[qemu.git] / block / snapshot.c

/*
 * Block layer snapshot related functions
 *
 * Copyright (c) 2003-2008 Fabrice Bellard
 *
 * 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 "block/snapshot.h"
#include "block/block_int.h"
#include "qapi/qmp/qerror.h"

QemuOptsList internal_snapshot_opts = {
    .name = "snapshot",
    .head = QTAILQ_HEAD_INITIALIZER(internal_snapshot_opts.head),
    .desc = {
        {
            .name = SNAPSHOT_OPT_ID,
            .type = QEMU_OPT_STRING,
            .help = "snapshot id"
        },{
            .name = SNAPSHOT_OPT_NAME,
            .type = QEMU_OPT_STRING,
            .help = "snapshot name"
        },{
            /* end of list */
        }
    },
};

int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,
                       const char *name)
{
    QEMUSnapshotInfo *sn_tab, *sn;
    int nb_sns, i, ret;

    ret = -ENOENT;
    nb_sns = bdrv_snapshot_list(bs, &sn_tab);
    if (nb_sns < 0) {
        return ret;
    }
    for (i = 0; i < nb_sns; i++) {
        sn = &sn_tab[i];
        if (!strcmp(sn->id_str, name) || !strcmp(sn->name, name)) {
            *sn_info = *sn;
            ret = 0;
            break;
        }
    }
    g_free(sn_tab);
    return ret;
}

/**
 * Look up an internal snapshot by @id and @name.
 * @bs: block device to search
 * @id: unique snapshot ID, or NULL
 * @name: snapshot name, or NULL
 * @sn_info: location to store information on the snapshot found
 * @errp: location to store error, will be set only for exception
 *
 * This function will traverse snapshot list in @bs to search the matching
 * one, @id and @name are the matching condition:
 * If both @id and @name are specified, find the first one with id @id and
 * name @name.
 * If only @id is specified, find the first one with id @id.
 * If only @name is specified, find the first one with name @name.
 * if none is specified, abort().
 *
 * Returns: true when a snapshot is found and @sn_info will be filled, false
 * when error or not found. If all operation succeed but no matching one is
 * found, @errp will NOT be set.
 */
bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
                                       const char *id,
                                       const char *name,
                                       QEMUSnapshotInfo *sn_info,
                                       Error **errp)
{
    QEMUSnapshotInfo *sn_tab, *sn;
    int nb_sns, i;
    bool ret = false;

    assert(id || name);

    nb_sns = bdrv_snapshot_list(bs, &sn_tab);
    if (nb_sns < 0) {
        error_setg_errno(errp, -nb_sns, "Failed to get a snapshot list");
        return false;
    } else if (nb_sns == 0) {
        return false;
    }

    if (id && name) {
        for (i = 0; i < nb_sns; i++) {
            sn = &sn_tab[i];
            if (!strcmp(sn->id_str, id) && !strcmp(sn->name, name)) {
                *sn_info = *sn;
                ret = true;
                break;
            }
        }
    } else if (id) {
        for (i = 0; i < nb_sns; i++) {
            sn = &sn_tab[i];
            if (!strcmp(sn->id_str, id)) {
                *sn_info = *sn;
                ret = true;
                break;
            }
        }
    } else if (name) {
        for (i = 0; i < nb_sns; i++) {
            sn = &sn_tab[i];
            if (!strcmp(sn->name, name)) {
                *sn_info = *sn;
                ret = true;
                break;
            }
        }
    }

    g_free(sn_tab);
    return ret;
}

int bdrv_can_snapshot(BlockDriverState *bs)
{
    BlockDriver *drv = bs->drv;
    if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
        return 0;
    }

    if (!drv->bdrv_snapshot_create) {
        if (bs->file != NULL) {
            return bdrv_can_snapshot(bs->file->bs);
        }
        return 0;
    }

