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>
Rework the logic in qemuDomainSnapshotLoad() to set
vm->current_snapshot only once at the end of the loop, rather than
repeatedly querying it during the loop, to make it easier for the next
patch to use accessor functions rather than direct manipulation of
vm->current_snapshot. When encountering multiple snapshots claiming
to be current (based on the presence of an <active>1</active> element
in the XML, which libvirt only outputs for internal use and not for
any public API), this changes behavior from warning only once and
running with no current snapshot, to instead warning on each duplicate
and selecting the last one encountered (which is arbitrary based on
readdir() ordering, but actually stands a fair chance of being the
most-recently created snapshot whether by timestamp or by the
propensity of humans to name things in ascending order).
Note that the code in question is only run by libvirtd when it first
starts, reading state from disk from the previous run into memory for
this run. Since the data resides somewhere that only libvirt should be
touching (typically /var/lib/libvirt/qemu/snapshot/*), it should be
clean. So in the common case, the code touched here is unreachable.
But if someone is actually messing with files behind libvirt's back,
they deserve the change in behavior.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
The only use for the 'current' member of virDomainSnapshotDef was with
the PARSE/FORMAT_INTERNAL flag for controlling an internal-use
<active> element marking whether a particular snapshot definition was
current, and even then, only by the qemu driver on output, and by qemu
and test driver on input. But this duplicates vm->snapshot_current,
and gets in the way of potential simplifications to have qemu store a
single file for all snapshots rather than one file per snapshot. Get
rid of the member by adding a bool* parameter during parse (ignored if
the PARSE_INTERNAL flag is not set), and by adding a new flag during
format (if FORMAT_INTERNAL is set, the value printed in <active>
depends on the new FORMAT_CURRENT).
Then update the qemu driver accordingly, which involves hoisting
assignments to vm->current_snapshot to occur prior to any point where
a snapshot XML file is written (although qemu kept
vm->current_snapshot and snapshot->def_current in sync by the end of
the function, they were not always identical in the middle of
functions, so the shuffling gets a bit interesting). Later patches
will clean up some of that confusing churn to vm->current_snapshot.
Note: even if later patches refactor qemu to no longer use
FORMAT_INTERNAL for output (by storing bulk snapshot XML instead), we
will always need PARSE_INTERNAL for input (because on upgrade, a new
libvirt still has to parse XML left from a previous libvirt).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
When a future patch converts virDomainSnapshotDef to be a virObject,
we need to be careful that converting VIR_FREE() to virObjectUnref()
does not result in double frees. Reorder the assignment of def into
the object to the point after object is in the hash table (as
otherwise the virHashAddEntry() error path would have a shot at
freeing def prematurely).
Suggested-by: John Ferlan <ferlan@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Change the return value of virDomainSnapshotObjListParse() to return
the number of snapshots imported, and allow a return of 0 (the
original proposal of adding a flag to virDomainSnapshotCreateXML
required returning an arbitrary non-NULL snapshot, but that idea was
abandoned; and by returning a count, we are no longer constrained to a
non-empty list).
Document which flags are supported (namely, just SECURE) in
virDomainSnapshotObjListFormat().
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
An upcoming patch will be reworking virDomainSnapshotDef to have a
base class; minimize the churn by using a local variable to reduce the
number of dereferences required when acessing the domain definition
associated with the snapshot.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
The following virsh command was triggering a use-after-free:
$ virsh -c test:///default '
snapshot-create-as test s1
snapshot-create-as test s2
snapshot-delete --children-only test s1
snapshot-current --name test'
Domain snapshot s1 created
Domain snapshot s2 created
Domain snapshot s1 children deleted
error: name in virGetDomainSnapshot must not be NULL
I got lucky on that run - although the error message is quite
unexpected. On other runs, I was able to get a core dump, and
valgrind confirms there is a definitive problem.
The culprit? We were inconsistent about whether we set
vm->current_snapshot, snap->def->current, or both when updating how
the current snapshot was being tracked. As a result, deletion did not
see that snapshot s2 was previously current, and failed to update
vm->current_snapshot, so that the next API using the current snapshot
failed because it referenced stale memory for the now-gone s2 (instead
of the intended s1).
