On some storage pools this operation can also be time consuming - for
example require creating temporary volume, and volume.create() already
can be a coroutine.
This is also requirement for making common code used by start()/create()
etc be a coroutine, otherwise neither of them can be and will block
other operations.
Related to QubesOS/qubes-issues#4283
_wait_and_reraise() is similar to asyncio.gather(), but it preserves the
current behavior of waiting for all futures and only _then_ reraising
the first exception (if there is any) in line.
Also switch Storage.create() and Storage.clone() to _wait_and_reraise().
Previously, they called asyncio.wait() and implicitly swallowed all
exceptions.
With that syntax, the default timestamp would have been from the time of
the function's definition (not invocation). But all callers are passing
an explicit timestamp anyway.
Convert create(), verify(), remove(), start(), stop(), revert(),
resize(), and import_volume() into coroutine methods, via a decorator
that runs them in the event loop's thread-based default executor.
This reduces UI hangs by unblocking the event loop, and can e.g. speed
up VM starts by starting multiple volumes in parallel.
Instead of raising a NotImplementedError, just return self like 'file'
and lvm_thin. This is needed when Storage.clone() is modified in another
commit* to no longer swallow exceptions.
* "storage: factor out _wait_and_reraise(); fix clone/create"
Import volume data to a new _path_import (instead of _path_dirty) before
committing to _path_clean. In case the computer crashes while an import
operation is running, the partially written file should not be attached
to Xen on the next volume startup.
Use <name>-import.img as the filename like 'file' does, to be compatible
with qubes.tests.api_admin/TC_00_VMs/test_510_vm_volume_import.
When the AT_REPLACE flag for linkat() finally lands in the Linux kernel,
_replace_file() can be modified to use unnamed (O_TMPFILE) tempfiles.
Until then, make sure stale tempfiles from previous crashes can't hang
around for too long.
It's sort of useful to be able to revert a volume that has only ever
been started once to its empty state. And the lvm_thin driver allows it
too, so why not.
* qubesos/pr/228:
storage/lvm: filter out warning about intended over-provisioning
tests: fix getting kernel package version inside VM
tests/extra: add start_guid option to VMWrapper
vm/qubesvm: fire 'domain-start-failed' event even if fail was early
vm/qubesvm: check if all required devices are available before start
storage/lvm: fix reporting lvm command error
storage/lvm: save pool's revision_to_keep property
* lvm-snapshots:
tests: fix handling app.pools iteration
storage/lvm: add repr(ThinPool) for more meaningful test reports
tests: adjust for variable volume path
api/admin: expose volume path in admin.vm.volume.Info
tests: LVM: import, list_volumes, volatile volume, snapshot volume
tests: collect all SIGCHLD before cleaning event loop
storage/lvm: use temporary volume for data import
tests: ThinVolume.revert()
tests: LVM volume naming migration, and new naming in general
storage/lvm: improve handling interrupted commit
Resolve:
- no-else-return
- useless-object-inheritance
- useless-return
- consider-using-set-comprehension
- consider-using-in
- logging-not-lazy
Ignore:
- not-an-iterable - false possitives for asyncio coroutines
Ignore all the above in qubespolicy/__init__.py, as the file will be
moved to separate repository (core-qrexec) - it already has a copy
there, don't desynchronize them.
Do not write directly to main volume, instead create temporary volume
and only commit it to the main one when operation is finished. This
solve multiple problems:
- import operation can be aborted, without data loss
- importing new data over existing volume will not leave traces of
previous content - especially when importing smaller volume to bigger
one
- import operation can be reverted - it create separate revision,
similar to start/stop
- easier to prevent qube from starting during import operation
- template still can be used when importing new version
QubesOS/qubes-issues#2256
First rename volume to backup revision, regardless of revisions_to_keep,
then rename -snap to current volume. And only then remove backup
revision (if exceed revisions_to_keep). This way even if commit
operation is interrupted, there is still a volume with the data.
This requires also adjusting few functions to actually fallback to most
recent backup revision if the current volume isn't found - create
_vid_current property for this purpose.
Also, use -snap volume for clone operation and commit it normally later.
This makes it safer to interrupt or even revert.
QubesOS/qubes-issues#2256
Scripts do parse its output sometimes (especially `lvs`), so make sure
we always gets the same format, regardless of the environment. Including
decimal separator.
FixesQubesOS/qubes-issues#3753
Don't rely on timestamps to sort revisions - the clock can go backwards
due to time sync. Instead, use a monotonically increasing natural number
as the revision ID.
