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When dm_tree_find_node_by_uuid() fails to find passed uuid,
report in lof_debug the complete original uuid,
not the one stripped of LVM- prefix.
TODO: inspect manipulation with LVM- prefix here.
Fix parsing of 'Fail' status (using capital letter) for thin-pool.
Add also parsing of 'Error' state for thin-pool.
Add needs_check test for thin-pool.
Detect Fail state for thin.
Fixing regression caused by 197b5e6dc7.
So the 'TODO' part now finally know the answer - there is 'sparc64'
architecture which imposes limitation to read 64b words only through
64b aligned address.
Since we never could know how is the user going to use the returned
pointer and the userusually expects it's aligned on the highest CPU
required alignement, preserve it also for char*.
Fixes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=809685
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Wrong thin-pool feature flag ordering in dm table: It will lead to
unnecessary table reload.
Fix it by placeing feature flags in order they are returned from the
kernel so current 'table line diff' code will not see a difference.
Reinstate and extend checks removed by e1b111b02a.
The code has always assumed that only root has access to the directory
containing the fifos and that they are under the complete control of
dmeventd code. If anything is found not to be as expected, then open()
should certainly not be attempted!
When preloading thin-pool device node for already
existing/running thin-pool do not resume such thin-pool.
This allows to properly schedule commit point for metadata,
when thin-pool data or metadata volume is resized.
Extra space between 'cache' target and metadata device caused
string comparation being not equal and thus always causing
table reload even when uneeded.
If plugin's lvm command execution fails too often (>10 times),
there is no point to torture system more then necessary, just log
and drop monitoring in this case.
Improve event string parser to avoid unneeded alloc+free.
Daemon talk function uses '-' to mark NULL/missing field.
So restore the NULL pointer back on parser.
This should have made old tools like 'dmevent_tool' work again.
As now 'uuid' or 'dso' could become NULL and then be
properly used in _want_registered_device() function.
Since lvm2 always fill these parameters, this change should
have no effect on lvm2.
Add more functionality to size_changed function.
While 'existing' API only detected 0 for
unchanged, and !0 for changed,
new improved API will also detected if the
size has only went bigger - or there was
size reduction.
Function work for the whole dm-tree - so
no change is size is always 0.
only size extension 1.
and if some size reduction is there - returns -1.
This result can be used for better evaluation
whether we need to flush before suspend.
Implementing exit when 'dmeventd' is idle.
Default idle timeout set to 1 hour - after this time period
dmeventd will cleanly exit.
On systems with 'systemd' - service is automatically started with
next contact on dmeventd communication socket/fifo.
On other systems - new dmeventd starts again when lvm2 command detects
its missing and monitoring is needed.
Add support to unmonitor device when monitor recognizes there is
nothing to monitor anymore.
TODO: possibly API change with return value could be also used.
Redesign threading code:
- plugin registration runs within its new created thread for
improved parallel usage.
- wait task is created just once and used during whole plugin lifetime.
- event thread is based over 'events' filter being set - when
filter is 0, such thread is 'unused'.
- event loop is simplified.
- timeout thread is never signaling 'processing' thread.
- pending of events filter cnange is properly reported and
running event thread is signalled when possible.
- helgrind is not reporting problems.
Need here to keep control device opened while there is 'any' dso
plugin loaded - otherwise there would a race closing controlfd
inside lvm2 plugin while some other monitoring thread would
tried to execute another WAITEVENT task.
dm_report_compact_given_fields is the same as dm_report_compact_fields,
but it processes only given fields, not all the fields in the report
like dm_report_compact_field does.
Rework thread creation code to better use resources.
New code will not leak 'timeout' registered thread on error path.
Also if the thread already exist - avoid creation of thread
object and it's later destruction.
If the race is noticed during adding new monitoring thread,
such thread is put on cleanup list and -EEXIST is reported.
We want most of our units to be started before any local/remote mount
points are mounted - we used {local,remote}-fs.target for this purpose
before, but it was not 100% correct as there's even {local,remote}-fs-pre.target
special systemd unit reserved for this exact purpose.
See also man 7 systemd.special and "local-fs-pre.target"/"remote-fs-pre.target"
description.
When user specifies '--force' with remove/remove_all/wipe_table
use '--noflush --nolockfs' resume flags, so the operation
will not block when device underneath is blocked.
When using udev, the /dev/mapper entries are symlinks - fix the code
to count with this.
This patch also fixes the dmsetup mknodes and vgmknodes to properly
repair /dev/mapper content if it sees dangling symlink in /dev/mapper.
