Commit Graph

181 Commits

Author SHA1 Message Date
Pavel Hrdina
2ea493598f qemu_snapshot: fix memory leak when reverting external snapshot
The code cleaning up virStorageSource doesn't free data allocated by
virStorageSourceInit() so we need to call virStorageSourceDeinit()
explicitly.

Fixes: 8e66473781
Resolves: https://issues.redhat.com/browse/RHEL-33044
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2024-05-29 15:23:55 +02:00
Pavel Hrdina
0a164b74eb qemu_snapshot: correctly update metadata when deleting external snapshot with multiple branches
XML metadata for snapshot contains only single list of disk overlays
from the moment when the snapshot was taken. When user creates multiple
branches of snapshots the parent snapshot will still list only the
original disk overlays. This may cause an issue in a specific scenario:

     s1
      |
      +- s2
      +- s3 (active)

For this snapshot topology when we delete s2 metadata for s1 are not
updated. Now when we delete s1 the code operated with incorrect
overlays from s1 metadata in order to update s3 metadata resulting in no
changes to s3 metadata.

Now when user tries to delete s3 it fails with following error:

    error: Failed to delete snapshot s3
    error: operation failed: snapshot VM disk source and parent disk source are not the same

For the actual deletion there is a code to figure out the correct disk
source but it was not used to update metadata as well. Due to reasons
how block commit in libvirt works we need to create a copy of that disk
source in order to have it available when updating metadata as the
original source will be freed at that point.

Resolves: https://issues.redhat.com/browse/RHEL-26276
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2024-04-02 14:14:26 +02:00
Pavel Hrdina
79654f425c qemu_snapshot: call qemuSnapshotDeleteUpdateDisks only for external snapshots
Calling this function when deleting internal snapshot isn't required
because with internal snapshots all changes are done within the file
itself so there is no file deletion and no need to update snapshot
metadata.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2024-04-02 14:14:26 +02:00
Pavel Hrdina
189fdeff10 qemu_snapshot: create: don't require disk-only flag for offline external snapshot
Historically creating offline external snapshot required disk-only flag
as well. Now when user requests new snapshot for offline VM and at least
one disk is specified to use external snapshot we will no longer require
disk-only flag as all other not specified disk will use external
snapshots as well.

Resolves: https://issues.redhat.com/browse/RHEL-22797
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2024-01-30 13:54:42 +01:00
Pavel Hrdina
faa2e3bb54 qemu_snapshot: create: refactor external snapshot detection
Introduce new function qemuSnapshotCreateUseExternal() that will return
true if we will use external snapshots as default location.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2024-01-30 13:54:32 +01:00
Pavel Hrdina
7143c4e1f9 qemu_snapshot: fix detection if non-leaf snapshot isn't in active chain
The condition was completely wrong. As per the comment for function
virDomainMomentIsAncestor() it checks that the first argument is
descendant of the second argument.

Consider the following snapshot tree for VM:

  s1
    |
    +- s2
    |   |
    |   +- s3
    |
    +- s4
        |
        +- s5 (current)

When deleting s2 with the original code we checked if
virDomainMomentIsAncestor(s2, s5) which would return false basically for
any snapshot as s5 is leaf snapshot so no children.

When deleting s2 with fixed code we check if
virDomainMomentIsAncestor(s5, s2) which still returns false but when
deleting s4 it will correctly return true.

Before this fix it fails with the following error:

    error: Failed to delete snapshot s2
    error: invalid argument: could not find base disk source in disk source chain

After the fix it fails with correct error:

    error: Failed to delete snapshot s2
    error: unsupported configuration: deletion of non-leaf external snapshot that is not in active chain is not supported

Resolves: https://issues.redhat.com/browse/RHEL-23212
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2024-01-30 13:32:04 +01:00
Pavel Hrdina
3ad5817053 qemu_snapshot: fix reverting to inactive snapshot
When reverting to inactive snapshot updating the domain definition needs
to happen after the new overlays are created otherwise qemu-img will
correctly fail with error:

    Trying to create an image with the same filename as the backing file

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-11-16 15:29:45 +01:00
Pavel Hrdina
03a9a39c42 qemu_snapshot: fix snapshot deletion that had multiple children
When we revert to non-leaf snapshot and create new branch or branches
the overlay in snapshot metadata is no longer usable as a disk source
for deletion of that snapshot. We need to use other places to figure out
the correct storage source.

