LXR linux/fs/minix/itree

   1#include <linux/buffer_head.h>
   2#include "minix.h"
   3
   4enum {DIRECT = 7, DEPTH = 4};   /* Have triple indirect */
   5
   6typedef u32 block_t;    /* 32 bit, host order */
   7
   8static inline unsigned long block_to_cpu(block_t n)
   9{
  10        return n;
  11}
  12
  13static inline block_t cpu_to_block(unsigned long n)
  14{
  15        return n;
  16}
  17
  18static 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
  26static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
  27{
  28        int n = 0;
  29        struct super_block *sb = inode->i_sb;
  30
  31        if (block < 0) {
  32                printk("MINIX-fs: block_to_path: block %ld < 0 on dev %pg\n",
  33                        block, sb->s_bdev);
  34        } else if ((u64)block * (u64)sb->s_blocksize >=
  35                        minix_sb(sb)->s_max_size) {
  36                if (printk_ratelimit())
  37                        printk("MINIX-fs: block_to_path: "
  38                               "block %ld too big on dev %pg\n",
  39                                block, sb->s_bdev);
  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
  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