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Commit Graph

369 Commits

Author SHA1 Message Date
David Teigland
199b7b55c2 lvmcache: fix duplicate handling with multiple scans
Some commands scan labels to populate lvmcache multiple
times, i.e. lvmcache_init, scan labels to fill lvmcache,
lvmcache_destroy, then later repeat

Each time labels are scanned, duplicates are detected,
and preferred devices are chosen.  Each time this is done
within a single command, we want to choose the same
preferred devices.  So, check for existing preferences
when choosing preferred devices.

This also fixes a problem with the list of unused duplicate
devs when run in an lvm shell.  The devs had been allocated
from cmd memory, resulting in invalid list entries between
commands.
2016-06-07 15:15:51 -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
ed6ffc7a34 lvmetad: handle update failures
If a command gets stuck during an lvmetad update, lvmetad
will cancel that update after the timeout.  The next command
to check the lvmetad will see that lvmetad needs to be
populated because lvmetad will return token of "none" after
a timed out update (same as when lvmetad is not populated
at all after starting.)

If a command gets an error during an lvmetad update, it
will now just quit and leave its updating token in place.
That update will be cancelled after the timeout.
2016-06-07 10:17:00 -05:00
David Teigland
851ccfccaf lvmetad: remove disabled case for "scan error"
Failures while populating lvmetad will be handling
differently in a subsequent commit.
2016-06-07 10:17:00 -05:00
David Teigland
0e7f352c70 lvmetad: define special update in progress string 2016-06-07 10:17:00 -05:00
Peter Rajnoha
48877e215d coverity: missing check for id_write_format return value 2016-05-31 09:56:10 +02:00
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
ba9b7b69d9 pvremove: allow clearing a duplicate PV
Add a special case to allow modifying a duplicate PV
to erase it with pvremove -ff.
2016-05-16 14:40:43 -05:00
Alasdair G Kergon
a6203657a0 lvmetad: Fix client error when socket access fails. 2016-05-12 01:54:09 +01:00
David Teigland
b1ea27b1e2 lvmetad: disable if device scan fails
If a command begins repopulating the lvmetad cache,
and fails part way through, it should set the disabled
state in lvmetad so other commands don't use bad data.
If a subsequent scan succeeds, the disabled state is
cleared.
2016-05-06 09:00:00 -05:00
David Teigland
49d9582bed lvmcache: use active LVs and device sizes to choose between duplicates
If duplicate devices exist for a PV, and one device's
size matches the PV size, but the other doesn't, then
prefer the matching device.

If one device is used by an active LV, prefer that device.
2016-05-06 09:00:00 -05:00
David Teigland
d4e434d1e6 pvs: new attr and field for unchosen duplicate device
When there are duplicate devices for a PV, one device
is preferred and chosen to exist in the VG.  The other
devices are not used by lvm, but are displayed by pvs
with a new PV attr "d", indicating that they are
unchosen duplicate PVs.

The "duplicate" reporting field is set to "duplicate"
when the PV is an unchosen duplicate, and that field
is blank for the chosen PV.
2016-05-06 09:00:00 -05:00
David Teigland
d3d13e134a lvmcache: process duplicate PVs directly
Previously, duplicate PVs were processed as a side effect
of processing the "chosen" PV in lvmcache.  The duplicate
PV would be hacked into lvmcache temporarily in place of
the chosen PV.

In the old way, we had to always process the "chosen" PV
device, even if a duplicate of it was named on the command
line.  This meant we were processing a different device than
was asked for.  This could be worked around by naming
multiple duplicate devs on the command line in which case
they were swapped in and out of lvmcache for processing.

Now, the duplicate devs are processed directly in their
own processing loop.  This means we can remove the old
hacks related to processing dups as a side effect of
processing the chosen device.  We can now simply process
the device that was named on the command line.

When the same PVID exists on two or more devices, one device
is preferred and used in the VG, and the others are duplicates
and are not used in the VG.  The preferred device exists in
lvmcache as usual.  The duplicates exist in a specical list
of unused duplicate devices.

The duplicate devs have the "d" attribute and the "duplicate"
reporting field displays "duplicate" for them.

