Commit Graph

11343 Commits

Author SHA1 Message Date
Viktor Mihajlovski
08842171d4 virNodeGetCPUMap: Implement virsh support.
- Added a new host command nodecpumap
- Added documentation

Example:
$ virsh nodecpumap
CPUs present:  8
CPUs online:   3
CPU map:       y-y-y---

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2012-10-23 18:48:06 -06:00
Viktor Mihajlovski
d39291d4c0 libvirt.h.in: Add new cpumap macro VIR_CPU_USED
New macro VIR_CPU_USED added to facilitate the interpretation of
cpu maps.
Further, hardened the other cpumap macros against invocations
like VIR_CPU_USE(cpumap + 1, cpu)

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2012-10-23 18:48:04 -06:00
Viktor Mihajlovski
d804d35fac virNodeGetCPUMap: Implement wire protocol.
- Defined the wire protocol format for virNodeGetCPUMap and its
  arguments
- Implemented remote method invocation (remoteNodeGetCPUMap)
- Implemented method dispatcher (remoteDispatchNodeGetCPUMap)

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2012-10-23 18:46:48 -06:00
Viktor Mihajlovski
7ecc1d814a virNodeGetCPUMap: Define public API.
Adding a new API to obtain information about the
host node's present, online and offline CPUs.

int virNodeGetCPUMap(virConnectPtr conn,
                     unsigned char **cpumap,
                     unsigned int *online,
                     unsigned int flags);

The function will return the number of CPUs present on the host
or -1 on failure;
If cpumap is non-NULL virNodeGetCPUMap will allocate an array
containing a bit map representation of the online CPUs. It's
the callers responsibility to deallocate cpumap using free().
If online is non-NULL, the variable pointed to will contain
the number of online host node CPUs.
The variable flags has been added to support future extensions
and must be set to 0.

Extend the driver structure by nodeGetCPUMap entry in support of the
new API virNodeGetCPUMap.
Added implementation of virNodeGetCPUMap to libvirt.c

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2012-10-23 18:46:47 -06:00
Eric Blake
5a2e1185bd header: declare node memory parameter handling earlier
Commit 12ad7435 added new functions (virNodeGetMemoryParameters,
virNodeSetMemoryParameters) into the section of the file reserved
for deprecated names.  Fix this by moving things earlier; split
into two patches to make git diff easier to read.

* include/libvirt/libvirt.h.in: Move virNodeGetMemoryParameters
and friends earlier, add a note to prevent relapse.
2012-10-23 14:32:46 -06:00
Eric Blake
86e78667b8 header: declare typed parameter handling earlier
Commit 12ad7435 added new functions (virNodeGetMemoryParameters,
virNodeSetMemoryParameters) into the section of the file reserved
for deprecated names.  Fix this by moving things earlier; split
into two patches to make git diff easier to read.

* include/libvirt/libvirt.h.in: Move virTypedParameter earlier.
2012-10-23 14:32:45 -06:00
Eric Blake
cf9bced084 build: improve FORTIFY_SOURCE usage
Based on this coreutils bug report, since coreutils copied what
libvirt had done:
https://lists.gnu.org/archive/html/bug-coreutils/2012-10/msg00121.html

* m4/virt-compile-warnings.m4 (LIBVIRT_COMPILE_WARNINGS): Allow
for user to pre-define _FORTIFY_SOURCE.
2012-10-23 14:00:32 -06:00
Kyle Mestery
2f3e2c0c43 qemu_migration: Transport OVS per-port data during live migration
Transport Open vSwitch per-port data during live
migration by using the utility functions
virNetDevOpenvswitchGetMigrateData() and
virNetDevOpenvswitchSetMigrateData().

Signed-off-by: Kyle Mestery <kmestery@cisco.com>
2012-10-23 15:26:04 -04:00
Kyle Mestery
f6a2f97eb9 openvswitch: Add utility functions for getting and setting Open vSwitch per-port data
Add utility functions for Open vSwitch to both save
per-port data before a live migration, and restore the
per-port data after a live migration.

Signed-off-by: Kyle Mestery <kmestery@cisco.com>
2012-10-23 15:26:04 -04:00
Kyle Mestery
694d0c520b qemu_migration: Add hooks to transport network data during migration
Add the ability for the Qemu V3 migration protocol to
include transporting network configuration. A generic
framework is proposed with this patch to allow for the
transfer of opaque data.

