diff options
Diffstat (limited to 'contrib/qemu/block.c')
| -rw-r--r-- | contrib/qemu/block.c | 4604 |
1 files changed, 4604 insertions, 0 deletions
diff --git a/contrib/qemu/block.c b/contrib/qemu/block.c new file mode 100644 index 00000000000..b56024113b8 --- /dev/null +++ b/contrib/qemu/block.c @@ -0,0 +1,4604 @@ +/* + * 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 "monitor/monitor.h" +#include "block/block_int.h" +#include "block/blockjob.h" +#include "qemu/module.h" +#include "qapi/qmp/qjson.h" +#include "sysemu/sysemu.h" +#include "qemu/notify.h" +#include "block/coroutine.h" +#include "qmp-commands.h" +#include "qemu/timer.h" + +#ifdef CONFIG_BSD +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/queue.h> +#ifndef __DragonFly__ +#include <sys/disk.h> +#endif +#endif + +#ifdef _WIN32 +#include <windows.h> +#endif + +#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ + +typedef enum { + BDRV_REQ_COPY_ON_READ = 0x1, + BDRV_REQ_ZERO_WRITE = 0x2, +} BdrvRequestFlags; + +static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); +static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque); +static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque); +static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, + QEMUIOVector *iov); +static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, + QEMUIOVector *iov); +static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, + BdrvRequestFlags flags); +static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, + BdrvRequestFlags flags); +static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, + int64_t sector_num, + QEMUIOVector *qiov, + int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque, + bool is_write); +static void coroutine_fn bdrv_co_do_rw(void *opaque); +static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, + int64_t sector_num, int nb_sectors); + +static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors, + bool is_write, double elapsed_time, uint64_t *wait); +static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write, + double elapsed_time, uint64_t *wait); +static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors, + bool is_write, int64_t *wait); + +static QTAILQ_HEAD(, BlockDriverState) bdrv_states = + QTAILQ_HEAD_INITIALIZER(bdrv_states); + +static QLIST_HEAD(, BlockDriver) bdrv_drivers = + QLIST_HEAD_INITIALIZER(bdrv_drivers); + +/* 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 + +/* throttling disk I/O limits */ +void bdrv_io_limits_disable(BlockDriverState *bs) +{ + bs->io_limits_enabled = false; + + while (qemu_co_queue_next(&bs->throttled_reqs)); + + if (bs->block_timer) { + qemu_del_timer(bs->block_timer); + qemu_free_timer(bs->block_timer); + bs->block_timer = NULL; + } + + bs->slice_start = 0; + bs->slice_end = 0; +} + +static void bdrv_block_timer(void *opaque) +{ + BlockDriverState *bs = opaque; + + qemu_co_queue_next(&bs->throttled_reqs); +} + +void bdrv_io_limits_enable(BlockDriverState *bs) +{ + qemu_co_queue_init(&bs->throttled_reqs); + bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs); + bs->io_limits_enabled = true; +} + +bool bdrv_io_limits_enabled(BlockDriverState *bs) +{ + BlockIOLimit *io_limits = &bs->io_limits; + return io_limits->bps[BLOCK_IO_LIMIT_READ] + || io_limits->bps[BLOCK_IO_LIMIT_WRITE] + || io_limits->bps[BLOCK_IO_LIMIT_TOTAL] + || io_limits->iops[BLOCK_IO_LIMIT_READ] + || io_limits->iops[BLOCK_IO_LIMIT_WRITE] + || io_limits->iops[BLOCK_IO_LIMIT_TOTAL]; +} + +static void bdrv_io_limits_intercept(BlockDriverState *bs, + bool is_write, int nb_sectors) +{ + int64_t wait_time = -1; + + if (!qemu_co_queue_empty(&bs->throttled_reqs)) { + qemu_co_queue_wait(&bs->throttled_reqs); + } + + /* In fact, we hope to keep each request's timing, in FIFO mode. The next + * throttled requests will not be dequeued until the current request is + * allowed to be serviced. So if the current request still exceeds the + * limits, it will be inserted to the head. All requests followed it will + * be still in throttled_reqs queue. + */ + + while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) { + qemu_mod_timer(bs->block_timer, + wait_time + qemu_get_clock_ns(vm_clock)); + qemu_co_queue_wait_insert_head(&bs->throttled_reqs); + } + + qemu_co_queue_next(&bs->throttled_reqs); +} + +/* check if the path starts with "<protocol>:" */ +static 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(BlockDriverState *bs, char *dest, size_t sz) +{ + if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) { + pstrcpy(dest, sz, bs->backing_file); + } else { + path_combine(dest, sz, bs->filename, bs->backing_file); + } +} + +void bdrv_register(BlockDriver *bdrv) +{ + /* Block drivers without coroutine functions need emulation */ + if (!bdrv->bdrv_co_readv) { + bdrv->bdrv_co_readv = bdrv_co_readv_em; + bdrv->bdrv_co_writev = bdrv_co_writev_em; + + /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if + * the block driver lacks aio we need to emulate that too. + */ + if (!bdrv->bdrv_aio_readv) { + /* add AIO emulation layer */ + bdrv->bdrv_aio_readv = bdrv_aio_readv_em; + bdrv->bdrv_aio_writev = bdrv_aio_writev_em; + } + } + + QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); +} + +/* create a new block device (by default it is empty) */ +BlockDriverState *bdrv_new(const char *device_name) +{ + BlockDriverState *bs; + + bs = g_malloc0(sizeof(BlockDriverState)); + pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); + if (device_name[0] != '\0') { + QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); + } + bdrv_iostatus_disable(bs); + notifier_list_init(&bs->close_notifiers); + notifier_with_return_list_init(&bs->before_write_notifiers); + + 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; + QEMUOptionParameter *options; + int ret; +} CreateCo; + +static void coroutine_fn bdrv_create_co_entry(void *opaque) +{ + CreateCo *cco = opaque; + assert(cco->drv); + + cco->ret = cco->drv->bdrv_create(cco->filename, cco->options); +} + +int bdrv_create(BlockDriver *drv, const char* filename, + QEMUOptionParameter *options) +{ + int ret; + + Coroutine *co; + CreateCo cco = { + .drv = drv, + .filename = g_strdup(filename), + .options = options, + .ret = NOT_DONE, + }; + + if (!drv->bdrv_create) { + 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) { + qemu_aio_wait(); + } + } + + ret = cco.ret; + +out: + g_free(cco.filename); + return ret; +} + +int bdrv_create_file(const char* filename, QEMUOptionParameter *options) +{ + BlockDriver *drv; + + drv = bdrv_find_protocol(filename, true); + if (drv == NULL) { + return -ENOENT; + } + + return bdrv_create(drv, filename, options); +} + +/* + * 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 = "/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) +{ + 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_find_format("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; + } + } + return NULL; +} + +static int find_image_format(BlockDriverState *bs, const char *filename, + BlockDriver **pdrv) +{ + int score, score_max; + BlockDriver *drv1, *drv; + uint8_t buf[2048]; + int ret = 0; + + /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ + if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { + drv = bdrv_find_format("raw"); + if (!drv) { + ret = -ENOENT; + } + *pdrv = drv; + return ret; + } + + ret = bdrv_pread(bs, 0, buf, sizeof(buf)); + if (ret < 0) { + *pdrv = NULL; + return ret; + } + + score_max = 0; + drv = NULL; + QLIST_FOREACH(drv1, &bdrv_drivers, list) { + if (drv1->bdrv_probe) { + score = drv1->bdrv_probe(buf, ret, filename); + if (score > score_max) { + score_max = score; + drv = drv1; + } + } + } + if (!drv) { + ret = -ENOENT; + } + *pdrv = drv; + return ret; +} + +/** + * Set the current 'total_sectors' value + */ +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 (bs->sg) + 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 = length >> BDRV_SECTOR_BITS; + } + + 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; +} + +/** + * The copy-on-read flag is actually a reference count so multiple users may + * use the feature without worrying about clobbering its previous state. + * Copy-on-read stays enabled until all users have called to disable it. + */ +void bdrv_enable_copy_on_read(BlockDriverState *bs) +{ + bs->copy_on_read++; +} + +void bdrv_disable_copy_on_read(BlockDriverState *bs) +{ + assert(bs->copy_on_read > 0); + bs->copy_on_read--; +} + +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); + + /* + * Snapshots should be writable. + */ + if (bs->is_temporary) { + open_flags |= BDRV_O_RDWR; + } + + return open_flags; +} + +/* + * 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) +{ + int ret, open_flags; + const char *filename; + + 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"); + } + + trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name); + + /* bdrv_open() with directly using a protocol as drv. This layer is already + * opened, so assign it to bs (while file becomes a closed BlockDriverState) + * and return immediately. */ + if (file != NULL && drv->bdrv_file_open) { + bdrv_swap(file, bs); + return 0; + } + + bs->open_flags = flags; + bs->buffer_alignment = 512; + 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)) { + return -ENOTSUP; + } + + assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ + if (!bs->read_only && (flags & BDRV_O_COPY_ON_READ)) { + bdrv_enable_copy_on_read(bs); + } + + if (filename != NULL) { + pstrcpy(bs->filename, sizeof(bs->filename), filename); + } else { + bs->filename[0] = '\0'; + } + + 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_parse_filename || filename != NULL); + ret = drv->bdrv_file_open(bs, options, open_flags); + } else { + if (file == NULL) { + qerror_report(ERROR_CLASS_GENERIC_ERROR, "Can't use '%s' as a " + "block driver for the protocol level", + drv->format_name); + ret = -EINVAL; + goto free_and_fail; + } + assert(file != NULL); + bs->file = file; + ret = drv->bdrv_open(bs, options, open_flags); + } + + if (ret < 0) { + goto free_and_fail; + } + + ret = refresh_total_sectors(bs, bs->total_sectors); + if (ret < 0) { + goto free_and_fail; + } + +#ifndef _WIN32 + if (bs->is_temporary) { + assert(filename != NULL); + unlink(filename); + } +#endif + return 0; + +free_and_fail: + bs->file = NULL; + g_free(bs->opaque); + bs->opaque = NULL; + bs->drv = NULL; + return ret; +} + +/* + * Opens a file using a protocol (file, host_device, nbd, ...) + * + * 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_file_open. + */ +int bdrv_file_open(BlockDriverState **pbs, const char *filename, + QDict *options, int flags) +{ + BlockDriverState *bs; + BlockDriver *drv; + const char *drvname; + bool allow_protocol_prefix = false; + int ret; + + /* NULL means an empty set of options */ + if (options == NULL) { + options = qdict_new(); + } + + bs = bdrv_new(""); + bs->options = options; + options = qdict_clone_shallow(options); + + /* Fetch the file name from the options QDict if necessary */ + if (!filename) { + filename = qdict_get_try_str(options, "filename"); + } else if (filename && !qdict_haskey(options, "filename")) { + qdict_put(options, "filename", qstring_from_str(filename)); + allow_protocol_prefix = true; + } else { + qerror_report(ERROR_CLASS_GENERIC_ERROR, "Can't specify 'file' and " + "'filename' options at the same time"); + ret = -EINVAL; + goto fail; + } + + /* Find the right block driver */ + drvname = qdict_get_try_str(options, "driver"); + if (drvname) { + drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR)); + qdict_del(options, "driver"); + } else if (filename) { + drv = bdrv_find_protocol(filename, allow_protocol_prefix); + if (!drv) { + qerror_report(ERROR_CLASS_GENERIC_ERROR, "Unknown protocol"); + } + } else { + qerror_report(ERROR_CLASS_GENERIC_ERROR, + "Must specify either driver or file"); + drv = NULL; + } + + if (!drv) { + ret = -ENOENT; + goto fail; + } + + /* Parse the filename and open it */ + if (drv->bdrv_parse_filename && filename) { + Error *local_err = NULL; + drv->bdrv_parse_filename(filename, options, &local_err); + if (error_is_set(&local_err)) { + qerror_report_err(local_err); + error_free(local_err); + ret = -EINVAL; + goto fail; + } + qdict_del(options, "filename"); + } else if (!drv->bdrv_parse_filename && !filename) { + qerror_report(ERROR_CLASS_GENERIC_ERROR, + "The '%s' block driver requires a file name", + drv->format_name); + ret = -EINVAL; + goto fail; + } + + ret = bdrv_open_common(bs, NULL, options, flags, drv); + if (ret < 0) { + goto fail; + } + + /* Check if any unknown options were used */ + if (qdict_size(options) != 0) { + const QDictEntry *entry = qdict_first(options); + qerror_report(ERROR_CLASS_GENERIC_ERROR, "Block protocol '%s' doesn't " + "support the option '%s'", + drv->format_name, entry->key); + ret = -EINVAL; + goto fail; + } + QDECREF(options); + + bs->growable = 1; + *pbs = bs; + return 0; + +fail: + QDECREF(options); + if (!bs->drv) { + QDECREF(bs->options); + } + bdrv_delete(bs); + return ret; +} + +/* + * 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) +{ + char backing_filename[PATH_MAX]; + int back_flags, ret; + BlockDriver *back_drv = NULL; + + if (bs->backing_hd != NULL) { + QDECREF(options); + return 0; + } + + /* 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); + return 0; + } + + bs->backing_hd = bdrv_new(""); + bdrv_get_full_backing_filename(bs, backing_filename, + sizeof(backing_filename)); + + if (bs->backing_format[0] != '\0') { + back_drv = bdrv_find_format(bs->backing_format); + } + + /* backing files always opened read-only */ + back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT); + + ret = bdrv_open(bs->backing_hd, + *backing_filename ? backing_filename : NULL, options, + back_flags, back_drv); + if (ret < 0) { + bdrv_delete(bs->backing_hd); + bs->backing_hd = NULL; + bs->open_flags |= BDRV_O_NO_BACKING; + return ret; + } + return 0; +} + +static void extract_subqdict(QDict *src, QDict **dst, const char *start) +{ + const QDictEntry *entry, *next; + const char *p; + + *dst = qdict_new(); + entry = qdict_first(src); + + while (entry != NULL) { + next = qdict_next(src, entry); + if (strstart(entry->key, start, &p)) { + qobject_incref(entry->value); + qdict_put_obj(*dst, p, entry->value); + qdict_del(src, entry->key); + } + entry = next; + } +} + +/* + * 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. + */ +int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, + int flags, BlockDriver *drv) +{ + int ret; + /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ + char tmp_filename[PATH_MAX + 1]; + BlockDriverState *file = NULL; + QDict *file_options = NULL; + + /* NULL means an empty set of options */ + if (options == NULL) { + options = qdict_new(); + } + + bs->options = options; + options = qdict_clone_shallow(options); + + /* For snapshot=on, create a temporary qcow2 overlay */ + if (flags & BDRV_O_SNAPSHOT) { + BlockDriverState *bs1; + int64_t total_size; + BlockDriver *bdrv_qcow2; + QEMUOptionParameter *create_options; + char backing_filename[PATH_MAX]; + + if (qdict_size(options) != 0) { + error_report("Can't use snapshot=on with driver-specific options"); + ret = -EINVAL; + goto fail; + } + assert(filename != NULL); + + /* if snapshot, we create a temporary backing file and open it + instead of opening 'filename' directly */ + + /* if there is a backing file, use it */ + bs1 = bdrv_new(""); + ret = bdrv_open(bs1, filename, NULL, 0, drv); + if (ret < 0) { + bdrv_delete(bs1); + goto fail; + } + total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK; + + bdrv_delete(bs1); + + ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename)); + if (ret < 0) { + goto fail; + } + + /* Real path is meaningless for protocols */ + if (path_has_protocol(filename)) { + snprintf(backing_filename, sizeof(backing_filename), + "%s", filename); + } else if (!realpath(filename, backing_filename)) { + ret = -errno; + goto fail; + } + + bdrv_qcow2 = bdrv_find_format("qcow2"); + create_options = parse_option_parameters("", bdrv_qcow2->create_options, + NULL); + + set_option_parameter_int(create_options, BLOCK_OPT_SIZE, total_size); + set_option_parameter(create_options, BLOCK_OPT_BACKING_FILE, + backing_filename); + if (drv) { + set_option_parameter(create_options, BLOCK_OPT_BACKING_FMT, + drv->format_name); + } + + ret = bdrv_create(bdrv_qcow2, tmp_filename, create_options); + free_option_parameters(create_options); + if (ret < 0) { + goto fail; + } + + filename = tmp_filename; + drv = bdrv_qcow2; + bs->is_temporary = 1; + } + + /* Open image file without format layer */ + if (flags & BDRV_O_RDWR) { + flags |= BDRV_O_ALLOW_RDWR; + } + + extract_subqdict(options, &file_options, "file."); + + ret = bdrv_file_open(&file, filename, file_options, + bdrv_open_flags(bs, flags | BDRV_O_UNMAP)); + if (ret < 0) { + goto fail; + } + + /* Find the right image format driver */ + if (!drv) { + ret = find_image_format(file, filename, &drv); + } + + if (!drv) { + goto unlink_and_fail; + } + + /* Open the image */ + ret = bdrv_open_common(bs, file, options, flags, drv); + if (ret < 0) { + goto unlink_and_fail; + } + + if (bs->file != file) { + bdrv_delete(file); + file = NULL; + } + + /* If there is a backing file, use it */ + if ((flags & BDRV_O_NO_BACKING) == 0) { + QDict *backing_options; + + extract_subqdict(options, &backing_options, "backing."); + ret = bdrv_open_backing_file(bs, backing_options); + if (ret < 0) { + goto close_and_fail; + } + } + + /* Check if any unknown options were used */ + if (qdict_size(options) != 0) { + const QDictEntry *entry = qdict_first(options); + qerror_report(ERROR_CLASS_GENERIC_ERROR, "Block format '%s' used by " + "device '%s' doesn't support the option '%s'", + drv->format_name, bs->device_name, entry->key); + + ret = -EINVAL; + goto close_and_fail; + } + QDECREF(options); + + if (!bdrv_key_required(bs)) { + bdrv_dev_change_media_cb(bs, true); + } + + /* throttling disk I/O limits */ + if (bs->io_limits_enabled) { + bdrv_io_limits_enable(bs); + } + + return 0; + +unlink_and_fail: + if (file != NULL) { + bdrv_delete(file); + } + if (bs->is_temporary) { + unlink(filename); + } +fail: + QDECREF(bs->options); + QDECREF(options); + bs->options = NULL; + return ret; + +close_and_fail: + bdrv_close(bs); + QDECREF(options); + return ret; +} + +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; + if (bs_queue == NULL) { + bs_queue = g_new0(BlockReopenQueue, 1); + QSIMPLEQ_INIT(bs_queue); + } + + if (bs->file) { + bdrv_reopen_queue(bs_queue, bs->file, 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_set(errp, QERR_DEVICE_IS_READ_ONLY, + reopen_state->bs->device_name); + 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_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, + drv->format_name, reopen_state->bs->device_name, + "reopening of file"); + 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); +} + +/* + * 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) +{ + if (bs->job) { + block_job_cancel_sync(bs->job); + } + bdrv_drain_all(); /* complete I/O */ + bdrv_flush(bs); + bdrv_drain_all(); /* in case flush left pending I/O */ + notifier_list_notify(&bs->close_notifiers, bs); + + if (bs->drv) { + if (bs->backing_hd) { + bdrv_delete(bs->backing_hd); + bs->backing_hd = NULL; + } + bs->drv->bdrv_close(bs); + g_free(bs->opaque); +#ifdef _WIN32 + if (bs->is_temporary) { + unlink(bs->filename); + } +#endif + 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->growable = 0; + QDECREF(bs->options); + bs->options = NULL; + + if (bs->file != NULL) { + bdrv_delete(bs->file); + bs->file = NULL; + } + } + + bdrv_dev_change_media_cb(bs, false); + + /*throttling disk I/O limits*/ + if (bs->io_limits_enabled) { + bdrv_io_limits_disable(bs); + } +} + +void bdrv_close_all(void) +{ + BlockDriverState *bs; + + QTAILQ_FOREACH(bs, &bdrv_states, list) { + bdrv_close(bs); + } +} + +/* + * Wait for pending requests to complete across all BlockDriverStates + * + * This function does not flush data to disk, use bdrv_flush_all() for that + * after calling this function. + * + * Note that completion of an asynchronous I/O operation can trigger any + * number of other I/O operations on other devices---for example a coroutine + * can be arbitrarily complex and a constant flow of I/O can come until the + * coroutine is complete. Because of this, it is not possible to have a + * function to drain a single device's I/O queue. + */ +void bdrv_drain_all(void) +{ + BlockDriverState *bs; + bool busy; + + do { + busy = qemu_aio_wait(); + + /* FIXME: We do not have timer support here, so this is effectively + * a busy wait. + */ + QTAILQ_FOREACH(bs, &bdrv_states, list) { + if (!qemu_co_queue_empty(&bs->throttled_reqs)) { + qemu_co_queue_restart_all(&bs->throttled_reqs); + busy = true; + } + } + } while (busy); + + /* If requests are still pending there is a bug somewhere */ + QTAILQ_FOREACH(bs, &bdrv_states, list) { + assert(QLIST_EMPTY(&bs->tracked_requests)); + assert(qemu_co_queue_empty(&bs->throttled_reqs)); + } +} + +/* make a BlockDriverState anonymous by removing from bdrv_state list. + Also, NULL terminate the device_name to prevent double remove */ +void bdrv_make_anon(BlockDriverState *bs) +{ + if (bs->device_name[0] != '\0') { + QTAILQ_REMOVE(&bdrv_states, bs, list); + } + bs->device_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 */ + bs_dest->open_flags = bs_src->open_flags; + + /* dev info */ + bs_dest->dev_ops = bs_src->dev_ops; + bs_dest->dev_opaque = bs_src->dev_opaque; + bs_dest->dev = bs_src->dev; + bs_dest->buffer_alignment = bs_src->buffer_alignment; + bs_dest->copy_on_read = bs_src->copy_on_read; + + bs_dest->enable_write_cache = bs_src->enable_write_cache; + + /* i/o timing parameters */ + bs_dest->slice_start = bs_src->slice_start; + bs_dest->slice_end = bs_src->slice_end; + bs_dest->slice_submitted = bs_src->slice_submitted; + bs_dest->io_limits = bs_src->io_limits; + bs_dest->throttled_reqs = bs_src->throttled_reqs; + bs_dest->block_timer = bs_src->block_timer; + bs_dest->io_limits_enabled = bs_src->io_limits_enabled; + + /* 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_bitmap = bs_src->dirty_bitmap; + + /* job */ + bs_dest->in_use = bs_src->in_use; + bs_dest->job = bs_src->job; + + /* keep the same entry in bdrv_states */ + pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name), + bs_src->device_name); + bs_dest->list = bs_src->list; +} + +/* + * 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 is required to be anonymous. + * + * This function does not create any image files. + */ +void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) +{ + BlockDriverState tmp; + + /* bs_new must be anonymous and shouldn't have anything fancy enabled */ + assert(bs_new->device_name[0] == '\0'); + assert(bs_new->dirty_bitmap == NULL); + assert(bs_new->job == NULL); + assert(bs_new->dev == NULL); + assert(bs_new->in_use == 0); + assert(bs_new->io_limits_enabled == false); + assert(bs_new->block_timer == NULL); + + 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 shouldn't be in bdrv_states even after the swap! */ + assert(bs_new->device_name[0] == '\0'); + + /* Check a few fields that should remain attached to the device */ + assert(bs_new->dev == NULL); + assert(bs_new->job == NULL); + assert(bs_new->in_use == 0); + assert(bs_new->io_limits_enabled == false); + assert(bs_new->block_timer == NULL); + + 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 is required to be anonymous. + * + * 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. */ + bs_top->backing_hd = bs_new; + bs_top->open_flags &= ~BDRV_O_NO_BACKING; + pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file), + bs_new->filename); + pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format), + bs_new->drv ? bs_new->drv->format_name : ""); +} + +void bdrv_delete(BlockDriverState *bs) +{ + assert(!bs->dev); + assert(!bs->job); + assert(!bs->in_use); + + /* remove from list, if necessary */ + bdrv_make_anon(bs); + + bdrv_close(bs); + + g_free(bs); +} + +int bdrv_attach_dev(BlockDriverState *bs, void *dev) +/* TODO change to DeviceState *dev when all users are qdevified */ +{ + if (bs->dev) { + return -EBUSY; + } + bs->dev = dev; + bdrv_iostatus_reset(bs); + return 0; +} + +/* TODO qdevified devices don't use this, remove when devices are qdevified */ +void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev) +{ + if (bdrv_attach_dev(bs, dev) < 0) { + abort(); + } +} + +void bdrv_detach_dev(BlockDriverState *bs, void *dev) +/* TODO change to DeviceState *dev when all users are qdevified */ +{ + assert(bs->dev == dev); + bs->dev = NULL; + bs->dev_ops = NULL; + bs->dev_opaque = NULL; + bs->buffer_alignment = 512; +} + +/* TODO change to return DeviceState * when all users are qdevified */ +void *bdrv_get_attached_dev(BlockDriverState *bs) +{ + return bs->dev; +} + +void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, + void *opaque) +{ + bs->dev_ops = ops; + bs->dev_opaque = opaque; +} + +void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, + enum MonitorEvent ev, + BlockErrorAction action, bool is_read) +{ + QObject *data; + const char *action_str; + + switch (action) { + case BDRV_ACTION_REPORT: + action_str = "report"; + break; + case BDRV_ACTION_IGNORE: + action_str = "ignore"; + break; + case BDRV_ACTION_STOP: + action_str = "stop"; + break; + default: + abort(); + } + + data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }", + bdrv->device_name, + action_str, + is_read ? "read" : "write"); + monitor_protocol_event(ev, data); + + qobject_decref(data); +} + +static void bdrv_emit_qmp_eject_event(BlockDriverState *bs, bool ejected) +{ + QObject *data; + + data = qobject_from_jsonf("{ 'device': %s, 'tray-open': %i }", + bdrv_get_device_name(bs), ejected); + monitor_protocol_event(QEVENT_DEVICE_TRAY_MOVED, data); + + qobject_decref(data); +} + +static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load) +{ + if (bs->dev_ops && bs->dev_ops->change_media_cb) { + bool tray_was_closed = !bdrv_dev_is_tray_open(bs); + bs->dev_ops->change_media_cb(bs->dev_opaque, load); + if (tray_was_closed) { + /* tray open */ + bdrv_emit_qmp_eject_event(bs, true); + } + if (load) { + /* tray close */ + bdrv_emit_qmp_eject_event(bs, false); + } + } +} + +bool bdrv_dev_has_removable_media(BlockDriverState *bs) +{ + return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb); +} + +void bdrv_dev_eject_request(BlockDriverState *bs, bool force) +{ + if (bs->dev_ops && bs->dev_ops->eject_request_cb) { + bs->dev_ops->eject_request_cb(bs->dev_opaque, force); + } +} + +bool bdrv_dev_is_tray_open(BlockDriverState *bs) +{ + if (bs->dev_ops && bs->dev_ops->is_tray_open) { + return bs->dev_ops->is_tray_open(bs->dev_opaque); + } + return false; +} + +static void bdrv_dev_resize_cb(BlockDriverState *bs) +{ + if (bs->dev_ops && bs->dev_ops->resize_cb) { + bs->dev_ops->resize_cb(bs->dev_opaque); + } +} + +bool bdrv_dev_is_medium_locked(BlockDriverState *bs) +{ + if (bs->dev_ops && bs->dev_ops->is_medium_locked) { + return bs->dev_ops->is_medium_locked(bs->dev_opaque); + } + return false; +} + +/* + * 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->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; + int n, ro, open_flags; + int ret = 0; + uint8_t *buf; + char filename[PATH_MAX]; + + if (!drv) + return -ENOMEDIUM; + + if (!bs->backing_hd) { + return -ENOTSUP; + } + + if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) { + return -EBUSY; + } + + ro = bs->backing_hd->read_only; + /* Use pstrcpy (not strncpy): filename must be NUL-terminated. */ + pstrcpy(filename, sizeof(filename), bs->backing_hd->filename); + open_flags = bs->backing_hd->open_flags; + + if (ro) { + if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) { + return -EACCES; + } + } + + total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; + buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); + + for (sector = 0; sector < total_sectors; sector += n) { + if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) { + + if (bdrv_read(bs, sector, buf, n) != 0) { + ret = -EIO; + goto ro_cleanup; + } + + if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) { + ret = -EIO; + goto ro_cleanup; + } + } + } + + if (drv->bdrv_make_empty) { + ret = drv->bdrv_make_empty(bs); + 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); + +ro_cleanup: + g_free(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, list) { + if (bs->drv && bs->backing_hd) { + int ret = bdrv_commit(bs); + if (ret < 0) { + return ret; + } + } + } + return 0; +} + +/** + * Remove an active request from the tracked requests list + * + * This function should be called when a tracked request is completing. + */ +static void tracked_request_end(BdrvTrackedRequest *req) +{ + QLIST_REMOVE(req, list); + qemu_co_queue_restart_all(&req->wait_queue); +} + +/** + * Add an active request to the tracked requests list + */ +static void tracked_request_begin(BdrvTrackedRequest *req, + BlockDriverState *bs, + int64_t sector_num, + int nb_sectors, bool is_write) +{ + *req = (BdrvTrackedRequest){ + .bs = bs, + .sector_num = sector_num, + .nb_sectors = nb_sectors, + .is_write = is_write, + .co = qemu_coroutine_self(), + }; + + qemu_co_queue_init(&req->wait_queue); + + QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); +} + +/** + * Round a region to cluster boundaries + */ +void bdrv_round_to_clusters(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, + int64_t *cluster_sector_num, + int *cluster_nb_sectors) +{ + BlockDriverInfo bdi; + + if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { + *cluster_sector_num = sector_num; + *cluster_nb_sectors = nb_sectors; + } else { + int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; + *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); + *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + + nb_sectors, c); + } +} + +static bool tracked_request_overlaps(BdrvTrackedRequest *req, + int64_t sector_num, int nb_sectors) { + /* aaaa bbbb */ + if (sector_num >= req->sector_num + req->nb_sectors) { + return false; + } + /* bbbb aaaa */ + if (req->sector_num >= sector_num + nb_sectors) { + return false; + } + return true; +} + +static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, + int64_t sector_num, int nb_sectors) +{ + BdrvTrackedRequest *req; + int64_t cluster_sector_num; + int cluster_nb_sectors; + bool retry; + + /* If we touch the same cluster it counts as an overlap. This guarantees + * that allocating writes will be serialized and not race with each other + * for the same cluster. For example, in copy-on-read it ensures that the + * CoR read and write operations are atomic and guest writes cannot + * interleave between them. + */ + bdrv_round_to_clusters(bs, sector_num, nb_sectors, + &cluster_sector_num, &cluster_nb_sectors); + + do { + retry = false; + QLIST_FOREACH(req, &bs->tracked_requests, list) { + if (tracked_request_overlaps(req, cluster_sector_num, + cluster_nb_sectors)) { + /* Hitting this means there was a reentrant request, for + * example, a block driver issuing nested