Commit Graph

153 Commits

Author SHA1 Message Date
Peter Krempa
3f2d167d9c conf: Always format storage source auth and encryption under <source> for backing files
Historically there are two places where we format authentication and
encryption for a disk. The logich which formats it for backing files was
flawed though and didn't format it at all. This worked if the image
became a backing file through the means of a snapshot but not directly.

Force formatting of the source and encryption for any non-disk case to
fix the issue.

This caused problems in many places as we use the formatter to copy the
definition. Effectively any copy lost the secret definition.

https://bugzilla.redhat.com/show_bug.cgi?id=1789310
https://bugzilla.redhat.com/show_bug.cgi?id=1788898

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2020-01-13 12:53:58 +01:00
Daniel P. Berrangé
575d9d2504 conf: drop virCapsPtr param from snapshot & checkpoint APIs
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:17:27 +00:00
Daniel P. Berrangé
bf9d812956 conf: drop virCapsPtr param from domain parse APIs
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:17:27 +00:00
Daniel P. Berrangé
61bff77bf9 conf: drop virCapsPtr param from domain formatting APIs
This parameter is now unused and can be removed entirely.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:17:27 +00:00
Daniel P. Berrangé
92d412149c conf: sanitize virDomainObjFormat & virDomainDefFormat* APIs
Moving their instance parameter to be the first one, and give consistent
ordering of other parameters across all functions. Ensure that the xml
options are passed into both functions in prep for future work.

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-12-09 10:15:16 +00:00
Michal Privoznik
daeeb3603d conf: Use g_strdup_printf() instead of virAsprintf()
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-11-12 16:15:58 +01:00
Peter Krempa
0967708b81 util: buffer: Remove virBufferCheckError
The function now does not return an error so we can drop it fully.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-10-24 19:35:34 +02:00
Peter Krempa
e0a4a011c1 conf: snapshot: Remove 'update_current' parameter from virDomainSnapshotRedefinePrep
The variable is unused so we can drop it.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-10-24 19:35:34 +02:00
Peter Krempa
551dde9256 conf: snapshot: Don't clear current snapshot when redefining an existing one
There's no point in clearing the current snapshot when we are just
changing the definition of the current snapshot as by the virtue of the
'update_current' flag the same snapshot would become current in
qemuDomainSnapshotCreateXML.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-10-24 19:35:34 +02:00
Michal Privoznik
3b4df5d350 Drop needless ret variable
In few places we have the following code pattern:

  int ret;
  ... /* @ret is not accessed here */
  ret = f(...);
  return ret;

This pattern can be written less verbose:

  ...
  return f(...);

This patch was generated with following coccinelle spatch:

  @@
  type T;
  constant C;
  expression f;
  identifier ret;
  @@
  -T ret = C;
   ... when != ret
  -ret = f;
  -return ret;
  +return f;

Afterwards I needed to fix a few places, e.g. comment in
virDomainNetIPParseXML() was removed too because coccinelle
thinks it refers to @ret while in fact it doesn't. Also in few
places it replaced @ret declaration with a few spaces instead of
removing the line. But nothing terribly wrong.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
2019-10-24 08:10:37 +02:00
Ján Tomko
17561eb362 conf: use g_strdup instead of VIR_STRDUP
Replace all occurrences of
  if (VIR_STRDUP(a, b) < 0)
     /* effectively dead code */
with:
  a = g_strdup(b);

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-21 12:51:56 +02:00
Ján Tomko
efc266883f conf: use g_steal_pointer instead of VIR_STEAL_PTR
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-16 15:59:42 +02:00
Ján Tomko
45678bd70a Use g_autoptr instead of VIR_AUTOPTR
Since commit 44e7f02915
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOPTR aliases to g_autoptr. Replace all of its use by the GLib
macro version.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-16 12:06:43 +02:00
Ján Tomko
1e2ae2e311 Use g_autofree instead of VIR_AUTOFREE
Since commit 44e7f02915
    util: rewrite auto cleanup macros to use glib's equivalent