    return 1;
}

int bdrv_snapshot_create(BlockDriverState *bs,
                         QEMUSnapshotInfo *sn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv) {
        return -ENOMEDIUM;
    }
    if (drv->bdrv_snapshot_create) {
        return drv->bdrv_snapshot_create(bs, sn_info);
    }
    if (bs->file) {
        return bdrv_snapshot_create(bs->file->bs, sn_info);
    }
    return -ENOTSUP;
}

int bdrv_snapshot_goto(BlockDriverState *bs,
                       const char *snapshot_id)
{
    BlockDriver *drv = bs->drv;
    int ret, open_ret;

    if (!drv) {
        return -ENOMEDIUM;
    }
    if (drv->bdrv_snapshot_goto) {
        return drv->bdrv_snapshot_goto(bs, snapshot_id);
    }

    if (bs->file) {
        drv->bdrv_close(bs);
        ret = bdrv_snapshot_goto(bs->file->bs, snapshot_id);
        open_ret = drv->bdrv_open(bs, NULL, bs->open_flags, NULL);
        if (open_ret < 0) {
            bdrv_unref(bs->file->bs);
            bs->drv = NULL;
            return open_ret;
        }
        return ret;
    }

    return -ENOTSUP;
}

/**
 * Delete an internal snapshot by @snapshot_id and @name.
 * @bs: block device used in the operation
 * @snapshot_id: unique snapshot ID, or NULL
 * @name: snapshot name, or NULL
 * @errp: location to store error
 *
 * If both @snapshot_id and @name are specified, delete the first one with
 * id @snapshot_id and name @name.
 * If only @snapshot_id is specified, delete the first one with id
 * @snapshot_id.
 * If only @name is specified, delete the first one with name @name.
 * if none is specified, return -EINVAL.
 *
 * Returns: 0 on success, -errno on failure. If @bs is not inserted, return
 * -ENOMEDIUM. If @snapshot_id and @name are both NULL, return -EINVAL. If @bs
 * does not support internal snapshot deletion, return -ENOTSUP. If @bs does
 * not support parameter @snapshot_id or @name, or one of them is not correctly
 * specified, return -EINVAL. If @bs can't find one matching @id and @name,
 * return -ENOENT. If @errp != NULL, it will always be filled with error
 * message on failure.
 */
int bdrv_snapshot_delete(BlockDriverState *bs,
                         const char *snapshot_id,
                         const char *name,
                         Error **errp)
{
    BlockDriver *drv = bs->drv;
    if (!drv) {
        error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
        return -ENOMEDIUM;
    }
    if (!snapshot_id && !name) {
        error_setg(errp, "snapshot_id and name are both NULL");
        return -EINVAL;
    }

    /* drain all pending i/o before deleting snapshot */
    bdrv_drain(bs);

    if (drv->bdrv_snapshot_delete) {
        return drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
    }
    if (bs->file) {
        return bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
    }
    error_setg(errp, "Block format '%s' used by device '%s' "
               "does not support internal snapshot deletion",
               drv->format_name, bdrv_get_device_name(bs));
    return -ENOTSUP;
}

int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
                                       const char *id_or_name,
                                       Error **errp)
{
    int ret;
    Error *local_err = NULL;

    ret = bdrv_snapshot_delete(bs, id_or_name, NULL, &local_err);
    if (ret == -ENOENT || ret == -EINVAL) {
        error_free(local_err);
        local_err = NULL;
        ret = bdrv_snapshot_delete(bs, NULL, id_or_name, &local_err);
    }

    if (ret < 0) {
        error_propagate(errp, local_err);
    }
    return ret;
}

int bdrv_snapshot_list(BlockDriverState *bs,
                       QEMUSnapshotInfo **psn_info)
{
    BlockDriver *drv = bs->drv;
    if (!drv) {
        return -ENOMEDIUM;
    }
    if (drv->bdrv_snapshot_list) {
        return drv->bdrv_snapshot_list(bs, psn_info);
    }
    if (bs->file) {
        return bdrv_snapshot_list(bs->file->bs, psn_info);
    }
    return -ENOTSUP;
}

