qemu/block/blkdebug.c

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/*
* Block protocol for I/O error injection
*
* 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-common.h"
#include "block_int.h"
#include "module.h"
typedef struct BlkdebugVars {
int state;
/* If inject_errno != 0, an error is injected for requests */
int inject_errno;
/* Decides if all future requests fail (false) or only the next one and
* after the next request inject_errno is reset to 0 (true) */
bool inject_once;
/* Decides if aio_readv/writev fails right away (true) or returns an error
* return value only in the callback (false) */
bool inject_immediately;
} BlkdebugVars;
typedef struct BDRVBlkdebugState {
BlkdebugVars vars;
QLIST_HEAD(list, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
} BDRVBlkdebugState;
typedef struct BlkdebugAIOCB {
BlockDriverAIOCB common;
QEMUBH *bh;
int ret;
} BlkdebugAIOCB;
static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
static AIOPool blkdebug_aio_pool = {
.aiocb_size = sizeof(BlkdebugAIOCB),
.cancel = blkdebug_aio_cancel,
};
enum {
ACTION_INJECT_ERROR,
ACTION_SET_STATE,
};
typedef struct BlkdebugRule {
BlkDebugEvent event;
int action;
int state;
union {
struct {
int error;
int immediately;
int once;
} inject;
struct {
int new_state;
} set_state;
} options;
QLIST_ENTRY(BlkdebugRule) next;
} BlkdebugRule;
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 = "errno",
.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
};
static const char *event_names[BLKDBG_EVENT_MAX] = {
[BLKDBG_L1_UPDATE] = "l1_update",
[BLKDBG_L1_GROW_ALLOC_TABLE] = "l1_grow.alloc_table",
[BLKDBG_L1_GROW_WRITE_TABLE] = "l1_grow.write_table",
[BLKDBG_L1_GROW_ACTIVATE_TABLE] = "l1_grow.activate_table",
[BLKDBG_L2_LOAD] = "l2_load",
[BLKDBG_L2_UPDATE] = "l2_update",
[BLKDBG_L2_UPDATE_COMPRESSED] = "l2_update_compressed",
[BLKDBG_L2_ALLOC_COW_READ] = "l2_alloc.cow_read",
[BLKDBG_L2_ALLOC_WRITE] = "l2_alloc.write",
[BLKDBG_READ] = "read",
[BLKDBG_READ_AIO] = "read_aio",
[BLKDBG_READ_BACKING] = "read_backing",
[BLKDBG_READ_BACKING_AIO] = "read_backing_aio",
[BLKDBG_READ_COMPRESSED] = "read_compressed",
[BLKDBG_WRITE_AIO] = "write_aio",
[BLKDBG_WRITE_COMPRESSED] = "write_compressed",
[BLKDBG_VMSTATE_LOAD] = "vmstate_load",
[BLKDBG_VMSTATE_SAVE] = "vmstate_save",
[BLKDBG_COW_READ] = "cow_read",
[BLKDBG_COW_WRITE] = "cow_write",
[BLKDBG_REFTABLE_LOAD] = "reftable_load",
[BLKDBG_REFTABLE_GROW] = "reftable_grow",
[BLKDBG_REFBLOCK_LOAD] = "refblock_load",
[BLKDBG_REFBLOCK_UPDATE] = "refblock_update",
[BLKDBG_REFBLOCK_UPDATE_PART] = "refblock_update_part",
[BLKDBG_REFBLOCK_ALLOC] = "refblock_alloc",
[BLKDBG_REFBLOCK_ALLOC_HOOKUP] = "refblock_alloc.hookup",
[BLKDBG_REFBLOCK_ALLOC_WRITE] = "refblock_alloc.write",
[BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS] = "refblock_alloc.write_blocks",
[BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE] = "refblock_alloc.write_table",
[BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE] = "refblock_alloc.switch_table",
[BLKDBG_CLUSTER_ALLOC] = "cluster_alloc",
[BLKDBG_CLUSTER_ALLOC_BYTES] = "cluster_alloc_bytes",
[BLKDBG_CLUSTER_FREE] = "cluster_free",
};
static int get_event_by_name(const char *name, BlkDebugEvent *event)
{
int i;
for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
if (!strcmp(event_names[i], name)) {
*event = i;
return 0;
}
}
return -1;
}
struct add_rule_data {
BDRVBlkdebugState *s;
int action;
};
static int add_rule(QemuOpts *opts, void *opaque)
{
struct add_rule_data *d = opaque;
BDRVBlkdebugState *s = d->s;
const char* event_name;
BlkDebugEvent event;
struct BlkdebugRule *rule;
/* Find the right event for the rule */
event_name = qemu_opt_get(opts, "event");
if (!event_name || get_event_by_name(event_name, &event) < 0) {
return -1;
}
/* Set attributes common for all actions */
rule = qemu_mallocz(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);
break;
case ACTION_SET_STATE:
rule->options.set_state.new_state =
qemu_opt_get_number(opts, "new_state", 0);
break;
};
/* Add the rule */
QLIST_INSERT_HEAD(&s->rules[event], rule, next);
return 0;
}
static int read_config(BDRVBlkdebugState *s, const char *filename)
{
FILE *f;
int ret;
