If a (floppy) drive isn't selected for snapshot explicitly and is empty
don't try to snapshot it. For external snapshots this would fail as we
can't generate a name for the snapshot from an empty drive.
Reported-by: Pavel Hrdina <phrdina@redhat.com>
RNG schema as well as the qemu driver requires absolute paths for memory
and disk snapshot image files but the XML parser was not enforcing it.
Add checks to avoid problems in qemu where the configuration it creates
is invalid.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1126329
Replace:
if (virBufferError(&buf)) {
virBufferFreeAndReset(&buf);
virReportOOMError();
...
}
with:
if (virBufferCheckError(&buf) < 0)
...
This should not be a functional change (unless some callers
misused the virBuffer APIs - a different error would be reported
then)
As part of the work on backing chains, I'm finding that it would
be easier to directly manipulate chains of pointers (adding a
snapshot merely adjusts pointers to form the correct list) rather
than copy data from one struct to another. This patch converts
snapshot source to be a pointer.
In this patch, the pointer is ALWAYS allocated (any code that
increases ndisks now also allocates a source pointer for each
new disk), and all other changes are just mechanical fallout of
the new type; there should be no functional change. It is
possible that we may want to leave the pointer NULL for internal
snapshots in a later patch, but as that requires a closer audit
of the source to ensure we don't fault on a null dereference, I
didn't do it here.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Change
type of src.
* src/conf/snapshot_conf.c: Adjust all clients.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Domain snapshots should only permit an external snapshot into
a storage format that permits a backing chain, since the new
snapshot file necessarily must be backed by the existing file.
The C code for the qemu driver is a little bit stricter in
currently enforcing only qcow2 or qed, but at the XML parser
level, including virt-xml-validate, it is fairly easy to
enforce that a user can't request a 'raw' external snapshot.
* docs/schemas/storagecommon.rng (storageFormat): Split out...
(storageFormatBacking): ...new sublist.
* docs/schemas/domainsnapshot.rng (disksnapshotdriver): Use new
type.
* src/util/virstoragefile.h (virStorageFileFormat): Rearrange for
easier code management.
* src/util/virstoragefile.c (virStorageFileFormat, fileTypeInfo):
Likewise.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefParseXML): Use
new marker to limit selection of formats.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Right now, virStorageFileMetadata tracks bool backingStoreIsFile
for whether the backing string specified in metadata can be
resolved as a file (covering both block and regular file
resources) or is treated as a network protocol. But when
merging this struct with virStorageSource, it will be easier
to just actually track which type of resource it is, as well
as have a reserved value for the case where the resource type
is unknown (or had an error during probing).
* src/util/virstoragefile.h (virStorageType): Add a placeholder
value, swap order to match similar public enum.
* src/util/virstoragefile.c (virStorage): Update string mapping.
* src/conf/domain_conf.c (virDomainDiskSourceParse)
(virDomainDiskDefParseXML, virDomainDiskDefFormat)
(virDomainDiskSourceFormat): Adjust clients.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefParseXML):
Likewise.
* src/qemu/qemu_driver.c
(qemuDomainSnapshotPrepareDiskExternalBackingInactive)
(qemuDomainSnapshotPrepareDiskExternalOverlayActive)
(qemuDomainSnapshotPrepareDiskExternalOverlayInactive)
(qemuDomainSnapshotPrepareDiskInternal)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
* src/qemu/qemu_command.c (qemuGetDriveSourceString): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Now that we have a dedicated type for representing a disk source,
we might as well parse and format directly into that type instead
of piecemeal into pointers to members of the type.
* src/conf/domain_conf.h (virDomainDiskSourceDefFormatInternal)
(virDomainDiskSourceDefParse): Rename...
(virDomainDiskSourceFormat, virDomainDiskSourceParse): ...and
compress signatures.
* src/conf/domain_conf.c (virDomainDiskSourceParse)
(virDomainDiskSourceFormat): Rewrite to use common struct.
(virDomainDiskSourceDefFormat): Delete.
(virDomainDiskDefParseXML, virDomainDiskDefFormat): Update
callers.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefParseXML)
(virDomainSnapshotDiskDefFormat): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Now that we have a common struct, it's time to start using it!
Since external snapshots make a longer backing chain, it is
only natural to use the same struct for the file created by
the snapshot as what we use for <domain> disks.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Use common
struct instead of open-coded duplicate fields.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefClear)
(virDomainSnapshotDiskDefParseXML, virDomainSnapshotAlignDisks)
(virDomainSnapshotDiskDefFormat)
(virDomainSnapshotDiskGetActualType): Adjust clients.
