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Commit Graph

3870 Commits

Author SHA1 Message Date
David Teigland
a61272a6f0 Revert "lvs: disable scanning optimization"
This reverts commit 7474440d3b.

lvs can use the scanning optimization again since it has
been changed in:
"scanning: optimize by checking text offset and checksum"
2019-11-26 16:52:28 -06:00
Heinz Mauelshagen
29db9c6325 lvcreate: ensure striped raid region size is at least stripe size
The kernel MD runtime requires region size to be larger than stripe size
on striped raid layouts, thus the dm-raid target's constructor rejects
such request.

This causes e.g. an 'lvcreate --type raid10 -i3 -I4096 -R2048 -n lv vg' to fail.

Avoid failing late in the kernel by enforcing region size to be
larger or equal to stripe size.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1698225
2019-11-26 22:31:58 +01:00
David Teigland
2037476008 pvcreate,pvremove: fix reacquiring global lock after prompt
When pvcreate/pvremove prompt the user, they first release
the global lock, then acquire it again after the prompt,
to avoid blocking other commands while waiting for a user
response.  This release/reacquire changes the locking
order with respect to the hints flock (and potentially other
locks).  So, to avoid deadlock, use a nonblocking request
when reacquiring the global lock.
2019-11-26 14:34:43 -06:00
David Teigland
7474440d3b lvs: disable scanning optimization
The scanning optimization can produce warnings from
'lvs' when run concurrently with commands modifying LVs,
so disable the optimization until it can be improved.

Without the scanning optimization, lvs will always
read all PVs twice:

1. read metadata from all PVs, saving it in memory
2. for each VG
3. lock VG
4. reread metadata from all PVs in VG, replacing metadata
   saved from step 1
5. run command on VG
6. unlock VG

The optimization would usually cause step 4 to be skipped,
and PVs would be read only once.

Running the command in step 5 using metadata that was not
read under the VG lock is usually fine, except for the
fact that lvs attempts to validate the metadata by comparing
it to current dm state.  If other commands are modifying dm
state while lvs is running, lvs may see differences between
metadata from step 1 and dm state checked during step 5,
and print warnings.

(A better fix may be to detect the concurrent change and
fall back to rereading metadata in step 4 only when needed.)
2019-11-19 10:56:12 -06:00
Zdenek Kabelac
9af1d63b4d cov: use zalloc
Instead of malloc() memset() -> zalloc()
2019-11-14 18:06:42 +01:00
Zdenek Kabelac
1f4968289c pvck: check result of dev_get_size
Don't use garbage value for later computations.
2019-11-14 18:06:42 +01:00
Zdenek Kabelac
d67ce9e140 cov: fix mem leaking buffer
Free allocated buffer on function's exit.
Also check for fwrite() results.
2019-11-14 18:06:42 +01:00
Zdenek Kabelac
0bad3977df cov: avoid passing NULL to strstr function
When 'str1' would be NULL, there is no point to run 2nd. strstr().
2019-11-14 18:06:42 +01:00
Zdenek Kabelac
153e55c20e cov: check for retvalue 2019-11-14 18:06:42 +01:00
Zdenek Kabelac
82e6b820b8 cov: check for NULL
Since we check for NULL pointers earlier we need
to be consistent across function - since the NULL
would applies across whole function.

When dropping 'mda' check - we are actually
already dereferencing it before - so it can't
be NULL at that places (and it's validated
before entering  _read_mda_header_and_metadata).
2019-11-14 18:06:42 +01:00
David Teigland
6a8bd0c509 lvmlockd: fix cachevol locking
When a cachevol LV is attached, have the LV keep it's lock
allocated.  The lock on the cachevol won't be used while
it's attached.  When the cachevol is split a new lock does
not need to be allocated.  (Applies to cachevol usage by
both dm-cache and dm-writecache.)
2019-10-25 14:08:59 -05:00
David Teigland
5706764885 improve command definition matching using type
When a user includes "--type foo" in a command, only
look at command definitions with matching type, as
opposed to using matching/mismatching --type as a
vote for/against a given command def.  This means a
command with --type foo will prioritize a command def
with --type foo over other command defs that have
more matching options but an unmatching type.  This
makes it more likely that a closely matching command
def will be recommended.
2019-10-22 09:35:10 -05:00
David Teigland
967e2decd2 vgchange: remove bogus option restriction
for -A with -a
2019-10-21 13:29:57 -05:00
Zdenek Kabelac
644186e920 gcc: all paths will set ret
Set success on common path.
Fixes random failure on writecache uncaching path.
2019-10-21 15:32:35 +02:00
Zdenek Kabelac
dd7629ea09 cache: use _cpool for used cache-pools
When LV gets cached and uses cache-pool - such cache-pool
will now get _cpool suffix automatically.

