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qemu/block/blkdebug.c
Kevin Wolf a4b740db5e block: Take graph lock for most of .bdrv_open 
Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't hold the graph lock while calling it), and afterwards many
operations that require holding the graph lock, e.g. for accessing
bs->file.

This changes block drivers that follow this pattern to take the graph
lock after opening the child node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-24-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-11-08 17:56:18 +01:00

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/*
* Block protocol for I/O error injection
*
* Copyright (C) 2016-2017 Red Hat, Inc.
* Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
*
* 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 "qapi/error.h"
#include "qemu/cutils.h"
#include "qemu/config-file.h"
#include "block/block-io.h"
#include "block/block_int.h"
#include "block/qdict.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "qapi/qapi-visit-block-core.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qobject-input-visitor.h"
#include "sysemu/qtest.h"
/* All APIs are thread-safe */
typedef struct BDRVBlkdebugState {
/* IN: initialized in blkdebug_open() and never changed */
uint64_t align;
uint64_t max_transfer;
uint64_t opt_write_zero;
uint64_t max_write_zero;
uint64_t opt_discard;
uint64_t max_discard;
char *config_file; /* For blkdebug_refresh_filename() */
/* initialized in blkdebug_parse_perms() */
uint64_t take_child_perms;
uint64_t unshare_child_perms;
/* State. Protected by lock */
int state;
QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX];
QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
QemuMutex lock;
} BDRVBlkdebugState;
typedef struct BlkdebugAIOCB {
BlockAIOCB common;
int ret;
} BlkdebugAIOCB;
typedef struct BlkdebugSuspendedReq {
/* IN: initialized in suspend_request() */
Coroutine *co;
char *tag;
/* List entry protected BDRVBlkdebugState's lock */
QLIST_ENTRY(BlkdebugSuspendedReq) next;
} BlkdebugSuspendedReq;
enum {
ACTION_INJECT_ERROR,
ACTION_SET_STATE,
ACTION_SUSPEND,
ACTION__MAX,
};
typedef struct BlkdebugRule {
/* IN: initialized in add_rule() or blkdebug_debug_breakpoint() */
BlkdebugEvent event;
int action;
int state;
union {
struct {
uint64_t iotype_mask;
int error;
int immediately;
int once;
int64_t offset;
} inject;
struct {
int new_state;
} set_state;
struct {
char *tag;
} suspend;
} options;
/* List entries protected BDRVBlkdebugState's lock */
QLIST_ENTRY(BlkdebugRule) next;
QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
} BlkdebugRule;
QEMU_BUILD_BUG_MSG(BLKDEBUG_IO_TYPE__MAX > 64,
"BlkdebugIOType mask does not fit into an uint64_t");
static QemuOptsList inject_error_opts = {
.name = "inject-error",
.head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
.desc = {
{
.name = "event",
.type = QEMU_OPT_STRING,
},
{
.name = "state",
.type = QEMU_OPT_NUMBER,
},
{
.name = "iotype",
.type = QEMU_OPT_STRING,
},
{
.name = "errno",
.type = QEMU_OPT_NUMBER,
},
{
.name = "sector",
.type = QEMU_OPT_NUMBER,
},
{
.name = "once",
.type = QEMU_OPT_BOOL,
},
{
.name = "immediately",
.type = QEMU_OPT_BOOL,
},
{ /* end of list */ }
},
};
static QemuOptsList set_state_opts = {
.name = "set-state",
.head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
.desc = {
{
.name = "event",
.type = QEMU_OPT_STRING,
},
{
.name = "state",
.type = QEMU_OPT_NUMBER,
},
{
.name = "new_state",
.type = QEMU_OPT_NUMBER,
},
