--- /dev/null
+/*
+ * 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 "config-host.h"
+#include "qemu-common.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/qjson.h"
+#include "sysemu/block-backend.h"
+#include "sysemu/sysemu.h"
+#include "qemu/notify.h"
+#include "block/coroutine.h"
+#include "block/qapi.h"
+#include "qmp-commands.h"
+#include "qemu/timer.h"
+#include "qapi-event.h"
+#include "block/throttle-groups.h"
+
+#ifdef CONFIG_BSD
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/queue.h>
+#ifndef __DragonFly__
+#include <sys/disk.h>
+#endif
+#endif
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+/**
+ * A BdrvDirtyBitmap can be in three possible states:
+ * (1) successor is NULL and disabled is false: full r/w mode
+ * (2) successor is NULL and disabled is true: read only mode ("disabled")
+ * (3) successor is set: frozen mode.
+ * A frozen bitmap cannot be renamed, deleted, anonymized, cleared, set,
+ * or enabled. A frozen bitmap can only abdicate() or reclaim().
+ */
+struct BdrvDirtyBitmap {
+ HBitmap *bitmap; /* Dirty sector bitmap implementation */
+ BdrvDirtyBitmap *successor; /* Anonymous child; implies frozen status */
+ char *name; /* Optional non-empty unique ID */
+ int64_t size; /* Size of the bitmap (Number of sectors) */
+ bool disabled; /* Bitmap is read-only */
+ QLIST_ENTRY(BdrvDirtyBitmap) list;
+};
+
+#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
+
+static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
+ QTAILQ_HEAD_INITIALIZER(bdrv_states);
+
+static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
+ QTAILQ_HEAD_INITIALIZER(graph_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,
+ BlockDriver *drv, Error **errp);
+
+static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs);
+/* If non-zero, use only whitelisted block drivers */
+static int use_bdrv_whitelist;
+
+#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)
+{
+ BlockDriverState *bs = bdrv_new();
+
+ QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list);
+ return bs;
+}
+
+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]);
+ }
+ bdrv_iostatus_disable(bs);
+ notifier_list_init(&bs->close_notifiers);
+ 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();
+
+ return bs;
+}
+
+void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify)
+{
+ notifier_list_add(&bs->close_notifiers, notify);
+}
+
+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;
+}
+
+BlockDriver *bdrv_find_whitelisted_format(const char *format_name,
+ bool read_only)
+{
+ BlockDriver *drv = bdrv_find_format(format_name);
+ return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL;
+}
+
+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;
+}
+
+/**
+ * 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_flags(const char *mode, int *flags)
+{
+ *flags &= ~BDRV_O_CACHE_MASK;
+
+ if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
+ *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
+ } else if (!strcmp(mode, "directsync")) {
+ *flags |= BDRV_O_NOCACHE;
+ } else if (!strcmp(mode, "writeback")) {
+ *flags |= BDRV_O_CACHE_WB;
+ } else if (!strcmp(mode, "unsafe")) {
+ *flags |= BDRV_O_CACHE_WB;
+ *flags |= BDRV_O_NO_FLUSH;
+ } else if (!strcmp(mode, "writethrough")) {
+ /* this is the default */
+ } else {
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Returns the 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 int bdrv_temp_snapshot_flags(int flags)
+{
+ return (flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
+}
+
+/*
+ * Returns the flags that bs->file should get if a protocol driver is expected,
+ * based on the given flags for the parent BDS
+ */
+static int bdrv_inherited_flags(int flags)
+{
+ /* Enable protocol handling, disable format probing for bs->file */
+ flags |= BDRV_O_PROTOCOL;
+
+ /* Our block drivers take care to send flushes and respect unmap policy,
+ * so we can enable both unconditionally on lower layers. */
+ flags |= BDRV_O_CACHE_WB | 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);
+
+ return flags;
+}
+
+const BdrvChildRole child_file = {
+ .inherit_flags = bdrv_inherited_flags,
+};
+
+/*
+ * Returns the flags that bs->file should get if the use of formats (and not
+ * only protocols) is permitted for it, based on the given flags for the parent
+ * BDS
+ */
+static int bdrv_inherited_fmt_flags(int parent_flags)
+{
+ int flags = child_file.inherit_flags(parent_flags);
+ return flags & ~BDRV_O_PROTOCOL;
+}
+
+const BdrvChildRole child_format = {
+ .inherit_flags = bdrv_inherited_fmt_flags,
+};
+
+/*
+ * Returns the flags that bs->backing_hd should get, based on the given flags
+ * for the parent BDS
+ */
+static int bdrv_backing_flags(int flags)
+{
+ /* 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);
+
+ return flags;
+}
+
+static const BdrvChildRole child_backing = {
+ .inherit_flags = bdrv_backing_flags,
+};
+
+static int bdrv_open_flags(BlockDriverState *bs, int flags)
+{
+ int open_flags = flags | BDRV_O_CACHE_WB;
+
+ /*
+ * 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 bdrv_assign_node_name(BlockDriverState *bs,
+ const char *node_name,
+ Error **errp)
+{
+ if (!node_name) {
+ return;
+ }
+
+ /* Check for empty string or invalid characters */
+ if (!id_wellformed(node_name)) {
+ 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);
+ return;
+ }
+
+ /* takes care of avoiding duplicates node names */
+ if (bdrv_find_node(node_name)) {
+ error_setg(errp, "Duplicate node name");
+ return;
+ }
+
+ /* 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);
+}
+
+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",
+ },
+ { /* end of list */ }
+ },
+};
+
+/*
+ * Common part for opening disk images and files
+ *
+ * Removes all processed options from *options.
