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