minix/servers/ext2/path.c

/* This file contains the procedures that look up path names in the directory
 * system and determine the inode number that goes with a given path name.
 *
 *  The entry points into this file are
 *   eat_path:	 the 'main' routine of the path-to-inode conversion mechanism
 *   last_dir:	 find the final directory on a given path
 *   advance:	 parse one component of a path name
 *   search_dir: search a directory for a string and return its inode number
 *
 * Created (MFS based):
 *   February 2010 (Evgeniy Ivanov)
 */

#include "fs.h"
#include <assert.h>
#include <string.h>
#include <minix/endpoint.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "buf.h"
#include "inode.h"
#include "super.h"
#include <minix/vfsif.h>
#include <minix/libminixfs.h>

char dot1[2] = ".";	/* used for search_dir to bypass the access */
char dot2[3] = "..";	/* permissions for . and ..		    */

static char *get_name(char *name, char string[NAME_MAX+1]);
static int ltraverse(struct inode *rip, char *suffix);
static int parse_path(ino_t dir_ino, ino_t root_ino, int flags, struct
	inode **res_inop, size_t *offsetp, int *symlinkp);

/*===========================================================================*
 *                             fs_lookup				     *
 *===========================================================================*/
int fs_lookup()
{
  cp_grant_id_t grant;
  int r, r1, flags, symlinks;
  unsigned int len;
  size_t offset = 0, path_size;
  ino_t dir_ino, root_ino;
  struct inode *rip;

  grant		= (cp_grant_id_t) fs_m_in.REQ_GRANT;
  path_size	= (size_t) fs_m_in.REQ_PATH_SIZE;	/* Size of the buffer */
  len		= (int) fs_m_in.REQ_PATH_LEN;	/* including terminating nul */
  dir_ino	= (ino_t) fs_m_in.REQ_DIR_INO;
  root_ino	= (ino_t) fs_m_in.REQ_ROOT_INO;
  flags		= (int) fs_m_in.REQ_FLAGS;

  /* Check length. */
  if(len > sizeof(user_path)) return(E2BIG);	/* too big for buffer */
  if(len == 0) return(EINVAL);			/* too small */

  /* Copy the pathname and set up caller's user and group id */
  r = sys_safecopyfrom(VFS_PROC_NR, grant, /*offset*/ 0,
            (vir_bytes) user_path, (size_t) len, D);
  if(r != OK) return(r);

  /* Verify this is a null-terminated path. */
  if(user_path[len - 1] != '\0') return(EINVAL);

  memset(&credentials, 0, sizeof(credentials));
  if(!(flags & PATH_GET_UCRED)) { /* Do we have to copy uid/gid credentials? */
        caller_uid      = (uid_t) fs_m_in.REQ_UID;
        caller_gid      = (gid_t) fs_m_in.REQ_GID;
   } else {
         if((r=fs_lookup_credentials(&credentials,
               &caller_uid, &caller_gid,
               (cp_grant_id_t) fs_m_in.REQ_GRANT2,
               (size_t) fs_m_in.REQ_UCRED_SIZE)) != OK)
               return r;
  }

  /* Lookup inode */
  rip = NULL;
  r = parse_path(dir_ino, root_ino, flags, &rip, &offset, &symlinks);

  if(symlinks != 0 && (r == ELEAVEMOUNT || r == EENTERMOUNT || r == ESYMLINK)){
	len = strlen(user_path)+1;
	if(len > path_size) return(ENAMETOOLONG);

	r1 = sys_safecopyto(VFS_PROC_NR, grant, (vir_bytes) 0,
			    (vir_bytes) user_path, (size_t) len, D);
	if (r1 != OK) return(r1);
  }

  if(r == ELEAVEMOUNT || r == ESYMLINK) {
	  /* Report offset and the error */
	  fs_m_out.RES_OFFSET = offset;
	  fs_m_out.RES_SYMLOOP = symlinks;

	  return(r);
  }

  if (r != OK && r != EENTERMOUNT) return(r);

  fs_m_out.RES_INODE_NR		= rip->i_num;
  fs_m_out.RES_MODE		= rip->i_mode;
  fs_m_out.RES_FILE_SIZE_LO	= rip->i_size;
  fs_m_out.RES_SYMLOOP		= symlinks;
  fs_m_out.RES_UID		= rip->i_uid;
  fs_m_out.RES_GID		= rip->i_gid;

