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Analyzer here was rather confused about possiblity of loosing previously
assigned device pointers - fixed by passing zero initialize memory
before first assign.
Mask for strncpy() Coverity report warning would
actually need to copy buffer from 'tmp_name' instead of 'str'.
But replace it directly with single 'strncpy()' again for better readbility,
just mask out the warning reported for this strncpy instance
(so we do not need to put comment fro every call of strcpy_name_len).
- Use a new function for all instances of copying
a null-terminated string into a fixed size struct
field that is not null-terminated.
- use memcpy when copying between struct fields of
the same size
In testing where we inject large amounts of additional output in stderr
we can occassionally get truncated stdout from lvm. Catching and dumping
the json for debug before we re-raise the exception. As this doesn't
happen without the error injecting wrapper around lvm, the error seems to
be with the wrapper.
Signed-off-by: Tony Asleson <tasleson@redhat.com>
When exec'ing lvm, it's possible to get large amounts of both stdout
and stderr depending on the state of lvm and the size of the lvm
configuration. If we allow any of the buffers to fill we can end
up deadlocking the process. Ensure we are handling stdout & stderr
during lvm execution.
Ref. https://bugzilla.redhat.com/show_bug.cgi?id=1966636
Signed-off-by: Tony Asleson <tasleson@redhat.com>
When we are walking the new lvm state comparing it to the old state we can
run into an issue where we remove a VG that is no longer present from the
object manager, but is still needed by LVs that are left to be processed.
When we try to process existing LVs to see if their state needs to be
updated, or if they need to be removed, we need to be able to reference the
VG that was associated with it. However, if it's been removed from the
object manager we fail to find it which results in:
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/lvmdbusd/utils.py", line 666, in _run
self.rc = self.f(*self.args)
File "/usr/lib/python3.6/site-packages/lvmdbusd/fetch.py", line 36, in _main_thread_load
cache_refresh=False)[1]
File "/usr/lib/python3.6/site-packages/lvmdbusd/lv.py", line 146, in load_lvs
lv_name, object_path, refresh, emit_signal, cache_refresh)
File "/usr/lib/python3.6/site-packages/lvmdbusd/loader.py", line 68, in common
num_changes += dbus_object.refresh(object_state=o)
File "/usr/lib/python3.6/site-packages/lvmdbusd/automatedproperties.py", line 160, in refresh
search = self.lvm_id
File "/usr/lib/python3.6/site-packages/lvmdbusd/lv.py", line 483, in lvm_id
return self.state.lvm_id
File "/usr/lib/python3.6/site-packages/lvmdbusd/lv.py", line 173, in lvm_id
return "%s/%s" % (self.vg_name_lookup(), self.Name)
File "/usr/lib/python3.6/site-packages/lvmdbusd/lv.py", line 169, in vg_name_lookup
return cfg.om.get_object_by_path(self.Vg).Name
Instead of removing objects from the object manager immediately, we will
keep them in a list and remove them once we have processed all of the state.
Ref:
https://bugzilla.redhat.com/show_bug.cgi?id=1968752
As SUSE build tool reports the warning:
lvmlockd-core.c: In function 'client_thread_main':
lvmlockd-core.c:4959:37: warning: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size 6 [-Wformat-truncation=]
snprintf(buf, sizeof(buf), "path[%d]", i);
^~
lvmlockd-core.c:4959:31: note: directive argument in the range [0, 2147483647]
snprintf(buf, sizeof(buf), "path[%d]", i);
^~~~~~~~~~
To dismiss the compilation warning, enlarge the array "buf" to 17
bytes to support the max signed integer: string format 6 bytes + signed
integer 10 bytes + terminal char "\0".
Reported-by: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
To allow the IDM locking scheme be used by users, this patch hooks the
IDM wrapper; it also introducs a new locking type "idm" and we can use
it for global lock with option '-g idm'.
