Exemplo n.º 1
0
static int
rtems_rfs_rtems_dir_rmnod (rtems_filesystem_location_info_t* parent_pathloc,
                           rtems_filesystem_location_info_t* pathloc)
{
  rtems_rfs_file_system* fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino          parent = rtems_rfs_rtems_get_pathloc_ino (parent_pathloc);
  rtems_rfs_ino          ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  uint32_t               doff = rtems_rfs_rtems_get_pathloc_doff (pathloc);
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_DIR_RMNOD))
    printf ("rtems-rfs: dir-rmnod: parent:%" PRId32 " doff:%" PRIu32 ", ino:%" PRId32 "\n",
            parent, doff, ino);

  if (ino == RTEMS_RFS_ROOT_INO)
    return rtems_rfs_rtems_error ("dir_rmnod: root inode", EBUSY);

  rtems_rfs_rtems_lock (fs);
  
  rc = rtems_rfs_unlink (fs, parent, ino, doff, rtems_rfs_unlink_dir_if_empty);
  if (rc)
  {
    rtems_rfs_rtems_unlock (fs);
    return rtems_rfs_rtems_error ("dir_rmnod: unlinking", rc);
  }

  rtems_rfs_rtems_unlock (fs);
  return 0;
}
Exemplo n.º 2
0
/**
 * This routine processes the lseek() system call.
 *
 * @param iop
 * @param offset
 * @param whence
 * @return off_t
 */
static off_t
rtems_rfs_rtems_file_lseek (rtems_libio_t* iop,
                            off_t          offset,
                            int            whence)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  off_t                  old_offset;
  off_t                  new_offset;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_LSEEK))
    printf("rtems-rfs: file-lseek: handle:%p offset:%" PRIdoff_t "\n", file, offset);

  rtems_rfs_rtems_lock (rtems_rfs_file_fs (file));

  old_offset = iop->offset;
  new_offset = rtems_filesystem_default_lseek_file (iop, offset, whence);
  if (new_offset != -1)
  {
    rtems_rfs_pos pos = iop->offset;
    int           rc = rtems_rfs_file_seek (file, pos, &pos);

    if (rc)
    {
      rtems_rfs_rtems_error ("file_lseek: lseek", rc);
      iop->offset = old_offset;
      new_offset = -1;
    }
  }

  rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));

  return new_offset;
}
Exemplo n.º 3
0
static int
rtems_rfs_rtems_fchmod (const rtems_filesystem_location_info_t* pathloc,
                        mode_t                                  mode)
{
  rtems_rfs_file_system*  fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino           ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  rtems_rfs_inode_handle  inode;
  int                     rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FCHMOD))
    printf ("rtems-rfs-rtems: fchmod: in: ino:%" PRId32 " mode:%06" PRIomode_t "\n",
            ino, mode);

  rc = rtems_rfs_inode_open (fs, ino, &inode, true);
  if (rc)
  {
    return rtems_rfs_rtems_error ("fchmod: opening inode", rc);
  }

  rtems_rfs_inode_set_mode (&inode, mode);

  rc = rtems_rfs_inode_close (fs, &inode);
  if (rc > 0)
  {
    return rtems_rfs_rtems_error ("fchmod: closing inode", rc);
  }

  return 0;
}
Exemplo n.º 4
0
/**
 * This routine processes the lseek() system call.
 *
 * @param iop
 * @param offset
 * @param whence
 * @return off_t
 */
static off_t
rtems_rfs_rtems_file_lseek (rtems_libio_t* iop,
                            off_t          offset,
                            int            whence)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  rtems_rfs_pos          pos;
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_LSEEK))
    printf("rtems-rfs: file-lseek: handle:%p offset:%" PRIdoff_t "\n", file, offset);

  rtems_rfs_rtems_lock (rtems_rfs_file_fs (file));

  pos = iop->offset;