Signed-off-by: Kyle Mestery <kmestery@cisco.com>
Signed-off-by: Laine Stump <laine@laine.org>
2012-10-23 15:26:04 -04:00
Jim Fehlig
9785f2b6f2 Fix detection of Xen sysctl version 9
In commit 371ddc98, I mistakenly added the check for sysctl
version 9 after setting the hypercall version to 1, which will
fail with

error : xenHypervisorDoV1Op:967 : Unable to issue hypervisor
ioctl 3166208: Function not implemented

This check should be included along with the others that use
hypercall version 2.
2012-10-23 11:18:20 -06:00
Cole Robinson
767be8be72 selinux: Don't fail RestoreAll if file doesn't have a default label
When restoring selinux labels after a VM is stopped, any non-standard
path that doesn't have a default selinux label causes the process
to stop and exit early. This isn't really an error condition IMO.

Of course the selinux API could be erroring for some other reason
but hopefully that's rare enough to not need explicit handling.

Common example here is storing disk images in a non-standard location
like under /mnt.
2012-10-23 11:45:24 -04:00
Eric Blake
add633bdf9 build: print uids as unsigned
Reported by Michal Privoznik.

* src/security/security_dac.c (virSecurityDACGenLabel): Use
correct format.
2012-10-23 08:38:33 -06:00
Ján Tomko
9b704ab823 xml: omit domain name from comment if it contains double hyphen
We put a comment containing "virsh edit <domain_name>" at the start of
the XML. W3C recommendation forbids the use of "--" in comments [1] and
libvirt can't parse it either. This patch omits the domain name if it
contains a double hyphen.

[1] http://www.w3.org/TR/REC-xml/#sec-comments
2012-10-23 14:24:31 +02:00
Ján Tomko
b326765c80 storage: don't shadow global 'wait' declaration
Rename the 'wait' parameter to 'loop'.
This silences the warning:
storage/storage_backend.c:1348:34: error: declaration of 'wait' shadows
a global declaration [-Werror=shadow]
and fixes the build with -Werror.
--
Note: loop is pool backwards.
2012-10-23 13:56:59 +02:00
Christophe Fergeau
662f8a2ab3 Fix disabling of apparmor/selinux security drivers
When using --without-$name --without-secdriver-$name with $name being
selinux or apparmor, configure will fail saying that AppArmor/SELinux
development package must be installed.
This is caused by a small bug in --with-secdriver-$name handling in
configure.ac which treats --without-secdriver-$name when $name as if the
user had requested to enable $name when $name couldn't be detected on
the system.

This commit also makes sure the detection checks for disabled
secdrivers do not needlessly get run, especially as this could
cause an error as well in --with-$name --without-secdriver-$name
situations.
2012-10-23 08:56:03 +02:00
Eric Blake
6ee0e23744 maint: update to latest gnulib
* .gnulib: Update to latest, prior to freeze.
2012-10-22 20:25:44 -06:00
Eric Blake
33eaebe48e snapshot: sanity check when reusing file for snapshot
The snapshot code when reusing an existing file had hard-to-read
logic, as well as a missing sanity check: REUSE_EXT should require
the destination to already be present.

* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare): Require
destination on REUSE_EXT, rename variable for legibility.
2012-10-22 15:10:16 -06:00
Eric Blake
23a4df886d build: use correct printf types for uid/gid
Fixes a build failure on cygwin:
cc1: warnings being treated as errors
security/security_dac.c: In function 'virSecurityDACSetProcessLabel':
security/security_dac.c:862:5: error: format '%u' expects type 'unsigned int', but argument 7 has type 'uid_t' [-Wformat]
security/security_dac.c:862:5: error: format '%u' expects type 'unsigned int', but argument 8 has type 'gid_t' [-Wformat]

* src/security/security_dac.c (virSecurityDACSetProcessLabel)
(virSecurityDACGenLabel): Use proper casts.
2012-10-22 14:41:00 -06:00
Cole Robinson
2e99fa0385 Remove a couple duplicates from AUTHORS.in 2012-10-22 16:19:38 -04:00
Cole Robinson
77eff5eeb2 storage: Don't do wait loops from VolLookupByPath
virStorageVolLookupByPath is an API call that virt-manager uses
quite a bit when dealing with storage. This call use BackendStablePath
which has several usleep() heuristics that can be tripped up
and hang virt-manager for a while.