To support IDM locking type, the main change in the data structure is to
add pvs path arrary. The pvs list is transferred from the lvm commands,
when lvmlockd core layer receives message, it extracts the message with
the keyword "path[idx]". Finally, the pv list will pass to IDM lock
manager as the target drives for sending IDM SCSI commands.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Alongside the existed locking schemes of DLM and sanlock, this patch is
to introduce new locking scheme: In-Drive-Mutex (IDM).
With the IDM support in the drive, the locks are resident in the drive,
thus, the locking lease is maintained in a central place: the drive
firmware. We can consider this is a typical client-server model,
every host (or node) in the server cluster launches the request for
leasing mutex to a drive firmware, the drive firmware works as an
arbitrator to grant the mutex to a requester and it can reject other
applicants if the mutex has been acquired. To satisfy the LVM
activation for different modes, IDM supports two locking modes:
exclusive and shareable.
Every IDM is identified with two IDs, one is the host ID and another is
the resource ID. The resource ID is a unique identifier for what the
resource it's protected, in the integration with lvmlockd, the resource
ID is combined with VG's UUID and LV's UUID; for the global locking,
the bytes in resource ID are all zeros, and for the VG locking, the
LV's UUID is set as zero. Every host can generate a random UUID and
use it as the host ID for the SCSI command, this ID is used to clarify
the ownership for mutex.
For easily invoking the IDM commands to drive, like other locking
scheme (e.g. sanlock), a daemon program named IDM lock manager is
created, so the detailed IDM SCSI commands are encapsulated in the
daemon, and lvmlockd uses the wrapper APIs to communicate with the
daemon program.
This patch introduces the IDM locking wrapper layer, it forwards the
locking requests from lvmlockd to the IDM lock manager, and returns the
result from drives' responding.
One thing should be mentioned is the IDM's LVB. IDM supports LVB to max
7 bytes when stores into the drive, the most significant byte of 8 bytes
is reserved for control bits. For this reason, the patch maps the
timestamp in macrosecond unit with its cached LVB, essentially, if any
timestamp was updated by other nodes, that means the local LVB is
invalidate. When the timestamp is stored into drive's LVB, it's
possbile to cause time-going-backwards issue, which is introduced by the
time precision or missing synchronization acrossing over multiple nodes.
So the IDM wrapper fixes up the timestamp by increment 1 to the latest
value and write back into drive.
Currently LVB is used to track VG changes and its purpose is to notify
lvmetad cache invalidation when detects any metadata has been altered;
but lvmetad is not used anymore for caching metadata, LVB doesn't
really work. It's possible that the LVB functionality could be useful
again in the future, so let's enable it for IDM in the first place.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
If the 'act' has been already processed by add_client_result()
it could have been possibly release - so avoid accessin 'act->'
afterward and go for next item directly.
Enhance handling of interruptions of polling process and lvmpoll daemon.
Daemon should now react much faster on interrups (i.e. shutdown
sequence) and avoid taking lenghty sleep waiting on pvmove signaling.
with fork and exec to avoid use of shell.
largely copied from lib/misc/lvm-exec.c
require lvmlockctl_kill_command to be full path
use lvm config instead of lvmconfig to avoid need for LVM_DIR
The LVM devices file lists devices that lvm can use. The default
file is /etc/lvm/devices/system.devices, and the lvmdevices(8)
command is used to add or remove device entries. If the file
does not exist, or if lvm.conf includes use_devicesfile=0, then
lvm will not use a devices file. When the devices file is in use,
the regex filter is not used, and the filter settings in lvm.conf
or on the command line are ignored.
LVM records devices in the devices file using hardware-specific
IDs, such as the WWID, and attempts to use subsystem-specific
IDs for virtual device types. These device IDs are also written
in the VG metadata. When no hardware or virtual ID is available,
lvm falls back using the unstable device name as the device ID.
When devnames are used, lvm performs extra scanning to find
devices if their devname changes, e.g. after reboot.
When proper device IDs are used, an lvm command will not look
at devices outside the devices file, but when devnames are used
as a fallback, lvm will scan devices outside the devices file
to locate PVs on renamed devices. A config setting
search_for_devnames can be used to control the scanning for
renamed devname entries.