  /* This is only valid for block and character specials. But it doesn't
   * cause any harm to set RES_DEV always. */
  fs_m_out.RES_DEV		= (dev_t) rip->i_block[0];

  if(r == EENTERMOUNT) {
	  fs_m_out.RES_OFFSET	= offset;
	  put_inode(rip); /* Only return a reference to the final object */
  }

  return(r);
}


/*===========================================================================*
 *                             parse_path				     *
 *===========================================================================*/
static int parse_path(dir_ino, root_ino, flags, res_inop, offsetp, symlinkp)
ino_t dir_ino;
ino_t root_ino;
int flags;
struct inode **res_inop;
size_t *offsetp;
int *symlinkp;
{
  /* Parse the path in user_path, starting at dir_ino. If the path is the empty
   * string, just return dir_ino. It is upto the caller to treat an empty
   * path in a special way. Otherwise, if the path consists of just one or
   * more slash ('/') characters, the path is replaced with ".". Otherwise,
   * just look up the first (or only) component in path after skipping any
   * leading slashes.
   */
  int r, leaving_mount;
  struct inode *rip, *dir_ip;
  char *cp, *next_cp; /* component and next component */
  char component[NAME_MAX+1];

  /* Start parsing path at the first component in user_path */
  cp = user_path;

  /* No symlinks encountered yet */
  *symlinkp = 0;

  /* Find starting inode inode according to the request message */
  if((rip = find_inode(fs_dev, dir_ino)) == NULL)
	return(ENOENT);

  /* If dir has been removed return ENOENT. */
  if (rip->i_links_count == NO_LINK) return(ENOENT);

  dup_inode(rip);

  /* If the given start inode is a mountpoint, we must be here because the file
   * system mounted on top returned an ELEAVEMOUNT error. In this case, we must
   * only accept ".." as the first path component.
   */
  leaving_mount = rip->i_mountpoint; /* True iff rip is a mountpoint */

  /* Scan the path component by component. */
  while (TRUE) {
	if(cp[0] == '\0') {
		/* We're done; either the path was empty or we've parsed all
		   components of the path */

		*res_inop = rip;
		*offsetp += cp - user_path;

		/* Return EENTERMOUNT if we are at a mount point */
		if (rip->i_mountpoint) return(EENTERMOUNT);

		return(OK);
	}

	while(cp[0] == '/') cp++;
	next_cp = get_name(cp, component);
	if (next_cp == NULL) {
		put_inode(rip);
		return(err_code);
	}

	/* Special code for '..'. A process is not allowed to leave a chrooted
	 * environment. A lookup of '..' at the root of a mounted filesystem
	 * has to return ELEAVEMOUNT. In both cases, the caller needs search
	 * permission for the current inode, as it is used as directory.
	 */
	if(strcmp(component, "..") == 0) {
		/* 'rip' is now accessed as directory */
		if ((r = forbidden(rip, X_BIT)) != OK) {
			put_inode(rip);
			return(r);
		}

		if (rip->i_num == root_ino) {
			cp = next_cp;
			continue;	/* Ignore the '..' at a process' root
					   and move on to the next component */
		}

		if (rip->i_num == ROOT_INODE && !rip->i_sp->s_is_root) {
			/* Climbing up to parent FS */

			put_inode(rip);
			*offsetp += cp - user_path;
			return(ELEAVEMOUNT);
		}
	}

	/* Only check for a mount point if we are not coming from one. */
	if (!leaving_mount && rip->i_mountpoint) {
		/* Going to enter a child FS */

		*res_inop = rip;
		*offsetp += cp - user_path;
		return(EENTERMOUNT);
	}

	/* There is more path.  Keep parsing.
	 * If we're leaving a mountpoint, skip directory permission checks.
	 */
	dir_ip = rip;
	rip = advance(dir_ip, leaving_mount ? dot2 : component, CHK_PERM);
	if(err_code == ELEAVEMOUNT || err_code == EENTERMOUNT)
		err_code = OK;

	if (err_code != OK) {
		put_inode(dir_ip);
		return(err_code);
	}

	leaving_mount = 0;

	/* The call to advance() succeeded.  Fetch next component. */
	if (S_ISLNK(rip->i_mode)) {

		if (next_cp[0] == '\0' && (flags & PATH_RET_SYMLINK)) {
			put_inode(dir_ip);
			*res_inop = rip;
			*offsetp += next_cp - user_path;
			return(OK);
		}

		/* Extract path name from the symlink file */
		r = ltraverse(rip, next_cp);
		next_cp = user_path;
		*offsetp = 0;

