1// SPDX-License-Identifier: GPL-2.0
2#include <linux/buffer_head.h>
3#include "minix.h"
4
5enum {DIRECT = 7, DEPTH = 4};	/* Have triple indirect */
6
7typedef u32 block_t;	/* 32 bit, host order */
8
9static inline unsigned long block_to_cpu(block_t n)
10{
11	return n;
12}
13
14static inline block_t cpu_to_block(unsigned long n)
15{
16	return n;
17}
18
19static 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
27static 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
61int 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_result, create);
65}
66
67void V2_minix_truncate(struct inode * inode)
68{
69	truncate(inode);
70}
71
72unsigned V2_minix_blocks(loff_t size, struct super_block *sb)
73{
74	return nblocks(size, sb);
75}
76