Adding qemu as a submodule of KVMFORNFV

This Patch includes the changes to add qemu as a submodule to
kvmfornfv repo and make use of the updated latest qemu for the
execution of all testcase
Change-Id: I1280af507a857675c7f81d30c95255635667bdd7
Signed-off-by:RajithaY<rajithax.yerrumsetty@intel.com>

1 files changed, 0 insertions, 3983 deletions

diff --git a/qemu/block.c b/qemu/block.c
deleted file mode 100644
index d4939b49b..000000000
--- a/qemu/block.c
+++ /dev/null
@@ -1,3983 +0,0 @@
-/*
- * QEMU System Emulator block driver
- *
- * Copyright (c) 2003 Fabrice Bellard
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-#include "qemu/osdep.h"
-#include "trace.h"
-#include "block/block_int.h"
-#include "block/blockjob.h"
-#include "qemu/error-report.h"
-#include "qemu/module.h"
-#include "qapi/qmp/qerror.h"
-#include "qapi/qmp/qbool.h"
-#include "qapi/qmp/qjson.h"
-#include "sysemu/block-backend.h"
-#include "sysemu/sysemu.h"
-#include "qemu/notify.h"
-#include "qemu/coroutine.h"
-#include "block/qapi.h"
-#include "qmp-commands.h"
-#include "qemu/timer.h"
-#include "qapi-event.h"
-#include "block/throttle-groups.h"
-#include "qemu/cutils.h"
-#include "qemu/id.h"
-
-#ifdef CONFIG_BSD
-#include <sys/ioctl.h>
-#include <sys/queue.h>
-#ifndef __DragonFly__
-#include <sys/disk.h>
-#endif
-#endif
-
-#ifdef _WIN32
-#include <windows.h>
-#endif
-
-#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
-
-static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
-    QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
-
-static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
-    QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
-
-static QLIST_HEAD(, BlockDriver) bdrv_drivers =
-    QLIST_HEAD_INITIALIZER(bdrv_drivers);
-
-static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
-                             const char *reference, QDict *options, int flags,
-                             BlockDriverState *parent,
-                             const BdrvChildRole *child_role, Error **errp);
-
-/* If non-zero, use only whitelisted block drivers */
-static int use_bdrv_whitelist;
-
-static void bdrv_close(BlockDriverState *bs);
-
-#ifdef _WIN32
-static int is_windows_drive_prefix(const char *filename)
-{
-    return (((filename[0] >= 'a' && filename[0] <= 'z') ||
-             (filename[0] >= 'A' && filename[0] <= 'Z')) &&
-            filename[1] == ':');
-}
-
-int is_windows_drive(const char *filename)
-{
-    if (is_windows_drive_prefix(filename) &&
-        filename[2] == '\0')
-        return 1;
-    if (strstart(filename, "\\\\.\\", NULL) ||
-        strstart(filename, "//./", NULL))
-        return 1;
-    return 0;
-}
-#endif
-
-size_t bdrv_opt_mem_align(BlockDriverState *bs)
-{
-    if (!bs || !bs->drv) {
-        /* page size or 4k (hdd sector size) should be on the safe side */
-        return MAX(4096, getpagesize());
-    }
-
-    return bs->bl.opt_mem_alignment;
-}
-
-size_t bdrv_min_mem_align(BlockDriverState *bs)
-{
-    if (!bs || !bs->drv) {
-        /* page size or 4k (hdd sector size) should be on the safe side */
-        return MAX(4096, getpagesize());
-    }
-
-    return bs->bl.min_mem_alignment;
-}
-
-/* check if the path starts with "<protocol>:" */
-int path_has_protocol(const char *path)
-{
-    const char *p;
-
-#ifdef _WIN32
-    if (is_windows_drive(path) ||
-        is_windows_drive_prefix(path)) {
-        return 0;
-    }
-    p = path + strcspn(path, ":/\\");
-#else
-    p = path + strcspn(path, ":/");
-#endif
-
-    return *p == ':';
-}
-
-int path_is_absolute(const char *path)
-{
-#ifdef _WIN32
-    /* specific case for names like: "\\.\d:" */
-    if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
-        return 1;
-    }
-    return (*path == '/' || *path == '\\');
-#else
-    return (*path == '/');
-#endif
-}
-
-/* if filename is absolute, just copy it to dest. Otherwise, build a
-   path to it by considering it is relative to base_path. URL are
-   supported. */
-void path_combine(char *dest, int dest_size,
-                  const char *base_path,
-                  const char *filename)
-{
-    const char *p, *p1;
-    int len;
-
-    if (dest_size <= 0)
-        return;
-    if (path_is_absolute(filename)) {
-        pstrcpy(dest, dest_size, filename);
-    } else {
-        p = strchr(base_path, ':');
-        if (p)
-            p++;
-        else
-            p = base_path;
-        p1 = strrchr(base_path, '/');
-#ifdef _WIN32
-        {
-            const char *p2;
-            p2 = strrchr(base_path, '\\');
-            if (!p1 || p2 > p1)
-                p1 = p2;
-        }
-#endif
-        if (p1)
-            p1++;
-        else
-            p1 = base_path;
-        if (p1 > p)
-            p = p1;
-        len = p - base_path;
-        if (len > dest_size - 1)
-            len = dest_size - 1;
-        memcpy(dest, base_path, len);
-        dest[len] = '\0';
-        pstrcat(dest, dest_size, filename);
-    }
-}
-
-void bdrv_get_full_backing_filename_from_filename(const char *backed,
-                                                  const char *backing,
-                                                  char *dest, size_t sz,
-                                                  Error **errp)
-{
-    if (backing[0] == '\0' || path_has_protocol(backing) ||
-        path_is_absolute(backing))
-    {
-        pstrcpy(dest, sz, backing);
-    } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
-        error_setg(errp, "Cannot use relative backing file names for '%s'",
-                   backed);
-    } else {
-        path_combine(dest, sz, backed, backing);
-    }
-}
-
-void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
-                                    Error **errp)
-{
-    char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
-
-    bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
-                                                 dest, sz, errp);
-}
-
-void bdrv_register(BlockDriver *bdrv)
-{
-    bdrv_setup_io_funcs(bdrv);
-
-    QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
-}
-
-BlockDriverState *bdrv_new_root(void)
-{
-    return bdrv_new();
-}
-
-BlockDriverState *bdrv_new(void)
-{
-    BlockDriverState *bs;
-    int i;
-
-    bs = g_new0(BlockDriverState, 1);
-    QLIST_INIT(&bs->dirty_bitmaps);
-    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
-        QLIST_INIT(&bs->op_blockers[i]);
-    }
-    notifier_with_return_list_init(&bs->before_write_notifiers);
-    qemu_co_queue_init(&bs->throttled_reqs[0]);
-    qemu_co_queue_init(&bs->throttled_reqs[1]);
-    bs->refcnt = 1;
-    bs->aio_context = qemu_get_aio_context();
-
-    QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
-
-    return bs;
-}
-
-BlockDriver *bdrv_find_format(const char *format_name)
-{
-    BlockDriver *drv1;
-    QLIST_FOREACH(drv1, &bdrv_drivers, list) {
-        if (!strcmp(drv1->format_name, format_name)) {
-            return drv1;
-        }
-    }
-    return NULL;
-}
-
-static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
-{
-    static const char *whitelist_rw[] = {
-        CONFIG_BDRV_RW_WHITELIST
-    };
-    static const char *whitelist_ro[] = {
-        CONFIG_BDRV_RO_WHITELIST
-    };
-    const char **p;
-
-    if (!whitelist_rw[0] && !whitelist_ro[0]) {
-        return 1;               /* no whitelist, anything goes */
-    }
-
-    for (p = whitelist_rw; *p; p++) {
-        if (!strcmp(drv->format_name, *p)) {
-            return 1;
-        }
-    }
-    if (read_only) {
-        for (p = whitelist_ro; *p; p++) {
-            if (!strcmp(drv->format_name, *p)) {
-                return 1;
-            }
-        }
-    }
-    return 0;
-}
-
-bool bdrv_uses_whitelist(void)
-{
-    return use_bdrv_whitelist;
-}
-
-typedef struct CreateCo {
-    BlockDriver *drv;
-    char *filename;
-    QemuOpts *opts;
-    int ret;
-    Error *err;
-} CreateCo;
-
-static void coroutine_fn bdrv_create_co_entry(void *opaque)
-{
-    Error *local_err = NULL;
-    int ret;
-
-    CreateCo *cco = opaque;
-    assert(cco->drv);
-
-    ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err);
-    if (local_err) {
-        error_propagate(&cco->err, local_err);
-    }
-    cco->ret = ret;
-}
-
-int bdrv_create(BlockDriver *drv, const char* filename,
-                QemuOpts *opts, Error **errp)
-{
-    int ret;
-
-    Coroutine *co;
-    CreateCo cco = {
-        .drv = drv,
-        .filename = g_strdup(filename),
-        .opts = opts,
-        .ret = NOT_DONE,
-        .err = NULL,
-    };
-
-    if (!drv->bdrv_create) {
-        error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
-        ret = -ENOTSUP;
-        goto out;
-    }
-
-    if (qemu_in_coroutine()) {
-        /* Fast-path if already in coroutine context */
-        bdrv_create_co_entry(&cco);
-    } else {
-        co = qemu_coroutine_create(bdrv_create_co_entry);
-        qemu_coroutine_enter(co, &cco);
-        while (cco.ret == NOT_DONE) {
-            aio_poll(qemu_get_aio_context(), true);
-        }
-    }
-
-    ret = cco.ret;
-    if (ret < 0) {
-        if (cco.err) {
-            error_propagate(errp, cco.err);
-        } else {
-            error_setg_errno(errp, -ret, "Could not create image");
-        }
-    }
-
-out:
-    g_free(cco.filename);
-    return ret;
-}
-
-int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
-{
-    BlockDriver *drv;
-    Error *local_err = NULL;
-    int ret;
-
-    drv = bdrv_find_protocol(filename, true, errp);
-    if (drv == NULL) {
-        return -ENOENT;
-    }
-
-    ret = bdrv_create(drv, filename, opts, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-    }
-    return ret;
-}
-
-/**
- * Try to get @bs's logical and physical block size.
- * On success, store them in @bsz struct and return 0.
- * On failure return -errno.
- * @bs must not be empty.
- */
-int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
-{
-    BlockDriver *drv = bs->drv;
-
-    if (drv && drv->bdrv_probe_blocksizes) {
-        return drv->bdrv_probe_blocksizes(bs, bsz);
-    }
-
-    return -ENOTSUP;
-}
-
-/**
- * Try to get @bs's geometry (cyls, heads, sectors).
- * On success, store them in @geo struct and return 0.
- * On failure return -errno.
- * @bs must not be empty.
- */
-int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
-{
-    BlockDriver *drv = bs->drv;
-
-    if (drv && drv->bdrv_probe_geometry) {
-        return drv->bdrv_probe_geometry(bs, geo);
-    }
-
-    return -ENOTSUP;
-}
-
-/*
- * Create a uniquely-named empty temporary file.
- * Return 0 upon success, otherwise a negative errno value.
- */
-int get_tmp_filename(char *filename, int size)
-{
-#ifdef _WIN32
-    char temp_dir[MAX_PATH];
-    /* GetTempFileName requires that its output buffer (4th param)
-       have length MAX_PATH or greater.  */
-    assert(size >= MAX_PATH);
-    return (GetTempPath(MAX_PATH, temp_dir)
-            && GetTempFileName(temp_dir, "qem", 0, filename)
-            ? 0 : -GetLastError());
-#else
-    int fd;
-    const char *tmpdir;
-    tmpdir = getenv("TMPDIR");
-    if (!tmpdir) {
-        tmpdir = "/var/tmp";
-    }
-    if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
-        return -EOVERFLOW;
-    }
-    fd = mkstemp(filename);
-    if (fd < 0) {
-        return -errno;
-    }
-    if (close(fd) != 0) {
-        unlink(filename);
-        return -errno;
-    }
-    return 0;
-#endif
-}
-
-/*
- * Detect host devices. By convention, /dev/cdrom[N] is always
- * recognized as a host CDROM.
- */
-static BlockDriver *find_hdev_driver(const char *filename)
-{
-    int score_max = 0, score;
-    BlockDriver *drv = NULL, *d;
-
-    QLIST_FOREACH(d, &bdrv_drivers, list) {
-        if (d->bdrv_probe_device) {
-            score = d->bdrv_probe_device(filename);
-            if (score > score_max) {
-                score_max = score;
-                drv = d;
-            }
-        }
-    }
-
-    return drv;
-}
-
-BlockDriver *bdrv_find_protocol(const char *filename,
-                                bool allow_protocol_prefix,
-                                Error **errp)
-{
-    BlockDriver *drv1;
-    char protocol[128];
-    int len;
-    const char *p;
-
-    /* TODO Drivers without bdrv_file_open must be specified explicitly */
-
-    /*
-     * XXX(hch): we really should not let host device detection
-     * override an explicit protocol specification, but moving this
-     * later breaks access to device names with colons in them.
-     * Thanks to the brain-dead persistent naming schemes on udev-
-     * based Linux systems those actually are quite common.
-     */
-    drv1 = find_hdev_driver(filename);
-    if (drv1) {
-        return drv1;
-    }
-
-    if (!path_has_protocol(filename) || !allow_protocol_prefix) {
-        return &bdrv_file;
-    }
-
-    p = strchr(filename, ':');
-    assert(p != NULL);
-    len = p - filename;
-    if (len > sizeof(protocol) - 1)
-        len = sizeof(protocol) - 1;
-    memcpy(protocol, filename, len);
-    protocol[len] = '\0';
-    QLIST_FOREACH(drv1, &bdrv_drivers, list) {
-        if (drv1->protocol_name &&
-            !strcmp(drv1->protocol_name, protocol)) {
-            return drv1;
-        }
-    }
-
-    error_setg(errp, "Unknown protocol '%s'", protocol);
-    return NULL;
-}
-
-/*
- * Guess image format by probing its contents.
