1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
Commit Graph

285 Commits

Author SHA1 Message Date
Bryn M. Reeves
a0cf3d47f1 libdm: add latency histogram support
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.
2015-09-02 20:48:59 +01:00
Bryn M. Reeves
567189cc76 libdm: add per region precise timestamps property methods 2015-08-24 20:03:21 +01:00
Bryn M. Reeves
f4262026b6 libdm: add precise timestamps support to libdm-stats
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.
2015-08-24 20:03:21 +01:00
Bryn M. Reeves
386e91addb libdm: add dm_message_supports_precise_timestamps()
Add a function to test whether the kernel precise_timestamps
feature is available in the current device-mapper driver version.

Presence of precise_timestamps also implies the availability of
latency histograms.
2015-08-20 12:11:23 +01:00
Bryn M. Reeves
4227b2ebb4 libdm-stats: only return uint64_t when required
Several interfaced in libdm-stats return a uint64_t when it is
only used to signal success/failure: change all these uses to
return a simple int instead.
2015-08-17 16:59:52 +01:00
Bryn M. Reeves
00ed523659 libdm: add dm_stats_get_{current_}area_offset()
Add a method to retrieve the offset of an area within the
containing region (rather than the offset within the containing
device returned by dm_stats_get_area_start()).

Although users of the library can calculate this themselves it is
better to provide this through a method call to avoid users making
assumptions about the structure of regions and areas.
2015-08-14 22:03:37 +01:00
Alasdair G Kergon
043fb32c4b dmsetup: Restructure arg handling.
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).
2015-08-13 22:30:39 +01:00
Bryn M. Reeves
99f55abc56 libdm: add dm_timestamp_copy() 2015-08-12 15:09:57 +01:00
Zdenek Kabelac
79e9bde0ea libdm: rename to data_block_size
Use common name for pool device - as we use data_block_size
for thin pool metadata, use same name for cache_pool.

This change does not affect API.
2015-08-12 14:33:15 +02:00
Bryn M. Reeves
d62a8d2f15 dmstats: add libdm-stats library and 'dmsetup stats' command
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.
2015-08-09 14:37:58 +01:00
Bryn M. Reeves
54815fff06 libdm: remove report interval support
Don't do interval management and external timekeeping for stats in
dm_report: let applications handle this on their own.

Since this has not been included in a release remove it from the
library entirely and handle report timing directly inside dmsetup.
2015-08-08 11:48:12 +01:00
Bryn M. Reeves
666c77c0f2 libdm: add dm_report_column_headings
Add a function to print column headings regardless of whether they
have already been output. This will be used by dmstats to issue
periodic reminders of the column headings.

This patch removes a check for RH_HEADINGS_PRINTED from
_report_headings that prevents headings being displayed if the flag
is already set; this check is redundant since the only existing
caller (_output_as_columns()) already tests the flag before
calling the function.
2015-08-08 11:43:52 +01:00
Alasdair G Kergon
559ca8bc65 dmsetup: Report timestamps of ioctls with -vvv.
If enabled, record timestamp immediately after the ioctl() returns.
2015-08-05 08:28:35 +01:00
Alasdair G Kergon
2f334afb98 libdm: Whitespace. 2015-08-05 05:21:58 +01:00
Bryn M. Reeves
a161e29c59 dmsetup: Add --count and --interval to reports.
For example, to monitor active devices every second you can now run
dmsetup info -c --count 0.
2015-07-31 21:59:34 +01:00
Alasdair G Kergon
a28fb37b9e libdm: Add dm_timestamp functions. 2015-07-29 19:21:07 +01:00
Alasdair G Kergon
af1c7bf0c7 libdm: Add dm_size_to_string to libdevmapper.
Moved out from lib/display and a little documentation added.
It's tuned to LVM's requirements historically and its behaviour
might not always be what you would expect.
2015-07-27 21:30:20 +01:00
Alasdair G Kergon
1612c570b6 libdm: Use wrappers for all malloc functions.
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.
2015-07-22 23:11:48 +01:00
Jonathan Brassow
4daea88516 clean-up: typos s/bellow/below/ 2015-07-06 10:15:11 -05:00
Peter Rajnoha
335707b0e2 report: add infrastructure to recognize fuzzy reserved names and returning dynamic reserved values
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.
2015-07-03 10:47:09 +02:00
Peter Rajnoha
ded279f826 report: add support for time (basic)
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.
2015-06-30 15:15:10 +02:00
Peter Rajnoha
d8996a17d1 select: add support for range reserved values and flagging named-only values
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.
2015-06-30 10:47:50 +02:00
Peter Rajnoha
9465963faf config: add support for config value formatting flags
There are two basic groups of formatting flags (32 bits):
  - common ones applicable for all config value types (lower 16 bits)
  - type-related formatting flags (higher 16 bits)

With this patch, we initially support four new flags that
modify the the way the config value is displayed:

  Common flags:
  =============

  DM_CONFIG_VALUE_FMT_COMMON_ARRAY - causes array config values
    to be enclosed in "[ ]" even if there's only one item
    (previously, there was no way to recognize an array with one
     item and scalar value, hence array values with one member
     were always displayed without "[ ]" which libdm accepted
     when reading, but it may have been misleading for users)

  DM_CONFIG_VALUE_FMT_COMMON_EXTRA_SPACE - causes extra spaces to
    be inserted in "key = value" (or key = [ value, value, ... ] in
    case of arrays), compared to "key=value" seen on output before.
    This makes the output more readable for users.