{ /* end of list */ }
},
};
static QemuOptsList *config_groups[] = {
&inject_error_opts,
&set_state_opts,
NULL
};
struct add_rule_data {
BDRVBlkdebugState *s;
int action;
};
static int add_rule(void *opaque, QemuOpts *opts, Error **errp)
{
struct add_rule_data *d = opaque;
BDRVBlkdebugState *s = d->s;
const char *event_name;
int event;
struct BlkdebugRule *rule;
int64_t sector;
BlkdebugIOType iotype;
Error *local_error = NULL;
/* Find the right event for the rule */
event_name = qemu_opt_get(opts, "event");
if (!event_name) {
error_setg(errp, "Missing event name for rule");
return -1;
}
event = qapi_enum_parse(&BlkdebugEvent_lookup, event_name, -1, errp);
if (event < 0) {
return -1;
}
/* Set attributes common for all actions */
rule = g_malloc0(sizeof(*rule));
*rule = (struct BlkdebugRule) {
.event = event,
.action = d->action,
.state = qemu_opt_get_number(opts, "state", 0),
};
/* Parse action-specific options */
switch (d->action) {
case ACTION_INJECT_ERROR:
rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
rule->options.inject.once = qemu_opt_get_bool(opts, "once", 0);
rule->options.inject.immediately =
qemu_opt_get_bool(opts, "immediately", 0);
sector = qemu_opt_get_number(opts, "sector", -1);
rule->options.inject.offset =
sector == -1 ? -1 : sector * BDRV_SECTOR_SIZE;
iotype = qapi_enum_parse(&BlkdebugIOType_lookup,
qemu_opt_get(opts, "iotype"),
BLKDEBUG_IO_TYPE__MAX, &local_error);
if (local_error) {
error_propagate(errp, local_error);
g_free(rule);
return -1;
}
if (iotype != BLKDEBUG_IO_TYPE__MAX) {
rule->options.inject.iotype_mask = (1ull << iotype);
} else {
/* Apply the default */
rule->options.inject.iotype_mask =
(1ull << BLKDEBUG_IO_TYPE_READ)
| (1ull << BLKDEBUG_IO_TYPE_WRITE)
| (1ull << BLKDEBUG_IO_TYPE_WRITE_ZEROES)
| (1ull << BLKDEBUG_IO_TYPE_DISCARD)
| (1ull << BLKDEBUG_IO_TYPE_FLUSH);
}
break;
case ACTION_SET_STATE:
rule->options.set_state.new_state =
qemu_opt_get_number(opts, "new_state", 0);
break;
case ACTION_SUSPEND:
rule->options.suspend.tag =
g_strdup(qemu_opt_get(opts, "tag"));
break;
};
/* Add the rule */
qemu_mutex_lock(&s->lock);
QLIST_INSERT_HEAD(&s->rules[event], rule, next);
qemu_mutex_unlock(&s->lock);
return 0;
}
/* Called with lock held or from .bdrv_close */
static void remove_rule(BlkdebugRule *rule)
{
switch (rule->action) {
case ACTION_INJECT_ERROR:
case ACTION_SET_STATE:
break;
case ACTION_SUSPEND:
g_free(rule->options.suspend.tag);
break;
}
QLIST_REMOVE(rule, next);
g_free(rule);
}
static int read_config(BDRVBlkdebugState *s, const char *filename,
QDict *options, Error **errp)
{
FILE *f = NULL;
int ret;
struct add_rule_data d;
Error *local_err = NULL;
if (filename) {
f = fopen(filename, "r");
if (f == NULL) {
error_setg_errno(errp, errno, "Could not read blkdebug config file");
return -errno;
}
ret = qemu_config_parse(f, config_groups, filename, errp);
if (ret < 0) {
goto fail;
}
}
if (!qemu_config_parse_qdict(options, config_groups, errp)) {
ret = -EINVAL;
goto fail;
}
d.s = s;
d.action = ACTION_INJECT_ERROR;
qemu_opts_foreach(&inject_error_opts, add_rule, &d, &local_err);
if (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
d.action = ACTION_SET_STATE;
qemu_opts_foreach(&set_state_opts, add_rule, &d, &local_err);
if (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
ret = 0;
fail:
qemu_opts_reset(&inject_error_opts);
qemu_opts_reset(&set_state_opts);
if (f) {
fclose(f);
}
return ret;
}
/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
static void blkdebug_parse_filename(const char *filename, QDict *options,