'pvs' warns about duplicates, but the formal output only
includes the single preferred PV.

'pvs -a' has the same warnings, and the duplicate devs are
included in the output.

'pvs <path>' has the same warnings, and displays the named
device, whether it is preferred or a duplicate.
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
David Teigland
67da017fd2 lvmetad: remove client side altdev code
This is no longer used since lvmetad no longer
keeps track of alternate devices for duplicate PVs,
but is simply disabled when duplicates appear.
2016-05-06 09:00:00 -05:00
David Teigland
9539ee8098 lvmetad: set disabled flag in lvmetad if duplicate PVs are found
When devices are being scanned, if duplicate PVs are seen,
tell lvmetad to set its disabled flag because of duplicate PVs.
2016-05-06 08:59:59 -05:00
David Teigland
263c1a4db5 lvmetad: improve warning after lvmetad message fails
Make it more consistent with the other similar warning.
2016-04-27 15:38:34 -05:00
Zdenek Kabelac
bc239f15eb coverity: ignore some dm_strncpy results
Using them only for debug so ignorable.
Also don't mark stack char buffer alignment, compiler already knows
what's the best here.
2016-04-22 14:15:36 +02:00
David Teigland
6e6f8025ff lvmetad: fix compile without lvmetad
Last commit was missing stub function.
2016-04-21 10:06:47 -05:00
David Teigland
e44c4806db lvmetad: check pid for warning case
When command is not using lvmetad because
use_lvmetad=0 in the config, but the lvmetad
pidfile exists, print a warning (previously
this checked for the socket existing instead
of the pidfile existing.)
2016-04-21 09:50:59 -05:00
David Teigland
d00b70c789 lvmetad: check for socket in connect
We can connect if the socket is present, even
though the pidfile may not exist, since systemd
may start the process when the socket is opened.
2016-04-21 09:27:20 -05:00
Zdenek Kabelac
2763b928de lvmetad: fix compilation without lvmetad# 2016-04-21 00:34:01 +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
593900b795 lvmetad: use defines for disabled reason strings 2016-04-19 11:45:24 -05:00
David Teigland
1e380864e5 lvmetad: clear the disabled flag in lvmetad
After a device rescan that repopulates lvmetad,
if no reason for disabling lvmetad was seen
(lvm1 metadata or duplicate PVs), then clear
the disabled flag in lvmetad.  This allows
commands to resume using the lvmetad cache
after the cause for disabling it has been removed.
2016-04-19 09:41:18 -05:00
David Teigland
04a83148ce lvmetad: use the disabled flag in commands
Commands already check if the lvmetad token is valid,
and if not, they rescan devices to repopulate lvmetad
before running.  Now, in addition to checking the
lvmetad token, they also check if the lvmetad disabled
flag is set.  If so, they do not use the lvmetad cache
and revert to disk scanning.
2016-04-19 09:41:18 -05:00
David Teigland
ff867c2ef6 lvmetad: set disabled flag in lvmetad if lvm1 metadata is found
When devices are being scanned, if lvm1 metadata is seen,
tell lvmetad to set its disabled flag because of lvm1 metadata.
2016-04-19 09:41:18 -05:00
David Teigland
a4ef8fa25e lvmetad: add disabled state
A global flag in lvmetad indicates it has been disabled.
Other flags indicate the reason it was disabled.
These flags can be queried using get_global_info.

The lvmetactl debugging utility can set and clear the
disabled flag in lvmetad.  Nothing else sets the
disabled flag yet.

Commands will check these flags after connecting to
lvmetad.  If the disabled flag is set, the command
will not use the lvmetad cache, but revert to disk
scanning.

