f6dc1c31d3
If both the create options (qemu-img create -o ...) and the size parameter were given, the size parameter was silently ignored. Instead, make specifying two sizes an error. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
6578 lines
198 KiB
C
6578 lines
198 KiB
C
/*
|
|
* QEMU System Emulator block driver
|
|
*
|
|
* Copyright (c) 2003 Fabrice Bellard
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "block/trace.h"
|
|
#include "block/block_int.h"
|
|
#include "block/blockjob.h"
|
|
#include "block/nbd.h"
|
|
#include "block/qdict.h"
|
|
#include "qemu/error-report.h"
|
|
#include "module_block.h"
|
|
#include "qemu/main-loop.h"
|
|
#include "qemu/module.h"
|
|
#include "qapi/error.h"
|
|
#include "qapi/qmp/qdict.h"
|
|
#include "qapi/qmp/qjson.h"
|
|
#include "qapi/qmp/qnull.h"
|
|
#include "qapi/qmp/qstring.h"
|
|
#include "qapi/qobject-output-visitor.h"
|
|
#include "qapi/qapi-visit-block-core.h"
|
|
#include "sysemu/block-backend.h"
|
|
#include "sysemu/sysemu.h"
|
|
#include "qemu/notify.h"
|
|
#include "qemu/option.h"
|
|
#include "qemu/coroutine.h"
|
|
#include "block/qapi.h"
|
|
#include "qemu/timer.h"
|
|
#include "qemu/cutils.h"
|
|
#include "qemu/id.h"
|
|
|
|
#ifdef CONFIG_BSD
|
|
#include <sys/ioctl.h>
|
|
#include <sys/queue.h>
|
|
#ifndef __DragonFly__
|
|
#include <sys/disk.h>
|
|
#endif
|
|
#endif
|
|
|
|
#ifdef _WIN32
|
|
#include <windows.h>
|
|
#endif
|
|
|
|
#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
|
|
|
|
static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
|
|
QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
|
|
|
|
static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
|
|
QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
|
|
|
|
static QLIST_HEAD(, BlockDriver) bdrv_drivers =
|
|
QLIST_HEAD_INITIALIZER(bdrv_drivers);
|
|
|
|
static BlockDriverState *bdrv_open_inherit(const char *filename,
|
|
const char *reference,
|
|
QDict *options, int flags,
|
|
BlockDriverState *parent,
|
|
const BdrvChildRole *child_role,
|
|
Error **errp);
|
|
|
|
/* If non-zero, use only whitelisted block drivers */
|
|
static int use_bdrv_whitelist;
|
|
|
|
#ifdef _WIN32
|
|
static int is_windows_drive_prefix(const char *filename)
|
|
{
|
|
return (((filename[0] >= 'a' && filename[0] <= 'z') ||
|
|
(filename[0] >= 'A' && filename[0] <= 'Z')) &&
|
|
filename[1] == ':');
|
|
}
|
|
|
|
int is_windows_drive(const char *filename)
|
|
{
|
|
if (is_windows_drive_prefix(filename) &&
|
|
filename[2] == '\0')
|
|
return 1;
|
|
if (strstart(filename, "\\\\.\\", NULL) ||
|
|
strstart(filename, "//./", NULL))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
size_t bdrv_opt_mem_align(BlockDriverState *bs)
|
|
{
|
|
if (!bs || !bs->drv) {
|
|
/* page size or 4k (hdd sector size) should be on the safe side */
|
|
return MAX(4096, qemu_real_host_page_size);
|
|
}
|
|
|
|
return bs->bl.opt_mem_alignment;
|
|
}
|
|
|
|
size_t bdrv_min_mem_align(BlockDriverState *bs)
|
|
{
|
|
if (!bs || !bs->drv) {
|
|
/* page size or 4k (hdd sector size) should be on the safe side */
|
|
return MAX(4096, qemu_real_host_page_size);
|
|
}
|
|
|
|
return bs->bl.min_mem_alignment;
|
|
}
|
|
|
|
/* check if the path starts with "<protocol>:" */
|
|
int path_has_protocol(const char *path)
|
|
{
|
|
const char *p;
|
|
|
|
#ifdef _WIN32
|
|
if (is_windows_drive(path) ||
|
|
is_windows_drive_prefix(path)) {
|
|
return 0;
|
|
}
|
|
p = path + strcspn(path, ":/\\");
|
|
#else
|
|
p = path + strcspn(path, ":/");
|
|
#endif
|
|
|
|
return *p == ':';
|
|
}
|
|
|
|
int path_is_absolute(const char *path)
|
|
{
|
|
#ifdef _WIN32
|
|
/* specific case for names like: "\\.\d:" */
|
|
if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
|
|
return 1;
|
|
}
|
|
return (*path == '/' || *path == '\\');
|
|
#else
|
|
return (*path == '/');
|
|
#endif
|
|
}
|
|
|
|
/* if filename is absolute, just return its duplicate. Otherwise, build a
|
|
path to it by considering it is relative to base_path. URL are
|
|
supported. */
|
|
char *path_combine(const char *base_path, const char *filename)
|
|
{
|
|
const char *protocol_stripped = NULL;
|
|
const char *p, *p1;
|
|
char *result;
|
|
int len;
|
|
|
|
if (path_is_absolute(filename)) {
|
|
return g_strdup(filename);
|
|
}
|
|
|
|
if (path_has_protocol(base_path)) {
|
|
protocol_stripped = strchr(base_path, ':');
|
|
if (protocol_stripped) {
|
|
protocol_stripped++;
|
|
}
|
|
}
|
|
p = protocol_stripped ?: 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;
|
|
|
|
result = g_malloc(len + strlen(filename) + 1);
|
|
memcpy(result, base_path, len);
|
|
strcpy(result + len, filename);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Helper function for bdrv_parse_filename() implementations to remove optional
|
|
* protocol prefixes (especially "file:") from a filename and for putting the
|
|
* stripped filename into the options QDict if there is such a prefix.
|
|
*/
|
|
void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
|
|
QDict *options)
|
|
{
|
|
if (strstart(filename, prefix, &filename)) {
|
|
/* Stripping the explicit protocol prefix may result in a protocol
|
|
* prefix being (wrongly) detected (if the filename contains a colon) */
|
|
if (path_has_protocol(filename)) {
|
|
QString *fat_filename;
|
|
|
|
/* This means there is some colon before the first slash; therefore,
|
|
* this cannot be an absolute path */
|
|
assert(!path_is_absolute(filename));
|
|
|
|
/* And we can thus fix the protocol detection issue by prefixing it
|
|
* by "./" */
|
|
fat_filename = qstring_from_str("./");
|
|
qstring_append(fat_filename, filename);
|
|
|
|
assert(!path_has_protocol(qstring_get_str(fat_filename)));
|
|
|
|
qdict_put(options, "filename", fat_filename);
|
|
} else {
|
|
/* If no protocol prefix was detected, we can use the shortened
|
|
* filename as-is */
|
|
qdict_put_str(options, "filename", filename);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* Returns whether the image file is opened as read-only. Note that this can
|
|
* return false and writing to the image file is still not possible because the
|
|
* image is inactivated. */
|
|
bool bdrv_is_read_only(BlockDriverState *bs)
|
|
{
|
|
return bs->read_only;
|
|
}
|
|
|
|
int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
|
|
bool ignore_allow_rdw, Error **errp)
|
|
{
|
|
/* Do not set read_only if copy_on_read is enabled */
|
|
if (bs->copy_on_read && read_only) {
|
|
error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled",
|
|
bdrv_get_device_or_node_name(bs));
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Do not clear read_only if it is prohibited */
|
|
if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) &&
|
|
!ignore_allow_rdw)
|
|
{
|
|
error_setg(errp, "Node '%s' is read only",
|
|
bdrv_get_device_or_node_name(bs));
|
|
return -EPERM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Called by a driver that can only provide a read-only image.
|
|
*
|
|
* Returns 0 if the node is already read-only or it could switch the node to
|
|
* read-only because BDRV_O_AUTO_RDONLY is set.
|
|
*
|
|
* Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set
|
|
* or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg
|
|
* is not NULL, it is used as the error message for the Error object.
|
|
*/
|
|
int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
|
|
Error **errp)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!(bs->open_flags & BDRV_O_RDWR)) {
|
|
return 0;
|
|
}
|
|
if (!(bs->open_flags & BDRV_O_AUTO_RDONLY)) {
|
|
goto fail;
|
|
}
|
|
|
|
ret = bdrv_can_set_read_only(bs, true, false, NULL);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
bs->read_only = true;
|
|
bs->open_flags &= ~BDRV_O_RDWR;
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
error_setg(errp, "%s", errmsg ?: "Image is read-only");
|
|
return -EACCES;
|
|
}
|
|
|
|
/*
|
|
* If @backing is empty, this function returns NULL without setting
|
|
* @errp. In all other cases, NULL will only be returned with @errp
|
|
* set.
|
|
*
|
|
* Therefore, a return value of NULL without @errp set means that
|
|
* there is no backing file; if @errp is set, there is one but its
|
|
* absolute filename cannot be generated.
|
|
*/
|
|
char *bdrv_get_full_backing_filename_from_filename(const char *backed,
|
|
const char *backing,
|
|
Error **errp)
|
|
{
|
|
if (backing[0] == '\0') {
|
|
return NULL;
|
|
} else if (path_has_protocol(backing) || path_is_absolute(backing)) {
|
|
return g_strdup(backing);
|
|
} else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
|
|
error_setg(errp, "Cannot use relative backing file names for '%s'",
|
|
backed);
|
|
return NULL;
|
|
} else {
|
|
return path_combine(backed, backing);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If @filename is empty or NULL, this function returns NULL without
|
|
* setting @errp. In all other cases, NULL will only be returned with
|
|
* @errp set.
|
|
*/
|
|
static char *bdrv_make_absolute_filename(BlockDriverState *relative_to,
|
|
const char *filename, Error **errp)
|
|
{
|
|
char *dir, *full_name;
|
|
|
|
if (!filename || filename[0] == '\0') {
|
|
return NULL;
|
|
} else if (path_has_protocol(filename) || path_is_absolute(filename)) {
|
|
return g_strdup(filename);
|
|
}
|
|
|
|
dir = bdrv_dirname(relative_to, errp);
|
|
if (!dir) {
|
|
return NULL;
|
|
}
|
|
|
|
full_name = g_strconcat(dir, filename, NULL);
|
|
g_free(dir);
|
|
return full_name;
|
|
}
|
|
|
|
char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp)
|
|
{
|
|
return bdrv_make_absolute_filename(bs, bs->backing_file, errp);
|
|
}
|
|
|
|
void bdrv_register(BlockDriver *bdrv)
|
|
{
|
|
QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
|
|
}
|
|
|
|
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]);
|
|
}
|
|
notifier_with_return_list_init(&bs->before_write_notifiers);
|
|
qemu_co_mutex_init(&bs->reqs_lock);
|
|
qemu_mutex_init(&bs->dirty_bitmap_mutex);
|
|
bs->refcnt = 1;
|
|
bs->aio_context = qemu_get_aio_context();
|
|
|
|
qemu_co_queue_init(&bs->flush_queue);
|
|
|
|
for (i = 0; i < bdrv_drain_all_count; i++) {
|
|
bdrv_drained_begin(bs);
|
|
}
|
|
|
|
QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
|
|
|
|
return bs;
|
|
}
|
|
|
|
static BlockDriver *bdrv_do_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;
|
|
}
|
|
|
|
BlockDriver *bdrv_find_format(const char *format_name)
|
|
{
|
|
BlockDriver *drv1;
|
|
int i;
|
|
|
|
drv1 = bdrv_do_find_format(format_name);
|
|
if (drv1) {
|
|
return drv1;
|
|
}
|
|
|
|
/* The driver isn't registered, maybe we need to load a module */
|
|
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
|
|
if (!strcmp(block_driver_modules[i].format_name, format_name)) {
|
|
block_module_load_one(block_driver_modules[i].library_name);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return bdrv_do_find_format(format_name);
|
|
}
|
|
|
|
static int bdrv_format_is_whitelisted(const char *format_name, 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(format_name, *p)) {
|
|
return 1;
|
|
}
|
|
}
|
|
if (read_only) {
|
|
for (p = whitelist_ro; *p; p++) {
|
|
if (!strcmp(format_name, *p)) {
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
|
|
{
|
|
return bdrv_format_is_whitelisted(drv->format_name, read_only);
|
|
}
|
|
|
|
bool bdrv_uses_whitelist(void)
|
|
{
|
|
return use_bdrv_whitelist;
|
|
}
|
|
|
|
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_co_create_opts(cco->filename, cco->opts, &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_co_create_opts) {
|
|
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, &cco);
|
|
qemu_coroutine_enter(co);
|
|
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);
|
|
error_propagate(errp, local_err);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* Try to get @bs's logical and physical block size.
|
|
* On success, store them in @bsz struct and return 0.
|
|
* On failure return -errno.
|
|
* @bs must not be empty.
|
|
*/
|
|
int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (drv && drv->bdrv_probe_blocksizes) {
|
|
return drv->bdrv_probe_blocksizes(bs, bsz);
|
|
} else if (drv && drv->is_filter && bs->file) {
|
|
return bdrv_probe_blocksizes(bs->file->bs, bsz);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/**
|
|
* Try to get @bs's geometry (cyls, heads, sectors).
|
|
* On success, store them in @geo struct and return 0.
|
|
* On failure return -errno.
|
|
* @bs must not be empty.
|
|
*/
|
|
int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (drv && drv->bdrv_probe_geometry) {
|
|
return drv->bdrv_probe_geometry(bs, geo);
|
|
} else if (drv && drv->is_filter && bs->file) {
|
|
return bdrv_probe_geometry(bs->file->bs, geo);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/*
|
|
* Create a uniquely-named empty temporary file.
|
|
* Return 0 upon success, otherwise a negative errno value.
|
|
*/
|
|
int get_tmp_filename(char *filename, int size)
|
|
{
|
|
#ifdef _WIN32
|
|
char temp_dir[MAX_PATH];
|
|
/* GetTempFileName requires that its output buffer (4th param)
|
|
have length MAX_PATH or greater. */
|
|
assert(size >= MAX_PATH);
|
|
return (GetTempPath(MAX_PATH, temp_dir)
|
|
&& GetTempFileName(temp_dir, "qem", 0, filename)
|
|
? 0 : -GetLastError());
|
|
#else
|
|
int fd;
|
|
const char *tmpdir;
|
|
tmpdir = getenv("TMPDIR");
|
|
if (!tmpdir) {
|
|
tmpdir = "/var/tmp";
|
|
}
|
|
if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
|
|
return -EOVERFLOW;
|
|
}
|
|
fd = mkstemp(filename);
|
|
if (fd < 0) {
|
|
return -errno;
|
|
}
|
|
if (close(fd) != 0) {
|
|
unlink(filename);
|
|
return -errno;
|
|
}
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Detect host devices. By convention, /dev/cdrom[N] is always
|
|
* recognized as a host CDROM.
|
|
*/
|
|
static BlockDriver *find_hdev_driver(const char *filename)
|
|
{
|
|
int score_max = 0, score;
|
|
BlockDriver *drv = NULL, *d;
|
|
|
|
QLIST_FOREACH(d, &bdrv_drivers, list) {
|
|
if (d->bdrv_probe_device) {
|
|
score = d->bdrv_probe_device(filename);
|
|
if (score > score_max) {
|
|
score_max = score;
|
|
drv = d;
|
|
}
|
|
}
|
|
}
|
|
|
|
return drv;
|
|
}
|
|
|
|
static BlockDriver *bdrv_do_find_protocol(const char *protocol)
|
|
{
|
|
BlockDriver *drv1;
|
|
|
|
QLIST_FOREACH(drv1, &bdrv_drivers, list) {
|
|
if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) {
|
|
return drv1;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
BlockDriver *bdrv_find_protocol(const char *filename,
|
|
bool allow_protocol_prefix,
|
|
Error **errp)
|
|
{
|
|
BlockDriver *drv1;
|
|
char protocol[128];
|
|
int len;
|
|
const char *p;
|
|
int i;
|
|
|
|
/* 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';
|
|
|
|
drv1 = bdrv_do_find_protocol(protocol);
|
|
if (drv1) {
|
|
return drv1;
|
|
}
|
|
|
|
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
|
|
if (block_driver_modules[i].protocol_name &&
|
|
!strcmp(block_driver_modules[i].protocol_name, protocol)) {
|
|
block_module_load_one(block_driver_modules[i].library_name);
|
|
break;
|
|
}
|
|
}
|
|
|
|
drv1 = bdrv_do_find_protocol(protocol);
|
|
if (!drv1) {
|
|
error_setg(errp, "Unknown protocol '%s'", protocol);
|
|
}
|
|
return drv1;
|
|
}
|
|
|
|
/*
|
|
* 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(BlockBackend *file, 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 (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
|
|
*pdrv = &bdrv_raw;
|
|
return ret;
|
|
}
|
|
|
|
ret = blk_pread(file, 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.
|
|
*/
|
|
int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
/* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
|
|
if (bdrv_is_sg(bs))
|
|
return 0;
|
|
|
|
/* query actual device if possible, otherwise just trust the hint */
|
|
if (drv->bdrv_getlength) {
|
|
int64_t length = drv->bdrv_getlength(bs);
|
|
if (length < 0) {
|
|
return length;
|
|
}
|
|
hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
|
|
}
|
|
|
|
bs->total_sectors = hint;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Combines a QDict of new block driver @options with any missing options taken
|
|
* from @old_options, so that leaving out an option defaults to its old value.
|
|
*/
|
|
static void bdrv_join_options(BlockDriverState *bs, QDict *options,
|
|
QDict *old_options)
|
|
{
|
|
if (bs->drv && bs->drv->bdrv_join_options) {
|
|
bs->drv->bdrv_join_options(options, old_options);
|
|
} else {
|
|
qdict_join(options, old_options, false);
|
|
}
|
|
}
|
|
|
|
static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,
|
|
int open_flags,
|
|
Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
char *value = qemu_opt_get_del(opts, "detect-zeroes");
|
|
BlockdevDetectZeroesOptions detect_zeroes =
|
|
qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value,
|
|
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err);
|
|
g_free(value);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return detect_zeroes;
|
|
}
|
|
|
|
if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
|
|
!(open_flags & BDRV_O_UNMAP))
|
|
{
|
|
error_setg(errp, "setting detect-zeroes to unmap is not allowed "
|
|
"without setting discard operation to unmap");
|
|
}
|
|
|
|
return detect_zeroes;
|
|
}
|
|
|
|
/**
|
|
* 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_mode(const char *mode, int *flags, bool *writethrough)
|
|
{
|
|
*flags &= ~BDRV_O_CACHE_MASK;
|
|
|
|
if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
|
|
*writethrough = false;
|
|
*flags |= BDRV_O_NOCACHE;
|
|
} else if (!strcmp(mode, "directsync")) {
|
|
*writethrough = true;
|
|
*flags |= BDRV_O_NOCACHE;
|
|
} else if (!strcmp(mode, "writeback")) {
|
|
*writethrough = false;
|
|
} else if (!strcmp(mode, "unsafe")) {
|
|
*writethrough = false;
|
|
*flags |= BDRV_O_NO_FLUSH;
|
|
} else if (!strcmp(mode, "writethrough")) {
|
|
*writethrough = true;
|
|
} else {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static char *bdrv_child_get_parent_desc(BdrvChild *c)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
return g_strdup(bdrv_get_device_or_node_name(parent));
|
|
}
|
|
|
|
static void bdrv_child_cb_drained_begin(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
bdrv_do_drained_begin_quiesce(bs, NULL, false);
|
|
}
|
|
|
|
static bool bdrv_child_cb_drained_poll(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
return bdrv_drain_poll(bs, false, NULL, false);
|
|
}
|
|
|
|
static void bdrv_child_cb_drained_end(BdrvChild *child,
|
|
int *drained_end_counter)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
bdrv_drained_end_no_poll(bs, drained_end_counter);
|
|
}
|
|
|
|
static void bdrv_child_cb_attach(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
bdrv_apply_subtree_drain(child, bs);
|
|
}
|
|
|
|
static void bdrv_child_cb_detach(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
bdrv_unapply_subtree_drain(child, bs);
|
|
}
|
|
|
|
static int bdrv_child_cb_inactivate(BdrvChild *child)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
assert(bs->open_flags & BDRV_O_INACTIVE);
|
|
return 0;
|
|
}
|
|
|
|
static bool bdrv_child_cb_can_set_aio_ctx(BdrvChild *child, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
return bdrv_can_set_aio_context(bs, ctx, ignore, errp);
|
|
}
|
|
|
|
static void bdrv_child_cb_set_aio_ctx(BdrvChild *child, AioContext *ctx,
|
|
GSList **ignore)
|
|
{
|
|
BlockDriverState *bs = child->opaque;
|
|
return bdrv_set_aio_context_ignore(bs, ctx, ignore);
|
|
}
|
|
|
|
/*
|
|
* Returns the options and 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 void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
|
|
int parent_flags, QDict *parent_options)
|
|
{
|
|
*child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
|
|
|
|
/* For temporary files, unconditional cache=unsafe is fine */
|
|
qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
|
|
qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
|
|
|
|
/* Copy the read-only and discard options from the parent */
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_DISCARD);
|
|
|
|
/* aio=native doesn't work for cache.direct=off, so disable it for the
|
|
* temporary snapshot */
|
|
*child_flags &= ~BDRV_O_NATIVE_AIO;
|
|
}
|
|
|
|
/*
|
|
* Returns the options and flags that bs->file should get if a protocol driver
|
|
* is expected, based on the given options and flags for the parent BDS
|
|
*/
|
|
static void bdrv_inherited_options(int *child_flags, QDict *child_options,
|
|
int parent_flags, QDict *parent_options)
|
|
{
|
|
int flags = parent_flags;
|
|
|
|
/* Enable protocol handling, disable format probing for bs->file */
|
|
flags |= BDRV_O_PROTOCOL;
|
|
|
|
/* If the cache mode isn't explicitly set, inherit direct and no-flush from
|
|
* the parent. */
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
|
|
|
|
/* Inherit the read-only option from the parent if it's not set */
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_AUTO_READ_ONLY);
|
|
|
|
/* Our block drivers take care to send flushes and respect unmap policy,
|
|
* so we can default to enable both on lower layers regardless of the
|
|
* corresponding parent options. */
|
|
qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap");
|
|
|
|
/* Clear flags that only apply to the top layer */
|
|
flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ |
|
|
BDRV_O_NO_IO);
|
|
|
|
*child_flags = flags;
|
|
}
|
|
|
|
const BdrvChildRole child_file = {
|
|
.parent_is_bds = true,
|
|
.get_parent_desc = bdrv_child_get_parent_desc,
|
|
.inherit_options = bdrv_inherited_options,
|
|
.drained_begin = bdrv_child_cb_drained_begin,
|
|
.drained_poll = bdrv_child_cb_drained_poll,
|
|
.drained_end = bdrv_child_cb_drained_end,
|
|
.attach = bdrv_child_cb_attach,
|
|
.detach = bdrv_child_cb_detach,
|
|
.inactivate = bdrv_child_cb_inactivate,
|
|
.can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
|
|
.set_aio_ctx = bdrv_child_cb_set_aio_ctx,
|
|
};
|
|
|
|
/*
|
|
* Returns the options and flags that bs->file should get if the use of formats
|
|
* (and not only protocols) is permitted for it, based on the given options and
|
|
* flags for the parent BDS
|
|
*/
|
|
static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options,
|
|
int parent_flags, QDict *parent_options)
|
|
{
|
|
child_file.inherit_options(child_flags, child_options,
|
|
parent_flags, parent_options);
|
|
|
|
*child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO);
|
|
}
|
|
|
|
const BdrvChildRole child_format = {
|
|
.parent_is_bds = true,
|
|
.get_parent_desc = bdrv_child_get_parent_desc,
|
|
.inherit_options = bdrv_inherited_fmt_options,
|
|
.drained_begin = bdrv_child_cb_drained_begin,
|
|
.drained_poll = bdrv_child_cb_drained_poll,
|
|
.drained_end = bdrv_child_cb_drained_end,
|
|
.attach = bdrv_child_cb_attach,
|
|
.detach = bdrv_child_cb_detach,
|
|
.inactivate = bdrv_child_cb_inactivate,
|
|
.can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
|
|
.set_aio_ctx = bdrv_child_cb_set_aio_ctx,
|
|
};
|
|
|
|
static void bdrv_backing_attach(BdrvChild *c)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
BlockDriverState *backing_hd = c->bs;
|
|
|
|
assert(!parent->backing_blocker);
|
|
error_setg(&parent->backing_blocker,
|
|
"node is used as backing hd of '%s'",
|
|
bdrv_get_device_or_node_name(parent));
|
|
|
|
bdrv_refresh_filename(backing_hd);
|
|
|
|
parent->open_flags &= ~BDRV_O_NO_BACKING;
|
|
pstrcpy(parent->backing_file, sizeof(parent->backing_file),
|
|
backing_hd->filename);
|
|
pstrcpy(parent->backing_format, sizeof(parent->backing_format),
|
|
backing_hd->drv ? backing_hd->drv->format_name : "");
|
|
|
|
bdrv_op_block_all(backing_hd, parent->backing_blocker);
|
|
/* Otherwise we won't be able to commit or stream */
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
|
|
parent->backing_blocker);
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM,
|
|
parent->backing_blocker);
|
|
/*
|
|
* We do backup in 3 ways:
|
|
* 1. drive backup
|
|
* The target bs is new opened, and the source is top BDS
|
|
* 2. blockdev backup
|
|
* Both the source and the target are top BDSes.
