libvirt/src/libxl/libxl_domain.h
Jim Fehlig fa58f571ee libxl: Add lock process indicator to libxlDomainObjPrivate object
The libvirt libxl driver has no access to FDs associated with VM disks.
The disks are opened by libxl.so and any related FDs are not exposed to
applications. The prevents using virtlockd's auto-release feature to
release locks when the FD is closed. Acquiring and releasing locks is
explicitly handled by the libxl driver.

The current logic is structured such that locks are acquired in
libxlDomainStart and released in libxlDomainCleanup. This works well
except for migration, where the locks must be released on the source
host before the domain can be started on the destination host, but the
domain cannot be cleaned up until the migration confirmation stage.
When libxlDomainCleanup if finally called in the confirm stage, locks
are again released resulting in confusing errors from virtlockd and
libvirtd

virtlockd[8095]: resource busy: Lockspace resource 'xxxxxx' is not locked
libvirtd[8050]: resource busy: Lockspace resource 'xxxxxx' is not locked
libvirtd[8050]: Unable to release lease on testvm

The error is also encountered in some error cases, e.g. when
libxlDomainStart fails before acquiring locks and libxlDomainCleanup
is still used for cleanup.

In lieu of a mechanism to check if a lock has been acquired, this patch
takes an easy approach to fixing the unnecessary lock releases by adding
an indicator to the libxlDomainPrivate object that can be set when the
lock is acquired and cleared when the lock is released. libxlDomainCleanup
can then skip releasing the lock in cases where it was previously released
or never acquired in the first place.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-02-23 17:55:19 -07:00

160 lines
5.0 KiB
C

/*
* libxl_domain.h: libxl domain object private state
*
* Copyright (C) 2011-2014 SUSE LINUX Products GmbH, Nuernberg, Germany.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <libxl.h>
#include "domain_conf.h"
#include "libxl_conf.h"
#include "virchrdev.h"
#include "virenum.h"
#define JOB_MASK(job) (job == 0 ? 0 : 1 << (job - 1))
#define DEFAULT_JOB_MASK \
(JOB_MASK(LIBXL_JOB_DESTROY) | \
JOB_MASK(LIBXL_JOB_ABORT))
/* Only 1 job is allowed at any time
* A job includes *all* libxl.so api, even those just querying
* information, not merely actions */
enum libxlDomainJob {
LIBXL_JOB_NONE = 0, /* Always set to 0 for easy if (jobActive) conditions */
LIBXL_JOB_QUERY, /* Doesn't change any state */
LIBXL_JOB_DESTROY, /* Destroys the domain (cannot be masked out) */
LIBXL_JOB_MODIFY, /* May change state */
LIBXL_JOB_LAST
};
VIR_ENUM_DECL(libxlDomainJob);
struct libxlDomainJobObj {
virCond cond; /* Use to coordinate jobs */
enum libxlDomainJob active; /* Currently running job */
int owner; /* Thread which set current job */
unsigned long long started; /* When the job started */
virDomainJobInfoPtr current; /* Statistics for the current job */
};
typedef struct _libxlDomainObjPrivate libxlDomainObjPrivate;
typedef libxlDomainObjPrivate *libxlDomainObjPrivatePtr;
struct _libxlDomainObjPrivate {
virObjectLockable parent;
/* console */
virChrdevsPtr devs;
libxl_evgen_domain_death *deathW;
/* Flag to indicate the upcoming LIBXL_EVENT_TYPE_DOMAIN_DEATH is caused
* by libvirt and should not be handled separately */
bool ignoreDeathEvent;
virThreadPtr migrationDstReceiveThr;
unsigned short migrationPort;
char *lockState;
bool lockProcessRunning;
struct libxlDomainJobObj job;
bool hookRun; /* true if there was a hook run over this domain */
};
extern virDomainXMLPrivateDataCallbacks libxlDomainXMLPrivateDataCallbacks;
extern virDomainDefParserConfig libxlDomainDefParserConfig;
extern virXMLNamespace libxlDriverDomainXMLNamespace;
extern const struct libxl_event_hooks ev_hooks;
int
libxlDomainObjPrivateInitCtx(virDomainObjPtr vm);
int
libxlDomainObjBeginJob(libxlDriverPrivatePtr driver,
virDomainObjPtr obj,
enum libxlDomainJob job)
G_GNUC_WARN_UNUSED_RESULT;
void
libxlDomainObjEndJob(libxlDriverPrivatePtr driver,
virDomainObjPtr obj);
int
libxlDomainJobUpdateTime(struct libxlDomainJobObj *job)
G_GNUC_WARN_UNUSED_RESULT;
char *
libxlDomainManagedSavePath(libxlDriverPrivatePtr driver,
virDomainObjPtr vm);
int
libxlDomainSaveImageOpen(libxlDriverPrivatePtr driver,
libxlDriverConfigPtr cfg,
const char *from,
virDomainDefPtr *ret_def,
libxlSavefileHeaderPtr ret_hdr)
ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(5);
int
libxlDomainDestroyInternal(libxlDriverPrivatePtr driver,
virDomainObjPtr vm);
void
libxlDomainCleanup(libxlDriverPrivatePtr driver,
virDomainObjPtr vm);
/*
* Note: Xen 4.3 removed the const from the event handler signature.
* Detect which signature to use based on
* LIBXL_HAVE_NONCONST_EVENT_OCCURS_EVENT_ARG.
*/
#ifdef LIBXL_HAVE_NONCONST_EVENT_OCCURS_EVENT_ARG
# define VIR_LIBXL_EVENT_CONST /* empty */
#else
# define VIR_LIBXL_EVENT_CONST const
#endif
void
libxlDomainEventHandler(void *data,
VIR_LIBXL_EVENT_CONST libxl_event *event);
int
libxlDomainAutoCoreDump(libxlDriverPrivatePtr driver,
virDomainObjPtr vm);
int
libxlDomainSetVcpuAffinities(libxlDriverPrivatePtr driver,
virDomainObjPtr vm);
int
libxlDomainStartNew(libxlDriverPrivatePtr driver,
virDomainObjPtr vm,
bool start_paused);
int
libxlDomainStartRestore(libxlDriverPrivatePtr driver,
virDomainObjPtr vm,
bool start_paused,
int restore_fd,
uint32_t restore_ver);
bool
libxlDomainDefCheckABIStability(libxlDriverPrivatePtr driver,
virDomainDefPtr src,
virDomainDefPtr dst);