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-rw-r--r--drivers/char/ftape/zftape/zftape-write.c483
1 files changed, 483 insertions, 0 deletions
diff --git a/drivers/char/ftape/zftape/zftape-write.c b/drivers/char/ftape/zftape/zftape-write.c
new file mode 100644
index 000000000000..94327b8c97b9
--- /dev/null
+++ b/drivers/char/ftape/zftape/zftape-write.c
@@ -0,0 +1,483 @@
+/*
+ * Copyright (C) 1996, 1997 Claus 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-write.c,v $
+ * $Revision: 1.3 $
+ * $Date: 1997/11/06 00:50:29 $
+ *
+ * This file contains the writing 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.
+ */
+
+/* Local vars.
+ */
+static int last_write_failed;
+static int need_flush;
+
+void zft_prevent_flush(void)
+{
+ need_flush = 0;
+}
+
+static int zft_write_header_segments(__u8* buffer)
+{
+ int header_1_ok = 0;
+ int header_2_ok = 0;
+ unsigned int time_stamp;
+ TRACE_FUN(ft_t_noise);
+
+ TRACE_CATCH(ftape_abort_operation(),);
+ ftape_seek_to_bot(); /* prevents extra rewind */
+ if (GET4(buffer, 0) != FT_HSEG_MAGIC) {
+ TRACE_ABORT(-EIO, ft_t_err,
+ "wrong header signature found, aborting");
+ }
+ /* Be optimistic: */
+ PUT4(buffer, FT_SEG_CNT,
+ zft_written_segments + GET4(buffer, FT_SEG_CNT) + 2);
+ if ((time_stamp = zft_get_time()) != 0) {
+ PUT4(buffer, FT_WR_DATE, time_stamp);
+ if (zft_label_changed) {
+ PUT4(buffer, FT_LABEL_DATE, time_stamp);
+ }
+ }
+ TRACE(ft_t_noise,
+ "writing first header segment %d", ft_header_segment_1);
+ header_1_ok = zft_verify_write_segments(ft_header_segment_1,
+ buffer, FT_SEGMENT_SIZE,
+ zft_deblock_buf) >= 0;
+ TRACE(ft_t_noise,
+ "writing second header segment %d", ft_header_segment_2);
+ header_2_ok = zft_verify_write_segments(ft_header_segment_2,
+ buffer, FT_SEGMENT_SIZE,
+ zft_deblock_buf) >= 0;
+ if (!header_1_ok) {
+ TRACE(ft_t_warn, "Warning: "
+ "update of first header segment failed");
+ }
+ if (!header_2_ok) {
+ TRACE(ft_t_warn, "Warning: "
+ "update of second header segment failed");
+ }
+ if (!header_1_ok && !header_2_ok) {
+ TRACE_ABORT(-EIO, ft_t_err, "Error: "
+ "update of both header segments failed.");
+ }
+ TRACE_EXIT 0;
+}
+
+int zft_update_header_segments(void)
+{
+ TRACE_FUN(ft_t_noise);
+
+ /* must NOT use zft_write_protected, as it also includes the
+ * file access mode. But we also want to update when soft
+ * write protection is enabled (O_RDONLY)
+ */
+ if (ft_write_protected || zft_old_ftape) {
+ TRACE_ABORT(0, ft_t_noise, "Tape set read-only: no update");
+ }
+ if (!zft_header_read) {
+ TRACE_ABORT(0, ft_t_noise, "Nothing to update");
+ }
+ if (!zft_header_changed) {
+ zft_header_changed = zft_written_segments > 0;
+ }
+ if (!zft_header_changed && !zft_volume_table_changed) {
+ TRACE_ABORT(0, ft_t_noise, "Nothing to update");
+ }
+ TRACE(ft_t_noise, "Updating header segments");
+ if (ftape_get_status()->fti_state == writing) {
+ TRACE_CATCH(ftape_loop_until_writes_done(),);
+ }
+ TRACE_CATCH(ftape_abort_operation(),);
+
+ zft_deblock_segment = -1; /* invalidate the cache */
+ if (zft_header_changed) {
+ TRACE_CATCH(zft_write_header_segments(zft_hseg_buf),);
+ }
+ if (zft_volume_table_changed) {
+ TRACE_CATCH(zft_update_volume_table(ft_first_data_segment),);
+ }
+ zft_header_changed =
+ zft_volume_table_changed =
+ zft_label_changed =
+ zft_written_segments = 0;
+ TRACE_CATCH(ftape_abort_operation(),);
+ ftape_seek_to_bot();
+ TRACE_EXIT 0;
+}
+