struct add_rule_data d;
f = fopen(filename, "r");
if (f == NULL) {
return -errno;
}
ret = qemu_config_parse(f, config_groups, filename);
if (ret < 0) {
goto fail;
}
d.s = s;
d.action = ACTION_INJECT_ERROR;
qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
d.action = ACTION_SET_STATE;
qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
ret = 0;
fail:
qemu_opts_reset(&inject_error_opts);
qemu_opts_reset(&set_state_opts);
fclose(f);
return ret;
}
/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVBlkdebugState *s = bs->opaque;
int ret;
char *config, *c;
/* Parse the blkdebug: prefix */
if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
return -EINVAL;
}
filename += strlen("blkdebug:");
/* Read rules from config file */
c = strchr(filename, ':');
if (c == NULL) {
return -EINVAL;
}
config = strdup(filename);
config[c - filename] = '\0';
ret = read_config(s, config);
free(config);
if (ret < 0) {
return ret;
}
filename = c + 1;
/* Set initial state */
s->vars.state = 1;
/* Open the backing file */
ret = bdrv_file_open(&bs->file, filename, flags);
if (ret < 0) {
return ret;
}
return 0;
}
static void error_callback_bh(void *opaque)
{
struct BlkdebugAIOCB *acb = opaque;
qemu_bh_delete(acb->bh);
acb->common.cb(acb->common.opaque, acb->ret);
qemu_aio_release(acb);
}
static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
{
BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
qemu_aio_release(acb);
}
static BlockDriverAIOCB *inject_error(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
int error = s->vars.inject_errno;
struct BlkdebugAIOCB *acb;
QEMUBH *bh;
if (s->vars.inject_once) {
s->vars.inject_errno = 0;
}
if (s->vars.inject_immediately) {
return NULL;
}
acb = qemu_aio_get(&blkdebug_aio_pool, bs, cb, opaque);
acb->ret = -error;
bh = qemu_bh_new(error_callback_bh, acb);
acb->bh = bh;
qemu_bh_schedule(bh);
return &acb->common;
}
static BlockDriverAIOCB *blkdebug_aio_readv(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
if (s->vars.inject_errno) {
return inject_error(bs, cb, opaque);
}
BlockDriverAIOCB *acb =
bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
return acb;
}
static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
if (s->vars.inject_errno) {
return inject_error(bs, cb, opaque);
}
BlockDriverAIOCB *acb =
bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
return acb;
}
static void blkdebug_close(BlockDriverState *bs)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule, *next;
int i;
for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
QLIST_REMOVE(rule, next);
qemu_free(rule);
}
}
}
static int blkdebug_flush(BlockDriverState *bs)
{
return bdrv_flush(bs->file);
}
static BlockDriverAIOCB *blkdebug_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
return bdrv_aio_flush(bs->file, cb, opaque);
}
static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
BlkdebugVars *old_vars)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugVars *vars = &s->vars;
/* Only process rules for the current state */
if (rule->state && rule->state != old_vars->state) {
return;
}
/* Take the action */
switch (rule->action) {
case ACTION_INJECT_ERROR:
vars->inject_errno = rule->options.inject.error;
vars->inject_once = rule->options.inject.once;
vars->inject_immediately = rule->options.inject.immediately;
break;
case ACTION_SET_STATE:
vars->state = rule->options.set_state.new_state;
break;
}
}
static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
{
BDRVBlkdebugState *s = bs->opaque;
struct BlkdebugRule *rule;
BlkdebugVars old_vars = s->vars;
assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
QLIST_FOREACH(rule, &s->rules[event], next) {
process_rule(bs, rule, &old_vars);
}
}
static BlockDriver bdrv_blkdebug = {
.format_name = "blkdebug",
.protocol_name = "blkdebug",
.instance_size = sizeof(BDRVBlkdebugState),
.bdrv_file_open = blkdebug_open,
.bdrv_close = blkdebug_close,
.bdrv_flush = blkdebug_flush,
.bdrv_aio_readv = blkdebug_aio_readv,
.bdrv_aio_writev = blkdebug_aio_writev,
.bdrv_aio_flush = blkdebug_aio_flush,
.bdrv_debug_event = blkdebug_debug_event,
};
static void bdrv_blkdebug_init(void)
{
bdrv_register(&bdrv_blkdebug);
}
block_init(bdrv_blkdebug_init);