1 files changed, 336 insertions, 0 deletions

diff --git a/drivers/char/ftape/lowlevel/ftape-write.c b/drivers/char/ftape/lowlevel/ftape-write.c
new file mode 100644
index 000000000000..45601ec801ee
--- /dev/null
+++ b/drivers/char/ftape/lowlevel/ftape-write.c
@@ -0,0 +1,336 @@
+/*
+ *      Copyright (C) 1993-1995 Bas Laarhoven,
+ *                (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/lowlevel/ftape-write.c,v $
+ * $Revision: 1.3.4.1 $
+ * $Date: 1997/11/14 18:07:04 $
+ *
+ *      This file contains the writing code
+ *      for the QIC-117 floppy-tape driver for Linux.
+ */
+
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+
+#include <linux/ftape.h>
+#include <linux/qic117.h>
+#include "../lowlevel/ftape-tracing.h"
+#include "../lowlevel/ftape-write.h"
+#include "../lowlevel/ftape-read.h"
+#include "../lowlevel/ftape-io.h"
+#include "../lowlevel/ftape-ctl.h"
+#include "../lowlevel/ftape-rw.h"
+#include "../lowlevel/ftape-ecc.h"
+#include "../lowlevel/ftape-bsm.h"
+#include "../lowlevel/fdc-isr.h"
+
+/*      Global vars.
+ */
+
+/*      Local vars.
+ */
+static int last_write_failed;
+
+void ftape_zap_write_buffers(void)
+{
+        int i;
+
+        for (i = 0; i < ft_nr_buffers; ++i) {
+                ft_buffer[i]->status = done;
+        }
+        ftape_reset_buffer();
+}
+
+static int copy_and_gen_ecc(void *destination, 
+                            const void *source,
+                            const SectorMap bad_sector_map)
+{
+        int result;
+        struct memory_segment mseg;
+        int bads = count_ones(bad_sector_map);
+        TRACE_FUN(ft_t_any);
+
+        if (bads > 0) {
+                TRACE(ft_t_noise, "bad sectors in map: %d", bads);
+        }
+        if (bads + 3 >= FT_SECTORS_PER_SEGMENT) {
+                TRACE(ft_t_noise, "empty segment");
+                mseg.blocks = 0; /* skip entire segment */
+                result = 0;      /* nothing written */
+        } else {
+                mseg.blocks = FT_SECTORS_PER_SEGMENT - bads;
+                mseg.data = destination;
+                memcpy(mseg.data, source, (mseg.blocks - 3) * FT_SECTOR_SIZE);
+                result = ftape_ecc_set_segment_parity(&mseg);
+                if (result < 0) {
+                        TRACE(ft_t_err, "ecc_set_segment_parity failed");
+                } else {
+                        result = (mseg.blocks - 3) * FT_SECTOR_SIZE;
+                }
+        }
+        TRACE_EXIT result;
+}
+
+
+int ftape_start_writing(const ft_write_mode_t mode)
+{
+        buffer_struct *head = ftape_get_buffer(ft_queue_head);
+        int segment_id = head->segment_id;
+        int result;
+        buffer_state_enum wanted_state = (mode == FT_WR_DELETE
+                                          ? deleting
+                                          : writing);
+        TRACE_FUN(ft_t_flow);
+
+        if ((ft_driver_state != wanted_state) || head->status != waiting) {
+                TRACE_EXIT 0;
+        }
+        ftape_setup_new_segment(head, segment_id, 1);
+        if (mode == FT_WR_SINGLE) {
+                /* stop tape instead of pause */
+                head->next_segment = 0;
+        }
+        ftape_calc_next_cluster(head); /* prepare */
+        head->status = ft_driver_state; /* either writing or deleting */
+        if (ft_runner_status == idle) {
+                TRACE(ft_t_noise,
+                      "starting runner for segment %d", segment_id);
+                TRACE_CATCH(ftape_start_tape(segment_id,head->sector_offset),);
+        } else {
+                TRACE(ft_t_noise, "runner not idle, not starting tape");
+        }
+        /* go */
+        result = fdc_setup_read_write(head, (mode == FT_WR_DELETE
+                                             ? FDC_WRITE_DELETED : FDC_WRITE));
+        ftape_set_state(wanted_state); /* should not be necessary */
+        TRACE_EXIT result;
+}
+
+/*  Wait until all data is actually written to tape.