Fixes: https://gitlab.com/libvirt/libvirt/-/issues/534

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-11-16 15:29:03 +01:00
Peter Krempa
abab5130f8 qemu: Use 'format' nodename accessors for block dirty bitmap operations
In most cases the bitmap operations are relevant only on qcow2 images
thus the 'format' layer will be present. Although in certain specific
cases temporary bitmaps can be created on top of other images as well,
thus we use the 'effective' bitmap name in all cases for bitmap
operations.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-10-17 14:16:17 +02:00
Pavel Hrdina
819ae888ec qemu_snapshot: correctly load the saved memory state file
Original code assumed that the memory state file is only migration
stream but it has additional metadata stored by libvirt. To correctly
load the memory state file we need to reuse code that is used when
restoring domain from saved image.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-10-09 13:56:50 +02:00
Pavel Hrdina
2300e38e18 qemu_snapshot: fix reverting external snapshot when not all disks are included
We need to skip all disks that have snapshot type other than 'external'.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-10-09 13:56:50 +02:00
Jonathon Jongsma
1df106cc20 conf: add ability to configure a vdpa block disk device
vDPA block devices can be configured as follows:

    <disk type='vhostvdpa'>
      <source dev='/dev/vhost-vdpa-0'/>
    </disk>

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-09-12 11:06:41 -05:00
Michal Privoznik
895525db81 qemu: Move error messages onto a single line
Error messages are exempt from the 80 columns rule. Move them
onto one line.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2023-09-04 09:35:36 +02:00
Pavel Hrdina
cb3bc96e67 qemu_snapshot: allow snapshot revert for external snapshots
Now that the support to revert external snapshots is implemented we can
drop this check.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:43 +02:00
Pavel Hrdina
88d0e6748d qemu_snapshot: add checks for external snapshot deletion
With the introduction of external snapshot revert support we need to
error out in some cases when trying to delete some snapshots.

If users reverts to non-leaf snapshots and would try to delete it after
the revert is done it would not work currently as this operation would
require using block-stream which is not implemented for now as in this
case the snapshot has two children so the disk files have multiple
overlays.

Similarly if user reverts to non-leaf snapshot and would try to delete
snapshot that is non-leaf but not in currently active snapshot chain we
would still need to use block-commit operation. The issue here is that
in order to do that we would have to start new qemu process with
different domain definition than what is currently used by the domain.
If the current domain would be running it would complicate things even
more so this operation is not yet supported.

If user creates new snapshot after reverting to non-leaf snapshot it
creates a new branch. Deleting snapshot with multiple children will
require block-stream which is not implemented for now.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:42 +02:00
Pavel Hrdina
daf48171f1 qemu_snapshot: check only once if snapshot is external
There will be more external snapshot checks introduced by following
patch so group them together.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:40 +02:00
Pavel Hrdina
32cf4ed5cd qemu_snapshot: update backing store after deleting external snapshot
With introduction of external snapshot revert we will have to update
backing store of qcow images not actively used be QEMU manually.
The need for this patch comes from the fact that we stop and start QEMU
process therefore after revert not all existing snapshots will be known
to that QEMU process due to reverting to non-leaf snapshot or having
multiple branches.

We need to loop over all existing snapshots and check all disks to see
if they happen to have the image we are deleting as backing store and
update them to point to the new image except for images currently used
by the running QEMU process doing the merge operation.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:36 +02:00
Pavel Hrdina
1392be7092 qemu_snapshot: remove revertdisks when creating new snapshot
When user creates a new snapshot after reverting to non-leaf snapshot we
no longer need to store the temporary overlays as they will be part of
the VM XMLs stored in the newly created snapshot.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:30 +02:00
Pavel Hrdina
a68b849c51 qemu_snapshot: delete: properly update parent snapshot with revert data
When deleting external snapshot and parent snapshot is the currently
active snapshot as user reverted to it we need to properly update the
parent snapshot metadata.

