ftape-read.c

linux-2.6.15.6

			ftape_setup_new_segment(head, segment_id, -1);
			if (read_mode == FT_RD_SINGLE) {
				/* disable read-ahead */
				head->next_segment = 0;
			}
			ftape_calc_next_cluster(head);
			if (ft_runner_status == idle) {
				result = ftape_start_tape(segment_id,
							  head->sector_offset);
				if (result < 0) {
					TRACE_ABORT(result, ft_t_err, "Error: "
						    "segment %d unreachable",
						    segment_id);
				}
			}
			head->status = reading;
			fdc_setup_read_write(head, FDC_READ);
		}
	}
	/* not reached */
	TRACE_EXIT -EIO;
}

int ftape_read_header_segment(__u8 *address)
{
	int result;
	int header_segment;
	int first_failed = 0;
	int status;
	TRACE_FUN(ft_t_flow);

	ft_used_header_segment = -1;
	TRACE_CATCH(ftape_report_drive_status(&status),);
	TRACE(ft_t_flow, "reading...");
	/*  We're looking for the first header segment.
	 *  A header segment cannot contain bad sectors, therefor at the
	 *  tape start, segments with bad sectors are (according to QIC-40/80)
	 *  written with deleted data marks and must be skipped.
	 */
	memset(address, '\0', (FT_SECTORS_PER_SEGMENT - 3) * FT_SECTOR_SIZE); 
	result = 0;
#define HEADER_SEGMENT_BOUNDARY 68  /* why not 42? */
	for (header_segment = 0;
	     header_segment < HEADER_SEGMENT_BOUNDARY && result == 0;
	     ++header_segment) {
		/*  Set no read-ahead, the isr will force read-ahead whenever
		 *  it encounters deleted data !
		 */
		result = ftape_read_segment(header_segment,
					    address,
					    FT_RD_SINGLE);
		if (result < 0 && !first_failed) {
			TRACE(ft_t_err, "header segment damaged, trying backup");
			first_failed = 1;
			result = 0;	/* force read of next (backup) segment */
		}
	}
	if (result < 0 || header_segment >= HEADER_SEGMENT_BOUNDARY) {
		TRACE_ABORT(-EIO, ft_t_err,
			    "no readable header segment found");
	}
	TRACE_CATCH(ftape_abort_operation(),);
	ft_used_header_segment = header_segment;
	result = ftape_decode_header_segment(address);
 	TRACE_EXIT result;
}

int ftape_decode_header_segment(__u8 *address)
{
	unsigned int max_floppy_side;
	unsigned int max_floppy_track;
	unsigned int max_floppy_sector;
	unsigned int new_tape_len;
	TRACE_FUN(ft_t_flow);

	if (GET4(address, FT_SIGNATURE) == FT_D2G_MAGIC) {
		/* Ditto 2GB header segment. They encrypt the bad sector map.
		 * We decrypt it and store them in normal format.
		 * I hope this is correct.
		 */
		int i;
		TRACE(ft_t_warn,
		      "Found Ditto 2GB tape, "
		      "trying to decrypt bad sector map");
		for (i=256; i < 29 * FT_SECTOR_SIZE; i++) {
			address[i] = ~(address[i] - (i&0xff));
		}
		PUT4(address, 0,FT_HSEG_MAGIC);
	} else if (GET4(address, FT_SIGNATURE) != FT_HSEG_MAGIC) {
		TRACE_ABORT(-EIO, ft_t_err,
			    "wrong signature in header segment");
	}
	ft_format_code = (ft_format_type) address[FT_FMT_CODE];
	if (ft_format_code != fmt_big) {
		ft_header_segment_1   = GET2(address, FT_HSEG_1);
		ft_header_segment_2   = GET2(address, FT_HSEG_2);
		ft_first_data_segment = GET2(address, FT_FRST_SEG);
		ft_last_data_segment  = GET2(address, FT_LAST_SEG);
	} else {
		ft_header_segment_1   = GET4(address, FT_6_HSEG_1);
		ft_header_segment_2   = GET4(address, FT_6_HSEG_2);
		ft_first_data_segment = GET4(address, FT_6_FRST_SEG);
		ft_last_data_segment  = GET4(address, FT_6_LAST_SEG);
	}
	TRACE(ft_t_noise, "first data segment: %d", ft_first_data_segment);
	TRACE(ft_t_noise, "last  data segment: %d", ft_last_data_segment);
	TRACE(ft_t_noise, "header segments are %d and %d",
	      ft_header_segment_1, ft_header_segment_2);