+ *  
+ *  There is a problem: when the tape runs into logical EOT, then this
+ *  failes. We need to restart the runner in this case.
+ */
+int ftape_loop_until_writes_done(void)
+{
+        buffer_struct *head;
+        TRACE_FUN(ft_t_flow);
+
+        while ((ft_driver_state == writing || ft_driver_state == deleting) && 
+               ftape_get_buffer(ft_queue_head)->status != done) {
+                /* set the runner status to idle if at lEOT */
+                TRACE_CATCH(ftape_handle_logical_eot(), last_write_failed = 1);
+                /* restart the tape if necessary */
+                if (ft_runner_status == idle) {
+                        TRACE(ft_t_noise, "runner is idle, restarting");
+                        if (ft_driver_state == deleting) {
+                                TRACE_CATCH(ftape_start_writing(FT_WR_DELETE),
+                                            last_write_failed = 1);
+                        } else {
+                                TRACE_CATCH(ftape_start_writing(FT_WR_MULTI),
+                                            last_write_failed = 1);
+                        }
+                }
+                TRACE(ft_t_noise, "tail: %d, head: %d", 
+                      ftape_buffer_id(ft_queue_tail),
+                      ftape_buffer_id(ft_queue_head));
+                TRACE_CATCH(fdc_interrupt_wait(5 * FT_SECOND),
+                            last_write_failed = 1);
+                head = ftape_get_buffer(ft_queue_head);
+                if (head->status == error) {
+                        /* Allow escape from loop when signaled !
+                         */
+                        FT_SIGNAL_EXIT(_DONT_BLOCK);
+                        if (head->hard_error_map != 0) {
+                                /*  Implement hard write error recovery here
+                                 */
+                        }
+                        /* retry this one */
+                        head->status = waiting;
+                        if (ft_runner_status == aborting) {
+                                ftape_dumb_stop();
+                        }
+                        if (ft_runner_status != idle) {
+                                TRACE_ABORT(-EIO, ft_t_err,
+                                            "unexpected state: "
+                                            "ft_runner_status != idle");
+                        }
+                        ftape_start_writing(ft_driver_state == deleting
+                                            ? FT_WR_MULTI : FT_WR_DELETE);
+                }
+                TRACE(ft_t_noise, "looping until writes done");
+        }
+        ftape_set_state(idle);
+        TRACE_EXIT 0;
+}
+
+/*      Write given segment from buffer at address to tape.
+ */
+static int write_segment(const int segment_id,
+                         const void *address, 
+                         const ft_write_mode_t write_mode)
+{
+        int bytes_written = 0;
+        buffer_struct *tail;
+        buffer_state_enum wanted_state = (write_mode == FT_WR_DELETE
+                                          ? deleting : writing);
+        TRACE_FUN(ft_t_flow);
+
+        TRACE(ft_t_noise, "segment_id = %d", segment_id);
+        if (ft_driver_state != wanted_state) {
+                if (ft_driver_state == deleting ||
+                    wanted_state == deleting) {
+                        TRACE_CATCH(ftape_loop_until_writes_done(),);
+                }
+                TRACE(ft_t_noise, "calling ftape_abort_operation");
+                TRACE_CATCH(ftape_abort_operation(),);
+                ftape_zap_write_buffers();
+                ftape_set_state(wanted_state);
+        }
+        /*    if all buffers full we'll have to wait...
+         */
+        ftape_wait_segment(wanted_state);
+        tail = ftape_get_buffer(ft_queue_tail);
+        switch(tail->status) {
+        case done:
+                ft_history.defects += count_ones(tail->hard_error_map);
+                break;
+        case waiting:
+                /* this could happen with multiple EMPTY_SEGMENTs, but
+                 * shouldn't happen any more as we re-start the runner even
+                 * with an empty segment.
