/*
* Copyright (C) 1996, 1997 Claus-Justus Heine
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, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-rw.c,v $
* $Revision: 1.2 $
* $Date: 1997/10/05 19:19:08 $
*
* This file contains some common code for the r/w code for
* zftape.
*/
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/zftape.h>
#include "../zftape/zftape-init.h"
#include "../zftape/zftape-eof.h"
#include "../zftape/zftape-ctl.h"
#include "../zftape/zftape-write.h"
#include "../zftape/zftape-read.h"
#include "../zftape/zftape-rw.h"
#include "../zftape/zftape-vtbl.h"
/* Global vars.
*/
__u8 *zft_deblock_buf;
__u8 *zft_hseg_buf;
int zft_deblock_segment = -1;
zft_status_enum zft_io_state = zft_idle;
int zft_header_changed;
int zft_qic113; /* conform to old specs. and old zftape */
int zft_use_compression;
zft_position zft_pos = {
-1, /* seg_pos */
0, /* seg_byte_pos */
0, /* tape_pos */
0 /* volume_pos */
};
unsigned int zft_blk_sz = CONFIG_ZFT_DFLT_BLK_SZ;
__s64 zft_capacity;
unsigned int zft_written_segments;
int zft_label_changed;
/* Local vars.
*/
unsigned int zft_get_seg_sz(unsigned int segment)
{
int size;
TRACE_FUN(ft_t_any);
size = FT_SEGMENT_SIZE -
count_ones(ftape_get_bad_sector_entry(segment))*FT_SECTOR_SIZE;
if (size > 0) {
TRACE_EXIT (unsigned)size;
} else {
TRACE_EXIT 0;
}
}
/* ftape_set_flags(). Claus-Justus Heine, 1994/1995
*/
void zft_set_flags(unsigned minor_unit)
{
TRACE_FUN(ft_t_flow);
zft_use_compression = zft_qic_mode = 0;
switch (minor_unit & ZFT_MINOR_OP_MASK) {
case (ZFT_Q80_MODE | ZFT_ZIP_MODE):
case ZFT_ZIP_MODE:
zft_use_compression = 1;
case 0:
case ZFT_Q80_MODE:
zft_qic_mode = 1;
if (zft_mt_compression) { /* override the default */
zft_use_compression = 1;
}
break;
case ZFT_RAW_MODE:
TRACE(ft_t_noise, "switching to raw mode");
break;
default:
TRACE(ft_t_warn, "Warning:\n"
KERN_INFO "Wrong combination of minor device bits.\n"
KERN_INFO "Switching to raw read-only mode.");
zft_write_protected = 1;
break;
}
TRACE_EXIT;
}
/* computes the segment and byte offset inside the segment
* corresponding to tape_pos.
*
* tape_pos gives the offset in bytes from the beginning of the
* ft_first_data_segment *seg_byte_pos is the offset in the current
* segment in bytes
*
* Of, if this routine was called often one should cache the last data
* pos it was called with, but actually this is only needed in
* ftape_seek_block(), that is, almost never.
*/
int zft_calc_seg_byte_coord(int *seg_byte_pos, __s64 tape_pos)
{
int segment;
int seg_sz;
TRACE_FUN(ft_t_flow);
if (tape_pos == 0) {
*seg_byte_pos = 0;
segment = ft_first_data_segment;
} else {
seg_sz = 0;
for (segment = ft_first_data_segment;
((tape_pos > 0) && (segment <= ft_last_data_segment));
segment++) {
seg_sz = zft_get_seg_sz(segment);
tape_pos -= seg_sz;
}
if(tape_pos >= 0) {
/* the case tape_pos > != 0 means that the
* argument tape_pos lies beyond the EOT.
*/
*seg_byte_pos= 0;
} else { /* tape_pos < 0 */
segment--;
*seg_byte_pos= tape_pos + seg_sz;
}
}
TRACE_EXIT(segment);
}
/* ftape_calc_tape_pos().
*
* computes the offset in bytes from the beginning of the
* ft_first_data_segment inverse to ftape_calc_seg_byte_coord
*
* We should do some caching. But how:
*
* Each time the header segments are read in, this routine is called
* with ft_tracks_per_tape*segments_per_track argumnet. So this should be
* the time to reset the cache.