|
|
* 3. internal backup(used for block replication)
|
|
* Both the source and the target are backing file
|
|
*
|
|
* In case 1 and 2, neither the source nor the target is the backing file.
|
|
* In case 3, we will block the top BDS, so there is only one block job
|
|
* for the top BDS and its backing chain.
|
|
*/
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
|
|
parent->backing_blocker);
|
|
bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
|
|
parent->backing_blocker);
|
|
|
|
bdrv_child_cb_attach(c);
|
|
}
|
|
|
|
static void bdrv_backing_detach(BdrvChild *c)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
|
|
assert(parent->backing_blocker);
|
|
bdrv_op_unblock_all(c->bs, parent->backing_blocker);
|
|
error_free(parent->backing_blocker);
|
|
parent->backing_blocker = NULL;
|
|
|
|
bdrv_child_cb_detach(c);
|
|
}
|
|
|
|
/*
|
|
* Returns the options and flags that bs->backing should get, based on the
|
|
* given options and flags for the parent BDS
|
|
*/
|
|
static void bdrv_backing_options(int *child_flags, QDict *child_options,
|
|
int parent_flags, QDict *parent_options)
|
|
{
|
|
int flags = parent_flags;
|
|
|
|
/* The cache mode is inherited unmodified for backing files; except WCE,
|
|
* which is only applied on the top level (BlockBackend) */
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
|
|
qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
|
|
|
|
/* backing files always opened read-only */
|
|
qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
|
|
qdict_set_default_str(child_options, BDRV_OPT_AUTO_READ_ONLY, "off");
|
|
flags &= ~BDRV_O_COPY_ON_READ;
|
|
|
|
/* snapshot=on is handled on the top layer */
|
|
flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
|
|
|
|
*child_flags = flags;
|
|
}
|
|
|
|
static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
|
|
const char *filename, Error **errp)
|
|
{
|
|
BlockDriverState *parent = c->opaque;
|
|
bool read_only = bdrv_is_read_only(parent);
|
|
int ret;
|
|
|
|
if (read_only) {
|
|
ret = bdrv_reopen_set_read_only(parent, false, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = bdrv_change_backing_file(parent, filename,
|
|
base->drv ? base->drv->format_name : "");
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not update backing file link");
|
|
}
|
|
|
|
if (read_only) {
|
|
bdrv_reopen_set_read_only(parent, true, NULL);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
const BdrvChildRole child_backing = {
|
|
.parent_is_bds = true,
|
|
.get_parent_desc = bdrv_child_get_parent_desc,
|
|
.attach = bdrv_backing_attach,
|
|
.detach = bdrv_backing_detach,
|
|
.inherit_options = bdrv_backing_options,
|
|
.drained_begin = bdrv_child_cb_drained_begin,
|
|
.drained_poll = bdrv_child_cb_drained_poll,
|
|
.drained_end = bdrv_child_cb_drained_end,
|
|
.inactivate = bdrv_child_cb_inactivate,
|
|
.update_filename = bdrv_backing_update_filename,
|
|
.can_set_aio_ctx = bdrv_child_cb_can_set_aio_ctx,
|
|
.set_aio_ctx = bdrv_child_cb_set_aio_ctx,
|
|
};
|
|
|
|
static int bdrv_open_flags(BlockDriverState *bs, int flags)
|
|
{
|
|
int open_flags = flags;
|
|
|
|
/*
|
|
* 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);
|
|
|
|
return open_flags;
|
|
}
|
|
|
|
static void update_flags_from_options(int *flags, QemuOpts *opts)
|
|
{
|
|
*flags &= ~(BDRV_O_CACHE_MASK | BDRV_O_RDWR | BDRV_O_AUTO_RDONLY);
|
|
|
|
if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
|
|
*flags |= BDRV_O_NO_FLUSH;
|
|
}
|
|
|
|
if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_DIRECT, false)) {
|
|
*flags |= BDRV_O_NOCACHE;
|
|
}
|
|
|
|
if (!qemu_opt_get_bool_del(opts, BDRV_OPT_READ_ONLY, false)) {
|
|
*flags |= BDRV_O_RDWR;
|
|
}
|
|
|
|
if (qemu_opt_get_bool_del(opts, BDRV_OPT_AUTO_READ_ONLY, false)) {
|
|
*flags |= BDRV_O_AUTO_RDONLY;
|
|
}
|
|
}
|
|
|
|
static void update_options_from_flags(QDict *options, int flags)
|
|
{
|
|
if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
|
|
qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE);
|
|
}
|
|
if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) {
|
|
qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH,
|
|
flags & BDRV_O_NO_FLUSH);
|
|
}
|
|
if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) {
|
|
qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR));
|
|
}
|
|
if (!qdict_haskey(options, BDRV_OPT_AUTO_READ_ONLY)) {
|
|
qdict_put_bool(options, BDRV_OPT_AUTO_READ_ONLY,
|
|
flags & BDRV_O_AUTO_RDONLY);
|
|
}
|
|
}
|
|
|
|
static void bdrv_assign_node_name(BlockDriverState *bs,
|
|
const char *node_name,
|
|
Error **errp)
|
|
{
|
|
char *gen_node_name = NULL;
|
|
|
|
if (!node_name) {
|
|
node_name = gen_node_name = id_generate(ID_BLOCK);
|
|
} else if (!id_wellformed(node_name)) {
|
|
/*
|
|
* Check for empty string or invalid characters, but not if it is
|
|
* generated (generated names use characters not available to the user)
|
|
*/
|
|
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);
|
|
goto out;
|
|
}
|
|
|
|
/* takes care of avoiding duplicates node names */
|
|
if (bdrv_find_node(node_name)) {
|
|
error_setg(errp, "Duplicate node name");
|
|
goto out;
|
|
}
|
|
|
|
/* Make sure that the node name isn't truncated */
|
|
if (strlen(node_name) >= sizeof(bs->node_name)) {
|
|
error_setg(errp, "Node name too long");
|
|
goto out;
|
|
}
|
|
|
|
/* 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);
|
|
out:
|
|
g_free(gen_node_name);
|
|
}
|
|
|
|
static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
|
|
const char *node_name, QDict *options,
|
|
int open_flags, Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
int i, ret;
|
|
|
|
bdrv_assign_node_name(bs, node_name, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
bs->drv = drv;
|
|
bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
|
|
bs->opaque = g_malloc0(drv->instance_size);
|
|
|
|
if (drv->bdrv_file_open) {
|
|
assert(!drv->bdrv_needs_filename || bs->filename[0]);
|
|
ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
|
|
} else if (drv->bdrv_open) {
|
|
ret = drv->bdrv_open(bs, options, open_flags, &local_err);
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
|
|
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 open_failed;
|
|
}
|
|
|
|
ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
|
return ret;
|
|
}
|
|
|
|
bdrv_refresh_limits(bs, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
assert(bdrv_opt_mem_align(bs) != 0);
|
|
assert(bdrv_min_mem_align(bs) != 0);
|
|
assert(is_power_of_2(bs->bl.request_alignment));
|
|
|
|
for (i = 0; i < bs->quiesce_counter; i++) {
|
|
if (drv->bdrv_co_drain_begin) {
|
|
drv->bdrv_co_drain_begin(bs);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
open_failed:
|
|
bs->drv = NULL;
|
|
if (bs->file != NULL) {
|
|
bdrv_unref_child(bs, bs->file);
|
|
bs->file = NULL;
|
|
}
|
|
g_free(bs->opaque);
|
|
bs->opaque = NULL;
|
|
return ret;
|
|
}
|
|
|
|
BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
|
|
int flags, Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
int ret;
|
|
|
|
bs = bdrv_new();
|
|
bs->open_flags = flags;
|
|
bs->explicit_options = qdict_new();
|
|
bs->options = qdict_new();
|
|
bs->opaque = NULL;
|
|
|
|
update_options_from_flags(bs->options, flags);
|
|
|
|
ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp);
|
|
if (ret < 0) {
|
|
qobject_unref(bs->explicit_options);
|
|
bs->explicit_options = NULL;
|
|
qobject_unref(bs->options);
|
|
bs->options = NULL;
|
|
bdrv_unref(bs);
|
|
return NULL;
|
|
}
|
|
|
|
return bs;
|
|
}
|
|
|
|
QemuOptsList bdrv_runtime_opts = {
|
|
.name = "bdrv_common",
|
|
.head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
|
|
.desc = {
|
|
{
|
|
.name = "node-name",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "Node name of the block device node",
|
|
},
|
|
{
|
|
.name = "driver",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "Block driver to use for the node",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_CACHE_DIRECT,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Bypass software writeback cache on the host",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_CACHE_NO_FLUSH,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Ignore flush requests",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_READ_ONLY,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Node is opened in read-only mode",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_AUTO_READ_ONLY,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Node can become read-only if opening read-write fails",
|
|
},
|
|
{
|
|
.name = "detect-zeroes",
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "try to optimize zero writes (off, on, unmap)",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_DISCARD,
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "discard operation (ignore/off, unmap/on)",
|
|
},
|
|
{
|
|
.name = BDRV_OPT_FORCE_SHARE,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "always accept other writers (default: off)",
|
|
},
|
|
{ /* end of list */ }
|
|
},
|
|
};
|
|
|
|
/*
|
|
* Common part for opening disk images and files
|
|
*
|
|
* Removes all processed options from *options.
|
|
*/
|
|
static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
|
|
QDict *options, Error **errp)
|
|
{
|
|
int ret, open_flags;
|
|
const char *filename;
|
|
const char *driver_name = NULL;
|
|
const char *node_name = NULL;
|
|
const char *discard;
|
|
QemuOpts *opts;
|
|
BlockDriver *drv;
|
|
Error *local_err = NULL;
|
|
|
|
assert(bs->file == NULL);
|
|
assert(options != NULL && bs->options != options);
|
|
|
|
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
|
|
qemu_opts_absorb_qdict(opts, options, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
update_flags_from_options(&bs->open_flags, opts);
|
|
|
|
driver_name = qemu_opt_get(opts, "driver");
|
|
drv = bdrv_find_format(driver_name);
|
|
assert(drv != NULL);
|
|
|
|
bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false);
|
|
|
|
if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) {
|
|
error_setg(errp,
|
|
BDRV_OPT_FORCE_SHARE
|
|
"=on can only be used with read-only images");
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
if (file != NULL) {
|
|
bdrv_refresh_filename(blk_bs(file));
|
|
filename = blk_bs(file)->filename;
|
|
} else {
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting
|
|
* non-string types would require more care. When @options
|
|
* come from -blockdev or blockdev_add, its members are typed
|
|
* according to the QAPI schema, but when they come from
|
|
* -drive, they're all QString.
|
|
*/
|
|
filename = qdict_get_try_str(options, "filename");
|
|
}
|
|
|
|
if (drv->bdrv_needs_filename && (!filename || !filename[0])) {
|
|
error_setg(errp, "The '%s' block driver requires a file name",
|
|
drv->format_name);
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
trace_bdrv_open_common(bs, filename ?: "", bs->open_flags,
|
|
drv->format_name);
|
|
|
|
bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
|
|
|
|
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
|
|
if (!bs->read_only && bdrv_is_whitelisted(drv, true)) {
|
|
ret = bdrv_apply_auto_read_only(bs, NULL, NULL);
|
|
} else {
|
|
ret = -ENOTSUP;
|
|
}
|
|
if (ret < 0) {
|
|
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);
|
|
goto fail_opts;
|
|
}
|
|
}
|
|
|
|
/* bdrv_new() and bdrv_close() make it so */
|
|
assert(atomic_read(&bs->copy_on_read) == 0);
|
|
|
|
if (bs->open_flags & BDRV_O_COPY_ON_READ) {
|
|
if (!bs->read_only) {
|
|
bdrv_enable_copy_on_read(bs);
|
|
} else {
|
|
error_setg(errp, "Can't use copy-on-read on read-only device");
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
}
|
|
|
|
discard = qemu_opt_get(opts, BDRV_OPT_DISCARD);
|
|
if (discard != NULL) {
|
|
if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) {
|
|
error_setg(errp, "Invalid discard option");
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
}
|
|
|
|
bs->detect_zeroes =
|
|
bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto fail_opts;
|
|
}
|
|
|
|
if (filename != NULL) {
|
|
pstrcpy(bs->filename, sizeof(bs->filename), filename);
|
|
} else {
|
|
bs->filename[0] = '\0';
|
|
}
|
|
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
|
|
|
|
/* Open the image, either directly or using a protocol */
|
|
open_flags = bdrv_open_flags(bs, bs->open_flags);
|
|
node_name = qemu_opt_get(opts, "node-name");
|
|
|
|
assert(!drv->bdrv_file_open || file == NULL);
|
|
ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp);
|
|
if (ret < 0) {
|
|
goto fail_opts;
|
|
}
|
|
|
|
qemu_opts_del(opts);
|
|
return 0;
|
|
|
|
fail_opts:
|
|
qemu_opts_del(opts);
|
|
return ret;
|
|
}
|
|
|
|
static QDict *parse_json_filename(const char *filename, Error **errp)
|
|
{
|
|
QObject *options_obj;
|
|
QDict *options;
|
|
int ret;
|
|
|
|
ret = strstart(filename, "json:", &filename);
|
|
assert(ret);
|
|
|
|
options_obj = qobject_from_json(filename, errp);
|
|
if (!options_obj) {
|
|
error_prepend(errp, "Could not parse the JSON options: ");
|
|
return NULL;
|
|
}
|
|
|
|
options = qobject_to(QDict, options_obj);
|
|
if (!options) {
|
|
qobject_unref(options_obj);
|
|
error_setg(errp, "Invalid JSON object given");
|
|
return NULL;
|
|
}
|
|
|
|
qdict_flatten(options);
|
|
|
|
return options;
|
|
}
|
|
|
|
static void parse_json_protocol(QDict *options, const char **pfilename,
|
|
Error **errp)
|
|
{
|
|
QDict *json_options;
|
|
Error *local_err = NULL;
|
|
|
|
/* Parse json: pseudo-protocol */
|
|
if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
|
|
return;
|
|
}
|
|
|
|
json_options = parse_json_filename(*pfilename, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
|
|
/* Options given in the filename have lower priority than options
|
|
* specified directly */
|
|
qdict_join(options, json_options, false);
|
|
qobject_unref(json_options);
|
|
*pfilename = NULL;
|
|
}
|
|
|
|
/*
|
|
* Fills in default options for opening images and converts the legacy
|
|
* filename/flags pair to option QDict entries.
|
|
* The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
|
|
* block driver has been specified explicitly.
|
|
*/
|
|
static int bdrv_fill_options(QDict **options, const char *filename,
|
|
int *flags, Error **errp)
|
|
{
|
|
const char *drvname;
|
|
bool protocol = *flags & BDRV_O_PROTOCOL;
|
|
bool parse_filename = false;
|
|
BlockDriver *drv = NULL;
|
|
Error *local_err = NULL;
|
|
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting non-string
|
|
* types would require more care. When @options come from
|
|
* -blockdev or blockdev_add, its members are typed according to
|
|
* the QAPI schema, but when they come from -drive, they're all
|
|
* QString.
|
|
*/
|
|
drvname = qdict_get_try_str(*options, "driver");
|
|
if (drvname) {
|
|
drv = bdrv_find_format(drvname);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown driver '%s'", drvname);
|
|
return -ENOENT;
|
|
}
|
|
/* If the user has explicitly specified the driver, this choice should
|
|
* override the BDRV_O_PROTOCOL flag */
|
|
protocol = drv->bdrv_file_open;
|
|
}
|
|
|
|
if (protocol) {
|
|
*flags |= BDRV_O_PROTOCOL;
|
|
} else {
|
|
*flags &= ~BDRV_O_PROTOCOL;
|
|
}
|
|
|
|
/* Translate cache options from flags into options */
|
|
update_options_from_flags(*options, *flags);
|
|
|
|
/* Fetch the file name from the options QDict if necessary */
|
|
if (protocol && filename) {
|
|
if (!qdict_haskey(*options, "filename")) {
|
|
qdict_put_str(*options, "filename", 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 */
|
|
/* See cautionary note on accessing @options above */
|
|
filename = qdict_get_try_str(*options, "filename");
|
|
|
|
if (!drvname && protocol) {
|
|
if (filename) {
|
|
drv = bdrv_find_protocol(filename, parse_filename, errp);
|
|
if (!drv) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
drvname = drv->format_name;
|
|
qdict_put_str(*options, "driver", drvname);
|
|
} else {
|
|
error_setg(errp, "Must specify either driver or file");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
assert(drv || !protocol);
|
|
|
|
/* Driver-specific filename parsing */
|
|
if (drv && drv->bdrv_parse_filename && parse_filename) {
|
|
drv->bdrv_parse_filename(filename, *options, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!drv->bdrv_needs_filename) {
|
|
qdict_del(*options, "filename");
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
|
|
uint64_t perm, uint64_t shared,
|
|
GSList *ignore_children,
|
|
bool *tighten_restrictions, Error **errp);
|
|
static void bdrv_child_abort_perm_update(BdrvChild *c);
|
|
static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
|
|
static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
|
|
uint64_t *shared_perm);
|
|
|
|
typedef struct BlockReopenQueueEntry {
|
|
bool prepared;
|
|
bool perms_checked;
|
|
BDRVReopenState state;
|
|
QTAILQ_ENTRY(BlockReopenQueueEntry) entry;
|
|
} BlockReopenQueueEntry;
|
|
|
|
/*
|
|
* Return the flags that @bs will have after the reopens in @q have
|
|
* successfully completed. If @q is NULL (or @bs is not contained in @q),
|
|
* return the current flags.
|
|
*/
|
|
static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs)
|
|
{
|
|
BlockReopenQueueEntry *entry;
|
|
|
|
if (q != NULL) {
|
|
QTAILQ_FOREACH(entry, q, entry) {
|
|
if (entry->state.bs == bs) {
|
|
return entry->state.flags;
|
|
}
|
|
}
|
|
}
|
|
|
|
return bs->open_flags;
|
|
}
|
|
|
|
/* Returns whether the image file can be written to after the reopen queue @q
|
|
* has been successfully applied, or right now if @q is NULL. */
|
|
static bool bdrv_is_writable_after_reopen(BlockDriverState *bs,
|
|
BlockReopenQueue *q)
|
|
{
|
|
int flags = bdrv_reopen_get_flags(q, bs);
|
|
|
|
return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR;
|
|
}
|
|
|
|
/*
|
|
* Return whether the BDS can be written to. This is not necessarily
|
|
* the same as !bdrv_is_read_only(bs), as inactivated images may not
|
|
* be written to but do not count as read-only images.
