Accept XML describing a generic block job, and output it again as
needed. This may still need a few tweaks to match the documented XML
and RNG schema.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Introduce a few new public APIs related to incremental backups. This
builds on the previous notion of a checkpoint (without an existing
checkpoint, the new API is a full backup, differing from
virDomainBlockCopy in the point of time chosen and in operation on
multiple disks at once); and also allows creation of a new checkpoint
at the same time as starting the backup (after all, an incremental
backup is only useful if it covers the state since the previous
backup).
A backup job also affects filtering a listing of domains, as well as
adding event reporting for signaling when a push model backup
completes (where the hypervisor creates the backup); note that the
pull model does not have an event (starting the backup lets a third
party access the data, and only the third party knows when it is
finished).
The full list of new APIs:
virDomainBackupBegin;
virDomainBackupGetXMLDesc;
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Prepare for new backup APIs by describing the XML that will represent
a backup. The XML resembles snapshots and checkpoints in being able
to select actions for a set of disks, but has other differences. It
can support both push model (the hypervisor does the backup directly
into the destination file) and pull model (the hypervisor exposes an
access port for a third party to grab what is necessary). Add
testsuite coverage for some minimal uses of the XML.
The <disk> element within <domainbackup> tries to model the same
elements as a <disk> under <domain>, but sharing the RNG grammar
proved to be hairy. That is in part because while <domain> use
<source> to describe a host resource in use by the guest, a backup job
is using a host resource that is not visible to the guest: a push
backup action is instead describing a <target> (which ultimately could
be a remote network resource, but for simplicity the RNG just
validates a local file for now), and a pull backup action is instead
describing a temporary local file <scratch> (which probably should not
be a remote resource). A future refactoring may thus introduce some
way to parameterize RNG to accept <disk type='FOO'>...</disk> so that
the name of the subelement can be <source> for domain, or <target> or
<scratch> as needed for backups. Future patches may improve this area
of code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Commit f10562799 introduced a regression: if reverting to a snapshot
fails early (such as when we refuse to revert to an external
snapshot), we lose track of the domain's current snapshot.
Before that patch, we were tracking the notion of the domain's current
snapshot via two means: vm->current_snapshot (which was left untouched
on early exit) and snap->def->current (which only controls what gets
written to XML to remember snapshots across libvirtd restarts). That
patch was fixing a real bug: if a revert operation failed early, later
questions from the same libvirtd did not see any change to the current
snapsthot, but restarting libvirtd would now claim there is no current
snapshot. But it fixed it in the wrong direction, in that the current
snapshot was forgotten unconditionally, rather than only when the
snapshot to revert to has a chance of being useful.
It didn't help that the code after that patch had two separate spots
clearing the old notion of the current snapshot - one after
determining the snapshot to revert to was viable, the other
unconditionally on all failure exit paths. At any rate, the fix is
simple: drop the unconditional cleanup on error paths, and rely only
on the normal cleanup after early checks.
Sadly, it is not possible to test this bug in the existing
tests/virsh-snapshot, as the test driver does not have the same
prohibition against reverting to an external snapshot as the qemu
driver.
See: https://bugzilla.redhat.com/1738747
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190909205242.15406-1-eblake@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Fix some typos and grammar (calling something safer and error-prone is
odd, and 'ther eneeds' is an obvious typo), and reflow some long
lines.
Signed-off-by: Eric Blake <eblake@redhat.com>
Gnulib has added a patch that allows configmake.h to be included
without causing build failures on mingw if <winsock2.h> is later
included (whether directly, or indirectly such as through gnulib's
<unistd.h>).
This reverts commit fed58d83c6 ("build:
Fix checkpoint_conf on mingw"), now that we don't have to worry about
header inclusion ordering issues.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Requires adjustments to use verify_expr() which replaces
verify_true(), and to disable the new syntax check
'sc_prohibit_gnu_make_extensions' since we require GNU make.
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit fed58d83 was a hack to fix a mingw build failure due to header
inclusion order resulting in a clash over the use of DATADIR,
repeating a trick made several other times in the past. Better is to
revert that, and instead use pragmas to avoid the clash in the first
place, regardless of header ordering, solving it for everyone.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
readline-devel is an optional build dependency; when it is not
present, the output of 'virsh <<EOF ... EOF' is different in that the
input provided by the user is not echoed, and prompts become
interleaved on the same line as actual output, which in turn causes
the sed doing prompt filtering to mess up:
| ./virsh-snapshot
| --- exp 2019-07-31 18:42:31.107399428 -0300
| +++ out.cooked 2019-07-31 18:42:31.108399437 -0300
| @@ -1,8 +1,3 @@
| -
| -
| -Domain snapshot s3 created from 's3.xml'
| -Domain snapshot s2 created from 's2.xml'
| -Name: s2
| Domain: test
| Current: yes
| State: running
Maybe we should fix virsh in interactive mode to echo regardless of
whether readline-devel was used, but the quicker fix is to make the
test use 'virsh "..."' rather than reading its input from stdin.
Reported-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Checkpoints are definitely a news-worthy addition, even if the
virDomainBackup API is not going to make it until a later release.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>
I messed up formatting during conflict resolution across rebasing
while preparing my checkpoint patches :)
Signed-off-by: Eric Blake <eblake@redhat.com>
CI flagged a failing mingw build, due to:
In file included from ../../src/conf/checkpoint_conf.c:24:
../gnulib/lib/configmake.h:8:17: error: expected identifier or '(' before string constant
8 | #define DATADIR "/usr/i686-w64-mingw32/sys-root/mingw/share"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
As previously learned in commits bd205a90 and 976abdf6, gnulib's
configmake.h header does #define DATADIR "string...", while mingw's
<winsock2.h> expects to declare a type named DATADIR. As long as the
mingw system header is included first before configmake.h, the two
uses do not conflict, but until gnulib is patched to make configmake.h
automatically work around the issue, our immediate fix is the
workaround of rearranging our include order to insure no conflict.
