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Fix the anoying kernel message reported:
device-mapper: cache: 253:2: metadata operation 'dm_cache_commit' failed: error = -5
which has been reported while cachevol has been removed.
Happened via confusing variable - so switch the variable to commonly user '_size'
which presents a value in sector units and avoid 'scaling' this as extent length
by vg extent size when placing 'error' target on removal path.
Patch shouldn't have impact on actual users data, since at this moment
of removal all date should have been already flushed to origin device.
m
The previous patch improved read of pipe when lvm2 was looking
for default logical size, but we clearly must read pipe also
for -V case, when the logical size is already defined.
Still the place can be better to block only particular reshape
operations which ATM cause kernel problems.
We check if the new number of images is higher - and prevent to take
conversion if the volume is in use (i.e. thin-pool's data LV).
clang: it's supposedly impossible path to hit, as we should always
have origin_lv defined when running this path, but adding protection
isn't a big issue to make this obvious to analyzer.
Since _reserve_area() may fail due to error allocation failure,
add support to report this already reported failure upward.
FIXME: it's log_error() without causing direct command failure.
Although we expect min_chunk_size to be 32bit value, for
large size of caches it might be useful to do calcs 64bit.
So to avoid doing shift as signed 32bit - use unsigned 64bit
from the start.
reporting fields (-o) directly from kernel:
writecache_total_blocks
writecache_free_blocks
writecache_writeback_blocks
writecache_error
The data_percent field shows used cache blocks / total cache blocks.
Until we resolve reshape for 'stacked' devices, we need to disable it.
So users can no longer reshape i.e. thin-pool data volumes, causing
ATM bad thin-pool problems.
After the VG lock is taken for vg_read, reread the mda_header
and compare the metadata text offset and checksum to what was
seen during label scan. If it is unchanged, then the metadata
has not changed since the label scan, and the metadata does not
need to be reread under the lock for command processing.
For commands that do not make changes (e.g. reporting), the
mda_header is reread and checked on one mda to decide if the
full metadata rereading can be skipped. For other commands
(e.g. modifying the vg) the mda_header is reread and checked
from all PVs. (These could probably just check one mda also.)
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.
Avoid mem leaking hint on every loop continue and
allocate hint only when it's going to be added into list.
Switch to use 'dm_strncpy()' and validate sizes.
For dev_in_device_list() != 0 allocated 'devl' was
actually leaking - so instead allocate 'devl' only
when !dev_in_device_list() and indent code around.
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).
dev_unset_last_byte() must be called while the fd is still valid.
After a write error, dev_unset_last_byte() must be called before
closing the dev and resetting the fd.
In the write error path, dev_unset_last_byte() was being called
after label_scan_invalidate() which meant that it would not unset
the last_byte values.
After a write error, dev_unset_last_byte() is now called in
dev_write_bytes() before label_scan_invalidate(), instead of by
the caller of dev_write_bytes().
In the common case of a successful write, the sequence is still:
dev_set_last_byte(); dev_write_bytes(); dev_unset_last_byte();
Signed-off-by: Zhao Heming <heming.zhao@suse.com>
When resizing 2 volumes like thin-pool and it's metadata and they
would be of a different type - command would be actually expecting
both LVs being of a same segtype - and would throw an error in
case they are different.
This patch fixes is by setting a new segtype from last segment of
2nd. extented device.
Also it fixes the possible 'percentage' extension setup that
might have been used for 'primary' volume - while the 'secondary'
LV always goes with direct size - as we do not support 'percentage'
setup for them
This affects maily usage of thin-pool where the extension of
thin-pool data size may also lead to extension of metadata size.
Instead of checking all LVs in a VG - do just a direct copy of LVs
from the existing list ->segs_using_thin_lv.
TODO: maybe it could be better to expose seg_list to /tools...
Enhance lv_info with lv_info_with_name_check.
This 'variant' not only check existance if UUID in DM table
but also compares its DM name whether it's matching expected LV name.
Otherwise activation may 'skip' activation with rename in case the
DM UUID already exists, just device is different name.
This change make fairly easier manipulation with i.e. detached mirror
leg which ATM is using same UUID - just the LV name have been changed.
Used code was not able to run 'activation' (and do a rename) and just
skipped the call. So the code used to do a workaround and 'tried'
to deactivate such LV firts - this however work only in non-clvmd case,
as cluster was not having the lock for deactivated LV.
With this extended lv_info code will run 'activation' and will
synchronize the name to match expected LV name.
Patch extends _lv_info() with new paramter 'with_name_check',
which is later translated into 'name_check' argument for
_info_run() which in case of name mismatch evaluates the
check as if device does not exists.
Such call is only used in one place _lv_activate() which then
let activation run. All other invocation of _info() calls
are left intact.
TODO: fix mirror table manipulation (and raid)....
The return value from bcache_invalidate_fd() was not being checked.
So I've introduced a little function, _invalidate_fd() that always
calls bcache_abort_fd() if the write fails.
The resume of 'released' 'COW' should preceed the resume of origin.
The fact we need to do the sequence differently for merge was
cause by bugs fixed in 2 previous commits - so we no longer need
to recognize 'merging' and we should always go with single
sequence.
The importance of this order is - to properly remove '-real' device
from origin LV. When COW is activated as 2nd. '-real' device is
kept in table as it cannot be removed during 1st. resume of origin,
and later activation of COW LV no longer builds tree associated
with origin LV.
When checking device id of a thin device that is just being
merged - the snapshot actually could have been already finished
which means '-real' suffix for the LV is already gone and just LV
is there - so check explicitely for this condition and use
correct UUID for this case.
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.)
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.
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).
Since code is using -cdata and -cmeta UUID suffixes, it does not need
any new 'extra' ID to be generated and stored in metadata.
Since introduce of new 'segtype' cache+CACHE_USES_CACHEVOL we can
safely assume 'new' cache with cachevol will now be created
without extra metadata_id and data_id in metadata.
For backward compatibility, code still reads them in case older
version of metadata have them - so it still should be able
to activate such volumes.
Bonus is lowered size of lv structure used to store info about LV
(noticable with big volume groups).