VIR_AUTOFREE is just an alias for g_autofree. Use the GLib macros
directly instead of our custom aliases.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-10-16 12:06:43 +02:00
Daniel P. Berrangé
d5d6dbcfb5 build: remove all gnulib bit manipulation modules
We're using gnulib to get ffs, ffsl, rotl32, count_one_bits,
and count_leading_zeros. Except for rotl32 they can all be
replaced with gcc/clangs builtins. rotl32 is a one-line
trivial function.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-10-07 13:39:26 +01:00
Peter Krempa
efeb6232c6 conf: Drop pointless 'domain' argument from virDomainSnapshotRedefinePrep
'vm' is passed in which contains the definition which contains the UUID
so we don't need another parameter for this.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-09-27 15:23:42 +02:00
Peter Krempa
8aa2233099 conf: Use automatic pointers for xmlXPathContext
Clean up functions which grab and free the context to use VIR_AUTOPTR.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2019-09-19 14:31:15 +02:00
Peter Krempa
bfedd14955 util: xml: Add wrapper for xmlXPathNewContext
The wrapper reports libvirt errors for the libxml2 function so that
the same does not have to be repeated over and over.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2019-09-19 14:31:15 +02:00
Maxiwell S. Garcia
152c165d34 snapshot: Store both config and live XML in the snapshot domain
The snapshot-create operation of running guests saves the live
XML and uses it to replace the active and inactive domain in
case of revert. So, the config XML is ignored by the snapshot
process. This commit changes it and adds the config XML in the
snapshot XML as the <inactiveDomain> entry.

In case of offline guest, the behavior remains the same and the
config XML is saved in the snapshot XML as <domain> entry. The
behavior of older snapshots of running guests, that don't have
the new <inactiveDomain>, remains the same too. The revert, in
this case, overrides both active and inactive domain with the
<domain> entry. So, the <inactiveDomain> in the snapshot XML is
not required to snapshot work, but it's useful to preserve the
config XML of running guests.

Signed-off-by: Maxiwell S. Garcia <maxiwell@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
2019-09-11 13:09:45 +02:00
Jiri Denemark
577a1f98fc qemu: Pass correct qemuCaps to virDomainDefParseNode
Since qemuDomainDefPostParse callback requires qemuCaps, we need to make
sure it gets the capabilities stored in the domain's private data if the
domain is running. Passing NULL may cause QEMU capabilities probing to
be triggered in case QEMU binary changed in the meantime. When this
happens while a running domain object is locked, QMP event delivered to
the domain before QEMU capabilities probing finishes will deadlock the
event loop.

Several general snapshot and checkpoint APIs were lazily passing NULL as
the parseOpaque pointer instead of letting their callers pass the right
data. This patch fixes all paths leading to virDomainDefParseNode.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2019-08-09 13:55:54 +02:00
Peter Krempa
50e1e053a5 conf: snapshot: Provide a function to free virDomainSnapshotDiskDefPtr
Tests will need to parse such a definition so it also needs to be freed.
Provide a function for it.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-07-18 17:59:34 +02:00
Peter Krempa
3b8135b03e conf: snapshot: Export virDomainSnapshotDiskDefParseXML
Allow using it from the tests.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-07-18 17:59:34 +02:00
Eric Blake
e3989ce3ed snapshot: Factor out redefine cycle validation
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>
2019-07-12 15:12:29 -05:00
Eric Blake
88ae8b8b0c snapshot: Add internal option to validate XML against schema
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>
2019-07-10 17:13:26 -05:00
Eric Blake
57387ff54b snapshot: Make virDomainSnapshotDef a virObject
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>
2019-05-09 10:02:53 -05:00
Eric Blake
7fe07761a7 snapshot: Add virDomainSnapshotDefNew
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>
2019-05-09 09:51:51 -05:00
Eric Blake
098043eddd snapshot: s/current/parent/ as prep for virObject
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>
2019-05-09 09:48:07 -05:00
Eric Blake
36603bc568 snapshot: s/parent/parent_name/ as prep for virObject
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>
2019-05-09 09:43:41 -05:00
Eric Blake
1ec3e39742 conf: Add parameter to virDomainDiskSourceFormat
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>
2019-05-06 18:05:17 -05:00
Eric Blake
df2ae0d042 snapshot: Allow for post-parse override
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>
2019-04-16 21:55:59 -05:00
Eric Blake
5ba4d81ce9 snapshot: Factor out post-parse code
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>
2019-04-16 21:55:59 -05:00
Eric Blake
a007fcab3b snapshot: Don't expose testsuite-only state in snapshot XML
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>
2019-04-16 21:55:52 -05:00
Cole Robinson
1d31526b52 Always put _LAST enums on second line of VIR_ENUM_IMPL
Standardize on putting the _LAST enum value on the second line
of VIR_ENUM_IMPL invocations. Later patches that add string labels
to VIR_ENUM_IMPL will push most of these to the second line anyways,
so this saves some noise.

