Add higher level lock API for domain objects

To facilitate use of the locking plugins from hypervisor drivers,
introduce a higher level API for locking virDomainObjPtr instances.
In includes APIs targetted to VM startup, and hotplug/unplug

* src/Makefile.am: Add domain lock API
* src/locking/domain_lock.c, src/locking/domain_lock.h: High
  level API for domain locking
This commit is contained in:
Daniel P. Berrange 2011-01-24 12:16:30 +00:00
parent db98851c24
commit ad73a937ff
5 changed files with 360 additions and 1 deletions

View File

@ -96,7 +96,8 @@ DRIVER_SOURCES = \
libvirt.c libvirt_internal.h \
locking/lock_manager.c locking/lock_manager.h \
locking/lock_driver.h \
locking/lock_driver_nop.h locking/lock_driver_nop.c
locking/lock_driver_nop.h locking/lock_driver_nop.c \
locking/domain_lock.h locking/domain_lock.c
# XML configuration format handling sources

View File

@ -414,6 +414,17 @@ virDomainEventWatchdogNewFromDom;
virDomainEventWatchdogNewFromObj;
# domain_lock.h
virDomainLockProcessStart;
virDomainLockProcessInquire;
virDomainLockProcessPause;
virDomainLockProcessResume;
virDomainLockDiskAttach;
virDomainLockDiskDetach;
virDomainLockLeaseAttach;
virDomainLockLeaseDetach;
# domain_nwfilter.h
virDomainConfNWFilterInstantiate;
virDomainConfNWFilterRegister;

View File

@ -1,3 +1,10 @@
Using the Lock Manager APIs
===========================
This file describes how to use the lock manager APIs.
All the guest lifecycle sequences here have higher
level wrappers provided by the 'domain_lock.h' API,
which simplify thue usage
At libvirtd startup:

284
src/locking/domain_lock.c Normal file
View File

@ -0,0 +1,284 @@
/*
* domain_lock.c: Locking for domain lifecycle operations
*
* Copyright (C) 2010-2011 Red Hat, Inc.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <config.h>
#include <intprops.h>
#include "domain_lock.h"
#include "memory.h"
#include "uuid.h"
#include "virterror_internal.h"
#include "logging.h"
#define VIR_FROM_THIS VIR_FROM_LOCKING
static int virDomainLockManagerAddLease(virLockManagerPtr lock,
virDomainLeaseDefPtr lease)
{
unsigned int leaseFlags = 0;
virLockManagerParam lparams[] = {
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_STRING,
.key = "path",
.value = { .str = lease->path },
},
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_ULONG,
.key = "offset",
.value = { .ul = lease->offset },
},
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_STRING,
.key = "lockspace",
.value = { .str = lease->lockspace },
},
};
size_t nparams = ARRAY_CARDINALITY(lparams);
if (!lease->lockspace)
nparams--;
VIR_DEBUG("Add lease %s", lease->path);
if (virLockManagerAddResource(lock,
VIR_LOCK_MANAGER_RESOURCE_TYPE_LEASE,
lease->key,
nparams,
lparams,
leaseFlags) < 0) {
VIR_DEBUG("Failed to add lease %s", lease->path);
return -1;
}
return 0;
}
static int virDomainLockManagerAddDisk(virLockManagerPtr lock,
virDomainDiskDefPtr disk)
{
unsigned int diskFlags = 0;
if (!disk->src)
return 0;
if (!(disk->type == VIR_DOMAIN_DISK_TYPE_BLOCK ||
disk->type == VIR_DOMAIN_DISK_TYPE_FILE ||
disk->type == VIR_DOMAIN_DISK_TYPE_DIR))
return 0;
if (disk->readonly)
diskFlags |= VIR_LOCK_MANAGER_RESOURCE_READONLY;
if (disk->shared)
diskFlags |= VIR_LOCK_MANAGER_RESOURCE_SHARED;
VIR_DEBUG("Add disk %s", disk->src);
if (virLockManagerAddResource(lock,
VIR_LOCK_MANAGER_RESOURCE_TYPE_DISK,
disk->src,
0,
NULL,
diskFlags) < 0) {
VIR_DEBUG("Failed add disk %s", disk->src);
return -1;
}
return 0;
}
static virLockManagerPtr virDomainLockManagerNew(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
bool withResources)
{
virLockManagerPtr lock;
int i;
virLockManagerParam params[] = {
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_UUID,
.key = "uuid",
},
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_STRING,
.key = "name",
.value = { .str = dom->def->name },
},
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_UINT,
.key = "id",
.value = { .i = dom->def->id },
},
{ .type = VIR_LOCK_MANAGER_PARAM_TYPE_UINT,
.key = "pid",
.value = { .i = dom->pid },
},
};
VIR_DEBUG("plugin=%p dom=%p withResources=%d",
plugin, dom, withResources);
memcpy(params[0].value.uuid, dom->def->uuid, VIR_UUID_BUFLEN);
if (!(lock = virLockManagerNew(plugin,
VIR_LOCK_MANAGER_OBJECT_TYPE_DOMAIN,
ARRAY_CARDINALITY(params),
params,
0)))
goto error;
if (withResources) {
VIR_DEBUG("Adding leases");
for (i = 0 ; i < dom->def->nleases ; i++)
if (virDomainLockManagerAddLease(lock, dom->def->leases[i]) < 0)
goto error;
VIR_DEBUG("Adding disks");
for (i = 0 ; i < dom->def->ndisks ; i++)
if (virDomainLockManagerAddDisk(lock, dom->def->disks[i]) < 0)
goto error;
}
return lock;
error:
virLockManagerFree(lock);
return NULL;
}
int virDomainLockProcessStart(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
bool paused)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, true);
int ret;
if (paused)
ret = virLockManagerAcquire(lock, NULL, VIR_LOCK_MANAGER_ACQUIRE_REGISTER_ONLY);
else
ret = virLockManagerAcquire(lock, NULL, 0);
virLockManagerFree(lock);
return ret;
}
int virDomainLockProcessPause(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
char **state)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, true);
int ret = virLockManagerRelease(lock, state, 0);
virLockManagerFree(lock);
return ret;
}
int virDomainLockProcessResume(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
const char *state)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, true);
int ret = virLockManagerAcquire(lock, state, 0);
virLockManagerFree(lock);
return ret;
}
int virDomainLockProcessInquire(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
char **state)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, true);
int ret = virLockManagerInquire(lock, state, 0);
virLockManagerFree(lock);
return ret;
}
int virDomainLockDiskAttach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainDiskDefPtr disk)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, false);
int ret = -1;
if (virDomainLockManagerAddDisk(lock, disk) < 0)
goto cleanup;
if (virLockManagerAcquire(lock, NULL, 0) < 0)
goto cleanup;
cleanup:
virLockManagerFree(lock);
return ret;
}
int virDomainLockDiskDetach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainDiskDefPtr disk)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, false);
int ret = -1;
if (virDomainLockManagerAddDisk(lock, disk) < 0)
goto cleanup;
if (virLockManagerRelease(lock, NULL, 0) < 0)
goto cleanup;
cleanup:
virLockManagerFree(lock);
return ret;
}
int virDomainLockLeaseAttach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainLeaseDefPtr lease)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, false);
int ret = -1;
if (virDomainLockManagerAddLease(lock, lease) < 0)
goto cleanup;
if (virLockManagerAcquire(lock, NULL, 0) < 0)
goto cleanup;
cleanup:
virLockManagerFree(lock);
return ret;
}
int virDomainLockLeaseDetach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainLeaseDefPtr lease)
{
virLockManagerPtr lock = virDomainLockManagerNew(plugin, dom, false);
int ret = -1;
if (virDomainLockManagerAddLease(lock, lease) < 0)
goto cleanup;
if (virLockManagerRelease(lock, NULL, 0) < 0)
goto cleanup;
cleanup:
virLockManagerFree(lock);
return ret;
}

56
src/locking/domain_lock.h Normal file
View File

@ -0,0 +1,56 @@
/*
* domain_lock.c: Locking for domain lifecycle operations
*
* Copyright (C) 2010-2011 Red Hat, Inc.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef __VIR_DOMAIN_LOCK_H__
# define __VIR_DOMAIN_LOCK_H__
# include "internal.h"
# include "domain_conf.h"
# include "lock_manager.h"
int virDomainLockProcessStart(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
bool paused);
int virDomainLockProcessPause(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
char **state);
int virDomainLockProcessResume(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
const char *state);
int virDomainLockProcessInquire(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
char **state);
int virDomainLockDiskAttach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainDiskDefPtr disk);
int virDomainLockDiskDetach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainDiskDefPtr disk);
int virDomainLockLeaseAttach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainLeaseDefPtr lease);
int virDomainLockLeaseDetach(virLockManagerPluginPtr plugin,
virDomainObjPtr dom,
virDomainLeaseDefPtr lease);
#endif /* __VIR_DOMAIN_LOCK_H__ */