The first part of a cachevol LV is used for metadata,
and the rest of the space is used for data. The
division of space between metadata and data depends
on the total size of the cachevol.
The previous division gave more space than needed to
metadata, it was:
cachevol size 8M to 128M -> metadata size 16M *
cachevol size 128M to 1G -> metadata size 32M
cachevol size 1G and up -> metadata size 64M
(* if this resulted in over half the LV used as
metadata, then half the cachevol would be used
for metadata, and the other half for data.)
The division of space now gives less space to
metadata, it is:
cachevol size 8M to 16M -> metadata size 4M
cachevol size 16M to 4G -> metadata size 8M
cachevol size 4G to 16G -> metadata size 16M
cachevol size 16G to 32G -> metadata size 32M
cachevol size 32G and up -> metadata size 64M
When a VG contains some LVs with unknown segtypes, the user
should still be allowed to activate other LVs in the VG that
are understood.
$ lvs foo
WARNING: Unrecognised flag CACHE_USES_CACHEVOL in segment type cache+CACHE_USES_CACHEVOL.
WARNING: Unrecognised segment type cache+CACHE_USES_CACHEVOL
LV VG Attr LSize
lvol0 foo -wi------- 4.00m
other foo vwi---u--- 48.00m
$ lvcreate -l1 foo
WARNING: Unrecognised flag CACHE_USES_CACHEVOL in segment type cache+CACHE_USES_CACHEVOL.
WARNING: Unrecognised segment type cache+CACHE_USES_CACHEVOL
Cannot change VG foo with unknown segments in it!
Cannot process volume group foo
$ lvchange -ay foo/lvol0
WARNING: Unrecognised flag CACHE_USES_CACHEVOL in segment type cache+CACHE_USES_CACHEVOL.
WARNING: Unrecognised segment type cache+CACHE_USES_CACHEVOL
$ lvchange -ay foo/other
WARNING: Unrecognised flag CACHE_USES_CACHEVOL in segment type cache+CACHE_USES_CACHEVOL.
WARNING: Unrecognised segment type cache+CACHE_USES_CACHEVOL
Refusing activation of LV foo/other containing an unrecognised segment.
$ lvs foo
WARNING: Unrecognised flag CACHE_USES_CACHEVOL in segment type cache+CACHE_USES_CACHEVOL.
WARNING: Unrecognised segment type cache+CACHE_USES_CACHEVOL
LV VG Attr LSize
lvol0 foo -wi-a----- 4.00m
other foo vwi---u--- 48.00m
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.
Enhance activation of cached devices using cachevol.
Correctly instatiace cachevol -cdata & -cmeta devices with
'-' in name (as they are only layered devices).
Code is also a bit more compacted (although still not ideal,
as the usage of extra UUIDs stored in metadata is troublesome
and will be repaired later).
NOTE: this patch my brink potentially minor incompatiblity for 'runtime' upgrade
Let vgck --updatemetadata repair cases where different mdas
hold indepedently valid but unmatching copies of the metadata,
i.e. different text metadata checksums or text metadata sizes.
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.)
If a VG is forcibly changed from lock_type sanlock to
lock_type none, the internal lvmlock LV is left behind.
If that LV is not removed before vgremove is run on the
VG, then an internal check will be triggered by the
hidden lvmlock LV. So, check for and remove a left over
lvmlock LV during vgremove.
Add lots of vdo fields:
vdo_operating_mode - For vdo pools, its current operating mode.
vdo_compression_state - For vdo pools, whether compression is running.
vdo_index_state - For vdo pools, state of index for deduplication.
vdo_used_size - For vdo pools, currently used space.
vdo_saving_percent - For vdo pools, percentage of saved space.
vdo_compression - Set for compressed LV (vdopool).
vdo_deduplication - Set for deduplicated LV (vdopool).
vdo_use_metadata_hints - Use REQ_SYNC for writes (vdopool).
vdo_minimum_io_size - Minimum acceptable IO size (vdopool).
vdo_block_map_cache_size - Allocated caching size (vdopool).
vdo_block_map_era_length - Speed of cache writes (vdopool).
vdo_use_sparse_index - Sparse indexing (vdopool).
vdo_index_memory_size - Allocated indexing memory (vdopool).
vdo_slab_size - Increment size for growing (vdopool).
vdo_ack_threads - Acknowledging threads (vdopool).
vdo_bio_threads - IO submitting threads (vdopool).
vdo_bio_rotation - IO enqueue (vdopool).
vdo_cpu_threads - CPU threads for compression and hashing (vdopool).
vdo_hash_zone_threads - Threads for subdivide parts (vdopool).
vdo_logical_threads - Logical threads for subdivide parts (vdopool).
vdo_physical_threads - Physical threads for subdivide parts (vdopool).
vdo_max_discard - Maximum discard size volume can recieve (vdopool).
vdo_write_policy - Specified write policy (vdopool).
vdo_header_size - Header size at front of vdopool.
Previously only 'lvdisplay -m' was exposing them.
Since we now support activation of 'vdo' volume
without explicit activation of 'vdopool' it's now possible
to have active layer vdopool (-vpool) volume and
having vdopool itself inactive - yet still in this
case we can show available stats for this volume.
But we need to show correct activation status and other
standard info.
Avoid checking 'lv_is_active()' since special LV types does this
validation anyway what calling _percent() function and call it
ONLY when none of special types is queried.
This restores support for VDO resize (as with support for
separate VDO pool activation, plain query for lv_is_active()
is not working in this case).
If the linear mapping is lost (for whatever reason, i.e.
test suite forcible 'dmsetup remove' linear LV,
lvm2 had hard times figuring out how to deactivate such DM table.
So add function which is in case inactive VDO pool LV checks if
the pool is actually still active (-vpool device present) and
it has open count == 0. In this case deactivation is allowed
to continue and cleanup DM table.
- 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
. 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.
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).
When lvm2 is activating layered pool LV (to basically keep pool opened,
the other function used to be 'locking' be in sync with DM table)
use this LV in read-only mode - this prevents 'write' access into
data volume content of thin-pool.
Note: since EMPTY/unused thin-pool is created as 'public LV' for generic
use by any user who i.e. wish to maintain thin-pool and thins himself.