Current example: an empty mpath pool pointing to /dev/mapper makes
_any_ calls to virStorageVolLookupByPath take 5 seconds.

The sleep heuristics are actually only needed in certain cases
when we are waiting for new storage to appear, so let's skip the
timeout steps when calling from LookupByPath.
2012-10-22 16:15:12 -04:00
Cole Robinson
18d0632dc7 spec: Fix multilib issue with systemtap tapsets
If building on a 64bit host, rename the affected tapsets to <name>-64.stp.
This is similar to what the python package does in fedora.

https://bugzilla.redhat.com/show_bug.cgi?id=831425
2012-10-22 16:15:12 -04:00
Cole Robinson
7146d41634 docs: Fix installation of internals/*.html
We were just installing them in the top level html directory, which
broke navigation and overwrote other pages.

https://bugzilla.redhat.com/show_bug.cgi?id=837825
2012-10-22 16:15:12 -04:00
Cole Robinson
e58dfad4a4 qemu: Don't use -enable-nesting with qemu 1.2.0+
Since the option doesn't exist. Fixes booting with
cpu mode='host-model' and qemu 1.2.0
2012-10-22 16:15:12 -04:00
Doug Goldstein
2da776b1d6 qemu: Don't blindly assume VNC is supported
Currently it's assumed that qemu always supports VNC, however it is
definitely possible to compile qemu without VNC support so we should at
the very least check for it and handle that correctly.
2012-10-22 23:16:17 +08:00
Doug Goldstein
8be88034bf test: Don't assume VNC is always available
Several tests assume that VNC is always available and include it in
their configs and the expected command line. The tests have nothing to
do with graphics display so they shouldn't rely on VNC.
2012-10-22 23:16:11 +08:00
Eric Blake
d9d77bfa80 storage: let format probing work on root-squash NFS
Yet another instance of where using plain open() mishandles files
that live on root-squash NFS, and where improving the API can
improve the chance of a successful probe.

* src/util/storage_file.h (virStorageFileProbeFormat): Alter
signature.
* src/util/storage_file.c (virStorageFileProbeFormat): Use better
method for opening file.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Update caller.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
2012-10-22 09:04:57 -06:00
Osier Yang
e0ad466983 virsh: Fix segfault of snapshot-list
'snaps' is used after free()'ed.
2012-10-22 22:52:05 +08:00
Ján Tomko
b6ab7a067f migrate: v2: use VIR_DOMAIN_XML_MIGRATABLE when available
In v2 migration protocol, XML is obtained by calling domainGetXMLDesc.
This includes the default USB controller in XML, which breaks migration
to older libvirt (before 0.9.2).

Commit 409b5f5495
    qemu: Emit compatible XML when migrating a domain
only fixed this for v3 migration.

This patch uses the new VIR_DOMAIN_XML_MIGRATABLE flag (detected by
VIR_DRV_FEATURE_XML_MIGRATABLE) to obtain XML without the default controller,
enabling backward v2 migration.
2012-10-22 10:48:50 +02:00
Michal Privoznik
508451e4ad qemu: set seamless migration capability
As we switched to setting capabilities based on QMP communication,
qemu seamless-migration capability was not set. In the -help output
this knob is called seamless-migration=[on|off]. The equivalent in
QMP world is SPICE_MIGRATE_COMPLETED event (qemu upstream commit
2fdd16e2).
2012-10-22 10:09:47 +02:00
Osier Yang
b0f1ba47dd qemu: Fix the unused parameter which causes the build failure 2012-10-22 15:51:13 +08:00
Osier Yang
5828080f71 qemu: Cleanup the unused 'nodeinfo'
"nodeinfo" is not used in these two functions, and it's waste
of goto in qemuProcessSetEmulatorAffinites
2012-10-22 15:12:57 +08:00
Cole Robinson
2143ced7f5 docs: virsh: clarify behavior of send-key
https://bugzilla.redhat.com/show_bug.cgi?id=860004
2012-10-21 13:21:50 -04:00
Cole Robinson
b62f9b99dd Log parameters passed to virFileMakePath 2012-10-21 13:21:50 -04:00
Cole Robinson
7fcf8d9d69 Log file name passed to virConfReadFile 2012-10-21 13:21:50 -04:00
Cole Robinson
fe772f24a6 daemon: Avoid 'Could not find keytab file' in syslog
On F17 at least, every time libvirtd starts we get this in syslog:

libvirtd: Could not find keytab file: /etc/libvirt/krb5.tab: No such file or directory

This comes from cyrus-sasl, and happens regardless of whether the
gssapi plugin is requested, which is what actually uses
/etc/libvirt/krb5.tab.