- * This is not a good idea when your image is raw (CVE-2008-2004), but
- * we do it anyway for backward compatibility.
- *
- * @buf         contains the image's first @buf_size bytes.
- * @buf_size    is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
- *              but can be smaller if the image file is smaller)
- * @filename    is its filename.
- *
- * For all block drivers, call the bdrv_probe() method to get its
- * probing score.
- * Return the first block driver with the highest probing score.
- */
-BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
-                            const char *filename)
-{
-    int score_max = 0, score;
-    BlockDriver *drv = NULL, *d;
-
-    QLIST_FOREACH(d, &bdrv_drivers, list) {
-        if (d->bdrv_probe) {
-            score = d->bdrv_probe(buf, buf_size, filename);
-            if (score > score_max) {
-                score_max = score;
-                drv = d;
-            }
-        }
-    }
-
-    return drv;
-}
-
-static int find_image_format(BlockDriverState *bs, const char *filename,
-                             BlockDriver **pdrv, Error **errp)
-{
-    BlockDriver *drv;
-    uint8_t buf[BLOCK_PROBE_BUF_SIZE];
-    int ret = 0;
-
-    /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
-    if (bdrv_is_sg(bs) || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) {
-        *pdrv = &bdrv_raw;
-        return ret;
-    }
-
-    ret = bdrv_pread(bs, 0, buf, sizeof(buf));
-    if (ret < 0) {
-        error_setg_errno(errp, -ret, "Could not read image for determining its "
-                         "format");
-        *pdrv = NULL;
-        return ret;
-    }
-
-    drv = bdrv_probe_all(buf, ret, filename);
-    if (!drv) {
-        error_setg(errp, "Could not determine image format: No compatible "
-                   "driver found");
-        ret = -ENOENT;
-    }
-    *pdrv = drv;
-    return ret;
-}
-
-/**
- * Set the current 'total_sectors' value
- * Return 0 on success, -errno on error.
- */
-static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
-{
-    BlockDriver *drv = bs->drv;
-
-    /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
-    if (bdrv_is_sg(bs))
-        return 0;
-
-    /* query actual device if possible, otherwise just trust the hint */
-    if (drv->bdrv_getlength) {
-        int64_t length = drv->bdrv_getlength(bs);
-        if (length < 0) {
-            return length;
-        }
-        hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
-    }
-
-    bs->total_sectors = hint;
-    return 0;
-}
-
-/**
- * Combines a QDict of new block driver @options with any missing options taken
- * from @old_options, so that leaving out an option defaults to its old value.
- */
-static void bdrv_join_options(BlockDriverState *bs, QDict *options,
-                              QDict *old_options)
-{
-    if (bs->drv && bs->drv->bdrv_join_options) {
-        bs->drv->bdrv_join_options(options, old_options);
-    } else {
-        qdict_join(options, old_options, false);
-    }
-}
-
-/**
- * Set open flags for a given discard mode
- *
- * Return 0 on success, -1 if the discard mode was invalid.
- */
-int bdrv_parse_discard_flags(const char *mode, int *flags)
-{
-    *flags &= ~BDRV_O_UNMAP;
-
-    if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
-        /* do nothing */
-    } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) {
-        *flags |= BDRV_O_UNMAP;
-    } else {
-        return -1;
-    }
-
-    return 0;
-}
-
-/**
- * Set open flags for a given cache mode
- *
- * Return 0 on success, -1 if the cache mode was invalid.
- */
-int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
-{
-    *flags &= ~BDRV_O_CACHE_MASK;
-
-    if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
-        *writethrough = false;
-        *flags |= BDRV_O_NOCACHE;
-    } else if (!strcmp(mode, "directsync")) {
-        *writethrough = true;
-        *flags |= BDRV_O_NOCACHE;
-    } else if (!strcmp(mode, "writeback")) {
-        *writethrough = false;
-    } else if (!strcmp(mode, "unsafe")) {
-        *writethrough = false;
-        *flags |= BDRV_O_NO_FLUSH;
-    } else if (!strcmp(mode, "writethrough")) {
-        *writethrough = true;
-    } else {
-        return -1;
-    }
-
-    return 0;
-}
-
-/*
- * Returns the options and flags that a temporary snapshot should get, based on
- * the originally requested flags (the originally requested image will have
- * flags like a backing file)
- */
-static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
-                                       int parent_flags, QDict *parent_options)
-{
-    *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
-
-    /* For temporary files, unconditional cache=unsafe is fine */
-    qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
-    qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
-}
-
-/*
- * Returns the options and flags that bs->file should get if a protocol driver
- * is expected, based on the given options and flags for the parent BDS
- */
-static void bdrv_inherited_options(int *child_flags, QDict *child_options,
-                                   int parent_flags, QDict *parent_options)
-{
-    int flags = parent_flags;
-
-    /* Enable protocol handling, disable format probing for bs->file */
-    flags |= BDRV_O_PROTOCOL;
-
-    /* If the cache mode isn't explicitly set, inherit direct and no-flush from
-     * the parent. */
-    qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
-    qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
-
-    /* Our block drivers take care to send flushes and respect unmap policy,
-     * so we can default to enable both on lower layers regardless of the
-     * corresponding parent options. */
-    flags |= BDRV_O_UNMAP;
-
-    /* Clear flags that only apply to the top layer */
-    flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ |
-               BDRV_O_NO_IO);
-
-    *child_flags = flags;
-}
-
-const BdrvChildRole child_file = {
-    .inherit_options = bdrv_inherited_options,
-};
-
-/*
- * Returns the options and flags that bs->file should get if the use of formats
- * (and not only protocols) is permitted for it, based on the given options and
- * flags for the parent BDS
- */
-static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options,
-                                       int parent_flags, QDict *parent_options)
-{
-    child_file.inherit_options(child_flags, child_options,
-                               parent_flags, parent_options);
-
-    *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO);
-}
-
-const BdrvChildRole child_format = {
-    .inherit_options = bdrv_inherited_fmt_options,
-};
-
-/*
- * Returns the options and flags that bs->backing should get, based on the
- * given options and flags for the parent BDS
- */
-static void bdrv_backing_options(int *child_flags, QDict *child_options,
-                                 int parent_flags, QDict *parent_options)
-{
-    int flags = parent_flags;
-
-    /* The cache mode is inherited unmodified for backing files; except WCE,
-     * which is only applied on the top level (BlockBackend) */
-    qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
-    qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
-
-    /* backing files always opened read-only */
-    flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ);
-
-    /* snapshot=on is handled on the top layer */
-    flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
-
-    *child_flags = flags;
-}
-
-static const BdrvChildRole child_backing = {
-    .inherit_options = bdrv_backing_options,
-};
-
-static int bdrv_open_flags(BlockDriverState *bs, int flags)
-{
-    int open_flags = flags;
-
-    /*
-     * Clear flags that are internal to the block layer before opening the
-     * image.
-     */
-    open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL);
-
-    /*
-     * Snapshots should be writable.
-     */
-    if (flags & BDRV_O_TEMPORARY) {
-        open_flags |= BDRV_O_RDWR;
-    }
-
-    return open_flags;
-}
-
-static void update_flags_from_options(int *flags, QemuOpts *opts)
-{
-    *flags &= ~BDRV_O_CACHE_MASK;
-
-    assert(qemu_opt_find(opts, BDRV_OPT_CACHE_NO_FLUSH));
-    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
-        *flags |= BDRV_O_NO_FLUSH;
-    }
-
-    assert(qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT));
-    if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) {
-        *flags |= BDRV_O_NOCACHE;
-    }
-}
-
-static void update_options_from_flags(QDict *options, int flags)
-{
-    if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
-        qdict_put(options, BDRV_OPT_CACHE_DIRECT,
-                  qbool_from_bool(flags & BDRV_O_NOCACHE));
-    }
-    if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) {
-        qdict_put(options, BDRV_OPT_CACHE_NO_FLUSH,
-                  qbool_from_bool(flags & BDRV_O_NO_FLUSH));
-    }
-}
-
-static void bdrv_assign_node_name(BlockDriverState *bs,
-                                  const char *node_name,
-                                  Error **errp)
-{
-    char *gen_node_name = NULL;
-
-    if (!node_name) {
-        node_name = gen_node_name = id_generate(ID_BLOCK);
-    } else if (!id_wellformed(node_name)) {
-        /*
-         * Check for empty string or invalid characters, but not if it is
-         * generated (generated names use characters not available to the user)
-         */
-        error_setg(errp, "Invalid node name");
-        return;
-    }
-
-    /* takes care of avoiding namespaces collisions */
-    if (blk_by_name(node_name)) {
-        error_setg(errp, "node-name=%s is conflicting with a device id",
-                   node_name);
-        goto out;
-    }
-
-    /* takes care of avoiding duplicates node names */
-    if (bdrv_find_node(node_name)) {
-        error_setg(errp, "Duplicate node name");
-        goto out;
-    }
-
-    /* copy node name into the bs and insert it into the graph list */
-    pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
-    QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
-out:
-    g_free(gen_node_name);
-}
-
-static QemuOptsList bdrv_runtime_opts = {
-    .name = "bdrv_common",
-    .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
-    .desc = {
-        {
-            .name = "node-name",
-            .type = QEMU_OPT_STRING,
-            .help = "Node name of the block device node",
-        },
-        {
-            .name = "driver",
-            .type = QEMU_OPT_STRING,
-            .help = "Block driver to use for the node",
-        },
-        {
-            .name = BDRV_OPT_CACHE_DIRECT,
-            .type = QEMU_OPT_BOOL,
-            .help = "Bypass software writeback cache on the host",
-        },
-        {
-            .name = BDRV_OPT_CACHE_NO_FLUSH,
-            .type = QEMU_OPT_BOOL,
-            .help = "Ignore flush requests",
-        },
-        { /* end of list */ }
-    },
-};
-
-/*
- * Common part for opening disk images and files
- *
- * Removes all processed options from *options.
- */
-static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
-                            QDict *options, Error **errp)
-{
-    int ret, open_flags;
-    const char *filename;
-    const char *driver_name = NULL;
-    const char *node_name = NULL;
-    QemuOpts *opts;
-    BlockDriver *drv;
-    Error *local_err = NULL;
-
-    assert(bs->file == NULL);
-    assert(options != NULL && bs->options != options);
-
-    opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
-    qemu_opts_absorb_qdict(opts, options, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        ret = -EINVAL;
-        goto fail_opts;
-    }
-
-    driver_name = qemu_opt_get(opts, "driver");
-    drv = bdrv_find_format(driver_name);
-    assert(drv != NULL);
-
-    if (file != NULL) {
-        filename = file->bs->filename;
-    } else {
-        filename = qdict_get_try_str(options, "filename");
-    }
-
-    if (drv->bdrv_needs_filename && !filename) {
-        error_setg(errp, "The '%s' block driver requires a file name",
-                   drv->format_name);
-        ret = -EINVAL;
-        goto fail_opts;
-    }
-
-    trace_bdrv_open_common(bs, filename ?: "", bs->open_flags,
-                           drv->format_name);
-
-    node_name = qemu_opt_get(opts, "node-name");
-    bdrv_assign_node_name(bs, node_name, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        ret = -EINVAL;
-        goto fail_opts;
-    }
-
-    bs->request_alignment = 512;
-    bs->zero_beyond_eof = true;
-    bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
-
-    if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
-        error_setg(errp,
-                   !bs->read_only && bdrv_is_whitelisted(drv, true)
-                        ? "Driver '%s' can only be used for read-only devices"
-                        : "Driver '%s' is not whitelisted",
-                   drv->format_name);
-        ret = -ENOTSUP;
-        goto fail_opts;
-    }
-
-    assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
-    if (bs->open_flags & BDRV_O_COPY_ON_READ) {
-        if (!bs->read_only) {
-            bdrv_enable_copy_on_read(bs);
-        } else {
-            error_setg(errp, "Can't use copy-on-read on read-only device");
-            ret = -EINVAL;
-            goto fail_opts;
-        }
-    }
-
-    if (filename != NULL) {
-        pstrcpy(bs->filename, sizeof(bs->filename), filename);
-    } else {
-        bs->filename[0] = '\0';
-    }
-    pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
-
-    bs->drv = drv;
-    bs->opaque = g_malloc0(drv->instance_size);
-
-    /* Apply cache mode options */
-    update_flags_from_options(&bs->open_flags, opts);
-
-    /* Open the image, either directly or using a protocol */
-    open_flags = bdrv_open_flags(bs, bs->open_flags);
-    if (drv->bdrv_file_open) {
-        assert(file == NULL);
-        assert(!drv->bdrv_needs_filename || filename != NULL);
-        ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
-    } else {
-        if (file == NULL) {
-            error_setg(errp, "Can't use '%s' as a block driver for the "
-                       "protocol level", drv->format_name);
-            ret = -EINVAL;
-            goto free_and_fail;
-        }
-        bs->file = file;
-        ret = drv->bdrv_open(bs, options, open_flags, &local_err);
-    }
-
-    if (ret < 0) {
-        if (local_err) {
-            error_propagate(errp, local_err);
-        } else if (bs->filename[0]) {
-            error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
-        } else {
-            error_setg_errno(errp, -ret, "Could not open image");
-        }
-        goto free_and_fail;
-    }
-
-    ret = refresh_total_sectors(bs, bs->total_sectors);
-    if (ret < 0) {
-        error_setg_errno(errp, -ret, "Could not refresh total sector count");
-        goto free_and_fail;
-    }
-
-    bdrv_refresh_limits(bs, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        ret = -EINVAL;
-        goto free_and_fail;
-    }
-
-    assert(bdrv_opt_mem_align(bs) != 0);
-    assert(bdrv_min_mem_align(bs) != 0);
-    assert((bs->request_alignment != 0) || bdrv_is_sg(bs));
-
-    qemu_opts_del(opts);
-    return 0;
-
-free_and_fail:
-    bs->file = NULL;
-    g_free(bs->opaque);
-    bs->opaque = NULL;
-    bs->drv = NULL;
-fail_opts:
-    qemu_opts_del(opts);
-    return ret;
-}
-
-static QDict *parse_json_filename(const char *filename, Error **errp)
-{
-    QObject *options_obj;
-    QDict *options;
-    int ret;
-
-    ret = strstart(filename, "json:", &filename);
-    assert(ret);
-
-    options_obj = qobject_from_json(filename);
-    if (!options_obj) {
-        error_setg(errp, "Could not parse the JSON options");
-        return NULL;
-    }
-
-    if (qobject_type(options_obj) != QTYPE_QDICT) {
-        qobject_decref(options_obj);
-        error_setg(errp, "Invalid JSON object given");
-        return NULL;
-    }
-
-    options = qobject_to_qdict(options_obj);
-    qdict_flatten(options);
-
-    return options;
-}
-
-static void parse_json_protocol(QDict *options, const char **pfilename,
-                                Error **errp)
-{
-    QDict *json_options;
-    Error *local_err = NULL;
-
-    /* Parse json: pseudo-protocol */
-    if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
-        return;
-    }
-
-    json_options = parse_json_filename(*pfilename, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        return;
-    }
-
-    /* Options given in the filename have lower priority than options
-     * specified directly */
-    qdict_join(options, json_options, false);
-    QDECREF(json_options);
-    *pfilename = NULL;
-}
-
-/*
- * Fills in default options for opening images and converts the legacy
- * filename/flags pair to option QDict entries.
- * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
- * block driver has been specified explicitly.
- */
-static int bdrv_fill_options(QDict **options, const char *filename,
-                             int *flags, Error **errp)
-{
-    const char *drvname;
-    bool protocol = *flags & BDRV_O_PROTOCOL;
-    bool parse_filename = false;
-    BlockDriver *drv = NULL;
-    Error *local_err = NULL;
-
-    drvname = qdict_get_try_str(*options, "driver");
-    if (drvname) {
-        drv = bdrv_find_format(drvname);
-        if (!drv) {
-            error_setg(errp, "Unknown driver '%s'", drvname);
-            return -ENOENT;
-        }
-        /* If the user has explicitly specified the driver, this choice should
-         * override the BDRV_O_PROTOCOL flag */
-        protocol = drv->bdrv_file_open;
-    }
-
-    if (protocol) {
-        *flags |= BDRV_O_PROTOCOL;
-    } else {
-        *flags &= ~BDRV_O_PROTOCOL;
-    }
-
-    /* Translate cache options from flags into options */
-    update_options_from_flags(*options, *flags);
-
-    /* Fetch the file name from the options QDict if necessary */
-    if (protocol && filename) {
-        if (!qdict_haskey(*options, "filename")) {
-            qdict_put(*options, "filename", qstring_from_str(filename));
-            parse_filename = true;
-        } else {
-            error_setg(errp, "Can't specify 'file' and 'filename' options at "
-                             "the same time");
-            return -EINVAL;
-        }
-    }
-
-    /* Find the right block driver */
-    filename = qdict_get_try_str(*options, "filename");
-
-    if (!drvname && protocol) {
-        if (filename) {
-            drv = bdrv_find_protocol(filename, parse_filename, errp);
-            if (!drv) {
-                return -EINVAL;
-            }
-
-            drvname = drv->format_name;
-            qdict_put(*options, "driver", qstring_from_str(drvname));
-        } else {
-            error_setg(errp, "Must specify either driver or file");
-            return -EINVAL;
-        }
-    }
-
-    assert(drv || !protocol);
-
-    /* Driver-specific filename parsing */
-    if (drv && drv->bdrv_parse_filename && parse_filename) {
-        drv->bdrv_parse_filename(filename, *options, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            return -EINVAL;
-        }
-
-        if (!drv->bdrv_needs_filename) {
-            qdict_del(*options, "filename");
-        }
-    }
-
-    return 0;
-}
-
-BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
-                                  const char *child_name,
-                                  const BdrvChildRole *child_role)
-{
-    BdrvChild *child = g_new(BdrvChild, 1);
-    *child = (BdrvChild) {
-        .bs     = child_bs,
-        .name   = g_strdup(child_name),
-        .role   = child_role,
-    };
-
-    QLIST_INSERT_HEAD(&child_bs->parents, child, next_parent);
-
-    return child;
-}
-
-static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
-                                    BlockDriverState *child_bs,
-                                    const char *child_name,
-                                    const BdrvChildRole *child_role)
-{
-    BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role);
-    QLIST_INSERT_HEAD(&parent_bs->children, child, next);
-    return child;
-}
-
-static void bdrv_detach_child(BdrvChild *child)
-{
-    if (child->next.le_prev) {
-        QLIST_REMOVE(child, next);
-        child->next.le_prev = NULL;
-    }
-    QLIST_REMOVE(child, next_parent);
-    g_free(child->name);
-    g_free(child);
-}
-
-void bdrv_root_unref_child(BdrvChild *child)
-{
-    BlockDriverState *child_bs;
-
-    child_bs = child->bs;
-    bdrv_detach_child(child);
-    bdrv_unref(child_bs);
-}
-
-void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
-{
-    if (child == NULL) {
-        return;
-    }
-
-    if (child->bs->inherits_from == parent) {
-        child->bs->inherits_from = NULL;
-    }
-
-    bdrv_root_unref_child(child);
-}
-
-/*
- * Sets the backing file link of a BDS. A new reference is created; callers
- * which don't need their own reference any more must call bdrv_unref().
- */
-void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
-{
-    if (backing_hd) {
-        bdrv_ref(backing_hd);
-    }
-
-    if (bs->backing) {
-        assert(bs->backing_blocker);
-        bdrv_op_unblock_all(bs->backing->bs, bs->backing_blocker);
-        bdrv_unref_child(bs, bs->backing);
-    } else if (backing_hd) {
-        error_setg(&bs->backing_blocker,
-                   "node is used as backing hd of '%s'",
-                   bdrv_get_device_or_node_name(bs));
-    }
-
-    if (!backing_hd) {
-        error_free(bs->backing_blocker);
-        bs->backing_blocker = NULL;
-        bs->backing = NULL;
-        goto out;
-    }
-    bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing);
-    bs->open_flags &= ~BDRV_O_NO_BACKING;
-    pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
-    pstrcpy(bs->backing_format, sizeof(bs->backing_format),
-            backing_hd->drv ? backing_hd->drv->format_name : "");
-
-    bdrv_op_block_all(backing_hd, bs->backing_blocker);
-    /* Otherwise we won't be able to commit due to check in bdrv_commit */
-    bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
-                    bs->backing_blocker);
-out:
-    bdrv_refresh_limits(bs, NULL);
-}
-
-/*
- * Opens the backing file for a BlockDriverState if not yet open
- *
- * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
- * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
- * itself, all options starting with "${bdref_key}." are considered part of the
- * BlockdevRef.
- *
- * TODO Can this be unified with bdrv_open_image()?
- */
-int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
-                           const char *bdref_key, Error **errp)
-{
-    char *backing_filename = g_malloc0(PATH_MAX);
-    char *bdref_key_dot;
-    const char *reference = NULL;
-    int ret = 0;
-    BlockDriverState *backing_hd;
-    QDict *options;
-    QDict *tmp_parent_options = NULL;
-    Error *local_err = NULL;
-
-    if (bs->backing != NULL) {
-        goto free_exit;
-    }
-
-    /* NULL means an empty set of options */
-    if (parent_options == NULL) {
-        tmp_parent_options = qdict_new();
-        parent_options = tmp_parent_options;
-    }
-
-    bs->open_flags &= ~BDRV_O_NO_BACKING;
-
-    bdref_key_dot = g_strdup_printf("%s.", bdref_key);
-    qdict_extract_subqdict(parent_options, &options, bdref_key_dot);
-    g_free(bdref_key_dot);
-
-    reference = qdict_get_try_str(parent_options, bdref_key);
-    if (reference || qdict_haskey(options, "file.filename")) {
-        backing_filename[0] = '\0';
-    } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
-        QDECREF(options);
-        goto free_exit;
-    } else {
-        bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX,
-                                       &local_err);
-        if (local_err) {
-            ret = -EINVAL;
-            error_propagate(errp, local_err);
-            QDECREF(options);
-            goto free_exit;
-        }
-    }
-
-    if (!bs->drv || !bs->drv->supports_backing) {
-        ret = -EINVAL;
-        error_setg(errp, "Driver doesn't support backing files");
-        QDECREF(options);
-        goto free_exit;
-    }
-
-    if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
-        qdict_put(options, "driver", qstring_from_str(bs->backing_format));
-    }
-
-    backing_hd = NULL;
-    ret = bdrv_open_inherit(&backing_hd,
-                            *backing_filename ? backing_filename : NULL,
-                            reference, options, 0, bs, &child_backing,
-                            errp);
-    if (ret < 0) {
-        bs->open_flags |= BDRV_O_NO_BACKING;
-        error_prepend(errp, "Could not open backing file: ");
-        goto free_exit;
-    }
-
-    /* Hook up the backing file link; drop our reference, bs owns the
-     * backing_hd reference now */
-    bdrv_set_backing_hd(bs, backing_hd);
-    bdrv_unref(backing_hd);
-
-    qdict_del(parent_options, bdref_key);
-
-free_exit:
-    g_free(backing_filename);
-    QDECREF(tmp_parent_options);
-    return ret;
-}
-
-/*
- * Opens a disk image whose options are given as BlockdevRef in another block
- * device's options.
- *
- * If allow_none is true, no image will be opened if filename is false and no
- * BlockdevRef is given. NULL will be returned, but errp remains unset.
- *
- * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
- * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
- * itself, all options starting with "${bdref_key}." are considered part of the
- * BlockdevRef.
- *
- * The BlockdevRef will be removed from the options QDict.
- */
-BdrvChild *bdrv_open_child(const char *filename,
-                           QDict *options, const char *bdref_key,
-                           BlockDriverState* parent,
-                           const BdrvChildRole *child_role,
-                           bool allow_none, Error **errp)
-{
-    BdrvChild *c = NULL;
-    BlockDriverState *bs;
-    QDict *image_options;
-    int ret;
-    char *bdref_key_dot;
-    const char *reference;
-
-    assert(child_role != NULL);
-
-    bdref_key_dot = g_strdup_printf("%s.", bdref_key);
-    qdict_extract_subqdict(options, &image_options, bdref_key_dot);
-    g_free(bdref_key_dot);
-
-    reference = qdict_get_try_str(options, bdref_key);
-    if (!filename && !reference && !qdict_size(image_options)) {
-        if (!allow_none) {
-            error_setg(errp, "A block device must be specified for \"%s\"",
-                       bdref_key);
-        }
-        QDECREF(image_options);
-        goto done;
-    }
-
-    bs = NULL;
-    ret = bdrv_open_inherit(&bs, filename, reference, image_options, 0,
-                            parent, child_role, errp);
-    if (ret < 0) {
-        goto done;
-    }
-
-    c = bdrv_attach_child(parent, bs, bdref_key, child_role);
-
-done:
-    qdict_del(options, bdref_key);
-    return c;
-}
-
-static int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags,
-                                     QDict *snapshot_options, Error **errp)
-{
-    /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
-    char *tmp_filename = g_malloc0(PATH_MAX + 1);
-    int64_t total_size;
-    QemuOpts *opts = NULL;
-    BlockDriverState *bs_snapshot;
-    Error *local_err = NULL;
-    int ret;
-
-    /* if snapshot, we create a temporary backing file and open it
-       instead of opening 'filename' directly */
-
-    /* Get the required size from the image */
-    total_size = bdrv_getlength(bs);
-    if (total_size < 0) {
-        ret = total_size;
-        error_setg_errno(errp, -total_size, "Could not get image size");
-        goto out;
-    }
-
-    /* Create the temporary image */
-    ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
-    if (ret < 0) {
-        error_setg_errno(errp, -ret, "Could not get temporary filename");
-        goto out;
-    }
-
-    opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0,
-                            &error_abort);
-    qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
-    ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp);
-    qemu_opts_del(opts);
-    if (ret < 0) {
-        error_prepend(errp, "Could not create temporary overlay '%s': ",
-                      tmp_filename);
-        goto out;
-    }
-
-    /* Prepare options QDict for the temporary file */
-    qdict_put(snapshot_options, "file.driver",
-              qstring_from_str("file"));
-    qdict_put(snapshot_options, "file.filename",
-              qstring_from_str(tmp_filename));
-    qdict_put(snapshot_options, "driver",
-              qstring_from_str("qcow2"));
-
-    bs_snapshot = bdrv_new();
-
-    ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options,
-                    flags, &local_err);
-    snapshot_options = NULL;
-    if (ret < 0) {
-        error_propagate(errp, local_err);
-        goto out;
-    }
-
-    bdrv_append(bs_snapshot, bs);
-
-out:
-    QDECREF(snapshot_options);
-    g_free(tmp_filename);
-    return ret;
-}
-
-/*
- * Opens a disk image (raw, qcow2, vmdk, ...)
- *
- * options is a QDict of options to pass to the block drivers, or NULL for an
- * empty set of options. The reference to the QDict belongs to the block layer
- * after the call (even on failure), so if the caller intends to reuse the
- * dictionary, it needs to use QINCREF() before calling bdrv_open.
- *
- * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
- * If it is not NULL, the referenced BDS will be reused.
- *
- * The reference parameter may be used to specify an existing block device which
- * should be opened. If specified, neither options nor a filename may be given,
- * nor can an existing BDS be reused (that is, *pbs has to be NULL).