At this moment, thin-pool appears as writable LV. As soon as the 1st.
thinLV is created, layer volume will appear is 'read-only' LV from this moment.
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.
Fixes a regression from commit ba7ff96faf
"improve reading and repairing vg metadata"
where the error path for a vg name with invalid
charaters was missing an error flag, which led
to the caller not recognizing an error occured.
Previously, an error flag was hidden in the old
_vg_make_handle function.
Only the first entry of the filter array was being
included in the copy of the filter, rather than the
entire thing. The result is that hints would not be
refreshed if the filter was changed but the first
entry was unchanged.
Fixes a segfault in the recent commit e01fddc57:
"improve duplicate pv handling for md components"
While choosing between duplicates, the info struct is
not always valid; it may have been dropped already.
Remove the code that was still using the info struct for
size comparisons. The size comparisons were a bogus check
anyway because it was just preferring the dev that had
already been chosen, it wasn't actually comparing the
dev size to the PV size. It would be good to use a
dev/PV size comparison in the duplicate handling code, but
the PV size is not available until after vg_read, not
from the scan.
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.
Update configure and make code compilable if prlimit() is not present.
Since the code is suspicious do not cope yet with it's replacement
with set/getrlimit().
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...
Support internal removal of 'cache origin' volume - which we
do not normally expose to a user - however internal processing
loops may hit this condition (depending on order of list LVs).
So when this operation is internally requested - we automatically
try to remove it's 'holding' LV (cache LV) - which will also
remove the origin.
Drop the 'cluster-only' optimization so we do resume ALL device
before we try to wait on cookie before 'removal' operation.
It's more correct order of operation - alhtough possibly slightly
less efficient - but until we have correct list of operations
'in-progress' we can't do anything better.
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'.
Resuming of 'error' table entry followed with it's dirrect removal
is now troublesame with latest udev as it may skip processing of
udev rules for already 'dropped' device nodes.
As we cannot 'synchronize' with udev while we know we have devices
in suspended state - rework 'cleanup' so it collects nodes
for removal into pending_delete list and process the list with
synchronization once we are without any suspended nodes.
When pvmove is finished, we do a tricky operation since we try to
resume multiple different device that were all joined into 1 big tree.
Currently we use the infromation from existing live DM table,
where we can get list of all holders of pvmove device.
We look for these nodes (by uuid) in new metadata, and we do now a full
regular device add into dm tree structure. All devices should be
already PRELOAD with correct table before entering suspend state,
however for correctly working readahead we need to put correct info
also into RESUME tree. Since table are preloaded, the same table
is skip and resume, but correct read ahead is now set.
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.
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).
When there are more devices than the current soft
open file limit (default 1024), raise the soft limit
to the hard/max limit (default 4096).
Do this prior to scanning in case enough of the
devices are PVs that need to be kept open.
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.
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.)
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.
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.
This check was mistakenly removed when shifting code in commit
"separate code for setting devices from metadata parsing".
Put it back with some new conditions.
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.
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.
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.
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.
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.
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.)
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.
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
The vg read and vg write cases need to update lvmcache
differently, so create separate functions for them.
The read case now handles checking for outdated mdas
and moves them aside into a new list to be repaired in
a subsequent commit.
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.
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.
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.
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.
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.
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".
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.
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.
Recent kernel version from kernel commit:
de7180ff908b2bc0342e832dbdaa9a5f1ecaa33a
started to report in cache status line new flag:
no_discard_passdown
Whenever lvm spots unknown status it reports:
Unknown feature in status:
So add reconginzing this feature flag and also report this with
'lvs -o+kernel_discards'
When no_discard_passdown is found in status 'nopassdown' gets reported
for this field (roughly matching what we report for thin-pools).
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.
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.
If an md component is not excluded by other means and
vg_read is used to read metadata from it, then this new
check compares the device size with the PV size, and runs
a full md check on the device if the sizes don't match.
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.
wipe_lv knows it's going to write the device, so it
can open rw from the start. It was opening readonly,
and then dev_write needed to reopen it readwrite.
When hints are invalid and ignored, the list of hints
could be non-empty (from additions before an invalid
hint was found). This confused the calling code which
was checking for an empty list to see if hints were used.
Ensure the list is empty when hints are not used.
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.
When data are growing, adapt also size of metadata.
As we get way too many reports from users doing huge growths of
data portion while keep metadata small and avoiding using monitoring.
So to enhance the user-experience in case user requests grown of
thin-pool (without passing PV list for growth) - lvm2 will automaticaly
grown also the metadata part of thin-pool (if possible).
Add function for estimation of thin-pool metadata size for given size of
data. Function is using already existing internal API so it can
be reused for resize of thin-pool data.
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.
When an LV is active with a shared lock, a command can be
run to change the LV with --lockopt skiplv (to override the
exclusive lock the command ordinarily requires which is not
compatible with the outstanding shared lock.)
In this case, other commands may have the LV active and may
need to refresh the LV, so print warning stating this.
Udev is running udev-rule action upon 'resume'.
However lvm2 in special case is doing replacement of
'soon-to-be-removed' device with 'error' target for resuming
and then follows actual removal - the sequence is usually quick,
so when udev start action - it can result in 'strange' error
message in kernel log like:
Process '/usr/sbin/dmsetup info -j 253 -m 17 -c --nameprefixes --noheadings --rows -o name,uuid,suspended' failed with exit code 1.
To avoid this - we need to ensure there is synchronization wait for udev
between 'resume' and 'remove' part of this process.
However existing code put strict requirement to avoid synchronizing with
udev inside critical section - but this originally came from requirement
to not do anything special while there could be devices in
suspend-state. Now we are able to see differnce between critical section
with or without suspended devices. For udev synchronization only
suspended devices are prohibited to be there - so slightly relax
condition and allow calling and using 'fs_sync()' even inside critical
section - but there must not be any suspended device.
Allow using caching with VDO.
User can either cache a single vdopool or
a vdo LV - difference when the caching is put-in depends on a use-case
and it's upto user to decide which kind of speed is expected.
