dc523cd348
img_convert() and img_amend() use qemu_opts_do_parse(), which reports
errors with qerror_report_err(). Its error messages aren't helpful
here, the caller reports one that actually makes sense. Reproducer:
$ qemu-img convert -o backing_format=raw in.img out.img
qemu-img: Invalid parameter 'backing_format'
qemu-img: Invalid options for file format 'raw'
To fix, propagate errors through qemu_opts_do_parse(). This lifts the
error reporting into callers. Drop it from img_convert() and
img_amend(), keep it in qemu_chr_parse_compat(), bdrv_img_create().
Since I'm touching qemu_opts_do_parse() anyway, write a function
comment for it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
6167 lines
174 KiB
C
6167 lines
174 KiB
C
/*
|
|
* QEMU System Emulator block driver
|
|
*
|
|
* Copyright (c) 2003 Fabrice Bellard
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*
|
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* 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
|
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* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
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*
|
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* The above copyright notice and this permission notice shall be included in
|
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* all copies or substantial portions of the Software.
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*
|
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
#include "config-host.h"
|
|
#include "qemu-common.h"
|
|
#include "trace.h"
|
|
#include "block/block_int.h"
|
|
#include "block/blockjob.h"
|
|
#include "qemu/module.h"
|
|
#include "qapi/qmp/qjson.h"
|
|
#include "sysemu/block-backend.h"
|
|
#include "sysemu/sysemu.h"
|
|
#include "qemu/notify.h"
|
|
#include "block/coroutine.h"
|
|
#include "block/qapi.h"
|
|
#include "qmp-commands.h"
|
|
#include "qemu/timer.h"
|
|
#include "qapi-event.h"
|
|
|
|
#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
|
|
|
|
struct BdrvDirtyBitmap {
|
|
HBitmap *bitmap;
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|
QLIST_ENTRY(BdrvDirtyBitmap) list;
|
|
};
|
|
|
|
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
|
|
|
|
static BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque);
|
|
static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *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_preadv(BlockDriverState *bs,
|
|
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags);
|
|
static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
|
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int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags);
|
|
static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov,
|
|
int nb_sectors,
|
|
BdrvRequestFlags flags,
|
|
BlockCompletionFunc *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, BdrvRequestFlags flags);
|
|
|
|
static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
|
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QTAILQ_HEAD_INITIALIZER(bdrv_states);
|
|
|
|
static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
|
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QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
|
|
|
|
static QLIST_HEAD(, BlockDriver) bdrv_drivers =
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QLIST_HEAD_INITIALIZER(bdrv_drivers);
|
|
|
|
static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
|
|
int nr_sectors);
|
|
static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
|
|
int nr_sectors);
|
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/* 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') ||
|
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(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_set_io_limits(BlockDriverState *bs,
|
|
ThrottleConfig *cfg)
|
|
{
|
|
int i;
|
|
|
|
throttle_config(&bs->throttle_state, cfg);
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|
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|
for (i = 0; i < 2; i++) {
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qemu_co_enter_next(&bs->throttled_reqs[i]);
|
|
}
|
|
}
|
|
|
|
/* this function drain all the throttled IOs */
|
|
static bool bdrv_start_throttled_reqs(BlockDriverState *bs)
|
|
{
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|
bool drained = false;
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bool enabled = bs->io_limits_enabled;
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|
int i;
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|
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|
bs->io_limits_enabled = false;
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|
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for (i = 0; i < 2; i++) {
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|
while (qemu_co_enter_next(&bs->throttled_reqs[i])) {
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|
drained = true;
|
|
}
|
|
}
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|
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|
bs->io_limits_enabled = enabled;
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|
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|
return drained;
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|
}
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|
|
|
void bdrv_io_limits_disable(BlockDriverState *bs)
|
|
{
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|
bs->io_limits_enabled = false;
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|
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|
bdrv_start_throttled_reqs(bs);
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|
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|
throttle_destroy(&bs->throttle_state);
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|
}
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|
|
|
static void bdrv_throttle_read_timer_cb(void *opaque)
|
|
{
|
|
BlockDriverState *bs = opaque;
|
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qemu_co_enter_next(&bs->throttled_reqs[0]);
|
|
}
|
|
|
|
static void bdrv_throttle_write_timer_cb(void *opaque)
|
|
{
|
|
BlockDriverState *bs = opaque;
|
|
qemu_co_enter_next(&bs->throttled_reqs[1]);
|
|
}
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|
|
|
/* should be called before bdrv_set_io_limits if a limit is set */
|
|
void bdrv_io_limits_enable(BlockDriverState *bs)
|
|
{
|
|
assert(!bs->io_limits_enabled);
|
|
throttle_init(&bs->throttle_state,
|
|
bdrv_get_aio_context(bs),
|
|
QEMU_CLOCK_VIRTUAL,
|
|
bdrv_throttle_read_timer_cb,
|
|
bdrv_throttle_write_timer_cb,
|
|
bs);
|
|
bs->io_limits_enabled = true;
|
|
}
|
|
|
|
/* This function makes an IO wait if needed
|
|
*
|
|
* @nb_sectors: the number of sectors of the IO
|
|
* @is_write: is the IO a write
|
|
*/
|
|
static void bdrv_io_limits_intercept(BlockDriverState *bs,
|
|
unsigned int bytes,
|
|
bool is_write)
|
|
{
|
|
/* does this io must wait */
|
|
bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write);
|
|
|
|
/* if must wait or any request of this type throttled queue the IO */
|
|
if (must_wait ||
|
|
!qemu_co_queue_empty(&bs->throttled_reqs[is_write])) {
|
|
qemu_co_queue_wait(&bs->throttled_reqs[is_write]);
|
|
}
|
|
|
|
/* the IO will be executed, do the accounting */
|
|
throttle_account(&bs->throttle_state, is_write, bytes);
|
|
|
|
|
|
/* if the next request must wait -> do nothing */
|
|
if (throttle_schedule_timer(&bs->throttle_state, is_write)) {
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|
return;
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|
}
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|
|
|
/* else queue next request for execution */
|
|
qemu_co_queue_next(&bs->throttled_reqs[is_write]);
|
|
}
|
|
|
|
size_t bdrv_opt_mem_align(BlockDriverState *bs)
|
|
{
|
|
if (!bs || !bs->drv) {
|
|
/* 4k should be on the safe side */
|
|
return 4096;
|
|
}
|
|
|
|
return bs->bl.opt_mem_alignment;
|
|
}
|
|
|
|
/* check if the path starts with "<protocol>:" */
|
|
int path_has_protocol(const char *path)
|
|
{
|
|
const char *p;
|
|
|
|
#ifdef _WIN32
|
|
if (is_windows_drive(path) ||
|
|
is_windows_drive_prefix(path)) {
|
|
return 0;
|
|
}
|
|
p = path + strcspn(path, ":/\\");
|
|
#else
|
|
p = path + strcspn(path, ":/");
|
|
#endif
|
|
|
|
return *p == ':';
|
|
}
|
|
|
|
int path_is_absolute(const char *path)
|
|
{
|
|
#ifdef _WIN32
|
|
/* specific case for names like: "\\.\d:" */
|
|
if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
|
|
return 1;
|
|
}
|
|
return (*path == '/' || *path == '\\');
|
|
#else
|
|
return (*path == '/');
|
|
#endif
|
|
}
|
|
|
|
/* if filename is absolute, just copy it to dest. Otherwise, build a
|
|
path to it by considering it is relative to base_path. URL are
|
|
supported. */
|
|
void path_combine(char *dest, int dest_size,
|
|
const char *base_path,
|
|
const char *filename)
|
|
{
|
|
const char *p, *p1;
|
|
int len;
|
|
|
|
if (dest_size <= 0)
|
|
return;
|
|
if (path_is_absolute(filename)) {
|
|
pstrcpy(dest, dest_size, filename);
|
|
} else {
|
|
p = strchr(base_path, ':');
|
|
if (p)
|
|
p++;
|
|
else
|
|
p = base_path;
|
|
p1 = strrchr(base_path, '/');
|
|
#ifdef _WIN32
|
|
{
|
|
const char *p2;
|
|
p2 = strrchr(base_path, '\\');
|
|
if (!p1 || p2 > p1)
|
|
p1 = p2;
|
|
}
|
|
#endif
|
|
if (p1)
|
|
p1++;
|
|
else
|
|
p1 = base_path;
|
|
if (p1 > p)
|
|
p = p1;
|
|
len = p - base_path;
|
|
if (len > dest_size - 1)
|
|
len = dest_size - 1;
|
|
memcpy(dest, base_path, len);
|
|
dest[len] = '\0';
|
|
pstrcat(dest, dest_size, filename);
|
|
}
|
|
}
|
|
|
|
void bdrv_get_full_backing_filename_from_filename(const char *backed,
|
|
const char *backing,
|
|
char *dest, size_t sz,
|
|
Error **errp)
|
|
{
|
|
if (backing[0] == '\0' || path_has_protocol(backing) ||
|
|
path_is_absolute(backing))
|
|
{
|
|
pstrcpy(dest, sz, backing);
|
|
} else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
|
|
error_setg(errp, "Cannot use relative backing file names for '%s'",
|
|
backed);
|
|
} else {
|
|
path_combine(dest, sz, backed, backing);
|
|
}
|
|
}
|
|
|
|
void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
|
|
Error **errp)
|
|
{
|
|
char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
|
|
|
|
bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
|
|
dest, sz, errp);
|
|
}
|
|
|
|
void bdrv_register(BlockDriver *bdrv)
|
|
{
|
|
/* 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);
|
|
}
|
|
|
|
BlockDriverState *bdrv_new_root(void)
|
|
{
|
|
BlockDriverState *bs = bdrv_new();
|
|
|
|
QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list);
|
|
return bs;
|
|
}
|
|
|
|
BlockDriverState *bdrv_new(void)
|
|
{
|
|
BlockDriverState *bs;
|
|
int i;
|
|
|
|
bs = g_new0(BlockDriverState, 1);
|
|
QLIST_INIT(&bs->dirty_bitmaps);
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
QLIST_INIT(&bs->op_blockers[i]);
|
|
}
|
|
bdrv_iostatus_disable(bs);
|
|
notifier_list_init(&bs->close_notifiers);
|
|
notifier_with_return_list_init(&bs->before_write_notifiers);
|
|
qemu_co_queue_init(&bs->throttled_reqs[0]);
|
|
qemu_co_queue_init(&bs->throttled_reqs[1]);
|
|
bs->refcnt = 1;
|
|
bs->aio_context = qemu_get_aio_context();
|
|
|
|
return bs;
|
|
}
|
|
|
|
void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify)
|
|
{
|
|
notifier_list_add(&bs->close_notifiers, notify);
|
|
}
|
|
|
|
BlockDriver *bdrv_find_format(const char *format_name)
|
|
{
|
|
BlockDriver *drv1;
|
|
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
|
|
if (!strcmp(drv1->format_name, format_name)) {
|
|
return drv1;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
|
|
{
|
|
static const char *whitelist_rw[] = {
|
|
CONFIG_BDRV_RW_WHITELIST
|
|
};
|
|
static const char *whitelist_ro[] = {
|
|
CONFIG_BDRV_RO_WHITELIST
|
|
};
|
|
const char **p;
|
|
|
|
if (!whitelist_rw[0] && !whitelist_ro[0]) {
|
|
return 1; /* no whitelist, anything goes */
|
|
}
|
|
|
|
for (p = whitelist_rw; *p; p++) {
|
|
if (!strcmp(drv->format_name, *p)) {
|
|
return 1;
|
|
}
|
|
}
|
|
if (read_only) {
|
|
for (p = whitelist_ro; *p; p++) {
|
|
if (!strcmp(drv->format_name, *p)) {
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
BlockDriver *bdrv_find_whitelisted_format(const char *format_name,
|
|
bool read_only)
|
|
{
|
|
BlockDriver *drv = bdrv_find_format(format_name);
|
|
return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL;
|
|
}
|
|
|
|
typedef struct CreateCo {
|
|
BlockDriver *drv;
|
|
char *filename;
|
|
QemuOpts *opts;
|
|
int ret;
|
|
Error *err;
|
|
} CreateCo;
|
|
|
|
static void coroutine_fn bdrv_create_co_entry(void *opaque)
|
|
{
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
CreateCo *cco = opaque;
|
|
assert(cco->drv);
|
|
|
|
ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err);
|
|
if (local_err) {
|
|
error_propagate(&cco->err, local_err);
|
|
}
|
|
cco->ret = ret;
|
|
}
|
|
|
|
int bdrv_create(BlockDriver *drv, const char* filename,
|
|
QemuOpts *opts, Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
Coroutine *co;
|
|
CreateCo cco = {
|
|
.drv = drv,
|
|
.filename = g_strdup(filename),
|
|
.opts = opts,
|
|
.ret = NOT_DONE,
|
|
.err = NULL,
|
|
};
|
|
|
|
if (!drv->bdrv_create) {
|
|
error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
|
|
ret = -ENOTSUP;
|
|
goto out;
|
|
}
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_create_co_entry(&cco);
|
|
} else {
|
|
co = qemu_coroutine_create(bdrv_create_co_entry);
|
|
qemu_coroutine_enter(co, &cco);
|
|
while (cco.ret == NOT_DONE) {
|
|
aio_poll(qemu_get_aio_context(), true);
|
|
}
|
|
}
|
|
|
|
ret = cco.ret;
|
|
if (ret < 0) {
|
|
if (cco.err) {
|
|
error_propagate(errp, cco.err);
|
|
} else {
|
|
error_setg_errno(errp, -ret, "Could not create image");
|
|
}
|
|
}
|
|
|
|
out:
|
|
g_free(cco.filename);
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
|
|
{
|
|
BlockDriver *drv;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
drv = bdrv_find_protocol(filename, true, errp);
|
|
if (drv == NULL) {
|
|
return -ENOENT;
|
|
}
|
|
|
|
ret = bdrv_create(drv, filename, opts, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
Error *local_err = NULL;
|
|
|
|
memset(&bs->bl, 0, sizeof(bs->bl));
|
|
|
|
if (!drv) {
|
|
return;
|
|
}
|
|
|
|
/* Take some limits from the children as a default */
|
|
if (bs->file) {
|
|
bdrv_refresh_limits(bs->file, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length;
|
|
bs->bl.max_transfer_length = bs->file->bl.max_transfer_length;
|
|
bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
|
|
} else {
|
|
bs->bl.opt_mem_alignment = 512;
|
|
}
|
|
|
|
if (bs->backing_hd) {
|
|
bdrv_refresh_limits(bs->backing_hd, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
bs->bl.opt_transfer_length =
|
|
MAX(bs->bl.opt_transfer_length,
|
|
bs->backing_hd->bl.opt_transfer_length);
|
|
bs->bl.max_transfer_length =
|
|
MIN_NON_ZERO(bs->bl.max_transfer_length,
|
|
bs->backing_hd->bl.max_transfer_length);
|
|
bs->bl.opt_mem_alignment =
|
|
MAX(bs->bl.opt_mem_alignment,
|
|
bs->backing_hd->bl.opt_mem_alignment);
|
|
}
|
|
|
|
/* Then let the driver override it */
|
|
if (drv->bdrv_refresh_limits) {
|
|
drv->bdrv_refresh_limits(bs, errp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create a uniquely-named empty temporary file.
|
|
* Return 0 upon success, otherwise a negative errno value.
|
|
*/
|
|
int get_tmp_filename(char *filename, int size)
|
|
{
|
|
#ifdef _WIN32
|
|
char temp_dir[MAX_PATH];
|
|
/* GetTempFileName requires that its output buffer (4th param)
|
|
have length MAX_PATH or greater. */
|
|
assert(size >= MAX_PATH);
|
|
return (GetTempPath(MAX_PATH, temp_dir)
|
|
&& GetTempFileName(temp_dir, "qem", 0, filename)
|
|
? 0 : -GetLastError());
|
|
#else
|
|
int fd;
|
|
const char *tmpdir;
|
|
tmpdir = getenv("TMPDIR");
|
|
if (!tmpdir) {
|
|
tmpdir = "/var/tmp";
|
|
}
|
|
if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
|
|
return -EOVERFLOW;
|
|
}
|
|
fd = mkstemp(filename);
|
|
if (fd < 0) {
|
|
return -errno;
|
|
}
|
|
if (close(fd) != 0) {
|
|
unlink(filename);
|
|
return -errno;
|
|
}
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Detect host devices. By convention, /dev/cdrom[N] is always
|
|
* recognized as a host CDROM.
|
|
*/
|
|
static BlockDriver *find_hdev_driver(const char *filename)
|
|
{
|
|
int score_max = 0, score;
|
|
BlockDriver *drv = NULL, *d;
|
|
|
|
QLIST_FOREACH(d, &bdrv_drivers, list) {
|
|
if (d->bdrv_probe_device) {
|
|
score = d->bdrv_probe_device(filename);
|
|
if (score > score_max) {
|
|
score_max = score;
|
|
drv = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
return drv;
|
|
}
|
|
|
|
BlockDriver *bdrv_find_protocol(const char *filename,
|
|
bool allow_protocol_prefix,
|
|
Error **errp)
|
|
{
|
|
BlockDriver *drv1;
|
|
char protocol[128];
|
|
int len;
|
|
const char *p;
|
|
|
|
/* TODO Drivers without bdrv_file_open must be specified explicitly */
|
|
|
|
/*
|
|
* XXX(hch): we really should not let host device detection
|
|
* override an explicit protocol specification, but moving this
|
|
* later breaks access to device names with colons in them.
|
|
* Thanks to the brain-dead persistent naming schemes on udev-
|
|
* based Linux systems those actually are quite common.
|
|
*/
|
|
drv1 = find_hdev_driver(filename);
|
|
if (drv1) {
|
|
return drv1;
|
|
}
|
|
|
|
if (!path_has_protocol(filename) || !allow_protocol_prefix) {
|
|
return &bdrv_file;
|
|
}
|
|
|
|
p = strchr(filename, ':');
|
|
assert(p != NULL);
|
|
len = p - filename;
|
|
if (len > sizeof(protocol) - 1)
|
|
len = sizeof(protocol) - 1;
|
|
memcpy(protocol, filename, len);
|
|
protocol[len] = '\0';
|
|
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
|
|
if (drv1->protocol_name &&
|
|
!strcmp(drv1->protocol_name, protocol)) {
|
|
return drv1;
|
|
}
|
|
}
|
|
|
|
error_setg(errp, "Unknown protocol '%s'", protocol);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Guess image format by probing its contents.