* src/qemu/qemu_conf.c (qemuTranslateSnapshotDiskSourcePool):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskGetSourceString)
(qemuDomainSnapshotCreateInactiveExternal)
(qemuDomainSnapshotPrepareDiskExternalOverlayActive)
(qemuDomainSnapshotPrepareDiskExternal)
(qemuDomainSnapshotPrepare)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
* src/storage/storage_driver.c
(virStorageFileInitFromSnapshotDef): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Part of a series of cleanups to use new accessor methods.
Several places in domain_conf.c still open-code raw field access,
but that code will be touched later with the diskDef struct split
so I'm avoiding churn here.
* src/conf/domain_audit.c (virDomainAuditStart): Use accessors.
* src/conf/domain_conf.c (virDomainDiskIndexByName)
(virDomainDiskPathByName, virDomainDiskDefForeachPath)
(virDomainDiskSourceIsBlockType): Likewise.
* src/conf/snapshot_conf.c (virDomainSnapshotAlignDisks):
Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
While running domainsnapshotxml2xmltest, it was found that valgrind pointed out
the following memory leak:
==32176== 42 (32 direct, 10 indirect) bytes in 1 blocks are definitely lost in loss record 42 of 66
==32176== at 0x4A069EE: malloc (vg_replace_malloc.c:270)
==32176== by 0x4A06B62: realloc (vg_replace_malloc.c:662)
==32176== by 0x4C65A07: virReallocN (viralloc.c:243)
==32176== by 0x4C65B2E: virExpandN (viralloc.c:292)
==32176== by 0x4C65E30: virInsertElementsN (viralloc.c:434)
==32176== by 0x4CD71F3: virDomainDiskSourceDefParse (domain_conf.c:5078)
==32176== by 0x4CF6EF4: virDomainSnapshotDefParseNode (snapshot_conf.c:151)
==32176== by 0x4CF7314: virDomainSnapshotDefParseString (snapshot_conf.c:410)
==32176== by 0x41FB8D: testCompareXMLToXMLHelper (domainsnapshotxml2xmltest.c:100)
==32176== by 0x420FD1: virtTestRun (testutils.c:199)
==32176== by 0x41F859: mymain (domainsnapshotxml2xmltest.c:222)
==32176== by 0x42174D: virtTestMain (testutils.c:782)
==32176==
... and one more.
All leading spaces in domain snapshot xml format functions have been
replaced with appropriate calls to virBufferAdjustIndent(). This will
make it easier to call other similarly fixed format functions
(e.g. domain device format functions).
Many of the domain xml format functions (including all of the device
format functions) had hard-coded spaces, which made for incorrect
indentation when those functions were called in a different context
(for example, commit 2122cf39 added <interface> XML into the document
provided to a network hook script, and in this case it should have
been indented by 2 spaces, but was instead indented by 6 spaces).
To make it possible to insert a properly indented device anywhere into
an XML document, this patch removes hardcoded spaces from the
formatting functions, and calls virBufferAdjustIndent() at appropriate
places instead. (a regex search of domain_conf.c was done to assure
that all occurrences of hardcoded spaces were removed).
virDomainDiskSourceDefFormatInternal() is also called from
snapshot_conf.c, so two virBufferAdjustIndent() calls were temporarily
added around that call - those functions will have hardcoded spaces
removed in a separate patch.
This could cause some conflicts when backporting future changes to the
formatting functions to older branches, but fortunately the changes
are almost all trivial, so conflict resolution will be obvious.
All the data for getting the actual type is present in the snapshot
config. There is no need to have this function private to the qemu
driver and it will be re-used later in other parts of libvirt
Add support for specifying various types when doing snapshots. This will
later allow to do snapshots on network backed volumes. Disks of type
'volume' are not supported by snapshots (yet).
Also amend the test suite to check parsing of the various new disk
types that can now be specified.
Currently, during XML parsing, when a call to a FromString() function to
get an enum value fails, the error which is reported is either
VIR_ERR_CONFIG_UNSUPPORTED, VIR_ERR_INTERNAL_ERROR or VIR_ERR_XML_ERROR.
This commit makes such conversion failures consistently return
VIR_ERR_CONFIG_UNSUPPORTED.