Thus 'Pool' column for cached LV will now show either _cvol
or _cpool LV.
2019-10-21 15:31:33 +02:00
Zdenek Kabelac
23f660cf98 cache: drop _cpool suffix from unused cache-pool
Drop _cpool prefix if present and cache-pool is going to be unused.
2019-10-21 12:14:15 +02:00
Zdenek Kabelac
a5f8e7a96c lvconvert: use new functions 2019-10-21 12:14:15 +02:00
David Teigland
5714c8c9cc pvck: dump metadata search
Improve the implementation of extracting all text metadata
copies from the metadata area.  Use this for the existing
metadata_all dump option.

Add a new metadata_search dump option which does not use
lvm headers to find metadata, but looks in standard
locations.  This is useful if headers are damaged and
can't be used to locate metadata.

Adding '-v' to metadata_all or metadata_search will add
the description and creation_time to the printed list of
metadata instances that are found.
2019-10-18 12:26:29 -05:00
Zdenek Kabelac
a255385e3a cachevol: move cvol rename
Move rename of CVOL after archive().
2019-10-17 13:03:50 +02:00
Zdenek Kabelac
dab4a2c893 cachevol: move flag setting after taking archive
Before 'archive()' is called, lvm2 must not touch/modify metadata.
So move setting  CACHE_VOL related flags past this point.

Also make sure reading of cache segtype always restores this
flag properly (even if compatible flag would be lost).
2019-10-17 13:03:50 +02:00
David Teigland
998e7b1075 writecache: add cvol suffix to attached cachevol
When an LV is used as a writecache cachevol, give
it the LV name a _cvol suffix.  Remove the suffix
when the cachevol is detached, restoring the
original LV name.
2019-10-15 16:03:34 -05:00
David Teigland
91ee025d5b cache: change cachevol flags for backward compat
A cachevol LV had the CACHE_VOL status flag in metadata,
and the cache LV using it had no new flag.  This caused
problems if the new metadata was used by an old version
of lvm.  An old version of lvm would have two problems
processing the new metadata:

. The old lvm would return an error when reading the VG
  metadata when it saw the unknown CACHE_VOL status flag.

. The old lvm would return an error when reading the VG
  metadata because it would not find an expected cache pool
  attached to the cache LV (since the cache LV had a
  cachevol attached instead.)

Change the use of flags:

. Change the CACHE_VOL flag to be a COMPATIBLE flag (instead
  of a STATUS flag) so that old versions will not fail when
  they see it.

. When a cache LV is using a cachevol, the cache LV gets
  a new SEGTYPE flag CACHE_USES_CACHEVOL.  This flag is
  appended to the segtype name, so that old lvm versions
  will fail to use the LV because of an unknown segtype,
  as opposed to failing to read the VG.
2019-10-15 09:05:52 -05:00
Zdenek Kabelac
201ffbd04a cachevol: use lv_cache_remove
Use same routine for dropping cache.
2019-10-14 15:20:25 +02:00
Zdenek Kabelac
8d8047883e cachevol: use writethrough for partial removal
Instead of using 'noflush' option, switch cache_mode into WRITETHROUGH
which does not require flushing, when user confirmed he does not
want flushing for WRITEBACK (because of (partially) missing caching PV)
2019-10-14 15:15:14 +02:00
Zdenek Kabelac
8a8e6ebba2 cachevol: rename converted LV to _cvol
When converting existing public LV to internally used
'CacheVol' LV - rename LV to LV_cvol.

When splitting CacheVol, remove _cvol suffix.
2019-10-14 15:15:12 +02:00
Zdenek Kabelac
f6d171ffe3 cachevol: wipe 'normal' device
For wiping we activate and clear 'regular' devices,
since in case of whole process interuption (i.e. kill -9)
we leave metadata & DM table and workable state all the time.
2019-10-14 15:14:46 +02:00
Zdenek Kabelac
ddaf2002c9 lvconvert: use struct initializer
Always good to keep rest of structure initilized with zeros.
2019-10-14 15:13:47 +02:00
Zdenek Kabelac
76a9a86fd3 lvconvert: fix return value when zeroing fails
Use correct error return code for fail path.
2019-10-14 15:13:33 +02:00
David Teigland
d6ffc99052 vgck: fix updatemetadata writing different descriptions
vgck --updatemetadata would write the same correct
metadata to good mdas, and then to bad mdas, but the
sequence of vg_write/vg_commit calls betwen good and
bad mdas could cause a different description field to
be generated for good/bad mdas. (The description field
describing the command was recently included in the
ondisk copy of the metadata text.)
2019-10-11 12:57:32 -05:00
David Teigland
fe16d296b0 pvmove: remove some cmirror related code
which is no longer used
2019-10-11 11:31:42 -05:00
David Teigland
7368cf8e7d pvck: handle PVs with zero metadata copies 2019-09-30 16:20:17 -05:00
David Teigland
0c23d3fc84 pvscan: use quick activation only with matching PV device names
When the PV device names in the VG metadata do not match the
current PV device names seen on the system, do not use the
optimized activation function (that avoids extra device scanning.)

