storage_driver.c

/*
 * storage_driver.c: core driver for storage APIs
 *
 * Copyright (C) 2006-2014 Red Hat, Inc.
 * Copyright (C) 2006-2008 Daniel P. Berrange
 *
 * 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/>.
 *
 * Author: Daniel P. Berrange <berrange@redhat.com>
 */

#include <config.h>

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>

#if HAVE_PWD_H
# include <pwd.h>
#endif
#include <errno.h>
#include <string.h>

#include "virerror.h"
#include "datatypes.h"
#include "driver.h"
#include "storage_driver.h"
#include "storage_conf.h"
#include "viralloc.h"
#include "storage_backend.h"
#include "virlog.h"
#include "virfile.h"
#include "fdstream.h"
#include "configmake.h"
#include "virstring.h"
#include "viraccessapicheck.h"
#include "dirname.h"

#define VIR_FROM_THIS VIR_FROM_STORAGE

VIR_LOG_INIT("storage.storage_driver");

static virStorageDriverStatePtr driverState;

static int storageStateCleanup(void);

typedef struct _virStorageVolStreamInfo virStorageVolStreamInfo;
typedef virStorageVolStreamInfo *virStorageVolStreamInfoPtr;
struct _virStorageVolStreamInfo {
    char *pool_name;
};

static void storageDriverLock(virStorageDriverStatePtr driver)
{
    virMutexLock(&driver->lock);
}
static void storageDriverUnlock(virStorageDriverStatePtr driver)
{
    virMutexUnlock(&driver->lock);
}

static void
storageDriverAutostart(virStorageDriverStatePtr driver)
{
    size_t i;
    virConnectPtr conn = NULL;

    /* XXX Remove hardcoding of QEMU URI */
    if (driverState->privileged)
        conn = virConnectOpen("qemu:///system");
    else
        conn = virConnectOpen("qemu:///session");
    /* Ignoring NULL conn - let backends decide */

    for (i = 0; i < driver->pools.count; i++) {
        virStoragePoolObjPtr pool = driver->pools.objs[i];
        virStorageBackendPtr backend;
        bool started = false;

        virStoragePoolObjLock(pool);
        if ((backend = virStorageBackendForType(pool->def->type)) == NULL) {
            VIR_ERROR(_("Missing backend %d"), pool->def->type);
            virStoragePoolObjUnlock(pool);
            continue;
        }

        if (backend->checkPool &&
            backend->checkPool(conn, pool, &started) < 0) {
            virErrorPtr err = virGetLastError();
            VIR_ERROR(_("Failed to initialize storage pool '%s': %s"),
                      pool->def->name, err ? err->message :
                      _("no error message found"));
            virStoragePoolObjUnlock(pool);
            continue;
        }

        if (!started &&
            pool->autostart &&
            !virStoragePoolObjIsActive(pool)) {
            if (backend->startPool &&
                backend->startPool(conn, pool) < 0) {
                virErrorPtr err = virGetLastError();
                VIR_ERROR(_("Failed to autostart storage pool '%s': %s"),
                          pool->def->name, err ? err->message :
                          _("no error message found"));
                virStoragePoolObjUnlock(pool);
                continue;
            }
            started = true;
        }

        if (started) {
            if (backend->refreshPool(conn, pool) < 0) {
                virErrorPtr err = virGetLastError();
                if (backend->stopPool)
                    backend->stopPool(conn, pool);
                VIR_ERROR(_("Failed to autostart storage pool '%s': %s"),
                          pool->def->name, err ? err->message :
                          _("no error message found"));
                virStoragePoolObjUnlock(pool);
                continue;
            }
            pool->active = 1;
        }
        virStoragePoolObjUnlock(pool);
    }

    virObjectUnref(conn);
}

/**
 * virStorageStartup:
 *
 * Initialization function for the QEmu daemon
 */
static int
storageStateInitialize(bool privileged,
                       virStateInhibitCallback callback ATTRIBUTE_UNUSED,
                       void *opaque ATTRIBUTE_UNUSED)
{
    char *base = NULL;

    if (VIR_ALLOC(driverState) < 0)
        return -1;

    if (virMutexInit(&driverState->lock) < 0) {
        VIR_FREE(driverState);
        return -1;
    }
    storageDriverLock(driverState);

    if (privileged) {
        if (VIR_STRDUP(base, SYSCONFDIR "/libvirt") < 0)
            goto error;
    } else {
        base = virGetUserConfigDirectory();
        if (!base)
            goto error;
    }
    driverState->privileged = privileged;

    /* Configuration paths are either $USER_CONFIG_HOME/libvirt/storage/... (session) or
     * /etc/libvirt/storage/... (system).
     */
    if (virAsprintf(&driverState->configDir,
                    "%s/storage", base) == -1)
        goto error;

    if (virAsprintf(&driverState->autostartDir,
                    "%s/storage/autostart", base) == -1)
        goto error;

    VIR_FREE(base);

    if (virStoragePoolLoadAllConfigs(&driverState->pools,
                                     driverState->configDir,
                                     driverState->autostartDir) < 0)
        goto error;

    storageDriverUnlock(driverState);
    return 0;

 error:
    VIR_FREE(base);
    storageDriverUnlock(driverState);
    storageStateCleanup();
    return -1;
}

/**
 * storageStateAutoStart:
 *
 * Function to auto start the storage driver
 */
static void
storageStateAutoStart(void)
{
    if (!driverState)
        return;

    storageDriverLock(driverState);
    storageDriverAutostart(driverState);
    storageDriverUnlock(driverState);
}

/**
 * storageStateReload:
 *
 * Function to restart the storage driver, it will recheck the configuration
 * files and update its state
 */
static int
storageStateReload(void)
{
    if (!driverState)
        return -1;

    storageDriverLock(driverState);
    virStoragePoolLoadAllConfigs(&driverState->pools,
                                 driverState->configDir,
                                 driverState->autostartDir);
    storageDriverAutostart(driverState);
    storageDriverUnlock(driverState);

    return 0;
}


/**
 * storageStateCleanup
 *
 * Shutdown the storage driver, it will stop all active storage pools
 */
static int
storageStateCleanup(void)
{
    if (!driverState)
        return -1;

    storageDriverLock(driverState);

    /* free inactive pools */
    virStoragePoolObjListFree(&driverState->pools);

    VIR_FREE(driverState->configDir);
    VIR_FREE(driverState->autostartDir);
    storageDriverUnlock(driverState);
    virMutexDestroy(&driverState->lock);
    VIR_FREE(driverState);

    return 0;
}



static virStoragePoolPtr
storagePoolLookupByUUID(virConnectPtr conn,
                        const unsigned char *uuid)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    virStoragePoolPtr ret = NULL;

    storageDriverLock(driver);
    pool = virStoragePoolObjFindByUUID(&driver->pools, uuid);
    storageDriverUnlock(driver);

    if (!pool) {
        char uuidstr[VIR_UUID_STRING_BUFLEN];
        virUUIDFormat(uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s'"), uuidstr);
        return NULL;
    }

    if (virStoragePoolLookupByUUIDEnsureACL(conn, pool->def) < 0)
        goto cleanup;

    ret = virGetStoragePool(conn, pool->def->name, pool->def->uuid,
                            NULL, NULL);

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static virStoragePoolPtr
storagePoolLookupByName(virConnectPtr conn,
                        const char *name)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    virStoragePoolPtr ret = NULL;

    storageDriverLock(driver);
    pool = virStoragePoolObjFindByName(&driver->pools, name);
    storageDriverUnlock(driver);

    if (!pool) {
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching name '%s'"), name);
        return NULL;
    }

    if (virStoragePoolLookupByNameEnsureACL(conn, pool->def) < 0)
        goto cleanup;

    ret = virGetStoragePool(conn, pool->def->name, pool->def->uuid,
                            NULL, NULL);

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static virStoragePoolPtr
storagePoolLookupByVolume(virStorageVolPtr vol)
{
    virStorageDriverStatePtr driver = vol->conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    virStoragePoolPtr ret = NULL;

    storageDriverLock(driver);
    pool = virStoragePoolObjFindByName(&driver->pools, vol->pool);
    storageDriverUnlock(driver);

    if (!pool) {
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching name '%s'"), vol->pool);
        return NULL;
    }

    if (virStoragePoolLookupByVolumeEnsureACL(vol->conn, pool->def) < 0)
        goto cleanup;

    ret = virGetStoragePool(vol->conn, pool->def->name, pool->def->uuid,
                            NULL, NULL);

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static virDrvOpenStatus
storageOpen(virConnectPtr conn,
            virConnectAuthPtr auth ATTRIBUTE_UNUSED,
            unsigned int flags)
{
    virCheckFlags(VIR_CONNECT_RO, VIR_DRV_OPEN_ERROR);

    if (!driverState)
        return VIR_DRV_OPEN_DECLINED;

    conn->storagePrivateData = driverState;
    return VIR_DRV_OPEN_SUCCESS;
}

static int
storageClose(virConnectPtr conn)
{
    conn->storagePrivateData = NULL;
    return 0;
}

static int
storageConnectNumOfStoragePools(virConnectPtr conn)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    size_t i;
    int nactive = 0;

    if (virConnectNumOfStoragePoolsEnsureACL(conn) < 0)
        return -1;

    storageDriverLock(driver);
    for (i = 0; i < driver->pools.count; i++) {
        virStoragePoolObjPtr obj = driver->pools.objs[i];
        virStoragePoolObjLock(obj);
        if (virConnectNumOfStoragePoolsCheckACL(conn, obj->def) &&
            virStoragePoolObjIsActive(obj))
            nactive++;
        virStoragePoolObjUnlock(obj);
    }
    storageDriverUnlock(driver);

    return nactive;
}

static int
storageConnectListStoragePools(virConnectPtr conn,
                               char **const names,
                               int nnames)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    int got = 0;
    size_t i;

    if (virConnectListStoragePoolsEnsureACL(conn) < 0)
        return -1;

    storageDriverLock(driver);
    for (i = 0; i < driver->pools.count && got < nnames; i++) {
        virStoragePoolObjPtr obj = driver->pools.objs[i];
        virStoragePoolObjLock(obj);
        if (virConnectListStoragePoolsCheckACL(conn, obj->def) &&
            virStoragePoolObjIsActive(obj)) {
            if (VIR_STRDUP(names[got], obj->def->name) < 0) {
                virStoragePoolObjUnlock(obj);
                goto cleanup;
            }
            got++;
        }
        virStoragePoolObjUnlock(obj);
    }
    storageDriverUnlock(driver);
    return got;

