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Diffstat (limited to 'drivers/char/ftape/zftape/zftape-read.c')
-rw-r--r--drivers/char/ftape/zftape/zftape-read.c377
1 files changed, 0 insertions, 377 deletions
diff --git a/drivers/char/ftape/zftape/zftape-read.c b/drivers/char/ftape/zftape/zftape-read.c
deleted file mode 100644
index 214bf03dce6..00000000000
--- a/drivers/char/ftape/zftape/zftape-read.c
+++ /dev/null
@@ -1,377 +0,0 @@
-/*
- * 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-read.c,v $
- * $Revision: 1.2 $
- * $Date: 1997/10/05 19:19:06 $
- *
- * This file contains the high level reading code
- * for the QIC-117 floppy-tape driver for Linux.
- */
-
-#include <linux/errno.h>
-#include <linux/mm.h>
-
-#include <linux/zftape.h>
-
-#include <asm/uaccess.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.
- */
-int zft_just_before_eof;
-
-/* Local vars.
- */
-static int buf_len_rd;
-
-void zft_zap_read_buffers(void)
-{
- buf_len_rd = 0;
-}
-
-int zft_read_header_segments(void)
-{
- TRACE_FUN(ft_t_flow);
-
- zft_header_read = 0;
- TRACE_CATCH(zft_vmalloc_once(&zft_hseg_buf, FT_SEGMENT_SIZE),);
- TRACE_CATCH(ftape_read_header_segment(zft_hseg_buf),);
- TRACE(ft_t_info, "Segments written since first format: %d",
- (int)GET4(zft_hseg_buf, FT_SEG_CNT));
- zft_qic113 = (ft_format_code != fmt_normal &&
- ft_format_code != fmt_1100ft &&
- ft_format_code != fmt_425ft);
- TRACE(ft_t_info, "ft_first_data_segment: %d, ft_last_data_segment: %d",
- ft_first_data_segment, ft_last_data_segment);
- zft_capacity = zft_get_capacity();
- zft_old_ftape = zft_ftape_validate_label(&zft_hseg_buf[FT_LABEL]);
- if (zft_old_ftape) {
- TRACE(ft_t_info,
-"Found old ftaped tape, emulating eof marks, entering read-only mode");
- zft_ftape_extract_file_marks(zft_hseg_buf);
- TRACE_CATCH(zft_fake_volume_headers(zft_eof_map,
- zft_nr_eof_marks),);
- } else {
- /* the specs say that the volume table must be
- * initialized with zeroes during formatting, so it
- * MUST be readable, i.e. contain vaid ECC
- * information.
- */
- TRACE_CATCH(ftape_read_segment(ft_first_data_segment,
- zft_deblock_buf,
- FT_RD_SINGLE),);
- TRACE_CATCH(zft_extract_volume_headers(zft_deblock_buf),);
- }
- zft_header_read = 1;
- zft_set_flags(zft_unit);
- zft_reset_position(&zft_pos);
- TRACE_EXIT 0;
-}
-
-int zft_fetch_segment_fraction(const unsigned int segment, void *buffer,
- const ft_read_mode_t read_mode,
- const unsigned int start,
- const unsigned int size)
-{
- int seg_sz;
- TRACE_FUN(ft_t_flow);
-
- if (segment == zft_deblock_segment) {
- TRACE(ft_t_data_flow,
- "re-using segment %d already in deblock buffer",
- segment);
- seg_sz = zft_get_seg_sz(segment);
- if (start > seg_sz) {
- TRACE_ABORT(-EINVAL, ft_t_bug,
- "trying to read beyond end of segment:\n"
- KERN_INFO "seg_sz : %d\n"
- KERN_INFO "start : %d\n"
- KERN_INFO "segment: %d",
- seg_sz, start, segment);
- }
- if ((start + size) > seg_sz) {
- TRACE_EXIT seg_sz - start;
- }
- TRACE_EXIT size;
- }
- seg_sz = ftape_read_segment_fraction(segment, buffer, read_mode,
- start, size);
- TRACE(ft_t_data_flow, "segment %d, result %d", segment, seg_sz);
- if ((int)seg_sz >= 0 && start == 0 && size == FT_SEGMENT_SIZE) {
- /* this implicitly assumes that we are always called with
- * buffer == zft_deblock_buf
- */
- zft_deblock_segment = segment;
- } else {
- zft_deblock_segment = -1;
- }
- TRACE_EXIT seg_sz;
-}
-
-/*
- * out:
- *
- * int *read_cnt: the number of bytes we removed from the
- * zft_deblock_buf (result)
- *
- * int *to_do : the remaining size of the read-request. Is changed.