Internal detection of SCSI device being in-use by DM mpath has been
performed several times for each component device - this could be
eventually racy - so instead when we do remember 1st. checked result
for device being mpath and use it consistenly over the filter runtime.
Move DM usage into dev_manager.c source file.
Also convert STATUS to INFO ioctl - as that's enough
to obtain UUID - this also avoid issuing unwanted flush on checked DM
device for being mpath.
Activation would not be allowed anyway, but we can
check for these cases early and avoid wasted time in
pvscan managing online files an attempting activation.
This is the default bcache size that is created at the
start of the command. It needs to be large enough to
hold a single copy of metadata for a given VG, or the
VG cannot be read or written (since the entire VG would
not fit into available memory.)
Increasing the default reduces the chances of anyone
needing to increase the default to use their VG.
The size can be set in lvm.conf global/io_memory_size;
the lower limit is 4 MiB and the upper limit is 128 MiB.
When a single copy of metadata gets within 1MB of the
current io_memory_size value, begin printing a warning
that the io_memory_size should be increased.
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.
and "cachepool" to refer to a cache on a cache pool object.
The problem was that the --cachepool option was being used
to refer to both a cache pool object, and to a standard LV
used for caching. This could be somewhat confusing, and it
made it less clear when each kind would be used. By
separating them, it's clear when a cachepool or a cachevol
should be used.
Previously:
- lvm would use the cache pool approach when the user passed
a cache-pool LV to the --cachepool option.
- lvm would use the cache vol approach when the user passed
a standard LV in the --cachepool option.
Now:
- lvm will always use the cache pool approach when the user
uses the --cachepool option.
- lvm will always use the cache vol approach when the user
uses the --cachevol option.
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.
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.
When aay was included in the pvscan --cache command,
the activation part was complaining about the unusual
state of the hint file since it had been recreated
just prior.
udev_dev_is_md_component and udev_dev_is_mpath_component
are not used for obtaining the device list, but they still
use libudev for device info. When there are problems with
udev, these functions can get stuck. So, use the existing
obtain_device_list_from_udev config setting to also control
whether these "is component" functions are used, which gives
us a way to avoid using libudev entirely when it's causing
problems.
Whenever thin-pool chunk size is unspecified and left for lvm calculation
try to select the size as nearest highest power-of-2 instead of
just being a multiple of 64KiB.
Fixing recent commit 022ebb0cfe
Resize already has size that needs to be counted with,
otherwise upsizing operation could turn into size reduction one.
Since the parse_vdo_pool_status() become vdo_manip API part,
and there will be no 'dm' matching status parser,
the API can be simplified and closely match thin API here.
Now with newer VDO kvdo target we can start to use standard mechanism
to enable resize of VDO volumes.
VDO pool can be grown.
Virtual volume grows on top of VDO pool when is not big enough.
Reduced VDOLV is calling discard for reduced areas - this can
take long time!
TODO: implement some pollable mechanism for out-of-lock TRIM.
When using 'lvcreate -l100%VG' and there is big disproportion between
real available space and requested setting - automatically fallback
to 100%FREE.
Difference can be seen when VG is big and already most space was
allocated, so the requestion 100%VG can end (and by spec for % modifier
it's correct) as LV with size of 1%VG. Usually this is not a big
problem - buit in some cases - like cache-pool allocation, this
can result a big difference for chunksize selection.
With this patch it's more closely match common-sense logic without
the need of reitteration of too big changes in lvm2 core ATM.
TODO: in the future there should be allocator solving all allocations
in a single call.
lvm uses 'minimum_io_size' name to exactly match VDO naming here,
however in all common cases _size is using 'sector/512b' unit.
But in this case the value is in bytes and can have only 2 values:
either 512 or 4096.
It's probably not worth to rename it internaly, so we can just
drop comment - instead of using 1 or 8.
Thought let's think about it....
An idea from Zdenek for better ensuring valid hints by invalidating
them when pvscan --cache <device> sees a new PV, which is a case
where we know that hints should be invalidated. This is triggered
from systemd/udev logic, and there may be some cases where it would
invalidate hints that the existing methods wouldn't detect.
If there are two independent scripts doing:
vgchange --lockstart vg
lvchange -ay vg/lv
The first vgchange to do the lockstart will wait for
the lockstart to complete before returning.
The second vgchange to do the lockstart will see that
the start is already in progress (from the first) and
will do nothing. This means the second does not wait
for any lockstart to complete, and moves on to the
lvchange which may find the lockspace still starting
and fail.
To fix this, make the vgchange lockstart command
wait for any lockstart's in progress to complete.
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.)
The systemd generators are executed very early during the switch
from initramfs to system partition and the syslog is not yet fully
operational - it may cause blocking, if some debug logging is enabled
at the same time in /etc/lvm/lvm.conf log{} section.
To avoid timeouting and killing this generator - rather enhance lvm
code to suppress any syslog communication when LVM_SUPPRESS_SYSLOG
envvar is set.
Use of this envvar is needed since the parsing of i.e. cmdline options
that could eventually override lvm.conf setting happens in this case
way too late and number of lines could have been already streamed to
syslog.
In few cases error paths from initialization were returned as
'success == 1'.
Also assing num_mb with single compare checking valid sector_size.
For dumb compiler make num_mb always defined.
Drop very old original format of VDO target and focus on V2 version.
So some variables were renamed or replaced.
There is no compatibility preserved (with assumption so far this is
experimental feature and there is no real user).
Note - version currently VDO calls this version 6.2.
This is a followup patch to commit edb72cb70c
to support related lvm2 test suite tests.
A 'global/support_mirrored_mirror_log' bool configuration variable gets
introduced allowing the creation of, or conversion to mirrored 'mirror'
logs if set. The capability to create these in turn allows the rest of
the tests to perform activation of such existing LVs and their conversions
to disk/core 'mirror' logs.
Display a disclaimer warning if enabled that this is not for regular use.
Add definition of the enabled config option to respective test scripts.
Related: rhbz1643562
Scenario: Given an existed LV `lvol0`, I want to create another LV
on the PVs used by `lvol0`.
I use `build_parallel_areas_from_lv()` to obtain the `pv_list` of each segments.
