msdos_dir.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

             *
             * unfortunately there is no method to extract ino except to 
             * open fat-file descriptor :( ... so, open it
             */
      
            /* get number of cluster we are working with */
            rc = fat_file_ioctl(iop->pathinfo.mt_entry, fat_fd, F_CLU_NUM,
                                j * bts2rd, &cur_cln);
            if (rc != RC_OK)
            {
                rtems_semaphore_release(fs_info->vol_sema);
                return rc;
            }

            rc = fat_file_open(iop->pathinfo.mt_entry, cur_cln, i, 
                               &tmp_fat_fd);
            if (rc != RC_OK)
            {
                rtems_semaphore_release(fs_info->vol_sema);
                return rc;
            }

            tmp_fat_fd->info_cln = cur_cln;
            tmp_fat_fd->info_ofs = i;

            /* fill in dirent structure */
            /* XXX: from what and in what d_off should be computed ?! */
            tmp_dirent.d_off = start + cmpltd;
            tmp_dirent.d_reclen = sizeof(struct dirent);
            tmp_dirent.d_ino = tmp_fat_fd->ino;
	    /*
	     * convert dir entry from fixed 8+3 format (without dot)
	     * to 0..8 + 1dot + 0..3 format
	     */
	    tmp_dirent.d_namlen = 
	      msdos_format_dirent_with_dot(tmp_dirent.d_name,
					 fs_info->cl_buf + i); /* src text */
            memcpy(buffer + cmpltd, &tmp_dirent, sizeof(struct dirent));
   
            iop->offset = iop->offset + sizeof(struct dirent);
            cmpltd += (sizeof(struct dirent));
            count -= (sizeof(struct dirent));
      
            /* inode number extracted, close fat-file */
            rc = fat_file_close(iop->pathinfo.mt_entry, tmp_fat_fd);
            if (rc != RC_OK)
            {
                rtems_semaphore_release(fs_info->vol_sema);
                return rc;
            }

            if (count <= 0)
                break;
        }
        j++;
    }

    rtems_semaphore_release(fs_info->vol_sema);
    return cmpltd;
}

/* msdos_dir_write --
 *     no write for directory
 */

/* msdos_dir_lseek --
 *
 *  This routine will behave in one of three ways based on the state of
 *  argument whence. Based on the state of its value the offset argument will
 *  be interpreted using one of the following methods:
 *
 *     SEEK_SET - offset is the absolute byte offset from the start of the
 *                logical start of the dirent sequence that represents the
 *                directory
 *     SEEK_CUR - offset is used as the relative byte offset from the current
 *                directory position index held in the iop structure
 *     SEEK_END - N/A --> This will cause an assert.
 *
 * PARAMETERS:
 *     iop    - file control block
 *     offset - offset
 *     whence - predefine directive
 *
 * RETURNS:
 *     RC_OK on success, or -1 if error occured (errno 
 *     set apropriately).
 */
int 
msdos_dir_lseek(rtems_libio_t *iop, off_t offset, int whence)
{
    switch (whence) 
    {
        case SEEK_SET:
        case SEEK_CUR: 
            break;
        /* 
         * Movement past the end of the directory via lseek is not a 
         * permitted operation
         */
        case SEEK_END:
        default:
            set_errno_and_return_minus_one( EINVAL );
            break;
    }
    return RC_OK;
}

/* msdos_dir_stat --
 * 
 * This routine will obtain the following information concerning the current
 * directory:
 *     st_dev      device id
 *     st_ino      node serial number :)
 *     st_mode     mode extracted from the node
 *     st_size     total size in bytes
 *     st_blksize  blocksize for filesystem I/O
 *     st_blocks   number of blocks allocated 
 *     stat_mtime  time of last modification
 *
 * PARAMETERS:
 *     loc - this directory
 *     buf - stat buffer provided by user
 *
 * RETURNS:
 *     RC_OK and filled stat buffer on success, or -1 if error occured (errno 
 *     set apropriately).
 */
int 
msdos_dir_stat(
    rtems_filesystem_location_info_t *loc,
    struct stat                      *buf
    )
{
    rtems_status_code  sc = RTEMS_SUCCESSFUL;
    msdos_fs_info_t   *fs_info = loc->mt_entry->fs_info; 
    fat_file_fd_t     *fat_fd = loc->node_access;

    sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
                                MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
    if (sc != RTEMS_SUCCESSFUL)
        set_errno_and_return_minus_one(EIO);
  
    buf->st_dev = fs_info->fat.vol.dev;
    buf->st_ino = fat_fd->ino;
    buf->st_mode  = S_IFDIR;
    buf->st_rdev = 0ll;
    buf->st_size = fat_fd->fat_file_size;
    buf->st_blocks = fat_fd->fat_file_size >> FAT_SECTOR512_BITS;
    buf->st_blksize = fs_info->fat.vol.bps;
    buf->st_mtime = fat_fd->mtime;
  
    rtems_semaphore_release(fs_info->vol_sema);
    return RC_OK;
}

/* msdos_dir_truncate --
 *     No truncate for directory.
 *
 * PARAMETERS:
 *
 * RETURNS:
 *
 */

