Ensure that there are no leftover image files for the volume, e.g. from
an unsuccessful removal of a previous incarnation of this vid, or from
an messily restored pool filesystem backup. We don't want to preserve
any stale data (revisions) or metadata (size) in the new incarnation.
The size config parameter might be a string coming from XML.
The Volume base class handles the conversion to integer already.
FixesQubesOS/qubes-issues#5219.
This should allow importing a volume and changing the size at the
same time, without performing the resize operation on original
volume first.
The internal API has been renamed to internal.vm.volume.ImportBegin
to avoid confusion, and for symmetry with ImportEnd.
See QubesOS/qubes-issues#5239.
Don't fall back on 'cp' if the FICLONE ioctl gives an errno that's not
plausibly reflink specific, because in such a case any fallback could
theoretically mask real but intermittent system/storage errors.
Looking through ioctl_ficlone(2) and the kernel source, it should be
sufficient to do the fallback only on EBADF/EINVAL/EOPNOTSUPP/EXDEV.
(EISDIR/ETXTBSY don't apply to this storage driver, which will never
legitimately attempt to reflink a directory or an active - in the
storage domain - swap file.)
One alternative would look like
import ctypes
sizeof_int = ctypes.sizeof(ctypes.c_int)
FICLONE = (1073741824 % 256**sizeof_int) | 37897 | (sizeof_int << 16)
but, even if the above really(?) is a 100% correct Python port of
$ echo FICLONE | cpp -include linux/fs.h | tail -n 1
it still seems more likely that the ctypes package is somehow buggy
somewhere than for Qubes storage to run on an exotic architecture with
non 32 bit ints (in the foreseeable future).
So just document the baked in assumption.
The default (= text) mode for a loop device which contains a VM image
looked weird, even though it didn't make a difference here because the
dev_io object was never actually read from.
Pool.volumes property is implemented in a base class, individual drivers
should provide list_volumes() method as a backend for that property.
Fix this in a LinuxKernel pool.
Don't realy on a volume configuration only, it's easy to miss updating
it. Specifically, import_volume() function didn't updated the size based
on the source volume.
The size that the actual VM sees is based on the
file size, and so is the filesystem inside. Outdated size property can
lead to a data loss if the user perform an action based on a incorrect
assumption - like extending size, which actually will shrink the volume.
FixesQubesOS/qubes-issues#4821
admin.pool.UsageDetails reports the usage data, unlike
admin.pool.Info, which should report the config/unchangeable data.
At the moment admin.Pool.Info still reports usage, to maintain
compatibility, but once all relevant tools are updated,
it should just return configuration data.
Added usage_details method to Pool class
(returns a dictionary with detailed information
on pool usage) and LVM implementation that returns
metadata info.
Needed for QubesOS/qubes-issues#5053
During regular VM shutdown, the VM should sync() anyway. (And
admin.vm.volume.Import does fdatasync(), which is also fine.) But let's
be extra careful.
There were (at least) five ways for the volume's nominal size and the
volume image file's actual size to desynchronize:
- loading a stale qubes.xml if a crash happened right after resizing the
image but before saving the updated qubes.xml (-> previously fixed)
- restarting a snap_on_start volume after resizing the volume or its
source volume (-> previously fixed)
- reverting to a differently sized revision
- importing a volume
- user tinkering with image files
Rather than trying to fix these one by one and hoping that there aren't
any others, override the volume size getter itself to always update from
the image file size. (If the getter is called though the storage API, it
takes the volume lock to avoid clobbering the nominal size when resize()
is running concurrently.)
And change the volume lock from an asyncio.Lock to a threading.Lock -
locking is now handled before coroutinization.
This will allow the coroutinized resize() and a new *not* coroutinized
size() getter from one of the next commits ("storage/reflink: preferably
get volume size from image size") to both run under the volume lock.
Successfully resize volumes without any currently existing image file,
e.g. cleanly stopped volatile volumes: Just update the nominal size in
this case.
Disk usage may change dynamically not only at VM start/stop. Refresh the
size cache before checking usage property, but no more than once every
30sec (refresh interval of disk space widget)
FixesQubesOS/qubes-issues#4888
Return meaningful value for kernels_dir if VM has no 'kernel' volume.
Right now it's mostly useful for tests, but could be also used for new
VM classes which doesn't have modules.img, but still use dom0-provided
kernel.
Pool setup/destroy may be a time consuming operation, allow them to be
asynchronous. Fortunately add_pool and remove_pool are used only through
Admin API, so the change does not require modification of other
components.