- */
-static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename,
-                             const char *reference, QDict *options, int flags,
-                             BlockDriverState *parent,
-                             const BdrvChildRole *child_role, Error **errp)
-{
-    int ret;
-    BdrvChild *file = NULL;
-    BlockDriverState *bs;
-    BlockDriver *drv = NULL;
-    const char *drvname;
-    const char *backing;
-    Error *local_err = NULL;
-    QDict *snapshot_options = NULL;
-    int snapshot_flags = 0;
-
-    assert(pbs);
-    assert(!child_role || !flags);
-    assert(!child_role == !parent);
-
-    if (reference) {
-        bool options_non_empty = options ? qdict_size(options) : false;
-        QDECREF(options);
-
-        if (*pbs) {
-            error_setg(errp, "Cannot reuse an existing BDS when referencing "
-                       "another block device");
-            return -EINVAL;
-        }
-
-        if (filename || options_non_empty) {
-            error_setg(errp, "Cannot reference an existing block device with "
-                       "additional options or a new filename");
-            return -EINVAL;
-        }
-
-        bs = bdrv_lookup_bs(reference, reference, errp);
-        if (!bs) {
-            return -ENODEV;
-        }
-
-        if (bs->throttle_state) {
-            error_setg(errp, "Cannot reference an existing block device for "
-                       "which I/O throttling is enabled");
-            return -EINVAL;
-        }
-
-        bdrv_ref(bs);
-        *pbs = bs;
-        return 0;
-    }
-
-    if (*pbs) {
-        bs = *pbs;
-    } else {
-        bs = bdrv_new();
-    }
-
-    /* NULL means an empty set of options */
-    if (options == NULL) {
-        options = qdict_new();
-    }
-
-    /* json: syntax counts as explicit options, as if in the QDict */
-    parse_json_protocol(options, &filename, &local_err);
-    if (local_err) {
-        ret = -EINVAL;
-        goto fail;
-    }
-
-    bs->explicit_options = qdict_clone_shallow(options);
-
-    if (child_role) {
-        bs->inherits_from = parent;
-        child_role->inherit_options(&flags, options,
-                                    parent->open_flags, parent->options);
-    }
-
-    ret = bdrv_fill_options(&options, filename, &flags, &local_err);
-    if (local_err) {
-        goto fail;
-    }
-
-    bs->open_flags = flags;
-    bs->options = options;
-    options = qdict_clone_shallow(options);
-
-    /* Find the right image format driver */
-    drvname = qdict_get_try_str(options, "driver");
-    if (drvname) {
-        drv = bdrv_find_format(drvname);
-        if (!drv) {
-            error_setg(errp, "Unknown driver: '%s'", drvname);
-            ret = -EINVAL;
-            goto fail;
-        }
-    }
-
-    assert(drvname || !(flags & BDRV_O_PROTOCOL));
-
-    backing = qdict_get_try_str(options, "backing");
-    if (backing && *backing == '\0') {
-        flags |= BDRV_O_NO_BACKING;
-        qdict_del(options, "backing");
-    }
-
-    /* Open image file without format layer */
-    if ((flags & BDRV_O_PROTOCOL) == 0) {
-        if (flags & BDRV_O_RDWR) {
-            flags |= BDRV_O_ALLOW_RDWR;
-        }
-        if (flags & BDRV_O_SNAPSHOT) {
-            snapshot_options = qdict_new();
-            bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options,
-                                       flags, options);
-            bdrv_backing_options(&flags, options, flags, options);
-        }
-
-        bs->open_flags = flags;
-
-        file = bdrv_open_child(filename, options, "file", bs,
-                               &child_file, true, &local_err);
-        if (local_err) {
-            ret = -EINVAL;
-            goto fail;
-        }
-    }
-
-    /* Image format probing */
-    bs->probed = !drv;
-    if (!drv && file) {
-        ret = find_image_format(file->bs, filename, &drv, &local_err);
-        if (ret < 0) {
-            goto fail;
-        }
-        /*
-         * This option update would logically belong in bdrv_fill_options(),
-         * but we first need to open bs->file for the probing to work, while
-         * opening bs->file already requires the (mostly) final set of options
-         * so that cache mode etc. can be inherited.
-         *
-         * Adding the driver later is somewhat ugly, but it's not an option
-         * that would ever be inherited, so it's correct. We just need to make
-         * sure to update both bs->options (which has the full effective
-         * options for bs) and options (which has file.* already removed).
-         */
-        qdict_put(bs->options, "driver", qstring_from_str(drv->format_name));
-        qdict_put(options, "driver", qstring_from_str(drv->format_name));
-    } else if (!drv) {
-        error_setg(errp, "Must specify either driver or file");
-        ret = -EINVAL;
-        goto fail;
-    }
-
-    /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
-    assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open);
-    /* file must be NULL if a protocol BDS is about to be created
-     * (the inverse results in an error message from bdrv_open_common()) */
-    assert(!(flags & BDRV_O_PROTOCOL) || !file);
-
-    /* Open the image */
-    ret = bdrv_open_common(bs, file, options, &local_err);
-    if (ret < 0) {
-        goto fail;
-    }
-
-    if (file && (bs->file != file)) {
-        bdrv_unref_child(bs, file);
-        file = NULL;
-    }
-
-    /* If there is a backing file, use it */
-    if ((flags & BDRV_O_NO_BACKING) == 0) {
-        ret = bdrv_open_backing_file(bs, options, "backing", &local_err);
-        if (ret < 0) {
-            goto close_and_fail;
-        }
-    }
-
-    bdrv_refresh_filename(bs);
-
-    /* Check if any unknown options were used */
-    if (options && (qdict_size(options) != 0)) {
-        const QDictEntry *entry = qdict_first(options);
-        if (flags & BDRV_O_PROTOCOL) {
-            error_setg(errp, "Block protocol '%s' doesn't support the option "
-                       "'%s'", drv->format_name, entry->key);
-        } else {
-            error_setg(errp,
-                       "Block format '%s' does not support the option '%s'",
-                       drv->format_name, entry->key);
-        }
-
-        ret = -EINVAL;
-        goto close_and_fail;
-    }
-
-    if (!bdrv_key_required(bs)) {
-        if (bs->blk) {
-            blk_dev_change_media_cb(bs->blk, true);
-        }
-    } else if (!runstate_check(RUN_STATE_PRELAUNCH)
-               && !runstate_check(RUN_STATE_INMIGRATE)
-               && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */
-        error_setg(errp,
-                   "Guest must be stopped for opening of encrypted image");
-        ret = -EBUSY;
-        goto close_and_fail;
-    }
-
-    QDECREF(options);
-    *pbs = bs;
-
-    /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
-     * temporary snapshot afterwards. */
-    if (snapshot_flags) {
-        ret = bdrv_append_temp_snapshot(bs, snapshot_flags, snapshot_options,
-                                        &local_err);
-        snapshot_options = NULL;
-        if (local_err) {
-            goto close_and_fail;
-        }
-    }
-
-    return 0;
-
-fail:
-    if (file != NULL) {
-        bdrv_unref_child(bs, file);
-    }
-    QDECREF(snapshot_options);
-    QDECREF(bs->explicit_options);
-    QDECREF(bs->options);
-    QDECREF(options);
-    bs->options = NULL;
-    if (!*pbs) {
-        /* If *pbs is NULL, a new BDS has been created in this function and
-           needs to be freed now. Otherwise, it does not need to be closed,
-           since it has not really been opened yet. */
-        bdrv_unref(bs);
-    }
-    if (local_err) {
-        error_propagate(errp, local_err);
-    }
-    return ret;
-
-close_and_fail:
-    /* See fail path, but now the BDS has to be always closed */
-    if (*pbs) {
-        bdrv_close(bs);
-    } else {
-        bdrv_unref(bs);
-    }
-    QDECREF(snapshot_options);
-    QDECREF(options);
-    if (local_err) {
-        error_propagate(errp, local_err);
-    }
-    return ret;
-}
-
-int bdrv_open(BlockDriverState **pbs, const char *filename,
-              const char *reference, QDict *options, int flags, Error **errp)
-{
-    return bdrv_open_inherit(pbs, filename, reference, options, flags, NULL,
-                             NULL, errp);
-}
-
-typedef struct BlockReopenQueueEntry {
-     bool prepared;
-     BDRVReopenState state;
-     QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry;
-} BlockReopenQueueEntry;
-
-/*
- * Adds a BlockDriverState to a simple queue for an atomic, transactional
- * reopen of multiple devices.
- *
- * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
- * already performed, or alternatively may be NULL a new BlockReopenQueue will
- * be created and initialized. This newly created BlockReopenQueue should be
- * passed back in for subsequent calls that are intended to be of the same
- * atomic 'set'.
- *
- * bs is the BlockDriverState to add to the reopen queue.
- *
- * options contains the changed options for the associated bs
- * (the BlockReopenQueue takes ownership)
- *
- * flags contains the open flags for the associated bs
- *
- * returns a pointer to bs_queue, which is either the newly allocated
- * bs_queue, or the existing bs_queue being used.
- *
- */
-static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
-                                                 BlockDriverState *bs,
-                                                 QDict *options,
-                                                 int flags,
-                                                 const BdrvChildRole *role,
-                                                 QDict *parent_options,
-                                                 int parent_flags)
-{
-    assert(bs != NULL);
-
-    BlockReopenQueueEntry *bs_entry;
-    BdrvChild *child;
-    QDict *old_options, *explicit_options;
-
-    if (bs_queue == NULL) {
-        bs_queue = g_new0(BlockReopenQueue, 1);
-        QSIMPLEQ_INIT(bs_queue);
-    }
-
-    if (!options) {
-        options = qdict_new();
-    }
-
-    /*
-     * Precedence of options:
-     * 1. Explicitly passed in options (highest)
-     * 2. Set in flags (only for top level)
-     * 3. Retained from explicitly set options of bs
-     * 4. Inherited from parent node
-     * 5. Retained from effective options of bs
-     */
-
-    if (!parent_options) {
-        /*
-         * Any setting represented by flags is always updated. If the
-         * corresponding QDict option is set, it takes precedence. Otherwise
-         * the flag is translated into a QDict option. The old setting of bs is
-         * not considered.
-         */
-        update_options_from_flags(options, flags);
-    }
-
-    /* Old explicitly set values (don't overwrite by inherited value) */
-    old_options = qdict_clone_shallow(bs->explicit_options);
-    bdrv_join_options(bs, options, old_options);
-    QDECREF(old_options);
-
-    explicit_options = qdict_clone_shallow(options);
-
-    /* Inherit from parent node */
-    if (parent_options) {
-        assert(!flags);
-        role->inherit_options(&flags, options, parent_flags, parent_options);
-    }
-
-    /* Old values are used for options that aren't set yet */
-    old_options = qdict_clone_shallow(bs->options);
-    bdrv_join_options(bs, options, old_options);
-    QDECREF(old_options);
-
-    /* bdrv_open() masks this flag out */
-    flags &= ~BDRV_O_PROTOCOL;
-
-    QLIST_FOREACH(child, &bs->children, next) {
-        QDict *new_child_options;
-        char *child_key_dot;
-
-        /* reopen can only change the options of block devices that were
-         * implicitly created and inherited options. For other (referenced)
-         * block devices, a syntax like "backing.foo" results in an error. */
-        if (child->bs->inherits_from != bs) {
-            continue;
-        }
-
-        child_key_dot = g_strdup_printf("%s.", child->name);
-        qdict_extract_subqdict(options, &new_child_options, child_key_dot);
-        g_free(child_key_dot);
-
-        bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, 0,
-                                child->role, options, flags);
-    }
-
-    bs_entry = g_new0(BlockReopenQueueEntry, 1);
-    QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry);
-
-    bs_entry->state.bs = bs;
-    bs_entry->state.options = options;
-    bs_entry->state.explicit_options = explicit_options;
-    bs_entry->state.flags = flags;
-
-    return bs_queue;
-}
-
-BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
-                                    BlockDriverState *bs,
-                                    QDict *options, int flags)
-{
-    return bdrv_reopen_queue_child(bs_queue, bs, options, flags,
-                                   NULL, NULL, 0);
-}
-
-/*
- * Reopen multiple BlockDriverStates atomically & transactionally.
- *
- * The queue passed in (bs_queue) must have been built up previous
- * via bdrv_reopen_queue().
- *
- * Reopens all BDS specified in the queue, with the appropriate
- * flags.  All devices are prepared for reopen, and failure of any
- * device will cause all device changes to be abandonded, and intermediate
- * data cleaned up.
- *
- * If all devices prepare successfully, then the changes are committed
- * to all devices.
- *
- */
-int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
-{
-    int ret = -1;
-    BlockReopenQueueEntry *bs_entry, *next;
-    Error *local_err = NULL;
-
-    assert(bs_queue != NULL);
-
-    bdrv_drain_all();
-
-    QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
-        if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
-            error_propagate(errp, local_err);
-            goto cleanup;
-        }
-        bs_entry->prepared = true;
-    }
-
-    /* If we reach this point, we have success and just need to apply the
-     * changes
-     */
-    QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
-        bdrv_reopen_commit(&bs_entry->state);
-    }
-
-    ret = 0;
-
-cleanup:
-    QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
-        if (ret && bs_entry->prepared) {
-            bdrv_reopen_abort(&bs_entry->state);
-        } else if (ret) {
-            QDECREF(bs_entry->state.explicit_options);
-        }
-        QDECREF(bs_entry->state.options);
-        g_free(bs_entry);
-    }
-    g_free(bs_queue);
-    return ret;
-}
-
-
-/* Reopen a single BlockDriverState with the specified flags. */
-int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
-{
-    int ret = -1;
-    Error *local_err = NULL;
-    BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
-
-    ret = bdrv_reopen_multiple(queue, &local_err);
-    if (local_err != NULL) {
-        error_propagate(errp, local_err);
-    }
-    return ret;
-}
-
-
-/*
- * Prepares a BlockDriverState for reopen. All changes are staged in the
- * 'opaque' field of the BDRVReopenState, which is used and allocated by
- * the block driver layer .bdrv_reopen_prepare()
- *
- * bs is the BlockDriverState to reopen
- * flags are the new open flags
- * queue is the reopen queue
- *
- * Returns 0 on success, non-zero on error.  On error errp will be set
- * as well.
