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Commit Graph

15533 Commits

Author SHA1 Message Date
David Teigland
aa833bdd8a bcache: intercept test mode before write
Don't allow writes in test mode.  test mode should be
more sophisticated than just faking writes, and this
should be a last defense for cases where test mode is
not being checked correctly.
2018-04-20 11:22:48 -05:00
David Teigland
9b6a62f944 lvmcache: simplify
Recent changes allow some major simplification of the way
lvmcache works and is used.  lvmcache_label_scan is now
called in a controlled fashion at the start of commands,
and not via various unpredictable side effects.  Remove
various calls to it from other places.  lvmcache_label_scan
should not be called from anywhere during a command, because
it produces an incorrect representation of PVs with no MDAs,
and misclassifies them as orphans.  This has been a long
standing problem.  The invalid flag and rescanning based on
that is no longer used and removed.  The 'force' variation is
no longer needed and removed.
2018-04-20 11:22:48 -05:00
David Teigland
c0973e70a5 dev_cache: clean up scan
Pull out all of the twisted logic and simply call dev_cache_scan
at the start of the command prior to label scan.
2018-04-20 11:22:48 -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
45e5e702c1 scan: improve io error checking and reporting 2018-04-20 11:22:48 -05:00
David Teigland
6d05859862 bcache: let caller see an error 2018-04-20 11:22:48 -05:00
David Teigland
ae21305ee7 scan: drop bcache between lvm shell commands
A running lvm shell keeps all lvm devices open
unless the bcache is dropped.
2018-04-20 11:22:48 -05:00
David Teigland
a01a8d7172 tests: vgck now exits with error for bad vg 2018-04-20 11:22:48 -05:00
David Teigland
a9b0aa5c17 lvmetad: more fixes related to bcache
Need to open devs prior to bcache io.
2018-04-20 11:22:48 -05:00
David Teigland
e351f8bc66 lvmetad: need to set up bcache in another place
We need to find one common place to set up bcache
for the lvmetad case, instead of adding calls in
various places.
2018-04-20 11:22:48 -05:00
David Teigland
7e33bd1335 lvmetad: fix process_each_label
Was missing the call to populate lvmcache info from lvmetad
at the start of process_each_label.
2018-04-20 11:22:48 -05:00
David Teigland
ddb5de7a98 clvm: fix bcache scan handling
We can't let clvmd keep all scanned devs open,
which prevents them from being removed.  So
drop the bcache data (and close fds) affter
doing a label scan.

Also set up bcache before the clvm-specific
vg_read (which needs to rescan the vg's devs
using bcache) and destroy the bcache after.
2018-04-20 11:22:48 -05:00
David Teigland
196579af1f scan: check for errors in text layer
The scanning code in the format_text layer
has previously ignored errors.  Start checking
for and returning them.
2018-04-20 11:22:47 -05:00
David Teigland
44726ed9cb scan: remove lvmcache info for failed devs
When scanning a device fails, drop an lvmcache
info struct for it.
2018-04-20 11:22:47 -05:00
David Teigland
1717d4cb17 lvmcache: add shorter way to delete dev info
Don't make the caller look up the info first.
2018-04-20 11:22:47 -05:00
David Teigland
570c6239ee bcache: fix error handling
The error handling code wasn't working, but it
appears that just removing it is what we need.
The doesn't really need any different behavior
related to bcache blocks on an io error, it just
wants to know if there was an error.
2018-04-20 11:22:47 -05:00
David Teigland
217f3f8741 scan: add function to drop bcache blocks
which can be a little more efficient that destroy.
2018-04-20 11:22:47 -05:00
David Teigland
da2b155a9d scan: invalidate bcache for dev after errors
If there are errors reading or writing dev,
invalidate bcache for it.
2018-04-20 11:22:47 -05:00
David Teigland
4331182964 bcache: add some error messages for debugging 2018-04-20 11:22:47 -05:00
David Teigland
21057676a1 scan: create bcache with minimum number of blocks
In some odd cases (e.g. tests) there are very few devices
which results in creating too few blocks in bcache, so
create bcache with a minimum number of blocks.
2018-04-20 11:22:47 -05:00
David Teigland
e49b114f7e bcache: use wrappers for bcache read write in lvm
Using a wrapper makes it easier to disable bcache if needed.
2018-04-20 11:22:47 -05:00
David Teigland
8065492046 bcache: do all writes through bcache 2018-04-20 11:22:47 -05:00
David Teigland
8b26a007b1 misc bcache fixes from ejt 2018-04-20 11:22:47 -05:00
David Teigland
0da296003d vgchange: invalidate bcache for stacked LVs when deactivating
An LV with a stacked PV will be open in bcache and needs to be
invalidated to close the fd before attempting to deactivate.
2018-04-20 11:22:47 -05:00
David Teigland
34fd818caf scan: drop bcache and close fd for LV with stacked PV
When a PV is stacked on an LV, the LV will be kept in
bcache, and the open fd on the LV may interfere with
processing the LV.  So, drop/close a bcache fd for
an LV before processing the LV.
2018-04-20 11:22:47 -05:00
David Teigland
c2b10daf69 scan: put dev back on caller's list
Commit 6e442875613915e506440e59a290b56756df2521 missed
adding devs back to caller's list.
2018-04-20 11:22:47 -05:00
David Teigland
e7670d3338 pvck: use bcache 2018-04-20 11:22:47 -05:00
David Teigland
b504bb809e scan: use 128K bcache block size 2018-04-20 11:22:46 -05:00
David Teigland
ae093df3f1 test: vgsplit-usage if LVM1 tests 2018-04-20 11:22:46 -05:00
David Teigland
d75aa55784 disable LVM1 tests 2018-04-20 11:22:46 -05:00
David Teigland
96a61337b0 lvmdiskscan: use the new label_scan
instead of doing it's own.
2018-04-20 11:22:46 -05:00
David Teigland
28255e3eee scan: always setup bcache for commands using lvmetad
Do this at the start of the command so that it doesn't
need to be checked and set up in every function that
could need it.
2018-04-20 11:22:46 -05:00
David Teigland
f328532f05 scan: leave the caller's dev list unchanged
When scanning the list of devs from the caller
they are moved to another temporary list, but
were never returned to the original list.
2018-04-20 11:22:46 -05:00
David Teigland
7bce66c5e8 scan: setup bcache for commands using lvmetad
Commands using lvmetad will not begin with a proper
label_scan which initializes bcache, but may later
decide they need to scan a set of devs, in which case
they'll need bcache set up at that point.
2018-04-20 11:22:46 -05:00
David Teigland
6e580465b5 vgremove: fix force remove on devs with damaged metadata
The improved detection of bad metadata when scanning
(where errors were ignored before) means we now have to
override some errors when forcibly erasing damaged metadata.
2018-04-20 11:22:46 -05:00
David Teigland
37471bb477 scan: skip extra scan in vg_read
Drop an extra label scan in the recovery part
of vg_read.  This is a temporary improvement
until the pending replacement for the broken
recovery code burried in vg_read.
2018-04-20 11:22:46 -05:00
David Teigland
e4f478d86d scan: handle request to scan missing dev 2018-04-20 11:22:46 -05:00
David Teigland
89f54a5094 remove debugging print 2018-04-20 11:22:46 -05:00
David Teigland
c29899b910 remove unused variable in _pvremove_check_single 2018-04-20 11:22:46 -05:00
David Teigland
a1e3398ffc scan: handle no devices
Still create bcache.
2018-04-20 11:22:46 -05:00
David Teigland
9d2add1361 scan: add a dev to bcache before each read to handle write path
This is a temporary hacky workaround to the problem of
reads going through bcache and writes not using bcache.
The write path wants to read parts of data that it is
incrementally writing to disk, but the reads (using
bcache) don't work because the writes are not in the
bcache.  For now, add a dev to bcache before each attempt
to read it in case it's being used on the write path.
2018-04-20 11:22:46 -05:00
David Teigland
6c67c7557c scan: use separate fd for bcache
Create a new dev->bcache_fd that the scanning code owns
and is in charge of opening/closing.  This prevents other
parts of lvm code (which do various open/close) from
interfering with the bcache fd.  A number of dev_open
and dev_close are removed from the reading path since
the read path now uses the bcache.