However, the returned `pv_list` is not properly initialized, which causes
segfault in subsequent operations.
Ensure configure.h is always 1st. included header.
Maybe we could eventually introduce gcc -include option, but for now
this better uses dependency tracking.
Also move _REENTRANT and _GNU_SOURCE into configure.h so it
doesn't need to be present in various source files.
This ensures consistent compilation of headers like stdio.h since
it may produce different declaration.
There's a small window during creation of a new RaidLV when
rmeta SubLVs are made visible to wipe them in order to prevent
erroneous discovery of stale RAID metadata. In case a crash
prevents the SubLVs from being committed hidden after such
wiping, the RaidLV can still be activated with the SubLVs visible.
During deactivation though, a deadlock occurs because the visible
SubLVs are deactivated before the RaidLV.
The patch adds _check_raid_sublvs to the raid validation in merge.c,
an activation check to activate.c (paranoid, because the merge.c check
will prevent activation in case of visible SubLVs) and shares the
existing wiping function _clear_lvs in raid_manip.c moved to lv_manip.c
and renamed to activate_and_wipe_lvlist to remove code duplication.
Whilst on it, introduce activate_and_wipe_lv to share with
(lvconvert|lvchange).c.
Resolves: rhbz1633167
In RHEL7 we marked mirrored mirror logs as deprecated and
added a related message. This patch prohibits creating new
'mirror' LVs with that log type or converting existing LVs
to have one.
Existing LVs with mirrored mirror log can be activated
and converted to disk/core logs.
Avoid double deprecation message when running lvconvert.
Resolves: rhbz1643562
commit de28637
scan: use full md filter when md 1.0 devices are present
missed the fact that md superblock version 0.90 also puts
metadata at the end of the device, so the full md filter
needs to be used when either 0.90 or 1.0 is present.
. When using default settings, this commit should change
nothing. The first PE continues to be placed at 1 MiB
resulting in a metadata area size of 1020 KiB (for
4K page sizes; slightly smaller for larger page sizes.)
. When default_data_alignment is disabled in lvm.conf,
align pe_start at 1 MiB, based on a default metadata area
size that adapts to the page size. Previously, disabling
this option would result in mda_size that was too small
for common use, and produced a 64 KiB aligned pe_start.
. Customized pe_start and mda_size values continue to be
set as before in lvm.conf and command line.
. Remove the configure option for setting default_data_alignment
at build time.
. Improve alignment related option descriptions.
. Add section about alignment to pvcreate man page.
Previously, DEFAULT_PVMETADATASIZE was 255 sectors.
However, the fact that the config setting named
"default_data_alignment" has a default value of 1 (MiB)
meant that DEFAULT_PVMETADATASIZE was having no effect.
The metadata area size is the space between the start of
the metadata area (page size offset from the start of the
device) and the first PE (1 MiB by default due to
default_data_alignment 1.) The result is a 1020 KiB metadata
area on machines with 4KiB page size (1024 KiB - 4 KiB),
and smaller on machines with larger page size.
If default_data_alignment was set to 0 (disabled), then
DEFAULT_PVMETADATASIZE 255 would take effect, and produce a
metadata area that was 188 KiB and pe_start of 192 KiB.
This was too small for common use.
This is fixed by making the default metadata area size a
computed value that matches the value produced by
default_data_alignment.
The pvscan systemd service for autoactivation was
mistakenly dropped along with the lvmetad related
services.
The activation generator program now looks at the new
lvm.conf setting "event_activation" (default 1) to
switch between event activation and direct activation.
Previously, the old use_lvmetad setting was used to
switch between event and direct activation.
fix lseek error check
fix read/write error checks
handle zero return from read and write
don't return an error for short io
fix partial read/write loop
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.
Commit 813347cf84 added extra validation,
however in this particular we do want to trim suffix out so rather ignore
resulting error code here intentionaly.
If a single, standard LV is specified as the cache, use
it directly instead of converting it into a cache-pool
object with two separate LVs (for data and metadata).
With a single LV as the cache, lvm will use blocks at the
beginning for metadata, and the rest for data. Separate
dm linear devices are set up to point at the metadata and
data areas of the LV. These dm devs are given to the
dm-cache target to use.
The single LV cache cannot be resized without recreating it.
If the --poolmetadata option is used to specify an LV for
metadata, then a cache pool will be created (with separate
LVs for data and metadata.)
Usage:
$ lvcreate -n main -L 128M vg /dev/loop0
$ lvcreate -n fast -L 64M vg /dev/loop1
$ lvs -a vg
LV VG Attr LSize Type Devices
main vg -wi-a----- 128.00m linear /dev/loop0(0)
fast vg -wi-a----- 64.00m linear /dev/loop1(0)
$ lvconvert --type cache --cachepool fast vg/main
$ lvs -a vg
LV VG Attr LSize Origin Pool Type Devices
[fast] vg Cwi---C--- 64.00m linear /dev/loop1(0)
main vg Cwi---C--- 128.00m [main_corig] [fast] cache main_corig(0)
[main_corig] vg owi---C--- 128.00m linear /dev/loop0(0)
$ lvchange -ay vg/main
$ dmsetup ls
vg-fast_cdata (253:4)
vg-fast_cmeta (253:5)
vg-main_corig (253:6)
vg-main (253:24)
vg-fast (253:3)
$ dmsetup table
vg-fast_cdata: 0 98304 linear 253:3 32768
vg-fast_cmeta: 0 32768 linear 253:3 0
vg-main_corig: 0 262144 linear 7:0 2048
vg-main: 0 262144 cache 253:5 253:4 253:6 128 2 metadata2 writethrough mq 0
vg-fast: 0 131072 linear 7:1 2048
$ lvchange -an vg/min
$ lvconvert --splitcache vg/main
$ lvs -a vg
LV VG Attr LSize Type Devices
fast vg -wi------- 64.00m linear /dev/loop1(0)
main vg -wi------- 128.00m linear /dev/loop0(0)
The lvmlock LV size was not adjusted correctly for 512 vs 4K
sector sizes which influence the lease size used by sanlock.