$ lvs -o name,tags vg
LV LV Tags
lvol0
lvol1 mytag
Before this patch:
$ lvs -o name,tags vg -S 'tags=""'
Failed to parse string list value for selection field lv_tags.
Selection syntax error at 'tags=""'.
Use 'help' for selection to get more help.
(and the same for -S 'tags={}' and -S 'tags=[]')
With this patch applied:
$ lvs -o name,tags vg -S 'tags=""'
LV LV Tags
lvol0
(and the same for -S 'tags={}' and -S 'tags=[]')
Avoid validation of free space in pool, when no messages are passed.
Patch a3c7e326c3 add new check for
pool overload - but this check should not be made if there are
no messages and transaction_id is still within 'bounds' (bigger by 1).
librt doesn't have a pkgconfig file so use Libs.private: -lrt instead
to declare the dependency directly.
The same applies for -lm which is also used and which hasn't been
defined in the devmapper.pc file yet.
Add support to dmstats to create and report histograms.
Add a --histogram switch to 'create' that accepts a string
description of bin boundaries and DR_STATS and DR_STATS_META fields
to report bin configuration and absolute and relative histogram
values:
hist_bins
hist_bounds
hist_ranges
hist_count
hist_count_bounds
hist_count_ranges
hist_percent
hist_percent_bounds
hist_percent_ranges
A new 'histogram' subcommand displays a report that emphasizes
histogram data as either counters or percentage values.
Add support for creating, parsing, and reporting dm-stats latency
histograms on kernels that support precise_timestamps.
Histograms are specified as a series of time values that give the
boundaries of the bins into which I/O counts accumulate (with
implicit lower and upper bounds on the first and last bins).
A new type, struct dm_histogram, is introduced to represent
histogram values and bin boundaries.
The boundary values may be given as either a string of values (with
optional unit suffixes) or as a zero terminated array of uint64_t
values expressing boundary times in nanoseconds.
A new bounds argument is added to dm_stats_create_region() which
accepts a pointer to a struct dm_histogram initialised with bounds
values.
Histogram data associated with a region is parsed during a call to
dm_stats_populate() and used to build a table of histogram values
that are pointed to from the containing area's counter set. The
histogram for a specified area may then be obtained and interogated
for values and properties.
This relies on kernel support to provide the boundary values in
a @stats_list response: this will be present in 4.3 and 4.2-stable. A
check for a minimum driver version of 4.33.0 is implemented to ensure
that this is present (4.32.0 has the necessary precise_timestamps and
histogram features but is unable to report these via @stats_list).
Access methods are provided to retrieve histogram values and bounds
as well as simple string representations of the counts and bin
boundaries. Methods are also available to return the total count
for a histogram and the relative value (as a dm_percent_t) of a
specified bin.
Add support for the kernel precise_timestamps feature. This allows
regions to be created using counters with nanosecond precision.
A new dm_stats method, dm_stats_set_precise_timestamps() causes all
future regions created with this handle to attempt to enable precise
counters.
Introduce enums and global variables to record cleanly which command we
are processing and eliminate the historically inconsistent use of the
shifted argv[0] and fix assorted bugs discovered along the way.
Add dm_report_is_empty() to indicate there is no data awaiting output
and use this to suppress dmsetup report headings when no data is output
so we don't get a stray line saying 'Help' at the end of reporting help.
Define a report type (as the interface requires) so -o all selects
the right fields in splitname. (A fix for stats list will follow.)
Exit immediately if no device is supplied to dmsetup wipe_table instead
of hitting errors later and failing.
Adjust the command name printed in usage/help output to match command
invoked (most of the time).
The '--force' switch is only used by dmstats to allow either
creation or deletion of one or more regions on all devices.
These operations do not carry any risk: just a possible mess of
region IDs to be cleaned up.
Remove the use of '--force' for stats commands and change current
uses to a new '--alldevices' switch.
Add the libdm-stats module to libdm: this implements a simple interface
for creating, managing and interrogating I/O statistics regions and
areas on device-mapper devices.
The library interface is documented in libdevmapper.h and provides a
'dm_stats' handle that is used to perform statistics operations and
obtain data.
Public methods are provided to create and destroy handles and to list,
create, and destroy statistics regions as well as to obtain and parse
counter data and calculate rate-based metrics.
This commit also adds a 'dmsetup stats' (aka 'dmstats') command with
'clear', 'create', 'delete', 'list', 'print', and 'report' sub-commands.
