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kernel/linux-imx6_3.14.28/fs/efs/symlink.c 1.15 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * symlink.c
   *
   * Copyright (c) 1999 Al Smith
   *
   * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
   */
  
  #include <linux/string.h>
  #include <linux/pagemap.h>
  #include <linux/buffer_head.h>
  #include "efs.h"
  
  static int efs_symlink_readpage(struct file *file, struct page *page)
  {
  	char *link = kmap(page);
  	struct buffer_head * bh;
  	struct inode * inode = page->mapping->host;
  	efs_block_t size = inode->i_size;
  	int err;
    
  	err = -ENAMETOOLONG;
  	if (size > 2 * EFS_BLOCKSIZE)
  		goto fail;
    
  	/* read first 512 bytes of link target */
  	err = -EIO;
  	bh = sb_bread(inode->i_sb, efs_bmap(inode, 0));
  	if (!bh)
  		goto fail;
  	memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
  	brelse(bh);
  	if (size > EFS_BLOCKSIZE) {
  		bh = sb_bread(inode->i_sb, efs_bmap(inode, 1));
  		if (!bh)
  			goto fail;
  		memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
  		brelse(bh);
  	}
  	link[size] = '\0';
  	SetPageUptodate(page);
  	kunmap(page);
  	unlock_page(page);
  	return 0;
  fail:
  	SetPageError(page);
  	kunmap(page);
  	unlock_page(page);
  	return err;
  }
  
  const struct address_space_operations efs_symlink_aops = {
  	.readpage	= efs_symlink_readpage
  };