dmeventd: (workaround) fix mirror DSO to work with lvmetad
Automatic dmeventd repair of mirrors with active lvmetad configured
(mirror_image_fault_policy = "allocate") fails because the lvscan
run before the repair in the mirror DSO does not update the
lvmetad cache properly thus "lvconvert --repair ..." fails.
Need to scan the mirror LV before and after the repair
to have proper cache content after the repair finished.
The cache can't be relied on or the repair will fail.
Bryn M. Reeves [Fri, 16 Dec 2016 13:42:08 +0000 (13:42 +0000)]
dmstats: start dmfilemapd when creating or updating file maps
Launch an instance of the filemap monitoring daemon when creating,
or updating, a file mapped group, unless the --nomonitor switch is
given.
Unless --foreground is given the daemon will detach from the
terminal and run in the background until it is signaled or the
daemon termination conditions are met.
The --follow={inode|path} switch is added to control the daemon
behaviour when files are moved, unlinked, or renamed while they
are being monitored.
The daemon runs with the same verbosity as the dmstats command
that starts it.
Bryn M. Reeves [Thu, 15 Dec 2016 20:10:27 +0000 (20:10 +0000)]
daemons: add dmfilemapd
Add a daemon that can be launched to monitor a group of regions
corresponding to the extents of a file, and to update the regions as the
file's allocation changes.
The daemon is intended to be started from a library interface, but can
also be run from the command line:
Where fd is a file descriptor open on the mapped file, group_id is the
group identifier of the mapped group and mode is either "inode" or
"path". E.g.:
# dmfilemapd 3 0 vm.img inode 1 3 3<vm.img
...
If foreground is non-zero, the daemon will not fork to run in the
background. If verbose is non-zero, libdm and daemon log messages will
be printed.
It is possible for the group identifier to change when regions are
re-mapped: this occurs when the group leader is deleted (regroup=1 in
dm_stats_update_regions_from_fd()), and another region is created before
the daemon has a chance to recreate the leader region.
The operation is inherently racey since there is currently no way to
atomically move or resize a dm_stats region while retaining its
region_id.
Detect this condition and update the group_id value stored in the
filemap monitor.
A function is also provided in the the stats API to launch the filemap
monitoring daemon:
This carries out the first fork and execs dmfilemapd with the arguments
specified.
A dm_filemapd_mode_t value is specified by the mode argument: either
DM_FILEMAPD_FOLLOW_INODE, or DM_FILEMAPD_FOLLOW_PATH. A helper function,
dm_filemapd_mode_from_string(), is provided to parse a string containing
a valid mode name into the appropriate dm_filemapd_mode_t value.
lvconvert: prompt when splitting off a tracked LV of a 2-legged raid1 LV
Splitting off an image LV of a 2-legged raid1 LV tracking changes
causes loosing partial resilience for any newly written data set.
Full resilience will be provided again after the split off image LV
got merged back in and the new data set got fully synchronized.
Reason being that the data is only stored on the remaining single
writable image during the split.
Ask user to avoid uninformed loss of such partial resilience.
David Teigland [Tue, 7 Mar 2017 22:55:07 +0000 (16:55 -0600)]
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.
David Teigland [Tue, 7 Mar 2017 18:08:23 +0000 (12:08 -0600)]
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.
David Teigland [Tue, 7 Mar 2017 17:47:44 +0000 (11:47 -0600)]
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.
Reshaping a raid5 LV to one stripe aiming to convert it to
raid1 (and optionally to linear) reports the wrong LV size
when still having reshape space allocated.
The lv_extend/_lv_reduce API doesn't cope with resizing RaidLVs
with allocated reshape space and ongoing conversions. Prohibit
resizing during conversions and remove the reshape space before
processing resize. Add missing seg->data_copies initialisation.
For the time being raid10 is limited to even number of total stripes
as is and 2 data copies. The number of stripes provided on creation
of a raid10(_near) LV with -i/--stripes gets doubled to define
that even total number of stripes (i.e. images).
Apply the same on disk adding conversions (reshapes) with
"lvconvert --stripes RaidLV" (e.g. 2 stripes = 4 images
total converted to 3 stripes = 6 images total).
David Teigland [Fri, 3 Mar 2017 22:10:40 +0000 (16:10 -0600)]
man: move the full UNIT description
Part of the UNIT description was still living in the
--size description. Move it to the Size[UNIT] description
since it is used by other options, not just --size.
David Teigland [Fri, 3 Mar 2017 21:57:51 +0000 (15:57 -0600)]
man/help: poolmetadatasize option can take relative value
In lvcreate/lvconvert, --poolmetdatasize can only be an
absolute value, but in lvresize/lvextend, --poolmetadatasize
can be given a + relative value.
The val types only currently support relative values that
go in both directions +|-. Further work is needed to add
val types that can be relative in only one direction, and
switching various option values to one those depending on
the command name. Then poolmetdatasize will not appear
with a +|- option in lvcreate/lvconvert, and will
appear with only the + option in lvresize/lvextend.
Enhance the raid report functions for the recently added LV fields
reshape_len, reshape_len_le, data_offset, new_data_offset, data_copies,
data_stripes and parity_chunks to cope with "lvs --select".
David Teigland [Thu, 2 Mar 2017 22:33:14 +0000 (16:33 -0600)]
help: show extents option for lvcreate
A special case is needed to display
--extents for lvcreate since the cmd defs
treat --extents as an automatic alternative
to --size (to avoid duplicating every cmd def).
lvs: enhance stripes and region size field descriptions
Now that we got the "data_stripes" field key, adjust the "stripes" field description.