+ */
+static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
+ QDict *options, int flags, BlockDriver *drv, Error **errp)
+{
+ int ret, open_flags;
+ const char *filename;
+ const char *node_name = NULL;
+ QemuOpts *opts;
+ Error *local_err = NULL;
+
+ assert(drv != NULL);
+ assert(bs->file == NULL);
+ assert(options != NULL && bs->options != options);
+
+ if (file != NULL) {
+ filename = file->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);
+ return -EINVAL;
+ }
+
+ trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
+
+ 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;
+ }
+
+ 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->guest_block_size = 512;
+ bs->request_alignment = 512;
+ bs->zero_beyond_eof = true;
+ open_flags = bdrv_open_flags(bs, flags);
+ bs->read_only = !(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 (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);
+
+ bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
+
+ /* Open the image, either directly or using a protocol */
+ 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;
+ }
+
+ if (bs->encrypted) {
+ error_report("Encrypted images are deprecated");
+ error_printf("Support for them will be removed in a future release.\n"
+ "You can use 'qemu-img convert' to convert your image"
+ " to an unencrypted one.\n");
+ }
+
+ 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;
+}
+
+/*
+ * 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 **pfilename,
+ int *flags, BlockDriver *drv, Error **errp)
+{
+ const char *filename = *pfilename;
+ const char *drvname;
+ bool protocol = *flags & BDRV_O_PROTOCOL;
+ bool parse_filename = false;
+ BlockDriver *tmp_drv;
+ Error *local_err = NULL;
+
+ /* Parse json: pseudo-protocol */
+ if (filename && g_str_has_prefix(filename, "json:")) {
+ QDict *json_options = parse_json_filename(filename, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return -EINVAL;
+ }
+
+ /* Options given in the filename have lower priority than options
+ * specified directly */
+ qdict_join(*options, json_options, false);
+ QDECREF(json_options);
+ *pfilename = filename = NULL;
+ }
+
+ drvname = qdict_get_try_str(*options, "driver");
+
+ /* If the user has explicitly specified the driver, this choice should
+ * override the BDRV_O_PROTOCOL flag */
+ tmp_drv = drv;
+ if (!tmp_drv && drvname) {
+ tmp_drv = bdrv_find_format(drvname);
+ }
+ if (tmp_drv) {
+ protocol = tmp_drv->bdrv_file_open;
+ }
+
+ if (protocol) {
+ *flags |= BDRV_O_PROTOCOL;
+ } else {
+ *flags &= ~BDRV_O_PROTOCOL;
+ }
+
+ /* 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 (drv) {
+ if (drvname) {
+ error_setg(errp, "Driver specified twice");
+ return -EINVAL;
+ }
+ drvname = drv->format_name;
+ qdict_put(*options, "driver", qstring_from_str(drvname));
+ } else {
+ 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;
+ }
+ } else if (drvname) {
+ drv = bdrv_find_format(drvname);
+ if (!drv) {
+ error_setg(errp, "Unknown driver '%s'", drvname);
+ return -ENOENT;
+ }
+ }
+ }
+
+ 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;
+}
+
+static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
+ BlockDriverState *child_bs,
+ const BdrvChildRole *child_role)
+{
+ BdrvChild *child = g_new(BdrvChild, 1);
+ *child = (BdrvChild) {
+ .bs = child_bs,
+ .role = child_role,
+ };
+
+ QLIST_INSERT_HEAD(&parent_bs->children, child, next);
+
+ return child;
+}
+
+static void bdrv_detach_child(BdrvChild *child)
+{
+ QLIST_REMOVE(child, next);
+ g_free(child);
+}
+
+void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
+{
+ BlockDriverState *child_bs = child->bs;
+
+ if (child->bs->inherits_from == parent) {
+ child->bs->inherits_from = NULL;
+ }
+
+ bdrv_detach_child(child);
+ bdrv_unref(child_bs);
+}
+
+void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
+{
+
+ if (bs->backing_hd) {
+ assert(bs->backing_blocker);
+ bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker);
+ bdrv_detach_child(bs->backing_child);
+ } else if (backing_hd) {
+ error_setg(&bs->backing_blocker,
+ "node is used as backing hd of '%s'",
+ bdrv_get_device_or_node_name(bs));
+ }
+
+ bs->backing_hd = backing_hd;
+ if (!backing_hd) {
+ error_free(bs->backing_blocker);
+ bs->backing_blocker = NULL;
+ bs->backing_child = NULL;
+ goto out;
+ }
+ bs->backing_child = bdrv_attach_child(bs, backing_hd, &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(bs->backing_hd, bs->backing_blocker);
+ /* Otherwise we won't be able to commit due to check in bdrv_commit */
+ bdrv_op_unblock(bs->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
+ *
+ * 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 is transferred to this
+ * function (even on failure), so if the caller intends to reuse the dictionary,
+ * it needs to use QINCREF() before calling bdrv_file_open.
+ */
+int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
+{
+ char *backing_filename = g_malloc0(PATH_MAX);
+ int ret = 0;
+ BlockDriverState *backing_hd;
+ Error *local_err = NULL;
+
+ if (bs->backing_hd != NULL) {
+ QDECREF(options);
+ goto free_exit;
+ }
+
+ /* NULL means an empty set of options */
+ if (options == NULL) {
+ options = qdict_new();
+ }
+
+ bs->open_flags &= ~BDRV_O_NO_BACKING;
+ if (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;
+ }
+
+ backing_hd = bdrv_new();
+
+ if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
+ qdict_put(options, "driver", qstring_from_str(bs->backing_format));
+ }
+
+ assert(bs->backing_hd == NULL);
+ ret = bdrv_open_inherit(&backing_hd,
+ *backing_filename ? backing_filename : NULL,
+ NULL, options, 0, bs, &child_backing,
+ NULL, &local_err);
+ if (ret < 0) {
+ bdrv_unref(backing_hd);
+ backing_hd = NULL;
+ bs->open_flags |= BDRV_O_NO_BACKING;
+ error_setg(errp, "Could not open backing file: %s",
+ error_get_pretty(local_err));
+ error_free(local_err);
+ goto free_exit;
+ }
+
+ bdrv_set_backing_hd(bs, backing_hd);
+
+free_exit:
+ g_free(backing_filename);
+ 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, NULL, errp);
+ if (ret < 0) {
+ goto done;
+ }
+
+ c = bdrv_attach_child(parent, bs, child_role);
+
+done:
+ qdict_del(options, bdref_key);
+ return c;
+}
+
+/*
+ * This is a version of bdrv_open_child() that returns 0/-EINVAL instead of
+ * a BdrvChild object.
+ *
+ * If allow_none is true, no image will be opened if filename is false and no
+ * BlockdevRef is given. *pbs will remain unchanged and 0 will be returned.
+ *
+ * To conform with the behavior of bdrv_open(), *pbs has to be NULL.