- *
- * in:
- *
- * char *buff : buff is the address of the upper part of the user
- * buffer, that hasn't been filled with data yet.
- * int buf_pos_read: copy of buf_pos_rd
- * int buf_len_read: copy of buf_len_rd
- * char *zft_deblock_buf: ftape_zft_deblock_buf
- *
- * returns the amount of data actually copied to the user-buffer
- *
- * to_do MUST NOT SHRINK except to indicate an EOT. In this case to_do
- * has to be set to 0. We cannot return -ENOSPC, because we return the
- * amount of data actually * copied to the user-buffer
- */
-static int zft_simple_read (int *read_cnt,
- __u8 __user *dst_buf,
- const int to_do,
- const __u8 *src_buf,
- const int seg_sz,
- const zft_position *pos,
- const zft_volinfo *volume)
-{
- TRACE_FUN(ft_t_flow);
-
- if (seg_sz - pos->seg_byte_pos < to_do) {
- *read_cnt = seg_sz - pos->seg_byte_pos;
- } else {
- *read_cnt = to_do;
- }
- if (copy_to_user(dst_buf,
- src_buf + pos->seg_byte_pos, *read_cnt) != 0) {
- TRACE_EXIT -EFAULT;
- }
- TRACE(ft_t_noise, "nr bytes just read: %d", *read_cnt);
- TRACE_EXIT *read_cnt;
-}
-
-/* req_len: gets clipped due to EOT of EOF.
- * req_clipped: is a flag indicating whether req_len was clipped or not
- * volume: contains information on current volume (blk_sz etc.)
- */
-static int check_read_access(int *req_len,
- const zft_volinfo **volume,
- int *req_clipped,
- const zft_position *pos)
-{
- static __s64 remaining;
- static int eod;
- TRACE_FUN(ft_t_flow);
-
- if (zft_io_state != zft_reading) {
- if (zft_offline) { /* offline includes no_tape */
- TRACE_ABORT(-ENXIO, ft_t_warn,
- "tape is offline or no cartridge");
- }
- if (!ft_formatted) {
- TRACE_ABORT(-EACCES,
- ft_t_warn, "tape is not formatted");
- }
- /* now enter defined state, read header segment if not
- * already done and flush write buffers
- */
- TRACE_CATCH(zft_def_idle_state(),);
- zft_io_state = zft_reading;
- if (zft_tape_at_eod(pos)) {
- eod = 1;
- TRACE_EXIT 1;
- }
- eod = 0;
- *volume = zft_find_volume(pos->seg_pos);
- /* get the space left until EOF */
- remaining = zft_check_for_eof(*volume, pos);
- buf_len_rd = 0;
- TRACE(ft_t_noise, "remaining: " LL_X ", vol_no: %d",
- LL(remaining), (*volume)->count);
- } else if (zft_tape_at_eod(pos)) {
- if (++eod > 2) {
- TRACE_EXIT -EIO; /* st.c also returns -EIO */
- } else {
- TRACE_EXIT 1;
- }
- }
- if ((*req_len % (*volume)->blk_sz) != 0) {
- /* this message is informational only. The user gets the
- * proper return value
- */
- TRACE_ABORT(-EINVAL, ft_t_info,
- "req_len %d not a multiple of block size %d",
- *req_len, (*volume)->blk_sz);
- }
- /* As GNU tar doesn't accept partial read counts when the
- * multiple volume flag is set, we make sure to return the
- * requested amount of data. Except, of course, at the end of
- * the tape or file mark.
- */
- remaining -= *req_len;
- if (remaining <= 0) {
- TRACE(ft_t_noise,
- "clipped request from %d to %d.",
- *req_len, (int)(*req_len + remaining));
- *req_len += remaining;
- *req_clipped = 1;
- } else {
- *req_clipped = 0;
- }
- TRACE_EXIT 0;
-}
-
-/* this_segs_size: the current segment's size.
- * buff: the USER-SPACE buffer provided by the calling function.
- * req_len: how much data should be read at most.
- * volume: contains information on current volume (blk_sz etc.)