  rc = rtems_rfs_file_seek (file, pos, &pos);
  if (rc)
  {
    rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));
    return rtems_rfs_rtems_error ("file_lseek: lseek", rc);
  }

  rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));

  return iop->offset;
}
Exemplo n.º 5
0
/**
 * This routine processes the read() system call.
 *
 * @param iop
 * @param buffer
 * @param count
 * @return int
 */
static ssize_t
rtems_rfs_rtems_file_read (rtems_libio_t* iop,
                           void*          buffer,
                           size_t         count)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  rtems_rfs_pos          pos;
  uint8_t*               data = buffer;
  ssize_t                read = 0;
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_READ))
    printf("rtems-rfs: file-read: handle:%p count:%zd\n", file, count);

  rtems_rfs_rtems_lock (rtems_rfs_file_fs (file));

  pos = iop->offset;

  if (pos < rtems_rfs_file_size (file))
  {
    while (count)
    {
      size_t size;

      rc = rtems_rfs_file_io_start (file, &size, true);
      if (rc > 0)
      {
        read = rtems_rfs_rtems_error ("file-read: read: io-start", rc);
        break;
      }

      if (size == 0)
        break;

      if (size > count)
        size = count;

      memcpy (data, rtems_rfs_file_data (file), size);

      data  += size;
      count -= size;
      read  += size;

      rc = rtems_rfs_file_io_end (file, size, true);
      if (rc > 0)
      {
        read = rtems_rfs_rtems_error ("file-read: read: io-end", rc);
        break;
      }
    }
  }

  if (read >= 0)
    iop->offset = pos + read;

  rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));

  return read;
}
Exemplo n.º 6
0
static int
rtems_rfs_rtems_fchmod (const rtems_filesystem_location_info_t* pathloc,
                        mode_t                                  mode)
{
  rtems_rfs_file_system*  fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino           ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  rtems_rfs_inode_handle  inode;
  uint16_t                imode;
#if defined (RTEMS_POSIX_API)
  uid_t                   uid;
#endif
  int                     rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FCHMOD))
    printf ("rtems-rfs-rtems: fchmod: in: ino:%" PRId32 " mode:%06" PRIomode_t "\n",
            ino, mode);

  rc = rtems_rfs_inode_open (fs, ino, &inode, true);
  if (rc)
  {
    return rtems_rfs_rtems_error ("fchmod: opening inode", rc);
  }

  imode = rtems_rfs_inode_get_mode (&inode);

  /*
   *  Verify I am the owner of the node or the super user.
   */
#if defined (RTEMS_POSIX_API)
  uid = geteuid();

  if ((uid != rtems_rfs_inode_get_uid (&inode)) && (uid != 0))
  {
    rtems_rfs_inode_close (fs, &inode);
    return rtems_rfs_rtems_error ("fchmod: checking uid", EPERM);
  }
#endif

  imode &= ~(S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX);
  imode |= mode & (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX);

  rtems_rfs_inode_set_mode (&inode, imode);

  rc = rtems_rfs_inode_close (fs, &inode);
  if (rc > 0)
  {
    return rtems_rfs_rtems_error ("fchmod: closing inode", rc);
  }

  return 0;
}
Exemplo n.º 7
0
static int
rtems_rfs_rtems_file_open (rtems_libio_t* iop,
                           const char*    pathname,
                           int            oflag,
                           mode_t         mode)
{
  rtems_rfs_file_system* fs = rtems_rfs_rtems_pathloc_dev (&iop->pathinfo);
  rtems_rfs_ino          ino;
  rtems_rfs_file_handle* file;
  int                    flags;
  int                    rc;

  flags = 0;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_OPEN))
    printf("rtems-rfs: file-open: path:%s ino:%" PRId32 " flags:%04i mode:%04" PRIu32 "\n",
           pathname, ino, flags, mode);

  rtems_rfs_rtems_lock (fs);

  ino = rtems_rfs_rtems_get_iop_ino (iop);

  rc = rtems_rfs_file_open (fs, ino, flags, &file);
  if (rc > 0)
  {
    rtems_rfs_rtems_unlock (fs);
    return rtems_rfs_rtems_error ("file-open: open", rc);
  }