Signed-off-by: Cole Robinson <crobinso@redhat.com>
2019-04-11 12:47:23 -04:00
Peter Krempa
dfaf170df5 conf: Replace virDomainDiskSourceParse by virDomainStorageSourceParse
virDomainDiskSourceParse was now just a thin wrapper without any extra
value. Replace all usage of it by the function it calls and remove the
function.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-04-03 11:58:09 +02:00
Peter Krempa
5f6f803ca1 conf: Merge virDomainDiskSourceFormatInternal into virDomainDiskSourceFormat
Remove the wrapper and fix callers.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2019-04-03 11:58:09 +02:00
Eric Blake
a6d822cee3 Revert "snapshot: Allow NULL to virDomainSnapshotObjGetDef"
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>
2019-03-27 09:21:45 -05:00
Eric Blake
6b90a84738 snapshot: Allow NULL to virDomainSnapshotObjGetDef
Doing so can simplify some callers.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2019-03-27 08:14:42 -05:00
Eric Blake
0b4fac6afd Revert "snapshot: Add virDomainSnapshotObjListFormat"
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>
2019-03-26 15:07:47 -05:00
Eric Blake
9884b2d185 snapshot: Avoid infloop during REDEFINE
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>
2019-03-25 08:50:45 -05:00
Eric Blake
e055a816af snapshot: Rename virDomainSnapshotObjPtr
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>
2019-03-22 01:18:34 -05:00
Eric Blake
1ab05da228 snapshot: Switch type of virDomainSnapshotObj.def
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>
2019-03-22 01:18:34 -05:00
Eric Blake
ffc0fbebe2 snapshot: Factor out virDomainMomentDef class
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>
2019-03-22 01:18:34 -05:00
Eric Blake
55c2ab3e2b snapshot: Access snapshot def directly when needed
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>
2019-03-22 01:18:33 -05:00
Eric Blake
4819f54bd3 snapshot: Track current snapshot in virDomainSnapshotObjList
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>
2019-03-22 01:15:20 -05:00
Eric Blake
f105627992 snapshot: Drop virDomainSnapshotDef.current
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>
2019-03-22 01:15:20 -05:00
Eric Blake
9b75154c07 snapshot: Break out virDomainSnapshotObjList into its own file
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>
2019-03-15 11:43:09 -05:00
Eric Blake
21b2651e72 snapshot: Export two functions prior to file split
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>
2019-03-15 11:37:59 -05:00
Eric Blake
ca20690e9f snapshot: Break out virDomainSnapshotObj into its own file
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>
2019-03-15 11:34:32 -05:00
Eric Blake
b647d2195d snapshots: Support topological visits
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>
2019-03-12 20:46:09 -05:00
Eric Blake
1b57269cbc snapshot: Add virDomainSnapshotObjListParse
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>
2019-03-07 17:42:07 -06:00