 cleanup:
    storageDriverUnlock(driver);
    for (i = 0; i < got; i++)
        VIR_FREE(names[i]);
    memset(names, 0, nnames * sizeof(*names));
    return -1;
}

static int
storageConnectNumOfDefinedStoragePools(virConnectPtr conn)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    size_t i;
    int nactive = 0;

    if (virConnectNumOfDefinedStoragePoolsEnsureACL(conn) < 0)
        return -1;

    storageDriverLock(driver);
    for (i = 0; i < driver->pools.count; i++) {
        virStoragePoolObjPtr obj = driver->pools.objs[i];
        virStoragePoolObjLock(obj);
        if (virConnectNumOfDefinedStoragePoolsCheckACL(conn, obj->def) &&
            !virStoragePoolObjIsActive(obj))
            nactive++;
        virStoragePoolObjUnlock(obj);
    }
    storageDriverUnlock(driver);

    return nactive;
}

static int
storageConnectListDefinedStoragePools(virConnectPtr conn,
                                      char **const names,
                                      int nnames)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    int got = 0;
    size_t i;

    if (virConnectListDefinedStoragePoolsEnsureACL(conn) < 0)
        return -1;

    storageDriverLock(driver);
    for (i = 0; i < driver->pools.count && got < nnames; i++) {
        virStoragePoolObjPtr obj = driver->pools.objs[i];
        virStoragePoolObjLock(obj);
        if (virConnectListDefinedStoragePoolsCheckACL(conn, obj->def) &&
            !virStoragePoolObjIsActive(obj)) {
            if (VIR_STRDUP(names[got], obj->def->name) < 0) {
                virStoragePoolObjUnlock(obj);
                goto cleanup;
            }
            got++;
        }
        virStoragePoolObjUnlock(obj);
    }
    storageDriverUnlock(driver);
    return got;

 cleanup:
    storageDriverUnlock(driver);
    for (i = 0; i < got; i++) {
        VIR_FREE(names[i]);
    }
    memset(names, 0, nnames * sizeof(*names));
    return -1;
}

/* This method is required to be re-entrant / thread safe, so
   uses no driver lock */
static char *
storageConnectFindStoragePoolSources(virConnectPtr conn,
                                     const char *type,
                                     const char *srcSpec,
                                     unsigned int flags)
{
    int backend_type;
    virStorageBackendPtr backend;
    char *ret = NULL;

    if (virConnectFindStoragePoolSourcesEnsureACL(conn) < 0)
        return NULL;

    backend_type = virStoragePoolTypeFromString(type);
    if (backend_type < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("unknown storage pool type %s"), type);
        goto cleanup;
    }

    backend = virStorageBackendForType(backend_type);
    if (backend == NULL)
        goto cleanup;

    if (!backend->findPoolSources) {
        virReportError(VIR_ERR_NO_SUPPORT,
                       _("pool type '%s' does not support source "
                         "discovery"), type);
        goto cleanup;
    }

    ret = backend->findPoolSources(conn, srcSpec, flags);

 cleanup:
    return ret;
}


static virStoragePoolObjPtr
virStoragePoolObjFromStoragePool(virStoragePoolPtr pool)
{
    virStorageDriverStatePtr driver = pool->conn->storagePrivateData;
    char uuidstr[VIR_UUID_STRING_BUFLEN];
    virStoragePoolObjPtr ret;

    storageDriverLock(driver);
    if (!(ret = virStoragePoolObjFindByUUID(&driver->pools, pool->uuid))) {
        virUUIDFormat(pool->uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s' (%s)"),
                       uuidstr, pool->name);
    }
    storageDriverUnlock(driver);

    return ret;
}


static int storagePoolIsActive(virStoragePoolPtr pool)
{
    virStoragePoolObjPtr obj;
    int ret = -1;

    if (!(obj = virStoragePoolObjFromStoragePool(pool)))
        return -1;

    if (virStoragePoolIsActiveEnsureACL(pool->conn, obj->def) < 0)
        goto cleanup;

    ret = virStoragePoolObjIsActive(obj);

 cleanup:
    virStoragePoolObjUnlock(obj);
    return ret;
}

static int storagePoolIsPersistent(virStoragePoolPtr pool)
{
    virStoragePoolObjPtr obj;
    int ret = -1;

    if (!(obj = virStoragePoolObjFromStoragePool(pool)))
        return -1;

    if (virStoragePoolIsPersistentEnsureACL(pool->conn, obj->def) < 0)
        goto cleanup;

    ret = obj->configFile ? 1 : 0;

 cleanup:
    virStoragePoolObjUnlock(obj);
    return ret;
}


static virStoragePoolPtr
storagePoolCreateXML(virConnectPtr conn,
                     const char *xml,
                     unsigned int flags)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    virStoragePoolDefPtr def;
    virStoragePoolObjPtr pool = NULL;
    virStoragePoolPtr ret = NULL;
    virStorageBackendPtr backend;

    virCheckFlags(0, NULL);

    storageDriverLock(driver);
    if (!(def = virStoragePoolDefParseString(xml)))
        goto cleanup;

    if (virStoragePoolCreateXMLEnsureACL(conn, def) < 0)
        goto cleanup;

    if (virStoragePoolObjIsDuplicate(&driver->pools, def, 1) < 0)
        goto cleanup;

    if (virStoragePoolSourceFindDuplicate(&driver->pools, def) < 0)
        goto cleanup;

    if ((backend = virStorageBackendForType(def->type)) == NULL)
        goto cleanup;

    if (!(pool = virStoragePoolObjAssignDef(&driver->pools, def)))
        goto cleanup;
    def = NULL;

    if (backend->startPool &&
        backend->startPool(conn, pool) < 0) {
        virStoragePoolObjRemove(&driver->pools, pool);
        pool = NULL;
        goto cleanup;
    }

    if (backend->refreshPool(conn, pool) < 0) {
        if (backend->stopPool)
            backend->stopPool(conn, pool);
        virStoragePoolObjRemove(&driver->pools, pool);
        pool = NULL;
        goto cleanup;
    }
    VIR_INFO("Creating storage pool '%s'", pool->def->name);
    pool->active = 1;

    ret = virGetStoragePool(conn, pool->def->name, pool->def->uuid,
                            NULL, NULL);

 cleanup:
    virStoragePoolDefFree(def);
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driver);
    return ret;
}

static virStoragePoolPtr
storagePoolDefineXML(virConnectPtr conn,
                     const char *xml,
                     unsigned int flags)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    virStoragePoolDefPtr def;
    virStoragePoolObjPtr pool = NULL;
    virStoragePoolPtr ret = NULL;

    virCheckFlags(0, NULL);

    storageDriverLock(driver);
    if (!(def = virStoragePoolDefParseString(xml)))
        goto cleanup;

    if (virStoragePoolDefineXMLEnsureACL(conn, def) < 0)
        goto cleanup;

    if (virStoragePoolObjIsDuplicate(&driver->pools, def, 0) < 0)
        goto cleanup;

    if (virStoragePoolSourceFindDuplicate(&driver->pools, def) < 0)
        goto cleanup;

    if (virStorageBackendForType(def->type) == NULL)
        goto cleanup;

    if (!(pool = virStoragePoolObjAssignDef(&driver->pools, def)))
        goto cleanup;

    if (virStoragePoolObjSaveDef(driver, pool, def) < 0) {
        virStoragePoolObjRemove(&driver->pools, pool);
        def = NULL;
        goto cleanup;
    }
    def = NULL;

    VIR_INFO("Defining storage pool '%s'", pool->def->name);
    ret = virGetStoragePool(conn, pool->def->name, pool->def->uuid,
                            NULL, NULL);

 cleanup:
    virStoragePoolDefFree(def);
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driver);
    return ret;
}

static int
storagePoolUndefine(virStoragePoolPtr obj)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    int ret = -1;

    storageDriverLock(driver);
    if (!(pool = virStoragePoolObjFindByUUID(&driver->pools, obj->uuid))) {
        char uuidstr[VIR_UUID_STRING_BUFLEN];
        virUUIDFormat(obj->uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s' (%s)"),
                       uuidstr, obj->name);
        goto cleanup;
    }

    if (virStoragePoolUndefineEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if (virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is still active"),
                       pool->def->name);
        goto cleanup;
    }

    if (pool->asyncjobs > 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("pool '%s' has asynchronous jobs running."),
                       pool->def->name);
        goto cleanup;
    }

    if (virStoragePoolObjDeleteDef(pool) < 0)
        goto cleanup;

    if (unlink(pool->autostartLink) < 0 && errno != ENOENT && errno != ENOTDIR) {
        char ebuf[1024];
        VIR_ERROR(_("Failed to delete autostart link '%s': %s"),
                  pool->autostartLink, virStrerror(errno, ebuf, sizeof(ebuf)));
    }

    VIR_FREE(pool->configFile);
    VIR_FREE(pool->autostartLink);

    VIR_INFO("Undefining storage pool '%s'", pool->def->name);
    virStoragePoolObjRemove(&driver->pools, pool);
    pool = NULL;
    ret = 0;

 cleanup:
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driver);
    return ret;
}

static int
storagePoolCreate(virStoragePoolPtr obj,
                  unsigned int flags)
{
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    int ret = -1;

    virCheckFlags(0, -1);

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolCreateEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    if (virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is already active"),
                       pool->def->name);
        goto cleanup;
    }
    if (backend->startPool &&
        backend->startPool(obj->conn, pool) < 0)
        goto cleanup;

    if (backend->refreshPool(obj->conn, pool) < 0) {
        if (backend->stopPool)
            backend->stopPool(obj->conn, pool);
        goto cleanup;
    }

    VIR_INFO("Starting up storage pool '%s'", pool->def->name);
    pool->active = 1;
    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static int
storagePoolBuild(virStoragePoolPtr obj,
                 unsigned int flags)
{
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    int ret = -1;