Old revision example: private.img@2018-01-02-03T04:05:06Z (ignored now)
New revision example: private.img.123@2018-01-02-03T04:05:06Z
* devel-storage-fixes:
storage/file: use proper exception instead of assert
storage/file: import data into temporary volume
storage/lvm: check for LVM LV existence and type when creating ThinPool
storage/lvm: fix size reporting just after creating LV
Similar to LVM changes, this fixes/improves multiple things:
- no old data visible in the volume
- failed import do not leave broken volume
- parially imported data not visible to running VM
QubesOS/qubes-issues#3169
* storage-properties:
storage: use None for size/usage properties if unknown
tests: call search_pool_containing_dir with various dirs and pools
storage: make DirectoryThinPool helper less verbose, add sudo
api/admin: add 'included_in' to admin.pool.Info call
storage: add Pool.included_in() method for checking nested pools
storage: move and generalize RootThinPool helper class
storage/kernels: refuse changes to 'rw' and 'revisions_to_keep'
api/admin: implement admin.vm.volume.Set.rw method
api/admin: include 'revisions_to_keep' and 'is_outdated' in volume info
It may happen that one pool is inside a volume of other pool. This is
the case for example for varlibqubes pool (file driver,
dir_path=/var/lib/qubes) and default lvm pool (lvm_thin driver). The
latter include whole root filesystem, so /var/lib/qubes too.
This is relevant for proper disk space calculation - to not count some
space twice.
QubesOS/qubes-issues#3240QubesOS/qubes-issues#3241
This pool driver support only rw=False and revisions_to_keep=0 volumes.
Since there is API for changing those properties dynamically, block it
at pool driver level, instead of silently ignoring them.
Some kernels (like pvgrub2) may not provide modules.img and it isn't an
error. Don't break VM startup in that case, skip that device instead.
FixesQubesOS/qubes-issues#3563
If revisions_to_keep is 0, it may nevertheless have been > 0 before, so
it makes sense to call _remove_revisions() and hold back none (not all)
of the revisions in this case.
This adds the file-reflink storage driver. It is never selected
automatically for pool creation, especially not the creation of
'varlibqubes' (though it can be used if set up manually).
The code is quite small:
reflink.py lvm.py file.py + block-snapshot
sloccount 334 lines 447 (134%) 570 (171%)
Background: btrfs and XFS (but not yet ZFS) support instant copies of
individual files through the 'FICLONE' ioctl behind 'cp --reflink'.
Which file-reflink uses to snapshot VM image files without an extra
device-mapper layer. All the snapshots are essentially freestanding;
there's no functional origin vs. snapshot distinction.
In contrast to 'file'-on-btrfs, file-reflink inherently avoids
CoW-on-CoW. Which is a bigger issue now on R4.0, where even AppVMs'
private volumes are CoW. (And turning off the lower, filesystem-level
CoW for 'file'-on-btrfs images would turn off data checksums too, i.e.
protection against bit rot.)
Also in contrast to 'file', all storage features are supported,
including
- any number of revisions_to_keep
- volume.revert()
- volume.is_outdated
- online fstrim/discard
Example tree of a file-reflink pool - *-dirty.img are connected to Xen:
- /var/lib/testpool/appvms/foo/volatile-dirty.img
- /var/lib/testpool/appvms/foo/root-dirty.img
- /var/lib/testpool/appvms/foo/root.img
- /var/lib/testpool/appvms/foo/private-dirty.img
- /var/lib/testpool/appvms/foo/private.img
- /var/lib/testpool/appvms/foo/private.img@2018-01-02T03:04:05Z
- /var/lib/testpool/appvms/foo/private.img@2018-01-02T04:05:06Z
- /var/lib/testpool/appvms/foo/private.img@2018-01-02T05:06:07Z
- /var/lib/testpool/appvms/bar/...
- /var/lib/testpool/appvms/...
- /var/lib/testpool/template-vms/fedora-26/...
- /var/lib/testpool/template-vms/...
It looks similar to a 'file' pool tree, and in fact file-reflink is
drop-in compatible:
$ qvm-shutdown --all --wait
$ systemctl stop qubesd
$ sed 's/ driver="file"/ driver="file-reflink"/g' -i.bak /var/lib/qubes/qubes.xml
$ systemctl start qubesd
$ sudo rm -f /path/to/pool/*/*/*-cow.img*
If the user tries to create a fresh file-reflink pool on a filesystem
that doesn't support reflinks, qvm-pool will abort and mention the
'setup_check=no' option. Which can be passed to force a fallback on
regular sparse copies, with of course lots of time/space overhead. The
same fallback code is also used when initially cloning a VM from a
foreign pool, or from another file-reflink pool on a different
mountpoint.