+ */
+int bdrv_open_image(BlockDriverState **pbs, const char *filename,
+ QDict *options, const char *bdref_key,
+ BlockDriverState* parent, const BdrvChildRole *child_role,
+ bool allow_none, Error **errp)
+{
+ Error *local_err = NULL;
+ BdrvChild *c;
+
+ assert(pbs);
+ assert(*pbs == NULL);
+
+ c = bdrv_open_child(filename, options, bdref_key, parent, child_role,
+ allow_none, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return -EINVAL;
+ }
+
+ if (c != NULL) {
+ *pbs = c->bs;
+ }
+
+ return 0;
+}
+
+int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, 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;
+ QDict *snapshot_options;
+ 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, &local_err);
+ qemu_opts_del(opts);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not create temporary overlay "
+ "'%s': %s", tmp_filename,
+ error_get_pretty(local_err));
+ error_free(local_err);
+ goto out;
+ }
+
+ /* Prepare a new options QDict for the temporary file */
+ snapshot_options = qdict_new();
+ qdict_put(snapshot_options, "file.driver",
+ qstring_from_str("file"));
+ qdict_put(snapshot_options, "file.filename",
+ qstring_from_str(tmp_filename));
+
+ bs_snapshot = bdrv_new();
+
+ ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options,
+ flags, &bdrv_qcow2, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ goto out;
+ }
+
+ bdrv_append(bs_snapshot, bs);
+
+out:
+ 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,
+ BlockDriver *drv, Error **errp)
+{
+ int ret;
+ BlockDriverState *file = NULL, *bs;
+ const char *drvname;
+ Error *local_err = 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;
+ }
+ 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();
+ }
+
+ if (child_role) {
+ bs->inherits_from = parent;
+ flags = child_role->inherit_flags(parent->open_flags);
+ }
+
+ ret = bdrv_fill_options(&options, &filename, &flags, drv, &local_err);
+ if (local_err) {
+ goto fail;
+ }
+
+ /* Find the right image format driver */
+ drv = NULL;
+ drvname = qdict_get_try_str(options, "driver");
+ if (drvname) {
+ drv = bdrv_find_format(drvname);
+ qdict_del(options, "driver");
+ if (!drv) {
+ error_setg(errp, "Unknown driver: '%s'", drvname);
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ assert(drvname || !(flags & BDRV_O_PROTOCOL));
+
+ bs->open_flags = flags;
+ bs->options = options;
+ options = qdict_clone_shallow(options);
+
+ /* 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_flags = bdrv_temp_snapshot_flags(flags);
+ flags = bdrv_backing_flags(flags);
+ }
+
+ assert(file == NULL);
+ bs->open_flags = flags;
+ ret = bdrv_open_image(&file, filename, options, "file",
+ bs, &child_file, true, &local_err);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ /* Image format probing */
+ bs->probed = !drv;
+ if (!drv && file) {
+ ret = find_image_format(file, filename, &drv, &local_err);
+ if (ret < 0) {
+ goto fail;
+ }
+ } 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, flags, drv, &local_err);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ if (file && (bs->file != file)) {
+ bdrv_unref(file);
+ file = NULL;
+ }
+
+ /* If there is a backing file, use it */
+ if ((flags & BDRV_O_NO_BACKING) == 0) {
+ QDict *backing_options;
+
+ qdict_extract_subqdict(options, &backing_options, "backing.");
+ ret = bdrv_open_backing_file(bs, backing_options, &local_err);
+ if (ret < 0) {
+ goto close_and_fail;
+ }
+ }
+
+ bdrv_refresh_filename(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, &local_err);
+ if (local_err) {
+ goto close_and_fail;
+ }
+ }
+
+ /* 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' used by device '%s' doesn't "
+ "support the option '%s'", drv->format_name,
+ bdrv_get_device_name(bs), 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;
+ return 0;
+
+fail:
+ if (file != NULL) {
+ bdrv_unref(file);
+ }
+ 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(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,
+ BlockDriver *drv, Error **errp)
+{
+ return bdrv_open_inherit(pbs, filename, reference, options, flags, NULL,
+ NULL, drv, 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.
+ *
+ * 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.
+ *
+ */
+BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
+ BlockDriverState *bs, int flags)
+{
+ assert(bs != NULL);
+
+ BlockReopenQueueEntry *bs_entry;
+ BdrvChild *child;
+
+ if (bs_queue == NULL) {
+ bs_queue = g_new0(BlockReopenQueue, 1);
+ QSIMPLEQ_INIT(bs_queue);
+ }
+
+ /* bdrv_open() masks this flag out */
+ flags &= ~BDRV_O_PROTOCOL;
+
+ QLIST_FOREACH(child, &bs->children, next) {
+ int child_flags;
+
+ if (child->bs->inherits_from != bs) {
+ continue;
+ }
+
+ child_flags = child->role->inherit_flags(flags);
+ bdrv_reopen_queue(bs_queue, child->bs, child_flags);
+ }
+
+ bs_entry = g_new0(BlockReopenQueueEntry, 1);
+ QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry);
+
+ bs_entry->state.bs = bs;
+ bs_entry->state.flags = flags;
+
+ return bs_queue;
+}
+
+/*
+ * 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);
+ }
+ 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, 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;
+
+ assert(reopen_state != NULL);
+ assert(reopen_state->bs->drv != NULL);
+ drv = reopen_state->bs->drv;
+
+ /* 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_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive",
+ strerror(-ret));
+ 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;
+ }
+
+ ret = 0;
+
+error:
+ 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 */
+ reopen_state->bs->open_flags = reopen_state->flags;
+ reopen_state->bs->enable_write_cache = !!(reopen_state->flags &
+ BDRV_O_CACHE_WB);
+ 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);
+ }
+}
+
+
+void bdrv_close(BlockDriverState *bs)
+{
+ BdrvAioNotifier *ban, *ban_next;
+
+ if (bs->job) {
+ block_job_cancel_sync(bs->job);
+ }
+ bdrv_drain(bs); /* complete I/O */
+ bdrv_flush(bs);
+ bdrv_drain(bs); /* in case flush left pending I/O */
+ notifier_list_notify(&bs->close_notifiers, bs);
+
+ if (bs->drv) {
+ BdrvChild *child, *next;
+
+ bs->drv->bdrv_close(bs);
+
+ if (bs->backing_hd) {
+ BlockDriverState *backing_hd = bs->backing_hd;
+ bdrv_set_backing_hd(bs, NULL);
+ bdrv_unref(backing_hd);
+ }
+
+ 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->drv = 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);
+ bs->options = NULL;
+ QDECREF(bs->full_open_options);
+ bs->full_open_options = NULL;
+
+ if (bs->file != NULL) {
+ bdrv_unref(bs->file);
+ bs->file = NULL;
+ }
+ }
+
+ if (bs->blk) {
+ blk_dev_change_media_cb(bs->blk, false);
+ }
+
+ /*throttling disk I/O limits*/
+ if (bs->io_limits_enabled) {
+ bdrv_io_limits_disable(bs);
+ }
+
+ QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
+ g_free(ban);
+ }
+ QLIST_INIT(&bs->aio_notifiers);
+}
+
+void bdrv_close_all(void)
+{
+ BlockDriverState *bs;
+
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(aio_context);
+ bdrv_close(bs);
+ aio_context_release(aio_context);
+ }
+}
+
+/* make a BlockDriverState anonymous by removing from bdrv_state and
+ * graph_bdrv_state list.