See the library documentation and the dmstats.8 manual page for detailed
API and command descriptions.
Whenver reporting field name is registered with libdevmapper and if
the field name contains any number of underscores ('_'), libdm
can now automatically recognize any of its variant without any
underscores used.
For example:
..for underscores in prefixes:
pvs -o pv_name
pvs -o name
pvs -o pvname (newly recognized besides pvname)
..for underscores in the name:
lvs -o cache_mode
lvs -o cachemode
..or even multiple underscores:
pvs -o pv___na___me
It's all variant of the same field name.
Move the DEBUG_MEM decision inside libdevmapper.so instead of exposing
it in libdevmapper.h which causes failures if the binary and library
were compiled with opposite debugging settings.
Add support for sending message in suspend tree for thin-pools.
When this operation is requested whole subtree suspend is then skipped.
This is experimantal support for new lvm2 code for sending message
in suspend phase where 'thin-pool origin-only suspend' will send
messages instead of really suspending thin-pool tree.
When suspening thin volume origin-only - only thin volume is suspended,
then messages are posted and thin-pool suspend is skipped.
With fuzzy names we mean the names for which it's hard or even impossible
to enumerate all possible variations of the name - the name needs to
be evaluated. An example of fuzzy name is a name which has a base
(substring) which matches and it can contain arbitrary variations
around this base. We can cover human language better with fuzzy
names as people may use several different names (or sentences) to
denote the same thing.
With dynamic values we mean the values which are not constants
and they need to be evaluated in runtime. An example of dynamic
value is a value which depends on current system state (e.g. time,
current configuration or any other state which may change and it
needs runtime evaluation).
There's a handler that can be registered with reporting/selection
using dm_report_reserved_handler instance. This is a central point
in which the computation/evaluation happens when processing reserved
values. Currently, there are two actions declared:
DM_REPORT_RESERVED_PARSE_FUZZY_NAME
(translates fuzzy name into canonical name)
DM_REPORT_RESERVED_GET_DYNAMIC_VALUE
(gets value for canonical name)
The handler is then registered as value in struct
dm_report_reserved_value (see explaining comments besided
the struct dm_report_reserved_value in libdevmapper.h).
Also, this patch provides support for simple caching of values
used during report/selection via dm_report_value_cache_{set,get}.
This is supposed to be used mainly in the dm_report_reserved_handler
instances to save values among calls so all the handler calls work
with the same base value used in computation/evaluation and/or
possibly to save resources if the evaluation is more time-consuming.
The cache is attached to the dm_report handle and so the cache is
dropped one dm_report is dropped.
This patch adds support for time values used in reporting fields.
The raw values are always stored as number of seconds since epoch.
The support that comes with this patch is the basic one which allows
only for recognition of strictly formatted date and time in selection
criteria (the format follows a subset of formats defined by ISO 8601):
date time timezone
date:
YYYY-MM-DD (or shortly YYYYMMDD)
YYYY-MM (shortly YYYYMM), auto DD=1
YYYY, auto MM=01 and DD=01
time:
hh:mm:ss (or shortly hhmmss)
hh:mm (or shortly hhmm), auto ss=0
hh (or shortly hh), auto mm=0, auto ss=0
timezone (always with + or - sign):
+hh:mm or -hh:mm (or shortly +hhmm or -hhmm)
+hh or -hh
Or directly the time (number of seconds) since Epoch (1970-01-01 00:00:00 UTC)
when the number value is prefixed by "@":
@number_of_seconds_since_epoch
This patch also adds aliases for comparison operators
used together with time values which are more intuitive
to use:
since (as alias for >=)
after (as alias for >)
until (as alias for <=)
before (as alias for <)
For example:
$ lvmconfig --type full report/time_format
time_format="%Y-%m-%d %T %z %Z [%s]"
$ lvs -o name,time vg
LV Time
lvol0 2015-06-28 21:25:41 +0200 CEST [1435519541]
lvol1 2015-06-30 03:25:43 +0200 CEST [1435627543]
lvol2 2015-04-26 14:52:20 +0200 CEST [1430052740]
lvol3 2015-06-30 14:52:23 +0200 CEST [1435668743]
$ lvs vg -o name,time -S 'time since "2015-04-26 15:00" && time until "2015-06-30"'
LV Time
lvol0 2015-06-28 21:25:41 +0200 CEST [1435519541]
lvol1 2015-06-30 03:25:43 +0200 CEST [1435627543]
lvol3 2015-06-30 14:52:23 +0200 CEST [1435668743]
$ lvs vg -o name,time -S 'time since "2015-04-26 15:00" && time until "2015-06-30 6:00"'
LV Time
lvol0 2015-06-28 21:25:41 +0200 CEST [1435519541]
lvol1 2015-06-30 03:25:43 +0200 CEST [1435627543]
$ lvs vg -o name,time -S 'time since @1435519541'
LV Time
lvol0 2015-06-28 21:25:41 +0200 CEST [1435519541]
lvol1 2015-06-30 03:25:43 +0200 CEST [1435627543]
lvol3 2015-06-30 14:52:23 +0200 CEST [1435668743]
This is basic time recognition support that is directly a part of
libdevmapper. Recognition of more free-form expressions will be a
part of subsequent patches.