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_OPEN))
    printf("rtems-rfs: file-open: handle:%p\n", file);

  iop->size = rtems_rfs_file_size (file);
  rtems_rfs_rtems_set_iop_file_handle (iop, file);

  rtems_rfs_rtems_unlock (fs);
  return 0;
}
Exemplo n.º 8
0
/**
 * Rename the node.
 */
static int
rtems_rfs_rtems_rename(const rtems_filesystem_location_info_t* old_parent_loc,
                       const rtems_filesystem_location_info_t* old_loc,
                       const rtems_filesystem_location_info_t* new_parent_loc,
                       const char*                             new_name,
                       size_t                                  new_name_len)
{
  rtems_rfs_file_system*  fs = rtems_rfs_rtems_pathloc_dev (old_loc);
  rtems_rfs_ino           old_parent;
  rtems_rfs_ino           new_parent;
  rtems_rfs_ino           ino;
  uint32_t                doff;
  int                     rc;

  old_parent = rtems_rfs_rtems_get_pathloc_ino (old_parent_loc);
  new_parent = rtems_rfs_rtems_get_pathloc_ino (new_parent_loc);

  ino  = rtems_rfs_rtems_get_pathloc_ino (old_loc);
  doff = rtems_rfs_rtems_get_pathloc_doff (old_loc);

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_RENAME))
    printf ("rtems-rfs: rename: ino:%" PRId32 " doff:%" PRIu32 ", new parent:%" PRId32 "\n",
            ino, doff, new_parent);

  /*
   * Link to the inode before unlinking so the inode is not erased when
   * unlinked.
   */
  rc = rtems_rfs_link (fs, new_name, new_name_len, new_parent, ino, true);
  if (rc)
  {
    return rtems_rfs_rtems_error ("rename: linking", rc);
  }

  /*
   * Unlink all inodes even directories with the dir option as false because a
   * directory may not be empty.
   */
  rc = rtems_rfs_unlink (fs, old_parent, ino, doff,
                         rtems_rfs_unlink_dir_allowed);
  if (rc)
  {
    return rtems_rfs_rtems_error ("rename: unlinking", rc);
  }

  return 0;
}
Exemplo n.º 9
0
static int
rtems_rfs_rtems_chown (const rtems_filesystem_location_info_t *pathloc,
                       uid_t                                   owner,
                       gid_t                                   group)
{
  rtems_rfs_file_system* fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino          ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  rtems_rfs_inode_handle inode;
#if defined (RTEMS_POSIX_API)
  uid_t                  uid;
#endif
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_CHOWN))
    printf ("rtems-rfs-rtems: chown: in: ino:%" PRId32 " uid:%d gid:%d\n",
            ino, owner, group);

  rc = rtems_rfs_inode_open (fs, ino, &inode, true);
  if (rc > 0)
  {
    return rtems_rfs_rtems_error ("chown: opening inode", rc);
  }

  /*
   *  Verify I am the owner of the node or the super user.
   */

#if defined (RTEMS_POSIX_API)
  uid = geteuid();

  if ((uid != rtems_rfs_inode_get_uid (&inode)) && (uid != 0))
  {
    rtems_rfs_inode_close (fs, &inode);
    return rtems_rfs_rtems_error ("chown: not able", EPERM);
  }
#endif

  rtems_rfs_inode_set_uid_gid (&inode, owner, group);

  rc = rtems_rfs_inode_close (fs, &inode);
  if (rc)
  {
    return rtems_rfs_rtems_error ("chown: closing inode", rc);
  }