|
|
* This is not a good idea when your image is raw (CVE-2008-2004), but
|
|
* we do it anyway for backward compatibility.
|
|
*
|
|
* @buf contains the image's first @buf_size bytes.
|
|
* @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
|
|
* but can be smaller if the image file is smaller)
|
|
* @filename is its filename.
|
|
*
|
|
* For all block drivers, call the bdrv_probe() method to get its
|
|
* probing score.
|
|
* Return the first block driver with the highest probing score.
|
|
*/
|
|
BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
|
|
const char *filename)
|
|
{
|
|
int score_max = 0, score;
|
|
BlockDriver *drv = NULL, *d;
|
|
|
|
QLIST_FOREACH(d, &bdrv_drivers, list) {
|
|
if (d->bdrv_probe) {
|
|
score = d->bdrv_probe(buf, buf_size, filename);
|
|
if (score > score_max) {
|
|
score_max = score;
|
|
drv = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
return drv;
|
|
}
|
|
|
|
static int find_image_format(BlockDriverState *bs, const char *filename,
|
|
BlockDriver **pdrv, Error **errp)
|
|
{
|
|
BlockDriver *drv;
|
|
uint8_t buf[BLOCK_PROBE_BUF_SIZE];
|
|
int ret = 0;
|
|
|
|
/* Return the raw BlockDriver * to scsi-generic devices or empty drives */
|
|
if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) {
|
|
*pdrv = &bdrv_raw;
|
|
return ret;
|
|
}
|
|
|
|
ret = bdrv_pread(bs, 0, buf, sizeof(buf));
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not read image for determining its "
|
|
"format");
|
|
*pdrv = NULL;
|
|
return ret;
|
|
}
|
|
|
|
drv = bdrv_probe_all(buf, ret, filename);
|
|
if (!drv) {
|
|
error_setg(errp, "Could not determine image format: No compatible "
|
|
"driver found");
|
|
ret = -ENOENT;
|
|
}
|
|
*pdrv = drv;
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* Set the current 'total_sectors' value
|
|
* Return 0 on success, -errno on error.
|
|
*/
|
|
static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
/* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
|
|
if (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 = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
|
|
}
|
|
|
|
bs->total_sectors = hint;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Set open flags for a given discard mode
|
|
*
|
|
* Return 0 on success, -1 if the discard mode was invalid.
|
|
*/
|
|
int bdrv_parse_discard_flags(const char *mode, int *flags)
|
|
{
|
|
*flags &= ~BDRV_O_UNMAP;
|
|
|
|
if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
|
|
/* do nothing */
|
|
} else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) {
|
|
*flags |= BDRV_O_UNMAP;
|
|
} else {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Set open flags for a given cache mode
|
|
*
|
|
* Return 0 on success, -1 if the cache mode was invalid.
|
|
*/
|
|
int bdrv_parse_cache_flags(const char *mode, int *flags)
|
|
{
|
|
*flags &= ~BDRV_O_CACHE_MASK;
|
|
|
|
if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
|
|
*flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB;
|
|
} else if (!strcmp(mode, "directsync")) {
|
|
*flags |= BDRV_O_NOCACHE;
|
|
} else if (!strcmp(mode, "writeback")) {
|
|
*flags |= BDRV_O_CACHE_WB;
|
|
} else if (!strcmp(mode, "unsafe")) {
|
|
*flags |= BDRV_O_CACHE_WB;
|
|
*flags |= BDRV_O_NO_FLUSH;
|
|
} else if (!strcmp(mode, "writethrough")) {
|
|
/* this is the default */
|
|
} else {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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--;
|
|
}
|
|
|
|
/*
|
|
* Returns the flags that a temporary snapshot should get, based on the
|
|
* originally requested flags (the originally requested image will have flags
|
|
* like a backing file)
|
|
*/
|
|
static int bdrv_temp_snapshot_flags(int flags)
|
|
{
|
|
return (flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
|
|
}
|
|
|
|
/*
|
|
* Returns the flags that bs->file should get, based on the given flags for
|
|
* the parent BDS
|
|
*/
|
|
static int bdrv_inherited_flags(int flags)
|
|
{
|
|
/* Enable protocol handling, disable format probing for bs->file */
|
|
flags |= BDRV_O_PROTOCOL;
|
|
|
|
/* Our block drivers take care to send flushes and respect unmap policy,
|
|
* so we can enable both unconditionally on lower layers. */
|
|
flags |= BDRV_O_CACHE_WB | BDRV_O_UNMAP;
|
|
|
|
/* Clear flags that only apply to the top layer */
|
|
flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ);
|
|
|
|
return flags;
|
|
}
|
|
|
|
/*
|
|
* Returns the flags that bs->backing_hd should get, based on the given flags
|
|
* for the parent BDS
|
|
*/
|
|
static int bdrv_backing_flags(int flags)
|
|
{
|
|
/* backing files always opened read-only */
|
|
flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ);
|
|
|
|
/* snapshot=on is handled on the top layer */
|
|
flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
|
|
|
|
return flags;
|
|
}
|
|
|
|
static int bdrv_open_flags(BlockDriverState *bs, int flags)
|
|
{
|
|
int open_flags = flags | BDRV_O_CACHE_WB;
|
|
|
|
/*
|
|
* Clear flags that are internal to the block layer before opening the
|
|
* image.
|
|
*/
|
|
open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL);
|
|
|
|
/*
|
|
* Snapshots should be writable.
|
|
*/
|
|
if (flags & BDRV_O_TEMPORARY) {
|
|
open_flags |= BDRV_O_RDWR;
|
|
}
|
|
|
|
return open_flags;
|
|
}
|
|
|
|
static void bdrv_assign_node_name(BlockDriverState *bs,
|
|
const char *node_name,
|
|
Error **errp)
|
|
{
|
|
if (!node_name) {
|
|
return;
|
|
}
|
|
|
|
/* Check for empty string or invalid characters */
|
|
if (!id_wellformed(node_name)) {
|
|
error_setg(errp, "Invalid node name");
|
|
return;
|
|
}
|
|
|
|
/* takes care of avoiding namespaces collisions */
|
|
if (blk_by_name(node_name)) {
|
|
error_setg(errp, "node-name=%s is conflicting with a device id",
|
|
node_name);
|
|
return;
|
|
}
|
|
|
|
/* takes care of avoiding duplicates node names */
|
|
if (bdrv_find_node(node_name)) {
|
|
error_setg(errp, "Duplicate node name");
|
|
return;
|
|
}
|
|
|
|
/* copy node name into the bs and insert it into the graph list */
|
|
pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
|
|
QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
|
|
}
|
|
|
|
/*
|
|
* Common part for opening disk images and files
|
|
*
|
|
* Removes all processed options from *options.
|
|
*/
|
|
static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
|
|
QDict *options, int flags, BlockDriver *drv, Error **errp)
|
|
{
|
|
int ret, open_flags;
|
|
const char *filename;
|
|
const char *node_name = NULL;
|
|
Error *local_err = NULL;
|
|
|
|
assert(drv != NULL);
|
|
assert(bs->file == NULL);
|
|
assert(options != NULL && bs->options != options);
|
|
|
|
if (file != NULL) {
|
|
filename = file->filename;
|
|
} else {
|
|
filename = qdict_get_try_str(options, "filename");
|
|
}
|
|
|
|
if (drv->bdrv_needs_filename && !filename) {
|
|
error_setg(errp, "The '%s' block driver requires a file name",
|
|
drv->format_name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name);
|
|
|
|
node_name = qdict_get_try_str(options, "node-name");
|
|
bdrv_assign_node_name(bs, node_name, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
qdict_del(options, "node-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->guest_block_size = 512;
|
|
bs->request_alignment = 512;
|
|
bs->zero_beyond_eof = true;
|
|
open_flags = bdrv_open_flags(bs, flags);
|
|
bs->read_only = !(open_flags & BDRV_O_RDWR);
|
|
|
|
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
|
|
error_setg(errp,
|
|
!bs->read_only && bdrv_is_whitelisted(drv, true)
|
|
? "Driver '%s' can only be used for read-only devices"
|
|
: "Driver '%s' is not whitelisted",
|
|
drv->format_name);
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */
|
|
if (flags & BDRV_O_COPY_ON_READ) {
|
|
if (!bs->read_only) {
|
|
bdrv_enable_copy_on_read(bs);
|
|
} else {
|
|
error_setg(errp, "Can't use copy-on-read on read-only device");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
if (filename != NULL) {
|
|
pstrcpy(bs->filename, sizeof(bs->filename), filename);
|
|
} else {
|
|
bs->filename[0] = '\0';
|
|
}
|
|
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
|
|
|
|
bs->drv = drv;
|
|
bs->opaque = g_malloc0(drv->instance_size);
|
|
|
|
bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB);
|
|
|
|
/* Open the image, either directly or using a protocol */
|
|
if (drv->bdrv_file_open) {
|
|
assert(file == NULL);
|
|
assert(!drv->bdrv_needs_filename || filename != NULL);
|
|
ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
|
|
} else {
|
|
if (file == NULL) {
|
|
error_setg(errp, "Can't use '%s' as a block driver for the "
|
|
"protocol level", drv->format_name);
|
|
ret = -EINVAL;
|
|
goto free_and_fail;
|
|
}
|
|
bs->file = file;
|
|
ret = drv->bdrv_open(bs, options, open_flags, &local_err);
|
|
}
|
|
|
|
if (ret < 0) {
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
} else if (bs->filename[0]) {
|
|
error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
|
|
} else {
|
|
error_setg_errno(errp, -ret, "Could not open image");
|
|
}
|
|
goto free_and_fail;
|
|
}
|
|
|
|
ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
|
goto free_and_fail;
|
|
}
|
|
|
|
bdrv_refresh_limits(bs, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto free_and_fail;
|
|
}
|
|
|
|
assert(bdrv_opt_mem_align(bs) != 0);
|
|
assert((bs->request_alignment != 0) || bs->sg);
|
|
return 0;
|
|
|
|
free_and_fail:
|
|
bs->file = NULL;
|
|
g_free(bs->opaque);
|
|
bs->opaque = NULL;
|
|
bs->drv = NULL;
|
|
return ret;
|
|
}
|
|
|
|
static QDict *parse_json_filename(const char *filename, Error **errp)
|
|
{
|
|
QObject *options_obj;
|
|
QDict *options;
|
|
int ret;
|
|
|
|
ret = strstart(filename, "json:", &filename);
|
|
assert(ret);
|
|
|
|
options_obj = qobject_from_json(filename);
|
|
if (!options_obj) {
|
|
error_setg(errp, "Could not parse the JSON options");
|
|
return NULL;
|
|
}
|
|
|
|
if (qobject_type(options_obj) != QTYPE_QDICT) {
|
|
qobject_decref(options_obj);
|
|
error_setg(errp, "Invalid JSON object given");
|
|
return NULL;
|
|
}
|
|
|
|
options = qobject_to_qdict(options_obj);
|
|
qdict_flatten(options);
|
|
|
|
return options;
|
|
}
|
|
|
|
/*
|
|
* Fills in default options for opening images and converts the legacy
|
|
* filename/flags pair to option QDict entries.
|
|
*/
|
|
static int bdrv_fill_options(QDict **options, const char **pfilename, int flags,
|
|
BlockDriver *drv, Error **errp)
|
|
{
|
|
const char *filename = *pfilename;
|
|
const char *drvname;
|
|
bool protocol = flags & BDRV_O_PROTOCOL;
|
|
bool parse_filename = false;
|
|
Error *local_err = NULL;
|
|
|
|
/* Parse json: pseudo-protocol */
|
|
if (filename && g_str_has_prefix(filename, "json:")) {
|
|
QDict *json_options = parse_json_filename(filename, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Options given in the filename have lower priority than options
|
|
* specified directly */
|
|
qdict_join(*options, json_options, false);
|
|
QDECREF(json_options);
|
|
*pfilename = filename = NULL;
|
|
}
|
|
|
|
/* Fetch the file name from the options QDict if necessary */
|
|
if (protocol && filename) {
|
|
if (!qdict_haskey(*options, "filename")) {
|
|
qdict_put(*options, "filename", qstring_from_str(filename));
|
|
parse_filename = true;
|
|
} else {
|
|
error_setg(errp, "Can't specify 'file' and 'filename' options at "
|
|
"the same time");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Find the right block driver */
|
|
filename = qdict_get_try_str(*options, "filename");
|
|
drvname = qdict_get_try_str(*options, "driver");
|
|
|
|
if (drv) {
|
|
if (drvname) {
|
|
error_setg(errp, "Driver specified twice");
|
|
return -EINVAL;
|
|
}
|
|
drvname = drv->format_name;
|
|
qdict_put(*options, "driver", qstring_from_str(drvname));
|
|
} else {
|
|
if (!drvname && protocol) {
|
|
if (filename) {
|
|
drv = bdrv_find_protocol(filename, parse_filename, errp);
|
|
if (!drv) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
drvname = drv->format_name;
|
|
qdict_put(*options, "driver", qstring_from_str(drvname));
|
|
} else {
|
|
error_setg(errp, "Must specify either driver or file");
|
|
return -EINVAL;
|
|
}
|
|
} else if (drvname) {
|
|
drv = bdrv_find_format(drvname);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown driver '%s'", drvname);
|
|
return -ENOENT;
|
|
}
|
|
}
|
|
}
|
|
|
|
assert(drv || !protocol);
|
|
|
|
/* Driver-specific filename parsing */
|
|
if (drv && drv->bdrv_parse_filename && parse_filename) {
|
|
drv->bdrv_parse_filename(filename, *options, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!drv->bdrv_needs_filename) {
|
|
qdict_del(*options, "filename");
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd)
|
|
{
|
|
|
|
if (bs->backing_hd) {
|
|
assert(bs->backing_blocker);
|
|
bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker);
|
|
} else if (backing_hd) {
|
|
error_setg(&bs->backing_blocker,
|
|
"device is used as backing hd of '%s'",
|
|
bdrv_get_device_name(bs));
|
|
}
|
|
|
|
bs->backing_hd = backing_hd;
|
|
if (!backing_hd) {
|
|
error_free(bs->backing_blocker);
|
|
bs->backing_blocker = NULL;
|
|
goto out;
|
|
}
|
|
bs->open_flags &= ~BDRV_O_NO_BACKING;
|
|
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename);
|
|
pstrcpy(bs->backing_format, sizeof(bs->backing_format),
|
|
backing_hd->drv ? backing_hd->drv->format_name : "");
|
|
|
|
bdrv_op_block_all(bs->backing_hd, bs->backing_blocker);
|
|
/* Otherwise we won't be able to commit due to check in bdrv_commit */
|
|
bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
|
|
bs->backing_blocker);
|
|
out:
|
|
bdrv_refresh_limits(bs, NULL);
|
|
}
|
|
|
|
/*
|
|
* Opens the backing file for a BlockDriverState if not yet open
|
|
*
|
|
* options is a QDict of options to pass to the block drivers, or NULL for an
|
|
* empty set of options. The reference to the QDict is transferred to this
|
|
* function (even on failure), so if the caller intends to reuse the dictionary,
|
|
* it needs to use QINCREF() before calling bdrv_file_open.
|
|
*/
|
|
int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp)
|
|
{
|
|
char *backing_filename = g_malloc0(PATH_MAX);
|
|
int ret = 0;
|
|
BlockDriverState *backing_hd;
|
|
Error *local_err = NULL;
|
|
|
|
if (bs->backing_hd != NULL) {
|
|
QDECREF(options);
|
|
goto free_exit;
|
|
}
|
|
|
|
/* NULL means an empty set of options */
|
|
if (options == NULL) {
|
|
options = qdict_new();
|
|
}
|
|
|
|
bs->open_flags &= ~BDRV_O_NO_BACKING;
|
|
if (qdict_haskey(options, "file.filename")) {
|
|
backing_filename[0] = '\0';
|
|
} else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
|
|
QDECREF(options);
|
|
goto free_exit;
|
|
} else {
|
|
bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -EINVAL;
|
|
error_propagate(errp, local_err);
|
|
QDECREF(options);
|
|
goto free_exit;
|
|
}
|
|
}
|
|
|
|
if (!bs->drv || !bs->drv->supports_backing) {
|
|
ret = -EINVAL;
|
|
error_setg(errp, "Driver doesn't support backing files");
|
|
QDECREF(options);
|
|
goto free_exit;
|
|
}
|
|
|
|
backing_hd = bdrv_new();
|
|
|
|
if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
|
|
qdict_put(options, "driver", qstring_from_str(bs->backing_format));
|
|
}
|
|
|
|
assert(bs->backing_hd == NULL);
|
|
ret = bdrv_open(&backing_hd,
|
|
*backing_filename ? backing_filename : NULL, NULL, options,
|
|
bdrv_backing_flags(bs->open_flags), NULL, &local_err);
|
|
if (ret < 0) {
|
|
bdrv_unref(backing_hd);
|
|
backing_hd = NULL;
|
|
bs->open_flags |= BDRV_O_NO_BACKING;
|
|
error_setg(errp, "Could not open backing file: %s",
|
|
error_get_pretty(local_err));
|
|
error_free(local_err);
|
|
goto free_exit;
|
|
}
|
|
bdrv_set_backing_hd(bs, backing_hd);
|
|
|
|
free_exit:
|
|
g_free(backing_filename);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Opens a disk image whose options are given as BlockdevRef in another block
|
|
* device's options.
|
|
*
|
|
* If allow_none is true, no image will be opened if filename is false and no
|
|
* BlockdevRef is given. *pbs will remain unchanged and 0 will be returned.
|
|
*
|
|
* bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
|
|
* That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
|
|
* itself, all options starting with "${bdref_key}." are considered part of the
|
|
* BlockdevRef.
|
|
*
|
|
* The BlockdevRef will be removed from the options QDict.