Copy the paradigm used in domain_conf.c of using <unistd.h> to trigger
the indirect inclusion of <winsock2.h> on mingw.
Fixes: 1a4df34a
Signed-off-by: Eric Blake <eblake@redhat.com>
Earlier patches mentioned that the initial implementation will prevent
snapshots and checkpoints from being used on the same domain at once.
However, the actual restriction is done in this separate patch to make
it easier to lift that restriction via a revert, when we are finally
ready to tackle that integration in the future.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Time to actually issue the QMP transactions that create and delete
persistent checkpoints, resolving TODOs intentionally left earlier in
the series. For create, we only need one transaction: inside, we
visit all disks affected by the checkpoint, and create a new enabled
bitmap, as well as disabling the bitmap of the first ancestor
checkpoint (if any) that also had a bitmap. For deletion, we need
multiple QMP calls: for each disk, if there is an ancestor checkpoint
with a bitmap, then the bitmap must be merged (including activating
the ancestor bitmap if the leaf node changes), all before deleting the
bitmap from the checkpoint being removed.
Signed-off-by: Eric Blake <eblake@redhat.com>
Qemu bitmap operations require knowing the node name associated with
the format layer (the qcow2 file); as upcoming patches will be
grabbing that information frequently, make a helper function to access
it.
Another potential benefit of this function is that we have a single
place where we could insert a QMP node-name scraping call if we don't
currently know the node name, when -blockdev is not supported;
however, the goal is that we hopefully don't ever have to do that
because we instead scrape node names only at the point where they
change.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
A lot of this work heavily copies from the existing snapshot APIs.
What's more, this patch is (intentionally) very similar to the
checkpoint code just added in the test driver, to the point that qemu
checkpoints are not fully usable in this patch, but it at least
bisects and builds cleanly. The separation between patches is done
because the grunt work of saving and restoring XML and tracking
relations between checkpoints is common to the test driver, while the
later patch adding integration with QMP is specific to qemu.
Also note that the interlocking to prevent checkpoints and snapshots
from existing at the same time will be a separate patch, to make it
easier to revert that restriction when we finally round out the design
for supporting interaction between the two concepts.
Signed-off-by: Eric Blake <eblake@redhat.com>
This is similar to the existing directory for snapshots; the domain
will save one xml file per checkpoint, for reloading on the next
libvirtd restart. Fortunately, since checkpoints mandate RNG
validation, we are assured that the checkpoint name will be usable as
a file name (no abuse of '../escape' as a checkpoint name, for
example).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Similar to virsh-snapshots. Provides decent coverage of the checkpoint
API, the test driver implementation, and the virsh access to the API.
A later patch will worry about testing that snapshots and checkpoints
are mutually exclusive (in part so it is easier to revert that when we
finally implement the interaction and lift that restriction).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
A lot of this work heavily copies from the existing snapshot APIs.
The test driver doesn't really have to do anything more than just
expose an interface into libvirt metadata, making it possible to test
saving and restoring XML, and tracking relations between multiple
checkpoints.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Introduce a bunch of new virsh commands for managing checkpoints in
isolation. More commands are needed for performing incremental
backups, but these commands were easy to implement by modeling heavily
after virsh-snapshot.c. There is no need for checkpoint-revert or
checkpoint-current since those snapshot APIs have no checkpoint
counterpart. Similarly, it is not necessary to change which
checkpoint is current when redefining from XML, since until we
integrate checkpoints with snapshots, there is only a linear chain
(and you can deduce the current checkpoint by instead using
'checkpoint-list --leaves'). Other aspects of checkpoint-list are
also a bit simpler than the snapshot counterpart, in part because we
don't have to cater to back-compat to older API.
Upcoming patches will test these interfaces once the test driver
supports checkpoints.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The remote code generator had to be taught about the new
virDomainCheckpointPtr type, at which point the remote driver code for
checkpoints can be generated.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Creating a checkpoint does not modify guest-visible state,
but does modify host resources. Rather than reuse existing
domain:write, domain:block_write, or domain:snapshot access
controls, it seems better to introduce a new access control
specific to tasks related to checkpoints and incremental
backups of guest disk state.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Wire up the use of a checkpoint list into each domain, similar to the
existing snapshot list. This includes adding a function for checking
that a redefine operation fits in with the existing list, as well as
various filtering capabilities over the list contents.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Create a new file for managing a list of checkpoint objects, borrowing
heavily from existing virDomainSnapshotObjList paradigms.
Note that while snapshots definitely have a use case for multiple
children to a single parent (create a base snapshot, create a child
snapshot, revert to the base, then create another child snapshot),
it's harder to predict how checkpoints will play out with reverting to
prior points in time. Thus, in initial use, given a list of
checkpoints, you never have more than one child, and we can treat the
most-recent leaf node as the parent of the next node creation, without
having to expose a notion of a current node in XML or public API.
However, as the snapshot machinery is already generic, it is easier to
reuse the generic machinery that tracks relations between domain
moments than it is to open-code a new list-management scheme just for
checkpoints (hence, we still have internal functions related to a
current checkpoint, even though that has no observable effect
externally, as well as the addition of a function to easily find the
lone leaf in the list to use as the current checkpoint).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Add a new file checkpoint_conf.c that performs the translation to and
from new XML describing a checkpoint. The code shares a common base
class with snapshots, since a checkpoint similarly represents the
domain state at a moment in time. Add some basic testing of round trip
XML handling through the new code.
