603c15a253
git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@80 6ac86273-5f31-0410-b378-82cca8765d1b
638 lines
19 KiB
C
638 lines
19 KiB
C
/****************************************************************/
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/* */
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/* blockio.c */
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/* DOS-C */
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/* */
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/* Block cache functions and device driver interface */
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/* */
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/* Copyright (c) 1995 */
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/* Pasquale J. Villani */
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/* All Rights Reserved */
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/* */
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/* This file is part of DOS-C. */
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/* */
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/* DOS-C is free software; you can redistribute it and/or */
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/* modify it under the terms of the GNU General Public License */
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/* as published by the Free Software Foundation; either version */
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/* 2, or (at your option) any later version. */
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/* */
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/* DOS-C is distributed in the hope that it will be useful, but */
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/* WITHOUT ANY WARRANTY; without even the implied warranty of */
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/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
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/* the GNU General Public License for more details. */
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/* */
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/* You should have received a copy of the GNU General Public */
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/* License along with DOS-C; see the file COPYING. If not, */
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/* write to the Free Software Foundation, 675 Mass Ave, */
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/* Cambridge, MA 02139, USA. */
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/* */
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/****************************************************************/
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#include "portab.h"
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#include "globals.h"
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#ifdef VERSION_STRINGS
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static BYTE *blockioRcsId = "$Id$";
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#endif
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/*
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* $Log$
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* Revision 1.6 2000/10/30 00:32:08 jimtabor
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* Minor Fixes
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*
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* Revision 1.5 2000/10/30 00:21:15 jimtabor
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* Adding Brian Reifsnyder Fix for Int 25/26
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* 2000/9/04 Brian Reifsnyder
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* Modified dskxfer() such that error codes are now returned.
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* Functions that rely on dskxfer() have also been modified accordingly.
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*
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* Revision 1.4 2000/05/25 20:56:21 jimtabor
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* Fixed project history
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*
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* Revision 1.3 2000/05/11 04:26:26 jimtabor
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* Added code for DOS FN 69 & 6C
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*
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* Revision 1.2 2000/05/08 04:29:59 jimtabor
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* Update CVS to 2020
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*
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* Revision 1.1.1.1 2000/05/06 19:34:53 jhall1
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* The FreeDOS Kernel. A DOS kernel that aims to be 100% compatible with
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* MS-DOS. Distributed under the GNU GPL.
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*
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* Revision 1.15 2000/04/29 05:13:16 jtabor
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* Added new functions and clean up code
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*
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* Revision 1.14 2000/03/09 06:07:10 kernel
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* 2017f updates by James Tabor
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*
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* Revision 1.13 1999/08/25 03:18:07 jprice
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* ror4 patches to allow TC 2.01 compile.
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*
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* Revision 1.12 1999/08/10 18:03:39 jprice
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* ror4 2011-03 patch
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*
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* Revision 1.11 1999/05/03 06:25:45 jprice
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* Patches from ror4 and many changed of signed to unsigned variables.
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*
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* Revision 1.10 1999/05/03 04:55:35 jprice
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* Changed getblock & getbuf so that they leave at least 3 buffer for FAT data.
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*
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* Revision 1.9 1999/04/21 01:44:40 jprice
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* no message
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*
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* Revision 1.8 1999/04/18 05:28:39 jprice
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* no message
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*
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* Revision 1.7 1999/04/16 21:43:40 jprice
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* ror4 multi-sector IO
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*
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* Revision 1.6 1999/04/16 00:53:32 jprice
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* Optimized FAT handling
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*
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* Revision 1.5 1999/04/12 23:41:53 jprice
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* Using getbuf to write data instead of getblock
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* using getblock made it read the block before it wrote it
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*
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* Revision 1.4 1999/04/11 05:28:10 jprice
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* Working on multi-block IO
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*
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* Revision 1.3 1999/04/11 04:33:38 jprice
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* ror4 patches
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*
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* Revision 1.1.1.1 1999/03/29 15:41:43 jprice
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* New version without IPL.SYS
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*
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* Revision 1.5 1999/02/09 02:54:23 jprice
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* Added Pat's 1937 kernel patches
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*
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* Revision 1.4 1999/02/01 01:43:27 jprice
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* Fixed findfirst function to find volume label with Windows long filenames
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*
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* Revision 1.3 1999/01/30 08:25:34 jprice
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* Clean up; Fixed bug with set attribute function. If you tried to
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* change the attributes of a directory, it would erase it.