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolBuildEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    if (virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is already active"),
                       pool->def->name);
        goto cleanup;
    }

    if (backend->buildPool &&
        backend->buildPool(obj->conn, pool, flags) < 0)
        goto cleanup;
    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}


static int
storagePoolDestroy(virStoragePoolPtr obj)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    int ret = -1;

    storageDriverLock(driver);
    if (!(pool = virStoragePoolObjFindByUUID(&driver->pools, obj->uuid))) {
        char uuidstr[VIR_UUID_STRING_BUFLEN];
        virUUIDFormat(obj->uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s' (%s)"),
                       uuidstr, obj->name);
        goto cleanup;
    }

    if (virStoragePoolDestroyEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }

    if (pool->asyncjobs > 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("pool '%s' has asynchronous jobs running."),
                       pool->def->name);
        goto cleanup;
    }

    if (backend->stopPool &&
        backend->stopPool(obj->conn, pool) < 0)
        goto cleanup;

    virStoragePoolObjClearVols(pool);

    pool->active = 0;
    VIR_INFO("Shutting down storage pool '%s'", pool->def->name);

    if (pool->configFile == NULL) {
        virStoragePoolObjRemove(&driver->pools, pool);
        pool = NULL;
    } else if (pool->newDef) {
        virStoragePoolDefFree(pool->def);
        pool->def = pool->newDef;
        pool->newDef = NULL;
    }
    ret = 0;

 cleanup:
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driver);
    return ret;
}

static int
storagePoolDelete(virStoragePoolPtr obj,
                  unsigned int flags)
{
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    int ret = -1;

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolDeleteEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    if (virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is still active"),
                       pool->def->name);
        goto cleanup;
    }

    if (pool->asyncjobs > 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("pool '%s' has asynchronous jobs running."),
                              pool->def->name);
        goto cleanup;
    }

    if (!backend->deletePool) {
        virReportError(VIR_ERR_NO_SUPPORT,
                       "%s", _("pool does not support pool deletion"));
        goto cleanup;
    }
    if (backend->deletePool(obj->conn, pool, flags) < 0)
        goto cleanup;
    VIR_INFO("Deleting storage pool '%s'", pool->def->name);
    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}


static int
storagePoolRefresh(virStoragePoolPtr obj,
                   unsigned int flags)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    int ret = -1;

    virCheckFlags(0, -1);

    storageDriverLock(driver);
    if (!(pool = virStoragePoolObjFindByUUID(&driver->pools, obj->uuid))) {
        char uuidstr[VIR_UUID_STRING_BUFLEN];
        virUUIDFormat(obj->uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s' (%s)"),
                       uuidstr, obj->name);
        goto cleanup;
    }

    if (virStoragePoolRefreshEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }

    if (pool->asyncjobs > 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("pool '%s' has asynchronous jobs running."),
                       pool->def->name);
        goto cleanup;
    }

    virStoragePoolObjClearVols(pool);
    if (backend->refreshPool(obj->conn, pool) < 0) {
        if (backend->stopPool)
            backend->stopPool(obj->conn, pool);

        pool->active = 0;

        if (pool->configFile == NULL) {
            virStoragePoolObjRemove(&driver->pools, pool);
            pool = NULL;
        }
        goto cleanup;
    }
    ret = 0;

 cleanup:
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driver);
    return ret;
}


static int
storagePoolGetInfo(virStoragePoolPtr obj,
                   virStoragePoolInfoPtr info)
{
    virStoragePoolObjPtr pool;
    int ret = -1;

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolGetInfoEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if (virStorageBackendForType(pool->def->type) == NULL)
        goto cleanup;

    memset(info, 0, sizeof(virStoragePoolInfo));
    if (pool->active)
        info->state = VIR_STORAGE_POOL_RUNNING;
    else
        info->state = VIR_STORAGE_POOL_INACTIVE;
    info->capacity = pool->def->capacity;
    info->allocation = pool->def->allocation;
    info->available = pool->def->available;
    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static char *
storagePoolGetXMLDesc(virStoragePoolPtr obj,
                      unsigned int flags)
{
    virStoragePoolObjPtr pool;
    virStoragePoolDefPtr def;
    char *ret = NULL;

    virCheckFlags(VIR_STORAGE_XML_INACTIVE, NULL);

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return NULL;

    if (virStoragePoolGetXMLDescEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if ((flags & VIR_STORAGE_XML_INACTIVE) && pool->newDef)
        def = pool->newDef;
    else
        def = pool->def;

    ret = virStoragePoolDefFormat(def);

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static int
storagePoolGetAutostart(virStoragePoolPtr obj,
                        int *autostart)
{
    virStoragePoolObjPtr pool;
    int ret = -1;

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolGetAutostartEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if (!pool->configFile) {
        *autostart = 0;
    } else {
        *autostart = pool->autostart;
    }
    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static int
storagePoolSetAutostart(virStoragePoolPtr obj,
                        int autostart)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    int ret = -1;

    storageDriverLock(driver);
    pool = virStoragePoolObjFindByUUID(&driver->pools, obj->uuid);

    if (!pool) {
        char uuidstr[VIR_UUID_STRING_BUFLEN];
        virUUIDFormat(obj->uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s' (%s)"),
                       uuidstr, obj->name);
        goto cleanup;
    }

    if (virStoragePoolSetAutostartEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if (!pool->configFile) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       "%s", _("pool has no config file"));
        goto cleanup;
    }

    autostart = (autostart != 0);

    if (pool->autostart != autostart) {
        if (autostart) {
            if (virFileMakePath(driver->autostartDir) < 0) {
                virReportSystemError(errno,
                                     _("cannot create autostart directory %s"),
                                     driver->autostartDir);
                goto cleanup;
            }

            if (symlink(pool->configFile, pool->autostartLink) < 0) {
                virReportSystemError(errno,
                                     _("Failed to create symlink '%s' to '%s'"),
                                     pool->autostartLink, pool->configFile);
                goto cleanup;
            }
        } else {
            if (unlink(pool->autostartLink) < 0 &&
                errno != ENOENT && errno != ENOTDIR) {
                virReportSystemError(errno,
                                     _("Failed to delete symlink '%s'"),
                                     pool->autostartLink);
                goto cleanup;
            }
        }
        pool->autostart = autostart;
    }
    ret = 0;

 cleanup:
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driver);
    return ret;
}


static int
storagePoolNumOfVolumes(virStoragePoolPtr obj)
{
    virStoragePoolObjPtr pool;
    int ret = -1;
    size_t i;

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolNumOfVolumesEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }
    ret = 0;
    for (i = 0; i < pool->volumes.count; i++) {
        if (virStoragePoolNumOfVolumesCheckACL(obj->conn, pool->def,
                                               pool->volumes.objs[i]))
            ret++;
    }

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static int
storagePoolListVolumes(virStoragePoolPtr obj,
                       char **const names,
                       int maxnames)
{
    virStoragePoolObjPtr pool;
    size_t i;
    int n = 0;

    memset(names, 0, maxnames * sizeof(*names));

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return -1;

    if (virStoragePoolListVolumesEnsureACL(obj->conn, pool->def) < 0)
        goto cleanup;

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }

    for (i = 0; i < pool->volumes.count && n < maxnames; i++) {
        if (!virStoragePoolListVolumesCheckACL(obj->conn, pool->def,
                                               pool->volumes.objs[i]))
            continue;
        if (VIR_STRDUP(names[n++], pool->volumes.objs[i]->name) < 0)
            goto cleanup;
    }

    virStoragePoolObjUnlock(pool);
    return n;

 cleanup:
    virStoragePoolObjUnlock(pool);
    for (n = 0; n < maxnames; n++)
        VIR_FREE(names[n]);

    memset(names, 0, maxnames * sizeof(*names));
    return -1;
}

static int
storagePoolListAllVolumes(virStoragePoolPtr pool,
                          virStorageVolPtr **vols,
                          unsigned int flags)
{
    virStoragePoolObjPtr obj;
    size_t i;
    virStorageVolPtr *tmp_vols = NULL;
    virStorageVolPtr vol = NULL;
    int nvols = 0;
    int ret = -1;

    virCheckFlags(0, -1);

    if (!(obj = virStoragePoolObjFromStoragePool(pool)))
        return -1;

    if (virStoragePoolListAllVolumesEnsureACL(pool->conn, obj->def) < 0)
        goto cleanup;

    if (!virStoragePoolObjIsActive(obj)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), obj->def->name);
        goto cleanup;
    }

     /* Just returns the volumes count */
    if (!vols) {
        ret = obj->volumes.count;
        goto cleanup;
    }

    if (VIR_ALLOC_N(tmp_vols, obj->volumes.count + 1) < 0)
        goto cleanup;

    for (i = 0; i < obj->volumes.count; i++) {
        if (!virStoragePoolListAllVolumesCheckACL(pool->conn, obj->def,
                                                  obj->volumes.objs[i]))
            continue;
        if (!(vol = virGetStorageVol(pool->conn, obj->def->name,
                                     obj->volumes.objs[i]->name,
                                     obj->volumes.objs[i]->key,
                                     NULL, NULL)))
            goto cleanup;
        tmp_vols[nvols++] = vol;
    }

    *vols = tmp_vols;
    tmp_vols = NULL;
    ret = nvols;

 cleanup:
    if (tmp_vols) {
        for (i = 0; i < nvols; i++) {
            if (tmp_vols[i])
                virStorageVolFree(tmp_vols[i]);
        }
        VIR_FREE(tmp_vols);
    }

    virStoragePoolObjUnlock(obj);

    return ret;
}

static virStorageVolPtr
storageVolLookupByName(virStoragePoolPtr obj,
                       const char *name)
{
    virStoragePoolObjPtr pool;
    virStorageVolDefPtr vol;
    virStorageVolPtr ret = NULL;

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return NULL;

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }

    vol = virStorageVolDefFindByName(pool, name);

    if (!vol) {
        virReportError(VIR_ERR_NO_STORAGE_VOL,
                       _("no storage vol with matching name '%s'"),
                       name);
        goto cleanup;
    }

    if (virStorageVolLookupByNameEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    ret = virGetStorageVol(obj->conn, pool->def->name, vol->name, vol->key,
                           NULL, NULL);

