libvirt/src/xen/xen_inotify.c
2010-04-06 01:46:42 +02:00

492 lines
15 KiB
C

/*
* xen_inofify.c: Xen notification of xml file activity in the
* following dirs:
* /etc/xen
* /var/lib/xend/domains
*
* Copyright (C) 2010 Red Hat, Inc.
* Copyright (C) 2008 VirtualIron
*
* 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
*
* Author: Ben Guthro
*/
#include <config.h>
#include <dirent.h>
#include <sys/inotify.h>
#include "virterror_internal.h"
#include "datatypes.h"
#include "driver.h"
#include "memory.h"
#include "event.h"
#include "xen_driver.h"
#include "conf.h"
#include "domain_conf.h"
#include "xen_inotify.h"
#include "xend_internal.h"
#include "logging.h"
#include "uuid.h"
#include "xm_internal.h" /* for xenXMDomainConfigParse */
#define VIR_FROM_THIS VIR_FROM_XEN_INOTIFY
#define virXenInotifyError(code, ...) \
virReportErrorHelper(NULL, VIR_FROM_XEN_INOTIFY, code, __FILE__, \
__FUNCTION__, __LINE__, __VA_ARGS__)
struct xenUnifiedDriver xenInotifyDriver = {
xenInotifyOpen, /* open */
xenInotifyClose, /* close */
NULL, /* version */
NULL, /* hostname */
NULL, /* nodeGetInfo */
NULL, /* getCapabilities */
NULL, /* listDomains */
NULL, /* numOfDomains */
NULL, /* domainCreateLinux */
NULL, /* domainSuspend */
NULL, /* domainResume */
NULL, /* domainShutdown */
NULL, /* domainReboot */
NULL, /* domainDestroy */
NULL, /* domainGetOSType */
NULL, /* domainGetMaxMemory */
NULL, /* domainSetMaxMemory */
NULL, /* domainSetMemory */
NULL, /* domainGetInfo */
NULL, /* domainSave */
NULL, /* domainRestore */
NULL, /* domainCoreDump */
NULL, /* domainSetVcpus */
NULL, /* domainPinVcpu */
NULL, /* domainGetVcpus */
NULL, /* domainGetMaxVcpus */
NULL, /* listDefinedDomains */
NULL, /* numOfDefinedDomains */
NULL, /* domainCreate */
NULL, /* domainDefineXML */
NULL, /* domainUndefine */
NULL, /* domainAttachDeviceFlags */
NULL, /* domainDetachDeviceFlags */
NULL, /* domainUpdateDeviceFlags */
NULL, /* domainGetAutostart */
NULL, /* domainSetAutostart */
NULL, /* domainGetSchedulerType */
NULL, /* domainGetSchedulerParameters */
NULL, /* domainSetSchedulerParameters */
};
static int
xenInotifyXenCacheLookup(virConnectPtr conn,
const char *filename,
char **name, unsigned char *uuid) {
xenUnifiedPrivatePtr priv = conn->privateData;
xenXMConfCachePtr entry;
if (!(entry = virHashLookup(priv->configCache, filename))) {
DEBUG("No config found for %s", filename);
return -1;
}
*name = strdup(entry->def->name);
memcpy(uuid, entry->def->uuid, VIR_UUID_BUFLEN);
if (!*name) {
DEBUG0("Error getting dom from def");
virReportOOMError();
return -1;
}
return 0;
}
static int
xenInotifyXendDomainsDirLookup(virConnectPtr conn, const char *filename,
char **name, unsigned char *uuid) {
int i;
virDomainPtr dom;
const char *uuid_str;
unsigned char rawuuid[VIR_UUID_BUFLEN];
xenUnifiedPrivatePtr priv = conn->privateData;
/* xend is managing domains. we will get
* a filename in the manner:
* /var/lib/xend/domains/<uuid>/
*/
uuid_str = filename + strlen(XEND_DOMAINS_DIR) + 1;
if (virUUIDParse(uuid_str, rawuuid) < 0) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
_("parsing uuid %s"), uuid_str);
return -1;
}
/* call directly into xend here, as driver may not yet
be set during open while we are building our
initial list of domains */
DEBUG("Looking for dom with uuid: %s", uuid_str);
/* XXX Should not have to go via a virDomainPtr obj instance */
if(!(dom = xenDaemonLookupByUUID(conn, rawuuid))) {
/* If we are here, the domain has gone away.