|
|
*/
|
|
bool bdrv_is_writable(BlockDriverState *bs)
|
|
{
|
|
return bdrv_is_writable_after_reopen(bs, NULL);
|
|
}
|
|
|
|
static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
|
|
BdrvChild *c, const BdrvChildRole *role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t parent_perm, uint64_t parent_shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
assert(bs->drv && bs->drv->bdrv_child_perm);
|
|
bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
|
|
parent_perm, parent_shared,
|
|
nperm, nshared);
|
|
/* TODO Take force_share from reopen_queue */
|
|
if (child_bs && child_bs->force_share) {
|
|
*nshared = BLK_PERM_ALL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check whether permissions on this node can be changed in a way that
|
|
* @cumulative_perms and @cumulative_shared_perms are the new cumulative
|
|
* permissions of all its parents. This involves checking whether all necessary
|
|
* permission changes to child nodes can be performed.
|
|
*
|
|
* Will set *tighten_restrictions to true if and only if new permissions have to
|
|
* be taken or currently shared permissions are to be unshared. Otherwise,
|
|
* errors are not fatal as long as the caller accepts that the restrictions
|
|
* remain tighter than they need to be. The caller still has to abort the
|
|
* transaction.
|
|
* @tighten_restrictions cannot be used together with @q: When reopening, we may
|
|
* encounter fatal errors even though no restrictions are to be tightened. For
|
|
* example, changing a node from RW to RO will fail if the WRITE permission is
|
|
* to be kept.
|
|
*
|
|
* A call to this function must always be followed by a call to bdrv_set_perm()
|
|
* or bdrv_abort_perm_update().
|
|
*/
|
|
static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q,
|
|
uint64_t cumulative_perms,
|
|
uint64_t cumulative_shared_perms,
|
|
GSList *ignore_children,
|
|
bool *tighten_restrictions, Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *c;
|
|
int ret;
|
|
|
|
assert(!q || !tighten_restrictions);
|
|
|
|
if (tighten_restrictions) {
|
|
uint64_t current_perms, current_shared;
|
|
uint64_t added_perms, removed_shared_perms;
|
|
|
|
bdrv_get_cumulative_perm(bs, ¤t_perms, ¤t_shared);
|
|
|
|
added_perms = cumulative_perms & ~current_perms;
|
|
removed_shared_perms = current_shared & ~cumulative_shared_perms;
|
|
|
|
*tighten_restrictions = added_perms || removed_shared_perms;
|
|
}
|
|
|
|
/* Write permissions never work with read-only images */
|
|
if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
|
|
!bdrv_is_writable_after_reopen(bs, q))
|
|
{
|
|
if (!bdrv_is_writable_after_reopen(bs, NULL)) {
|
|
error_setg(errp, "Block node is read-only");
|
|
} else {
|
|
uint64_t current_perms, current_shared;
|
|
bdrv_get_cumulative_perm(bs, ¤t_perms, ¤t_shared);
|
|
if (current_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
|
|
error_setg(errp, "Cannot make block node read-only, there is "
|
|
"a writer on it");
|
|
} else {
|
|
error_setg(errp, "Cannot make block node read-only and create "
|
|
"a writer on it");
|
|
}
|
|
}
|
|
|
|
return -EPERM;
|
|
}
|
|
|
|
/* Check this node */
|
|
if (!drv) {
|
|
return 0;
|
|
}
|
|
|
|
if (drv->bdrv_check_perm) {
|
|
return drv->bdrv_check_perm(bs, cumulative_perms,
|
|
cumulative_shared_perms, errp);
|
|
}
|
|
|
|
/* Drivers that never have children can omit .bdrv_child_perm() */
|
|
if (!drv->bdrv_child_perm) {
|
|
assert(QLIST_EMPTY(&bs->children));
|
|
return 0;
|
|
}
|
|
|
|
/* Check all children */
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
uint64_t cur_perm, cur_shared;
|
|
bool child_tighten_restr;
|
|
|
|
bdrv_child_perm(bs, c->bs, c, c->role, q,
|
|
cumulative_perms, cumulative_shared_perms,
|
|
&cur_perm, &cur_shared);
|
|
ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared, ignore_children,
|
|
tighten_restrictions ? &child_tighten_restr
|
|
: NULL,
|
|
errp);
|
|
if (tighten_restrictions) {
|
|
*tighten_restrictions |= child_tighten_restr;
|
|
}
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Notifies drivers that after a previous bdrv_check_perm() call, the
|
|
* permission update is not performed and any preparations made for it (e.g.
|
|
* taken file locks) need to be undone.
|
|
*
|
|
* This function recursively notifies all child nodes.
|
|
*/
|
|
static void bdrv_abort_perm_update(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *c;
|
|
|
|
if (!drv) {
|
|
return;
|
|
}
|
|
|
|
if (drv->bdrv_abort_perm_update) {
|
|
drv->bdrv_abort_perm_update(bs);
|
|
}
|
|
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
bdrv_child_abort_perm_update(c);
|
|
}
|
|
}
|
|
|
|
static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms,
|
|
uint64_t cumulative_shared_perms)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *c;
|
|
|
|
if (!drv) {
|
|
return;
|
|
}
|
|
|
|
/* Update this node */
|
|
if (drv->bdrv_set_perm) {
|
|
drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms);
|
|
}
|
|
|
|
/* Drivers that never have children can omit .bdrv_child_perm() */
|
|
if (!drv->bdrv_child_perm) {
|
|
assert(QLIST_EMPTY(&bs->children));
|
|
return;
|
|
}
|
|
|
|
/* Update all children */
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
uint64_t cur_perm, cur_shared;
|
|
bdrv_child_perm(bs, c->bs, c, c->role, NULL,
|
|
cumulative_perms, cumulative_shared_perms,
|
|
&cur_perm, &cur_shared);
|
|
bdrv_child_set_perm(c, cur_perm, cur_shared);
|
|
}
|
|
}
|
|
|
|
static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
|
|
uint64_t *shared_perm)
|
|
{
|
|
BdrvChild *c;
|
|
uint64_t cumulative_perms = 0;
|
|
uint64_t cumulative_shared_perms = BLK_PERM_ALL;
|
|
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
cumulative_perms |= c->perm;
|
|
cumulative_shared_perms &= c->shared_perm;
|
|
}
|
|
|
|
*perm = cumulative_perms;
|
|
*shared_perm = cumulative_shared_perms;
|
|
}
|
|
|
|
static char *bdrv_child_user_desc(BdrvChild *c)
|
|
{
|
|
if (c->role->get_parent_desc) {
|
|
return c->role->get_parent_desc(c);
|
|
}
|
|
|
|
return g_strdup("another user");
|
|
}
|
|
|
|
char *bdrv_perm_names(uint64_t perm)
|
|
{
|
|
struct perm_name {
|
|
uint64_t perm;
|
|
const char *name;
|
|
} permissions[] = {
|
|
{ BLK_PERM_CONSISTENT_READ, "consistent read" },
|
|
{ BLK_PERM_WRITE, "write" },
|
|
{ BLK_PERM_WRITE_UNCHANGED, "write unchanged" },
|
|
{ BLK_PERM_RESIZE, "resize" },
|
|
{ BLK_PERM_GRAPH_MOD, "change children" },
|
|
{ 0, NULL }
|
|
};
|
|
|
|
char *result = g_strdup("");
|
|
struct perm_name *p;
|
|
|
|
for (p = permissions; p->name; p++) {
|
|
if (perm & p->perm) {
|
|
char *old = result;
|
|
result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name);
|
|
g_free(old);
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Checks whether a new reference to @bs can be added if the new user requires
|
|
* @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
|
|
* set, the BdrvChild objects in this list are ignored in the calculations;
|
|
* this allows checking permission updates for an existing reference.
|
|
*
|
|
* See bdrv_check_perm() for the semantics of @tighten_restrictions.
|
|
*
|
|
* Needs to be followed by a call to either bdrv_set_perm() or
|
|
* bdrv_abort_perm_update(). */
|
|
static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q,
|
|
uint64_t new_used_perm,
|
|
uint64_t new_shared_perm,
|
|
GSList *ignore_children,
|
|
bool *tighten_restrictions,
|
|
Error **errp)
|
|
{
|
|
BdrvChild *c;
|
|
uint64_t cumulative_perms = new_used_perm;
|
|
uint64_t cumulative_shared_perms = new_shared_perm;
|
|
|
|
assert(!q || !tighten_restrictions);
|
|
|
|
/* There is no reason why anyone couldn't tolerate write_unchanged */
|
|
assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED);
|
|
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (g_slist_find(ignore_children, c)) {
|
|
continue;
|
|
}
|
|
|
|
if ((new_used_perm & c->shared_perm) != new_used_perm) {
|
|
char *user = bdrv_child_user_desc(c);
|
|
char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm);
|
|
|
|
if (tighten_restrictions) {
|
|
*tighten_restrictions = true;
|
|
}
|
|
|
|
error_setg(errp, "Conflicts with use by %s as '%s', which does not "
|
|
"allow '%s' on %s",
|
|
user, c->name, perm_names, bdrv_get_node_name(c->bs));
|
|
g_free(user);
|
|
g_free(perm_names);
|
|
return -EPERM;
|
|
}
|
|
|
|
if ((c->perm & new_shared_perm) != c->perm) {
|
|
char *user = bdrv_child_user_desc(c);
|
|
char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm);
|
|
|
|
if (tighten_restrictions) {
|
|
*tighten_restrictions = true;
|
|
}
|
|
|
|
error_setg(errp, "Conflicts with use by %s as '%s', which uses "
|
|
"'%s' on %s",
|
|
user, c->name, perm_names, bdrv_get_node_name(c->bs));
|
|
g_free(user);
|
|
g_free(perm_names);
|
|
return -EPERM;
|
|
}
|
|
|
|
cumulative_perms |= c->perm;
|
|
cumulative_shared_perms &= c->shared_perm;
|
|
}
|
|
|
|
return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms,
|
|
ignore_children, tighten_restrictions, errp);
|
|
}
|
|
|
|
/* Needs to be followed by a call to either bdrv_child_set_perm() or
|
|
* bdrv_child_abort_perm_update(). */
|
|
static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
|
|
uint64_t perm, uint64_t shared,
|
|
GSList *ignore_children,
|
|
bool *tighten_restrictions, Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c);
|
|
ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children,
|
|
tighten_restrictions, errp);
|
|
g_slist_free(ignore_children);
|
|
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (!c->has_backup_perm) {
|
|
c->has_backup_perm = true;
|
|
c->backup_perm = c->perm;
|
|
c->backup_shared_perm = c->shared_perm;
|
|
}
|
|
/*
|
|
* Note: it's OK if c->has_backup_perm was already set, as we can find the
|
|
* same child twice during check_perm procedure
|
|
*/
|
|
|
|
c->perm = perm;
|
|
c->shared_perm = shared;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
|
|
{
|
|
uint64_t cumulative_perms, cumulative_shared_perms;
|
|
|
|
c->has_backup_perm = false;
|
|
|
|
c->perm = perm;
|
|
c->shared_perm = shared;
|
|
|
|
bdrv_get_cumulative_perm(c->bs, &cumulative_perms,
|
|
&cumulative_shared_perms);
|
|
bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms);
|
|
}
|
|
|
|
static void bdrv_child_abort_perm_update(BdrvChild *c)
|
|
{
|
|
if (c->has_backup_perm) {
|
|
c->perm = c->backup_perm;
|
|
c->shared_perm = c->backup_shared_perm;
|
|
c->has_backup_perm = false;
|
|
}
|
|
|
|
bdrv_abort_perm_update(c->bs);
|
|
}
|
|
|
|
int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
|
|
Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
bool tighten_restrictions;
|
|
|
|
ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL,
|
|
&tighten_restrictions, &local_err);
|
|
if (ret < 0) {
|
|
bdrv_child_abort_perm_update(c);
|
|
if (tighten_restrictions) {
|
|
error_propagate(errp, local_err);
|
|
} else {
|
|
/*
|
|
* Our caller may intend to only loosen restrictions and
|
|
* does not expect this function to fail. Errors are not
|
|
* fatal in such a case, so we can just hide them from our
|
|
* caller.
|
|
*/
|
|
error_free(local_err);
|
|
ret = 0;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
bdrv_child_set_perm(c, perm, shared);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_child_refresh_perms(BlockDriverState *bs, BdrvChild *c, Error **errp)
|
|
{
|
|
uint64_t parent_perms, parent_shared;
|
|
uint64_t perms, shared;
|
|
|
|
bdrv_get_cumulative_perm(bs, &parent_perms, &parent_shared);
|
|
bdrv_child_perm(bs, c->bs, c, c->role, NULL, parent_perms, parent_shared,
|
|
&perms, &shared);
|
|
|
|
return bdrv_child_try_set_perm(c, perms, shared, errp);
|
|
}
|
|
|
|
void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
|
|
const BdrvChildRole *role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
*nperm = perm & DEFAULT_PERM_PASSTHROUGH;
|
|
*nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
|
|
}
|
|
|
|
void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
|
|
const BdrvChildRole *role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
bool backing = (role == &child_backing);
|
|
assert(role == &child_backing || role == &child_file);
|
|
|
|
if (!backing) {
|
|
int flags = bdrv_reopen_get_flags(reopen_queue, bs);
|
|
|
|
/* Apart from the modifications below, the same permissions are
|
|
* forwarded and left alone as for filters */
|
|
bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared,
|
|
&perm, &shared);
|
|
|
|
/* Format drivers may touch metadata even if the guest doesn't write */
|
|
if (bdrv_is_writable_after_reopen(bs, reopen_queue)) {
|
|
perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
}
|
|
|
|
/* bs->file always needs to be consistent because of the metadata. We
|
|
* can never allow other users to resize or write to it. */
|
|
if (!(flags & BDRV_O_NO_IO)) {
|
|
perm |= BLK_PERM_CONSISTENT_READ;
|
|
}
|
|
shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
|
|
} else {
|
|
/* We want consistent read from backing files if the parent needs it.
|
|
* No other operations are performed on backing files. */
|
|
perm &= BLK_PERM_CONSISTENT_READ;
|
|
|
|
/* If the parent can deal with changing data, we're okay with a
|
|
* writable and resizable backing file. */
|
|
/* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
|
|
if (shared & BLK_PERM_WRITE) {
|
|
shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
} else {
|
|
shared = 0;
|
|
}
|
|
|
|
shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
|
|
BLK_PERM_WRITE_UNCHANGED;
|
|
}
|
|
|
|
if (bs->open_flags & BDRV_O_INACTIVE) {
|
|
shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
|
|
}
|
|
|
|
*nperm = perm;
|
|
*nshared = shared;
|
|
}
|
|
|
|
static void bdrv_replace_child_noperm(BdrvChild *child,
|
|
BlockDriverState *new_bs)
|
|
{
|
|
BlockDriverState *old_bs = child->bs;
|
|
int new_bs_quiesce_counter;
|
|
int drain_saldo;
|
|
|
|
assert(!child->frozen);
|
|
|
|
if (old_bs && new_bs) {
|
|
assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
|
|
}
|
|
|
|
new_bs_quiesce_counter = (new_bs ? new_bs->quiesce_counter : 0);
|
|
drain_saldo = new_bs_quiesce_counter - child->parent_quiesce_counter;
|
|
|
|
/*
|
|
* If the new child node is drained but the old one was not, flush
|
|
* all outstanding requests to the old child node.
|
|
*/
|
|
while (drain_saldo > 0 && child->role->drained_begin) {
|
|
bdrv_parent_drained_begin_single(child, true);
|
|
drain_saldo--;
|
|
}
|
|
|
|
if (old_bs) {
|
|
/* Detach first so that the recursive drain sections coming from @child
|
|
* are already gone and we only end the drain sections that came from
|
|
* elsewhere. */
|
|
if (child->role->detach) {
|
|
child->role->detach(child);
|
|
}
|
|
QLIST_REMOVE(child, next_parent);
|
|
}
|
|
|
|
child->bs = new_bs;
|
|
|
|
if (new_bs) {
|
|
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
|
|
|
|
/*
|
|
* Detaching the old node may have led to the new node's
|
|
* quiesce_counter having been decreased. Not a problem, we
|
|
* just need to recognize this here and then invoke
|
|
* drained_end appropriately more often.
|
|
*/
|
|
assert(new_bs->quiesce_counter <= new_bs_quiesce_counter);
|
|
drain_saldo += new_bs->quiesce_counter - new_bs_quiesce_counter;
|
|
|
|
/* Attach only after starting new drained sections, so that recursive
|
|
* drain sections coming from @child don't get an extra .drained_begin
|
|
* callback. */
|
|
if (child->role->attach) {
|
|
child->role->attach(child);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the old child node was drained but the new one is not, allow
|
|
* requests to come in only after the new node has been attached.
|
|
*/
|
|
while (drain_saldo < 0 && child->role->drained_end) {
|
|
bdrv_parent_drained_end_single(child);
|
|
drain_saldo++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Updates @child to change its reference to point to @new_bs, including
|
|
* checking and applying the necessary permisson updates both to the old node
|
|
* and to @new_bs.
|
|
*
|
|
* NULL is passed as @new_bs for removing the reference before freeing @child.
|
|
*
|
|
* If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
|
|
* function uses bdrv_set_perm() to update the permissions according to the new
|
|
* reference that @new_bs gets.
|
|
*/
|
|
static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
|
|
{
|
|
BlockDriverState *old_bs = child->bs;
|
|
uint64_t perm, shared_perm;
|
|
|
|
bdrv_replace_child_noperm(child, new_bs);
|
|
|
|
/*
|
|
* Start with the new node's permissions. If @new_bs is a (direct
|
|
* or indirect) child of @old_bs, we must complete the permission
|
|
* update on @new_bs before we loosen the restrictions on @old_bs.
|
|
* Otherwise, bdrv_check_perm() on @old_bs would re-initiate
|
|
* updating the permissions of @new_bs, and thus not purely loosen
|
|
* restrictions.
|
|
*/
|
|
if (new_bs) {
|
|
bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
|
|
bdrv_set_perm(new_bs, perm, shared_perm);
|
|
}
|
|
|
|
if (old_bs) {
|
|
/* Update permissions for old node. This is guaranteed to succeed
|
|
* because we're just taking a parent away, so we're loosening
|
|
* restrictions. */
|
|
bool tighten_restrictions;
|
|
int ret;
|
|
|
|
bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
|
|
ret = bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL,
|
|
&tighten_restrictions, NULL);
|
|
assert(tighten_restrictions == false);
|
|
if (ret < 0) {
|
|
/* We only tried to loosen restrictions, so errors are not fatal */
|
|
bdrv_abort_perm_update(old_bs);
|
|
} else {
|
|
bdrv_set_perm(old_bs, perm, shared_perm);
|
|
}
|
|
|
|
/* When the parent requiring a non-default AioContext is removed, the
|
|
* node moves back to the main AioContext */
|
|
bdrv_try_set_aio_context(old_bs, qemu_get_aio_context(), NULL);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function steals the reference to child_bs from the caller.
|
|
* That reference is later dropped by bdrv_root_unref_child().
|
|
*
|
|
* On failure NULL is returned, errp is set and the reference to
|
|
* child_bs is also dropped.
|
|
*
|
|
* The caller must hold the AioContext lock @child_bs, but not that of @ctx
|
|
* (unless @child_bs is already in @ctx).
|
|
*/
|
|
BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
|
|
const char *child_name,
|
|
const BdrvChildRole *child_role,
|
|
AioContext *ctx,
|
|
uint64_t perm, uint64_t shared_perm,
|
|
void *opaque, Error **errp)
|
|
{
|
|
BdrvChild *child;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, NULL,
|
|
errp);
|
|
if (ret < 0) {
|
|
bdrv_abort_perm_update(child_bs);
|
|
bdrv_unref(child_bs);
|
|
return NULL;
|
|
}
|
|
|
|
child = g_new(BdrvChild, 1);
|
|
*child = (BdrvChild) {
|
|
.bs = NULL,
|
|
.name = g_strdup(child_name),
|
|
.role = child_role,
|
|
.perm = perm,
|
|
.shared_perm = shared_perm,
|
|
.opaque = opaque,
|
|
};
|
|
|
|
/* If the AioContexts don't match, first try to move the subtree of
|
|
* child_bs into the AioContext of the new parent. If this doesn't work,
|
|
* try moving the parent into the AioContext of child_bs instead. */
|
|
if (bdrv_get_aio_context(child_bs) != ctx) {
|
|
ret = bdrv_try_set_aio_context(child_bs, ctx, &local_err);
|
|
if (ret < 0 && child_role->can_set_aio_ctx) {
|
|
GSList *ignore = g_slist_prepend(NULL, child);;
|
|
ctx = bdrv_get_aio_context(child_bs);
|
|
if (child_role->can_set_aio_ctx(child, ctx, &ignore, NULL)) {
|
|
error_free(local_err);
|
|
ret = 0;
|
|
g_slist_free(ignore);
|
|
ignore = g_slist_prepend(NULL, child);;
|
|
child_role->set_aio_ctx(child, ctx, &ignore);
|
|
}
|
|
g_slist_free(ignore);
|
|
}
|
|
if (ret < 0) {
|
|
error_propagate(errp, local_err);
|
|
g_free(child);
|
|
bdrv_abort_perm_update(child_bs);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* This performs the matching bdrv_set_perm() for the above check. */
|
|
bdrv_replace_child(child, child_bs);
|
|
|
|
return child;
|
|
}
|
|
|
|
/*
|
|
* This function transfers the reference to child_bs from the caller
|
|
* to parent_bs. That reference is later dropped by parent_bs on
|
|
* bdrv_close() or if someone calls bdrv_unref_child().
|
|
*
|
|
* On failure NULL is returned, errp is set and the reference to
|
|
* child_bs is also dropped.
|
|
*
|
|
* If @parent_bs and @child_bs are in different AioContexts, the caller must
|
|
* hold the AioContext lock for @child_bs, but not for @parent_bs.
