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Commit Graph

736 Commits

Author SHA1 Message Date
David Teigland
c98a25aab1 print warning about in-use orphans
Warn about a PV that has the in-use flag set, but appears in
the orphan VG (no VG was found referencing it.)

There are a number of conditions that could lead to this:

. The PV was created with no mdas and is used in a VG with
  other PVs (with metadata) that have not yet appeared on
  the system.  So, no VG metadata is found by lvm which
  references the in-use PV with no mdas.

. vgremove could have failed after clearing mdas but
  before clearing the in-use flag.  In this case, the
  in-use flag needs to be manually cleared on the PV.

. The PV may have damanged/unrecognized VG metadata
  that lvm could not read.

. The PV may have no mdas, and the PVs with the metadata
  may have damaged/unrecognized metadata.
2017-06-01 11:18:42 -05:00
David Teigland
f3c90e90f8 disable repairing in-use flag on orphan PVs
A PV holding VG metadata that lvm can't understand
(e.g. damaged, checksum error, unrecognized flag)
will appear as an in-use orphan, and will be cleared
by this repair code.  Disable this repair until the
code can keep track of these problematic PVs, and
distinguish them from actual in-use orphans.
2017-06-01 09:53:14 -05:00
David Teigland
7a0f46e2f8 add comment about PV in-use repair
copied from commit message for
d97f1c89de
2017-05-23 16:59:46 -05:00
Alasdair G Kergon
fbe7464df5 metadata: Unlock VG on more _vg_make_handle error paths
Internal error: VG lock vg0 must be requested before vg3, not after.
Internal error: 3 device(s) were left open and have been closed.
2017-05-23 01:38:02 +01:00
Alasdair G Kergon
80900dcf76 metadata: Fix metadata repair when devs still missing.
_check_reappeared_pv() incorrectly clears the MISSING_PV flags of
PVs with unknown devices.
While one caller avoids passing such PVs into the function, the other
doesn't.  Move the check inside the function so it's not forgotten.

Without this patch, if the normal VG reading code tries to repair
inconsistent metadata while there is an unknown PV, it incorrectly
considers the missing PVs no longer to be missing and produces
incorrect 'pvs' output omitting the missing PV, for example.

Easy reproducer:
Create a VG with 3 PVs pv1, pv2, pv3.
Hide pv2.
Run vgreduce --removemissing.
Reinstate the hidden PV pv2 and at the same time hide a different PV
pv3.
Run 'pvs' - incorrect output.
Run 'pvs' again - correct output.

See https://bugzilla.redhat.com/1434054
2017-05-11 02:17:34 +01:00
David Teigland
d45531712d vg_read: check for NULL dev to avoid segfault
There are certain situations (not fully understood)
where is_missing_pv() is false, but pv->dev is NULL,
so this adds a check for NULL pv->dev after is_missing_pv()
to avoid a segfault.
2017-05-10 10:45:41 -05:00
David Teigland
19267fa6aa lvmlockd: test mode doesn't work
The --test option is not yet compatible with shared VGs
because changes are made in lvmlockd that cannot be
reversed or faked.
2017-02-13 08:20:10 -06:00
Zdenek Kabelac
a3579aafc5 cleanup: use matching signed number comparation 2017-02-13 10:06:19 +01:00
Zdenek Kabelac
b6301aa977 cleanup: use fall through
gcc gets 'selective' on having commented fall through case.
2017-02-13 10:06:18 +01:00
Zdenek Kabelac
377288fe03 cleanup: reuse existing code 2017-01-03 14:55:16 +01:00
Zdenek Kabelac
c5aeb21015 cleanup: zero baton in struct initilizer 2016-12-09 15:15:02 +01:00
Zdenek Kabelac
1a4f13eb6e cleanup: add some dots and use display_lvname
Just some more VG/LV printing.
2016-11-25 15:01:27 +01:00
Zdenek Kabelac
1d58074d9f debug: more stacktrace corrections
Continue previous patch dropping some unneeded stack traces
after printed log_error/warn messages.
2016-11-25 14:58:28 +01:00
Peter Rajnoha
070c0d31ab metadata: fix automatic updates of PV extension headers to newest version
Before, the automatic update from older to newer version of PV extension
header happened within vg_write call. This may have caused problems under
some circumnstances where there's a code in between vg_write and vg_commit
which may have failed. In such situation, we reverted precommitted metadata
and put back the state to working version of VG metadata.