When the device names do not match, it's a clue that there could
be duplicate PVs, in which case we want to scan all devicess to
find any duplicates and stop the activation if found.

This does not prevent autoactivating a VG from the incorrect
duplicate PV, because the incorrect duplicate may appear by itself
first.  At that point its duplicate PV does not exist to be seen.
(A future enhancement could use the WWID to strengthen this
detection.)
2019-09-30 11:38:10 -05:00
Zdenek Kabelac
5c0264d689 vdo: restore monitoring of vdo pool
Switch to -vpool layered name needs to monitor proper device.
2019-09-30 13:34:34 +02:00
David Teigland
9a8e6ad014 lvconvert: enable --uncache with dm-writecache cachevol
splitcache followed by an automatic lvremove of
the cachevol LV
2019-09-24 15:51:05 -05:00
David Teigland
76dd9b2b51 writecache: move code into new file
put writecache specific code in writecache_manip.c

should be no functional change
2019-09-24 15:51:05 -05:00
David Teigland
f27625f005 lvconvert: enable --uncache with dm-cache cachevol
splitcache followed by an automatic lvremove of
the cachevol LV
2019-09-24 15:50:58 -05:00
David Teigland
4464004362 lvconvert: separate splitcache and uncache functions
Reorg code so there are separate functions for splitcache
and uncache for both cachepool and cachevol.  Should be no
functional change.
2019-09-24 13:55:21 -05:00
David Teigland
4fe4c30e7a lvconvert: allow --cache shortcut for --type cache with cachevol 2019-09-23 14:21:09 -05:00
David Teigland
6f7d7089b4 writecache: use dm suffixes and lv attributes
- use internal CACHE_VOL flag on cachevol LV
- add suffixes to dm uuids for internal LVs
- display appropriate letters in the LV attr field
- display writecache's cachevol in lvs output
2019-09-20 14:08:51 -05:00
David Teigland
5d3bced5ea lvconvert: detaching cachevol with missing PVs
. For dm-cache in writethrough, always allow splitcache,
  whether the cache is missing PVs or not.

. For dm-cache in writeback, if the cache is missing PVs,
  allow splitcache with force and yes.

. For dm-writecache, if the cache is missing PVs,
  allow splitcache with force and yes.
2019-09-20 09:59:37 -05:00
David Teigland
b46dce0bad lvchange: allow activating cachevol 2019-09-20 09:59:37 -05:00
Zdenek Kabelac
6612d8dd5e vdo: enhance activation with layer -vpool
Enhance 'activation' experience for VDO pool to more closely match
what happens for thin-pools where we do use a 'fake' LV to keep pool
running even when no thinLVs are active. This gives user a choice
whether he want to keep thin-pool running (wihout possibly lenghty
activation/deactivation process)

As we do plan to support multple VDO LVs to be mapped into a single VDO,
we want to give user same experience and 'use-patter' as with thin-pools.

This patch gives option to activate VDO pool only without activating
VDO LV.

Also due to 'fake' layering LV we can protect usage of VDO pool from
command like 'mkfs' which do require exlusive access to the volume,
which is no longer possible.

Note: VDO pool contains 1024 initial sectors as 'empty' header - such
header is also exposed in layered LV (as read-only LV).
For blkid we are indentified as LV with UUID suffix - thus private DM
device of lvm2 - so we do not need to store any extra info in this
header space (aka zero is good enough).
2019-09-17 13:17:19 +02:00
Zdenek Kabelac
7612c21f55 lvconvert: improve validation thin and cache pool conversion
Limit convertible LVs to thin-pool and cache-pools.
Also fix return code on  interal error path to return ECMD_FAILED.
2019-09-17 13:13:49 +02:00
David Teigland
3e5e7fd6c9 pvscan: allow use of noudevsync option
When pvscan is used to activate a VG via an
asynchronous service (i.e. lvm2-pvscan), there
is no requirement that the command wait for
udev to create device nodes before returning.

