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Commit Graph

171 Commits

Author SHA1 Message Date
David Teigland
f2c1de783c integrity: always default to journal mode
lvconvert was defaulting to bitmap mode,
and lvcreate was defaulting to journal mode.
2020-09-01 17:12:28 -05:00
Zdenek Kabelac
fd96f1014b gcc: zero-sized array to fexlible array C99
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.
2020-09-01 17:57:50 +02:00
Zdenek Kabelac
b918afb693 tools: move struct element before variable lenght list
Move prio field before 'variable' struct array field.
Interesting why this has not been catched yet.

TODO: think about test case
2020-08-28 21:43:02 +02:00
David Teigland
2aed2a41f7 lvcreate: new cache or writecache lv with single command
To create a new cache or writecache LV with a single command:

lvcreate --type cache|writecache
    -n Name -L Size --cachedevice PVfast VG [PVslow ...]

- A new main linear|striped LV is created as usual, using the
  specified -n Name and -L Size, and using the optionally
  specified PVslow devices.
- Then, a new cachevol LV is created internally, using PVfast
  specified by the cachedevice option.
- Then, the cachevol is attached to the main LV, converting the
  main LV to type cache|writecache.

Include --cachesize Size to specify the size of cache|writecache
to create from the specified --cachedevice PVs, otherwise the
entire cachedevice PV is used.  The --cachedevice option can be
repeated to create the cache from multiple devices, or the
cachedevice option can contain a tag name specifying a set of PVs
to allocate the cache from.

To create a new cache or writecache LV with a single command
using an existing cachevol LV:

lvcreate --type cache|writecache
    -n Name -L Size --cachevol LVfast VG [PVslow ...]

- A new main linear|striped LV is created as usual, using the
  specified -n Name and -L Size, and using the optionally
  specified PVslow devices.
- Then, the cachevol LVfast is attached to the main LV, converting
  the main LV to type cache|writecache.

In cases where more advanced types (for the main LV or cachevol LV)
are needed, they should be created independently and then combined
with lvconvert.

Example
-------

user creates a new VG with one slow device and one fast device:

$ vgcreate vg /dev/slow1 /dev/fast1

user creates a new 8G main LV on /dev/slow1 that uses all of
/dev/fast1 as a writecache:

$ lvcreate --type writecache --cachedevice /dev/fast1
    -n main -L 8G vg /dev/slow1

Example
-------

user creates a new VG with two slow devs and two fast devs:

$ vgcreate vg /dev/slow1 /dev/slow2 /dev/fast1 /dev/fast2

user creates a new 8G main LV on /dev/slow1 and /dev/slow2
that uses all of /dev/fast1 and /dev/fast2 as a writecache:

$ lvcreate --type writecache --cachedevice /dev/fast1 --cachedevice /dev/fast2
    -n main -L 8G vg /dev/slow1 /dev/slow2

Example
-------

A user has several slow devices and several fast devices in their VG,
the slow devs have tag @slow, the fast devs have tag @fast.

user creates a new 8G main LV on the slow devs with a
2G writecache on the fast devs:

$ lvcreate --type writecache -n main -L 8G
    --cachedevice @fast --cachesize 2G vg @slow
2020-06-16 13:46:51 -05:00
David Teigland
d9e8895a96 Allow dm-integrity to be used for raid images
dm-integrity stores checksums of the data written to an
LV, and returns an error if data read from the LV does
not match the previously saved checksum.  When used on
raid images, dm-raid will correct the error by reading
the block from another image, and the device user sees
no error.  The integrity metadata (checksums) are stored
on an internal LV allocated by lvm for each linear image.
The internal LV is allocated on the same PV as the image.

Create a raid LV with an integrity layer over each
raid image (for raid levels 1,4,5,6,10):

lvcreate --type raidN --raidintegrity y [options]

Add an integrity layer to images of an existing raid LV:

lvconvert --raidintegrity y LV

Remove the integrity layer from images of a raid LV:

lvconvert --raidintegrity n LV

Settings

Use --raidintegritymode journal|bitmap (journal is default)
to configure the method used by dm-integrity to ensure
crash consistency.

