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Currently both start and offset should always be divisible by alignment,
so this should have no effect, but a later patch will increase alignment
so these variables can no longer be optimised out.
Expand out the metadata wrapping calculations to prepare
to support a larger alignment.
The current alignment is 512 bytes so
(mdac_area_start + rlocn->offset) % alignment is zero.
Mark the first metadata area on each text format PV as MDA_PRIMARY.
Pass this information down to the device layer so that when
there are two metadata areas on a block device, we can easily
distinguish two independent streams of I/O.
Introduce enum dev_io_reason to categorise block device I/O
in debug messages so it's obvious what it is for.
DEV_IO_SIGNATURES /* Scanning device signatures */
DEV_IO_LABEL /* LVM PV disk label */
DEV_IO_MDA_HEADER /* Text format metadata area header */
DEV_IO_MDA_CONTENT /* Text format metadata area content */
DEV_IO_FMT1 /* Original LVM1 metadata format */
DEV_IO_POOL /* Pool metadata format */
DEV_IO_LV /* Content written to an LV */
DEV_IO_LOG /* Logging messages */
When an ignored metadata area gets flagged for use again, make sure the
code doesn't try to parse its old metadata. Firstly by trying to detect
this situation and skipping the read (while still remembering the
position reached in the circular buffer), and secondly by clearing the
invalid live metadata location on disk as a precaution when subsequently
writing out the precommitted metadata.
Problems showed up when a metadata area in one VG got moved to
another VG in ignored state (still holding metadata for the original
VG) and then later got brought into use in the new VG - only the header
should be read in this case, not any of the metadata content.
vgmerge suffers from a similar problem to the one fixed in commit
8146548d25 ("vgsplit: Fix intermediate
metadata corruption.")
When merging, splitting or renaming VGs, use a new PV status flag
PV_MOVED_VG to mark the PVs that hold metadata with the old VG name and
use this to provide PV-level granularity instead of incorrectly assuming
all PVs in the VG are the same.
Changing the VG of a PV uses the same on-disk mechanism as vgrename.
This relies on recognising both the old and new VG names. Prior to this
patch the vgsplit code incorrectly provided the new VG name twice
instead of the old and new ones. This lead the low-level mechanism not
to recognise the device as already belonging to a VG and so paying no
attention to the location of its existing metadata, sometimes partly
overwriting it and then later trying to read the corrupt metadata and
issuing a checksum error.
Fix code checking that the 2nd mda which is at the end of disk really
fits the available free space and avoid any DA and MDA interleaving when
we already have DA preallocated. This mainly applies when we're restoring
a PV from VG backup using pvcreate --restorefile where we may already have
some DA preallocated - this means the PV was in a VG before with already
allocated space from it (the LVs were created). Hence we need to avoid
stepping into DA - the MDA can never ever be inside in such case!
The code responsible for this calculation was already in
_text_pv_add_metadata_area fn, but it had a bug in the calculation where
we subtracted one more sector by mistake and then the code could still
incorrectly allocate the MDA inside existing DA. The patch also renames
the variable in the code so it doesn't confuse us in future.
Also, if the 2nd mda doesn't fit, don't silently continue with just 1
MDA (at the start of the disk). If 2nd mda was requested and we can't
create that due to unavailable space, error out correctly (the patch
also adds a test to shell/pvcreate-operation.sh for this case).
A number of places are working on a specific dev when they
call lvmcache_info_from_pvid() to look up an info struct
based on a pvid. In those cases, pass the dev being used
to lvmcache_info_from_pvid(). When a dev is specified,
lvmcache_info_from_pvid() will verify that the cached
info it's using matches the dev being processed before
returning the info. Calling code will not mistakenly
get info for the wrong dev when duplicate devs exist.
This confusion was happening when scanning labels when
duplicate devs existed. label_read for the first dev
would add an info struct to lvmcache for that dev/pvid.
label_read for the second dev would see the pvid in
lvmcache from first dev, and mistakenly conclude that
the label_read from the second dev can be skipped
because it's already been done. By verifying that the
dev for the cached pvid matches the dev being read,
this mismatch is avoided and the label is actually read
from the second duplicate.
