[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;
    int ret;

    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_drained_begin(bs);

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

    bdrv_drained_end(bs);
    return ret;
}

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	{
de08c606 WX	231	BlockDriver *drv = bs->drv;
27a7649a PB	232	int ret;
27a7649a PB	233
de08c606	234	if (!drv) {
c6bd8c70	235	error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
de08c606 WX	236	return -ENOMEDIUM;
de08c606 WX	237	}
a89d89d3 WX	238	if (!snapshot_id && !name) {
	239	error_setg(errp, "snapshot_id and name are both NULL");
	240	return -EINVAL;
	241	}
3432a192 ZH	242
3432a192 ZH	243	/* drain all pending i/o before deleting snapshot */
27a7649a	244	bdrv_drained_begin(bs);
3432a192	245
de08c606	246	if (drv->bdrv_snapshot_delete) {
27a7649a PB	247	ret = drv->bdrv_snapshot_delete(bs, snapshot_id, name, errp);
	248	} else if (bs->file) {
	249	ret = bdrv_snapshot_delete(bs->file->bs, snapshot_id, name, errp);
	250	} else {
	251	error_setg(errp, "Block format '%s' used by device '%s' "
	252	"does not support internal snapshot deletion",
	253	drv->format_name, bdrv_get_device_name(bs));
	254	ret = -ENOTSUP;
de08c606	255	}
27a7649a PB	256
	257	bdrv_drained_end(bs);
	258	return ret;
de08c606 WX	259	}
de08c606 WX	260
25af925f DL	261	int bdrv_snapshot_delete_by_id_or_name(BlockDriverState *bs,
	262	const char *id_or_name,
	263	Error **errp)
a89d89d3 WX	264	{
	265	int ret;
	266	Error *local_err = NULL;
	267
	268	ret = bdrv_snapshot_delete(bs, id_or_name, NULL, &local_err);
	269	if (ret == -ENOENT \|\| ret == -EINVAL) {
	270	error_free(local_err);
	271	local_err = NULL;
	272	ret = bdrv_snapshot_delete(bs, NULL, id_or_name, &local_err);
	273	}
	274
	275	if (ret < 0) {
	276	error_propagate(errp, local_err);
	277	}
25af925f	278	return ret;
a89d89d3 WX	279	}
a89d89d3 WX	280
de08c606 WX	281	int bdrv_snapshot_list(BlockDriverState *bs,
	282	QEMUSnapshotInfo **psn_info)
	283	{
	284	BlockDriver *drv = bs->drv;
	285	if (!drv) {
	286	return -ENOMEDIUM;
	287	}
	288	if (drv->bdrv_snapshot_list) {
	289	return drv->bdrv_snapshot_list(bs, psn_info);
	290	}
	291	if (bs->file) {
9a4f4c31	292	return bdrv_snapshot_list(bs->file->bs, psn_info);
de08c606 WX	293	}
	294	return -ENOTSUP;
	295	}
	296
7b4c4781 WX	297	/**
	298	* Temporarily load an internal snapshot by @snapshot_id and @name.
	299	* @bs: block device used in the operation
	300	* @snapshot_id: unique snapshot ID, or NULL
	301	* @name: snapshot name, or NULL
	302	* @errp: location to store error
	303	*
	304	* If both @snapshot_id and @name are specified, load the first one with
	305	* id @snapshot_id and name @name.
	306	* If only @snapshot_id is specified, load the first one with id
	307	* @snapshot_id.
	308	* If only @name is specified, load the first one with name @name.
	309	* if none is specified, return -EINVAL.
	310	*
	311	* Returns: 0 on success, -errno on fail. If @bs is not inserted, return
	312	* -ENOMEDIUM. If @bs is not readonly, return -EINVAL. If @bs did not support
	313	* internal snapshot, return -ENOTSUP. If qemu can't find a matching @id and
	314	* @name, return -ENOENT. If @errp != NULL, it will always be filled on
	315	* failure.
	316	*/
de08c606	317	int bdrv_snapshot_load_tmp(BlockDriverState *bs,
7b4c4781 WX	318	const char *snapshot_id,
	319	const char *name,
	320	Error **errp)
de08c606 WX	321	{
de08c606 WX	322	BlockDriver *drv = bs->drv;
7b4c4781	323
de08c606	324	if (!drv) {
c6bd8c70	325	error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, bdrv_get_device_name(bs));
de08c606 WX	326	return -ENOMEDIUM;
de08c606 WX	327	}
7b4c4781 WX	328	if (!snapshot_id && !name) {
	329	error_setg(errp, "snapshot_id and name are both NULL");
	330	return -EINVAL;
	331	}
de08c606	332	if (!bs->read_only) {
7b4c4781	333	error_setg(errp, "Device is not readonly");
de08c606 WX	334	return -EINVAL;
	335	}
	336	if (drv->bdrv_snapshot_load_tmp) {
7b4c4781	337	return drv->bdrv_snapshot_load_tmp(bs, snapshot_id, name, errp);
de08c606	338	}