The test driver code was copied from the qemu code (which DOES track
both pieces of state everywhere), but was purposefully simplified
because the test driver does not have to write persistent snapshot
state to the file system. But when you realize that the only reason
snap->def->current needs to exist is when writing out one file per
snapshot for qemu, it's just as easy to state that the test driver
never has to mess with the field (rather than chasing down which
places forgot to set the field), and have vm->current_snapshot be the
sole source of truth in the test driver.
Ideally, I'd get rid of the 'current' member in virDomainSnapshotDef,
as well as the 'current_snapshot' member in virDomainDef, and instead
track the current member in virDomainSnapshotObjList, coupled with
writing ALL snapshot state for qemu in a single file (where I can use
<snapshots current='...'> as a wrapper, rather than
VIR_DOMAIN_SNAPSHOT_FORMAT_INTERNAL to output <current>1</current> XML
on a per-snapshot file basis). But that's a bigger change, so for now
I'm just patching things to avoid the test driver segfault.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
snapshot_conf.h was mixing three separate types: the snapshot
definition, the snapshot object, and the snapshot object list.
Separate out the snapshot object list code into its own file, and
update includes for affected clients.
This is just code motion, but done in preparation of sharing a lot of
the object list code with checkpoints.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The next patch will require access to the helper functions
virDomainSnapshotDefFormatInternal and
virDomainSnapshotRedefineValidate from two different files; make the
file split easier by exporting these functions.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
snapshot_conf.h was mixing three separate types: the snapshot
definition, the snapshot object, and the snapshot object list.
Separate out the snapshot object code into its own file, which
includes moving a typedef to avoid circular inclusions.
Mostly straight code motion, although I fixed a comment along
the way, now that virDomainSnapshotForEachDescendent now
guarantees a topological visit (missed in b647d219).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
It's easier to locate a typedef if they are stored in sorted order;
do so mechanically via:
$ sed -i '/typedef struct/ {N; N; s/\n//g}' src/conf/virconftypes.h
$ # sorting the lines
$ sed -i '/typedef struct/ s/;/;\n/g' src/conf/virconftypes.h
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
As explained in the previous patch, collecting pointer typedefs into a
common header makes it easier to avoid circular inclusions. Continue
the efforts by pulling the appropriate typedefs from capabilities.h
into the new header.
This patch is just straight code motion (all typedefs are listed in
the same order before and after the patch); a later patch will sort
things for legibility.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Right now, snapshot_conf.h is rather large - it deals with three
separate types: virDomainSnapshotDef (the snapshot definition as it
maps to XML), virDomainSnapshotObj (an object containing a def and the
relationship to other snapshots), and virDomainSnapshotObjList (a list
of snapshot objects), where two of the three types are currently
public rather than opaque. What's more, the types are circular: a
snapshot def includes a virDomainPtr, which contains a snapshot list,
which includes a snapshot object, which includes a snapshot def.
In order to split the three objects into separate files, while still
allowing each header to use sane typedefs to incomplete pointers, the
obvious solution is to lift the typedefs into yet another header, with
no other dependencies. Start the split by factoring out all struct
typedefs from domain_conf.h (enum typedefs don't get used in function
signatures, and function typedefs tend not to suffer from circular
referencing, so those stay put). The only other exception is
virDomainStateReason, which is only ever used directly rather than via
a pointer.
This patch is just straight code motion (all typedefs are listed in
the same order before and after the patch); a later patch will sort
things for legibility.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Checking that the derived class is larger than the requested parent
class saves us from some obvious mistakes, but as written, it does not
catch all the cases; in particular, it is easy to forget to update a
VIR_CLASS_NEW when changing the 'parent' member from virObject to
virObjectLockabale, but where the size checks don't catch that. Add a
parameter for one more layer of sanity checking.
It would be cool if we could get gcc to stringize typeof(parent) into
the string name of that type, so that we could confirm that the
precise parent class is in use rather than just a struct that happens
to have the same size as the parent class. But sizeof checks are
better than nothing.