'journalctl -fu qubesd' will show all file-reflink copy/rename/remove
operations on VM creation/startup/shutdown/etc.
Even when volume is not persistent (like TemplateBasedVM:root), it
should be resizeable. Just the new size, similarly to the volume
content, will be reverted after qube shutdown.
Additionally, when VM is running, volume resize should affect _only_ its
temporary snapshot. This way resize can be properly reverted together
with actual volume changes (which include resize2fs call).
FixesQubesOS/qubes-issues#3519
Do not check for accepted value only in constructor, do that in property
setter. This will allow enforcing the limit regardless of how the value
was set.
This is preparation for dynamic revisions_to_keep change.
QubesOS/qubes-issues#3256
- make it clear that failed qubes.ResizeDisk service call means the need
to resize filesystem manually (but not necessarily the volume itself)
- propagate exceptions raised by async storage pool implementations
Related QubesOS/qubes-issues#3173
* bug3164:
tests: add regression test for #3164
storage/lvm: make sure volume cache is refreshed after changes
storage/lvm: fix Volume.verify()
storage/lvm: remove old volume only after successfully cloning new one
In some cases, it may happen that new volume (`self._vid_snap`) does not
exists. This is normally an error, but even in such a case, do not
remove the only remaining instance of volume (`self.vid`). Instead,
rename it temporarily and remove only after new volume is successfully
cloned.
FixesQubesOS/qubes-issues#3164
This applies to qvm-template-postprocess, which at the beginning try to
resize root volume to appropriate size. It makes more sense to silently
succeed here, instead of forcing every client-side utility to check if
the volume have already desired size.
On certain locales (e.g. danish) `usage_percent` will output a comma-separated number, which will make `attr` point the last two decimal points, s.t. `return vol_info['attr'][4] == 'a'` (in the `verify` func) will fail and `qubesd` wont run.
First, cache objects created with init_volume - this is the only place
where we have full volume configuration (including snap_on_start and
save_on_stop properties).
But also implement get_volume method, to get a volume instance for given
volume id. Such volume instance may be incomplete (other attributes are
available only in owning domain configuration), but it will be enough
for basic operations - like cheching and changing its size, cloning
etc.
Listing volumes still use list of physically present volumes.
This makes it possible to start qubesd service, without physical
presence of some storage devices. Starting VMs using such storage would
still fail, of course.
FixesQubesOS/qubes-issues#2960
* tests-storage:
tests: register libvirt events
tests: even more agressive cleanup in tearDown
app: do not wrap libvirt_conn.close() in auto-reconnect wrapper
api: keep track of established connections
tests: drop VM cleanup from tearDownClass, fix asyncio usage in tearDown
storage: fix Storage.clone and Storage.clone_volume
tests: more tests fixes
firewall: raise ValueError on invalid hostname in dsthost=
qmemman: don't load qubes.xml
tests: fix AdminVM test
tests: create temporary files in /tmp
tests: remove renaming test - it isn't supported anymore
tests: various fixes for storage tests
tests: fix removing LVM volumes
tests: fix asyncio usage in some tests
tests: minor fixes to api/admin tests
storage/file: create -cow.img only when needed
storage: move volume_config['source'] filling to one place
app: do not create 'default' storage pool
app: add missing setters for default_pool* global properties
* qdb-watch:
tests: add qdb_watch test
ext/block: make use of QubesDB watch
vm: add API for watching changes in QubesDB
vm: optimize imports
api/admin: don't send internal events in admin.Events
Add explanation why admin.vm.volume.Import is a custom script
Follow change of qubesdb path return type
Rename vm.qdb to vm.untrusted_qdb
Don't set 'source' volume in various places (each VM class constructor
etc), do it as part of volume initialization. And when it needs to be
re-calculated, call storage.init_volume again.
This code was duplicated, and as usual in such a case, those copies
were different - one have set 'size', the other one not.
QubesOS/qubes-issues#2256
Since we have app.default_pool* properties, create appropriately named
pool and let those properties choose the right pool. This also means we
don't need to specify pool name in default volume config anymore
QubesOS/qubes-issues#2256
Specify empty 'source' field, so it gets filled with appropriate
template's images. Then also fix recursive 'source' handling - DispVM
root volume should point at TemplateVM's root volume as a source, not a
AppVM's one - which is also only a snapshot.
FixesQubesOS/qubes-issues#2896
