 08:20:10 -06:00
David Teigland
1e2420bca8 commands: new method for defining commands
. Define a prototype for every lvm command.
. Match every user command with one definition.
. Generate help text and man pages from them.

The new file command-lines.in defines a prototype for every
unique lvm command.  A unique lvm command is a unique
combination of: command name + required option args +
required positional args.  Each of these prototypes also
includes the optional option args and optional positional
args that the command will accept, a description, and a
unique string ID for the definition.  Any valid command
will match one of the prototypes.

Here's an example of the lvresize command definitions from
command-lines.in, there are three unique lvresize commands:

lvresize --size SizeMB LV
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync, --reportformat String, --resizefs,
--stripes Number, --stripesize SizeKB, --poolmetadatasize SizeMB
OP: PV ...
ID: lvresize_by_size
DESC: Resize an LV by a specified size.

lvresize LV PV ...
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync,
--reportformat String, --resizefs, --stripes Number, --stripesize SizeKB
ID: lvresize_by_pv
DESC: Resize an LV by specified PV extents.
FLAGS: SECONDARY_SYNTAX

lvresize --poolmetadatasize SizeMB LV_thinpool
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync,
--reportformat String, --stripes Number, --stripesize SizeKB
OP: PV ...
ID: lvresize_pool_metadata_by_size
DESC: Resize a pool metadata SubLV by a specified size.

The three commands have separate definitions because they have
different required parameters.  Required parameters are specified
on the first line of the definition.  Optional options are
listed after OO, and optional positional args are listed after OP.

This data is used to generate corresponding command definition
structures for lvm in command-lines.h.  usage/help output is also
auto generated, so it is always in sync with the definitions.

Every user-entered command is compared against the set of
command structures, and matched with one.  An error is
reported if an entered command does not have the required
parameters for any definition.  The closest match is printed
as a suggestion, and running lvresize --help will display
the usage for each possible lvresize command.

The prototype syntax used for help/man output includes
required --option and positional args on the first line,
and optional --option and positional args enclosed in [ ]
on subsequent lines.

  command_name <required_opt_args> <required_pos_args>
          [ <optional_opt_args> ]
          [ <optional_pos_args> ]

Command definitions that are not to be advertised/suggested
have the flag SECONDARY_SYNTAX.  These commands will not be
printed in the normal help output.

Man page prototypes are also generated from the same original
command definitions, and are always in sync with the code
and help text.

Very early in command execution, a matching command definition
is found.  lvm then knows the operation being done, and that
the provided args conform to the definition.  This will allow
lots of ad hoc checking/validation to be removed throughout
the code.

Each command definition can also be routed to a specific
function to implement it.  The function is associated with
an enum value for the command definition (generated from
the ID string.)  These per-command-definition implementation
functions have not yet been created, so all commands
currently fall back to the existing per-command-name
implementation functions.

Using per-command-definition functions will allow lots of
code to be removed which tries to figure out what the
command is meant to do.  This is currently based on ad hoc
and complicated option analysis.  When using the new
functions, what the command is doing is already known
from the associated command definition.
2017-02-13 08:20:10 -06:00
Zdenek Kabelac
ec93f37b86 toolcontext: action for LVM_RUN_BY_DMEVENTD env var
When LVM_RUN_BY_DMEVENTD is set to 1, ensure there will
be no interaction with dmeventd.
2017-01-23 14:55:47 +01:00
Zdenek Kabelac
4a7f2155c1 clean: move code to lib part
Move actual processing part of the lvm2_disable_dmeventd_monitoring()
into a /lib part so we can reuse the code later for other cases.
2017-01-23 14:55:28 +01:00
Zdenek Kabelac
1d58074d9f debug: more stacktrace corrections
Continue previous patch dropping some unneeded stack traces
after printed log_error/warn messages.
2016-11-25 14:58:28 +01:00
Zdenek Kabelac
d8fc4d093e conf: support zero for missing_stripe_filler
Make it easier to replace missing segments with 'zero' returning
target - otherwise user would have to create some extra target
to provide zeros as /dev/zero can't be used (not a block device).

Also break code loop when segment is found and make it an INTERNAL_ERROR
where it's missing.
2016-11-11 16:58:16 +01:00
Zdenek Kabelac
e54cce245f cleanup: skip checking for just assigned string
When 'stripe_filler' has been just set to 'error',
do not check it again for not being 'error'.
2016-11-11 16:52:24 +01:00
Peter Rajnoha
b5e093624d toolcontext: read all configuration sources when checking config values in lvm2-activation-generator through lighweight toolcontext handler
We added lightweight toolcontext handle to avoid useless initialization
of some parts of the context and also to avoid problems when using the
handle very soon at system boot, like in lvm2-activation-generator
through lvm2app interface. However, we missed reading all the other
config sources like lvmlocal.conf as well as any tag config - we need to
read these too to get the final config value which may be overriden in
any of these additional config sources.

