1 /* 2 * BTRFS filesystem implementation for U-Boot 3 * 4 * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include "btrfs.h" 10 #include <malloc.h> 11 12 static int get_subvol_name(u64 subvolid, char *name, int max_len) 13 { 14 struct btrfs_root_ref rref; 15 struct btrfs_inode_ref iref; 16 struct btrfs_root root; 17 u64 dir; 18 char tmp[max(BTRFS_VOL_NAME_MAX, BTRFS_NAME_MAX)]; 19 char *ptr; 20 21 ptr = name + max_len - 1; 22 *ptr = '\0'; 23 24 while (subvolid != BTRFS_FS_TREE_OBJECTID) { 25 subvolid = btrfs_lookup_root_ref(subvolid, &rref, tmp); 26 27 if (subvolid == -1ULL) 28 return -1; 29 30 ptr -= rref.name_len + 1; 31 if (ptr < name) 32 goto too_long; 33 34 memcpy(ptr + 1, tmp, rref.name_len); 35 *ptr = '/'; 36 37 if (btrfs_find_root(subvolid, &root, NULL)) 38 return -1; 39 40 dir = rref.dirid; 41 42 while (dir != BTRFS_FIRST_FREE_OBJECTID) { 43 dir = btrfs_lookup_inode_ref(&root, dir, &iref, tmp); 44 45 if (dir == -1ULL) 46 return -1; 47 48 ptr -= iref.name_len + 1; 49 if (ptr < name) 50 goto too_long; 51 52 memcpy(ptr + 1, tmp, iref.name_len); 53 *ptr = '/'; 54 } 55 } 56 57 if (ptr == name + max_len - 1) { 58 name[0] = '/'; 59 name[1] = '\0'; 60 } else { 61 memmove(name, ptr, name + max_len - ptr); 62 } 63 64 return 0; 65 66 too_long: 67 printf("%s: subvolume name too long\n", __func__); 68 return -1; 69 } 70 71 u64 btrfs_get_default_subvol_objectid(void) 72 { 73 struct btrfs_dir_item item; 74 75 if (btrfs_lookup_dir_item(&btrfs_info.tree_root, 76 btrfs_info.sb.root_dir_objectid, "default", 7, 77 &item)) 78 return BTRFS_FS_TREE_OBJECTID; 79 return item.location.objectid; 80 } 81 82 static void list_subvols(u64 tree, char *nameptr, int max_name_len, int level) 83 { 84 struct btrfs_key key, *found_key; 85 struct btrfs_path path; 86 struct btrfs_root_ref *ref; 87 int res; 88 89 key.objectid = tree; 90 key.type = BTRFS_ROOT_REF_KEY; 91 key.offset = 0; 92 93 if (btrfs_search_tree(&btrfs_info.tree_root, &key, &path)) 94 return; 95 96 do { 97 found_key = btrfs_path_leaf_key(&path); 98 if (btrfs_comp_keys_type(&key, found_key)) 99 break; 100 101 ref = btrfs_path_item_ptr(&path, struct btrfs_root_ref); 102 btrfs_root_ref_to_cpu(ref); 103 104 printf("ID %llu parent %llu name ", found_key->offset, tree); 105 if (nameptr && !get_subvol_name(found_key->offset, nameptr, 106 max_name_len)) 107 printf("%s\n", nameptr); 108 else 109 printf("%.*s\n", (int) ref->name_len, 110 (const char *) (ref + 1)); 111 112 if (level > 0) 113 list_subvols(found_key->offset, nameptr, max_name_len, 114 level - 1); 115 else 116 printf("%s: Too much recursion, maybe skipping some " 117 "subvolumes\n", __func__); 118 } while (!(res = btrfs_next_slot(&path))); 119 120 btrfs_free_path(&path); 121 } 122 123 void btrfs_list_subvols(void) 124 { 125 char *nameptr = malloc(4096); 126 127 list_subvols(BTRFS_FS_TREE_OBJECTID, nameptr, nameptr ? 4096 : 0, 40); 128 129 if (nameptr) 130 free(nameptr); 131 } 132