David Teigland [Wed, 3 Nov 2021 17:03:29 +0000 (12:03 -0500)]
vgchange -aay: optimize device scan using pvs_online files
Port the old pvscan -aay scanning optimization to vgchange -aay.
The optimization uses pvs_online files created by pvscan --cache
to derive a list of devices to use when activating a VG. This
allows autoactivation of a VG to avoid scanning all devices, and
only scan the devices used by the VG itself. The optimization is
applied internally using the device hints interface.
The new option "--autoactivation event" is given to pvscan and
vgchange commands that are called by event activation. This
informs the command that it is being used for event activation,
so that it can apply checks and optimizations that are specific
to event activation. Those include:
- skipping the command if lvm.conf event_activation=0
- checking that a VG is complete before activating it
- using pvs_online files to limit device scanning
David Teigland [Thu, 15 Jul 2021 21:33:50 +0000 (16:33 -0500)]
add hints interface to the pvs_online file information
The information in /run/lvm/pvs_online/<pvid> files can
be used to build a list of devices for a given VG.
The pvscan -aay command has long used this information to
activate a VG while scanning only devices in that VG, which
is an important optimization for autoactivation.
This patch implements the same thing through the existing
device hints interface, so that the optimization can be
applied elsewhere. A future patch will take advantage of
this optimization in vgchange -aay, which is now used in
place of pvscan -aay for event activation.
David Teigland [Tue, 2 Nov 2021 20:42:26 +0000 (15:42 -0500)]
filter-sysfs: skip when device id is set
When a device id is set for a device, using an idtype other
than devname, it means that sysfs has been used with the device
to match the device id. So, checking for a sysfs entry for the
device in filter-sysfs is redundant. For any other cases not
covered by this (e.g. devname ids), have filter-sysfs simply
stat /sys/dev/block/major:minor to test if the device exists
in sysfs.
The extensive processing done by filter-sysfs init is removed.
It was taking an immense amount of time with many devices, e.g.
. 1024 PVs in 520 VGs
. 520 concurrent vgchange -ay <vgname> commands
. vgchange scans only PVs in the named VG (based on pvs_online
files from a pending patch)
A large number of the vgchange commands were taking over 1 min,
and nearly half of that time was used by filter-sysfs init.
With this patch, the vgchange commands take about half the time.
David Teigland [Mon, 25 Oct 2021 17:11:17 +0000 (12:11 -0500)]
vgimportdevices: skip lvmlockd locking
Help bootstrapping existing shared vgs into the devices file.
Reading the vg in vgimportdevices would require locking to be
started, but vgchange lockstart won't see the vg if it's not
in the devices file. The lvmlockd locks are not protecting
vg modifications so skipping them here won't be a problem.
Zdenek Kabelac [Sat, 16 Oct 2021 20:08:50 +0000 (22:08 +0200)]
configure.ac: remove unused part
As we are not using 'enable-compat' for anything, remove this section.
Also remove duplicated check for blkid.
Move setting of some AC_ARG_ENABLE defaults into the macro so it's always
defined.
Zdenek Kabelac [Fri, 15 Oct 2021 07:55:08 +0000 (09:55 +0200)]
configure.ac: enhance systemd testing
Enhance logic for checking supported systemd version,
while doing only a single check for systemd package.
For version checking use PKG_CHECK_EXISTS() macro.
Also use one pkg check for blkid.
Avoid checking version for thin/cache_check when tools are not present
on system.
Zdenek Kabelac [Thu, 14 Oct 2021 20:36:33 +0000 (22:36 +0200)]
configure.ac: improvement
Handle automatically new setttings
--disable-systemd-journal
--disable-appmachineid
Both setting will check presence of apropriate header files.
In case they are present, build will try to automatically build with
them (adding systemd dependency)
User can anytime disabled them and drop systemd dependency.
Also add --with-default-use-devices-file configure option to
select automatically default value for this option.
For this moment keep default upstream as 0
Zdenek Kabelac [Thu, 14 Oct 2021 21:31:21 +0000 (23:31 +0200)]
archiving: update refactoring
Commit 5ea426e65628218569ede461312d80ba5d1c50fb handled case with
file path without '/' incorrectly - there is valid use-case so
switch 'log_error()' to valid code branch.
David Teigland [Wed, 13 Oct 2021 19:13:54 +0000 (14:13 -0500)]
toollib: remove all devices list from process_each_pv
Reporting non-PVs / "all devices" is only done by
pvs -a or pvdisplay -a, so avoid the work managing
a list of all devices in process_each_pv.
In the case when it's needed, use the results of
label_scan which already determines which devs
are not PVs.