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}


static virStorageVolPtr
storageVolLookupByKey(virConnectPtr conn,
                      const char *key)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    size_t i;
    virStorageVolPtr ret = NULL;

    storageDriverLock(driver);
    for (i = 0; i < driver->pools.count && !ret; i++) {
        virStoragePoolObjLock(driver->pools.objs[i]);
        if (virStoragePoolObjIsActive(driver->pools.objs[i])) {
            virStorageVolDefPtr vol =
                virStorageVolDefFindByKey(driver->pools.objs[i], key);

            if (vol) {
                if (virStorageVolLookupByKeyEnsureACL(conn, driver->pools.objs[i]->def, vol) < 0) {
                    virStoragePoolObjUnlock(driver->pools.objs[i]);
                    goto cleanup;
                }

                ret = virGetStorageVol(conn,
                                       driver->pools.objs[i]->def->name,
                                       vol->name,
                                       vol->key,
                                       NULL, NULL);
            }
        }
        virStoragePoolObjUnlock(driver->pools.objs[i]);
    }

    if (!ret)
        virReportError(VIR_ERR_NO_STORAGE_VOL,
                       _("no storage vol with matching key %s"), key);

 cleanup:
    storageDriverUnlock(driver);
    return ret;
}

static virStorageVolPtr
storageVolLookupByPath(virConnectPtr conn,
                       const char *path)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    size_t i;
    virStorageVolPtr ret = NULL;
    char *cleanpath;

    cleanpath = virFileSanitizePath(path);
    if (!cleanpath)
        return NULL;

    storageDriverLock(driver);
    for (i = 0; i < driver->pools.count && !ret; i++) {
        virStoragePoolObjPtr pool = driver->pools.objs[i];
        virStorageVolDefPtr vol;
        char *stable_path = NULL;

        virStoragePoolObjLock(pool);

        if (!virStoragePoolObjIsActive(pool)) {
           virStoragePoolObjUnlock(pool);
           continue;
        }

        switch ((virStoragePoolType) pool->def->type) {
            case VIR_STORAGE_POOL_DIR:
            case VIR_STORAGE_POOL_FS:
            case VIR_STORAGE_POOL_NETFS:
            case VIR_STORAGE_POOL_LOGICAL:
            case VIR_STORAGE_POOL_DISK:
            case VIR_STORAGE_POOL_ISCSI:
            case VIR_STORAGE_POOL_SCSI:
            case VIR_STORAGE_POOL_MPATH:
                stable_path = virStorageBackendStablePath(pool,
                                                          cleanpath,
                                                          false);
                if (stable_path == NULL) {
                    /* Don't break the whole lookup process if it fails on
                     * getting the stable path for some of the pools.
                     */
                    VIR_WARN("Failed to get stable path for pool '%s'",
                             pool->def->name);
                    virStoragePoolObjUnlock(pool);
                    continue;
                }
                break;

            case VIR_STORAGE_POOL_GLUSTER:
            case VIR_STORAGE_POOL_RBD:
            case VIR_STORAGE_POOL_SHEEPDOG:
            case VIR_STORAGE_POOL_ZFS:
            case VIR_STORAGE_POOL_LAST:
                if (VIR_STRDUP(stable_path, path) < 0) {
                     virStoragePoolObjUnlock(pool);
                    goto cleanup;
                }
                break;
        }

        vol = virStorageVolDefFindByPath(pool, stable_path);
        VIR_FREE(stable_path);

        if (vol) {
            if (virStorageVolLookupByPathEnsureACL(conn, pool->def, vol) < 0) {
                virStoragePoolObjUnlock(pool);
                goto cleanup;
            }

            ret = virGetStorageVol(conn, pool->def->name,
                                   vol->name, vol->key,
                                   NULL, NULL);
        }

        virStoragePoolObjUnlock(pool);
    }

    if (!ret) {
        if (STREQ(path, cleanpath)) {
            virReportError(VIR_ERR_NO_STORAGE_VOL,
                           _("no storage vol with matching path '%s'"), path);
        } else {
            virReportError(VIR_ERR_NO_STORAGE_VOL,
                           _("no storage vol with matching path '%s' (%s)"),
                           path, cleanpath);
        }
    }

 cleanup:
    VIR_FREE(cleanpath);
    storageDriverUnlock(driver);
    return ret;
}


static int
storageVolDeleteInternal(virStorageVolPtr obj,
                         virStorageBackendPtr backend,
                         virStoragePoolObjPtr pool,
                         virStorageVolDefPtr vol,
                         unsigned int flags,
                         bool updateMeta)
{
    size_t i;
    int ret = -1;

    if (!backend->deleteVol) {
        virReportError(VIR_ERR_NO_SUPPORT,
                       "%s", _("storage pool does not support vol deletion"));

        goto cleanup;
    }

    if (backend->deleteVol(obj->conn, pool, vol, flags) < 0)
        goto cleanup;

    /* Update pool metadata - don't update meta data from error paths
     * in this module since the allocation/available weren't adjusted yet
     */
    if (updateMeta) {
        pool->def->allocation -= vol->target.allocation;
        pool->def->available += vol->target.allocation;
    }

    for (i = 0; i < pool->volumes.count; i++) {
        if (pool->volumes.objs[i] == vol) {
            VIR_INFO("Deleting volume '%s' from storage pool '%s'",
                     vol->name, pool->def->name);
            virStorageVolDefFree(vol);

            VIR_DELETE_ELEMENT(pool->volumes.objs, i, pool->volumes.count);
            break;
        }
    }
    ret = 0;

 cleanup:
    return ret;
}


static virStorageVolDefPtr
virStorageVolDefFromVol(virStorageVolPtr obj,
                        virStoragePoolObjPtr *pool,
                        virStorageBackendPtr *backend)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStorageVolDefPtr vol = NULL;

    *pool = NULL;

    storageDriverLock(driver);
    *pool = virStoragePoolObjFindByName(&driver->pools, obj->pool);
    storageDriverUnlock(driver);

    if (!*pool) {
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching name '%s'"),
                       obj->pool);
        return NULL;
    }

    if (!virStoragePoolObjIsActive(*pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"),
                       (*pool)->def->name);
        goto error;
    }

    if (!(vol = virStorageVolDefFindByName(*pool, obj->name))) {
        virReportError(VIR_ERR_NO_STORAGE_VOL,
                       _("no storage vol with matching name '%s'"),
                       obj->name);
        goto error;
    }

    if (backend) {
        if (!(*backend = virStorageBackendForType((*pool)->def->type)))
            goto error;
    }

    return vol;

 error:
    virStoragePoolObjUnlock(*pool);
    *pool = NULL;

    return NULL;
}


static int
storageVolDelete(virStorageVolPtr obj,
                 unsigned int flags)
{
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    virStorageVolDefPtr vol = NULL;
    int ret = -1;

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return -1;

    if (virStorageVolDeleteEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (vol->in_use) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still in use."),
                       vol->name);
        goto cleanup;
    }

    if (vol->building) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still being allocated."),
                       vol->name);
        goto cleanup;
    }

    if (storageVolDeleteInternal(obj, backend, pool, vol, flags, true) < 0)
        goto cleanup;

    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}


static virStorageVolPtr
storageVolCreateXML(virStoragePoolPtr obj,
                    const char *xmldesc,
                    unsigned int flags)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    virStorageVolDefPtr voldef = NULL;
    virStorageVolPtr ret = NULL, volobj = NULL;
    virStorageVolDefPtr buildvoldef = NULL;

    virCheckFlags(VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA, NULL);

    if (!(pool = virStoragePoolObjFromStoragePool(obj)))
        return NULL;

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    voldef = virStorageVolDefParseString(pool->def, xmldesc);
    if (voldef == NULL)
        goto cleanup;

    if (virStorageVolCreateXMLEnsureACL(obj->conn, pool->def, voldef) < 0)
        goto cleanup;

    if (virStorageVolDefFindByName(pool, voldef->name)) {
        virReportError(VIR_ERR_STORAGE_VOL_EXIST,
                       _("'%s'"), voldef->name);
        goto cleanup;
    }

    if (VIR_REALLOC_N(pool->volumes.objs,
                      pool->volumes.count+1) < 0)
        goto cleanup;

    if (!backend->createVol) {
        virReportError(VIR_ERR_NO_SUPPORT,
                       "%s", _("storage pool does not support volume "
                               "creation"));
        goto cleanup;
    }

    /* Wipe any key the user may have suggested, as volume creation
     * will generate the canonical key.  */
    VIR_FREE(voldef->key);
    if (backend->createVol(obj->conn, pool, voldef) < 0) {
        goto cleanup;
    }

    pool->volumes.objs[pool->volumes.count++] = voldef;
    volobj = virGetStorageVol(obj->conn, pool->def->name, voldef->name,
                              voldef->key, NULL, NULL);
    if (!volobj) {
        pool->volumes.count--;
        goto cleanup;
    }

    if (VIR_ALLOC(buildvoldef) < 0) {
        voldef = NULL;
        goto cleanup;
    }

    /* Make a shallow copy of the 'defined' volume definition, since the
     * original allocation value will change as the user polls 'info',
     * but we only need the initial requested values
     */
    memcpy(buildvoldef, voldef, sizeof(*voldef));

    if (backend->buildVol) {
        int buildret;

        /* Drop the pool lock during volume allocation */
        pool->asyncjobs++;
        voldef->building = true;
        virStoragePoolObjUnlock(pool);

        buildret = backend->buildVol(obj->conn, pool, buildvoldef, flags);

        storageDriverLock(driver);
        virStoragePoolObjLock(pool);
        storageDriverUnlock(driver);

        voldef->building = false;
        pool->asyncjobs--;

        if (buildret < 0) {
            VIR_FREE(buildvoldef);
            storageVolDeleteInternal(volobj, backend, pool, voldef,
                                     0, false);
            voldef = NULL;
            goto cleanup;
        }

    }

    /* Update pool metadata */
    pool->def->allocation += buildvoldef->target.allocation;
    pool->def->available -= buildvoldef->target.allocation;

