Example #1
0
/* msdos_creat_node --
 *     Create a new node. Determine if the name is a long name. If long we to
 *     scan the directory to create a short entry.
 *
 *



 *     If a new node is file, FAT 32 Bytes Directory
 *     Entry Structure is initialized, free space is found in parent
 *     directory and structure is written to the disk. In case of directory,
 *     all above steps present and also new cluster is allocated for a
 *     new directory and dot and dotdot nodes are created in alloceted cluster.
 *
 * PARAMETERS:
 *     parent_loc - parent (directory we are going to create node in)
 *     type       - new node type (file or directory)
 *     name       - new node name
 *     mode       - mode
 *     link_info  - fs_info of existing node for a pseudo "hard-link"
 *                  (see msdos_file.c, msdos_link for documentation)
 *
 * RETURNS:
 *     RC_OK on success, or -1 if error occured (errno set appropriately).
 *
 */
int
msdos_creat_node(const rtems_filesystem_location_info_t  *parent_loc,
                 fat_file_type_t                          type,
                 const char                              *name,
                 int                                      name_len,
                 mode_t                                   mode,
                 const fat_file_fd_t                     *link_fd)
{
    int               rc = RC_OK;
    ssize_t           ret = 0;
    msdos_fs_info_t  *fs_info = parent_loc->mt_entry->fs_info;
    fat_file_fd_t    *parent_fat_fd = parent_loc->node_access;
    fat_file_fd_t    *fat_fd = NULL;
    time_t            now;
    uint16_t          time_val = 0;
    uint16_t          date = 0;
    fat_dir_pos_t     dir_pos;
    msdos_name_type_t name_type;
    char              short_node[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];
    char              dot_dotdot[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE * 2];
    char              link_node[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];
    uint32_t          sec = 0;
    uint32_t          byte = 0;

    fat_dir_pos_init(&dir_pos);

    memset(short_node, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);
    memset(dot_dotdot, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE * 2);

    if (name_len > MSDOS_NAME_MAX_LFN_WITH_DOT) {
        rtems_set_errno_and_return_minus_one(ENAMETOOLONG);
    }

    name_type = msdos_long_to_short (fs_info->converter,
                                     name, name_len,
                                     MSDOS_DIR_NAME(short_node),
                                     MSDOS_NAME_MAX);
    if (name_type == MSDOS_NAME_INVALID) {
        rtems_set_errno_and_return_minus_one(EINVAL);
    }

    /* fill reserved field */
    *MSDOS_DIR_NT_RES(short_node) = MSDOS_RES_NT_VALUE;

    /* set up last write date and time */
    now = time(NULL);
    fat_file_set_ctime_mtime(parent_fat_fd, now);

    msdos_date_unix2dos(now, &date, &time_val);
    *MSDOS_DIR_CRT_TIME(short_node) = CT_LE_W(time_val);
    *MSDOS_DIR_CRT_DATE(short_node) = CT_LE_W(date);
    *MSDOS_DIR_WRITE_TIME(short_node) = CT_LE_W(time_val);
    *MSDOS_DIR_WRITE_DATE(short_node) = CT_LE_W(date);
    *MSDOS_DIR_LAST_ACCESS_DATE(short_node) = CT_LE_W(date);

    /* initialize directory/file size */
    *MSDOS_DIR_FILE_SIZE(short_node) = MSDOS_INIT_DIR_SIZE;

    if (type == FAT_DIRECTORY) {
      *MSDOS_DIR_ATTR(short_node) |= MSDOS_ATTR_DIRECTORY;
    }
    else if (type == FAT_HARD_LINK) {
      /*
       * when we establish a (temporary) hard link,
       * we must copy some information from the original
       * node to the newly created
       */
      /*
       * read the original directory entry
       */
      sec = fat_cluster_num_to_sector_num(&fs_info->fat,
                                          link_fd->dir_pos.sname.cln);
      sec += (link_fd->dir_pos.sname.ofs >> fs_info->fat.vol.sec_log2);
      byte = (link_fd->dir_pos.sname.ofs & (fs_info->fat.vol.bps - 1));

      ret = _fat_block_read(&fs_info->fat,
                            sec, byte, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE,
                            link_node);
      if (ret < 0) {
          return -1;
      }
      /*
       * copy various attributes
       */
      *MSDOS_DIR_ATTR(short_node)          =*MSDOS_DIR_ATTR(link_node);
      *MSDOS_DIR_CRT_TIME_TENTH(short_node)=*MSDOS_DIR_CRT_TIME_TENTH(link_node);
      *MSDOS_DIR_CRT_TIME(short_node)      =*MSDOS_DIR_CRT_TIME(link_node);
      *MSDOS_DIR_CRT_DATE(short_node)      =*MSDOS_DIR_CRT_DATE(link_node);

