static int reset_top_delta(struct ploop_disk_images_data *di,
struct ploop_snapshot_switch_param *param)
{
int ret;
char *old_top_delta_fname = NULL;
char conf[PATH_MAX];
char conf_tmp[PATH_MAX];
const char *guid = param->guid;
ret = ploop_di_remove_image(di, di->top_guid, 0, &old_top_delta_fname);
if (ret)
return ret;
ploop_di_change_guid(di, guid, TOPDELTA_UUID);
get_disk_descriptor_fname(di, conf, sizeof(conf));
snprintf(conf_tmp, sizeof(conf_tmp), "%s.tmp", conf);
ret = ploop_store_diskdescriptor(conf_tmp, di);
if (ret)
goto err;
if (rename(conf_tmp, conf)) {
ploop_err(errno, "Can't rename %s %s",
conf_tmp, conf);
ret = SYSEXIT_RENAME;
goto err;
}
/* destroy precached info */
drop_statfs_info(di->images[0]->file);
if (old_top_delta_fname != NULL) {
ploop_log(0, "Removing %s", old_top_delta_fname);
if (unlink(old_top_delta_fname))
ploop_err(errno, "Can't unlink %s",
old_top_delta_fname);
}
err:
if (ret && unlink(conf_tmp))
ploop_err(errno, "Can't unlink %s", conf_tmp);
free(old_top_delta_fname);
return ret;
}
int ploop_switch_snapshot_ex(struct ploop_disk_images_data *di,
struct ploop_snapshot_switch_param *param)
{
int ret;
int fd;
char dev[64];
char uuid[UUID_SIZE];
char file_uuid[UUID_SIZE];
char new_top_delta_fname[PATH_MAX] = "";
char *old_top_delta_fname = NULL;
char conf[PATH_MAX];
char conf_tmp[PATH_MAX];
off_t size;
const char *guid = param->guid;
int flags = param->flags;
__u32 blocksize;
int version;
int snap_id;
if (!is_valid_guid(guid)) {
ploop_err(0, "Incorrect guid %s", guid);
return SYSEXIT_PARAM;
}
if (ploop_lock_dd(di))
return SYSEXIT_LOCK;
if (is_old_snapshot_format(di)) {
ret = SYSEXIT_PARAM;
goto err_cleanup1;
}
ret = SYSEXIT_PARAM;
if (strcmp(di->top_guid, guid) == 0) {
ploop_err(errno, "Nothing to do, already on %s snapshot",
guid);
goto err_cleanup1;
}
snap_id = find_snapshot_by_guid(di, guid);
if (snap_id== -1) {
ploop_err(0, "Can't find snapshot by uuid %s",
guid);
goto err_cleanup1;
}
if (di->snapshots[snap_id]->temporary) {
ploop_err(0, "Snapshot %s is temporary", guid);
goto err_cleanup1;
}
if (flags & PLOOP_SNAP_SKIP_TOPDELTA_CREATE) {
ret = reset_top_delta(di, param);
goto err_cleanup1;
}
// Read image param from snapshot we going to switch on
ret = get_image_param(di, guid, &size, &blocksize, &version);
if (ret)
goto err_cleanup1;
ret = gen_uuid_pair(uuid, sizeof(uuid), file_uuid, sizeof(file_uuid));
if (ret) {
ploop_err(errno, "Can't generate uuid");
goto err_cleanup1;
}
if (!(flags & PLOOP_SNAP_SKIP_TOPDELTA_DESTROY)) {
// device should be stopped
ret = ploop_find_dev_by_dd(di, dev, sizeof(dev));
if (ret == -1) {
ret = SYSEXIT_SYS;
goto err_cleanup1;
} else if (ret == 0) {
ret = SYSEXIT_PARAM;
ploop_err(0, "Unable to perform switch to snapshot operation"
" on running device (%s)",