Currently, we use this lightweight toolcontext handle to read
global/use_lvmetad and global/use_lvmpolld config values in
lvm2-activation-generator using lvm2app interface (lvm_config_find_bool
lvm2app function).
2016-09-23 14:57:44 +02:00
Peter Rajnoha
e8985c71bc config: add support for CFG_DISALLOW_INTERACTIVE flag to mark settings as not suitable for override in interactive mode
Some settings are not suitable for override in interactive/shell
mode because such settings may confuse the code and it may end
up with unexpected behaviour. This is because of the fact that
once we're in the interactive/shell mode, we have already applied
some settings for the shell itself and we can't override them
further because we're already using those settings to drive the
interactive/shell mode. Such settings would get ignored silently
or, in worse case, they would mess up the existing configuration.
2016-08-09 18:49:11 +02:00
Peter Rajnoha
f21afddeb7 lvm: shell: extend log report to cover whole lvm shell's main loop
When lvm commands are executed in lvm shell, we cover the whole lvm
command execution within this shell now. That means, all messages logged
and status caught during each command execution is now recorded in the
log report, including overall command's return code.
2016-08-09 18:49:10 +02:00
Peter Rajnoha
1fde4bf4d0 refactor: move report grouping and log reporting handles from processing_handle to cmd_context
With patches that will follow, this will make it possible to widen log
report coverage when commands are executed from lvm shell so the amount
of messages that may end up in stderr/stdout instead of log report are
minimized.
2016-08-09 18:24:45 +02:00
Peter Rajnoha
06ce9b4e42 log: separate output and make it possible to use given FDs
Currently, the output is separated in 3 parts and each part can go into
a separate and user-defined file descriptor:

  - common output (stdout by default, customizable by LVM_OUT_FD environment variable)
  - error output (stderr by default, customizable by LVM_ERR_FD environment variable)
  - report output (stdout by default, customizable by LVM_REPORT_FD environment variable)

For example, each type of output goes to different output file:

  [0] fedora/~ # export LVM_REPORT_FD=3

  [0] fedora/~ # lvs fedora vg/abc 1>out 2>err 3>report

  [0] fedora/~ # cat out

  [0] fedora/~ # cat err
    Volume group "vg" not found
    Cannot process volume group vg

  [0] fedora/~ # cat report
    LV   VG     Attr       LSize   Layout     Role       CTime
    root fedora -wi-ao----  19.00g linear     public     Wed May 27 2015 08:09:21
    swap fedora -wi-ao---- 500.00m linear     public     Wed May 27 2015 08:09:21

Another example in LVM shell where the report goes to "report" file:

  [0] fedora/~ # export LVM_REPORT_FD=3
  [0] fedora/~ # lvm 3>report

  (in lvm shell)
  lvm> vgs

  (content of "report" file)
  [1] fedora/~ # cat report
    VG     #PV #LV #SN Attr   VSize  VFree
    fedora   1   2   0 wz--n- 19.49g    0

  (in lvm shell)
  lvm> lvs

  (content of "report" file)
  [1] fedora/~ # cat report
    VG     #PV #LV #SN Attr   VSize  VFree
    fedora   1   2   0 wz--n- 19.49g    0
    LV   VG     Attr       LSize   Layout     Role       CTime
    root fedora -wi-ao----  19.00g linear     public     Wed May 27 2015 08:09:21
    swap fedora -wi-ao---- 500.00m linear     public     Wed May 27 2015 08:09:21
2016-08-09 18:24:45 +02:00
Peter Rajnoha
751163a743 libdm: log: remove log_print_bypass_report calls and register new print_log_libdm for libdm during lvm initialization instead
This fixes commit f50d4011cd which
introduced a problem when using older lvm2 code with newer libdm.
In this case, the old LVM didn't recognize new _LOG_BYPASS_REPORT flag
that libdm-report code used. This ended up with no output at all
from libdm where log_print_bypass_report was called because the
_LOG_BYPASS_REPORT was not masked properly in lvm2's print_log fn
which was called as callback function for logging.

With this patch, the lvm2 registers separate print_log_libdm logging
function for libdm instead. The print_log_libdm is exactly the same
as print_log (used throughout lvm2 code) but it checks whether we're
printing common line on output where "common" means not going to stderr,
not a warning and not an error and if we are, it adds the
_LOG_BYPASS_REPORT flag so the log_print goes directly to output, not
to any log report.

