[qemu.git] / block / blkdebug.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 "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_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_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 = 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);
        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 = g_strdup(filename);
    config[c - filename] = '\0';
    ret = read_config(s, config);
    g_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);
    }

    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;

    if (s->vars.inject_errno) {
        return inject_error(bs, cb, opaque);
    }

    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) {
            QLIST_REMOVE(rule, next);
            g_free(rule);
        }
    }
}

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 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_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,
};

static void bdrv_blkdebug_init(void)
{
    bdrv_register(&bdrv_blkdebug);
}

block_init(bdrv_blkdebug_init);
Commit	Line	Data
6a143727 KW	1	/*
	2	* Block protocol for I/O error injection
	3	*
	4	* Copyright (c) 2010 Kevin Wolf <kwolf@redhat.com>
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24
	25	#include "qemu-common.h"
	26	#include "block_int.h"
	27	#include "module.h"
	28
b9f66d96 KW	29	typedef struct BlkdebugVars {
	30	int state;
	31
	32	/* If inject_errno != 0, an error is injected for requests */
	33	int inject_errno;
	34
	35	/* Decides if all future requests fail (false) or only the next one and
	36	* after the next request inject_errno is reset to 0 (true) */
	37	bool inject_once;
	38
	39	/* Decides if aio_readv/writev fails right away (true) or returns an error
	40	* return value only in the callback (false) */
	41	bool inject_immediately;
	42	} BlkdebugVars;
	43
6a143727	44	typedef struct BDRVBlkdebugState {
b9f66d96	45	BlkdebugVars vars;
8b9b0cc2	46	QLIST_HEAD(list, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
6a143727 KW	47	} BDRVBlkdebugState;
6a143727 KW	48
b9f66d96 KW	49	typedef struct BlkdebugAIOCB {
	50	BlockDriverAIOCB common;
	51	QEMUBH *bh;
	52	int ret;
	53	} BlkdebugAIOCB;
	54
	55	static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
	56
	57	static AIOPool blkdebug_aio_pool = {
	58	.aiocb_size = sizeof(BlkdebugAIOCB),
	59	.cancel = blkdebug_aio_cancel,
	60	};
	61
8b9b0cc2 KW	62	enum {
	63	ACTION_INJECT_ERROR,
	64	ACTION_SET_STATE,
	65	};
	66
	67	typedef struct BlkdebugRule {
	68	BlkDebugEvent event;
	69	int action;
	70	int state;
	71	union {
	72	struct {
	73	int error;
	74	int immediately;
	75	int once;
	76	} inject;
	77	struct {
	78	int new_state;
	79	} set_state;
	80	} options;
	81	QLIST_ENTRY(BlkdebugRule) next;
	82	} BlkdebugRule;
	83
	84	static QemuOptsList inject_error_opts = {
	85	.name = "inject-error",
	86	.head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
	87	.desc = {
	88	{
	89	.name = "event",
	90	.type = QEMU_OPT_STRING,
	91	},
	92	{
	93	.name = "state",
	94	.type = QEMU_OPT_NUMBER,
	95	},
	96	{
	97	.name = "errno",
	98	.type = QEMU_OPT_NUMBER,
	99	},
	100	{
	101	.name = "once",
	102	.type = QEMU_OPT_BOOL,
	103	},
	104	{
	105	.name = "immediately",
	106	.type = QEMU_OPT_BOOL,
	107	},
	108	{ /* end of list */ }
	109	},
	110	};
	111
	112	static QemuOptsList set_state_opts = {