dev);
goto err_cleanup1;
}
ret = ploop_di_remove_image(di, di->top_guid, 0, &old_top_delta_fname);
if (ret)
goto err_cleanup1;
} else if (param->guid_old != NULL) {
if (!is_valid_guid(param->guid_old)) {
ret = SYSEXIT_PARAM;
ploop_err(0, "Incorrect guid %s", param->guid_old);
goto err_cleanup1;
}
if (find_snapshot_by_guid(di, param->guid_old) != -1) {
ret = SYSEXIT_PARAM;
ploop_err(0, "Incorrect guid_old %s: already exists",
param->guid_old);
goto err_cleanup1;
}
ploop_di_change_guid(di, di->top_guid, param->guid_old);
}
snprintf(new_top_delta_fname, sizeof(new_top_delta_fname), "%s.%s",
di->images[0]->file, file_uuid);
ret = ploop_di_add_image(di, new_top_delta_fname, TOPDELTA_UUID, guid);
if (ret)
goto err_cleanup1;
get_disk_descriptor_fname(di, conf, sizeof(conf));
snprintf(conf_tmp, sizeof(conf_tmp), "%s.tmp", conf);
ret = ploop_store_diskdescriptor(conf_tmp, di);
if (ret)
goto err_cleanup1;
// offline snapshot
fd = create_snapshot_delta(new_top_delta_fname, blocksize, size, version);
if (fd == -1) {
ret = SYSEXIT_CREAT;
goto err_cleanup2;
}
close(fd);
if (rename(conf_tmp, conf)) {
ploop_err(errno, "Can't rename %s %s",
conf_tmp, conf);
ret = SYSEXIT_RENAME;
goto err_cleanup3;
}
/* destroy precached info */
drop_statfs_info(di->images[0]->file);
if (old_top_delta_fname != NULL) {
ploop_log(0, "Removing %s", old_top_delta_fname);
if (unlink(old_top_delta_fname) && errno != ENOENT)
ploop_err(errno, "Can't unlink %s",
old_top_delta_fname);
}
ploop_log(0, "ploop snapshot has been successfully switched");
err_cleanup3:
if (ret && unlink(new_top_delta_fname))
ploop_err(errno, "Can't unlink %s",
conf_tmp);
err_cleanup2:
if (ret && unlink(conf_tmp))
ploop_err(errno, "Can't unlink %s",
conf_tmp);
err_cleanup1:
ploop_unlock_dd(di);
free(old_top_delta_fname);
return ret;
}
/* delete snapshot by guid
* 1) if guid is not active and last -> delete guid
* 2) if guid is not last merge with child -> delete child
*/
static int do_delete_snapshot(struct ploop_disk_images_data *di, const char *guid)
{
int ret;
char conf[PATH_MAX];
int nelem = 0;
char dev[64];
int snap_id;
if (is_old_snapshot_format(di))
return SYSEXIT_PARAM;
snap_id = find_snapshot_by_guid(di, guid);
if (snap_id == -1) {
ploop_err(0, "Can't find snapshot by uuid %s",
guid);
return SYSEXIT_NOSNAP;
}
ret = ploop_find_dev_by_dd(di, dev, sizeof(dev));
if (ret == -1)
return SYSEXIT_SYS;
else if (ret == 0 && strcmp(di->top_guid, guid) == 0) {
ret = SYSEXIT_PARAM;
ploop_err(0, "Unable to delete active snapshot %s",
guid);
return SYSEXIT_PARAM;
}
nelem = ploop_get_child_count_by_uuid(di, guid);
if (nelem == 0) {
struct ploop_snapshot_data *snap = di->snapshots[snap_id];
if (strcmp(snap->parent_guid, NONE_UUID) == 0) {
ploop_err(0, "Unable to delete base image");