The lvmetad connection is created within the
init_connections() path during command startup,
rather than via the old lvmetad_active() check.
The old lvmetad_active() checks are replaced
with lvmetad_used() which is a simple check that
tests if the command is using/connected to lvmetad.
The old lvmetad_set_active(cmd, 0) calls, which
stopped the command from using lvmetad (to revert to
disk scanning), are replaced with lvmetad_make_unused(cmd).
Use process_each_vg() to lock and read the old VG,
and then call the main vgrename code.
When real VG names are used (not a UUID in place of the
old name), the command still pre-locks the new name
(when strcmp wants it locked first), before calling
process_each_vg on the old name.
In the case where the old name is replaced with a UUID,
process_each_vg now translates that UUID into the real
VG name, which it locks and reads. In this case, we
cannot do pre-locking to maintain lock ordering because
the old name is unknown. So, in this case the strcmp
based lock ordering is suppressed and the old name is
always locked first. This opens a remote chance for
lock ordering conflict between racing vgrenames between
two names where one or both commands use the UUID.
When checking minimum mda size, make sure the mda_size after alignment
and calculation is more than 0 - if there's no place for an MDA at the
end of the disk, the _text_pv_add_metadata_area does not try to add it
there and it returns (because we already have the MDA at the start of
the disk at least).
Actually, we don't need extra condition as introduced in commit
00348c0a63. We should fix the last
condition:
(mdac->rlocn.size >= mdah->size)
...which should be:
(MDA_HEADER_SIZE + (rlocn ? rlocn->size : 0) + mdac->rlocn.size >= mdah->size))
Where the "mdac" is new metadata, the "rlocn" is old metadata.
So the main problem with the previous condition was that it
didn't count in MDA_HEADER_SIZE properly (and possible existing
metadata - the "rlocn"). This could have caused the error state
where metadata in ring buffer overlap to not be hit.
Replace the new condition introduced in 00348c0a63
with the improved one for the condition that existed there
already but it was just incomplete.
We're already checking whether old and new meta do not overlap in
ring buffer (as we need to keep both old and new meta during vg_write
up until vg_commit).
We also need to check whether the new metadata do not overlap
themselves in case we don't have old metadata yet (...because
we're in vgcreate). This could happen if we're creating a VG so
that the very first metadata written are long enough that it wraps
themselves in metadata ring buffer.
Although we limited the minimum metadata area size better with the
previous commit ccb8da404d which
makes the initial VG metadata overlap in ring buffer to be less
probable, the risk of hitting this overlap condition is still there
if we still manage to generate big enough metadata somehow.
For example, users can provide many and/or long VG tags during vgcreate
so that the VG metadata is long enough to start to wrap in the ring
buffer again...
Also, leave out the note about "circular buffer" which is
an internal imeplementation detail anyway and not quite
informational for users:
Before this patch:
$ vgcreate vg1 /dev/sda
VG vg1 metadata too large for circular buffer
Failed to write VG vg1.
With this patch applied:
$ vgcreate vg1 /dev/sda
VG vg1 metadata too large: size of metadata to write is 691 bytes while PV metadata area size on /dev/sda is 512 bytes.
Failed to write VG vg1.
When using lvm shell, some structures which are cached in memory may be
reused. This happens for the struct label (a part of lvmcache_info
structure) when lvmetad is used in which case the PV scan is not
done that would normally overwrite these label structures in memory
and making them up-to-date.
This is all consequence of the fact that struct lvmcache_info and
struct label are not always assigned in the same part of the code.
For example, if lvmetad *is not* used, parts of the struct label are
reassigned in label_read fn while struct lvmcache_info is created
elsewhere. No part of the code reused struct label (and its "dev"
field) before calling label_read fn. That's why the real bug is
hidden when using lvm shell without lvmetad.
However, with lvmetad and lvm shell, the situation is a bit different.
The label_read fn is not called if lvmetad *is* used, hence the
struct label may have ended up not initialized properly.