Of note - this code intentionally differs from snapshots in that XML
schema validation is unconditional, rather than based on a public API
flag. We have many existing interfaces that still need to add a flag
for opt-in schema validation, but those interfaces have existing
clients that may not have been producing strictly-compliant XML, or we
may still uncover bugs where our RNG grammar is inconsistent with our
code (where omitting the opt-in flag allows existing apps to keep
working while waiting for an RNG patch). But since checkpoints are
brand-new, it's easier to ensure the code matches the schema by always
using the schema. If needed, a later patch could extend the API and
add a flag to turn on to request schema validation, rather than having
it forced (possibly just the validation of the <domain> sub-element
during REDEFINE) - but if a user encounters XML that looks like it
should be good but fails to validate with our RNG schema, they would
either have to upgrade to a new libvirt that adds the new flag, or
upgrade to a new libvirt that fixes the RNG schema, which implies
adding such a flag won't help much.
Also, the redefine flag requires the <domain> sub-element to be
present, rather than catering to historical back-compat to older
versions.
Signed-off-by: Eric Blake <eblake@redhat.com>
Now that various new API have been added or are coming soon, it is
worth a landing page that gives an overview of capturing various
pieces of guest state, and which APIs are best suited to which tasks.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Introduce a bunch of new public APIs related to backup checkpoints.
Checkpoints are modeled heavily after virDomainSnapshotPtr (both
represent a point in time of the guest), although a snapshot exists
with the intent of rolling back to that state, while a checkpoint
exists to make it possible to create an incremental backup at a later
time. We may have a future hypervisor that can completely manage
checkpoints without libvirt metadata, but the first two planned
hypervisors (qemu and test) both always use libvirt for tracking
metadata relations between checkpoints, so for now, I've deferred
the counterpart of virDomainSnapshotHasMetadata for a separate
API addition at a later date if there is ever a need for it.
Note that until we allow snapshots and checkpoints to exist
simultaneously on the same domain (although the actual prevention of
this will be in a separate patch for the sake of an easier revert down
the road), that it is not possible to branch out to create more than
one checkpoint child to a given parent, although it may become
possible later when we revert to a snapshot that coincides with a
checkpoint. This also means that for now, the decision of which
checkpoint becomes the parent of a newly created one is the only
checkpoint with no child (so while there are APIs for dealing with a
current snapshot, we do not need those for checkpoints). We may end
up exposing a notion of a current checkpoint later, but it's easier to
add stuff when proven needed than to blindly support it now and wish
we hadn't exposed it.
The following map shows the API relations to snapshots, with new APIs
on the right:
Operate on a domain object to create/redefine a child:
virDomainSnapshotCreateXML virDomainCheckpointCreateXML
Operate on a child object for lifetime management:
virDomainSnapshotDelete virDomainCheckpointDelete
virDomainSnapshotFree virDomainCheckpointFree
virDomainSnapshotRef virDomainCheckpointRef
Operate on a child object to learn more about it:
virDomainSnapshotGetXMLDesc virDomainCheckpointGetXMLDesc
virDomainSnapshotGetConnect virDomainCheckpointGetConnect
virDomainSnapshotGetDomain virDomainCheckpointGetDomain
virDomainSnapshotGetName virDomainCheckpiontGetName
virDomainSnapshotGetParent virDomainCheckpiontGetParent
virDomainSnapshotHasMetadata (deferred for later)
virDomainSnapshotIsCurrent (no counterpart, see note above)
Operate on a domain object to list all children:
virDomainSnapshotNum (no counterparts, these are the old
virDomainSnapshotListNames racy interfaces)
virDomainSnapshotListAllSnapshots virDomainListAllCheckpoints
Operate on a child object to list descendents:
virDomainSnapshotNumChildren (no counterparts, these are the old
virDomainSnapshotListChildrenNames racy interfaces)
virDomainSnapshotListAllChildren virDomainCheckpointListAllChildren
Operate on a domain to locate a particular child:
virDomainSnapshotLookupByName virDomainCheckpointLookupByName
virDomainSnapshotCurrent (no counterpart, see note above)
virDomainHasCurrentSnapshot (no counterpart, old racy interface)
Operate on a snapshot to roll back to earlier state:
virDomainSnapshotRevert (no counterpart, instead checkpoints
are used in incremental backups via
XML to virDomainBackupBegin)
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Prepare for new checkpoint APIs by describing the XML that will
represent a checkpoint. The checkpoint XML is modeled heavily after
virDomainSnapshotPtr. See the docs for more details.
Add testsuite coverage for some minimal uses of the XML (bare minimum,
the sample from html, and a full dumpxml, and some counter-examples
that should fail schema validation). Although use of the REDEFINE flag
will require the <domain> subelement to be present, it is easier for
most of the tests to provide counterpart output produced with the
NO_DOMAIN flag (particularly since synthesizing a valid <domain>
during testing is not trivial).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
If we are using -blockdev, then node names are always available
(because we set them). But when not using it, we have to scrape node
names from QMP, and want to do so as infrequently as possible. We
were scraping node names after reconnecting a new libvirtd to an
existing guest (see qemuProcessReconnect), and after any block job
that may have changed the set of node names we care about (legacy
block jobs), but forgot to scrape the names when first starting a
guest. Do so now in order to allow the checkpoint code to always have
access to a node name without having to repeat a node name scrape
itself.