return SYSEXIT_PARAM;
}
if (strcmp(di->top_guid, guid) == 0) {
int id = find_snapshot_by_guid(di, snap->parent_guid);
if (id == -1) {
ploop_err(0, "Can't find snapshot by uuid %s",
snap->parent_guid);
return SYSEXIT_PARAM;
}
if (di->snapshots[id]->temporary) {
ploop_err(0, "Unable to delete top delta,"
" parent snapshot is temporary");
return SYSEXIT_PARAM;
}
}
char *fname = find_image_by_guid(di, guid);
if (fname == NULL) {
ploop_err(0, "Unable to find image by uuid %s",
guid);
return SYSEXIT_PARAM;
}
ret = check_snapshot_mount(di, guid, fname, snap->temporary);
if (ret)
return ret;
fname = NULL;
/* snapshot is not active and last -> delete */
ret = ploop_di_remove_image(di, guid, 1, &fname);
if (ret)
return ret;
get_disk_descriptor_fname(di, conf, sizeof(conf));
ret = ploop_store_diskdescriptor(conf, di);
if (ret) {
free(fname);
return ret;
}
ploop_log(0, "Removing %s", fname);
if (fname != NULL && unlink(fname)) {
ploop_err(errno, "unlink %s", fname);
free(fname);
return SYSEXIT_UNLINK;
}
free(fname);
if (ret == 0)
ploop_log(0, "ploop snapshot %s has been successfully deleted",
guid);
} else if (nelem == 1) {
const char *child_guid = ploop_find_child_by_guid(di, guid);
if (child_guid == NULL) {
ploop_err(0, "Can't find child of uuid %s", guid);
return SYSEXIT_PARAM;
}
ret = ploop_merge_snapshot_by_guid(di, child_guid, NULL);
} else if (!di->snapshots[snap_id]->temporary) {
ploop_log(1, "Warning: Unable to delete snapshot %s as there are %d references"
" to it; marking it as temporary instead",
guid, nelem);
di->snapshots[snap_id]->temporary = 1;
get_disk_descriptor_fname(di, conf, sizeof(conf));
ret = ploop_store_diskdescriptor(conf, di);
}
return ret;
}
static int do_create_snapshot(struct ploop_disk_images_data *di,
const char *guid, const char *snap_dir, int temporary)
{
int ret;
int fd;
char dev[64];
char snap_guid[UUID_SIZE];
char file_guid[UUID_SIZE];
char fname[PATH_MAX];
char conf[PATH_MAX];
char conf_tmp[PATH_MAX];
int online = 0;
int n;
off_t size;
__u32 blocksize;
int version;
if (guid != NULL && !is_valid_guid(guid)) {
ploop_err(0, "Incorrect guid %s", guid);
return SYSEXIT_PARAM;
}
if (is_old_snapshot_format(di))
return SYSEXIT_PARAM;
ret = gen_uuid_pair(snap_guid, sizeof(snap_guid),
file_guid, sizeof(file_guid));
if (ret) {
ploop_err(errno, "Can't generate uuid");
return ret;
}
if (guid != NULL) {
if (find_snapshot_by_guid(di, guid) != -1) {
ploop_err(0, "The snapshot %s already exist",
guid);
return SYSEXIT_PARAM;
}
strcpy(snap_guid, guid);
}
n = get_snapshot_count(di);
if (n == -1) {
return SYSEXIT_PARAM;
} else if (n > 128-2) {
/* The number of images limited by 128
so the snapshot limit 128 - base_image - one_reserverd
*/
ploop_err(errno, "Unable to create a snapshot."
