[mirror_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 BDRVBlkdebugState {
    int state;
    int new_state;
    QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
    QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
} BDRVBlkdebugState;

typedef struct BlkdebugAIOCB {
    BlockDriverAIOCB common;
    QEMUBH *bh;
    int ret;
} BlkdebugAIOCB;

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,
};

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;
    } 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_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);
        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;
    };

    /* 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;

    /* Allow usage without config file */
    if (!*filename) {
        return 0;
    }

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

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;
    }
    return injected;
}

static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
{
    BDRVBlkdebugState *s = bs->opaque;
    struct BlkdebugRule *rule;
    bool injected;

    assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);

    injected = false;
    s->new_state = s->state;
    QLIST_FOREACH(rule, &s->rules[event], next) {
        injected = process_rule(bs, rule, injected);
    }
    s->state = s->new_state;
}

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
	29	typedef struct BDRVBlkdebugState {
571cd43e	30	int state;
8f96b5be	31	int new_state;
571cd43e PB	32	QLIST_HEAD(, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
571cd43e PB	33	QSIMPLEQ_HEAD(, BlkdebugRule) active_rules;
6a143727 KW	34	} BDRVBlkdebugState;
6a143727 KW	35
b9f66d96 KW	36	typedef struct BlkdebugAIOCB {
	37	BlockDriverAIOCB common;
	38	QEMUBH *bh;
	39	int ret;
	40	} BlkdebugAIOCB;
	41
	42	static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb);
	43
d7331bed	44	static const AIOCBInfo blkdebug_aiocb_info = {
b9f66d96 KW	45	.aiocb_size = sizeof(BlkdebugAIOCB),
	46	.cancel = blkdebug_aio_cancel,
	47	};
	48
8b9b0cc2 KW	49	enum {
	50	ACTION_INJECT_ERROR,
	51	ACTION_SET_STATE,
	52	};
	53
	54	typedef struct BlkdebugRule {
	55	BlkDebugEvent event;
	56	int action;
	57	int state;
	58	union {
	59	struct {
	60	int error;
	61	int immediately;
	62	int once;
e4780db4	63	int64_t sector;
8b9b0cc2 KW	64	} inject;
	65	struct {
	66	int new_state;
	67	} set_state;
	68	} options;
	69	QLIST_ENTRY(BlkdebugRule) next;
571cd43e	70	QSIMPLEQ_ENTRY(BlkdebugRule) active_next;
8b9b0cc2 KW	71	} BlkdebugRule;
	72
	73	static QemuOptsList inject_error_opts = {
	74	.name = "inject-error",
	75	.head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
	76	.desc = {
	77	{
	78	.name = "event",
	79	.type = QEMU_OPT_STRING,
	80	},
	81	{
	82	.name = "state",
	83	.type = QEMU_OPT_NUMBER,
	84	},
	85	{
	86	.name = "errno",
	87	.type = QEMU_OPT_NUMBER,
	88	},
e4780db4 PB	89	{
	90	.name = "sector",
	91	.type = QEMU_OPT_NUMBER,
	92	},
8b9b0cc2 KW	93	{
	94	.name = "once",
	95	.type = QEMU_OPT_BOOL,
	96	},
	97	{
	98	.name = "immediately",
	99	.type = QEMU_OPT_BOOL,
	100	},
	101	{ /* end of list */ }
	102	},
	103	};
	104
	105	static QemuOptsList set_state_opts = {
	106	.name = "set-state",
327cdad4	107	.head = QTAILQ_HEAD_INITIALIZER(set_state_opts.head),
8b9b0cc2 KW	108	.desc = {
	109	{
	110	.name = "event",
	111	.type = QEMU_OPT_STRING,
	112	},
	113	{
	114	.name = "state",
	115	.type = QEMU_OPT_NUMBER,
	116	},
	117	{
	118	.name = "new_state",
	119	.type = QEMU_OPT_NUMBER,
	120	},
	121	{ /* end of list */ }
	122	},
	123	};
	124
	125	static QemuOptsList *config_groups[] = {
	126	&inject_error_opts,
	127	&set_state_opts,
	128	NULL
