diff options
Diffstat (limited to 'libbtrfsutil/subvolume.c')
| -rw-r--r-- | libbtrfsutil/subvolume.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/libbtrfsutil/subvolume.c b/libbtrfsutil/subvolume.c index 4f71cb06..28b38e5a 100644 --- a/libbtrfsutil/subvolume.c +++ b/libbtrfsutil/subvolume.c @@ -838,6 +838,173 @@ out_iter: return err; } +static enum btrfs_util_error snapshot_subvolume_children(int fd, int parent_fd, + const char *name, + uint64_t *async_transid) +{ + struct btrfs_util_subvolume_iterator *iter; + enum btrfs_util_error err; + int dstfd; + + dstfd = openat(parent_fd, name, O_RDONLY); + if (dstfd == -1) + return BTRFS_UTIL_ERROR_OPEN_FAILED; + + err = btrfs_util_create_subvolume_iterator_fd(fd, 0, 0, &iter); + if (err) + goto out; + + for (;;) { + char child_name[BTRFS_SUBVOL_NAME_MAX + 1]; + char *child_path; + int child_fd, new_parent_fd; + uint64_t tmp_transid; + + err = btrfs_util_subvolume_iterator_next(iter, &child_path, + NULL); + if (err) { + if (err == BTRFS_UTIL_ERROR_STOP_ITERATION) + err = BTRFS_UTIL_OK; + break; + } + + /* Remove the placeholder directory. */ + if (unlinkat(dstfd, child_path, AT_REMOVEDIR) == -1) { + free(child_path); + err = BTRFS_UTIL_ERROR_RMDIR_FAILED; + break; + } + + child_fd = openat(fd, child_path, O_RDONLY); + if (child_fd == -1) { + free(child_path); + err = BTRFS_UTIL_ERROR_OPEN_FAILED; + break; + } + + err = openat_parent_and_name(dstfd, child_path, child_name, + sizeof(child_name), + &new_parent_fd); + free(child_path); + if (err) { + SAVE_ERRNO_AND_CLOSE(child_fd); + break; + } + + err = btrfs_util_create_snapshot_fd2(child_fd, new_parent_fd, + child_name, 0, + async_transid ? &tmp_transid : NULL, + NULL); + SAVE_ERRNO_AND_CLOSE(child_fd); + SAVE_ERRNO_AND_CLOSE(new_parent_fd); + if (err) + break; + if (async_transid && tmp_transid > *async_transid) + *async_transid = tmp_transid; + } + + btrfs_util_destroy_subvolume_iterator(iter); +out: + SAVE_ERRNO_AND_CLOSE(dstfd); + return err; +} + +PUBLIC enum btrfs_util_error btrfs_util_create_snapshot(const char *source, + const char *path, + int flags, + uint64_t *async_transid, + struct btrfs_util_qgroup_inherit *qgroup_inherit) +{ + enum btrfs_util_error err; + int fd; + + fd = open(source, O_RDONLY); + if (fd == -1) + return BTRFS_UTIL_ERROR_OPEN_FAILED; + + err = btrfs_util_create_snapshot_fd(fd, path, flags, async_transid, + qgroup_inherit); + SAVE_ERRNO_AND_CLOSE(fd); + return err; +} + +PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd(int fd, + const char *path, + int flags, + uint64_t *async_transid, + struct btrfs_util_qgroup_inherit *qgroup_inherit) +{ + char name[BTRFS_SUBVOL_NAME_MAX + 1]; + enum btrfs_util_error err; + int parent_fd; + + err = openat_parent_and_name(AT_FDCWD, path, name, sizeof(name), + &parent_fd); + if (err) + return err; + + err = btrfs_util_create_snapshot_fd2(fd, parent_fd, name, flags, + async_transid, qgroup_inherit); + SAVE_ERRNO_AND_CLOSE(parent_fd); + return err; +} + +PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd, + int parent_fd, + const char *name, + int flags, + uint64_t *async_transid, + struct btrfs_util_qgroup_inherit *qgroup_inherit) +{ + struct btrfs_ioctl_vol_args_v2 args = {.fd = fd}; + enum btrfs_util_error err; + size_t len; + int ret; + + if ((flags & ~BTRFS_UTIL_CREATE_SNAPSHOT_MASK) || + ((flags & BTRFS_UTIL_CREATE_SNAPSHOT_READ_ONLY) && + (flags & BTRFS_UTIL_CREATE_SNAPSHOT_RECURSIVE))) { + errno = EINVAL; + return BTRFS_UTIL_ERROR_INVALID_ARGUMENT; + } + + if (flags & BTRFS_UTIL_CREATE_SNAPSHOT_READ_ONLY) + args.flags |= BTRFS_SUBVOL_RDONLY; + if (async_transid) + args.flags |= BTRFS_SUBVOL_CREATE_ASYNC; + if (qgroup_inherit) { + args.flags |= BTRFS_SUBVOL_QGROUP_INHERIT; + args.qgroup_inherit = (struct btrfs_qgroup_inherit *)qgroup_inherit; + args.size = (sizeof(*args.qgroup_inherit) + + args.qgroup_inherit->num_qgroups * + sizeof(args.qgroup_inherit->qgroups[0])); + } + + len = strlen(name); + if (len >= sizeof(args.name)) { + errno = ENAMETOOLONG; + return BTRFS_UTIL_ERROR_INVALID_ARGUMENT; + } + memcpy(args.name, name, len); + args.name[len] = '\0'; + + ret = ioctl(parent_fd, BTRFS_IOC_SNAP_CREATE_V2, &args); + if (ret == -1) + return BTRFS_UTIL_ERROR_SUBVOL_CREATE_FAILED; + + if (async_transid) + *async_transid = args.transid; + + if (flags & BTRFS_UTIL_CREATE_SNAPSHOT_RECURSIVE) { + err = snapshot_subvolume_children(fd, parent_fd, name, + async_transid); + if (err) + return err; + } + + return BTRFS_UTIL_OK; +} + PUBLIC void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_iterator *iter) { if (iter) { |