/**
 * Temporarily load an internal snapshot by @snapshot_id and @name.
 * @bs: block device used in the operation
 * @snapshot_id: unique snapshot ID, or NULL
 * @name: snapshot name, or NULL
 * @errp: location to store error
 *
 * If both @snapshot_id and @name are specified, load the first one with
 * id @snapshot_id and name @name.
 * If only @snapshot_id is specified, load the first one with id
 * @snapshot_id.
 * If only @name is specified, load the first one with name @name.
 * if none is specified, return -EINVAL.
 *
 * Returns: 0 on success, -errno on fail. If @bs is not inserted, return
 * -ENOMEDIUM. If @bs is not readonly, return -EINVAL. If @bs did not support
 * internal snapshot, return -ENOTSUP. If qemu can't find a matching @id and
 * @name, return -ENOENT. If @errp != NULL, it will always be filled on
 * failure.
 */
int bdrv_snapshot_load_tmp(BlockDriverState *bs,
                           const char *snapshot_id,
                           const char *name,
                           Error **errp)
{
    BlockDriver *drv = bs->drv;

    if (!drv) {
        error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
        return -ENOMEDIUM;
    }
    if (!snapshot_id && !name) {
        error_setg(errp, "snapshot_id and name are both NULL");
        return -EINVAL;
    }
    if (!bs->read_only) {
        error_setg(errp, "Device is not readonly");
        return -EINVAL;
    }
    if (drv->bdrv_snapshot_load_tmp) {
        return drv->bdrv_snapshot_load_tmp(bs, snapshot_id, name, errp);
    }
    error_setg(errp, "Block format '%s' used by device '%s' "
               "does not support temporarily loading internal snapshots",
               drv->format_name, bdrv_get_device_name(bs));
    return -ENOTSUP;
}

int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
                                         const char *id_or_name,
                                         Error **errp)
{
    int ret;
    Error *local_err = NULL;

    ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err);
    if (ret == -ENOENT || ret == -EINVAL) {
        error_free(local_err);
        local_err = NULL;
        ret = bdrv_snapshot_load_tmp(bs, NULL, id_or_name, &local_err);
    }

    if (local_err) {
        error_propagate(errp, local_err);
    }

    return ret;
}


/* Group operations. All block drivers are involved.
 * These functions will properly handle dataplane (take aio_context_acquire
 * when appropriate for appropriate block drivers) */

bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
{
    bool ok = true;
    BlockDriverState *bs = NULL;

    while (ok && (bs = bdrv_next(bs))) {
        AioContext *ctx = bdrv_get_aio_context(bs);

        aio_context_acquire(ctx);
        if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) {
            ok = bdrv_can_snapshot(bs);
        }
        aio_context_release(ctx);
    }

    *first_bad_bs = bs;
    return ok;
}

int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs,
                             Error **err)
{
    int ret = 0;
    BlockDriverState *bs = NULL;
    QEMUSnapshotInfo sn1, *snapshot = &sn1;

    while (ret == 0 && (bs = bdrv_next(bs))) {
        AioContext *ctx = bdrv_get_aio_context(bs);

        aio_context_acquire(ctx);
        if (bdrv_can_snapshot(bs) &&
                bdrv_snapshot_find(bs, snapshot, name) >= 0) {
            ret = bdrv_snapshot_delete_by_id_or_name(bs, name, err);
        }
        aio_context_release(ctx);
    }

    *first_bad_bs = bs;
    return ret;
}


int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs)
{
    int err = 0;
    BlockDriverState *bs = NULL;

    while (err == 0 && (bs = bdrv_next(bs))) {
        AioContext *ctx = bdrv_get_aio_context(bs);

        aio_context_acquire(ctx);
        if (bdrv_can_snapshot(bs)) {
            err = bdrv_snapshot_goto(bs, name);
        }
        aio_context_release(ctx);
    }