Note that I did NOT change the fact that we require derived classes to
be larger (as the difference in size makes it easy to tell classes
apart), which means that even if a derived class has no functionality
to add (but rather exists for compiler-enforced type-safety), it must
still include a dummy member. But I did fix the wording of the error
message to match the code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Based on recent list questions about the proposed addition of
virDomainCheckpointCreateXML(REDEFINE), it is worth adding some
clarification to the existing snapshot redefine documentation that is
serving as the basis for checkpoints.
Normal snapshot creation requires very few elements from the user XML
(libvirt can pick sane defaults for items that are omitted, and many
fields, including <domain>, are documented as readonly output fields
ignored on input, produced by drivers that track it). But during
REDEFINE, the API wants the complete XML produced by an earlier
virDomainSnapshotGetXMLDesc; as the domain definition has likely
changed since the snapshot was first created, libvirt is unable to
recreate a <domain> sub-element that matches the original output
representing the domain state at the time the snapshot was first
created. In fact, reverting without a <domain> sub-element is risky
enough that we had to add a FORCE flag for virDomainSnapshotRevert().
In short, we only support omitting domain for qemu because of
backwards-compatibility to snapshots created before 0.9.5 started
capturing <domain>; even though there are other drivers like vbox that
do not output <domain> because they have other reliable ways to
revert.
And based on the confusion caused when omitting <domain> from snapshot
XML, the initial design for checkpoints in later patches will make
<domain> a mandatory element during its REDEFINE.
[Side note: the fact that <domain> can appear in <domainsnapshot> is a
reason we cannot add a new API for a bulk listing or redefine of all
snapshots of a single domain in one XML call (for example, a 1M
<domain> XML * 16 snapshots explodes into 16M in a bulk form, which
gets difficult to send over RPC). Perhaps we could add a flag to
request that the <domain> sub-element be omitted on output, but such
output is no longer suitable for sane REDEFINE input.]
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
I had to inspect the code to learn whether a final virObjectUnref()
calls ALL dispose callbacks in child-to-parent order (akin to C++
destructors), or whether I manually had to call a parent-class dispose
when writing a child class dispose method. The answer is the
former. (Thankfully, since VIR_FREE wipes out pointers for safety,
even if I had guessed wrong, I probably would not have tripped over a
double-free fault when the parent dispose ran for the second time). I
also had to read the code to learn if a dispose method was even
mandatory (it is not, although getting NULL through VIR_CLASS_NEW
requires a macro). While at it, the VIR_CLASS_NEW macro requires that
the virObject component at offset 0 be reached through the name
'parent', not 'object'.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
An upcoming patch wants to reuse XML parsing of both unix and tcp
network host descriptions in the context of setting up a backup
NBD server. Make that easier by refactoring the existing parser.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
We copy-and-paste a lot of our docs, as evidenced by the number of
*GetXMLDesc() functions which had the same unusual indentation and
missing capital in the second sentence of the returns paragraph.
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit 09eb1ae0 added a new enum type for xenbus, and adjusted
affected switch statements in the qemu driver, but failed to notice
that the vbox driver had a similar switch statement.
Signed-off-by: Eric Blake <eblake@redhat.com>
For snapshots, virsh already has a (shockingly naive [1]) client-side
topological sorter with the --tree option. But as a series of REDEFINE
calls must be presented in topological order, it's worth letting the
server do the work for us, especially since the server can give us a
topological sorting with less effort than our naive client
reconstruction.
[1] The XXX comment in virshSnapshotListCollect() about --tree being
O(n^3) is telling; https://en.wikipedia.org/wiki/Topological_sorting
is an interesting resource describing Kahn's algorithm and other
approaches for O(n) topological sorting for anyone motivated to use a
more elegant algorithm than brute force - but that doesn't affect this
patch.
For now, I am purposefully NOT implementing virsh fallback code to
provide a topological sort when the flag was rejected as unsupported;
we can worry about that down the road if users actually demonstrate
that they use new virsh but old libvirt to even need the fallback.
(The code we use for --tree could be repurposed to be such a fallback,
whether or not we keep it naive or improve it to be faster - but
again, no one should spend time on a fallback without evidence that we
need it.)