Future patches may need to clean up qemuDomainSetBlockThreshold (if
node names are always available, then it doesn't need to repeat a
scrape) and/or hotplug and media changes (if the addition of new nodes
can result in a null node name, then scraping at that point in time
would be appropriate). But for now, this patch addresses only the
most common instance of a missing node name.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Creating an 'exp' output file, but never comparing it against the
actual output, does not actually constitute testing the output. :)
Fixes: 280a2b41e
Signed-off-by: Eric Blake <eblake@redhat.com>
Changes noticed while copying to similar aspects of checkpoints.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Any message that is easy to trigger (as evidenced by the testsuite
update) should not use 'internal error' as its category.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
virDomainSnapshotFindByName(list, NULL) should return NULL, rather
than the internal-use-only metaroot. Most existing callers pass in a
non-NULL name; the few external callers that don't are immediately
calling virDomainMomentSetParent (which indeed needs the metaroot
rather than NULL if the parent name is NULL); but as the leaky
abstraction is ugly, it is worth instead making
virDomainMomentSetParent static and adding a new function for
resolving the parent link of a brand new moment within its list. The
existing external uses of virDomainMomentSetParent always succeed
(either the new moment has parent_name of NULL to become a new root,
or has parent_name set to a strdup of the previous current moment);
hence, our new function does not need a return value (but it still has
a VIR_WARN in case future uses break our assumptions about failure
being impossible).
Missed when commit 02c4e24d refactored things to attempt to remove
direct metaroot manipulations out of the qemu and test drivers into
internal-only details, and made more obvious when commit dc8d3dc6
factored it out into a separate file.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The code to check whether a redefined snapshot/checkpoint XML is
attempting to create a cycle in the list of moments is lengthy, and
common between the two types of list. Therefore, it belongs in the
shared base file.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
We've been doing a terrible job of performing XML validation in our
various API that parse XML with a corresponding schema (we started
with domains back in commit dd69a14f, v1.2.12, but didn't catch all
domain-related APIs, didn't document the use of the flag, and didn't
cover other XML). New APIs (like checkpoints) should do the validation
unconditionally, but it doesn't hurt to continue retrofitting existing
APIs to at least allow the option.
While there are many APIs that could be improved, this patch focuses
on wiring up a new snapshot XML creation flag through all the
hypervisors that support snapshots, as well as exposing it in 'virsh
snapshot-create'. For 'virsh snapshot-create-as', we blindly set the
flag without a command-line option, since the XML we create from the
command line should generally always comply (note that validation
might cause failures where it used to succeed, such as if we tighten
the RNG to reject a name of '../\n'); but blindly passing the flag
means we also have to add in fallback code to disable validation if
the server is too old to understand the flag.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Similar to VIR_DOMAIN_DEF_PARSE_VALIDATE_SCHEMA; the next patch will
put it to use with a counterpart public API flag.
No need to change qemudomainsnapshotxml2xmltest to use the flag, since
the testsuite already has a separate virschematest that does the same.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
We no longer need to special-case xenUnified, since 1dac5fbbbb
dropped support for that naming scheme.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Continuous integration caught that although 'make syntax-check' was
sufficient to let me be aware that I had to change bhyve to use
s/virDomainShutdownEnsureACL/virDomainShutdownFlagsEnsureACL/, it was
not sufficient to note which ACL functions require 2 vs. 3 arguments
for flag validation.
Fixes: eded8aad
Signed-off-by: Eric Blake <eblake@redhat.com>
Even though we don't accept any flags, it is unfriendly to callers
that use the modern API to have to fall back to the flag-free API.
Note that virDomainBlockStats does not trivially forward to
virDomainBlockStatsFlags, so that one is omitted for now.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Even though we don't accept any flags, it is unfriendly to callers
that use the modern API to have to fall back to the flag-free API.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Even though we don't accept any flags, it is unfriendly to callers
that use the modern API to have to fall back to the flag-free API.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Even though we don't accept any flags, it is unfriendly to callers
that use the modern API to have to fall back to the flag-free API.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
The docs talked about an active snapshot when they meant an active
domain; they also claimed the flag was a no-op for hypervisors with no
snapshot metadata even though the flag is currently rejected as
unrecognized for hypervisors with no snapshot support at all. A later
patch may teach more drivers to ignore the flag as a no-op, but that
shouldn't conflict with the wording chosen here (since a new client
talking to an old server still runs into the same issue, even if a
newer server becomes more tolerant).
Reported-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Make it obvious that the domainsnapshotxml2xml test is only run when
compiling in support for qemu.
Suggested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Similar to commit a487890d for qemu, a little bit of refactoring in
the snapshot delete code will make it easier to reuse functionality
for checkpoints.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
The upcoming virDomainBackup() API needs to take advantage of the
ability to expose a bitmap as part of nbd-server-add for a pull-mode
backup (this is the recently-added QEMU_CAPS_NBD_BITMAP capability).
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
The upcoming virDomainBackup() API needs to take advantage of various
qcow2 bitmap manipulations as the basis to virDomainCheckpoints and
incremental backups. Add four functions to expose
block-dirty-bitmap-{add,enable,disable,merge} (this is the
recently-added QEMU_CAPS_BITMAP_MERGE capability).
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Add two capabilities for testing features required for the upcoming
virDomainBackupBegin: use block-dirty-bitmap-merge as the generic
witness of bitmap support needed for checkpoints (since all of the
bitmap management functionalities were finalized in the same qemu 4.0
release), and the bitmap parameter to nbd-server-add for pull-mode
backup support. Even though both capabilities are likely to be
present or absent together (that is, it is unlikely to encounter a
qemu that backports only one of the two), it still makes sense to keep
two capabilities as the two uses are orthogonal (full backups don't
require checkpoints, push mode backups don't require NBD bitmap
support, and checkpoints can be used for more than just incremental
backups).