|
|
*/
|
|
BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
|
|
BlockDriverState *child_bs,
|
|
const char *child_name,
|
|
const BdrvChildRole *child_role,
|
|
Error **errp)
|
|
{
|
|
BdrvChild *child;
|
|
uint64_t perm, shared_perm;
|
|
|
|
bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
|
|
|
|
assert(parent_bs->drv);
|
|
bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL,
|
|
perm, shared_perm, &perm, &shared_perm);
|
|
|
|
child = bdrv_root_attach_child(child_bs, child_name, child_role,
|
|
bdrv_get_aio_context(parent_bs),
|
|
perm, shared_perm, parent_bs, errp);
|
|
if (child == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
QLIST_INSERT_HEAD(&parent_bs->children, child, next);
|
|
return child;
|
|
}
|
|
|
|
static void bdrv_detach_child(BdrvChild *child)
|
|
{
|
|
if (child->next.le_prev) {
|
|
QLIST_REMOVE(child, next);
|
|
child->next.le_prev = NULL;
|
|
}
|
|
|
|
bdrv_replace_child(child, NULL);
|
|
|
|
g_free(child->name);
|
|
g_free(child);
|
|
}
|
|
|
|
void bdrv_root_unref_child(BdrvChild *child)
|
|
{
|
|
BlockDriverState *child_bs;
|
|
|
|
child_bs = child->bs;
|
|
bdrv_detach_child(child);
|
|
bdrv_unref(child_bs);
|
|
}
|
|
|
|
/**
|
|
* Clear all inherits_from pointers from children and grandchildren of
|
|
* @root that point to @root, where necessary.
|
|
*/
|
|
static void bdrv_unset_inherits_from(BlockDriverState *root, BdrvChild *child)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (child->bs->inherits_from == root) {
|
|
/*
|
|
* Remove inherits_from only when the last reference between root and
|
|
* child->bs goes away.
|
|
*/
|
|
QLIST_FOREACH(c, &root->children, next) {
|
|
if (c != child && c->bs == child->bs) {
|
|
break;
|
|
}
|
|
}
|
|
if (c == NULL) {
|
|
child->bs->inherits_from = NULL;
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(c, &child->bs->children, next) {
|
|
bdrv_unset_inherits_from(root, c);
|
|
}
|
|
}
|
|
|
|
void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
|
|
{
|
|
if (child == NULL) {
|
|
return;
|
|
}
|
|
|
|
bdrv_unset_inherits_from(parent, child);
|
|
bdrv_root_unref_child(child);
|
|
}
|
|
|
|
|
|
static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
|
|
{
|
|
BdrvChild *c;
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (c->role->change_media) {
|
|
c->role->change_media(c, load);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Return true if you can reach parent going through child->inherits_from
|
|
* recursively. If parent or child are NULL, return false */
|
|
static bool bdrv_inherits_from_recursive(BlockDriverState *child,
|
|
BlockDriverState *parent)
|
|
{
|
|
while (child && child != parent) {
|
|
child = child->inherits_from;
|
|
}
|
|
|
|
return child != NULL;
|
|
}
|
|
|
|
/*
|
|
* Sets the backing file link of a BDS. A new reference is created; callers
|
|
* which don't need their own reference any more must call bdrv_unref().
|
|
*/
|
|
void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
|
|
Error **errp)
|
|
{
|
|
bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
|
|
bdrv_inherits_from_recursive(backing_hd, bs);
|
|
|
|
if (bdrv_is_backing_chain_frozen(bs, backing_bs(bs), errp)) {
|
|
return;
|
|
}
|
|
|
|
if (backing_hd) {
|
|
bdrv_ref(backing_hd);
|
|
}
|
|
|
|
if (bs->backing) {
|
|
bdrv_unref_child(bs, bs->backing);
|
|
}
|
|
|
|
if (!backing_hd) {
|
|
bs->backing = NULL;
|
|
goto out;
|
|
}
|
|
|
|
bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing,
|
|
errp);
|
|
/* If backing_hd was already part of bs's backing chain, and
|
|
* inherits_from pointed recursively to bs then let's update it to
|
|
* point directly to bs (else it will become NULL). */
|
|
if (bs->backing && update_inherits_from) {
|
|
backing_hd->inherits_from = bs;
|
|
}
|
|
|
|
out:
|
|
bdrv_refresh_limits(bs, NULL);
|
|
}
|
|
|
|
/*
|
|
* Opens the backing file for a BlockDriverState if not yet open
|
|
*
|
|
* bdref_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.
|
|
*
|
|
* TODO Can this be unified with bdrv_open_image()?
|
|
*/
|
|
int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
|
|
const char *bdref_key, Error **errp)
|
|
{
|
|
char *backing_filename = NULL;
|
|
char *bdref_key_dot;
|
|
const char *reference = NULL;
|
|
int ret = 0;
|
|
bool implicit_backing = false;
|
|
BlockDriverState *backing_hd;
|
|
QDict *options;
|
|
QDict *tmp_parent_options = NULL;
|
|
Error *local_err = NULL;
|
|
|
|
if (bs->backing != NULL) {
|
|
goto free_exit;
|
|
}
|
|
|
|
/* NULL means an empty set of options */
|
|
if (parent_options == NULL) {
|
|
tmp_parent_options = qdict_new();
|
|
parent_options = tmp_parent_options;
|
|
}
|
|
|
|
bs->open_flags &= ~BDRV_O_NO_BACKING;
|
|
|
|
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
|
|
qdict_extract_subqdict(parent_options, &options, bdref_key_dot);
|
|
g_free(bdref_key_dot);
|
|
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting non-string
|
|
* types would require more care. When @parent_options come from
|
|
* -blockdev or blockdev_add, its members are typed according to
|
|
* the QAPI schema, but when they come from -drive, they're all
|
|
* QString.
|
|
*/
|
|
reference = qdict_get_try_str(parent_options, bdref_key);
|
|
if (reference || qdict_haskey(options, "file.filename")) {
|
|
/* keep backing_filename NULL */
|
|
} else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
|
|
qobject_unref(options);
|
|
goto free_exit;
|
|
} else {
|
|
if (qdict_size(options) == 0) {
|
|
/* If the user specifies options that do not modify the
|
|
* backing file's behavior, we might still consider it the
|
|
* implicit backing file. But it's easier this way, and
|
|
* just specifying some of the backing BDS's options is
|
|
* only possible with -drive anyway (otherwise the QAPI
|
|
* schema forces the user to specify everything). */
|
|
implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file);
|
|
}
|
|
|
|
backing_filename = bdrv_get_full_backing_filename(bs, &local_err);
|
|
if (local_err) {
|
|
ret = -EINVAL;
|
|
error_propagate(errp, local_err);
|
|
qobject_unref(options);
|
|
goto free_exit;
|
|
}
|
|
}
|
|
|
|
if (!bs->drv || !bs->drv->supports_backing) {
|
|
ret = -EINVAL;
|
|
error_setg(errp, "Driver doesn't support backing files");
|
|
qobject_unref(options);
|
|
goto free_exit;
|
|
}
|
|
|
|
if (!reference &&
|
|
bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
|
|
qdict_put_str(options, "driver", bs->backing_format);
|
|
}
|
|
|
|
backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs,
|
|
&child_backing, errp);
|
|
if (!backing_hd) {
|
|
bs->open_flags |= BDRV_O_NO_BACKING;
|
|
error_prepend(errp, "Could not open backing file: ");
|
|
ret = -EINVAL;
|
|
goto free_exit;
|
|
}
|
|
|
|
if (implicit_backing) {
|
|
bdrv_refresh_filename(backing_hd);
|
|
pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
|
|
backing_hd->filename);
|
|
}
|
|
|
|
/* Hook up the backing file link; drop our reference, bs owns the
|
|
* backing_hd reference now */
|
|
bdrv_set_backing_hd(bs, backing_hd, &local_err);
|
|
bdrv_unref(backing_hd);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto free_exit;
|
|
}
|
|
|
|
qdict_del(parent_options, bdref_key);
|
|
|
|
free_exit:
|
|
g_free(backing_filename);
|
|
qobject_unref(tmp_parent_options);
|
|
return ret;
|
|
}
|
|
|
|
static BlockDriverState *
|
|
bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key,
|
|
BlockDriverState *parent, const BdrvChildRole *child_role,
|
|
bool allow_none, Error **errp)
|
|
{
|
|
BlockDriverState *bs = NULL;
|
|
QDict *image_options;
|
|
char *bdref_key_dot;
|
|
const char *reference;
|
|
|
|
assert(child_role != NULL);
|
|
|
|
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
|
|
qdict_extract_subqdict(options, &image_options, bdref_key_dot);
|
|
g_free(bdref_key_dot);
|
|
|
|
/*
|
|
* Caution: while qdict_get_try_str() is fine, getting non-string
|
|
* types would require more care. When @options come from
|
|
* -blockdev or blockdev_add, its members are typed according to
|
|
* the QAPI schema, but when they come from -drive, they're all
|
|
* QString.
|
|
*/
|
|
reference = qdict_get_try_str(options, bdref_key);
|
|
if (!filename && !reference && !qdict_size(image_options)) {
|
|
if (!allow_none) {
|
|
error_setg(errp, "A block device must be specified for \"%s\"",
|
|
bdref_key);
|
|
}
|
|
qobject_unref(image_options);
|
|
goto done;
|
|
}
|
|
|
|
bs = bdrv_open_inherit(filename, reference, image_options, 0,
|
|
parent, child_role, errp);
|
|
if (!bs) {
|
|
goto done;
|
|
}
|
|
|
|
done:
|
|
qdict_del(options, bdref_key);
|
|
return bs;
|
|
}
|
|
|
|
/*
|
|
* Opens a disk image whose options are given as BlockdevRef in another block
|
|
* device's options.
|
|
*
|
|
* If allow_none is true, no image will be opened if filename is false and no
|
|
* BlockdevRef is given. NULL will be returned, but errp remains unset.
|
|
*
|
|
* bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
|
|
* That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
|
|
* itself, all options starting with "${bdref_key}." are considered part of the
|
|
* BlockdevRef.
|
|
*
|
|
* The BlockdevRef will be removed from the options QDict.
|
|
*/
|
|
BdrvChild *bdrv_open_child(const char *filename,
|
|
QDict *options, const char *bdref_key,
|
|
BlockDriverState *parent,
|
|
const BdrvChildRole *child_role,
|
|
bool allow_none, Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role,
|
|
allow_none, errp);
|
|
if (bs == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
return bdrv_attach_child(parent, bs, bdref_key, child_role, errp);
|
|
}
|
|
|
|
/* TODO Future callers may need to specify parent/child_role in order for
|
|
* option inheritance to work. Existing callers use it for the root node. */
|
|
BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp)
|
|
{
|
|
BlockDriverState *bs = NULL;
|
|
Error *local_err = NULL;
|
|
QObject *obj = NULL;
|
|
QDict *qdict = NULL;
|
|
const char *reference = NULL;
|
|
Visitor *v = NULL;
|
|
|
|
if (ref->type == QTYPE_QSTRING) {
|
|
reference = ref->u.reference;
|
|
} else {
|
|
BlockdevOptions *options = &ref->u.definition;
|
|
assert(ref->type == QTYPE_QDICT);
|
|
|
|
v = qobject_output_visitor_new(&obj);
|
|
visit_type_BlockdevOptions(v, NULL, &options, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
visit_complete(v, &obj);
|
|
|
|
qdict = qobject_to(QDict, obj);
|
|
qdict_flatten(qdict);
|
|
|
|
/* bdrv_open_inherit() defaults to the values in bdrv_flags (for
|
|
* compatibility with other callers) rather than what we want as the
|
|
* real defaults. Apply the defaults here instead. */
|
|
qdict_set_default_str(qdict, BDRV_OPT_CACHE_DIRECT, "off");
|
|
qdict_set_default_str(qdict, BDRV_OPT_CACHE_NO_FLUSH, "off");
|
|
qdict_set_default_str(qdict, BDRV_OPT_READ_ONLY, "off");
|
|
qdict_set_default_str(qdict, BDRV_OPT_AUTO_READ_ONLY, "off");
|
|
|
|
}
|
|
|
|
bs = bdrv_open_inherit(NULL, reference, qdict, 0, NULL, NULL, errp);
|
|
obj = NULL;
|
|
|
|
fail:
|
|
qobject_unref(obj);
|
|
visit_free(v);
|
|
return bs;
|
|
}
|
|
|
|
static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
|
|
int flags,
|
|
QDict *snapshot_options,
|
|
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;
|
|
BlockDriverState *bs_snapshot = NULL;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
|
|
/* if snapshot, we create a temporary backing file and open it
|
|
instead of opening 'filename' directly */
|
|
|
|
/* Get the required size from the image */
|
|
total_size = bdrv_getlength(bs);
|
|
if (total_size < 0) {
|
|
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, errp);
|
|
qemu_opts_del(opts);
|
|
if (ret < 0) {
|
|
error_prepend(errp, "Could not create temporary overlay '%s': ",
|
|
tmp_filename);
|
|
goto out;
|
|
}
|
|
|
|
/* Prepare options QDict for the temporary file */
|
|
qdict_put_str(snapshot_options, "file.driver", "file");
|
|
qdict_put_str(snapshot_options, "file.filename", tmp_filename);
|
|
qdict_put_str(snapshot_options, "driver", "qcow2");
|
|
|
|
bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp);
|
|
snapshot_options = NULL;
|
|
if (!bs_snapshot) {
|
|
goto out;
|
|
}
|
|
|
|
/* bdrv_append() consumes a strong reference to bs_snapshot
|
|
* (i.e. it will call bdrv_unref() on it) even on error, so in
|
|
* order to be able to return one, we have to increase
|
|
* bs_snapshot's refcount here */
|
|
bdrv_ref(bs_snapshot);
|
|
bdrv_append(bs_snapshot, bs, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
bs_snapshot = NULL;
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
qobject_unref(snapshot_options);
|
|
g_free(tmp_filename);
|
|
return bs_snapshot;
|
|
}
|
|
|
|
/*
|
|
* 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 qobject_ref() before calling bdrv_open.
|
|
*
|
|
* If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
|
|
* If it is not NULL, the referenced BDS will be reused.
|
|
*
|
|
* The reference parameter may be used to specify an existing block device which
|
|
* should be opened. If specified, neither options nor a filename may be given,
|
|
* nor can an existing BDS be reused (that is, *pbs has to be NULL).
|
|
*/
|
|
static BlockDriverState *bdrv_open_inherit(const char *filename,
|
|
const char *reference,
|
|
QDict *options, int flags,
|
|
BlockDriverState *parent,
|
|
const BdrvChildRole *child_role,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
BlockBackend *file = NULL;
|
|
BlockDriverState *bs;
|
|
BlockDriver *drv = NULL;
|
|
BdrvChild *child;
|
|
const char *drvname;
|
|
const char *backing;
|
|
Error *local_err = NULL;
|
|
QDict *snapshot_options = NULL;
|
|
int snapshot_flags = 0;
|
|
|
|
assert(!child_role || !flags);
|
|
assert(!child_role == !parent);
|
|
|
|
if (reference) {
|
|
bool options_non_empty = options ? qdict_size(options) : false;
|
|
qobject_unref(options);
|
|
|
|
if (filename || options_non_empty) {
|
|
error_setg(errp, "Cannot reference an existing block device with "
|
|
"additional options or a new filename");
|
|
return NULL;
|
|
}
|
|
|
|
bs = bdrv_lookup_bs(reference, reference, errp);
|
|
if (!bs) {
|
|
return NULL;
|
|
}
|
|
|
|
bdrv_ref(bs);
|
|
return bs;
|
|
}
|
|
|
|
bs = bdrv_new();
|
|
|
|
/* NULL means an empty set of options */
|
|
if (options == NULL) {
|
|
options = qdict_new();
|
|
}
|
|
|
|
/* json: syntax counts as explicit options, as if in the QDict */
|
|
parse_json_protocol(options, &filename, &local_err);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
|
|
bs->explicit_options = qdict_clone_shallow(options);
|
|
|
|
if (child_role) {
|
|
bs->inherits_from = parent;
|
|
child_role->inherit_options(&flags, options,
|
|
parent->open_flags, parent->options);
|
|
}
|
|
|
|
ret = bdrv_fill_options(&options, filename, &flags, &local_err);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
|
|
* Caution: getting a boolean member of @options requires care.
|
|
* When @options come from -blockdev or blockdev_add, members are
|
|
* typed according to the QAPI schema, but when they come from
|
|
* -drive, they're all QString.
|
|
*/
|
|
if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") &&
|
|
!qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) {
|
|
flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR);
|
|
} else {
|
|
flags &= ~BDRV_O_RDWR;
|
|
}
|
|
|
|
if (flags & BDRV_O_SNAPSHOT) {
|
|
snapshot_options = qdict_new();
|
|
bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options,
|
|
flags, options);
|
|
/* Let bdrv_backing_options() override "read-only" */
|
|
qdict_del(options, BDRV_OPT_READ_ONLY);
|
|
bdrv_backing_options(&flags, options, flags, options);
|
|
}
|
|
|
|
bs->open_flags = flags;
|
|
bs->options = options;
|
|
options = qdict_clone_shallow(options);
|
|
|
|
/* Find the right image format driver */
|
|
/* See cautionary note on accessing @options above */
|
|
drvname = qdict_get_try_str(options, "driver");
|
|
if (drvname) {
|
|
drv = bdrv_find_format(drvname);
|
|
if (!drv) {
|
|
error_setg(errp, "Unknown driver: '%s'", drvname);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
assert(drvname || !(flags & BDRV_O_PROTOCOL));
|
|
|
|
/* See cautionary note on accessing @options above */
|
|
backing = qdict_get_try_str(options, "backing");
|
|
if (qobject_to(QNull, qdict_get(options, "backing")) != NULL ||
|
|
(backing && *backing == '\0'))
|
|
{
|
|
if (backing) {
|
|
warn_report("Use of \"backing\": \"\" is deprecated; "
|
|
"use \"backing\": null instead");
|
|
}
|
|
flags |= BDRV_O_NO_BACKING;
|
|
qdict_del(bs->explicit_options, "backing");
|
|
qdict_del(bs->options, "backing");
|
|
qdict_del(options, "backing");
|
|
}
|
|
|
|
/* Open image file without format layer. This BlockBackend is only used for
|
|
* probing, the block drivers will do their own bdrv_open_child() for the
|
|
* same BDS, which is why we put the node name back into options. */
|
|
if ((flags & BDRV_O_PROTOCOL) == 0) {
|
|
BlockDriverState *file_bs;
|
|
|
|
file_bs = bdrv_open_child_bs(filename, options, "file", bs,
|
|
&child_file, true, &local_err);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
if (file_bs != NULL) {
|
|
/* Not requesting BLK_PERM_CONSISTENT_READ because we're only
|
|
* looking at the header to guess the image format. This works even
|
|
* in cases where a guest would not see a consistent state. */
|
|
file = blk_new(bdrv_get_aio_context(file_bs), 0, BLK_PERM_ALL);
|
|
blk_insert_bs(file, file_bs, &local_err);
|
|
bdrv_unref(file_bs);
|
|
if (local_err) {
|
|
goto fail;
|
|
}
|
|
|
|
qdict_put_str(options, "file", bdrv_get_node_name(file_bs));
|
|
}
|
|
}
|
|
|
|
/* Image format probing */
|
|
bs->probed = !drv;
|
|
if (!drv && file) {
|
|
ret = find_image_format(file, filename, &drv, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
/*
|
|
* This option update would logically belong in bdrv_fill_options(),
|
|
* but we first need to open bs->file for the probing to work, while
|
|
* opening bs->file already requires the (mostly) final set of options
|
|
* so that cache mode etc. can be inherited.
|
|
*
|
|
* Adding the driver later is somewhat ugly, but it's not an option
|
|
* that would ever be inherited, so it's correct. We just need to make
|
|
* sure to update both bs->options (which has the full effective
|
|
* options for bs) and options (which has file.* already removed).
|
|
*/
|
|
qdict_put_str(bs->options, "driver", drv->format_name);
|
|
qdict_put_str(options, "driver", drv->format_name);
|
|
} else if (!drv) {
|
|
error_setg(errp, "Must specify either driver or file");
|
|
goto fail;
|
|
}
|
|
|
|
/* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
|
|
assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open);
|
|
/* file must be NULL if a protocol BDS is about to be created
|
|
* (the inverse results in an error message from bdrv_open_common()) */
|
|
assert(!(flags & BDRV_O_PROTOCOL) || !file);
|
|
|
|
/* Open the image */
|
|
ret = bdrv_open_common(bs, file, options, &local_err);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
if (file) {
|
|
blk_unref(file);
|
|
file = NULL;
|
|
}
|
|
|
|
/* If there is a backing file, use it */
|
|
if ((flags & BDRV_O_NO_BACKING) == 0) {
|
|
ret = bdrv_open_backing_file(bs, options, "backing", &local_err);
|
|
if (ret < 0) {
|
|
goto close_and_fail;
|
|
}
|
|
}
|
|
|
|
/* Remove all children options and references
|
|
* from bs->options and bs->explicit_options */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
char *child_key_dot;
|
|
child_key_dot = g_strdup_printf("%s.", child->name);
|
|
qdict_extract_subqdict(bs->explicit_options, NULL, child_key_dot);
|
|
qdict_extract_subqdict(bs->options, NULL, child_key_dot);
|
|
qdict_del(bs->explicit_options, child->name);
|
|
qdict_del(bs->options, child->name);
|
|
g_free(child_key_dot);
|
|
}
|
|
|
|
/* Check if any unknown options were used */
|
|
if (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' does not support the option '%s'",
|
|
drv->format_name, entry->key);
|
|
}
|
|
|
|
goto close_and_fail;
|
|
}
|
|
|
|
bdrv_parent_cb_change_media(bs, true);
|
|
|
|
qobject_unref(options);
|
|
options = NULL;
|
|
|
|
/* For snapshot=on, create a temporary qcow2 overlay. bs points to the
|
|
* temporary snapshot afterwards. */
|
|
if (snapshot_flags) {
|
|
BlockDriverState *snapshot_bs;
|
|
snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags,
|
|
snapshot_options, &local_err);
|
|
snapshot_options = NULL;
|
|
if (local_err) {
|
|
goto close_and_fail;
|
|
}
|
|
/* We are not going to return bs but the overlay on top of it
|
|
* (snapshot_bs); thus, we have to drop the strong reference to bs
|
|
* (which we obtained by calling bdrv_new()). bs will not be deleted,
|
|
* though, because the overlay still has a reference to it. */
|
|
bdrv_unref(bs);
|
|
bs = snapshot_bs;
|
|
}
|
|
|
|
return bs;
|
|
|
|
fail:
|
|
blk_unref(file);
|
|
qobject_unref(snapshot_options);
|
|
qobject_unref(bs->explicit_options);
|
|
qobject_unref(bs->options);
|
|
qobject_unref(options);
|
|
bs->options = NULL;
|
|
bs->explicit_options = NULL;
|
|
bdrv_unref(bs);
|
|
error_propagate(errp, local_err);
|
|
return NULL;
|
|
|
|
close_and_fail:
|
|
bdrv_unref(bs);
|
|
qobject_unref(snapshot_options);
|
|
qobject_unref(options);
|
|
error_propagate(errp, local_err);
|
|
return NULL;
|
|
}
|
|
|
|
BlockDriverState *bdrv_open(const char *filename, const char *reference,
|
|
QDict *options, int flags, Error **errp)
|
|
{
|
|
return bdrv_open_inherit(filename, reference, options, flags, NULL,
|
|
NULL, errp);
|
|
}
|
|
|
|
/* Return true if the NULL-terminated @list contains @str */
|
|
static bool is_str_in_list(const char *str, const char *const *list)
|
|
{
|
|
if (str && list) {
|
|
int i;
|
|
for (i = 0; list[i] != NULL; i++) {
|
|
if (!strcmp(str, list[i])) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check that every option set in @bs->options is also set in
|
|
* @new_opts.