		/* Symloop limit reached? */
		if (++(*symlinkp) > SYMLOOP_MAX)
			r = ELOOP;

		if (r != OK) {
			put_inode(dir_ip);
			put_inode(rip);
			return(r);
		}

		if (next_cp[0] == '/') {
                        put_inode(dir_ip);
                        put_inode(rip);
                        return(ESYMLINK);
		}

		put_inode(rip);
		dup_inode(dir_ip);
		rip = dir_ip;
	}

	put_inode(dir_ip);
	cp = next_cp; /* Process subsequent component in next round */
  }

}


/*===========================================================================*
 *                             ltraverse				     *
 *===========================================================================*/
static int ltraverse(rip, suffix)
register struct inode *rip;	/* symbolic link */
char *suffix;			/* current remaining path. Has to point in the
				 * user_path buffer
				 */
{
/* Traverse a symbolic link. Copy the link text from the inode and insert
 * the text into the path. Return error code or report success. Base
 * directory has to be determined according to the first character of the
 * new pathname.
 */

  block_t blink;	/* block containing link text */
  size_t llen;		/* length of link */
  size_t slen;		/* length of suffix */
  struct buf *bp;	/* buffer containing link text */
  const char *sp;	/* start of link text */

  llen = (size_t) rip->i_size;

  if (llen >= MAX_FAST_SYMLINK_LENGTH) {
	/* normal symlink */
	if ((blink = read_map(rip, (off_t) 0)) == NO_BLOCK)
		return(EIO);
	bp = get_block(rip->i_dev, blink, NORMAL);
	sp = bp->b_data;
  } else {
	/* fast symlink, stored in inode */
	sp = (const char*) rip->i_block;
  }

  slen = strlen(suffix);

  /* The path we're parsing looks like this:
   * /already/processed/path/<link> or
   * /already/processed/path/<link>/not/yet/processed/path
   * After expanding the <link>, the path will look like
   * <expandedlink> or
   * <expandedlink>/not/yet/processed
   * In both cases user_path must have enough room to hold <expandedlink>.
   * However, in the latter case we have to move /not/yet/processed to the
   * right place first, before we expand <link>. When strlen(<expandedlink>) is
   * smaller than strlen(/already/processes/path), we move the suffix to the
   * left. Is strlen(<expandedlink>) greater then we move it to the right. Else
   * we do nothing.
   */

  if (slen > 0) { /* Do we have path after the link? */
	/* For simplicity we require that suffix starts with a slash */
	if (suffix[0] != '/') {
		panic("ltraverse: suffix does not start with a slash");
	}

	/* To be able to expand the <link>, we have to move the 'suffix'
	 * to the right place.
	 */
	if (slen + llen + 1 > sizeof(user_path))
		return(ENAMETOOLONG);/* <expandedlink>+suffix+\0 does not fit*/
	if ((unsigned)(suffix - user_path) != llen) {
		/* Move suffix left or right if needed */
		memmove(&user_path[llen], suffix, slen+1);
	}
  } else {
	if (llen + 1 > sizeof(user_path))
		return(ENAMETOOLONG); /* <expandedlink> + \0 does not fit */

	/* Set terminating nul */
	user_path[llen]= '\0';
  }

  /* Everything is set, now copy the expanded link to user_path */
  memmove(user_path, sp, llen);

  if (llen >= MAX_FAST_SYMLINK_LENGTH)
	put_block(bp, DIRECTORY_BLOCK);

  return(OK);
}


/*===========================================================================*
 *				advance					     *
 *===========================================================================*/
struct inode *advance(dirp, string, chk_perm)
struct inode *dirp;		/* inode for directory to be searched */
char string[NAME_MAX + 1];	/* component name to look for */
int chk_perm;			/* check permissions when string is looked up*/
{
/* Given a directory and a component of a path, look up the component in
 * the directory, find the inode, open it, and return a pointer to its inode
 * slot.
 */
  ino_t numb;
  struct inode *rip;

  /* If 'string' is empty, return an error. */
  if (string[0] == '\0') {
	err_code = ENOENT;
	return(NULL);
  }

  /* Check for NULL. */
  if (dirp == NULL) return(NULL);

  /* If 'string' is not present in the directory, signal error. */
  if ( (err_code = search_dir(dirp, string, &numb, LOOK_UP,
			      chk_perm, 0)) != OK) {
	return(NULL);
  }

