David Teigland [Thu, 1 Aug 2019 20:04:10 +0000 (15:04 -0500)]
improve duplicate pv handling for md components
Eliminate md components at the start so they don't
interfere with actual duplicates, and don't need
to be removed later. This also allows for choosing
no copy of a PVID if they all happen to be md
components.
David Teigland [Thu, 1 Aug 2019 19:43:19 +0000 (14:43 -0500)]
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).
dmeventd: avoid bail out preventing repair in raid plugin
Problem:
even though dead raid component devices are detected, the
raid plugin is bailing out thus preventing a repair attempt.
Rational:
in case of component device errors, the MD resynchronization
thread runs in parallel with the thrown event being processed
by the raid plugin. The plugin retrieves the raid device status
but that still reflects insync regions as 0 (when it should
already be total regions) because the MD thread didn't update it yet.
Solution:
Remove the insync regions check and let lvconvert carry out its
pre-repair checks and optionally carry out a repair attempt.
Zdenek Kabelac [Mon, 17 Jun 2019 20:47:35 +0000 (22:47 +0200)]
tests: replaces grep -q usage
Since we use 'set -euE -o pipefail' for shell execution,
any failure of any command in the 'piped' shell can result
in failure of whole executed chain - resulting in typically
unsually test skip, that was left unnoticed.
Since checked command have usually short output, the simplest
fix seems to be to let grep parse whole output instead
of quiting after first match.
Fix versioning for updated symbols dm_stats_create_region
and dm_stats_create_region.
Only the latest symbol should have global entry.
Since I'm not sure what is currenlty the best option for
old symbols - we added support for easy commenting of them
(so we do not lose information when the symbol appeared
for the first time.)
Note: some old already deleted symbols should have been
restored as comments.
David Teigland [Thu, 1 Aug 2019 15:06:47 +0000 (10:06 -0500)]
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.
David Teigland [Fri, 26 Jul 2019 19:21:08 +0000 (14:21 -0500)]
Fix rounding writes up to sector size
Do this at two levels, although one would be enough to
fix the problem seen recently:
- Ignore any reported sector size other than 512 of 4096.
If either sector size (physical or logical) is reported
as 512, then use 512. If neither are reported as 512,
and one or the other is reported as 4096, then use 4096.
If neither is reported as either 512 or 4096, then use 512.
- When rounding up a limited write in bcache to be a multiple
of the sector size, check that the resulting write size is
not larger than the bcache block itself. (This shouldn't
happen if the sector size is 512 or 4096.)
David Teigland [Mon, 1 Jul 2019 20:00:34 +0000 (15:00 -0500)]
metadata: extend writes to zero space
Previously, consecutive copies of metadata would have garbage
data in the space between them. After metadata wrapping,
the garbage would be portions of old metadata. This made
analysis of the metadata area more difficult.
This would happen because the start of new copy of metadata
is advanced from the end of the last copy to start at the
next 512 byte boundary.
Zero the space between consecutive copies of metadata by
extending each metadata write to end at the next 512 byte
boundary. The size of the metadata itself is not extended,
only the write. The buffer being written contains the
metadata text followed by the necessary number of zeros.
David Teigland [Tue, 9 Jul 2019 19:48:31 +0000 (14:48 -0500)]
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.
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).
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.
Peter Rajnoha [Thu, 4 Jul 2019 10:57:55 +0000 (12:57 +0200)]
udev: do not overwrite ID_MODEL in 69-dm-lvm-metad.rules
We've been assigning this in 69-dm-lvm-metad.rules:
ENV{ID_MODEL}="LVM PV $env{ID_FS_UUID_ENC} on /dev/$name"
This was for the description to appear for each systemd device
unit representing this device, for example:
$systemctl -a | grep "LVM PV"
dev-block-252:2.device loaded active plugged LVM PV JhxC7B-YTgk-3jIU-5GVo-c4gV-W8t3-UUz06p on /dev/vda2 2
dev-disk-by\x2did-lvm\x2dpv\x2duuid\x2dJhxC7B\x2dYTgk\x2d3jIU\x2d5GVo\x2dc4gV\x2dW8t3\x2dUUz06p.device loaded active plugged LVM PV JhxC7B-YTgk-3jIU-5GVo-c4gV-W8t3-UUz06p on /dev/vda2 2
...
However, there could be an actual ID_MODEL that people are interested in
more than the fact that this is an LVM PV and so we shouldn't overwrite
the value.