	/*    Verify tape parameters...
	 *    QIC-40/80 spec:                 tape_parameters:
	 *
	 *    segments-per-track              segments_per_track
	 *    tracks-per-cartridge            tracks_per_tape
	 *    max-floppy-side                 (segments_per_track *
	 *                                    tracks_per_tape - 1) /
	 *                                    ftape_segments_per_head
	 *    max-floppy-track                ftape_segments_per_head /
	 *                                    ftape_segments_per_cylinder - 1
	 *    max-floppy-sector               ftape_segments_per_cylinder *
	 *                                    FT_SECTORS_PER_SEGMENT
	 */
	ft_segments_per_track = GET2(address, FT_SPT);
	ft_tracks_per_tape    = address[FT_TPC];
	max_floppy_side       = address[FT_FHM];
	max_floppy_track      = address[FT_FTM];
	max_floppy_sector     = address[FT_FSM];
	TRACE(ft_t_noise, "(fmt/spt/tpc/fhm/ftm/fsm) = %d/%d/%d/%d/%d/%d",
	      ft_format_code, ft_segments_per_track, ft_tracks_per_tape,
	      max_floppy_side, max_floppy_track, max_floppy_sector);
	new_tape_len = ftape_tape_len;
	switch (ft_format_code) {
	case fmt_425ft:
		new_tape_len = 425;
		break;
	case fmt_normal:
		if (ftape_tape_len == 0) {	/* otherwise 307 ft */
			new_tape_len = 205;
		}
		break;
	case fmt_1100ft:
		new_tape_len = 1100;
		break;
	case fmt_var:{
			int segments_per_1000_inch = 1;		/* non-zero default for switch */
			switch (ft_qic_std) {
			case QIC_TAPE_QIC40:
				segments_per_1000_inch = 332;
				break;
			case QIC_TAPE_QIC80:
				segments_per_1000_inch = 488;
				break;
			case QIC_TAPE_QIC3010:
				segments_per_1000_inch = 730;
				break;
			case QIC_TAPE_QIC3020:
				segments_per_1000_inch = 1430;
				break;
			}
			new_tape_len = (1000 * ft_segments_per_track +
					(segments_per_1000_inch - 1)) / segments_per_1000_inch;
			break;
		}
	case fmt_big:{
			int segments_per_1000_inch = 1;		/* non-zero default for switch */
			switch (ft_qic_std) {
			case QIC_TAPE_QIC40:
				segments_per_1000_inch = 332;
				break;
			case QIC_TAPE_QIC80:
				segments_per_1000_inch = 488;
				break;
			case QIC_TAPE_QIC3010:
				segments_per_1000_inch = 730;
				break;
			case QIC_TAPE_QIC3020:
				segments_per_1000_inch = 1430;
				break;
			default:
				TRACE_ABORT(-EIO, ft_t_bug,
			"%x QIC-standard with fmt-code %d, please report",
					    ft_qic_std, ft_format_code);
			}
			new_tape_len = ((1000 * ft_segments_per_track +
					 (segments_per_1000_inch - 1)) / 
					segments_per_1000_inch);
			break;
		}
	default:
		TRACE_ABORT(-EIO, ft_t_err,
			    "unknown tape format, please report !");
	}
	if (new_tape_len != ftape_tape_len) {
		ftape_tape_len = new_tape_len;
		TRACE(ft_t_info, "calculated tape length is %d ft",
		      ftape_tape_len);
		ftape_calc_timeouts(ft_qic_std, ft_data_rate, ftape_tape_len);
	}
	if (ft_segments_per_track == 0 && ft_tracks_per_tape == 0 &&
	    max_floppy_side == 0 && max_floppy_track == 0 &&
	    max_floppy_sector == 0) {
		/*  QIC-40 Rev E and earlier has no values in the header.
		 */
		ft_segments_per_track = 68;
		ft_tracks_per_tape = 20;
		max_floppy_side = 1;
		max_floppy_track = 169;
		max_floppy_sector = 128;
	}
	/*  This test will compensate for the wrong parameter on tapes
	 *  formatted by Conner software.
	 */
	if (ft_segments_per_track == 150 &&
	    ft_tracks_per_tape == 28 &&
	    max_floppy_side == 7 &&
	    max_floppy_track == 149 &&