    VIR_INFO("Creating volume '%s' in storage pool '%s'",
             volobj->name, pool->def->name);
    ret = volobj;
    volobj = NULL;
    voldef = NULL;

 cleanup:
    virObjectUnref(volobj);
    virStorageVolDefFree(voldef);
    VIR_FREE(buildvoldef);
    if (pool)
        virStoragePoolObjUnlock(pool);
    return ret;
}

static virStorageVolPtr
storageVolCreateXMLFrom(virStoragePoolPtr obj,
                        const char *xmldesc,
                        virStorageVolPtr vobj,
                        unsigned int flags)
{
    virStorageDriverStatePtr driver = obj->conn->storagePrivateData;
    virStoragePoolObjPtr pool, origpool = NULL;
    virStorageBackendPtr backend;
    virStorageVolDefPtr origvol = NULL, newvol = NULL;
    virStorageVolPtr ret = NULL, volobj = NULL;
    unsigned long long allocation;
    int buildret;

    virCheckFlags(VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA, NULL);

    storageDriverLock(driver);
    pool = virStoragePoolObjFindByUUID(&driver->pools, obj->uuid);
    if (pool && STRNEQ(obj->name, vobj->pool)) {
        virStoragePoolObjUnlock(pool);
        origpool = virStoragePoolObjFindByName(&driver->pools, vobj->pool);
        virStoragePoolObjLock(pool);
    }
    storageDriverUnlock(driver);
    if (!pool) {
        char uuidstr[VIR_UUID_STRING_BUFLEN];
        virUUIDFormat(obj->uuid, uuidstr);
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching uuid '%s' (%s)"),
                       uuidstr, obj->name);
        goto cleanup;
    }

    if (STRNEQ(obj->name, vobj->pool) && !origpool) {
        virReportError(VIR_ERR_NO_STORAGE_POOL,
                       _("no storage pool with matching name '%s'"),
                       vobj->pool);
        goto cleanup;
    }

    if (!virStoragePoolObjIsActive(pool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"), pool->def->name);
        goto cleanup;
    }

    if (origpool && !virStoragePoolObjIsActive(origpool)) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("storage pool '%s' is not active"),
                       origpool->def->name);
        goto cleanup;
    }

    if ((backend = virStorageBackendForType(pool->def->type)) == NULL)
        goto cleanup;

    origvol = virStorageVolDefFindByName(origpool ? origpool : pool, vobj->name);
    if (!origvol) {
        virReportError(VIR_ERR_NO_STORAGE_VOL,
                       _("no storage vol with matching name '%s'"),
                       vobj->name);
        goto cleanup;
    }

    newvol = virStorageVolDefParseString(pool->def, xmldesc);
    if (newvol == NULL)
        goto cleanup;

    if (virStorageVolCreateXMLFromEnsureACL(obj->conn, pool->def, newvol) < 0)
        goto cleanup;

    if (virStorageVolDefFindByName(pool, newvol->name)) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("storage volume name '%s' already in use."),
                       newvol->name);
        goto cleanup;
    }

    /* Is there ever a valid case for this? */
    if (newvol->target.capacity < origvol->target.capacity)
        newvol->target.capacity = origvol->target.capacity;

    /* Make sure allocation is at least as large as the destination cap,
     * to make absolutely sure we copy all possible contents */
    if (newvol->target.allocation < origvol->target.capacity)
        newvol->target.allocation = origvol->target.capacity;

    if (!backend->buildVolFrom) {
        virReportError(VIR_ERR_NO_SUPPORT,
                       "%s", _("storage pool does not support volume creation from an existing volume"));
        goto cleanup;
    }

    if (origvol->building) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still being allocated."),
                       origvol->name);
        goto cleanup;
    }

    if (backend->refreshVol &&
        backend->refreshVol(obj->conn, pool, origvol) < 0)
        goto cleanup;

    if (VIR_REALLOC_N(pool->volumes.objs,
                      pool->volumes.count+1) < 0)
        goto cleanup;

    /* 'Define' the new volume so we get async progress reporting.
     * Wipe any key the user may have suggested, as volume creation
     * will generate the canonical key.  */
    VIR_FREE(newvol->key);
    if (backend->createVol(obj->conn, pool, newvol) < 0) {
        goto cleanup;
    }

    pool->volumes.objs[pool->volumes.count++] = newvol;
    volobj = virGetStorageVol(obj->conn, pool->def->name, newvol->name,
                              newvol->key, NULL, NULL);
    if (!volobj) {
        pool->volumes.count--;
        goto cleanup;
    }

    /* Drop the pool lock during volume allocation */
    pool->asyncjobs++;
    newvol->building = true;
    origvol->in_use++;
    virStoragePoolObjUnlock(pool);

    if (origpool) {
        origpool->asyncjobs++;
        virStoragePoolObjUnlock(origpool);
    }

    buildret = backend->buildVolFrom(obj->conn, pool, newvol, origvol, flags);

    storageDriverLock(driver);
    virStoragePoolObjLock(pool);
    if (origpool)
        virStoragePoolObjLock(origpool);
    storageDriverUnlock(driver);

    origvol->in_use--;
    newvol->building = false;
    allocation = newvol->target.allocation;
    pool->asyncjobs--;

    if (origpool) {
        origpool->asyncjobs--;
        virStoragePoolObjUnlock(origpool);
        origpool = NULL;
    }

    if (buildret < 0) {
        storageVolDeleteInternal(volobj, backend, pool, newvol, 0, false);
        newvol = NULL;
        goto cleanup;
    }
    newvol = NULL;

    /* Updating pool metadata */
    pool->def->allocation += allocation;
    pool->def->available -= allocation;

    VIR_INFO("Creating volume '%s' in storage pool '%s'",
             volobj->name, pool->def->name);
    ret = volobj;
    volobj = NULL;

 cleanup:
    virObjectUnref(volobj);
    virStorageVolDefFree(newvol);
    if (pool)
        virStoragePoolObjUnlock(pool);
    if (origpool)
        virStoragePoolObjUnlock(origpool);
    return ret;
}


static int
storageVolDownload(virStorageVolPtr obj,
                   virStreamPtr stream,
                   unsigned long long offset,
                   unsigned long long length,
                   unsigned int flags)
{
    virStorageBackendPtr backend;
    virStoragePoolObjPtr pool = NULL;
    virStorageVolDefPtr vol = NULL;
    int ret = -1;

    virCheckFlags(0, -1);

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return -1;

    if (virStorageVolDownloadEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (vol->building) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still being allocated."),
                       vol->name);
        goto cleanup;
    }

    if (!backend->downloadVol) {
        virReportError(VIR_ERR_NO_SUPPORT, "%s",
                       _("storage pool doesn't support volume download"));
        goto cleanup;
    }

    ret = backend->downloadVol(obj->conn, pool, vol, stream,
                               offset, length, flags);

 cleanup:
    virStoragePoolObjUnlock(pool);

    return ret;
}


/**
 * Frees opaque data.
 *
 * @opaque Data to be freed.
 */
static void
virStorageVolPoolRefreshDataFree(void *opaque)
{
    virStorageVolStreamInfoPtr cbdata = opaque;

    VIR_FREE(cbdata->pool_name);
    VIR_FREE(cbdata);
}

/**
 * Thread to handle the pool refresh
 *
 * @st Pointer to stream being closed.
 * @opaque Domain's device information structure.
 */
static void
virStorageVolPoolRefreshThread(void *opaque)
{

    virStorageVolStreamInfoPtr cbdata = opaque;
    virStoragePoolObjPtr pool = NULL;
    virStorageBackendPtr backend;

    storageDriverLock(driverState);
    if (!(pool = virStoragePoolObjFindByName(&driverState->pools,
                                             cbdata->pool_name)))
        goto cleanup;

    if (!(backend = virStorageBackendForType(pool->def->type)))
        goto cleanup;

    virStoragePoolObjClearVols(pool);
    if (backend->refreshPool(NULL, pool) < 0)
        VIR_DEBUG("Failed to refresh storage pool");

 cleanup:
    if (pool)
        virStoragePoolObjUnlock(pool);
    storageDriverUnlock(driverState);
    virStorageVolPoolRefreshDataFree(cbdata);
}

/**
 * Callback being called if a FDstream is closed. Will spin off a thread
 * to perform a pool refresh.
 *
 * @st Pointer to stream being closed.
 * @opaque Buffer to hold the pool name to be rereshed
 */
static void
virStorageVolFDStreamCloseCb(virStreamPtr st ATTRIBUTE_UNUSED,
                             void *opaque)
{
    virThread thread;

    if (virThreadCreate(&thread, false, virStorageVolPoolRefreshThread,
                        opaque) < 0) {
        /* Not much else can be done */
        VIR_ERROR(_("Failed to create thread to handle pool refresh"));
        goto error;
    }
    return; /* Thread will free opaque data */

 error:
    virStorageVolPoolRefreshDataFree(opaque);
}

static int
storageVolUpload(virStorageVolPtr obj,
                 virStreamPtr stream,
                 unsigned long long offset,
                 unsigned long long length,
                 unsigned int flags)
{
    virStorageBackendPtr backend;
    virStoragePoolObjPtr pool = NULL;
    virStorageVolDefPtr vol = NULL;
    virStorageVolStreamInfoPtr cbdata = NULL;
    int ret = -1;

    virCheckFlags(0, -1);

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return -1;

    if (virStorageVolUploadEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (vol->in_use) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still in use."),
                       vol->name);
        goto cleanup;
    }

    if (vol->building) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still being allocated."),
                       vol->name);
        goto cleanup;
    }

    if (!backend->uploadVol) {
        virReportError(VIR_ERR_NO_SUPPORT, "%s",
                       _("storage pool doesn't support volume upload"));
        goto cleanup;
    }

    /* If we have a refreshPool, use the callback routine in order to
     * refresh the pool after the volume upload stream closes. This way
     * we make sure the volume and pool data are refreshed without user
     * interaction and we can just lookup the backend in the callback
     * routine in order to call the refresh API.
     */
    if (backend->refreshPool) {
        if (VIR_ALLOC(cbdata) < 0 ||
            VIR_STRDUP(cbdata->pool_name, pool->def->name) < 0)
            goto cleanup;
    }

    ret = backend->uploadVol(obj->conn, pool, vol, stream,
                             offset, length, flags);

    /* Add cleanup callback - call after uploadVol since the stream
     * is then fully set up
     */
    if (cbdata) {
        virFDStreamSetInternalCloseCb(stream,
                                      virStorageVolFDStreamCloseCb,
                                      cbdata, NULL);
        cbdata = NULL;
    }

 cleanup:
    virStoragePoolObjUnlock(pool);
    if (cbdata)
        virStorageVolPoolRefreshDataFree(cbdata);

    return ret;
}

static int
storageVolResize(virStorageVolPtr obj,
                 unsigned long long capacity,
                 unsigned int flags)
{
    virStorageBackendPtr backend;
    virStoragePoolObjPtr pool = NULL;
    virStorageVolDefPtr vol = NULL;
    unsigned long long abs_capacity;
    int ret = -1;

    virCheckFlags(VIR_STORAGE_VOL_RESIZE_ALLOCATE |
                  VIR_STORAGE_VOL_RESIZE_DELTA |
                  VIR_STORAGE_VOL_RESIZE_SHRINK, -1);