requests. This must + * never happen since it means deadlock. + */ + assert(qemu_coroutine_self() != req->co); + + qemu_co_queue_wait(&req->wait_queue); + retry = true; + break; + } + } + } while (retry); +} + +/* + * 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. + */ +BlockDriverState *bdrv_find_overlay(BlockDriverState *active, + BlockDriverState *bs) +{ + BlockDriverState *overlay = NULL; + BlockDriverState *intermediate; + + assert(active != NULL); + assert(bs != NULL); + + /* if bs is the same as active, then by definition it has no overlay + */ + if (active == bs) { + return NULL; + } + + intermediate = active; + while (intermediate->backing_hd) { + if (intermediate->backing_hd == bs) { + overlay = intermediate; + break; + } + intermediate = intermediate->backing_hd; + } + + return overlay; +} + +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 + * + * Error conditions: + * if active == top, that is considered an error + * + */ +int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, + BlockDriverState *base) +{ + 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_malloc0(sizeof(BlkIntermediateStates)); + 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 */ + ret = bdrv_change_backing_file(new_top_bs, base_bs->filename, + base_bs->drv ? base_bs->drv->format_name : ""); + if (ret) { + goto exit; + } + new_top_bs->backing_hd = base_bs; + + + QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { + /* so that bdrv_close() does not recursively close the chain */ + intermediate_state->bs->backing_hd = NULL; + bdrv_delete(intermediate_state->bs); + } + ret = 0; + +exit: + QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { + g_free(intermediate_state); + } + return ret; +} + + +static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, + size_t size) +{ + int64_t len; + + if (!bdrv_is_inserted(bs)) + return -ENOMEDIUM; + + if (bs->growable) + return 0; + + len = bdrv_getlength(bs); + + if (offset < 0) + return -EIO; + + if ((offset > len) || (len - offset < size)) + return -EIO; + + return 0; +} + +static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, + int nb_sectors) +{ + return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, + nb_sectors * BDRV_SECTOR_SIZE); +} + +typedef struct RwCo { + BlockDriverState *bs; + int64_t sector_num; + int nb_sectors; + QEMUIOVector *qiov; + bool is_write; + int ret; +} RwCo; + +static void coroutine_fn bdrv_rw_co_entry(void *opaque) +{ + RwCo *rwco = opaque; + + if (!rwco->is_write) { + rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num, + rwco->nb_sectors, rwco->qiov, 0); + } else { + rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num, + rwco->nb_sectors, rwco->qiov, 0); + } +} + +/* + * Process a vectored synchronous request using coroutines + */ +static int bdrv_rwv_co(BlockDriverState *bs, int64_t sector_num, + QEMUIOVector *qiov, bool is_write) +{ + Coroutine *co; + RwCo rwco = { + .bs = bs, + .sector_num = sector_num, + .nb_sectors = qiov->size >> BDRV_SECTOR_BITS, + .qiov = qiov, + .is_write = is_write, + .ret = NOT_DONE, + }; + assert((qiov->size & (BDRV_SECTOR_SIZE - 1)) == 0); + + /** + * In sync call context, when the vcpu is blocked, this throttling timer + * will not fire; so the I/O throttling function has to be disabled here + * if it has been enabled. + */ + if (bs->io_limits_enabled) { + fprintf(stderr, "Disabling I/O throttling on '%s' due " + "to synchronous I/O.\n", bdrv_get_device_name(bs)); + bdrv_io_limits_disable(bs); + } + + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + bdrv_rw_co_entry(&rwco); + } else { + co = qemu_coroutine_create(bdrv_rw_co_entry); + qemu_coroutine_enter(co, &rwco); + while (rwco.ret == NOT_DONE) { + qemu_aio_wait(); + } + } + return rwco.ret; +} + +/* + * Process a synchronous request using coroutines + */ +static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, + int nb_sectors, bool is_write) +{ + QEMUIOVector qiov; + struct iovec iov = { + .iov_base = (void *)buf, + .iov_len = nb_sectors * BDRV_SECTOR_SIZE, + }; + + qemu_iovec_init_external(&qiov, &iov, 1); + return bdrv_rwv_co(bs, sector_num, &qiov, is_write); +} + +/* return < 0 if error. See bdrv_write() for the return codes */ +int bdrv_read(BlockDriverState *bs, int64_t sector_num, + uint8_t *buf, int nb_sectors) +{ + return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false); +} + +/* Just like bdrv_read(), but with I/O throttling temporarily disabled */ +int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, + uint8_t *buf, int nb_sectors) +{ + bool enabled; + int ret; + + enabled = bs->io_limits_enabled; + bs->io_limits_enabled = false; + ret = bdrv_read(bs, 0, buf, 1); + bs->io_limits_enabled = enabled; + return ret; +} + +/* Return < 0 if error. Important errors are: + -EIO generic I/O error (may happen for all errors) + -ENOMEDIUM No media inserted. + -EINVAL Invalid sector number or nb_sectors + -EACCES Trying to write a read-only device +*/ +int bdrv_write(BlockDriverState *bs, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true); +} + +int bdrv_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov) +{ + return bdrv_rwv_co(bs, sector_num, qiov, true); +} + +int bdrv_pread(BlockDriverState *bs, int64_t offset, + void *buf, int count1) +{ + uint8_t tmp_buf[BDRV_SECTOR_SIZE]; + int len, nb_sectors, count; + int64_t sector_num; + int ret; + + count = count1; + /* first read to align to sector start */ + len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); + if (len > count) + len = count; + sector_num = offset >> BDRV_SECTOR_BITS; + if (len > 0) { + if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) + return ret; + memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len); + count -= len; + if (count == 0) + return count1; + sector_num++; + buf += len; + } + + /* read the sectors "in place" */ + nb_sectors = count >> BDRV_SECTOR_BITS; + if (nb_sectors > 0) { + if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0) + return ret; + sector_num += nb_sectors; + len = nb_sectors << BDRV_SECTOR_BITS; + buf += len; + count -= len; + } + + /* add data from the last sector */ + if (count > 0) { + if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) + return ret; + memcpy(buf, tmp_buf, count); + } + return count1; +} + +int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) +{ + uint8_t tmp_buf[BDRV_SECTOR_SIZE]; + int len, nb_sectors, count; + int64_t sector_num; + int ret; + + count = qiov->size; + + /* first write to align to sector start */ + len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); + if (len > count) + len = count; + sector_num = offset >> BDRV_SECTOR_BITS; + if (len > 0) { + if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) + return ret; + qemu_iovec_to_buf(qiov, 0, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), + len); + if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) + return ret; + count -= len; + if (count == 0) + return qiov->size; + sector_num++; + } + + /* write the sectors "in place" */ + nb_sectors = count >> BDRV_SECTOR_BITS; + if (nb_sectors > 0) { + QEMUIOVector qiov_inplace; + + qemu_iovec_init(&qiov_inplace, qiov->niov); + qemu_iovec_concat(&qiov_inplace, qiov, len, + nb_sectors << BDRV_SECTOR_BITS); + ret = bdrv_writev(bs, sector_num, &qiov_inplace); + qemu_iovec_destroy(&qiov_inplace); + if (ret < 0) { + return ret; + } + + sector_num += nb_sectors; + len = nb_sectors << BDRV_SECTOR_BITS; + count -= len; + } + + /* add data from the last sector */ + if (count > 0) { + if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) + return ret; + qemu_iovec_to_buf(qiov, qiov->size - count, tmp_buf, count); + if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) + return ret; + } + return qiov->size; +} + +int bdrv_pwrite(BlockDriverState *bs, int64_t offset, + const void *buf, int count1) +{ + QEMUIOVector qiov; + struct iovec iov = { + .iov_base = (void *) buf, + .iov_len = count1, + }; + + qemu_iovec_init_external(&qiov, &iov, 1); + return bdrv_pwritev(bs, offset, &qiov); +} + +/* + * Writes to the file and ensures that no writes are reordered across this + * request (acts as a barrier) + * + * Returns 0 on success, -errno in error cases. + */ +int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, + const void *buf, int count) +{ + int ret; + + ret = bdrv_pwrite(bs, offset, buf, count); + if (ret < 0) { + return ret; + } + + /* No flush needed for cache modes that already do it */ + if (bs->enable_write_cache) { + bdrv_flush(bs); + } + + return 0; +} + +static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) +{ + /* Perform I/O through a temporary buffer so that users who scribble over + * their read buffer while the operation is in progress do not end up + * modifying the image file. This is critical for zero-copy guest I/O + * where anything might happen inside guest memory. + */ + void *bounce_buffer; + + BlockDriver *drv = bs->drv; + struct iovec iov; + QEMUIOVector bounce_qiov; + int64_t cluster_sector_num; + int cluster_nb_sectors; + size_t skip_bytes; + int ret; + + /* Cover entire cluster so no additional backing file I/O is required when + * allocating cluster in the image file. + */ + bdrv_round_to_clusters(bs, sector_num, nb_sectors, + &cluster_sector_num, &cluster_nb_sectors); + + trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, + cluster_sector_num, cluster_nb_sectors); + + iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; + iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len); + qemu_iovec_init_external(&bounce_qiov, &iov, 1); + + ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, + &bounce_qiov); + if (ret < 0) { + goto err; + } + + if (drv->bdrv_co_write_zeroes && + buffer_is_zero(bounce_buffer, iov.iov_len)) { + ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, + cluster_nb_sectors); + } else { + /* This does not change the data on the disk, it is not necessary + * to flush even in cache=writethrough mode. + */ + ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, + &bounce_qiov); + } + + if (ret < 0) { + /* It might be okay to ignore write errors for guest requests. If this + * is a deliberate copy-on-read then we don't want to ignore the error. + * Simply report it in all cases. + */ + goto err; + } + + skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; + qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, + nb_sectors * BDRV_SECTOR_SIZE); + +err: + qemu_vfree(bounce_buffer); + return ret; +} + +/* + * Handle a read request in coroutine context + */ +static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, + BdrvRequestFlags flags) +{ + BlockDriver *drv = bs->drv; + BdrvTrackedRequest req; + int ret; + + if (!drv) { + return -ENOMEDIUM; + } + if (bdrv_check_request(bs, sector_num, nb_sectors)) { + return -EIO; + } + + /* throttling disk read I/O */ + if (bs->io_limits_enabled) { + bdrv_io_limits_intercept(bs, false, nb_sectors); + } + + if (bs->copy_on_read) { + flags |= BDRV_REQ_COPY_ON_READ; + } + if (flags & BDRV_REQ_COPY_ON_READ) { + bs->copy_on_read_in_flight++; + } + + if (bs->copy_on_read_in_flight) { + wait_for_overlapping_requests(bs, sector_num, nb_sectors); + } + + tracked_request_begin(&req, bs, sector_num, nb_sectors, false); + + if (flags & BDRV_REQ_COPY_ON_READ) { + int pnum; + + ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum); + if (ret < 0) { + goto out; + } + + if (!ret || pnum != nb_sectors) { + ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); + goto out; + } + } + + ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); + +out: + tracked_request_end(&req); + + if (flags & BDRV_REQ_COPY_ON_READ) { + bs->copy_on_read_in_flight--; + } + + return ret; +} + +int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) +{ + trace_bdrv_co_readv(bs, sector_num, nb_sectors); + + return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); +} + +int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) +{ + trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); + + return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, + BDRV_REQ_COPY_ON_READ); +} + +static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, + int64_t sector_num, int nb_sectors) +{ + BlockDriver *drv = bs->drv; + QEMUIOVector qiov; + struct iovec iov; + int ret; + + /* TODO Emulate only part of misaligned requests instead of letting block + * drivers return -ENOTSUP and emulate everything */ + + /* First try the efficient write zeroes operation */ + if (drv->bdrv_co_write_zeroes) { + ret = drv->bdrv_co_write_zeroes(bs, sector_num, nb_sectors); + if (ret != -ENOTSUP) { + return ret; + } + } + + /* Fall back to bounce buffer if write zeroes is unsupported */ + iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE; + iov.iov_base = qemu_blockalign(bs, iov.iov_len); + memset(iov.iov_base, 0, iov.iov_len); + qemu_iovec_init_external(&qiov, &iov, 1); + + ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, &qiov); + + qemu_vfree(iov.iov_base); + return ret; +} + +/* + * Handle a write request in coroutine context + */ +static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, + BdrvRequestFlags flags) +{ + BlockDriver *drv = bs->drv; + BdrvTrackedRequest req; + int ret; + + if (!bs->drv) { + return -ENOMEDIUM; + } + if (bs->read_only) { + return -EACCES; + } + if (bdrv_check_request(bs, sector_num, nb_sectors)) { + return -EIO; + } + + /* throttling disk write I/O */ + if (bs->io_limits_enabled) { + bdrv_io_limits_intercept(bs, true, nb_sectors); + } + + if (bs->copy_on_read_in_flight) { + wait_for_overlapping_requests(bs, sector_num, nb_sectors); + } + + tracked_request_begin(&req, bs, sector_num, nb_sectors, true); + + ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); + + if (ret < 0) { + /* Do nothing, write notifier decided to fail this request */ + } else if (flags & BDRV_REQ_ZERO_WRITE) { + ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors); + } else { + ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); + } + + if (ret == 0 && !bs->enable_write_cache) { + ret = bdrv_co_flush(bs); + } + + if (bs->dirty_bitmap) { + bdrv_set_dirty(bs, sector_num, nb_sectors); + } + + if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { + bs->wr_highest_sector = sector_num + nb_sectors - 1; + } + + tracked_request_end(&req); + + return ret; +} + +int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) +{ + trace_bdrv_co_writev(bs, sector_num, nb_sectors); + + return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); +} + +int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, + int64_t sector_num, int nb_sectors) +{ + trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors); + + return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, + BDRV_REQ_ZERO_WRITE); +} + +/** + * 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; + if (bdrv_in_use(bs)) + return -EBUSY; + ret = drv->bdrv_truncate(bs, offset); + if (ret == 0) { + ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); + bdrv_dev_resize_cb(bs); + } + 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; +} + +/** + * Length of a file in bytes. Return < 0 if error or unknown. + */ +int64_t bdrv_getlength(BlockDriverState *bs) +{ + BlockDriver *drv = bs->drv; + if (!drv) + return -ENOMEDIUM; + + if (bs->growable || bdrv_dev_has_removable_media(bs)) { + if (drv->bdrv_getlength) { + return drv->bdrv_getlength(bs); + } + } + return bs->total_sectors * 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 length; + length = bdrv_getlength(bs); + if (length < 0) + length = 0; + else + length = length >> BDRV_SECTOR_BITS; + *nb_sectors_ptr = length; +} + +/* throttling disk io limits */ +void bdrv_set_io_limits(BlockDriverState *bs, + BlockIOLimit *io_limits) +{ + bs->io_limits = *io_limits; + bs->io_limits_enabled = bdrv_io_limits_enabled(bs); +} + +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) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT; + case BLOCKDEV_ON_ERROR_STOP: + return BDRV_ACTION_STOP; + case BLOCKDEV_ON_ERROR_REPORT: + return BDRV_ACTION_REPORT; + case BLOCKDEV_ON_ERROR_IGNORE: + return BDRV_ACTION_IGNORE; + default: + 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); + bdrv_emit_qmp_error_event(bs, QEVENT_BLOCK_IO_ERROR, action, is_read); + if (action == BDRV_ACTION_STOP) { + vm_stop(RUN_STATE_IO_ERROR); + bdrv_iostatus_set_err(bs, 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; + /* call the change callback now, we skipped it on open */ + bdrv_dev_change_media_cb(bs, true); + } + return ret; +} + +const char *bdrv_get_format_name(BlockDriverState *bs) +{ + return bs->drv ? bs->drv->format_name : NULL; +} + +void bdrv_iterate_format(void (*it)(void *opaque, const char *name), + void *opaque) +{ + BlockDriver *drv; + + QLIST_FOREACH(drv, &bdrv_drivers, list) { + it(opaque, drv->format_name); + } +} + +BlockDriverState *bdrv_find(const char *name) +{ + BlockDriverState *bs; + + QTAILQ_FOREACH(bs, &bdrv_states, list) { + if (!strcmp(name, bs->device_name)) { + return bs; + } + } + return NULL; +} + +BlockDriverState *bdrv_next(BlockDriverState *bs) +{ + if (!bs) { + return QTAILQ_FIRST(&bdrv_states); + } + return QTAILQ_NEXT(bs, list); +} + +void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) +{ + BlockDriverState *bs; + + QTAILQ_FOREACH(bs, &bdrv_states, list) { + it(opaque, bs); + } +} + +const char *bdrv_get_device_name(BlockDriverState *bs) +{ + return bs->device_name; +} + +int bdrv_get_flags(BlockDriverState *bs) +{ + return bs->open_flags; +} + +int bdrv_flush_all(void) +{ + BlockDriverState *bs; + int result = 0; + + QTAILQ_FOREACH(bs, &bdrv_states, list) { + int ret = bdrv_flush(bs); + if (ret < 0 && !result) { + result = ret; + } + } + + return result; +} + +int bdrv_has_zero_init_1(BlockDriverState *bs) +{ + return 1; +} + +int bdrv_has_zero_init(BlockDriverState *bs) +{ + assert(bs->drv); + + if (bs->drv->bdrv_has_zero_init) { + return bs->drv->bdrv_has_zero_init(bs); + } + + /* safe default */ + return 0; +} + +typedef struct BdrvCoIsAllocatedData { + BlockDriverState *bs; + BlockDriverState *base; + int64_t sector_num; + int nb_sectors; + int *pnum; + int ret; + bool done; +} BdrvCoIsAllocatedData; + +/* + * Returns true iff the specified sector is present in the disk image. Drivers + * not implementing the functionality are assumed to not support backing files, + * hence all their sectors are reported as allocated. + * + * If 'sector_num' is beyond the end of the disk image the return value is 0 + * and 'pnum' is set to 0. + * + * 'pnum' is set to the number of sectors (including and immediately following + * the specified sector) that are known to be in the same + * allocated/unallocated state. + * + * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes + * beyond the end of the disk image it will be clamped. + */ +int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, int *pnum) +{ + int64_t n; + + if (sector_num >= bs->total_sectors) { + *pnum = 0; + return 0; + } + + n = bs->total_sectors - sector_num; + if (n < nb_sectors) { + nb_sectors = n; + } + + if (!bs->drv->bdrv_co_is_allocated) { + *pnum = nb_sectors; + return 1; + } + + return bs->drv->bdrv_co_is_allocated(bs, sector_num, nb_sectors, pnum); +} + +/* Coroutine wrapper for bdrv_is_allocated() */ +static void coroutine_fn bdrv_is_allocated_co_entry(void *opaque) +{ + BdrvCoIsAllocatedData *data = opaque; + BlockDriverState *bs = data->bs; + + data->ret = bdrv_co_is_allocated(bs, data->sector_num, data->nb_sectors, + data->pnum); + data->done = true; +} + +/* + * Synchronous wrapper around bdrv_co_is_allocated(). + * + * See bdrv_co_is_allocated() for details. + */ +int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, + int *pnum) +{ + Coroutine *co; + BdrvCoIsAllocatedData data = { + .bs = bs, + .sector_num = sector_num, + .nb_sectors = nb_sectors, + .pnum = pnum, + .done = false, + }; + + co = qemu_coroutine_create(bdrv_is_allocated_co_entry); + qemu_coroutine_enter(co, &data); + while (!data.done) { + qemu_aio_wait(); + } + return data.ret; +} + +/* + * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] + * + * Return true if the given sector is allocated in any image between + * BASE and TOP (inclusive). BASE can be NULL to check if the given + * sector is allocated in any image of the chain. Return false otherwise. + * + * 'pnum' is set to the number of sectors (including and immediately following + * the specified sector) that are known to be in the same + * allocated/unallocated state. + * + */ +int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, + BlockDriverState *base, + int64_t sector_num, + int nb_sectors, int *pnum) +{ + BlockDriverState *intermediate; + int ret, n = nb_sectors; + + intermediate = top; + while (intermediate && intermediate != base) { + int pnum_inter; + ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors, + &pnum_inter); + if (ret < 0) { + return ret; + } else if (ret) { + *pnum = pnum_inter; + return 1; + } + + /* + * [sector_num, nb_sectors] is unallocated on top but intermediate + * might have + * + * [sector_num+x, nr_sectors] allocated. + */ + if (n > pnum_inter && + (intermediate == top || + sector_num + pnum_inter < intermediate->total_sectors)) { + n = pnum_inter; + } + + intermediate = intermediate->backing_hd; + } + + *pnum = n; + return 0; +} + +/* Coroutine wrapper for bdrv_is_allocated_above() */ +static void coroutine_fn bdrv_is_allocated_above_co_entry(void *opaque) +{ + BdrvCoIsAllocatedData *data = opaque; + BlockDriverState *top = data->bs; + BlockDriverState *base = data->base; + + data->ret = bdrv_co_is_allocated_above(top, base, data->sector_num, + data->nb_sectors, data->pnum); + data->done = true; +} + +/* + * Synchronous wrapper around bdrv_co_is_allocated_above(). + * + * See bdrv_co_is_allocated_above() for details. + */ +int bdrv_is_allocated_above(BlockDriverState *top, BlockDriverState *base, + int64_t sector_num, int nb_sectors, int *pnum) +{ + Coroutine *co; + BdrvCoIsAllocatedData data = { + .bs = top, + .base = base, + .sector_num = sector_num, + .nb_sectors = nb_sectors, + .pnum = pnum, + .done = false, + }; + + co = qemu_coroutine_create(bdrv_is_allocated_above_co_entry); + qemu_coroutine_enter(co, &data); + while (!data.done) { + qemu_aio_wait(); + } + return data.ret; +} + +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_write_compressed(BlockDriverState *bs, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + BlockDriver *drv = bs->drv; + if (!drv) + return -ENOMEDIUM; + if (!drv->bdrv_write_compressed) + return -ENOTSUP; + if (bdrv_check_request(bs, sector_num, nb_sectors)) + return -EIO; + + assert(!bs->dirty_bitmap); + + return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); +} + +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); +} + +int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, + int64_t pos, int size) +{ + QEMUIOVector qiov; + struct iovec iov = { + .iov_base = (void *) buf, + .iov_len = size, + }; + + qemu_iovec_init_external(&qiov, &iov, 1); + return bdrv_writev_vmstate(bs, &qiov, pos); +} + +int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) +{ + BlockDriver *drv = bs->drv; + + if (!drv) { + return -ENOMEDIUM; + } else if (drv->bdrv_save_vmstate) { + return drv->bdrv_save_vmstate(bs, qiov, pos); + } else if (bs->file) { + return bdrv_writev_vmstate(bs->file, qiov, pos); + } + + return -ENOTSUP; +} + +int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, + int64_t pos, int size) +{ + BlockDriver *drv = bs->drv; + if (!drv) + return -ENOMEDIUM; + if (drv->bdrv_load_vmstate) + return drv->bdrv_load_vmstate(bs, buf, pos, size); + if (bs->file) + return bdrv_load_vmstate(bs->file, buf, pos, size); + return -ENOTSUP; +} + +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_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); +} + +BlockDriverState *bdrv_find_base(BlockDriverState *bs) +{ + BlockDriverState *curr_bs = NULL; + + if (!bs) { + return NULL; + } + + curr_bs = bs; + + while (curr_bs->backing_hd) { + curr_bs = curr_bs->backing_hd; + } + return curr_bs; +} + +/**************************************************************/ +/* async I/Os */ + +BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, + QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); + + return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, + cb, opaque, false); +} + +BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, + QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); + + return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, + cb, opaque, true); +} + + +typedef struct MultiwriteCB { + int error; + int num_requests; + int num_callbacks; + struct { + BlockDriverCompletionFunc *cb; + void *opaque; + QEMUIOVector *free_qiov; + } callbacks[]; +} MultiwriteCB; + +static void multiwrite_user_cb(MultiwriteCB *mcb) +{ + int i; + + for (i = 0; i < mcb->num_callbacks; i++) { + mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); + if (mcb->callbacks[i].free_qiov) { + qemu_iovec_destroy(mcb->callbacks[i].free_qiov); + } + g_free(mcb->callbacks[i].free_qiov); + } +} + +static void multiwrite_cb(void *opaque, int ret) +{ + MultiwriteCB *mcb = opaque; + + trace_multiwrite_cb(mcb, ret); + + if (ret < 0 && !mcb->error) { + mcb->error = ret; + } + + mcb->num_requests--; + if (mcb->num_requests == 0) { + multiwrite_user_cb(mcb); + g_free(mcb); + } +} + +static int multiwrite_req_compare(const void *a, const void *b) +{ + const BlockRequest *req1 = a, *req2 = b; + + /* + * Note that we can't simply subtract req2->sector from req1->sector + * here as that could overflow the return value. + */ + if (req1->sector > req2->sector) { + return 1; + } else if (req1->sector < req2->sector) { + return -1; + } else { + return 0; + } +} + +/* + * Takes a bunch of requests and tries to merge them. Returns the number of + * requests that remain after merging. + */ +static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, + int num_reqs, MultiwriteCB *mcb) +{ + int i, outidx; + + // Sort requests by start sector + qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); + + // Check if adjacent requests touch the same clusters. If so, combine them, + // filling up gaps with zero sectors. + outidx = 0; + for (i = 1; i < num_reqs; i++) { + int merge = 0; + int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; + + // Handle exactly sequential writes and overlapping writes. + if (reqs[i].sector <= oldreq_last) { + merge = 1; + } + + if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { + merge = 0; + } + + if (merge) { + size_t size; + QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); + qemu_iovec_init(qiov, + reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); + + // Add the first request to the merged one. If the requests are + // overlapping, drop the last sectors of the first request. + size = (reqs[i].sector - reqs[outidx].sector) << 9; + qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); + + // We should need to add any zeros between the two requests + assert (reqs[i].sector <= oldreq_last); + + // Add the second request + qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); + + reqs[outidx].nb_sectors = qiov->size >> 9; + reqs[outidx].qiov = qiov; + + mcb->callbacks[i].free_qiov = reqs[outidx].qiov; + } else { + outidx++; + reqs[outidx].sector = reqs[i].sector; + reqs[outidx].nb_sectors = reqs[i].nb_sectors; + reqs[outidx].qiov = reqs[i].qiov; + } + } + + return outidx + 1; +} + +/* + * Submit multiple AIO write requests at once. + * + * On success, the function returns 0 and all requests in the reqs array have + * been submitted. In error case this function returns -1, and any of the + * requests may or may not be submitted yet. In particular, this means that the + * callback will be called for some of the requests, for others it won't. The + * caller must check the error field of the BlockRequest to wait for the right + * callbacks (if error != 0, no callback will be called). + * + * The implementation may modify the contents of the reqs array, e.g. to merge + * requests. However, the fields opaque and error are left unmodified as they + * are used to signal failure for a single request to the caller. + */ +int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) +{ + MultiwriteCB *mcb; + int i; + + /* don't submit writes if we don't have a medium */ + if (bs->drv == NULL) { + for (i = 0; i < num_reqs; i++) { + reqs[i].error = -ENOMEDIUM; + } + return -1; + } + + if (num_reqs == 0) { + return 0; + } + + // Create MultiwriteCB structure + mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); + mcb->num_requests = 0; + mcb->num_callbacks = num_reqs; + + for (i = 0; i < num_reqs; i++) { + mcb->callbacks[i].cb = reqs[i].cb; + mcb->callbacks[i].opaque = reqs[i].opaque; + } + + // Check for mergable requests + num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); + + trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); + + /* Run the aio requests. */ + mcb->num_requests = num_reqs; + for (i = 0; i < num_reqs; i++) { + bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov, + reqs[i].nb_sectors, multiwrite_cb, mcb); + } + + return 0; +} + +void bdrv_aio_cancel(BlockDriverAIOCB *acb) +{ + acb->aiocb_info->cancel(acb); +} + +/* block I/O throttling */ +static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors, + bool is_write, double elapsed_time, uint64_t *wait) +{ + uint64_t bps_limit = 0; + uint64_t extension; + double bytes_limit, bytes_base, bytes_res; + double slice_time, wait_time; + + if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { + bps_limit = bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]; + } else if (bs->io_limits.bps[is_write]) { + bps_limit = bs->io_limits.bps[is_write]; + } else { + if (wait) { + *wait = 0; + } + + return false; + } + + slice_time = bs->slice_end - bs->slice_start; + slice_time /= (NANOSECONDS_PER_SECOND); + bytes_limit = bps_limit * slice_time; + bytes_base = bs->slice_submitted.bytes[is_write]; + if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { + bytes_base += bs->slice_submitted.bytes[!is_write]; + } + + /* bytes_base: the bytes of data which have been read/written; and + * it is obtained from the history statistic info. + * bytes_res: the remaining bytes of data which need to be read/written. + * (bytes_base + bytes_res) / bps_limit: used to calcuate + * the total time for completing reading/writting all data. + */ + bytes_res = (unsigned) nb_sectors * BDRV_SECTOR_SIZE; + + if (bytes_base + bytes_res <= bytes_limit) { + if (wait) { + *wait = 0; + } + + return false; + } + + /* Calc approx time to dispatch */ + wait_time = (bytes_base + bytes_res) / bps_limit - elapsed_time; + + /* When the I/O rate at runtime exceeds the limits, + * bs->slice_end need to be extended in order that the current statistic + * info can be kept until the timer fire, so it is increased and tuned + * based on the result of experiment. + */ + extension = wait_time * NANOSECONDS_PER_SECOND; + extension = DIV_ROUND_UP(extension, BLOCK_IO_SLICE_TIME) * + BLOCK_IO_SLICE_TIME; + bs->slice_end += extension; + if (wait) { + *wait = wait_time * NANOSECONDS_PER_SECOND; + } + + return true; +} + +static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write, + double elapsed_time, uint64_t *wait) +{ + uint64_t iops_limit = 0; + double ios_limit, ios_base; + double slice_time, wait_time; + + if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { + iops_limit = bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]; + } else if (bs->io_limits.iops[is_write]) { + iops_limit = bs->io_limits.iops[is_write]; + } else { + if (wait) { + *wait = 0; + } + + return false; + } + + slice_time = bs->slice_end - bs->slice_start; + slice_time /= (NANOSECONDS_PER_SECOND); + ios_limit = iops_limit * slice_time; + ios_base = bs->slice_submitted.ios[is_write]; + if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { + ios_base += bs->slice_submitted.ios[!is_write]; + } + + if (ios_base + 1 <= ios_limit) { + if (wait) { + *wait = 0; + } + + return false; + } + + /* Calc approx time to dispatch, in seconds */ + wait_time = (ios_base + 1) / iops_limit; + if (wait_time > elapsed_time) { + wait_time = wait_time - elapsed_time; + } else { + wait_time = 0; + } + + /* Exceeded current slice, extend it by another slice time */ + bs->slice_end += BLOCK_IO_SLICE_TIME; + if (wait) { + *wait = wait_time * NANOSECONDS_PER_SECOND; + } + + return true; +} + +static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors, + bool is_write, int64_t *wait) +{ + int64_t now, max_wait; + uint64_t bps_wait = 0, iops_wait = 0; + double elapsed_time; + int bps_ret, iops_ret; + + now = qemu_get_clock_ns(vm_clock); + if (now > bs->slice_end) { + bs->slice_start = now; + bs->slice_end = now + BLOCK_IO_SLICE_TIME; + memset(&bs->slice_submitted, 0, sizeof(bs->slice_submitted)); + } + + elapsed_time = now - bs->slice_start; + elapsed_time /= (NANOSECONDS_PER_SECOND); + + bps_ret = bdrv_exceed_bps_limits(bs, nb_sectors, + is_write, elapsed_time, &bps_wait); + iops_ret = bdrv_exceed_iops_limits(bs, is_write, + elapsed_time, &iops_wait); + if (bps_ret || iops_ret) { + max_wait = bps_wait > iops_wait ? bps_wait : iops_wait; + if (wait) { + *wait = max_wait; + } + + now = qemu_get_clock_ns(vm_clock); + if (bs->slice_end < now + max_wait) { + bs->slice_end = now + max_wait; + } + + return true; + } + + if (wait) { + *wait = 0; + } + + bs->slice_submitted.bytes[is_write] += (int64_t)nb_sectors * + BDRV_SECTOR_SIZE; + bs->slice_submitted.ios[is_write]++; + + return false; +} + +/**************************************************************/ +/* async block device emulation */ + +typedef struct BlockDriverAIOCBSync { + BlockDriverAIOCB common; + QEMUBH *bh; + int ret; + /* vector translation state */ + QEMUIOVector *qiov; + uint8_t *bounce; + int is_write; +} BlockDriverAIOCBSync; + +static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) +{ + BlockDriverAIOCBSync *acb = + container_of(blockacb, BlockDriverAIOCBSync, common); + qemu_bh_delete(acb->bh); + acb->bh = NULL; + qemu_aio_release(acb); +} + +static const AIOCBInfo bdrv_em_aiocb_info = { + .aiocb_size = sizeof(BlockDriverAIOCBSync), + .cancel = bdrv_aio_cancel_em, +}; + +static void bdrv_aio_bh_cb(void *opaque) +{ + BlockDriverAIOCBSync *acb = opaque; + + if (!acb->is_write) + qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); + qemu_vfree(acb->bounce); + acb->common.cb(acb->common.opaque, acb->ret); + qemu_bh_delete(acb->bh); + acb->bh = NULL; + qemu_aio_release(acb); +} + +static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, + int64_t sector_num, + QEMUIOVector *qiov, + int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque, + int is_write) + +{ + BlockDriverAIOCBSync *acb; + + acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque); + acb->is_write = is_write; + acb->qiov = qiov; + acb->bounce = qemu_blockalign(bs, qiov->size); + acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); + + if (is_write) { + qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); + acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); + } else { + acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); + } + + qemu_bh_schedule(acb->bh); + + return &acb->common; +} + +static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); +} + +static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); +} + + +typedef struct BlockDriverAIOCBCoroutine { + BlockDriverAIOCB common; + BlockRequest req; + bool is_write; + bool *done; + QEMUBH* bh; +} BlockDriverAIOCBCoroutine; + +static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb) +{ + BlockDriverAIOCBCoroutine *acb = + container_of(blockacb, BlockDriverAIOCBCoroutine, common); + bool done = false; + + acb->done = &done; + while (!done) { + qemu_aio_wait(); + } +} + +static const AIOCBInfo bdrv_em_co_aiocb_info = { + .aiocb_size = sizeof(BlockDriverAIOCBCoroutine), + .cancel = bdrv_aio_co_cancel_em, +}; + +static void bdrv_co_em_bh(void *opaque) +{ + BlockDriverAIOCBCoroutine *acb = opaque; + + acb->common.cb(acb->common.opaque, acb->req.error); + + if (acb->done) { + *acb->done = true; + } + + qemu_bh_delete(acb->bh); + qemu_aio_release(acb); +} + +/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ +static void coroutine_fn bdrv_co_do_rw(void *opaque) +{ + BlockDriverAIOCBCoroutine *acb = opaque; + BlockDriverState *bs = acb->common.bs; + + if (!acb->is_write) { + acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, + acb->req.nb_sectors, acb->req.qiov, 0); + } else { + acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, + acb->req.nb_sectors, acb->req.qiov, 0); + } + + acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); + qemu_bh_schedule(acb->bh); +} + +static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, + int64_t sector_num, + QEMUIOVector *qiov, + int nb_sectors, + BlockDriverCompletionFunc *cb, + void *opaque, + bool is_write) +{ + Coroutine *co; + BlockDriverAIOCBCoroutine *acb; + + acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); + acb->req.sector = sector_num; + acb->req.nb_sectors = nb_sectors; + acb->req.qiov = qiov; + acb->is_write = is_write; + acb->done = NULL; + + co = qemu_coroutine_create(bdrv_co_do_rw); + qemu_coroutine_enter(co, acb); + + return &acb->common; +} + +static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) +{ + BlockDriverAIOCBCoroutine *acb = opaque; + BlockDriverState *bs = acb->common.bs; + + acb->req.error = bdrv_co_flush(bs); + acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); + qemu_bh_schedule(acb->bh); +} + +BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, + BlockDriverCompletionFunc *cb, void *opaque) +{ + trace_bdrv_aio_flush(bs, opaque); + + Coroutine *co; + BlockDriverAIOCBCoroutine *acb; + + acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); + acb->done = NULL; + + co = qemu_coroutine_create(bdrv_aio_flush_co_entry); + qemu_coroutine_enter(co, acb); + + return &acb->common; +} + +static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) +{ + BlockDriverAIOCBCoroutine *acb = opaque; + BlockDriverState *bs = acb->common.bs; + + acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); + acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); + qemu_bh_schedule(acb->bh); +} + +BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + Coroutine *co; + BlockDriverAIOCBCoroutine *acb; + + trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); + + acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); + acb->req.sector = sector_num; + acb->req.nb_sectors = nb_sectors; + acb->done = NULL; + co = qemu_coroutine_create(bdrv_aio_discard_co_entry); + qemu_coroutine_enter(co, acb); + + return &acb->common; +} + +void bdrv_init(void) +{ + module_call_init(MODULE_INIT_BLOCK); +} + +void bdrv_init_with_whitelist(void) +{ + use_bdrv_whitelist = 1; + bdrv_init(); +} + +void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs, + BlockDriverCompletionFunc *cb, void *opaque) +{ + BlockDriverAIOCB *acb; + + acb = g_slice_alloc(aiocb_info->aiocb_size); + acb->aiocb_info = aiocb_info; + acb->bs = bs; + acb->cb = cb; + acb->opaque = opaque; + return acb; +} + +void qemu_aio_release(void *p) +{ + BlockDriverAIOCB *acb = p; + g_slice_free1(acb->aiocb_info->aiocb_size, acb); +} + +/**************************************************************/ +/* Coroutine block device emulation */ + +typedef struct CoroutineIOCompletion { + Coroutine *coroutine; + int ret; +} CoroutineIOCompletion; + +static void bdrv_co_io_em_complete(void *opaque, int ret) +{ + CoroutineIOCompletion *co = opaque; + + co->ret = ret; + qemu_coroutine_enter(co->coroutine, NULL); +} + +static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *iov, + bool is_write) +{ + CoroutineIOCompletion co = { + .coroutine = qemu_coroutine_self(), + }; + BlockDriverAIOCB *acb; + + if (is_write) { + acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, + bdrv_co_io_em_complete, &co); + } else { + acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, + bdrv_co_io_em_complete, &co); + } + + trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); + if (!acb) { + return -EIO; + } + qemu_coroutine_yield(); + + return co.ret; +} + +static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, + QEMUIOVector *iov) +{ + return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); +} + +static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, + QEMUIOVector *iov) +{ + return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); +} + +static void coroutine_fn bdrv_flush_co_entry(void *opaque) +{ + RwCo *rwco = opaque; + + rwco->ret = bdrv_co_flush(rwco->bs); +} + +int coroutine_fn bdrv_co_flush(BlockDriverState *bs) +{ + int ret; + + if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { + return 0; + } + + /* Write back cached data to the OS even with cache=unsafe */ + BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); + if (bs->drv->bdrv_co_flush_to_os) { + ret = bs->drv->bdrv_co_flush_to_os(bs); + if (ret < 0) { + return ret; + } + } + + /* But don't actually force it to the disk with cache=unsafe */ + if (bs->open_flags & BDRV_O_NO_FLUSH) { + goto flush_parent; + } + + BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); + if (bs->drv->bdrv_co_flush_to_disk) { + ret = bs->drv->bdrv_co_flush_to_disk(bs); + } else if (bs->drv->bdrv_aio_flush) { + BlockDriverAIOCB *acb; + CoroutineIOCompletion co = { + .coroutine = qemu_coroutine_self(), + }; + + acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); + if (acb == NULL) { + ret = -EIO; + } else { + qemu_coroutine_yield(); + ret = co.ret; + } + } else { + /* + * Some block drivers always operate in either writethrough or unsafe + * mode and don't support bdrv_flush therefore. Usually qemu doesn't + * know how the server works (because the behaviour is hardcoded or + * depends on server-side configuration), so we can't ensure that + * everything is safe on disk. Returning an error doesn't work because + * that would break guests even if the server operates in writethrough + * mode. + * + * Let's hope the user knows what he's doing. + */ + ret = 0; + } + if (ret < 0) { + return ret; + } + + /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH + * in the case of cache=unsafe, so there are no useless flushes. + */ +flush_parent: + return bdrv_co_flush(bs->file); +} + +void bdrv_invalidate_cache(BlockDriverState *bs) +{ + if (bs->drv && bs->drv->bdrv_invalidate_cache) { + bs->drv->bdrv_invalidate_cache(bs); + } +} + +void bdrv_invalidate_cache_all(void) +{ + BlockDriverState *bs; + + QTAILQ_FOREACH(bs, &bdrv_states, list) { + bdrv_invalidate_cache(bs); + } +} + +void bdrv_clear_incoming_migration_all(void) +{ + BlockDriverState *bs; + + QTAILQ_FOREACH(bs, &bdrv_states, list) { + bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); + } +} + +int bdrv_flush(BlockDriverState *bs) +{ + Coroutine *co; + RwCo rwco = { + .bs = bs, + .ret = NOT_DONE, + }; + + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + bdrv_flush_co_entry(&rwco); + } else { + co = qemu_coroutine_create(bdrv_flush_co_entry); + qemu_coroutine_enter(co, &rwco); + while (rwco.ret == NOT_DONE) { + qemu_aio_wait(); + } + } + + return rwco.ret; +} + +static void coroutine_fn bdrv_discard_co_entry(void *opaque) +{ + RwCo *rwco = opaque; + + rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); +} + +int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, + int nb_sectors) +{ + if (!bs->drv) { + return -ENOMEDIUM; + } else if (bdrv_check_request(bs, sector_num, nb_sectors)) { + return -EIO; + } else if (bs->read_only) { + return -EROFS; + } + + if (bs->dirty_bitmap) { + bdrv_reset_dirty(bs, sector_num, nb_sectors); + } + + /* Do nothing if disabled. */ + if (!(bs->open_flags & BDRV_O_UNMAP)) { + return 0; + } + + if (bs->drv->bdrv_co_discard) { + return bs->drv->bdrv_co_discard(bs, sector_num, nb_sectors); + } else if (bs->drv->bdrv_aio_discard) { + BlockDriverAIOCB *acb; + CoroutineIOCompletion co = { + .coroutine = qemu_coroutine_self(), + }; + + acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, + bdrv_co_io_em_complete, &co); + if (acb == NULL) { + return -EIO; + } else { + qemu_coroutine_yield(); + return co.ret; + } + } else { + return 0; + } +} + +int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) +{ + Coroutine *co; + RwCo rwco = { + .bs = bs, + .sector_num = sector_num, + .nb_sectors = nb_sectors, + .ret = NOT_DONE, + }; + + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + bdrv_discard_co_entry(&rwco); + } else { + co = qemu_coroutine_create(bdrv_discard_co_entry); + qemu_coroutine_enter(co, &rwco); + while (rwco.ret == NOT_DONE) { + qemu_aio_wait(); + } + } + + return rwco.ret; +} + +/**************************************************************/ +/* 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; + + if (drv && drv->bdrv_eject) { + drv->bdrv_eject(bs, eject_flag); + } + + if (bs->device_name[0] != '\0') { + bdrv_emit_qmp_eject_event(bs, eject_flag); + } +} + +/** + * 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); + } +} + +/* needed for generic scsi interface */ + +int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) +{ + BlockDriver *drv = bs->drv; + + if (drv && drv->bdrv_ioctl) + return drv->bdrv_ioctl(bs, req, buf); + return -ENOTSUP; +} + +BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, + unsigned long int req, void *buf, + BlockDriverCompletionFunc *cb, void *opaque) +{ + BlockDriver *drv = bs->drv; + + if (drv && drv->bdrv_aio_ioctl) + return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); + return NULL; +} + +void bdrv_set_buffer_alignment(BlockDriverState *bs, int align) +{ + bs->buffer_alignment = align; +} + +void *qemu_blockalign(BlockDriverState *bs, size_t size) +{ + return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size); +} + +/* + * Check if all memory in this vector is sector aligned. + */ +bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) +{ + int i; + + for (i = 0; i < qiov->niov; i++) { + if ((uintptr_t) qiov->iov[i].iov_base % bs->buffer_alignment) { + return false; + } + } + + return true; +} + +void bdrv_set_dirty_tracking(BlockDriverState *bs, int granularity) +{ + int64_t bitmap_size; + + assert((granularity & (granularity - 1)) == 0); + + if (granularity) { + granularity >>= BDRV_SECTOR_BITS; + assert(!bs->dirty_bitmap); + bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS); + bs->dirty_bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1); + } else { + if (bs->dirty_bitmap) { + hbitmap_free(bs->dirty_bitmap); + bs->dirty_bitmap = NULL; + } + } +} + +int bdrv_get_dirty(BlockDriverState *bs, int64_t sector) +{ + if (bs->dirty_bitmap) { + return hbitmap_get(bs->dirty_bitmap, sector); + } else { + return 0; + } +} + +void bdrv_dirty_iter_init(BlockDriverState *bs, HBitmapIter *hbi) +{ + hbitmap_iter_init(hbi, bs->dirty_bitmap, 0); +} + +void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, + int nr_sectors) +{ + hbitmap_set(bs->dirty_bitmap, cur_sector, nr_sectors); +} + +void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, + int nr_sectors) +{ + hbitmap_reset(bs->dirty_bitmap, cur_sector, nr_sectors); +} + +int64_t bdrv_get_dirty_count(BlockDriverState *bs) +{ + if (bs->dirty_bitmap) { + return hbitmap_count(bs->dirty_bitmap); + } else { + return 0; + } +} + +void bdrv_set_in_use(BlockDriverState *bs, int in_use) +{ + assert(bs->in_use != in_use); + bs->in_use = in_use; +} + +int bdrv_in_use(BlockDriverState *bs) +{ + return bs->in_use; +} + +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_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, + enum BlockAcctType type) +{ + assert(type < BDRV_MAX_IOTYPE); + + cookie->bytes = bytes; + cookie->start_time_ns = get_clock(); + cookie->type = type; +} + +void +bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie) +{ + assert(cookie->type < BDRV_MAX_IOTYPE); + + bs->nr_bytes[cookie->type] += cookie->bytes; + bs->nr_ops[cookie->type]++; + bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns; +} + +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) +{ + QEMUOptionParameter *param = NULL, *create_options = NULL; + QEMUOptionParameter *backing_fmt, *backing_file, *size; + BlockDriverState *bs = NULL; + BlockDriver *drv, *proto_drv; + BlockDriver *backing_drv = 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); + if (!proto_drv) { + error_setg(errp, "Unknown protocol '%s'", filename); + return; + } + + create_options = append_option_parameters(create_options, + drv->create_options); + create_options = append_option_parameters(create_options, + proto_drv->create_options); + + /* Create parameter list with default values */ + param = parse_option_parameters("", create_options, param); + + set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size); + + /* Parse -o options */ + if (options) { + param = parse_option_parameters(options, create_options, param); + if (param == NULL) { + error_setg(errp, "Invalid options for file format '%s'.", fmt); + goto out; + } + } + + if (base_filename) { + if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE, + base_filename)) { + error_setg(errp, "Backing file not supported for file format '%s'", + fmt); + goto out; + } + } + + if (base_fmt) { + if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) { + error_setg(errp, "Backing file format not supported for file " + "format '%s'", fmt); + goto out; + } + } + + backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE); + if (backing_file && backing_file->value.s) { + if (!strcmp(filename, backing_file->value.s)) { + error_setg(errp, "Error: Trying to create an image with the " + "same filename as the backing file"); + goto out; + } + } + + backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT); + if (backing_fmt && backing_fmt->value.s) { + backing_drv = bdrv_find_format(backing_fmt->value.s); + if (!backing_drv) { + error_setg(errp, "Unknown backing file format '%s'", + backing_fmt->value.s); + 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 = get_option_parameter(param, BLOCK_OPT_SIZE); + if (size && size->value.n == -1) { + if (backing_file && backing_file->value.s) { + uint64_t size; + char buf[32]; + int back_flags; + + /* backing files always opened read-only */ + back_flags = + flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); + + bs = bdrv_new(""); + + ret = bdrv_open(bs, backing_file->value.s, NULL, back_flags, + backing_drv); + if (ret < 0) { + error_setg_errno(errp, -ret, "Could not open '%s'", + backing_file->value.s); + goto out; + } + bdrv_get_geometry(bs, &size); + size *= 512; + + snprintf(buf, sizeof(buf), "%" PRId64, size); + set_option_parameter(param, BLOCK_OPT_SIZE, buf); + } else { + error_setg(errp, "Image creation needs a size parameter"); + goto out; + } + } + + if (!quiet) { + printf("Formatting '%s', fmt=%s ", filename, fmt); + print_option_parameters(param); + puts(""); + } + ret = bdrv_create(drv, filename, param); + if (ret < 0) { + if (ret == -ENOTSUP) { + error_setg(errp,"Formatting or formatting option not supported for " + "file format '%s'", fmt); + } else if (ret == -EFBIG) { + const char *cluster_size_hint = ""; + if (get_option_parameter(create_options, BLOCK_OPT_CLUSTER_SIZE)) { + 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); + } else { + error_setg(errp, "%s: error while creating %s: %s", filename, fmt, + strerror(-ret)); + } + } + +out: + free_option_parameters(create_options); + free_option_parameters(param); + + if (bs) { + bdrv_delete(bs); + } +} + +AioContext *bdrv_get_aio_context(BlockDriverState *bs) +{ + /* Currently BlockDriverState always uses the main loop AioContext */ + return qemu_get_aio_context(); +} + +void bdrv_add_before_write_notifier(BlockDriverState *bs, + NotifierWithReturn *notifier) +{ + notifier_with_return_list_add(&bs->before_write_notifiers, notifier); +} |