|
|
*
|
|
* To conform with the behavior of bdrv_open(), *pbs has to be NULL.
|
|
*/
|
|
int bdrv_open_image(BlockDriverState **pbs, const char *filename,
|
|
QDict *options, const char *bdref_key, int flags,
|
|
bool allow_none, Error **errp)
|
|
{
|
|
QDict *image_options;
|
|
int ret;
|
|
char *bdref_key_dot;
|
|
const char *reference;
|
|
|
|
assert(pbs);
|
|
assert(*pbs == NULL);
|
|
|
|
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
|
|
qdict_extract_subqdict(options, &image_options, bdref_key_dot);
|
|
g_free(bdref_key_dot);
|
|
|
|
reference = qdict_get_try_str(options, bdref_key);
|
|
if (!filename && !reference && !qdict_size(image_options)) {
|
|
if (allow_none) {
|
|
ret = 0;
|
|
} else {
|
|
error_setg(errp, "A block device must be specified for \"%s\"",
|
|
bdref_key);
|
|
ret = -EINVAL;
|
|
}
|
|
QDECREF(image_options);
|
|
goto done;
|
|
}
|
|
|
|
ret = bdrv_open(pbs, filename, reference, image_options, flags, NULL, errp);
|
|
|
|
done:
|
|
qdict_del(options, bdref_key);
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp)
|
|
{
|
|
/* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
|
|
char *tmp_filename = g_malloc0(PATH_MAX + 1);
|
|
int64_t total_size;
|
|
QemuOpts *opts = NULL;
|
|
QDict *snapshot_options;
|
|
BlockDriverState *bs_snapshot;
|
|
Error *local_err;
|
|
int ret;
|
|
|
|
/* if snapshot, we create a temporary backing file and open it
|
|
instead of opening 'filename' directly */
|
|
|
|
/* Get the required size from the image */
|
|
total_size = bdrv_getlength(bs);
|
|
if (total_size < 0) {
|
|
ret = total_size;
|
|
error_setg_errno(errp, -total_size, "Could not get image size");
|
|
goto out;
|
|
}
|
|
|
|
/* Create the temporary image */
|
|
ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not get temporary filename");
|
|
goto out;
|
|
}
|
|
|
|
opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0,
|
|
&error_abort);
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
|
|
ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, &local_err);
|
|
qemu_opts_del(opts);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not create temporary overlay "
|
|
"'%s': %s", tmp_filename,
|
|
error_get_pretty(local_err));
|
|
error_free(local_err);
|
|
goto out;
|
|
}
|
|
|
|
/* Prepare a new options QDict for the temporary file */
|
|
snapshot_options = qdict_new();
|
|
qdict_put(snapshot_options, "file.driver",
|
|
qstring_from_str("file"));
|
|
qdict_put(snapshot_options, "file.filename",
|
|
qstring_from_str(tmp_filename));
|
|
|
|
bs_snapshot = bdrv_new();
|
|
|
|
ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options,
|
|
flags, &bdrv_qcow2, &local_err);
|
|
if (ret < 0) {
|
|
error_propagate(errp, local_err);
|
|
goto out;
|
|
}
|
|
|
|
bdrv_append(bs_snapshot, bs);
|
|
|
|
out:
|
|
g_free(tmp_filename);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Opens a disk image (raw, qcow2, vmdk, ...)
|
|
*
|
|
* options is a QDict of options to pass to the block drivers, or NULL for an
|
|
* empty set of options. The reference to the QDict belongs to the block layer
|
|
* after the call (even on failure), so if the caller intends to reuse the
|
|
* dictionary, it needs to use QINCREF() before calling bdrv_open.
|
|
*
|
|
* If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
|
|
* If it is not NULL, the referenced BDS will be reused.
|
|
*
|
|
* The reference parameter may be used to specify an existing block device which
|
|
* should be opened. If specified, neither options nor a filename may be given,
|
|
* nor can an existing BDS be reused (that is, *pbs has to be NULL).
|
|
*/
|
|
int bdrv_open(BlockDriverState **pbs, const char *filename,
|
|
const char *reference, QDict *options, int flags,
|
|
BlockDriver *drv, Error **errp)
|
|
{
|
|
int ret;
|
|
BlockDriverState *file = NULL, *bs;
|
|
const char *drvname;
|
|
Error *local_err = NULL;
|
|
int snapshot_flags = 0;
|
|
|
|
assert(pbs);
|
|
|
|
if (reference) {
|
|
bool options_non_empty = options ? qdict_size(options) : false;
|
|
QDECREF(options);
|
|
|
|
if (*pbs) {
|
|
error_setg(errp, "Cannot reuse an existing BDS when referencing "
|
|
"another block device");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (filename || options_non_empty) {
|
|
error_setg(errp, "Cannot reference an existing block device with "
|
|
"additional options or a new filename");
|
|
return -EINVAL;
|
|
}
|
|
|
|
bs = bdrv_lookup_bs(reference, reference, errp);
|
|
if (!bs) {
|
|
return -ENODEV;
|
|
}
|
|
bdrv_ref(bs);
|
|
*pbs = bs;
|
|
return 0;
|
|
}
|
|
|
|
if (*pbs) {
|
|
bs = *pbs;
|
|
} else {
|
|
bs = bdrv_new();
|
|
}
|
|
|
|
/* NULL means an empty set of options */
|
|
if (options == NULL) {
|
|
options = qdict_new();
|
|
}
|
|
|
|
ret = bdrv_fill_options(&options, &filename, flags, drv, &local_err);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
|
|
/* Find the right image format driver */
|
|
drv = NULL;
|
|
drvname = qdict_get_try_str(options, "driver");
|
|
if (drvname) {
|
|
drv = bdrv_find_format(drvname);
|
|
qdict_del(options, "driver");
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown driver: '%s'", drvname);
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
assert(drvname || !(flags & BDRV_O_PROTOCOL));
|
|
if (drv && !drv->bdrv_file_open) {
|
|
/* If the user explicitly wants a format driver here, we'll need to add
|
|
* another layer for the protocol in bs->file */
|
|
flags &= ~BDRV_O_PROTOCOL;
|
|
}
|
|
|
|
bs->options = options;
|
|
options = qdict_clone_shallow(options);
|
|
|
|
/* Open image file without format layer */
|
|
if ((flags & BDRV_O_PROTOCOL) == 0) {
|
|
if (flags & BDRV_O_RDWR) {
|
|
flags |= BDRV_O_ALLOW_RDWR;
|
|
}
|
|
if (flags & BDRV_O_SNAPSHOT) {
|
|
snapshot_flags = bdrv_temp_snapshot_flags(flags);
|
|
flags = bdrv_backing_flags(flags);
|
|
}
|
|
|
|
assert(file == NULL);
|
|
ret = bdrv_open_image(&file, filename, options, "file",
|
|
bdrv_inherited_flags(flags),
|
|
true, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
/* Image format probing */
|
|
bs->probed = !drv;
|
|
if (!drv && file) {
|
|
ret = find_image_format(file, filename, &drv, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
} else if (!drv) {
|
|
error_setg(errp, "Must specify either driver or file");
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
/* Open the image */
|
|
ret = bdrv_open_common(bs, file, options, flags, drv, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
if (file && (bs->file != file)) {
|
|
bdrv_unref(file);
|
|
file = NULL;
|
|
}
|
|
|
|
/* If there is a backing file, use it */
|
|
if ((flags & BDRV_O_NO_BACKING) == 0) {
|
|
QDict *backing_options;
|
|
|
|
qdict_extract_subqdict(options, &backing_options, "backing.");
|
|
ret = bdrv_open_backing_file(bs, backing_options, &local_err);
|
|
if (ret < 0) {
|
|
goto close_and_fail;
|
|
}
|
|
}
|
|
|
|
bdrv_refresh_filename(bs);
|
|
|
|
/* For snapshot=on, create a temporary qcow2 overlay. bs points to the
|
|
* temporary snapshot afterwards. */
|
|
if (snapshot_flags) {
|
|
ret = bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err);
|
|
if (local_err) {
|
|
goto close_and_fail;
|
|
}
|
|
}
|
|
|
|
/* Check if any unknown options were used */
|
|
if (options && (qdict_size(options) != 0)) {
|
|
const QDictEntry *entry = qdict_first(options);
|
|
if (flags & BDRV_O_PROTOCOL) {
|
|
error_setg(errp, "Block protocol '%s' doesn't support the option "
|
|
"'%s'", drv->format_name, entry->key);
|
|
} else {
|
|
error_setg(errp, "Block format '%s' used by device '%s' doesn't "
|
|
"support the option '%s'", drv->format_name,
|
|
bdrv_get_device_name(bs), entry->key);
|
|
}
|
|
|
|
ret = -EINVAL;
|
|
goto close_and_fail;
|
|
}
|
|
|
|
if (!bdrv_key_required(bs)) {
|
|
if (bs->blk) {
|
|
blk_dev_change_media_cb(bs->blk, true);
|
|
}
|
|
} else if (!runstate_check(RUN_STATE_PRELAUNCH)
|
|
&& !runstate_check(RUN_STATE_INMIGRATE)
|
|
&& !runstate_check(RUN_STATE_PAUSED)) { /* HACK */
|
|
error_setg(errp,
|
|
"Guest must be stopped for opening of encrypted image");
|
|
ret = -EBUSY;
|
|
goto close_and_fail;
|
|
}
|
|
|
|
QDECREF(options);
|
|
*pbs = bs;
|
|
return 0;
|
|
|
|
fail:
|
|
if (file != NULL) {
|
|
bdrv_unref(file);
|
|
}
|
|
QDECREF(bs->options);
|
|
QDECREF(options);
|
|
bs->options = NULL;
|
|
if (!*pbs) {
|
|
/* If *pbs is NULL, a new BDS has been created in this function and
|
|
needs to be freed now. Otherwise, it does not need to be closed,
|
|
since it has not really been opened yet. */
|
|
bdrv_unref(bs);
|
|
}
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
}
|
|
return ret;
|
|
|
|
close_and_fail:
|
|
/* See fail path, but now the BDS has to be always closed */
|
|
if (*pbs) {
|
|
bdrv_close(bs);
|
|
} else {
|
|
bdrv_unref(bs);
|
|
}
|
|
QDECREF(options);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/* bdrv_open() masks this flag out */
|
|
flags &= ~BDRV_O_PROTOCOL;
|
|
|
|
if (bs->file) {
|
|
bdrv_reopen_queue(bs_queue, bs->file, bdrv_inherited_flags(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,
|
|
bdrv_get_device_name(reopen_state->bs));
|
|
goto error;
|
|
}
|
|
|
|
|
|
ret = bdrv_flush(reopen_state->bs);
|
|
if (ret) {
|
|
error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive",
|
|
strerror(-ret));
|
|
goto error;
|
|
}
|
|
|
|
if (drv->bdrv_reopen_prepare) {
|
|
ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
|
|
if (ret) {
|
|
if (local_err != NULL) {
|
|
error_propagate(errp, local_err);
|
|
} else {
|
|
error_setg(errp, "failed while preparing to reopen image '%s'",
|
|
reopen_state->bs->filename);
|
|
}
|
|
goto error;
|
|
}
|
|
} else {
|
|
/* It is currently mandatory to have a bdrv_reopen_prepare()
|
|
* handler for each supported drv. */
|
|
error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
|
|
drv->format_name, bdrv_get_device_name(reopen_state->bs),
|
|
"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);
|
|
|
|
bdrv_refresh_limits(reopen_state->bs, NULL);
|
|
}
|
|
|
|
/*
|
|
* Abort the reopen, and delete and free the staged changes in
|
|
* reopen_state
|
|
*/
|
|
void bdrv_reopen_abort(BDRVReopenState *reopen_state)
|
|
{
|
|
BlockDriver *drv;
|
|
|
|
assert(reopen_state != NULL);
|
|
drv = reopen_state->bs->drv;
|
|
assert(drv != NULL);
|
|
|
|
if (drv->bdrv_reopen_abort) {
|
|
drv->bdrv_reopen_abort(reopen_state);
|
|
}
|
|
}
|
|
|
|
|
|
void bdrv_close(BlockDriverState *bs)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_next;
|
|
|
|
if (bs->job) {
|
|
block_job_cancel_sync(bs->job);
|
|
}
|
|
bdrv_drain_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) {
|
|
BlockDriverState *backing_hd = bs->backing_hd;
|
|
bdrv_set_backing_hd(bs, NULL);
|
|
bdrv_unref(backing_hd);
|
|
}
|
|
bs->drv->bdrv_close(bs);
|
|
g_free(bs->opaque);
|
|
bs->opaque = NULL;
|
|
bs->drv = NULL;
|
|
bs->copy_on_read = 0;
|
|
bs->backing_file[0] = '\0';
|
|
bs->backing_format[0] = '\0';
|
|
bs->total_sectors = 0;
|
|
bs->encrypted = 0;
|
|
bs->valid_key = 0;
|
|
bs->sg = 0;
|
|
bs->zero_beyond_eof = false;
|
|
QDECREF(bs->options);
|
|
bs->options = NULL;
|
|
QDECREF(bs->full_open_options);
|
|
bs->full_open_options = NULL;
|
|
|
|
if (bs->file != NULL) {
|
|
bdrv_unref(bs->file);
|
|
bs->file = NULL;
|
|
}
|
|
}
|
|
|
|
if (bs->blk) {
|
|
blk_dev_change_media_cb(bs->blk, false);
|
|
}
|
|
|
|
/*throttling disk I/O limits*/
|
|
if (bs->io_limits_enabled) {
|
|
bdrv_io_limits_disable(bs);
|
|
}
|
|
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
|
|
g_free(ban);
|
|
}
|
|
QLIST_INIT(&bs->aio_notifiers);
|
|
}
|
|
|
|
void bdrv_close_all(void)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
aio_context_acquire(aio_context);
|
|
bdrv_close(bs);
|
|
aio_context_release(aio_context);
|
|
}
|
|
}
|
|
|
|
/* Check if any requests are in-flight (including throttled requests) */
|
|
static bool bdrv_requests_pending(BlockDriverState *bs)
|
|
{
|
|
if (!QLIST_EMPTY(&bs->tracked_requests)) {
|
|
return true;
|
|
}
|
|
if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) {
|
|
return true;
|
|
}
|
|
if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) {
|
|
return true;
|
|
}
|
|
if (bs->file && bdrv_requests_pending(bs->file)) {
|
|
return true;
|
|
}
|
|
if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) {
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool bdrv_drain_one(BlockDriverState *bs)
|
|
{
|
|
bool bs_busy;
|
|
|
|
bdrv_flush_io_queue(bs);
|
|
bdrv_start_throttled_reqs(bs);
|
|
bs_busy = bdrv_requests_pending(bs);
|
|
bs_busy |= aio_poll(bdrv_get_aio_context(bs), bs_busy);
|
|
return bs_busy;
|
|
}
|
|
|
|
/*
|
|
* Wait for pending requests to complete on a single BlockDriverState subtree
|
|
*
|
|
* See the warning in bdrv_drain_all(). This function can only be called if
|
|
* you are sure nothing can generate I/O because you have op blockers
|
|
* installed.
|
|
*
|
|
* Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState
|
|
* AioContext.
|
|
*/
|
|
void bdrv_drain(BlockDriverState *bs)
|
|
{
|
|
while (bdrv_drain_one(bs)) {
|
|
/* Keep iterating */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
/* Always run first iteration so any pending completion BHs run */
|
|
bool busy = true;
|
|
BlockDriverState *bs;
|
|
|
|
while (busy) {
|
|
busy = false;
|
|
|
|
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
aio_context_acquire(aio_context);
|
|
busy |= bdrv_drain_one(bs);
|
|
aio_context_release(aio_context);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* make a BlockDriverState anonymous by removing from bdrv_state and
|
|
* graph_bdrv_state list.
|
|
Also, NULL terminate the device_name to prevent double remove */
|
|
void bdrv_make_anon(BlockDriverState *bs)
|
|
{
|
|
/*
|
|
* Take care to remove bs from bdrv_states only when it's actually
|
|
* in it. Note that bs->device_list.tqe_prev is initially null,
|
|
* and gets set to non-null by QTAILQ_INSERT_TAIL(). Establish
|
|
* the useful invariant "bs in bdrv_states iff bs->tqe_prev" by
|
|
* resetting it to null on remove.
|
|
*/
|
|
if (bs->device_list.tqe_prev) {
|
|
QTAILQ_REMOVE(&bdrv_states, bs, device_list);
|
|
bs->device_list.tqe_prev = NULL;
|
|
}
|
|
if (bs->node_name[0] != '\0') {
|
|
QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
|
|
}
|
|
bs->node_name[0] = '\0';
|
|
}
|
|
|
|
static void bdrv_rebind(BlockDriverState *bs)
|
|
{
|
|
if (bs->drv && bs->drv->bdrv_rebind) {
|
|
bs->drv->bdrv_rebind(bs);
|
|
}
|
|
}
|
|
|
|
static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
|
|
BlockDriverState *bs_src)
|
|
{
|
|
/* move some fields that need to stay attached to the device */
|
|
|
|
/* dev info */
|
|
bs_dest->guest_block_size = bs_src->guest_block_size;
|
|
bs_dest->copy_on_read = bs_src->copy_on_read;
|
|
|
|
bs_dest->enable_write_cache = bs_src->enable_write_cache;
|
|
|
|
/* i/o throttled req */
|
|
memcpy(&bs_dest->throttle_state,
|
|
&bs_src->throttle_state,
|
|
sizeof(ThrottleState));
|
|
bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0];
|
|
bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1];
|
|
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_bitmaps = bs_src->dirty_bitmaps;
|
|
|
|
/* reference count */
|
|
bs_dest->refcnt = bs_src->refcnt;
|
|
|
|
/* job */
|
|
bs_dest->job = bs_src->job;
|
|
|
|
/* keep the same entry in bdrv_states */
|
|
bs_dest->device_list = bs_src->device_list;
|
|
bs_dest->blk = bs_src->blk;
|
|
|
|
memcpy(bs_dest->op_blockers, bs_src->op_blockers,
|
|
sizeof(bs_dest->op_blockers));
|
|
}
|
|
|
|
/*
|
|
* Swap bs contents for two image chains while they are live,
|
|
* while keeping required fields on the BlockDriverState that is
|
|
* actually attached to a device.
