qemu-e2k/blockdev.c

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/*
* QEMU host block devices
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright (c) 2003-2008 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"
block: New BlockBackend A block device consists of a frontend device model and a backend. A block backend has a tree of block drivers doing the actual work. The tree is managed by the block layer. We currently use a single abstraction BlockDriverState both for tree nodes and the backend as a whole. Drawbacks: * Its API includes both stuff that makes sense only at the block backend level (root of the tree) and stuff that's only for use within the block layer. This makes the API bigger and more complex than necessary. Moreover, it's not obvious which interfaces are meant for device models, and which really aren't. * Since device models keep a reference to their backend, the backend object can't just be destroyed. But for media change, we need to replace the tree. Our solution is to make the BlockDriverState generic, with actual driver state in a separate object, pointed to by member opaque. That lets us replace the tree by deinitializing and reinitializing its root. This special need of the root makes the data structure awkward everywhere in the tree. The general plan is to separate the APIs into "block backend", for use by device models, monitor and whatever other code dealing with block backends, and "block driver", for use by the block layer and whatever other code (if any) dealing with trees and tree nodes. Code dealing with block backends, device models in particular, should become completely oblivious of BlockDriverState. This should let us clean up both APIs, and the tree data structures. This commit is a first step. It creates a minimal "block backend" API: type BlockBackend and functions to create, destroy and find them. BlockBackend objects are created and destroyed exactly when root BlockDriverState objects are created and destroyed. "Root" in the sense of "in bdrv_states". They're not yet used for anything; that'll come shortly. A root BlockDriverState is created with bdrv_new_root(), so where to create a BlockBackend is obvious. Where these roots get destroyed isn't always as obvious. It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error paths of blockdev_init(), blk_connect(). That leaves destruction of objects successfully created by blockdev_init() and blk_connect(). blockdev_init() is used only by drive_new() and qmp_blockdev_add(). Objects created by the latter are currently indestructible (see commit 48f364d "blockdev: Refuse to drive_del something added with blockdev-add" and commit 2d246f0 "blockdev: Introduce DriveInfo.enable_auto_del"). Objects created by the former get destroyed by drive_del(). Objects created by blk_connect() get destroyed by blk_disconnect(). BlockBackend is reference-counted. Its reference count never exceeds one so far, but that's going to change. In drive_del(), the BB's reference count is surely one now. The BDS's reference count is greater than one when something else is holding a reference, such as a block job. In this case, the BB is destroyed right away, but the BDS lives on until all extra references get dropped. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-07 13:59:04 +02:00
#include "sysemu/block-backend.h"
#include "sysemu/blockdev.h"
#include "hw/block/block.h"
#include "block/blockjob.h"
#include "block/qdict.h"
#include "block/throttle-groups.h"
#include "monitor/monitor.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "qemu/qemu-print.h"
#include "qemu/config-file.h"
#include "qapi/qapi-commands-block.h"
#include "qapi/qapi-commands-transaction.h"
#include "qapi/qapi-visit-block-core.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"
#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qobject-output-visitor.h"
#include "sysemu/sysemu.h"
#include "sysemu/iothread.h"
#include "block/block_int.h"
#include "block/trace.h"
#include "sysemu/runstate.h"
#include "sysemu/replay.h"
#include "qemu/cutils.h"
#include "qemu/help_option.h"
#include "qemu/main-loop.h"
#include "qemu/throttle-options.h"
QTAILQ_HEAD(, BlockDriverState) monitor_bdrv_states =
QTAILQ_HEAD_INITIALIZER(monitor_bdrv_states);
void bdrv_set_monitor_owned(BlockDriverState *bs)
{
QTAILQ_INSERT_TAIL(&monitor_bdrv_states, bs, monitor_list);
}
static const char *const if_name[IF_COUNT] = {
[IF_NONE] = "none",
[IF_IDE] = "ide",
[IF_SCSI] = "scsi",
[IF_FLOPPY] = "floppy",
[IF_PFLASH] = "pflash",
[IF_MTD] = "mtd",
[IF_SD] = "sd",
[IF_VIRTIO] = "virtio",
[IF_XEN] = "xen",
};
static int if_max_devs[IF_COUNT] = {
/*
* Do not change these numbers! They govern how drive option
* index maps to unit and bus. That mapping is ABI.