- *
- * On failure, bdrv_reopen_abort() will be called to clean up any data.
- * It is the responsibility of the caller to then call the abort() or
- * commit() for any other BDS that have been left in a prepare() state
- *
- */
-int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
-                        Error **errp)
-{
-    int ret = -1;
-    Error *local_err = NULL;
-    BlockDriver *drv;
-    QemuOpts *opts;
-    const char *value;
-
-    assert(reopen_state != NULL);
-    assert(reopen_state->bs->drv != NULL);
-    drv = reopen_state->bs->drv;
-
-    /* Process generic block layer options */
-    opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
-    qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        ret = -EINVAL;
-        goto error;
-    }
-
-    update_flags_from_options(&reopen_state->flags, opts);
-
-    /* node-name and driver must be unchanged. Put them back into the QDict, so
-     * that they are checked at the end of this function. */
-    value = qemu_opt_get(opts, "node-name");
-    if (value) {
-        qdict_put(reopen_state->options, "node-name", qstring_from_str(value));
-    }
-
-    value = qemu_opt_get(opts, "driver");
-    if (value) {
-        qdict_put(reopen_state->options, "driver", qstring_from_str(value));
-    }
-
-    /* if we are to stay read-only, do not allow permission change
-     * to r/w */
-    if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) &&
-        reopen_state->flags & BDRV_O_RDWR) {
-        error_setg(errp, "Node '%s' is read only",
-                   bdrv_get_device_or_node_name(reopen_state->bs));
-        goto error;
-    }
-
-
-    ret = bdrv_flush(reopen_state->bs);
-    if (ret) {
-        error_setg_errno(errp, -ret, "Error flushing drive");
-        goto error;
-    }
-
-    if (drv->bdrv_reopen_prepare) {
-        ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
-        if (ret) {
-            if (local_err != NULL) {
-                error_propagate(errp, local_err);
-            } else {
-                error_setg(errp, "failed while preparing to reopen image '%s'",
-                           reopen_state->bs->filename);
-            }
-            goto error;
-        }
-    } else {
-        /* It is currently mandatory to have a bdrv_reopen_prepare()
-         * handler for each supported drv. */
-        error_setg(errp, "Block format '%s' used by node '%s' "
-                   "does not support reopening files", drv->format_name,
-                   bdrv_get_device_or_node_name(reopen_state->bs));
-        ret = -1;
-        goto error;
-    }
-
-    /* Options that are not handled are only okay if they are unchanged
-     * compared to the old state. It is expected that some options are only
-     * used for the initial open, but not reopen (e.g. filename) */
-    if (qdict_size(reopen_state->options)) {
-        const QDictEntry *entry = qdict_first(reopen_state->options);
-
-        do {
-            QString *new_obj = qobject_to_qstring(entry->value);
-            const char *new = qstring_get_str(new_obj);
-            const char *old = qdict_get_try_str(reopen_state->bs->options,
-                                                entry->key);
-
-            if (!old || strcmp(new, old)) {
-                error_setg(errp, "Cannot change the option '%s'", entry->key);
-                ret = -EINVAL;
-                goto error;
-            }
-        } while ((entry = qdict_next(reopen_state->options, entry)));
-    }
-
-    ret = 0;
-
-error:
-    qemu_opts_del(opts);
-    return ret;
-}
-
-/*
- * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
- * makes them final by swapping the staging BlockDriverState contents into
- * the active BlockDriverState contents.
- */
-void bdrv_reopen_commit(BDRVReopenState *reopen_state)
-{
-    BlockDriver *drv;
-
-    assert(reopen_state != NULL);
-    drv = reopen_state->bs->drv;
-    assert(drv != NULL);
-
-    /* If there are any driver level actions to take */
-    if (drv->bdrv_reopen_commit) {
-        drv->bdrv_reopen_commit(reopen_state);
-    }
-
-    /* set BDS specific flags now */
-    QDECREF(reopen_state->bs->explicit_options);
-
-    reopen_state->bs->explicit_options   = reopen_state->explicit_options;
-    reopen_state->bs->open_flags         = reopen_state->flags;
-    reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
-
-    bdrv_refresh_limits(reopen_state->bs, NULL);
-}
-
-/*
- * Abort the reopen, and delete and free the staged changes in
- * reopen_state
- */
-void bdrv_reopen_abort(BDRVReopenState *reopen_state)
-{
-    BlockDriver *drv;
-
-    assert(reopen_state != NULL);
-    drv = reopen_state->bs->drv;
-    assert(drv != NULL);
-
-    if (drv->bdrv_reopen_abort) {
-        drv->bdrv_reopen_abort(reopen_state);
-    }
-
-    QDECREF(reopen_state->explicit_options);
-}
-
-
-static void bdrv_close(BlockDriverState *bs)
-{
-    BdrvAioNotifier *ban, *ban_next;
-
-    assert(!bs->job);
-
-    /* Disable I/O limits and drain all pending throttled requests */
-    if (bs->throttle_state) {
-        bdrv_io_limits_disable(bs);
-    }
-
-    bdrv_drained_begin(bs); /* complete I/O */
-    bdrv_flush(bs);
-    bdrv_drain(bs); /* in case flush left pending I/O */
-
-    bdrv_release_named_dirty_bitmaps(bs);
-    assert(QLIST_EMPTY(&bs->dirty_bitmaps));
-
-    if (bs->blk) {
-        blk_dev_change_media_cb(bs->blk, false);
-    }
-
-    if (bs->drv) {
-        BdrvChild *child, *next;
-
-        bs->drv->bdrv_close(bs);
-        bs->drv = NULL;
-
-        bdrv_set_backing_hd(bs, NULL);
-
-        if (bs->file != NULL) {
-            bdrv_unref_child(bs, bs->file);
-            bs->file = NULL;
-        }
-
-        QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
-            /* TODO Remove bdrv_unref() from drivers' close function and use
-             * bdrv_unref_child() here */
-            if (child->bs->inherits_from == bs) {
-                child->bs->inherits_from = NULL;
-            }
-            bdrv_detach_child(child);
-        }
-
-        g_free(bs->opaque);
-        bs->opaque = NULL;
-        bs->copy_on_read = 0;
-        bs->backing_file[0] = '\0';
-        bs->backing_format[0] = '\0';
-        bs->total_sectors = 0;
-        bs->encrypted = 0;
-        bs->valid_key = 0;
-        bs->sg = 0;
-        bs->zero_beyond_eof = false;
-        QDECREF(bs->options);
-        QDECREF(bs->explicit_options);
-        bs->options = NULL;
-        QDECREF(bs->full_open_options);
-        bs->full_open_options = NULL;
-    }
-
-    QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
-        g_free(ban);
-    }
-    QLIST_INIT(&bs->aio_notifiers);
-    bdrv_drained_end(bs);
-}
-
-void bdrv_close_all(void)
-{
-    BlockDriverState *bs;
-    AioContext *aio_context;
-
-    /* Drop references from requests still in flight, such as canceled block
-     * jobs whose AIO context has not been polled yet */
-    bdrv_drain_all();
-
-    blk_remove_all_bs();
-    blockdev_close_all_bdrv_states();
-
-    /* Cancel all block jobs */
-    while (!QTAILQ_EMPTY(&all_bdrv_states)) {
-        QTAILQ_FOREACH(bs, &all_bdrv_states, bs_list) {
-            aio_context = bdrv_get_aio_context(bs);
-
-            aio_context_acquire(aio_context);
-            if (bs->job) {
-                block_job_cancel_sync(bs->job);
-                aio_context_release(aio_context);
-                break;
-            }
-            aio_context_release(aio_context);
-        }
-
-        /* All the remaining BlockDriverStates are referenced directly or
-         * indirectly from block jobs, so there needs to be at least one BDS
-         * directly used by a block job */
-        assert(bs);
-    }
-}
-
-/* Fields that need to stay with the top-level BDS */
-static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
-                                     BlockDriverState *bs_src)
-{
-    /* move some fields that need to stay attached to the device */
-}
-
-static void change_parent_backing_link(BlockDriverState *from,
-                                       BlockDriverState *to)
-{
-    BdrvChild *c, *next;
-
-    if (from->blk) {
-        /* FIXME We bypass blk_set_bs(), so we need to make these updates
-         * manually. The root problem is not in this change function, but the
-         * existence of BlockDriverState.blk. */
-        to->blk = from->blk;
-        from->blk = NULL;
-    }
-
-    QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
-        assert(c->role != &child_backing);
-        c->bs = to;
-        QLIST_REMOVE(c, next_parent);
-        QLIST_INSERT_HEAD(&to->parents, c, next_parent);
-        bdrv_ref(to);
-        bdrv_unref(from);
-    }
-}
-
-static void swap_feature_fields(BlockDriverState *bs_top,
-                                BlockDriverState *bs_new)
-{
-    BlockDriverState tmp;
-
-    bdrv_move_feature_fields(&tmp, bs_top);
-    bdrv_move_feature_fields(bs_top, bs_new);
-    bdrv_move_feature_fields(bs_new, &tmp);
-
-    assert(!bs_new->throttle_state);
-    if (bs_top->throttle_state) {
-        assert(bs_top->io_limits_enabled);
-        bdrv_io_limits_enable(bs_new, throttle_group_get_name(bs_top));
-        bdrv_io_limits_disable(bs_top);
-    }
-}
-
-/*
- * Add new bs contents at the top of an image chain while the chain is
- * live, while keeping required fields on the top layer.
- *
- * This will modify the BlockDriverState fields, and swap contents
- * between bs_new and bs_top. Both bs_new and bs_top are modified.
- *
- * bs_new must not be attached to a BlockBackend.
- *
- * This function does not create any image files.
- *
- * bdrv_append() takes ownership of a bs_new reference and unrefs it because
- * that's what the callers commonly need. bs_new will be referenced by the old
- * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
- * reference of its own, it must call bdrv_ref().
- */
-void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
-{
-    assert(!bdrv_requests_pending(bs_top));
-    assert(!bdrv_requests_pending(bs_new));
-
-    bdrv_ref(bs_top);
-    change_parent_backing_link(bs_top, bs_new);
-
-    /* Some fields always stay on top of the backing file chain */
-    swap_feature_fields(bs_top, bs_new);
-
-    bdrv_set_backing_hd(bs_new, bs_top);
-    bdrv_unref(bs_top);
-
-    /* bs_new is now referenced by its new parents, we don't need the
-     * additional reference any more. */
-    bdrv_unref(bs_new);
-}
-
-void bdrv_replace_in_backing_chain(BlockDriverState *old, BlockDriverState *new)
-{
-    assert(!bdrv_requests_pending(old));
-    assert(!bdrv_requests_pending(new));
-
-    bdrv_ref(old);
-
-    if (old->blk) {
-        /* As long as these fields aren't in BlockBackend, but in the top-level
-         * BlockDriverState, it's not possible for a BDS to have two BBs.
-         *
-         * We really want to copy the fields from old to new, but we go for a
-         * swap instead so that pointers aren't duplicated and cause trouble.
-         * (Also, bdrv_swap() used to do the same.) */
-        assert(!new->blk);
-        swap_feature_fields(old, new);
-    }
-    change_parent_backing_link(old, new);
-
-    /* Change backing files if a previously independent node is added to the
-     * chain. For active commit, we replace top by its own (indirect) backing
-     * file and don't do anything here so we don't build a loop. */
-    if (new->backing == NULL && !bdrv_chain_contains(backing_bs(old), new)) {
-        bdrv_set_backing_hd(new, backing_bs(old));
-        bdrv_set_backing_hd(old, NULL);
-    }
-
-    bdrv_unref(old);
-}
-
-static void bdrv_delete(BlockDriverState *bs)
-{
-    assert(!bs->job);
-    assert(bdrv_op_blocker_is_empty(bs));
-    assert(!bs->refcnt);
-
-    bdrv_close(bs);
-
-    /* remove from list, if necessary */
-    if (bs->node_name[0] != '\0') {
-        QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
-    }
-    QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
-
-    g_free(bs);
-}
-
-/*
- * Run consistency checks on an image
- *
- * Returns 0 if the check could be completed (it doesn't mean that the image is
- * free of errors) or -errno when an internal error occurred. The results of the
- * check are stored in res.
- */
-int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
-{
-    if (bs->drv == NULL) {
-        return -ENOMEDIUM;
-    }
-    if (bs->drv->bdrv_check == NULL) {
-        return -ENOTSUP;
-    }
-
-    memset(res, 0, sizeof(*res));
-    return bs->drv->bdrv_check(bs, res, fix);
-}
-
-#define COMMIT_BUF_SECTORS 2048
-
-/* commit COW file into the raw image */
-int bdrv_commit(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-    int64_t sector, total_sectors, length, backing_length;
-    int n, ro, open_flags;
-    int ret = 0;
-    uint8_t *buf = NULL;
-
-    if (!drv)
-        return -ENOMEDIUM;
-
-    if (!bs->backing) {
-        return -ENOTSUP;
-    }
-
-    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) ||
-        bdrv_op_is_blocked(bs->backing->bs, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) {
-        return -EBUSY;
-    }
-
-    ro = bs->backing->bs->read_only;
-    open_flags =  bs->backing->bs->open_flags;
-
-    if (ro) {
-        if (bdrv_reopen(bs->backing->bs, open_flags | BDRV_O_RDWR, NULL)) {
-            return -EACCES;
-        }
-    }
-
-    length = bdrv_getlength(bs);
-    if (length < 0) {
-        ret = length;
-        goto ro_cleanup;
-    }
-
-    backing_length = bdrv_getlength(bs->backing->bs);
-    if (backing_length < 0) {
-        ret = backing_length;
-        goto ro_cleanup;
-    }
-
-    /* If our top snapshot is larger than the backing file image,
-     * grow the backing file image if possible.  If not possible,
-     * we must return an error */
-    if (length > backing_length) {
-        ret = bdrv_truncate(bs->backing->bs, length);
-        if (ret < 0) {
-            goto ro_cleanup;
-        }
-    }
-
-    total_sectors = length >> BDRV_SECTOR_BITS;
-
-    /* qemu_try_blockalign() for bs will choose an alignment that works for
-     * bs->backing->bs as well, so no need to compare the alignment manually. */
-    buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
-    if (buf == NULL) {
-        ret = -ENOMEM;
-        goto ro_cleanup;
-    }
-
-    for (sector = 0; sector < total_sectors; sector += n) {
-        ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n);
-        if (ret < 0) {
-            goto ro_cleanup;
-        }
-        if (ret) {
-            ret = bdrv_read(bs, sector, buf, n);
-            if (ret < 0) {
-                goto ro_cleanup;
-            }
-
-            ret = bdrv_write(bs->backing->bs, sector, buf, n);
-            if (ret < 0) {
-                goto ro_cleanup;
-            }
-        }
-    }
-
-    if (drv->bdrv_make_empty) {
-        ret = drv->bdrv_make_empty(bs);
-        if (ret < 0) {
-            goto ro_cleanup;
-        }
-        bdrv_flush(bs);
-    }
-
-    /*
-     * Make sure all data we wrote to the backing device is actually
-     * stable on disk.
