/* vi: set sw=4 ts=4: *//* * link.c --- create links in a ext2fs directory * * Copyright (C) 1993, 1994 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */#include <stdio.h>#include <string.h>#if HAVE_UNISTD_H#include <unistd.h>#endif#include "ext2_fs.h"#include "ext2fs.h"struct link_struct  {	const char	*name;	int		namelen;	ext2_ino_t	inode;	int		flags;	int		done;	struct ext2_super_block *sb;};static int link_proc(struct ext2_dir_entry *dirent,		     int	offset,		     int	blocksize,		     char	*buf,		     void	*priv_data){	struct link_struct *ls = (struct link_struct *) priv_data;	struct ext2_dir_entry *next;	int rec_len, min_rec_len;	int ret = 0;	rec_len = EXT2_DIR_REC_LEN(ls->namelen);	/*	 * See if the following directory entry (if any) is unused;	 * if so, absorb it into this one.	 */	next = (struct ext2_dir_entry *) (buf + offset + dirent->rec_len);	if ((offset + dirent->rec_len < blocksize - 8) &&	    (next->inode == 0) &&	    (offset + dirent->rec_len + next->rec_len <= blocksize)) {		dirent->rec_len += next->rec_len;		ret = DIRENT_CHANGED;	}	/*	 * If the directory entry is used, see if we can split the	 * directory entry to make room for the new name.  If so,	 * truncate it and return.	 */	if (dirent->inode) {		min_rec_len = EXT2_DIR_REC_LEN(dirent->name_len & 0xFF);		if (dirent->rec_len < (min_rec_len + rec_len))			return ret;		rec_len = dirent->rec_len - min_rec_len;		dirent->rec_len = min_rec_len;		next = (struct ext2_dir_entry *) (buf + offset +						  dirent->rec_len);		next->inode = 0;		next->name_len = 0;		next->rec_len = rec_len;		return DIRENT_CHANGED;	}	/*	 * If we get this far, then the directory entry is not used.	 * See if we can fit the request entry in.  If so, do it.	 */	if (dirent->rec_len < rec_len)		return ret;	dirent->inode = ls->inode;	dirent->name_len = ls->namelen;	strncpy(dirent->name, ls->name, ls->namelen);	if (ls->sb->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE)		dirent->name_len |= (ls->flags & 0x7) << 8;	ls->done++;	return DIRENT_ABORT|DIRENT_CHANGED;}/* * Note: the low 3 bits of the flags field are used as the directory * entry filetype. */#ifdef __TURBOC__# pragma argsused#endiferrcode_t ext2fs_link(ext2_filsys fs, ext2_ino_t dir, const char *name,		      ext2_ino_t ino, int flags){	errcode_t		retval;	struct link_struct	ls;	struct ext2_inode	inode;	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);	if (!(fs->flags & EXT2_FLAG_RW))		return EXT2_ET_RO_FILSYS;	ls.name = name;	ls.namelen = name ? strlen(name) : 0;	ls.inode = ino;	ls.flags = flags;	ls.done = 0;	ls.sb = fs->super;	retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,				    0, link_proc, &ls);	if (retval)		return retval;	if (!ls.done)		return EXT2_ET_DIR_NO_SPACE;	if ((retval = ext2fs_read_inode(fs, dir, &inode)) != 0)		return retval;	if (inode.i_flags & EXT2_INDEX_FL) {		inode.i_flags &= ~EXT2_INDEX_FL;		if ((retval = ext2fs_write_inode(fs, dir, &inode)) != 0)			return retval;	}	return 0;}