	129	};
	130
	131	static const char *event_names[BLKDBG_EVENT_MAX] = {
8252278a KW	132	[BLKDBG_L1_UPDATE] = "l1_update",
	133	[BLKDBG_L1_GROW_ALLOC_TABLE] = "l1_grow.alloc_table",
	134	[BLKDBG_L1_GROW_WRITE_TABLE] = "l1_grow.write_table",
	135	[BLKDBG_L1_GROW_ACTIVATE_TABLE] = "l1_grow.activate_table",
	136
	137	[BLKDBG_L2_LOAD] = "l2_load",
	138	[BLKDBG_L2_UPDATE] = "l2_update",
	139	[BLKDBG_L2_UPDATE_COMPRESSED] = "l2_update_compressed",
	140	[BLKDBG_L2_ALLOC_COW_READ] = "l2_alloc.cow_read",
	141	[BLKDBG_L2_ALLOC_WRITE] = "l2_alloc.write",
	142
8252278a	143	[BLKDBG_READ_AIO] = "read_aio",
8252278a KW	144	[BLKDBG_READ_BACKING_AIO] = "read_backing_aio",
	145	[BLKDBG_READ_COMPRESSED] = "read_compressed",
	146
	147	[BLKDBG_WRITE_AIO] = "write_aio",
	148	[BLKDBG_WRITE_COMPRESSED] = "write_compressed",
	149
	150	[BLKDBG_VMSTATE_LOAD] = "vmstate_load",
	151	[BLKDBG_VMSTATE_SAVE] = "vmstate_save",
	152
	153	[BLKDBG_COW_READ] = "cow_read",
	154	[BLKDBG_COW_WRITE] = "cow_write",
	155
	156	[BLKDBG_REFTABLE_LOAD] = "reftable_load",
	157	[BLKDBG_REFTABLE_GROW] = "reftable_grow",
	158
	159	[BLKDBG_REFBLOCK_LOAD] = "refblock_load",
	160	[BLKDBG_REFBLOCK_UPDATE] = "refblock_update",
	161	[BLKDBG_REFBLOCK_UPDATE_PART] = "refblock_update_part",
	162	[BLKDBG_REFBLOCK_ALLOC] = "refblock_alloc",
	163	[BLKDBG_REFBLOCK_ALLOC_HOOKUP] = "refblock_alloc.hookup",
	164	[BLKDBG_REFBLOCK_ALLOC_WRITE] = "refblock_alloc.write",
	165	[BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS] = "refblock_alloc.write_blocks",
	166	[BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE] = "refblock_alloc.write_table",
	167	[BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE] = "refblock_alloc.switch_table",
	168
	169	[BLKDBG_CLUSTER_ALLOC] = "cluster_alloc",
	170	[BLKDBG_CLUSTER_ALLOC_BYTES] = "cluster_alloc_bytes",
	171	[BLKDBG_CLUSTER_FREE] = "cluster_free",
8b9b0cc2 KW	172	};
	173
	174	static int get_event_by_name(const char name, BlkDebugEvent event)
	175	{
	176	int i;
	177
	178	for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
	179	if (!strcmp(event_names[i], name)) {
	180	*event = i;
	181	return 0;
	182	}
	183	}
	184
	185	return -1;
	186	}
	187
	188	struct add_rule_data {
	189	BDRVBlkdebugState *s;
	190	int action;
	191	};
	192
	193	static int add_rule(QemuOpts opts, void opaque)
	194	{
	195	struct add_rule_data *d = opaque;
	196	BDRVBlkdebugState *s = d->s;
	197	const char* event_name;
	198	BlkDebugEvent event;
	199	struct BlkdebugRule *rule;
	200
	201	/* Find the right event for the rule */
	202	event_name = qemu_opt_get(opts, "event");
	203	if (!event_name \|\| get_event_by_name(event_name, &event) < 0) {
	204	return -1;
	205	}
	206
	207	/* Set attributes common for all actions */
7267c094	208	rule = g_malloc0(sizeof(*rule));
8b9b0cc2 KW	209	*rule = (struct BlkdebugRule) {
	210	.event = event,
	211	.action = d->action,
	212	.state = qemu_opt_get_number(opts, "state", 0),
	213	};
	214
	215	/* Parse action-specific options */
	216	switch (d->action) {
	217	case ACTION_INJECT_ERROR:
	218	rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
	219	rule->options.inject.once = qemu_opt_get_bool(opts, "once", 0);
	220	rule->options.inject.immediately =
	221	qemu_opt_get_bool(opts, "immediately", 0);
e4780db4	222	rule->options.inject.sector = qemu_opt_get_number(opts, "sector", -1);
8b9b0cc2 KW	223	break;
	224
	225	case ACTION_SET_STATE:
	226	rule->options.set_state.new_state =
	227	qemu_opt_get_number(opts, "new_state", 0);
	228	break;
	229	};
	230
	231	/* Add the rule */
	232	QLIST_INSERT_HEAD(&s->rules[event], rule, next);
	233
	234	return 0;
	235	}
	236
	237	static int read_config(BDRVBlkdebugState s, const char filename)