    *first_bad_bs = bs;
    return err;
}

int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)
{
    QEMUSnapshotInfo sn;
    int err = 0;
    BlockDriverState *bs = NULL;

    while (err == 0 && (bs = bdrv_next(bs))) {
        AioContext *ctx = bdrv_get_aio_context(bs);

        aio_context_acquire(ctx);
        if (bdrv_can_snapshot(bs)) {
            err = bdrv_snapshot_find(bs, &sn, name);
        }
        aio_context_release(ctx);
    }

    *first_bad_bs = bs;
    return err;
}

int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
                             BlockDriverState *vm_state_bs,
                             uint64_t vm_state_size,
                             BlockDriverState **first_bad_bs)
{
    int err = 0;
    BlockDriverState *bs = NULL;

    while (err == 0 && (bs = bdrv_next(bs))) {
        AioContext *ctx = bdrv_get_aio_context(bs);

        aio_context_acquire(ctx);
        if (bs == vm_state_bs) {
            sn->vm_state_size = vm_state_size;
            err = bdrv_snapshot_create(bs, sn);
        } else if (bdrv_can_snapshot(bs)) {
            sn->vm_state_size = 0;
            err = bdrv_snapshot_create(bs, sn);
        }
        aio_context_release(ctx);
    }

    *first_bad_bs = bs;
    return err;
}

BlockDriverState *bdrv_all_find_vmstate_bs(void)
{
    bool not_found = true;
    BlockDriverState *bs = NULL;

    while (not_found && (bs = bdrv_next(bs))) {
        AioContext *ctx = bdrv_get_aio_context(bs);

