-/* This file is derived from source code for the Nachos
- instructional operating system. The Nachos copyright notice
- is reproduced in full below. */
-
-/* Copyright (c) 1992-1996 The Regents of the University of California.
- All rights reserved.
-
- Permission to use, copy, modify, and distribute this software
- and its documentation for any purpose, without fee, and
- without written agreement is hereby granted, provided that the
- above copyright notice and the following two paragraphs appear
- in all copies of this software.
-
- IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO
- ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR
- CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE
- AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA
- HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
- THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
- WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS"
- BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
- PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
- MODIFICATIONS.
-*/
-
-#include "filesys.h"
-#include "bitmap.h"
-#include "debug.h"
-#include "directory.h"
-#include "disk.h"
-#include "file.h"
-#include "filehdr.h"
-#include "lib.h"
-
-/* Filesystem.
-
- The filesystem consists of a set of files. Each file has a
- header, represented by struct filehdr, that is stored by
- itself in a single sector (see filehdr.h). The header
- contains the file's length in bytes and an array that lists
- the sector numbers for the file's contents.
-
- Two files are special. The first special file is the free
- map, whose header is always stored in sector 0
- (FREE_MAP_SECTOR). The free map stores a bitmap (see
- lib/bitmap.h) that contains one bit for each sector on the
- disk. Each bit that corresponds to a sector within a file is
- set to true, and the other bits, which are not part of any
- file, are set to false.
-
- The second special file is the root directory, whose header is
- always stored in sector 1 (ROOT_DIR_SECTOR). The root
- directory file stores an array of `struct dir_entry' (see
- directory.h), each of which, if it is in use, associates a
- filename with the sector of the file's header.
-
- The filesystem implemented here has the following limitations:
-
- - No synchronization. Concurrent accesses will interfere
- with one another.
-
- - File size is fixed at creation time. Because the root
- directory is represented as a file, the number of files
- that may be created is also limited.
-
- - No indirect blocks. This limits maximum file size to the
- number of sector pointers that fit in a single sector
- times the size of a sector, or 126 * 512 == 63 kB given
- 32-bit sizes and 512-byte sectors.
-
- - No nested subdirectories.
-
- - Filenames limited to 14 characters.
-
- - A system crash mid-operation may corrupt the disk in a way
- that cannot be repaired automatically. No `fsck' tool is
- provided in any case.
-
- Note: for the purposes of the "user processes" assignment
- (project 2), please treat all the code in the filesys
- directory as a black box. No changes should be needed. For
- that project, a single lock external to the filesystem code
- suffices. */
-
-/* File header sectors for system files. */
-#define FREE_MAP_SECTOR 0 /* Free map file header sector. */
-#define ROOT_DIR_SECTOR 1 /* Root directory file header sector. */
-
-/* Root directory. */
-#define NUM_DIR_ENTRIES 10 /* Maximum number of directory entries. */
-#define ROOT_DIR_FILE_SIZE /* Root directory file size in bytes. */ \
- (sizeof (struct dir_entry) * NUM_DIR_ENTRIES)
-
-/* The disk that contains the filesystem. */