From 3f2546b2ef55b661fd8dd69682b38992225e86f6 Mon Sep 17 00:00:00 2001 From: fishsoupisgood Date: Mon, 29 Apr 2019 01:17:54 +0100 Subject: Initial import of qemu-2.4.1 --- block.c | 4253 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 4253 insertions(+) create mode 100644 block.c (limited to 'block.c') diff --git a/block.c b/block.c new file mode 100644 index 00000000..d088ee02 --- /dev/null +++ b/block.c @@ -0,0 +1,4253 @@ +/* + * 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 +#include +#include +#include +#ifndef __DragonFly__ +#include +#endif +#endif + +#ifdef _WIN32 +#include +#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 ":" */ +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; +} -- cgit v1.2.3