LXR linux/fs/minix/itree

   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