-     */
-    if (bs->backing) {
-        bdrv_flush(bs->backing->bs);
-    }
-
-    ret = 0;
-ro_cleanup:
-    qemu_vfree(buf);
-
-    if (ro) {
-        /* ignoring error return here */
-        bdrv_reopen(bs->backing->bs, open_flags & ~BDRV_O_RDWR, NULL);
-    }
-
-    return ret;
-}
-
-/*
- * Return values:
- * 0        - success
- * -EINVAL  - backing format specified, but no file
- * -ENOSPC  - can't update the backing file because no space is left in the
- *            image file header
- * -ENOTSUP - format driver doesn't support changing the backing file
- */
-int bdrv_change_backing_file(BlockDriverState *bs,
-    const char *backing_file, const char *backing_fmt)
-{
-    BlockDriver *drv = bs->drv;
-    int ret;
-
-    /* Backing file format doesn't make sense without a backing file */
-    if (backing_fmt && !backing_file) {
-        return -EINVAL;
-    }
-
-    if (drv->bdrv_change_backing_file != NULL) {
-        ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
-    } else {
-        ret = -ENOTSUP;
-    }
-
-    if (ret == 0) {
-        pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
-        pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
-    }
-    return ret;
-}
-
-/*
- * Finds the image layer in the chain that has 'bs' as its backing file.
- *
- * active is the current topmost image.
- *
- * Returns NULL if bs is not found in active's image chain,
- * or if active == bs.
- *
- * Returns the bottommost base image if bs == NULL.
- */
-BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
-                                    BlockDriverState *bs)
-{
-    while (active && bs != backing_bs(active)) {
-        active = backing_bs(active);
-    }
-
-    return active;
-}
-
-/* Given a BDS, searches for the base layer. */
-BlockDriverState *bdrv_find_base(BlockDriverState *bs)
-{
-    return bdrv_find_overlay(bs, NULL);
-}
-
-/*
- * Drops images above 'base' up to and including 'top', and sets the image
- * above 'top' to have base as its backing file.
- *
- * Requires that the overlay to 'top' is opened r/w, so that the backing file
- * information in 'bs' can be properly updated.
- *
- * E.g., this will convert the following chain:
- * bottom <- base <- intermediate <- top <- active
- *
- * to
- *
- * bottom <- base <- active
- *
- * It is allowed for bottom==base, in which case it converts:
- *
- * base <- intermediate <- top <- active
- *
- * to
- *
- * base <- active
- *
- * If backing_file_str is non-NULL, it will be used when modifying top's
- * overlay image metadata.
- *
- * Error conditions:
- *  if active == top, that is considered an error
- *
- */
-int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
-                           BlockDriverState *base, const char *backing_file_str)
-{
-    BlockDriverState *new_top_bs = NULL;
-    int ret = -EIO;
-
-    if (!top->drv || !base->drv) {
-        goto exit;
-    }
-
-    new_top_bs = bdrv_find_overlay(active, top);
-
-    if (new_top_bs == NULL) {
-        /* we could not find the image above 'top', this is an error */
-        goto exit;
-    }
-
-    /* special case of new_top_bs->backing->bs already pointing to base - nothing
-     * to do, no intermediate images */
-    if (backing_bs(new_top_bs) == base) {
-        ret = 0;
-        goto exit;
-    }
-
-    /* Make sure that base is in the backing chain of top */
-    if (!bdrv_chain_contains(top, base)) {
-        goto exit;
-    }
-
-    /* success - we can delete the intermediate states, and link top->base */
-    backing_file_str = backing_file_str ? backing_file_str : base->filename;
-    ret = bdrv_change_backing_file(new_top_bs, backing_file_str,
-                                   base->drv ? base->drv->format_name : "");
-    if (ret) {
-        goto exit;
-    }
-    bdrv_set_backing_hd(new_top_bs, base);
-
-    ret = 0;
-exit:
-    return ret;
-}
-
-/**
- * Truncate file to 'offset' bytes (needed only for file protocols)
- */
-int bdrv_truncate(BlockDriverState *bs, int64_t offset)
-{
-    BlockDriver *drv = bs->drv;
-    int ret;
-    if (!drv)
-        return -ENOMEDIUM;
-    if (!drv->bdrv_truncate)
-        return -ENOTSUP;
-    if (bs->read_only)
-        return -EACCES;
-
-    ret = drv->bdrv_truncate(bs, offset);
-    if (ret == 0) {
-        ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
-        bdrv_dirty_bitmap_truncate(bs);
-        if (bs->blk) {
-            blk_dev_resize_cb(bs->blk);
-        }
-    }
-    return ret;
-}
-
-/**
- * Length of a allocated file in bytes. Sparse files are counted by actual
- * allocated space. Return < 0 if error or unknown.
- */
-int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv) {
-        return -ENOMEDIUM;
-    }
-    if (drv->bdrv_get_allocated_file_size) {
-        return drv->bdrv_get_allocated_file_size(bs);
-    }
-    if (bs->file) {
-        return bdrv_get_allocated_file_size(bs->file->bs);
-    }
-    return -ENOTSUP;
-}
-
-/**
- * Return number of sectors on success, -errno on error.
- */
-int64_t bdrv_nb_sectors(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-
-    if (!drv)
-        return -ENOMEDIUM;
-
-    if (drv->has_variable_length) {
-        int ret = refresh_total_sectors(bs, bs->total_sectors);
-        if (ret < 0) {
-            return ret;
-        }
-    }
-    return bs->total_sectors;
-}
-
-/**
- * Return length in bytes on success, -errno on error.
- * The length is always a multiple of BDRV_SECTOR_SIZE.
- */
-int64_t bdrv_getlength(BlockDriverState *bs)
-{
-    int64_t ret = bdrv_nb_sectors(bs);
-
-    ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret;
-    return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
-}
-
-/* return 0 as number of sectors if no device present or error */
-void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
-{
-    int64_t nb_sectors = bdrv_nb_sectors(bs);
-
-    *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
-}
-
-int bdrv_is_read_only(BlockDriverState *bs)
-{
-    return bs->read_only;
-}
-
-int bdrv_is_sg(BlockDriverState *bs)
-{
-    return bs->sg;
-}
-
-int bdrv_is_encrypted(BlockDriverState *bs)
-{
-    if (bs->backing && bs->backing->bs->encrypted) {
-        return 1;
-    }
-    return bs->encrypted;
-}
-
-int bdrv_key_required(BlockDriverState *bs)
-{
-    BdrvChild *backing = bs->backing;
-
-    if (backing && backing->bs->encrypted && !backing->bs->valid_key) {
-        return 1;
-    }
-    return (bs->encrypted && !bs->valid_key);
-}
-
-int bdrv_set_key(BlockDriverState *bs, const char *key)
-{
-    int ret;
-    if (bs->backing && bs->backing->bs->encrypted) {
-        ret = bdrv_set_key(bs->backing->bs, key);
-        if (ret < 0)
-            return ret;
-        if (!bs->encrypted)
-            return 0;
-    }
-    if (!bs->encrypted) {
-        return -EINVAL;
-    } else if (!bs->drv || !bs->drv->bdrv_set_key) {
-        return -ENOMEDIUM;
-    }
-    ret = bs->drv->bdrv_set_key(bs, key);
-    if (ret < 0) {
-        bs->valid_key = 0;
-    } else if (!bs->valid_key) {
-        bs->valid_key = 1;
-        if (bs->blk) {
-            /* call the change callback now, we skipped it on open */
-            blk_dev_change_media_cb(bs->blk, true);
-        }
-    }
-    return ret;
-}
-
-/*
- * Provide an encryption key for @bs.
- * If @key is non-null:
- *     If @bs is not encrypted, fail.
- *     Else if the key is invalid, fail.
- *     Else set @bs's key to @key, replacing the existing key, if any.
- * If @key is null:
- *     If @bs is encrypted and still lacks a key, fail.
- *     Else do nothing.
- * On failure, store an error object through @errp if non-null.
- */
-void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp)
-{
-    if (key) {
-        if (!bdrv_is_encrypted(bs)) {
-            error_setg(errp, "Node '%s' is not encrypted",
-                      bdrv_get_device_or_node_name(bs));
-        } else if (bdrv_set_key(bs, key) < 0) {
-            error_setg(errp, QERR_INVALID_PASSWORD);
-        }
-    } else {
-        if (bdrv_key_required(bs)) {
-            error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED,
-                      "'%s' (%s) is encrypted",
-                      bdrv_get_device_or_node_name(bs),
-                      bdrv_get_encrypted_filename(bs));
-        }
-    }
-}
-
-const char *bdrv_get_format_name(BlockDriverState *bs)
-{
-    return bs->drv ? bs->drv->format_name : NULL;
-}
-
-static int qsort_strcmp(const void *a, const void *b)
-{
-    return strcmp(a, b);
-}
-
-void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
-                         void *opaque)
-{
-    BlockDriver *drv;
-    int count = 0;
-    int i;
-    const char **formats = NULL;
-
-    QLIST_FOREACH(drv, &bdrv_drivers, list) {
-        if (drv->format_name) {
-            bool found = false;
-            int i = count;
-            while (formats && i && !found) {
-                found = !strcmp(formats[--i], drv->format_name);
-            }
-
-            if (!found) {
-                formats = g_renew(const char *, formats, count + 1);
-                formats[count++] = drv->format_name;
-            }
-        }
-    }
-
-    qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
-
-    for (i = 0; i < count; i++) {
-        it(opaque, formats[i]);
-    }
-
-    g_free(formats);
-}
-
-/* This function is to find a node in the bs graph */
-BlockDriverState *bdrv_find_node(const char *node_name)
-{
-    BlockDriverState *bs;
-
-    assert(node_name);
-
-    QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
-        if (!strcmp(node_name, bs->node_name)) {
-            return bs;
-        }
-    }
-    return NULL;
-}
-
-/* Put this QMP function here so it can access the static graph_bdrv_states. */
-BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
-{
-    BlockDeviceInfoList *list, *entry;
-    BlockDriverState *bs;
-
-    list = NULL;
-    QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
-        BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
-        if (!info) {
-            qapi_free_BlockDeviceInfoList(list);
-            return NULL;
-        }
-        entry = g_malloc0(sizeof(*entry));
-        entry->value = info;
-        entry->next = list;
-        list = entry;
-    }
-
-    return list;
-}
-
-BlockDriverState *bdrv_lookup_bs(const char *device,
-                                 const char *node_name,
-                                 Error **errp)
-{
-    BlockBackend *blk;
-    BlockDriverState *bs;
-
-    if (device) {
-        blk = blk_by_name(device);
-
-        if (blk) {
-            bs = blk_bs(blk);
-            if (!bs) {
-                error_setg(errp, "Device '%s' has no medium", device);
-            }
-
-            return bs;
-        }
-    }
-
-    if (node_name) {
-        bs = bdrv_find_node(node_name);
-
-        if (bs) {
-            return bs;
-        }
-    }
-
-    error_setg(errp, "Cannot find device=%s nor node_name=%s",
-                     device ? device : "",
-                     node_name ? node_name : "");
-    return NULL;
-}
-
-/* If 'base' is in the same chain as 'top', return true. Otherwise,
- * return false.  If either argument is NULL, return false. */
-bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
-{
-    while (top && top != base) {
-        top = backing_bs(top);
-    }
-
-    return top != NULL;
-}
-
-BlockDriverState *bdrv_next_node(BlockDriverState *bs)
-{
-    if (!bs) {
-        return QTAILQ_FIRST(&graph_bdrv_states);
-    }