Initialization

When integrity is added to an LV, the kernel needs to
initialize the integrity metadata/checksums for all blocks
in the LV.  The data corruption checking performed by
dm-integrity will only operate on areas of the LV that
are already initialized.  The progress of integrity
initialization is reported by the "syncpercent" LV
reporting field (and under the Cpy%Sync lvs column.)

Example: create a raid1 LV with integrity:

$ lvcreate --type raid1 -m1 --raidintegrity y -n rr -L1G foo
  Creating integrity metadata LV rr_rimage_0_imeta with size 12.00 MiB.
  Logical volume "rr_rimage_0_imeta" created.
  Creating integrity metadata LV rr_rimage_1_imeta with size 12.00 MiB.
  Logical volume "rr_rimage_1_imeta" created.
  Logical volume "rr" created.
$ lvs -a foo
  LV                  VG  Attr       LSize  Origin              Cpy%Sync
  rr                  foo rwi-a-r---  1.00g                     4.93
  [rr_rimage_0]       foo gwi-aor---  1.00g [rr_rimage_0_iorig] 41.02
  [rr_rimage_0_imeta] foo ewi-ao---- 12.00m
  [rr_rimage_0_iorig] foo -wi-ao----  1.00g
  [rr_rimage_1]       foo gwi-aor---  1.00g [rr_rimage_1_iorig] 39.45
  [rr_rimage_1_imeta] foo ewi-ao---- 12.00m
  [rr_rimage_1_iorig] foo -wi-ao----  1.00g
  [rr_rmeta_0]        foo ewi-aor---  4.00m
  [rr_rmeta_1]        foo ewi-aor---  4.00m
2020-04-15 12:10:32 -05:00
David Teigland
2da6f01c15 pvck: show specific dump option values 2019-12-10 11:07:07 -06:00
David Teigland
3145a85583 pvck: repair headers and metadata
To write a new/repaired pv_header and label_header:

  pvck --repairtype pv_header --file <file> <device>

This uses the metadata input file to find the PV UUID,
device size, and data offset.

To write new/repaired metadata text and mda_header:

  pvck --repairtype metadata --file <file> <device>

This requires a good pv_header which points to one or two
metadata areas.  Any metadata areas referenced by the
pv_header are updated with the specified metadata and
a new mda_header. "--settings mda_num=1|2" can be used
to select one mda to repair.

To combine all header and metadata repairs:

  pvck --repair --file <file> <device>

It's best to use a raw metadata file as input, that was
extracted from another PV in the same VG (or from another
metadata area on the same PV.)  pvck will also accept a
metadata backup file, but that will produce metadata that
is not identical to other metadata copies on other PVs
and other areas.  So, when using a backup file, consider
using it to update metadata on all PVs/areas.

To get a raw metadata file to use for the repair, see
pvck --dump metadata|metadata_search.

List all instances of metadata from the metadata area:
  pvck --dump metadata_search <device>

Save one instance of metadata at the given offset to
the specified file (this file can be used for repair):

  pvck --dump metadata_search --file <file>
    --settings "metadata_offset=<off>" <device>
2019-11-27 11:13:47 -06:00
David Teigland
b4402bd821 exported vg handling
The exported VG checking/enforcement was scattered and
inconsistent.  This centralizes it and makes it consistent,
following the existing approach for foreign and shared
VGs/PVs, which are very similar to exported VGs/PVs.

The access policy that now applies to foreign/shared/exported
VGs/PVs, is that if a foreign/shared/exported VG/PV is named
on the command line (i.e. explicitly requested by the user),
and the command is not permitted to operate on it because it
is foreign/shared/exported, then an access error is reported
and the command exits with an error.  But, if the command is
processing all VGs/PVs, and happens to come across a
foreign/shared/exported VG/PV (that is not explicitly named on
the command line), then the command silently skips it and does
not produce an error.

A command using tags or --select handles inaccessible VGs/PVs
the same way as a command processing all VGs/PVs, and will
not report/return errors if these inaccessible VGs/PVs exist.