It's possible that waiting for udev is slow
enough to cause the service running the command
to time out.  So, allow the --noudevsync option
to be given to pvscan to skip waiting for udev.

(This commit is not changing the lvm2-pvscan
service itself to use --noudevsync.)

Still unknown is whether there are any complex
LV activation cases in which lvm itself requires
access to a device node, in which case the udev
wait could be needed by lvm itself.

(When running an activation command directly
from the command line, it's generally expected
that the activated LVs are ready to use when
the command is finished, so lvm waits for
udev to finish creating the dev nodes.)
2019-09-10 09:47:33 -05:00
Heinz Mauelshagen
aae2e872b4 lvchange: add --resync help/manual text relative to 'R' attribute
Add information that --resync clears the 'R' attribute
on not initially synchronized mirror/RAID LVs.

Related: 1708299
2019-09-06 14:18:29 +02:00
David Teigland
25b58310e3 pvscan: avoid full scan for activation
When an online PV completed a VG, the standard
activation functions were used to activate the VG.
These functions use a full scan of all devs.
When many pvscans are run during startup and need
to activate many VGs, scanning all devs from all
the pvscans can take a long time.

Optimize VG activation in pvscan to scan only the
devs in the VG being activated.  This makes use of
the online file info that was used to determine
the VG was complete.

The downside of this approach is that pvscan activation
will not detect duplicate PVs and block activation,
where a normal activation command (which scans all
devices) would.
2019-09-03 10:11:16 -05:00
Zdenek Kabelac
4b1dcc2eeb lv_manip: add synchronizations
New udev in rawhide seems to be 'dropping' udev rule operations for devices
that are no longer existing - while this is 'probably' a bug - it's
revealing moments in lvm2 that likely should not run in a single
transaction and we should wait for a cookie before submitting more work.

TODO: it seem more 'error' paths should always include synchronization
before starting deactivating 'just activated' devices.
We should probably figure out some 'automatic' solution for this instead
of placing sync_local_dev_name() all over the place...
2019-08-26 15:32:19 +02:00
Zdenek Kabelac
0bdd6d6240 pvmove: add missing synchronization
Between 'resume' and 'remove' we need to wait for udev to synchronize,
otherwise udev may 'skip' resume event processing if the udev node
is already gone.
2019-08-20 12:44:39 +02:00
David Teigland
0534cd9cd4 pvscan: disable sleeping and retrying for udev
When systemd is running pvscans, udev may not be
entirely initialized, so the pvscan should not
sleep and retry waiting for udev info.
2019-08-16 14:41:26 -05:00
David Teigland
83261b79b5 pvscan cache: use lvmcache_label_scan
instead of the lower level label_scan.  The lvmcache wrapper
around label_scan checks for and eliminates more duplicate devs
and md components.
2019-08-16 13:26:12 -05:00
David Teigland
677833ce6f lvmcache: renaming functions and variables
related to duplicates, no functional changes.
2019-08-16 13:26:11 -05:00
David Teigland
65bcd16be2 md component detection addition in vg_read
Usually md components are eliminated in label scan and/or
duplicate resolution, but they could sometimes get into
the vg_read stage, where set_pv_devices compares the
device to the PV.

If set_pv_devices runs an md component check and finds
one, vg_read should eliminate the components.

In set_pv_devices, run an md component check always
if the PV is smaller than the device (this is not
very common.)  If the PV is larger than the device,
(more common), do the component check when the config
setting is "auto" (the default).
2019-08-16 13:24:34 -05:00
Zdenek Kabelac
cc4a92b13c cov: ensure cname exists before derefering it
Just make it clear to analyzers  cname can't be NULL.
TODO: maybe exclude NULL at front of the function...
2019-08-09 12:57:07 +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
7657313740 pvck: fix looping dump metadata_all
dump metadata_all wouldn't quit if the metadata wrapped.
2019-07-12 14:09:06 -05:00
David Teigland
4567c6a2b2 enable full md component detection at the right time
An active md device with an end superblock causes lvm to
enable full md component detection.  This was being done
within the filter loop instead of before, so the full
filtering of some devs could be missed.

Also incorporate the recently added config setting that
controls the md component detection.
2019-07-10 13:30:50 -05:00
David Teigland
b16abb3816 pvscan: fix PV online when device has a different size
Fix commit 7836e7aa1c
"pvscan: ignore device with incorrect size"

which caused pvscan to not consider a PV online (for purposes
of event based activation) if the PV and device sizes differed.