Also, we already have a symlink /dev/disk/by-id/lvm-pv-uuid-<PV_UUID>
created which is then reflected as device unit (all device's symlinks
have systemd device unit representation) so we can still reach this
information in systemd unit listings even without setting the ID_MODEL.
David Teigland [Tue, 2 Jul 2019 15:59:40 +0000 (10:59 -0500)]
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.
David Teigland [Fri, 21 Jun 2019 18:37:11 +0000 (13:37 -0500)]
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.
David Teigland [Tue, 11 Jun 2019 21:17:24 +0000 (16:17 -0500)]
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.
David Teigland [Tue, 18 Jun 2019 21:10:06 +0000 (16:10 -0500)]
metadata: include description with command in metadata areas
Previously the VG metadata description field (which contains
the command line) was only included in backup/archive copies
of the metadata. Now also include it in the metadata written
to the metadata areas.
David Teigland [Fri, 14 Jun 2019 14:26:08 +0000 (09:26 -0500)]
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"
Zdenek Kabelac [Tue, 11 Jun 2019 14:40:44 +0000 (16:40 +0200)]
tests: correct checked target name
So when the target name happened to be a suffix of another one,
the grep was filtering incorrect line
(i.e. dm-cache && dm-writecache) - so do a line head matching.
David Teigland [Mon, 10 Jun 2019 16:35:26 +0000 (11:35 -0500)]
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.
David Teigland [Fri, 7 Jun 2019 19:30:03 +0000 (14:30 -0500)]
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.
David Teigland [Mon, 10 Jun 2019 15:07:30 +0000 (10:07 -0500)]
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.
Marian Csontos [Mon, 10 Jun 2019 15:05:04 +0000 (17:05 +0200)]
Merge remote-tracking branch 'origin/master'
* origin/master: (22 commits)
tests: add metadata-bad-mdaheader.sh
tests: add metadata-bad-text.sh
tests: add outdated-pv.sh
tests: add metadata-old.sh
tests: add missing-pv missing-pv-unused
metadata.c: removed unused code
improve reading and repairing vg metadata
add a warning message when updating old metadata
vgcfgbackup add error messages
vgck --updatemetadata is a new command
move pv header repairs to vg_write
process_each_pv handle outdated pvs
move wipe_outdated_pvs to vg_write
create separate lvmcache update functions for read and write
fix vg_commit return value
change args for text label read function
add mda arg to add_mda
keep track of which mdas have old metadata in lvmcache
ability to keep track of outdated pvs in lvmcache
ability to keep track of bad mdas in lvmcache
...
David Teigland [Fri, 24 May 2019 17:04:37 +0000 (12:04 -0500)]
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.
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.)
David Teigland [Wed, 6 Feb 2019 19:39:41 +0000 (13:39 -0600)]
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.
David Teigland [Tue, 5 Feb 2019 20:02:24 +0000 (14:02 -0600)]
fix vg_commit return value
The existing comment was desribing the correct behavior,
but the code didn't match. The commit is successful if
one mda was committed. Making it depend on the result of
the internal lvmcache update was wrong.
David Teigland [Tue, 5 Feb 2019 19:40:34 +0000 (13:40 -0600)]
change args for text label read function
Have the caller pass the label_sector to the read
function so the read function can set the sector
field in the label struct, instead of having the
read function return a pointer to the label for
the caller to set the sector field.
Also have the read function return a flag indicating
to the caller that the scanned device was identified
as a duplicate pv.
David Teigland [Tue, 5 Feb 2019 18:55:51 +0000 (12:55 -0600)]
ability to keep track of outdated pvs in lvmcache
Outdated PVs hold metadata for VG from which they
have been removed. Add the ability to keep track
of these in lvmcache.
This will be used for more advanced repair in a
subsequent commit.
David Teigland [Tue, 5 Feb 2019 18:39:08 +0000 (12:39 -0600)]
ability to keep track of bad mdas in lvmcache
mda's that cannot be processed by lvm because of
some corruption can be kept on a separate list.
These will be used for more advanced repair in a
subsequent commit.
David Teigland [Tue, 5 Feb 2019 18:08:00 +0000 (12:08 -0600)]
add flags to keep track of bad metadata
When reading metadata headers and text, use a new set
of flags to identify specific errors that are seen.
These will be used for more advanced repair in a
subsequent commit.
David Teigland [Tue, 21 May 2019 17:06:34 +0000 (12:06 -0500)]
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".
git://sourceware.org / lvm2.git / log