qemu/block/blkdebug.c
Max Reitz afa50193cd qcow2-refcount: Repair shared refcount blocks
If the refcount of a refcount block is greater than one, we can at least
try to repair that problem by duplicating the affected block.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-02 10:06:59 +02:00

649 lines
18 KiB
C

/*
* 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 "qemu/config-file.h"
#include "block/block_int.h"
#include "qemu/module.h"
typedef struct BDRVBlkdebugState {
int state;
int new_state;
QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs;
} BDRVBlkdebugState;
typedef struct BlkdebugAIOCB {
BlockDriverAIOCB common;
QEMUBH *bh;
int ret;
} BlkdebugAIOCB;
typedef struct BlkdebugSuspendedReq {
Coroutine *co;
char *tag;
QLIST_ENTRY(BlkdebugSuspendedReq) next;
} BlkdebugSuspendedReq;
static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
static const AIOCBInfo blkdebug_aiocb_info = {
.aiocb_size = sizeof(BlkdebugAIOCB),
.cancel = blkdebug_aio_cancel,
};
enum {
ACTION_INJECT_ERROR,
ACTION_SET_STATE,
ACTION_SUSPEND,
};
typedef struct BlkdebugRule {
BlkDebugEvent event;
int action;
int state;
union {
struct {
int error;
int immediately;
int once;
int64_t sector;
} inject;
struct {
int new_state;
} set_state;
struct {
char *tag;
} suspend;
} options;
QLIST_ENTRY(BlkdebugRule) next;
QSIMPLEQ_ENTRY(BlkdebugRule) active_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 = "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
};
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_AIO] = "read_aio",
[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_REFTABLE_UPDATE] = "reftable_update",
[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",
[BLKDBG_FLUSH_TO_OS] = "flush_to_os",
[BLKDBG_FLUSH_TO_DISK] = "flush_to_disk",
};
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 = 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);
rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
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 */
QLIST_INSERT_HEAD(&s->rules[event], rule, next);
return 0;
}
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)
{
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 void blkdebug_parse_filename(const char *filename, QDict *options,
Error **errp)
{
const char *c;
/* Parse the blkdebug: prefix */
if (!strstart(filename, "blkdebug:", &filename)) {
error_setg(errp, "File name string must start with 'blkdebug:'");
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 - 1);
qdict_put(options, "config", config_path);
}
/* TODO Allow multi-level nesting and set file.filename here */
filename = c + 1;
qdict_put(options, "x-image", qstring_from_str(filename));
}
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]",
},
{ /* end of list */ }
},
};
static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags)
{
BDRVBlkdebugState *s = bs->opaque;
QemuOpts *opts;
Error *local_err = NULL;
const char *filename, *config;
int ret;
opts = qemu_opts_create_nofail(&runtime_opts);
qemu_opts_absorb_qdict(opts, options, &local_err);
if (error_is_set(&local_err)) {
qerror_report_err(local_err);
error_free(local_err);
ret = -EINVAL;
goto fail;
}
/* Read rules from config file */
config = qemu_opt_get(opts, "config");
if (config) {
ret = read_config(s, config);
if (ret < 0) {
goto fail;
}
}
/* Set initial state */
s->state = 1;
/* Open the backing file */
filename = qemu_opt_get(opts, "x-image");
if (filename == NULL) {
ret = -EINVAL;
goto fail;
}
ret = bdrv_file_open(&bs->file, filename, NULL, flags);
if (ret < 0) {
goto fail;
}
ret = 0;
fail:
qemu_opts_del(opts);
return ret;
}
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, BlkdebugRule *rule)
{
BDRVBlkdebugState *s = bs->opaque;
int error = rule->options.inject.error;
struct BlkdebugAIOCB *acb;
QEMUBH *bh;
if (rule->options.inject.once) {
QSIMPLEQ_INIT(&s->active_rules);
}
if (rule->options.inject.immediately) {
return NULL;
}