There was missing assignment for the dev field in struct label
in _text_pv_write fn which caused this problem to appear in
lvm shell with lvmetad, for example:
Before this patch:
lvm> pvcreate /dev/sda
Physical volume "/dev/sda" successfully created
lvm> pvs /dev/sda
PV VG Fmt Attr PSize PFree
unknown device lvm2 --- 128.00m 128.00m
With this patch applied:
lvm> pvcreate /dev/sda
Physical volume "/dev/sda" successfully created
lvm> pvs /dev/sda
PV VG Fmt Attr PSize PFree
/dev/sda lvm2 --- 128.00m 128.00m
Also, this problem had not appeared before changes introduced
by commits e1a63905d1 through
3a6f91d713 which, among other
things, added proper label field type reporting. Before, label
reporting was the same as using struct physical_volume which
has its own dev field assigned and so this problem was not exposed.
Use 64bit arithmentic for PV size calculation (Coverity).
Also remove sector shift for compared PV size, since all
values are already held in sectors.
This fixes validatio of PV size when restoring PV
from vg metadata backup file.
When performing initial allocation (so there is nothing yet to
cling to), use the list of tags in allocation/cling_tag_list to
partition the PVs. We implement this by maintaining a list of
tags that have been "used up" as we proceed and ignoring further
devices that have a tag on the list.
https://bugzilla.redhat.com/983600
pv_write is called both to write orphans and to rewrite PV headers
of PVs in VGs. It needs to select the correct VG id so that the
internal cache state gets updated correctly.
It only affected commands that involved further steps after
the pv_write and was often masked because the metadata would
be re-read off disk and correct itself.
"Incorrect metadata area header checksum" warnings appeared.
Example:
Create vg1 containing dev1, dev2 and dev3.
Hide dev1 and dev2 from the system.
Fix up vg1 with vgreduce --removemissing.
Bring back dev1 and dev2.
In a single operation reinstate dev1 and dev2 into vg1 (vgextend).
Done as separate operations (automatically fix-up dev1 and dev2 as orphans,
then vgextend) it worked, but done all in one go the internal cache got
corrupted and warnings about checksum errors appeared.
The code never mixes reads of committed and precommitted metadata,
so there's no need to attempt to set PRECOMMITTED when
*use_previous_vg is being set.
Refactor the recent metadata-reading optimisation patches.
Remove the recently-added cache fields from struct labeller
and struct format_instance.
Instead, introduce struct lvmcache_vgsummary to wrap the VG information
that lvmcache holds and add the metadata size and checksum to it.
Allow this VG summary information to be looked up by metadata size +
checksum. Adjust the debug log messages to make it clear when this
shortcut has been successful.
(This changes the optimisation slightly, and might be extendable
further.)
Add struct cached_vg_fmtdata to format-specific vg_read calls to
preserve state alongside the VG across separate calls and indicate
if the details supplied match, avoiding the need to read and
process the VG metadata again.
Use similar logic as with text_vg_import_fd() and avoid repeated
parsing of same mda and its config tree for vgname_from_mda().
Remember last parsed vgname, vgid and creation_host in labeller
structure and if the metadata have the same size and checksum,
return this stored info.
TODO: The reuse of labeller struct is not ideal, some lvmcache API for
this functionality would be nicer.
This is probably not optimal, but makes the lvmetad case mimic non-lvmetad code
more closely. It also fixes vgremove of a partially corrupt VG with lvmetad, as
_vg_write_raw (and consequently, entire vg_write) currently panics when it
encounters a corrupt MDA. Ideally, we'd be able to explicitly control when it is
safe to ignore them.
The size of any metadata must be ignored when calculating the size of an
orphan PV.
Bug introduced by 603b45e0ed ("pvresize: Do
not use pv_read (get the PV from orphan VG).")
The metadata/disk_areas setting was incorrectly registered as
"string" configuration option but it's a section where each area
is defined in its own subsection with "start_sector", "size" and "id"
setting.
This setting is not officialy supported, it's undocumented and it's
used solely for debugging.
Note: At this moment, it does not seem to be working with lvmetad!