After the delete is done the new overlay files will be the currently
used files created when snapshot revert was done, replacing the original
overlay files.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:29 +02:00
Pavel Hrdina
7c402396ec qemu_snapshot: add support to delete external snapshot without block commit
When block commit is not needed we can just simply unlink the
disk files.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:27 +02:00
Pavel Hrdina
d84538fbad qemu_snapshot: prepare data for non-active leaf external snapshot deletion
In this case there is no need to run block commit and using qemu process
at all.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:26 +02:00
Pavel Hrdina
a3152a506b qemu_snapshot: add merge to external snapshot delete prepare data
Before external snapshot revert every delete operation did block commit
in order to delete a snapshot. But now when user reverts to non-leaf
snapshot deleting leaf snapshot will not have any overlay files so we
can just simply delete the snapshot images.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:25 +02:00
Pavel Hrdina
b0876595a3 qemu_snapshot: extract external snapshot delete prepare to function
This part of code is about to grow to make deletion work when user
reverts to non-leaf snapshot.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:23 +02:00
Pavel Hrdina
443221bbf1 qemu_snapshot: rename qemuSnapshotDeleteExternalPrepare
The new name reflects that we prepare data for external snapshot
deletion and the old name will be used later for different part of code.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:22 +02:00
Pavel Hrdina
8e66473781 qemu_snapshot: introduce external snapshot revert support
When reverting to external snapshot we need to create new overlay qcow2
files from the disk files the VM had when the snapshot was taken.

There are some specifics and limitations when reverting to a snapshot:

1) When reverting to last snapshot we need to first create new overlay
   files before we can safely delete the old overlay files in case the
   creation fails so we have still recovery option when we error out.

   These new files will not have the suffix as when the snapshot was
   created as renaming the original files in order to use the same file
   names as when the snapshot was created would add unnecessary
   complexity to the code.

2) When reverting to any snapshot we will always create overlay files
   for every disk the VM had when the snapshot was done. Otherwise we
   would have to figure out if there is any other qcow2 image already
   using any of the VM disks as backing store and that itself might be
   extremely complex and in some cases impossible.

3) When reverting from any state the current overlay files will be
   always removed as that VM state is not meant to be saved. It's the
   same as with internal snapshots. If user want's to keep the current
   state before reverting they need to create a new snapshot. For now
   this will only work if the current snapshot is the last.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:20 +02:00
Pavel Hrdina
96fa494f88 qemu_snapshot: use VIR_ASYNC_JOB_SNAPSHOT when reverting snapshot
Both creating and deleting snapshot are using VIR_ASYNC_JOB_SNAPSHOT but
reverting is using VIR_ASYNC_JOB_START. Let's unify it to make it
consistent for all snapshot operations.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:18 +02:00
Pavel Hrdina
537f9136b7 qemu_snapshot: move external disk prepare to single function
We will need to reuse the functionality when reverting external
snapshots.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:16 +02:00
Pavel Hrdina
a8f3e2f104 qemuSnapshotCreateQcow2Files: use domain definition directly
To create new overlay files when external snapshot revert support is
introduced we will be using different domain definition than what is
currently used by the domain.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:15 +02:00
Pavel Hrdina
9b94a9e8ab qemu_snapshot: introduce qemuSnapshotCreateQcow2Files
Extract creation of qcow2 files for external snapshots to separate
function as we will need it for external snapshot revert code.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:11 +02:00
Pavel Hrdina
db9e253fc4 qemu_snapshot: use virDomainDiskByName while updating domain def
When creating external snapshot this function is called only when the VM
is not running so there is only one definition to care about. However,
it will be used by external snapshot revert code for active and inactive
definition and they may be different if a disk was (un)plugged only for
the active or inactive definition.