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*
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* Revision 1.2 1999/01/22 04:15:28 jprice
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* Formating
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*
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* Revision 1.1.1.1 1999/01/20 05:51:00 jprice
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* Imported sources
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*
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*
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* Rev 1.8 06 Dec 1998 8:43:16 patv
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* Changes in block I/O because of new I/O subsystem.
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*
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* Rev 1.7 22 Jan 1998 4:09:00 patv
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* Fixed pointer problems affecting SDA
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*
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* Rev 1.6 04 Jan 1998 23:14:36 patv
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* Changed Log for strip utility
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*
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* Rev 1.5 03 Jan 1998 8:36:02 patv
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* Converted data area to SDA format
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*
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* Rev 1.4 16 Jan 1997 12:46:34 patv
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* pre-Release 0.92 feature additions
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*
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* Rev 1.3 29 May 1996 21:15:10 patv
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* bug fixes for v0.91a
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*
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* Rev 1.2 01 Sep 1995 17:48:46 patv
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* First GPL release.
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*
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* Rev 1.1 30 Jul 1995 20:50:28 patv
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* Eliminated version strings in ipl
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*
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* Rev 1.0 02 Jul 1995 8:04:06 patv
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* Initial revision.
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*/
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/************************************************************************/
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/* */
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/* block cache routines */
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/* */
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/************************************************************************/
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/* */
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/* Initialize the buffer structure */
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/* */
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/* XXX: This should go into `INIT_TEXT'. -- ror4 */
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VOID FAR init_buffers(void)
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{
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REG WORD i;
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REG WORD count;
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for (i = 0; i < Config.cfgBuffers; ++i)
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{
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buffers[i].b_unit = 0;
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buffers[i].b_flag = 0;
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buffers[i].b_blkno = 0;
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buffers[i].b_copies = 0;
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buffers[i].b_offset_lo = 0;
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buffers[i].b_offset_hi = 0;
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if (i < (Config.cfgBuffers - 1))
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buffers[i].b_next = &buffers[i + 1];
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else
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buffers[i].b_next = NULL;
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}
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firstbuf = &buffers[0];
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lastbuf = &buffers[Config.cfgBuffers - 1];
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}
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/* Extract the block number from a buffer structure. */
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ULONG getblkno(struct buffer FAR * bp)
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{
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if (bp->b_blkno == 0xffffu)
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return bp->b_huge_blkno;
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else
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return bp->b_blkno;
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}
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/* Set the block number of a buffer structure. (The caller should */
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/* set the unit number before calling this function.) */
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VOID setblkno(struct buffer FAR * bp, ULONG blkno)
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{
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if (blkno >= 0xffffu)
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{
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bp->b_blkno = 0xffffu;
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bp->b_huge_blkno = blkno;
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}
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else
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{
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bp->b_blkno = blkno;
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/* bp->b_dpbp = &blk_devices[bp->b_unit]; */
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bp->b_dpbp = CDSp->cds_table[bp->b_unit].cdsDpb;
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}
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}
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/* */
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/* Return the address of a buffer structure containing the */
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/* requested block. */
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/* */
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/* returns: */
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/* requested block with data */
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/* failure: */
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/* returns NULL */
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/* */
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struct buffer FAR *getblock(ULONG blkno, COUNT dsk)
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{
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REG struct buffer FAR *bp;
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REG struct buffer FAR *lbp;
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REG struct buffer FAR *mbp;
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REG BYTE fat_count = 0;
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/* Search through buffers to see if the required block */