This helped to avoid mistaking MD components for PVs, and is
replaced by triggering an md component check when PV and device
sizes differ (which happens in set_pv_device).
2019-07-09 13:45:09 -05:00
Heinz Mauelshagen
1b63a219f4 lvconvert: allow --stripes/--stripesize in 'mirror' conversions
This allows the creation of a striped mirror leg(s) during upconvert
by adding lvconvert command line options --stripes/--stripesize
for 'mirror' to tools/command-lines.in.

In case multiple mirror legs are being added, all will have the
same requested striped layout.

Resolves: rhbz1720705
2019-07-08 19:32:17 +02:00
David Teigland
f938545687 cache: warn and prompt for writeback with cachevol
The cache repair utility does not yet work with a cachevol
(where metadata and data exist on the same LV.)  So, warn
and prompt if writeback is specified with a cachevol.
2019-07-02 11:03:03 -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
d16142f90f scanning: open devs rw when rescanning for write
When vg_read rescans devices with the intention of
writing the VG, the label rescan can open the devs
RW so they do not need to be closed and reopened
RW in dev_write_bytes.
2019-06-21 10:57:49 -05:00
David Teigland
82b137ef2f vgchange: don't fail monitor command if vg is exported
When monitoring, skip exported VGs without causing a command
failure.

The lvm2-monitor service runs 'vgchange --monitor y', so
any exported VG on the system would cause the service to
fail.
2019-06-20 15:59:36 -05:00
David Teigland
9f5e46965b fix man page generation
The man page generation for pvchange/lvchange/vgchange was
incorrect (leaving out some option listings) as a result of
commit e225bf5 "fix command definition for pvchange -a"
2019-06-14 09:26:08 -05:00
David Teigland
7eaa3adedf vgchange: change debug message level
A debug message was mistakely left visible.
2019-06-11 16:14:07 -05:00
David Teigland
4bb7d3da0e lvmcache: remove wrapper around lvmcache_get_vgnameids
This was left over from when there was an lvmetad
version of the function.
2019-06-11 14:10:14 -05:00
David Teigland
0f350ba890 remove unused trustcache option 2019-06-11 11:42:49 -05:00
David Teigland
e225bf59ff fix command definition for pvchange -a
The -a was being included in the set of "one or more"
options instead of an actual required option.  Even
though the cmd def was not implementing the restrictions
correctly, the command internally was.

Adjust the cmd def code which did not support a command
with some real required options and a set of "one or more"
options.
2019-06-10 13:43:20 -05:00
David Teigland
49b8846567 lvmcache: remove unused function
Drop lvmcache_fmt_from_vgname(), the way it was called made
it identical to the existing lvmcache_vginfo_from_vgname().
2019-06-10 10:38:32 -05:00
David Teigland
550536474f vgsplit: simplify vg creation
The way that this command now uses the global lock
followed by a label scan, it can simply check if the
new VG name exists, and if not lock it and create it.
2019-06-10 10:38:32 -05:00
David Teigland
a07cc8dbef reset cmd wipe_outdated_pvs
at the start of a command, which is needed in case the cmd
struct is reused.
2019-06-10 10:34:58 -05:00
David Teigland
36cbc6db24 locking: reset global_ex flag at end of cmd
These two flags may be not reset at the end of
the command when the unlock is implicit, which
is a problem if the cmd struct is reused.
Clear the flags in the general fin_locking.
2019-06-10 10:34:58 -05:00
David Teigland
ba7ff96faf improve reading and repairing vg metadata
The fact that vg repair is implemented as a part of vg read
has led to a messy and complicated implementation of vg_read,
and limited and uncontrolled repair capability.  This splits
read and repair apart.

Summary
-------

- take all kinds of various repairs out of vg_read
- vg_read no longer writes anything
- vg_read now simply reads and returns vg metadata
- vg_read ignores bad or old copies of metadata
- vg_read proceeds with a single good copy of metadata
- improve error checks and handling when reading
- keep track of bad (corrupt) copies of metadata in lvmcache
- keep track of old (seqno) copies of metadata in lvmcache
- keep track of outdated PVs in lvmcache
- vg_write will do basic repairs
- new command vgck --updatemetdata will do all repairs

Details
-------

- In scan, do not delete dev from lvmcache if reading/processing fails;
  the dev is still present, and removing it makes it look like the dev
  is not there.  Records are now kept about the problems with each PV
  so they be fixed/repaired in the appropriate places.

- In scan, record a bad mda on failure, and delete the mda from
  mda in use list so it will not be used by vg_read or vg_write,
  only by repair.

