vm: fix potential null deref

[minix.git] / 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);
  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);
        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 = b_data(bp);
  } 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)
        strlcpy(string, ".", NAME_MAX + 1);  /* 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*) &b_data(bp);
             CUR_DISC_DIR_POS(dp, &b_data(bp)) < 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 */
                                lmfs_markdirty(bp);

                                /* 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 = IN_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;
                        lmfs_markdirty(bp);
                        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*) &b_data(bp);
        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;
  }
  lmfs_markdirty(bp);
  put_block(bp, DIRECTORY_BLOCK);
  ldir_ptr->i_update |= CTIME | MTIME;  /* mark mtime for update later */
  ldir_ptr->i_dirt = IN_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);

}