Existing code is not affected by the new capabilities.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Migration always uses a TCP socket for NBD servers, because we don't
support same-host migration. But upcoming pull-mode incremental backup
needs to also support a Unix socket, for retrieving the backup from
the same host. Support this by plumbing virStorageNetHostDef through
the monitor calls, since that is a nice reusable struct that can track
both TCP and Unix sockets.
Update qemumonitorjsontest to verify both forms of the QMP command.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Time to remove the cleanup labels rendered useless in the previous
patch. There are still plenty of other tests that could be further
simplified, but I've already spent enough time in this file for now.
Signed-off-by: Eric Blake <eblake@redhat.com>
The DO_TEST() macro in qemumonitorjsontest.c was not passing the
schema through, which meant that we were not validating any of those
tests for correct usage according to the schema.
In the process of mechanically altering tests to pass the schema
through, use VIR_AUTOPTR on all of the affected test instances. The
next patch will do some further cleanups that it exposes.
Tested by using this hack, where the test mistakenly passed pre-patch,
but correctly diagnosed the garbage post-patch:
| diff --git i/src/qemu/qemu_monitor_json.c w/src/qemu/qemu_monitor_json.c
| index 53a7de8b77..86d8450814 100644
| --- i/src/qemu/qemu_monitor_json.c
| +++ w/src/qemu/qemu_monitor_json.c
| @@ -1532,7 +1532,8 @@ qemuMonitorJSONGetStatus(qemuMonitorPtr mon,
| if (reason)
| *reason = VIR_DOMAIN_PAUSED_UNKNOWN;
|
| - if (!(cmd = qemuMonitorJSONMakeCommand("query-status", NULL)))
| + if (!(cmd = qemuMonitorJSONMakeCommand("query-status",
| + "s:garbage", "foo", NULL)))
| return -1;
|
| if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
Suggested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Simplify the GEN_TEST_FUNC() and target of the DO_TEST_SIMPLE() macros
by using autoptr support.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Upcoming tests are going to use VIR_AUTOPTR to simplify test cleanup.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
In refactoring the snapshot code to prepare for checkpoints, I changed
qemuDomainMomentDiscardAll to take a callback that would handle the
cleanup of either a snapshot or a checkpoint, but failed to set the
callback on one of the two snapshot callers. As a result, 'virsh
undefine $dom --snapshots-metadata' crashed on a NULL function
dereference.
Fixes: a487890d37
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1707708
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
This brings about a couple of benefits:
- use of VIR_AUTOUNREF() simplifies several callers
- Fixes a todo about virDomainMomentObjList not being polymorphic enough
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
In preparation for making virDomainSnapshotDef a descendant of
virObject, it is time to fix all callers that allocate an object to
use virDomainSnapshotDefNew() instead of VIR_ALLOC(). Fortunately,
there aren't very many :)
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
VIR_CLASS_NEW insists that descendents of virObject have 'parent' as
the name of their inherited base class member at offset 0. While it
would be possible to write a new class-creation macro that takes the
actual field name 'current', and rewrite VIR_CLASS_NEW to call the new
macro with the hard-coded name 'parent', it seems less confusing if
all object code uses similar naming. Thus, this is a mechanical rename
in preparation of making virDomainSnapshotDef a descendent of
virObject.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
VIR_CLASS_NEW insists that descendents of virObject have 'parent' as
the name of their inherited base class member at offset 0. While it
would be possible to write a new class-creation macro that takes the
actual field name, and rewrite VIR_CLASS_NEW to call the new macro
with the hard-coded name 'parent', so that we could make
virDomainMomentDef use a custom name for its base class, it seems less
confusing if all object code uses similar naming. Thus, this is a
mechanical rename in preparation of making virDomainSnapshotDef a
descendent of virObject, when we can no longer use 'parent' for a
different purpose than the base class.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Commits 4bc42986 and 218c81ea removed virDomainStorageSourceFormat on
the grounds that there were no external callers; however, the upcoming
backup code wants to output a <target> (push mode) or <scratch> (pull
mode) element that is in all other respects identical to a domain's
<source> element, where the previous virDomainStorageSourceFormat fit
the bill nicely. But rather than reverting the commits, it's easier to
just add an additional parameter for the element name to use, and
update all callers.
Signed-off-by: Eric Blake <eblake@redhat.com>
Now that we can override the post-parse handling, let's update the
testsuite to provide the desired timestamp/name rather than ignoring
the non-deterministic one that was previously being generated. A few
output files need timestamps added now that they are no longer
ignored.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Wire up the accessor functions necessary for the testsuite to install
an alternative post-parse handler from normal drivers. I could have
modified the signature for virDomainXMLOptionNew() to take another
parameter, but thought it was easier to add a new set function rather
than chase down all existing callers. Until code actually sets the
override, there is no change in behavior.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Move the non-deterministic code that sets snapshot properties
independently of what the incoming XML described to instead live in a
default post-parse function common to virDomainMoment (as checkpoints
will also reuse it in later patches). This patch is just code motion,
with no difference to any callers; but the next patch will further
refactor things to allow for a per-driver override, used by the
testsuite to perform deterministic post-parse actions for better
coverage of parser/formatter code.
Note that the post-parse code is intentionally not run during a
snapshot redefine, since that code path already requires a valid
snapshot name and creation time from the XML.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
None of the existing drivers actually use the 0-valued 'nostate'
snapshot state; rather, it was a fluke of implementation. In fact,
some drivers, like qemu, actively reject 'nostate' as invalid during a
snapshot redefine. Normally, a driver computes the state post-parse
from the current domain, and thus virDomainSnapshotGetXMLDesc() will
never expose the state. However, since the testsuite lacks any
associated domain to copy state from, and lacks post-parse processing
that normal drivers have, the testsuite output had several spots with
the state, coupled with a regex filter to ignore the oddity.