      /*
       * copy/set "file size", "first cluster"
       */
      *MSDOS_DIR_FILE_SIZE(short_node)     =*MSDOS_DIR_FILE_SIZE(link_node);

      *MSDOS_DIR_FIRST_CLUSTER_LOW(short_node) =
           *MSDOS_DIR_FIRST_CLUSTER_LOW(link_node);
      *MSDOS_DIR_FIRST_CLUSTER_HI(short_node) =
           *MSDOS_DIR_FIRST_CLUSTER_HI(link_node);
      /*
       * set "archive bit" due to changes
       */
      *MSDOS_DIR_ATTR(short_node) |= MSDOS_ATTR_ARCHIVE;
    }
/* msdos_find_name --
 *     Find the node which correspondes to the name, open fat-file which
 *     correspondes to the found node and close fat-file which correspondes
 *     to the node we searched in.
 *
 * PARAMETERS:
 *     parent_loc - parent node description
 *     name       - name to find
 *
 * RETURNS:
 *     RC_OK and updated 'parent_loc' on success, or -1 if error
 *     occured (errno set apropriately)
 *
 */
int
msdos_find_name(
    rtems_filesystem_location_info_t *parent_loc,
    char                             *name
    )
{
    int              rc = RC_OK;
    msdos_fs_info_t *fs_info = parent_loc->mt_entry->fs_info;
    fat_file_fd_t   *fat_fd = NULL;
    fat_auxiliary_t  aux;
    unsigned short   time_val = 0;
    unsigned short   date = 0;
    char             node_entry[MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE];

    memset(node_entry, 0, MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE);

    /*
     * find the node which correspondes to the name in the directory pointed by
     * 'parent_loc'
     */
    rc = msdos_get_name_node(parent_loc, name, &aux, node_entry);
    if (rc != RC_OK)
        return rc;

    /* open fat-file corresponded to the found node */
    rc = fat_file_open(parent_loc->mt_entry, aux.cln, aux.ofs, &fat_fd);
    if (rc != RC_OK)
        return rc;

    /*
     * I don't like this if, but: we should do it , or should write new file
     * size and first cluster num to the disk after each write operation
     * (even if one byte is written  - that is TOO non-optimize) because
     * otherwise real values of these fields stored in fat-file descriptor
     * may be accidentely rewritten with wrong values stored on the disk
     */
    if (fat_fd->links_num == 1)
    {
        fat_fd->info_cln = aux.cln;
        fat_fd->info_ofs = aux.ofs;
        fat_fd->cln = MSDOS_EXTRACT_CLUSTER_NUM(node_entry);
        fat_fd->first_char = *MSDOS_DIR_NAME(node_entry);

        time_val = *MSDOS_DIR_WRITE_TIME(node_entry);
        date = *MSDOS_DIR_WRITE_DATE(node_entry);

        fat_fd->mtime = msdos_date_dos2unix(CF_LE_W(time_val), CF_LE_W(date));

        if ((*MSDOS_DIR_ATTR(node_entry)) & MSDOS_ATTR_DIRECTORY)
        {
            fat_fd->fat_file_type = FAT_DIRECTORY;
            fat_fd->size_limit = MSDOS_MAX_DIR_LENGHT;

            rc = fat_file_size(parent_loc->mt_entry, fat_fd);
            if (rc != RC_OK)
            {
                fat_file_close(parent_loc->mt_entry, fat_fd);
                return rc;
            }
        }
        else
        {
            fat_fd->fat_file_size = CF_LE_L(*MSDOS_DIR_FILE_SIZE(node_entry));
            fat_fd->fat_file_type = FAT_FILE;
            fat_fd->size_limit = MSDOS_MAX_FILE_SIZE;
        }

        /* these data is not actual for zero-length fat-file */
        fat_fd->map.file_cln = 0;
        fat_fd->map.disk_cln = fat_fd->cln;

        if ((fat_fd->fat_file_size != 0) &&
            (fat_fd->fat_file_size <= fs_info->fat.vol.bpc))
        {
            fat_fd->map.last_cln = fat_fd->cln;
        }
        else
        {
            fat_fd->map.last_cln = FAT_UNDEFINED_VALUE;
        }
    }

    /* close fat-file corresponded to the node we searched in */
    rc = fat_file_close(parent_loc->mt_entry, parent_loc->node_access);
    if (rc != RC_OK)
    {
        fat_file_close(parent_loc->mt_entry, fat_fd);
        return rc;
    }

    /* update node_info_ptr field */
    parent_loc->node_access = fat_fd;

    return rc;
}