When changing the parsing and formatting functions in commit
43f2ccdc73 I forgot to update the qemu
disk alignment function for snapshots that automatically adds snapshot
configs for disks that were not mentioned in the XML. The function
allocated a new disk snapshot definition but did not correctly
initialize the snapshot disk source type variable. This resulted into
the disks considered as block devices and invalid XML was generated.
Reported by John Ferlan.
Consider the following valid snapshot XML as the <driver> element is
allowed to be empty in the domainsnapshot.rng schema:
$ cat snap.xml
<domainsnapshot>
<disks>
<disk name='vda' snapshot='external'>
<source file='/tmp/foo'/>
<driver/>
</disk>
</disks>
</domainsnapshot>
produces the following error:
$ virsh snapshot-create domain snap.xml
error: internal error: unknown disk snapshot driver '(null)'
The driver type is parsed as NULL from the XML as the attribute is not
present and then directly used to produce the error message.
With this patch the attempt to parse the driver type is skipped if not
present to avoid changing the schema to forbid the empty driver element.
Disk source elements for snapshots were using separate code from our
config parser. As snapshots can be stored on more than just regular
files, we will need the universal parser to allow us to expose a variety
of snapshot disk targets. This patch reuses the config parsers and
formatters to do the job.
This initial support only changes the code without any visible XML
change.
'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can). But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).
Fix up remaining offenders in src/conf, and their fallout.
* src/conf/snapshot_conf.h (virDomainSnapshotAssignDef)
(virDomainSnapshotFindByName): Drop attempt at const.
* src/conf/interface_conf.h (virInterfaceObjIsActive)
(virInterfaceDefFormat): Use intended type.
(virInterfaceFindByMACString, virInterfaceFindByName)
(virInterfaceAssignDef, virInterfaceRemove): Drop attempt at
const.
* src/conf/network_conf.h (virNetworkObjIsActive)
(virNetworkDefFormat, virNetworkDefForwardIf)
(virNetworkDefGetIpByIndex, virNetworkIpDefPrefix)
(virNetworkIpDefNetmask): Use intended type.
(virNetworkFindByUUID, virNetworkFindByName, virNetworkAssignDef)
(virNetworkObjAssignDef, virNetworkRemoveInactive)
(virNetworkBridgeInUse, virNetworkSetBridgeName)
(virNetworkAllocateBridge): Drop attempt at const.
* src/conf/netdev_vlan_conf.h (virNetDevVlanFormat): Make
const-correct.
* src/conf/node_device_conf.h (virNodeDeviceHasCap)
(virNodeDeviceDefFormat): Use intended type.
(virNodeDeviceFindByName, virNodeDeviceFindBySysfsPath)
(virNodeDeviceAssignDef, virNodeDeviceObjRemove)
(virNodeDeviceGetParentHost): Drop attempt at const.
* src/conf/secret_conf.h (virSecretDefFormat): Use intended type.
* src/conf/snapshot_conf.c (virDomainSnapshotAssignDef)
(virDomainSnapshotFindByName): Fix fallout.
* src/conf/interface_conf.c (virInterfaceBridgeDefFormat)
(virInterfaceBondDefFormat, virInterfaceVlanDefFormat)
(virInterfaceProtocolDefFormat, virInterfaceDefDevFormat)
(virInterfaceDefFormat, virInterfaceFindByMACString)
(virInterfaceFindByName, virInterfaceAssignDef)
(virInterfaceRemove): Likewise.
* src/conf/network_conf.c
(VIR_ENUM_IMPL, virNetworkFindByName, virNetworkObjAssignDef)
(virNetworkAssignDef, virNetworkRemoveInactive)
(virNetworkDefGetIpByIndex, virNetworkIpDefPrefix)
(virNetworkIpDefNetmask, virNetworkDHCPHostDefParseXML)
(virNetworkIpDefFormat, virNetworkRouteDefFormat)
(virPortGroupDefFormat, virNetworkForwardNatDefFormat)
(virNetworkDefFormatInternal, virNetworkBridgeInUse)
(virNetworkAllocateBridge, virNetworkSetBridgeName)
(virNetworkDNSDefFormat, virNetworkDefFormat): Likewise.
* src/conf/netdev_vlan_conf.c (virNetDevVlanFormat): Likewise.
* src/conf/node_device_conf.c (virNodeDeviceHasCap)
(virNodeDeviceFindBySysfsPath, virNodeDeviceFindByName)
(virNodeDeviceAssignDef, virNodeDeviceObjRemove)
(virNodeDeviceDefFormat, virNodeDeviceGetParentHost): Likewise.