*
* All controllers used to implement if=T drives need to support
* if_max_devs[T] units, for any T with if_max_devs[T] != 0.
* Otherwise, some index values map to "impossible" bus, unit
* values.
*
* For instance, if you change [IF_SCSI] to 255, -drive
* if=scsi,index=12 no longer means bus=1,unit=5, but
* bus=0,unit=12. With an lsi53c895a controller (7 units max),
* the drive can't be set up. Regression.
*/
[IF_IDE] = 2,
[IF_SCSI] = 7,
};
/**
* Boards may call this to offer board-by-board overrides
* of the default, global values.
*/
void override_max_devs(BlockInterfaceType type, int max_devs)
{
BlockBackend *blk;
DriveInfo *dinfo;
if (max_devs <= 0) {
return;
}
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
if (dinfo->type == type) {
fprintf(stderr, "Cannot override units-per-bus property of"
" the %s interface, because a drive of that type has"
" already been added.\n", if_name[type]);
g_assert_not_reached();
}
}
if_max_devs[type] = max_devs;
}
/*
* We automatically delete the drive when a device using it gets
* unplugged. Questionable feature, but we can't just drop it.
* Device models call blockdev_mark_auto_del() to schedule the
* automatic deletion, and generic qdev code calls blockdev_auto_del()
* when deletion is actually safe.
*/
void blockdev_mark_auto_del(BlockBackend *blk)
{
DriveInfo *dinfo = blk_legacy_dinfo(blk);
BlockJob *job;
if (!dinfo) {
return;
}
for (job = block_job_next(NULL); job; job = block_job_next(job)) {
if (block_job_has_bdrv(job, blk_bs(blk))) {
AioContext *aio_context = job->job.aio_context;
aio_context_acquire(aio_context);
job_cancel(&job->job, false);
aio_context_release(aio_context);
}
}
dinfo->auto_del = 1;
}
void blockdev_auto_del(BlockBackend *blk)
{
DriveInfo *dinfo = blk_legacy_dinfo(blk);
if (dinfo && dinfo->auto_del) {
monitor_remove_blk(blk);
blk_unref(blk);
}
}
static int drive_index_to_bus_id(BlockInterfaceType type, int index)
{
int max_devs = if_max_devs[type];
return max_devs ? index / max_devs : 0;
}
static int drive_index_to_unit_id(BlockInterfaceType type, int index)
{
int max_devs = if_max_devs[type];
return max_devs ? index % max_devs : index;
}
QemuOpts *drive_add(BlockInterfaceType type, int index, const char *file,
const char *optstr)
{
QemuOpts *opts;
opts = qemu_opts_parse_noisily(qemu_find_opts("drive"), optstr, false);
if (!opts) {
return NULL;
}
if (type != IF_DEFAULT) {
qemu_opt_set(opts, "if", if_name[type], &error_abort);
}
if (index >= 0) {
qemu_opt_set_number(opts, "index", index, &error_abort);
}
if (file)
qemu_opt_set(opts, "file", file, &error_abort);
return opts;
}
DriveInfo *drive_get(BlockInterfaceType type, int bus, int unit)
{
BlockBackend *blk;
DriveInfo *dinfo;
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
if (dinfo && dinfo->type == type
&& dinfo->bus == bus && dinfo->unit == unit) {
return dinfo;
}
}
return NULL;
}
/*
* Check board claimed all -drive that are meant to be claimed.
* Fatal error if any remain unclaimed.