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/* is already in a buffer */
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#ifdef DISPLAY_GETBLOCK
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printf("[getblock %d, blk %ld, buf ", dsk, blkno);
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#endif
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bp = firstbuf;
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lbp = NULL;
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mbp = NULL;
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while (bp != NULL)
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{
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if ((bp->b_flag & BFR_VALID) && (bp->b_unit == dsk)
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&& (getblkno(bp) == blkno))
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{
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/* found it -- rearrange LRU links */
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if (lbp != NULL)
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{
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lbp->b_next = bp->b_next;
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bp->b_next = firstbuf;
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firstbuf = bp;
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}
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#ifdef DISPLAY_GETBLOCK
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printf("HIT]\n");
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#endif
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return (bp);
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}
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else
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{
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if (bp->b_flag & BFR_FAT)
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fat_count++;
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mbp = lbp; /* move along to next buffer */
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lbp = bp;
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bp = bp->b_next;
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}
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}
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/* The block we need is not in a buffer, we must make a buffer */
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/* available, and fill it with the desired block */
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/* detach lru buffer */
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#ifdef DISPLAY_GETBLOCK
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printf("MISS]\n");
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#endif
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/* make sure we keep at least 3 buffers for the FAT. If this is not a */
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/* FAT buffer, or there are at least 3 already, then we can use this */
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/* buffer. */
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/* otherwise, search again, and find the last non-FAT buffer. */
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if ((lbp->b_flag & BFR_FAT) && (fat_count < 3))
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{
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bp = firstbuf;
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lbp = NULL;
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mbp = NULL;
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while ((bp != NULL) && (bp->b_flag & BFR_FAT))
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{
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/* if this is a FAT buffer, then move to the next one, else we found */
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/* the one we want. */
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mbp = lbp; /* move along to next buffer */
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lbp = bp;
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bp = bp->b_next;
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}
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/* if we get to the end of the list here, then we must only have 3 */
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/* buffers, which is not suppose to happen, but if it does, then we */
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/* end up using the last buffer (even though it is FAT). */
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if (bp == NULL)
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{
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/* put lbp at the top of the chain. */
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if (mbp != NULL)
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mbp->b_next = NULL;
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lbp->b_next = firstbuf;
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firstbuf = bp = lbp;
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}
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else if (lbp != NULL)
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{
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lbp->b_next = bp->b_next;
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bp->b_next = firstbuf;
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firstbuf = bp;
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}
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lbp = bp;
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}
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else
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{
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/* put lbp at the top of the chain. */
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if (mbp != NULL)
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mbp->b_next = NULL;
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lbp->b_next = firstbuf;
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firstbuf = lbp;
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}
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/* take the buffer than lbp points to and flush it, then read new block. */
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if (flush1(lbp) && fill(lbp, blkno, dsk)) /* success */
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mbp = lbp;
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else
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mbp = NULL; /* failure */
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return (mbp);
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}
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/*
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Return the address of a buffer structure for the
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requested block. This is for writing new data to a block, so
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we really don't care what is in the buffer now.
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returns:
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TRUE = buffer available, flushed if necessary
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parameter is filled with pointer to buffer
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FALSE = there was an error flushing the buffer.
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parameter is set to NULL
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*/
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BOOL getbuf(struct buffer FAR ** pbp, ULONG blkno, COUNT dsk)
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{
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REG struct buffer FAR *bp;
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REG struct buffer FAR *lbp;