+static int read_merge_buffer(int seg_pos, __u8 *buffer, int offset, int seg_sz)
+{
+ int result = 0;
+ const ft_trace_t old_tracing = TRACE_LEVEL;
+ TRACE_FUN(ft_t_flow);
+
+ if (zft_qic_mode) {
+ /* writing in the middle of a volume is NOT allowed
+ *
+ */
+ TRACE(ft_t_noise, "No need to read a segment");
+ memset(buffer + offset, 0, seg_sz - offset);
+ TRACE_EXIT 0;
+ }
+ TRACE(ft_t_any, "waiting");
+ ftape_start_writing(FT_WR_MULTI);
+ TRACE_CATCH(ftape_loop_until_writes_done(),);
+
+ TRACE(ft_t_noise, "trying to read segment %d from offset %d",
+ seg_pos, offset);
+ SET_TRACE_LEVEL(ft_t_bug);
+ result = zft_fetch_segment_fraction(seg_pos, buffer,
+ FT_RD_SINGLE,
+ offset, seg_sz - offset);
+ SET_TRACE_LEVEL(old_tracing);
+ if (result != (seg_sz - offset)) {
+ TRACE(ft_t_noise, "Ignore error: read_segment() result: %d",
+ result);
+ memset(buffer + offset, 0, seg_sz - offset);
+ }
+ TRACE_EXIT 0;
+}
+
+/* flush the write buffer to tape and write an eof-marker at the
+ * current position if not in raw mode. This function always
+ * positions the tape before the eof-marker. _ftape_close() should
+ * then advance to the next segment.
+ *
+ * the parameter "finish_volume" describes whether to position before
+ * or after the possibly created file-mark. We always position after
+ * the file-mark when called from ftape_close() and a flush was needed
+ * (that is ftape_write() was the last tape operation before calling
+ * ftape_flush) But we always position before the file-mark when this
+ * function get's called from outside ftape_close()
+ */
+int zft_flush_buffers(void)
+{
+ int result;
+ int data_remaining;
+ int this_segs_size;
+ TRACE_FUN(ft_t_flow);
+
+ TRACE(ft_t_data_flow,
+ "entered, ftape_state = %d", ftape_get_status()->fti_state);
+ if (ftape_get_status()->fti_state != writing && !need_flush) {
+ TRACE_ABORT(0, ft_t_noise, "no need for flush");
+ }
+ zft_io_state = zft_idle; /* triggers some initializations for the
+ * read and write routines
+ */
+ if (last_write_failed) {
+ ftape_abort_operation();
+ TRACE_EXIT -EIO;
+ }
+ TRACE(ft_t_noise, "flushing write buffers");
+ this_segs_size = zft_get_seg_sz(zft_pos.seg_pos);
+ if (this_segs_size == zft_pos.seg_byte_pos) {
+ zft_pos.seg_pos ++;
+ data_remaining = zft_pos.seg_byte_pos = 0;
+ } else {
+ data_remaining = zft_pos.seg_byte_pos;
+ }
+ /* If there is any data not written to tape yet, append zero's
+ * up to the end of the sector (if using compression) or merge
+ * it with the data existing on the tape Then write the
+ * segment(s) to tape.
+ */
+ TRACE(ft_t_noise, "Position:\n"
+ KERN_INFO "seg_pos : %d\n"
+ KERN_INFO "byte pos : %d\n"
+ KERN_INFO "remaining: %d",
+ zft_pos.seg_pos, zft_pos.seg_byte_pos, data_remaining);
+ if (data_remaining > 0) {
+ do {
+ this_segs_size = zft_get_seg_sz(zft_pos.seg_pos);
+ if (this_segs_size > data_remaining) {
+ TRACE_CATCH(read_merge_buffer(zft_pos.seg_pos,
+ zft_deblock_buf,
+ data_remaining,
+ this_segs_size),
+ last_write_failed = 1);
+ }
+ result = ftape_write_segment(zft_pos.seg_pos,
+ zft_deblock_buf,
+ FT_WR_MULTI);
+ if (result != this_segs_size) {
+ TRACE(ft_t_err, "flush buffers failed");
+ zft_pos.tape_pos -= zft_pos.seg_byte_pos;
+ zft_pos.seg_byte_pos = 0;
+
+ last_write_failed = 1;
+ TRACE_EXIT result;
+ }
+ zft_written_segments ++;
+ TRACE(ft_t_data_flow,
+ "flush, moved out buffer: %d", result);
+ /* need next segment for more data (empty segments?)
