int find_name_in_backref(struct btrfs_path *path, const char * name, int name_len, struct btrfs_inode_ref **ref_ret) { struct extent_buffer *leaf; struct btrfs_inode_ref *ref; unsigned long ptr; unsigned long name_ptr; u32 item_size; u32 cur_offset = 0; int len; leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); while (cur_offset < item_size) { ref = (struct btrfs_inode_ref *)(ptr + cur_offset); len = btrfs_inode_ref_name_len(leaf, ref); name_ptr = (unsigned long)(ref + 1); cur_offset += len + sizeof(*ref); if (len != name_len) continue; if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) { *ref_ret = ref; return 1; } } return 0; }
static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, struct btrfs_path *path, iterate_irefs_t *iterate, void *ctx) { int ret = 0; int slot; u32 cur; u32 len; u32 name_len; u64 parent = 0; int found = 0; struct extent_buffer *eb; struct btrfs_item *item; struct btrfs_inode_ref *iref; struct btrfs_key found_key; while (!ret) { ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, &found_key); if (ret < 0) break; if (ret) { ret = found ? 0 : -ENOENT; break; } ++found; parent = found_key.offset; slot = path->slots[0]; eb = btrfs_clone_extent_buffer(path->nodes[0]); if (!eb) { ret = -ENOMEM; break; } extent_buffer_get(eb); btrfs_release_path(path); item = btrfs_item_nr(slot); iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { name_len = btrfs_inode_ref_name_len(eb, iref); /* path must be released before calling iterate()! */ pr_debug("following ref at offset %u for inode %llu in " "tree %llu\n", cur, found_key.objectid, fs_root->objectid); ret = iterate(parent, name_len, (unsigned long)(iref + 1), eb, ctx); if (ret) break; len = sizeof(*iref) + name_len; iref = (struct btrfs_inode_ref *)((char *)iref + len); } free_extent_buffer(eb); } btrfs_release_path(path); return ret; }
/* * this iterates to turn a name (from iref/extref) into a full filesystem path. * Elements of the path are separated by '/' and the path is guaranteed to be * 0-terminated. the path is only given within the current file system. * Therefore, it never starts with a '/'. the caller is responsible to provide * "size" bytes in "dest". the dest buffer will be filled backwards. finally, * the start point of the resulting string is returned. this pointer is within * dest, normally. * in case the path buffer would overflow, the pointer is decremented further * as if output was written to the buffer, though no more output is actually * generated. that way, the caller can determine how much space would be * required for the path to fit into the buffer. in that case, the returned * value will be smaller than dest. callers must check this! */ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, u32 name_len, unsigned long name_off, struct extent_buffer *eb_in, u64 parent, char *dest, u32 size) { int slot; u64 next_inum; int ret; s64 bytes_left = ((s64)size) - 1; struct extent_buffer *eb = eb_in; struct btrfs_key found_key; struct btrfs_inode_ref *iref; if (bytes_left >= 0) dest[bytes_left] = '\0'; while (1) { bytes_left -= name_len; if (bytes_left >= 0) read_extent_buffer(eb, dest + bytes_left, name_off, name_len); if (eb != eb_in) free_extent_buffer(eb); ret = inode_ref_info(parent, 0, fs_root, path, &found_key); if (ret > 0) ret = -ENOENT; if (ret) break; next_inum = found_key.offset; /* regular exit ahead */ if (parent == next_inum) break; slot = path->slots[0]; eb = path->nodes[0]; /* make sure we can use eb after releasing the path */ if (eb != eb_in) eb->refs++; btrfs_release_path(path); iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); name_len = btrfs_inode_ref_name_len(eb, iref); name_off = (unsigned long)(iref + 1); parent = next_inum; --bytes_left; if (bytes_left >= 0) dest[bytes_left] = '/'; } btrfs_release_path(path); if (ret) return ERR_PTR(ret); return dest + bytes_left; }
static void print_inode_ref_item(struct extent_buffer *eb, u32 size, struct btrfs_inode_ref *ref) { u32 cur = 0; u32 len; u32 name_len; u64 index; char namebuf[BTRFS_NAME_LEN]; while (cur < size) { name_len = btrfs_inode_ref_name_len(eb, ref); index = btrfs_inode_ref_index(eb, ref); len = (name_len <= sizeof(namebuf))? name_len: sizeof(namebuf); read_extent_buffer(eb, namebuf, (unsigned long)(ref + 1), len); printf("\t\tinode ref index %llu namelen %u name: %.*s\n", (unsigned long long)index, name_len, len, namebuf); len = sizeof(*ref) + name_len; ref = (struct btrfs_inode_ref *)((char *)ref + len); cur += len; } }
static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root, struct btrfs_path *path, iterate_irefs_t *iterate, void *ctx) { int ret = 0; int slot; u32 cur; u32 len; u32 name_len; u64 parent = 0; int found = 0; struct extent_buffer *eb; struct btrfs_item *item; struct btrfs_inode_ref *iref; struct btrfs_key found_key; while (!ret) { path->leave_spinning = 1; ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path, &found_key); if (ret < 0) break; if (ret) { ret = found ? 0 : -ENOENT; break; } ++found; parent = found_key.offset; slot = path->slots[0]; eb = path->nodes[0]; /* make sure we can use eb after releasing the path */ atomic_inc(&eb->refs); btrfs_tree_read_lock(eb); btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); btrfs_release_path(path); item = btrfs_item_nr(eb, slot); iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref); for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) { name_len = btrfs_inode_ref_name_len(eb, iref); /* path must be released before calling iterate()! */ pr_debug("following ref at offset %u for inode %llu in " "tree %llu\n", cur, (unsigned long long)found_key.objectid, (unsigned long long)fs_root->objectid); ret = iterate(parent, name_len, (unsigned long)(iref + 1), eb, ctx); if (ret) break; len = sizeof(*iref) + name_len; iref = (struct btrfs_inode_ref *)((char *)iref + len); } btrfs_tree_read_unlock_blocking(eb); free_extent_buffer(eb); } btrfs_release_path(path); return ret; }