  return 0;
}
Exemplo n.º 10
0
/**
 * This routine processes the close() system call.  Note that there is nothing
 * to flush at this point.
 *
 * @param iop
 * @return int
 */
static int
rtems_rfs_rtems_file_close (rtems_libio_t* iop)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  rtems_rfs_file_system* fs = rtems_rfs_file_fs (file);
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_CLOSE))
    printf("rtems-rfs: file-close: handle:%p\n", file);

  rtems_rfs_rtems_lock (fs);

  rc = rtems_rfs_file_close (fs, file);
  if (rc > 0)
    rc = rtems_rfs_rtems_error ("file-close: file close", rc);

  rtems_rfs_rtems_unlock (fs);
  return rc;
}
Exemplo n.º 11
0
/**
 * This routine processes the ftruncate() system call.
 *
 * @param iop
 * @param length
 * @return int
 */
static int
rtems_rfs_rtems_file_ftruncate (rtems_libio_t* iop,
                                off_t          length)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_FTRUNC))
    printf("rtems-rfs: file-ftrunc: handle:%p length:%" PRIdoff_t "\n", file, length);

  rtems_rfs_rtems_lock (rtems_rfs_file_fs (file));

  rc = rtems_rfs_file_set_size (file, length);
  if (rc)
    rc = rtems_rfs_rtems_error ("file_ftruncate: set size", rc);

  rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));

  return rc;
}
Exemplo n.º 12
0
static ssize_t
rtems_rfs_rtems_readlink (const rtems_filesystem_location_info_t* pathloc,
                          char*                                   buf,
                          size_t                                  bufsize)
{
  rtems_rfs_file_system*  fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino           ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  size_t                  length;
  int                     rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_READLINK))
    printf ("rtems-rfs-rtems: readlink: in: ino:%" PRId32 "\n", ino);

  rc = rtems_rfs_symlink_read (fs, ino, buf, bufsize, &length);
  if (rc)
  {
    return rtems_rfs_rtems_error ("readlink: reading link", rc);
  }

  return (ssize_t) length;
}
Exemplo n.º 13
0
/**
 * Routine to remove a node from the RFS file system.
 *
 * @param parent_pathloc
 * @param pathloc
 * @return int
 */
int
rtems_rfs_rtems_rmnod (const rtems_filesystem_location_info_t* parent_pathloc,
                       const rtems_filesystem_location_info_t* pathloc)
{
  rtems_rfs_file_system* fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino          parent = rtems_rfs_rtems_get_pathloc_ino (parent_pathloc);
  rtems_rfs_ino          ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  uint32_t               doff = rtems_rfs_rtems_get_pathloc_doff (pathloc);
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_RMNOD))
    printf ("rtems-rfs: rmnod: parent:%" PRId32 " doff:%" PRIu32 ", ino:%" PRId32 "\n",
            parent, doff, ino);

  rc = rtems_rfs_unlink (fs, parent, ino, doff, rtems_rfs_unlink_dir_if_empty);
  if (rc)
  {
    return rtems_rfs_rtems_error ("rmnod: unlinking", rc);
  }

  return 0;
}
Exemplo n.º 14
0
/**
 * The following rouine creates a new link node under parent with the name
 * given in name. The link node is set to point to the node at targetloc.
 */
static int
rtems_rfs_rtems_link (const rtems_filesystem_location_info_t *parentloc,
                      const rtems_filesystem_location_info_t *targetloc,
                      const char *name,
                      size_t namelen)
{
  rtems_rfs_file_system* fs = rtems_rfs_rtems_pathloc_dev (targetloc);
  rtems_rfs_ino          target = rtems_rfs_rtems_get_pathloc_ino (targetloc);
  rtems_rfs_ino          parent = rtems_rfs_rtems_get_pathloc_ino (parentloc);
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_LINK))
    printf ("rtems-rfs-rtems: link: in: parent:%" PRId32 " target:%" PRId32 "\n",
            parent, target);

  rc = rtems_rfs_link (fs, name, namelen, parent, target, false);
  if (rc)
  {
    return rtems_rfs_rtems_error ("link: linking", rc);
	}