- In scan, succeed if any good mda on a device is found, instead of
  failing if any is bad.  The bad/old copies of metadata should not
  interfere with normal usage while good copies can be used.

- In scan, add a record of old mdas in lvmcache for later, do not repair
  them while reading, and do not let them prevent us from finding and
  using a good copy of metadata from elsewhere.  One result is that
  "inconsistent metadata" is no longer a read error, but instead a
  record in lvmcache that can be addressed separate from the read.

- Treat a dev with no good mdas like a dev with no mdas, which is an
  existing case we already handle.

- Don't use a fake vg "handle" for returning an error from vg_read,
  or the vg_read_error function for getting that error number;
  just return null if the vg cannot be read or used, and an error_flags
  arg with flags set for the specific kind of error (which can be used
  later for determining the kind of repair.)

- Saving an original copy of the vg metadata, for purposes of reverting
  a write, is now done explicitly in vg_read instead of being hidden in
  the vg_make_handle function.

- When a vg is not accessible due to "access restrictions" but is
  otherwise fine, return the vg through the new error_vg arg so that
  process_each_pv can skip the PVs in the VG while processing.
  (This is a temporary accomodation for the way process_each_pv
  tracks which devs have been looked at, and can be dropped later
  when process_each_pv implementation dev tracking is changed.)

- vg_read does not try to fix or recover a vg, but now just reads the
  metadata, checks access restrictions and returns it.
  (Checking access restrictions might be better done outside of vg_read,
   but this is a later improvement.)

- _vg_read now simply makes one attempt to read metadata from
  each mda, and uses the most recent copy to return to the caller
  in the form of a 'vg' struct.
  (bad mdas were excluded during the scan and are not retried)
  (old mdas were not excluded during scan and are retried here)

- vg_read uses _vg_read to get the latest copy of metadata from mdas,
  and then makes various checks against it to produce warnings,
  and to check if VG access is allowed (access restrictions include:
  writable, foreign, shared, clustered, missing pvs).

- Things that were previously silently/automatically written by vg_read
  that are now done by vg_write, based on the records made in lvmcache
  during the scan and read:
  . clearing the missing flag
  . updating old copies of metadata
  . clearing outdated pvs
  . updating pv header flags

- Bad/corrupt metadata are now repaired; they were not before.

Test changes
------------

- A read command no longer writes the VG to repair it, so add a write
  command to do a repair.
  (inconsistent-metadata, unlost-pv)

- When a missing PV is removed from a VG, and then the device is
  enabled again, vgck --updatemetadata is needed to clear the
  outdated PV before it can be used again, where it wasn't before.
  (lvconvert-repair-policy, lvconvert-repair-raid, lvconvert-repair,
   mirror-vgreduce-removemissing, pv-ext-flags, unlost-pv)

Reading bad/old metadata
------------------------

- "bad metadata": the mda_header or metadata text has invalid fields
  or can't be parsed by lvm.  This is a form of corruption that would
  not be caused by known failure scenarios.  A checksum error is
  typically included among the errors reported.

- "old metadata": a valid copy of the metadata that has a smaller seqno
  than other copies of the metadata.  This can happen if the device
  failed, or io failed, or lvm failed while commiting new metadata
  to all the metadata areas.  Old metadata on a PV that has been
  removed from the VG is the "outdated" case below.

When a VG has some PVs with bad/old metadata, lvm can simply ignore
the bad/old copies, and use a good copy.  This is why there are
multiple copies of the metadata -- so it's available even when some
of the copies cannot be used.  The bad/old copies do not have to be
repaired before the VG can be used (the repair can happen later.)

A PV with no good copies of the metadata simply falls back to being
treated like a PV with no mdas; a common and harmless configuration.

When bad/old metadata exists, lvm warns the user about it, and
suggests repairing it using a new metadata repair command.
Bad metadata in particular is something that users will want to
investigate and repair themselves, since it should not happen and
may indicate some other problem that needs to be fixed.

PVs with bad/old metadata are not the same as missing devices.
Missing devices will block various kinds of VG modification or
activation, but bad/old metadata will not.

Previously, lvm would attempt to repair bad/old metadata whenever
it was read.  This was unnecessary since lvm does not require every
copy of the metadata to be used.  It would also hide potential
problems that should be investigated by the user.  It was also
dangerous in cases where the VG was on shared storage.  The user
is now allowed to investigate potential problems and decide how
and when to repair them.