|
|
*
|
|
* Options listed in the common_options list and in
|
|
* @bs->drv->mutable_opts are skipped.
|
|
*
|
|
* Return 0 on success, otherwise return -EINVAL and set @errp.
|
|
*/
|
|
static int bdrv_reset_options_allowed(BlockDriverState *bs,
|
|
const QDict *new_opts, Error **errp)
|
|
{
|
|
const QDictEntry *e;
|
|
/* These options are common to all block drivers and are handled
|
|
* in bdrv_reopen_prepare() so they can be left out of @new_opts */
|
|
const char *const common_options[] = {
|
|
"node-name", "discard", "cache.direct", "cache.no-flush",
|
|
"read-only", "auto-read-only", "detect-zeroes", NULL
|
|
};
|
|
|
|
for (e = qdict_first(bs->options); e; e = qdict_next(bs->options, e)) {
|
|
if (!qdict_haskey(new_opts, e->key) &&
|
|
!is_str_in_list(e->key, common_options) &&
|
|
!is_str_in_list(e->key, bs->drv->mutable_opts)) {
|
|
error_setg(errp, "Option '%s' cannot be reset "
|
|
"to its default value", e->key);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Returns true if @child can be reached recursively from @bs
|
|
*/
|
|
static bool bdrv_recurse_has_child(BlockDriverState *bs,
|
|
BlockDriverState *child)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (bs == child) {
|
|
return true;
|
|
}
|
|
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
if (bdrv_recurse_has_child(c->bs, child)) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* 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 QTAILQ_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.
|
|
*
|
|
* options contains the changed options for the associated bs
|
|
* (the BlockReopenQueue takes ownership)
|
|
*
|
|
* 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.
|
|
*
|
|
* bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
|
|
*/
|
|
static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
|
|
BlockDriverState *bs,
|
|
QDict *options,
|
|
const BdrvChildRole *role,
|
|
QDict *parent_options,
|
|
int parent_flags,
|
|
bool keep_old_opts)
|
|
{
|
|
assert(bs != NULL);
|
|
|
|
BlockReopenQueueEntry *bs_entry;
|
|
BdrvChild *child;
|
|
QDict *old_options, *explicit_options, *options_copy;
|
|
int flags;
|
|
QemuOpts *opts;
|
|
|
|
/* Make sure that the caller remembered to use a drained section. This is
|
|
* important to avoid graph changes between the recursive queuing here and
|
|
* bdrv_reopen_multiple(). */
|
|
assert(bs->quiesce_counter > 0);
|
|
|
|
if (bs_queue == NULL) {
|
|
bs_queue = g_new0(BlockReopenQueue, 1);
|
|
QTAILQ_INIT(bs_queue);
|
|
}
|
|
|
|
if (!options) {
|
|
options = qdict_new();
|
|
}
|
|
|
|
/* Check if this BlockDriverState is already in the queue */
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
if (bs == bs_entry->state.bs) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Precedence of options:
|
|
* 1. Explicitly passed in options (highest)
|
|
* 2. Retained from explicitly set options of bs
|
|
* 3. Inherited from parent node
|
|
* 4. Retained from effective options of bs
|
|
*/
|
|
|
|
/* Old explicitly set values (don't overwrite by inherited value) */
|
|
if (bs_entry || keep_old_opts) {
|
|
old_options = qdict_clone_shallow(bs_entry ?
|
|
bs_entry->state.explicit_options :
|
|
bs->explicit_options);
|
|
bdrv_join_options(bs, options, old_options);
|
|
qobject_unref(old_options);
|
|
}
|
|
|
|
explicit_options = qdict_clone_shallow(options);
|
|
|
|
/* Inherit from parent node */
|
|
if (parent_options) {
|
|
flags = 0;
|
|
role->inherit_options(&flags, options, parent_flags, parent_options);
|
|
} else {
|
|
flags = bdrv_get_flags(bs);
|
|
}
|
|
|
|
if (keep_old_opts) {
|
|
/* Old values are used for options that aren't set yet */
|
|
old_options = qdict_clone_shallow(bs->options);
|
|
bdrv_join_options(bs, options, old_options);
|
|
qobject_unref(old_options);
|
|
}
|
|
|
|
/* We have the final set of options so let's update the flags */
|
|
options_copy = qdict_clone_shallow(options);
|
|
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
|
|
qemu_opts_absorb_qdict(opts, options_copy, NULL);
|
|
update_flags_from_options(&flags, opts);
|
|
qemu_opts_del(opts);
|
|
qobject_unref(options_copy);
|
|
|
|
/* bdrv_open_inherit() sets and clears some additional flags internally */
|
|
flags &= ~BDRV_O_PROTOCOL;
|
|
if (flags & BDRV_O_RDWR) {
|
|
flags |= BDRV_O_ALLOW_RDWR;
|
|
}
|
|
|
|
if (!bs_entry) {
|
|
bs_entry = g_new0(BlockReopenQueueEntry, 1);
|
|
QTAILQ_INSERT_TAIL(bs_queue, bs_entry, entry);
|
|
} else {
|
|
qobject_unref(bs_entry->state.options);
|
|
qobject_unref(bs_entry->state.explicit_options);
|
|
}
|
|
|
|
bs_entry->state.bs = bs;
|
|
bs_entry->state.options = options;
|
|
bs_entry->state.explicit_options = explicit_options;
|
|
bs_entry->state.flags = flags;
|
|
|
|
/* This needs to be overwritten in bdrv_reopen_prepare() */
|
|
bs_entry->state.perm = UINT64_MAX;
|
|
bs_entry->state.shared_perm = 0;
|
|
|
|
/*
|
|
* If keep_old_opts is false then it means that unspecified
|
|
* options must be reset to their original value. We don't allow
|
|
* resetting 'backing' but we need to know if the option is
|
|
* missing in order to decide if we have to return an error.
|
|
*/
|
|
if (!keep_old_opts) {
|
|
bs_entry->state.backing_missing =
|
|
!qdict_haskey(options, "backing") &&
|
|
!qdict_haskey(options, "backing.driver");
|
|
}
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
QDict *new_child_options = NULL;
|
|
bool child_keep_old = keep_old_opts;
|
|
|
|
/* reopen can only change the options of block devices that were
|
|
* implicitly created and inherited options. For other (referenced)
|
|
* block devices, a syntax like "backing.foo" results in an error. */
|
|
if (child->bs->inherits_from != bs) {
|
|
continue;
|
|
}
|
|
|
|
/* Check if the options contain a child reference */
|
|
if (qdict_haskey(options, child->name)) {
|
|
const char *childref = qdict_get_try_str(options, child->name);
|
|
/*
|
|
* The current child must not be reopened if the child
|
|
* reference is null or points to a different node.
|
|
*/
|
|
if (g_strcmp0(childref, child->bs->node_name)) {
|
|
continue;
|
|
}
|
|
/*
|
|
* If the child reference points to the current child then
|
|
* reopen it with its existing set of options (note that
|
|
* it can still inherit new options from the parent).
|
|
*/
|
|
child_keep_old = true;
|
|
} else {
|
|
/* Extract child options ("child-name.*") */
|
|
char *child_key_dot = g_strdup_printf("%s.", child->name);
|
|
qdict_extract_subqdict(explicit_options, NULL, child_key_dot);
|
|
qdict_extract_subqdict(options, &new_child_options, child_key_dot);
|
|
g_free(child_key_dot);
|
|
}
|
|
|
|
bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options,
|
|
child->role, options, flags, child_keep_old);
|
|
}
|
|
|
|
return bs_queue;
|
|
}
|
|
|
|
BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
|
|
BlockDriverState *bs,
|
|
QDict *options, bool keep_old_opts)
|
|
{
|
|
return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, NULL, 0,
|
|
keep_old_opts);
|
|
}
|
|
|
|
/*
|
|
* 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 abandoned, and intermediate
|
|
* data cleaned up.
|
|
*
|
|
* If all devices prepare successfully, then the changes are committed
|
|
* to all devices.
|
|
*
|
|
* All affected nodes must be drained between bdrv_reopen_queue() and
|
|
* bdrv_reopen_multiple().
|
|
*/
|
|
int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp)
|
|
{
|
|
int ret = -1;
|
|
BlockReopenQueueEntry *bs_entry, *next;
|
|
|
|
assert(bs_queue != NULL);
|
|
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
assert(bs_entry->state.bs->quiesce_counter > 0);
|
|
if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, errp)) {
|
|
goto cleanup;
|
|
}
|
|
bs_entry->prepared = true;
|
|
}
|
|
|
|
QTAILQ_FOREACH(bs_entry, bs_queue, entry) {
|
|
BDRVReopenState *state = &bs_entry->state;
|
|
ret = bdrv_check_perm(state->bs, bs_queue, state->perm,
|
|
state->shared_perm, NULL, NULL, errp);
|
|
if (ret < 0) {
|
|
goto cleanup_perm;
|
|
}
|
|
/* Check if new_backing_bs would accept the new permissions */
|
|
if (state->replace_backing_bs && state->new_backing_bs) {
|
|
uint64_t nperm, nshared;
|
|
bdrv_child_perm(state->bs, state->new_backing_bs,
|
|
NULL, &child_backing, bs_queue,
|
|
state->perm, state->shared_perm,
|
|
&nperm, &nshared);
|
|
ret = bdrv_check_update_perm(state->new_backing_bs, NULL,
|
|
nperm, nshared, NULL, NULL, errp);
|
|
if (ret < 0) {
|
|
goto cleanup_perm;
|
|
}
|
|
}
|
|
bs_entry->perms_checked = true;
|
|
}
|
|
|
|
/*
|
|
* If we reach this point, we have success and just need to apply the
|
|
* changes.
|
|
*
|
|
* Reverse order is used to comfort qcow2 driver: on commit it need to write
|
|
* IN_USE flag to the image, to mark bitmaps in the image as invalid. But
|
|
* children are usually goes after parents in reopen-queue, so go from last
|
|
* to first element.
|
|
*/
|
|
QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) {
|
|
bdrv_reopen_commit(&bs_entry->state);
|
|
}
|
|
|
|
ret = 0;
|
|
cleanup_perm:
|
|
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
|
|
BDRVReopenState *state = &bs_entry->state;
|
|
|
|
if (!bs_entry->perms_checked) {
|
|
continue;
|
|
}
|
|
|
|
if (ret == 0) {
|
|
bdrv_set_perm(state->bs, state->perm, state->shared_perm);
|
|
} else {
|
|
bdrv_abort_perm_update(state->bs);
|
|
if (state->replace_backing_bs && state->new_backing_bs) {
|
|
bdrv_abort_perm_update(state->new_backing_bs);
|
|
}
|
|
}
|
|
}
|
|
cleanup:
|
|
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
|
|
if (ret) {
|
|
if (bs_entry->prepared) {
|
|
bdrv_reopen_abort(&bs_entry->state);
|
|
}
|
|
qobject_unref(bs_entry->state.explicit_options);
|
|
qobject_unref(bs_entry->state.options);
|
|
}
|
|
if (bs_entry->state.new_backing_bs) {
|
|
bdrv_unref(bs_entry->state.new_backing_bs);
|
|
}
|
|
g_free(bs_entry);
|
|
}
|
|
g_free(bs_queue);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
BlockReopenQueue *queue;
|
|
QDict *opts = qdict_new();
|
|
|
|
qdict_put_bool(opts, BDRV_OPT_READ_ONLY, read_only);
|
|
|
|
bdrv_subtree_drained_begin(bs);
|
|
queue = bdrv_reopen_queue(NULL, bs, opts, true);
|
|
ret = bdrv_reopen_multiple(queue, errp);
|
|
bdrv_subtree_drained_end(bs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q,
|
|
BdrvChild *c)
|
|
{
|
|
BlockReopenQueueEntry *entry;
|
|
|
|
QTAILQ_FOREACH(entry, q, entry) {
|
|
BlockDriverState *bs = entry->state.bs;
|
|
BdrvChild *child;
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (child == c) {
|
|
return entry;
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs,
|
|
uint64_t *perm, uint64_t *shared)
|
|
{
|
|
BdrvChild *c;
|
|
BlockReopenQueueEntry *parent;
|
|
uint64_t cumulative_perms = 0;
|
|
uint64_t cumulative_shared_perms = BLK_PERM_ALL;
|
|
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
parent = find_parent_in_reopen_queue(q, c);
|
|
if (!parent) {
|
|
cumulative_perms |= c->perm;
|
|
cumulative_shared_perms &= c->shared_perm;
|
|
} else {
|
|
uint64_t nperm, nshared;
|
|
|
|
bdrv_child_perm(parent->state.bs, bs, c, c->role, q,
|
|
parent->state.perm, parent->state.shared_perm,
|
|
&nperm, &nshared);
|
|
|
|
cumulative_perms |= nperm;
|
|
cumulative_shared_perms &= nshared;
|
|
}
|
|
}
|
|
*perm = cumulative_perms;
|
|
*shared = cumulative_shared_perms;
|
|
}
|
|
|
|
/*
|
|
* Take a BDRVReopenState and check if the value of 'backing' in the
|
|
* reopen_state->options QDict is valid or not.
|
|
*
|
|
* If 'backing' is missing from the QDict then return 0.
|
|
*
|
|
* If 'backing' contains the node name of the backing file of
|
|
* reopen_state->bs then return 0.
|
|
*
|
|
* If 'backing' contains a different node name (or is null) then check
|
|
* whether the current backing file can be replaced with the new one.
|
|
* If that's the case then reopen_state->replace_backing_bs is set to
|
|
* true and reopen_state->new_backing_bs contains a pointer to the new
|
|
* backing BlockDriverState (or NULL).
|
|
*
|
|
* Return 0 on success, otherwise return < 0 and set @errp.
|
|
*/
|
|
static int bdrv_reopen_parse_backing(BDRVReopenState *reopen_state,
|
|
Error **errp)
|
|
{
|
|
BlockDriverState *bs = reopen_state->bs;
|
|
BlockDriverState *overlay_bs, *new_backing_bs;
|
|
QObject *value;
|
|
const char *str;
|
|
|
|
value = qdict_get(reopen_state->options, "backing");
|
|
if (value == NULL) {
|
|
return 0;
|
|
}
|
|
|
|
switch (qobject_type(value)) {
|
|
case QTYPE_QNULL:
|
|
new_backing_bs = NULL;
|
|
break;
|
|
case QTYPE_QSTRING:
|
|
str = qobject_get_try_str(value);
|
|
new_backing_bs = bdrv_lookup_bs(NULL, str, errp);
|
|
if (new_backing_bs == NULL) {
|
|
return -EINVAL;
|
|
} else if (bdrv_recurse_has_child(new_backing_bs, bs)) {
|
|
error_setg(errp, "Making '%s' a backing file of '%s' "
|
|
"would create a cycle", str, bs->node_name);
|
|
return -EINVAL;
|
|
}
|
|
break;
|
|
default:
|
|
/* 'backing' does not allow any other data type */
|
|
g_assert_not_reached();
|
|
}
|
|
|
|
/*
|
|
* TODO: before removing the x- prefix from x-blockdev-reopen we
|
|
* should move the new backing file into the right AioContext
|
|
* instead of returning an error.
|
|
*/
|
|
if (new_backing_bs) {
|
|
if (bdrv_get_aio_context(new_backing_bs) != bdrv_get_aio_context(bs)) {
|
|
error_setg(errp, "Cannot use a new backing file "
|
|
"with a different AioContext");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find the "actual" backing file by skipping all links that point
|
|
* to an implicit node, if any (e.g. a commit filter node).
|
|
*/
|
|
overlay_bs = bs;
|
|
while (backing_bs(overlay_bs) && backing_bs(overlay_bs)->implicit) {
|
|
overlay_bs = backing_bs(overlay_bs);
|
|
}
|
|
|
|
/* If we want to replace the backing file we need some extra checks */
|
|
if (new_backing_bs != backing_bs(overlay_bs)) {
|
|
/* Check for implicit nodes between bs and its backing file */
|
|
if (bs != overlay_bs) {
|
|
error_setg(errp, "Cannot change backing link if '%s' has "
|
|
"an implicit backing file", bs->node_name);
|
|
return -EPERM;
|
|
}
|
|
/* Check if the backing link that we want to replace is frozen */
|
|
if (bdrv_is_backing_chain_frozen(overlay_bs, backing_bs(overlay_bs),
|
|
errp)) {
|
|
return -EPERM;
|
|
}
|
|
reopen_state->replace_backing_bs = true;
|
|
if (new_backing_bs) {
|
|
bdrv_ref(new_backing_bs);
|
|
reopen_state->new_backing_bs = new_backing_bs;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
int old_flags;
|
|
Error *local_err = NULL;
|
|
BlockDriver *drv;
|
|
QemuOpts *opts;
|
|
QDict *orig_reopen_opts;
|
|
char *discard = NULL;
|
|
bool read_only;
|
|
bool drv_prepared = false;
|
|
|
|
assert(reopen_state != NULL);
|
|
assert(reopen_state->bs->drv != NULL);
|
|
drv = reopen_state->bs->drv;
|
|
|
|
/* This function and each driver's bdrv_reopen_prepare() remove
|
|
* entries from reopen_state->options as they are processed, so
|
|
* we need to make a copy of the original QDict. */
|
|
orig_reopen_opts = qdict_clone_shallow(reopen_state->options);
|
|
|
|
/* Process generic block layer options */
|
|
opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
|
|
qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/* This was already called in bdrv_reopen_queue_child() so the flags
|
|
* are up-to-date. This time we simply want to remove the options from
|
|
* QemuOpts in order to indicate that they have been processed. */
|
|
old_flags = reopen_state->flags;
|
|
update_flags_from_options(&reopen_state->flags, opts);
|
|
assert(old_flags == reopen_state->flags);
|
|
|
|
discard = qemu_opt_get_del(opts, BDRV_OPT_DISCARD);
|
|
if (discard != NULL) {
|
|
if (bdrv_parse_discard_flags(discard, &reopen_state->flags) != 0) {
|
|
error_setg(errp, "Invalid discard option");
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
reopen_state->detect_zeroes =
|
|
bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/* All other options (including node-name and driver) must be unchanged.
|
|
* Put them back into the QDict, so that they are checked at the end
|
|
* of this function. */
|
|
qemu_opts_to_qdict(opts, reopen_state->options);
|
|
|
|
/* If we are to stay read-only, do not allow permission change
|
|
* to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
|
|
* not set, or if the BDS still has copy_on_read enabled */
|
|
read_only = !(reopen_state->flags & BDRV_O_RDWR);
|
|
ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
|
|
/* Calculate required permissions after reopening */
|
|
bdrv_reopen_perm(queue, reopen_state->bs,
|
|
&reopen_state->perm, &reopen_state->shared_perm);
|
|
|
|
ret = bdrv_flush(reopen_state->bs);
|
|
if (ret) {
|
|
error_setg_errno(errp, -ret, "Error flushing drive");
|
|
goto error;
|
|
}
|
|
|
|
if (drv->bdrv_reopen_prepare) {
|
|
/*
|
|
* If a driver-specific option is missing, it means that we
|
|
* should reset it to its default value.
|
|
* But not all options allow that, so we need to check it first.
|
|
*/
|
|
ret = bdrv_reset_options_allowed(reopen_state->bs,
|
|
reopen_state->options, errp);
|
|
if (ret) {
|
|
goto error;
|
|
}
|
|
|
|
ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
|
|
if (ret) {
|
|
if (local_err != NULL) {
|
|
error_propagate(errp, local_err);
|
|
} else {
|
|
bdrv_refresh_filename(reopen_state->bs);
|
|
error_setg(errp, "failed while preparing to reopen image '%s'",
|
|
reopen_state->bs->filename);
|
|
}
|
|
goto error;
|
|
}
|
|
} else {
|
|
/* It is currently mandatory to have a bdrv_reopen_prepare()
|
|
* handler for each supported drv. */
|
|
error_setg(errp, "Block format '%s' used by node '%s' "
|
|
"does not support reopening files", drv->format_name,
|
|
bdrv_get_device_or_node_name(reopen_state->bs));
|
|
ret = -1;
|
|
goto error;
|
|
}
|
|
|
|
drv_prepared = true;
|
|
|
|
/*
|
|
* We must provide the 'backing' option if the BDS has a backing
|
|
* file or if the image file has a backing file name as part of
|
|
* its metadata. Otherwise the 'backing' option can be omitted.