	return 0;
}
Exemplo n.º 15
0
/**
 * This routine processes the write() system call.
 *
 * @param iop
 * @param buffer
 * @param count
 * @return ssize_t
 */
static ssize_t
rtems_rfs_rtems_file_write (rtems_libio_t* iop,
                            const void*    buffer,
                            size_t         count)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  rtems_rfs_pos          pos;
  rtems_rfs_pos          file_size;
  const uint8_t*         data = buffer;
  ssize_t                write = 0;
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_WRITE))
    printf("rtems-rfs: file-write: handle:%p count:%zd\n", file, count);

  rtems_rfs_rtems_lock (rtems_rfs_file_fs (file));

  pos = iop->offset;
  file_size = rtems_rfs_file_size (file);
  if (pos > file_size)
  {
    /*
     * If the iop position is past the physical end of the file we need to set
     * the file size to the new length before writing.  The
     * rtems_rfs_file_io_end() will grow the file subsequently.
     */
    rc = rtems_rfs_file_set_size (file, pos);
    if (rc)
    {
      rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));
      return rtems_rfs_rtems_error ("file-write: write extend", rc);
    }

    rtems_rfs_file_set_bpos (file, pos);
  }
  else if (pos < file_size && rtems_libio_iop_is_append(iop))
  {
    pos = file_size;
    rc = rtems_rfs_file_seek (file, pos, &pos);
    if (rc)
    {
      rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));
      return rtems_rfs_rtems_error ("file-write: write append seek", rc);
    }
  }

  while (count)
  {
    size_t size = count;

    rc = rtems_rfs_file_io_start (file, &size, false);
    if (rc)
    {
      /*
       * If we have run out of space and have written some data return that
       * amount first as the inode will have accounted for it. This means
       * there was no error and the return code from can be ignored.
       */
      if (!write)
        write = rtems_rfs_rtems_error ("file-write: write open", rc);
      break;
    }

    if (size > count)
      size = count;

    memcpy (rtems_rfs_file_data (file), data, size);

    data  += size;
    count -= size;
    write  += size;

    rc = rtems_rfs_file_io_end (file, size, false);
    if (rc)
    {
      write = rtems_rfs_rtems_error ("file-write: write close", rc);
      break;
    }
  }

  if (write >= 0)
    iop->offset = pos + write;

  rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));

  return write;
}
Exemplo n.º 16
0
int
rtems_rfs_rtems_fstat (const rtems_filesystem_location_info_t* pathloc,
                       struct stat*                            buf)
{
  rtems_rfs_file_system* fs = rtems_rfs_rtems_pathloc_dev (pathloc);
  rtems_rfs_ino          ino = rtems_rfs_rtems_get_pathloc_ino (pathloc);
  rtems_rfs_inode_handle inode;
  rtems_rfs_file_shared* shared;
  uint16_t               mode;
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_STAT))
    printf ("rtems-rfs-rtems: stat: in: ino:%" PRId32 "\n", ino);

  rc = rtems_rfs_inode_open (fs, ino, &inode, true);
  if (rc)
  {
    return rtems_rfs_rtems_error ("stat: opening inode", rc);
  }

  mode = rtems_rfs_inode_get_mode (&inode);

  if (RTEMS_RFS_S_ISCHR (mode) || RTEMS_RFS_S_ISBLK (mode))
  {
    buf->st_rdev =
      rtems_filesystem_make_dev_t (rtems_rfs_inode_get_block (&inode, 0),
                                   rtems_rfs_inode_get_block (&inode, 1));
  }

  buf->st_dev     = rtems_rfs_fs_device (fs);
  buf->st_ino     = rtems_rfs_inode_ino (&inode);
  buf->st_mode    = rtems_rfs_rtems_mode (mode);
  buf->st_nlink   = rtems_rfs_inode_get_links (&inode);
  buf->st_uid     = rtems_rfs_inode_get_uid (&inode);
  buf->st_gid     = rtems_rfs_inode_get_gid (&inode);