Repairing bad/old metadata
--------------------------

When label scan sees bad metadata in an mda, that mda is removed
from the lvmcache info->mdas list.  This means that vg_read will
skip it, and not attempt to read/process it again.  If it was
the only in-use mda on a PV, that PV is treated like a PV with
no mdas.  It also means that vg_write will also skip the bad mda,
and not attempt to write new metadata to it.  The only way to
repair bad metadata is with the metadata repair command.

When label scan sees old metadata in an mda, that mda is kept
in the lvmcache info->mdas list.  This means that vg_read will
read/process it again, and likely see the same mismatch with
the other copies of the metadata.  Like the label_scan, the
vg_read will simply ignore the old copy of the metadata and
use the latest copy.  If the command is modifying the vg
(e.g. lvcreate), then vg_write, which writes new metadata to
every mda on info->mdas, will write the new metadata to the
mda that had the old version.  If successful, this will resolve
the old metadata problem (without needing to run a metadata
repair command.)

Outdated PVs
------------

An outdated PV is a PV that has an old copy of VG metadata
that shows it is a member of the VG, but the latest copy of
the VG metadata does not include this PV.  This happens if
the PV is disconnected, vgreduce --removemissing is run to
remove the PV from the VG, then the PV is reconnected.
In this case, the outdated PV needs have its outdated metadata
removed and the PV used flag needs to be cleared.  This repair
will be done by the subsequent repair command.  It is also done
if vgremove is run on the VG.

MISSING PVs
-----------

When a device is missing, most commands will refuse to modify
the VG.  This is the simple case.  More complicated is when
a command is allowed to modify the VG while it is missing a
device.

When a VG is written while a device is missing for one of it's PVs,
the VG metadata is written to disk with the MISSING flag on the PV
with the missing device.  When the VG is next used, it is treated
as if the PV with the MISSING flag still has a missing device, even
if that device has reappeared.

If all LVs that were using a PV with the MISSING flag are removed
or repaired so that the MISSING PV is no longer used, then the
next time the VG metadata is written, the MISSING flag will be
dropped.

Alternative methods of clearing the MISSING flag are:

vgreduce --removemissing will remove PVs with missing devices,
or PVs with the MISSING flag where the device has reappeared.

vgextend --restoremissing will clear the MISSING flag on PVs
where the device has reappeared, allowing the VG to be used
normally.  This must be done with caution since the reappeared
device may have old data that is inconsistent with data on other PVs.

Bad mda repair
--------------

The new command:
vgck --updatemetadata VG

first uses vg_write to repair old metadata, and other basic
issues mentioned above (old metadata, outdated PVs, pv_header
flags, MISSING_PV flags).  It will also go further and repair
bad metadata:

. text metadata that has a bad checksum
. text metadata that is not parsable
. corrupt mda_header checksum and version fields

(To keep a clean diff, #if 0 is added around functions that
are replaced by new code.  These commented functions are
removed by the following commit.)
2019-06-07 15:54:04 -05:00
David Teigland
5dd32680b0 vgcfgbackup add error messages 2019-06-07 15:54:04 -05:00
David Teigland
47effdc025 vgck --updatemetadata is a new command
uses vg_write to correct more common or less severe issues,
and also adds the ability to repair some metadata corruption
that couldn't be handled previously.
2019-06-07 15:54:04 -05:00
David Teigland
89914a541f process_each_pv handle outdated pvs
process_each_pv should account for outdated pvs
in the list of all devices it is processing.
2019-06-07 15:54:04 -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
2b241eb1f6 pvck: use new dump routines for old output
Use the recently added dump routines to produce the
old/traditional pvck output, and remove the code that
had been used for that.

The validation/checking done by the new routines means
that new lines prefixed with CHECK are printed for
incorrect values.
2019-06-05 16:28:52 -05:00
David Teigland
bada89a224 pvck: dump metadata_all
This searches the entire metadata area for any
copy of the metadata and dumps it to file.
2019-06-05 12:25:34 -05:00
David Teigland
d18e491f68 pvck: dump headers and metadata
Add 'pvck --dump headers' to print all the
lvm ondisk structs.  Also checks the values
and prints any problems.