acb = qemu_aio_get(&blkdebug_aiocb_info, 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;
BlkdebugRule *rule = NULL;
QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
if (rule->options.inject.sector == -1 ||
(rule->options.inject.sector >= sector_num &&
rule->options.inject.sector < sector_num + nb_sectors)) {
break;
}
}
if (rule && rule->options.inject.error) {
return inject_error(bs, cb, opaque, rule);
}
return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
}
static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule = NULL;
QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
if (rule->options.inject.sector == -1 ||
(rule->options.inject.sector >= sector_num &&
rule->options.inject.sector < sector_num + nb_sectors)) {
break;
}
}
if (rule && rule->options.inject.error) {
return inject_error(bs, cb, opaque, rule);
}
return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
}
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) {
remove_rule(rule);
}
}
}
static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugSuspendedReq r;
r = (BlkdebugSuspendedReq) {
.co = qemu_coroutine_self(),
.tag = g_strdup(rule->options.suspend.tag),
};
remove_rule(rule);
QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next);
printf("blkdebug: Suspended request '%s'\n", r.tag);
qemu_coroutine_yield();
printf("blkdebug: Resuming request '%s'\n", r.tag);
QLIST_REMOVE(&r, next);
g_free(r.tag);
}
static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
bool injected)
{
BDRVBlkdebugState *s = bs->opaque;
/* Only process rules for the current state */
if (rule->state && rule->state != s->state) {
return injected;
}
/* Take the action */
switch (rule->action) {
case ACTION_INJECT_ERROR:
if (!injected) {
QSIMPLEQ_INIT(&s->active_rules);
injected = true;
}
QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
break;
case ACTION_SET_STATE:
s->new_state = rule->options.set_state.new_state;
break;
case ACTION_SUSPEND:
suspend_request(bs, rule);
break;
}
return injected;
}
static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
{
BDRVBlkdebugState *s = bs->opaque;
struct BlkdebugRule *rule, *next;
bool injected;
assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
injected = false;
s->new_state = s->state;
QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) {
injected = process_rule(bs, rule, injected);
}
s->state = s->new_state;
}
static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event,
const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
struct BlkdebugRule *rule;
BlkDebugEvent blkdebug_event;
if (get_event_by_name(event, &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),
};
QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next);
return 0;
}
static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugSuspendedReq *r;
QLIST_FOREACH(r, &s->suspended_reqs, next) {
if (!strcmp(r->tag, tag)) {
qemu_coroutine_enter(r->co, NULL);
return 0;
}
}
return -ENOENT;
}
static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag)
{
BDRVBlkdebugState *s = bs->opaque;
BlkdebugSuspendedReq *r;
QLIST_FOREACH(r, &s->suspended_reqs, next) {
if (!strcmp(r->tag, tag)) {
return true;
}
}
return false;
}
static int64_t blkdebug_getlength(BlockDriverState *bs)
{
return bdrv_getlength(bs->file);
}
static BlockDriver bdrv_blkdebug = {
.format_name = "blkdebug",
.protocol_name = "blkdebug",
.instance_size = sizeof(BDRVBlkdebugState),
.bdrv_parse_filename = blkdebug_parse_filename,
.bdrv_file_open = blkdebug_open,
.bdrv_close = blkdebug_close,
.bdrv_getlength = blkdebug_getlength,
.bdrv_aio_readv = blkdebug_aio_readv,
.bdrv_aio_writev = blkdebug_aio_writev,
.bdrv_debug_event = blkdebug_debug_event,
.bdrv_debug_breakpoint = blkdebug_debug_breakpoint,
.bdrv_debug_resume = blkdebug_debug_resume,
.bdrv_debug_is_suspended = blkdebug_debug_is_suspended,
};
static void bdrv_blkdebug_init(void)
{
bdrv_register(&bdrv_blkdebug);
}
block_init(bdrv_blkdebug_init);