diff options
Diffstat (limited to 'src/shared/btrfs-util.c')
| -rw-r--r-- | src/shared/btrfs-util.c | 163 |
1 files changed, 137 insertions, 26 deletions
diff --git a/src/shared/btrfs-util.c b/src/shared/btrfs-util.c index a95cb8394..fc795cb18 100644 --- a/src/shared/btrfs-util.c +++ b/src/shared/btrfs-util.c @@ -124,14 +124,14 @@ int btrfs_subvol_snapshot_fd(int old_fd, const char *new_path, bool read_only, b r = copy_directory_fd(old_fd, new_path, true); if (r < 0) { - btrfs_subvol_remove(new_path); + btrfs_subvol_remove(new_path, false); return r; } if (read_only) { r = btrfs_subvol_set_read_only(new_path, true); if (r < 0) { - btrfs_subvol_remove(new_path); + btrfs_subvol_remove(new_path, false); return r; } } @@ -211,30 +211,6 @@ int btrfs_subvol_make_label(const char *path) { return mac_smack_fix(path, false, false); } -int btrfs_subvol_remove(const char *path) { - struct btrfs_ioctl_vol_args args = {}; - _cleanup_close_ int fd = -1; - const char *subvolume; - int r; - - assert(path); - - r = extract_subvolume_name(path, &subvolume); - if (r < 0) - return r; - - fd = open_parent(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); - if (fd < 0) - return fd; - - strncpy(args.name, subvolume, sizeof(args.name)-1); - - if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args) < 0) - return -errno; - - return 0; -} - int btrfs_subvol_set_read_only_fd(int fd, bool b) { uint64_t flags, nflags; struct stat st; @@ -798,3 +774,138 @@ int btrfs_resize_loopback(const char *p, uint64_t new_size, bool grow_only) { return btrfs_resize_loopback_fd(fd, new_size, grow_only); } + +static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol_id, bool recursive) { + struct btrfs_ioctl_search_args args = { + .key.tree_id = BTRFS_ROOT_TREE_OBJECTID, + + .key.min_objectid = BTRFS_FIRST_FREE_OBJECTID, + .key.max_objectid = BTRFS_LAST_FREE_OBJECTID, + + .key.min_type = BTRFS_ROOT_BACKREF_KEY, + .key.max_type = BTRFS_ROOT_BACKREF_KEY, + + .key.min_transid = 0, + .key.max_transid = (uint64_t) -1, + }; + + struct btrfs_ioctl_vol_args vol_args = {}; + _cleanup_close_ int subvol_fd = -1; + int r; + + assert(fd >= 0); + assert(subvolume); + + /* First, try to remove the subvolume. If it happens to be + * already empty, this will just work. */ + strncpy(vol_args.name, subvolume, sizeof(vol_args.name)-1); + if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) >= 0) + return 0; + if (!recursive || errno != ENOTEMPTY) + return -errno; + + /* OK, the subvolume is not empty, let's look for child + * subvolumes, and remove them, first */ + subvol_fd = openat(fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); + if (subvol_fd < 0) + return -errno; + + if (subvol_id == 0) { + r = btrfs_subvol_get_id_fd(subvol_fd, &subvol_id); + if (r < 0) + return r; + } + + args.key.min_offset = args.key.max_offset = subvol_id; + + while (btrfs_ioctl_search_args_compare(&args) <= 0) { + const struct btrfs_ioctl_search_header *sh; + unsigned i; + + args.key.nr_items = 256; + if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) + return -errno; + + if (args.key.nr_items <= 0) + break; + + FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) { + _cleanup_free_ char *p = NULL; + const struct btrfs_root_ref *ref; + struct btrfs_ioctl_ino_lookup_args ino_args; + + btrfs_ioctl_search_args_set(&args, sh); + + if (sh->type != BTRFS_ROOT_BACKREF_KEY) + continue; + if (sh->offset != subvol_id) + continue; + + ref = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh); + + p = strndup((char*) ref + sizeof(struct btrfs_root_ref), le64toh(ref->name_len)); + if (!p) + return -ENOMEM; + + zero(ino_args); + ino_args.treeid = subvol_id; + ino_args.objectid = ref->dirid; + + if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0) + return -errno; + + if (isempty(ino_args.name)) + /* Subvolume is in the top-level + * directory of the subvolume. */ + r = subvol_remove_children(subvol_fd, p, sh->objectid, recursive); + else { + _cleanup_close_ int child_fd = -1; + + /* Subvolume is somewhere further down, + * hence we need to open the + * containing directory first */ + + child_fd = openat(subvol_fd, ino_args.name, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); + if (child_fd < 0) + return -errno; + + r = subvol_remove_children(child_fd, p, sh->objectid, recursive); + } + if (r < 0) + return r; + } + + /* Increase search key by one, to read the next item, if we can. */ + if (!btrfs_ioctl_search_args_inc(&args)) + break; + } + + /* OK, the child subvolumes should all be gone now, let's try + * again to remove the subvolume */ + if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) < 0) + return -errno; + + return 0; +} + +int btrfs_subvol_remove(const char *path, bool recursive) { + _cleanup_close_ int fd = -1; + const char *subvolume; + int r; + + assert(path); + + r = extract_subvolume_name(path, &subvolume); + if (r < 0) + return r; + + fd = open_parent(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); + if (fd < 0) + return fd; + + return subvol_remove_children(fd, subvolume, 0, recursive); +} + +int btrfs_subvol_remove_fd(int fd, const char *subvolume, bool recursive) { + return subvol_remove_children(fd, subvolume, 0, recursive); +} |