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REG struct buffer FAR *mbp;
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REG BYTE fat_count = 0;
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/* Search through buffers to see if the required block */
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/* is already in a buffer */
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#ifdef DISPLAY_GETBLOCK
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printf("[getbuf %d, blk %ld, buf ", dsk, blkno);
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#endif
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bp = firstbuf;
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lbp = NULL;
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mbp = NULL;
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while (bp != NULL)
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{
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if ((bp->b_flag & BFR_VALID) && (bp->b_unit == dsk)
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&& (getblkno(bp) == blkno))
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{
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/* found it -- rearrange LRU links */
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if (lbp != NULL)
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{
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lbp->b_next = bp->b_next;
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bp->b_next = firstbuf;
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firstbuf = bp;
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}
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*pbp = bp;
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#ifdef DISPLAY_GETBLOCK
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printf("HIT]\n");
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#endif
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return TRUE;
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}
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else
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{
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if (bp->b_flag & BFR_FAT)
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fat_count++;
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mbp = lbp; /* move along to next buffer */
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lbp = bp;
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bp = bp->b_next;
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}
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}
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/* The block we need is not in a buffer, we must make a buffer */
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/* available. */
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#ifdef DISPLAY_GETBLOCK
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printf("MISS]\n");
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#endif
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/* make sure we keep at least 3 buffers for the FAT. If this is not a */
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/* FAT buffer, or there are at least 3 already, then we can use this */
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/* buffer. */
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/* otherwise, search again, and find the last non-FAT buffer. */
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if ((lbp->b_flag & BFR_FAT) && (fat_count < 3))
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{
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bp = firstbuf;
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lbp = NULL;
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mbp = NULL;
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while ((bp != NULL) && (bp->b_flag & BFR_FAT))
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{
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/* if this is a FAT buffer, then move to the next one, else we found */
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/* the one we want. */
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mbp = lbp; /* move along to next buffer */
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lbp = bp;
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bp = bp->b_next;
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}
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/* if we get to the end of the list here, then we must only have 3 */
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/* buffers, which is not suppose to happen, but if it does, then we */
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/* end up using the last buffer (even though it is FAT). */
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if (bp == NULL)
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{
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/* put lbp at the top of the chain. */
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if (mbp != NULL)
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mbp->b_next = NULL;
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lbp->b_next = firstbuf;
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firstbuf = bp = lbp;
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}
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else if (lbp != NULL)
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{
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lbp->b_next = bp->b_next;
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bp->b_next = firstbuf;
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firstbuf = bp;
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}
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lbp = bp;
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}
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else
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{
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/* put lbp at the top of the chain. */
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if (mbp != NULL)
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mbp->b_next = NULL;
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lbp->b_next = firstbuf;
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firstbuf = lbp;
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}
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/* take the buffer than lbp points to and flush it, then make it available. */
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if (flush1(lbp)) /* success */
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{
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lbp->b_flag = 0;
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lbp->b_unit = dsk;
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setblkno(lbp, blkno);
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*pbp = lbp;
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return TRUE;
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}
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else
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/* failure */
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{
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*pbp = NULL;
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return FALSE;
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}
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}
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/* */
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/* Mark all buffers for a disk as not valid */
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/* */
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VOID setinvld(REG COUNT dsk)
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{
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REG struct buffer FAR *bp;