To test this feature:

$ lvmetactl get_global_info
response = "OK"
global_invalid = 0
global_disable = 0
disable_reason = "none"
token = "filter:3041577944"

$ vgs
(should report VGs from lvmetad)

$ lvmetactl set_global_disable 1

$ lvmetactl get_global_info
response = "OK"
global_invalid = 0
global_disable = 1
disable_reason = "DIRECT"
token = "filter:3041577944"

$ vgs
  WARNING: Not using lvmetad because the disable flag was set directly.
(should report VGs without contacting lvmetad)

$ lvmetactl set_global_disable 0

$ vgs
(should report VGs from lvmetad)
2016-04-19 09:41:18 -05:00
David Teigland
a400eba174 lvmlockd: skip unnecessary lvmetad cache update
In cases where a VG is reread from disk, but the
seqno matches what is currently in lvmetad, the
metadata in lvmetad doesn't need to be updated.
2016-04-19 09:19:32 -05:00
David Teigland
579bd92009 lvmetad: add FIXME to comment 2016-04-13 14:08:29 -05:00
David Teigland
56c68b3476 lvmetad: preemptively check and rescan in commands
Move checking the lvmetad state, and the possible rescan,
out of lvmetad_send() to the start of the command.

Previously, the token mismatch and rescan would occur
within lvmetad_send() for some other request.  Now,
the token mismatch is detected earlier, so the
rescan can be done before the main command is in
progress.  Rescanning deep within the processing of
another command will disturb the lvmcache state of
that other command.

A rescan already exists at the start of the command
for the case where foreign VGs are going to be read.
This same rescan is now also performed when there is
an lvmetad token mismatch (from a changed global_filter).

The commands pvscan/vgscan/lvscan/vgimport are excluded
from this preemptive checking/rescanning for lvmetad
because they want to do rescanning themselves explicitly.

If rescanning devices fails, then lvmetad has not been
correctly repopulated and should not be used, so make
the command revert to not using lvmetad.
2016-04-13 14:05:42 -05:00
Zdenek Kabelac
a28c81cbae debug: unify some tracing messages
Introduce  FMTVGID - although it might be possibly better to ensure
vgid is always \0 ended string.

Unify some lvmcache reported messages.
2016-04-12 13:06:16 +02:00
Zdenek Kabelac
af148a9d77 cleanup: avoid gcc warns
Some older systems may had global declaration to cause gcc warning.
Rename for cases we don't care...
2016-04-08 20:20:16 +02:00
Zdenek Kabelac
1a9f743eef cleanup: drop unneeded test
dmfree tests for NULL
2016-02-25 23:30:25 +01:00
Peter Rajnoha
42ae586fa7 lvmcache: fix missing free of vginfo->system_id causing mem leak 2016-02-25 16:25:27 +01:00
Zdenek Kabelac
b08eb91df1 coverity: check for info pointer existance
Since we already check in few other places  'info' is not NULL,
do the same for others - however when info would be NULL
it more or less looks like internal error.
2016-02-23 21:40:16 +01:00
Zdenek Kabelac
2d6ef123a6 cleanup: indent changes
Some code indention.
Use dm_strncpy() for simplier code.

TODO: we could possibly use   %32s  for printing pvid...
so maybe adding extra  FMT_PVID....
2016-02-22 14:26:15 +01:00
Zdenek Kabelac
30a73d1604 lvmetad: fix error path
Coverity noticed the internal error path would  be using uninit struct.
So always make sure reply is initilized.
2016-02-22 14:15:53 +01:00
Peter Rajnoha
71ea2e1602 lvmcache/lvmetad: cache PV extension version
Store PV extension version in lvmcache/lvmetad for use throughout the code.
2016-02-15 12:44:46 +01:00
Peter Rajnoha
7593221f94 lvmcache/lvmetad: cache PV extension flags
Store PV extension flags in lvmcache/lvmetad for use throughout the code.
2016-02-15 12:44:46 +01:00
Peter Rajnoha
1f5dfb7369 lvmcache: invalidate all cached dev sizes if all VGs got unlocked 2016-01-22 14:16:00 +01:00
Zdenek Kabelac
fcbef05aae doc: change fsf address
Hmm rpmlint suggest fsf is using a different address these days,
so lets keep it up-to-date
2016-01-21 12:11:37 +01:00
David Teigland
e710bac03d Revert "lvmcache: skip drop when vg_write lock is not held"
This reverts e28e22b9e1
The problem that that commit was fixing (pytest failure)
no longer appears with the current code, so the commit is
not needed.