This patch allows for registration and recognition of reserved
values which are ranges, so they're composed of two values actually
to denote the lower and upper bound for the range (stored as an array
with exactly two items to define the boundaries).
Also, this patch allows for flagging reserved values as named-only
which means that such values are not strictly reserved. The strictly
reserved values are reserved values as used before this patch.
Distinction between strictly-reserved and named-only values
is clearly visible with comparisons. Normally, strictly reserved
value is not accounted for if we do "greater than" or "lower than"
comparisons, for example:
1 2 3 ....
|
abc
- we have "abc" as reserved value for field with value "2"
- the value reported for the field is "abc" (or "2", it doesn't matter here)
- the selection we're processing is -S 'field < abc'
- the result of the selection gives nothing as "abc" is strictly
reserved value (bound to "2") and there's no order defined for
it and it would only match if we directly compared the value
(so -S 'field = abc' would match)
With named-only values, the "abc" is named-only value for "2",
so selection -S 'field < abc" is the same as using -S 'field < 2'.
The "abc" is just an alias for some value so the value or its
assigned name can be used equally in selection criteria.
There are reports of unexplained ioctl failures when using dmeventd.
An explanation might be that the wrong value of errno is being used.
Change libdevmapper to store an errno set by from dm ioctl() directly
and provide it to the caller through a new dm_task_get_errno() function.
[Replaced f9510548667754d9209b232348ccd2d806c0f1d8]
Introduce new implmentation of dm_task_get_info() function
with support for reading internal_suspend.
.
This time it is done in a 'versioned' way.
We keep the old fashion dm_task_get_info(Base) to implement
the old behavior of 1.02.95 libdm code.
libdm version 1.02.96 introduced 'macro' wrapper
dm_task_get_info_with_deferred_remove with new implementation
of dm_task_get_info() - we cannot do anything else then to
provide compatible version of this symbol.
Now in version 1.02.97 we add new versioned implementation of
dm_task_get_info(DM_1_02_97) symbol.
This has the effect that i.e. rpm build will finaly resolve proper
dependency on a new symbol - so it will be no longer possible,
to build a new binary and use old library
(rpm -q --provides will show libdevmapper.so.1.02(DM_1_02_97)(64bit))
Also the history is now tracked. If a new function is added (or
reimplemented), it needs to be placed in proper file,
so it could be exported with right versioning symbol.
File .exported_symbols.Base should and any existing older DM
should be treated as read-only after a release.
Also - only libdm has been currently enhanced with versioned .Base
file, as soon as other libs (liblvm, libdevmapper-event) needs changes
they should also get their exported symbol files - meanwhile
make.tmpl handles both cases.
Scenario:
$ vgs -o+vg_mda_copies
VG #PV #LV #SN Attr VSize VFree #VMdaCps
fedora 1 2 0 wz--n- 9.51g 0 unmanaged
vg 16 9 0 wz--n- 1.94g 1.83g 2
$ lvs -o+read_ahead vg/lvol6 vg/lvol7
LV VG Attr LSize Pool Origin Data% Rahead
lvol6 vg Vwi-a-tz-- 1.00g pool lvol5 0.00 auto
lvol7 vg Vwi---tz-k 1.00g pool lvol6 256.00k
Before this patch:
$vgs -o vg_name,vg_mda_copies -S 'vg_mda_copies < unmanaged'
VG #VMdaCps
vg 2
Problem:
Reserved values can be only used with exact match = or !=, not <,<=,>,>=.
In the example above, the "unamanaged" is internally represented as
18446744073709551615, but this should be ignored while not comparing
field directly with "unmanaged" reserved name with = or !=. Users
should not be aware of this internal mapping of the reserved value
name to its internal value and hence it doesn't make sense for such
reserved value to take place in results of <,<=,> and >=.