So this achieves the same goal as in f50d4011cd,
just doing it in a way that newer libdm is still compatible with older
lvm2 code (libdm-report is the only code using log_print).

Looking at the opposite mixture - older libdm with newer lvm2 code,
that won't be compilable because the new log report functionality
that is in lvm2 also requires new dm_report_group_* libdm functions
so we don't need to care here.
2016-06-23 14:45:52 +02:00
Peter Rajnoha
79eaaee50a filters: add comments about internal filter position in filter chain 2016-06-23 09:37:51 +02:00
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
Peter Rajnoha
89e2aef63a tools: add 'lvm lastlog' command for interactive query and display of last command's log
If we're running in lvm shell, we can keep last command's log report
for further query with possible different selection criteria for easy
log lookup.
2016-06-20 11:33:43 +02:00
Peter Rajnoha
c33c0545af refactor: move 'interactive' field from struct command_line to struct cmd_context as 'is_interactive' switch 2016-06-20 11:33:43 +02:00
David Teigland
199b7b55c2 lvmcache: fix duplicate handling with multiple scans
Some commands scan labels to populate lvmcache multiple
times, i.e. lvmcache_init, scan labels to fill lvmcache,
lvmcache_destroy, then later repeat

Each time labels are scanned, duplicates are detected,
and preferred devices are chosen.  Each time this is done
within a single command, we want to choose the same
preferred devices.  So, check for existing preferences
when choosing preferred devices.

This also fixes a problem with the list of unused duplicate
devs when run in an lvm shell.  The devs had been allocated
from cmd memory, resulting in invalid list entries between
commands.
2016-06-07 15:15:51 -05:00
David Teigland
7fd4119d24 liblvm: allow config settings to be read without full lvm cmd
A program may be using liblvm2app for simply checking a config
setting in lvm.conf.  In this case, a full lvm context is not
needed, only cmd->cft (which are the config settings read from
lvm.conf).

lvm_config_find_bool() can now be passed a NULL lvm context
in which case it will only create cmd->cft, check the config
setting asked for, and destroy the cmd.
2016-05-18 09:04:25 -05:00
David Teigland
87d9406725 lib: fix init error handling
When setting up a toolcontext, the lib init function
was detecting an error when there was none, and then
it was returning an incompletely initialized cmd struct
instead of NULL.  The effect was that the lib would try
to use the uninitialized cmd struct and segfault.
This would happen if a non-fatal error occurred during
cmd setup, e.g. user permission failed on lvmetad socket,
causing cmd to fall back to scanning and not use lvmetad.

The only real error condition is when create_toolcontext
returns NULL.  If cmd is returned, the lib can use it.
2016-05-12 13:07:52 -05:00
David Teigland
1134ab6324 lvmetad: warn about making changes while not using lvmetad
If lvmetad is running, and a command opts to not use it
(--config global/use_lvmetad=0), and the command changes
metadata, then the metadata change is not visible to
lvmetad.  Subsequent commands using lvmetad to change
metadata may cause corruption based on the invalid
lvmetad state.

Eventually we can set the disabled state in lvmetad
to prevent this problem, but for now print a warning
about the possibility.
2016-04-21 10:28:01 -05:00
David Teigland
e44c4806db lvmetad: check pid for warning case
When command is not using lvmetad because
use_lvmetad=0 in the config, but the lvmetad
pidfile exists, print a warning (previously
this checked for the socket existing instead
of the pidfile existing.)
2016-04-21 09:50:59 -05:00
David Teigland
5e9e43074a lvmetad: rework command connection setup and checking
The lvmetad connection is created within the
init_connections() path during command startup,
rather than via the old lvmetad_active() check.

The old lvmetad_active() checks are replaced
with lvmetad_used() which is a simple check that
tests if the command is using/connected to lvmetad.

The old lvmetad_set_active(cmd, 0) calls, which
stopped the command from using lvmetad (to revert to
disk scanning), are replaced with lvmetad_make_unused(cmd).
2016-04-19 14:00:02 -05:00
David Teigland
2d5dc6512e dbus: add notification from commands
When a command modifies a PV or VG, or changes the
activation state of an LV, it will send a dbus
notification when the command is finished.  This
can be enabled/disabled with a config setting.
2016-03-07 10:06:09 -06:00
Peter Rajnoha
9a34de9cb9 cmd: add 'nohistory' option and wire it up in cmd_context
The --nohistory switch will cause historical LVs to not be recorded
in metadata on demand.
2016-03-03 13:49:15 +01:00
Peter Rajnoha
f7e0a4cc18 cmd: add '-H|--history' switch and wire it up in cmd_context and processing_handle
This patch adds "include_historical_lvs" field to struct cmd_context to
make it possible for the command to switch between original funcionality
where no historical LVs are processed and functionality where historical
LVs are taken into account (and reported or processed further). The switch
between these modes is done using the '-H|--history' switch on command
line.