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return -1;

    if (virStorageVolResizeEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (vol->in_use) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still in use."),
                       vol->name);
        goto cleanup;
    }

    if (vol->building) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still being allocated."),
                       vol->name);
        goto cleanup;
    }

    if (flags & VIR_STORAGE_VOL_RESIZE_DELTA) {
        abs_capacity = vol->target.capacity + capacity;
        flags &= ~VIR_STORAGE_VOL_RESIZE_DELTA;
    } else {
        abs_capacity = capacity;
    }

    if (abs_capacity < vol->target.allocation) {
        virReportError(VIR_ERR_INVALID_ARG, "%s",
                       _("can't shrink capacity below "
                         "existing allocation"));
        goto cleanup;
    }

    if (abs_capacity < vol->target.capacity &&
        !(flags & VIR_STORAGE_VOL_RESIZE_SHRINK)) {
        virReportError(VIR_ERR_INVALID_ARG, "%s",
                       _("Can't shrink capacity below current "
                         "capacity with shrink flag explicitly specified"));
        goto cleanup;
    }

    if (abs_capacity > vol->target.capacity + pool->def->available) {
        virReportError(VIR_ERR_OPERATION_FAILED, "%s",
                       _("Not enough space left on storage pool"));
        goto cleanup;
    }

    if (!backend->resizeVol) {
        virReportError(VIR_ERR_NO_SUPPORT, "%s",
                       _("storage pool does not support changing of "
                         "volume capacity"));
        goto cleanup;
    }

    if (backend->resizeVol(obj->conn, pool, vol, abs_capacity, flags) < 0)
        goto cleanup;

    vol->target.capacity = abs_capacity;
    if (flags & VIR_STORAGE_VOL_RESIZE_ALLOCATE)
        vol->target.allocation = abs_capacity;

    /* Update pool metadata */
    pool->def->allocation += (abs_capacity - vol->target.capacity);
    pool->def->available -= (abs_capacity - vol->target.capacity);

    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);

    return ret;
}


static int
storageVolWipePattern(virStorageVolPtr obj,
                      unsigned int algorithm,
                      unsigned int flags)
{
    virStorageBackendPtr backend;
    virStoragePoolObjPtr pool = NULL;
    virStorageVolDefPtr vol = NULL;
    int ret = -1;

    virCheckFlags(0, -1);

    if (algorithm >= VIR_STORAGE_VOL_WIPE_ALG_LAST) {
        virReportError(VIR_ERR_INVALID_ARG,
                       _("wiping algorithm %d not supported"),
                       algorithm);
        return -1;
    }

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return -1;


    if (virStorageVolWipePatternEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (vol->in_use) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still in use."),
                       vol->name);
        goto cleanup;
    }

    if (vol->building) {
        virReportError(VIR_ERR_OPERATION_INVALID,
                       _("volume '%s' is still being allocated."),
                       vol->name);
        goto cleanup;
    }

    if (!backend->wipeVol) {
        virReportError(VIR_ERR_NO_SUPPORT, "%s",
                       _("storage pool doesn't support volume wiping"));
        goto cleanup;
    }

    ret = backend->wipeVol(obj->conn, pool, vol, algorithm, flags);

 cleanup:
    virStoragePoolObjUnlock(pool);

    return ret;
}

static int
storageVolWipe(virStorageVolPtr obj,
               unsigned int flags)
{
    return storageVolWipePattern(obj, VIR_STORAGE_VOL_WIPE_ALG_ZERO, flags);
}


static int
storageVolGetInfo(virStorageVolPtr obj,
                  virStorageVolInfoPtr info)
{
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    virStorageVolDefPtr vol;
    int ret = -1;

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return -1;

    if (virStorageVolGetInfoEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (backend->refreshVol &&
        backend->refreshVol(obj->conn, pool, vol) < 0)
        goto cleanup;

    memset(info, 0, sizeof(*info));
    info->type = vol->type;
    info->capacity = vol->target.capacity;
    info->allocation = vol->target.allocation;
    ret = 0;

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static char *
storageVolGetXMLDesc(virStorageVolPtr obj,
                     unsigned int flags)
{
    virStoragePoolObjPtr pool;
    virStorageBackendPtr backend;
    virStorageVolDefPtr vol;
    char *ret = NULL;

    virCheckFlags(0, NULL);

    if (!(vol = virStorageVolDefFromVol(obj, &pool, &backend)))
        return NULL;

    if (virStorageVolGetXMLDescEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    if (backend->refreshVol &&
        backend->refreshVol(obj->conn, pool, vol) < 0)
        goto cleanup;

    ret = virStorageVolDefFormat(pool->def, vol);

 cleanup:
    virStoragePoolObjUnlock(pool);

    return ret;
}

static char *
storageVolGetPath(virStorageVolPtr obj)
{
    virStoragePoolObjPtr pool;
    virStorageVolDefPtr vol;
    char *ret = NULL;

    if (!(vol = virStorageVolDefFromVol(obj, &pool, NULL)))
        return NULL;

    if (virStorageVolGetPathEnsureACL(obj->conn, pool->def, vol) < 0)
        goto cleanup;

    ignore_value(VIR_STRDUP(ret, vol->target.path));

 cleanup:
    virStoragePoolObjUnlock(pool);
    return ret;
}

static int
storageConnectListAllStoragePools(virConnectPtr conn,
                                  virStoragePoolPtr **pools,
                                  unsigned int flags)
{
    virStorageDriverStatePtr driver = conn->storagePrivateData;
    int ret = -1;

    virCheckFlags(VIR_CONNECT_LIST_STORAGE_POOLS_FILTERS_ALL, -1);

    if (virConnectListAllStoragePoolsEnsureACL(conn) < 0)
        goto cleanup;

    storageDriverLock(driver);
    ret = virStoragePoolObjListExport(conn, driver->pools, pools,
                                      virConnectListAllStoragePoolsCheckACL, flags);
    storageDriverUnlock(driver);

 cleanup:
    return ret;
}


static virStorageDriver storageDriver = {
    .name = "storage",
    .storageOpen = storageOpen, /* 0.4.0 */
    .storageClose = storageClose, /* 0.4.0 */
    .connectNumOfStoragePools = storageConnectNumOfStoragePools, /* 0.4.0 */
    .connectListStoragePools = storageConnectListStoragePools, /* 0.4.0 */
    .connectNumOfDefinedStoragePools = storageConnectNumOfDefinedStoragePools, /* 0.4.0 */
    .connectListDefinedStoragePools = storageConnectListDefinedStoragePools, /* 0.4.0 */
    .connectListAllStoragePools = storageConnectListAllStoragePools, /* 0.10.2 */
    .connectFindStoragePoolSources = storageConnectFindStoragePoolSources, /* 0.4.0 */
    .storagePoolLookupByName = storagePoolLookupByName, /* 0.4.0 */
    .storagePoolLookupByUUID = storagePoolLookupByUUID, /* 0.4.0 */
    .storagePoolLookupByVolume = storagePoolLookupByVolume, /* 0.4.0 */
    .storagePoolCreateXML = storagePoolCreateXML, /* 0.4.0 */
    .storagePoolDefineXML = storagePoolDefineXML, /* 0.4.0 */
    .storagePoolBuild = storagePoolBuild, /* 0.4.0 */
    .storagePoolUndefine = storagePoolUndefine, /* 0.4.0 */
    .storagePoolCreate = storagePoolCreate, /* 0.4.0 */
    .storagePoolDestroy = storagePoolDestroy, /* 0.4.0 */
    .storagePoolDelete = storagePoolDelete, /* 0.4.0 */
    .storagePoolRefresh = storagePoolRefresh, /* 0.4.0 */
    .storagePoolGetInfo = storagePoolGetInfo, /* 0.4.0 */
    .storagePoolGetXMLDesc = storagePoolGetXMLDesc, /* 0.4.0 */
    .storagePoolGetAutostart = storagePoolGetAutostart, /* 0.4.0 */
    .storagePoolSetAutostart = storagePoolSetAutostart, /* 0.4.0 */
    .storagePoolNumOfVolumes = storagePoolNumOfVolumes, /* 0.4.0 */
    .storagePoolListVolumes = storagePoolListVolumes, /* 0.4.0 */
    .storagePoolListAllVolumes = storagePoolListAllVolumes, /* 0.10.2 */

    .storageVolLookupByName = storageVolLookupByName, /* 0.4.0 */
    .storageVolLookupByKey = storageVolLookupByKey, /* 0.4.0 */
    .storageVolLookupByPath = storageVolLookupByPath, /* 0.4.0 */
    .storageVolCreateXML = storageVolCreateXML, /* 0.4.0 */
    .storageVolCreateXMLFrom = storageVolCreateXMLFrom, /* 0.6.4 */
    .storageVolDownload = storageVolDownload, /* 0.9.0 */
    .storageVolUpload = storageVolUpload, /* 0.9.0 */
    .storageVolDelete = storageVolDelete, /* 0.4.0 */
    .storageVolWipe = storageVolWipe, /* 0.8.0 */
    .storageVolWipePattern = storageVolWipePattern, /* 0.9.10 */
    .storageVolGetInfo = storageVolGetInfo, /* 0.4.0 */
    .storageVolGetXMLDesc = storageVolGetXMLDesc, /* 0.4.0 */
    .storageVolGetPath = storageVolGetPath, /* 0.4.0 */
    .storageVolResize = storageVolResize, /* 0.9.10 */

    .storagePoolIsActive = storagePoolIsActive, /* 0.7.3 */
    .storagePoolIsPersistent = storagePoolIsPersistent, /* 0.7.3 */
};


static virStateDriver stateDriver = {
    .name = "Storage",
    .stateInitialize = storageStateInitialize,
    .stateAutoStart = storageStateAutoStart,
    .stateCleanup = storageStateCleanup,
    .stateReload = storageStateReload,
};

int storageRegister(void)
{
    if (virRegisterStorageDriver(&storageDriver) < 0)
        return -1;
    if (virRegisterStateDriver(&stateDriver) < 0)
        return -1;
    return 0;
}