Related to the devices file, the new command option
--devices <devnames> allows a list of devices to be specified for
the command to use, overriding the devices file. The listed
devices act as a sort of devices file in terms of limiting which
devices lvm will see and use. Devices that are not listed will
appear to be missing to the lvm command.
Multiple devices files can be kept in /etc/lvm/devices, which
allows lvm to be used with different sets of devices, e.g.
system devices do not need to be exposed to a specific application,
and the application can use lvm on its own set of devices that are
not exposed to the system. The option --devicesfile <filename> is
used to select the devices file to use with the command. Without
the option set, the default system devices file is used.
Setting --devicesfile "" causes lvm to not use a devices file.
An existing, empty devices file means lvm will see no devices.
The new command vgimportdevices adds PVs from a VG to the devices
file and updates the VG metadata to include the device IDs.
vgimportdevices -a will import all VGs into the system devices file.
LVM commands run by dmeventd not use a devices file by default,
and will look at all devices on the system. A devices file can
be created for dmeventd (/etc/lvm/devices/dmeventd.devices) If
this file exists, lvm commands run by dmeventd will use it.
Internal implementaion:
- device_ids_read - read the devices file
. add struct dev_use (du) to cmd->use_devices for each devices file entry
- dev_cache_scan - get /dev entries
. add struct device (dev) to dev_cache for each device on the system
- device_ids_match - match devices file entries to /dev entries
. match each du on cmd->use_devices to a dev in dev_cache, using device ID
. on match, set du->dev, dev->id, dev->flags MATCHED_USE_ID
- label_scan - read lvm headers and metadata from devices
. filters are applied, those that do not need data from the device
. filter-deviceid skips devs without MATCHED_USE_ID, i.e.
skips /dev entries that are not listed in the devices file
. read lvm label from dev
. filters are applied, those that use data from the device
. read lvm metadata from dev
. add info/vginfo structs for PVs/VGs (info is "lvmcache")
- device_ids_find_renamed_devs - handle devices with unstable devname ID
where devname changed
. this step only needed when devs do not have proper device IDs,
and their dev names change, e.g. after reboot sdb becomes sdc.
. detect incorrect match because PVID in the devices file entry
does not match the PVID found when the device was read above
. undo incorrect match between du and dev above
. search system devices for new location of PVID
. update devices file with new devnames for PVIDs on renamed devices
. label_scan the renamed devs
- continue with command processing
cmd context has 'threaded' value that used be set
by clvmd - and allowed proper memory locking management.
Reuse same bit for dmeventd.
Since dmeventd is using 300KiB stack per thread,
we will ignore any user settings for allocation/reserved_stack
until some better solution is find.
This avoids crashing of dmevend when user changes this value
and because in most cases lvm2 should work ok with 64K stack
size, this change should not cause any problems.
Switch remaining zero sized struct to flexible arrays to be C99
complient.
These simple rules should apply:
- The incomplete array type must be the last element within the structure.
- There cannot be an array of structures that contain a flexible array member.
- Structures that contain a flexible array member cannot be used as a member of another structure.
- The structure must contain at least one named member in addition to the flexible array member.
Although some of the code pieces should be still improved.
The lock adopt feature was disabled since it had used
lvmetad as a source of info. This replaces the lvmetad
info with a local file and enables the adopt feature again
(enabled with lvmlockd --adopt 1).
dmeventd is 'scanning' statuses in loop (most usually in 10sec
intervals) - and meanwhile it sleeps within:
pthread_cond_timedwait()
However this function call tends to wakeup sometimes a short amount of
time sooner - and our code still believe the 'right time' has not yet
arrived and basically for a moment 'busy-looped' on calling this
function - so for systems with 'clock_gettime()' present we obtain
time and we go 10ms to the future second - this avoids unneeded
repeated invocation of our time scheduling loop.
TODO: monitoring during 1 hour 'time-change'...