*
* Also, it might be in the future that the bad sector map gets
* changed. -> reset the cache
*/
static int seg_pos;
static __s64 tape_pos;
__s64 zft_get_capacity(void)
{
seg_pos = ft_first_data_segment;
tape_pos = 0;
while (seg_pos <= ft_last_data_segment) {
tape_pos += zft_get_seg_sz(seg_pos ++);
}
return tape_pos;
}
__s64 zft_calc_tape_pos(int segment)
{
int d1, d2, d3;
TRACE_FUN(ft_t_any);
if (segment > ft_last_data_segment) {
TRACE_EXIT zft_capacity;
}
if (segment < ft_first_data_segment) {
TRACE_EXIT 0;
}
d2 = segment - seg_pos;
if (-d2 > 10) {
d1 = segment - ft_first_data_segment;
if (-d2 > d1) {
tape_pos = 0;
seg_pos = ft_first_data_segment;
d2 = d1;
}
}
if (d2 > 10) {
d3 = ft_last_data_segment - segment;
if (d2 > d3) {
tape_pos = zft_capacity;
seg_pos = ft_last_data_segment + 1;
d2 = -d3;
}
}
if (d2 > 0) {
while (seg_pos < segment) {
tape_pos += zft_get_seg_sz(seg_pos++);
}
} else {
while (seg_pos > segment) {
tape_pos -= zft_get_seg_sz(--seg_pos);
}
}
TRACE(ft_t_noise, "new cached pos: %d", seg_pos);
TRACE_EXIT tape_pos;
}
/* copy Z-label string to buffer, keeps track of the correct offset in
* `buffer'
*/
void zft_update_label(__u8 *buffer)
{
TRACE_FUN(ft_t_flow);
if (strncmp(&buffer[FT_LABEL], ZFTAPE_LABEL,
sizeof(ZFTAPE_LABEL)-1) != 0) {
TRACE(ft_t_info, "updating label from \"%s\" to \"%s\"",
&buffer[FT_LABEL], ZFTAPE_LABEL);
strcpy(&buffer[FT_LABEL], ZFTAPE_LABEL);
memset(&buffer[FT_LABEL] + sizeof(ZFTAPE_LABEL) - 1, ' ',
FT_LABEL_SZ - sizeof(ZFTAPE_LABEL + 1));
PUT4(buffer, FT_LABEL_DATE, 0);
zft_label_changed = zft_header_changed = 1; /* changed */
}
TRACE_EXIT;
}
int zft_verify_write_segments(unsigned int segment,
__u8 *data, size_t size,
__u8 *buffer)
{
int result;
__u8 *write_buf;
__u8 *src_buf;
int single;
int seg_pos;
int seg_sz;
int remaining;
ft_write_mode_t write_mode;
TRACE_FUN(ft_t_flow);
seg_pos = segment;
seg_sz = zft_get_seg_sz(seg_pos);
src_buf = data;
single = size <= seg_sz;
remaining = size;
do {
TRACE(ft_t_noise, "\n"
KERN_INFO "remaining: %d\n"
KERN_INFO "seg_sz : %d\n"
KERN_INFO "segment : %d",
remaining, seg_sz, seg_pos);
if (remaining == seg_sz) {
write_buf = src_buf;
write_mode = single ? FT_WR_SINGLE : FT_WR_MULTI;
remaining = 0;
} else if (remaining > seg_sz) {
write_buf = src_buf;
write_mode = FT_WR_ASYNC; /* don't start tape */
remaining -= seg_sz;
} else { /* remaining < seg_sz */
write_buf = buffer;
memcpy(write_buf, src_buf, remaining);
memset(&write_buf[remaining],'\0',seg_sz-remaining);
write_mode = single ? FT_WR_SINGLE : FT_WR_MULTI;
remaining = 0;
}
if ((result = ftape_write_segment(seg_pos,
write_buf,
write_mode)) != seg_sz) {
TRACE(ft_t_err, "Error: "
"Couldn't write segment %d", seg_pos);
TRACE_EXIT result < 0 ? result : -EIO; /* bail out */
}
zft_written_segments ++;
seg_sz = zft_get_seg_sz(++seg_pos);
src_buf += result;
} while (remaining > 0);
if (ftape_get_status()->fti_state == writing) {
TRACE_CATCH(ftape_loop_until_writes_done(),);
TRACE_CATCH(ftape_abort_operation(),);
zft_prevent_flush();
}
seg_pos = segment;
src_buf = data;
remaining = size;
do {
TRACE_CATCH(result = ftape_read_segment(seg_pos, buffer,
single ? FT_RD_SINGLE
: FT_RD_AHEAD),);
if (memcmp(src_buf, buffer,
remaining > result ? result : remaining) != 0) {
TRACE_ABORT(-EIO, ft_t_err,
"Failed to verify written segment %d",
seg_pos);
}
remaining -= result;
TRACE(ft_t_noise, "verify successful:\n"
KERN_INFO "segment : %d\n"
KERN_INFO "segsize : %d\n"
KERN_INFO "remaining: %d",
seg_pos, result, remaining);
src_buf += seg_sz;
seg_pos++;
} while (remaining > 0);
TRACE_EXIT size;
}
/* zft_erase(). implemented compression-handling
*
* calculate the first data-segment when using/not using compression.
*
* update header-segment and compression-map-segment.
*/
int zft_erase(void)
{
int result = 0;
TRACE_FUN(ft_t_flow);
if (!zft_header_read) {
TRACE_CATCH(zft_vmalloc_once((void **)&zft_hseg_buf,
FT_SEGMENT_SIZE),);
/* no need to read the vtbl and compression map */
TRACE_CATCH(ftape_read_header_segment(zft_hseg_buf),);
if ((zft_old_ftape =
zft_ftape_validate_label(&zft_hseg_buf[FT_LABEL]))) {
zft_ftape_extract_file_marks(zft_hseg_buf);
}
TRACE(ft_t_noise,
"ft_first_data_segment: %d, ft_last_data_segment: %d",
ft_first_data_segment, ft_last_data_segment);
zft_qic113 = (ft_format_code != fmt_normal &&
ft_format_code != fmt_1100ft &&
ft_format_code != fmt_425ft);
}
if (zft_old_ftape) {
zft_clear_ftape_file_marks();
zft_old_ftape = 0; /* no longer old ftape */
}
PUT2(zft_hseg_buf, FT_CMAP_START, 0);
zft_volume_table_changed = 1;
zft_capacity = zft_get_capacity();
zft_init_vtbl();
/* the rest must be done in ftape_update_header_segments
*/
zft_header_read = 1;
zft_header_changed = 1; /* force update of timestamp */
result = zft_update_header_segments();
ftape_abort_operation();
zft_reset_position(&zft_pos);
zft_set_flags (zft_unit);
TRACE_EXIT result;
}
unsigned int zft_get_time(void)
{
unsigned int date = FT_TIME_STAMP(2097, 11, 30, 23, 59, 59); /* fun */
return date;
}