Error **errp)
{
const char *c;
/* Parse the blkdebug: prefix */
if (!strstart(filename, "blkdebug:", &filename)) {
/* There was no prefix; therefore, all options have to be already
present in the QDict (except for the filename) */
qdict_put_str(options, "x-image", filename);
return;
}
/* Parse config file path */
c = strchr(filename, ':');
if (c == NULL) {
error_setg(errp, "blkdebug requires both config file and image path");
return;
}
if (c != filename) {
QString *config_path;
config_path = qstring_from_substr(filename, 0, c - filename);
qdict_put(options, "config", config_path);
}
/* TODO Allow multi-level nesting and set file.filename here */
filename = c + 1;
qdict_put_str(options, "x-image", filename);
}
static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options,
const char *prefix, Error **errp)
{
int ret = 0;
QDict *subqdict = NULL;
QObject *crumpled_subqdict = NULL;
Visitor *v = NULL;
BlockPermissionList *perm_list = NULL, *element;
*dest = 0;
qdict_extract_subqdict(options, &subqdict, prefix);
if (!qdict_size(subqdict)) {
goto out;
}
crumpled_subqdict = qdict_crumple(subqdict, errp);
if (!crumpled_subqdict) {
ret = -EINVAL;
goto out;
}
v = qobject_input_visitor_new(crumpled_subqdict);
if (!visit_type_BlockPermissionList(v, NULL, &perm_list, errp)) {
ret = -EINVAL;
goto out;
}
for (element = perm_list; element; element = element->next) {
*dest |= bdrv_qapi_perm_to_blk_perm(element->value);
}
out:
qapi_free_BlockPermissionList(perm_list);
visit_free(v);
qobject_unref(subqdict);
qobject_unref(crumpled_subqdict);
return ret;
}
static int blkdebug_parse_perms(BDRVBlkdebugState *s, QDict *options,
Error **errp)
{
int ret;
ret = blkdebug_parse_perm_list(&s->take_child_perms, options,
"take-child-perms.", errp);
if (ret < 0) {
return ret;
}
ret = blkdebug_parse_perm_list(&s->unshare_child_perms, options,
"unshare-child-perms.", errp);
if (ret < 0) {
return ret;
}
return 0;
}
static QemuOptsList runtime_opts = {
.name = "blkdebug",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
.name = "config",
.type = QEMU_OPT_STRING,
.help = "Path to the configuration file",
},
{
.name = "x-image",
.type = QEMU_OPT_STRING,
.help = "[internal use only, will be removed]",
},
{
.name = "align",
.type = QEMU_OPT_SIZE,
.help = "Required alignment in bytes",
},
{
.name = "max-transfer",
.type = QEMU_OPT_SIZE,
.help = "Maximum transfer size in bytes",
},
{
.name = "opt-write-zero",
.type = QEMU_OPT_SIZE,
.help = "Optimum write zero alignment in bytes",
},
{
.name = "max-write-zero",
.type = QEMU_OPT_SIZE,
.help = "Maximum write zero size in bytes",
},
{
.name = "opt-discard",
.type = QEMU_OPT_SIZE,
.help = "Optimum discard alignment in bytes",
},
{
.name = "max-discard",
.type = QEMU_OPT_SIZE,
.help = "Maximum discard size in bytes",
},
{ /* end of list */ }
},
};
static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVBlkdebugState *s = bs->opaque;
QemuOpts *opts;
int ret;
uint64_t align;
qemu_mutex_init(&s->lock);
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
ret = -EINVAL;
goto out;
}
/* Read rules from config file or command line options */
s->config_file = g_strdup(qemu_opt_get(opts, "config"));
ret = read_config(s, s->config_file, options, errp);
if (ret) {
goto out;
}
/* Set initial state */
s->state = 1;
/* Parse permissions modifiers before opening the image file */
ret = blkdebug_parse_perms(s, options, errp);
if (ret < 0) {
goto out;
}
/* Open the image file */