It is better to follow the lead of other XML defaults, by not
outputting anything during format if post-parse defaults have not been
applied, and rejecting the default value during parsing. The testsuite
needs a bit of an update, by adding another flag for when to simulate
a post-parse action of setting a snapshot state, but none of the
drivers are impacted other than rejecting XML that was previously
already suspicious in nature.
Similarly, don't expose creation time 0 (for now, only possible if a
user redefined a snapshot to claim creation at the Epoch, but also
happens once setting the creation time is deferred to a post-parse
handler).
This is also a step towards cleaning up snapshot_conf.c to separate
its existing post-parse work (namely, setting the creationTime and
default snapshot name) from the pure parsing work, so that we can get
rid of the testsuite hack of regex filtering of the XML and instead
have more accurate testing of our parser/formatter code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Upcoming changes want to separate out a post-parse massaging of
snapshots separate from parsing the XML, so as not to be dependent on
filtering out an ever-changing timestamp from the testsuite. Along the
way, this means we will want to add yet another conditional to the
snapshot xml2xml tests on whether to perform post-processing steps to
canned values. This will be easier to read if we consolidate all the
decisions into a flags variable, instead of adding yet another
boolean.
While at it, drop the redundant inout test of "noparent" (once is
enough).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Commit b647d2195 introduced a use-after-free situation when the caller
is trying to delete a snapshot and its children: if the callback
function deletes the parent, it is no longer safe to query the parent
to learn which children also need to be deleted (where we previously
saved deleting the parent for last). To fix the problem, while still
maintaining support for topological visits of callback functions, we
have to stash off any information needed for later traversal prior to
using a callback function (virDomainMomentForEachChild already does
this, it is only virDomainMomentActOnDescendant that was running into
problems).
Sadly, the testsuite did not cover the problem at the time. Worse,
even though I later added commit 280a2b41e to catch problems like
this, and even though that test is indeed sufficient to detect the
problem when run under valgrind or suitable MALLOC_PERTURB_ settings,
I'm guilty of not running the test in such an environment. Thus,
v5.2.0 has a regression that could have been prevented had we used the
testsuite to its full power. On the bright side, deleting snapshots
requires ACL domain:snapshot, which is arguably as powerful as
domain:write, so I don't think this use-after-free forms a security
hole.
At some point, it would be nice to convert virDomainMomentObj into a
virObject, at which point, the solution is even simpler: add
virObjectRef/Unref around the callback. But as that will require
auditing even more places in the code, I went with the simplest patch
for the regression fix.
Fixes: b647d2195
Reported-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Tested-by: Roman Bogorodskiy <bogorodskiy@gmail.com>
In a constrained CI environment, where it is intentional that attempts
to write outside the current directory will fail, virsh-snapshot was
failing:
@@ -1,2 +1,3 @@
error: invalid argument: parent s3 for snapshot s2 not found
error: marker
+error: Failed to create '/home/travis/.cache/libvirt/virsh': Permission denied
FAIL virsh-snapshot (exit status: 1)
But we've already solved the problem in virsh-uriprecedence: tell
virsh to use XDG locations pointing to somewhere we can write rather
than its default of falling back to $HOME with the test being at risk
of breaking due to the user's environment and/or unacceptably altering
the user's normal cache. Hoist that solution into test-lib.sh, so
that all scripts can use it as needed. While at it, fix a latent typo
where XDG_RUNTIME_HOME was set to a literal relative directory name
"XDG_CACHE_HOME" (the typo did not affect virsh-uriprecedence, but
could matter to other clients).
Fixes: 280a2b41
Fixes: 398de147
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Most of our completers used the pattern:
if ((nITEM = virITEMListAll()) < 0)
return NULL;
but the virDomainSnapshot and virStorageVolume completers were instead
using goto error. If the ListAll fails with -1, the cleanup label was
running a loop of 'size_t i < int nITEM', which is an extreme waste of
CPU cycles. Broken since their introduction in v4.1.
Fixes: f81f8b62
Fixes: 4cb4b649
Reported-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Even though Coverity can prove that 'last' is always set if the prior
loop executed, gcc 8.0.1 cannot:
CC conf/libvirt_conf_la-virdomainmomentobjlist.lo
../../src/conf/virdomainmomentobjlist.c: In function 'virDomainMomentMoveChildren':
../../src/conf/virdomainmomentobjlist.c:178:19: error: 'last' may be used uninitialized in this function [-Werror=maybe-uninitialized]
last->sibling = to->first_child;
~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
Rewrite the loop to a form that should be easier for static analysis
to work with.
Fixes: ced0898f86
Reported-by: Bjoern Walk <bwalk@linux.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This reverts commit 6b90a84738.