	    max_floppy_sector == 128) {
TRACE(ft_t_info, "the famous CONNER bug: max_floppy_side off by one !");
		max_floppy_side = 6;
	}
	/*  These tests will compensate for the wrong parameter on tapes
	 *  formatted by ComByte Windows software.
	 *
	 *  First, for 205 foot tapes
	 */
	if (ft_segments_per_track == 100 &&
	    ft_tracks_per_tape == 28 &&
	    max_floppy_side == 9 &&
	    max_floppy_track == 149 &&
	    max_floppy_sector == 128) {
TRACE(ft_t_info, "the ComByte bug: max_floppy_side incorrect!");
		max_floppy_side = 4;
	}
	/* Next, for 307 foot tapes. */
	if (ft_segments_per_track == 150 &&
	    ft_tracks_per_tape == 28 &&
	    max_floppy_side == 9 &&
	    max_floppy_track == 149 &&
	    max_floppy_sector == 128) {
TRACE(ft_t_info, "the ComByte bug: max_floppy_side incorrect!");
		max_floppy_side = 6;
	}
	/*  This test will compensate for the wrong parameter on tapes
	 *  formatted by Colorado Windows software.
	 */
	if (ft_segments_per_track == 150 &&
	    ft_tracks_per_tape == 28 &&
	    max_floppy_side == 6 &&
	    max_floppy_track == 150 &&
	    max_floppy_sector == 128) {
TRACE(ft_t_info, "the famous Colorado bug: max_floppy_track off by one !");
		max_floppy_track = 149;
	}
	ftape_segments_per_head = ((max_floppy_sector/FT_SECTORS_PER_SEGMENT) *
				   (max_floppy_track + 1));
	/*  This test will compensate for some bug reported by Dima
	 *  Brodsky.  Seems to be a Colorado bug, either. (freebee
	 *  Imation tape shipped together with Colorado T3000
	 */
	if ((ft_format_code == fmt_var || ft_format_code == fmt_big) &&
	    ft_tracks_per_tape == 50 &&
	    max_floppy_side == 54 &&
	    max_floppy_track == 255 &&
	    max_floppy_sector == 128) {
TRACE(ft_t_info, "the famous ??? bug: max_floppy_track off by one !");
		max_floppy_track = 254;
	}
	/*
	 *    Verify drive_configuration with tape parameters
	 */
	if (ftape_segments_per_head == 0 || ftape_segments_per_cylinder == 0 ||
	  ((ft_segments_per_track * ft_tracks_per_tape - 1) / ftape_segments_per_head
	   != max_floppy_side) ||
	    (ftape_segments_per_head / ftape_segments_per_cylinder - 1 != max_floppy_track) ||
	(ftape_segments_per_cylinder * FT_SECTORS_PER_SEGMENT != max_floppy_sector)
#ifdef TESTING
	    || ((ft_format_code == fmt_var || ft_format_code == fmt_big) && 
		(max_floppy_track != 254 || max_floppy_sector != 128))
#endif
	   ) {
		char segperheadz = ftape_segments_per_head ? ' ' : '?';
		char segpercylz  = ftape_segments_per_cylinder ? ' ' : '?';
		TRACE(ft_t_err,"Tape parameters inconsistency, please report");
		TRACE(ft_t_err, "reported = %d/%d/%d/%d/%d/%d",
		      ft_format_code,
		      ft_segments_per_track,
		      ft_tracks_per_tape,
		      max_floppy_side,
		      max_floppy_track,
		      max_floppy_sector);
		TRACE(ft_t_err, "required = %d/%d/%d/%d%c/%d%c/%d",
		      ft_format_code,
		      ft_segments_per_track,
		      ft_tracks_per_tape,
		      ftape_segments_per_head ?
		      ((ft_segments_per_track * ft_tracks_per_tape -1) / 
		       ftape_segments_per_head ) :
			(ft_segments_per_track * ft_tracks_per_tape -1),
			segperheadz,
		      ftape_segments_per_cylinder ?
		      (ftape_segments_per_head / 
		       ftape_segments_per_cylinder - 1 ) :
			ftape_segments_per_head - 1,
			segpercylz,
		      (ftape_segments_per_cylinder * FT_SECTORS_PER_SEGMENT));
		TRACE_EXIT -EIO;
	}
	ftape_extract_bad_sector_map(address);
 	TRACE_EXIT 0;
}