However, we don't have revert for PV write operation at the moment. So
if we updated PV headers already and we reverted vg_write due to failure
in subsequent code (before vg_commit), we ended up with lost VG metadata
(because old metadata pointers got reset by the PV write operation).

To minimize problematic situations here, we should put vg_write and
vg_commit that is done after PV header rewrites as close to each
other as possible.

This patch moves the automatic PV header rewrite for new extension
header part from vg_write to _vg_read where it's done the same way
as we do any other VG repairs if detected during VG read operation
(under VG write lock).
2016-07-26 16:22:55 +02:00
Zdenek Kabelac
4e1bf7acd3 coverity: add some tests for function results
Even though they cannot normally happen...
2016-07-13 21:52:14 +02:00
David Teigland
ff3c4ed1c0 lvmetad: two phase vg_remove
Apply the same idea as vg_update.
Before doing the VG remove on disk, invalidate
the VG in lvmetad.  After the VG is removed,
remove the VG in lvmetad.  If the command fails
after removing the VG on disk, but before removing
the VG metadata from lvmetad, then a subsequent
command will see the INVALID flag and not use the
stale metadata from lvmetad.
2016-06-28 02:30:36 +01:00
David Teigland
a7c45ddc59 lvmetad: two phase vg_update
Previously, a command sent lvmetad new VG metadata in vg_commit().
In vg_commit(), devices are suspended, so any memory allocation
done by the command while sending to lvmetad, or by lvmetad while
updating its cache could deadlock if memory reclaim was triggered.

Now lvmetad is updated in unlock_vg(), after devices are resumed.
The new method for updating VG metadata in lvmetad is in two phases:

1. In vg_write(), before devices are suspended, the command sends
   lvmetad a short message ("set_vg_info") telling it what the new
   VG seqno will be.  lvmetad sees that the seqno is newer than
   the seqno of its cached VG, so it sets the INVALID flag for the
   cached VG.  If sending the message to lvmetad fails, the command
   fails before the metadata is committed and the change is not made.
   If sending the message succeeds, vg_commit() is called.

2. In unlock_vg(), after devices are resumed, the command sends
   lvmetad the standard vg_update message with the new metadata.
   lvmetad sees that the seqno in the new metadata matches the
   seqno it saved from set_vg_info, and knows it has the latest
   copy, so it clears the INVALID flag for the cached VG.

If a command fails between 1 and 2 (after committing the VG on disk,
but before sending lvmetad the new metadata), the cached VG retains
the INVALID flag in lvmetad.  A subsequent command will read the
cached VG from lvmetad, see the INVALID flag, ignore the cached
copy, read the VG from disk instead, update the lvmetad copy
with the latest copy from disk, (this clears the INVALID flag
in lvmetad), and use the correct VG metadata for the command.

(This INVALID mechanism already existed for use by lvmlockd.)
2016-06-28 02:30:31 +01:00
David Teigland
cc3e7c7c31 lvmetad: remove unused code for other format types
lvmetad is no longer used at all with the lvm1 format,
so the text format is the only one that uses lvmetad.
2016-06-28 02:30:25 +01:00
David Teigland
ebd2758dab vgimportclone: add native command
This is cleaner and more efficient than the script.
The args and usage are unchanged.
2016-06-22 13:13:10 -05:00
David Teigland
01156de6f7 lvmcache: add optional dev arg to lvmcache_info_from_pvid
A number of places are working on a specific dev when they
call lvmcache_info_from_pvid() to look up an info struct
based on a pvid.  In those cases, pass the dev being used
to lvmcache_info_from_pvid().  When a dev is specified,
lvmcache_info_from_pvid() will verify that the cached
info it's using matches the dev being processed before
returning the info.  Calling code will not mistakenly
get info for the wrong dev when duplicate devs exist.

