summaryrefslogtreecommitdiff
path: root/drivers/char/ftape/zftape/zftape-rw.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/ftape/zftape/zftape-rw.c')
-rw-r--r--drivers/char/ftape/zftape/zftape-rw.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/drivers/char/ftape/zftape/zftape-rw.c b/drivers/char/ftape/zftape/zftape-rw.c
new file mode 100644
index 000000000000..a61ef50f3dfc
--- /dev/null
+++ b/drivers/char/ftape/zftape/zftape-rw.c
@@ -0,0 +1,376 @@
+/*
+ * 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/config.h> /* for CONFIG_ZFT_DFLT_BLK_SZ */
+#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;
+}
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-19 10:03:34 +0300