--- /dev/null
+/*
+ * 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);
+ }
+ 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, 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, snapshot_id);
+ open_ret = drv->bdrv_open(bs, NULL, bs->open_flags, NULL);
+ if (open_ret < 0) {
+ bdrv_unref(bs->file);
+ 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, 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;
+}
+
+void 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);
+ }
+}
+
+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, 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;
+}
Code Review / kvmfornfv.git / blobdiff