search for, and create a domain from the stored
list info */
for (i = 0 ; i < priv->configInfoList->count ; i++) {
if (!memcmp(rawuuid, priv->configInfoList->doms[i]->uuid, VIR_UUID_BUFLEN)) {
*name = strdup(priv->configInfoList->doms[i]->name);
if (!*name) {
virReportOOMError();
return -1;
}
memcpy(uuid, priv->configInfoList->doms[i]->uuid, VIR_UUID_BUFLEN);
DEBUG0("Found dom on list");
return 0;
}
}
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("finding dom on config list"));
return -1;
}
if (!(*name = strdup(dom->name))) {
virReportOOMError();
return -1;
}
memcpy(uuid, dom->uuid, VIR_UUID_BUFLEN);
virDomainFree(dom);
/* succeeded too find domain by uuid */
return 0;
}
static int
xenInotifyDomainLookup(virConnectPtr conn,
const char *filename,
char **name, unsigned char *uuid) {
xenUnifiedPrivatePtr priv = conn->privateData;
if (priv->useXenConfigCache)
return xenInotifyXenCacheLookup(conn, filename, name, uuid);
else
return xenInotifyXendDomainsDirLookup(conn, filename, name, uuid);
}
static virDomainEventPtr
xenInotifyDomainEventFromFile(virConnectPtr conn,
const char *filename,
int type, int detail) {
virDomainEventPtr event;
char *name = NULL;
unsigned char uuid[VIR_UUID_BUFLEN];
if (xenInotifyDomainLookup(conn, filename, &name, uuid) < 0)
return NULL;
event = virDomainEventNew(-1, name, uuid, type, detail);
VIR_FREE(name);
return event;
}
static int
xenInotifyXendDomainsDirRemoveEntry(virConnectPtr conn,
const char *fname) {
xenUnifiedPrivatePtr priv = conn->privateData;
const char *uuidstr = fname + strlen(XEND_DOMAINS_DIR) + 1;
unsigned char uuid[VIR_UUID_BUFLEN];
int i;
if (virUUIDParse(uuidstr, uuid) < 0) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
_("parsing uuid %s"), uuidstr);
return -1;
}
/* match and remove on uuid */
for (i = 0 ; i < priv->configInfoList->count ; i++) {
if (!memcmp(uuid, priv->configInfoList->doms[i]->uuid, VIR_UUID_BUFLEN)) {
VIR_FREE(priv->configInfoList->doms[i]->name);
VIR_FREE(priv->configInfoList->doms[i]);
if (i < (priv->configInfoList->count - 1))
memmove(priv->configInfoList->doms + i,
priv->configInfoList->doms + i + 1,
sizeof(*(priv->configInfoList->doms)) *
(priv->configInfoList->count - (i + 1)));
if (VIR_REALLOC_N(priv->configInfoList->doms,
priv->configInfoList->count - 1) < 0) {
; /* Failure to reduce memory allocation isn't fatal */
}
priv->configInfoList->count--;
return 0;
}
}
return -1;
}
static int
xenInotifyXendDomainsDirAddEntry(virConnectPtr conn,
const char *fname) {
char *name = NULL;
unsigned char uuid[VIR_UUID_BUFLEN];
xenUnifiedPrivatePtr priv = conn->privateData;
if (xenInotifyDomainLookup(conn, fname, &name, uuid) < 0) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("Error looking up domain"));
return -1;
}
if (xenUnifiedAddDomainInfo(priv->configInfoList,
-1, name, uuid) < 0) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("Error adding file to config cache"));
VIR_FREE(name);
return -1;
}
VIR_FREE(name);
return 0;
}
static int
xenInotifyRemoveDomainConfigInfo(virConnectPtr conn,
const char *fname) {
xenUnifiedPrivatePtr priv = conn->privateData;
return priv->useXenConfigCache ?
xenXMConfigCacheRemoveFile(conn, fname) :
xenInotifyXendDomainsDirRemoveEntry(conn, fname);
}
static int
xenInotifyAddDomainConfigInfo(virConnectPtr conn,
const char *fname) {
xenUnifiedPrivatePtr priv = conn->privateData;
return priv->useXenConfigCache ?