ret = bdrv_open_file_child(qemu_opt_get(opts, "x-image"), options, "image",
bs, errp);
if (ret < 0) {
goto out;
}
bdrv_graph_rdlock_main_loop();
bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
(BDRV_REQ_FUA & bs->file->bs->supported_write_flags);
bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
bs->file->bs->supported_zero_flags);
ret = -EINVAL;
/* Set alignment overrides */
s->align = qemu_opt_get_size(opts, "align", 0);
if (s->align && (s->align >= INT_MAX || !is_power_of_2(s->align))) {
error_setg(errp, "Cannot meet constraints with align %" PRIu64,
s->align);
goto out_rdlock;
}
align = MAX(s->align, bs->file->bs->bl.request_alignment);
s->max_transfer = qemu_opt_get_size(opts, "max-transfer", 0);
if (s->max_transfer &&
(s->max_transfer >= INT_MAX ||
!QEMU_IS_ALIGNED(s->max_transfer, align))) {
error_setg(errp, "Cannot meet constraints with max-transfer %" PRIu64,
s->max_transfer);
goto out_rdlock;
}
s->opt_write_zero = qemu_opt_get_size(opts, "opt-write-zero", 0);
if (s->opt_write_zero &&
(s->opt_write_zero >= INT_MAX ||
!QEMU_IS_ALIGNED(s->opt_write_zero, align))) {
error_setg(errp, "Cannot meet constraints with opt-write-zero %" PRIu64,
s->opt_write_zero);
goto out_rdlock;
}
s->max_write_zero = qemu_opt_get_size(opts, "max-write-zero", 0);
if (s->max_write_zero &&
(s->max_write_zero >= INT_MAX ||
!QEMU_IS_ALIGNED(s->max_write_zero,
MAX(s->opt_write_zero, align)))) {
error_setg(errp, "Cannot meet constraints with max-write-zero %" PRIu64,
s->max_write_zero);
goto out_rdlock;
}
s->opt_discard = qemu_opt_get_size(opts, "opt-discard", 0);
if (s->opt_discard &&
(s->opt_discard >= INT_MAX ||
!QEMU_IS_ALIGNED(s->opt_discard, align))) {
error_setg(errp, "Cannot meet constraints with opt-discard %" PRIu64,
s->opt_discard);
goto out_rdlock;
}
s->max_discard = qemu_opt_get_size(opts, "max-discard", 0);
if (s->max_discard &&
(s->max_discard >= INT_MAX ||
!QEMU_IS_ALIGNED(s->max_discard,
MAX(s->opt_discard, align)))) {
error_setg(errp, "Cannot meet constraints with max-discard %" PRIu64,
s->max_discard);
goto out_rdlock;
}
bdrv_debug_event(bs, BLKDBG_NONE);
ret = 0;
out_rdlock:
bdrv_graph_rdunlock_main_loop();
out:
if (ret < 0) {
qemu_mutex_destroy(&s->lock);
g_free(s->config_file);
}
qemu_opts_del(opts);
return ret;
}
static int coroutine_fn rule_check(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, BlkdebugIOType iotype)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule = NULL;
int error;
bool immediately;
qemu_mutex_lock(&s->lock);
QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
uint64_t inject_offset = rule->options.inject.offset;
if ((inject_offset == -1 ||
(bytes && inject_offset >= offset &&
inject_offset < offset + bytes)) &&
(rule->options.inject.iotype_mask & (1ull << iotype)))
{
break;
}
}
if (!rule || !rule->options.inject.error) {
qemu_mutex_unlock(&s->lock);
return 0;
}
immediately = rule->options.inject.immediately;
error = rule->options.inject.error;
if (rule->options.inject.once) {
QSIMPLEQ_REMOVE(&s->active_rules, rule, BlkdebugRule, active_next);
remove_rule(rule);
}
qemu_mutex_unlock(&s->lock);
if (!immediately) {
aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self());
qemu_coroutine_yield();
}
return -error;
}
static int coroutine_fn GRAPH_RDLOCK
blkdebug_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
QEMUIOVector *qiov, BdrvRequestFlags flags)
{
int err;
/* Sanity check block layer guarantees */
assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
if (bs->bl.max_transfer) {