The new policy fixes the exit codes on a somewhat random set of
commands that previously exited with an error if they were
looking at all VGs/PVs and an exported VG existed on the system.

There should be no change to which commands are allowed/disallowed
on exported VGs/PVs.

Certain LV commands (lvs/lvdisplay/lvscan) would previously not
display LVs from an exported VG (for unknown reasons).  This has
not changed.  The lvm fullreport command would previously report
info about an exported VG but not about the LVs in it.  This
has changed to include all info from the exported VG.
2019-06-25 15:39:08 -05:00
David Teigland
a9eaab6beb Use "cachevol" to refer to cache on a single LV
and "cachepool" to refer to a cache on a cache pool object.

The problem was that the --cachepool option was being used
to refer to both a cache pool object, and to a standard LV
used for caching.  This could be somewhat confusing, and it
made it less clear when each kind would be used.  By
separating them, it's clear when a cachepool or a cachevol
should be used.

Previously:

- lvm would use the cache pool approach when the user passed
  a cache-pool LV to the --cachepool option.

- lvm would use the cache vol approach when the user passed
  a standard LV in the --cachepool option.

Now:

- lvm will always use the cache pool approach when the user
  uses the --cachepool option.

- lvm will always use the cache vol approach when the user
  uses the --cachevol option.
2019-02-27 08:52:34 -06:00
David Teigland
6620dc9475 add device hints to reduce scanning
Save the list of PVs in /run/lvm/hints.  These hints
are used to reduce scanning in a number of commands
to only the PVs on the system, or only the PVs in a
requested VG (rather than all devices on the system.)
2019-01-15 10:23:47 -06:00
David Teigland
3ae5569570 Add dm-writecache support
dm-writecache is used like dm-cache with a standard LV
as the cache.

$ lvcreate -n main -L 128M -an foo /dev/loop0

$ lvcreate -n fast -L 32M -an foo /dev/pmem0

$ lvconvert --type writecache --cachepool fast foo/main

$ lvs -a foo -o+devices
  LV            VG  Attr       LSize   Origin        Devices
  [fast]        foo -wi-------  32.00m               /dev/pmem0(0)
  main          foo Cwi------- 128.00m [main_wcorig] main_wcorig(0)
  [main_wcorig] foo -wi------- 128.00m               /dev/loop0(0)

$ lvchange -ay foo/main

$ dmsetup table
foo-main_wcorig: 0 262144 linear 7:0 2048
foo-main: 0 262144 writecache p 253:4 253:3 4096 0
foo-fast: 0 65536 linear 259:0 2048

$ lvchange -an foo/main

$ lvconvert --splitcache foo/main

$ lvs -a foo -o+devices
  LV   VG  Attr       LSize   Devices
  fast foo -wi-------  32.00m /dev/pmem0(0)
  main foo -wi------- 128.00m /dev/loop0(0)
2018-11-06 14:18:41 -06:00
David Teigland
1365f0d4c8 remove unneded check to skip filter init
There's no more persistent filter so we don't need
to check for it.
2018-09-12 16:30:50 -05:00
David Teigland
117160b27e Remove lvmetad
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.
2018-07-11 11:26:42 -05:00
Zdenek Kabelac
7b8aa4af57 lvconvert: support to convert lv into vdopool
Support:

lvconvert --type vdo-pool  vg/lv

lvconvert --vdopool  vg/lv   --virtualsize 10G
2018-07-09 15:29:16 +02:00
Joe Thornber
7f97c7ea9a build: Don't generate symlinks in include/ dir
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/
2018-05-14 10:30:20 +01:00
David Teigland
aee27dc7ba scan: skip device rescan in vg_read
For reporting commands (pvs,vgs,lvs,pvdisplay,vgdisplay,lvdisplay)
we do not need to repeat the label scan of devices in vg_read if
they all had matching metadata in the initial label scan.  The
data read by label scan can just be reused for the vg_read.
This cuts the amount of device i/o in half, from two reads of
each device to one.  We have to be careful to avoid repairing
the VG if we've skipped rescanning.  (The VG repair code is very
poor, and will be redone soon.)
2018-04-20 11:23:14 -05:00
David Teigland
89c65d4f71 remove unnecessary REQUIRES_FULL_LABEL_SCAN
we always scan all devices
2018-04-20 11:22:48 -05:00
David Teigland
d9a77e8bb4 lvmcache: simplify metadata cache
The copy of VG metadata stored in lvmcache was not being used
in general.  It pretended to be a generic VG metadata cache,
but was not being used except for clvmd activation.  There
it was used to avoid reading from disk while devices were
suspended, i.e. in resume.