All labellers always use the "private" (void *) field as the fmt pointer. Making
this fact explicit in the type of the labeller simplifies the label reporting
code which needs to extract the format. Moreover, it removes a number of
error-prone casts from the code.
When reading an info about MDAs from lvmetad, we need to use 64 bit
int to read the value of the offset/size, otherwise the value is
overflows and then it's used throughout!
This is dangerous if we're trying to write such metadata area then,
mostly visible if we're using 2 mdas where the 2nd one is at the end
of the underlying device and hence the value of the mda offset is
high enough to cause problems:
(the offset trimmed to value of 0 instead of 4096m, so we write
at the very start of the disk (or elsewhere if the offset has
some other value!)
[1] raw/~ # lvcreate -s -l 100%FREE vg --virtualsize 4097m
Logical volume "lvol0" created
[1] raw/~ # pvcreate --metadatacopies 2 /dev/vg/lvol0
Physical volume "/dev/vg/lvol0" successfully created
[1] raw/~ # hexdump -n 512 /dev/vg/lvol0
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
0000200
[1] raw/~ # pvchange -u /dev/vg/lvol0
Physical volume "/dev/vg/lvol0" changed
1 physical volume changed / 0 physical volumes not changed
[1] raw/~ # hexdump -n 512 /dev/vg/lvol0
0000000 d43e d2a5 4c20 4d56 2032 5b78 4135 7225
0000010 4e30 3e2a 0001 0000 0000 0000 0000 0000
0000020 0000 0010 0000 0000 0000 0000 0000 0000
0000030 0000 0000 0000 0000 0000 0000 0000 0000
*
0000200
=======
(the offset overflows to undefined values which is far behind
the end of the disk)
[1] raw/~ # lvcreate -s -l 100%FREE vg --virtualsize 100g
Logical volume "lvol0" created
[1] raw/~ # pvcreate --metadatacopies 2 /dev/vg/lvol0
Physical volume "/dev/vg/lvol0" successfully created
[1] raw/~ # pvchange -u /dev/vg/lvol0
/dev/vg/lvol0: lseek 18446744073708503040 failed: Invalid argument
/dev/vg/lvol0: lseek 18446744073708503040 failed: Invalid argument
Failed to store physical volume "/dev/vg/lvol0"
0 physical volumes changed / 1 physical volume not changed
If "vgcreate/lvcreate --profile <profile_name>" is used, the profile
name is automatically stored in metadata for making it possible to
load it automatically next time the VG/LV is used.
When vgname has not existed in metadata, it has crashed on double free
in format_instance destroy() - since VG was created, used FID and was
released - which also released FID, so further use was accessing bad
memory.
Fix it for this code path before release_vg() so FID will exists
when _vg_read_file_name() returns NULL.
For example, the old call and reference:
find_config_tree_str(cmd, "devices/dir", DEFAULT_DEV_DIR)
...now becomes:
find_config_tree_str(cmd, devices_dir_CFG)
So we're referring to the named configuration ID instead
of passing the configuration path and the default value
is taken from central config definition in config_settings.h
automatically.
The PV header extension information (PV header extension version, flags
and list of Embedding Area locations) is stored just beyond the PV header base.
When calculating the Embedding Area start value (ea_start), the same logic is
used as when calculating the pe_start value for Data Area - the value must
follow exactly the same alignment restrictions for its start value
(the alignment detected automatically or provided via command line using
the --dataalignment and --dataalignmentoffset arguments).
The Embedding Area is placed at the very start of the PV, starting at
ea_start. The Data Area starting at pe_start is placed next. The pe_start is
still properly aligned. Due to the pe_start alignment, it's possible that the
resulting Embedding Area size (ea_size) ends up bigger in size than requested
(but never less than requested).
PV header extension comes just beyond the existing PV header base:
PV header base (existing):
- uuid
- device size
- null-terminated list of Data Areas
- null-terminater list of MetaData Areas
PV header extension:
- extension version
- flags
- null-terminated list of Embedding Areas
This patch also adds "eas" (Embedding Areas) list to lvmcache (lvmcache_info)
and it also adds support for common operations on the list (just like for
already existing "das" - Data Areas list):
- lvmcache_add_ea
- lvmcache_update_eas
- lvmcache_foreach_ea
- lvmcache_del_eas
Also, add ea_start and ea_size to struct physical_volume for processing
PV Embedding Area location throughout the code (currently only one
Embedding Area is supported, though the definition on disk allows for
more if needed in the future...).