xenXMConfigCacheAddFile(conn, fname) :
xenInotifyXendDomainsDirAddEntry(conn, fname);
}
static void
xenInotifyEvent(int watch ATTRIBUTE_UNUSED,
int fd,
int events ATTRIBUTE_UNUSED,
void *data)
{
char buf[1024];
char fname[1024];
struct inotify_event *e;
int got;
char *tmp, *name;
virConnectPtr conn = data;
xenUnifiedPrivatePtr priv = NULL;
DEBUG0("got inotify event");
if( conn && conn->privateData ) {
priv = conn->privateData;
} else {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("conn, or private data is NULL"));
return;
}
xenUnifiedLock(priv);
reread:
got = read(fd, buf, sizeof(buf));
if (got == -1) {
if (errno == EINTR)
goto reread;
goto cleanup;
}
tmp = buf;
while (got) {
if (got < sizeof(struct inotify_event))
goto cleanup; /* bad */
e = (struct inotify_event *)tmp;
tmp += sizeof(struct inotify_event);
got -= sizeof(struct inotify_event);
if (got < e->len)
goto cleanup;
tmp += e->len;
got -= e->len;
name = (char *)&(e->name);
snprintf(fname, 1024, "%s/%s",
priv->configDir, name);
if (e->mask & (IN_DELETE | IN_MOVED_FROM)) {
virDomainEventPtr event =
xenInotifyDomainEventFromFile(conn, fname,
VIR_DOMAIN_EVENT_UNDEFINED,
VIR_DOMAIN_EVENT_UNDEFINED_REMOVED);
if (event)
xenUnifiedDomainEventDispatch(conn->privateData, event);
else
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("looking up dom"));
if (xenInotifyRemoveDomainConfigInfo(conn, fname) < 0 ) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("Error adding file to config cache"));
goto cleanup;
}
} else if (e->mask & ( IN_CREATE | IN_CLOSE_WRITE | IN_MOVED_TO) ) {
virDomainEventPtr event;
if (xenInotifyAddDomainConfigInfo(conn, fname) < 0 ) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("Error adding file to config cache"));
goto cleanup;
}
event = xenInotifyDomainEventFromFile(conn, fname,
VIR_DOMAIN_EVENT_DEFINED,
VIR_DOMAIN_EVENT_DEFINED_ADDED);
if (event)
xenUnifiedDomainEventDispatch(conn->privateData, event);
else
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("looking up dom"));
}
}
cleanup:
xenUnifiedUnlock(priv);
}
/**
* xenInotifyOpen:
* @conn: pointer to the connection block
* @name: URL for the target, NULL for local
* @flags: combination of virDrvOpenFlag(s)
*
* Connects and starts listening for inotify events
*
* Returns 0 or -1 in case of error.
*/
virDrvOpenStatus
xenInotifyOpen(virConnectPtr conn,
virConnectAuthPtr auth ATTRIBUTE_UNUSED,
int flags ATTRIBUTE_UNUSED)
{
DIR *dh;
struct dirent *ent;
char path[PATH_MAX];
xenUnifiedPrivatePtr priv = (xenUnifiedPrivatePtr) conn->privateData;
if (priv->configDir) {
priv->useXenConfigCache = 1;
} else {
/* /var/lib/xend/domains/<uuid>/config.sxp */
priv->configDir = XEND_DOMAINS_DIR;
priv->useXenConfigCache = 0;
if (VIR_ALLOC(priv->configInfoList) < 0) {
virReportOOMError();
return -1;
}
/* populate initial list */
if (!(dh = opendir(priv->configDir))) {
virReportSystemError(errno,
_("cannot open directory: %s"),
priv->configDir);
return -1;
}
while ((ent = readdir(dh))) {
if (STRPREFIX(ent->d_name, "."))
continue;
/* Build the full file path */
if ((strlen(priv->configDir) + 1 +
strlen(ent->d_name) + 1) > PATH_MAX)
continue;
strcpy(path, priv->configDir);
strcat(path, "/");
strcat(path, ent->d_name);
if (xenInotifyAddDomainConfigInfo(conn, path) < 0 ) {
virXenInotifyError(VIR_ERR_INTERNAL_ERROR,
"%s", _("Error adding file to config list"));
closedir(dh);
return -1;
}
}
closedir(dh);
}
if ((priv->inotifyFD = inotify_init()) < 0) {
virReportSystemError(errno,
"%s", _("initializing inotify"));
return -1;
}
DEBUG("Adding a watch on %s", priv->configDir);
if (inotify_add_watch(priv->inotifyFD,
priv->configDir,
IN_CREATE |
IN_CLOSE_WRITE | IN_DELETE |
IN_MOVED_TO | IN_MOVED_FROM) < 0) {
virReportSystemError(errno,
_("adding watch on %s"),
priv->configDir);
return -1;
}
DEBUG0("Building initial config cache");
if (priv->useXenConfigCache &&
xenXMConfigCacheRefresh (conn) < 0) {
DEBUG("Failed to enable XM config cache %s", conn->err.message);
return -1;
}
DEBUG0("Registering with event loop");
/* Add the handle for monitoring */
if ((priv->inotifyWatch = virEventAddHandle(priv->inotifyFD, VIR_EVENT_HANDLE_READABLE,
xenInotifyEvent, conn, NULL)) < 0) {
DEBUG0("Failed to add inotify handle, disabling events");
}
return 0;
}
/**
* xenInotifyClose:
* @conn: pointer to the connection block
*
* Close and stop listening for inotify events
*
* Returns 0 in case of success or -1 in case of error.
*/
int
xenInotifyClose(virConnectPtr conn)
{
xenUnifiedPrivatePtr priv = conn->privateData;
if (priv->configInfoList)
xenUnifiedDomainInfoListFree(priv->configInfoList);
if (priv->inotifyWatch != -1)
virEventRemoveHandle(priv->inotifyWatch);
close(priv->inotifyFD);
return 0;
}