        aio_context_acquire(ctx);
        not_found = !bdrv_can_snapshot(bs);
        aio_context_release(ctx);
    }
    return bs;
}
Commit	Line	Data
de08c606 WX	1	/*
	2	* Block layer snapshot related functions
	3	*
	4	* Copyright (c) 2003-2008 Fabrice Bellard
	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 "block/snapshot.h"
	26	#include "block/block_int.h"
cc7a8ea7	27	#include "qapi/qmp/qerror.h"
de08c606	28
8c116b0e WX	29	QemuOptsList internal_snapshot_opts = {
	30	.name = "snapshot",
	31	.head = QTAILQ_HEAD_INITIALIZER(internal_snapshot_opts.head),
	32	.desc = {
	33	{
	34	.name = SNAPSHOT_OPT_ID,
	35	.type = QEMU_OPT_STRING,
	36	.help = "snapshot id"
	37	},{
	38	.name = SNAPSHOT_OPT_NAME,
	39	.type = QEMU_OPT_STRING,
	40	.help = "snapshot name"
	41	},{
	42	/* end of list */
	43	}
	44	},
	45	};
	46
de08c606 WX	47	int bdrv_snapshot_find(BlockDriverState bs, QEMUSnapshotInfo sn_info,
	48	const char *name)
	49	{
	50	QEMUSnapshotInfo sn_tab, sn;
	51	int nb_sns, i, ret;
	52
	53	ret = -ENOENT;
	54	nb_sns = bdrv_snapshot_list(bs, &sn_tab);
	55	if (nb_sns < 0) {
	56	return ret;
	57	}
	58	for (i = 0; i < nb_sns; i++) {
	59	sn = &sn_tab[i];
	60	if (!strcmp(sn->id_str, name) \|\| !strcmp(sn->name, name)) {
	61	sn_info = sn;
	62	ret = 0;
	63	break;
	64	}
	65	}
	66	g_free(sn_tab);
	67	return ret;
	68	}
	69
2ea1dd75 WX	70	/**
	71	* Look up an internal snapshot by @id and @name.
	72	* @bs: block device to search
	73	* @id: unique snapshot ID, or NULL
	74	* @name: snapshot name, or NULL
	75	* @sn_info: location to store information on the snapshot found
	76	* @errp: location to store error, will be set only for exception
	77	*
	78	* This function will traverse snapshot list in @bs to search the matching
	79	* one, @id and @name are the matching condition:
	80	* If both @id and @name are specified, find the first one with id @id and
	81	* name @name.
	82	* If only @id is specified, find the first one with id @id.
	83	* If only @name is specified, find the first one with name @name.
	84	* if none is specified, abort().
	85	*
	86	* Returns: true when a snapshot is found and @sn_info will be filled, false
	87	* when error or not found. If all operation succeed but no matching one is
	88	* found, @errp will NOT be set.
	89	*/
	90	bool bdrv_snapshot_find_by_id_and_name(BlockDriverState *bs,
	91	const char *id,
	92	const char *name,
	93	QEMUSnapshotInfo *sn_info,
	94	Error **errp)
	95	{
	96	QEMUSnapshotInfo sn_tab, sn;
	97	int nb_sns, i;
	98	bool ret = false;
	99
	100	assert(id \|\| name);
	101
	102	nb_sns = bdrv_snapshot_list(bs, &sn_tab);
	103	if (nb_sns < 0) {
	104	error_setg_errno(errp, -nb_sns, "Failed to get a snapshot list");
	105	return false;
	106	} else if (nb_sns == 0) {
	107	return false;
	108	}
	109
	110	if (id && name) {
	111	for (i = 0; i < nb_sns; i++) {
	112	sn = &sn_tab[i];
	113	if (!strcmp(sn->id_str, id) && !strcmp(sn->name, name)) {
	114	sn_info = sn;
	115	ret = true;
	116	break;
	117	}
	118	}
	119	} else if (id) {
	120	for (i = 0; i < nb_sns; i++) {
	121	sn = &sn_tab[i];
	122	if (!strcmp(sn->id_str, id)) {
	123	sn_info = sn;
	124	ret = true;
	125	break;
	126	}
	127	}
	128	} else if (name) {
	129	for (i = 0; i < nb_sns; i++) {
	130	sn = &sn_tab[i];
	131	if (!strcmp(sn->name, name)) {
	132	sn_info = sn;
	133	ret = true;
134	break;
135	}
136	}
137	}
138
139	g_free(sn_tab);
140	return ret;
141	}
142
de08c606 WX	143	int bdrv_can_snapshot(BlockDriverState *bs)
	144	{
	145	BlockDriver *drv = bs->drv;