Also, define FMT_EAS format flag to mark that the format actually
supports Embedding Areas (currently format-text only).
If zero metadata copies are used, there's no further recalculation of
PV alignment that happens when adding metadata areas to the PV and
which actually calculates the alignment correctly as a matter of fact.
So fix this for "PV without MDA" case as well.
Before this patch:
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 1 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 12.00m
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 0 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 8.00m
After this patch:
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 1 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 12.00m
[1] raw/~ # pvcreate --dataalignment 8m --dataalignmentoffset 4m
--metadatacopies 0 /dev/sda
Physical volume "/dev/sda" successfully created
[1] raw/~ # pvs -o pv_name,pe_start
PV 1st PE
/dev/sda 12.00m
Also, remove a superfluous condition "pv->pe_start < pv->pe_align" in:
if (pe_start == PV_PE_START_CALC && pv->pe_start < pv->pe_align)
pv->pe_start = pv->pe_align ...
This part of the condition is not reachable as with the PV_PE_START_CALC,
we always have pv->pe_start set to 0 from the PV struct initialisation
(...the pv->pe_start value is just being calculated).
We were using daemon_send_simple until now, but it is no longer adequate, since
we need to manipulate requests in a generic way (adding a validity token to each
request), and the tree-based request interface is much more suitable for this.
Add 3rd daemon return state "unknown" for lookups that are carried out
successfully but don't find the item requested.
Avoid issuing error messages when it's expected that a device that's
being looked up in lvmetad might not be there.
Move commod code to destroy orphan VG into free_orphan_vg() function.
Use orphan vgmem for creation of PV lists.
Remove some free_pv_fid() calls (FIXME: check all of them)
FIXME: Check whether we could merge release_vg back again for all VGs.
Use static buffer instead of stack allocated buffer.
This reduces stack size usage of lvm tool and the
change is very simple.
Since the whole library is not thread safe - it should not
add any new problems - and if there will be some conversion
it's easy to convert this to use some preallocated buffer.
leaving behind the LVM-specific parts of the code (convenience wrappers that
handle `struct device` and `struct cmd_context`, basically). A number of
functions have been renamed (in addition to getting a dm_ prefix) -- namely,
all of the config interface now has a dm_config_ prefix.
There's a very high memory usage when calling _pv_analyse_mda_raw (e.g. while
executing pvck) that can end up with "out of memory".
_pv_analyse_mda_raw scans for metadata in the MDA, iteratively increasing the
size to scan with SECTOR_SIZE until we find a probable config section or we're
at the edge of the metadata area. However, when using a memory pool, we're also
iteratively chasing for bigger and bigger mempool chunk which can't be found
and so we're always allocating a new one, consuming more and more memory...
This patch just changes the mempool to direct memory allocation in this
problematic part of the code.
Move the free_vg() to vg.c and replace free_vg with release_vg
and make the _free_vg internal.
Patch is needed for sharing VG in vginfo cache so the release_vg function name
is a better fit here.
transient error), stemming from the following sequence of events:
1) devices fail IO, triggering repair
2) dmeventd starts fixing up the mirror
3) during the downconversion, a new metadata version is written
--> the devices come back online here
4) the mirror device suspend/resume is called to update DM tables
5) during the suspend/resume cycle, *pre*-commit metadata is read;
however, since the failed devices are now back online, we get back
inconsistent set of precommit metadata and the whole operation fails
The patch relaxes the check that fails in step 5 above, namely by ignoring
inconsistencies coming from PVs that are marked MISSING.
Before, we used vg_write_lock_held call to determnine the way a device is
opened. Unfortunately, this opened many devices in RW mode when it was not
really necessary. With the OPTIONS+="watch" rule used in the udev rules,
this could fire numerous events while closing such devices (and it caused
useless scans from within udev rules in return).