+ Also, NULL terminate the device_name to prevent double remove */
+void bdrv_make_anon(BlockDriverState *bs)
+{
+ /*
+ * Take care to remove bs from bdrv_states only when it's actually
+ * in it. Note that bs->device_list.tqe_prev is initially null,
+ * and gets set to non-null by QTAILQ_INSERT_TAIL(). Establish
+ * the useful invariant "bs in bdrv_states iff bs->tqe_prev" by
+ * resetting it to null on remove.
+ */
+ if (bs->device_list.tqe_prev) {
+ QTAILQ_REMOVE(&bdrv_states, bs, device_list);
+ bs->device_list.tqe_prev = NULL;
+ }
+ if (bs->node_name[0] != '\0') {
+ QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
+ }
+ bs->node_name[0] = '\0';
+}
+
+static void bdrv_rebind(BlockDriverState *bs)
+{
+ if (bs->drv && bs->drv->bdrv_rebind) {
+ bs->drv->bdrv_rebind(bs);
+ }
+}
+
+static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
+ BlockDriverState *bs_src)
+{
+ /* move some fields that need to stay attached to the device */
+
+ /* dev info */
+ bs_dest->guest_block_size = bs_src->guest_block_size;
+ bs_dest->copy_on_read = bs_src->copy_on_read;
+
+ bs_dest->enable_write_cache = bs_src->enable_write_cache;
+
+ /* i/o throttled req */
+ bs_dest->throttle_state = bs_src->throttle_state,
+ bs_dest->io_limits_enabled = bs_src->io_limits_enabled;
+ bs_dest->pending_reqs[0] = bs_src->pending_reqs[0];
+ bs_dest->pending_reqs[1] = bs_src->pending_reqs[1];
+ bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0];
+ bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1];
+ memcpy(&bs_dest->round_robin,
+ &bs_src->round_robin,
+ sizeof(bs_dest->round_robin));
+ memcpy(&bs_dest->throttle_timers,
+ &bs_src->throttle_timers,
+ sizeof(ThrottleTimers));
+
+ /* r/w error */
+ bs_dest->on_read_error = bs_src->on_read_error;
+ bs_dest->on_write_error = bs_src->on_write_error;
+
+ /* i/o status */
+ bs_dest->iostatus_enabled = bs_src->iostatus_enabled;
+ bs_dest->iostatus = bs_src->iostatus;
+
+ /* dirty bitmap */
+ bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps;
+
+ /* reference count */
+ bs_dest->refcnt = bs_src->refcnt;
+
+ /* job */
+ bs_dest->job = bs_src->job;
+
+ /* keep the same entry in bdrv_states */
+ bs_dest->device_list = bs_src->device_list;
+ bs_dest->blk = bs_src->blk;
+
+ memcpy(bs_dest->op_blockers, bs_src->op_blockers,
+ sizeof(bs_dest->op_blockers));
+}
+
+/*
+ * Swap bs contents for two image chains while they are live,
+ * while keeping required fields on the BlockDriverState that is
+ * actually attached to a device.
+ *
+ * This will modify the BlockDriverState fields, and swap contents
+ * between bs_new and bs_old. Both bs_new and bs_old are modified.
+ *
+ * bs_new must not be attached to a BlockBackend.
+ *
+ * This function does not create any image files.
+ */
+void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
+{
+ BlockDriverState tmp;
+ BdrvChild *child;
+
+ bdrv_drain(bs_new);
+ bdrv_drain(bs_old);
+
+ /* The code needs to swap the node_name but simply swapping node_list won't
+ * work so first remove the nodes from the graph list, do the swap then
+ * insert them back if needed.
+ */
+ if (bs_new->node_name[0] != '\0') {
+ QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list);
+ }
+ if (bs_old->node_name[0] != '\0') {
+ QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list);
+ }
+
+ /* If the BlockDriverState is part of a throttling group acquire
+ * its lock since we're going to mess with the protected fields.
+ * Otherwise there's no need to worry since no one else can touch
+ * them. */
+ if (bs_old->throttle_state) {
+ throttle_group_lock(bs_old);
+ }
+
+ /* bs_new must be unattached and shouldn't have anything fancy enabled */
+ assert(!bs_new->blk);
+ assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
+ assert(bs_new->job == NULL);
+ assert(bs_new->io_limits_enabled == false);
+ assert(bs_new->throttle_state == NULL);
+ assert(!throttle_timers_are_initialized(&bs_new->throttle_timers));
+
+ tmp = *bs_new;
+ *bs_new = *bs_old;
+ *bs_old = tmp;
+
+ /* there are some fields that should not be swapped, move them back */
+ bdrv_move_feature_fields(&tmp, bs_old);
+ bdrv_move_feature_fields(bs_old, bs_new);
+ bdrv_move_feature_fields(bs_new, &tmp);
+
+ /* bs_new must remain unattached */
+ assert(!bs_new->blk);
+
+ /* Check a few fields that should remain attached to the device */
+ assert(bs_new->job == NULL);
+ assert(bs_new->io_limits_enabled == false);
+ assert(bs_new->throttle_state == NULL);
+ assert(!throttle_timers_are_initialized(&bs_new->throttle_timers));
+
+ /* Release the ThrottleGroup lock */
+ if (bs_old->throttle_state) {
+ throttle_group_unlock(bs_old);
+ }
+
+ /* insert the nodes back into the graph node list if needed */
+ if (bs_new->node_name[0] != '\0') {
+ QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list);
+ }
+ if (bs_old->node_name[0] != '\0') {
+ QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list);
+ }
+
+ /*
+ * Update lh_first.le_prev for non-empty lists.