There's no order defined for reserved values!!! It's a special
*reserved* value that is taken out of the usual value range
of that type.
This is very similar to what we have already fixed with
2f7f6932dc, but it's the other way round
now - we're using reserved value name in selection criteria now
(in the patch 2f7f693, we had concrete value and we compared it
with the reserved value). So this patch completes patch 2f7f693.
This patch also fixes this problem:
$ lvs -o+read_ahead vg/lvol6 vg/lvol7 -S 'read_ahead > 32k'
LV VG Attr LSize Pool Origin Data% Rahead
lvol6 vg Vwi-a-tz-- 1.00g pool lvol5 0.00 auto
lvol7 vg Vwi---tz-k 1.00g pool lvol6 256.00k
Problem:
In the example above, the internal reserved value "auto" is in the
range of selection "> 32k" - it shouldn't match as well. Here the
"auto" is internally represented as MAX_DBL and of course, numerically,
MAX_DBL > 256k. But for users, the reserved value should be uncomparable
to any number so the mapping of the reserved value name to its interna
value is transparent to users. Again, there's no order defined for
reserved values and hence it should never match if using <,<=,>,>=
operators.
This is actually exactly the same problem as already described in
2f7f6932dc, but that patch failed for
size field types because of incorrect internal representation used.
With this patch applied, both problematic scenarios mentioned
above are fixed now:
$ vgs -o vg_name,vg_mda_copies -S 'vg_mda_copies < unmanaged'
(blank)
$ lvs -o+read_ahead vg/lvol6 vg/lvol7 -S 'read_ahead > 32k'
LV VG Attr LSize Pool Origin Rahead
lvol7 vg Vwi---tz-k 1.00g pool lvol6 256.00k
The new dm_report_object_is_selected fn makes it possible to opt whether the
object reported should be displayed on output or not. Also, in addition to
that, it makes it possible to save the result of selection (either 0 or 1).
So dm_report_object_is_selected is simply more general form of object
reporting fn - combinations now allow for:
dm_report_object_is_selected(rh, object, 1, NULL):
This is exactly the original dm_report_object fn and it's fully equal
to it.
dm_report_object_is_selected(rh, object, 0, selected):
Do not display the result on output, but save info whether the object
is selected or not in 'selected' variable.
dm_report_object_is_selected(rh, object, 1, selected):
Display the result on output (if it passes selection criteria) and save
whether the object is selected or not in 'selected' variable.
dm_report_object(rh, object, 0, NULL):
This combination is not allowed - it will end up with internal error.
We're either interested in selection status or we want to display the
result on output or both, but never nothing of the two.
Support error_if_no_space feature for thin pools.
Report more info about thinpool status:
(out_of_data (D), metadata_read_only (M), failed (F) also as health
attribute.)
Add new dm_report_compact_fields function to cause report outout
(dm_report_output) to ignore fields which don't have any value set
in any of the rows reported. This provides support for compact report
output where only fields which have something to report are displayed.
The dm_report_set_output_selection was not implemented in the end -
we have dm_report_init_with_selection instead. This is just a remnant
from development code that got into libdevmapper.h by mistake.
Support new PASSTHROUGH 'feature' flag.
Add dm_config_node to pass in policy args.
Really use origin_uuid instead of using extra call
to pass seg_areas.
Switch to 64bit feature flag bit set so there is
enough space in future for new bits...
When transaction_id is set 0 for thin-pool, libdm avoids validation
of thin-pool, unless there are real messages to be send to thin-pool.
This relaxes strict policy which always required to know
in front transaction_id for the kernel target.
It now allows to activate thin-pool with any transaction_id
(when transaction_id is passed in)
It is now upto application to validate transaction_id from life
thin-pool volume with transaction_id within it's own metadata.
Some values are reserved for special purpose like 'undefined', 'unmanaged' etc.
When using >, <, >= and < comparison operators where the range is considered,
do not include reserved values as proper values in this range which
would otherwise result in not so obvious criteria match (as the reserved value is
actually transparent for the user). It's incorrect.
Example scenario:
$ vgs -o vg_name,vg_mda_copies vg1 vg2
VG #VMdaCps
vg1 1
vg2 unmanaged
The "unmanaged" is actually mapped onto reserved value
18446744073709551615 (2^64 - 1) internally.