/* ----------- file handlers cooperating with storage driver --------------- */
static bool
virStorageFileIsInitialized(virStorageSourcePtr src)
{
    return src && src->drv;
}


static bool
virStorageFileSupportsBackingChainTraversal(virStorageSourcePtr src)
{
    int actualType = virStorageSourceGetActualType(src);
    virStorageFileBackendPtr backend;

    if (!src)
        return false;

    if (src->drv) {
        backend = src->drv->backend;
    } else {
        if (!(backend = virStorageFileBackendForTypeInternal(actualType,
                                                             src->protocol,
                                                             false)))
            return false;
    }

    return backend->storageFileGetUniqueIdentifier &&
           backend->storageFileReadHeader &&
           backend->storageFileAccess;
}


/**
 * virStorageFileSupportsSecurityDriver:
 *
 * @src: a storage file structure
 *
 * Check if a storage file supports operations needed by the security
 * driver to perform labelling
 */
bool
virStorageFileSupportsSecurityDriver(virStorageSourcePtr src)
{
    int actualType = virStorageSourceGetActualType(src);
    virStorageFileBackendPtr backend;

    if (!src)
        return false;

    if (src->drv) {
        backend = src->drv->backend;
    } else {
        if (!(backend = virStorageFileBackendForTypeInternal(actualType,
                                                             src->protocol,
                                                             false)))
            return false;
    }

    return !!backend->storageFileChown;
}


void
virStorageFileDeinit(virStorageSourcePtr src)
{
    if (!virStorageFileIsInitialized(src))
        return;

    if (src->drv->backend &&
        src->drv->backend->backendDeinit)
        src->drv->backend->backendDeinit(src);

    VIR_FREE(src->drv);
}


/**
 * virStorageFileInitAs:
 *
 * @src: storage source definition
 * @uid: uid used to access the file, or -1 for current uid
 * @gid: gid used to access the file, or -1 for current gid
 *
 * Initialize a storage source to be used with storage driver. Use the provided
 * uid and gid if possible for the operations.
 *
 * Returns 0 if the storage file was successfully initialized, -1 if the
 * initialization failed. Libvirt error is reported.
 */
int
virStorageFileInitAs(virStorageSourcePtr src,
                     uid_t uid, gid_t gid)
{
    int actualType = virStorageSourceGetActualType(src);
    if (VIR_ALLOC(src->drv) < 0)
        return -1;

    if (uid == (uid_t) -1)
        src->drv->uid = geteuid();
    else
        src->drv->uid = uid;

    if (gid == (gid_t) -1)
        src->drv->gid = getegid();
    else
        src->drv->gid = gid;

    if (!(src->drv->backend = virStorageFileBackendForType(actualType,
                                                           src->protocol)))
        goto error;

    if (src->drv->backend->backendInit &&
        src->drv->backend->backendInit(src) < 0)
        goto error;

    return 0;

 error:
    VIR_FREE(src->drv);
    return -1;
}


/**
 * virStorageFileInit:
 *
 * See virStorageFileInitAs. The file is initialized to be accessed by the
 * current user.
 */
int
virStorageFileInit(virStorageSourcePtr src)
{
    return virStorageFileInitAs(src, -1, -1);
}


/**
 * virStorageFileCreate: Creates an empty storage file via storage driver
 *
 * @src: file structure pointing to the file
 *
 * Returns 0 on success, -2 if the function isn't supported by the backend,
 * -1 on other failure. Errno is set in case of failure.
 */
int
virStorageFileCreate(virStorageSourcePtr src)
{
    int ret;

    if (!virStorageFileIsInitialized(src) ||
        !src->drv->backend->storageFileCreate) {
        errno = ENOSYS;
        return -2;
    }

    ret = src->drv->backend->storageFileCreate(src);

    VIR_DEBUG("created storage file %p: ret=%d, errno=%d",
              src, ret, errno);

    return ret;
}


/**
 * virStorageFileUnlink: Unlink storage file via storage driver
 *
 * @src: file structure pointing to the file
 *
 * Unlinks the file described by the @file structure.
 *
 * Returns 0 on success, -2 if the function isn't supported by the backend,
 * -1 on other failure. Errno is set in case of failure.
 */
int
virStorageFileUnlink(virStorageSourcePtr src)
{
    int ret;

    if (!virStorageFileIsInitialized(src) ||
        !src->drv->backend->storageFileUnlink) {
        errno = ENOSYS;
        return -2;
    }

    ret = src->drv->backend->storageFileUnlink(src);

    VIR_DEBUG("unlinked storage file %p: ret=%d, errno=%d",
              src, ret, errno);

    return ret;
}


/**
 * virStorageFileStat: returns stat struct of a file via storage driver
 *
 * @src: file structure pointing to the file
 * @stat: stat structure to return data
 *
 * Returns 0 on success, -2 if the function isn't supported by the backend,
 * -1 on other failure. Errno is set in case of failure.
*/
int
virStorageFileStat(virStorageSourcePtr src,
                   struct stat *st)
{
    int ret;

    if (!virStorageFileIsInitialized(src) ||
        !src->drv->backend->storageFileStat) {
        errno = ENOSYS;
        return -2;
    }

    ret = src->drv->backend->storageFileStat(src, st);

    VIR_DEBUG("stat of storage file %p: ret=%d, errno=%d",
              src, ret, errno);

    return ret;
}


/**
 * virStorageFileReadHeader: read the beginning bytes of a file into a buffer
 *
 * @src: file structure pointing to the file
 * @max_len: maximum number of bytes read from the storage file
 * @buf: buffer to read the data into. buffer shall be freed by caller)
 *
 * Returns the count of bytes read on success and -1 on failure, -2 if the
 * function isn't supported by the backend. Libvirt error is reported on failure.
 */
ssize_t
virStorageFileReadHeader(virStorageSourcePtr src,
                         ssize_t max_len,
                         char **buf)
{
    ssize_t ret;

    if (!virStorageFileIsInitialized(src)) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("storage file backend not initialized"));
        return -1;
    }

    if (!src->drv->backend->storageFileReadHeader) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("storage file header reading is not supported for "
                         "storage type %s (protocol: %s)"),
                       virStorageTypeToString(src->type),
                       virStorageNetProtocolTypeToString(src->protocol));
        return -2;
    }

    ret = src->drv->backend->storageFileReadHeader(src, max_len, buf);

    VIR_DEBUG("read of storage header %p: ret=%zd", src, ret);

    return ret;
}


/*
 * virStorageFileGetUniqueIdentifier: Get a unique string describing the volume
 *
 * @src: file structure pointing to the file
 *
 * Returns a string uniquely describing a single volume (canonical path).
 * The string shall not be freed and is valid until the storage file is
 * deinitialized. Returns NULL on error and sets a libvirt error code */
const char *
virStorageFileGetUniqueIdentifier(virStorageSourcePtr src)
{
    if (!virStorageFileIsInitialized(src)) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("storage file backend not initialized"));
        return NULL;
    }

    if (!src->drv->backend->storageFileGetUniqueIdentifier) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("unique storage file identifier not implemented for "
                          "storage type %s (protocol: %s)'"),
                       virStorageTypeToString(src->type),
                       virStorageNetProtocolTypeToString(src->protocol));
        return NULL;
    }

    return src->drv->backend->storageFileGetUniqueIdentifier(src);
}


/**
 * virStorageFileAccess: Check accessibility of a storage file
 *
 * @src: storage file to check access permissions
 * @mode: accessibility check options (see man 2 access)
 *
 * Returns 0 on success, -1 on error and sets errno. No libvirt
 * error is reported. Returns -2 if the operation isn't supported
 * by libvirt storage backend.
 */
int
virStorageFileAccess(virStorageSourcePtr src,
                     int mode)
{
    if (!virStorageFileIsInitialized(src) ||
        !src->drv->backend->storageFileAccess) {
        errno = ENOSYS;
        return -2;
    }

    return src->drv->backend->storageFileAccess(src, mode);
}


/**
 * virStorageFileChown: Change owner of a storage file
 *
 * @src: storage file to change owner of
 * @uid: new owner id
 * @gid: new group id
 *
 * Returns 0 on success, -1 on error and sets errno. No libvirt
 * error is reported. Returns -2 if the operation isn't supported
 * by libvirt storage backend.
 */
int
virStorageFileChown(virStorageSourcePtr src,
                    uid_t uid,
                    gid_t gid)
{
    if (!virStorageFileIsInitialized(src) ||
        !src->drv->backend->storageFileChown) {
        errno = ENOSYS;
        return -2;
    }

    VIR_DEBUG("chown of storage file %p to %d:%d", src, uid, gid);

    return src->drv->backend->storageFileChown(src, uid, gid);
}


/* Recursive workhorse for virStorageFileGetMetadata.  */
static int
virStorageFileGetMetadataRecurse(virStorageSourcePtr src,
                                 uid_t uid, gid_t gid,
                                 bool allow_probe,
                                 virHashTablePtr cycle)
{
    int ret = -1;
    const char *uniqueName;
    char *buf = NULL;
    ssize_t headerLen;
    virStorageSourcePtr backingStore = NULL;
    int backingFormat;

    VIR_DEBUG("path=%s format=%d uid=%d gid=%d probe=%d",
              src->path, src->format,
              (int)uid, (int)gid, allow_probe);

    /* exit if we can't load information about the current image */
    if (!virStorageFileSupportsBackingChainTraversal(src))
        return 0;

    if (virStorageFileInitAs(src, uid, gid) < 0)
        return -1;

    if (virStorageFileAccess(src, F_OK) < 0) {
        virReportSystemError(errno,
                             _("Cannot access backing file %s"),
                             src->path);
        goto cleanup;
    }

    if (!(uniqueName = virStorageFileGetUniqueIdentifier(src)))
        goto cleanup;

    if (virHashLookup(cycle, uniqueName)) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("backing store for %s (%s) is self-referential"),
                       src->path, uniqueName);
        goto cleanup;
    }

    if (virHashAddEntry(cycle, uniqueName, (void *)1) < 0)
        goto cleanup;

    if ((headerLen = virStorageFileReadHeader(src, VIR_STORAGE_MAX_HEADER,
                                              &buf)) < 0)
        goto cleanup;

    if (virStorageFileGetMetadataInternal(src, buf, headerLen,
                                          &backingFormat) < 0)
        goto cleanup;