+ *
+ * The head of the op blocker list doesn't change because it is moved back
+ * in bdrv_move_feature_fields().
+ */
+ assert(QLIST_EMPTY(&bs_old->tracked_requests));
+ assert(QLIST_EMPTY(&bs_new->tracked_requests));
+
+ QLIST_FIX_HEAD_PTR(&bs_new->children, next);
+ QLIST_FIX_HEAD_PTR(&bs_old->children, next);
+
+ /* Update references in bs->opaque and children */
+ QLIST_FOREACH(child, &bs_old->children, next) {
+ if (child->bs->inherits_from == bs_new) {
+ child->bs->inherits_from = bs_old;
+ }
+ }
+ QLIST_FOREACH(child, &bs_new->children, next) {
+ if (child->bs->inherits_from == bs_old) {
+ child->bs->inherits_from = bs_new;
+ }
+ }
+
+ bdrv_rebind(bs_new);
+ bdrv_rebind(bs_old);
+}
+
+/*
+ * 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.
+ */
+void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
+{
+ bdrv_swap(bs_new, bs_top);
+
+ /* The contents of 'tmp' will become bs_top, as we are
+ * swapping bs_new and bs_top contents. */
+ bdrv_set_backing_hd(bs_top, bs_new);
+}
+
+static void bdrv_delete(BlockDriverState *bs)
+{
+ assert(!bs->job);
+ assert(bdrv_op_blocker_is_empty(bs));
+ assert(!bs->refcnt);
+ assert(QLIST_EMPTY(&bs->dirty_bitmaps));
+
+ bdrv_close(bs);
+
+ /* remove from list, if necessary */
+ bdrv_make_anon(bs);
+
+ 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_hd) {
+ return -ENOTSUP;
+ }
+
+ if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) ||
+ bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) {
+ return -EBUSY;
+ }
+
+ ro = bs->backing_hd->read_only;
+ open_flags = bs->backing_hd->open_flags;
+
+ if (ro) {
+ if (bdrv_reopen(bs->backing_hd, 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_hd);
+ 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_hd, 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_hd 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_hd, 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_hd) {
+ bdrv_flush(bs->backing_hd);
+ }
+
+ ret = 0;
+ro_cleanup:
+ qemu_vfree(buf);
+
+ if (ro) {
+ /* ignoring error return here */
+ bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
+ }
+
+ return ret;
+}
+
+int bdrv_commit_all(void)
+{
+ BlockDriverState *bs;
+
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
+ AioContext *aio_context = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(aio_context);
+ if (bs->drv && bs->backing_hd) {
+ int ret = bdrv_commit(bs);
+ if (ret < 0) {
+ aio_context_release(aio_context);
+ return ret;
+ }
+ }
+ aio_context_release(aio_context);
+ }
+ return 0;
+}
+
+/*
+ * 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 != active->backing_hd) {
+ active = active->backing_hd;
+ }
+
+ return active;
+}
+
+/* Given a BDS, searches for the base layer. */
+BlockDriverState *bdrv_find_base(BlockDriverState *bs)
+{
+ return bdrv_find_overlay(bs, NULL);
+}
+
+typedef struct BlkIntermediateStates {
+ BlockDriverState *bs;
+ QSIMPLEQ_ENTRY(BlkIntermediateStates) entry;
+} BlkIntermediateStates;
+
+
+/*
+ * 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 *intermediate;
+ BlockDriverState *base_bs = NULL;
+ BlockDriverState *new_top_bs = NULL;
+ BlkIntermediateStates *intermediate_state, *next;
+ int ret = -EIO;
+
+ QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete;
+ QSIMPLEQ_INIT(&states_to_delete);
+
+ 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_hd already pointing to base - nothing
+ * to do, no intermediate images */
+ if (new_top_bs->backing_hd == base) {
+ ret = 0;
+ goto exit;
+ }
+
+ intermediate = top;
+
+ /* now we will go down through the list, and add each BDS we find
+ * into our deletion queue, until we hit the 'base'
+ */
+ while (intermediate) {
+ intermediate_state = g_new0(BlkIntermediateStates, 1);
+ intermediate_state->bs = intermediate;
+ QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry);
+
+ if (intermediate->backing_hd == base) {
+ base_bs = intermediate->backing_hd;
+ break;
+ }
+ intermediate = intermediate->backing_hd;
+ }
+ if (base_bs == NULL) {
+ /* something went wrong, we did not end at the base. safely
+ * unravel everything, and exit with error */
+ goto exit;
+ }
+
+ /* success - we can delete the intermediate states, and link top->base */
+ backing_file_str = backing_file_str ? backing_file_str : base_bs->filename;
+ ret = bdrv_change_backing_file(new_top_bs, backing_file_str,
+ base_bs->drv ? base_bs->drv->format_name : "");
+ if (ret) {
+ goto exit;
+ }
+ bdrv_set_backing_hd(new_top_bs, base_bs);
+
+ QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
+ /* so that bdrv_close() does not recursively close the chain */
+ bdrv_set_backing_hd(intermediate_state->bs, NULL);
+ bdrv_unref(intermediate_state->bs);
+ }
+ ret = 0;
+
+exit:
+ QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
+ g_free(intermediate_state);
+ }
+ 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);
+ }
+ 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;
+}
+
+void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
+ BlockdevOnError on_write_error)
+{
+ bs->on_read_error = on_read_error;
+ bs->on_write_error = on_write_error;
+}
+
+BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read)
+{
+ return is_read ? bs->on_read_error : bs->on_write_error;
+}
+
+BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error)
+{
+ BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error;
+
+ switch (on_err) {
+ case BLOCKDEV_ON_ERROR_ENOSPC:
+ return (error == ENOSPC) ?
+ BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
+ case BLOCKDEV_ON_ERROR_STOP:
+ return BLOCK_ERROR_ACTION_STOP;
+ case BLOCKDEV_ON_ERROR_REPORT:
+ return BLOCK_ERROR_ACTION_REPORT;
+ case BLOCKDEV_ON_ERROR_IGNORE:
+ return BLOCK_ERROR_ACTION_IGNORE;
+ default:
+ abort();
+ }
+}
+
+static void send_qmp_error_event(BlockDriverState *bs,
+ BlockErrorAction action,
+ bool is_read, int error)
+{
+ IoOperationType optype;
+
+ optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
+ qapi_event_send_block_io_error(bdrv_get_device_name(bs), optype, action,
+ bdrv_iostatus_is_enabled(bs),
+ error == ENOSPC, strerror(error),
+ &error_abort);
+}
+
+/* This is done by device models because, while the block layer knows
+ * about the error, it does not know whether an operation comes from
+ * the device or the block layer (from a job, for example).
+ */
+void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
+ bool is_read, int error)
+{
+ assert(error >= 0);
+
+ if (action == BLOCK_ERROR_ACTION_STOP) {
+ /* First set the iostatus, so that "info block" returns an iostatus
+ * that matches the events raised so far (an additional error iostatus
+ * is fine, but not a lost one).
+ */
+ bdrv_iostatus_set_err(bs, error);
+
+ /* Then raise the request to stop the VM and the event.
+ * qemu_system_vmstop_request_prepare has two effects. First,
+ * it ensures that the STOP event always comes after the
+ * BLOCK_IO_ERROR event. Second, it ensures that even if management
+ * can observe the STOP event and do a "cont" before the STOP
+ * event is issued, the VM will not stop. In this case, vm_start()
+ * also ensures that the STOP/RESUME pair of events is emitted.
+ */
+ qemu_system_vmstop_request_prepare();
+ send_qmp_error_event(bs, action, is_read, error);
+ qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
+ } else {
+ send_qmp_error_event(bs, action, is_read, error);
+ }
+}
+
+int bdrv_is_read_only(BlockDriverState *bs)
+{
+ return bs->read_only;
+}
+
+int bdrv_is_sg(BlockDriverState *bs)
+{
+ return bs->sg;
+}
+
+int bdrv_enable_write_cache(BlockDriverState *bs)
+{
+ return bs->enable_write_cache;
+}
+
+void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
+{
+ bs->enable_write_cache = wce;
+
+ /* so a reopen() will preserve wce */
+ if (wce) {
+ bs->open_flags |= BDRV_O_CACHE_WB;
+ } else {
+ bs->open_flags &= ~BDRV_O_CACHE_WB;
+ }
+}
+
+int bdrv_is_encrypted(BlockDriverState *bs)
+{
+ if (bs->backing_hd && bs->backing_hd->encrypted)
+ return 1;
+ return bs->encrypted;
+}
+
+int bdrv_key_required(BlockDriverState *bs)
+{
+ BlockDriverState *backing_hd = bs->backing_hd;
+
+ if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
+ return 1;
+ return (bs->encrypted && !bs->valid_key);
+}
+
+int bdrv_set_key(BlockDriverState *bs, const char *key)
+{
+ int ret;
+ if (bs->backing_hd && bs->backing_hd->encrypted) {
+ ret = bdrv_set_key(bs->backing_hd, 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(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) {
+ return blk_bs(blk);
+ }
+ }
+
+ 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 = top->backing_hd;
+ }
+
+ return top != NULL;
+}
+
+BlockDriverState *bdrv_next_node(BlockDriverState *bs)
+{
+ if (!bs) {
+ return QTAILQ_FIRST(&graph_bdrv_states);
+ }
+ return QTAILQ_NEXT(bs, node_list);
+}
+
+BlockDriverState *bdrv_next(BlockDriverState *bs)
+{
+ if (!bs) {
+ return QTAILQ_FIRST(&bdrv_states);
+ }
+ return QTAILQ_NEXT(bs, device_list);
+}
+
+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_hd) {
+ 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_hd) {
+ 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_hd || !(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_hd && bs->backing_hd->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;
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ 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_hd; curr_bs = curr_bs->backing_hd) {
+
+ /* 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_hd;
+ 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_hd;
+ 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_hd) {
+ return 0;
+ }
+
+ return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
+}
+
+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_INCOMING)) {
+ return;
+ }
+ bs->open_flags &= ~BDRV_O_INCOMING;
+
+ if (bs->drv->bdrv_invalidate_cache) {
+ bs->drv->bdrv_invalidate_cache(bs, &local_err);
+ } else if (bs->file) {
+ bdrv_invalidate_cache(bs->file, &local_err);
+ }
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ ret = refresh_total_sectors(bs, bs->total_sectors);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not refresh total sector count");
+ return;
+ }
+}
+
+void bdrv_invalidate_cache_all(Error **errp)
+{
+ BlockDriverState *bs;
+ Error *local_err = NULL;
+
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
+ 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;
+ }
+ }
+}
+
+/**************************************************************/
+/* removable device support */
+
+/**
+ * Return TRUE if the media is present
+ */
+int bdrv_is_inserted(BlockDriverState *bs)
+{
+ BlockDriver *drv = bs->drv;
+
+ if (!drv)
+ return 0;
+ if (!drv->bdrv_is_inserted)
+ return 1;
+ return drv->bdrv_is_inserted(bs);
+}
+
+/**
+ * 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);
+ }
+}
+
+void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
+{
+ bs->guest_block_size = align;
+}
+
+BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
+{
+ BdrvDirtyBitmap *bm;
+
+ assert(name);
+ QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+ if (bm->name && !strcmp(name, bm->name)) {
+ return bm;
+ }
+ }
+ return NULL;
+}
+
+void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
+{
+ assert(!bdrv_dirty_bitmap_frozen(bitmap));
+ g_free(bitmap->name);
+ bitmap->name = NULL;
+}
+
+BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
+ uint32_t granularity,
+ const char *name,
+ Error **errp)
+{
+ int64_t bitmap_size;
+ BdrvDirtyBitmap *bitmap;
+ uint32_t sector_granularity;
+
+ assert((granularity & (granularity - 1)) == 0);
+
+ if (name && bdrv_find_dirty_bitmap(bs, name)) {
+ error_setg(errp, "Bitmap already exists: %s", name);
+ return NULL;
+ }
+ sector_granularity = granularity >> BDRV_SECTOR_BITS;
+ assert(sector_granularity);
+ bitmap_size = bdrv_nb_sectors(bs);
+ if (bitmap_size < 0) {
+ error_setg_errno(errp, -bitmap_size, "could not get length of device");
+ errno = -bitmap_size;
+ return NULL;
+ }
+ bitmap = g_new0(BdrvDirtyBitmap, 1);
+ bitmap->bitmap = hbitmap_alloc(bitmap_size, ctz32(sector_granularity));
+ bitmap->size = bitmap_size;
+ bitmap->name = g_strdup(name);
+ bitmap->disabled = false;
+ QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
+ return bitmap;
+}
+
+bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
+{
+ return bitmap->successor;
+}
+
+bool bdrv_dirty_bitmap_enabled(BdrvDirtyBitmap *bitmap)
+{
+ return !(bitmap->disabled || bitmap->successor);
+}
+
+DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
+{
+ if (bdrv_dirty_bitmap_frozen(bitmap)) {
+ return DIRTY_BITMAP_STATUS_FROZEN;
+ } else if (!bdrv_dirty_bitmap_enabled(bitmap)) {
+ return DIRTY_BITMAP_STATUS_DISABLED;
+ } else {
+ return DIRTY_BITMAP_STATUS_ACTIVE;
+ }
+}
+
+/**
+ * Create a successor bitmap destined to replace this bitmap after an operation.