assert(bytes <= bs->bl.max_transfer);
}
err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_READ);
if (err) {
return err;
}
return bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
}
static int coroutine_fn GRAPH_RDLOCK
blkdebug_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
QEMUIOVector *qiov, BdrvRequestFlags flags)
{
int err;
/* Sanity check block layer guarantees */
assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
if (bs->bl.max_transfer) {
assert(bytes <= bs->bl.max_transfer);
}
err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE);
if (err) {
return err;
}
return bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
}
static int GRAPH_RDLOCK coroutine_fn blkdebug_co_flush(BlockDriverState *bs)
{
int err = rule_check(bs, 0, 0, BLKDEBUG_IO_TYPE_FLUSH);
if (err) {
return err;
}
return bdrv_co_flush(bs->file->bs);
}
static int coroutine_fn GRAPH_RDLOCK
blkdebug_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
BdrvRequestFlags flags)
{
uint32_t align = MAX(bs->bl.request_alignment,
bs->bl.pwrite_zeroes_alignment);
int err;
/* Only pass through requests that are larger than requested
* preferred alignment (so that we test the fallback to writes on
* unaligned portions), and check that the block layer never hands
* us anything unaligned that crosses an alignment boundary. */
if (bytes < align) {
assert(QEMU_IS_ALIGNED(offset, align) ||
QEMU_IS_ALIGNED(offset + bytes, align) ||
DIV_ROUND_UP(offset, align) ==
DIV_ROUND_UP(offset + bytes, align));
return -ENOTSUP;
}
assert(QEMU_IS_ALIGNED(offset, align));
assert(QEMU_IS_ALIGNED(bytes, align));
if (bs->bl.max_pwrite_zeroes) {
assert(bytes <= bs->bl.max_pwrite_zeroes);
}
err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_WRITE_ZEROES);
if (err) {
return err;
}
return bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
}
static int coroutine_fn GRAPH_RDLOCK
blkdebug_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
{
uint32_t align = bs->bl.pdiscard_alignment;
int err;
/* Only pass through requests that are larger than requested
* minimum alignment, and ensure that unaligned requests do not
* cross optimum discard boundaries. */
if (bytes < bs->bl.request_alignment) {
assert(QEMU_IS_ALIGNED(offset, align) ||
QEMU_IS_ALIGNED(offset + bytes, align) ||
DIV_ROUND_UP(offset, align) ==
DIV_ROUND_UP(offset + bytes, align));
return -ENOTSUP;
}
assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
if (align && bytes >= align) {
assert(QEMU_IS_ALIGNED(offset, align));
assert(QEMU_IS_ALIGNED(bytes, align));
}
if (bs->bl.max_pdiscard) {
assert(bytes <= bs->bl.max_pdiscard);
}
err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_DISCARD);
if (err) {
return err;
}
return bdrv_co_pdiscard(bs->file, offset, bytes);
}
static int coroutine_fn GRAPH_RDLOCK
blkdebug_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset,
int64_t bytes, int64_t *pnum, int64_t *map,
BlockDriverState **file)
{
int err;
assert(QEMU_IS_ALIGNED(offset | bytes, bs->bl.request_alignment));
err = rule_check(bs, offset, bytes, BLKDEBUG_IO_TYPE_BLOCK_STATUS);
if (err) {
return err;
}
assert(bs->file && bs->file->bs);
*pnum = bytes;
*map = offset;
*file = bs->file->bs;
return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID;
}
static void blkdebug_close(BlockDriverState *bs)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule, *next;
int i;
for (i = 0; i < BLKDBG__MAX; i++) {
QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
remove_rule(rule);
}
}
g_free(s->config_file);