|
|
*/
|
|
if (drv->supports_backing && reopen_state->backing_missing &&
|
|
(backing_bs(reopen_state->bs) || reopen_state->bs->backing_file[0])) {
|
|
error_setg(errp, "backing is missing for '%s'",
|
|
reopen_state->bs->node_name);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Allow changing the 'backing' option. The new value can be
|
|
* either a reference to an existing node (using its node name)
|
|
* or NULL to simply detach the current backing file.
|
|
*/
|
|
ret = bdrv_reopen_parse_backing(reopen_state, errp);
|
|
if (ret < 0) {
|
|
goto error;
|
|
}
|
|
qdict_del(reopen_state->options, "backing");
|
|
|
|
/* Options that are not handled are only okay if they are unchanged
|
|
* compared to the old state. It is expected that some options are only
|
|
* used for the initial open, but not reopen (e.g. filename) */
|
|
if (qdict_size(reopen_state->options)) {
|
|
const QDictEntry *entry = qdict_first(reopen_state->options);
|
|
|
|
do {
|
|
QObject *new = entry->value;
|
|
QObject *old = qdict_get(reopen_state->bs->options, entry->key);
|
|
|
|
/* Allow child references (child_name=node_name) as long as they
|
|
* point to the current child (i.e. everything stays the same). */
|
|
if (qobject_type(new) == QTYPE_QSTRING) {
|
|
BdrvChild *child;
|
|
QLIST_FOREACH(child, &reopen_state->bs->children, next) {
|
|
if (!strcmp(child->name, entry->key)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (child) {
|
|
const char *str = qobject_get_try_str(new);
|
|
if (!strcmp(child->bs->node_name, str)) {
|
|
continue; /* Found child with this name, skip option */
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* TODO: When using -drive to specify blockdev options, all values
|
|
* will be strings; however, when using -blockdev, blockdev-add or
|
|
* filenames using the json:{} pseudo-protocol, they will be
|
|
* correctly typed.
|
|
* In contrast, reopening options are (currently) always strings
|
|
* (because you can only specify them through qemu-io; all other
|
|
* callers do not specify any options).
|
|
* Therefore, when using anything other than -drive to create a BDS,
|
|
* this cannot detect non-string options as unchanged, because
|
|
* qobject_is_equal() always returns false for objects of different
|
|
* type. In the future, this should be remedied by correctly typing
|
|
* all options. For now, this is not too big of an issue because
|
|
* the user can simply omit options which cannot be changed anyway,
|
|
* so they will stay unchanged.
|
|
*/
|
|
if (!qobject_is_equal(new, old)) {
|
|
error_setg(errp, "Cannot change the option '%s'", entry->key);
|
|
ret = -EINVAL;
|
|
goto error;
|
|
}
|
|
} while ((entry = qdict_next(reopen_state->options, entry)));
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
/* Restore the original reopen_state->options QDict */
|
|
qobject_unref(reopen_state->options);
|
|
reopen_state->options = qobject_ref(orig_reopen_opts);
|
|
|
|
error:
|
|
if (ret < 0 && drv_prepared) {
|
|
/* drv->bdrv_reopen_prepare() has succeeded, so we need to
|
|
* call drv->bdrv_reopen_abort() before signaling an error
|
|
* (bdrv_reopen_multiple() will not call bdrv_reopen_abort()
|
|
* when the respective bdrv_reopen_prepare() has failed) */
|
|
if (drv->bdrv_reopen_abort) {
|
|
drv->bdrv_reopen_abort(reopen_state);
|
|
}
|
|
}
|
|
qemu_opts_del(opts);
|
|
qobject_unref(orig_reopen_opts);
|
|
g_free(discard);
|
|
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;
|
|
BlockDriverState *bs;
|
|
BdrvChild *child;
|
|
|
|
assert(reopen_state != NULL);
|
|
bs = reopen_state->bs;
|
|
drv = 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 */
|
|
qobject_unref(bs->explicit_options);
|
|
qobject_unref(bs->options);
|
|
|
|
bs->explicit_options = reopen_state->explicit_options;
|
|
bs->options = reopen_state->options;
|
|
bs->open_flags = reopen_state->flags;
|
|
bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
|
|
bs->detect_zeroes = reopen_state->detect_zeroes;
|
|
|
|
if (reopen_state->replace_backing_bs) {
|
|
qdict_del(bs->explicit_options, "backing");
|
|
qdict_del(bs->options, "backing");
|
|
}
|
|
|
|
/* Remove child references from bs->options and bs->explicit_options.
|
|
* Child options were already removed in bdrv_reopen_queue_child() */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
qdict_del(bs->explicit_options, child->name);
|
|
qdict_del(bs->options, child->name);
|
|
}
|
|
|
|
/*
|
|
* Change the backing file if a new one was specified. We do this
|
|
* after updating bs->options, so bdrv_refresh_filename() (called
|
|
* from bdrv_set_backing_hd()) has the new values.
|
|
*/
|
|
if (reopen_state->replace_backing_bs) {
|
|
BlockDriverState *old_backing_bs = backing_bs(bs);
|
|
assert(!old_backing_bs || !old_backing_bs->implicit);
|
|
/* Abort the permission update on the backing bs we're detaching */
|
|
if (old_backing_bs) {
|
|
bdrv_abort_perm_update(old_backing_bs);
|
|
}
|
|
bdrv_set_backing_hd(bs, reopen_state->new_backing_bs, &error_abort);
|
|
}
|
|
|
|
bdrv_refresh_limits(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);
|
|
}
|
|
}
|
|
|
|
|
|
static void bdrv_close(BlockDriverState *bs)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_next;
|
|
BdrvChild *child, *next;
|
|
|
|
assert(!bs->refcnt);
|
|
|
|
bdrv_drained_begin(bs); /* complete I/O */
|
|
bdrv_flush(bs);
|
|
bdrv_drain(bs); /* in case flush left pending I/O */
|
|
|
|
if (bs->drv) {
|
|
if (bs->drv->bdrv_close) {
|
|
bs->drv->bdrv_close(bs);
|
|
}
|
|
bs->drv = NULL;
|
|
}
|
|
|
|
QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
|
|
bdrv_unref_child(bs, child);
|
|
}
|
|
|
|
bs->backing = NULL;
|
|
bs->file = NULL;
|
|
g_free(bs->opaque);
|
|
bs->opaque = NULL;
|
|
atomic_set(&bs->copy_on_read, 0);
|
|
bs->backing_file[0] = '\0';
|
|
bs->backing_format[0] = '\0';
|
|
bs->total_sectors = 0;
|
|
bs->encrypted = false;
|
|
bs->sg = false;
|
|
qobject_unref(bs->options);
|
|
qobject_unref(bs->explicit_options);
|
|
bs->options = NULL;
|
|
bs->explicit_options = NULL;
|
|
qobject_unref(bs->full_open_options);
|
|
bs->full_open_options = NULL;
|
|
|
|
bdrv_release_named_dirty_bitmaps(bs);
|
|
assert(QLIST_EMPTY(&bs->dirty_bitmaps));
|
|
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
|
|
g_free(ban);
|
|
}
|
|
QLIST_INIT(&bs->aio_notifiers);
|
|
bdrv_drained_end(bs);
|
|
}
|
|
|
|
void bdrv_close_all(void)
|
|
{
|
|
assert(job_next(NULL) == NULL);
|
|
nbd_export_close_all();
|
|
|
|
/* Drop references from requests still in flight, such as canceled block
|
|
* jobs whose AIO context has not been polled yet */
|
|
bdrv_drain_all();
|
|
|
|
blk_remove_all_bs();
|
|
blockdev_close_all_bdrv_states();
|
|
|
|
assert(QTAILQ_EMPTY(&all_bdrv_states));
|
|
}
|
|
|
|
static bool should_update_child(BdrvChild *c, BlockDriverState *to)
|
|
{
|
|
GQueue *queue;
|
|
GHashTable *found;
|
|
bool ret;
|
|
|
|
if (c->role->stay_at_node) {
|
|
return false;
|
|
}
|
|
|
|
/* If the child @c belongs to the BDS @to, replacing the current
|
|
* c->bs by @to would mean to create a loop.
|
|
*
|
|
* Such a case occurs when appending a BDS to a backing chain.
|
|
* For instance, imagine the following chain:
|
|
*
|
|
* guest device -> node A -> further backing chain...
|
|
*
|
|
* Now we create a new BDS B which we want to put on top of this
|
|
* chain, so we first attach A as its backing node:
|
|
*
|
|
* node B
|
|
* |
|
|
* v
|
|
* guest device -> node A -> further backing chain...
|
|
*
|
|
* Finally we want to replace A by B. When doing that, we want to
|
|
* replace all pointers to A by pointers to B -- except for the
|
|
* pointer from B because (1) that would create a loop, and (2)
|
|
* that pointer should simply stay intact:
|
|
*
|
|
* guest device -> node B
|
|
* |
|
|
* v
|
|
* node A -> further backing chain...
|
|
*
|
|
* In general, when replacing a node A (c->bs) by a node B (@to),
|
|
* if A is a child of B, that means we cannot replace A by B there
|
|
* because that would create a loop. Silently detaching A from B
|
|
* is also not really an option. So overall just leaving A in
|
|
* place there is the most sensible choice.
|
|
*
|
|
* We would also create a loop in any cases where @c is only
|
|
* indirectly referenced by @to. Prevent this by returning false
|
|
* if @c is found (by breadth-first search) anywhere in the whole
|
|
* subtree of @to.
|
|
*/
|
|
|
|
ret = true;
|
|
found = g_hash_table_new(NULL, NULL);
|
|
g_hash_table_add(found, to);
|
|
queue = g_queue_new();
|
|
g_queue_push_tail(queue, to);
|
|
|
|
while (!g_queue_is_empty(queue)) {
|
|
BlockDriverState *v = g_queue_pop_head(queue);
|
|
BdrvChild *c2;
|
|
|
|
QLIST_FOREACH(c2, &v->children, next) {
|
|
if (c2 == c) {
|
|
ret = false;
|
|
break;
|
|
}
|
|
|
|
if (g_hash_table_contains(found, c2->bs)) {
|
|
continue;
|
|
}
|
|
|
|
g_queue_push_tail(queue, c2->bs);
|
|
g_hash_table_add(found, c2->bs);
|
|
}
|
|
}
|
|
|
|
g_queue_free(queue);
|
|
g_hash_table_destroy(found);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
|
|
Error **errp)
|
|
{
|
|
BdrvChild *c, *next;
|
|
GSList *list = NULL, *p;
|
|
uint64_t perm = 0, shared = BLK_PERM_ALL;
|
|
int ret;
|
|
|
|
/* Make sure that @from doesn't go away until we have successfully attached
|
|
* all of its parents to @to. */
|
|
bdrv_ref(from);
|
|
|
|
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
|
|
bdrv_drained_begin(from);
|
|
|
|
/* Put all parents into @list and calculate their cumulative permissions */
|
|
QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
|
|
assert(c->bs == from);
|
|
if (!should_update_child(c, to)) {
|
|
continue;
|
|
}
|
|
if (c->frozen) {
|
|
error_setg(errp, "Cannot change '%s' link to '%s'",
|
|
c->name, from->node_name);
|
|
goto out;
|
|
}
|
|
list = g_slist_prepend(list, c);
|
|
perm |= c->perm;
|
|
shared &= c->shared_perm;
|
|
}
|
|
|
|
/* Check whether the required permissions can be granted on @to, ignoring
|
|
* all BdrvChild in @list so that they can't block themselves. */
|
|
ret = bdrv_check_update_perm(to, NULL, perm, shared, list, NULL, errp);
|
|
if (ret < 0) {
|
|
bdrv_abort_perm_update(to);
|
|
goto out;
|
|
}
|
|
|
|
/* Now actually perform the change. We performed the permission check for
|
|
* all elements of @list at once, so set the permissions all at once at the
|
|
* very end. */
|
|
for (p = list; p != NULL; p = p->next) {
|
|
c = p->data;
|
|
|
|
bdrv_ref(to);
|
|
bdrv_replace_child_noperm(c, to);
|
|
bdrv_unref(from);
|
|
}
|
|
|
|
bdrv_get_cumulative_perm(to, &perm, &shared);
|
|
bdrv_set_perm(to, perm, shared);
|
|
|
|
out:
|
|
g_slist_free(list);
|
|
bdrv_drained_end(from);
|
|
bdrv_unref(from);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* bdrv_append() takes ownership of a bs_new reference and unrefs it because
|
|
* that's what the callers commonly need. bs_new will be referenced by the old
|
|
* parents of bs_top after bdrv_append() returns. If the caller needs to keep a
|
|
* reference of its own, it must call bdrv_ref().
|
|
*/
|
|
void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
|
|
Error **errp)
|
|
{
|
|
Error *local_err = NULL;
|
|
|
|
bdrv_set_backing_hd(bs_new, bs_top, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto out;
|
|
}
|
|
|
|
bdrv_replace_node(bs_top, bs_new, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
bdrv_set_backing_hd(bs_new, NULL, &error_abort);
|
|
goto out;
|
|
}
|
|
|
|
/* bs_new is now referenced by its new parents, we don't need the
|
|
* additional reference any more. */
|
|
out:
|
|
bdrv_unref(bs_new);
|
|
}
|
|
|
|
static void bdrv_delete(BlockDriverState *bs)
|
|
{
|
|
assert(bdrv_op_blocker_is_empty(bs));
|
|
assert(!bs->refcnt);
|
|
|
|
/* remove from list, if necessary */
|
|
if (bs->node_name[0] != '\0') {
|
|
QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
|
|
}
|
|
QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
|
|
|
|
bdrv_close(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.
|
|
*/
|
|
static int coroutine_fn bdrv_co_check(BlockDriverState *bs,
|
|
BdrvCheckResult *res, BdrvCheckMode fix)
|
|
{
|
|
if (bs->drv == NULL) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (bs->drv->bdrv_co_check == NULL) {
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
memset(res, 0, sizeof(*res));
|
|
return bs->drv->bdrv_co_check(bs, res, fix);
|
|
}
|
|
|
|
typedef struct CheckCo {
|
|
BlockDriverState *bs;
|
|
BdrvCheckResult *res;
|
|
BdrvCheckMode fix;
|
|
int ret;
|
|
} CheckCo;
|
|
|
|
static void coroutine_fn bdrv_check_co_entry(void *opaque)
|
|
{
|
|
CheckCo *cco = opaque;
|
|
cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix);
|
|
aio_wait_kick();
|
|
}
|
|
|
|
int bdrv_check(BlockDriverState *bs,
|
|
BdrvCheckResult *res, BdrvCheckMode fix)
|
|
{
|
|
Coroutine *co;
|
|
CheckCo cco = {
|
|
.bs = bs,
|
|
.res = res,
|
|
.ret = -EINPROGRESS,
|
|
.fix = fix,
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_check_co_entry(&cco);
|
|
} else {
|
|
co = qemu_coroutine_create(bdrv_check_co_entry, &cco);
|
|
bdrv_coroutine_enter(bs, co);
|
|
BDRV_POLL_WHILE(bs, cco.ret == -EINPROGRESS);
|
|
}
|
|
|
|
return cco.ret;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
/* 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 ?: "");
|
|
pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
|
|
backing_file ?: "");
|
|
}
|
|
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 != backing_bs(active)) {
|
|
active = backing_bs(active);
|
|
}
|
|
|
|
return active;
|
|
}
|
|
|
|
/* Given a BDS, searches for the base layer. */
|
|
BlockDriverState *bdrv_find_base(BlockDriverState *bs)
|
|
{
|
|
return bdrv_find_overlay(bs, NULL);
|
|
}
|
|
|
|
/*
|
|
* Return true if at least one of the backing links between @bs and
|
|
* @base is frozen. @errp is set if that's the case.
|
|
* @base must be reachable from @bs, or NULL.
|
|
*/
|
|
bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
|
|
Error **errp)
|
|
{
|
|
BlockDriverState *i;
|
|
|
|
for (i = bs; i != base; i = backing_bs(i)) {
|
|
if (i->backing && i->backing->frozen) {
|
|
error_setg(errp, "Cannot change '%s' link from '%s' to '%s'",
|
|
i->backing->name, i->node_name,
|
|
backing_bs(i)->node_name);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Freeze all backing links between @bs and @base.
|
|
* If any of the links is already frozen the operation is aborted and
|
|
* none of the links are modified.
|
|
* @base must be reachable from @bs, or NULL.
|
|
* Returns 0 on success. On failure returns < 0 and sets @errp.
|
|
*/
|
|
int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
|
|
Error **errp)
|
|
{
|
|
BlockDriverState *i;
|
|
|
|
if (bdrv_is_backing_chain_frozen(bs, base, errp)) {
|
|
return -EPERM;
|
|
}
|
|
|
|
for (i = bs; i != base; i = backing_bs(i)) {
|
|
if (i->backing && backing_bs(i)->never_freeze) {
|
|
error_setg(errp, "Cannot freeze '%s' link to '%s'",
|
|
i->backing->name, backing_bs(i)->node_name);
|
|
return -EPERM;
|
|
}
|
|
}
|
|
|
|
for (i = bs; i != base; i = backing_bs(i)) {
|
|
if (i->backing) {
|
|
i->backing->frozen = true;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unfreeze all backing links between @bs and @base. The caller must
|
|
* ensure that all links are frozen before using this function.
|
|
* @base must be reachable from @bs, or NULL.
|
|
*/
|
|
void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base)
|
|
{
|
|
BlockDriverState *i;
|
|
|
|
for (i = bs; i != base; i = backing_bs(i)) {
|
|
if (i->backing) {
|
|
assert(i->backing->frozen);
|
|
i->backing->frozen = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 *top, BlockDriverState *base,
|
|
const char *backing_file_str)
|
|
{
|
|
BlockDriverState *explicit_top = top;
|
|
bool update_inherits_from;
|
|
BdrvChild *c, *next;
|
|
Error *local_err = NULL;
|
|
int ret = -EIO;
|
|
|
|
bdrv_ref(top);
|
|
bdrv_subtree_drained_begin(top);
|
|
|
|
if (!top->drv || !base->drv) {
|
|
goto exit;
|
|
}
|
|
|
|
/* Make sure that base is in the backing chain of top */
|
|
if (!bdrv_chain_contains(top, base)) {
|
|
goto exit;
|
|
}
|
|
|
|
/* This function changes all links that point to top and makes
|
|
* them point to base. Check that none of them is frozen. */
|
|
QLIST_FOREACH(c, &top->parents, next_parent) {
|
|
if (c->frozen) {
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
/* If 'base' recursively inherits from 'top' then we should set
|
|
* base->inherits_from to top->inherits_from after 'top' and all
|
|
* other intermediate nodes have been dropped.
|
|
* If 'top' is an implicit node (e.g. "commit_top") we should skip
|
|
* it because no one inherits from it. We use explicit_top for that. */
|
|
while (explicit_top && explicit_top->implicit) {
|
|
explicit_top = backing_bs(explicit_top);
|
|
}
|
|
update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top);
|
|
|
|
/* success - we can delete the intermediate states, and link top->base */
|
|
/* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
|
|
* we've figured out how they should work. */
|
|
if (!backing_file_str) {
|
|
bdrv_refresh_filename(base);
|
|
backing_file_str = base->filename;
|
|
}
|
|
|
|
QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
|
|
/* Check whether we are allowed to switch c from top to base */
|
|
GSList *ignore_children = g_slist_prepend(NULL, c);
|
|
ret = bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
|
|
ignore_children, NULL, &local_err);
|
|
g_slist_free(ignore_children);
|
|
if (ret < 0) {
|
|
error_report_err(local_err);
|
|
goto exit;
|
|
}
|
|
|
|
/* If so, update the backing file path in the image file */
|
|
if (c->role->update_filename) {
|
|
ret = c->role->update_filename(c, base, backing_file_str,
|
|
&local_err);
|
|
if (ret < 0) {
|
|
bdrv_abort_perm_update(base);
|
|
error_report_err(local_err);
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
/* Do the actual switch in the in-memory graph.
|
|
* Completes bdrv_check_update_perm() transaction internally. */
|
|
bdrv_ref(base);
|
|
bdrv_replace_child(c, base);
|
|
bdrv_unref(top);
|
|
}
|
|
|
|
if (update_inherits_from) {
|
|
base->inherits_from = explicit_top->inherits_from;
|
|
}
|
|
|
|
ret = 0;
|
|
exit:
|
|
bdrv_subtree_drained_end(top);
|
|
bdrv_unref(top);
|
|
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->bs);
|
|
}
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
/*
|
|
* bdrv_measure:
|
|
* @drv: Format driver
|
|
* @opts: Creation options for new image
|
|
* @in_bs: Existing image containing data for new image (may be NULL)
|
|
* @errp: Error object
|
|
* Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
|
|
* or NULL on error
|
|
*
|
|
* Calculate file size required to create a new image.
|
|
*
|
|
* If @in_bs is given then space for allocated clusters and zero clusters
|
|
* from that image are included in the calculation. If @opts contains a
|
|
* backing file that is shared by @in_bs then backing clusters may be omitted
|
|
* from the calculation.
|
|
*
|
|
* If @in_bs is NULL then the calculation includes no allocated clusters
|
|
* unless a preallocation option is given in @opts.
|
|
*
|
|
* Note that @in_bs may use a different BlockDriver from @drv.
|
|
*
|
|
* If an error occurs the @errp pointer is set.
|
|
*/
|
|
BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
|
|
BlockDriverState *in_bs, Error **errp)
|
|
{
|
|
if (!drv->bdrv_measure) {
|
|
error_setg(errp, "Block driver '%s' does not support size measurement",
|
|
drv->format_name);
|
|
return NULL;
|
|
}
|
|
|
|
return drv->bdrv_measure(opts, in_bs, errp);
|
|
}
|
|
|
|
/**
|
|
* Return number of sectors on success, -errno on error.
|
|
*/
|
|
int64_t bdrv_nb_sectors(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv)
|
|
return -ENOMEDIUM;
|
|
|
|
if (drv->has_variable_length) {
|
|
int ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
return bs->total_sectors;
|
|
}
|
|
|
|
/**
|
|
* Return length in bytes on success, -errno on error.
|
|
* The length is always a multiple of BDRV_SECTOR_SIZE.