It turns out gcc -O2 is not happy with it, complaining:
/home/pipo/libvirt/src/qemu/qemu_driver.c: In function 'qemuDomainSnapshotCreateXML':
/home/pipo/libvirt/src/qemu/qemu_driver.c:15389:26: error: potential null pointer dereference [-Werror=null-dereference]
bool memory = snapdef->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
~~~~~~~^~~~~~~~
/home/pipo/libvirt/src/qemu/qemu_driver.c:15389:26: error: potential null pointer dereference [-Werror=null-dereference]
In file included from /home/pipo/libvirt/src/util/virbuffer.h:27,
from /home/pipo/libvirt/src/conf/capabilities.h:27,
from /home/pipo/libvirt/src/conf/domain_conf.h:32,
from /home/pipo/libvirt/src/qemu/qemu_agent.h:26,
from /home/pipo/libvirt/src/qemu/qemu_driver.c:40:
/home/pipo/libvirt/src/util/viralloc.h:125:34: error: potential null pointer dereference [-Werror=null-dereference]
# define VIR_ALLOC_N(ptr, count) virAllocN(&(ptr), sizeof(*(ptr)), (count), true, \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
VIR_FROM_THIS, __FILE__, __FUNCTION__, __LINE__)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/pipo/libvirt/src/qemu/qemu_driver.c:15103:9: note: in expansion of macro 'VIR_ALLOC_N'
if (VIR_ALLOC_N(ret, snapdef->ndisks) < 0)
^~~~~~~~~~~
/home/pipo/libvirt/src/qemu/qemu_driver.c:15798:45: error: null pointer dereference [-Werror=null-dereference]
virDomainSnapshotObjGetDef(snap)->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
As the patch simplified one or two callers at the risk of making
many other callers now candidates to trigger aggressive compiler
warnings, it isn't worth it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Use the common base class virDomainMoment for iterator callbacks
related to snapshots from the qemu code, so that when checkpoint
operations are introduced, they can share the same callbacks.
Simplify the code for qemuDomainSnapshotCurrent by better utilizing
virDomainMoment helpers.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The qemu driver already had a full-blown virDomainMomentObjPtr to
check against, and the test driver ought to have one since we get
better error checking that the user passed in a valid object. Removes
the need for a helper function added in commit commit 4819f54b.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Prepare for introducing a bunch of new public APIs related to
backup checkpoints by first introducing a new internal type
and errors associated with that type. Checkpoints are modeled
heavily after virDomainSnapshotPtr (both represent a point in
time of the guest), although a snapshot exists with the intent
of rolling back to that state, while a checkpoint exists to
make it possible to create an incremental backup at a later
time.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Since I was copying this text to form checkpoint XML and API
documentation, I might as well make improvements along the way. Most
of these changes are based on reviews of the checkpoint docs.
Among other things: grammar tweaks, point to a single source of
documentation rather than repeating verbosity, reword things for
easier legibility.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This reverts commit 86c0ed6f70, and
subsequent refactorings of the function into new files. There are no
callers of this function - I had originally proposed it for
implementing a new bulk snapshot API, but that proved to be too
invasive given RPC limits. I also tried using it for streamlining how
the qemu driver stores snapshot state across libvirtd restarts
internally, but in the end, the risks of a new internal format
outweighed the benefits of one file per snapshot.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This reverts commit 1b57269cbc, and
subsequent refactorings of the function into new files. There are no
callers of this function - I had originally proposed it for
implementing a new bulk snapshot API, but that proved to be too
invasive given RPC limits. I also tried using it for streamlining how
the qemu driver stores snapshot state across libvirtd restarts
internally, but in the end, the risks of a new internal format
outweighed the benefits of one file per snapshot.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Rather than hard-coding the snapshot filter bit values into the
generic code, add another layer of indirection: callers must map which
of their public filter bits correspond to supported moment bits, then
pass two separate flags (the ones translated for moment code to
operate on, and the remaining ones for the filter callback to operate
on).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Had this been in place earlier, I would have avoided the bugs in
commit 0baf6945 and 55c2ab3e. Writing the test required me to extend
the power of virsh - creating enough snapshots to cause fanout
requires enough input in a single session that adding comments and
markers makes it easier to check that output is correct. It's still a
bit odd that with test:///default, reverting to a snapshot changes the
domain from running to paused (possibly a bug in how the test driver
copied from the qemu driver) - but the important part is that the test
is reproducible, and any future tweaks we make to snapshot code have
less chance of breaking successful command sequences.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
Since test:///default resets state on every connection, writing a test
that covers a sequence of commands must be done from a single
session. But if the test wants to exercise particular failure modes as
well as successes, it can be nice to leave witnesses in the stderr
stream immediately before and after the spot where the expected error
should be, to ensure the rest of the script is not causing errors.
Do this by adding an --err option.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
As the previous commit mentioned, argv mode (such as when you feed
virsh via stdin with <<\EOF instead of via a single shell argument)
didn't permit comments. Do this by treating any command name token
that starts with # as a comment which silently eats all remaining
arguments to the next newline or semicolon.
Note that batch mode recognizes unquoted # at the start of any word as
a command as part of the tokenizer, while this patch only treats # at
the start of the command word as a comment (any other # remaining by
the time vshCommandParse() is processing things was already quoted
during the tokenzier, and as such was probably intended as the actual
argument to the command word earlier in the line).
Now I can do something like:
$ virsh -c test:///default <<EOF
# setup
snapshot-create-as test s1
snapshot-create-as test s2
# check
snapshot-list test --name
EOF
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
Continuing from what I did in commit 4817dec0, now I want to write a
sequence that is self-documenting. So I need comments :)
Now I can do something like:
$ virsh -c test:///default '
# setup
snapshot-create-as test s1
snapshot-create-as test s2
# check
snapshot-list test --name
'
Note that this does NOT accept comments in argv mode, another patch
will tackle that.
(If I'm not careful, I might turn virsh into a full-fledged 'sh'
replacement? Here's hoping I don't go that far...)