|
|
*
|
|
* This will modify the BlockDriverState fields, and swap contents
|
|
* between bs_new and bs_old. Both bs_new and bs_old are modified.
|
|
*
|
|
* bs_new must not be attached to a BlockBackend.
|
|
*
|
|
* This function does not create any image files.
|
|
*/
|
|
void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old)
|
|
{
|
|
BlockDriverState tmp;
|
|
|
|
/* The code needs to swap the node_name but simply swapping node_list won't
|
|
* work so first remove the nodes from the graph list, do the swap then
|
|
* insert them back if needed.
|
|
*/
|
|
if (bs_new->node_name[0] != '\0') {
|
|
QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list);
|
|
}
|
|
if (bs_old->node_name[0] != '\0') {
|
|
QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list);
|
|
}
|
|
|
|
/* bs_new must be unattached and shouldn't have anything fancy enabled */
|
|
assert(!bs_new->blk);
|
|
assert(QLIST_EMPTY(&bs_new->dirty_bitmaps));
|
|
assert(bs_new->job == NULL);
|
|
assert(bs_new->io_limits_enabled == false);
|
|
assert(!throttle_have_timer(&bs_new->throttle_state));
|
|
|
|
tmp = *bs_new;
|
|
*bs_new = *bs_old;
|
|
*bs_old = tmp;
|
|
|
|
/* there are some fields that should not be swapped, move them back */
|
|
bdrv_move_feature_fields(&tmp, bs_old);
|
|
bdrv_move_feature_fields(bs_old, bs_new);
|
|
bdrv_move_feature_fields(bs_new, &tmp);
|
|
|
|
/* bs_new must remain unattached */
|
|
assert(!bs_new->blk);
|
|
|
|
/* Check a few fields that should remain attached to the device */
|
|
assert(bs_new->job == NULL);
|
|
assert(bs_new->io_limits_enabled == false);
|
|
assert(!throttle_have_timer(&bs_new->throttle_state));
|
|
|
|
/* insert the nodes back into the graph node list if needed */
|
|
if (bs_new->node_name[0] != '\0') {
|
|
QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list);
|
|
}
|
|
if (bs_old->node_name[0] != '\0') {
|
|
QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list);
|
|
}
|
|
|
|
bdrv_rebind(bs_new);
|
|
bdrv_rebind(bs_old);
|
|
}
|
|
|
|
/*
|
|
* Add new bs contents at the top of an image chain while the chain is
|
|
* live, while keeping required fields on the top layer.
|
|
*
|
|
* This will modify the BlockDriverState fields, and swap contents
|
|
* between bs_new and bs_top. Both bs_new and bs_top are modified.
|
|
*
|
|
* bs_new must not be attached to a BlockBackend.
|
|
*
|
|
* This function does not create any image files.
|
|
*/
|
|
void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top)
|
|
{
|
|
bdrv_swap(bs_new, bs_top);
|
|
|
|
/* The contents of 'tmp' will become bs_top, as we are
|
|
* swapping bs_new and bs_top contents. */
|
|
bdrv_set_backing_hd(bs_top, bs_new);
|
|
}
|
|
|
|
static void bdrv_delete(BlockDriverState *bs)
|
|
{
|
|
assert(!bs->job);
|
|
assert(bdrv_op_blocker_is_empty(bs));
|
|
assert(!bs->refcnt);
|
|
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
|
|
|
|
bdrv_close(bs);
|
|
|
|
/* remove from list, if necessary */
|
|
bdrv_make_anon(bs);
|
|
|
|
g_free(bs);
|
|
}
|
|
|
|
/*
|
|
* Run consistency checks on an image
|
|
*
|
|
* Returns 0 if the check could be completed (it doesn't mean that the image is
|
|
* free of errors) or -errno when an internal error occurred. The results of the
|
|
* check are stored in res.
|
|
*/
|
|
int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
|
|
{
|
|
if (bs->drv == NULL) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (bs->drv->bdrv_check == NULL) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
memset(res, 0, sizeof(*res));
|
|
return bs->drv->bdrv_check(bs, res, fix);
|
|
}
|
|
|
|
#define COMMIT_BUF_SECTORS 2048
|
|
|
|
/* commit COW file into the raw image */
|
|
int bdrv_commit(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int64_t sector, total_sectors, length, backing_length;
|
|
int n, ro, open_flags;
|
|
int ret = 0;
|
|
uint8_t *buf = NULL;
|
|
|
|
if (!drv)
|
|
return -ENOMEDIUM;
|
|
|
|
if (!bs->backing_hd) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT_SOURCE, NULL) ||
|
|
bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, NULL)) {
|
|
return -EBUSY;
|
|
}
|
|
|
|
ro = bs->backing_hd->read_only;
|
|
open_flags = bs->backing_hd->open_flags;
|
|
|
|
if (ro) {
|
|
if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) {
|
|
return -EACCES;
|
|
}
|
|
}
|
|
|
|
length = bdrv_getlength(bs);
|
|
if (length < 0) {
|
|
ret = length;
|
|
goto ro_cleanup;
|
|
}
|
|
|
|
backing_length = bdrv_getlength(bs->backing_hd);
|
|
if (backing_length < 0) {
|
|
ret = backing_length;
|
|
goto ro_cleanup;
|
|
}
|
|
|
|
/* If our top snapshot is larger than the backing file image,
|
|
* grow the backing file image if possible. If not possible,
|
|
* we must return an error */
|
|
if (length > backing_length) {
|
|
ret = bdrv_truncate(bs->backing_hd, length);
|
|
if (ret < 0) {
|
|
goto ro_cleanup;
|
|
}
|
|
}
|
|
|
|
total_sectors = length >> BDRV_SECTOR_BITS;
|
|
|
|
/* qemu_try_blockalign() for bs will choose an alignment that works for
|
|
* bs->backing_hd as well, so no need to compare the alignment manually. */
|
|
buf = qemu_try_blockalign(bs, COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE);
|
|
if (buf == NULL) {
|
|
ret = -ENOMEM;
|
|
goto ro_cleanup;
|
|
}
|
|
|
|
for (sector = 0; sector < total_sectors; sector += n) {
|
|
ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n);
|
|
if (ret < 0) {
|
|
goto ro_cleanup;
|
|
}
|
|
if (ret) {
|
|
ret = bdrv_read(bs, sector, buf, n);
|
|
if (ret < 0) {
|
|
goto ro_cleanup;
|
|
}
|
|
|
|
ret = bdrv_write(bs->backing_hd, sector, buf, n);
|
|
if (ret < 0) {
|
|
goto ro_cleanup;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (drv->bdrv_make_empty) {
|
|
ret = drv->bdrv_make_empty(bs);
|
|
if (ret < 0) {
|
|
goto ro_cleanup;
|
|
}
|
|
bdrv_flush(bs);
|
|
}
|
|
|
|
/*
|
|
* Make sure all data we wrote to the backing device is actually
|
|
* stable on disk.
|
|
*/
|
|
if (bs->backing_hd) {
|
|
bdrv_flush(bs->backing_hd);
|
|
}
|
|
|
|
ret = 0;
|
|
ro_cleanup:
|
|
qemu_vfree(buf);
|
|
|
|
if (ro) {
|
|
/* ignoring error return here */
|
|
bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_commit_all(void)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
aio_context_acquire(aio_context);
|
|
if (bs->drv && bs->backing_hd) {
|
|
int ret = bdrv_commit(bs);
|
|
if (ret < 0) {
|
|
aio_context_release(aio_context);
|
|
return ret;
|
|
}
|
|
}
|
|
aio_context_release(aio_context);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
if (req->serialising) {
|
|
req->bs->serialising_in_flight--;
|
|
}
|
|
|
|
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 offset,
|
|
unsigned int bytes, bool is_write)
|
|
{
|
|
*req = (BdrvTrackedRequest){
|
|
.bs = bs,
|
|
.offset = offset,
|
|
.bytes = bytes,
|
|
.is_write = is_write,
|
|
.co = qemu_coroutine_self(),
|
|
.serialising = false,
|
|
.overlap_offset = offset,
|
|
.overlap_bytes = bytes,
|
|
};
|
|
|
|
qemu_co_queue_init(&req->wait_queue);
|
|
|
|
QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
|
|
}
|
|
|
|
static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
|
|
{
|
|
int64_t overlap_offset = req->offset & ~(align - 1);
|
|
unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
|
|
- overlap_offset;
|
|
|
|
if (!req->serialising) {
|
|
req->bs->serialising_in_flight++;
|
|
req->serialising = true;
|
|
}
|
|
|
|
req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
|
|
req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
|
|
}
|
|
|
|
/**
|
|
* 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 int bdrv_get_cluster_size(BlockDriverState *bs)
|
|
{
|
|
BlockDriverInfo bdi;
|
|
int ret;
|
|
|
|
ret = bdrv_get_info(bs, &bdi);
|
|
if (ret < 0 || bdi.cluster_size == 0) {
|
|
return bs->request_alignment;
|
|
} else {
|
|
return bdi.cluster_size;
|
|
}
|
|
}
|
|
|
|
static bool tracked_request_overlaps(BdrvTrackedRequest *req,
|
|
int64_t offset, unsigned int bytes)
|
|
{
|
|
/* aaaa bbbb */
|
|
if (offset >= req->overlap_offset + req->overlap_bytes) {
|
|
return false;
|
|
}
|
|
/* bbbb aaaa */
|
|
if (req->overlap_offset >= offset + bytes) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
|
|
{
|
|
BlockDriverState *bs = self->bs;
|
|
BdrvTrackedRequest *req;
|
|
bool retry;
|
|
bool waited = false;
|
|
|
|
if (!bs->serialising_in_flight) {
|
|
return false;
|
|
}
|
|
|
|
do {
|
|
retry = false;
|
|
QLIST_FOREACH(req, &bs->tracked_requests, list) {
|
|
if (req == self || (!req->serialising && !self->serialising)) {
|
|
continue;
|
|
}
|
|
if (tracked_request_overlaps(req, self->overlap_offset,
|
|
self->overlap_bytes))
|
|
{
|
|
/* 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);
|
|
|
|
/* If the request is already (indirectly) waiting for us, or
|
|
* will wait for us as soon as it wakes up, then just go on
|
|
* (instead of producing a deadlock in the former case). */
|
|
if (!req->waiting_for) {
|
|
self->waiting_for = req;
|
|
qemu_co_queue_wait(&req->wait_queue);
|
|
self->waiting_for = NULL;
|
|
retry = true;
|
|
waited = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
} while (retry);
|
|
|
|
return waited;
|
|
}
|
|
|
|
/*
|
|
* Return values:
|
|
* 0 - success
|
|
* -EINVAL - backing format specified, but no file
|
|
* -ENOSPC - can't update the backing file because no space is left in the
|
|
* image file header
|
|
* -ENOTSUP - format driver doesn't support changing the backing file
|
|
*/
|
|
int bdrv_change_backing_file(BlockDriverState *bs,
|
|
const char *backing_file, const char *backing_fmt)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int ret;
|
|
|
|
/* Backing file format doesn't make sense without a backing file */
|
|
if (backing_fmt && !backing_file) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (drv->bdrv_change_backing_file != NULL) {
|
|
ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
|
|
} else {
|
|
ret = -ENOTSUP;
|
|
}
|
|
|
|
if (ret == 0) {
|
|
pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
|
|
pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Finds the image layer in the chain that has 'bs' as its backing file.
|
|
*
|
|
* active is the current topmost image.
|
|
*
|
|
* Returns NULL if bs is not found in active's image chain,
|
|
* or if active == bs.
|
|
*
|
|
* Returns the bottommost base image if bs == NULL.
|
|
*/
|
|
BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
|
|
BlockDriverState *bs)
|
|
{
|
|
while (active && bs != active->backing_hd) {
|
|
active = active->backing_hd;
|
|
}
|
|
|
|
return active;
|
|
}
|
|
|
|
/* Given a BDS, searches for the base layer. */
|
|
BlockDriverState *bdrv_find_base(BlockDriverState *bs)
|
|
{
|
|
return bdrv_find_overlay(bs, NULL);
|
|
}
|
|
|
|
typedef struct BlkIntermediateStates {
|
|
BlockDriverState *bs;
|
|
QSIMPLEQ_ENTRY(BlkIntermediateStates) entry;
|
|
} BlkIntermediateStates;
|
|
|
|
|
|
/*
|
|
* Drops images above 'base' up to and including 'top', and sets the image
|
|
* above 'top' to have base as its backing file.
|
|
*
|
|
* Requires that the overlay to 'top' is opened r/w, so that the backing file
|
|
* information in 'bs' can be properly updated.
|
|
*
|
|
* E.g., this will convert the following chain:
|
|
* bottom <- base <- intermediate <- top <- active
|
|
*
|
|
* to
|
|
*
|
|
* bottom <- base <- active
|
|
*
|
|
* It is allowed for bottom==base, in which case it converts:
|
|
*
|
|
* base <- intermediate <- top <- active
|
|
*
|
|
* to
|
|
*
|
|
* base <- active
|
|
*
|
|
* If backing_file_str is non-NULL, it will be used when modifying top's
|
|
* overlay image metadata.
|
|
*
|
|
* Error conditions:
|
|
* if active == top, that is considered an error
|
|
*
|
|
*/
|
|
int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
|
|
BlockDriverState *base, const char *backing_file_str)
|
|
{
|
|
BlockDriverState *intermediate;
|
|
BlockDriverState *base_bs = NULL;
|
|
BlockDriverState *new_top_bs = NULL;
|
|
BlkIntermediateStates *intermediate_state, *next;
|
|
int ret = -EIO;
|
|
|
|
QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete;
|
|
QSIMPLEQ_INIT(&states_to_delete);
|
|
|
|
if (!top->drv || !base->drv) {
|
|
goto exit;
|
|
}
|
|
|
|
new_top_bs = bdrv_find_overlay(active, top);
|
|
|
|
if (new_top_bs == NULL) {
|
|
/* we could not find the image above 'top', this is an error */
|
|
goto exit;
|
|
}
|
|
|
|
/* special case of new_top_bs->backing_hd already pointing to base - nothing
|
|
* to do, no intermediate images */
|
|
if (new_top_bs->backing_hd == base) {
|
|
ret = 0;
|
|
goto exit;
|
|
}
|
|
|
|
intermediate = top;
|
|
|
|
/* now we will go down through the list, and add each BDS we find
|
|
* into our deletion queue, until we hit the 'base'
|
|
*/
|
|
while (intermediate) {
|
|
intermediate_state = g_new0(BlkIntermediateStates, 1);
|
|
intermediate_state->bs = intermediate;
|
|
QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry);
|
|
|
|
if (intermediate->backing_hd == base) {
|
|
base_bs = intermediate->backing_hd;
|
|
break;
|
|
}
|
|
intermediate = intermediate->backing_hd;
|
|
}
|
|
if (base_bs == NULL) {
|
|
/* something went wrong, we did not end at the base. safely
|
|
* unravel everything, and exit with error */
|
|
goto exit;
|
|
}
|
|
|
|
/* success - we can delete the intermediate states, and link top->base */
|
|
backing_file_str = backing_file_str ? backing_file_str : base_bs->filename;
|
|
ret = bdrv_change_backing_file(new_top_bs, backing_file_str,
|
|
base_bs->drv ? base_bs->drv->format_name : "");
|
|
if (ret) {
|
|
goto exit;
|
|
}
|
|
bdrv_set_backing_hd(new_top_bs, base_bs);
|
|
|
|
QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
|
|
/* so that bdrv_close() does not recursively close the chain */
|
|
bdrv_set_backing_hd(intermediate_state->bs, NULL);
|
|
bdrv_unref(intermediate_state->bs);
|
|
}
|
|
ret = 0;
|
|
|
|
exit:
|
|
QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
|
|
g_free(intermediate_state);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
|
|
size_t size)
|
|
{
|
|
if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
|
|
return -EIO;
|
|
}
|
|
|
|
if (!bdrv_is_inserted(bs)) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
if (offset < 0) {
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors)
|
|
{
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EIO;
|
|
}
|
|
|
|
return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
|
|
nb_sectors * BDRV_SECTOR_SIZE);
|
|
}
|
|
|
|
typedef struct RwCo {
|
|
BlockDriverState *bs;
|
|
int64_t offset;
|
|
QEMUIOVector *qiov;
|
|
bool is_write;
|
|
int ret;
|
|
BdrvRequestFlags flags;
|
|
} RwCo;
|
|
|
|
static void coroutine_fn bdrv_rw_co_entry(void *opaque)
|
|
{
|
|
RwCo *rwco = opaque;
|
|
|
|
if (!rwco->is_write) {
|
|
rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset,
|
|
rwco->qiov->size, rwco->qiov,
|
|
rwco->flags);
|
|
} else {
|
|
rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset,
|
|
rwco->qiov->size, rwco->qiov,
|
|
rwco->flags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Process a vectored synchronous request using coroutines
|
|
*/
|
|
static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
|
|
QEMUIOVector *qiov, bool is_write,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
Coroutine *co;
|
|
RwCo rwco = {
|
|
.bs = bs,
|
|
.offset = offset,
|
|
.qiov = qiov,
|
|
.is_write = is_write,
|
|
.ret = NOT_DONE,
|
|
.flags = flags,
|
|
};
|
|
|
|
/**
|
|
* 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 {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_rw_co_entry);
|
|
qemu_coroutine_enter(co, &rwco);
|
|
while (rwco.ret == NOT_DONE) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
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, BdrvRequestFlags flags)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *)buf,
|
|
.iov_len = nb_sectors * BDRV_SECTOR_SIZE,
|
|
};
|
|
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS,
|
|
&qiov, is_write, flags);
|
|
}
|
|
|
|
/* 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, 0);
|
|
}
|
|
|
|
/* 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, sector_num, buf, nb_sectors);
|
|
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, 0);
|
|
}
|
|
|
|
int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, BdrvRequestFlags flags)
|
|
{
|
|
return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
|
|
BDRV_REQ_ZERO_WRITE | flags);
|
|
}
|
|
|
|
/*
|
|
* Completely zero out a block device with the help of bdrv_write_zeroes.