A common bug we hit with this was with the lvremove command which was unable
to remove the LV since it was being opened from within the udev rules. This
patch should minimize such situations (at least with respect to LVM handling
of devices).
Though there's still a possibility someone will open a device 'outside' in
parallel and fire the event based on the watch rule when closing a device
once opened for RW.
Avoid using of already released memory when duplicated MDA is found.
As get_pv_from_vg_by_id() may call lvmcache_label_scan() use the local copy
of the vgname and vgid on the stack as vginfo may dissapear and code was
then accessing garbage in memory.
i.e. pvs /dev/loop0
(when /dev/loop0 and /dev/loop1 has same MDA content)
Invalid read of size 1
at 0x523C986: dm_hash_lookup (hash.c:325)
by 0x440C8C: vginfo_from_vgname (lvmcache.c:399)
by 0x4605C0: _create_vg_text_instance (format-text.c:1882)
by 0x46140D: _text_create_text_instance (format-text.c:2243)
by 0x47EB49: _vg_read (metadata.c:2887)
by 0x47FBD8: vg_read_internal (metadata.c:3231)
by 0x477594: get_pv_from_vg_by_id (metadata.c:344)
by 0x45F07A: _get_pv_if_in_vg (format-text.c:1400)
by 0x45F0B9: _populate_pv_fields (format-text.c:1414)
by 0x45F40F: _text_pv_read (format-text.c:1493)
by 0x480431: _pv_read (metadata.c:3500)
by 0x4802B2: pv_read (metadata.c:3462)
Address 0x652ab80 is 0 bytes inside a block of size 4 free'd
at 0x4C2756E: free (vg_replace_malloc.c:366)
by 0x442277: _free_vginfo (lvmcache.c:963)
by 0x44235E: _drop_vginfo (lvmcache.c:992)
by 0x442B23: _lvmcache_update_vgname (lvmcache.c:1165)
by 0x443449: lvmcache_update_vgname_and_id (lvmcache.c:1358)
by 0x443C07: lvmcache_add (lvmcache.c:1492)
by 0x46588C: _text_read (text_label.c:271)
by 0x466A65: label_read (label.c:289)
by 0x4413FC: lvmcache_label_scan (lvmcache.c:635)
by 0x4605AD: _create_vg_text_instance (format-text.c:1881)
by 0x46140D: _text_create_text_instance (format-text.c:2243)
by 0x47EB49: _vg_read (metadata.c:2887)
Add testing script
This is essential for proper format instance ref_count support. We must
use these functions to set the fid everywhere from now on, even the NULL
value!
We'd like to use the fid mempool for text_context that is stored
in the instance (we used cmd mempool before, so the order of
initialisation was not a matter, but now it is since we need to
create the fid mempool first which happens in create_instance fn).
The text_context initialisation is not needed anywhere outside the
create_instance fn so move it there.
Format instances can be created anytime on demand and it contains
metadata area information mostly (at least for now, but in the future,
we may store more things here to update/edit in a PV/VG). In case we
have lots of metadata areas, memory consumption will rise. Using cmd
context mempool is not quite optimal here because it is destroyed too
late. So let's use a separate mempool for format instances.
Reference counting is used because fids could be shared, e.g. each PV
has either a PV-based fid or VG-based fid. If it's VG-based, each PV has
a shared fid with the VG - a reference to VG's fid.
We allow writing non-orphan PVs only for resize now. The "orphan PV" assert
in pv_write fn uses the "allow_non_orphan" parameter to control this assert.
However, we should find a more elaborate solution so we can remove this
restriction altogether (pv_write together with vg_write is not atomic, we
need to find a safe mechanism so there's an easy revert possible in case of
an error).
If the PV is already part of the VG (so the pv->fid == vg->fid), it makes no
sense to attach the mdas information from PV to a VG. Instead, we read new
PV metadata information from cache and attach it to the VG fid.
Add supporting functions to work with the format instance and metadata area
structures stored within the format instance. Add support for simple indexing
of metadata areas using PV id and mda order (for on-disk PV only for now, we
can extend the indexing even for other mdas if needed - we only need to define
a proper key for the index).
