diff options
Diffstat (limited to 'drivers/char/ftape/zftape/zftape-rw.c')
| -rw-r--r-- | drivers/char/ftape/zftape/zftape-rw.c | 377 |
1 files changed, 377 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 000000000..d8ae9f1e7 --- /dev/null +++ b/drivers/char/ftape/zftape/zftape-rw.c @@ -0,0 +1,377 @@ +/* + * 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 <asm/segment.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 = NULL; +__u8 *zft_hseg_buf = NULL; +int zft_deblock_segment = -1; +zft_status_enum zft_io_state = zft_idle; +int zft_header_changed = 0; +int zft_bad_sector_map_changed = 0; +int zft_qic113 = 0; /* conform to old specs. and old zftape */ +int zft_use_compression = 0; +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 = 0; + +unsigned int zft_written_segments = 0; +int zft_label_changed = 0; + +/* 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 = 0; +static __s64 tape_pos = 0; + +__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; +} |