+ * Requires that the bitmap is not frozen and has no successor.
+ */
+int bdrv_dirty_bitmap_create_successor(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap, Error **errp)
+{
+ uint64_t granularity;
+ BdrvDirtyBitmap *child;
+
+ if (bdrv_dirty_bitmap_frozen(bitmap)) {
+ error_setg(errp, "Cannot create a successor for a bitmap that is "
+ "currently frozen");
+ return -1;
+ }
+ assert(!bitmap->successor);
+
+ /* Create an anonymous successor */
+ granularity = bdrv_dirty_bitmap_granularity(bitmap);
+ child = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
+ if (!child) {
+ return -1;
+ }
+
+ /* Successor will be on or off based on our current state. */
+ child->disabled = bitmap->disabled;
+
+ /* Install the successor and freeze the parent */
+ bitmap->successor = child;
+ return 0;
+}
+
+/**
+ * For a bitmap with a successor, yield our name to the successor,
+ * delete the old bitmap, and return a handle to the new bitmap.
+ */
+BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
+ BdrvDirtyBitmap *bitmap,
+ Error **errp)
+{
+ char *name;
+ BdrvDirtyBitmap *successor = bitmap->successor;
+
+ if (successor == NULL) {
+ error_setg(errp, "Cannot relinquish control if "
+ "there's no successor present");
+ return NULL;
+ }
+
+ name = bitmap->name;
+ bitmap->name = NULL;
+ successor->name = name;
+ bitmap->successor = NULL;
+ bdrv_release_dirty_bitmap(bs, bitmap);
+
+ return successor;
+}
+
+/**
+ * In cases of failure where we can no longer safely delete the parent,
+ * we may wish to re-join the parent and child/successor.
+ * The merged parent will be un-frozen, but not explicitly re-enabled.
+ */
+BdrvDirtyBitmap *bdrv_reclaim_dirty_bitmap(BlockDriverState *bs,
+ BdrvDirtyBitmap *parent,
+ Error **errp)
+{
+ BdrvDirtyBitmap *successor = parent->successor;
+
+ if (!successor) {
+ error_setg(errp, "Cannot reclaim a successor when none is present");
+ return NULL;
+ }
+
+ if (!hbitmap_merge(parent->bitmap, successor->bitmap)) {
+ error_setg(errp, "Merging of parent and successor bitmap failed");
+ return NULL;
+ }
+ bdrv_release_dirty_bitmap(bs, successor);
+ parent->successor = NULL;
+
+ return parent;
+}
+
+/**
+ * Truncates _all_ bitmaps attached to a BDS.
+ */
+static void bdrv_dirty_bitmap_truncate(BlockDriverState *bs)
+{
+ BdrvDirtyBitmap *bitmap;
+ uint64_t size = bdrv_nb_sectors(bs);
+
+ QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
+ assert(!bdrv_dirty_bitmap_frozen(bitmap));
+ hbitmap_truncate(bitmap->bitmap, size);
+ bitmap->size = size;
+ }
+}
+
+void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
+{
+ BdrvDirtyBitmap *bm, *next;
+ QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
+ if (bm == bitmap) {
+ assert(!bdrv_dirty_bitmap_frozen(bm));
+ QLIST_REMOVE(bitmap, list);
+ hbitmap_free(bitmap->bitmap);
+ g_free(bitmap->name);
+ g_free(bitmap);
+ return;
+ }
+ }
+}
+
+void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+ assert(!bdrv_dirty_bitmap_frozen(bitmap));
+ bitmap->disabled = true;
+}
+
+void bdrv_enable_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+ assert(!bdrv_dirty_bitmap_frozen(bitmap));
+ bitmap->disabled = false;
+}
+
+BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
+{
+ BdrvDirtyBitmap *bm;
+ BlockDirtyInfoList *list = NULL;
+ BlockDirtyInfoList **plist = &list;
+
+ QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+ BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
+ BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
+ info->count = bdrv_get_dirty_count(bm);
+ info->granularity = bdrv_dirty_bitmap_granularity(bm);
+ info->has_name = !!bm->name;
+ info->name = g_strdup(bm->name);
+ info->status = bdrv_dirty_bitmap_status(bm);
+ entry->value = info;
+ *plist = entry;
+ plist = &entry->next;
+ }
+
+ return list;
+}
+
+int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector)
+{
+ if (bitmap) {
+ return hbitmap_get(bitmap->bitmap, sector);
+ } else {
+ return 0;
+ }
+}
+
+/**
+ * Chooses a default granularity based on the existing cluster size,
+ * but clamped between [4K, 64K]. Defaults to 64K in the case that there
+ * is no cluster size information available.
