mirror of
https://github.com/morgan9e/systemd
synced 2026-04-15 00:47:10 +09:00
99 lines
2.6 KiB
C
99 lines
2.6 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
|
|
#include <linux/btrfs.h>
|
|
#include <sys/ioctl.h>
|
|
|
|
#include "btrfs.h"
|
|
#include "fd-util.h"
|
|
#include "fs-util.h"
|
|
#include "path-util.h"
|
|
|
|
int btrfs_validate_subvolume_name(const char *name) {
|
|
|
|
if (!filename_is_valid(name))
|
|
return -EINVAL;
|
|
|
|
if (strlen(name) > BTRFS_SUBVOL_NAME_MAX)
|
|
return -E2BIG;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int extract_subvolume_name(const char *path, char **ret) {
|
|
_cleanup_free_ char *fn = NULL;
|
|
int r;
|
|
|
|
assert(path);
|
|
assert(ret);
|
|
|
|
r = path_extract_filename(path, &fn);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = btrfs_validate_subvolume_name(fn);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
*ret = TAKE_PTR(fn);
|
|
return 0;
|
|
}
|
|
|
|
int btrfs_subvol_make(int dir_fd, const char *path) {
|
|
struct btrfs_ioctl_vol_args args = {};
|
|
_cleanup_free_ char *subvolume = NULL, *parent = NULL;
|
|
_cleanup_close_ int fd = -EBADF;
|
|
int r;
|
|
|
|
assert(dir_fd >= 0 || dir_fd == AT_FDCWD);
|
|
assert(!isempty(path));
|
|
|
|
r = extract_subvolume_name(path, &subvolume);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = path_extract_directory(path, &parent);
|
|
if (r < 0) {
|
|
if (r != -EDESTADDRREQ) /* Propagate error, unless only a filename was specified, which is OK */
|
|
return r;
|
|
|
|
dir_fd = fd_reopen_condition(dir_fd, O_CLOEXEC, O_PATH, &fd); /* drop O_PATH if it is set */
|
|
if (dir_fd < 0)
|
|
return dir_fd;
|
|
} else {
|
|
fd = openat(dir_fd, parent, O_DIRECTORY|O_RDONLY|O_CLOEXEC, 0);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
dir_fd = fd;
|
|
}
|
|
|
|
strncpy(args.name, subvolume, sizeof(args.name)-1);
|
|
|
|
return RET_NERRNO(ioctl(dir_fd, BTRFS_IOC_SUBVOL_CREATE, &args));
|
|
}
|
|
|
|
int btrfs_subvol_make_fallback(int dir_fd, const char *path, mode_t mode) {
|
|
mode_t old, combined;
|
|
int r;
|
|
|
|
assert(path);
|
|
|
|
/* Let's work like mkdir(), i.e. take the specified mode, and mask it with the current umask. */
|
|
old = umask(~mode);
|
|
combined = old | ~mode;
|
|
if (combined != ~mode)
|
|
umask(combined);
|
|
r = btrfs_subvol_make(dir_fd, path);
|
|
umask(old);
|
|
|
|
if (r >= 0)
|
|
return 1; /* subvol worked */
|
|
if (!ERRNO_IS_NOT_SUPPORTED(r))
|
|
return r;
|
|
|
|
if (mkdirat(dir_fd, path, mode) < 0)
|
|
return -errno;
|
|
|
|
return 0; /* plain directory */
|
|
}
|