While cyrus-sasl shouldn't complain, we can easily make it shut up by
commenting out the keytab value by default.

Also update the keytab comment to the more modern one from qemu's
sasl config file.
2012-10-21 13:21:07 -04:00
Laine Stump
6f8a8b30c9 network: don't allow multiple default portgroups
This resolves: https://bugzilla.redhat.com/show_bug.cgi?id=868483

virNetworkUpdate, virNetworkDefine, and virNetworkCreate all three
allow network definitions to contain multiple <portgroup> elements
with default='yes'. Only a single default portgroup should be allowed
for each network.

This patch updates networkValidate() (called by both
virNetworkCreate() and virNetworkDefine()) and
virNetworkDefUpdatePortGroup (called by virNetworkUpdate() to not
allow multiple default portgroups.
2012-10-20 21:29:19 -04:00
Laine Stump
1cb1f9dabf network: always create dnsmasq hosts and addnhosts files, even if empty
This fixes the problem reported in:

  https://bugzilla.redhat.com/show_bug.cgi?id=868389

Previously, the dnsmasq hosts file (used for static dhcp entries, and
addnhosts file (used for additional dns host entries) were only
created/referenced on the dnsmasq commandline if there was something
to put in them at the time the network was started. Once we can update
a network definition while it's active (which is now possible with
virNetworkUpdate), this is no longer a valid strategy - if there were
0 dhcp static hosts (resulting in no reference to the hosts file on the
commandline), then one was later added, the commandline wouldn't have
linked dnsmasq up to the file, so even though we create it, dnsmasq
doesn't pay any attention.

The solution is to just always create these files and reference them
on the dnsmasq commandline (almost always, anyway). That way dnsmasq
can notice when a new entry is added at runtime (a SIGHUP is sent to
dnsmasq by virNetworkUdpate whenever a host entry is added or removed)

The exception to this is that the dhcp static hosts file isn't created
if there are no lease ranges *and* no static hosts. This is because in
this case dnsmasq won't be setup to listen for dhcp requests anyway -
in that case, if the count of dhcp hosts goes from 0 to 1, dnsmasq
will need to be restarted anyway (to get it listening on the dhcp
port). Likewise, if the dhcp hosts count goes from 1 to 0 (and there
are no dhcp ranges) we need to restart dnsmasq so that it will stop
listening on port 67. These special situations are handled in the
bridge driver's networkUpdate() by checking for ((bool)
nranges||nhosts) both before and after the update, and triggering a
dnsmasq restart if the before and after don't match.
2012-10-20 21:29:19 -04:00
Laine Stump
78fab2770b network: free/null newDef if network fails to start
https://bugzilla.redhat.com/show_bug.cgi?id=866364

pointed out a crash due to virNetworkObjAssignDef free'ing
network->newDef without NULLing it afterward. A fix for this is in
upstream commit b7e9202401. While the
NULLing of newDef was a legitimate fix, newDef should have already
been empty (NULL) anyway (as indicated in the comment that was deleted
by that commit).

The reason that newDef had a non-NULL value (i.e. the root cause) was
that networkStartNetwork() had failed after populating
network->newDef, but then neglected to free/NULL newDef in the
cleanup.

(A bit of background here: network->newDef should contain the
persistent config of a network when a network is active (and of course
only when it is persisten), and NULL at all other times. There is also
a network->def which should contain the persistent definition of the
network when it is inactive, and the current live state at all other
times. The idea is that you can make changes to network->newDef which
will take effect the next time the network is restarted, but won't
mess with the current state of the network (virDomainObj has a similar
pair of virDomainDefs that behave in the same fashion). Personally I
think there should be a network->live and network->config, and the
location of the persistent config should *always* be in
network->config, but that's for a later cleanup).

