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kernel/linux-rt-4.4.41/fs/minix/itree_v2.c 1.88 KB
5113f6f70   김현기   kernel add
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  #include <linux/buffer_head.h>
  #include "minix.h"
  
  enum {DIRECT = 7, DEPTH = 4};	/* Have triple indirect */
  
  typedef u32 block_t;	/* 32 bit, host order */
  
  static inline unsigned long block_to_cpu(block_t n)
  {
  	return n;
  }
  
  static inline block_t cpu_to_block(unsigned long n)
  {
  	return n;
  }
  
  static inline block_t *i_data(struct inode *inode)
  {
  	return (block_t *)minix_i(inode)->u.i2_data;
  }
  
  #define DIRCOUNT 7
  #define INDIRCOUNT(sb) (1 << ((sb)->s_blocksize_bits - 2))
  
  static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
  {
  	int n = 0;
  	char b[BDEVNAME_SIZE];
  	struct super_block *sb = inode->i_sb;
  
  	if (block < 0) {
  		printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s
  ",
  			block, bdevname(sb->s_bdev, b));
  	} else if ((u64)block * (u64)sb->s_blocksize >=
  			minix_sb(sb)->s_max_size) {
  		if (printk_ratelimit())
  			printk("MINIX-fs: block_to_path: "
  			       "block %ld too big on dev %s
  ",
  				block, bdevname(sb->s_bdev, b));
  	} else if (block < DIRCOUNT) {
  		offsets[n++] = block;
  	} else if ((block -= DIRCOUNT) < INDIRCOUNT(sb)) {
  		offsets[n++] = DIRCOUNT;
  		offsets[n++] = block;
  	} else if ((block -= INDIRCOUNT(sb)) < INDIRCOUNT(sb) * INDIRCOUNT(sb)) {
  		offsets[n++] = DIRCOUNT + 1;
  		offsets[n++] = block / INDIRCOUNT(sb);
  		offsets[n++] = block % INDIRCOUNT(sb);
  	} else {
  		block -= INDIRCOUNT(sb) * INDIRCOUNT(sb);
  		offsets[n++] = DIRCOUNT + 2;
  		offsets[n++] = (block / INDIRCOUNT(sb)) / INDIRCOUNT(sb);
  		offsets[n++] = (block / INDIRCOUNT(sb)) % INDIRCOUNT(sb);
  		offsets[n++] = block % INDIRCOUNT(sb);
  	}
  	return n;
  }
  
  #include "itree_common.c"
  
  int V2_minix_get_block(struct inode * inode, long block,
  			struct buffer_head *bh_result, int create)
  {
  	return get_block(inode, block, bh_result, create);
  }
  
  void V2_minix_truncate(struct inode * inode)
  {
  	truncate(inode);
  }
  
  unsigned V2_minix_blocks(loff_t size, struct super_block *sb)
  {
  	return nblocks(size, sb);
  }