  Type-related flags:
  ===================

  DM_CONFIG_VALUE_FMT_INT_OCTAL - prints integers in octal form with
    "0" as a prefix (libdm's config reading code can handle this via
    strtol just fine so it's properly recognized as number in octal
    form already if there's "0" used as prefix)

  DM_CONFIG_VALUE_FMT_STRING_NO_QUOTES - makes it possible to print
    strings without enclosing " "

This patch also adds dm_config_value_set_format_flags and
dm_config_value_get_format_flags functions to set and get
these formatting flags.
2015-06-24 11:13:37 +02:00
Zdenek Kabelac
69132f55ea libdm: add dm_tree_node_set_thin_pool_read_only
Support thin-pool tree node with activation in read-only mode.
(Native kernel API).
2015-06-18 15:15:39 +02:00
Alasdair G Kergon
eeb498627c libdm: Add dm_task_get_errno to return ioctl errno.
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]
2015-05-26 15:13:49 +01:00
Zdenek Kabelac
797c18d543 libdm: new dm_task_get_info with internal_suspend
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.
2015-05-15 16:48:22 +02:00
Peter Rajnoha
123a3383a0 libdm: report: add dm_report_object_is_selected
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.
2015-02-10 16:04:38 +01:00
Zdenek Kabelac
2908ab3eed thin: errrorwhenfull support
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.)
2015-01-14 14:52:05 +01:00
Zdenek Kabelac
d202f43fff cleanup: update API for segment reporting
API for seg reporting is breaking internal lvm coding - it cannot
use vgmem mem pool for allocation of reported value.
So use separate pool instead of 'vgmem' for non vg related allocations

Add consts for many function params - but still many other are left
for now as non-const - needs deeper level of change even on libdm side.
2015-01-14 14:50:08 +01:00
Peter Rajnoha
f867dc6b29 libdm: report: compact output applicable only if report is buffered 2014-12-05 14:18:51 +01:00
Peter Rajnoha
5edf6a56c4 libdm: report: add dm_report_compact_fields
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.
2014-12-05 12:00:28 +01:00
Peter Rajnoha
44394cd246 libdm: remove unimplemented dm_report_set_output_selection fn
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.
2014-12-05 11:54:25 +01:00
Petr Rockai
de2c5ab2ac libdm-config: Implement dm_config_remove_node. 2014-11-20 16:51:06 +01:00
Petr Rockai
274a7a68b8 libdm-config: Implement dm_config_flatten. 2014-11-20 16:51:06 +01:00
Alasdair G Kergon
9a5910bdf9 pre-release 2014-11-11 14:13:00 +00:00
Zdenek Kabelac
20b22cd023 libdm: still better API
Do not use 'any' policy name as a value in config tree - so we stick
with 'policy_settings' and extra 'policy_name' for libdm params.

Update lvm2 API as well.

Example of supported metadata:

 policy = "mq"
 policy_settings {
      migration_threshold = 2048
      sequential_threshold = 512
      random_threshold = 4
      read_promote_adjustment = 10
 }
2014-11-11 00:54:03 +01:00
Zdenek Kabelac
824019531c libdm: tunning cache API
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...
2014-11-10 22:05:48 +01:00
Zdenek Kabelac
482e572e5d libdm: add DM_LIST_HEAD_INIT macro
Support to initialize dm_list struct members.
2014-10-24 16:39:31 +02:00
Peter Rajnoha
02dc3c773e report: add dm_report_field_string_list_unsorted 2014-08-25 16:11:40 +02:00
Alasdair G Kergon
42e07d2bce dmsetup: Support remove --deferred.
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>
2014-08-16 00:34:48 +01:00
Alasdair G Kergon
7cff640d9a activation: Fix upgrades using uuid suffixes.
2.02.106 added suffixes to some LV uuids in the kernel.

If any of these LVs is activated with 2.02.105 or earlier,
and then a later version is used, the LVs appear invisible and
activation commands fail.

The code now has to check the kernel for both old and new uuids.
2014-07-30 21:55:11 +01:00
Peter Rajnoha
0956fd230f report: adapt selection code to recognize per-field reserved values
In contrast to per-type reserved values that are applied for all fields
of that type, per-field reserved values are only applied for concrete
field only.