This removes the code that attempted to make this look
like a generic metadata cache, and replaces with with
something narrowly targetted to what it's actually used for.

This is a way of passing the VG from suspend to resume in
clvmd.  Since in the case of clvmd one caller can't simply
pass the same VG to both suspend and resume, suspend needs
to stash the VG somewhere that resume can grab it from.
(resume doesn't want to read it from disk since devices
are suspended.)  The lvmcache vginfo struct is used as a
convenient place to stash the VG to pass it from suspend
to resume, even though it isn't related to the lvmcache
or vginfo.  These suspended_vg* vginfo fields should
not be used or touched anywhere else, they are only to
be used for passing the VG data from suspend to resume
in clvmd.  The VG data being passed between suspend and
resume is never modified, and will only exist in the
brief period between suspend and resume in clvmd.

suspend has both old (current) and new (precommitted)
copies of the VG metadata.  It stashes both of these in
the vginfo prior to suspending devices.  When vg_commit
is successful, it sets a flag in vginfo as before,
signaling the transition from old to new metadata.

resume grabs the VG stashed by suspend.  If the vg_commit
happened, it grabs the new VG, and if the vg_commit didn't
happen it grabs the old VG.  The VG is then used to resume
LVs.

This isolates clvmd-specific code and usage from the
normal lvm vg_read code, making the code simpler and
the behavior easier to verify.

Sequence of operations:

- lv_suspend() has both vg_old and vg_new
  and stashes a copy of each onto the vginfo:
  lvmcache_save_suspended_vg(vg_old);
  lvmcache_save_suspended_vg(vg_new);

- vg_commit() happens, which causes all clvmd
  instances to call lvmcache_commit_metadata(vg).
  A flag is set in the vginfo indicating the
  transition from the old to new VG:
  vginfo->suspended_vg_committed = 1;

- lv_resume() needs either vg_old or vg_new
  to use in resuming LVs.  It doesn't want to
  read the VG from disk since devices are
  suspended, so it gets the VG stashed by
  lv_suspend:
  vg = lvmcache_get_suspended_vg(vgid);

If the vg_commit did not happen, suspended_vg_committed
will not be set, and in this case, lvmcache_get_suspended_vg()
will return the old VG instead of the new VG, and it will
resume LVs based on the old metadata.
2018-04-20 11:22:45 -05:00
Zdenek Kabelac
7323557379 cleanup: add _mb_ to regiosize option
Just like with others mentions default unit in function name.
2018-04-20 12:17:01 +02:00
Alasdair G Kergon
598fcccf45 persistent filter: Skip import before rescan
The persistent filter should not be imported by any command that doesn't
use it so take addtional note of REQUIRES_FULL_LABEL_SCAN (for vgrename)
and introduce IGNORE_PERSISTENT_FILTER for vgscan and pvscan.
2017-11-13 19:45:16 +00:00
Zdenek Kabelac
a65649b45d lvconvert: support repair of cache/cachepool
Extend repair for cache and cachepool target
and user 'lvconvert_repair' routine name.
2017-09-20 15:14:16 +02:00
David Teigland
1460cac273 vgchange: split out code for systemid
Use the command definitions to separate the implementation
of vgchange systemid from the rest of vgchange.
2017-07-24 14:12:08 -05:00
David Teigland
07cd88dcfa vgchange: split out code for lockstart and lockstop
Use the command definitions to separate the implementation
of lockstop and lockstart from the rest of vgchange.
2017-07-24 14:12:08 -05:00
David Teigland
f611b68f3c vgchange: separate change locktype and allow recovery
Add an independent command definition for "vgchange --locktype",
and split the implementation out of the set of common metadata
changes.  It is unlike normal metadata changes, and can only
be run by itself.  (Changing the lock type is similar in
principle to changing the VG name or the VG system ID; it
effects the ability of any host to see or access the VG.)