David Teigland [Wed, 9 Dec 2020 16:59:40 +0000 (10:59 -0600)]
pvscan: add options listlvs listvg checkcomplete
pvscan --cache <dev>
. read only dev
. create online file for dev
pvscan --listvg <dev>
. read only dev
. list VG using dev
pvscan --listlvs <dev>
. read only dev
. list VG using dev
. list LVs using dev
pvscan --cache --listvg [--checkcomplete] <dev>
. read only dev
. create online file for dev
. list VG using dev
. [check online files and report if VG is complete]
pvscan --cache --listlvs [--checkcomplete] <dev>
. read only dev
. create online file for dev
. list VG using dev
. list LVs using dev
. [check online files and report if VG is complete]
. [check online files and report if LVs are complete]
[--vgonline]
can be used with --checkcomplete, to enable use of a vg online
file. This results in only the first pvscan command to see
the complete VG to report 'VG complete', and others will report
'VG finished'. This allows the caller to easily run a single
activation of the VG.
[--udevoutput]
can be used with --cache --listvg --checkcomplete, to enable
an output mode that prints LVM_VG_NAME_COMPLETE='vgname' that
a udev rule can import, and prevents other output from the
command (other output causes udev to ignore the command.)
The list of complete LVs is meant to be passed to lvchange -aay,
or the complete VG used with vgchange -aay.
When --checkcomplete is used, lvm assumes that that the output
will be used to trigger event-based autoactivation, so the pvscan
does nothing if event_activation=0 and --checkcomplete is used.
David Teigland [Wed, 20 May 2020 15:59:38 +0000 (10:59 -0500)]
system_id: new appmachineid option
The new system_id_source="appmachineid" will cause
lvm to use an lvm-specific derivation of the machine-id,
instead of the machine-id directly. This is now
recommended in place of using machineid.
Zdenek Kabelac [Fri, 1 Oct 2021 14:19:53 +0000 (16:19 +0200)]
archiving: refactor code to allocate less memory
Do not store full path with each archived name reduces memory usage if
the directory has thousands of entries and just add 'dir' path when
needed.
Also emit info print message to a user if the total size of archived
files for a VG is more then 128MiB or 8192 files.
TODO: Consider wheather adding a new 'lvm.conf archive{option}' to support
trimming these wild archive sizes can make situation better.
We already support retain_min && retain_days - but if user is
generating too many and too large archives with minutes - maybe archiving
should be disabled by a user - as it's not producing anything largely usable
and just slows-down command ??
If we add 'retain_max & retain_max_size' the condition will go against
each other and we need to chose priorities.
David Teigland [Tue, 28 Sep 2021 19:58:03 +0000 (14:58 -0500)]
handle bad metadata text in vg_read path
Corrupt metadata text (with good mda header) was being handled
in the label_scan phase, but not in the vg_read phase. This
was sufficient because metadata areas would always be read and
checksummed during label_scan (metadata parsing was skipped
previously as an optimization.)
Now, some metadata areas will not be read and checksummed
at all during the label_scan phase, only during the vg_read
phase. This means that bad metadata text may first be detected
in the vg_read phase. So, add equivalent bad metadata handling
to the vg_read path to match the label_scan path.
With larger metadata, decoding 'localtime()' for hinting time creation
of every LV may cause excessive check of /etc/localtime file.
Set TZ to ":/etc/localtime" so glibc reads this file just once
instead of check everytime if there has anything changed.
metadata: optimize reading metadata copies in scan
While being in lockless scanning phase, we can avoid reading and checking
matching metadata copies if we already know them from other PV
and just rely on matching metadata header information.
These copies will be examined later during locked metadata read/write
access.
This patch may postpone discovering some read failures to locked phase.
When creating lvm2 metadata for VG, lvm2 allocate some buffer,
and if buffer is not big enough, the buffer is 'reallocated' bigger,
and whole metadata creation is repeated until metadata fits.
We can try to use 'previous' metadata size as hint to reduce looping
here.
Previous patch f853a1bc7afdebb44aeb8c1167e8784d155cad84 enabled
ima measurement unconditionally for every status call,
but it needs to be set only for 'dmsetup measure' command.
Useful when asking for UUID of each device where the list
could be now returned directly with NAME && UUID for each device.
Returning UUID is done in backward-compatible way. There's one unused
32-bit word value after the event number. This patch sets the bit
DM_NAME_LIST_FLAG_HAS_UUID if UUID is present and
DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID if it isn't (if none of these bits is
set, then we have an old kernel that doesn't support returning UUIDs). The
UUID is stored after this word. The 'next' value is updated to point after
the UUID, so that old version of libdevmapper will skip the UUID without
attempting to interpret it.