When lvmlock was automatically extended, the zeroing through
bcache wasn't working.
lvm uses a bcache block size of 128K. A bcache block
at the end of the metadata area will overlap the PEs
from which LVs are allocated. How much depends on
alignments. When lvm reads and writes one of these
bcache blocks to update VG metadata, it can also be
reading and writing PEs that belong to an LV.
If these overlapping PEs are being written to by the
LV user (e.g. filesystem) at the same time that lvm
is modifying VG metadata in the overlapping bcache
block, then the user's updates to the PEs can be lost.
This patch is a quick hack to prevent lvm from writing
past the end of the metadata area.
This reverts commit 16ae968d24.
We need to come up with a better fix, because we fall short
wiping all known signatures when not using the wipe_lv API.
lvm metadata writes, commits and activations are performed
for (newly) allocated RAID metadata SubLVs to wipe any preexisiting
data thus avoid false raid superblock positives on RaidLV activation.
This process can be interrupted by command or system crashs
thus leaving stale SubLVs in the lvm metadata as a problem.
Because we hold an exclusive lock in this metadata SubLV wiping
process, we can address this problem by avoiding aforementioned
commits/writes/activations altogether wiping the respective first
sector of the first physical extent allocated to any metadata SubLV
directly via the existing dev_set() API.
Succeeds all LVM RAID tests.
Related: rhbz1633167
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.
Previously the size was limited by checking if the
old and new copies of the metadata overlapped.
This generally limited the size to about half of
the total space, but it could be larger given the
size differences between old and new. Now add a
direct check to limit the size to half the space.
Remove another instance of an invalid check for metadata
overflow during read. The previous instance was removed
in commit 5fb15b193.
This was checking for metadata that that overflowed the
circular disk metadata buffer during read, but such metadata
cannot be written, so it shouldn't be possible to find see.
Also, the check was incorrect and could trigger when there
was no overflow.
This fixes a problem in commit e6bb780d24, in which the
back compat handling for the old locking_type=4 was
incorrectly translated to mean the same thing as --readonly,
which prevented activation because activation uses an
exclusive vg lock. Previously, locking_type=4 allowed
activation.
If we see locking_type 4 in an old config, translate it to
the new combination of --readonly and --sysinit, which we
now define to mean the --readonly behavior with an exception
to allow activation.
The vg_write/vg_commit code was imprecise, uncommented, and
hard to understand. Rewrite it with clearer, cleaner code,
extensive comments, descriptions of how it works, and add
more info in debugging output.
The minor changes in behavior are to things that were
either incorrect or probably unintended:
- vg_write/vg_commit no longer check that the current vgname at
the start of the text metadata matches the vgname being written.
This has already been done at least twice by the time they are
called, and repeating it again against the same cached data has
no use.
- A fragment of old removed code had been left behind that checked
if the old unused alignment policy would wrap. It was still
being checked to decide if the metadata area was full, which
could possibly cause an incorrect full metadata failure.
- vg_remove now clears both the raw_locns in the mda_header that
point to committed metadata (raw_locn slot 0) and precommitted
metadata (raw_locn slot 1). Previously it fully cleared the
committed slot, and would only clear the offset field in the
precommitted slot if it saw a problem with the metadata in the
vg being removed.
- read_metadata_location_summary was wrongly comparing the number
of wrapped bytes with an offset to report an error about the
metadata being too large. This wrong check is removed, it
could have resulted in erroneous errors.
Allow "lvconvert --type linear RaidLV" on a raid4 LV
providing convenient interim steps to convert to linear.
Add respective new test
lvconvert-raid-takeover-raid4_to_linear.sh
and
lvconvert-raid-takeover-linear_to_raid4.sh
for linear to raid4 once on it.
When converting from striped/raid0/raid0_meta
to raid6 with > 2 stripes, allow possible
direct conversion (to raid6_n_6).
In case of 2 stripes, first convert to raid5_n to restripe
to at least 3 data stripes (the raid6 minimum in lvm2) in
a second conversion before finally converting to raid6_n_6.
As before, raid6_n_6 then can be converted
to any other raid6 layout.
Enhance lvconvert-raid-takeover.sh to test the
2 stripes conversions to raid6.
Resolves: rhbz1624038
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.
This is the number of concurrent async io requests that
the scan layer will submit to the bcache layer. There
will be an open fd for each of these, so it is best to
keep this well below the default limit for max open files
(1024), otherwise lvm may get EMFILE from open(2) when
there are around 1024 devices to scan on the system.
"lvconvert --type linear RaidLV" on striped and raid4/5/6/10
have to provide the convenient interim layouts. Fix involves
a cleanup to the convenience type function.
As a result of testing, add missing sync waits to
lvconvert-raid-reshape-linear_to_raid6-single-type.sh.
Resolves: rhbz1447809
Conversion to striped from raid0/raid0_meta is directly possible.
Fix a regression setting superfluous interim raid5_n conversion type
introduced by commit bd7cdd0b09.
Add new test script lvconvert-raid0-striped.sh.
Resolves: rhbz1608067
With improved mirror activation code --splitmirror issue poppedup
since there was missing proper preload code and deactivation
for splitted mirror leg.
If a mirror LV is listed in read_only_volume_list, it would
still be activated rw. The activation would initially be
readonly, but the monitoring function would immediately
change it to rw. This was a regression from commit
fade45b1d1 mirror: improve table update
The monitoring function needs to copy the read_only setting
into the new set of mirror activation options it uses.
When vgcreate does an automatic pvcreate, it opens the
dev with O_EXCL to ensure no other subsystem is using
the device. This exclusive fd remained in bcache and
prevented activation parts of lvm from using the dev.
This appeared with vgcreate of a sanlock VG because of
the unique combination where the dev is not yet a PV,
so pvcreate is needed, and the vgcreate also creates
and activates an internal LV for sanlock.
Fix this by closing the exclusive fd after it's used
by pvcreate so that it won't interfere with other
bits of lvm that may try to use the device.
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.
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.
When lvmetad is not used, use temporary files to record
which PVs have appeared. Use these temp files to determine
when a VG is complete, to trigger autoactivation.
This change allows us to remove lvmetad while keeping the
same autoactivation behavior that lvmetad provides.