  /* The component has been found in the directory.  Get inode. */
  if ( (rip = get_inode(dirp->i_dev, (int) numb)) == NULL)  {
	return(NULL);
  }

  /* The following test is for "mountpoint/.." where mountpoint is a
   * mountpoint. ".." will refer to the root of the mounted filesystem,
   * but has to become a reference to the parent of the 'mountpoint'
   * directory.
   *
   * This case is recognized by the looked up name pointing to a
   * root inode, and the directory in which it is held being a
   * root inode, _and_ the name[1] being '.'. (This is a test for '..'
   * and excludes '.'.)
   */
  if (rip->i_num == ROOT_INODE) {
	  if (dirp->i_num == ROOT_INODE) {
		  if (string[1] == '.') {
			  if (!rip->i_sp->s_is_root) {
				  /* Climbing up mountpoint */
				  err_code = ELEAVEMOUNT;
			  }
		  }
	  }
  }

  /* See if the inode is mounted on.  If so, switch to root directory of the
   * mounted file system.  The super_block provides the linkage between the
   * inode mounted on and the root directory of the mounted file system.
   */
  if (rip->i_mountpoint) {
	  /* Mountpoint encountered, report it */
	  err_code = EENTERMOUNT;
  }

  return(rip);
}


/*===========================================================================*
 *				get_name				     *
 *===========================================================================*/
static char *get_name(path_name, string)
char *path_name;		/* path name to parse */
char string[NAME_MAX+1];	/* component extracted from 'old_name' */
{
/* Given a pointer to a path name in fs space, 'path_name', copy the first
 * component to 'string' (truncated if necessary, always nul terminated).
 * A pointer to the string after the first component of the name as yet
 * unparsed is returned.  Roughly speaking,
 * 'get_name' = 'path_name' - 'string'.
 *
 * This routine follows the standard convention that /usr/ast, /usr//ast,
 * //usr///ast and /usr/ast/ are all equivalent.
 *
 * If len of component is greater, than allowed, then return 0.
 */
  size_t len;
  char *cp, *ep;

  cp = path_name;

  /* Skip leading slashes */
  while (cp[0] == '/') cp++;

  /* Find the end of the first component */
  ep = cp;
  while(ep[0] != '\0' && ep[0] != '/')
	ep++;

  len = (size_t) (ep - cp);

  if (len > NAME_MAX || len > EXT2_NAME_MAX) {
  	err_code = ENAMETOOLONG;
	return(NULL);
  }

  /* Special case of the string at cp is empty */
  if (len == 0)
	strcpy(string, ".");  /* Return "." */
  else {
	memcpy(string, cp, len);
	string[len]= '\0';
  }

  return(ep);
}


/*===========================================================================*
 *				search_dir				     *
 *===========================================================================*/
int search_dir(ldir_ptr, string, numb, flag, check_permissions, ftype)
register struct inode *ldir_ptr; /* ptr to inode for dir to search */
char string[NAME_MAX + 1];	 /* component to search for */
ino_t *numb;			 /* pointer to inode number */
int flag;			 /* LOOK_UP, ENTER, DELETE or IS_EMPTY */
int check_permissions;		 /* check permissions when flag is !IS_EMPTY */
int ftype;			 /* used when ENTER and
				  * INCOMPAT_FILETYPE */
{
/* This function searches the directory whose inode is pointed to by 'ldip':
 * if (flag == ENTER)  enter 'string' in the directory with inode # '*numb';
 * if (flag == DELETE) delete 'string' from the directory;
 * if (flag == LOOK_UP) search for 'string' and return inode # in 'numb';
 * if (flag == IS_EMPTY) return OK if only . and .. in dir else ENOTEMPTY;
 *
 *    if 'string' is dot1 or dot2, no access permissions are checked.
 */

  register struct ext2_disk_dir_desc  *dp = NULL;
  register struct ext2_disk_dir_desc  *prev_dp = NULL;
  register struct buf *bp = NULL;
  int i, r, e_hit, t, match;
  mode_t bits;
  off_t pos;
  unsigned new_slots;
  block_t b;
  int extended = 0;
  int required_space = 0;
  int string_len = 0;