Also add 'struct dm_report_field_reserved_value' to libdm for per-field
reserved value definition. This is defined by field number (an index
in the 'fields' array which is given for the dm_report_init_with_selection
function during report initialization) and the value to use for any
of the specified reserved names.
2014-07-04 15:50:50 +02:00
Peter Rajnoha
100342605c libdm: fix double const for "value" in dm_report_reserved_value structure
C++ may have
2014-06-30 09:44:23 +02:00
Peter Rajnoha
a40bc36b2e libdevmapper: revoke commit 7c86131233
We have "help" and "?" defined as implicit fields now. As such, we
don't need to export these names in libdevmapper (as it was introduced
by commit 7c86131233 within this release).
If anyone uses these field names by mistake, the libdevmapper code can
error out correctly if it detects that the set of explicit field names
(the ones supplied by "fields" arg in dm_report_init/dm_report_init_with_selection)
contains any of the implicit field names (the ones defined internally
by libdevmapper itself).
2014-06-19 16:09:32 +02:00
Peter Rajnoha
51a86dc2f8 report: select: add support for percent selection 2014-06-17 16:27:21 +02:00
Peter Rajnoha
cfed0d09e8 report: select: refactor: move percent handling code to libdm for reuse 2014-06-17 16:27:21 +02:00
Peter Rajnoha
35c4e4489c report: select: add support for reserved value recognition in report selection string - add struct dm_report_reserved_value
Make dm_report_init_with_selection to accept an argument with an
array of reserved values where each element contains a triple:

  {dm report field type, reserved value, array of strings representing this value}

When the selection is parsed, we always check whether a string
representation of some reserved value is not hit and if it is,
we use the reserved value assigned for this string instead of
trying to parse it as a value of certain field type.

This makes it possible to define selections like:

   ... --select lv_major=undefined (or -1 or unknown or undef or whatever string representations are registered for this reserved value in the future)
   ... --select lv_read_ahead=auto
   ... --select vg_mda_copies=unmanaged

With this, each time the field value of certain type is hit
and when we compare it with the selection, we use the proper
value for comparison.

For now, register these reserved values that are used at the moment
(also more descriptive names are used for the values):

  const uint64_t _reserved_number_undef_64 = UINT64_MAX;
  const uint64_t _reserved_number_unmanaged_64 = UINT64_MAX - 1;
  const uint64_t _reserved_size_auto_64 = UINT64_MAX;

 {
  {DM_REPORT_FIELD_TYPE_NUMBER, _reserved_number_undef_64, {"-1", "undefined", "undef", "unknown", NULL}},
  {DM_REPORT_FIELD_TYPE_NUMBER, _reserved_number_unmanaged_64, {"unmanaged", NULL}},
  {DM_REPORT_FIELD_TYPE_SIZE, _reserved_size_auto_64, {"auto", NULL}},
  NULL
 }

Same reserved value of different field types do not collide.
All arrays are null-terminated.

The list of reserved values is automatically displayed within
selection help output:

  Selection operands
  ------------------
  ...

  Reserved values
  ---------------
    -1, undefined, undef, unknown   - Reserved value for undefined numeric value. [number]
    unmanaged                       - Reserved value for unmanaged number of metadata copies in VG. [number]
    auto                            - Reserved value for size that is automatically calculated. [size]

  Selection operators
  -------------------
  ...
2014-06-17 16:27:21 +02:00
Peter Rajnoha
a6694cfc29 report: select: add DM_REPORT_FIELD_TYPE_STRING_LIST to make a difference between STRING and STRING_LIST
The {pv,vg,lv,seg}_tags and lv_modules fields are reported as string
lists using the new dm_report_field_string_list - so we just pass
the list to the fn that takes care of reporting and item sorting itself.
2014-06-17 16:27:20 +02:00
Peter Rajnoha
76467bdcfd report: select: add dm_report_field_string_list to libdm
Add a separate dm_report_field_string_list fn to libdevmapper to
support reporting string lists. Before, the code used libdevmappers's
dm_report_field_string fn which required formatting the list to a
single string. This functionality is now moved to libdevmapper
and the code that needs to report the string list just needs
to pass the list itself and libdevmapper will take care of this.
This also enhances code reuse.

The dm_report_field_string_list also accepts an argument to define
custom delimiter to use. If not defined, a default "," (comma) is
used as item delimiter in the string list reported.

The dm_report_field_string_list automatically sorts the items in
the list before formatting it to a final string. It also encodes
the position and length within the final string where each element
can be found. This can be used to support checking against each
list item reported since since when formatted as a single string
for the actual report, we would lose this information otherwise
(we don't want to copy each item, the position and length within
the final string is enough for us to get the original items back).

When such lists are checked against the selection tree, we can check
each item individually this way and we can support operators like
"match any" and "match all".
2014-06-17 16:27:20 +02:00
Peter Rajnoha
5abdb52fdc report: select: refactor: move str_list to libdm
The list of strings is used quite frequently and we'd like to reuse
this simple structure for report selection support too. Make it part
of libdevmapper for general reuse throughout the code.

This also simplifies the LVM code a bit since we don't need to
include and manage lvm-types.h anymore (the string list was the
only structure defined there).
2014-06-17 16:27:20 +02:00