+ */
+ if (result < data_remaining) {
+ if (result > 0) {
+ /* move remainder to buffer beginning
+ */
+ memmove(zft_deblock_buf,
+ zft_deblock_buf + result,
+ FT_SEGMENT_SIZE - result);
+ }
+ }
+ data_remaining -= result;
+ zft_pos.seg_pos ++;
+ } while (data_remaining > 0);
+ TRACE(ft_t_any, "result: %d", result);
+ zft_deblock_segment = --zft_pos.seg_pos;
+ if (data_remaining == 0) { /* first byte next segment */
+ zft_pos.seg_byte_pos = this_segs_size;
+ } else { /* after data previous segment, data_remaining < 0 */
+ zft_pos.seg_byte_pos = data_remaining + result;
+ }
+ } else {
+ TRACE(ft_t_noise, "zft_deblock_buf empty");
+ zft_pos.seg_pos --;
+ zft_pos.seg_byte_pos = zft_get_seg_sz (zft_pos.seg_pos);
+ ftape_start_writing(FT_WR_MULTI);
+ }
+ TRACE(ft_t_any, "waiting");
+ if ((result = ftape_loop_until_writes_done()) < 0) {
+ /* that's really bad. What to to with zft_tape_pos?
+ */
+ TRACE(ft_t_err, "flush buffers failed");
+ }
+ TRACE(ft_t_any, "zft_seg_pos: %d, zft_seg_byte_pos: %d",
+ zft_pos.seg_pos, zft_pos.seg_byte_pos);
+ last_write_failed =
+ need_flush = 0;
+ TRACE_EXIT result;
+}
+
+/* return-value: the number of bytes removed from the user-buffer
+ *
+ * out:
+ * int *write_cnt: how much actually has been moved to the
+ * zft_deblock_buf
+ * int req_len : MUST NOT BE CHANGED, except at EOT, in
+ * which case it may be adjusted
+ * in :
+ * char *buff : the user buffer
+ * int buf_pos_write : copy of buf_len_wr int
+ * this_segs_size : the size in bytes of the actual segment
+ * char
+ * *zft_deblock_buf : zft_deblock_buf
+ */
+static int zft_simple_write(int *cnt,
+ __u8 *dst_buf, const int seg_sz,
+ const __u8 __user *src_buf, const int req_len,
+ const zft_position *pos,const zft_volinfo *volume)
+{
+ int space_left;
+ TRACE_FUN(ft_t_flow);
+
+ /* volume->size holds the tape capacity while volume is open */
+ if (pos->tape_pos + volume->blk_sz > volume->size) {
+ TRACE_EXIT -ENOSPC;
+ }
+ /* remaining space in this segment, NOT zft_deblock_buf
+ */
+ space_left = seg_sz - pos->seg_byte_pos;
+ *cnt = req_len < space_left ? req_len : space_left;
+ if (copy_from_user(dst_buf + pos->seg_byte_pos, src_buf, *cnt) != 0) {
+ TRACE_EXIT -EFAULT;
+ }
+ TRACE_EXIT *cnt;
+}
+
+static int check_write_access(int req_len,
+ const zft_volinfo **volume,
+ zft_position *pos,
+ const unsigned int blk_sz)
+{
+ int result;
+ TRACE_FUN(ft_t_flow);
+
+ if ((req_len % zft_blk_sz) != 0) {
+ TRACE_ABORT(-EINVAL, ft_t_info,
+ "write-count %d must be multiple of block-size %d",
+ req_len, blk_sz);
+ }
+ if (zft_io_state == zft_writing) {
+ /* all other error conditions have been checked earlier
+ */
+ TRACE_EXIT 0;
+ }
+ zft_io_state = zft_idle;
+ TRACE_CATCH(zft_check_write_access(pos),);
+ /* If we haven't read the header segment yet, do it now.