-    return QTAILQ_NEXT(bs, node_list);
-}
-
-/* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by
- * the monitor or attached to a BlockBackend */
-BlockDriverState *bdrv_next(BlockDriverState *bs)
-{
-    if (!bs || bs->blk) {
-        bs = blk_next_root_bs(bs);
-        if (bs) {
-            return bs;
-        }
-    }
-
-    /* Ignore all BDSs that are attached to a BlockBackend here; they have been
-     * handled by the above block already */
-    do {
-        bs = bdrv_next_monitor_owned(bs);
-    } while (bs && bs->blk);
-    return bs;
-}
-
-const char *bdrv_get_node_name(const BlockDriverState *bs)
-{
-    return bs->node_name;
-}
-
-/* TODO check what callers really want: bs->node_name or blk_name() */
-const char *bdrv_get_device_name(const BlockDriverState *bs)
-{
-    return bs->blk ? blk_name(bs->blk) : "";
-}
-
-/* This can be used to identify nodes that might not have a device
- * name associated. Since node and device names live in the same
- * namespace, the result is unambiguous. The exception is if both are
- * absent, then this returns an empty (non-null) string. */
-const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
-{
-    return bs->blk ? blk_name(bs->blk) : bs->node_name;
-}
-
-int bdrv_get_flags(BlockDriverState *bs)
-{
-    return bs->open_flags;
-}
-
-int bdrv_has_zero_init_1(BlockDriverState *bs)
-{
-    return 1;
-}
-
-int bdrv_has_zero_init(BlockDriverState *bs)
-{
-    assert(bs->drv);
-
-    /* If BS is a copy on write image, it is initialized to
-       the contents of the base image, which may not be zeroes.  */
-    if (bs->backing) {
-        return 0;
-    }
-    if (bs->drv->bdrv_has_zero_init) {
-        return bs->drv->bdrv_has_zero_init(bs);
-    }
-
-    /* safe default */
-    return 0;
-}
-
-bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
-{
-    BlockDriverInfo bdi;
-
-    if (bs->backing) {
-        return false;
-    }
-
-    if (bdrv_get_info(bs, &bdi) == 0) {
-        return bdi.unallocated_blocks_are_zero;
-    }
-
-    return false;
-}
-
-bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
-{
-    BlockDriverInfo bdi;
-
-    if (bs->backing || !(bs->open_flags & BDRV_O_UNMAP)) {
-        return false;
-    }
-
-    if (bdrv_get_info(bs, &bdi) == 0) {
-        return bdi.can_write_zeroes_with_unmap;
-    }
-
-    return false;
-}
-
-const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
-{
-    if (bs->backing && bs->backing->bs->encrypted)
-        return bs->backing_file;
-    else if (bs->encrypted)
-        return bs->filename;
-    else
-        return NULL;
-}
-
-void bdrv_get_backing_filename(BlockDriverState *bs,
-                               char *filename, int filename_size)
-{
-    pstrcpy(filename, filename_size, bs->backing_file);
-}
-
-int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
-{
-    BlockDriver *drv = bs->drv;
-    if (!drv)
-        return -ENOMEDIUM;
-    if (!drv->bdrv_get_info)
-        return -ENOTSUP;
-    memset(bdi, 0, sizeof(*bdi));
-    return drv->bdrv_get_info(bs, bdi);
-}
-
-ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-    if (drv && drv->bdrv_get_specific_info) {
-        return drv->bdrv_get_specific_info(bs);
-    }
-    return NULL;
-}
-
-void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
-{
-    if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
-        return;
-    }
-
-    bs->drv->bdrv_debug_event(bs, event);
-}
-
-int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
-                          const char *tag)
-{
-    while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
-        bs = bs->file ? bs->file->bs : NULL;
-    }
-
-    if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
-        return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
-    }
-
-    return -ENOTSUP;
-}
-
-int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
-{
-    while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
-        bs = bs->file ? bs->file->bs : NULL;
-    }
-
-    if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
-        return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
-    }
-
-    return -ENOTSUP;
-}
-
-int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
-{
-    while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
-        bs = bs->file ? bs->file->bs : NULL;
-    }
-
-    if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
-        return bs->drv->bdrv_debug_resume(bs, tag);
-    }
-
-    return -ENOTSUP;
-}
-
-bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
-{
-    while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
-        bs = bs->file ? bs->file->bs : NULL;
-    }
-
-    if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
-        return bs->drv->bdrv_debug_is_suspended(bs, tag);
-    }
-
-    return false;
-}
-
-int bdrv_is_snapshot(BlockDriverState *bs)
-{
-    return !!(bs->open_flags & BDRV_O_SNAPSHOT);
-}
-
-/* backing_file can either be relative, or absolute, or a protocol.  If it is
- * relative, it must be relative to the chain.  So, passing in bs->filename
- * from a BDS as backing_file should not be done, as that may be relative to
- * the CWD rather than the chain. */
-BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
-        const char *backing_file)
-{
-    char *filename_full = NULL;
-    char *backing_file_full = NULL;
-    char *filename_tmp = NULL;
-    int is_protocol = 0;
-    BlockDriverState *curr_bs = NULL;
-    BlockDriverState *retval = NULL;
-
-    if (!bs || !bs->drv || !backing_file) {
-        return NULL;
-    }
-
-    filename_full     = g_malloc(PATH_MAX);
-    backing_file_full = g_malloc(PATH_MAX);
-    filename_tmp      = g_malloc(PATH_MAX);
-
-    is_protocol = path_has_protocol(backing_file);
-
-    for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
-
-        /* If either of the filename paths is actually a protocol, then
-         * compare unmodified paths; otherwise make paths relative */
-        if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
-            if (strcmp(backing_file, curr_bs->backing_file) == 0) {
-                retval = curr_bs->backing->bs;
-                break;
-            }
-        } else {
-            /* If not an absolute filename path, make it relative to the current
-             * image's filename path */
-            path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
-                         backing_file);
-
-            /* We are going to compare absolute pathnames */
-            if (!realpath(filename_tmp, filename_full)) {
-                continue;
-            }
-
-            /* We need to make sure the backing filename we are comparing against
-             * is relative to the current image filename (or absolute) */
-            path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
-                         curr_bs->backing_file);
-
-            if (!realpath(filename_tmp, backing_file_full)) {
-                continue;
-            }
-
-            if (strcmp(backing_file_full, filename_full) == 0) {
-                retval = curr_bs->backing->bs;
-                break;
-            }
-        }
-    }
-
-    g_free(filename_full);
-    g_free(backing_file_full);
-    g_free(filename_tmp);
-    return retval;
-}
-
-int bdrv_get_backing_file_depth(BlockDriverState *bs)
-{
-    if (!bs->drv) {
-        return 0;
-    }
-
-    if (!bs->backing) {
-        return 0;
-    }
-
-    return 1 + bdrv_get_backing_file_depth(bs->backing->bs);
-}
-
-void bdrv_init(void)
-{
-    module_call_init(MODULE_INIT_BLOCK);
-}
-
-void bdrv_init_with_whitelist(void)
-{
-    use_bdrv_whitelist = 1;
-    bdrv_init();
-}
-
-void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
-{
-    Error *local_err = NULL;
-    int ret;
-
-    if (!bs->drv)  {
-        return;
-    }
-
-    if (!(bs->open_flags & BDRV_O_INACTIVE)) {
-        return;
-    }
-    bs->open_flags &= ~BDRV_O_INACTIVE;
-
-    if (bs->drv->bdrv_invalidate_cache) {
-        bs->drv->bdrv_invalidate_cache(bs, &local_err);
-    } else if (bs->file) {
-        bdrv_invalidate_cache(bs->file->bs, &local_err);
-    }
-    if (local_err) {
-        bs->open_flags |= BDRV_O_INACTIVE;
-        error_propagate(errp, local_err);
-        return;
-    }
-
-    ret = refresh_total_sectors(bs, bs->total_sectors);
-    if (ret < 0) {
-        bs->open_flags |= BDRV_O_INACTIVE;
-        error_setg_errno(errp, -ret, "Could not refresh total sector count");
-        return;
-    }
-}
-
-void bdrv_invalidate_cache_all(Error **errp)
-{
-    BlockDriverState *bs = NULL;
-    Error *local_err = NULL;
-
-    while ((bs = bdrv_next(bs)) != NULL) {
-        AioContext *aio_context = bdrv_get_aio_context(bs);
-
-        aio_context_acquire(aio_context);
-        bdrv_invalidate_cache(bs, &local_err);
-        aio_context_release(aio_context);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            return;
-        }
-    }
-}
-
-static int bdrv_inactivate(BlockDriverState *bs)
-{
-    int ret;
-
-    if (bs->drv->bdrv_inactivate) {
-        ret = bs->drv->bdrv_inactivate(bs);
-        if (ret < 0) {
-            return ret;
-        }
-    }
-
-    bs->open_flags |= BDRV_O_INACTIVE;
-    return 0;
-}
-
-int bdrv_inactivate_all(void)
-{
-    BlockDriverState *bs = NULL;
-    int ret;
-
-    while ((bs = bdrv_next(bs)) != NULL) {
-        AioContext *aio_context = bdrv_get_aio_context(bs);
-
-        aio_context_acquire(aio_context);
-        ret = bdrv_inactivate(bs);
-        aio_context_release(aio_context);
-        if (ret < 0) {
-            return ret;
-        }
-    }
-
-    return 0;
-}
-
-/**************************************************************/
-/* removable device support */
-
-/**
- * Return TRUE if the media is present
- */
-bool bdrv_is_inserted(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-    BdrvChild *child;
-
-    if (!drv) {
-        return false;
-    }
-    if (drv->bdrv_is_inserted) {
-        return drv->bdrv_is_inserted(bs);
-    }
-    QLIST_FOREACH(child, &bs->children, next) {
-        if (!bdrv_is_inserted(child->bs)) {
-            return false;
-        }
-    }
-    return true;
-}
-
-/**
- * Return whether the media changed since the last call to this
- * function, or -ENOTSUP if we don't know.  Most drivers don't know.
- */
-int bdrv_media_changed(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-
-    if (drv && drv->bdrv_media_changed) {
-        return drv->bdrv_media_changed(bs);
-    }
-    return -ENOTSUP;
-}
-
-/**
- * If eject_flag is TRUE, eject the media. Otherwise, close the tray
- */
-void bdrv_eject(BlockDriverState *bs, bool eject_flag)
-{
-    BlockDriver *drv = bs->drv;
-    const char *device_name;
-
-    if (drv && drv->bdrv_eject) {
-        drv->bdrv_eject(bs, eject_flag);
-    }
-
-    device_name = bdrv_get_device_name(bs);
-    if (device_name[0] != '\0') {
-        qapi_event_send_device_tray_moved(device_name,
-                                          eject_flag, &error_abort);
-    }
-}
-
-/**
- * Lock or unlock the media (if it is locked, the user won't be able
- * to eject it manually).
- */
-void bdrv_lock_medium(BlockDriverState *bs, bool locked)
-{
-    BlockDriver *drv = bs->drv;
-
-    trace_bdrv_lock_medium(bs, locked);
-
-    if (drv && drv->bdrv_lock_medium) {
-        drv->bdrv_lock_medium(bs, locked);
-    }
-}
-
-/* Get a reference to bs */
-void bdrv_ref(BlockDriverState *bs)
-{
-    bs->refcnt++;
-}
-
-/* Release a previously grabbed reference to bs.
