1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/buffer_head.h> |
3 | #include "minix.h" |
4 | |
5 | enum {DIRECT = 7, DEPTH = 4}; /* Have triple indirect */ |
6 | |
7 | typedef u32 block_t; /* 32 bit, host order */ |
8 | |
9 | static inline unsigned long block_to_cpu(block_t n) |
10 | { |
11 | return n; |
12 | } |
13 | |
14 | static inline block_t cpu_to_block(unsigned long n) |
15 | { |
16 | return n; |
17 | } |
18 | |
19 | static inline block_t *i_data(struct inode *inode) |
20 | { |
21 | return (block_t *)minix_i(inode)->u.i2_data; |
22 | } |
23 | |
24 | #define DIRCOUNT 7 |
25 | #define INDIRCOUNT(sb) (1 << ((sb)->s_blocksize_bits - 2)) |
26 | |
27 | static int block_to_path(struct inode * inode, long block, int offsets[DEPTH]) |
28 | { |
29 | int n = 0; |
30 | struct super_block *sb = inode->i_sb; |
31 | |
32 | if (block < 0) { |
33 | printk("MINIX-fs: block_to_path: block %ld < 0 on dev %pg\n" , |
34 | block, sb->s_bdev); |
35 | return 0; |
36 | } |
37 | if ((u64)block * (u64)sb->s_blocksize >= sb->s_maxbytes) |
38 | return 0; |
39 | |
40 | if (block < DIRCOUNT) { |
41 | offsets[n++] = block; |
42 | } else if ((block -= DIRCOUNT) < INDIRCOUNT(sb)) { |
43 | offsets[n++] = DIRCOUNT; |
44 | offsets[n++] = block; |
45 | } else if ((block -= INDIRCOUNT(sb)) < INDIRCOUNT(sb) * INDIRCOUNT(sb)) { |
46 | offsets[n++] = DIRCOUNT + 1; |
47 | offsets[n++] = block / INDIRCOUNT(sb); |
48 | offsets[n++] = block % INDIRCOUNT(sb); |
49 | } else { |
50 | block -= INDIRCOUNT(sb) * INDIRCOUNT(sb); |
51 | offsets[n++] = DIRCOUNT + 2; |
52 | offsets[n++] = (block / INDIRCOUNT(sb)) / INDIRCOUNT(sb); |
53 | offsets[n++] = (block / INDIRCOUNT(sb)) % INDIRCOUNT(sb); |
54 | offsets[n++] = block % INDIRCOUNT(sb); |
55 | } |
56 | return n; |
57 | } |
58 | |
59 | #include "itree_common.c" |
60 | |
61 | int V2_minix_get_block(struct inode * inode, long block, |
62 | struct buffer_head *bh_result, int create) |
63 | { |
64 | return get_block(inode, block, bh: bh_result, create); |
65 | } |
66 | |
67 | void V2_minix_truncate(struct inode * inode) |
68 | { |
69 | truncate(inode); |
70 | } |
71 | |
72 | unsigned V2_minix_blocks(loff_t size, struct super_block *sb) |
73 | { |
74 | return nblocks(size, sb); |
75 | } |
76 | |