|
|
*/
|
|
int64_t bdrv_getlength(BlockDriverState *bs)
|
|
{
|
|
int64_t ret = bdrv_nb_sectors(bs);
|
|
|
|
ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret;
|
|
return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
|
|
}
|
|
|
|
/* return 0 as number of sectors if no device present or error */
|
|
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
|
|
{
|
|
int64_t nb_sectors = bdrv_nb_sectors(bs);
|
|
|
|
*nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
|
|
}
|
|
|
|
bool bdrv_is_sg(BlockDriverState *bs)
|
|
{
|
|
return bs->sg;
|
|
}
|
|
|
|
bool bdrv_is_encrypted(BlockDriverState *bs)
|
|
{
|
|
if (bs->backing && bs->backing->bs->encrypted) {
|
|
return true;
|
|
}
|
|
return bs->encrypted;
|
|
}
|
|
|
|
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(*(char *const *)a, *(char *const *)b);
|
|
}
|
|
|
|
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
|
|
void *opaque, bool read_only)
|
|
{
|
|
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;
|
|
|
|
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, read_only)) {
|
|
continue;
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) {
|
|
const char *format_name = block_driver_modules[i].format_name;
|
|
|
|
if (format_name) {
|
|
bool found = false;
|
|
int j = count;
|
|
|
|
if (use_bdrv_whitelist &&
|
|
!bdrv_format_is_whitelisted(format_name, read_only)) {
|
|
continue;
|
|
}
|
|
|
|
while (formats && j && !found) {
|
|
found = !strcmp(formats[--j], format_name);
|
|
}
|
|
|
|
if (!found) {
|
|
formats = g_renew(const char *, formats, count + 1);
|
|
formats[count++] = format_name;
|
|
}
|
|
}
|
|
}
|
|
|
|
qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
|
|
|
|
for (i = 0; i < count; i++) {
|
|
it(opaque, formats[i]);
|
|
}
|
|
|
|
g_free(formats);
|
|
}
|
|
|
|
/* This function is to find a node in the bs graph */
|
|
BlockDriverState *bdrv_find_node(const char *node_name)
|
|
{
|
|
BlockDriverState *bs;
|
|
|
|
assert(node_name);
|
|
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
if (!strcmp(node_name, bs->node_name)) {
|
|
return bs;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Put this QMP function here so it can access the static graph_bdrv_states. */
|
|
BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
|
|
{
|
|
BlockDeviceInfoList *list, *entry;
|
|
BlockDriverState *bs;
|
|
|
|
list = NULL;
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
|
|
if (!info) {
|
|
qapi_free_BlockDeviceInfoList(list);
|
|
return NULL;
|
|
}
|
|
entry = g_malloc0(sizeof(*entry));
|
|
entry->value = info;
|
|
entry->next = list;
|
|
list = entry;
|
|
}
|
|
|
|
return list;
|
|
}
|
|
|
|
#define QAPI_LIST_ADD(list, element) do { \
|
|
typeof(list) _tmp = g_new(typeof(*(list)), 1); \
|
|
_tmp->value = (element); \
|
|
_tmp->next = (list); \
|
|
(list) = _tmp; \
|
|
} while (0)
|
|
|
|
typedef struct XDbgBlockGraphConstructor {
|
|
XDbgBlockGraph *graph;
|
|
GHashTable *graph_nodes;
|
|
} XDbgBlockGraphConstructor;
|
|
|
|
static XDbgBlockGraphConstructor *xdbg_graph_new(void)
|
|
{
|
|
XDbgBlockGraphConstructor *gr = g_new(XDbgBlockGraphConstructor, 1);
|
|
|
|
gr->graph = g_new0(XDbgBlockGraph, 1);
|
|
gr->graph_nodes = g_hash_table_new(NULL, NULL);
|
|
|
|
return gr;
|
|
}
|
|
|
|
static XDbgBlockGraph *xdbg_graph_finalize(XDbgBlockGraphConstructor *gr)
|
|
{
|
|
XDbgBlockGraph *graph = gr->graph;
|
|
|
|
g_hash_table_destroy(gr->graph_nodes);
|
|
g_free(gr);
|
|
|
|
return graph;
|
|
}
|
|
|
|
static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor *gr, void *node)
|
|
{
|
|
uintptr_t ret = (uintptr_t)g_hash_table_lookup(gr->graph_nodes, node);
|
|
|
|
if (ret != 0) {
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Start counting from 1, not 0, because 0 interferes with not-found (NULL)
|
|
* answer of g_hash_table_lookup.
|
|
*/
|
|
ret = g_hash_table_size(gr->graph_nodes) + 1;
|
|
g_hash_table_insert(gr->graph_nodes, node, (void *)ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void xdbg_graph_add_node(XDbgBlockGraphConstructor *gr, void *node,
|
|
XDbgBlockGraphNodeType type, const char *name)
|
|
{
|
|
XDbgBlockGraphNode *n;
|
|
|
|
n = g_new0(XDbgBlockGraphNode, 1);
|
|
|
|
n->id = xdbg_graph_node_num(gr, node);
|
|
n->type = type;
|
|
n->name = g_strdup(name);
|
|
|
|
QAPI_LIST_ADD(gr->graph->nodes, n);
|
|
}
|
|
|
|
static void xdbg_graph_add_edge(XDbgBlockGraphConstructor *gr, void *parent,
|
|
const BdrvChild *child)
|
|
{
|
|
typedef struct {
|
|
unsigned int flag;
|
|
BlockPermission num;
|
|
} PermissionMap;
|
|
|
|
static const PermissionMap permissions[] = {
|
|
{ BLK_PERM_CONSISTENT_READ, BLOCK_PERMISSION_CONSISTENT_READ },
|
|
{ BLK_PERM_WRITE, BLOCK_PERMISSION_WRITE },
|
|
{ BLK_PERM_WRITE_UNCHANGED, BLOCK_PERMISSION_WRITE_UNCHANGED },
|
|
{ BLK_PERM_RESIZE, BLOCK_PERMISSION_RESIZE },
|
|
{ BLK_PERM_GRAPH_MOD, BLOCK_PERMISSION_GRAPH_MOD },
|
|
{ 0, 0 }
|
|
};
|
|
const PermissionMap *p;
|
|
XDbgBlockGraphEdge *edge;
|
|
|
|
QEMU_BUILD_BUG_ON(1UL << (ARRAY_SIZE(permissions) - 1) != BLK_PERM_ALL + 1);
|
|
|
|
edge = g_new0(XDbgBlockGraphEdge, 1);
|
|
|
|
edge->parent = xdbg_graph_node_num(gr, parent);
|
|
edge->child = xdbg_graph_node_num(gr, child->bs);
|
|
edge->name = g_strdup(child->name);
|
|
|
|
for (p = permissions; p->flag; p++) {
|
|
if (p->flag & child->perm) {
|
|
QAPI_LIST_ADD(edge->perm, p->num);
|
|
}
|
|
if (p->flag & child->shared_perm) {
|
|
QAPI_LIST_ADD(edge->shared_perm, p->num);
|
|
}
|
|
}
|
|
|
|
QAPI_LIST_ADD(gr->graph->edges, edge);
|
|
}
|
|
|
|
|
|
XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp)
|
|
{
|
|
BlockBackend *blk;
|
|
BlockJob *job;
|
|
BlockDriverState *bs;
|
|
BdrvChild *child;
|
|
XDbgBlockGraphConstructor *gr = xdbg_graph_new();
|
|
|
|
for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) {
|
|
char *allocated_name = NULL;
|
|
const char *name = blk_name(blk);
|
|
|
|
if (!*name) {
|
|
name = allocated_name = blk_get_attached_dev_id(blk);
|
|
}
|
|
xdbg_graph_add_node(gr, blk, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND,
|
|
name);
|
|
g_free(allocated_name);
|
|
if (blk_root(blk)) {
|
|
xdbg_graph_add_edge(gr, blk, blk_root(blk));
|
|
}
|
|
}
|
|
|
|
for (job = block_job_next(NULL); job; job = block_job_next(job)) {
|
|
GSList *el;
|
|
|
|
xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
|
|
job->job.id);
|
|
for (el = job->nodes; el; el = el->next) {
|
|
xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data);
|
|
}
|
|
}
|
|
|
|
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
|
|
xdbg_graph_add_node(gr, bs, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER,
|
|
bs->node_name);
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
xdbg_graph_add_edge(gr, bs, child);
|
|
}
|
|
}
|
|
|
|
return xdbg_graph_finalize(gr);
|
|
}
|
|
|
|
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) {
|
|
bs = blk_bs(blk);
|
|
if (!bs) {
|
|
error_setg(errp, "Device '%s' has no medium", device);
|
|
}
|
|
|
|
return bs;
|
|
}
|
|
}
|
|
|
|
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 = backing_bs(top);
|
|
}
|
|
|
|
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_all_states(BlockDriverState *bs)
|
|
{
|
|
if (!bs) {
|
|
return QTAILQ_FIRST(&all_bdrv_states);
|
|
}
|
|
return QTAILQ_NEXT(bs, bs_list);
|
|
}
|
|
|
|
const char *bdrv_get_node_name(const BlockDriverState *bs)
|
|
{
|
|
return bs->node_name;
|
|
}
|
|
|
|
const char *bdrv_get_parent_name(const BlockDriverState *bs)
|
|
{
|
|
BdrvChild *c;
|
|
const char *name;
|
|
|
|
/* If multiple parents have a name, just pick the first one. */
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (c->role->get_name) {
|
|
name = c->role->get_name(c);
|
|
if (name && *name) {
|
|
return name;
|
|
}
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* TODO check what callers really want: bs->node_name or blk_name() */
|
|
const char *bdrv_get_device_name(const BlockDriverState *bs)
|
|
{
|
|
return bdrv_get_parent_name(bs) ?: "";
|
|
}
|
|
|
|
/* This can be used to identify nodes that might not have a device
|
|
* name associated. Since node and device names live in the same
|
|
* namespace, the result is unambiguous. The exception is if both are
|
|
* absent, then this returns an empty (non-null) string. */
|
|
const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
|
|
{
|
|
return bdrv_get_parent_name(bs) ?: bs->node_name;
|
|
}
|
|
|
|
int bdrv_get_flags(BlockDriverState *bs)
|
|
{
|
|
return bs->open_flags;
|
|
}
|
|
|
|
int bdrv_has_zero_init_1(BlockDriverState *bs)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
int bdrv_has_zero_init(BlockDriverState *bs)
|
|
{
|
|
if (!bs->drv) {
|
|
return 0;
|
|
}
|
|
|
|
/* 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) {
|
|
return 0;
|
|
}
|
|
if (bs->drv->bdrv_has_zero_init) {
|
|
return bs->drv->bdrv_has_zero_init(bs);
|
|
}
|
|
if (bs->file && bs->drv->is_filter) {
|
|
return bdrv_has_zero_init(bs->file->bs);
|
|
}
|
|
|
|
/* safe default */
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_has_zero_init_truncate(BlockDriverState *bs)
|
|
{
|
|
if (!bs->drv) {
|
|
return 0;
|
|
}
|
|
|
|
if (bs->backing) {
|
|
/* Depends on the backing image length, but better safe than sorry */
|
|
return 0;
|
|
}
|
|
if (bs->drv->bdrv_has_zero_init_truncate) {
|
|
return bs->drv->bdrv_has_zero_init_truncate(bs);
|
|
}
|
|
if (bs->file && bs->drv->is_filter) {
|
|
return bdrv_has_zero_init_truncate(bs->file->bs);
|
|
}
|
|
|
|
/* safe default */
|
|
return 0;
|
|
}
|
|
|
|
bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
|
|
{
|
|
BlockDriverInfo bdi;
|
|
|
|
if (bs->backing) {
|
|
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)
|
|
{
|
|
if (!(bs->open_flags & BDRV_O_UNMAP)) {
|
|
return false;
|
|
}
|
|
|
|
return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
|
|
void bdrv_get_backing_filename(BlockDriverState *bs,
|
|
char *filename, int filename_size)
|
|
{
|
|
pstrcpy(filename, filename_size, bs->backing_file);
|
|
}
|
|
|
|
int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
/* if bs->drv == NULL, bs is closed, so there's nothing to do here */
|
|
if (!drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (!drv->bdrv_get_info) {
|
|
if (bs->file && drv->is_filter) {
|
|
return bdrv_get_info(bs->file->bs, bdi);
|
|
}
|
|
return -ENOTSUP;
|
|
}
|
|
memset(bdi, 0, sizeof(*bdi));
|
|
return drv->bdrv_get_info(bs, bdi);
|
|
}
|
|
|
|
ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
|
|
Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (drv && drv->bdrv_get_specific_info) {
|
|
return drv->bdrv_get_specific_info(bs, errp);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
if (!drv || !drv->bdrv_get_specific_stats) {
|
|
return NULL;
|
|
}
|
|
return drv->bdrv_get_specific_stats(bs);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static BlockDriverState *bdrv_find_debug_node(BlockDriverState *bs)
|
|
{
|
|
while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
|
|
if (bs->file) {
|
|
bs = bs->file->bs;
|
|
continue;
|
|
}
|
|
|
|
if (bs->drv->is_filter && bs->backing) {
|
|
bs = bs->backing->bs;
|
|
continue;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
|
|
assert(bs->drv->bdrv_debug_remove_breakpoint);
|
|
return bs;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
|
|
const char *tag)
|
|
{
|
|
bs = bdrv_find_debug_node(bs);
|
|
if (bs) {
|
|
return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
|
|
}
|
|
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
|
|
{
|
|
bs = bdrv_find_debug_node(bs);
|
|
if (bs) {
|
|
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 ? bs->file->bs : NULL;
|
|
}
|
|
|
|
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 ? bs->file->bs : NULL;
|
|
}
|
|
|
|
if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
|
|
return bs->drv->bdrv_debug_is_suspended(bs, tag);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
is_protocol = path_has_protocol(backing_file);
|
|
|
|
for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
|
|
|
|
/* 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)) {
|
|
char *backing_file_full_ret;
|
|
|
|
if (strcmp(backing_file, curr_bs->backing_file) == 0) {
|
|
retval = curr_bs->backing->bs;
|
|
break;
|
|
}
|
|
/* Also check against the full backing filename for the image */
|
|
backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs,
|
|
NULL);
|
|
if (backing_file_full_ret) {
|
|
bool equal = strcmp(backing_file, backing_file_full_ret) == 0;
|
|
g_free(backing_file_full_ret);
|
|
if (equal) {
|
|
retval = curr_bs->backing->bs;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
/* If not an absolute filename path, make it relative to the current
|
|
* image's filename path */
|
|
filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file,
|
|
NULL);
|
|
/* We are going to compare canonicalized absolute pathnames */
|
|
if (!filename_tmp || !realpath(filename_tmp, filename_full)) {
|
|
g_free(filename_tmp);
|
|
continue;
|
|
}
|
|
g_free(filename_tmp);
|
|
|
|
/* We need to make sure the backing filename we are comparing against
|
|
* is relative to the current image filename (or absolute) */
|
|
filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL);
|
|
if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) {
|
|
g_free(filename_tmp);
|
|
continue;
|
|
}
|
|
g_free(filename_tmp);
|
|
|
|
if (strcmp(backing_file_full, filename_full) == 0) {
|
|
retval = curr_bs->backing->bs;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
g_free(filename_full);
|
|
g_free(backing_file_full);
|
|
return retval;
|
|
}
|
|
|
|
void bdrv_init(void)
|
|
{
|
|
module_call_init(MODULE_INIT_BLOCK);
|
|
}
|
|
|
|
void bdrv_init_with_whitelist(void)
|
|
{
|
|
use_bdrv_whitelist = 1;
|
|
bdrv_init();
|
|
}
|
|
|
|
static void coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
|
|
Error **errp)
|
|
{
|
|
BdrvChild *child, *parent;
|
|
uint64_t perm, shared_perm;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
BdrvDirtyBitmap *bm;
|
|
|
|
if (!bs->drv) {
|
|
return;
|
|
}
|
|
|
|
if (!(bs->open_flags & BDRV_O_INACTIVE)) {
|
|
return;
|
|
}
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_co_invalidate_cache(child->bs, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Update permissions, they may differ for inactive nodes.
|
|
*
|
|
* Note that the required permissions of inactive images are always a
|
|
* subset of the permissions required after activating the image. This
|
|
* allows us to just get the permissions upfront without restricting
|
|
* drv->bdrv_invalidate_cache().
|
|
*
|
|
* It also means that in error cases, we don't have to try and revert to
|
|
* the old permissions (which is an operation that could fail, too). We can
|
|
* just keep the extended permissions for the next time that an activation
|
|
* of the image is tried.
|
|
*/
|
|
bs->open_flags &= ~BDRV_O_INACTIVE;
|
|
bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
|
|
ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, NULL, &local_err);
|
|
if (ret < 0) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
bdrv_set_perm(bs, perm, shared_perm);
|
|
|
|
if (bs->drv->bdrv_co_invalidate_cache) {
|
|
bs->drv->bdrv_co_invalidate_cache(bs, &local_err);
|
|
if (local_err) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
}
|
|
|
|
FOR_EACH_DIRTY_BITMAP(bs, bm) {
|
|
bdrv_dirty_bitmap_skip_store(bm, false);
|
|
}
|
|
|
|
ret = refresh_total_sectors(bs, bs->total_sectors);
|
|
if (ret < 0) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_setg_errno(errp, -ret, "Could not refresh total sector count");
|
|
return;
|
|
}
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (parent->role->activate) {
|
|
parent->role->activate(parent, &local_err);
|
|
if (local_err) {
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
error_propagate(errp, local_err);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
typedef struct InvalidateCacheCo {
|
|
BlockDriverState *bs;
|
|
Error **errp;
|
|
bool done;
|
|
} InvalidateCacheCo;
|
|
|
|
static void coroutine_fn bdrv_invalidate_cache_co_entry(void *opaque)
|
|
{
|
|
InvalidateCacheCo *ico = opaque;
|
|
bdrv_co_invalidate_cache(ico->bs, ico->errp);
|
|
ico->done = true;
|
|
aio_wait_kick();
|
|
}
|
|
|
|
void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
|
|
{
|
|
Coroutine *co;
|
|
InvalidateCacheCo ico = {
|
|
.bs = bs,
|
|
.done = false,
|
|
.errp = errp
|
|
};
|
|
|
|
if (qemu_in_coroutine()) {
|
|
/* Fast-path if already in coroutine context */
|
|
bdrv_invalidate_cache_co_entry(&ico);
|
|
} else {
|
|
co = qemu_coroutine_create(bdrv_invalidate_cache_co_entry, &ico);
|
|
bdrv_coroutine_enter(bs, co);
|
|
BDRV_POLL_WHILE(bs, !ico.done);
|
|
}
|
|
}
|
|
|
|
void bdrv_invalidate_cache_all(Error **errp)
|
|
{
|
|
BlockDriverState *bs;
|
|
Error *local_err = NULL;
|
|
BdrvNextIterator it;
|
|
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
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);
|
|
bdrv_next_cleanup(&it);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool bdrv_has_bds_parent(BlockDriverState *bs, bool only_active)
|
|
{
|
|
BdrvChild *parent;
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (parent->role->parent_is_bds) {
|
|
BlockDriverState *parent_bs = parent->opaque;
|
|
if (!only_active || !(parent_bs->open_flags & BDRV_O_INACTIVE)) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int bdrv_inactivate_recurse(BlockDriverState *bs)
|
|
{
|
|
BdrvChild *child, *parent;
|
|
bool tighten_restrictions;
|
|
uint64_t perm, shared_perm;
|
|
int ret;
|
|
|
|
if (!bs->drv) {
|
|
return -ENOMEDIUM;
|
|
}
|
|
|
|
/* Make sure that we don't inactivate a child before its parent.
