int create_snapshot(const char *device, const char *delta, int syncfs)
{
int ret;
int lfd = -1;
int fd = -1;
off_t bdsize;
struct ploop_ctl_delta req;
__u32 blocksize;
int version;
ret = ploop_complete_running_operation(device);
if (ret)
return ret;
ret = get_image_param_online(device, &bdsize,
&blocksize, &version);
if (ret)
return ret;
lfd = open(device, O_RDONLY);
if (lfd < 0) {
ploop_err(errno, "Can't open device %s", device);
return SYSEXIT_DEVICE;
}
fd = create_snapshot_delta(delta, blocksize, bdsize, version);
if (fd < 0) {
ret = SYSEXIT_OPEN;
goto err;
}
memset(&req, 0, sizeof(req));
req.c.pctl_format = PLOOP_FMT_PLOOP1;
req.c.pctl_flags = syncfs ? PLOOP_FLAG_FS_SYNC : 0;
req.c.pctl_cluster_log = ffs(blocksize) - 1;
req.c.pctl_size = 0;
req.c.pctl_chunks = 1;
req.f.pctl_type = PLOOP_IO_AUTO;
ploop_log(0, "Creating snapshot dev=%s img=%s", device, delta);
ret = create_snapshot_ioctl(lfd, fd, &req);
if (ret)
unlink(delta);
err:
if (lfd >= 0)
close(lfd);
if (fd >= 0)
close(fd);
return ret;
}
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;
}
int create_snapshot(const char *device, const char *delta, int syncfs,
const __u8 *cbt_u, const char *prev_delta)
{
int ret;
int lfd = -1;
int fd = -1;
off_t bdsize;
struct ploop_ctl_delta req;
__u32 blocksize;
int version;
void *or_data = NULL;
ret = get_image_param_online(device, &bdsize,
&blocksize, &version);
if (ret)
return ret;
lfd = open(device, O_RDONLY|O_CLOEXEC);
if (lfd < 0) {
ploop_err(errno, "Can't open device %s", device);
return SYSEXIT_DEVICE;
}
fd = create_snapshot_delta(delta, blocksize, bdsize, version);
if (fd < 0) {
ret = SYSEXIT_OPEN;
goto err;
}
memset(&req, 0, sizeof(req));
req.c.pctl_format = PLOOP_FMT_PLOOP1;
req.c.pctl_flags = syncfs ? PLOOP_FLAG_FS_SYNC : 0;
req.c.pctl_cluster_log = ffs(blocksize) - 1;
req.c.pctl_size = 0;
req.c.pctl_chunks = 1;
req.f.pctl_type = PLOOP_IO_AUTO;
if (cbt_u != NULL) {
if ((ret = cbt_snapshot_prepare(lfd, cbt_u, &or_data))) {
unlink(delta);
goto err;
}
}
ploop_log(0, "Creating snapshot dev=%s img=%s", device, delta);
ret = create_snapshot_ioctl(lfd, fd, &req);
if (ret) {
unlink(delta);
goto err;
}
if (cbt_u != NULL) {
if ((ret = cbt_snapshot(lfd, cbt_u, prev_delta, or_data))) {
unlink(delta);
goto err;
}
}
err:
free(or_data);
if (lfd >= 0)
close(lfd);
if (fd >= 0)
close(fd);
return ret;
}