*/
void drive_check_orphaned(void)
{
BlockBackend *blk;
DriveInfo *dinfo;
Location loc;
bool orphans = false;
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
/*
* Ignore default drives, because we create certain default
* drives unconditionally, then leave them unclaimed. Not the
* users fault.
* Ignore IF_VIRTIO, because it gets desugared into -device,
* so we can leave failing to -device.
* Ignore IF_NONE, because leaving unclaimed IF_NONE remains
* available for device_add is a feature.
*/
if (dinfo->is_default || dinfo->type == IF_VIRTIO
|| dinfo->type == IF_NONE) {
continue;
}
if (!blk_get_attached_dev(blk)) {
loc_push_none(&loc);
qemu_opts_loc_restore(dinfo->opts);
error_report("machine type does not support"
" if=%s,bus=%d,unit=%d",
if_name[dinfo->type], dinfo->bus, dinfo->unit);
loc_pop(&loc);
orphans = true;
}
}
if (orphans) {
exit(1);
}
}
DriveInfo *drive_get_by_index(BlockInterfaceType type, int index)
{
return drive_get(type,
drive_index_to_bus_id(type, index),
drive_index_to_unit_id(type, index));
}
int drive_get_max_bus(BlockInterfaceType type)
{
int max_bus;
BlockBackend *blk;
DriveInfo *dinfo;
max_bus = -1;
for (blk = blk_next(NULL); blk; blk = blk_next(blk)) {
dinfo = blk_legacy_dinfo(blk);
if (dinfo && dinfo->type == type && dinfo->bus > max_bus) {
max_bus = dinfo->bus;
}
}
return max_bus;
}
static void bdrv_format_print(void *opaque, const char *name)
{
qemu_printf(" %s", name);
}
typedef struct {
QEMUBH *bh;
BlockDriverState *bs;
} BDRVPutRefBH;
static int parse_block_error_action(const char *buf, bool is_read, Error **errp)
{
if (!strcmp(buf, "ignore")) {
return BLOCKDEV_ON_ERROR_IGNORE;
} else if (!is_read && !strcmp(buf, "enospc")) {
return BLOCKDEV_ON_ERROR_ENOSPC;
} else if (!strcmp(buf, "stop")) {
return BLOCKDEV_ON_ERROR_STOP;
} else if (!strcmp(buf, "report")) {
return BLOCKDEV_ON_ERROR_REPORT;
} else {
error_setg(errp, "'%s' invalid %s error action",
buf, is_read ? "read" : "write");
return -1;
}
}
static bool parse_stats_intervals(BlockAcctStats *stats, QList *intervals,
Error **errp)
{
const QListEntry *entry;
for (entry = qlist_first(intervals); entry; entry = qlist_next(entry)) {
switch (qobject_type(entry->value)) {
case QTYPE_QSTRING: {
unsigned long long length;
const char *str = qstring_get_str(qobject_to(QString,
entry->value));
if (parse_uint_full(str, &length, 10) == 0 &&
length > 0 && length <= UINT_MAX) {
block_acct_add_interval(stats, (unsigned) length);
} else {
error_setg(errp, "Invalid interval length: %s", str);
return false;
}
break;
}
case QTYPE_QNUM: {
int64_t length = qnum_get_int(qobject_to(QNum, entry->value));
if (length > 0 && length <= UINT_MAX) {
block_acct_add_interval(stats, (unsigned) length);
} else {
error_setg(errp, "Invalid interval length: %" PRId64, length);
return false;
}
break;
}
default:
error_setg(errp, "The specification of stats-intervals is invalid");
return false;
}
}
return true;
}
typedef enum { MEDIA_DISK, MEDIA_CDROM } DriveMediaType;
/* All parameters but @opts are optional and may be set to NULL. */
static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
const char **throttling_group, ThrottleConfig *throttle_cfg,
BlockdevDetectZeroesOptions *detect_zeroes, Error **errp)
{
Error *local_error = NULL;
const char *aio;
if (bdrv_flags) {
if (qemu_opt_get_bool(opts, "copy-on-read", false)) {
*bdrv_flags |= BDRV_O_COPY_ON_READ;
}
if ((aio = qemu_opt_get(opts, "aio")) != NULL) {
if (bdrv_parse_aio(aio, bdrv_flags) < 0) {
error_setg(errp, "invalid aio option");
return;
}
}
}
/* disk I/O throttling */
if (throttling_group) {
*throttling_group = qemu_opt_get(opts, "throttling.group");