81e5f78a AG	339	error_setg(errp, "Block format '%s' used by device '%s' "
	340	"does not support temporarily loading internal snapshots",
	341	drv->format_name, bdrv_get_device_name(bs));
de08c606 WX	342	return -ENOTSUP;
de08c606 WX	343	}
7b4c4781 WX	344
	345	int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
	346	const char *id_or_name,
	347	Error **errp)
	348	{
	349	int ret;
	350	Error *local_err = NULL;
	351
	352	ret = bdrv_snapshot_load_tmp(bs, id_or_name, NULL, &local_err);
	353	if (ret == -ENOENT \|\| ret == -EINVAL) {
	354	error_free(local_err);
	355	local_err = NULL;
	356	ret = bdrv_snapshot_load_tmp(bs, NULL, id_or_name, &local_err);
	357	}
	358
84d18f06	359	if (local_err) {
7b4c4781 WX	360	error_propagate(errp, local_err);
	361	}
	362
	363	return ret;
	364	}
e9ff957a DL	365
	366
	367	/* Group operations. All block drivers are involved.
	368	* These functions will properly handle dataplane (take aio_context_acquire
	369	* when appropriate for appropriate block drivers) */
	370
	371	bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs)
	372	{
	373	bool ok = true;
	374	BlockDriverState *bs = NULL;
	375
	376	while (ok && (bs = bdrv_next(bs))) {
	377	AioContext *ctx = bdrv_get_aio_context(bs);
	378
	379	aio_context_acquire(ctx);
	380	if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) {
	381	ok = bdrv_can_snapshot(bs);
	382	}
	383	aio_context_release(ctx);
	384	}
	385
	386	*first_bad_bs = bs;
	387	return ok;
	388	}
9b00ea37 DL	389
	390	int bdrv_all_delete_snapshot(const char name, BlockDriverState *first_bad_bs,
	391	Error **err)
	392	{
	393	int ret = 0;
	394	BlockDriverState *bs = NULL;
	395	QEMUSnapshotInfo sn1, *snapshot = &sn1;
	396
	397	while (ret == 0 && (bs = bdrv_next(bs))) {
	398	AioContext *ctx = bdrv_get_aio_context(bs);
	399
	400	aio_context_acquire(ctx);
	401	if (bdrv_can_snapshot(bs) &&
	402	bdrv_snapshot_find(bs, snapshot, name) >= 0) {
	403	ret = bdrv_snapshot_delete_by_id_or_name(bs, name, err);
	404	}
	405	aio_context_release(ctx);
	406	}
	407
	408	*first_bad_bs = bs;
	409	return ret;
	410	}
4c1cdbaa DL	411
	412
	413	int bdrv_all_goto_snapshot(const char name, BlockDriverState *first_bad_bs)
	414	{
	415	int err = 0;
	416	BlockDriverState *bs = NULL;
	417
	418	while (err == 0 && (bs = bdrv_next(bs))) {
	419	AioContext *ctx = bdrv_get_aio_context(bs);
	420
	421	aio_context_acquire(ctx);
	422	if (bdrv_can_snapshot(bs)) {
	423	err = bdrv_snapshot_goto(bs, name);
	424	}
	425	aio_context_release(ctx);
	426	}
	427
	428	*first_bad_bs = bs;
	429	return err;
	430	}
723ccda1 DL	431
	432	int bdrv_all_find_snapshot(const char name, BlockDriverState *first_bad_bs)
	433	{
	434	QEMUSnapshotInfo sn;
	435	int err = 0;
	436	BlockDriverState *bs = NULL;
	437
	438	while (err == 0 && (bs = bdrv_next(bs))) {
	439	AioContext *ctx = bdrv_get_aio_context(bs);
	440
	441	aio_context_acquire(ctx);
	442	if (bdrv_can_snapshot(bs)) {
	443	err = bdrv_snapshot_find(bs, &sn, name);
	444	}
	445	aio_context_release(ctx);
	446	}
	447
	448	*first_bad_bs = bs;
	449	return err;
	450	}
a9085f9b DL	451
	452	int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
	453	BlockDriverState *vm_state_bs,
	454	uint64_t vm_state_size,
	455	BlockDriverState **first_bad_bs)
	456	{
	457	int err = 0;
	458	BlockDriverState *bs = NULL;
	459
	460	while (err == 0 && (bs = bdrv_next(bs))) {
	461	AioContext *ctx = bdrv_get_aio_context(bs);
	462
	463	aio_context_acquire(ctx);
	464	if (bs == vm_state_bs) {
	465	sn->vm_state_size = vm_state_size;
	466	err = bdrv_snapshot_create(bs, sn);
	467	} else if (bdrv_can_snapshot(bs)) {
	468	sn->vm_state_size = 0;
	469	err = bdrv_snapshot_create(bs, sn);
	470	}
	471	aio_context_release(ctx);
	472	}
	473
	474	*first_bad_bs = bs;
	475	return err;
	476	}
7cb14481 DL	477
	478	BlockDriverState *bdrv_all_find_vmstate_bs(void)
	479	{
	480	bool not_found = true;
	481	BlockDriverState *bs = NULL;
	482
	483	while (not_found && (bs = bdrv_next(bs))) {
	484	AioContext *ctx = bdrv_get_aio_context(bs);
	485
	486	aio_context_acquire(ctx);
	487	not_found = !bdrv_can_snapshot(bs);
	488	aio_context_release(ctx);
	489	}
	490	return bs;
	491	}