This driver isn't used in default Qubes 4.0 installation, but if we do
have it, let it follow defined API and its own documentation. And also
explicitly reject not supported operations:
- support only revisions_to_keep<=1, but do not support revert() anyway
(implemented version were wrong on so many levels...)
- use 'save_on_stop'/'snap_on_start' properties directly instead of
obsolete volume types
- don't call sudo - qubesd is running as root
- consistently use path, path_cow, path_source, path_source_cow
Also, add tests for BlockDevice instance returned by
FileVolume.block_device().
QubesOS/qubes-issues#2256
Do not always use pool named 'default'. Instead, have global
`default_pool` property to specify default storage pools.
Additionally add `default_pool_*` properties for each VM property, so
those can be set separately.
QubesOS/qubes-issues#2256
commit/recover/reset should really be handled in start/stop. Nothing
stops specific pool implementation to define such functions privately.
QubesOS/qubes-issues#2256
Always define those properties, always include them in volume config.
Also simplify overriding pool based on volume type defined by those:
override pool unless snap_on_start=True.
QubesOS/qubes-issues#2256
Add convenient collection wrapper for easier getting selected volume.
Storage pool implementation may still provide only volume listing
function (pool.list_volumes), or, additionally, optimized
pool.get_volume.
This means it is both possible to iterate over volumes:
```python
for volume in pool.volumes:
...
```
And get a single volume:
```python
volume = pool.volumes[vid]
```
QubesOS/qubes-issues#2256
Reference objects, not their IDs - this way when object is modified, it
is visible everywhere where it is used. Main changes:
- volume.pool - Pool object
- volume.source - Volume object
Since volume have Pool object reference now, move volume related
functions into Volume class (from Pool class). This avoids horrible
`storage.get_pool(volume).something(volume)` construct.
One issue here is since volume.source reference a Volume object from a
different VM - VM's template, now VM load order is important. Since we
don't have control over it, initialize vm.storage when needed - possibly
while initializing storage of different VM. Since we don't have cycles
in AppVM-TemplateVM dependencies, it is safe.
Also, since this commit, volume.source (if defined) always points at
volume of the same name from VM's template. Using volumes with something
else as a source is no longer supported.
QubesOS/qubes-issues#2256
When VM is renamed only volume.vid get updated, but not other attributes
calculated from it. Convert them to dynamic properties to not worry
about it.
QubesOS/qubes-issues#2256
vm.kernel property have type 'str'. Putting None there makes a lot of
troubles: it gets encoded as 'None' in qubes.xml and then loaded back as
'None' string, not None value. Also it isn't possible to assign None
value to str property throgh Admin API.
kernel='' is equally good to specify "no kernel from dom0".
QubesOS/qubes-issues#2622
Implement this in two parts:
1. Permissions checks, getting a path from appropriate storage pool
2. Actual data import
The first part is done by qubesd in a standard way, but then, instead of
accepting all the data (which may be several GB), return a path to which
a shell script (in practice: `dd` command) will write the data.
Then the script call back to qubesd again to report success/failure and
qubesd response from that call is actually returned to the user.
This way we do not pass all the data through qubesd, but still can
control the process from there in a meaningful way. Note that the last
part (second call to qubesd) may perform all kind of verification (like
a signature check on the data, or so) and can also prevent VM from
starting (hooking also domain-pre-start event) from not verified image.
QubesOS/qubes-issues#2622
Allow importing not only from another volume, but also raw data. In
practice, for all currently implemented storage pools, this is the same
as Pool.export, because path returned there is read-write. But lets not
abuse this fact, some future implementation may need different methods.
QubesOS/qubes-issues#2622QubesOS/qubes-issues#2256
Do not initialize it only at qubes.xml load time, but re-read vm.kernel
property each time the path is constructed. While at it, add support for
vm.kernel set to 'None' - simply don't include modules.img (xvdd) then.
Keep it uniform - QubesVM() object is responsible for handling
vm.dir_path, Storage() is responsible for handling disk volumes (which
may live in that directory
QubesOS/qubes-issues#2256
Allow specific pool implementation to provide asynchronous
implementation. vm.storage.* methods will detect if given implementation
is synchronous or asynchronous and will act accordingly.
Then it's up to pool implementation how asynchronous should be achieved.
Do not force it using threads (`run_in_executor()`). But pool
implementation is free to use threads, if consider it safe in a
particular case.
This commit does not touch any pool implementation - all of them are
still synchronous.
QubesOS/qubes-issues#2256
Use the right cow image and apply the second layer to provide read-write
access. The correct setup is:
- base image + base cow -> read-only snapshot (base changes "cached"
until committed)
- read-only snapshot + VM cow -> read-write snapshot (changes discarded
after VM shutdown)
This way, even VM without Qubes-specific startup scripts will can
benefit from Template VMs, while VMs with Qubes-specific startup scripts
may still see original root.img content (for possible signature
verification, when storage domain got implemented).
QubesOS/qubes-issues#2256
In case of LVM (at least), "internal" flag is initialized only when
listing volume attached to given VM, but not when listing them from the
pool. This looks like a limitation (bug?) of pool driver, it looks like
much nicer fix is to handle the flag in qvm-block tool (which list VMs
volumes anyway), than in LVM storage pool driver (which would need to
keep second copy of volumes list - just like file driver).
QubesOS/qubes-issues#2256
There are mutiple cases when snapshots are inconsistently created, for
example:
- "-back" snapshot created from the "new" data, instead of old one
- "-snap" created even when volume.snap_on_start=False
- probably more
Fix this by following volume.snap_on_start and volume.save_on_stop
directly, instead of using abstraction of old volume types.
QubesOS/qubes-issues#2256
Just calling pool.init_volume isn't enough - a lot of code depends on
additional data loaded into vm.storage object. Provide a convenient
wrapper for this.
At the same time, fix loading extra volumes from qubes.xml - don't fail
on volume not mentioned in initial vm.volume_config.
QubesOS/qubes-issues#2256
- add missing lvm remove call when commiting changes
- delay creating volatile image until domain startup (it will be created
then anyway)
- reset cache only when really changed anything
- attach VM to the volume (snapshot) created for its runtime - to not
expose changes (for example in root volume) to child VMs until
shutdown
QubesOS/qubes-issues#2412QubesOS/qubes-issues#2256
The wrapper doesn't do anything else than translating command
parameters, but it's load time is significant (because of python imports
mostly). Since we can't use python lvm API from non-root user anyway,
lets drop the wrapper and call `lvm` directly (or through sudo when
necessary).
This makes VM startup much faster - storage preparation is down from
over 10s to about 3s.
QubesOS/qubes-issues#2256
...instead of manual copy in python. DD is much faster and when used
with `conv=sparse` it will correctly preserve sparse image.
QubesOS/qubes-issues#2256
1. Add a helper function on vm.storage. This is equivalent of:
vm.storage.get_pool(vm.volumes[name]).export(vm.volumes[name])
2. Make sure the path returned by `export` on LVM volume is accessible.