The test driver makes it easy to test:
$ virsh -c test:///default '
snapshot-create-as test a
snapshot-create-as test c
snapshot-create-as test b
snapshot-list test
snapshot-list test --topological
snapshot-list test --descendants a
snapshot-list test --descendants a --topological
snapshot-list test --tree
snapshot-list test --tree --topological
'
Without any flags, virsh does client-side sorting alphabetically, and
lists 'b' before 'c' (even though 'c' is the parent of 'b'); with the
flag, virsh skips sorting, and you can now see that the server handed
back data in a correct ordering. As shown here with a simple linear
chain, there isn't any other possible ordering, so --tree mode doesn't
seem to care whether --topological is used. But it is possible to
compose more complicated DAGs with multiple children to a parent
(representing reverting back to a snapshot then creating more
snapshots along those divergent execution timelines), where it is then
possible (but not guaranteed) that adding the --topological flag
changes the --tree output (the client-side --tree algorithm breaks
ties based on alphabetical sorting between two nodes that share the
same parent, while the --topological sort skips the client-side
alphabetical sort and ends up exposing the server's internal order for
siblings, whether that be historical creation order or dependent on a
random hash seed). But even if the results differ, they will still be
topologically correct.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
snapshot_conf does all the hard work, the qemu driver just has to
accept the new flag.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
snapshot_conf does all the hard work, the test driver just has to
accept the new flag.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Wire up support for VIR_DOMAIN_SNAPSHOT_LIST_TOPOLOGICAL in the
domain-agnostic support code.
Clients of snapshot_conf using virDomainSnapshotForEachDescendant()
are using a depth-first visit but with postfix visits of a given
node. Changing this to a prefix visit of the given node instantly
turns this into a topologically-ordered visit. (A prefix
breadth-first visit would also be topologically sorted, but that
requires a queue while our recursion naturally has a stack).
With that change, we now always have a topological sort for
virDomainSnapshotListAllChildren() regardless of the new public API
flag. Then with one more tweak, we can also get a topological rather
than a faster random hash visit for virDomainListAllSnapshots(), by
doing a descendent walk from our internal metaroot (there, we let the
public API flag control behavior, because a topological sort DOES
require more stack and slightly more time).
Note that virDomainSnapshotForEach() still uses a random hash visit;
we could change that signature to take a tri-state for random, prefix,
or postfix visit if we ever had clients that cared about the
distinctions, but for now, none of the drivers seem to care.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
When using virDomainSnapshotCreateXML with the REDEFINE flag on
multiple snapshot metadata XML descriptions, we require that a child
cannot be redefined before its parent. Since libvirt already tracks a
DAG, it is more convenient if we can ensure that
virDomainListAllSnapshots() and friends have a way to return data in
an order that we can directly reuse, rather than having to
post-process the data ourselves to reconstruct the DAG.
Add VIR_DOMAIN_SNAPSHOT_LIST_TOPOLOGICAL as our new guarantee (well, a
guarantee at the time of the API call conclusion; there's always a
possible TOCTTOU race where someone redefining snapshots in between
the API results and the client actually using the list might render
the list out-of-date). Four listing APIs are directly benefitted by
the new flag; additionally, since we document that the older racy
ListNames interfaces should be sized by using the same flags on their
Num counterparts, the Num interfaces must document when they accept
(and ignore) the flag.
We could have supported the new flag just for the ListAll APIs (to
discourage people from using the older racy Num/ListNames APIs), but
it feels weird to special-case this flag value as being applicable to
only a subset of the API while all other List-related flags are
trivially applicable to all 6.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
In local testing, I accidentally introduced a self-test failure,
and spent way too much time debugging it. Make sure the testsuite
log includes some hint as to why command option validation failed.
Lone exception: allocation failure is unlikely during self-test,
and if it happens, we are better off asserting (vsh.c can do this,
even if libvirt.so cannot).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Acked-by: Peter Krempa <pkrempa@redhat.com>
Fix an incorrect @xmlDesc comment, as well as adding more details
about which XML element should be root.
