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authorAnand Avati <avati@redhat.com>2013-03-06 01:11:59 -0800
committerAnand Avati <avati@redhat.com>2013-09-03 11:25:33 -0700
commit0d60175bd684cf6a14f750579d82dbd1ba97fcbc (patch)
tree1571f530548196006526442f3fc027cb623bb6fa /contrib/qemu/block.c
parent7dbfbfd3694e02b90e8f3ce509f5279da1523a02 (diff)
contrib/qemu: Import qemu block source code
This qemu block format source code and its minimal dependency files will be used in the next patch to implement a qemu-block format translator. Change-Id: Ic87638972f7ea9b3df84d7a0539512a250c11c1c BUG: 986775 Signed-off-by: Anand Avati <avati@redhat.com> Reviewed-on: http://review.gluster.org/5366 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
Diffstat (limited to 'contrib/qemu/block.c')
-rw-r--r--contrib/qemu/block.c4604
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);
+}