This confusion was happening when scanning labels when
duplicate devs existed.  label_read for the first dev
would add an info struct to lvmcache for that dev/pvid.
label_read for the second dev would see the pvid in
lvmcache from first dev, and mistakenly conclude that
the label_read from the second dev can be skipped
because it's already been done.  By verifying that the
dev for the cached pvid matches the dev being read,
this mismatch is avoided and the label is actually read
from the second duplicate.
2016-06-07 15:15:47 -05:00
David Teigland
5dc2ed0c71 vgreduce: use process_each_vg 2016-05-25 16:41:59 -05:00
David Teigland
9b640c3684 pvscan: use process_each_vg for autoactivate
This refactors the code for autoactivation.  Previously,
as each PV was found, it would be sent to lvmetad, and
the VG would be autoactivated using a non-standard VG
processing function (the "activation_handler") called via
a function pointer from within the lvmetad notification path.

Now, any scanning that the command needs to do (scanning
only the named device args, or scanning all devices when
there are no args), is done first, before any activation
is attempted.  During the scans, the VG names are saved.
After scanning is complete, process_each_vg is used to do
autoactivation of the saved VG names.  This makes pvscan
activation much more similar to activation done with
vgchange or lvchange.

The separate autoactivate phase also means that if lvmetad
is disabled (either before or during the scan), the command
can continue with the activation step by simply not using
lvmetad and reverting to disk scanning to do the
activation.
2016-05-23 11:57:32 -05:00
David Teigland
e2d823eced metadata: move warning message about repairing VG
Move the message to just before the repair is going
to happen to avoid printing the message in cases
where repair is skipped.
2016-05-06 09:00:00 -05:00
David Teigland
8b7a78c728 lvmcache: improve duplicate PV handling
Wait to compare and choose alternate duplicate devices until
after all devices are scanned.  During scanning, the first
duplicate dev is kept in lvmcache, and others are kept in a
new list (_found_duplicate_devs).

After all devices are scanned, compare all the duplicates
available for a given PVID and decide which is best.

If the dev used in lvmcache is changed, drop the old dev
from lvmcache entirely and rescan the replacement dev.
Previously the VG metadata from the old dev was kept in
lvmcache and only the dev was replaced.

A new config setting devices/allow_changes_with_duplicate_pvs
can be set to 0 which disallows modifying a VG or activating
LVs in it when the VG contains PVs with duplicate devices.
Set to 1 is the old behavior which allowed the VG to be
changed.

The logic for which of two devs is preferred has changed.
The primary goal is to choose a device that is currently
in use if the other isn't, e.g. by an active LV.

. prefer dev with fs mounted if the other doesn't, else
. prefer dev that is dm if the other isn't, else
. prefer dev in subsystem if the other isn't

If neither device is preferred by these rules, then don't
change devices in lvmcache, leaving the one that was found
first.

The previous logic for preferring a device was:

. prefer dev in subsystem if the other isn't, else
. prefer dev without holders if the other has holders, else
. prefer dev that is dm if the other isn't
2016-05-06 09:00:00 -05:00
Zdenek Kabelac
ed9162cd88 cleanup: enhance warning message
Add WARNING: for log_warn.
Show device name which is marked missing.
2016-05-05 23:55:18 +02:00
David Teigland
3c53acb378 metadata: fix segfault when filters reject devices
Checking for devices uses is_missing_pv() to check
if there is a device for the PV.  is_missing_pv()
is based on the MISSING_PV flag, which does not
always correspond to !pv->dev.  When using lvmetad,
a command like:

pvs --config 'devices/filter=["a|/dev/sdb|", "r|.*|"]'

will cause a number of PVs to have NULL pv->dev, but
not the MISSING_PV flag.  So, NULL pv->dev needs to
also be checked.
2016-04-27 12:13:26 -05:00
Peter Rajnoha
379874a2d0 cleanup: do not mention segment in warning message if device not found for a PV when checking used/assumed devs for an LV
[0] fedora/~ # pvs --config 'devices/filter=["a|/dev/sda|", "r|.*|"]'
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Couldn't find device for segment belonging to fedora/root while checking used and assumed devices.
  WARNING: Couldn't find device for segment belonging to fedora/swap while checking used and assumed devices.
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda          lvm2 ---  128.00m 128.00m
  [unknown]  fedora lvm2 a-m   19.49g      0