When _daemon_read()/_client_read() fails during the read,
ensure memory allocated withing function is also release here
(so caller does not need to care). Also improve code readbility a bit
a for same functionality use more similar code.
Since we fixed linking of proper version of 'libdevmapper' with
linking lvm2 plugin correctly - we already have correct function
available linked with internal lvm library.
So drop unneeded include of parsing function.
When a LV loses an interface it ends up getting removed and recreated.
This happens after the VGs have been processed and updated. Thus when
this happens we need to re-check the VGs.
VDO pool LVs are represented by a new dbus interface VgVdo. Currently
the interface only has additional VDO properties, but when the
ability to support additional LV creation is added we can add a method
to the interface.
This reverts commit ad560a286a.
The reverted patch also removed the warning which we realized we need
to keep as valuable process information (see related bugzilla below).
In a followup patch, we'll keep the message and avoid bailing out thus
always allowing lvconvert to try repairing if 'allocate' fault policy set.
Related: https://bugzilla.redhat.com/show_bug.cgi?id=1751887
With Python 3.8 converting these directly to string using str()
no longer works, we need to convert these to integer first.
On Python 3.8:
>>> str(dbus.Int64(1))
'dbus.Int64(1)'
On Python 3.7 (and older):
>>> str(dbus.UInt64(1))
'1'
This is probably related to removing __str__ function from method
from int (dbus.UInt is subclass of int) which happened in 3.8, see
https://docs.python.org/3.8/whatsnew/3.8.html
Signed-off-by: Vojtech Trefny <vtrefny@redhat.com>
To avoid tiny race on checking arrival of signal and entering select
(that can latter remain stuck as signal was already delivered) switch
to use pselect().
If it would needed, we can eventually add extra code for older systems
without pselect(), but there are probably no such ancient systems in
use.
Update the previous commit to leave the vgname as
an arg instead of moving it into the select option,
(the compound select option rule is confusing the
dlm arg processing.)
Using --select 'lvname=LV && vgname=VG' avoids the problem
of the lvchange exit code not distinguishing an actual error
result vs the VG or LV not existing. (This is in case there
is an odd dlm/gfs2 setup where some nodes are running the dlm
but do not have access to the VG.)
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.
Lvm can at times have duplicate names. When this happens the daemon will
internally use vg_name:vg_uuid as the name for lookups, but display just
the vg_name externally. If an API user uses the Manager.LookUpByLvmId and
queries the vg name they will only get returned one result as the API
can only accommodate returning 1. The one returned is the first instance
found when sorting the volume groups by UUID.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1583510
When we have two logical volumes which switch their names at the
same time we are left with incorrect lookups. Anytime we find
an entry by doing a lookup by UUID or by name we will ensure
that the lookups are indeed correct.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1642176
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.
Since configure.h is a generated header and it's missing traditional
ifdefs preambule - it can be included & parsed multiple times.
Normally compiler is fine when defines have same value and there is
no warning - yet we don't need to parse this several times
and by adding -include directive we can ensure every file
in the package is rightly compile with configure.h as the
first header file.
When a VG is exported, the 'fullreport' returns an exit code of 5, but
otherwise returns the data we are wanting.
Signed-off-by: Tony Asleson <tasleson@redhat.com>
In some cases we get stuck where we are unable to retrieve the current
state of lvm as we are encountering an error. When the error is
persistent we will log and exit the daemon instead of consuming vast
amounts of resources.
Signed-off-by: Tony Asleson <tasleson@redhat.com>
A bit of chicken & egg problem - dmeventd needs to use old libdm library.
VDO is only part of new device_mapper internal library.
So include directly source file for parsing status - this fixes usability
problem of VDO plugin introduced with previous Makefile reshaping
patchset.
NOTE: source file needs to be keep then compilable in both environments.
Also add missing copyright header.
Since there is very little change there will be any new devel going
to happing with cmirror - avoid eating extra disk space and link
with already installed libdm which implements all use basic
function of dm list
Since dmeventd is 'libdm' based project, it needs to link
libdm library instead of its internal version
An external users may provide plugins loadeable by dmeventd.