At some point this command lost the ability to forcibly change
the lock type of a shared VG to "none" (making it a local VG).
This can be necessary to repair shared VGs (e.g. recovery steps
that occur in vg_read are disabled for shared VGs because
they are not locked properly, or recovering sanlock locks
when the PV holding them is lost.)

"vgchange --locktype none --lockopt force VG" is used as the
method of forcing the shared VG to become local so that it
can be repaired.
2017-07-24 14:12:08 -05:00
Alasdair G Kergon
396377bc03 pre-release
Removing some unused new lines and changing some incorrect "can't
release until this is fixed" comments.  Rename license.txt to make
it clear its merely an included file, not itself a licence.
2017-03-28 16:11:35 +01:00
David Teigland
c8671f6f79 commands: use correct relative signs with mirror option
As was recently done with relative signes for sizes/extents,
limit the signs used with the mirrors option, e.g.
lvcreate --mirrors now does not accept or advertise an
optional minus sign with the value.  lvconvert --mirrors
accepts +|-.
2017-03-10 15:41:29 -06:00
Zdenek Kabelac
7b748b7cb8 cache: allow to specify cachemetadataformat
OO_LVCREATE_CACHE accepts --cachemetadataformat.

Support new option --cachemetadataformat auto|1|2 for caching.
Word 'auto' can be also be given as '0'.
2017-03-10 19:33:01 +01:00
David Teigland
a6a2788e7c commands: clean up and unify signed option value handling
Add new values for different sign variations, resulting in:

size_VAL      no sign accepted
ssize_VAL     accepts + or -
psize_VAL     accepts +
nsize_VAL     accpets -

extents_VAL   no sign accepted
sextents_VAL  accepts + or -
pextents_VAL  accepts +
nextents_VAL  accepts -

Depending on the command being run, change the option
values for --size, --extents, --poolmetadatasize to
use the appropriate value from above.

lvcreate uses no sign (but accepts + and ignores it).
lvresize accepts +|- for a relative change.
lvextend accepts + for a relative change.
lvreduce accepts - for a relative change.
2017-03-08 12:54:43 -06:00
David Teigland
11f1556d5d commands: combine duplicate arrays for lv types and props
Like opt and val arrays in previous commit, combine duplicate
arrays for lv types and props in command.c and lvmcmdline.c.
Also move the command_names array to be defined in command.c
so it's consistent with the others.
2017-03-08 11:03:02 -06:00
David Teigland
690f604733 commands: combine duplicate arrays for opt and val
command.c and lvmcmdline.c each had a full array defining
all options and values.  This duplication was not removed
when the command.c code was merged into the run time.
2017-03-08 11:03:02 -06:00
David Teigland
b7831fc14a lvcreate/lvresize: the --size option accepts signed values
There was confusion in the code about whether or not the
--size option accepted a sign.  Make it consistent and clear
that it does.

This exposes a new problem in that an option can only
accept one value type, e.g. --size can only accept a
signed number, it cannot accept a positive or negative
number for some commands and reject negative numbers for
others.

In practice, lvcreate accepts only positive --size
values and lvresize accepts positive or negative --size
values.  There is currently no way to encode this
difference.  Until that is fixed, the man page output
is hacked to avoid printing the [+|-] prefix for sizes
in lvcreate.
2017-03-02 12:53:01 -06:00
David Teigland
74ba326007 man: use Size variable for a number with unit
Define a separate variable type Size to represent
a number that takes an optional UNIT.
2017-02-24 13:44:05 -06:00
David Teigland
f88ce5fb99 lvconvert: include swap behavior in generic pool syntax
For this syntax:
lvconvert --thinpool LV1 --poolmetadata LV2
lvconvert --cachepool LV1 --poolmetadata LV2

Restore the metadata swapping behavior in addition to
the pool creation behavior.  When LV1 is already a pool,
the metadata LV will be swapped with LV2.
When LV1 is not a pool, it will be converted to a
pool using the specified LV for metadata.

