/**
 * @file tarfs_common.h
 *
 * Contains defines of various constants and debugging macros
 *
 * @author Jaroslav Drazan <jaroslavdrazan@seznam.cz>
 * @author Petr Cermak <xgxg@seznam.cz>
 */

/* ************************************************************************* *
 *                                                                           *
 *   This program is free software; you can redistribute it and/or modify    *
 *   it under the terms of the GNU General Public License as published by    *
 *   the Free Software Foundation; either version 2 of the License, or       *
 *   (at your option) any later version.                                     *
 *                                                                           *
 * ************************************************************************* */


#ifndef __TARFS_COMMON__
#define __TARFS_COMMON__

// Uncomment this to enable debugging messages
//#define DEBUG

#define TARFS_BLKSIZE 512    /**< Size of one tar block */
#define TARFS_BLKSIZE_BITS 9 /**< No. of bits of size */
#define TARFS_MAGIC 0x4625   /**< Magic number of this filesystem */
#define FSNAME "tarfs"      /**< Registered name of this fs */
#define TARFS_EVAL  ((unsigned long) - 1)           /**< Error return value when returning unsigned long values */
#define TARFS_THISDIR_FPOS ((unsigned long) - 2)    /**< Value of filp->f_pos. Means '.' directory */
#define TARFS_PARENTDIR_FPOS ((unsigned long) - 3)  /**< Value of filp->f_pos. Means '..' directory */
#define TARFS_ROOT_INO ((unsigned long) - 4)        /**< Inode number of root directory if not present in tar */
#define TARFS_NUMLENGTH 11                          /**< Length of octal number in  tar */

/**
 * influences return value of function is_right_prefix()
 *
 * to allow reading/listing files added to tar archive later
 * it's nessery to search the archive to the end,
 * so the function is_right_prefix must return -1 also in case
 * dname doesn't contain fname.
 * So if this macro is set to 0, it's more effective to read dirs,
 * but adding files is not supported
 *
 * to allow reading added files set this macro to -1, otherwise to 0
 *
 * @see is_right_prefix()
 */
#define TARFS_CAN_ADD -1

#ifdef DEBUG
#define PRINTD(X) printk("<1>" X "\n");
#else
#define PRINTD(X)
#endif

#endif // __TARFS_CONSTS_H__