Enhance the "regionsize" field description to cover raids as well.
David Teigland [Thu, 2 Mar 2017 19:52:06 +0000 (13:52 -0600)]
commands: handle including an optional opt multiple times
When a cmd def includes multiple sets of options (OO_FOO),
allow multiple OO_FOO sets to contain the same option and
avoid repeating it in the cmd def.
David Teigland [Thu, 2 Mar 2017 18:53:01 +0000 (12:53 -0600)]
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.
Settings specified in other command line args take precedence over
profiles and --config, which takes precedence over settings in actual
config files.
Since commit 1e2420bca85da9a37570871cd70192e9ae831786 ('commands: new
method for defining commands') commands like this:
lvchange --config 'global/test=1' -ay vg
have been printing the 'TEST MODE' message, but nevertheless making
real changes.
During an ongoing reshape, the MD kernel runtime reads stripes relative
to data_offset and starts storing the reshaped stripes (with new raid
layout and/or new stripesize and/or new number of stripes) relative
to new_data_offset. This is to avoid writing over any data in place
which is non-atomic by nature and thus be recoverable without data loss
in the transition. MD uses the term out-of-place reshaping for it.
There's 2 other areas we don't have report capability for:
- number of data stripes vs. total stripes
(e.g. raid6 with 7 stripes toal has 5 data stripes)
- number of (rotating) parity/syndrome chunks
(e.g. raid6 with 7 stripes toal has 2 parity chunks; one
per stripe for P-Syndrome and another one for Q-Syndrome)
Thus, add the following reportable keys:
- reshape_len (in current units)
- reshape_len_le (in logical extents)
- data_offset (in sectors)
- new_data_offset ( " )
- data_stripes
- parity_chunks
Enhance lvchange-raid.sh, lvconvert-raid-reshape-linear_to_striped.sh,
lvconvert-raid-reshape-striped_to_linear.sh, lvconvert-raid-reshape.sh
and lvconvert-raid-takeover.sh to make use of new keys.
David Teigland [Tue, 28 Feb 2017 22:15:11 +0000 (16:15 -0600)]
commands: SECONDARY flag changes in cmd defs
Add/remove the SECONDARY_SYNTAX flag to cmd defs.
cmd defs with this flag will be listed under the
ADVANCED USAGE man page section, so that the main
USAGE section contains the most common commands
without distraction.
- When multiple cmd defs do the same thing, one variant
can be displayed in the first list.
- Very advanced, unusual or uncommon commands should be
in the second list.
lvconvert: libdm RAID API compatibility versioning
Commit 27384c52cf6a lowered the maximum number of devices
back to 64 for compatibility.
Because more members have been added to the API in
'struct dm_tree_node_raid_params *', we have to version
the public libdm RAID API to not break any existing users.
Changes:
- keep the previous 'struct dm_tree_node_raid_params' and
dm_tree_node_add_raid_target_with_params()/dm_tree_node_add_raid_target()
in order to expose the already released public RAID API
- introduce 'struct dm_tree_node_raid_params_v2' and additional functions
dm_tree_node_add_raid_target_with_params_v2()/dm_tree_node_add_raid_target_v2()
to be used by the new lvm2 lib reshape extentions
With this new API, the bitfields for rebuild/writemostly legs in
'struct dm_tree_node_raid_params_v2' can be raised to 256 bits
again (253 legs maximum supported in MD kernel).
Mind that we can limit the maximum usable number via the
DEFAULT_RAID{1}_MAX_IMAGES definition in defaults.h.
David Teigland [Fri, 24 Feb 2017 22:43:05 +0000 (16:43 -0600)]
commands: fixes for recent raid changes
- Combine the equivalent lvconvert --type raid defs.
(Two cmd defs must be different without relying
on LV type, which are not known at the time the
cmd def is matched.)
- Remove unused optional options from lvconvert --stripes,
and lvconvert --stripesize.
- Use Number for --stripes_long val type.
- Combine the cmd def for raid reshape cleanup into the
existing start_poll cmd def (they were duplicate defs).
Calls into the raid code from a poll opertion will be
added.
lvconvert: limit libdm to maximum of 64 RAID devices
Commit 64a2fad5d6c6 raised the maximum number of RAID devices to 64.
Commit e2354ea344c2 introduced RAID_BITMAP_SIZE as 4 to have
256 bits (4 * 64 bit array members), thus changing the libdm API
unnecessarilly for the time being.
To not change the API, reduce RAID_BITMAP_SIZE to 1.
Remove an unneeded definition of it from libdm-common.h.
If we ever decide to raise past 64, we'll version the API.
Example command to change the origin of a repository clone:
Public:
git remote set-url origin git://sourceware.org/git/lvm2.git
Committers:
git remote set-url origin git+ssh://sourceware.org/git/lvm2.git
David Teigland [Fri, 24 Feb 2017 20:17:58 +0000 (14:17 -0600)]
lvconvert: fix handling args in combining snapshots
Fixes commit 286d39ee3c433, which was correct except
for a reversed strstr. Now uses strchr, and modifies
a copy of the name so the original argv is preserved.
When requesting a regionsize change during conversions, check
for constraints or the command may fail in the kernel n case
the region size is too smalle or too large thus leaving any
new SubLVs behind.