The current code would crash so use virDomainDiskByName() to get the
correct disk from the domain definition based on the disk name and make
sure it exists.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:10 +02:00
Pavel Hrdina
4edd9e297a qemu_snapshot: introduce qemuSnapshotDomainDefUpdateDisk
Extract the code that updates disks in domain definition while creating
external snapshots. We will use it later in the external snapshot revert
code.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:09 +02:00
Pavel Hrdina
8f9d96199d virDomainSnapshotAlignDisks: Allow overriding user-configured snapshot default
This new option will be used by external snapshot revert code.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-08-22 16:06:08 +02:00
Peter Krempa
7e1b4cc19c qemu: snapshot: Allow inactive internal snapshots with uefi
Historically the snapshot code attempted to forbid internal snapshots
with UEFI both in active and inactive case. Unfortunately due to the
intricacies of UEFI probing this didn't really work for inactive VMs
which made users rely on the feature.

Now with the changes to store detected UEFI environment also in the
inactive definition this broke the feature for those users.

Since the varstore doesn't really change that much in the lifecycle of a
VM it usually is okay to simply leave it as is.

Restore the functionality for inactive snapshots by disabling the check.

In the future when uefi snapshotting will be added the rest of the
condition will also be removed.

Resolves: https://gitlab.com/libvirt/libvirt/-/issues/460
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-04-11 10:09:05 +02:00
Pavel Hrdina
d292ddf1cc qemu_snapshot: external: don't error out when updating metadata
Attaching disk into running VM the offline definition may not be
updated and we will end up with that disk existing only in live
definition. Creating snapshot with this state saves both live and
offline definition into snapshot metadata.

When we are deleting an external snapshot we are updating these
definitions in the snapshot metadata so we should just skip over
non-existing disks instead of reporting error.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2174700

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-04-03 14:32:40 +02:00
Jiri Denemark
71b19c4f08 qemu: Update format strings in translated messages
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2023-04-01 11:40:34 +02:00
Jiri Denemark
b1b037fa5b Introduce VIR_DOMAIN_PAUSED_API_ERROR
Some APIs (migration, save/restore, snapshot, ...) require a domain to
be suspended temporarily. In case resuming the domain fails, the domain
will be unexpectedly left paused when the API finishes. This situation
is reported via VIR_DOMAIN_EVENT_SUSPENDED event with
VIR_DOMAIN_EVENT_SUSPENDED_API_ERROR detail. But we do not have a
corresponding reason for VIR_DOMAIN_PAUSED state and the reason would
remain set to the value used when the domain was paused. So the state
reason would suggest the operation is still running.

This patch changes the state reason to a new VIR_DOMAIN_PAUSED_API_ERROR
to make it clear the API that paused the domain already finished, but
failed to resume the domain.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2023-03-15 10:52:14 +01:00
Pavel Hrdina
403c0cf17f qemu_snapshot: fix external snapshot deletion for non-active snapshots
For shutoff VMs we don't have the storage source backing chain
populated so it will fail this check and error out. Move it to
part that is done only when VM is running.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2023-03-09 17:16:11 +01:00
Pavel Hrdina
22a07239f5 qemu_snapshot: properly ignore disks with manual snapshot
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2173142

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2023-03-09 17:16:06 +01:00
Pavel Hrdina
e3957c2246 qemu_snapshot: refactor qemuSnapshotDeleteExternalPrepare
When user creates external snapshot with making only memory snapshot
without any disks deleting that snapshot failed without reporting any
meaningful error.

The issue is that the qemuSnapshotDeleteExternalPrepare function
returns NULL because the returned list is empty. This will not change
so to make it clear if the function fails or not return int instead and
have another parameter where we can pass the list.

With the fixed memory snapshot deletion it will now correctly delete
memory only snapshot as well.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2170826

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-02-21 18:27:22 +01:00
Pavel Hrdina
356e227208 qemu_snapshot: remove memory snapshot when deleting external snapshot
When deleting external snapshot we should remove the memory snapshot
file as well.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-02-21 18:27:22 +01:00
Peter Krempa
64366c0056 qemu: snapshot: Restructure control flow to detect errors sooner and work around compiler
Some compilers aren't happy when an automatically freed variable is used
just to free something (thus it's only assigned in the code):

When compiling qemuSnapshotDelete after recent commits they complain:

../src/qemu/qemu_snapshot.c:3153:61: error: variable 'delData' set but not used [-Werror,-Wunused-but-set-variable]
                g_autoslist(qemuSnapshotDeleteExternalData) delData = NULL;
                                                            ^

To work around the issue we can restructure the code which also has the
following semantic implications:
 - since qemuSnapshotDeleteExternalPrepare does validation we error out
   sooner than attempting to start the VM

 - we read the temporary variable at least in one code path

Fixes: 4a4d89a925
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2023-01-09 14:13:25 +01:00
Pavel Hrdina
85931fce74 qemu_snapshot: enable deletion of external snapshots
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:18 +01:00
Pavel Hrdina
cadbf40d05 qemu_process: abort snapshot delete when daemon starts
If the daemon crashes or is restarted while the snapshot delete is in
progress we have to handle it gracefully to not leave any block jobs
active.