|
|
* The operation is sped up by checking the block status and only writing
|
|
* zeroes to the device if they currently do not return zeroes. Optional
|
|
* flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP).
|
|
*
|
|
* Returns < 0 on error, 0 on success. For error codes see bdrv_write().
|
|
*/
|
|
int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
|
|
{
|
|
int64_t target_sectors, ret, nb_sectors, sector_num = 0;
|
|
int n;
|
|
|
|
target_sectors = bdrv_nb_sectors(bs);
|
|
if (target_sectors < 0) {
|
|
return target_sectors;
|
|
}
|
|
|
|
for (;;) {
|
|
nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS);
|
|
if (nb_sectors <= 0) {
|
|
return 0;
|
|
}
|
|
ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n);
|
|
if (ret < 0) {
|
|
error_report("error getting block status at sector %" PRId64 ": %s",
|
|
sector_num, strerror(-ret));
|
|
return ret;
|
|
}
|
|
if (ret & BDRV_BLOCK_ZERO) {
|
|
sector_num += n;
|
|
continue;
|
|
}
|
|
ret = bdrv_write_zeroes(bs, sector_num, n, flags);
|
|
if (ret < 0) {
|
|
error_report("error writing zeroes at sector %" PRId64 ": %s",
|
|
sector_num, strerror(-ret));
|
|
return ret;
|
|
}
|
|
sector_num += n;
|
|
}
|
|
}
|
|
|
|
int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *)buf,
|
|
.iov_len = bytes,
|
|
};
|
|
int ret;
|
|
|
|
if (bytes < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
return bytes;
|
|
}
|
|
|
|
int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
|
|
{
|
|
int ret;
|
|
|
|
ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
return qiov->size;
|
|
}
|
|
|
|
int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
|
|
const void *buf, int bytes)
|
|
{
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {
|
|
.iov_base = (void *) buf,
|
|
.iov_len = bytes,
|
|
};
|
|
|
|
if (bytes < 0) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
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_try_blockalign(bs, iov.iov_len);
|
|
if (bounce_buffer == NULL) {
|
|
ret = -ENOMEM;
|
|
goto err;
|
|
}
|
|
|
|
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, 0);
|
|
} 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;
|
|
}
|
|
|
|
/*
|
|
* Forwards an already correctly aligned request to the BlockDriver. This
|
|
* handles copy on read and zeroing after EOF; any other features must be
|
|
* implemented by the caller.
|
|
*/
|
|
static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
|
|
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
|
|
int64_t align, QEMUIOVector *qiov, int flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int ret;
|
|
|
|
int64_t sector_num = offset >> BDRV_SECTOR_BITS;
|
|
unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
|
|
|
|
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert(!qiov || bytes == qiov->size);
|
|
|
|
/* Handle Copy on Read and associated serialisation */
|
|
if (flags & BDRV_REQ_COPY_ON_READ) {
|
|
/* 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. */
|
|
mark_request_serialising(req, bdrv_get_cluster_size(bs));
|
|
}
|
|
|
|
wait_serialising_requests(req);
|
|
|
|
if (flags & BDRV_REQ_COPY_ON_READ) {
|
|
int pnum;
|
|
|
|
ret = bdrv_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;
|
|
}
|
|
}
|
|
|
|
/* Forward the request to the BlockDriver */
|
|
if (!bs->zero_beyond_eof) {
|
|
ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
|
|
} else {
|
|
/* Read zeros after EOF */
|
|
int64_t total_sectors, max_nb_sectors;
|
|
|
|
total_sectors = bdrv_nb_sectors(bs);
|
|
if (total_sectors < 0) {
|
|
ret = total_sectors;
|
|
goto out;
|
|
}
|
|
|
|
max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
|
|
align >> BDRV_SECTOR_BITS);
|
|
if (nb_sectors < max_nb_sectors) {
|
|
ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
|
|
} else if (max_nb_sectors > 0) {
|
|
QEMUIOVector local_qiov;
|
|
|
|
qemu_iovec_init(&local_qiov, qiov->niov);
|
|
qemu_iovec_concat(&local_qiov, qiov, 0,
|
|
max_nb_sectors * BDRV_SECTOR_SIZE);
|
|
|
|
ret = drv->bdrv_co_readv(bs, sector_num, max_nb_sectors,
|
|
&local_qiov);
|
|
|
|
qemu_iovec_destroy(&local_qiov);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
|
|
/* Reading beyond end of file is supposed to produce zeroes */
|
|
if (ret == 0 && total_sectors < sector_num + nb_sectors) {
|
|
uint64_t offset = MAX(0, total_sectors - sector_num);
|
|
uint64_t bytes = (sector_num + nb_sectors - offset) *
|
|
BDRV_SECTOR_SIZE;
|
|
qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
|
|
}
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Handle a read request in coroutine context
|
|
*/
|
|
static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs,
|
|
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvTrackedRequest req;
|
|
|
|
/* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
|
|
uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
|
|
uint8_t *head_buf = NULL;
|
|
uint8_t *tail_buf = NULL;
|
|
QEMUIOVector local_qiov;
|
|
bool use_local_qiov = false;
|
|
int ret;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
ret = bdrv_check_byte_request(bs, offset, bytes);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (bs->copy_on_read) {
|
|
flags |= BDRV_REQ_COPY_ON_READ;
|
|
}
|
|
|
|
/* throttling disk I/O */
|
|
if (bs->io_limits_enabled) {
|
|
bdrv_io_limits_intercept(bs, bytes, false);
|
|
}
|
|
|
|
/* Align read if necessary by padding qiov */
|
|
if (offset & (align - 1)) {
|
|
head_buf = qemu_blockalign(bs, align);
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 2);
|
|
qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
|
|
bytes += offset & (align - 1);
|
|
offset = offset & ~(align - 1);
|
|
}
|
|
|
|
if ((offset + bytes) & (align - 1)) {
|
|
if (!use_local_qiov) {
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 1);
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
}
|
|
tail_buf = qemu_blockalign(bs, align);
|
|
qemu_iovec_add(&local_qiov, tail_buf,
|
|
align - ((offset + bytes) & (align - 1)));
|
|
|
|
bytes = ROUND_UP(bytes, align);
|
|
}
|
|
|
|
tracked_request_begin(&req, bs, offset, bytes, false);
|
|
ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
|
|
use_local_qiov ? &local_qiov : qiov,
|
|
flags);
|
|
tracked_request_end(&req);
|
|
|
|
if (use_local_qiov) {
|
|
qemu_iovec_destroy(&local_qiov);
|
|
qemu_vfree(head_buf);
|
|
qemu_vfree(tail_buf);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS,
|
|
nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
#define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
|
|
|
|
static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
QEMUIOVector qiov;
|
|
struct iovec iov = {0};
|
|
int ret = 0;
|
|
|
|
int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_write_zeroes,
|
|
BDRV_REQUEST_MAX_SECTORS);
|
|
|
|
while (nb_sectors > 0 && !ret) {
|
|
int num = nb_sectors;
|
|
|
|
/* Align request. Block drivers can expect the "bulk" of the request
|
|
* to be aligned.
|
|
*/
|
|
if (bs->bl.write_zeroes_alignment
|
|
&& num > bs->bl.write_zeroes_alignment) {
|
|
if (sector_num % bs->bl.write_zeroes_alignment != 0) {
|
|
/* Make a small request up to the first aligned sector. */
|
|
num = bs->bl.write_zeroes_alignment;
|
|
num -= sector_num % bs->bl.write_zeroes_alignment;
|
|
} else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) {
|
|
/* Shorten the request to the last aligned sector. num cannot
|
|
* underflow because num > bs->bl.write_zeroes_alignment.
|
|
*/
|
|
num -= (sector_num + num) % bs->bl.write_zeroes_alignment;
|
|
}
|
|
}
|
|
|
|
/* limit request size */
|
|
if (num > max_write_zeroes) {
|
|
num = max_write_zeroes;
|
|
}
|
|
|
|
ret = -ENOTSUP;
|
|
/* First try the efficient write zeroes operation */
|
|
if (drv->bdrv_co_write_zeroes) {
|
|
ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags);
|
|
}
|
|
|
|
if (ret == -ENOTSUP) {
|
|
/* Fall back to bounce buffer if write zeroes is unsupported */
|
|
int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length,
|
|
MAX_WRITE_ZEROES_BOUNCE_BUFFER);
|
|
num = MIN(num, max_xfer_len);
|
|
iov.iov_len = num * BDRV_SECTOR_SIZE;
|
|
if (iov.iov_base == NULL) {
|
|
iov.iov_base = qemu_try_blockalign(bs, num * BDRV_SECTOR_SIZE);
|
|
if (iov.iov_base == NULL) {
|
|
ret = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE);
|
|
}
|
|
qemu_iovec_init_external(&qiov, &iov, 1);
|
|
|
|
ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov);
|
|
|
|
/* Keep bounce buffer around if it is big enough for all
|
|
* all future requests.
|
|
*/
|
|
if (num < max_xfer_len) {
|
|
qemu_vfree(iov.iov_base);
|
|
iov.iov_base = NULL;
|
|
}
|
|
}
|
|
|
|
sector_num += num;
|
|
nb_sectors -= num;
|
|
}
|
|
|
|
fail:
|
|
qemu_vfree(iov.iov_base);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Forwards an already correctly aligned write request to the BlockDriver.
|
|
*/
|
|
static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
|
|
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
|
|
QEMUIOVector *qiov, int flags)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
bool waited;
|
|
int ret;
|
|
|
|
int64_t sector_num = offset >> BDRV_SECTOR_BITS;
|
|
unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
|
|
|
|
assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
|
|
assert(!qiov || bytes == qiov->size);
|
|
|
|
waited = wait_serialising_requests(req);
|
|
assert(!waited || !req->serialising);
|
|
assert(req->overlap_offset <= offset);
|
|
assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
|
|
|
|
ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
|
|
|
|
if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
|
|
!(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes &&
|
|
qemu_iovec_is_zero(qiov)) {
|
|
flags |= BDRV_REQ_ZERO_WRITE;
|
|
if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
|
|
flags |= BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
}
|
|
|
|
if (ret < 0) {
|
|
/* Do nothing, write notifier decided to fail this request */
|
|
} else if (flags & BDRV_REQ_ZERO_WRITE) {
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV_ZERO);
|
|
ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags);
|
|
} else {
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV);
|
|
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
|
|
}
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV_DONE);
|
|
|
|
if (ret == 0 && !bs->enable_write_cache) {
|
|
ret = bdrv_co_flush(bs);
|
|
}
|
|
|
|
bdrv_set_dirty(bs, sector_num, nb_sectors);
|
|
|
|
block_acct_highest_sector(&bs->stats, sector_num, nb_sectors);
|
|
|
|
if (ret >= 0) {
|
|
bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Handle a write request in coroutine context
|
|
*/
|
|
static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
|
|
int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
BdrvTrackedRequest req;
|
|
/* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
|
|
uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
|
|
uint8_t *head_buf = NULL;
|
|
uint8_t *tail_buf = NULL;
|
|
QEMUIOVector local_qiov;
|
|
bool use_local_qiov = false;
|
|
int ret;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (bs->read_only) {
|
|
return -EACCES;
|
|
}
|
|
|
|
ret = bdrv_check_byte_request(bs, offset, bytes);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* throttling disk I/O */
|
|
if (bs->io_limits_enabled) {
|
|
bdrv_io_limits_intercept(bs, bytes, true);
|
|
}
|
|
|
|
/*
|
|
* Align write if necessary by performing a read-modify-write cycle.
|
|
* Pad qiov with the read parts and be sure to have a tracked request not
|
|
* only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
|
|
*/
|
|
tracked_request_begin(&req, bs, offset, bytes, true);
|
|
|
|
if (offset & (align - 1)) {
|
|
QEMUIOVector head_qiov;
|
|
struct iovec head_iov;
|
|
|
|
mark_request_serialising(&req, align);
|
|
wait_serialising_requests(&req);
|
|
|
|
head_buf = qemu_blockalign(bs, align);
|
|
head_iov = (struct iovec) {
|
|
.iov_base = head_buf,
|
|
.iov_len = align,
|
|
};
|
|
qemu_iovec_init_external(&head_qiov, &head_iov, 1);
|
|
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_HEAD);
|
|
ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align,
|
|
align, &head_qiov, 0);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
|
|
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 2);
|
|
qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
|
|
bytes += offset & (align - 1);
|
|
offset = offset & ~(align - 1);
|
|
}
|
|
|
|
if ((offset + bytes) & (align - 1)) {
|
|
QEMUIOVector tail_qiov;
|
|
struct iovec tail_iov;
|
|
size_t tail_bytes;
|
|
bool waited;
|
|
|
|
mark_request_serialising(&req, align);
|
|
waited = wait_serialising_requests(&req);
|
|
assert(!waited || !use_local_qiov);
|
|
|
|
tail_buf = qemu_blockalign(bs, align);
|
|
tail_iov = (struct iovec) {
|
|
.iov_base = tail_buf,
|
|
.iov_len = align,
|
|
};
|
|
qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
|
|
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_TAIL);
|
|
ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align,
|
|
align, &tail_qiov, 0);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
|
|
|
|
if (!use_local_qiov) {
|
|
qemu_iovec_init(&local_qiov, qiov->niov + 1);
|
|
qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
|
|
use_local_qiov = true;
|
|
}
|
|
|
|
tail_bytes = (offset + bytes) & (align - 1);
|
|
qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
|
|
|
|
bytes = ROUND_UP(bytes, align);
|
|
}
|
|
|
|
ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
|
|
use_local_qiov ? &local_qiov : qiov,
|
|
flags);
|
|
|
|
fail:
|
|
tracked_request_end(&req);
|
|
|
|
if (use_local_qiov) {
|
|
qemu_iovec_destroy(&local_qiov);
|
|
}
|
|
qemu_vfree(head_buf);
|
|
qemu_vfree(tail_buf);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
|
|
nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
|
|
}
|
|
|
|
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,
|
|
BdrvRequestFlags flags)
|
|
{
|
|
trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
|
|
|
|
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
|
flags &= ~BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
|
|
return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
|
|
BDRV_REQ_ZERO_WRITE | flags);
|
|
}
|
|
|
|
/**
|
|
* Truncate file to 'offset' bytes (needed only for file protocols)
|
|
*/
|
|
int bdrv_truncate(BlockDriverState *bs, int64_t offset)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
int ret;
|
|
if (!drv)
|
|
return -ENOMEDIUM;
|
|
if (!drv->bdrv_truncate)
|
|
return -ENOTSUP;
|
|
if (bs->read_only)
|
|
return -EACCES;
|
|
|
|
ret = drv->bdrv_truncate(bs, offset);
|
|
if (ret == 0) {
|
|
ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
|
|
if (bs->blk) {
|
|
blk_dev_resize_cb(bs->blk);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* Length of a allocated file in bytes. Sparse files are counted by actual
|
|
* allocated space. Return < 0 if error or unknown.
|
|
*/
|
|
int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (drv->bdrv_get_allocated_file_size) {
|
|
return drv->bdrv_get_allocated_file_size(bs);
|
|
}
|
|
if (bs->file) {
|
|
return bdrv_get_allocated_file_size(bs->file);
|
|
}
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/**
|
|
* Return number of sectors on success, -errno on error.
|
|
*/
|
|
int64_t bdrv_nb_sectors(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv)
|
|
return -ENOMEDIUM;
|
|
|
|
if (drv->has_variable_length) {
|
|
int ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
return bs->total_sectors;
|
|
}
|
|
|
|
/**
|
|
* Return length in bytes on success, -errno on error.
|
|
* The length is always a multiple of BDRV_SECTOR_SIZE.
|
|
*/
|
|
int64_t bdrv_getlength(BlockDriverState *bs)
|
|
{
|
|
int64_t ret = bdrv_nb_sectors(bs);
|
|
|
|
return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
|
|
}
|
|
|
|
/* return 0 as number of sectors if no device present or error */
|
|
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
|
|
{
|
|
int64_t nb_sectors = bdrv_nb_sectors(bs);
|
|
|
|
*nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
|
|
}
|
|
|
|
void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error,
|
|
BlockdevOnError on_write_error)
|
|
{
|
|
bs->on_read_error = on_read_error;
|
|
bs->on_write_error = on_write_error;
|
|
}
|
|
|
|
BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read)
|
|
{
|
|
return is_read ? bs->on_read_error : bs->on_write_error;
|
|
}
|
|
|
|
BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error)
|
|
{
|
|
BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error;
|
|
|
|
switch (on_err) {
|
|
case BLOCKDEV_ON_ERROR_ENOSPC:
|
|
return (error == ENOSPC) ?
|
|
BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT;
|
|
case BLOCKDEV_ON_ERROR_STOP:
|
|
return BLOCK_ERROR_ACTION_STOP;
|
|
case BLOCKDEV_ON_ERROR_REPORT:
|
|
return BLOCK_ERROR_ACTION_REPORT;
|
|
case BLOCKDEV_ON_ERROR_IGNORE:
|
|
return BLOCK_ERROR_ACTION_IGNORE;
|
|
default:
|
|
abort();
|
|
}
|
|
}
|
|
|
|
static void send_qmp_error_event(BlockDriverState *bs,
|
|
BlockErrorAction action,
|
|
bool is_read, int error)
|
|
{
|
|
IoOperationType optype;
|
|
|
|
optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE;
|
|
qapi_event_send_block_io_error(bdrv_get_device_name(bs), optype, action,
|
|
bdrv_iostatus_is_enabled(bs),
|
|
error == ENOSPC, strerror(error),
|
|
&error_abort);
|
|
}
|
|
|
|
/* This is done by device models because, while the block layer knows
|
|
* about the error, it does not know whether an operation comes from
|
|
* the device or the block layer (from a job, for example).
|
|
*/
|
|
void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action,
|
|
bool is_read, int error)
|
|
{
|
|
assert(error >= 0);
|
|
|
|
if (action == BLOCK_ERROR_ACTION_STOP) {
|
|
/* First set the iostatus, so that "info block" returns an iostatus
|
|
* that matches the events raised so far (an additional error iostatus
|
|
* is fine, but not a lost one).