" The maximum number of snapshots (%d) has been reached",
n-1);
return SYSEXIT_PARAM;
}
ret = ploop_find_dev_by_dd(di, dev, sizeof(dev));
if (ret == -1)
return SYSEXIT_SYS;
else if (ret == 0) {
online = 1;
ret = complete_running_operation(di, dev);
if (ret)
return ret;
} else {
ret = get_image_param_offline(di, di->top_guid, &size, &blocksize, &version);
if (ret == SYSEXIT_OPEN && errno == EBUSY) {
/* repair top delta */
char *topdelta[] = {find_image_by_guid(di, di->top_guid), NULL};
blocksize = di->blocksize;
ret = check_deltas(di, topdelta, 0, &blocksize);
if (ret)
return ret;
ret = get_image_param_offline(di, di->top_guid, &size, &blocksize, &version);
}
if (ret)
return ret;
}
ret = merge_temporary_snapshots(di);
if (ret)
return ret;
if (snap_dir != NULL) {
char *name;
char *dir;
dir = realpath(snap_dir, NULL);
if (dir == NULL) {
ploop_err(errno, "Error in realpath(%s)", snap_dir);
return SYSEXIT_CREAT;
}
name = strrchr(di->images[0]->file, '/');
if (name != NULL)
name++;
else
name = di->images[0]->file;
snprintf(fname, sizeof(fname), "%s/%s.%s",
dir, name, file_guid);
free(dir);
} else
snprintf(fname, sizeof(fname), "%s.%s",
di->images[0]->file, file_guid);
ploop_di_change_guid(di, di->top_guid, snap_guid);
if (temporary)
ploop_di_set_temporary(di, snap_guid);
ret = ploop_di_add_image(di, fname, TOPDELTA_UUID, snap_guid);
if (ret)
return ret;
get_disk_descriptor_fname(di, conf, sizeof(conf));
snprintf(conf_tmp, sizeof(conf_tmp), "%s.tmp", conf);
ret = ploop_store_diskdescriptor(conf_tmp, di);
if (ret)
return ret;
if (!online) {
// offline snapshot
fd = create_snapshot_delta(fname, blocksize, size, version);
if (fd < 0) {
ret = SYSEXIT_CREAT;
goto err;
}
close(fd);
} else {
// Always sync fs
ret = create_snapshot(dev, fname, 1);
if (ret)
goto err;
}
if (rename(conf_tmp, conf)) {
ploop_err(errno, "Can't rename %s %s",
conf_tmp, conf);
ret = SYSEXIT_RENAME;
}
if (ret && !online && unlink(fname))
ploop_err(errno, "Can't unlink %s",
fname);
ploop_log(0, "ploop %s %s has been successfully created",
get_snap_str(temporary), snap_guid);
err:
if (ret && unlink(conf_tmp))
ploop_err(errno, "Can't unlink %s", conf_tmp);
return ret;
}
void get_disk_descriptor_lock_fname(struct ploop_disk_images_data *di,
char *out, int size)
{
get_disk_descriptor_fname(di, out, size);
strcat(out, ".lck");
}
int do_create_snapshot(struct ploop_disk_images_data *di,
const char *guid, const char *snap_dir,
const char *cbt_uuid, int flags)
{
int ret, rc;
int fd;
char dev[64];
char snap_guid[UUID_SIZE];
char top_guid[UUID_SIZE];
char file_guid[UUID_SIZE];
char fname[PATH_MAX];
const char *prev_fname = NULL;
char conf[PATH_MAX];
char conf_tmp[PATH_MAX];
int online = 0;
int temporary = flags & SNAP_TYPE_TEMPORARY;
int n;
off_t size;
__u32 blocksize;
int version;
uuid_t u;
const __u8 *cbt_u = NULL;
if (cbt_uuid != NULL) {
ploop_log(0, "Create snapshot CBT uuid=%s", cbt_uuid);
if (uuid_parse(cbt_uuid, u)) {
ploop_log(-1, "Incorrect cbt uuid is specified %s",
cbt_uuid);
return SYSEXIT_PARAM;
}
cbt_u = u;
}
if (guid != NULL && !is_valid_guid(guid)) {
ploop_err(0, "Incorrect guid %s", guid);
return SYSEXIT_PARAM;
}
if (is_old_snapshot_format(di))
return SYSEXIT_PARAM;
ret = gen_uuid_pair(snap_guid, sizeof(snap_guid),
file_guid, sizeof(file_guid));
if (ret)
return ret;
if (di->vol && di->vol->parent) {
ret = ploop_uuid_generate(top_guid, sizeof(top_guid));
if (ret)
return ret;
} else
strcpy(top_guid, TOPDELTA_UUID);
if (guid != NULL) {
if (find_snapshot_by_guid(di, guid) != -1) {
ploop_err(0, "The snapshot %s already exist",
guid);
return SYSEXIT_PARAM;
}
strcpy(snap_guid, guid);
}
n = get_snapshot_count(di);
if (n == -1) {
return SYSEXIT_PARAM;
} else if (n > 128-2) {
/* The number of images limited by 128
so the snapshot limit 128 - base_image - one_reserverd
*/
ploop_err(errno, "Unable to create a snapshot."