}
if (throttle_cfg) {
throttle_config_init(throttle_cfg);
throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
qemu_opt_get_number(opts, "throttling.bps-total", 0);
throttle_cfg->buckets[THROTTLE_BPS_READ].avg =
qemu_opt_get_number(opts, "throttling.bps-read", 0);
throttle_cfg->buckets[THROTTLE_BPS_WRITE].avg =
qemu_opt_get_number(opts, "throttling.bps-write", 0);
throttle_cfg->buckets[THROTTLE_OPS_TOTAL].avg =
qemu_opt_get_number(opts, "throttling.iops-total", 0);
throttle_cfg->buckets[THROTTLE_OPS_READ].avg =
qemu_opt_get_number(opts, "throttling.iops-read", 0);
throttle_cfg->buckets[THROTTLE_OPS_WRITE].avg =
qemu_opt_get_number(opts, "throttling.iops-write", 0);
throttle_cfg->buckets[THROTTLE_BPS_TOTAL].max =
qemu_opt_get_number(opts, "throttling.bps-total-max", 0);
throttle_cfg->buckets[THROTTLE_BPS_READ].max =
qemu_opt_get_number(opts, "throttling.bps-read-max", 0);
throttle_cfg->buckets[THROTTLE_BPS_WRITE].max =
qemu_opt_get_number(opts, "throttling.bps-write-max", 0);
throttle_cfg->buckets[THROTTLE_OPS_TOTAL].max =
qemu_opt_get_number(opts, "throttling.iops-total-max", 0);
throttle_cfg->buckets[THROTTLE_OPS_READ].max =
qemu_opt_get_number(opts, "throttling.iops-read-max", 0);
throttle_cfg->buckets[THROTTLE_OPS_WRITE].max =
qemu_opt_get_number(opts, "throttling.iops-write-max", 0);
throttle_cfg->buckets[THROTTLE_BPS_TOTAL].burst_length =
qemu_opt_get_number(opts, "throttling.bps-total-max-length", 1);
throttle_cfg->buckets[THROTTLE_BPS_READ].burst_length =
qemu_opt_get_number(opts, "throttling.bps-read-max-length", 1);
throttle_cfg->buckets[THROTTLE_BPS_WRITE].burst_length =
qemu_opt_get_number(opts, "throttling.bps-write-max-length", 1);
throttle_cfg->buckets[THROTTLE_OPS_TOTAL].burst_length =
qemu_opt_get_number(opts, "throttling.iops-total-max-length", 1);
throttle_cfg->buckets[THROTTLE_OPS_READ].burst_length =
qemu_opt_get_number(opts, "throttling.iops-read-max-length", 1);
throttle_cfg->buckets[THROTTLE_OPS_WRITE].burst_length =
qemu_opt_get_number(opts, "throttling.iops-write-max-length", 1);
throttle_cfg->op_size =
qemu_opt_get_number(opts, "throttling.iops-size", 0);
if (!throttle_is_valid(throttle_cfg, errp)) {
return;
}
}
if (detect_zeroes) {
*detect_zeroes =
qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
qemu_opt_get(opts, "detect-zeroes"),
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
&local_error);
if (local_error) {
error_propagate(errp, local_error);
return;
}
}
}
/* Takes the ownership of bs_opts */
static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
Error **errp)
{
const char *buf;
int bdrv_flags = 0;
int on_read_error, on_write_error;
bool account_invalid, account_failed;
bool writethrough, read_only;
block: New BlockBackend A block device consists of a frontend device model and a backend. A block backend has a tree of block drivers doing the actual work. The tree is managed by the block layer. We currently use a single abstraction BlockDriverState both for tree nodes and the backend as a whole. Drawbacks: * Its API includes both stuff that makes sense only at the block backend level (root of the tree) and stuff that's only for use within the block layer. This makes the API bigger and more complex than necessary. Moreover, it's not obvious which interfaces are meant for device models, and which really aren't. * Since device models keep a reference to their backend, the backend object can't just be destroyed. But for media change, we need to replace the tree. Our solution is to make the BlockDriverState generic, with actual driver state in a separate object, pointed to by member opaque. That lets us replace