New strategy for memory locking to decrease the number of call to
to un/lock memory when processing critical lvm functions.
Introducing functions for critical section.
Inside the critical section - memory is always locked.
When leaving the critical section, the memory stays locked
until memlock_unlock() is called - this happens with
sync_local_dev_names() and sync_dev_names() function call.
memlock_reset() is needed to reset locking numbers after fork
(polldaemon).
The patch itself is mostly rename:
memlock_inc -> critical_section_inc
memlock_dec -> critical_section_dec
memlock -> critical_section
Daemons (clmvd, dmevent) are using memlock_daemon_inc&dec
(mlockall()) thus they will never release or relock memory they've
already locked memory.
Macros sync_local_dev_names() and sync_dev_names() are functions.
It's better for debugging - and also we do not need to add memlock.h
to locking.h header (for memlock_unlock() prototyp).
As const segment_type or const format_type are never released
use their non-const version and remove const downcast from dm_free calls.
This change fixes many gcc warnings we were getting from them.
To have better control were the config tree could be modified use more
const pointers and very carefully downcast them back to non-const
(for config tree merge).
Set cmd->independent_metadata_areas if metadata/dirs or disk_areas in use.
- Identify and record this state.
Don't skip full scan when independent mdas are present even if memlock is set.
- Clusters and OOM aren't supported, so no problem doing the proper scans.
Avoid revalidating the label cache immediately after scanning.
- A simple optimisation.
Support scanning for a single VG in independent mdas.
- Not used by the fix but I left it in anyway as later patches might use it.
In other LVM memory structures such as volume_group, the field
used to store flags is called "status", and on-disk fields are called
'flags', so rename the one inside metadata_area to be consistent.
Not only is it more consistent with existing code but is cleaner
to say "the status of this mda is ignored".
Background for this patch - prajnoha pinged me on IRC this morning
about a fix he was working on related to metadataignore when
metadata/dirs was set. I was reviewing my patches from this year
and realized the 'flags' field was probably not the best choice
when I originally did the metadataignore patches.
Add "devices/default_data_alignment" to lvm.conf to control the internal
default that LVM2 uses: 0==64k, 1==1MB, 2==2MB, etc.
If --dataalignment (or lvm.conf's "devices/data_alignment") is specified
then it is always used to align the start of the data area. This means
the md_chunk_alignment and data_alignment_detection are disabled if set.
(Same now applies to pvcreate --dataalignmentoffset, the specified value
will be used instead of the result from data_alignment_offset_detection)
set_pe_align() still looks to use the determined default alignment
(based on lvm.conf's default_data_alignment) if the default is a
multiple of the MD or topology detected values.
Pass metadataignore through PV creation / setup paths.
As a result of this cleanup, we can remove the unnecessary setting
of mda_ignore bits inside pvcreate_single(), after call to pv_create.
For now, just set metadataignore to '0' in some places. This is
equivalent to the prior functionality, although the 0 is given
by the caller not hardcoded in _mda_setup() call.
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Allow metadataignore flag to be passed in to pvcreate.
Ideally, more refactoring of the mda allocation / initialization
is warranted, but for now, we just add another parameter to 'add_mda'
to take an existing mda ignored flag. We need to do this or pv_write
loses the state of the mda 'ignored' flag before copying and writing
to disk.
Print device name when setting or clearing metadata ignore bit.
Example:
label/label.c:160 /dev/loop2: lvm2 label detected
cache/lvmcache.c:1136 lvmcache: /dev/loop2: now in VG #orphans_lvm2 (#orphans_lvm2)
metadata/metadata.c:4142 Setting mda ignored flag for metadata_locn /dev/loop2.
format_text/text_label.c:318 Skipping mda with ignored flag on device /dev/loop2 at offset 4096
There's an intermittent failure with vgcfgbackup that seems to have been
introduced with the metadataignore / vgmetadatacopies patchset.
Intermittent failures are often the result of uninitialized data,
so this patch calls zalloc in a few places it might matter.