	238	{
	239	FILE *f;
	240	int ret;
	241	struct add_rule_data d;
	242
312a2ba0 KW	243	/* Allow usage without config file */
	244	if (!*filename) {
	245	return 0;
	246	}
	247
8b9b0cc2 KW	248	f = fopen(filename, "r");
	249	if (f == NULL) {
	250	return -errno;
	251	}
	252
	253	ret = qemu_config_parse(f, config_groups, filename);
	254	if (ret < 0) {
	255	goto fail;
	256	}
	257
	258	d.s = s;
	259	d.action = ACTION_INJECT_ERROR;
	260	qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
	261
	262	d.action = ACTION_SET_STATE;
	263	qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
	264
	265	ret = 0;
	266	fail:
698f0d52 KW	267	qemu_opts_reset(&inject_error_opts);
698f0d52 KW	268	qemu_opts_reset(&set_state_opts);
8b9b0cc2 KW	269	fclose(f);
	270	return ret;
	271	}
	272
	273	/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
6a143727 KW	274	static int blkdebug_open(BlockDriverState bs, const char filename, int flags)
	275	{
	276	BDRVBlkdebugState *s = bs->opaque;
8b9b0cc2 KW	277	int ret;
8b9b0cc2 KW	278	char config, c;
6a143727	279
8b9b0cc2	280	/* Parse the blkdebug: prefix */
6a143727 KW	281	if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
	282	return -EINVAL;
	283	}
	284	filename += strlen("blkdebug:");
	285
8b9b0cc2 KW	286	/* Read rules from config file */
	287	c = strchr(filename, ':');
	288	if (c == NULL) {
	289	return -EINVAL;
	290	}
	291
031380d8	292	config = g_strdup(filename);
8b9b0cc2 KW	293	config[c - filename] = '\0';
8b9b0cc2 KW	294	ret = read_config(s, config);
031380d8	295	g_free(config);
8b9b0cc2 KW	296	if (ret < 0) {
	297	return ret;
	298	}
	299	filename = c + 1;
	300
8db520ce	301	/* Set initial state */
571cd43e	302	s->state = 1;
8db520ce	303
8b9b0cc2	304	/* Open the backing file */
66f82cee	305	ret = bdrv_file_open(&bs->file, filename, flags);
8b9b0cc2 KW	306	if (ret < 0) {
	307	return ret;
	308	}
	309
	310	return 0;
6a143727 KW	311	}
6a143727 KW	312
b9f66d96 KW	313	static void error_callback_bh(void *opaque)
	314	{
	315	struct BlkdebugAIOCB *acb = opaque;
	316	qemu_bh_delete(acb->bh);
	317	acb->common.cb(acb->common.opaque, acb->ret);
	318	qemu_aio_release(acb);
	319	}
	320
	321	static void blkdebug_aio_cancel(BlockDriverAIOCB *blockacb)
	322	{
b666d239	323	BlkdebugAIOCB *acb = container_of(blockacb, BlkdebugAIOCB, common);
b9f66d96 KW	324	qemu_aio_release(acb);
	325	}
	326
	327	static BlockDriverAIOCB inject_error(BlockDriverState bs,
571cd43e	328	BlockDriverCompletionFunc cb, void opaque, BlkdebugRule *rule)
b9f66d96 KW	329	{
b9f66d96 KW	330	BDRVBlkdebugState *s = bs->opaque;
571cd43e	331	int error = rule->options.inject.error;
b9f66d96 KW	332	struct BlkdebugAIOCB *acb;
	333	QEMUBH *bh;
	334
571cd43e PB	335	if (rule->options.inject.once) {
571cd43e PB	336	QSIMPLEQ_INIT(&s->active_rules);
b9f66d96 KW	337	}
b9f66d96 KW	338
571cd43e	339	if (rule->options.inject.immediately) {
b9f66d96 KW	340	return NULL;
	341	}
	342
d7331bed	343	acb = qemu_aio_get(&blkdebug_aiocb_info, bs, cb, opaque);
b9f66d96 KW	344	acb->ret = -error;
	345
	346	bh = qemu_bh_new(error_callback_bh, acb);
	347	acb->bh = bh;
	348	qemu_bh_schedule(bh);
	349
b666d239	350	return &acb->common;
b9f66d96 KW	351	}
b9f66d96 KW	352
6a143727 KW	353	static BlockDriverAIOCB blkdebug_aio_readv(BlockDriverState bs,
	354	int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
	355	BlockDriverCompletionFunc cb, void opaque)
	356	{
	357	BDRVBlkdebugState *s = bs->opaque;
e4780db4 PB	358	BlkdebugRule *rule = NULL;
	359
	360	QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
	361	if (rule->options.inject.sector == -1 \|\|
	362	(rule->options.inject.sector >= sector_num &&
	363	rule->options.inject.sector < sector_num + nb_sectors)) {