The previous dump metadata is also converted to
use these same routines, which do not depend on lvm
fully scanning/reading/processing the headers and
metadata on disk.  This makes it useful to get data in
cases where there is corruption that would otherwise
prevent the normal functions from working.
2019-06-03 15:13:32 -05:00
David Teigland
645dd27604 separate code for setting devices from metadata parsing
Pull the code that sets devs for PVs out of the metadata
parsing code and call it separately.
2019-05-23 11:57:38 -05:00
David Teigland
52586b1039 pvck: new dump option to extract metadata
The new command 'pvck --dump metadata PV' will extract
the current version of VG metadata from a PV for testing
and debugging.  --dump metadata_area extracts the entire
text metadata area.
2019-05-23 11:49:06 -05:00
David Teigland
6422b9ddc5 move the setting of use_full_md_check flag
from each command to one location in command init.
No functional change.
2019-05-21 11:51:58 -05:00
David Teigland
9f561f2206 pvscan: fix segfault in recent commit
commit aa75b31db5
  "pvscan: handle case of scanning PV without metadata last"

failed to recognize that an arg may be null in the case of
'pvscan --cache' (without -aay) which does not keep track
of complete VGs because it does not need to activate them.
2019-05-03 16:51:34 -05:00
David Teigland
3405ead1e0 pvs: remove unnecessary label scan
The scanning rework missed removing this instance of label scan.
It's no longer needed because of the way that label scan is always
run once from the start of the command.  This unnecessary scan
would be triggered by running 'pvs @tag'.
2019-05-03 16:16:29 -05:00
David Teigland
1e9e21a171 pvscan: don't record PV online after error reading metadata 2019-05-03 14:39:42 -05:00
Zdenek Kabelac
3c70ae1803 clean: avoid cleaning iterator on error path
Return error dirrectly instead of using 'out' code path.
2019-05-03 13:17:22 +02:00
David Teigland
d7054cd28a vgcreate: remove the lvmcache locking workaround
Recent cleanups and simplifications to lvmcache and locking
mean that the odd locking to workaround other issues is now
unnecessary.
2019-04-30 14:26:16 -05:00
David Teigland
366c1ac15b pvcreate: call label scan prior to pvcreate_each_device
and don't call it from inside pvcreate_each_device.
This avoids having to repeat it for users of
pvcreate_each_device (pvcreate/pvremove/vgcreate/vgextend.)
2019-04-30 14:10:27 -05:00
David Teigland
6d0f09f478 pvscan: remove fixme comment that is fixed
Remove the fixme comment describing the case that was
fixed by aa75b31db5
  "pvscan: handle case of scanning PV without metadata last"
2019-04-29 15:44:57 -05:00
David Teigland
c3e385c108 hints: skip hint flock if nolocking option is set 2019-04-29 13:01:15 -05:00
David Teigland
a519be8d4b remove retry for missed PVs in process_each_pv
This is no longer needed with the change to orphan
and global locks.
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
aa75b31db5 pvscan: handle case of scanning PV without metadata last
Handle the case where pvscan --cache -aay (with no dev args)
gets to the final PV, completing the VG, but that final PV does not
have VG metadata.  In this case, we need to use VG metadata from a
previously scanned PV in the same VG, which we saved for this
possibility.  Using this saved metadata, we can find which VG
this PVID belongs to, and then check if that VG is now complete,
and if so add the VG name to the list of complete VGs to be
autoactivated.
2019-04-15 11:27:49 -05:00
David Teigland
41ba2b568b tests: disable unworking pvscan case
and add corresponding fixme in the code
2019-04-12 15:40:38 -05:00
David Teigland
7836e7aa1c pvscan: ignore device with incorrect size
If a device looks like a PV, but its size does not
match the PV size in the metadata, then skip it for
purposes of autoactivation.  It's probably not wrong
device for the PV.
2019-04-05 16:44:00 -05:00
David Teigland
6f18186bfd pvscan: print more reasons for ignoring devices 2019-04-05 15:48:12 -05:00
David Teigland
f58a70c168 pvscan: don't print warning about lvmlockd not running
pvscan --cache ignores shared VGs, so it doesn't need to
consider lvmlockd, and shouldn't include a warning about it.
2019-04-05 14:04:42 -05:00
David Teigland
0ba316f102 pvscan: remove initialization case
In the past, the first 'pvscan --cache -aay dev' command
to run on the system would initialize the pvs_online dir
by scanning all devs and creating online files for all pvs
it found, and then autoactivating the VG (if complete) for
the named dev.  The idea was that the system may not have
been able to run pvscan commands for early devices, so the
first pvscan to run would need to "make up" for any devices
that had appeared previously, which the system was unable to
scan.  The problem or idea of making up for missed scans is
historical and should no longer be needed, so remove this
special init case.
2019-04-05 14:04:02 -05:00
David Teigland
6b89c0d4b7 pvscan: for init only autoactivate vg for named dev
When pvscan is run for the initialization case (the first
pvscan run on the system), it scans all devs and creates
online files for all PVs it finds.  Previously it would
then autoactivate every complete VG, but change this to
only autoactive the (complete) VG corresponding to the
named device arg(s).
2019-04-05 12:46:39 -05:00