Signed-off-by: Eric Blake <eblake@redhat.com>
Add a new function to make it possible to parse a list of snapshots
at once. This is a counterpart to an earlier patch making it
possible to produce all snapshots in a single XML string, and
intentionally parses the same top-level element <snapshots> with
an optional attribute current='name'.
Note that since we know we started with no relations at all, and
since checking parent relationships per-snapshot is not viable as
we don't control which order the snapshots appear in, that we are
fine with doing a final pass to update all parent/child
relationships among the definitions.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Pull out the portion of virDomainSnapshotRefinePrep() that deals
with definition sanity into a separate helper routine that can
be reused with bulk redefine, leaving behind only the code
specific to loop checking and in-place updates that are only
needed in single-definition handling.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Right now, the only callers of qemuDomainSnapshotDiscardAllMetadata()
are right before freeing the virDomainSnapshotObjList, so it did not
matter if the list's metaroot (which points to all the defined root
snapshots) is left inconsistent. But an upcoming patch will want to
clear all snapshots if a bulk redefine fails partway through, in
which case things must be reset. Make this work by teaching the
existing virDomainSnapshotUpdateRelations() to be safe regardless of
the incoming state of the metaroot (since we don't want to leak that
internal detail into qemu code), then fixing the qemu code to use
it after deleting all snapshots. Additionally, the qemu code must
reset vm->current_snapshot if the current snapshot was removed,
regardless of whether the overall removal succeeded or failed later.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Add a new function to output all of the domain's snapshots in one
buffer.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Split out an internal helper that produces format into a
virBuffer, similar to what domain_conf.c does, and making
the next patch easier to write.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
virDomainSnapshotDefFormat currently takes two sets of knobs:
an 'unsigned int flags' argument that can currently just be
VIR_DOMAIN_DEF_FORMAT_SECURE, and an 'int internal' argument used as
a bool to determine whether to output an additional element. It
then reuses the 'flags' knob to call into virDomainDefFormatInternal(),
which takes a different set of flags. In fact, prior to commit 0ecd6851
(1.2.12), the 'flags' argument actually took the public
VIR_DOMAIN_XML_SECURE, which was even more confusing. Let's borrow
from the style of that earlier commit, by introducing a function
for translating from the public flags (VIR_DOMAIN_SNAPSHOT_XML_SECURE
was just recently introduced) into a new enum specific to snapshot
formatting, and adjust all callers to use snapshot-specific enum
values when formatting, and where the formatter now uses a new
variable 'domainflags' to make it obvious when we are translating
from snapshot flags back to domain flags. We don't even have to
use the conversion function for drivers that don't accept the
public VIR_DOMAIN_SNAPSHOT_XML_SECURE flag.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Clean up the previous patch which abused switch on virDomainState
while working with a variable containing virDomainSnapshotState, by
converting the two affected switch statements to now use the right
enum.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
The existing virDomainSnapshotState is a superset of virDomainState,
adding one more state (disk-snapshot) on top of valid domain states.
But as written, the enum cannot be used for gcc validation that all
enum values are covered in a strongly-typed switch condition, because
the enum does not explicitly include the values it is adding to.
Copy the style used in qemu_blockjob.h of creating new enum names
for every inherited value, and update most clients to use the new
enum names anywhere snapshot state is referenced. The exception is
two switch statements in qemu code, which instead gain a fixme
comment about odd type usage (which will be cleaned up in the next
patch). The rest of the patch is fairly mechanical (I actually did
it by temporarily s/state/xstate/ in snapshot_conf.h to let the
compiler find which spots in the code used the field, did the
obvious search and replace in those functions, then undid the rename).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
qemuDomainSnapshotWriteMetadata does not modify the directory name,
and making it const-correct aids in writing an upcoming patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
The current qemu code rejects the combination of the two flags
VIR_DOMAIN_SNAPSHOT_CREATE_LIVE in tandem with
VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE, but rather late in the cycle
(after the snapshot was already parsed), and with a rather confusing
message (complaining that live snapshots require external storage,
even if the redefined snapshot already declares external storage).
Hoist the rejection message to occur earlier (before parsing any
XML, which also aids upcoming patches that will implement bulk
redefine), and with a more typical error message about mutually
exclusive flags.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Eric Blake