So external user of libdevmapper-event library has no other option
then to link with released libdevmapper library.
The complexity comes with lvm2 plugins.
The lvm2 plugin itself uses internal version of device_mapper,
but libdevmapper-event usage is libdm based - so there needs to be avoided
any breakage on compatibility of internal i.e. dm_task_run structures.
TODO: most likely dmeventd itself should be moved into libdm/dm-tools dir,
and only lvm2 plugins should be created as part of lvm project,
but those still need to link with libdevmapper.
If we don't know the meaning we will return the key with default text
instead of raising an exception and taking the daemon out in the
process.
Resolves: rhbz1657950
When we get bug reports we may not get the entire log, so lets
dump the fight recorder from newest to oldest as the one we
are interested in was likely to be the last command run.
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.
When sanlock_release returns an error because of an i/o
timeout releasing the lease on disk, lvmlockd should just
consider the lock released. sanlock will continue trying
to release the lease on disk after the original request
times out.
The choice about sector size and lease align size is
now made by the sanlock user, in this case lvmlockd.
This will allow lvmlockd to use other lease sizes in
the future. This also prevents breakage if hosts
report different sector sizes, or the sector size
reported by a device changes.
Thin plugin started to use configuble setting to allow to configure
usage of external scripts - however to read this value it needed to
execute internal command as dmeventd itself has no access to lvm.conf
and the API for dmeventd plugin has been kept stable.
The call of command itself was not normally 'a big issue' until users
started to use higher number of monitored LVs and execution of command
got stuck because other monitored resource already started to execute
some other lvm2 command and become blocked waiting on VG lock.
This scenario revealed necesity to somehow avoid calling lvm2 command
during resource registration - but this requires bigger changes - so
meanwhile this patch tries to minimize the possibility to hit this race
by obtaining any configurable setting just once - such patch is small
and covers majority of problem - yet better solution needs to be
introduced likely with bigger rework of dmeventd.
TODO: avoid blocking registration of resource with execution of lvm2
commands since those can get stuck waiting on mutexes.
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.
Introduce VDO plugin for monitoring VDO devices.
This plugin can be used also by other users, as plugin checks
for UUID prefix 'LVM-' and run lvm actions only on those
devices.
Non LVM- device are only monitored and log warnings
when usage threshold reaches 80%.
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.)
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/
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.
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.
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.
We can't let clvmd keep all scanned devs open,
which prevents them from being removed. So
drop the bcache data (and close fds) affter
doing a label scan.
Also set up bcache before the clvm-specific
vg_read (which needs to rescan the vg's devs
using bcache) and destroy the bcache after.
Since this function is called with 'fd == -1', but Coverity can't see
this path can't be visited with this argument, add explicit check for
valid descriptor.
When dmeventd thin plugin forks a configurable script, switch to use
execvp to pass whole environment present to dmeventd - so all configured
paths present at dmeventd startup are visible to script.
This was likely not a problem for common user enviroment,
however in test suite case variable like LVM_SYSTEM_DIR were
not actually used from test itself but rather from
a system present lvm.conf and this may have cause strange
behavior of a testing script.
Avoid using same return code for reporting 2 different things
and stricly report error code by return value and add new
parameter for reporting monitoring status.
This makes easier to recognize which error we got from dm_event
and continue only with ENOENT.
lvmdbusd executable script must use python3 interpreter detected by
configure script, as site-packages directory used for library is only
used by that interpreter.
When sanlock or dlm lock managers return an error number
that we don't recognize, replace it with a generic -ELMERR
which is defined in the set of special lvmlockd error
numbers. Otherwise, an unknown lock manager error number
could be misinterpreted for something else if it happened
to overlap another set of error numbers (which they have
not thus far.)
These less common errors returned from sanlock should
also cause sanlock to retry the lock acquire:
- i/o timeout occurs during sanlock_acquire().
other i/o on the same disk as the leases can cause
sanlock i/o timeouts.