- */
-static int empty_deblock_buf(__u8 __user *usr_buf, const int req_len,
- const __u8 *src_buf, const int seg_sz,
- zft_position *pos,
- const zft_volinfo *volume)
-{
- int cnt;
- int result = 0;
- TRACE_FUN(ft_t_flow);
-
- TRACE(ft_t_data_flow, "this_segs_size: %d", seg_sz);
- if (zft_use_compression && volume->use_compression) {
- TRACE_CATCH(zft_cmpr_lock(1 /* try to load */),);
- TRACE_CATCH(result= (*zft_cmpr_ops->read)(&cnt,
- usr_buf, req_len,
- src_buf, seg_sz,
- pos, volume),);
- } else {
- TRACE_CATCH(result= zft_simple_read (&cnt,
- usr_buf, req_len,
- src_buf, seg_sz,
- pos, volume),);
- }
- pos->volume_pos += result;
- pos->tape_pos += cnt;
- pos->seg_byte_pos += cnt;
- buf_len_rd -= cnt; /* remaining bytes in buffer */
- TRACE(ft_t_data_flow, "buf_len_rd: %d, cnt: %d", buf_len_rd, cnt);
- if(pos->seg_byte_pos >= seg_sz) {
- pos->seg_pos++;
- pos->seg_byte_pos = 0;
- }
- TRACE(ft_t_data_flow, "bytes moved out of deblock-buffer: %d", cnt);
- TRACE_EXIT result;
-}
-
-
-/* note: we store the segment id of the segment that is inside the
- * deblock buffer. This spares a lot of ftape_read_segment()s when we
- * use small block-sizes. The block-size may be 1kb (SECTOR_SIZE). In
- * this case a MTFSR 28 maybe still inside the same segment.
- */
-int _zft_read(char __user *buff, int req_len)
-{
- int req_clipped;
- int result = 0;
- int bytes_read = 0;
- static unsigned int seg_sz = 0;
- static const zft_volinfo *volume = NULL;
- TRACE_FUN(ft_t_flow);
-
- zft_resid = req_len;
- result = check_read_access(&req_len, &volume,
- &req_clipped, &zft_pos);
- switch(result) {
- case 0:
- break; /* nothing special */
- case 1:
- TRACE(ft_t_noise, "EOD reached");
- TRACE_EXIT 0; /* EOD */
- default:
- TRACE_ABORT(result, ft_t_noise,
- "check_read_access() failed with result %d",
- result);
- TRACE_EXIT result;
- }
- while (req_len > 0) {
- /* Allow escape from this loop on signal !
- */
- FT_SIGNAL_EXIT(_DONT_BLOCK);
- /* buf_len_rd == 0 means that we need to read a new
- * segment.
- */
- if (buf_len_rd == 0) {
- while((result = zft_fetch_segment(zft_pos.seg_pos,
- zft_deblock_buf,
- FT_RD_AHEAD)) == 0) {
- zft_pos.seg_pos ++;
- zft_pos.seg_byte_pos = 0;
- }
- if (result < 0) {
- zft_resid -= bytes_read;
- TRACE_ABORT(result, ft_t_noise,
- "zft_fetch_segment(): %d",
- result);
- }
- seg_sz = result;
- buf_len_rd = seg_sz - zft_pos.seg_byte_pos;
- }
- TRACE_CATCH(result = empty_deblock_buf(buff,
- req_len,
- zft_deblock_buf,
- seg_sz,
- &zft_pos,
- volume),
- zft_resid -= bytes_read);
- TRACE(ft_t_data_flow, "bytes just read: %d", result);
- bytes_read += result; /* what we got so far */
- buff += result; /* index in user-buffer */
- req_len -= result; /* what's left from req_len */
- } /* while (req_len > 0) */
- if (req_clipped) {
- TRACE(ft_t_data_flow,
- "maybe partial count because of eof mark");
- if (zft_just_before_eof && bytes_read == 0) {
- /* req_len was > 0, but user didn't get
- * anything the user has read in the eof-mark
- */
- zft_move_past_eof(&zft_pos);
- ftape_abort_operation();
- } else {
- /* don't skip to the next file before the user
- * tried to read a second time past EOF Just
- * mark that we are at EOF and maybe decrement
- * zft_seg_pos to stay in the same volume;
- */
- zft_just_before_eof = 1;
- zft_position_before_eof(&zft_pos, volume);
- TRACE(ft_t_noise, "just before eof");
- }
- }
- zft_resid -= result; /* for MTSTATUS */
- TRACE_EXIT bytes_read;
-}