	146	if (!drv \|\| !bdrv_is_inserted(bs) \|\| bdrv_is_read_only(bs)) {
	147	return 0;
	148	}
	149
	150	if (!drv->bdrv_snapshot_create) {
	151	if (bs->file != NULL) {
9a4f4c31	152	return bdrv_can_snapshot(bs->file->bs);
de08c606 WX	153	}
	154	return 0;
	155	}
	156
	157	return 1;
	158	}
	159
	160	int bdrv_snapshot_create(BlockDriverState *bs,
	161	QEMUSnapshotInfo *sn_info)
	162	{
	163	BlockDriver *drv = bs->drv;
	164	if (!drv) {
	165	return -ENOMEDIUM;
	166	}
	167	if (drv->bdrv_snapshot_create) {
	168	return drv->bdrv_snapshot_create(bs, sn_info);
	169	}
	170	if (bs->file) {
9a4f4c31	171	return bdrv_snapshot_create(bs->file->bs, sn_info);
de08c606 WX	172	}
	173	return -ENOTSUP;
	174	}
	175
	176	int bdrv_snapshot_goto(BlockDriverState *bs,
	177	const char *snapshot_id)
	178	{
	179	BlockDriver *drv = bs->drv;
	180	int ret, open_ret;
	181
	182	if (!drv) {
	183	return -ENOMEDIUM;
	184	}
	185	if (drv->bdrv_snapshot_goto) {
	186	return drv->bdrv_snapshot_goto(bs, snapshot_id);
	187	}
	188
	189	if (bs->file) {
	190	drv->bdrv_close(bs);
9a4f4c31	191	ret = bdrv_snapshot_goto(bs->file->bs, snapshot_id);
015a1036	192	open_ret = drv->bdrv_open(bs, NULL, bs->open_flags, NULL);
de08c606	193	if (open_ret < 0) {
9a4f4c31	194	bdrv_unref(bs->file->bs);
de08c606 WX	195	bs->drv = NULL;
	196	return open_ret;
	197	}
	198	return ret;
	199	}
	200
	201	return -ENOTSUP;
	202	}
	203
a89d89d3 WX	204	/**
	205	* Delete an internal snapshot by @snapshot_id and @name.
	206	* @bs: block device used in the operation
	207	* @snapshot_id: unique snapshot ID, or NULL
	208	* @name: snapshot name, or NULL
	209	* @errp: location to store error
	210	*
	211	* If both @snapshot_id and @name are specified, delete the first one with
	212	* id @snapshot_id and name @name.
	213	* If only @snapshot_id is specified, delete the first one with id
	214	* @snapshot_id.
	215	* If only @name is specified, delete the first one with name @name.
7b4c4781	216	* if none is specified, return -EINVAL.
a89d89d3 WX	217	*
	218	* Returns: 0 on success, -errno on failure. If @bs is not inserted, return
	219	* -ENOMEDIUM. If @snapshot_id and @name are both NULL, return -EINVAL. If @bs
	220	* does not support internal snapshot deletion, return -ENOTSUP. If @bs does
	221	* not support parameter @snapshot_id or @name, or one of them is not correctly
	222	* specified, return -EINVAL. If @bs can't find one matching @id and @name,
	223	* return -ENOENT. If @errp != NULL, it will always be filled with error
	224	* message on failure.
	225	*/
	226	int bdrv_snapshot_delete(BlockDriverState *bs,
	227	const char *snapshot_id,
	228	const char *name,
	229	Error **errp)
de08c606 WX	230	{
	231	BlockDriver *drv = bs->drv;
	232	if (!drv) {
c6bd8c70	233	error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
de08c606 WX	234	return -ENOMEDIUM;
de08c606 WX	235	}
a89d89d3 WX	236	if (!snapshot_id && !name) {
	237	error_setg(errp, "snapshot_id and name are both NULL");
	238	return -EINVAL;
	239	}
3432a192 ZH	240
3432a192 ZH	241	/* drain all pending i/o before deleting snapshot */
53ec73e2	242	bdrv_drain(bs);
3432a192	243
de08c606	244	if (drv->bdrv_snapshot_delete) {
a89d89d3	245	return drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
de08c606 WX	246	}
de08c606 WX	247	if (bs->file) {
9a4f4c31	248	return bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
de08c606	249	}
81e5f78a AG	250	error_setg(errp, "Block format '%s' used by device '%s' "