This syntax is no longer advertised because of the
ambiguous behavior.  The primary syntaxes for pool
creation and metadata swapping will be the advertised
methods.
2017-02-17 13:20:15 -06:00
David Teigland
7417c8acfa Revert "lvconvert: enable previous syntax to swap metadata"
This reverts commit 717363bb94.

These alternate forms for swapping metadata cannot be
distinguished from the command for creating a pool.
If we were to add these alternate forms for swapping
metadata, we would need to overload the pool creation
command defs, making those definitions ambiguous.
2017-02-14 16:02:54 -06:00
David Teigland
717363bb94 lvconvert: enable previous syntax to swap metadata 2017-02-13 14:41:54 -06:00
David Teigland
13a6368522 args: use arg parsing function for region size
Consolidate the validation of the region size arg
in a new arg parsing function.
2017-02-13 08:21:58 -06:00
David Teigland
46abc28a48 lvconvert: add command to change region size of a raid LV 2017-02-13 08:21:58 -06:00
David Teigland
c3faa5816d commands: move command def parsing into lvm binary
It was previously done at build time by the ccmd binary.
2017-02-13 08:20:10 -06:00
David Teigland
5c779b3231 args: add man page descriptions 2017-02-13 08:20:10 -06:00
David Teigland
46b2599d5c lvconvert: use command defs for raid/mirror types
All lvconvert functionality has been moved out of the
previous monolithic lvconvert code, except conversions
related to raid/mirror/striped/linear.  This switches
that remaining code to be based on command defs, and
standard process_each_lv arg processing.  This final
switch results in quite a bit of dead code that is
also removed.
2017-02-13 08:20:10 -06:00
David Teigland
86d8ab493b lvconvert: use command defs for mergemirrors
and route the generic --merge to one of the
specific merge functions
2017-02-13 08:20:10 -06:00
David Teigland
95e38607ec toollib: find VG name in option values when needed 2017-02-13 08:20:10 -06:00
David Teigland
0e3e611a13 lvconvert: use command defs for thin/cache/pool creation
Everything related to thin and cache.
2017-02-13 08:20:10 -06:00
David Teigland
d71aaca07b lvconvert: add startpoll command using command def
This is a new explicit version of 'lvconvert LV'
which has been an obscure way of triggering polling
to be restarted on an LV that was previously converted.
2017-02-13 08:20:10 -06:00
David Teigland
fa2a728a39 lvconvert: snapshot: use command definitions
Lift all the snapshot utilities (merge, split, combine)
out of the monolithic lvconvert implementation, using
the command definitions.  The old code associated with
these commands is now unused and will be removed separately.
2017-02-13 08:20:10 -06:00
David Teigland
35b9d4d6e9 lvconvert: repair and replace: use command definitions
This lifts the lvconvert --repair and --replace commands
out of the monolithic lvconvert implementation.  The
previous calls into repair/replace can no longer be
reached and will be removed in a separate commit.
2017-02-13 08:20:10 -06:00
David Teigland
52c60b7e7b lvchange: make use of command definitions
Reorganize the lvchange code to take advantage of
the command definition, and remove the validation
that is done by the command definintion rules.
2017-02-13 08:20:10 -06:00
David Teigland
1e2420bca8 commands: new method for defining commands
. Define a prototype for every lvm command.
. Match every user command with one definition.
. Generate help text and man pages from them.

The new file command-lines.in defines a prototype for every
unique lvm command.  A unique lvm command is a unique
combination of: command name + required option args +
required positional args.  Each of these prototypes also
includes the optional option args and optional positional
args that the command will accept, a description, and a
unique string ID for the definition.  Any valid command
will match one of the prototypes.

