linux/fs/minix/itree_v2.c
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   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        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 ((u64)block * (u64)sb->s_blocksize >=
  36                        minix_sb(sb)->s_max_size) {
  37                if (printk_ratelimit())
  38                        printk("MINIX-fs: block_to_path: "
  39                               "block %ld too big on dev %s\n",
  40                                block, bdevname(sb->s_bdev, b));
  41        } else if (block < DIRCOUNT) {
  42                offsets[n++] = block;
  43        } else if ((block -= DIRCOUNT) < INDIRCOUNT(sb)) {
  44                offsets[n++] = DIRCOUNT;
  45                offsets[n++] = block;
  46        } else if ((block -= INDIRCOUNT(sb)) < INDIRCOUNT(sb) * INDIRCOUNT(sb)) {
  47                offsets[n++] = DIRCOUNT + 1;
  48                offsets[n++] = block / INDIRCOUNT(sb);
  49                offsets[n++] = block % INDIRCOUNT(sb);
  50        } else {
  51                block -= INDIRCOUNT(sb) * INDIRCOUNT(sb);
  52                offsets[n++] = DIRCOUNT + 2;
  53                offsets[n++] = (block / INDIRCOUNT(sb)) / INDIRCOUNT(sb);
  54                offsets[n++] = (block / INDIRCOUNT(sb)) % INDIRCOUNT(sb);
  55                offsets[n++] = block % INDIRCOUNT(sb);
  56        }
  57        return n;
  58}
  59
  60#include "itree_common.c"
  61
  62int V2_minix_get_block(struct inode * inode, long block,
  63                        struct buffer_head *bh_result, int create)
  64{
  65        return get_block(inode, block, bh_result, create);
  66}
  67
  68void V2_minix_truncate(struct inode * inode)
  69{
  70        truncate(inode);
  71}
  72
  73unsigned V2_minix_blocks(loff_t size, struct super_block *sb)
  74{
  75        return nblocks(size, sb);
  76}
  77
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