qemu_mutex_destroy(&s->lock);
}
/* Called with lock held. */
static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugSuspendedReq *r;
r = g_new(BlkdebugSuspendedReq, 1);
r->co = qemu_coroutine_self();
r->tag = g_strdup(rule->options.suspend.tag);
remove_rule(rule);
QLIST_INSERT_HEAD(&s->suspended_reqs, r, next);
if (!qtest_enabled()) {
printf("blkdebug: Suspended request '%s'\n", r->tag);
}
}
/* Called with lock held. */
static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
int *action_count, int *new_state)
{
BDRVBlkdebugState *s = bs->opaque;
/* Only process rules for the current state */
if (rule->state && rule->state != s->state) {
return;
}
/* Take the action */
action_count[rule->action]++;
switch (rule->action) {
case ACTION_INJECT_ERROR:
if (action_count[ACTION_INJECT_ERROR] == 1) {
QSIMPLEQ_INIT(&s->active_rules);
}
QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
break;
case ACTION_SET_STATE:
*new_state = rule->options.set_state.new_state;
break;
case ACTION_SUSPEND:
suspend_request(bs, rule);
break;
}
}
static void coroutine_fn
blkdebug_co_debug_event(BlockDriverState *bs, BlkdebugEvent event)
{
BDRVBlkdebugState *s = bs->opaque;
struct BlkdebugRule *rule, *next;
int new_state;
int actions_count[ACTION__MAX] = { 0 };
assert((int)event >= 0 && event < BLKDBG__MAX);
WITH_QEMU_LOCK_GUARD(&s->lock) {
new_state = s->state;
QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
process_rule(bs, rule, actions_count, &new_state);
}
s->state = new_state;
}
while (actions_count[ACTION_SUSPEND] > 0) {
qemu_coroutine_yield();
actions_count[ACTION_SUSPEND]--;
}
}
static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
struct BlkdebugRule *rule;
int blkdebug_event;
blkdebug_event = qapi_enum_parse(&BlkdebugEvent_lookup, event, -1, NULL);
if (blkdebug_event < 0) {
return -ENOENT;
}
rule = g_malloc(sizeof(*rule));
*rule = (struct BlkdebugRule) {
.event = blkdebug_event,
.action = ACTION_SUSPEND,
.state = 0,
.options.suspend.tag = g_strdup(tag),
};
qemu_mutex_lock(&s->lock);
QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
qemu_mutex_unlock(&s->lock);
return 0;
}
/* Called with lock held. May temporarily release lock. */
static int resume_req_by_tag(BDRVBlkdebugState *s, const char *tag, bool all)
{
BlkdebugSuspendedReq *r;
retry:
/*
* No need for _SAFE, since a different coroutine can remove another node
* (not the current one) in this list, and when the current one is removed
* the iteration starts back from beginning anyways.
*/
QLIST_FOREACH(r, &s->suspended_reqs, next) {
if (!strcmp(r->tag, tag)) {
Coroutine *co = r->co;
if (!qtest_enabled()) {
printf("blkdebug: Resuming request '%s'\n", r->tag);
}
QLIST_REMOVE(r, next);
g_free(r->tag);
g_free(r);
qemu_mutex_unlock(&s->lock);
qemu_coroutine_enter(co);
qemu_mutex_lock(&s->lock);
if (all) {
goto retry;
}
return 0;
}
}
return -ENOENT;
}
static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
QEMU_LOCK_GUARD(&s->lock);
return resume_req_by_tag(s, tag, false);
}
static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs,
const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule, *next;
int i, ret = -ENOENT;
QEMU_LOCK_GUARD(&s->lock);
for (i = 0; i < BLKDBG__MAX; i++) {
QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
if (rule->action == ACTION_SUSPEND &&
!strcmp(rule->options.suspend.tag, tag)) {
remove_rule(rule);
ret = 0;
}
}
}
if (resume_req_by_tag(s, tag, true) == 0) {
ret = 0;
}
return ret;
}
static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugSuspendedReq *r;