	113	.name = "set-state",
327cdad4	114	.head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
8b9b0cc2 KW	115	.desc = {
	116	{
	117	.name = "event",
	118	.type = QEMU_OPT_STRING,
	119	},
	120	{
	121	.name = "state",
	122	.type = QEMU_OPT_NUMBER,
	123	},
	124	{
	125	.name = "new_state",
	126	.type = QEMU_OPT_NUMBER,
	127	},
	128	{ /* end of list */ }
	129	},
	130	};
	131
	132	static QemuOptsList *config_groups[] = {
	133	&inject_error_opts,
	134	&set_state_opts,
	135	NULL
	136	};
	137
	138	static const char *event_names[BLKDBG_EVENT_MAX] = {
8252278a KW	139	[BLKDBG_L1_UPDATE] = "l1_update",
	140	[BLKDBG_L1_GROW_ALLOC_TABLE] = "l1_grow.alloc_table",
	141	[BLKDBG_L1_GROW_WRITE_TABLE] = "l1_grow.write_table",
	142	[BLKDBG_L1_GROW_ACTIVATE_TABLE] = "l1_grow.activate_table",
	143
	144	[BLKDBG_L2_LOAD] = "l2_load",
	145	[BLKDBG_L2_UPDATE] = "l2_update",
	146	[BLKDBG_L2_UPDATE_COMPRESSED] = "l2_update_compressed",
	147	[BLKDBG_L2_ALLOC_COW_READ] = "l2_alloc.cow_read",
	148	[BLKDBG_L2_ALLOC_WRITE] = "l2_alloc.write",
	149
8252278a	150	[BLKDBG_READ_AIO] = "read_aio",
8252278a KW	151	[BLKDBG_READ_BACKING_AIO] = "read_backing_aio",
	152	[BLKDBG_READ_COMPRESSED] = "read_compressed",
	153
	154	[BLKDBG_WRITE_AIO] = "write_aio",
	155	[BLKDBG_WRITE_COMPRESSED] = "write_compressed",
	156
	157	[BLKDBG_VMSTATE_LOAD] = "vmstate_load",
	158	[BLKDBG_VMSTATE_SAVE] = "vmstate_save",
	159
	160	[BLKDBG_COW_READ] = "cow_read",
	161	[BLKDBG_COW_WRITE] = "cow_write",
	162
	163	[BLKDBG_REFTABLE_LOAD] = "reftable_load",
	164	[BLKDBG_REFTABLE_GROW] = "reftable_grow",
	165
	166	[BLKDBG_REFBLOCK_LOAD] = "refblock_load",
	167	[BLKDBG_REFBLOCK_UPDATE] = "refblock_update",
	168	[BLKDBG_REFBLOCK_UPDATE_PART] = "refblock_update_part",
	169	[BLKDBG_REFBLOCK_ALLOC] = "refblock_alloc",
	170	[BLKDBG_REFBLOCK_ALLOC_HOOKUP] = "refblock_alloc.hookup",
	171	[BLKDBG_REFBLOCK_ALLOC_WRITE] = "refblock_alloc.write",
	172	[BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS] = "refblock_alloc.write_blocks",
	173	[BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE] = "refblock_alloc.write_table",
	174	[BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE] = "refblock_alloc.switch_table",
	175
	176	[BLKDBG_CLUSTER_ALLOC] = "cluster_alloc",
	177	[BLKDBG_CLUSTER_ALLOC_BYTES] = "cluster_alloc_bytes",
	178	[BLKDBG_CLUSTER_FREE] = "cluster_free",
8b9b0cc2 KW	179	};
	180
	181	static int get_event_by_name(const char name, BlkDebugEvent event)
	182	{
	183	int i;
	184
	185	for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
	186	if (!strcmp(event_names[i], name)) {
	187	*event = i;
	188	return 0;
	189	}
	190	}
	191
	192	return -1;
	193	}
	194
	195	struct add_rule_data {
	196	BDRVBlkdebugState *s;
	197	int action;
	198	};
	199
	200	static int add_rule(QemuOpts opts, void opaque)
	201	{
	202	struct add_rule_data *d = opaque;
	203	BDRVBlkdebugState *s = d->s;
	204	const char* event_name;
	205	BlkDebugEvent event;
	206	struct BlkdebugRule *rule;
	207
	208	/* Find the right event for the rule */
	209	event_name = qemu_opt_get(opts, "event");
	210	if (!event_name \|\| get_event_by_name(event_name, &event) < 0) {
	211	return -1;
	212	}
	213
	214	/* Set attributes common for all actions */
7267c094	215	rule = g_malloc0(sizeof(*rule));
8b9b0cc2 KW	216	*rule = (struct BlkdebugRule) {
	217	.event = event,
	218	.action = d->action,