|
|
*/
|
|
bdrv_iostatus_set_err(bs, error);
|
|
|
|
/* Then raise the request to stop the VM and the event.
|
|
* qemu_system_vmstop_request_prepare has two effects. First,
|
|
* it ensures that the STOP event always comes after the
|
|
* BLOCK_IO_ERROR event. Second, it ensures that even if management
|
|
* can observe the STOP event and do a "cont" before the STOP
|
|
* event is issued, the VM will not stop. In this case, vm_start()
|
|
* also ensures that the STOP/RESUME pair of events is emitted.
|
|
*/
|
|
qemu_system_vmstop_request_prepare();
|
|
send_qmp_error_event(bs, action, is_read, error);
|
|
qemu_system_vmstop_request(RUN_STATE_IO_ERROR);
|
|
} else {
|
|
send_qmp_error_event(bs, action, is_read, error);
|
|
}
|
|
}
|
|
|
|
int bdrv_is_read_only(BlockDriverState *bs)
|
|
{
|
|
return bs->read_only;
|
|
}
|
|
|
|
int bdrv_is_sg(BlockDriverState *bs)
|
|
{
|
|
return bs->sg;
|
|
}
|
|
|
|
int bdrv_enable_write_cache(BlockDriverState *bs)
|
|
{
|
|
return bs->enable_write_cache;
|
|
}
|
|
|
|
void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce)
|
|
{
|
|
bs->enable_write_cache = wce;
|
|
|
|
/* so a reopen() will preserve wce */
|
|
if (wce) {
|
|
bs->open_flags |= BDRV_O_CACHE_WB;
|
|
} else {
|
|
bs->open_flags &= ~BDRV_O_CACHE_WB;
|
|
}
|
|
}
|
|
|
|
int bdrv_is_encrypted(BlockDriverState *bs)
|
|
{
|
|
if (bs->backing_hd && bs->backing_hd->encrypted)
|
|
return 1;
|
|
return bs->encrypted;
|
|
}
|
|
|
|
int bdrv_key_required(BlockDriverState *bs)
|
|
{
|
|
BlockDriverState *backing_hd = bs->backing_hd;
|
|
|
|
if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
|
|
return 1;
|
|
return (bs->encrypted && !bs->valid_key);
|
|
}
|
|
|
|
int bdrv_set_key(BlockDriverState *bs, const char *key)
|
|
{
|
|
int ret;
|
|
if (bs->backing_hd && bs->backing_hd->encrypted) {
|
|
ret = bdrv_set_key(bs->backing_hd, key);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (!bs->encrypted)
|
|
return 0;
|
|
}
|
|
if (!bs->encrypted) {
|
|
return -EINVAL;
|
|
} else if (!bs->drv || !bs->drv->bdrv_set_key) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
ret = bs->drv->bdrv_set_key(bs, key);
|
|
if (ret < 0) {
|
|
bs->valid_key = 0;
|
|
} else if (!bs->valid_key) {
|
|
bs->valid_key = 1;
|
|
if (bs->blk) {
|
|
/* call the change callback now, we skipped it on open */
|
|
blk_dev_change_media_cb(bs->blk, true);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Provide an encryption key for @bs.
|
|
* If @key is non-null:
|
|
* If @bs is not encrypted, fail.
|
|
* Else if the key is invalid, fail.
|
|
* Else set @bs's key to @key, replacing the existing key, if any.
|
|
* If @key is null:
|
|
* If @bs is encrypted and still lacks a key, fail.
|
|
* Else do nothing.
|
|
* On failure, store an error object through @errp if non-null.
|
|
*/
|
|
void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp)
|
|
{
|
|
if (key) {
|
|
if (!bdrv_is_encrypted(bs)) {
|
|
error_setg(errp, "Device '%s' is not encrypted",
|
|
bdrv_get_device_name(bs));
|
|
} else if (bdrv_set_key(bs, key) < 0) {
|
|
error_set(errp, QERR_INVALID_PASSWORD);
|
|
}
|
|
} else {
|
|
if (bdrv_key_required(bs)) {
|
|
error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED,
|
|
"'%s' (%s) is encrypted",
|
|
bdrv_get_device_name(bs),
|
|
bdrv_get_encrypted_filename(bs));
|
|
}
|
|
}
|
|
}
|
|
|
|
const char *bdrv_get_format_name(BlockDriverState *bs)
|
|
{
|
|
return bs->drv ? bs->drv->format_name : NULL;
|
|
}
|
|
|
|
static int qsort_strcmp(const void *a, const void *b)
|
|
{
|
|
return strcmp(a, b);
|
|
}
|
|
|
|
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
|
|
void *opaque)
|
|
{
|
|
BlockDriver *drv;
|
|
int count = 0;
|
|
int i;
|
|
const char **formats = NULL;
|
|
|
|
QLIST_FOREACH(drv, &bdrv_drivers, list) {
|
|
if (drv->format_name) {
|
|
bool found = false;
|
|
int i = count;
|
|
while (formats && i && !found) {
|
|
found = !strcmp(formats[--i], drv->format_name);
|
|
}
|
|
|
|
if (!found) {
|
|
formats = g_renew(const char *, formats, count + 1);
|
|
formats[count++] = drv->format_name;
|
|
}
|
|
}
|
|
}
|
|
|
|
qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
|
|
|
|
for (i = 0; i < count; i++) {
|
|
it(opaque, formats[i]);
|
|
}
|
|
|
|
g_free(formats);
|
|
}
|
|
|
|
/* This function is to find block backend bs */
|
|
/* TODO convert callers to blk_by_name(), then remove */
|
|
BlockDriverState *bdrv_find(const char *name)
|
|
{
|
|
BlockBackend *blk = blk_by_name(name);
|
|
|
|
return blk ? blk_bs(blk) : NULL;
|
|
}
|
|
|
|
/* This function is to find a node in the bs graph */
|
|
BlockDriverState *bdrv_find_node(const char *node_name)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
assert(node_name);
|
|
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
if (!strcmp(node_name, bs->node_name)) {
|
|
return bs;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Put this QMP function here so it can access the static graph_bdrv_states. */
|
|
BlockDeviceInfoList *bdrv_named_nodes_list(void)
|
|
{
|
|
BlockDeviceInfoList *list, *entry;
|
|
BlockDriverState *bs;
|
|
|
|
list = NULL;
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
entry = g_malloc0(sizeof(*entry));
|
|
entry->value = bdrv_block_device_info(bs);
|
|
entry->next = list;
|
|
list = entry;
|
|
}
|
|
|
|
return list;
|
|
}
|
|
|
|
BlockDriverState *bdrv_lookup_bs(const char *device,
|
|
const char *node_name,
|
|
Error **errp)
|
|
{
|
|
BlockBackend *blk;
|
|
BlockDriverState *bs;
|
|
|
|
if (device) {
|
|
blk = blk_by_name(device);
|
|
|
|
if (blk) {
|
|
return blk_bs(blk);
|
|
}
|
|
}
|
|
|
|
if (node_name) {
|
|
bs = bdrv_find_node(node_name);
|
|
|
|
if (bs) {
|
|
return bs;
|
|
}
|
|
}
|
|
|
|
error_setg(errp, "Cannot find device=%s nor node_name=%s",
|
|
device ? device : "",
|
|
node_name ? node_name : "");
|
|
return NULL;
|
|
}
|
|
|
|
/* If 'base' is in the same chain as 'top', return true. Otherwise,
|
|
* return false. If either argument is NULL, return false. */
|
|
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
|
|
{
|
|
while (top && top != base) {
|
|
top = top->backing_hd;
|
|
}
|
|
|
|
return top != NULL;
|
|
}
|
|
|
|
BlockDriverState *bdrv_next_node(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return QTAILQ_FIRST(&graph_bdrv_states);
|
|
}
|
|
return QTAILQ_NEXT(bs, node_list);
|
|
}
|
|
|
|
BlockDriverState *bdrv_next(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return QTAILQ_FIRST(&bdrv_states);
|
|
}
|
|
return QTAILQ_NEXT(bs, device_list);
|
|
}
|
|
|
|
const char *bdrv_get_node_name(const BlockDriverState *bs)
|
|
{
|
|
return bs->node_name;
|
|
}
|
|
|
|
/* TODO check what callers really want: bs->node_name or blk_name() */
|
|
const char *bdrv_get_device_name(const BlockDriverState *bs)
|
|
{
|
|
return bs->blk ? blk_name(bs->blk) : "";
|
|
}
|
|
|
|
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, device_list) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
int ret;
|
|
|
|
aio_context_acquire(aio_context);
|
|
ret = bdrv_flush(bs);
|
|
if (ret < 0 && !result) {
|
|
result = ret;
|
|
}
|
|
aio_context_release(aio_context);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
int bdrv_has_zero_init_1(BlockDriverState *bs)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
int bdrv_has_zero_init(BlockDriverState *bs)
|
|
{
|
|
assert(bs->drv);
|
|
|
|
/* If BS is a copy on write image, it is initialized to
|
|
the contents of the base image, which may not be zeroes. */
|
|
if (bs->backing_hd) {
|
|
return 0;
|
|
}
|
|
if (bs->drv->bdrv_has_zero_init) {
|
|
return bs->drv->bdrv_has_zero_init(bs);
|
|
}
|
|
|
|
/* safe default */
|
|
return 0;
|
|
}
|
|
|
|
bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
|
|
{
|
|
BlockDriverInfo bdi;
|
|
|
|
if (bs->backing_hd) {
|
|
return false;
|
|
}
|
|
|
|
if (bdrv_get_info(bs, &bdi) == 0) {
|
|
return bdi.unallocated_blocks_are_zero;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
|
|
{
|
|
BlockDriverInfo bdi;
|
|
|
|
if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
|
|
return false;
|
|
}
|
|
|
|
if (bdrv_get_info(bs, &bdi) == 0) {
|
|
return bdi.can_write_zeroes_with_unmap;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
typedef struct BdrvCoGetBlockStatusData {
|
|
BlockDriverState *bs;
|
|
BlockDriverState *base;
|
|
int64_t sector_num;
|
|
int nb_sectors;
|
|
int *pnum;
|
|
int64_t ret;
|
|
bool done;
|
|
} BdrvCoGetBlockStatusData;
|
|
|
|
/*
|
|
* Returns the allocation status of the specified sectors.
|
|
* 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.
|
|
*/
|
|
static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
int64_t total_sectors;
|
|
int64_t n;
|
|
int64_t ret, ret2;
|
|
|
|
total_sectors = bdrv_nb_sectors(bs);
|
|
if (total_sectors < 0) {
|
|
return total_sectors;
|
|
}
|
|
|
|
if (sector_num >= total_sectors) {
|
|
*pnum = 0;
|
|
return 0;
|
|
}
|
|
|
|
n = total_sectors - sector_num;
|
|
if (n < nb_sectors) {
|
|
nb_sectors = n;
|
|
}
|
|
|
|
if (!bs->drv->bdrv_co_get_block_status) {
|
|
*pnum = nb_sectors;
|
|
ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
|
|
if (bs->drv->protocol_name) {
|
|
ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);
|
|
if (ret < 0) {
|
|
*pnum = 0;
|
|
return ret;
|
|
}
|
|
|
|
if (ret & BDRV_BLOCK_RAW) {
|
|
assert(ret & BDRV_BLOCK_OFFSET_VALID);
|
|
return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
|
|
*pnum, pnum);
|
|
}
|
|
|
|
if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
|
|
ret |= BDRV_BLOCK_ALLOCATED;
|
|
}
|
|
|
|
if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
|
|
if (bdrv_unallocated_blocks_are_zero(bs)) {
|
|
ret |= BDRV_BLOCK_ZERO;
|
|
} else if (bs->backing_hd) {
|
|
BlockDriverState *bs2 = bs->backing_hd;
|
|
int64_t nb_sectors2 = bdrv_nb_sectors(bs2);
|
|
if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {
|
|
ret |= BDRV_BLOCK_ZERO;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (bs->file &&
|
|
(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
|
|
(ret & BDRV_BLOCK_OFFSET_VALID)) {
|
|
int file_pnum;
|
|
|
|
ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
|
|
*pnum, &file_pnum);
|
|
if (ret2 >= 0) {
|
|
/* Ignore errors. This is just providing extra information, it
|
|
* is useful but not necessary.
|
|
*/
|
|
if (!file_pnum) {
|
|
/* !file_pnum indicates an offset at or beyond the EOF; it is
|
|
* perfectly valid for the format block driver to point to such
|
|
* offsets, so catch it and mark everything as zero */
|
|
ret |= BDRV_BLOCK_ZERO;
|
|
} else {
|
|
/* Limit request to the range reported by the protocol driver */
|
|
*pnum = file_pnum;
|
|
ret |= (ret2 & BDRV_BLOCK_ZERO);
|
|
}
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Coroutine wrapper for bdrv_get_block_status() */
|
|
static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque)
|
|
{
|
|
BdrvCoGetBlockStatusData *data = opaque;
|
|
BlockDriverState *bs = data->bs;
|
|
|
|
data->ret = bdrv_co_get_block_status(bs, data->sector_num, data->nb_sectors,
|
|
data->pnum);
|
|
data->done = true;
|
|
}
|
|
|
|
/*
|
|
* Synchronous wrapper around bdrv_co_get_block_status().
|
|
*
|
|
* See bdrv_co_get_block_status() for details.
|
|
*/
|
|
int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
Coroutine *co;
|
|
BdrvCoGetBlockStatusData data = {
|
|
.bs = bs,
|
|
.sector_num = sector_num,
|
|
.nb_sectors = nb_sectors,
|
|
.pnum = pnum,
|
|
.done = false,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_get_block_status_co_entry(&data);
|
|
} else {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_get_block_status_co_entry);
|
|
qemu_coroutine_enter(co, &data);
|
|
while (!data.done) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
return data.ret;
|
|
}
|
|
|
|
int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
return !!(ret & BDRV_BLOCK_ALLOCATED);
|
|
}
|
|
|
|
/*
|
|
* 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 bdrv_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_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;
|
|
}
|
|
|
|
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;
|
|
int ret;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (!drv->bdrv_write_compressed) {
|
|
return -ENOTSUP;
|
|
}
|
|
ret = bdrv_check_request(bs, sector_num, nb_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
|
|
|
|
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);
|
|
}
|
|
|
|
ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_get_specific_info) {
|
|
return drv->bdrv_get_specific_info(bs);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
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_remove_breakpoint(BlockDriverState *bs, const char *tag)
|
|
{
|
|
while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
|
|
bs = bs->file;
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
|
|
return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
|
|
{
|
|
while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
|
|
bs = bs->file;
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
|
|
return bs->drv->bdrv_debug_resume(bs, tag);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
|
|
{
|
|
while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
|
|
bs = bs->file;
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
|
|
return bs->drv->bdrv_debug_is_suspended(bs, tag);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
int bdrv_is_snapshot(BlockDriverState *bs)
|
|
{
|
|
return !!(bs->open_flags & BDRV_O_SNAPSHOT);
|
|
}
|
|
|
|
/* backing_file can either be relative, or absolute, or a protocol. If it is
|
|
* relative, it must be relative to the chain. So, passing in bs->filename
|
|
* from a BDS as backing_file should not be done, as that may be relative to
|
|
* the CWD rather than the chain. */
|
|
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
|
|
const char *backing_file)
|
|
{
|
|
char *filename_full = NULL;
|
|
char *backing_file_full = NULL;
|
|
char *filename_tmp = NULL;
|
|
int is_protocol = 0;
|
|
BlockDriverState *curr_bs = NULL;
|
|
BlockDriverState *retval = NULL;
|
|
|
|
if (!bs || !bs->drv || !backing_file) {
|
|
return NULL;
|
|
}
|
|
|
|
filename_full = g_malloc(PATH_MAX);
|
|
backing_file_full = g_malloc(PATH_MAX);
|
|
filename_tmp = g_malloc(PATH_MAX);
|
|
|
|
is_protocol = path_has_protocol(backing_file);
|
|
|
|
for (curr_bs = bs; curr_bs->backing_hd; curr_bs = curr_bs->backing_hd) {
|
|
|
|
/* If either of the filename paths is actually a protocol, then
|
|
* compare unmodified paths; otherwise make paths relative */
|
|
if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
|
|
if (strcmp(backing_file, curr_bs->backing_file) == 0) {
|
|
retval = curr_bs->backing_hd;
|
|
break;
|
|
}
|
|
} else {
|
|
/* If not an absolute filename path, make it relative to the current
|
|
* image's filename path */
|
|
path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
|
|
backing_file);
|
|
|
|
/* We are going to compare absolute pathnames */
|
|
if (!realpath(filename_tmp, filename_full)) {
|
|
continue;
|
|
}
|
|
|
|
/* We need to make sure the backing filename we are comparing against
|
|
* is relative to the current image filename (or absolute) */
|
|
path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
|
|
curr_bs->backing_file);
|
|
|
|
if (!realpath(filename_tmp, backing_file_full)) {
|
|
continue;
|
|
}
|
|
|
|
if (strcmp(backing_file_full, filename_full) == 0) {
|
|
retval = curr_bs->backing_hd;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
g_free(filename_full);
|
|
g_free(backing_file_full);
|
|
g_free(filename_tmp);
|
|
return retval;
|
|
}
|
|
|
|
int bdrv_get_backing_file_depth(BlockDriverState *bs)
|
|
{
|
|
if (!bs->drv) {
|
|
return 0;
|
|
}
|
|
|
|
if (!bs->backing_hd) {
|
|
return 0;
|
|
}
|
|
|
|
return 1 + bdrv_get_backing_file_depth(bs->backing_hd);
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* async I/Os */
|
|
|
|
BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *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, 0,
|
|
cb, opaque, false);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
|
|
QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *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, 0,
|
|
cb, opaque, true);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque);
|
|
|
|
return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors,
|
|
BDRV_REQ_ZERO_WRITE | flags,
|
|
cb, opaque, true);
|
|
}
|
|
|
|
|
|
typedef struct MultiwriteCB {
|
|
int error;
|
|
int num_requests;
|
|
int num_callbacks;
|
|
struct {
|
|
BlockCompletionFunc *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 (bs->bl.max_transfer_length && reqs[outidx].nb_sectors +
|
|
reqs[i].nb_sectors > bs->bl.max_transfer_length) {
|
|
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);
|
|
|
|
// Add tail of first request, if necessary
|
|
if (qiov->size < reqs[outidx].qiov->size) {
|
|
qemu_iovec_concat(qiov, reqs[outidx].qiov, qiov->size,
|
|
reqs[outidx].qiov->size - 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;
|
|
}
|
|
}
|
|
|
|
block_acct_merge_done(&bs->stats, BLOCK_ACCT_WRITE, num_reqs - outidx - 1);
|
|
|
|
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_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov,
|
|
reqs[i].nb_sectors, reqs[i].flags,
|
|
multiwrite_cb, mcb,
|
|
true);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void bdrv_aio_cancel(BlockAIOCB *acb)
|
|
{
|
|
qemu_aio_ref(acb);
|
|
bdrv_aio_cancel_async(acb);
|
|
while (acb->refcnt > 1) {
|
|
if (acb->aiocb_info->get_aio_context) {
|
|
aio_poll(acb->aiocb_info->get_aio_context(acb), true);
|
|
} else if (acb->bs) {
|
|
aio_poll(bdrv_get_aio_context(acb->bs), true);
|
|
} else {
|
|
abort();
|
|
}
|
|
}
|
|
qemu_aio_unref(acb);
|
|
}
|
|
|
|
/* Async version of aio cancel. The caller is not blocked if the acb implements
|
|
* cancel_async, otherwise we do nothing and let the request normally complete.