|
|
* It will be covered by recursion from the yet active parent. */
|
|
if (bdrv_has_bds_parent(bs, true)) {
|
|
return 0;
|
|
}
|
|
|
|
assert(!(bs->open_flags & BDRV_O_INACTIVE));
|
|
|
|
/* Inactivate this node */
|
|
if (bs->drv->bdrv_inactivate) {
|
|
ret = bs->drv->bdrv_inactivate(bs);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
QLIST_FOREACH(parent, &bs->parents, next_parent) {
|
|
if (parent->role->inactivate) {
|
|
ret = parent->role->inactivate(parent);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
bs->open_flags |= BDRV_O_INACTIVE;
|
|
|
|
/* Update permissions, they may differ for inactive nodes */
|
|
bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
|
|
ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL,
|
|
&tighten_restrictions, NULL);
|
|
assert(tighten_restrictions == false);
|
|
if (ret < 0) {
|
|
/* We only tried to loosen restrictions, so errors are not fatal */
|
|
bdrv_abort_perm_update(bs);
|
|
} else {
|
|
bdrv_set_perm(bs, perm, shared_perm);
|
|
}
|
|
|
|
|
|
/* Recursively inactivate children */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
ret = bdrv_inactivate_recurse(child->bs);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_inactivate_all(void)
|
|
{
|
|
BlockDriverState *bs = NULL;
|
|
BdrvNextIterator it;
|
|
int ret = 0;
|
|
GSList *aio_ctxs = NULL, *ctx;
|
|
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
AioContext *aio_context = bdrv_get_aio_context(bs);
|
|
|
|
if (!g_slist_find(aio_ctxs, aio_context)) {
|
|
aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
|
|
aio_context_acquire(aio_context);
|
|
}
|
|
}
|
|
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
/* Nodes with BDS parents are covered by recursion from the last
|
|
* parent that gets inactivated. Don't inactivate them a second
|
|
* time if that has already happened. */
|
|
if (bdrv_has_bds_parent(bs, false)) {
|
|
continue;
|
|
}
|
|
ret = bdrv_inactivate_recurse(bs);
|
|
if (ret < 0) {
|
|
bdrv_next_cleanup(&it);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
|
|
AioContext *aio_context = ctx->data;
|
|
aio_context_release(aio_context);
|
|
}
|
|
g_slist_free(aio_ctxs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**************************************************************/
|
|
/* removable device support */
|
|
|
|
/**
|
|
* Return TRUE if the media is present
|
|
*/
|
|
bool bdrv_is_inserted(BlockDriverState *bs)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
BdrvChild *child;
|
|
|
|
if (!drv) {
|
|
return false;
|
|
}
|
|
if (drv->bdrv_is_inserted) {
|
|
return drv->bdrv_is_inserted(bs);
|
|
}
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (!bdrv_is_inserted(child->bs)) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* If eject_flag is TRUE, eject the media. Otherwise, close the tray
|
|
*/
|
|
void bdrv_eject(BlockDriverState *bs, bool eject_flag)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (drv && drv->bdrv_eject) {
|
|
drv->bdrv_eject(bs, eject_flag);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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);
|
|
}
|
|
}
|
|
|
|
/* 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]);
|
|
error_propagate_prepend(errp, error_copy(blocker->reason),
|
|
"Node '%s' is busy: ",
|
|
bdrv_get_device_or_node_name(bs));
|
|
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_img_create(const char *filename, const char *fmt,
|
|
const char *base_filename, const char *base_fmt,
|
|
char *options, uint64_t img_size, int flags, bool quiet,
|
|
Error **errp)
|
|
{
|
|
QemuOptsList *create_opts = NULL;
|
|
QemuOpts *opts = NULL;
|
|
const char *backing_fmt, *backing_file;
|
|
int64_t size;
|
|
BlockDriver *drv, *proto_drv;
|
|
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 parameter list */
|
|
create_opts = qemu_opts_append(create_opts, drv->create_opts);
|
|
create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
|
|
|
|
opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
|
|
|
|
/* Parse -o options */
|
|
if (options) {
|
|
qemu_opts_do_parse(opts, options, NULL, &local_err);
|
|
if (local_err) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (!qemu_opt_get(opts, BLOCK_OPT_SIZE)) {
|
|
qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
|
|
} else if (img_size != UINT64_C(-1)) {
|
|
error_setg(errp, "The image size must be specified only once");
|
|
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);
|
|
|
|
/* The size for the image must always be specified, unless we have a backing
|
|
* file and we have not been forbidden from opening it. */
|
|
size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size);
|
|
if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
|
|
BlockDriverState *bs;
|
|
char *full_backing;
|
|
int back_flags;
|
|
QDict *backing_options = NULL;
|
|
|
|
full_backing =
|
|
bdrv_get_full_backing_filename_from_filename(filename, backing_file,
|
|
&local_err);
|
|
if (local_err) {
|
|
goto out;
|
|
}
|
|
assert(full_backing);
|
|
|
|
/* backing files always opened read-only */
|
|
back_flags = flags;
|
|
back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
|
|
|
|
backing_options = qdict_new();
|
|
if (backing_fmt) {
|
|
qdict_put_str(backing_options, "driver", backing_fmt);
|
|
}
|
|
qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
|
|
|
|
bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
|
|
&local_err);
|
|
g_free(full_backing);
|
|
if (!bs && size != -1) {
|
|
/* Couldn't open BS, but we have a size, so it's nonfatal */
|
|
warn_reportf_err(local_err,
|
|
"Could not verify backing image. "
|
|
"This may become an error in future versions.\n");
|
|
local_err = NULL;
|
|
} else if (!bs) {
|
|
/* Couldn't open bs, do not have size */
|
|
error_append_hint(&local_err,
|
|
"Could not open backing image to determine size.\n");
|
|
goto out;
|
|
} else {
|
|
if (size == -1) {
|
|
/* Opened BS, have no size */
|
|
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);
|
|
}
|
|
} /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
|
|
|
|
if (size == -1) {
|
|
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);
|
|
error_propagate(errp, local_err);
|
|
}
|
|
|
|
AioContext *bdrv_get_aio_context(BlockDriverState *bs)
|
|
{
|
|
return bs ? bs->aio_context : qemu_get_aio_context();
|
|
}
|
|
|
|
void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co)
|
|
{
|
|
aio_co_enter(bdrv_get_aio_context(bs), co);
|
|
}
|
|
|
|
static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
|
|
{
|
|
QLIST_REMOVE(ban, list);
|
|
g_free(ban);
|
|
}
|
|
|
|
static void bdrv_detach_aio_context(BlockDriverState *bs)
|
|
{
|
|
BdrvAioNotifier *baf, *baf_tmp;
|
|
|
|
assert(!bs->walking_aio_notifiers);
|
|
bs->walking_aio_notifiers = true;
|
|
QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
|
|
if (baf->deleted) {
|
|
bdrv_do_remove_aio_context_notifier(baf);
|
|
} else {
|
|
baf->detach_aio_context(baf->opaque);
|
|
}
|
|
}
|
|
/* Never mind iterating again to check for ->deleted. bdrv_close() will
|
|
* remove remaining aio notifiers if we aren't called again.
|
|
*/
|
|
bs->walking_aio_notifiers = false;
|
|
|
|
if (bs->drv && bs->drv->bdrv_detach_aio_context) {
|
|
bs->drv->bdrv_detach_aio_context(bs);
|
|
}
|
|
|
|
if (bs->quiesce_counter) {
|
|
aio_enable_external(bs->aio_context);
|
|
}
|
|
bs->aio_context = NULL;
|
|
}
|
|
|
|
static void bdrv_attach_aio_context(BlockDriverState *bs,
|
|
AioContext *new_context)
|
|
{
|
|
BdrvAioNotifier *ban, *ban_tmp;
|
|
|
|
if (bs->quiesce_counter) {
|
|
aio_disable_external(new_context);
|
|
}
|
|
|
|
bs->aio_context = new_context;
|
|
|
|
if (bs->drv && bs->drv->bdrv_attach_aio_context) {
|
|
bs->drv->bdrv_attach_aio_context(bs, new_context);
|
|
}
|
|
|
|
assert(!bs->walking_aio_notifiers);
|
|
bs->walking_aio_notifiers = true;
|
|
QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) {
|
|
if (ban->deleted) {
|
|
bdrv_do_remove_aio_context_notifier(ban);
|
|
} else {
|
|
ban->attached_aio_context(new_context, ban->opaque);
|
|
}
|
|
}
|
|
bs->walking_aio_notifiers = false;
|
|
}
|
|
|
|
/*
|
|
* Changes the AioContext used for fd handlers, timers, and BHs by this
|
|
* BlockDriverState and all its children and parents.
|
|
*
|
|
* Must be called from the main AioContext.
|
|
*
|
|
* The caller must own the AioContext lock for the old AioContext of bs, but it
|
|
* must not own the AioContext lock for new_context (unless new_context is the
|
|
* same as the current context of bs).
|
|
*
|
|
* @ignore will accumulate all visited BdrvChild object. The caller is
|
|
* responsible for freeing the list afterwards.
|
|
*/
|
|
void bdrv_set_aio_context_ignore(BlockDriverState *bs,
|
|
AioContext *new_context, GSList **ignore)
|
|
{
|
|
AioContext *old_context = bdrv_get_aio_context(bs);
|
|
BdrvChild *child;
|
|
|
|
g_assert(qemu_get_current_aio_context() == qemu_get_aio_context());
|
|
|
|
if (old_context == new_context) {
|
|
return;
|
|
}
|
|
|
|
bdrv_drained_begin(bs);
|
|
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (g_slist_find(*ignore, child)) {
|
|
continue;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, child);
|
|
bdrv_set_aio_context_ignore(child->bs, new_context, ignore);
|
|
}
|
|
QLIST_FOREACH(child, &bs->parents, next_parent) {
|
|
if (g_slist_find(*ignore, child)) {
|
|
continue;
|
|
}
|
|
assert(child->role->set_aio_ctx);
|
|
*ignore = g_slist_prepend(*ignore, child);
|
|
child->role->set_aio_ctx(child, new_context, ignore);
|
|
}
|
|
|
|
bdrv_detach_aio_context(bs);
|
|
|
|
/* Acquire the new context, if necessary */
|
|
if (qemu_get_aio_context() != new_context) {
|
|
aio_context_acquire(new_context);
|
|
}
|
|
|
|
bdrv_attach_aio_context(bs, new_context);
|
|
|
|
/*
|
|
* If this function was recursively called from
|
|
* bdrv_set_aio_context_ignore(), there may be nodes in the
|
|
* subtree that have not yet been moved to the new AioContext.
|
|
* Release the old one so bdrv_drained_end() can poll them.
|
|
*/
|
|
if (qemu_get_aio_context() != old_context) {
|
|
aio_context_release(old_context);
|
|
}
|
|
|
|
bdrv_drained_end(bs);
|
|
|
|
if (qemu_get_aio_context() != old_context) {
|
|
aio_context_acquire(old_context);
|
|
}
|
|
if (qemu_get_aio_context() != new_context) {
|
|
aio_context_release(new_context);
|
|
}
|
|
}
|
|
|
|
static bool bdrv_parent_can_set_aio_context(BdrvChild *c, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
if (g_slist_find(*ignore, c)) {
|
|
return true;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, c);
|
|
|
|
/* A BdrvChildRole that doesn't handle AioContext changes cannot
|
|
* tolerate any AioContext changes */
|
|
if (!c->role->can_set_aio_ctx) {
|
|
char *user = bdrv_child_user_desc(c);
|
|
error_setg(errp, "Changing iothreads is not supported by %s", user);
|
|
g_free(user);
|
|
return false;
|
|
}
|
|
if (!c->role->can_set_aio_ctx(c, ctx, ignore, errp)) {
|
|
assert(!errp || *errp);
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool bdrv_child_can_set_aio_context(BdrvChild *c, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
if (g_slist_find(*ignore, c)) {
|
|
return true;
|
|
}
|
|
*ignore = g_slist_prepend(*ignore, c);
|
|
return bdrv_can_set_aio_context(c->bs, ctx, ignore, errp);
|
|
}
|
|
|
|
/* @ignore will accumulate all visited BdrvChild object. The caller is
|
|
* responsible for freeing the list afterwards. */
|
|
bool bdrv_can_set_aio_context(BlockDriverState *bs, AioContext *ctx,
|
|
GSList **ignore, Error **errp)
|
|
{
|
|
BdrvChild *c;
|
|
|
|
if (bdrv_get_aio_context(bs) == ctx) {
|
|
return true;
|
|
}
|
|
|
|
QLIST_FOREACH(c, &bs->parents, next_parent) {
|
|
if (!bdrv_parent_can_set_aio_context(c, ctx, ignore, errp)) {
|
|
return false;
|
|
}
|
|
}
|
|
QLIST_FOREACH(c, &bs->children, next) {
|
|
if (!bdrv_child_can_set_aio_context(c, ctx, ignore, errp)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
int bdrv_child_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
|
|
BdrvChild *ignore_child, Error **errp)
|
|
{
|
|
GSList *ignore;
|
|
bool ret;
|
|
|
|
ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
|
|
ret = bdrv_can_set_aio_context(bs, ctx, &ignore, errp);
|
|
g_slist_free(ignore);
|
|
|
|
if (!ret) {
|
|
return -EPERM;
|
|
}
|
|
|
|
ignore = ignore_child ? g_slist_prepend(NULL, ignore_child) : NULL;
|
|
bdrv_set_aio_context_ignore(bs, ctx, &ignore);
|
|
g_slist_free(ignore);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int bdrv_try_set_aio_context(BlockDriverState *bs, AioContext *ctx,
|
|
Error **errp)
|
|
{
|
|
return bdrv_child_try_set_aio_context(bs, ctx, NULL, errp);
|
|
}
|
|
|
|
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 &&
|
|
ban->deleted == false)
|
|
{
|
|
if (bs->walking_aio_notifiers) {
|
|
ban->deleted = true;
|
|
} else {
|
|
bdrv_do_remove_aio_context_notifier(ban);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
abort();
|
|
}
|
|
|
|
int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
|
|
BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
|
|
Error **errp)
|
|
{
|
|
if (!bs->drv) {
|
|
error_setg(errp, "Node is ejected");
|
|
return -ENOMEDIUM;
|
|
}
|
|
if (!bs->drv->bdrv_amend_options) {
|
|
error_setg(errp, "Block driver '%s' does not support option amendment",
|
|
bs->drv->format_name);
|
|
return -ENOTSUP;
|
|
}
|
|
return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque, errp);
|
|
}
|
|
|
|
/* 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;
|
|
BdrvNextIterator it;
|
|
|
|
/* walk down the bs forest recursively */
|
|
for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
|
|
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) {
|
|
bdrv_next_cleanup(&it);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
|
|
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_recurse_is_first_non_filter(parent_bs, 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;
|
|
}
|
|
|
|
/**
|
|
* Iterates through the list of runtime option keys that are said to
|
|
* be "strong" for a BDS. An option is called "strong" if it changes
|
|
* a BDS's data. For example, the null block driver's "size" and
|
|
* "read-zeroes" options are strong, but its "latency-ns" option is
|
|
* not.
|
|
*
|
|
* If a key returned by this function ends with a dot, all options
|
|
* starting with that prefix are strong.
|
|
*/
|
|
static const char *const *strong_options(BlockDriverState *bs,
|
|
const char *const *curopt)
|
|
{
|
|
static const char *const global_options[] = {
|
|
"driver", "filename", NULL
|
|
};
|
|
|
|
if (!curopt) {
|
|
return &global_options[0];
|
|
}
|
|
|
|
curopt++;
|
|
if (curopt == &global_options[ARRAY_SIZE(global_options) - 1] && bs->drv) {
|
|
curopt = bs->drv->strong_runtime_opts;
|
|
}
|
|
|
|
return (curopt && *curopt) ? curopt : NULL;
|
|
}
|
|
|
|
/**
|
|
* Copies all strong runtime options from bs->options to the given
|
|
* QDict. The set of strong option keys is determined by invoking
|
|
* strong_options().
|
|
*
|
|
* Returns true iff any strong option was present in bs->options (and
|
|
* thus copied to the target QDict) with the exception of "filename"
|
|
* and "driver". The caller is expected to use this value to decide
|
|
* whether the existence of strong options prevents the generation of
|
|
* a plain filename.
|
|
*/
|
|
static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs)
|
|
{
|
|
bool found_any = false;
|
|
const char *const *option_name = NULL;
|
|
|
|
if (!bs->drv) {
|
|
return false;
|
|
}
|
|
|
|
while ((option_name = strong_options(bs, option_name))) {
|
|
bool option_given = false;
|
|
|
|
assert(strlen(*option_name) > 0);
|
|
if ((*option_name)[strlen(*option_name) - 1] != '.') {
|
|
QObject *entry = qdict_get(bs->options, *option_name);
|
|
if (!entry) {
|
|
continue;
|
|
}
|
|
|
|
qdict_put_obj(d, *option_name, qobject_ref(entry));
|
|
option_given = true;
|
|
} else {
|
|
const QDictEntry *entry;
|
|
for (entry = qdict_first(bs->options); entry;
|
|
entry = qdict_next(bs->options, entry))
|
|
{
|
|
if (strstart(qdict_entry_key(entry), *option_name, NULL)) {
|
|
qdict_put_obj(d, qdict_entry_key(entry),
|
|
qobject_ref(qdict_entry_value(entry)));
|
|
option_given = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* While "driver" and "filename" need to be included in a JSON filename,
|
|
* their existence does not prohibit generation of a plain filename. */
|
|
if (!found_any && option_given &&
|
|
strcmp(*option_name, "driver") && strcmp(*option_name, "filename"))
|
|
{
|
|
found_any = true;
|
|
}
|
|
}
|
|
|
|
if (!qdict_haskey(d, "driver")) {
|
|
/* Drivers created with bdrv_new_open_driver() may not have a
|
|
* @driver option. Add it here. */
|
|
qdict_put_str(d, "driver", bs->drv->format_name);
|
|
}
|
|
|
|
return found_any;
|
|
}
|
|
|
|
/* Note: This function may return false positives; it may return true
|
|
* even if opening the backing file specified by bs's image header
|
|
* would result in exactly bs->backing. */
|
|
static bool bdrv_backing_overridden(BlockDriverState *bs)
|
|
{
|
|
if (bs->backing) {
|
|
return strcmp(bs->auto_backing_file,
|
|
bs->backing->bs->filename);
|
|
} else {
|
|
/* No backing BDS, so if the image header reports any backing
|
|
* file, it must have been suppressed */
|
|
return bs->auto_backing_file[0] != '\0';
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
BdrvChild *child;
|
|
QDict *opts;
|
|
bool backing_overridden;
|
|
bool generate_json_filename; /* Whether our default implementation should
|
|
fill exact_filename (false) or not (true) */
|
|
|
|
if (!drv) {
|
|
return;
|
|
}
|
|
|
|
/* This BDS's file name may depend on any of its children's file names, so
|
|
* refresh those first */
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
bdrv_refresh_filename(child->bs);
|
|
}
|
|
|
|
if (bs->implicit) {
|
|
/* For implicit nodes, just copy everything from the single child */
|
|
child = QLIST_FIRST(&bs->children);
|
|
assert(QLIST_NEXT(child, next) == NULL);
|
|
|
|
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
|
|
child->bs->exact_filename);
|
|
pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename);
|
|
|
|
bs->full_open_options = qobject_ref(child->bs->full_open_options);
|
|
|
|
return;
|
|
}
|
|
|
|
backing_overridden = bdrv_backing_overridden(bs);
|
|
|
|
if (bs->open_flags & BDRV_O_NO_IO) {
|
|
/* Without I/O, the backing file does not change anything.
|
|
* Therefore, in such a case (primarily qemu-img), we can
|
|
* pretend the backing file has not been overridden even if
|
|
* it technically has been. */
|
|
backing_overridden = false;
|
|
}
|
|
|
|
/* Gather the options QDict */
|
|
opts = qdict_new();
|
|
generate_json_filename = append_strong_runtime_options(opts, bs);
|
|
generate_json_filename |= backing_overridden;
|
|
|
|
if (drv->bdrv_gather_child_options) {
|
|
/* Some block drivers may not want to present all of their children's
|
|
* options, or name them differently from BdrvChild.name */
|
|
drv->bdrv_gather_child_options(bs, opts, backing_overridden);
|
|
} else {
|
|
QLIST_FOREACH(child, &bs->children, next) {
|
|
if (child->role == &child_backing && !backing_overridden) {
|
|
/* We can skip the backing BDS if it has not been overridden */
|
|
continue;
|
|
}
|
|
|
|
qdict_put(opts, child->name,
|
|
qobject_ref(child->bs->full_open_options));
|
|
}
|
|
|
|
if (backing_overridden && !bs->backing) {
|
|
/* Force no backing file */
|
|
qdict_put_null(opts, "backing");
|
|
}
|
|
}
|
|
|
|
qobject_unref(bs->full_open_options);
|
|
bs->full_open_options = opts;
|
|
|
|
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';
|
|
|
|
drv->bdrv_refresh_filename(bs);
|
|
} else if (bs->file) {
|
|
/* Try to reconstruct valid information from the underlying file */
|
|
|
|
bs->exact_filename[0] = '\0';
|
|
|
|
/*
|
|
* We can use the underlying file's filename if:
|
|
* - it has a filename,
|
|
* - the file is a protocol BDS, and
|
|
* - opening that file (as this BDS's format) will automatically create
|
|
* the BDS tree we have right now, that is:
|
|
* - the user did not significantly change this BDS's behavior with
|
|
* some explicit (strong) options
|
|
* - no non-file child of this BDS has been overridden by the user
|
|
* Both of these conditions are represented by generate_json_filename.
|
|
*/
|
|
if (bs->file->bs->exact_filename[0] &&
|
|
bs->file->bs->drv->bdrv_file_open &&
|
|
!generate_json_filename)
|
|
{
|
|
strcpy(bs->exact_filename, bs->file->bs->exact_filename);
|
|
}
|
|
}
|
|
|
|
if (bs->exact_filename[0]) {
|
|
pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
|
|
} else {
|
|
QString *json = qobject_to_json(QOBJECT(bs->full_open_options));
|
|
snprintf(bs->filename, sizeof(bs->filename), "json:%s",
|
|
qstring_get_str(json));
|
|
qobject_unref(json);
|
|
}
|
|
}
|
|
|
|
char *bdrv_dirname(BlockDriverState *bs, Error **errp)
|
|
{
|
|
BlockDriver *drv = bs->drv;
|
|
|
|
if (!drv) {
|
|
error_setg(errp, "Node '%s' is ejected", bs->node_name);
|
|
return NULL;
|
|
}
|
|
|
|
if (drv->bdrv_dirname) {
|
|
return drv->bdrv_dirname(bs, errp);
|
|
}
|
|
|
|
if (bs->file) {
|
|
return bdrv_dirname(bs->file->bs, errp);
|
|
}
|
|
|
|
bdrv_refresh_filename(bs);
|
|
if (bs->exact_filename[0] != '\0') {
|
|
return path_combine(bs->exact_filename, "");
|
|
}
|
|
|
|
error_setg(errp, "Cannot generate a base directory for %s nodes",
|
|
drv->format_name);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Hot add/remove a BDS's child. So the user can take a child offline when
|
|
* it is broken and take a new child online
|
|
*/
|
|
void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
|
|
Error **errp)
|
|
{
|
|
|
|
if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) {
|
|
error_setg(errp, "The node %s does not support adding a child",
|
|
bdrv_get_device_or_node_name(parent_bs));
|
|
return;
|
|
}
|
|
|
|
if (!QLIST_EMPTY(&child_bs->parents)) {
|
|
error_setg(errp, "The node %s already has a parent",
|
|
child_bs->node_name);
|
|
return;
|
|
}
|
|
|
|
parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp);
|
|
}
|
|
|
|
void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp)
|
|
{
|
|
BdrvChild *tmp;
|
|
|
|
if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) {
|
|
error_setg(errp, "The node %s does not support removing a child",
|
|
bdrv_get_device_or_node_name(parent_bs));
|
|
return;
|
|
}
|
|
|
|
QLIST_FOREACH(tmp, &parent_bs->children, next) {
|
|
if (tmp == child) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!tmp) {
|
|
error_setg(errp, "The node %s does not have a child named %s",
|
|
bdrv_get_device_or_node_name(parent_bs),
|
|
bdrv_get_device_or_node_name(child->bs));
|
|
return;
|
|
}
|
|
|
|
parent_bs->drv->bdrv_del_child(parent_bs, child, errp);
|
|
}
|