	251	"does not support internal snapshot deletion",
	252	drv->format_name, bdrv_get_device_name(bs));
de08c606 WX	253	return -ENOTSUP;
	254	}
	255
25af925f DL	256	int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
	257	const char *id_or_name,
	258	Error **errp)
a89d89d3 WX	259	{
	260	int ret;
	261	Error *local_err = NULL;
	262
	263	ret = bdrv_snapshot_delete(bs, id_or_name, NULL, &local_err);
	264	if (ret == -ENOENT \|\| ret == -EINVAL) {
	265	error_free(local_err);
	266	local_err = NULL;
	267	ret = bdrv_snapshot_delete(bs, NULL, id_or_name, &local_err);
	268	}
	269
	270	if (ret < 0) {
	271	error_propagate(errp, local_err);
	272	}
25af925f	273	return ret;
a89d89d3 WX	274	}
a89d89d3 WX	275
de08c606 WX	276	int bdrv_snapshot_list(BlockDriverState *bs,
	277	QEMUSnapshotInfo **psn_info)
	278	{
	279	BlockDriver *drv = bs->drv;
	280	if (!drv) {
	281	return -ENOMEDIUM;
	282	}
	283	if (drv->bdrv_snapshot_list) {
	284	return drv->bdrv_snapshot_list(bs, psn_info);
	285	}
	286	if (bs->file) {
9a4f4c31	287	return bdrv_snapshot_list(bs->file->bs, psn_info);
de08c606 WX	288	}
	289	return -ENOTSUP;
	290	}
	291
7b4c4781 WX	292	/**
	293	* Temporarily load an internal snapshot by @snapshot_id and @name.
	294	* @bs: block device used in the operation
	295	* @snapshot_id: unique snapshot ID, or NULL
	296	* @name: snapshot name, or NULL
	297	* @errp: location to store error
	298	*
	299	* If both @snapshot_id and @name are specified, load the first one with
	300	* id @snapshot_id and name @name.
	301	* If only @snapshot_id is specified, load the first one with id
	302	* @snapshot_id.
	303	* If only @name is specified, load the first one with name @name.
	304	* if none is specified, return -EINVAL.
	305	*
	306	* Returns: 0 on success, -errno on fail. If @bs is not inserted, return
	307	* -ENOMEDIUM. If @bs is not readonly, return -EINVAL. If @bs did not support
	308	* internal snapshot, return -ENOTSUP. If qemu can't find a matching @id and
	309	* @name, return -ENOENT. If @errp != NULL, it will always be filled on
	310	* failure.
	311	*/
de08c606	312	int bdrv_snapshot_load_tmp(BlockDriverState *bs,
7b4c4781 WX	313	const char *snapshot_id,
	314	const char *name,
	315	Error **errp)
de08c606 WX	316	{
de08c606 WX	317	BlockDriver *drv = bs->drv;
7b4c4781	318
de08c606	319	if (!drv) {
c6bd8c70	320	error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
de08c606 WX	321	return -ENOMEDIUM;
de08c606 WX	322	}
7b4c4781 WX	323	if (!snapshot_id && !name) {
	324	error_setg(errp, "snapshot_id and name are both NULL");
	325	return -EINVAL;
	326	}
de08c606	327	if (!bs->read_only) {
7b4c4781	328	error_setg(errp, "Device is not readonly");
de08c606 WX	329	return -EINVAL;
	330	}
	331	if (drv->bdrv_snapshot_load_tmp) {
7b4c4781	332	return drv->bdrv_snapshot_load_tmp(bs, snapshot_id, name, errp);
de08c606	333	}
81e5f78a AG	334	error_setg(errp, "Block format '%s' used by device '%s' "
	335	"does not support temporarily loading internal snapshots",
	336	drv->format_name, bdrv_get_device_name(bs));
de08c606 WX	337	return -ENOTSUP;
de08c606 WX	338	}
7b4c4781 WX	339
	340	int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
	341	const char *id_or_name,
	342	Error **errp)
	343	{
	344	int ret;
	345	Error *local_err = NULL;
	346
	347	ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err);
	348	if (ret == -ENOENT \|\| ret == -EINVAL) {
	349	error_free(local_err);
	350	local_err = NULL;
	351	ret = bdrv_snapshot_load_tmp(bs, NULL, id_or_name, &local_err);