QEMU_LOCK_GUARD(&s->lock);
QLIST_FOREACH(r, &s->suspended_reqs, next) {
if (!strcmp(r->tag, tag)) {
return true;
}
}
return false;
}
static int64_t coroutine_fn GRAPH_RDLOCK
blkdebug_co_getlength(BlockDriverState *bs)
{
return bdrv_co_getlength(bs->file->bs);
}
static void GRAPH_RDLOCK blkdebug_refresh_filename(BlockDriverState *bs)
{
BDRVBlkdebugState *s = bs->opaque;
const QDictEntry *e;
int ret;
if (!bs->file->bs->exact_filename[0]) {
return;
}
for (e = qdict_first(bs->full_open_options); e;
e = qdict_next(bs->full_open_options, e))
{
/* Real child options are under "image", but "x-image" may
* contain a filename */
if (strcmp(qdict_entry_key(e), "config") &&
strcmp(qdict_entry_key(e), "image") &&
strcmp(qdict_entry_key(e), "x-image") &&
strcmp(qdict_entry_key(e), "driver"))
{
return;
}
}
ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename),
"blkdebug:%s:%s",
s->config_file ?: "", bs->file->bs->exact_filename);
if (ret >= sizeof(bs->exact_filename)) {
/* An overflow makes the filename unusable, so do not report any */
bs->exact_filename[0] = 0;
}
}
static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVBlkdebugState *s = bs->opaque;
if (s->align) {
bs->bl.request_alignment = s->align;
}
if (s->max_transfer) {
bs->bl.max_transfer = s->max_transfer;
}
if (s->opt_write_zero) {
bs->bl.pwrite_zeroes_alignment = s->opt_write_zero;
}
if (s->max_write_zero) {
bs->bl.max_pwrite_zeroes = s->max_write_zero;
}
if (s->opt_discard) {
bs->bl.pdiscard_alignment = s->opt_discard;
}
if (s->max_discard) {
bs->bl.max_pdiscard = s->max_discard;
}
}
static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue, Error **errp)
{
return 0;
}
static void blkdebug_child_perm(BlockDriverState *bs, BdrvChild *c,
BdrvChildRole role,
BlockReopenQueue *reopen_queue,
uint64_t perm, uint64_t shared,
uint64_t *nperm, uint64_t *nshared)
{
BDRVBlkdebugState *s = bs->opaque;
bdrv_default_perms(bs, c, role, reopen_queue,
perm, shared, nperm, nshared);
*nperm |= s->take_child_perms;
*nshared &= ~s->unshare_child_perms;
}
static const char *const blkdebug_strong_runtime_opts[] = {
"config",
"inject-error.",
"set-state.",
"align",
"max-transfer",
"opt-write-zero",
"max-write-zero",
"opt-discard",
"max-discard",
NULL
};
static BlockDriver bdrv_blkdebug = {
.format_name = "blkdebug",
.protocol_name = "blkdebug",
.instance_size = sizeof(BDRVBlkdebugState),
.is_filter = true,
.bdrv_parse_filename = blkdebug_parse_filename,
.bdrv_file_open = blkdebug_open,
.bdrv_close = blkdebug_close,
.bdrv_reopen_prepare = blkdebug_reopen_prepare,
.bdrv_child_perm = blkdebug_child_perm,
.bdrv_co_getlength = blkdebug_co_getlength,
.bdrv_refresh_filename = blkdebug_refresh_filename,
.bdrv_refresh_limits = blkdebug_refresh_limits,
.bdrv_co_preadv = blkdebug_co_preadv,
.bdrv_co_pwritev = blkdebug_co_pwritev,
.bdrv_co_flush_to_disk = blkdebug_co_flush,
.bdrv_co_pwrite_zeroes = blkdebug_co_pwrite_zeroes,
.bdrv_co_pdiscard = blkdebug_co_pdiscard,
.bdrv_co_block_status = blkdebug_co_block_status,
.bdrv_co_debug_event = blkdebug_co_debug_event,
.bdrv_debug_breakpoint = blkdebug_debug_breakpoint,
.bdrv_debug_remove_breakpoint
= blkdebug_debug_remove_breakpoint,
.bdrv_debug_resume = blkdebug_debug_resume,
.bdrv_debug_is_suspended = blkdebug_debug_is_suspended,
.strong_runtime_opts = blkdebug_strong_runtime_opts,
};
static void bdrv_blkdebug_init(void)
{
bdrv_register(&bdrv_blkdebug);
}
block_init(bdrv_blkdebug_init);
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