* src/conf/secret_conf.c (virSecretDefFormatUsage)
(virSecretDefFormat): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
The virDomainSnapshotDefParse method assigned to def->ndisks
before allocating def->disks. Thus if an OOM occurred, the
cleanup code would access out of bounds.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Just to reduce the indentation levels. Remove the unneeded
NULL check for disk->file, as virBufferEscapeString doesn't
print anything with NULL arguments.
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
This patch is the result of running:
for i in $(git ls-files | grep -v html | grep -v \.po$ ); do
sed -i -e "s/virDomainXMLConf/virDomainXMLOption/g" -e "s/xmlconf/xmlopt/g" $i
done
and a few manual tweaks.
The virCaps structure gathered a ton of irrelevant data over time that.
The original reason is that it was propagated to the XML parser
functions.
This patch aims to create a new data structure virDomainXMLConf that
will contain immutable data that are used by the XML parser. This will
allow two things we need:
1) Get rid of the stuff from virCaps
2) Allow us to add callbacks to check and add driver specific stuff
after domain XML is parsed.
This first attempt removes pointers to private data allocation functions
to this new structure and update all callers and function that require
them.
When a disk-only snapshot is requested the domain is treated as if it
was offline. This forbids to mix memory checkpoints with the DISK_ONLY
flag.
This patch improves the error message and mentions the restriction in
the virsh man page.
Relatively straight-forward. And since qemu was already using
VIR_DOMAIN_SNAPSHOT_FILTERS_ALL, with 6 different APIs all calling
into this common code, I've instantly added all 5 flags to 6 APIs.
* src/conf/snapshot_conf.h (VIR_DOMAIN_SNAPSHOT_FILTERS_ALL):
Enable new filters.
* src/conf/snapshot_conf.c (virDomainSnapshotObjListGetNames):
Prep the new flags.
(virDomainSnapshotObjListCopyNames): Actually do the filtering.
For disk snapshots, the user could request an external snapshot
but not supply a filename; later on, we would check this condition
and generate a suitable name if possible, or gracefully error out
when not possible (such as when the original file was a block
device). But unless we come up with a suitable way to generate
external memory file names, we have no later code point that was
checking for NULL, so we should forbid this up front.
* src/conf/snapshot_conf.c (virDomainSnapshotDefParseString):
Avoid NULL deref, since we don't generate names yet.
This patch adds a helper to determine if snapshots are external and uses
the helper to fix detection of those in snapshot deletion code.
Snapshots are external if they have an external memory image or if the
disk locations are external. As mixed snapshots are forbidden for now
we need to check just one disk to know.
There were not previous callers with require_match set to true.
I originally implemented this bool with the intent of supporting
ESX snapshot semantics, where the choice of internal vs. external
vs. non-checkpointable must be made at domain start, but as ESX
has not been wired up to use it yet, we might as well fix it to
work with our next qemu patch for now, and worry about any further
improvements (changing the bool to a flags argument) if the ESX
driver decides to use this function in the future.
* src/conf/snapshot_conf.c (virDomainSnapshotAlignDisks): Alter
logic when require_match is true to deal with new XML.
Each <domainsnapshot> can now contain an optional <memory>
element that describes how the VM state was handled, similar
to disk snapshots. The new element will always appear in
output; for back-compat, an input that lacks the element will
assume 'no' or 'internal' according to the domain state.
Along with this change, it is now possible to pass <disks> in
the XML for an offline snapshot; this also needs to be wired up
in a future patch, to make it possible to choose internal vs.
external on a per-disk basis for each disk in an offline domain.
At that point, using the --disk-only flag for an offline domain
will be able to work.
For some examples below, remember that qemu supports the
following snapshot actions:
qemu-img: offline external and internal disk
savevm: online internal VM and disk
migrate: online external VM
transaction: online external disk
=====
<domainsnapshot>
<memory snapshot='no'/>
...
</domainsnapshot>
implies that there is no VM state saved (mandatory for
offline and disk-only snapshots, not possible otherwise);
using qemu-img for offline domains and transaction for online.
=====
<domainsnapshot>
<memory snapshot='internal'/>
...
</domainsnapshot>
state is saved inside one of the disks (as in qemu's 'savevm'
system checkpoint implementation). If needed in the future,
we can also add an attribute pointing out _which_ disk saved
the internal state; maybe disk='vda'.
=====
<domainsnapshot>
<memory snapshot='external' file='/path/to/state'/>
...