With that in place, open(O_EXCL) for pvcreate/pvremove
can then be fixed.  That wouldn't work previously because
of other open fds.
2018-04-20 11:22:46 -05:00
David Teigland
4343280ebc process_each_label: use lvmcache
In the same way as the other process_each functions.
In the common case all the info that's needed can be
used from lvmcache after a label scan.  But this means
that unchosen devs for duplicate PVs need to be handled
explicitly.
2018-04-20 11:22:46 -05:00
David Teigland
f17c2cf7c6 pvremove: device check doesn't require label_read
It just needs to check if the device was found during
the scan, which means checking if it exists in lvmcache.
2018-04-20 11:22:45 -05:00
David Teigland
29c6c17121 format-text.c log message fixes 2018-04-20 11:22:45 -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
David Teigland
79c4971210 label_scan: remove extra label scan and read for orphan PVs
When process_each_pv() calls vg_read() on the orphan VG, the
internal implementation was doing an unnecessary
lvmcache_label_scan() and two unnecessary label_read() calls
on each orphan.  Some of those unnecessary label scans/reads
would sometimes be skipped due to caching, but the code was
always doing at least one unnecessary read on each orphan.

The common format_text case was also unecessarily calling into
the format-specific pv_read() function which actually did nothing.

By analyzing each case in which vg_read() was being called on
the orphan VG, we can say that all of the label scans/reads
in vg_read_orphans are unnecessary:

1. reporting commands: the information saved in lvmcache by
the original label scan can be reported.  There is no advantage
to repeating the label scan on the orphans a second time before
reporting it.

2. pvcreate/vgcreate/vgextend: these all share a common
implementation in pvcreate_each_device().  That function
already rescans labels after acquiring the orphan VG lock,
which ensures that the command is using valid lvmcache
information.
2018-04-20 11:22:45 -05:00
David Teigland
5f138f3604 vgcreate: improve the use of label_scan
The old code was doing unnecessary label scans when
checking to see if the new VG name exists.  A single
label_scan is sufficient if it is done after the
new VG lock is held.
2018-04-20 11:22:45 -05:00
David Teigland
e3e5beec74 lvmetad: use new label_scan for update from pvscan
Take advantage of the common implementation with aio
and reduced disk reads.
2018-04-20 11:22:43 -05:00
David Teigland
9c71fa0214 lvmetad: use new label_scan for update from lvmlockd
When lvmlockd indicates that the lvmetad cache is out of
date because of changes by another node, lvmetad_pvscan_vg()
rescans the devices in the VG to update lvmetad.  Use the
new label_scan in this function to use the common code and
take advantage of the new aio and reduced reads.
2018-04-20 11:21:41 -05:00