|
|
* In either case the completion callback must be called. */
|
|
void bdrv_aio_cancel_async(BlockAIOCB *acb)
|
|
{
|
|
if (acb->aiocb_info->cancel_async) {
|
|
acb->aiocb_info->cancel_async(acb);
|
|
}
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* async block device emulation */
|
|
|
|
typedef struct BlockAIOCBSync {
|
|
BlockAIOCB common;
|
|
QEMUBH *bh;
|
|
int ret;
|
|
/* vector translation state */
|
|
QEMUIOVector *qiov;
|
|
uint8_t *bounce;
|
|
int is_write;
|
|
} BlockAIOCBSync;
|
|
|
|
static const AIOCBInfo bdrv_em_aiocb_info = {
|
|
.aiocb_size = sizeof(BlockAIOCBSync),
|
|
};
|
|
|
|
static void bdrv_aio_bh_cb(void *opaque)
|
|
{
|
|
BlockAIOCBSync *acb = opaque;
|
|
|
|
if (!acb->is_write && acb->ret >= 0) {
|
|
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_unref(acb);
|
|
}
|
|
|
|
static BlockAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov,
|
|
int nb_sectors,
|
|
BlockCompletionFunc *cb,
|
|
void *opaque,
|
|
int is_write)
|
|
|
|
{
|
|
BlockAIOCBSync *acb;
|
|
|
|
acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque);
|
|
acb->is_write = is_write;
|
|
acb->qiov = qiov;
|
|
acb->bounce = qemu_try_blockalign(bs, qiov->size);
|
|
acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb);
|
|
|
|
if (acb->bounce == NULL) {
|
|
acb->ret = -ENOMEM;
|
|
} else 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 BlockAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
|
}
|
|
|
|
static BlockAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
|
}
|
|
|
|
|
|
typedef struct BlockAIOCBCoroutine {
|
|
BlockAIOCB common;
|
|
BlockRequest req;
|
|
bool is_write;
|
|
bool *done;
|
|
QEMUBH* bh;
|
|
} BlockAIOCBCoroutine;
|
|
|
|
static const AIOCBInfo bdrv_em_co_aiocb_info = {
|
|
.aiocb_size = sizeof(BlockAIOCBCoroutine),
|
|
};
|
|
|
|
static void bdrv_co_em_bh(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
|
|
acb->common.cb(acb->common.opaque, acb->req.error);
|
|
|
|
qemu_bh_delete(acb->bh);
|
|
qemu_aio_unref(acb);
|
|
}
|
|
|
|
/* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
|
|
static void coroutine_fn bdrv_co_do_rw(void *opaque)
|
|
{
|
|
BlockAIOCBCoroutine *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, acb->req.flags);
|
|
} else {
|
|
acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
|
|
acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
|
|
}
|
|
|
|
acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
|
|
qemu_bh_schedule(acb->bh);
|
|
}
|
|
|
|
static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
|
|
int64_t sector_num,
|
|
QEMUIOVector *qiov,
|
|
int nb_sectors,
|
|
BdrvRequestFlags flags,
|
|
BlockCompletionFunc *cb,
|
|
void *opaque,
|
|
bool is_write)
|
|
{
|
|
Coroutine *co;
|
|
BlockAIOCBCoroutine *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->req.flags = flags;
|
|
acb->is_write = is_write;
|
|
|
|
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)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
|
|
acb->req.error = bdrv_co_flush(bs);
|
|
acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
|
|
qemu_bh_schedule(acb->bh);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
trace_bdrv_aio_flush(bs, opaque);
|
|
|
|
Coroutine *co;
|
|
BlockAIOCBCoroutine *acb;
|
|
|
|
acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
|
|
|
|
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)
|
|
{
|
|
BlockAIOCBCoroutine *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
|
|
acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
|
|
acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
|
|
qemu_bh_schedule(acb->bh);
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
Coroutine *co;
|
|
BlockAIOCBCoroutine *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;
|
|
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,
|
|
BlockCompletionFunc *cb, void *opaque)
|
|
{
|
|
BlockAIOCB *acb;
|
|
|
|
acb = g_slice_alloc(aiocb_info->aiocb_size);
|
|
acb->aiocb_info = aiocb_info;
|
|
acb->bs = bs;
|
|
acb->cb = cb;
|
|
acb->opaque = opaque;
|
|
acb->refcnt = 1;
|
|
return acb;
|
|
}
|
|
|
|
void qemu_aio_ref(void *p)
|
|
{
|
|
BlockAIOCB *acb = p;
|
|
acb->refcnt++;
|
|
}
|
|
|
|
void qemu_aio_unref(void *p)
|
|
{
|
|
BlockAIOCB *acb = p;
|
|
assert(acb->refcnt > 0);
|
|
if (--acb->refcnt == 0) {
|
|
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(),
|
|
};
|
|
BlockAIOCB *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) {
|
|
BlockAIOCB *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, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
if (!bs->drv) {
|
|
return;
|
|
}
|
|
|
|
if (!(bs->open_flags & BDRV_O_INCOMING)) {
|
|
return;
|
|
}
|
|
bs->open_flags &= ~BDRV_O_INCOMING;
|
|
|
|
if (bs->drv->bdrv_invalidate_cache) {
|
|
bs->drv->bdrv_invalidate_cache(bs, &local_err);
|
|
} else if (bs->file) {
|
|
bdrv_invalidate_cache(bs->file, &local_err);
|
|
}
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
|
|
ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
|
return;
|
|
}
|
|
}
|
|
|
|
void bdrv_invalidate_cache_all(Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
Error *local_err = NULL;
|
|
|
|
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
aio_context_acquire(aio_context);
|
|
bdrv_invalidate_cache(bs, &local_err);
|
|
aio_context_release(aio_context);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
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 {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_flush_co_entry);
|
|
qemu_coroutine_enter(co, &rwco);
|
|
while (rwco.ret == NOT_DONE) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
|
|
return rwco.ret;
|
|
}
|
|
|
|
typedef struct DiscardCo {
|
|
BlockDriverState *bs;
|
|
int64_t sector_num;
|
|
int nb_sectors;
|
|
int ret;
|
|
} DiscardCo;
|
|
static void coroutine_fn bdrv_discard_co_entry(void *opaque)
|
|
{
|
|
DiscardCo *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)
|
|
{
|
|
int max_discard, ret;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
ret = bdrv_check_request(bs, sector_num, nb_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
} else if (bs->read_only) {
|
|
return -EROFS;
|
|
}
|
|
|
|
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 && !bs->drv->bdrv_aio_discard) {
|
|
return 0;
|
|
}
|
|
|
|
max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
|
|
while (nb_sectors > 0) {
|
|
int ret;
|
|
int num = nb_sectors;
|
|
|
|
/* align request */
|
|
if (bs->bl.discard_alignment &&
|
|
num >= bs->bl.discard_alignment &&
|
|
sector_num % bs->bl.discard_alignment) {
|
|
if (num > bs->bl.discard_alignment) {
|
|
num = bs->bl.discard_alignment;
|
|
}
|
|
num -= sector_num % bs->bl.discard_alignment;
|
|
}
|
|
|
|
/* limit request size */
|
|
if (num > max_discard) {
|
|
num = max_discard;
|
|
}
|
|
|
|
if (bs->drv->bdrv_co_discard) {
|
|
ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
|
|
} else {
|
|
BlockAIOCB *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();
|
|
ret = co.ret;
|
|
}
|
|
}
|
|
if (ret && ret != -ENOTSUP) {
|
|
return ret;
|
|
}
|
|
|
|
sector_num += num;
|
|
nb_sectors -= num;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
|
|
{
|
|
Coroutine *co;
|
|
DiscardCo 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 {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
co = qemu_coroutine_create(bdrv_discard_co_entry);
|
|
qemu_coroutine_enter(co, &rwco);
|
|
while (rwco.ret == NOT_DONE) {
|
|
aio_poll(aio_context, true);
|
|
}
|
|
}
|
|
|
|
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;
|
|
const char *device_name;
|
|
|
|
if (drv && drv->bdrv_eject) {
|
|
drv->bdrv_eject(bs, eject_flag);
|
|
}
|
|
|
|
device_name = bdrv_get_device_name(bs);
|
|
if (device_name[0] != '\0') {
|
|
qapi_event_send_device_tray_moved(device_name,
|
|
eject_flag, &error_abort);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Lock or unlock the media (if it is locked, the user won't be able
|
|
* to eject it manually).
|
|
*/
|
|
void bdrv_lock_medium(BlockDriverState *bs, bool locked)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
trace_bdrv_lock_medium(bs, locked);
|
|
|
|
if (drv && drv->bdrv_lock_medium) {
|
|
drv->bdrv_lock_medium(bs, locked);
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
|
|
unsigned long int req, void *buf,
|
|
BlockCompletionFunc *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_guest_block_size(BlockDriverState *bs, int align)
|
|
{
|
|
bs->guest_block_size = align;
|
|
}
|
|
|
|
void *qemu_blockalign(BlockDriverState *bs, size_t size)
|
|
{
|
|
return qemu_memalign(bdrv_opt_mem_align(bs), size);
|
|
}
|
|
|
|
void *qemu_blockalign0(BlockDriverState *bs, size_t size)
|
|
{
|
|
return memset(qemu_blockalign(bs, size), 0, size);
|
|
}
|
|
|
|
void *qemu_try_blockalign(BlockDriverState *bs, size_t size)
|
|
{
|
|
size_t align = bdrv_opt_mem_align(bs);
|
|
|
|
/* Ensure that NULL is never returned on success */
|
|
assert(align > 0);
|
|
if (size == 0) {
|
|
size = align;
|
|
}
|
|
|
|
return qemu_try_memalign(align, size);
|
|
}
|
|
|
|
void *qemu_try_blockalign0(BlockDriverState *bs, size_t size)
|
|
{
|
|
void *mem = qemu_try_blockalign(bs, size);
|
|
|
|
if (mem) {
|
|
memset(mem, 0, size);
|
|
}
|
|
|
|
return mem;
|
|
}
|
|
|
|
/*
|
|
* Check if all memory in this vector is sector aligned.
|
|
*/
|
|
bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
|
|
{
|
|
int i;
|
|
size_t alignment = bdrv_opt_mem_align(bs);
|
|
|
|
for (i = 0; i < qiov->niov; i++) {
|
|
if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
|
|
return false;
|
|
}
|
|
if (qiov->iov[i].iov_len % alignment) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity,
|
|
Error **errp)
|
|
{
|
|
int64_t bitmap_size;
|
|
BdrvDirtyBitmap *bitmap;
|
|
|
|
assert((granularity & (granularity - 1)) == 0);
|
|
|
|
granularity >>= BDRV_SECTOR_BITS;
|
|
assert(granularity);
|
|
bitmap_size = bdrv_nb_sectors(bs);
|
|
if (bitmap_size < 0) {
|
|
error_setg_errno(errp, -bitmap_size, "could not get length of device");
|
|
errno = -bitmap_size;
|
|
return NULL;
|
|
}
|
|
bitmap = g_new0(BdrvDirtyBitmap, 1);
|
|
bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
|
|
QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
|
|
return bitmap;
|
|
}
|
|
|
|
void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
|
|
{
|
|
BdrvDirtyBitmap *bm, *next;
|
|
QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
|
|
if (bm == bitmap) {
|
|
QLIST_REMOVE(bitmap, list);
|
|
hbitmap_free(bitmap->bitmap);
|
|
g_free(bitmap);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
|
|
{
|
|
BdrvDirtyBitmap *bm;
|
|
BlockDirtyInfoList *list = NULL;
|
|
BlockDirtyInfoList **plist = &list;
|
|
|
|
QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
|
|
BlockDirtyInfo *info = g_new0(BlockDirtyInfo, 1);
|
|
BlockDirtyInfoList *entry = g_new0(BlockDirtyInfoList, 1);
|
|
info->count = bdrv_get_dirty_count(bs, bm);
|
|
info->granularity =
|
|
((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap));
|
|
entry->value = info;
|
|
*plist = entry;
|
|
plist = &entry->next;
|
|
}
|
|
|
|
return list;
|
|
}
|
|
|
|
int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector)
|
|
{
|
|
if (bitmap) {
|
|
return hbitmap_get(bitmap->bitmap, sector);
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
void bdrv_dirty_iter_init(BlockDriverState *bs,
|
|
BdrvDirtyBitmap *bitmap, HBitmapIter *hbi)
|
|
{
|
|
hbitmap_iter_init(hbi, bitmap->bitmap, 0);
|
|
}
|
|
|
|
void bdrv_set_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
|
|
int64_t cur_sector, int nr_sectors)
|
|
{
|
|
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
|
|
}
|
|
|
|
void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
|
|
int64_t cur_sector, int nr_sectors)
|
|
{
|
|
hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
|
|
}
|
|
|
|
static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
|
|
int nr_sectors)
|
|
{
|
|
BdrvDirtyBitmap *bitmap;
|
|
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
|
|
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
|
|
}
|
|
}
|
|
|
|
static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
|
|
int nr_sectors)
|
|
{
|
|
BdrvDirtyBitmap *bitmap;
|
|
QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
|
|
hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
|
|
}
|
|
}
|
|
|
|
int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
|
|
{
|
|
return hbitmap_count(bitmap->bitmap);
|
|
}
|
|
|
|
/* Get a reference to bs */
|
|
void bdrv_ref(BlockDriverState *bs)
|
|
{
|
|
bs->refcnt++;
|
|
}
|
|
|
|
/* Release a previously grabbed reference to bs.
