xref: /openbmc/linux/fs/minix/itree_v2.c (revision 63dc02bd)
1 #include <linux/buffer_head.h>
2 #include "minix.h"
3 
4 enum {DIRECT = 7, DEPTH = 4};	/* Have triple indirect */
5 
6 typedef u32 block_t;	/* 32 bit, host order */
7 
8 static inline unsigned long block_to_cpu(block_t n)
9 {
10 	return n;
11 }
12 
13 static inline block_t cpu_to_block(unsigned long n)
14 {
15 	return n;
16 }
17 
18 static inline block_t *i_data(struct inode *inode)
19 {
20 	return (block_t *)minix_i(inode)->u.i2_data;
21 }
22 
23 #define DIRCOUNT 7
24 #define INDIRCOUNT(sb) (1 << ((sb)->s_blocksize_bits - 2))
25 
26 static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
27 {
28 	int n = 0;
29 	char b[BDEVNAME_SIZE];
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 %s\n",
34 			block, bdevname(sb->s_bdev, b));
35 	} else if (block >= (minix_sb(inode->i_sb)->s_max_size/sb->s_blocksize)) {
36 		if (printk_ratelimit())
37 			printk("MINIX-fs: block_to_path: "
38 			       "block %ld too big on dev %s\n",
39 				block, bdevname(sb->s_bdev, b));
40 	} else 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_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