  /* If 'ldir_ptr' is not a pointer to a dir inode, error. */
  if ( (ldir_ptr->i_mode & I_TYPE) != I_DIRECTORY)  {
	return(ENOTDIR);
  }

  r = OK;

  if (flag != IS_EMPTY) {
	bits = (flag == LOOK_UP ? X_BIT : W_BIT | X_BIT);

	if (string == dot1 || string == dot2) {
		if (flag != LOOK_UP) r = read_only(ldir_ptr);
				     /* only a writable device is required. */
        } else if(check_permissions) {
		r = forbidden(ldir_ptr, bits); /* check access permissions */
	}
  }
  if (r != OK) return(r);

  new_slots = 0;
  e_hit = FALSE;
  match = 0;    	/* set when a string match occurs */
  pos = 0;

  if (flag == ENTER) {
	string_len = strlen(string);
	required_space = MIN_DIR_ENTRY_SIZE + string_len;
	required_space += (required_space & 0x03) == 0 ? 0 :
			     (DIR_ENTRY_ALIGN - (required_space & 0x03) );

	if (ldir_ptr->i_last_dpos < ldir_ptr->i_size &&
	    ldir_ptr->i_last_dentry_size <= required_space)
		pos = ldir_ptr->i_last_dpos;
  }

  for (; pos < ldir_ptr->i_size; pos += ldir_ptr->i_sp->s_block_size) {
	b = read_map(ldir_ptr, pos);	/* get block number */

	/* Since directories don't have holes, 'b' cannot be NO_BLOCK. */
	bp = get_block(ldir_ptr->i_dev, b, NORMAL);	/* get a dir block */
	prev_dp = NULL; /* New block - new first dentry, so no prev. */

	if (bp == NO_BLOCK)
		panic("get_block returned NO_BLOCK");
	assert(bp != NULL);

	/* Search a directory block.
	 * Note, we set prev_dp at the end of the loop.
	 */
	for (dp = (struct ext2_disk_dir_desc*) &bp->b_data;
	     CUR_DISC_DIR_POS(dp, &bp->b_data) < ldir_ptr->i_sp->s_block_size;
	     dp = NEXT_DISC_DIR_DESC(dp) ) {
		/* Match occurs if string found. */
		if (flag != ENTER && dp->d_ino != NO_ENTRY) {
			if (flag == IS_EMPTY) {
				/* If this test succeeds, dir is not empty. */
				if (ansi_strcmp(dp->d_name, ".", dp->d_name_len) != 0 &&
				    ansi_strcmp(dp->d_name, "..", dp->d_name_len) != 0) match = 1;
			} else {
				if (ansi_strcmp(dp->d_name, string, dp->d_name_len) == 0){
					match = 1;
				}
			}
		}

		if (match) {
			/* LOOK_UP or DELETE found what it wanted. */
			r = OK;
			if (flag == IS_EMPTY) r = ENOTEMPTY;
			else if (flag == DELETE) {
				if (dp->d_name_len >= sizeof(ino_t)) {
					/* Save d_ino for recovery. */
					t = dp->d_name_len - sizeof(ino_t);
					*((ino_t *) &dp->d_name[t]) = dp->d_ino;
				}
				dp->d_ino = NO_ENTRY;	/* erase entry */
				bp->b_dirt = DIRTY;

				/* If we don't support HTree (directory index),
				 * which is fully compatible ext2 feature,
				 * we should reset EXT2_INDEX_FL, when modify
				 * linked directory structure.
				 *
				 * @TODO: actually we could just reset it for
				 * each directory, but I added if() to not
				 * forget about it later, when add HTree
				 * support.
				 */
				if (!HAS_COMPAT_FEATURE(ldir_ptr->i_sp,
							COMPAT_DIR_INDEX))
					ldir_ptr->i_flags &= ~EXT2_INDEX_FL;
				if (pos < ldir_ptr->i_last_dpos) {
					ldir_ptr->i_last_dpos = pos;
					ldir_ptr->i_last_dentry_size =
						conv2(le_CPU, dp->d_rec_len);
				}
				ldir_ptr->i_update |= CTIME | MTIME;
				ldir_ptr->i_dirt = DIRTY;
				/* Now we have cleared dentry, if it's not
				 * the first one, merge it with previous one.
				 * Since we assume, that existing dentry must be
				 * correct, there is no way to spann a data block.
				 */
				if (prev_dp) {
					u16_t temp = conv2(le_CPU,
							prev_dp->d_rec_len);
					temp += conv2(le_CPU,
							dp->d_rec_len);
					prev_dp->d_rec_len = conv2(le_CPU,
							temp);
				}
			} else {
				/* 'flag' is LOOK_UP */
				*numb = (ino_t) conv4(le_CPU, dp->d_ino);
			}
			put_block(bp, DIRECTORY_BLOCK);
			return(r);
		}