The include_historical_lvs state is then passed to process_each_* fns
using the "include_historical_lvs" field within struct processing_handle.
2016-03-03 13:49:14 +01:00
David Teigland
57cd94b9e3 pvs: replace 'unknown device' with [unknown]
A config setting can restore the old string.
2016-03-01 11:12:03 -06:00
M.H. Tsai
3b76e9fd98 config: fix verbose type to int
'verbose' was marked as a boolean option while it
takes integer args - so it has limited usage to 0 or 1,
but we supported 0-4 at least.

Fix it by switching to corrent int type.
(Hopefully noone was trying to use this variable as true/yes/false/no
way - as the would be unsupported/undocumented).
2016-02-11 18:30:39 +01:00
Peter Rajnoha
136fd8f2f6 conf: add metadata/check_pv_device_sizes 2016-01-22 14:16:00 +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
1417ed304b cleanup: rename 'invisible devices' to 'hidden devices' 2016-01-13 15:22:46 +01:00
Peter Rajnoha
e168b5de75 conf: add report/mark_invisible_devices 2016-01-13 12:01:10 +01:00
Zdenek Kabelac
45e749493c cleanup: ensuring string is not NULL
Coverity cannot see the string cannot be NULL so make it explicit.
2015-11-09 17:04:10 +01:00
Zdenek Kabelac
72d700b064 toolcontext: do not change already set dm_log
If the dm_log is already set to non-default logger,
avoid to change it.
2015-10-13 14:39:37 +02:00
Peter Rajnoha
b77497cbd8 filters: make sure regex filter is evaluated before any filter that needs disk access
The regex filter (controlled by devices/filter lvm.conf setting) was
evaluated as the very last filter. However, this is not optimal when
it comes to restricting disk access - users define devices/filter
as well as devices/global_filter to avoid this.

The devices/global_filter is already positioned at the beginning of the
filter chain. We need to do the same for devices/filter.

Filter chains before this patch:

  A: when lvmetad is not used:
       persistent_filter -> sysfs_filter -> global_regex_filter ->
       type_filter -> usable->filter -> mpath_component_filter ->
       partition_filter -> md_component_filter -> fw_raid_filter ->
       regex_filter

  B: when lvmetad is used:

    B1: to update lvmetad:
      sysfs_filter -> global_regex_filter -> type_filter ->
      usable_filter -> mpath_component_filter -> partition_filter ->
      md_component_filter -> fw_raid_filter

    B2: to retrieve info from lvmetad:
      persistent_filter -> usable_filter -> regex_filter

From the chain list above we can see that particularly in case when
lvmetad is not used, the regex filter is the very last one that is
processed. If lvmetad is used, it doesn't matter much as there's
the global_regex_filter which is used instead when updating lvmetad
and when retrieving info from lvmetad, putting regex_filter in front
of usable_filter wouldn't change much since usabled_filter is not
reading disks directly.

This patch puts the regex filter to the front even in case lvmetad
is not used, hence reinstating the state as it was before commit
a7be3b12df (which moved the regex_filter
position in the chain). Still, the arguments for the commit
a7be3b12df still apply and they're
still satisfied since component filters (MD, mpath...) are evaluated
first just before updating lvmetad.

So with this patch, we end up with:

  A: when lvmetad is not used:
       persistent_filter -> sysfs_filter -> global_regex_filter ->
       regex_filter -> type_filter -> usable->filter ->
       mpath_component_filter -> partition_filter ->
       md_component_filter -> fw_raid_filter

  B: when lvmetad is used:

    B1: to update lvmetad:
      sysfs_filter -> global_regex_filter -> type_filter ->
      usable_filter -> mpath_component_filter -> partition_filter ->
      md_component_filter -> fw_raid_filter

    B2: to retrieve info from lvmetad:
      persistent_filter -> regex_filter -> usable_filter

This way, specifying the regex_filter in non-lvmetad case causes
the devices to be filtered based on regex first before processing
any other filters which can access disks (like md_component_filter).

This patch also streamlines the code for better readability.
2015-09-08 15:28:10 +02:00