- * If after releasing, reference count is zero, the BlockDriverState is
- * deleted. */
-void bdrv_unref(BlockDriverState *bs)
-{
-    if (!bs) {
-        return;
-    }
-    assert(bs->refcnt > 0);
-    if (--bs->refcnt == 0) {
-        bdrv_delete(bs);
-    }
-}
-
-struct BdrvOpBlocker {
-    Error *reason;
-    QLIST_ENTRY(BdrvOpBlocker) list;
-};
-
-bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
-{
-    BdrvOpBlocker *blocker;
-    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
-    if (!QLIST_EMPTY(&bs->op_blockers[op])) {
-        blocker = QLIST_FIRST(&bs->op_blockers[op]);
-        if (errp) {
-            *errp = error_copy(blocker->reason);
-            error_prepend(errp, "Node '%s' is busy: ",
-                          bdrv_get_device_or_node_name(bs));
-        }
-        return true;
-    }
-    return false;
-}
-
-void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
-{
-    BdrvOpBlocker *blocker;
-    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
-
-    blocker = g_new0(BdrvOpBlocker, 1);
-    blocker->reason = reason;
-    QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
-}
-
-void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
-{
-    BdrvOpBlocker *blocker, *next;
-    assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
-    QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
-        if (blocker->reason == reason) {
-            QLIST_REMOVE(blocker, list);
-            g_free(blocker);
-        }
-    }
-}
-
-void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
-{
-    int i;
-    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
-        bdrv_op_block(bs, i, reason);
-    }
-}
-
-void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
-{
-    int i;
-    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
-        bdrv_op_unblock(bs, i, reason);
-    }
-}
-
-bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
-{
-    int i;
-
-    for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
-        if (!QLIST_EMPTY(&bs->op_blockers[i])) {
-            return false;
-        }
-    }
-    return true;
-}
-
-void bdrv_img_create(const char *filename, const char *fmt,
-                     const char *base_filename, const char *base_fmt,
-                     char *options, uint64_t img_size, int flags,
-                     Error **errp, bool quiet)
-{
-    QemuOptsList *create_opts = NULL;
-    QemuOpts *opts = NULL;
-    const char *backing_fmt, *backing_file;
-    int64_t size;
-    BlockDriver *drv, *proto_drv;
-    Error *local_err = NULL;
-    int ret = 0;
-
-    /* Find driver and parse its options */
-    drv = bdrv_find_format(fmt);
-    if (!drv) {
-        error_setg(errp, "Unknown file format '%s'", fmt);
-        return;
-    }
-
-    proto_drv = bdrv_find_protocol(filename, true, errp);
-    if (!proto_drv) {
-        return;
-    }
-
-    if (!drv->create_opts) {
-        error_setg(errp, "Format driver '%s' does not support image creation",
-                   drv->format_name);
-        return;
-    }
-
-    if (!proto_drv->create_opts) {
-        error_setg(errp, "Protocol driver '%s' does not support image creation",
-                   proto_drv->format_name);
-        return;
-    }
-
-    create_opts = qemu_opts_append(create_opts, drv->create_opts);
-    create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
-
-    /* Create parameter list with default values */
-    opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
-    qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
-
-    /* Parse -o options */
-    if (options) {
-        qemu_opts_do_parse(opts, options, NULL, &local_err);
-        if (local_err) {
-            error_report_err(local_err);
-            local_err = NULL;
-            error_setg(errp, "Invalid options for file format '%s'", fmt);
-            goto out;
-        }
-    }
-
-    if (base_filename) {
-        qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err);
-        if (local_err) {
-            error_setg(errp, "Backing file not supported for file format '%s'",
-                       fmt);
-            goto out;
-        }
-    }
-
-    if (base_fmt) {
-        qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err);
-        if (local_err) {
-            error_setg(errp, "Backing file format not supported for file "
-                             "format '%s'", fmt);
-            goto out;
-        }
-    }
-
-    backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
-    if (backing_file) {
-        if (!strcmp(filename, backing_file)) {
-            error_setg(errp, "Error: Trying to create an image with the "
-                             "same filename as the backing file");
-            goto out;
-        }
-    }
-
-    backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
-
-    // The size for the image must always be specified, with one exception:
-    // If we are using a backing file, we can obtain the size from there
-    size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
-    if (size == -1) {
-        if (backing_file) {
-            BlockDriverState *bs;
-            char *full_backing = g_new0(char, PATH_MAX);
-            int64_t size;
-            int back_flags;
-            QDict *backing_options = NULL;
-
-            bdrv_get_full_backing_filename_from_filename(filename, backing_file,
-                                                         full_backing, PATH_MAX,
-                                                         &local_err);
-            if (local_err) {
-                g_free(full_backing);
-                goto out;
-            }
-
-            /* backing files always opened read-only */
-            back_flags = flags;
-            back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
-
-            if (backing_fmt) {
-                backing_options = qdict_new();
-                qdict_put(backing_options, "driver",
-                          qstring_from_str(backing_fmt));
-            }
-
-            bs = NULL;
-            ret = bdrv_open(&bs, full_backing, NULL, backing_options,
-                            back_flags, &local_err);
-            g_free(full_backing);
-            if (ret < 0) {
-                goto out;
-            }
-            size = bdrv_getlength(bs);
-            if (size < 0) {
-                error_setg_errno(errp, -size, "Could not get size of '%s'",
-                                 backing_file);
-                bdrv_unref(bs);
-                goto out;
-            }
-
-            qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);
-
-            bdrv_unref(bs);
-        } else {
-            error_setg(errp, "Image creation needs a size parameter");
-            goto out;
-        }
-    }
-
-    if (!quiet) {
-        printf("Formatting '%s', fmt=%s ", filename, fmt);
-        qemu_opts_print(opts, " ");
-        puts("");
-    }
-
-    ret = bdrv_create(drv, filename, opts, &local_err);
-
-    if (ret == -EFBIG) {
-        /* This is generally a better message than whatever the driver would
-         * deliver (especially because of the cluster_size_hint), since that
-         * is most probably not much different from "image too large". */
-        const char *cluster_size_hint = "";
-        if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) {
-            cluster_size_hint = " (try using a larger cluster size)";
-        }
-        error_setg(errp, "The image size is too large for file format '%s'"
-                   "%s", fmt, cluster_size_hint);
-        error_free(local_err);
-        local_err = NULL;
-    }
-
-out:
-    qemu_opts_del(opts);
-    qemu_opts_free(create_opts);
-    if (local_err) {
-        error_propagate(errp, local_err);
-    }
-}
-
-AioContext *bdrv_get_aio_context(BlockDriverState *bs)
-{
-    return bs->aio_context;
-}
-
-void bdrv_detach_aio_context(BlockDriverState *bs)
-{
-    BdrvAioNotifier *baf;
-
-    if (!bs->drv) {
-        return;
-    }
-
-    QLIST_FOREACH(baf, &bs->aio_notifiers, list) {
-        baf->detach_aio_context(baf->opaque);
-    }
-
-    if (bs->throttle_state) {
-        throttle_timers_detach_aio_context(&bs->throttle_timers);
-    }
-    if (bs->drv->bdrv_detach_aio_context) {
-        bs->drv->bdrv_detach_aio_context(bs);
-    }
-    if (bs->file) {
-        bdrv_detach_aio_context(bs->file->bs);
-    }
-    if (bs->backing) {
-        bdrv_detach_aio_context(bs->backing->bs);
-    }
-
-    bs->aio_context = NULL;
-}
-
-void bdrv_attach_aio_context(BlockDriverState *bs,
-                             AioContext *new_context)
-{
-    BdrvAioNotifier *ban;
-
-    if (!bs->drv) {
-        return;
-    }
-
-    bs->aio_context = new_context;
-
-    if (bs->backing) {
-        bdrv_attach_aio_context(bs->backing->bs, new_context);
-    }
-    if (bs->file) {
-        bdrv_attach_aio_context(bs->file->bs, new_context);
-    }
-    if (bs->drv->bdrv_attach_aio_context) {
-        bs->drv->bdrv_attach_aio_context(bs, new_context);
-    }
-    if (bs->throttle_state) {
-        throttle_timers_attach_aio_context(&bs->throttle_timers, new_context);
-    }
-
-    QLIST_FOREACH(ban, &bs->aio_notifiers, list) {
-        ban->attached_aio_context(new_context, ban->opaque);
-    }
-}
-
-void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
-{
-    bdrv_drain(bs); /* ensure there are no in-flight requests */
-
-    bdrv_detach_aio_context(bs);
-
-    /* This function executes in the old AioContext so acquire the new one in
-     * case it runs in a different thread.
-     */
-    aio_context_acquire(new_context);
-    bdrv_attach_aio_context(bs, new_context);
-    aio_context_release(new_context);
-}
-
-void bdrv_add_aio_context_notifier(BlockDriverState *bs,
-        void (*attached_aio_context)(AioContext *new_context, void *opaque),
-        void (*detach_aio_context)(void *opaque), void *opaque)
-{
-    BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1);
-    *ban = (BdrvAioNotifier){
-        .attached_aio_context = attached_aio_context,
-        .detach_aio_context   = detach_aio_context,
-        .opaque               = opaque
-    };
-
-    QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
-}
-
-void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
-                                      void (*attached_aio_context)(AioContext *,
-                                                                   void *),
-                                      void (*detach_aio_context)(void *),
-                                      void *opaque)
-{
-    BdrvAioNotifier *ban, *ban_next;
-
-    QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
-        if (ban->attached_aio_context == attached_aio_context &&
-            ban->detach_aio_context   == detach_aio_context   &&
-            ban->opaque               == opaque)
-        {
-            QLIST_REMOVE(ban, list);
-            g_free(ban);
-
-            return;
-        }
-    }
-
-    abort();
-}
-
-int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
-                       BlockDriverAmendStatusCB *status_cb, void *cb_opaque)
-{
-    if (!bs->drv->bdrv_amend_options) {
-        return -ENOTSUP;
-    }
-    return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque);
-}
-
-/* This function will be called by the bdrv_recurse_is_first_non_filter method
- * of block filter and by bdrv_is_first_non_filter.
- * It is used to test if the given bs is the candidate or recurse more in the
- * node graph.
- */
-bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
-                                      BlockDriverState *candidate)
-{
-    /* return false if basic checks fails */
-    if (!bs || !bs->drv) {
-        return false;
-    }
-
-    /* the code reached a non block filter driver -> check if the bs is
-     * the same as the candidate. It's the recursion termination condition.
-     */
-    if (!bs->drv->is_filter) {
-        return bs == candidate;
-    }
-    /* Down this path the driver is a block filter driver */
-
-    /* If the block filter recursion method is defined use it to recurse down
-     * the node graph.
-     */
-    if (bs->drv->bdrv_recurse_is_first_non_filter) {
-        return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
-    }
-
-    /* the driver is a block filter but don't allow to recurse -> return false
-     */
-    return false;
-}
-
-/* This function checks if the candidate is the first non filter bs down it's
- * bs chain. Since we don't have pointers to parents it explore all bs chains
- * from the top. Some filters can choose not to pass down the recursion.
- */
-bool bdrv_is_first_non_filter(BlockDriverState *candidate)
-{
-    BlockDriverState *bs = NULL;
-
-    /* walk down the bs forest recursively */
-    while ((bs = bdrv_next(bs)) != NULL) {
-        bool perm;
-
-        /* try to recurse in this top level bs */
-        perm = bdrv_recurse_is_first_non_filter(bs, candidate);
-
-        /* candidate is the first non filter */
-        if (perm) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
-BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
-                                        const char *node_name, Error **errp)
-{
-    BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
-    AioContext *aio_context;
-
-    if (!to_replace_bs) {
-        error_setg(errp, "Node name '%s' not found", node_name);
-        return NULL;
-    }
-
-    aio_context = bdrv_get_aio_context(to_replace_bs);
-    aio_context_acquire(aio_context);
-
-    if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
-        to_replace_bs = NULL;
-        goto out;
-    }
-
-    /* We don't want arbitrary node of the BDS chain to be replaced only the top
-     * most non filter in order to prevent data corruption.
-     * Another benefit is that this tests exclude backing files which are
-     * blocked by the backing blockers.
-     */
-    if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
-        error_setg(errp, "Only top most non filter can be replaced");
-        to_replace_bs = NULL;
-        goto out;
-    }
-
-out:
-    aio_context_release(aio_context);
-    return to_replace_bs;
-}
-
-static bool append_open_options(QDict *d, BlockDriverState *bs)
-{
-    const QDictEntry *entry;
-    QemuOptDesc *desc;
-    BdrvChild *child;
-    bool found_any = false;
-    const char *p;
-
-    for (entry = qdict_first(bs->options); entry;
-         entry = qdict_next(bs->options, entry))
-    {
-        /* Exclude options for children */
-        QLIST_FOREACH(child, &bs->children, next) {
-            if (strstart(qdict_entry_key(entry), child->name, &p)
-                && (!*p || *p == '.'))
-            {
-                break;
-            }
-        }
-        if (child) {
-            continue;
-        }
-
-        /* And exclude all non-driver-specific options */
-        for (desc = bdrv_runtime_opts.desc; desc->name; desc++) {
-            if (!strcmp(qdict_entry_key(entry), desc->name)) {
-                break;
-            }
-        }
-        if (desc->name) {
-            continue;
-        }
-
-        qobject_incref(qdict_entry_value(entry));
-        qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry));
-        found_any = true;
-    }
-
-    return found_any;
-}
-
-/* Updates the following BDS fields:
- *  - exact_filename: A filename which may be used for opening a block device
- *                    which (mostly) equals the given BDS (even without any
- *                    other options; so reading and writing must return the same
- *                    results, but caching etc. may be different)
- *  - full_open_options: Options which, when given when opening a block device
- *                       (without a filename), result in a BDS (mostly)
- *                       equalling the given one
- *  - filename: If exact_filename is set, it is copied here. Otherwise,
- *              full_open_options is converted to a JSON object, prefixed with
- *              "json:" (for use through the JSON pseudo protocol) and put here.
- */
-void bdrv_refresh_filename(BlockDriverState *bs)
-{
-    BlockDriver *drv = bs->drv;
-    QDict *opts;
-
-    if (!drv) {
-        return;
-    }
-
-    /* This BDS's file name will most probably depend on its file's name, so
-     * refresh that first */
-    if (bs->file) {
-        bdrv_refresh_filename(bs->file->bs);
-    }
-
-    if (drv->bdrv_refresh_filename) {
-        /* Obsolete information is of no use here, so drop the old file name
-         * information before refreshing it */
-        bs->exact_filename[0] = '\0';
-        if (bs->full_open_options) {
-            QDECREF(bs->full_open_options);
-            bs->full_open_options = NULL;
-        }
-
-        opts = qdict_new();
-        append_open_options(opts, bs);
-        drv->bdrv_refresh_filename(bs, opts);
-        QDECREF(opts);
-    } else if (bs->file) {
-        /* Try to reconstruct valid information from the underlying file */
-        bool has_open_options;
-
-        bs->exact_filename[0] = '\0';
-        if (bs->full_open_options) {
-            QDECREF(bs->full_open_options);
-            bs->full_open_options = NULL;
-        }
-
-        opts = qdict_new();
-        has_open_options = append_open_options(opts, bs);
-
-        /* If no specific options have been given for this BDS, the filename of
-         * the underlying file should suffice for this one as well */
-        if (bs->file->bs->exact_filename[0] && !has_open_options) {
-            strcpy(bs->exact_filename, bs->file->bs->exact_filename);
-        }
-        /* Reconstructing the full options QDict is simple for most format block
-         * drivers, as long as the full options are known for the underlying
-         * file BDS. The full options QDict of that file BDS should somehow
-         * contain a representation of the filename, therefore the following
-         * suffices without querying the (exact_)filename of this BDS. */
-        if (bs->file->bs->full_open_options) {
-            qdict_put_obj(opts, "driver",
-                          QOBJECT(qstring_from_str(drv->format_name)));
-            QINCREF(bs->file->bs->full_open_options);
-            qdict_put_obj(opts, "file",
-                          QOBJECT(bs->file->bs->full_open_options));
-
-            bs->full_open_options = opts;
-        } else {
-            QDECREF(opts);
-        }
-    } else if (!bs->full_open_options && qdict_size(bs->options)) {
-        /* There is no underlying file BDS (at least referenced by BDS.file),
-         * so the full options QDict should be equal to the options given
-         * specifically for this block device when it was opened (plus the
-         * driver specification).
-         * Because those options don't change, there is no need to update
-         * full_open_options when it's already set. */
-
-        opts = qdict_new();
-        append_open_options(opts, bs);
-        qdict_put_obj(opts, "driver",
-                      QOBJECT(qstring_from_str(drv->format_name)));
-
-        if (bs->exact_filename[0]) {
-            /* This may not work for all block protocol drivers (some may
-             * require this filename to be parsed), but we have to find some
-             * default solution here, so just include it. If some block driver
-             * does not support pure options without any filename at all or
-             * needs some special format of the options QDict, it needs to
-             * implement the driver-specific bdrv_refresh_filename() function.
-             */
-            qdict_put_obj(opts, "filename",
-                          QOBJECT(qstring_from_str(bs->exact_filename)));
-        }
-
-        bs->full_open_options = opts;
-    }
-
-    if (bs->exact_filename[0]) {
-        pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
-    } else if (bs->full_open_options) {
-        QString *json = qobject_to_json(QOBJECT(bs->full_open_options));
-        snprintf(bs->filename, sizeof(bs->filename), "json:%s",
-                 qstring_get_str(json));
-        QDECREF(json);
-    }
-}