The temp files are created in /run/lvm/pvs_online/ and are
named for the PVID of the PV. The files contain the
major:minor of the device the PV was read from.
e.g. if VG foo has dev1 and dev2, then:
. pvscan --cache -aay dev1
reads vg metadata from dev1
creates /run/lvm/pvs_online/<pvid-of-dev1>
checks if all vg->pvs are online: no
. pvscan --cache -aay dev2
reads vg metadata from dev2
creates /run/lvm/pvs_online/<pvid-of-dev2>
checks if all vg->pvs are online: yes
autoactivates vg
A 'pvscan --cache dev' (without -aay) still records that
dev is online.
A 'pvscan --cache --major X --minor Y' after a device is
gone will remove the temp file for it.
A 'pvscan --cache [-aay]' (no devs) resets the state of
temp files by removing them all, then scanning all devs
and creating temp files for PVs that are found.
If no online files exist, the first pvscan --cache scans
all devs and creates temp files for any PVs found.
The scope of the temp files is only pvscan, and they are only
used for pvscan-based autoactivation. No other commands are
concerned with or aware of these temp files. When lvm creates
or removes PVs, no attempt is made to update the temp files.
Support vgchange usage with VDO segtype.
Also changing extent size need small update for vdo virtual extent.
TODO: API needs enhancements so it's not about adding ifs() everywhere.
When user create vdo-pool - use different automatic name.
So unlike with traditional LVs using lvol0, lvol1
use vpool0, vpool1...
TODO: apply similar for thin-pool & cache-pool...
To support autoloading of VDO dm target driver loading of 'kvdo'
kernel module is needed - ATM it's not using 'dm-vdo' name.
So to support this strange name - add temporarily solution to
autoload kvdo kernel module in this case.
When lvm2 command is executed in test mode, discard ioctl is skipped.
This may cause even data-loose in case, issuing discard for released
areas was enabled and user 'tested' lvreduce.
When allocating thin-pool with more then 1 device - try to
allocate 'metadataLV' with reuse of log-type allocation for mirror LV.
It should be naturally place on other device then 'dataLV'.
However due to somewhat hard to follow allocation logic code,
it's been rejected allocation in cases where there was not
enough space for data or metadata on single PV, thus to successed,
usage of segments was mandatory.
While user may use:
allocation/thin_pool_metadata_require_separate_pvs=1
to enforce separe meta and data LV - on default settings, this is not
enable thus segment allocation is meant to work.
NOTE:
As already said - the original intention of this whole 'if()' is unclear,
so try to split this test into multiple more simple tests that are more readable.
TODO: more validation.
Allow creation of any virtual segment type with just --virtualsize
specified without any real extent size give.
TODO: likely --type error,zero might be later enhanced to use -V
(along with -L) - but since those targets do not allocate real
space, supporting -V makes sense with them.
Amound of linked libraries grows.
Most of them we don't need to lock in, since we are not using
them in locked section, so skip locking them in memory.
It's important to lock memory beforo running SUSPEND ioctl - but whole
lvm preload runs in memory unlocked environment - as in this phase
memory allocation is allowed and is meant to happen.
Once all targets are preload and ready (confirmed from all targets)
we start suspending tree - and here the memory allocation (or i.e.
opening files) is no longer allowed - as it may cause kernel deadlock.
udev creates a train wreck of events if we open devices
with RDWR. Until we can fix/disable/scrap udev, work around
this by opening RDONLY and then closing/reopening RDWR when
a write is needed. This invalidates the bcache blocks for
the device before writing so it can trigger unnecessary
rereading.
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.)
The md filter can operate in two native modes:
- normal: reads only the start of each device
- full: reads both the start and end of each device
md 1.0 devices place the superblock at the end of the device,
so components of this version will only be identified and
excluded when lvm uses the full md filter.
Previously, the full md filter was only used in commands
that could write to the device. Now, the full md filter
is also applied when there is an md 1.0 device present
on the system. This means the 'pvs' command can avoid
displaying md 1.0 components (at the cost of doubling
the i/o to every device on the system.)
(The md filter can operate in a third mode, using udev,
but this is disabled by default because there have been
problems with reliability of the info returned from udev.)
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.
vgreduce, vgremove and vgcfgrestore were acquiring
the orphan lock in the midst of command processing
instead of at the start of the command. (The orphan
lock moved to being acquired at the start of the
command back when pvcreate/vgcreate/vgextend were
reworked based on pvcreate_each_device.)
vgsplit also needed a small update to avoid reacquiring
a VG lock that it already held (for the new VG name).
A few places were calling a function to check if a
VG lock was held. The only place it was actually
needed is for pvcreate which wants to do its own
locking (and scanning) around process_each_pv.
The locking/scanning exceptions for pvcreate in
process_each_pv/vg_read can be enabled by just passing
a couple of flags instead of checking if the VG is
already locked. This also means that these special
cases won't be enabled unknowingly in other places
where they shouldn't be used.
When pvmoving LV - the target for LV is a mirror so the validation
that checked the type is matching was incorrect.
While we need a more generic enhancment of LVS output for pvmoved LVs,
for now at least stop showing internal errors and 'X' symbols in attrs.
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.
The options: --nolocking, --readonly, --sysinit
override, or make exceptions to, the normal file locking
behavior. Implement these by just checking for the
options in the file locking path instead of using
special locking types.
Basic LV functions:
activate_lv(), deactivate_lv(),
suspend_lv(), resume_lv()
were routed through the locking infrastruture on the way to:
lv_activate_with_filter(), lv_deactivate(),
lv_suspend_if_active(), lv_resume_if_active()
This commit removes the locking infrastructure from the
middle and calls the later functions directly from the former.
There were a couple of ancillary steps that the locking
infrastructure added along the way which are still included:
- critical section inc/dec during suspend/resume
- checking for active component LVs during activate
The "activation" file lock (serializing activation) has not
been kept because activation commands have been changed to
take the VG file lock exclusively which makes the activation
lock unused and unnecessary.
Four commands lock two VGs at a time:
- vgsplit and vgmerge already have their own logic to
acquire the locks in the correct order.
- vgimportclone and vgrename disable this ordering check.