Probably not worth mentioning "segments" here, just state that devices
for an LV can't be all found during the check - it's less mysterious for
user then:

[0] fedora/~ # pvs --config 'devices/filter=["a|/dev/sda|", "r|.*|"]'
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Couldn't find all devices for LV fedora/root while checking used and assumed devices.
  WARNING: Couldn't find all devices for LV fedora/swap while checking used and assumed devices.
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda          lvm2 ---  128.00m 128.00m
  [unknown]  fedora lvm2 a-m   19.49g      0
2016-04-25 11:44:24 +02:00
Peter Rajnoha
9d976c0002 metadata: log warning instead of error if device not found while checking used and assumed devs
When checking assumed PVs against real devices used for LVs and if
there's no device assigned for an assumed PV (e.g. due to filters),
do log_warn instead of log_error and continue checking LV segments
and associated assumed PVs further, just like we do log_warn elsewhere
in this situation.

This way user will see the warning for each LV which couldn't be
checked completely against real PVs used. Before, we logged only
the very first occurence of missing device for an LV in a VG and we
returned from the function doing this check for all the LVs in VG
immediately which may be a bit misleading because it didn't tell
user about all the other LVs and whether they could be checked
or not.

For example, we have this setup:

[0] fedora/~ # pvs
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda          lvm2 ---  128.00m 128.00m
  /dev/vda2  fedora lvm2 a--   19.49g      0

[0] fedora/~ # lvs -o+devices
  LV   VG     Attr       LSize   Devices
  root fedora -wi-ao----  19.00g /dev/vda2(0)
  swap fedora -wi-ao---- 500.00m /dev/vda2(4864)

Before this patch (only the very first LV in a VG is logged to have a
problem while checking used and assumed devices):

[0] fedora/~ # pvs --config 'devices/filter=["a|/dev/sda|", "r|.*|"]'
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  Couldn't find device for segment belonging to fedora/root while checking used and assumed devices.
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda          lvm2 ---  128.00m 128.00m
  [unknown]  fedora lvm2 a-m   19.49g      0

With this patch applied (all LVs where we hit problem while checking
used and assumed devices are logged and it's warning, not error):

[0] fedora/~ # pvs --config 'devices/filter=["a|/dev/sda|", "r|.*|"]'
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Device for PV Qcxpcy-XgtP-UD3s-PmG0-qLyE-Z0ho-DYsxoz not found or rejected by a filter.
  WARNING: Couldn't find device for segment belonging to fedora/root while checking used and assumed devices.
  WARNING: Couldn't find device for segment belonging to fedora/swap while checking used and assumed devices.
  PV         VG     Fmt  Attr PSize   PFree
  /dev/sda          lvm2 ---  128.00m 128.00m
  [unknown]  fedora lvm2 a-m   19.49g      0
2016-04-25 11:27:28 +02:00
Zdenek Kabelac
8c4b717f4d coverity: drop abadoing object
As mempool is destroyed on by caller don't bother for
mempool freeing here.
2016-04-22 01:13:35 +02:00
David Teigland
5e9e43074a lvmetad: rework command connection setup and checking
The lvmetad connection is created within the
init_connections() path during command startup,
rather than via the old lvmetad_active() check.

The old lvmetad_active() checks are replaced
with lvmetad_used() which is a simple check that
tests if the command is using/connected to lvmetad.

The old lvmetad_set_active(cmd, 0) calls, which
stopped the command from using lvmetad (to revert to
disk scanning), are replaced with lvmetad_make_unused(cmd).
2016-04-19 14:00:02 -05:00
David Teigland
a6a32a7c0e metadata: don't repair shared VGs
When the in-use flag looks like it needs to be repaired.
2016-04-19 09:19:32 -05:00
Peter Rajnoha
94f78e0183 coverity: fix some issues reported by coverity for recent code 2016-03-22 16:03:55 +01:00
Peter Rajnoha
f231bdb20b metadata: use own mem pool to report PV device mismatch in VG 2016-03-21 14:39:11 +01:00
Peter Rajnoha
03b0a78640 dev: detect mismatch between devices used and devices assumed for an LV
It's possible for an LVM LV to use a device during activation which
then differs from device which LVM assumes based on metadata later on.