Such reseved value is already caught on selection criteria input
properly:
$ vgs -o name,vg_mda_copies vg1 vg2 -S 'vg_mda_copies=18446744073709551615'
Numeric value 18446744073709551615 found in selection is reserved.
However, we still need to fix situaton where the reserved value may be
included in resulting range:
Before this patch:
$ vgs -o vg_name,vg_mda_copies vg1 vg2 -S 'vg_mda_copies >= 1'
VG #VMdaCps
vg1 1
vg2 unmanaged
With this patch applied:
$ vgs -o vg_name,vg_mda_copies vg1 vg2 -S 'vg_mda_copies >= 1'
VG #VMdaCps
vg1 1
From the examples above, we can see that without this patch applied,
the vg_mda_copies >= 1 also matched the reserved value 18446744073709551615
(which is represented by the "unamanged" string on report). When
applying the operators, such values must be skipped! They're meant to
be matched only against their string representation only, e.g.:
$ vgs -o name,vg_mda_copies vg1 vg2 -S 'vg_mda_copies=unmanaged'
VG #VMdaCps
vg2 unmanaged
...or any synonyms:
$ vgs -o name,vg_mda_copies vg1 vg2 -S 'vg_mda_copies=undefined'
VG #VMdaCps
vg2 unmanaged
This is probably better approach than 3880ca5eca.
If dm module is not loaded during dm_is_dm_major call, there are no
lines for dm in /proc/devices, of course. Normally, dm_is_dm_major
is called to check existing devices, hence if module is not loaded,
we can expect there's no DM device present at the same time so we
can directly return 0 here (meaning the major number being inspected
is not dm device's one).
See also https://bugzilla.redhat.com/show_bug.cgi?id=1059711.
For dm_is_dm_major to determine whether the major number given as
an argument belongs to a DM device, libdm code needs to know what
the actual DM major is to do the comparison.
It may happen that the dm-mod module is not loaded during this
call and so for the completness let's try our best before we start
giving various errors - we can still make use of dm-mod autoloading,
though only since kernels 2.6.36 where this feature was introduced.
Add extra safety detection for thin pool transaction id
and query pool status after confirmed message.
In case there is a missmatch, immeditelly abort further
processing.
This patch adds a new flag --deferred to dmsetup remove. If this flag is
specified and the device is open, it is scheduled to be deleted on
close.
struct dm_info is extended.
The existing dm_task_get_info() is converted into a wrapper around the
new version dm_task_get_info_with_deferred_remove() so existing binaries
can still use the old smaller structure.
Recompiled code will pick up the new larger structure.
From: Mikulas Patocka <mpatocka@redhat.com>
Using "[ ]" operator together with "&&" (or ",") inside causes the
string list to be matched if and only if all the items given match
the value reported and the number of items also match. This is
strict list matching and the original behaviour we already have.
In contrast to that, the new "{ }" operator together with "&&" inside
causes the string list to be matched if and only if all the items given
match the value reported but the number of items don't need to match.
So we can provide a subset in selection criteria and if the subset
is found, it matches.
For example:
$ lvs -o name,tags
LV LV Tags
lvol0 a
lvol1 a,b
lvol2 b,c,x
lvol3 a,b,y
$ lvs -o name,tags -S 'tags=[a,b]'
LV LV Tags
lvol1 a,b
$ lvs -o name,tags -S 'tags={a,b}'
LV LV Tags
lvol1 a,b
lvol3 a,b,y
So in the example above the a,b is subset of a,b,y and therefore
it also matches.
Clearly, when using "||" (or "#") inside, the { } and [ ] is the
same:
$ lvs -o name,tags -S 'tags=[a#b]'
LV LV Tags
lvol0 a
lvol1 a,b
lvol2 b,c,x
lvol3 a,b,y
$ lvs -o name,tags -S 'tags={a#b}'
LV LV Tags
lvol0 a
lvol1 a,b
lvol2 b,c,x
lvol3 a,b,y
Also in addition to the above feature, fix list with single value
matching when using [ ]:
Before this patch:
$ lvs -o name,tags -S 'tags=[a]'
LV LV Tags
lvol0 a
lvol1 a,b
lvol3 a,b,y
With this patch applied:
$ lvs -o name,tags -S 'tags=[a]'
LV LV Tags
lvol0 a
In case neither [] or {} is used, assume {} (the behaviour is not
changed here):
$ lvs -o name,tags -S 'tags=a'
LV LV Tags
lvol0 a
lvol1 a,b
lvol3 a,b,y
So in new terms 'tags=a' is equal to 'tags={a}'.