Since I love things to be symmetric, I created a new function called
virNetworkObjUnsetDefTransient(), which reverses the effects of
virNetworkObjSetDefTransient(). I don't really like the name of the
new function, but then I also didn't really like the name of the old
one either (it's just named that way to match a similar function in
the domain conf code).
2012-10-20 02:43:16 -04:00
Eric Blake
a172dfbe2e blockjob: avoid segv on early error
Gcc with optimization warns:
../../src/qemu/qemu_driver.c: In function 'qemuDomainBlockCommit':
../../src/qemu/qemu_driver.c:12813:46: error: 'disk' may be used uninitialized in this function [-Werror=maybe-uninitialized]
../../src/qemu/qemu_driver.c:12698:25: note: 'disk' was declared here
cc1: all warnings being treated as errors

so obviously I had only been testing with optimization off.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Guard cleanup.
2012-10-19 21:17:00 -06:00
Eric Blake
2e43cb8e90 blockjob: properly label disks for qemu block-commit
I finally have all the pieces in place to perform a block-commit with
SELinux enforcing.  There's still missing cleanup work when the commit
completes, but doing that requires tracking both the backing chain and
the base and top files within that chain in domain XML across libvirtd
restarts.  Furthermore, from a security standpoint, once you have
granted access, you must assume any damage that can be done will be
done; later revoking access is nice to minimize the window of damage,
but less important as it does not affect the fact that damage can be
done in the first place.  Therefore, deferring the revoke efforts until
we have better XML tracking of what chain operations are in effect,
including across a libvirtd restart, is reasonable.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Label disks as
needed.
(qemuDomainPrepareDiskChainElement): Cast away const.
2012-10-19 17:56:39 -06:00
Eric Blake
35a2f5bc52 blockjob: refactor qemu disk chain permission grants
Previously, snapshot code did its own permission granting (lock
manager, cgroup device controller, and security manager labeling)
inline.  But now that we are adding block-commit and block-copy
which also have to change permissions, it's better to reuse
common code for the task.  While snapshot should fall back to
no access if read-write access failed, block-commit will want to
fall back to read-only access.  The common code doesn't know
whether failure to grant read-write access should revert to no
access (snapshot, block-copy) or read-only access (block-commit).
This code can also be used to revoke access to unused files after
block-pull.

It might be nice to clean things up in a future patch by adding
new functions to the lock manager, cgroup manager, and security
manager that takes a single file name and applies context of a
disk to that file, rather than the current semantics of applying
context to the entire chain already associated to a disk.  That
way, we could avoid the games this patch plays of temporarily
swapping out the disk->src and related fields of the disk.  But
that would involve more code changes, so this patch really is
the smallest hack for doing the necessary work; besides, this
patch is more or less code motion (the hack was already employed
by the snapshot creation code, we are just making it reusable).

* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive): Refactor labeling hacks...
(qemuDomainPrepareDiskChainElement): ...into new function.
2012-10-19 17:49:06 -06:00
Eric Blake
0a220e2225 blockjob: implement shallow commit flag in qemu
Now that we can crawl the chain of backing files, we can do
argument validation and implement the 'shallow' flag.  In
testing this, I discovered that it can be handy to pass the
shallow flag and an explicit base, as a means of validating
that the base is indeed the file we expected.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): Crawl through
chain to implement shallow flag.
* src/libvirt.c (virDomainBlockCommit): Relax API.
2012-10-19 17:35:11 -06:00
Eric Blake
2cbc1fd892 blockjob: wire up online qemu block-commit
This is the bare minimum to kick off a block commit.  In particular,
flags support is missing (shallow requires us to crawl the backing
chain to determine the file name to pass to the qemu monitor command;
delete requires us to track what needs to be deleted at the time
the completion event fires).  Also, we are relying on qemu to do
error checking (such as validating 'top' and 'base' as being members
of the backing chain), including the fact that the current qemu code
does not support committing the active layer (although it is still
planned to add that before qemu 1.3).  Since the active layer won't
change, we have it easy and do not have to alter the domain XML.
Additionally, this will fail if SELinux is enforcing, because we fail
to grant qemu proper read/write access to the files it will modify.

* src/qemu/qemu_driver.c (qemuDomainBlockCommit): New function.
(qemuDriver): Register it.
2012-10-19 17:35:11 -06:00
Eric Blake
3f38c7e3a9 blockjob: manage qemu block-commit monitor command
qemu 1.3 will be adding a 'block-commit' monitor command, per
qemu.git commit ed61fc1.  It matches nicely to the libvirt API
virDomainBlockCommit.