That commit is a problem for pvchange, because it prevents
lvmcache from retaining VG metadata even while the global
lock is held.  pvchange holds the global lock to ensure
that VG metadata is kept in lvmcache throughout processing.
If the cache is not kept, a PV with zero MDAs will appear
first in its actual VG and then appear again in the orphan VG.
It wrongly appears a second time in the orphan VG only if
the actual VG is dropped from lvmcache.
2016-01-14 13:34:36 -06:00
David Teigland
796461a912 vgrename: use process_each_vg
Use process_each_vg() to lock and read the old VG,
and then call the main vgrename code.

When real VG names are used (not a UUID in place of the
old name), the command still pre-locks the new name
(when strcmp wants it locked first), before calling
process_each_vg on the old name.

In the case where the old name is replaced with a UUID,
process_each_vg now translates that UUID into the real
VG name, which it locks and reads.  In this case, we
cannot do pre-locking to maintain lock ordering because
the old name is unknown.  So, in this case the strcmp
based lock ordering is suppressed and the old name is
always locked first.  This opens a remote chance for
lock ordering conflict between racing vgrenames between
two names where one or both commands use the UUID.
2015-12-14 14:26:47 -06:00
David Teigland
92e1422707 process_each_pv: do full scan earlier to find new devices
Before commit c1f246fedf,
_get_all_devices() did a full device scan before
get_vgnameids() was called.  The full scan in
_get_all_devices() is from calling dev_iter_create(f, 1).
The '1' arg forces a full scan.

By doing a full scan in _get_all_devices(), new devices
were added to dev-cache before get_vgnameids() began
scanning labels.  So, labels would be read from new devices.
(e.g. by the first 'pvs' command after the new device appeared.)

After that commit, _get_all_devices() was called
after get_vgnameids() was finished scanning labels.
So, new devices would be missed while scanning labels.
When _get_all_devices() saw the new devices (after
labels were scanned), those devices were added to
the .cache file.  This meant that the second 'pvs'
command would see the devices because they would be
in .cache.

Now, the full device scan is factored out of
_get_all_devices() and called by itself at the
start of the command so that new devices will
be known before get_vgnameids() scans labels.
2015-12-14 10:02:29 -06:00
David Teigland
3bcdf5d14b lvmcache: change duplicate VG name warnings to verbose
When two different VGs with the same name exist,
they are both stored in lvmcache using the vginfo->next
list.  Previously, the code would print warnings (sometimes)
when adding VGs to this list.  Now the duplicate VG names
are handled by higher level code, so this list no longer
needs to print warnings about duplicate VG names being found.
2015-12-01 09:30:23 -06:00
David Teigland
88cef47b18 vg_read: look up vgid from name
After recent changes to process_each, vg_read() is usually
given both the vgname and vgid for the intended VG.

However, in some cases vg_read() is given a vgid with
no vgname, or is given a vgname with no vgid.

When given a vgid with no vgname, vg_read() uses lvmcache
to look up the vgname using the vgid.  If the vgname is
not found, vg_read() fails.

When given a vgname with no vgid, vg_read() should also
use lvmcache to look up the vgid using the vgname.
If the vgid is not found, vg_read() fails.

If the lvmcache lookup finds multiple vgids for the
vgname, then the lookup fails, causing vg_read() to fail
because the intended VG is uncertain.

Usually, both vgname and vgid for the intended VG are passed
to vg_read(), which means the lvmcache translations
between vgname and vgid are not done.
2015-12-01 09:18:48 -06:00
David Teigland
eb22f7c8f7 lvmcache: new function to check if VG is foreign
When not using lvmetad, this uses the system_id field in
the cached vginfo structs that are populated during a scan.

When using lvmetad, this requests the VG from lvmetad, and
checks the system_id field in the returned metadata.
2015-11-30 11:54:56 -06:00
David Teigland
d3ca18e489 lvmcache: include system_id in vginfo cache
Save system_id just like creation_host and lock_type
strings in vginfo cache.
2015-11-30 11:32:17 -06:00
David Teigland
1f357532bb lvmetad: include both vgid and vgname in lookup request
When the command already knows both the vgid and vgname,
it should send both to lvmetad for a more exact request,
and it can save lvmetad the work of a name lookup.
2015-11-30 10:57:30 -06:00