+ * This will verify the configuration, get the bad sector
+ * table and read the volume table segment
+ */
+ if (!zft_header_read) {
+ TRACE_CATCH(zft_read_header_segments(),);
+ }
+ /* fine. Now the tape is either at BOT or at EOD,
+ * Write start of volume now
+ */
+ TRACE_CATCH(zft_open_volume(pos, blk_sz, zft_use_compression),);
+ *volume = zft_find_volume(pos->seg_pos);
+ DUMP_VOLINFO(ft_t_noise, "", *volume);
+ zft_just_before_eof = 0;
+ /* now merge with old data if necessary */
+ if (!zft_qic_mode && pos->seg_byte_pos != 0){
+ result = zft_fetch_segment(pos->seg_pos,
+ zft_deblock_buf,
+ FT_RD_SINGLE);
+ if (result < 0) {
+ if (result == -EINTR || result == -ENOSPC) {
+ TRACE_EXIT result;
+ }
+ TRACE(ft_t_noise,
+ "ftape_read_segment() result: %d. "
+ "This might be normal when using "
+ "a newly\nformatted tape", result);
+ memset(zft_deblock_buf, '\0', pos->seg_byte_pos);
+ }
+ }
+ zft_io_state = zft_writing;
+ TRACE_EXIT 0;
+}
+
+static int fill_deblock_buf(__u8 *dst_buf, const int seg_sz,
+ zft_position *pos, const zft_volinfo *volume,
+ const char __user *usr_buf, const int req_len)
+{
+ int cnt = 0;
+ int result = 0;
+ TRACE_FUN(ft_t_flow);
+
+ if (seg_sz == 0) {
+ TRACE_ABORT(0, ft_t_data_flow, "empty segment");
+ }
+ TRACE(ft_t_data_flow, "\n"
+ KERN_INFO "remaining req_len: %d\n"
+ KERN_INFO " buf_pos: %d",
+ req_len, pos->seg_byte_pos);
+ /* zft_deblock_buf will not contain a valid segment any longer */
+ zft_deblock_segment = -1;
+ if (zft_use_compression) {
+ TRACE_CATCH(zft_cmpr_lock(1 /* try to load */),);
+ TRACE_CATCH(result= (*zft_cmpr_ops->write)(&cnt,
+ dst_buf, seg_sz,
+ usr_buf, req_len,
+ pos, volume),);
+ } else {
+ TRACE_CATCH(result= zft_simple_write(&cnt,
+ dst_buf, seg_sz,
+ usr_buf, req_len,
+ pos, volume),);
+ }
+ pos->volume_pos += result;
+ pos->seg_byte_pos += cnt;
+ pos->tape_pos += cnt;
+ TRACE(ft_t_data_flow, "\n"
+ KERN_INFO "removed from user-buffer : %d bytes.\n"
+ KERN_INFO "copied to zft_deblock_buf: %d bytes.\n"
+ KERN_INFO "zft_tape_pos : " LL_X " bytes.",
+ result, cnt, LL(pos->tape_pos));
+ TRACE_EXIT result;
+}
+
+
+/* called by the kernel-interface routine "zft_write()"
+ */
+int _zft_write(const char __user *buff, int req_len)
+{
+ int result = 0;
+ int written = 0;
+ int write_cnt;
+ int seg_sz;
+ static const zft_volinfo *volume = NULL;
+ TRACE_FUN(ft_t_flow);
+
+ zft_resid = req_len;
+ last_write_failed = 1; /* reset to 0 when successful */
+ /* check if write is allowed
+ */
+ TRACE_CATCH(check_write_access(req_len, &volume,&zft_pos,zft_blk_sz),);
+ while (req_len > 0) {
+ /* Allow us to escape from this loop with a signal !
+ */
+ FT_SIGNAL_EXIT(_DONT_BLOCK);
+ seg_sz = zft_get_seg_sz(zft_pos.seg_pos);
+ if ((write_cnt = fill_deblock_buf(zft_deblock_buf,
+ seg_sz,
+ &zft_pos,
+ volume,
+ buff,
+ req_len)) < 0) {
+ zft_resid -= written;
+ if (write_cnt == -ENOSPC) {
+ /* leave the remainder to flush_buffers()
+ */
+ TRACE(ft_t_info, "No space left on device");
+ last_write_failed = 0;
+ if (!need_flush) {
+ need_flush = written > 0;
+ }
+ TRACE_EXIT written > 0 ? written : -ENOSPC;
+ } else {
+ TRACE_EXIT result;
+ }
+ }
+ if (zft_pos.seg_byte_pos == seg_sz) {
+ TRACE_CATCH(ftape_write_segment(zft_pos.seg_pos,
+ zft_deblock_buf,
+ FT_WR_ASYNC),
+ zft_resid -= written);
+ zft_written_segments ++;
+ zft_pos.seg_byte_pos = 0;
+ zft_deblock_segment = zft_pos.seg_pos;
+ ++zft_pos.seg_pos;
+ }
+ written += write_cnt;
+ buff += write_cnt;
+ req_len -= write_cnt;
+ } /* while (req_len > 0) */
+ TRACE(ft_t_data_flow, "remaining in blocking buffer: %d",
+ zft_pos.seg_byte_pos);
+ TRACE(ft_t_data_flow, "just written bytes: %d", written);
+ last_write_failed = 0;
+ zft_resid -= written;
+ need_flush = need_flush || written > 0;
+ TRACE_EXIT written; /* bytes written */
+}
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