Here's an example of the lvresize command definitions from
command-lines.in, there are three unique lvresize commands:

lvresize --size SizeMB LV
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync, --reportformat String, --resizefs,
--stripes Number, --stripesize SizeKB, --poolmetadatasize SizeMB
OP: PV ...
ID: lvresize_by_size
DESC: Resize an LV by a specified size.

lvresize LV PV ...
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync,
--reportformat String, --resizefs, --stripes Number, --stripesize SizeKB
ID: lvresize_by_pv
DESC: Resize an LV by specified PV extents.
FLAGS: SECONDARY_SYNTAX

lvresize --poolmetadatasize SizeMB LV_thinpool
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync,
--reportformat String, --stripes Number, --stripesize SizeKB
OP: PV ...
ID: lvresize_pool_metadata_by_size
DESC: Resize a pool metadata SubLV by a specified size.

The three commands have separate definitions because they have
different required parameters.  Required parameters are specified
on the first line of the definition.  Optional options are
listed after OO, and optional positional args are listed after OP.

This data is used to generate corresponding command definition
structures for lvm in command-lines.h.  usage/help output is also
auto generated, so it is always in sync with the definitions.

Every user-entered command is compared against the set of
command structures, and matched with one.  An error is
reported if an entered command does not have the required
parameters for any definition.  The closest match is printed
as a suggestion, and running lvresize --help will display
the usage for each possible lvresize command.

The prototype syntax used for help/man output includes
required --option and positional args on the first line,
and optional --option and positional args enclosed in [ ]
on subsequent lines.

  command_name <required_opt_args> <required_pos_args>
          [ <optional_opt_args> ]
          [ <optional_pos_args> ]

Command definitions that are not to be advertised/suggested
have the flag SECONDARY_SYNTAX.  These commands will not be
printed in the normal help output.

Man page prototypes are also generated from the same original
command definitions, and are always in sync with the code
and help text.

Very early in command execution, a matching command definition
is found.  lvm then knows the operation being done, and that
the provided args conform to the definition.  This will allow
lots of ad hoc checking/validation to be removed throughout
the code.

Each command definition can also be routed to a specific
function to implement it.  The function is associated with
an enum value for the command definition (generated from
the ID string.)  These per-command-definition implementation
functions have not yet been created, so all commands
currently fall back to the existing per-command-name
implementation functions.

Using per-command-definition functions will allow lots of
code to be removed which tries to figure out what the
command is meant to do.  This is currently based on ad hoc
and complicated option analysis.  When using the new
functions, what the command is doing is already known
from the associated command definition.
2017-02-13 08:20:10 -06:00
Zdenek Kabelac
9f65a3f0c5 lvmcmdline: support uint32
Add simple function to wrap usage for only uint32 numbers.
Unlike  'int_arg'  which accepts full range of 64bit number
this function will error on numbers out of this range:

   <0, UINT32_MAX>
2017-01-03 14:55:16 +01:00
Peter Rajnoha
d23c5b9318 args: add priorities for grouping args
Groupable args (the ones marked with ARG_GROUPABLE flag) start a new
group of args if:
  - this is the first time we hit such a groupable arg,
  - or if non-countable arg is repeated.

However, there may be cases where we want to give priorities when
forming groups and hence force new group creation if we hit an arg
with higher grouping priority.

For example, let's assume (for now) hypothetical sequence of args used:

  lvs -o lv_name --configreport log -o log_type --configreport lv -o +vg_name

Without giving any priorites, we end up with:

  lvs -o lv_name --configreport log -o log_type --configreport lv -o +vg_name
     |                            | |                           | |          |
     \__________GROUP1___________/   \________GROUP2___________/   \_GROUP3_/

This is because we hit "-o" as the first groupable arg. The --configreport,
even though it's groupable too, it falls into the previous "-o" group.

While we may need to give priority to the --configreport arg that should
always start a new group in this scenario instead:

  lvs -o lv_name --configreport log -o log_type --configreport lv -o +vg_name
      |         | |                            | |                           |
      \_GROUP1_/   \_________GROUP2___________/   \_________GROUP3__________/

So here "-o" started a new group but since "--configreport" has higher
priority than "-o", it starts fresh new group now and hence the rest of
the command line's args are grouped by --configreport now.
2016-06-20 11:33:42 +02:00