+ */
+uint32_t bdrv_get_default_bitmap_granularity(BlockDriverState *bs)
+{
+ BlockDriverInfo bdi;
+ uint32_t granularity;
+
+ if (bdrv_get_info(bs, &bdi) >= 0 && bdi.cluster_size > 0) {
+ granularity = MAX(4096, bdi.cluster_size);
+ granularity = MIN(65536, granularity);
+ } else {
+ granularity = 65536;
+ }
+
+ return granularity;
+}
+
+uint32_t bdrv_dirty_bitmap_granularity(BdrvDirtyBitmap *bitmap)
+{
+ return BDRV_SECTOR_SIZE << hbitmap_granularity(bitmap->bitmap);
+}
+
+void bdrv_dirty_iter_init(BdrvDirtyBitmap *bitmap, HBitmapIter *hbi)
+{
+ hbitmap_iter_init(hbi, bitmap->bitmap, 0);
+}
+
+void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int nr_sectors)
+{
+ assert(bdrv_dirty_bitmap_enabled(bitmap));
+ hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+}
+
+void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
+ int64_t cur_sector, int nr_sectors)
+{
+ assert(bdrv_dirty_bitmap_enabled(bitmap));
+ hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+}
+
+void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap)
+{
+ assert(bdrv_dirty_bitmap_enabled(bitmap));
+ hbitmap_reset_all(bitmap->bitmap);
+}
+
+void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
+ int nr_sectors)
+{
+ BdrvDirtyBitmap *bitmap;
+ QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
+ if (!bdrv_dirty_bitmap_enabled(bitmap)) {
+ continue;
+ }
+ hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+ }
+}
+
+/**
+ * Advance an HBitmapIter to an arbitrary offset.
+ */
+void bdrv_set_dirty_iter(HBitmapIter *hbi, int64_t offset)
+{
+ assert(hbi->hb);
+ hbitmap_iter_init(hbi, hbi->hb, offset);
+}
+
+int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap)
+{
+ return hbitmap_count(bitmap->bitmap);
+}
+
+/* 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) {
+ error_setg(errp, "Node '%s' is busy: %s",
+ bdrv_get_device_or_node_name(bs),
+ error_get_pretty(blocker->reason));
+ }
+ 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_iostatus_enable(BlockDriverState *bs)
+{
+ bs->iostatus_enabled = true;
+ bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+}
+
+/* The I/O status is only enabled if the drive explicitly
+ * enables it _and_ the VM is configured to stop on errors */
+bool bdrv_iostatus_is_enabled(const BlockDriverState *bs)
+{
+ return (bs->iostatus_enabled &&
+ (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC ||
+ bs->on_write_error == BLOCKDEV_ON_ERROR_STOP ||
+ bs->on_read_error == BLOCKDEV_ON_ERROR_STOP));
+}
+
+void bdrv_iostatus_disable(BlockDriverState *bs)
+{
+ bs->iostatus_enabled = false;
+}
+
+void bdrv_iostatus_reset(BlockDriverState *bs)
+{
+ if (bdrv_iostatus_is_enabled(bs)) {
+ bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
+ if (bs->job) {
+ block_job_iostatus_reset(bs->job);
+ }
+ }
+}
+
+void bdrv_iostatus_set_err(BlockDriverState *bs, int error)
+{
+ assert(bdrv_iostatus_is_enabled(bs));
+ if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
+ bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
+ BLOCK_DEVICE_IO_STATUS_FAILED;
+ }
+}
+
+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;
+ BlockDriver *backing_drv = NULL;
+ 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);
+ if (backing_fmt) {
+ backing_drv = bdrv_find_format(backing_fmt);
+ if (!backing_drv) {
+ error_setg(errp, "Unknown backing file format '%s'",
+ backing_fmt);
+ goto out;
+ }
+ }
+
+ // 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;
+
+ 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 & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
+
+ bs = NULL;
+ ret = bdrv_open(&bs, full_backing, NULL, NULL, back_flags,
+ backing_drv, &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->io_limits_enabled) {
+ 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);
+ }
+ if (bs->backing_hd) {
+ bdrv_detach_aio_context(bs->backing_hd);
+ }
+
+ 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_hd) {
+ bdrv_attach_aio_context(bs->backing_hd, new_context);
+ }
+ if (bs->file) {
+ bdrv_attach_aio_context(bs->file, new_context);
+ }
+ if (bs->drv->bdrv_attach_aio_context) {
+ bs->drv->bdrv_attach_aio_context(bs, new_context);
+ }
+ if (bs->io_limits_enabled) {
+ 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)
+{
+ if (!bs->drv->bdrv_amend_options) {
+ return -ENOTSUP;
+ }
+ return bs->drv->bdrv_amend_options(bs, opts, status_cb);
+}
+
+/* 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;
+
+ /* walk down the bs forest recursively */
+ QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
+ 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(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_is_first_non_filter(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;
+ bool found_any = false;
+
+ for (entry = qdict_first(bs->options); entry;
+ entry = qdict_next(bs->options, entry))
+ {
+ /* Only take options for this level and exclude all non-driver-specific
+ * options */
+ if (!strchr(qdict_entry_key(entry), '.') &&
+ strcmp(qdict_entry_key(entry), "node-name"))
+ {
+ 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);
+ }
+
+ 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;
+ }
+
+ drv->bdrv_refresh_filename(bs);
+ } 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->exact_filename[0] && !has_open_options) {
+ strcpy(bs->exact_filename, bs->file->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->full_open_options) {
+ qdict_put_obj(opts, "driver",
+ QOBJECT(qstring_from_str(drv->format_name)));
+ QINCREF(bs->file->full_open_options);
+ qdict_put_obj(opts, "file", QOBJECT(bs->file->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);
+ }
+}
+
+/* This accessor function purpose is to allow the device models to access the
+ * BlockAcctStats structure embedded inside a BlockDriverState without being
+ * aware of the BlockDriverState structure layout.
+ * It will go away when the BlockAcctStats structure will be moved inside
+ * the device models.
+ */
+BlockAcctStats *bdrv_get_stats(BlockDriverState *bs)
+{
+ return &bs->stats;
+}
Code Review / kvmfornfv.git / blobdiff