		/* Check for free slot for the benefit of ENTER. */
		if (flag == ENTER && dp->d_ino == NO_ENTRY) {
			/* we found a free slot, check if it has enough space */
			if (required_space <= conv2(le_CPU, dp->d_rec_len)) {
				e_hit = TRUE;	/* we found a free slot */
				break;
			}
		}
		/* Can we shrink dentry? */
		if (flag == ENTER && required_space <= DIR_ENTRY_SHRINK(dp)) {
			/* Shrink directory and create empty slot, now
			 * dp->d_rec_len = DIR_ENTRY_ACTUAL_SIZE + DIR_ENTRY_SHRINK.
			 */
			int new_slot_size = conv2(le_CPU, dp->d_rec_len);
			int actual_size = DIR_ENTRY_ACTUAL_SIZE(dp);
			new_slot_size -= actual_size;
			dp->d_rec_len = conv2(le_CPU, actual_size);
			dp = NEXT_DISC_DIR_DESC(dp);
			dp->d_rec_len = conv2(le_CPU, new_slot_size);
			/* if we fail before writing real ino */
			dp->d_ino = NO_ENTRY;
			bp->b_dirt = DIRTY;
			e_hit = TRUE;	/* we found a free slot */
			break;
		}

		prev_dp = dp;
	}

	/* The whole block has been searched or ENTER has a free slot. */
	if (e_hit) break;	/* e_hit set if ENTER can be performed now */
	put_block(bp, DIRECTORY_BLOCK); /* otherwise, continue searching dir */
  }

  /* The whole directory has now been searched. */
  if (flag != ENTER) {
	return(flag == IS_EMPTY ? OK : ENOENT);
  }

  /* When ENTER next time, start searching for free slot from
   * i_last_dpos. It gives solid performance improvement.
   */
  ldir_ptr->i_last_dpos = pos;
  ldir_ptr->i_last_dentry_size = required_space;

  /* This call is for ENTER.  If no free slot has been found so far, try to
   * extend directory.
   */
  if (e_hit == FALSE) { /* directory is full and no room left in last block */
	new_slots++;		/* increase directory size by 1 entry */
	if ( (bp = new_block(ldir_ptr, ldir_ptr->i_size)) == NULL)
		return(err_code);
	dp = (struct ext2_disk_dir_desc*) &bp->b_data;
	dp->d_rec_len = conv2(le_CPU, ldir_ptr->i_sp->s_block_size);
	dp->d_name_len = DIR_ENTRY_MAX_NAME_LEN(dp); /* for failure */
	extended = 1;
  }

  /* 'bp' now points to a directory block with space. 'dp' points to slot. */
  dp->d_name_len = string_len;
  for (i = 0; i < NAME_MAX && i < dp->d_name_len && string[i]; i++)
	dp->d_name[i] = string[i];
  dp->d_ino = (int) conv4(le_CPU, *numb);
  if (HAS_INCOMPAT_FEATURE(ldir_ptr->i_sp, INCOMPAT_FILETYPE)) {
	/* Convert ftype (from inode.i_mode) to dp->d_file_type */
	if (ftype == I_REGULAR)
		dp->d_file_type = EXT2_FT_REG_FILE;
	else if (ftype == I_DIRECTORY)
		dp->d_file_type = EXT2_FT_DIR;
	else if (ftype == I_SYMBOLIC_LINK)
		dp->d_file_type = EXT2_FT_SYMLINK;
	else if (ftype == I_BLOCK_SPECIAL)
		dp->d_file_type = EXT2_FT_BLKDEV;
	else if (ftype == I_CHAR_SPECIAL)
		dp->d_file_type = EXT2_FT_CHRDEV;
	else if (ftype == I_NAMED_PIPE)
		dp->d_file_type = EXT2_FT_FIFO;
	else
		dp->d_file_type = EXT2_FT_UNKNOWN;
  }
  bp->b_dirt = DIRTY;
  put_block(bp, DIRECTORY_BLOCK);
  ldir_ptr->i_update |= CTIME | MTIME;	/* mark mtime for update later */
  ldir_ptr->i_dirt = DIRTY;

  if (new_slots == 1) {
	ldir_ptr->i_size += (off_t) conv2(le_CPU, dp->d_rec_len);
	/* Send the change to disk if the directory is extended. */
	if (extended) rw_inode(ldir_ptr, WRITING);
  }
  return(OK);

}