</domainsnapshot>
This is not wired up yet, but future patches will allow this to
control a combination of 'virsh save /path/to/state' plus disk
snapshots from the same point in time.
=====
So for 1.0.1 (and later, as needed), I plan to implement this table
of combinations, with '*' designating new code and '+' designating
existing code reached through new combinations of xml and/or the
existing DISK_ONLY flag:
domain memory disk disk-only | result
-----------------------------------------
offline omit omit any | memory=no disk=int, via qemu-img
offline no omit any |+memory=no disk=int, via qemu-img
offline omit/no no any | invalid combination (nothing to snapshot)
offline omit/no int any |+memory=no disk=int, via qemu-img
offline omit/no ext any |*memory=no disk=ext, via qemu-img
offline int/ext any any | invalid combination (no memory to save)
online omit omit off | memory=int disk=int, via savevm
online omit omit on | memory=no disk=default, via transaction
online omit no/ext off | unsupported for now
online omit no on | invalid combination (nothing to snapshot)
online omit ext on | memory=no disk=ext, via transaction
online omit int off |+memory=int disk=int, via savevm
online omit int on | unsupported for now
online no omit any |+memory=no disk=default, via transaction
online no no any | invalid combination (nothing to snapshot)
online no int any | unsupported for now
online no ext any |+memory=no disk=ext, via transaction
online int/ext any on | invalid combination (disk-only vs. memory)
online int omit off |+memory=int disk=int, via savevm
online int no/ext off | unsupported for now
online int int off |+memory=int disk=int, via savevm
online ext omit off |*memory=ext disk=default, via migrate+trans
online ext no off |+memory=ext disk=no, via migrate
online ext int off | unsupported for now
online ext ext off |*memory=ext disk=ext, via migrate+transaction
* docs/schemas/domainsnapshot.rng (memory): New RNG element.
* docs/formatsnapshot.html.in: Document it.
* src/conf/snapshot_conf.h (virDomainSnapshotDef): New fields.
* src/conf/domain_conf.c (virDomainSnapshotDefFree)
(virDomainSnapshotDefParseString, virDomainSnapshotDefFormat):
Manage new fields.
* tests/domainsnapshotxml2xmltest.c: New test.
* tests/domainsnapshotxml2xmlin/*.xml: Update existing tests.
* tests/domainsnapshotxml2xmlout/*.xml: Likewise.
This is the last use of raw strings for disk formats throughout
the src/conf directory.
* src/conf/snapshot_conf.h (_virDomainSnapshotDiskDef): Store enum
rather than string for disk type.
* src/conf/snapshot_conf.c (virDomainSnapshotDiskDefClear)
(virDomainSnapshotDiskDefParseXML, virDomainSnapshotDefFormat):
Adjust users.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateSingleDiskActive): Likewise.
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
The name 'virDomainDiskSnapshot' didn't fit in with our normal
conventions of using a prefix hinting that it is related to a
virDomainSnapshotPtr. Also, a future patch will reuse the
enum for declaring where the VM memory is stored.
* src/conf/snapshot_conf.h (virDomainDiskSnapshot): Rename...
(virDomainSnapshotLocation): ...to this.
(_virDomainSnapshotDiskDef): Update clients.
* src/conf/domain_conf.h (_virDomainDiskDef): Likewise.
* src/libvirt_private.syms (domain_conf.h): Likewise.
* src/conf/domain_conf.c (virDomainDiskDefParseXML)
(virDomainDiskDefFormat): Likewise.
* src/conf/snapshot_conf.c: (virDomainSnapshotDiskDefParseXML)
(virDomainSnapshotAlignDisks, virDomainSnapshotDefFormat):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotCreateDiskActive, qemuDomainSnapshotCreateXML):
Likewise.
This has several benefits:
1. Future snapshot-related code has a definite place to go (and I
_will_ be adding some)
2. Snapshot errors now use the VIR_FROM_DOMAIN_SNAPSHOT error
classification, which has been underutilized (previously only in
libvirt.c)
* src/conf/domain_conf.h, domain_conf.c: Split...
* src/conf/snapshot_conf.h, snapshot_conf.c: ...into new files.
* src/Makefile.am (DOMAIN_CONF_SOURCES): Build new files.
* po/POTFILES.in: Mark new file for translation.
* src/vbox/vbox_tmpl.c: Update caller.
* src/esx/esx_driver.c: Likewise.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_domain.h: Likewise.