	219	.state = qemu_opt_get_number(opts, "state", 0),
	220	};
	221
	222	/* Parse action-specific options */
	223	switch (d->action) {
	224	case ACTION_INJECT_ERROR:
	225	rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
	226	rule->options.inject.once = qemu_opt_get_bool(opts, "once", 0);
	227	rule->options.inject.immediately =
	228	qemu_opt_get_bool(opts, "immediately", 0);
	229	break;
	230
	231	case ACTION_SET_STATE:
	232	rule->options.set_state.new_state =
	233	qemu_opt_get_number(opts, "new_state", 0);
	234	break;
	235	};
	236
	237	/* Add the rule */
	238	QLIST_INSERT_HEAD(&s->rules[event], rule, next);
	239
	240	return 0;
	241	}
	242
	243	static int read_config(BDRVBlkdebugState s, const char filename)
	244	{
	245	FILE *f;
	246	int ret;
	247	struct add_rule_data d;
	248
	249	f = fopen(filename, "r");
	250	if (f == NULL) {
	251	return -errno;
	252	}
	253
	254	ret = qemu_config_parse(f, config_groups, filename);
	255	if (ret < 0) {
	256	goto fail;
	257	}
	258
	259	d.s = s;
	260	d.action = ACTION_INJECT_ERROR;
	261	qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
	262
	263	d.action = ACTION_SET_STATE;
	264	qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
	265
	266	ret = 0;
	267	fail:
698f0d52 KW	268	qemu_opts_reset(&inject_error_opts);
698f0d52 KW	269	qemu_opts_reset(&set_state_opts);
8b9b0cc2 KW	270	fclose(f);
	271	return ret;
	272	}
	273
	274	/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
6a143727 KW	275	static int blkdebug_open(BlockDriverState bs, const char filename, int flags)
	276	{
	277	BDRVBlkdebugState *s = bs->opaque;
8b9b0cc2 KW	278	int ret;
8b9b0cc2 KW	279	char config, c;
6a143727	280
8b9b0cc2	281	/* Parse the blkdebug: prefix */
6a143727 KW	282	if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
	283	return -EINVAL;
	284	}
	285	filename += strlen("blkdebug:");
	286
8b9b0cc2 KW	287	/* Read rules from config file */
	288	c = strchr(filename, ':');
	289	if (c == NULL) {
	290	return -EINVAL;
	291	}
	292
031380d8	293	config = g_strdup(filename);
8b9b0cc2 KW	294	config[c - filename] = '\0';
8b9b0cc2 KW	295	ret = read_config(s, config);
031380d8	296	g_free(config);
8b9b0cc2 KW	297	if (ret < 0) {
	298	return ret;
	299	}
	300	filename = c + 1;
	301
8db520ce KW	302	/* Set initial state */
	303	s->vars.state = 1;
	304
8b9b0cc2	305	/* Open the backing file */
66f82cee	306	ret = bdrv_file_open(&bs->file, filename, flags);
8b9b0cc2 KW	307	if (ret < 0) {
	308	return ret;
	309	}
	310
	311	return 0;
6a143727 KW	312	}
6a143727 KW	313
b9f66d96 KW	314	static void error_callback_bh(void *opaque)
	315	{
	316	struct BlkdebugAIOCB *acb = opaque;
	317	qemu_bh_delete(acb->bh);
	318	acb->common.cb(acb->common.opaque, acb->ret);
	319	qemu_aio_release(acb);
	320	}
	321
	322	static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
	323	{
b666d239	324	BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
b9f66d96 KW	325	qemu_aio_release(acb);
	326	}
	327
	328	static BlockDriverAIOCB inject_error(BlockDriverState bs,
	329	BlockDriverCompletionFunc cb, void opaque)
	330	{
	331	BDRVBlkdebugState *s = bs->opaque;
	332	int error = s->vars.inject_errno;
	333	struct BlkdebugAIOCB *acb;
	334	QEMUBH *bh;
	335
	336	if (s->vars.inject_once) {
	337	s->vars.inject_errno = 0;
	338	}
	339
	340	if (s->vars.inject_immediately) {
	341	return NULL;
	342	}
	343
	344	acb = qemu_aio_get(&blkdebug_aio_pool, bs, cb, opaque);