* src/qemu/qemu_capabilities.h (QEMU_CAPS_BLOCK_COMMIT): New bit.
* src/qemu/qemu_capabilities.c (qemuCapsProbeQMPCommands): Set it.
* src/qemu/qemu_monitor.h (qemuMonitorBlockCommit): New prototype.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockCommit):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorBlockCommit): Implement it.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockCommit):
Likewise.
(qemuMonitorJSONHandleBlockJobImpl)
(qemuMonitorJSONGetBlockJobInfoOne): Handle new event type.
2012-10-19 17:35:11 -06:00
Eric Blake
67aea3fb78 blockjob: remove unused parameters after previous patch
Minor cleanup made possible by previous simplifications.

* src/qemu/qemu_cgroup.h (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup): Alter signature.
* src/qemu/qemu_cgroup.c (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup, qemuSetupCgroup): Update all uses.
* src/qemu/qemu_hotplug.c (qemuDomainDetachPciDiskDevice)
(qemuDomainDetachDiskDevice): Likewise.
* src/qemu/qemu_driver.c (qemuDomainAttachDeviceDiskLive)
(qemuDomainChangeDiskMediaLive)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive): Likewise.
2012-10-19 17:35:11 -06:00
Eric Blake
38c4a9cc40 storage: use cache to walk backing chain
We used to walk the backing file chain at least twice per disk,
once to set up cgroup device whitelisting, and once to set up
security labeling.  Rather than walk the chain every iteration,
which possibly includes calls to fork() in order to open root-squashed
NFS files, we can exploit the cache of the previous patch.

* src/conf/domain_conf.h (virDomainDiskDefForeachPath): Alter
signature.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Require caller
to supply backing chain via disk, if recursion is desired.
* src/security/security_dac.c
(virSecurityDACSetSecurityImageLabel): Adjust caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityImageLabel): Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup): Likewise.
(qemuSetupCgroup): Pre-populate chain.
2012-10-19 17:35:11 -06:00
Eric Blake
4d34c92947 storage: cache backing chain while qemu domain is live
Technically, we should not be re-probing any file that qemu might
be currently writing to.  As such, we should cache the backing
file chain prior to starting qemu.  This patch adds the cache,
but does not use it until the next patch.

Ultimately, we want to also store the chain in domain XML, so that
it is remembered across libvirtd restarts, and so that the only
kosher way to modify the backing chain of an offline domain will be
through libvirt API calls, but we aren't there yet.  So for now, we
merely invalidate the cache any time we do a live operation that
alters the chain (block-pull, block-commit, external disk snapshot),
as well as tear down the cache when the domain is not running.

* src/conf/domain_conf.h (_virDomainDiskDef): New field.
* src/conf/domain_conf.c (virDomainDiskDefFree): Clean new field.
* src/qemu/qemu_domain.h (qemuDomainDetermineDiskChain): New
prototype.
* src/qemu/qemu_domain.c (qemuDomainDetermineDiskChain): New
function.
* src/qemu/qemu_driver.c (qemuDomainAttachDeviceDiskLive)
(qemuDomainChangeDiskMediaLive): Pre-populate chain.
(qemuDomainSnapshotCreateSingleDiskActive): Uncache chain before
snapshot.
* src/qemu/qemu_process.c (qemuProcessHandleBlockJob): Update
chain after block pull.
2012-10-19 17:35:10 -06:00
Eric Blake
5eaf605447 storage: make it easier to find file within chain
In order to temporarily label files read/write during a commit
operation, we need to crawl the backing chain and find the absolute
file name that needs labeling in the first place, as well as the
name of the file that owns the backing file.

* src/util/storage_file.c (virStorageFileChainLookup): New
function.
* src/util/storage_file.h: Declare it.
* src/libvirt_private.syms (storage_file.h): Export it.
2012-10-19 17:35:10 -06:00
Eric Blake
82507838e0 storage: remember relative names in backing chain
In order to search for a backing file name as literally present
in a chain, we need to remember if the chain had relative names.
Also, searching for absolute names is easier if we only have
to canonicalize once, rather than on every iteration.

* src/util/storage_file.h (_virStorageFileMetadata): Add field.
* src/util/storage_file.c (virStorageFileGetMetadataFromBuf):
(virStorageFileFreeMetadata): Manage it
(absolutePathFromBaseFile): Store absolute names in canonical form.
2012-10-19 17:35:10 -06:00