  /*
   * Need to check is the ino is an open file. If so we take the values from
   * the open file rather than the inode.
   */
  shared = rtems_rfs_file_get_shared (fs, rtems_rfs_inode_ino (&inode));

  if (shared)
  {
    buf->st_atime   = rtems_rfs_file_shared_get_atime (shared);
    buf->st_mtime   = rtems_rfs_file_shared_get_mtime (shared);
    buf->st_ctime   = rtems_rfs_file_shared_get_ctime (shared);
    buf->st_blocks  = rtems_rfs_file_shared_get_block_count (shared);

    if (S_ISLNK (buf->st_mode))
      buf->st_size = rtems_rfs_file_shared_get_block_offset (shared);
    else
      buf->st_size = rtems_rfs_file_shared_get_size (fs, shared);
  }
  else
  {
    buf->st_atime   = rtems_rfs_inode_get_atime (&inode);
    buf->st_mtime   = rtems_rfs_inode_get_mtime (&inode);
    buf->st_ctime   = rtems_rfs_inode_get_ctime (&inode);
    buf->st_blocks  = rtems_rfs_inode_get_block_count (&inode);

    if (S_ISLNK (buf->st_mode))
      buf->st_size = rtems_rfs_inode_get_block_offset (&inode);
    else
      buf->st_size = rtems_rfs_inode_get_size (fs, &inode);
  }

  buf->st_blksize = rtems_rfs_fs_block_size (fs);

  rc = rtems_rfs_inode_close (fs, &inode);
  if (rc > 0)
  {
    return rtems_rfs_rtems_error ("stat: closing inode", rc);
  }

  return 0;
}
Exemplo n.º 17
0
/**
 * This routine processes the write() system call.
 *
 * @param iop
 * @param buffer
 * @param count
 * @return ssize_t
 */
static ssize_t
rtems_rfs_rtems_file_write (rtems_libio_t* iop,
                            const void*    buffer,
                            size_t         count)
{
  rtems_rfs_file_handle* file = rtems_rfs_rtems_get_iop_file_handle (iop);
  rtems_rfs_pos          pos;
  const uint8_t*         data = buffer;
  ssize_t                write = 0;
  int                    rc;

  if (rtems_rfs_rtems_trace (RTEMS_RFS_RTEMS_DEBUG_FILE_WRITE))
    printf("rtems-rfs: file-write: handle:%p count:%zd\n", file, count);

  rtems_rfs_rtems_lock (rtems_rfs_file_fs (file));

  pos = iop->offset;

  /*
   * If the iop position is past the physical end of the file we need to set
   * the file size to the new length before writing. If the position equals the
   * size of file we are still past the end of the file as positions number
   * from 0. For a specific position we need a file that has a length of one
   * more.
   */

  if (pos >= rtems_rfs_file_size (file))
  {
    rc = rtems_rfs_file_set_size (file, pos + 1);
    if (rc)
    {
      rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));
      return rtems_rfs_rtems_error ("file-write: write extend", rc);
    }
  }

  rtems_rfs_file_set_bpos (file, pos);

  while (count)
  {
    size_t size = count;

    rc = rtems_rfs_file_io_start (file, &size, false);
    if (rc)
    {
      write = rtems_rfs_rtems_error ("file-write: write open", rc);
      break;
    }

    if (size > count)
      size = count;

    memcpy (rtems_rfs_file_data (file), data, size);

    data  += size;
    count -= size;
    write  += size;

    rc = rtems_rfs_file_io_end (file, size, false);
    if (rc)
    {
      write = rtems_rfs_rtems_error ("file-write: write close", rc);
      break;
    }
  }

  iop->size = rtems_rfs_file_size (file);

  rtems_rfs_rtems_unlock (rtems_rfs_file_fs (file));

  return write;
}