	364	break;
	365	}
	366	}
b9f66d96	367
571cd43e PB	368	if (rule && rule->options.inject.error) {
571cd43e PB	369	return inject_error(bs, cb, opaque, rule);
b9f66d96 KW	370	}
b9f66d96 KW	371
368e8dd1	372	return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
6a143727 KW	373	}
	374
	375	static BlockDriverAIOCB blkdebug_aio_writev(BlockDriverState bs,
	376	int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
	377	BlockDriverCompletionFunc cb, void opaque)
	378	{
	379	BDRVBlkdebugState *s = bs->opaque;
e4780db4 PB	380	BlkdebugRule *rule = NULL;
	381
	382	QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
	383	if (rule->options.inject.sector == -1 \|\|
	384	(rule->options.inject.sector >= sector_num &&
	385	rule->options.inject.sector < sector_num + nb_sectors)) {
	386	break;
	387	}
	388	}
b9f66d96	389
571cd43e PB	390	if (rule && rule->options.inject.error) {
571cd43e PB	391	return inject_error(bs, cb, opaque, rule);
b9f66d96 KW	392	}
b9f66d96 KW	393
368e8dd1	394	return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, cb, opaque);
6a143727 KW	395	}
	396
	397	static void blkdebug_close(BlockDriverState *bs)
	398	{
	399	BDRVBlkdebugState *s = bs->opaque;
8b9b0cc2 KW	400	BlkdebugRule rule, next;
	401	int i;
	402
	403	for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
	404	QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
	405	QLIST_REMOVE(rule, next);
7267c094	406	g_free(rule);
8b9b0cc2 KW	407	}
8b9b0cc2 KW	408	}
6a143727 KW	409	}
6a143727 KW	410
571cd43e	411	static bool process_rule(BlockDriverState bs, struct BlkdebugRule rule,
8f96b5be	412	bool injected)
8b9b0cc2 KW	413	{
8b9b0cc2 KW	414	BDRVBlkdebugState *s = bs->opaque;
8b9b0cc2 KW	415
8b9b0cc2 KW	416	/* Only process rules for the current state */
8f96b5be	417	if (rule->state && rule->state != s->state) {
571cd43e	418	return injected;
8b9b0cc2 KW	419	}
	420
	421	/* Take the action */
	422	switch (rule->action) {
	423	case ACTION_INJECT_ERROR:
571cd43e PB	424	if (!injected) {
	425	QSIMPLEQ_INIT(&s->active_rules);
	426	injected = true;
	427	}
	428	QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next);
8b9b0cc2 KW	429	break;
	430
	431	case ACTION_SET_STATE:
8f96b5be	432	s->new_state = rule->options.set_state.new_state;
8b9b0cc2 KW	433	break;
8b9b0cc2 KW	434	}
571cd43e	435	return injected;
8b9b0cc2 KW	436	}
	437
	438	static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
	439	{
	440	BDRVBlkdebugState *s = bs->opaque;
	441	struct BlkdebugRule *rule;
571cd43e	442	bool injected;
8b9b0cc2	443
95ee3914	444	assert((int)event >= 0 && event < BLKDBG_EVENT_MAX);
8b9b0cc2	445
571cd43e	446	injected = false;
8f96b5be	447	s->new_state = s->state;
8b9b0cc2	448	QLIST_FOREACH(rule, &s->rules[event], next) {
8f96b5be	449	injected = process_rule(bs, rule, injected);
8b9b0cc2	450	}
8f96b5be	451	s->state = s->new_state;
8b9b0cc2 KW	452	}
8b9b0cc2 KW	453
e1302255 PB	454	static int64_t blkdebug_getlength(BlockDriverState *bs)
	455	{
	456	return bdrv_getlength(bs->file);
	457	}
	458
6a143727 KW	459	static BlockDriver bdrv_blkdebug = {
	460	.format_name = "blkdebug",
	461	.protocol_name = "blkdebug",
	462
	463	.instance_size = sizeof(BDRVBlkdebugState),
	464
66f82cee	465	.bdrv_file_open = blkdebug_open,
6a143727	466	.bdrv_close = blkdebug_close,
e1302255	467	.bdrv_getlength = blkdebug_getlength,
6a143727 KW	468
	469	.bdrv_aio_readv = blkdebug_aio_readv,
	470	.bdrv_aio_writev = blkdebug_aio_writev,
8b9b0cc2 KW	471
8b9b0cc2 KW	472	.bdrv_debug_event = blkdebug_debug_event,
6a143727 KW	473	};
	474
	475	static void bdrv_blkdebug_init(void)
	476	{
	477	bdrv_register(&bdrv_blkdebug);
	478	}
	479
	480	block_init(bdrv_blkdebug_init);