For example, such device mismatch can occur if LVM doesn't have
complete view of devices during activation or if filters are
misbehaving or they're incorrectly set during activation.

This patch adds code that can detect this mismatch by creating
VG UUID and LV UUID index while scanning devices for device cache.

The VG UUID index maps VG UUID to a device list. Each device in the
list has a device layered above as a holder which is an LVM LV device
and for which we know the VG UUID (and similarly for LV UUID index).

We can acquire VG and LV UUID by reading /sys/block/<dm_dev_name>/dm/uuid.
So these indices represent the actual state of PV device use in
the system by LVs and then we compare that to what LVM assumes
based on metadata.

For example:

[0] fedora/~ # lsblk /dev/sdq /dev/sdr /dev/sds /dev/sdt
NAME         MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
sdq           65:0    0  104M  0 disk
|-vg-lvol0   253:2    0  200M  0 lvm
`-mpath_dev1 253:3    0  104M  0 mpath
sdr           65:16   0  104M  0 disk
`-mpath_dev1 253:3    0  104M  0 mpath
sds           65:32   0  104M  0 disk
|-vg-lvol0   253:2    0  200M  0 lvm
`-mpath_dev2 253:4    0  104M  0 mpath
sdt           65:48   0  104M  0 disk
`-mpath_dev2 253:4    0  104M  0 mpath

In this case the vg-lvol0 is mapped onto sdq and sds becauset this is
what was available and seen during activation. Then later on, sdr and
sdt appeared and mpath devices were created out of sdq+sdr (mpath_dev1)
and sds+sdt (mpath_dev2). Now, LVM assumes (correctly) that mpath_dev1
and mpath_dev2 are the PVs that should be used, not the mpath
components (sdq/sdr, sds/sdt).

[0] fedora/~ # pvs
  Found duplicate PV xSUix1GJ2SK82ACFuKzFLAQi8xMfFxnO: using /dev/mapper/mpath_dev1 not /dev/sdq
  Using duplicate PV /dev/mapper/mpath_dev1 from subsystem DM, replacing /dev/sdq
  Found duplicate PV MvHyMVabtSqr33AbkUrobq1LjP8oiTRm: using /dev/mapper/mpath_dev2 not /dev/sds
  Using duplicate PV /dev/mapper/mpath_dev2 from subsystem DM, ignoring /dev/sds
  WARNING: Device mismatch detected for vg/lvol0 which is accessing /dev/sdq, /dev/sds instead of /dev/mapper/mpath_dev1, /dev/mapper/mpath_dev2.
  PV                     VG     Fmt  Attr PSize   PFree
  /dev/mapper/mpath_dev1 vg     lvm2 a--  100.00m      0
  /dev/mapper/mpath_dev2 vg     lvm2 a--  100.00m      0
2016-03-21 11:40:40 +01:00
Peter Rajnoha
9918d95490 metadata: do not issue warning message about PV dev size being 0 when the device has gone just after VG read
There's a window between doing VG read and checking PV device size
against real device size. If the device is removed in this window,
the dev cache still holds struct device and pv->dev still references
that and that PV is not marked as missing. However, if we're trying
to get size for such device, the open fails because that device
doesn't exists anymore.

We called existing pv_dev_size in _check_pv_dev_sizes fn. But
pv_dev_size assigned a size of 0 if the dev_get_size it called failed
(because the device is gone).