Different flavors of activate_lv() and lv_is_active()
which are meaningful in a clustered VG can be eliminated
and replaced with whatever that flavor already falls back
to in a local VG.
e.g. lv_is_active_exclusive_locally() is distinct from
lv_is_active() in a clustered VG, but in a local VG they
are equivalent. So, all instances of the variant are
replaced with the basic local equivalent.
For local VGs, the same behavior remains as before.
For shared VGs, lvmlockd was written with the explicit
requirement of local behavior from these functions
(lvmlockd requires locking_type 1), so the behavior
in shared VGs also remains the same.
Remove the io error message from bcache.c since it is not
very useful without the device path.
Make the io error messages from dev_read_bytes/dev_write_bytes
more user friendly.
"lvconvert --type {linear|striped|raid*} ..." on a striped/linear
LV provides convenience interim type to convert to the requested
final layout similar to the given raid* <-> raid* conveninece types.
Whilst on it, add missing raid5_n convenince type from raid5* to raid10.
Resolves: rhbz1439925
Resolves: rhbz1447809
Resolves: rhbz1573255
In this command, lvcreate creates a new LV and then combines
it with an existing cache pool, producing a cache LV. This
command was previously not allowed in in a shared VG.
When the lvmlockd lock is shared, upgrade it to ex
when repair (writing) is needed during vg_read.
Pass the lockd state through additional read-related
functions so the instances of repair scattered through
vg_read can be handled.
(Temporary solution until the ad hoc repairs can be
pulled out of vg_read into a top level, centralized
repair function.)
It's not an error if a command requests the global lock
when it has already acquired it. It shouldn't happen,
but there could be cases we've not found.
We have been warning about duplicate devices (and disabling lvmetad)
immediately when the dup was detected (during label_scan). Move the
warnings (and the disabling) to happen later, after label_scan is
finished.
This lets us avoid an unwanted warning message about duplicates
in the special case were md components are eliminated during the
duplicate device resolution.
This minor patch fixes grammar in a few messages which get
printed to users. It also fixes the same grammar mistake in
several comments.
Signed-off-by: Rick Elrod <relrod@redhat.com>
--
The device-mapper directory now holds a copy of libdm source. At
the moment this code is identical to libdm. Over time code will
migrate out to appropriate places (see doc/refactoring.txt).
The libdm directory still exists, and contains the source for the
libdevmapper shared library, which we will continue to ship (though
not neccessarily update).
All code using libdm should now use the version in device-mapper.
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/
md devices using an older superblock version have
superblocks at the end of the md device. For commands
that skip reading the end of devices during filtering,
the md component devs will be scanned, and will appear
as duplicate PVs to the original md device. Remove
these md components from the list of unused duplicate
devices, so they are treated as if they had been
ignored during filtering. This avoids the restrictions
that are placed on using PVs with duplicates.
All these functions are now used as utilities,
e.g. for ioctl (not for io), and need to
open/close the device each time they are called.
(Many of the opens can probably be eliminated by
just using the bcache fd for the ioctl.)
with the --labelsector option. We probably don't
need all this code to support any value for this
option; it's unclear how, when, why it would be
used.
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.
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.
To avoid the chance of freeing a saved vg while another
code path is using it, defer freeing saved vgs until
all the lvmcache content is dropped for the vg.
In case "lvconvert -mN RaidLV" was used on a degraded
raid1 LV, success was returned instead of an error.
Provide message to inform about the need to repair first
before changing number of mirrors and exit with error.
Add new lvconvert-m-raid1-degraded.sh test.
Resolves: rhbz1573960
I don't like having this in a common header because it means you end
up including too much and causing unneccessary dependencies. eg,
lib/misc/lib.h includes libdevmapper.h, internationalisation, and
logging stuff.
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.
The mixed up vg repair code in vg_read was trying
to repair a vg when vg_read was called by clvmd.
The clvmd daemon isn't supposed to be repairing
or writing a vg.
(This is a temporary workaround; vg repair will soon
be pulled out of vg_read so it can be called in a
controlled way and consolidated instead of spread
around.)
Shift refresh of mirror table right into monitor_dev_for_events().
Use !vg_write_lock_held() to recognize use of lvchange/vgchange.
(this shall change if this would no longer work, but requires
futher some API changes).
With this patch dm mirror table is only refreshed when necassary.
Also update WARNING message about mirror usage without monitoring
and display LV name.
bcache_invalidate() now returns a bool to indicate success. If fails
if the block is currently held, or the block is dirty and writeback
fails.
Added a bunch of unit tests for the invalidate functions.
Fixed some bugs to do with invalidating errored blocks.
In some pvmove tests, clvmd uses the new (precommitted)
saved_vg, but then requests the old saved_vg, and
expects that the new saved_vg be returned instead of
the old. So, when returning the new saved_vg, forget
the old one so we don't return it again.
The filters save information about devices that should
be ignored, so if we need to repeat a scan (unusual,
but happens in clvmd), we need to update the filters.
When clvmd does a full label scan just prior to
calling _vg_read(), pass a new flag into _vg_read
to indicate that the normal rescan of VG devs is
not needed.
After reading a VG, stash it in lvmcache as "saved_vg".
Before reading the VG again, try to use the saved_vg.
The saved_vg is dropped on VG lock operations.
The copy of the VG which clvmd stashes in lvmcache should
not only be used between suspend and resume, but between
sequential LV operations in clvmd, so that clvmd does not
need to reread the VG for each one. Prepare for that by
renaming the stashed VG as "saved_vg".
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.)
Don't allow writes in test mode. test mode should be
more sophisticated than just faking writes, and this
should be a last defense for cases where test mode is
not being checked correctly.
Recent changes allow some major simplification of the way
lvmcache works and is used. lvmcache_label_scan is now
called in a controlled fashion at the start of commands,
and not via various unpredictable side effects. Remove
various calls to it from other places. lvmcache_label_scan
should not be called from anywhere during a command, because
it produces an incorrect representation of PVs with no MDAs,
and misclassifies them as orphans. This has been a long
standing problem. The invalid flag and rescanning based on
that is no longer used and removed. The 'force' variation is
no longer needed and removed.