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bp = firstbuf;
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while (bp)
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{
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if (bp->b_unit == dsk)
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bp->b_flag = 0;
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bp = bp->b_next;
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}
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}
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/* */
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/* Flush all buffers for a disk */
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/* */
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/* returns: */
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/* TRUE on success */
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/* */
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BOOL flush_buffers(REG COUNT dsk)
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{
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REG struct buffer FAR *bp;
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REG BOOL ok = TRUE;
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bp = firstbuf;
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while (bp)
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{
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if (bp->b_unit == dsk)
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if (!flush1(bp))
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ok = FALSE;
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bp = bp->b_next;
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}
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return ok;
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}
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/* */
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/* Write one disk buffer */
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/* */
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BOOL flush1(struct buffer FAR * bp)
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{
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/* All lines with changes on 9/4/00 by BER marked below */
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UWORD result; /* BER 9/4/00 */
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if ((bp->b_flag & BFR_VALID) && (bp->b_flag & BFR_DIRTY))
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{
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result = dskxfer(bp->b_unit, getblkno(bp),
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(VOID FAR *) bp->b_buffer, 1, DSKWRITE); /* BER 9/4/00 */
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if (bp->b_flag & BFR_FAT)
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{
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int i = bp->b_copies;
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LONG blkno = getblkno(bp);
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UWORD offset = ((UWORD) bp->b_offset_hi << 8) | bp->b_offset_lo;
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while (--i > 0)
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{
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blkno += offset;
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result = dskxfer(bp->b_unit, blkno,
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(VOID FAR *) bp->b_buffer, 1, DSKWRITE); /* BER 9/4/00 */
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}
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}
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}
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else
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result = TRUE; /* This negates any error code returned in result...BER */
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bp->b_flag &= ~BFR_DIRTY; /* even if error, mark not dirty */
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if (!result) /* otherwise system has trouble */
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bp->b_flag &= ~BFR_VALID; /* continuing. */
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return (TRUE); /* Forced to TRUE...was like this before dskxfer() */
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/* returned error codes...BER */
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}
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/* */
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/* Write all disk buffers */
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/* */
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BOOL flush(void)
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{
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REG struct buffer FAR *bp;
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REG BOOL ok;
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ok = TRUE;
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bp = firstbuf;
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while (bp)
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|
{
|
|
if (!flush1(bp))
|
|
ok = FALSE;
|
|
bp->b_flag &= ~BFR_VALID;
|
|
bp = bp->b_next;
|
|
}
|
|
|
|
int2f_Remote_call(REM_FLUSHALL, 0, 0, 0, 0, 0, 0);
|
|
|
|
return (ok);
|
|
}
|
|
|
|
/* */
|
|
/* Fill the indicated disk buffer with the current track and sector */
|
|
/* */
|
|
/* This function assumes that the buffer is ready for use and that the
|
|
sector is not already in the buffer ring */
|
|
BOOL fill(REG struct buffer FAR * bp, ULONG blkno, COUNT dsk)
|
|
{
|
|
/* Changed 9/4/00 BER */
|
|
UWORD result;
|
|
|
|
result = dskxfer(dsk, blkno, (VOID FAR *) bp->b_buffer, 1, DSKREAD);
|
|
/* End of change */
|
|
bp->b_flag = BFR_VALID | BFR_DATA;
|
|
bp->b_unit = dsk;
|
|
setblkno(bp, blkno);
|
|
|
|
/* Changed 9/4/00 BER */
|
|
if(result==0) return(TRUE); /* Temporary code to convert the result to */
|
|
else return(FALSE); /* the old BOOL result...BER */
|
|
|
|
/* return (result); This is what should eventually be returned */
|
|
/* End of change */
|
|
}
|
|
|
|
/************************************************************************/
|
|
/* */
|
|
/* Device Driver Interface Functions */
|
|
/* */
|
|
/************************************************************************/
|
|
/* */
|
|
/* Transfer one or more blocks to/from disk */
|
|
/* */
|
|
|
|
/* Changed to UWORD 9/4/00 BER */
|
|
UWORD dskxfer(COUNT dsk, ULONG blkno, VOID FAR * buf, UWORD numblocks, COUNT mode)
|
|
/* End of change */
|
|
{
|
|
/* REG struct dpb *dpbp = &blk_devices[dsk]; */
|
|
|
|
REG struct dpb *dpbp = (struct dpb *)CDSp->cds_table[dsk].cdsDpb;
|
|
|
|
for (;;)
|
|
{
|
|
IoReqHdr.r_length = sizeof(request);
|
|
IoReqHdr.r_unit = dpbp->dpb_subunit;
|
|
IoReqHdr.r_command =
|
|
mode == DSKWRITE ?
|
|
(verify_ena ? C_OUTVFY : C_OUTPUT)
|
|
: C_INPUT;
|
|
IoReqHdr.r_status = 0;
|
|
IoReqHdr.r_meddesc = dpbp->dpb_mdb;
|
|
IoReqHdr.r_trans = (BYTE FAR *) buf;
|
|
IoReqHdr.r_count = numblocks;
|
|
if (blkno >= MAXSHORT)
|
|
{
|
|
IoReqHdr.r_start = HUGECOUNT;
|
|
IoReqHdr.r_huge = blkno;
|
|
}
|
|
else
|
|
IoReqHdr.r_start = blkno;
|
|
execrh((request FAR *) & IoReqHdr, dpbp->dpb_device);
|
|
if (!(IoReqHdr.r_status & S_ERROR) && (IoReqHdr.r_status & S_DONE))
|
|
break;
|
|
else
|
|
{
|
|
/* Changed 9/4/00 BER */
|
|
return (IoReqHdr.r_status);
|
|
|
|
/* Skip the abort, retry, fail code...it needs fixed...BER */
|
|
/* End of change */
|
|
|
|
loop:
|
|
switch (block_error(&IoReqHdr, dpbp->dpb_unit, dpbp->dpb_device))
|
|
{
|
|
case ABORT:
|
|
case FAIL:
|
|
return (IoReqHdr.r_status);
|
|
|
|
case RETRY:
|
|
continue;
|
|
|
|
case CONTINUE:
|
|
break;
|
|
|
|
default:
|
|
goto loop;
|
|
}
|
|
}
|
|
}
|
|
/* *** Changed 9/4/00 BER */
|
|
return 0; /* Success! Return 0 for a successful operation. */
|
|
/* End of change */
|
|
|
|
}
|