Eric Lee / smarc-fsl-linux-kernel

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fs/affs/dir.c 3.73 KB
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1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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  /*
   *  linux/fs/affs/dir.c
   *
   *  (c) 1996  Hans-Joachim Widmaier - Rewritten
   *
   *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
   *
   *  (C) 1992  Eric Youngdale Modified for ISO 9660 filesystem.
   *
   *  (C) 1991  Linus Torvalds - minix filesystem
   *
   *  affs directory handling functions
   *
   */
  
  #include "affs.h"
  
  static int affs_readdir(struct file *, void *, filldir_t);
4b6f5d20b   Arjan van de Ven   [PATCH] Make most... 
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  const struct file_operations affs_dir_operations = {
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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  	.read		= generic_read_dir,
59af1584b   Al Viro   [PATCH] fix ->lls... 
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  	.llseek		= generic_file_llseek,
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  	.readdir	= affs_readdir,
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  	.fsync		= affs_file_fsync,
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  };
  
  /*
   * directories can handle most operations...
   */
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  const struct inode_operations affs_dir_inode_operations = {
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  	.create		= affs_create,
  	.lookup		= affs_lookup,
  	.link		= affs_link,
  	.unlink		= affs_unlink,
  	.symlink	= affs_symlink,
  	.mkdir		= affs_mkdir,
  	.rmdir		= affs_rmdir,
  	.rename		= affs_rename,
  	.setattr	= affs_notify_change,
  };
  
  static int
  affs_readdir(struct file *filp, void *dirent, filldir_t filldir)
  {
010596cc3   Josef "Jeff" Sipek   [PATCH] affs: cha... 
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  	struct inode		*inode = filp->f_path.dentry->d_inode;
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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  	struct super_block	*sb = inode->i_sb;
  	struct buffer_head	*dir_bh;
  	struct buffer_head	*fh_bh;
  	unsigned char		*name;
  	int			 namelen;
  	u32			 i;
  	int			 hash_pos;
  	int			 chain_pos;
  	u32			 f_pos;
  	u32			 ino;
  	int			 stored;
  	int			 res;
  
  	pr_debug("AFFS: readdir(ino=%lu,f_pos=%lx)
  ",inode->i_ino,(unsigned long)filp->f_pos);
  
  	stored = 0;
  	res    = -EIO;
  	dir_bh = NULL;
  	fh_bh  = NULL;
  	f_pos  = filp->f_pos;
  
  	if (f_pos == 0) {
  		filp->private_data = (void *)0;
  		if (filldir(dirent, ".", 1, f_pos, inode->i_ino, DT_DIR) < 0)
  			return 0;
  		filp->f_pos = f_pos = 1;
  		stored++;
  	}
  	if (f_pos == 1) {
010596cc3   Josef "Jeff" Sipek   [PATCH] affs: cha... 
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  		if (filldir(dirent, "..", 2, f_pos, parent_ino(filp->f_path.dentry), DT_DIR) < 0)
1da177e4c   Linus Torvalds   Linux-2.6.12-rc2 
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  			return stored;
  		filp->f_pos = f_pos = 2;
  		stored++;
  	}
  
  	affs_lock_dir(inode);
  	chain_pos = (f_pos - 2) & 0xffff;
  	hash_pos  = (f_pos - 2) >> 16;
  	if (chain_pos == 0xffff) {
  		affs_warning(sb, "readdir", "More than 65535 entries in chain");
  		chain_pos = 0;
  		hash_pos++;
  		filp->f_pos = ((hash_pos << 16) | chain_pos) + 2;
  	}
  	dir_bh = affs_bread(sb, inode->i_ino);
  	if (!dir_bh)
  		goto readdir_out;
  
  	/* If the directory hasn't changed since the last call to readdir(),
  	 * we can jump directly to where we left off.
  	 */
  	ino = (u32)(long)filp->private_data;
  	if (ino && filp->f_version == inode->i_version) {
  		pr_debug("AFFS: readdir() left off=%d
  ", ino);
  		goto inside;
  	}
  
  	ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
  	for (i = 0; ino && i < chain_pos; i++) {
  		fh_bh = affs_bread(sb, ino);
  		if (!fh_bh) {
  			affs_error(sb, "readdir","Cannot read block %d", i);
  			goto readdir_out;
  		}
  		ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
  		affs_brelse(fh_bh);
  		fh_bh = NULL;
  	}
  	if (ino)
  		goto inside;
  	hash_pos++;
  
  	for (; hash_pos < AFFS_SB(sb)->s_hashsize; hash_pos++) {
  		ino = be32_to_cpu(AFFS_HEAD(dir_bh)->table[hash_pos]);
  		if (!ino)
  			continue;
  		f_pos = (hash_pos << 16) + 2;
  inside:
  		do {
  			fh_bh = affs_bread(sb, ino);
  			if (!fh_bh) {
  				affs_error(sb, "readdir","Cannot read block %d", ino);
  				goto readdir_done;
  			}
  
  			namelen = min(AFFS_TAIL(sb, fh_bh)->name[0], (u8)30);
  			name = AFFS_TAIL(sb, fh_bh)->name + 1;
  			pr_debug("AFFS: readdir(): filldir(\"%.*s\", ino=%u), hash=%d, f_pos=%x
  ",
  				 namelen, name, ino, hash_pos, f_pos);
  			if (filldir(dirent, name, namelen, f_pos, ino, DT_UNKNOWN) < 0)
  				goto readdir_done;
  			stored++;
  			f_pos++;
  			ino = be32_to_cpu(AFFS_TAIL(sb, fh_bh)->hash_chain);
  			affs_brelse(fh_bh);
  			fh_bh = NULL;
  		} while (ino);
  	}
  readdir_done:
  	filp->f_pos = f_pos;
  	filp->f_version = inode->i_version;
  	filp->private_data = (void *)(long)ino;
  	res = stored;
  
  readdir_out:
  	affs_brelse(dir_bh);
  	affs_brelse(fh_bh);
  	affs_unlock_dir(inode);
  	pr_debug("AFFS: readdir()=%d
  ", stored);
  	return res;
  }