- low level disk paxos contention between hosts naturally
causes one host to not acquire the lease. There are a
couple special error numbers associated with these cases
that should just be recognized as a normal failure to
acquire the lease.
In HA cluster, we have "clvm" resource agent to manage clvmd daemon.
The agent invokes clvmd like: "clvmd -T90 -d0", which always prints
a scaring error message:
"""
local socket: connect failed: No such file or directory
"""
When specifed with "-d" option, clvmd tries to check if an instance
of the clvmd daemon is already running through a testing connection.
The connect() will fail with this ENOENT error in such case, so supress
the error message in such case.
TODO: add missing error reaction code - since ofter log_error, program
is not supposed to continue running (log_error() is for reporting
stopping problems).
Signed-off-by: Eric Ren <zren@suse.com>
When dmeventd receives SIGTERM/INT/HUP/QUIT it validates if exit is possible.
If there was any device still monitored, such exit request used to
be ignored/refused. This 'usually' worked reasonably well, however if there
is very short time period between last device is unmonitored and signal
reception - there was possibility such EXIT was ignored, as dmeventd has
not yet got into idle state even commands like 'vgchange -an' has already
finished.
This patch changes logic towards scheduling EXIT to the nearest
point when there is no monitored device.
EXIT is never forgotten.
NOTE: if there is only a single monitored device and someone sends
SIGTERM and later someone uses i.e. 'lvchange --refresh' after
unmonitoring dmeventd will exit and new instance needs to be
started.
If you send a SIGUSR1 (10) to the daemon it will dump all the
threads current stacks to stdout. This will be useful when the
daemon is apparently hung and not processing requests.
eg.
$ sudo kill -10 <daemon pid>
Make sure that any and all code that executes in the main thread is
wrapped with a try/except block to ensure that at the very least
we log when things are going wrong.
In some cases we are seeing where there are no VGs, but the data returned from
lvm shows that the PVs have the following for the VG:
"vg_name":"[unknown]", "vg_uuid":""
The code was only checking for the exitence of the VG name and we called into
the function get_object_path_by_uuid_lvm_id which requires both the VG name and
the LV name to exist (asserts this) which results in the following stack trace:
Traceback (most recent call last):
File "/home/tasleson/lvm2/daemons/lvmdbusd/utils.py", line 563, in runner
obj._run()
File "/home/tasleson/lvm2/daemons/lvmdbusd/utils.py", line 584, in _run
self.rc = self.f(*self.args)
File "/home/tasleson/lvm2/daemons/lvmdbusd/fetch.py", line 26, in
_main_thread_load
cache_refresh=False)[1]
File "/home/tasleson/lvm2/daemons/lvmdbusd/pv.py", line 48, in load_pvs
emit_signal, cache_refresh)
File "/home/tasleson/lvm2/daemons/lvmdbusd/loader.py", line 37, in common
objects = retrieve(search_keys, cache_refresh=False)
File "/home/tasleson/lvm2/daemons/lvmdbusd/pv.py", line 40, in
pvs_state_retrieve
p["pv_attr"], p["pv_tags"], p["vg_name"], p["vg_uuid"]))
File "/home/tasleson/lvm2/daemons/lvmdbusd/pv.py", line 84, in __init__
vg_uuid, vg_name, vg_obj_path_generate)
File "/home/tasleson/lvm2/daemons/lvmdbusd/objectmanager.py", line 318,
in get_object_path_by_uuid_lvm_id
assert uuid
AssertionError
When executing in the main thread, if we encounter an exception we
will bypass the notify_all call on the condition and the calling thread
never wakes up.
@staticmethod
def runner(obj):
# noinspection PyProtectedMember
Exception thrown here
----> obj._run()
So the following code doesn't run, which causes calling thread to hang
with obj.cond:
obj.function_complete = True
obj.cond.notify_all()
Additionally for some unknown reason the stderr is lost.
Best guess is it's something to do with scheduling a python function
into the GLib.idle_add. That made finding issue quite difficult.