    /* check whether we need to go deeper */
    if (!src->backingStoreRaw) {
        ret = 0;
        goto cleanup;
    }

    if (!(backingStore = virStorageSourceNewFromBacking(src)))
        goto cleanup;

    if (backingFormat == VIR_STORAGE_FILE_AUTO && !allow_probe)
        backingStore->format = VIR_STORAGE_FILE_RAW;
    else if (backingFormat == VIR_STORAGE_FILE_AUTO_SAFE)
        backingStore->format = VIR_STORAGE_FILE_AUTO;
    else
        backingStore->format = backingFormat;

    if (virStorageFileGetMetadataRecurse(backingStore,
                                         uid, gid, allow_probe,
                                         cycle) < 0) {
        /* if we fail somewhere midway, just accept and return a
         * broken chain */
        ret = 0;
        goto cleanup;
    }

    src->backingStore = backingStore;
    backingStore = NULL;
    ret = 0;

 cleanup:
    VIR_FREE(buf);
    virStorageFileDeinit(src);
    virStorageSourceFree(backingStore);
    return ret;
}


/**
 * virStorageFileGetMetadata:
 *
 * Extract metadata about the storage volume with the specified
 * image format. If image format is VIR_STORAGE_FILE_AUTO, it
 * will probe to automatically identify the format.  Recurses through
 * the entire chain.
 *
 * Open files using UID and GID (or pass -1 for the current user/group).
 * Treat any backing files without explicit type as raw, unless ALLOW_PROBE.
 *
 * Callers are advised never to use VIR_STORAGE_FILE_AUTO as a
 * format, since a malicious guest can turn a raw file into any
 * other non-raw format at will.
 *
 * Caller MUST free result after use via virStorageSourceFree.
 */
int
virStorageFileGetMetadata(virStorageSourcePtr src,
                          uid_t uid, gid_t gid,
                          bool allow_probe)
{
    VIR_DEBUG("path=%s format=%d uid=%d gid=%d probe=%d",
              src->path, src->format, (int)uid, (int)gid, allow_probe);

    virHashTablePtr cycle = NULL;
    char *canonPath = NULL;
    int ret = -1;

    if (!(cycle = virHashCreate(5, NULL)))
        return -1;

    if (src->format <= VIR_STORAGE_FILE_NONE)
        src->format = allow_probe ? VIR_STORAGE_FILE_AUTO : VIR_STORAGE_FILE_RAW;

    ret = virStorageFileGetMetadataRecurse(src, uid, gid,
                                           allow_probe, cycle);

    VIR_FREE(canonPath);
    virHashFree(cycle);
    return ret;
}


static int
virStorageAddISCSIPoolSourceHost(virDomainDiskDefPtr def,
                                 virStoragePoolDefPtr pooldef)
{
    int ret = -1;
    char **tokens = NULL;

    /* Only support one host */
    if (pooldef->source.nhost != 1) {
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                       _("Expected exactly 1 host for the storage pool"));
        goto cleanup;
    }

    /* iscsi pool only supports one host */
    def->src->nhosts = 1;

    if (VIR_ALLOC_N(def->src->hosts, def->src->nhosts) < 0)
        goto cleanup;

    if (VIR_STRDUP(def->src->hosts[0].name, pooldef->source.hosts[0].name) < 0)
        goto cleanup;

    if (virAsprintf(&def->src->hosts[0].port, "%d",
                    pooldef->source.hosts[0].port ?
                    pooldef->source.hosts[0].port :
                    3260) < 0)
        goto cleanup;

    /* iscsi volume has name like "unit:0:0:1" */
    if (!(tokens = virStringSplit(def->src->srcpool->volume, ":", 0)))
        goto cleanup;

    if (virStringListLength(tokens) != 4) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("unexpected iscsi volume name '%s'"),
                       def->src->srcpool->volume);
        goto cleanup;
    }

    /* iscsi pool has only one source device path */
    if (virAsprintf(&def->src->path, "%s/%s",
                    pooldef->source.devices[0].path,
                    tokens[3]) < 0)
        goto cleanup;

    /* Storage pool have not supported these 2 attributes yet,
     * use the defaults.
     */
    def->src->hosts[0].transport = VIR_STORAGE_NET_HOST_TRANS_TCP;
    def->src->hosts[0].socket = NULL;

    def->src->protocol = VIR_STORAGE_NET_PROTOCOL_ISCSI;

    ret = 0;

 cleanup:
    virStringFreeList(tokens);
    return ret;
}


static int
virStorageTranslateDiskSourcePoolAuth(virDomainDiskDefPtr def,
                                      virStoragePoolSourcePtr source)
{
    int ret = -1;

    /* Only necessary when authentication set */
    if (!source->auth) {
        ret = 0;
        goto cleanup;
    }
    def->src->auth = virStorageAuthDefCopy(source->auth);
    if (!def->src->auth)
        goto cleanup;
    ret = 0;

 cleanup:
    return ret;
}


int
virStorageTranslateDiskSourcePool(virConnectPtr conn,
                                  virDomainDiskDefPtr def)
{
    virStoragePoolDefPtr pooldef = NULL;
    virStoragePoolPtr pool = NULL;
    virStorageVolPtr vol = NULL;
    char *poolxml = NULL;
    virStorageVolInfo info;
    int ret = -1;
    virErrorPtr savedError = NULL;

    if (def->src->type != VIR_STORAGE_TYPE_VOLUME)
        return 0;

    if (!def->src->srcpool)
        return 0;

    if (!(pool = virStoragePoolLookupByName(conn, def->src->srcpool->pool)))
        return -1;

    if (virStoragePoolIsActive(pool) != 1) {
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                       _("storage pool '%s' containing volume '%s' "
                         "is not active"),
                       def->src->srcpool->pool, def->src->srcpool->volume);
        goto cleanup;
    }

    if (!(vol = virStorageVolLookupByName(pool, def->src->srcpool->volume)))
        goto cleanup;

    if (virStorageVolGetInfo(vol, &info) < 0)
        goto cleanup;

    if (!(poolxml = virStoragePoolGetXMLDesc(pool, 0)))
        goto cleanup;

    if (!(pooldef = virStoragePoolDefParseString(poolxml)))
        goto cleanup;

    def->src->srcpool->pooltype = pooldef->type;
    def->src->srcpool->voltype = info.type;

    if (def->src->srcpool->mode && pooldef->type != VIR_STORAGE_POOL_ISCSI) {
        virReportError(VIR_ERR_XML_ERROR, "%s",
                       _("disk source mode is only valid when "
                         "storage pool is of iscsi type"));
        goto cleanup;
    }

    VIR_FREE(def->src->path);
    virStorageNetHostDefFree(def->src->nhosts, def->src->hosts);
    virStorageAuthDefFree(def->src->auth);

    switch ((virStoragePoolType) pooldef->type) {
    case VIR_STORAGE_POOL_DIR:
    case VIR_STORAGE_POOL_FS:
    case VIR_STORAGE_POOL_NETFS:
    case VIR_STORAGE_POOL_LOGICAL:
    case VIR_STORAGE_POOL_DISK:
    case VIR_STORAGE_POOL_SCSI:
    case VIR_STORAGE_POOL_ZFS:
        if (!(def->src->path = virStorageVolGetPath(vol)))
            goto cleanup;

        if (def->startupPolicy && info.type != VIR_STORAGE_VOL_FILE) {
            virReportError(VIR_ERR_XML_ERROR, "%s",
                           _("'startupPolicy' is only valid for "
                             "'file' type volume"));
            goto cleanup;
        }


        switch (info.type) {
        case VIR_STORAGE_VOL_FILE:
            def->src->srcpool->actualtype = VIR_STORAGE_TYPE_FILE;
            break;

        case VIR_STORAGE_VOL_DIR:
            def->src->srcpool->actualtype = VIR_STORAGE_TYPE_DIR;
            break;

        case VIR_STORAGE_VOL_BLOCK:
            def->src->srcpool->actualtype = VIR_STORAGE_TYPE_BLOCK;
            break;

        case VIR_STORAGE_VOL_NETWORK:
        case VIR_STORAGE_VOL_NETDIR:
            virReportError(VIR_ERR_INTERNAL_ERROR,
                           _("unexpected storage volume type '%s' "
                             "for storage pool type '%s'"),
                           virStorageVolTypeToString(info.type),
                           virStoragePoolTypeToString(pooldef->type));
            goto cleanup;
        }

        break;

    case VIR_STORAGE_POOL_ISCSI:
        if (def->startupPolicy) {
            virReportError(VIR_ERR_XML_ERROR, "%s",
                           _("'startupPolicy' is only valid for "
                             "'file' type volume"));
            goto cleanup;
        }

       switch (def->src->srcpool->mode) {
       case VIR_STORAGE_SOURCE_POOL_MODE_DEFAULT:
       case VIR_STORAGE_SOURCE_POOL_MODE_LAST:
           def->src->srcpool->mode = VIR_STORAGE_SOURCE_POOL_MODE_HOST;
           /* fallthrough */
       case VIR_STORAGE_SOURCE_POOL_MODE_HOST:
           def->src->srcpool->actualtype = VIR_STORAGE_TYPE_BLOCK;
           if (!(def->src->path = virStorageVolGetPath(vol)))
               goto cleanup;
           break;

       case VIR_STORAGE_SOURCE_POOL_MODE_DIRECT:
           def->src->srcpool->actualtype = VIR_STORAGE_TYPE_NETWORK;
           def->src->protocol = VIR_STORAGE_NET_PROTOCOL_ISCSI;

           if (virStorageTranslateDiskSourcePoolAuth(def, &pooldef->source) < 0)
               goto cleanup;

           if (virStorageAddISCSIPoolSourceHost(def, pooldef) < 0)
               goto cleanup;
           break;
       }
       break;

    case VIR_STORAGE_POOL_MPATH:
    case VIR_STORAGE_POOL_RBD:
    case VIR_STORAGE_POOL_SHEEPDOG:
    case VIR_STORAGE_POOL_GLUSTER:
    case VIR_STORAGE_POOL_LAST:
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                       _("using '%s' pools for backing 'volume' disks "
                         "isn't yet supported"),
                       virStoragePoolTypeToString(pooldef->type));
        goto cleanup;
    }

    ret = 0;
 cleanup:
    if (ret < 0)
        savedError = virSaveLastError();
    if (pool)
        virStoragePoolFree(pool);
    if (vol)
        virStorageVolFree(vol);
    if (savedError) {
        virSetError(savedError);
        virFreeError(savedError);
    }

    VIR_FREE(poolxml);
    virStoragePoolDefFree(pooldef);
    return ret;
}