" The maximum number of snapshots (%d) has been reached",
n-1);
return SYSEXIT_PARAM;
}
rc = ploop_find_dev_by_dd(di, dev, sizeof(dev));
if (rc == -1)
return SYSEXIT_SYS;
if (rc == 0) {
if (flags & SNAP_TYPE_OFFLINE) {
ret = get_image_param_online(dev, &size,
&blocksize, &version);
} else {
online = 1;
ret = complete_running_operation(di, dev);
}
if (ret)
return ret;
} else {
ret = get_image_param_offline(di, di->top_guid, &size, &blocksize, &version);
if (ret == SYSEXIT_OPEN && errno == EBUSY) {
/* repair top delta */
char *topdelta[] = {find_image_by_guid(di, di->top_guid), NULL};
blocksize = di->blocksize;
ret = check_deltas(di, topdelta, 0, &blocksize, NULL);
if (ret)
return ret;
ret = get_image_param_offline(di, di->top_guid, &size, &blocksize, &version);
}
if (ret)
return ret;
}
ret = merge_temporary_snapshots(di);
if (ret)
return ret;
if (snap_dir != NULL) {
char *name;
char *dir;
dir = realpath(snap_dir, NULL);
if (dir == NULL) {
ploop_err(errno, "Error in realpath(%s)", snap_dir);
return SYSEXIT_CREAT;
}
name = strrchr(di->images[0]->file, '/');
if (name != NULL)
name++;
else
name = di->images[0]->file;
snprintf(fname, sizeof(fname), "%s/%s.%s",
dir, name, file_guid);
free(dir);
} else
snprintf(fname, sizeof(fname), "%s.%s",
di->images[0]->file, file_guid);
prev_fname = find_image_by_guid(di, di->top_guid);
if (prev_fname == NULL) {
ploop_err(0, "Unable to find image by uuid %s",
di->top_guid);
return SYSEXIT_PARAM;
}
ploop_di_change_guid(di, di->top_guid, snap_guid);
if (temporary)
ploop_di_set_temporary(di, snap_guid);
ret = ploop_di_add_image(di, fname, top_guid, snap_guid);
if (ret)
return ret;
get_disk_descriptor_fname(di, conf, sizeof(conf));
snprintf(conf_tmp, sizeof(conf_tmp), "%s.tmp", conf);
ret = ploop_store_diskdescriptor(conf_tmp, di);
if (ret)
return ret;
if (!online) {
// offline snapshot
ret = 0;
fd = create_snapshot_delta(fname, blocksize, size, version);
if (fd < 0) {
ret = SYSEXIT_CREAT;
goto err;
}
close(fd);
if (cbt_u != NULL)
ret = write_empty_cbt_to_image(fname, prev_fname, cbt_u);
else if (di->mode != PLOOP_RAW_MODE) {
if (rc == 0)
ret = cbt_dump(di, dev, fname);
else
ret = ploop_move_cbt(fname, prev_fname);
}
if (ret)
goto err;
} else {
// Always sync fs
ret = create_snapshot(dev, fname, 1, cbt_u, prev_fname);
if (ret)
goto err;
}
if (rename(conf_tmp, conf)) {
ploop_err(errno, "Can't rename %s %s",
conf_tmp, conf);
ret = SYSEXIT_RENAME;
}
if (ret && !online && unlink(fname))
ploop_err(errno, "Can't unlink %s",
fname);
ploop_log(0, "ploop %s %s has been successfully created",
get_snap_str(temporary), snap_guid);
err:
if (ret && unlink(conf_tmp))
ploop_err(errno, "Can't unlink %s", conf_tmp);
return ret;
}