	345	acb->ret = -error;
	346
	347	bh = qemu_bh_new(error_callback_bh, acb);
	348	acb->bh = bh;
	349	qemu_bh_schedule(bh);
	350
b666d239	351	return &acb->common;
b9f66d96 KW	352	}
b9f66d96 KW	353
6a143727 KW	354	static BlockDriverAIOCB blkdebug_aio_readv(BlockDriverState bs,
	355	int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
	356	BlockDriverCompletionFunc cb, void opaque)
	357	{
	358	BDRVBlkdebugState *s = bs->opaque;
b9f66d96 KW	359
	360	if (s->vars.inject_errno) {
	361	return inject_error(bs, cb, opaque);
	362	}
	363
368e8dd1	364	return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
6a143727 KW	365	}
	366
	367	static BlockDriverAIOCB blkdebug_aio_writev(BlockDriverState bs,
	368	int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
	369	BlockDriverCompletionFunc cb, void opaque)
	370	{
	371	BDRVBlkdebugState *s = bs->opaque;
b9f66d96 KW	372
	373	if (s->vars.inject_errno) {
	374	return inject_error(bs, cb, opaque);
	375	}
	376
368e8dd1	377	return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
6a143727 KW	378	}
	379
	380	static void blkdebug_close(BlockDriverState *bs)
	381	{
	382	BDRVBlkdebugState *s = bs->opaque;
8b9b0cc2 KW	383	BlkdebugRule rule, next;
	384	int i;
	385
	386	for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
	387	QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
	388	QLIST_REMOVE(rule, next);
7267c094	389	g_free(rule);
8b9b0cc2 KW	390	}
8b9b0cc2 KW	391	}
6a143727 KW	392	}
6a143727 KW	393
8b9b0cc2 KW	394	static void process_rule(BlockDriverState bs, struct BlkdebugRule rule,
	395	BlkdebugVars *old_vars)
	396	{
	397	BDRVBlkdebugState *s = bs->opaque;
	398	BlkdebugVars *vars = &s->vars;
	399
	400	/* Only process rules for the current state */
	401	if (rule->state && rule->state != old_vars->state) {
	402	return;
	403	}
	404
	405	/* Take the action */
	406	switch (rule->action) {
	407	case ACTION_INJECT_ERROR:
	408	vars->inject_errno = rule->options.inject.error;
	409	vars->inject_once = rule->options.inject.once;
	410	vars->inject_immediately = rule->options.inject.immediately;
	411	break;
	412
	413	case ACTION_SET_STATE:
	414	vars->state = rule->options.set_state.new_state;
	415	break;
	416	}
	417	}
	418
	419	static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
	420	{
	421	BDRVBlkdebugState *s = bs->opaque;
	422	struct BlkdebugRule *rule;
	423	BlkdebugVars old_vars = s->vars;
	424
95ee3914	425	assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
8b9b0cc2 KW	426
	427	QLIST_FOREACH(rule, &s->rules[event], next) {
	428	process_rule(bs, rule, &old_vars);
	429	}
	430	}
	431
e1302255 PB	432	static int64_t blkdebug_getlength(BlockDriverState *bs)
	433	{
	434	return bdrv_getlength(bs->file);
	435	}
	436
6a143727 KW	437	static BlockDriver bdrv_blkdebug = {
	438	.format_name = "blkdebug",
	439	.protocol_name = "blkdebug",
	440
	441	.instance_size = sizeof(BDRVBlkdebugState),
	442
66f82cee	443	.bdrv_file_open = blkdebug_open,
6a143727	444	.bdrv_close = blkdebug_close,
e1302255	445	.bdrv_getlength = blkdebug_getlength,
6a143727 KW	446
	447	.bdrv_aio_readv = blkdebug_aio_readv,
	448	.bdrv_aio_writev = blkdebug_aio_writev,
8b9b0cc2 KW	449
8b9b0cc2 KW	450	.bdrv_debug_event = blkdebug_debug_event,
6a143727 KW	451	};
	452
	453	static void bdrv_blkdebug_init(void)
	454	{
	455	bdrv_register(&bdrv_blkdebug);
	456	}
	457
	458	block_init(bdrv_blkdebug_init);