the tree by deinitializing and reinitializing its root. This special need of the root makes the data structure awkward everywhere in the tree. The general plan is to separate the APIs into "block backend", for use by device models, monitor and whatever other code dealing with block backends, and "block driver", for use by the block layer and whatever other code (if any) dealing with trees and tree nodes. Code dealing with block backends, device models in particular, should become completely oblivious of BlockDriverState. This should let us clean up both APIs, and the tree data structures. This commit is a first step. It creates a minimal "block backend" API: type BlockBackend and functions to create, destroy and find them. BlockBackend objects are created and destroyed exactly when root BlockDriverState objects are created and destroyed. "Root" in the sense of "in bdrv_states". They're not yet used for anything; that'll come shortly. A root BlockDriverState is created with bdrv_new_root(), so where to create a BlockBackend is obvious. Where these roots get destroyed isn't always as obvious. It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error paths of blockdev_init(), blk_connect(). That leaves destruction of objects successfully created by blockdev_init() and blk_connect(). blockdev_init() is used only by drive_new() and qmp_blockdev_add(). Objects created by the latter are currently indestructible (see commit 48f364d "blockdev: Refuse to drive_del something added with blockdev-add" and commit 2d246f0 "blockdev: Introduce DriveInfo.enable_auto_del"). Objects created by the former get destroyed by drive_del(). Objects created by blk_connect() get destroyed by blk_disconnect(). BlockBackend is reference-counted. Its reference count never exceeds one so far, but that's going to change. In drive_del(), the BB's reference count is surely one now. The BDS's reference count is greater than one when something else is holding a reference, such as a block job. In this case, the BB is destroyed right away, but the BDS lives on until all extra references get dropped. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-07 13:59:04 +02:00
BlockBackend *blk;
BlockDriverState *bs;
ThrottleConfig cfg;
int snapshot = 0;
Error *error = NULL;
QemuOpts *opts;
QDict *interval_dict = NULL;
QList *interval_list = NULL;
const char *id;
BlockdevDetectZeroesOptions detect_zeroes =
BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
const char *throttling_group = NULL;
/* Check common options by copying from bs_opts to opts, all other options
* stay in bs_opts for processing by bdrv_open(). */
id = qdict_get_try_str(bs_opts, "id");
opts = qemu_opts_create(&qemu_common_drive_opts, id, 1, errp);
if (!opts) {
goto err_no_opts;
}
error: Eliminate error_propagate() with Coccinelle, part 1 When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. Convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... return ... } to if (!foo(..., errp)) { ... ... return ... } where nothing else needs @err. Coccinelle script: @rule1 forall@ identifier fun, err, errp, lbl; expression list args, args2; binary operator op; constant c1, c2; symbol false; @@ if ( ( - fun(args, &err, args2) + fun(args, errp, args2) | - !fun(args, &err, args2) + !fun(args, errp, args2) | - fun(args, &err, args2) op c1 + fun(args, errp, args2) op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; ) } @rule2 forall@ identifier fun, err, errp, lbl; expression list args, args2; expression var; binary operator op; constant c1, c2; symbol false; @@ - var = fun(args, &err, args2); + var = fun(args, errp, args2); ... when != err if ( ( var | !var | var op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; | return var; ) } @depends on rule1 || rule2@ identifier err; @@ - Error *err = NULL; ... when != err Not exactly elegant, I'm afraid. The "when != lbl:" is necessary to avoid transforming if (fun(args, &err)) { goto out } ... out: error_propagate(errp, err); even though other paths to label out still need the error_propagate(). For an actual example, see sclp_realize(). Without the "when strict", Coccinelle transforms vfio_msix_setup(), incorrectly. I don't know what exactly "when strict" does, only that it helps here. The match of return is narrower than what I want, but I can't figure out how to express "return where the operand doesn't use @err". For an example where it's too narrow, see vfio_intx_enable(). Silently fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Converted manually. Line breaks tidied up manually. One nested declaration of @local_err deleted manually. Preexisting unwanted blank line dropped in hw/riscv/sifive_e.c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-07 18:06:02 +02:00
if (!qemu_opts_absorb_qdict(opts, bs_opts, errp)) {
goto early_err;
}
if (id) {
qdict_del(bs_opts, "id");
}
/* extract parameters */
snapshot = qemu_opt_get_bool(opts, "snapshot", 0);
account_invalid = qemu_opt_get_bool(opts, "stats-account-invalid", true);
account_failed = qemu_opt_get_bool(opts, "stats-account-failed", true);
writethrough = !qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true);
id = qemu_opts_id(opts);
qdict_extract_subqdict(bs_opts, &interval_dict, "stats-intervals.");
qdict_array_split(interval_dict, &interval_list);
if (qdict_size(interval_dict) != 0) {
error_setg(errp, "Invalid option stats-intervals.%s",
qdict_first(interval_dict)->key);
goto early_err;
}
extract_common_blockdev_options(opts, &bdrv_flags, &throttling_group, &cfg,
&detect_zeroes, &error);
if (error) {
error_propagate(errp, error);
goto early_err;
}
if ((buf = qemu_opt_get(opts, "format")) != NULL) {
if (is_help_option(buf)) {
qemu_printf("Supported formats:");
bdrv_iterate_format(bdrv_format_print, NULL, false);
qemu_printf("\nSupported formats (read-only):");
bdrv_iterate_format(bdrv_format_print, NULL, true);
qemu_printf("\n");
goto early_err;
}
if (qdict_haskey(bs_opts, "driver")) {
error_setg(errp, "Cannot specify both 'driver' and 'format'");
goto early_err;
}
qdict_put_str(bs_opts, "driver", buf);
}
on_write_error = BLOCKDEV_ON_ERROR_ENOSPC;
if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
on_write_error = parse_block_error_action(buf, 0, &error);
if (error) {
error_propagate(errp, error);
goto early_err;
}
}
on_read_error = BLOCKDEV_ON_ERROR_REPORT;
if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
on_read_error = parse_block_error_action(buf, 1, &error);
if (error) {
error_propagate(errp, error);
goto early_err;
}
}
if (snapshot) {
bdrv_flags |= BDRV_O_SNAPSHOT;
}
read_only = qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false);
/* init */
if ((!file || !*file) && !qdict_size(bs_opts)) {
BlockBackendRootState *blk_rs;
blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
blk_rs = blk_get_root_state(blk);
blk_rs->open_flags = bdrv_flags | (read_only ? 0 : BDRV_O_RDWR);
blk_rs->detect_zeroes = detect_zeroes;
qobject_unref(bs_opts);
} else {
if (file && !*file) {
file = NULL;
}
/* bdrv_open() 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(bs_opts, BDRV_OPT_CACHE_DIRECT, "off");
qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off");
qdict_set_default_str(bs_opts, BDRV_OPT_READ_ONLY,
read_only ? "on" : "off");
qdict_set_default_str(bs