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
get_subvol_name(u64 subvolid,char * name,int max_len)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
btrfs_get_default_subvol_objectid(void)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
list_subvols(u64 tree,char * nameptr,int max_name_len,int level)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
btrfs_list_subvols(void)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