/* msdos_dir_sync --
 *     The following routine does a syncronization on a MSDOS directory node.
 *     DIR_WrtTime, DIR_WrtDate and DIR_fileSize fields of 32 Bytes Directory 
 *     Entry Structure should not be updated for directories, so only call 
 *     to corresponding fat-file routine.
 *
 * PARAMETERS:
 *     iop - file control block
 *
 * RETURNS:
 *     RC_OK on success, or -1 if error occured (errno set apropriately).
 */
int
msdos_dir_sync(rtems_libio_t *iop)
{
    int                rc = RC_OK;
    rtems_status_code  sc = RTEMS_SUCCESSFUL;
    fat_file_fd_t     *fat_fd = iop->file_info;
    msdos_fs_info_t   *fs_info = iop->pathinfo.mt_entry->fs_info;
  
    sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
                                MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
    if (sc != RTEMS_SUCCESSFUL)
        set_errno_and_return_minus_one(EIO);
  
    rc = fat_file_datasync(iop->pathinfo.mt_entry, fat_fd);

    rtems_semaphore_release(fs_info->vol_sema);
    return rc;
}

/* msdos_dir_rmnod --
 *     Remove directory node. 
 *
 *     Check that this directory node is not opened as fat-file, is empty and 
 *     not filesystem root node. If all this conditions met then delete.
 *
 * PARAMETERS:
 *     pathloc - node description
 *
 * RETURNS:
 *     RC_OK on success, or -1 if error occured (errno set apropriately).
 */
int 
msdos_dir_rmnod(rtems_filesystem_location_info_t *pathloc)
{
    int                rc = RC_OK;
    rtems_status_code  sc = RTEMS_SUCCESSFUL;
    msdos_fs_info_t   *fs_info = pathloc->mt_entry->fs_info; 
    fat_file_fd_t     *fat_fd = pathloc->node_access;
    rtems_boolean      is_empty = FALSE;
  
    sc = rtems_semaphore_obtain(fs_info->vol_sema, RTEMS_WAIT,
                                MSDOS_VOLUME_SEMAPHORE_TIMEOUT);
    if (sc != RTEMS_SUCCESSFUL)
        set_errno_and_return_minus_one(EIO);
  
    /*
     * We deny attemp to delete open directory (if directory is current 
     * directory we assume it is open one)
     */
    if (fat_fd->links_num > 1)
    {
        rtems_semaphore_release(fs_info->vol_sema);
        set_errno_and_return_minus_one(EBUSY);
    } 
  
    /*
     * You cannot remove a node that still has children
     */
    rc = msdos_dir_is_empty(pathloc->mt_entry, fat_fd, &is_empty); 
    if (rc != RC_OK)
    {
        rtems_semaphore_release(fs_info->vol_sema);
        return rc;
    }

    if (!is_empty)
    {
        rtems_semaphore_release(fs_info->vol_sema); 
        set_errno_and_return_minus_one(ENOTEMPTY);
    }     

    /*
     * You cannot remove the file system root node.
     */
    if (pathloc->mt_entry->mt_fs_root.node_access == pathloc->node_access)
    {
        rtems_semaphore_release(fs_info->vol_sema);
        set_errno_and_return_minus_one(EBUSY);
    }

    /*
     * You cannot remove a mountpoint.
     * not used - mount() not implemenetd yet.
     */

    /* mark file removed */
    rc = msdos_set_first_char4file_name(pathloc->mt_entry, fat_fd->info_cln, 
                                        fat_fd->info_ofs, 
                                        MSDOS_THIS_DIR_ENTRY_EMPTY);
    if (rc != RC_OK)
    {
        rtems_semaphore_release(fs_info->vol_sema);
        return rc;
    }

    fat_file_mark_removed(pathloc->mt_entry, fat_fd); 

    rtems_semaphore_release(fs_info->vol_sema);
    return rc;
}