	352	}
	353
84d18f06	354	if (local_err) {
7b4c4781 WX	355	error_propagate(errp, local_err);
	356	}
	357
	358	return ret;
	359	}
e9ff957a DL	360
	361
	362	/* Group operations. All block drivers are involved.
	363	* These functions will properly handle dataplane (take aio_context_acquire
	364	* when appropriate for appropriate block drivers) */
	365
	366	bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
	367	{
	368	bool ok = true;
	369	BlockDriverState *bs = NULL;
	370
	371	while (ok && (bs = bdrv_next(bs))) {
	372	AioContext *ctx = bdrv_get_aio_context(bs);
	373
	374	aio_context_acquire(ctx);
	375	if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) {
	376	ok = bdrv_can_snapshot(bs);
	377	}
	378	aio_context_release(ctx);
	379	}
	380
	381	*first_bad_bs = bs;
	382	return ok;
	383	}
9b00ea37 DL	384
	385	int bdrv_all_delete_snapshot(const char name, BlockDriverState *first_bad_bs,
	386	Error **err)
	387	{
	388	int ret = 0;
	389	BlockDriverState *bs = NULL;
	390	QEMUSnapshotInfo sn1, *snapshot = &sn1;
	391
	392	while (ret == 0 && (bs = bdrv_next(bs))) {
	393	AioContext *ctx = bdrv_get_aio_context(bs);
	394
	395	aio_context_acquire(ctx);
	396	if (bdrv_can_snapshot(bs) &&
	397	bdrv_snapshot_find(bs, snapshot, name) >= 0) {
	398	ret = bdrv_snapshot_delete_by_id_or_name(bs, name, err);
	399	}
	400	aio_context_release(ctx);
	401	}
	402
	403	*first_bad_bs = bs;
	404	return ret;
	405	}
4c1cdbaa DL	406
	407
	408	int bdrv_all_goto_snapshot(const char name, BlockDriverState *first_bad_bs)
	409	{
	410	int err = 0;
	411	BlockDriverState *bs = NULL;
	412
	413	while (err == 0 && (bs = bdrv_next(bs))) {
	414	AioContext *ctx = bdrv_get_aio_context(bs);
	415
	416	aio_context_acquire(ctx);
	417	if (bdrv_can_snapshot(bs)) {
	418	err = bdrv_snapshot_goto(bs, name);
	419	}
	420	aio_context_release(ctx);
	421	}
	422
	423	*first_bad_bs = bs;
	424	return err;
	425	}
723ccda1 DL	426
	427	int bdrv_all_find_snapshot(const char name, BlockDriverState *first_bad_bs)
	428	{
	429	QEMUSnapshotInfo sn;
	430	int err = 0;
	431	BlockDriverState *bs = NULL;
	432
	433	while (err == 0 && (bs = bdrv_next(bs))) {
	434	AioContext *ctx = bdrv_get_aio_context(bs);
	435
	436	aio_context_acquire(ctx);
	437	if (bdrv_can_snapshot(bs)) {
	438	err = bdrv_snapshot_find(bs, &sn, name);
	439	}
	440	aio_context_release(ctx);
	441	}
	442
	443	*first_bad_bs = bs;
	444	return err;
	445	}
a9085f9b DL	446
	447	int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
	448	BlockDriverState *vm_state_bs,
	449	uint64_t vm_state_size,
	450	BlockDriverState **first_bad_bs)
	451	{
	452	int err = 0;
	453	BlockDriverState *bs = NULL;
	454
	455	while (err == 0 && (bs = bdrv_next(bs))) {
	456	AioContext *ctx = bdrv_get_aio_context(bs);
	457
	458	aio_context_acquire(ctx);
	459	if (bs == vm_state_bs) {
	460	sn->vm_state_size = vm_state_size;
	461	err = bdrv_snapshot_create(bs, sn);
	462	} else if (bdrv_can_snapshot(bs)) {
	463	sn->vm_state_size = 0;
	464	err = bdrv_snapshot_create(bs, sn);
	465	}
	466	aio_context_release(ctx);
	467	}
	468
	469	*first_bad_bs = bs;
	470	return err;
	471	}
7cb14481 DL	472
	473	BlockDriverState *bdrv_all_find_vmstate_bs(void)
	474	{
	475	bool not_found = true;
	476	BlockDriverState *bs = NULL;
	477
	478	while (not_found && (bs = bdrv_next(bs))) {
	479	AioContext *ctx = bdrv_get_aio_context(bs);
	480
	481	aio_context_acquire(ctx);
	482	not_found = !bdrv_can_snapshot(bs);
	483	aio_context_release(ctx);
	484	}
	485	return bs;
	486	}