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
Commit 55c2ab3e accidentally introduced an infinite loop while
checking whether a redefined snapshot would cause an infinite loop in
chasing its parents back to a root. Alas, 'make check' did not catch
it, so my next patch will be a testsuite improvement that would have
hung and prevented the bug from being checked in to begin with.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
Now that the generic moment code does pretty much everything that both
snapshots and checkpoints will need, it's time to replace the
now-duplicate code in virdomainsnapshotobjlist.c with simpler calls
into the generic code. I considered using sub-classing (a
'virDomainMomentObjList parent;' member, but that requires making the
opaque type visible in headers; so for now, I stuck with a container
instead (a 'virDomainMomentObjListPtr base;' member).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
The new code here very heavily resembles the code in
virDomainSnapshotObjList. There are still a couple of spots that are
tied a little too heavily to snapshots (the free function lacks a
polymorphic cleanup until we refactor code to use virObject; and an
upcoming patch will add internal VIR_DOMAIN_MOMENT_LIST flags to
replace the snapshot flag bits), but in general this is fairly close
to the state needed to add checkpoint lists.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Now that we have made virDomainMomentObj sufficiently generic to
support both snapshots and checkpoints, it is time to rename the file
that it lives in. The split between a generic object and a list of the
generic objects doesn't buy us as much, so it will be easier to stick
all the moment list code in one file, with more code moving in the
next patch. The changes during the move are fairly minor, although it
is worth pointing out that the log/error messages for the new file
report that they are from "domain", since the file will eventually be
shared by both "domain snapshot" and "domain checkpoint".
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Now that the core of SnapshotObj is agnostic to snapshots and can be
shared with upcoming checkpoint code, it is time to rename the struct
and the functions specific to list operations. A later patch will
shuffle which file holds the common code. This is a fairly mechanical
patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Another step towards making the object list reusable for both
snapshots and checkpoints: the list code only ever needs items that
are in the common virDomainMomentDef base type. This undoes a lot of
the churn in accessing common members added in the previous patch, and
the bulk of the patch is mechanical. But there was one spot where I
had to unroll a VIR_STEAL_PTR to work around changed types.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Pull out the common parts of virDomainSnapshotDef that will be reused
for virDomainCheckpointDef into a new base class. Adjust all callers
that use the direct fields (some of it is churn that disappears when
the next patch refactors virDomainSnapshotObj; oh well...).
Someday, I hope to switch this type to be a subclass of virObject, but
that requires a more thorough audit of cleanup paths, and besides
minimal incremental changes are easier to review.
As for the choice of naming:
I promised my teenage daughter Evelyn that I'd give her credit for her
contribution to this commit. I asked her "What would be a good name
for a base class for DomainSnapshot and DomainCheckpoint". After
explaining what a base class was (using the classic OOB Square and
Circle inherit from Shape), she came up with "DomainMoment", which is
way better than my initial thought of "DomainPointInTime" or
"DomainPIT".
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Separate the algorithm for which list members to vist (which is
generic and can be shared with checkpoints, provided that common
filtering bits are either declared with the same value or have a
mapping from public API to common value) from the decision on which
members to return (which is specific to snapshots). The typedef for
the callback function feels a bit heavy here, but will make it easier
to move the common portions in a later patch.
As part of the refactoring, note that the macros for selecting filter
bits are specific to listing functionality, so they belong better in
virdomainsnapshotobjlist.h (missed in commit 9b75154c).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
An upcoming patch will rework virDomainSnapshotObjList to be generic
for both snapshots and checkpoints; reduce the churn by adding a new
accessor virDomainSnapshotObjGetDef() which returns the
snapshot-specific definition even when the list is rewritten to
operate only on a base class, then using it at sites that that are
specific to snapshots. Use VIR_STEAL_PTR when appropriate in the
affected lines.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Rather than allowing a leaky abstraction where multiple drivers have
to open-code operations that update the relations in a
virDomainSnapshotObjList, it is better to add accessor functions so
that updates to relations are maintained closer to the internals.
This patch finishes the job started in the previous patch, by getting
rid of all direct access to nchildren, first_child, or sibling outside
of the lowest level functions, making it easier to refactor later on.
The lone new caller to virDomainSnapshotObjListSize() checks for a
return != 0, because it wants to handles errors (-1, only possible if
the hash table wasn't allocated) and existing snapshots (> 0) in the
same manner; we can drop the check for a current snapshot on the
grounds that there shouldn't be one if there are no snapshots.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Rather than allowing a leaky abstraction where multiple drivers have
to open-code operations that update the relations in a
virDomainSnapshotObjList, it is better to add accessor functions so
that updates to relations are maintained closer to the internals.
This patch starts the task with a single new function:
virDomainSnapshotMoveChildren(). The logic might not be immediately
obvious [okay, that's an understatement - the existing code uses black
magic ;-)], so here's an overview: The old code has an implicit for
loop around each call to qemuDomainSnapshotReparentChildren() by using
virDomainSnapshotForEachChild() (you'll need a wider context than
git's default of 3 lines to see that); the new code has a more visible
for loop. Then it helps if you realize that the code is making two
separate changes to each child object: STRDUP of the new parent name
prior to writing XML files (unchanged), and touching up the pointer to
the parent object (refactored); the end result is the same whether a
single pass made both changes (both in driver code), or whether it is
split into two passes making one change each (one in driver code, the
other in the new accessor).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
It is easier to track the current snapshot as part of the list of
snapshots. In particular, doing so lets us guarantee that the current
snapshot is cleared if that snapshot is removed from the list (rather
than depending on the caller to do so, and risking a use-after-free
problem, such as the one recently patched in 1db9d0efbf). This
requires the addition of several new accessor functions, as well as a
useful return type for virDomainSnapshotObjListRemove(). A few error
handling sites that were previously setting vm->current_snapshot =
NULL can now be dropped, because the previous function call has now
done it already. Also, qemuDomainRevertToSnapshot() was setting the
current vm twice, so keep only the one used on the success path.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Eric Blake