|
|
* If after releasing, reference count is zero, the BlockDriverState is
|
|
* deleted. */
|
|
void bdrv_unref(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return;
|
|
}
|
|
assert(bs->refcnt > 0);
|
|
if (--bs->refcnt == 0) {
|
|
bdrv_delete(bs);
|
|
}
|
|
}
|
|
|
|
struct BdrvOpBlocker {
|
|
Error *reason;
|
|
QLIST_ENTRY(BdrvOpBlocker) list;
|
|
};
|
|
|
|
bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
|
|
{
|
|
BdrvOpBlocker *blocker;
|
|
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
|
|
if (!QLIST_EMPTY(&bs->op_blockers[op])) {
|
|
blocker = QLIST_FIRST(&bs->op_blockers[op]);
|
|
if (errp) {
|
|
error_setg(errp, "Device '%s' is busy: %s",
|
|
bdrv_get_device_name(bs),
|
|
error_get_pretty(blocker->reason));
|
|
}
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
|
|
{
|
|
BdrvOpBlocker *blocker;
|
|
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
|
|
|
|
blocker = g_new0(BdrvOpBlocker, 1);
|
|
blocker->reason = reason;
|
|
QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
|
|
}
|
|
|
|
void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
|
|
{
|
|
BdrvOpBlocker *blocker, *next;
|
|
assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
|
|
QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
|
|
if (blocker->reason == reason) {
|
|
QLIST_REMOVE(blocker, list);
|
|
g_free(blocker);
|
|
}
|
|
}
|
|
}
|
|
|
|
void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
|
|
{
|
|
int i;
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
bdrv_op_block(bs, i, reason);
|
|
}
|
|
}
|
|
|
|
void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
|
|
{
|
|
int i;
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
bdrv_op_unblock(bs, i, reason);
|
|
}
|
|
}
|
|
|
|
bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
|
|
if (!QLIST_EMPTY(&bs->op_blockers[i])) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void bdrv_iostatus_enable(BlockDriverState *bs)
|
|
{
|
|
bs->iostatus_enabled = true;
|
|
bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
|
|
}
|
|
|
|
/* The I/O status is only enabled if the drive explicitly
|
|
* enables it _and_ the VM is configured to stop on errors */
|
|
bool bdrv_iostatus_is_enabled(const BlockDriverState *bs)
|
|
{
|
|
return (bs->iostatus_enabled &&
|
|
(bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC ||
|
|
bs->on_write_error == BLOCKDEV_ON_ERROR_STOP ||
|
|
bs->on_read_error == BLOCKDEV_ON_ERROR_STOP));
|
|
}
|
|
|
|
void bdrv_iostatus_disable(BlockDriverState *bs)
|
|
{
|
|
bs->iostatus_enabled = false;
|
|
}
|
|
|
|
void bdrv_iostatus_reset(BlockDriverState *bs)
|
|
{
|
|
if (bdrv_iostatus_is_enabled(bs)) {
|
|
bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK;
|
|
if (bs->job) {
|
|
block_job_iostatus_reset(bs->job);
|
|
}
|
|
}
|
|
}
|
|
|
|
void bdrv_iostatus_set_err(BlockDriverState *bs, int error)
|
|
{
|
|
assert(bdrv_iostatus_is_enabled(bs));
|
|
if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) {
|
|
bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE :
|
|
BLOCK_DEVICE_IO_STATUS_FAILED;
|
|
}
|
|
}
|
|
|
|
void bdrv_img_create(const char *filename, const char *fmt,
|
|
const char *base_filename, const char *base_fmt,
|
|
char *options, uint64_t img_size, int flags,
|
|
Error **errp, bool quiet)
|
|
{
|
|
QemuOptsList *create_opts = NULL;
|
|
QemuOpts *opts = NULL;
|
|
const char *backing_fmt, *backing_file;
|
|
int64_t size;
|
|
BlockDriver *drv, *proto_drv;
|
|
BlockDriver *backing_drv = NULL;
|
|
Error *local_err = NULL;
|
|
int ret = 0;
|
|
|
|
/* Find driver and parse its options */
|
|
drv = bdrv_find_format(fmt);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown file format '%s'", fmt);
|
|
return;
|
|
}
|
|
|
|
proto_drv = bdrv_find_protocol(filename, true, errp);
|
|
if (!proto_drv) {
|
|
return;
|
|
}
|
|
|
|
if (!drv->create_opts) {
|
|
error_setg(errp, "Format driver '%s' does not support image creation",
|
|
drv->format_name);
|
|
return;
|
|
}
|
|
|
|
if (!proto_drv->create_opts) {
|
|
error_setg(errp, "Protocol driver '%s' does not support image creation",
|
|
proto_drv->format_name);
|
|
return;
|
|
}
|
|
|
|
create_opts = qemu_opts_append(create_opts, drv->create_opts);
|
|
create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
|
|
|
|
/* Create parameter list with default values */
|
|
opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
|
|
|
|
/* Parse -o options */
|
|
if (options) {
|
|
qemu_opts_do_parse(opts, options, NULL, &local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
local_err = NULL;
|
|
error_setg(errp, "Invalid options for file format '%s'", fmt);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (base_filename) {
|
|
qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err);
|
|
if (local_err) {
|
|
error_setg(errp, "Backing file not supported for file format '%s'",
|
|
fmt);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (base_fmt) {
|
|
qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err);
|
|
if (local_err) {
|
|
error_setg(errp, "Backing file format not supported for file "
|
|
"format '%s'", fmt);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
|
|
if (backing_file) {
|
|
if (!strcmp(filename, backing_file)) {
|
|
error_setg(errp, "Error: Trying to create an image with the "
|
|
"same filename as the backing file");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
|
|
if (backing_fmt) {
|
|
backing_drv = bdrv_find_format(backing_fmt);
|
|
if (!backing_drv) {
|
|
error_setg(errp, "Unknown backing file format '%s'",
|
|
backing_fmt);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
// The size for the image must always be specified, with one exception:
|
|
// If we are using a backing file, we can obtain the size from there
|
|
size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
|
|
if (size == -1) {
|
|
if (backing_file) {
|
|
BlockDriverState *bs;
|
|
char *full_backing = g_new0(char, PATH_MAX);
|
|
int64_t size;
|
|
int back_flags;
|
|
|
|
bdrv_get_full_backing_filename_from_filename(filename, backing_file,
|
|
full_backing, PATH_MAX,
|
|
&local_err);
|
|
if (local_err) {
|
|
g_free(full_backing);
|
|
goto out;
|
|
}
|
|
|
|
/* backing files always opened read-only */
|
|
back_flags =
|
|
flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
|
|
|
|
bs = NULL;
|
|
ret = bdrv_open(&bs, full_backing, NULL, NULL, back_flags,
|
|
backing_drv, &local_err);
|
|
g_free(full_backing);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
size = bdrv_getlength(bs);
|
|
if (size < 0) {
|
|
error_setg_errno(errp, -size, "Could not get size of '%s'",
|
|
backing_file);
|
|
bdrv_unref(bs);
|
|
goto out;
|
|
}
|
|
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);
|
|
|
|
bdrv_unref(bs);
|
|
} else {
|
|
error_setg(errp, "Image creation needs a size parameter");
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (!quiet) {
|
|
printf("Formatting '%s', fmt=%s", filename, fmt);
|
|
qemu_opts_print(opts, " ");
|
|
puts("");
|
|
}
|
|
|
|
ret = bdrv_create(drv, filename, opts, &local_err);
|
|
|
|
if (ret == -EFBIG) {
|
|
/* This is generally a better message than whatever the driver would
|
|
* deliver (especially because of the cluster_size_hint), since that
|
|
* is most probably not much different from "image too large". */
|
|
const char *cluster_size_hint = "";
|
|
if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) {
|
|
cluster_size_hint = " (try using a larger cluster size)";
|
|
}
|
|
error_setg(errp, "The image size is too large for file format '%s'"
|
|
"%s", fmt, cluster_size_hint);
|
|
error_free(local_err);
|
|
local_err = NULL;
|
|
}
|
|
|
|
out:
|
|
qemu_opts_del(opts);
|
|
qemu_opts_free(create_opts);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
}
|
|
}
|
|
|
|
AioContext *bdrv_get_aio_context(BlockDriverState *bs)
|
|
{
|
|
return bs->aio_context;
|
|
}
|
|
|
|
void bdrv_detach_aio_context(BlockDriverState *bs)
|
|
{
|
|
BdrvAioNotifier *baf;
|
|
|
|
if (!bs->drv) {
|
|
return;
|
|
}
|
|
|
|
QLIST_FOREACH(baf, &bs->aio_notifiers, list) {
|
|
baf->detach_aio_context(baf->opaque);
|
|
}
|
|
|
|
if (bs->io_limits_enabled) {
|
|
throttle_detach_aio_context(&bs->throttle_state);
|
|
}
|
|
if (bs->drv->bdrv_detach_aio_context) {
|
|
bs->drv->bdrv_detach_aio_context(bs);
|
|
}
|
|
if (bs->file) {
|
|
bdrv_detach_aio_context(bs->file);
|
|
}
|
|
if (bs->backing_hd) {
|
|
bdrv_detach_aio_context(bs->backing_hd);
|
|
}
|
|
|
|
bs->aio_context = NULL;
|
|
}
|
|
|
|
void bdrv_attach_aio_context(BlockDriverState *bs,
|
|
AioContext *new_context)
|
|
{
|
|
BdrvAioNotifier *ban;
|
|
|
|
if (!bs->drv) {
|
|
return;
|
|
}
|
|
|
|
bs->aio_context = new_context;
|
|
|
|
if (bs->backing_hd) {
|
|
bdrv_attach_aio_context(bs->backing_hd, new_context);
|
|
}
|
|
if (bs->file) {
|
|
bdrv_attach_aio_context(bs->file, new_context);
|
|
}
|
|
if (bs->drv->bdrv_attach_aio_context) {
|
|
bs->drv->bdrv_attach_aio_context(bs, new_context);
|
|
}
|
|
if (bs->io_limits_enabled) {
|
|
throttle_attach_aio_context(&bs->throttle_state, new_context);
|
|
}
|
|
|
|
QLIST_FOREACH(ban, &bs->aio_notifiers, list) {
|
|
ban->attached_aio_context(new_context, ban->opaque);
|
|
}
|
|
}
|
|
|
|
void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
|
|
{
|
|
bdrv_drain_all(); /* ensure there are no in-flight requests */
|
|
|
|
bdrv_detach_aio_context(bs);
|
|
|
|
/* This function executes in the old AioContext so acquire the new one in
|
|
* case it runs in a different thread.
|
|
*/
|
|
aio_context_acquire(new_context);
|
|
bdrv_attach_aio_context(bs, new_context);
|
|
aio_context_release(new_context);
|
|
}
|
|
|
|
void bdrv_add_aio_context_notifier(BlockDriverState *bs,
|
|
void (*attached_aio_context)(AioContext *new_context, void *opaque),
|
|
void (*detach_aio_context)(void *opaque), void *opaque)
|
|
{
|
|
BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1);
|
|
*ban = (BdrvAioNotifier){
|
|
.attached_aio_context = attached_aio_context,
|
|
.detach_aio_context = detach_aio_context,
|
|
.opaque = opaque
|
|
};
|
|
|
|
QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
|
|
}
|
|
|
|
void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
|
|
void (*attached_aio_context)(AioContext *,
|
|
void *),
|
|
void (*detach_aio_context)(void *),
|
|
void *opaque)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_next;
|
|
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
|
|
if (ban->attached_aio_context == attached_aio_context &&
|
|
ban->detach_aio_context == detach_aio_context &&
|
|
ban->opaque == opaque)
|
|
{
|
|
QLIST_REMOVE(ban, list);
|
|
g_free(ban);
|
|
|
|
return;
|
|
}
|
|
}
|
|
|
|
abort();
|
|
}
|
|
|
|
void bdrv_add_before_write_notifier(BlockDriverState *bs,
|
|
NotifierWithReturn *notifier)
|
|
{
|
|
notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
|
|
}
|
|
|
|
int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
|
|
BlockDriverAmendStatusCB *status_cb)
|
|
{
|
|
if (!bs->drv->bdrv_amend_options) {
|
|
return -ENOTSUP;
|
|
}
|
|
return bs->drv->bdrv_amend_options(bs, opts, status_cb);
|
|
}
|
|
|
|
/* This function will be called by the bdrv_recurse_is_first_non_filter method
|
|
* of block filter and by bdrv_is_first_non_filter.
|
|
* It is used to test if the given bs is the candidate or recurse more in the
|
|
* node graph.
|
|
*/
|
|
bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
|
|
BlockDriverState *candidate)
|
|
{
|
|
/* return false if basic checks fails */
|
|
if (!bs || !bs->drv) {
|
|
return false;
|
|
}
|
|
|
|
/* the code reached a non block filter driver -> check if the bs is
|
|
* the same as the candidate. It's the recursion termination condition.
|
|
*/
|
|
if (!bs->drv->is_filter) {
|
|
return bs == candidate;
|
|
}
|
|
/* Down this path the driver is a block filter driver */
|
|
|
|
/* If the block filter recursion method is defined use it to recurse down
|
|
* the node graph.
|
|
*/
|
|
if (bs->drv->bdrv_recurse_is_first_non_filter) {
|
|
return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
|
|
}
|
|
|
|
/* the driver is a block filter but don't allow to recurse -> return false
|
|
*/
|
|
return false;
|
|
}
|
|
|
|
/* This function checks if the candidate is the first non filter bs down it's
|
|
* bs chain. Since we don't have pointers to parents it explore all bs chains
|
|
* from the top. Some filters can choose not to pass down the recursion.
|
|
*/
|
|
bool bdrv_is_first_non_filter(BlockDriverState *candidate)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
/* walk down the bs forest recursively */
|
|
QTAILQ_FOREACH(bs, &bdrv_states, device_list) {
|
|
bool perm;
|
|
|
|
/* try to recurse in this top level bs */
|
|
perm = bdrv_recurse_is_first_non_filter(bs, candidate);
|
|
|
|
/* candidate is the first non filter */
|
|
if (perm) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
BlockDriverState *check_to_replace_node(const char *node_name, Error **errp)
|
|
{
|
|
BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
|
|
AioContext *aio_context;
|
|
|
|
if (!to_replace_bs) {
|
|
error_setg(errp, "Node name '%s' not found", node_name);
|
|
return NULL;
|
|
}
|
|
|
|
aio_context = bdrv_get_aio_context(to_replace_bs);
|
|
aio_context_acquire(aio_context);
|
|
|
|
if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
|
|
to_replace_bs = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/* We don't want arbitrary node of the BDS chain to be replaced only the top
|
|
* most non filter in order to prevent data corruption.
|
|
* Another benefit is that this tests exclude backing files which are
|
|
* blocked by the backing blockers.
|
|
*/
|
|
if (!bdrv_is_first_non_filter(to_replace_bs)) {
|
|
error_setg(errp, "Only top most non filter can be replaced");
|
|
to_replace_bs = NULL;
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
aio_context_release(aio_context);
|
|
return to_replace_bs;
|
|
}
|
|
|
|
void bdrv_io_plug(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_io_plug) {
|
|
drv->bdrv_io_plug(bs);
|
|
} else if (bs->file) {
|
|
bdrv_io_plug(bs->file);
|
|
}
|
|
}
|
|
|
|
void bdrv_io_unplug(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_io_unplug) {
|
|
drv->bdrv_io_unplug(bs);
|
|
} else if (bs->file) {
|
|
bdrv_io_unplug(bs->file);
|
|
}
|
|
}
|
|
|
|
void bdrv_flush_io_queue(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_flush_io_queue) {
|
|
drv->bdrv_flush_io_queue(bs);
|
|
} else if (bs->file) {
|
|
bdrv_flush_io_queue(bs->file);
|
|
}
|
|
}
|
|
|
|
static bool append_open_options(QDict *d, BlockDriverState *bs)
|
|
{
|
|
const QDictEntry *entry;
|
|
bool found_any = false;
|
|
|
|
for (entry = qdict_first(bs->options); entry;
|
|
entry = qdict_next(bs->options, entry))
|
|
{
|
|
/* Only take options for this level and exclude all non-driver-specific
|
|
* options */
|
|
if (!strchr(qdict_entry_key(entry), '.') &&
|
|
strcmp(qdict_entry_key(entry), "node-name"))
|
|
{
|
|
qobject_incref(qdict_entry_value(entry));
|
|
qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry));
|
|
found_any = true;
|
|
}
|
|
}
|
|
|
|
return found_any;
|
|
}
|
|
|
|
/* Updates the following BDS fields:
|
|
* - exact_filename: A filename which may be used for opening a block device
|
|
* which (mostly) equals the given BDS (even without any
|
|
* other options; so reading and writing must return the same
|
|
* results, but caching etc. may be different)
|
|
* - full_open_options: Options which, when given when opening a block device
|
|
* (without a filename), result in a BDS (mostly)
|
|
* equalling the given one
|
|
* - filename: If exact_filename is set, it is copied here. Otherwise,
|
|
* full_open_options is converted to a JSON object, prefixed with
|
|
* "json:" (for use through the JSON pseudo protocol) and put here.
|
|
*/
|
|
void bdrv_refresh_filename(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
QDict *opts;
|
|
|
|
if (!drv) {
|
|
return;
|
|
}
|
|
|
|
/* This BDS's file name will most probably depend on its file's name, so
|
|
* refresh that first */
|
|
if (bs->file) {
|
|
bdrv_refresh_filename(bs->file);
|
|
}
|
|
|
|
if (drv->bdrv_refresh_filename) {
|
|
/* Obsolete information is of no use here, so drop the old file name
|
|
* information before refreshing it */
|
|
bs->exact_filename[0] = '\0';
|
|
if (bs->full_open_options) {
|
|
QDECREF(bs->full_open_options);
|
|
bs->full_open_options = NULL;
|
|
}
|
|
|
|
drv->bdrv_refresh_filename(bs);
|
|
} else if (bs->file) {
|
|
/* Try to reconstruct valid information from the underlying file */
|
|
bool has_open_options;
|
|
|
|
bs->exact_filename[0] = '\0';
|
|
if (bs->full_open_options) {
|
|
QDECREF(bs->full_open_options);
|
|
bs->full_open_options = NULL;
|
|
}
|
|
|
|
opts = qdict_new();
|
|
has_open_options = append_open_options(opts, bs);
|
|
|
|
/* If no specific options have been given for this BDS, the filename of
|
|
* the underlying file should suffice for this one as well */
|
|
if (bs->file->exact_filename[0] && !has_open_options) {
|
|
strcpy(bs->exact_filename, bs->file->exact_filename);
|
|
}
|
|
/* Reconstructing the full options QDict is simple for most format block
|
|
* drivers, as long as the full options are known for the underlying
|
|
* file BDS. The full options QDict of that file BDS should somehow
|
|
* contain a representation of the filename, therefore the following
|
|
* suffices without querying the (exact_)filename of this BDS. */
|
|
if (bs->file->full_open_options) {
|
|
qdict_put_obj(opts, "driver",
|
|
QOBJECT(qstring_from_str(drv->format_name)));
|
|
QINCREF(bs->file->full_open_options);
|
|
qdict_put_obj(opts, "file", QOBJECT(bs->file->full_open_options));
|
|
|
|
bs->full_open_options = opts;
|
|
} else {
|
|
QDECREF(opts);
|
|
}
|
|
} else if (!bs->full_open_options && qdict_size(bs->options)) {
|
|
/* There is no underlying file BDS (at least referenced by BDS.file),
|
|
* so the full options QDict should be equal to the options given
|
|
* specifically for this block device when it was opened (plus the
|
|
* driver specification).
|
|
* Because those options don't change, there is no need to update
|
|
* full_open_options when it's already set. */
|
|
|
|
opts = qdict_new();
|
|
append_open_options(opts, bs);
|
|
qdict_put_obj(opts, "driver",
|
|
QOBJECT(qstring_from_str(drv->format_name)));
|
|
|
|
if (bs->exact_filename[0]) {
|
|
/* This may not work for all block protocol drivers (some may
|
|
* require this filename to be parsed), but we have to find some
|
|
* default solution here, so just include it. If some block driver
|
|
* does not support pure options without any filename at all or
|
|
* needs some special format of the options QDict, it needs to
|
|
* implement the driver-specific bdrv_refresh_filename() function.
|
|
*/
|
|
qdict_put_obj(opts, "filename",
|
|
QOBJECT(qstring_from_str(bs->exact_filename)));
|
|
}
|
|
|
|
bs->full_open_options = opts;
|
|
}
|
|
|
|
if (bs->exact_filename[0]) {
|
|
pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
|
|
} else if (bs->full_open_options) {
|
|
QString *json = qobject_to_json(QOBJECT(bs->full_open_options));
|
|
snprintf(bs->filename, sizeof(bs->filename), "json:%s",
|
|
qstring_get_str(json));
|
|
QDECREF(json);
|
|
}
|
|
}
|
|
|
|
/* This accessor function purpose is to allow the device models to access the
|
|
* BlockAcctStats structure embedded inside a BlockDriverState without being
|
|
* aware of the BlockDriverState structure layout.
|
|
* It will go away when the BlockAcctStats structure will be moved inside
|
|
* the device models.
|
|
*/
|
|
BlockAcctStats *bdrv_get_stats(BlockDriverState *bs)
|
|
{
|
|
return &bs->stats;
|
|
}
|