+                 */
+                bytes_written = -EAGAIN;
+                break;
+        case error:
+                /*  setup for a retry
+                 */
+                tail->status = waiting;
+                bytes_written = -EAGAIN; /* force retry */
+                if (tail->hard_error_map != 0) {
+                        TRACE(ft_t_warn, 
+                              "warning: %d hard error(s) in written segment",
+                              count_ones(tail->hard_error_map));
+                        TRACE(ft_t_noise, "hard_error_map = 0x%08lx", 
+                              (long)tail->hard_error_map);
+                        /*  Implement hard write error recovery here
+                         */
+                }
+                break;
+        default:
+                TRACE_ABORT(-EIO, ft_t_err,
+                            "wait for empty segment failed, tail status: %d",
+                            tail->status);
+        }
+        /*    should runner stop ?
+         */
+        if (ft_runner_status == aborting) {
+                buffer_struct *head = ftape_get_buffer(ft_queue_head);
+                if (head->status == wanted_state) {
+                        head->status = done; /* ???? */
+                }
+                /*  don't call abort_operation(), we don't want to zap
+                 *  the dma buffers
+                 */
+                TRACE_CATCH(ftape_dumb_stop(),);
+        } else {
+                /*  If just passed last segment on tape: wait for BOT
+                 *  or EOT mark. Sets ft_runner_status to idle if at lEOT
+                 *  and successful 
+                 */
+                TRACE_CATCH(ftape_handle_logical_eot(),);
+        }
+        if (tail->status == done) {
+                /* now at least one buffer is empty, fill it with our
+                 * data.  skip bad sectors and generate ecc.
+                 * copy_and_gen_ecc return nr of bytes written, range
+                 * 0..29 Kb inclusive!  
+                 *
+                 * Empty segments are handled inside coyp_and_gen_ecc()
+                 */
+                if (write_mode != FT_WR_DELETE) {
+                        TRACE_CATCH(bytes_written = copy_and_gen_ecc(
+                                tail->address, address,
+                                ftape_get_bad_sector_entry(segment_id)),);
+                }
+                tail->segment_id = segment_id;
+                tail->status = waiting;
+                tail = ftape_next_buffer(ft_queue_tail);
+        }
+        /*  Start tape only if all buffers full or flush mode.
+         *  This will give higher probability of streaming.
+         */
+        if (ft_runner_status != running && 
+            ((tail->status == waiting &&
+              ftape_get_buffer(ft_queue_head) == tail) ||
+             write_mode != FT_WR_ASYNC)) {
+                TRACE_CATCH(ftape_start_writing(write_mode),);
+        }
+        TRACE_EXIT bytes_written;
+}
+
+/*  Write as much as fits from buffer to the given segment on tape
+ *  and handle retries.
+ *  Return the number of bytes written (>= 0), or:
+ *      -EIO          write failed
+ *      -EINTR        interrupted by signal
+ *      -ENOSPC       device full
+ */
+int ftape_write_segment(const int segment_id,
+                        const void *buffer, 
+                        const ft_write_mode_t flush)
+{
+        int retry = 0;
+        int result;
+        TRACE_FUN(ft_t_flow);
+
+        ft_history.used |= 2;
+        if (segment_id >= ft_tracks_per_tape*ft_segments_per_track) {
+                /* tape full */
+                TRACE_ABORT(-ENOSPC, ft_t_err,
+                            "invalid segment id: %d (max %d)", 
+                            segment_id, 
+                            ft_tracks_per_tape * ft_segments_per_track -1);
+        }
+        for (;;) {
+                if ((result = write_segment(segment_id, buffer, flush)) >= 0) {
+                        if (result == 0) { /* empty segment */
+                                TRACE(ft_t_noise,
+                                      "empty segment, nothing written");
+                        }
+                        TRACE_EXIT result;
+                }
+                if (result == -EAGAIN) {
+                        if (++retry > 100) { /* give up */
+                                TRACE_ABORT(-EIO, ft_t_err,
+                                      "write failed, >100 retries in segment");
+                        }
+                        TRACE(ft_t_warn, "write error, retry %d (%d)",
+                              retry,
+                              ftape_get_buffer(ft_queue_tail)->segment_id);
+                } else {
+                        TRACE_ABORT(result, ft_t_err,
+                                    "write_segment failed, error: %d", result);
+                }
+                /* Allow escape from loop when signaled !
+                 */
+                FT_SIGNAL_EXIT(_DONT_BLOCK);
+        }
+}