So call the dev_get_size directly and check for the return code
in _check_pv_dev_sizes and go further only if we really know the
device size. This is to avoid confusing warning messages like:

  Device /dev/sdd1 has size of 0 sectors which is smaller than corresponding PV size of 31455207 sectors. Was device resized?
  One or more devices used as PVs in VG helter_skelter have changed sizes.
2016-03-10 13:11:15 +01:00
David Teigland
2d5dc6512e dbus: add notification from commands
When a command modifies a PV or VG, or changes the
activation state of an LV, it will send a dbus
notification when the command is finished.  This
can be enabled/disabled with a config setting.
2016-03-07 10:06:09 -06:00
Peter Rajnoha
8a601454e1 metadata: automatically remove invalid (dangling) historical LVs
Historical LV is valid as long as there is at least one live LV among
its ancestors. If we find any invalid (dangling) historical LVs, remove
them automatically.
2016-03-03 13:50:59 +01:00
Peter Rajnoha
1297b0c8be metadata: also validate historical LVs in VG in vg_validate and check_lv_segments 2016-03-03 13:50:59 +01:00
Peter Rajnoha
fc628e92ba metadata: also look at historical LVs when checking LV name availability
Live LVs and historical LVs are in one namespace and the name needs to
be unique in whole VG.
2016-03-03 13:50:59 +01:00
Peter Rajnoha
ff6e124a33 conf: add metadata/lvs_history_timeout configuration setting 2016-03-03 13:50:59 +01:00
Peter Rajnoha
74272e163d metadata: add vg_strip_outdated_historical_lvs fn and call it during VG read
The vg_strip_outdated_historical_lvs iterates over the list of historical LVs
we have and it shoots down the ones which are outdated.

Configuration hook to set the timeout will be in subsequent patch.
2016-03-03 13:50:59 +01:00
Peter Rajnoha
f833a6d074 metadata: add historical_glv_remove 2016-03-03 13:50:57 +01:00
Peter Rajnoha
c45af2df4e metadata: add find_historical_glv fn
The find_historical_glv is helper function that looks up historical
LV in struct volume_group's historical_lvs list and returns it if
found.
2016-03-03 13:46:39 +01:00
Peter Rajnoha
790b2e8748 metadata: create historical LVs when LVs are removed and interconnect with live LVs
When an LV is being removed, we create an instance of
"struct historical_logical_volume" wrapped up in
"struct generic_logical_volume".

All instances of "struct historical_logical_volume" are then recorded in
"historical_lvs" list which is part of "struct volume_group".

The "historical LV" is then interconnected with "live LVs" to
connect a history chain for the live LV.
2016-03-03 11:26:51 +01:00
Zdenek Kabelac
e04a0184cb cleanup: use lv_is_partial
Check for PARTIAL_LV flag in standard way.
2016-03-03 10:17:03 +01:00
David Teigland
172bad0d56 Use a common message for a used PV
Change some inconsistent messages and adopt
the new wording "PV %s is used by" in place
of "PV %s is marked as belonging to"
or "PV %s belongs to".
2016-02-25 14:23:41 -06:00
David Teigland
a77ded3001 replace pvcreate_params with pvcreate_each_params
"pvcreate_each_params" was a temporary name used
to transition from the old "pvcreate_params".

Remove the old pvcreate_params struct and rename the
new pvcreate_each_params struct to pvcreate_params.
Rename various pvcreate_each_params terms to simply
pvcreate_params.
2016-02-25 09:14:10 -06:00
David Teigland
4de6caf5b5 redefine pvcreate structs
New pv_create_args struct contains all the specific
parameters for creating a PV, independent of the
command.
2016-02-25 09:14:10 -06:00
David Teigland
c201ee09bd metadata: add fixme about code used only by liblvm 2016-02-25 09:14:10 -06:00
David Teigland
a9940bd3c9 vgcreate: use the common toollib pv create
Use the new pvcreate_each_device() function from
toollib, previously added for pvcreate, in place
of the old pvcreate_vol().

This also requires shifting the location where the
lock is acquired for the new VG name.  The lock for
the new VG is supposed to be acquired before pvcreate.
This means splitting the vg_lock_newname() out of
vg_create(), and calling vg_lock_newname() directly
before pvcreate, and then calling the remainder of
vg_create() after pvcreate.

The new function vg_lock_and_create() now does
vg_lock_newname() + vg_create(), like the previous
version of vg_create().

The lock on the new VG name is released before the
pvcreate and reacquired after the pvcreate because
pvcreate needs to reset lvmcache, which doesn't work
when locks are held.  An exception could likely be
made for the new VG name lock, which would allow
vgcreate to hold the new VG name lock across the
pvcreate step.
2016-02-25 09:14:09 -06:00