For now we will simply abort the snapshot delete operation so user can
start it again. We need to refuse deleting external snapshots if there
is already another active job as we would have to figure out which jobs
we can abort.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:16 +01:00
Pavel Hrdina
565bcb5d79 qemu_snapshot: when deleting snapshot invalidate parent snapshot
When deleting external snapshots the operation may fail at any point
which could lead to situation that some disks finished the block commit
operation but for some disks it failed and the libvirt job ends.

In order to make sure that the qcow2 images are in consistent state
introduce new element "<snapshotDeleteInProgress/>" that will mark the
disk in snapshot metadata as invalid until the snapshot delete is
completed successfully.

This will prevent deleting snapshot with the invalid disk and in future
reverting to snapshot with the invalid disk.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:07 +01:00
Pavel Hrdina
7190582fbc qemu_snapshot: update metadata when deleting snapshots
With external snapshots we need to modify the metadata bit more then
what is required for internal snapshots. Mainly the storage source
location changes with every external snapshot.

This means that if we delete non-leaf snapshot we need to update all
children snapshots and modify the disk sources for all affected disks.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:06 +01:00
Pavel Hrdina
e27f081967 qemu_snapshot: implement deletion of external snapshot
When deleting snapshot we are starting block-commit job over all disks
that are part of the snapshot.

This operation may fail as it writes data changes to the backing qcow2
image so we need to wait for all the disks to finish the operation and
wait for correct signal from QEMU. If deleting active snapshot we will
get `ready` signal and for inactive snapshots we need to disable
autofinalize in order to get `pending` signal.

At this point if commit for any disk fails for some reason and we abort
the VM is still in consistent state and user can fix the reason why the
deletion failed.

After that we do `pivot` or `finalize` if it's active snapshot or not to
finish the block job. It still may fail but there is nothing else we can
do about it.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:05 +01:00
Pavel Hrdina
4a4d89a925 qemu_snapshot: prepare data for external snapshot deletion
In order to save some CPU cycles we will collect all the necessary data
to delete external snapshot before we even start. They will be later
used by code that deletes the snapshots and updates metadata when
needed.

With external snapshots we need data that libvirt gets from running QEMU
process so if the VM is not running we need to start paused QEMU process
for the snapshot deletion and kill at afterwards.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:04 +01:00
Pavel Hrdina
2038c1cd3a qemu_snapshot: convert snapshot delete to async domain job
Deleting external snapshots will require to run it as async domain job,
the same way as we do for snapshot creation.

For internal snapshots modify the job mask in order to forbid any other
job to be started.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:02 +01:00
Pavel Hrdina
f5def5cd11 qemu_snapshot: error out when deleting internal snapshot on non-active disk
Deleting internal snapshot when the currently active disk image is
different than where the internal snapshot was taken doesn't work
correctly.

This applies to a running VM only as we are using QMP command and
talking to the QEMU process that is using different disk.

This works correctly when the VM is shut of as in this case we spawn
qemu-img process to delete the snapshot.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:33:01 +01:00
Pavel Hrdina
4475c69787 qemu_snapshot: refactor validation of snapshot delete
Prepare the validation function for external snapshot delete support.

There is one exception when deleting `children-only` snapshots. If the
snapshot tree is like this example:

    snap1 (external)
     |
     +- snap2 (internal)
         |
         +- snap3 (internal)
             |
             +- snap4 (internal)

and user calls `snapshot-delete snap1 --children-only` the current
snapshot is external but all the children snapshots are internal only
and we are able to delete it.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2023-01-09 13:32:59 +01:00