Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 5914 insertions, 0 deletions

diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
new file mode 100644
index 000000000000..c585c7bef247
--- /dev/null
+++ b/drivers/scsi/osst.c
@@ -0,0 +1,5914 @@
+/*
+  SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
+  file Documentation/scsi/st.txt for more information.
+
+  History:
+
+  OnStream SCSI Tape support (osst) cloned from st.c by
+  Willem Riede (osst@riede.org) Feb 2000
+  Fixes ... Kurt Garloff <garloff@suse.de> Mar 2000
+
+  Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
+  Contribution and ideas from several people including (in alphabetical
+  order) Klaus Ehrenfried, Wolfgang Denk, Steve Hirsch, Andreas Koppenh"ofer,
+  Michael Leodolter, Eyal Lebedinsky, J"org Weule, and Eric Youngdale.
+
+  Copyright 1992 - 2002 Kai Makisara / 2000 - 2004 Willem Riede
+	 email osst@riede.org
+
+  $Header: /cvsroot/osst/Driver/osst.c,v 1.73 2005/01/01 21:13:34 wriede Exp $
+
+  Microscopic alterations - Rik Ling, 2000/12/21
+  Last st.c sync: Tue Oct 15 22:01:04 2002 by makisara
+  Some small formal changes - aeb, 950809
+*/
+
+static const char * cvsid = "$Id: osst.c,v 1.73 2005/01/01 21:13:34 wriede Exp $";
+static const char * osst_version = "0.99.3";
+
+/* The "failure to reconnect" firmware bug */
+#define OSST_FW_NEED_POLL_MIN 10601 /*(107A)*/
+#define OSST_FW_NEED_POLL_MAX 10704 /*(108D)*/
+#define OSST_FW_NEED_POLL(x,d) ((x) >= OSST_FW_NEED_POLL_MIN && (x) <= OSST_FW_NEED_POLL_MAX && d->host->this_id != 7)
+
+#include <linux/module.h>
+
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/proc_fs.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/mtio.h>
+#include <linux/ioctl.h>
+#include <linux/fcntl.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <linux/blkdev.h>
+#include <linux/moduleparam.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/delay.h>
+#include <asm/uaccess.h>
+#include <asm/dma.h>
+#include <asm/system.h>
+
+/* The driver prints some debugging information on the console if DEBUG
+   is defined and non-zero. */
+#define DEBUG 0
+
+/* The message level for the debug messages is currently set to KERN_NOTICE
+   so that people can easily see the messages. Later when the debugging messages
+   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
+#define OSST_DEB_MSG  KERN_NOTICE
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/scsi_request.h>
+
+#define ST_KILOBYTE 1024
+
+#include "st.h"
+#include "osst.h"
+#include "osst_options.h"
+#include "osst_detect.h"
+
+static int max_dev = 0;
+static int write_threshold_kbs = 0;
+static int max_sg_segs = 0;
+
+#ifdef MODULE
+MODULE_AUTHOR("Willem Riede");
+MODULE_DESCRIPTION("OnStream {DI-|FW-|SC-|USB}{30|50} Tape Driver");
+MODULE_LICENSE("GPL");
+
+module_param(max_dev, int, 0444);
+MODULE_PARM_DESC(max_dev, "Maximum number of OnStream Tape Drives to attach (4)");
+
+module_param(write_threshold_kbs, int, 0644);
+MODULE_PARM_DESC(write_threshold_kbs, "Asynchronous write threshold (KB; 32)");
+
+module_param(max_sg_segs, int, 0644);
+MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (9)");
+#else
+static struct osst_dev_parm {
+       char   *name;
+       int    *val;
+} parms[] __initdata = {
+       { "max_dev",             &max_dev             },
+       { "write_threshold_kbs", &write_threshold_kbs },
+       { "max_sg_segs",         &max_sg_segs         }
+};
+#endif
+
+static char *osst_formats[ST_NBR_MODES] ={"", "l", "m", "a"};
+
+/* Some default definitions have been moved to osst_options.h */
+#define OSST_BUFFER_SIZE (OSST_BUFFER_BLOCKS * ST_KILOBYTE)
+#define OSST_WRITE_THRESHOLD (OSST_WRITE_THRESHOLD_BLOCKS * ST_KILOBYTE)
+
+/* The buffer size should fit into the 24 bits for length in the
+   6-byte SCSI read and write commands. */
+#if OSST_BUFFER_SIZE >= (2 << 24 - 1)
+#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
+#endif
+
+#if DEBUG
+static int debugging = 1;
+/* uncomment define below to test error recovery */
+// #define OSST_INJECT_ERRORS 1 
+#endif
+
+/* Do not retry! The drive firmware already retries when appropriate,
+   and when it tries to tell us something, we had better listen... */
+#define MAX_RETRIES 0
+
+#define NO_TAPE  NOT_READY
+
+#define OSST_WAIT_POSITION_COMPLETE   (HZ > 200 ? HZ / 200 : 1)
+#define OSST_WAIT_WRITE_COMPLETE      (HZ / 12)
+#define OSST_WAIT_LONG_WRITE_COMPLETE (HZ / 2)
+	
+#define OSST_TIMEOUT (200 * HZ)
+#define OSST_LONG_TIMEOUT (1800 * HZ)
+
+#define TAPE_NR(x) (iminor(x) & ~(-1 << ST_MODE_SHIFT))
+#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
+#define TAPE_REWIND(x) ((iminor(x) & 0x80) == 0)
+#define TAPE_IS_RAW(x) (TAPE_MODE(x) & (ST_NBR_MODES >> 1))
+
+/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
+   24 bits) */
+#define SET_DENS_AND_BLK 0x10001
+
+static int osst_buffer_size       = OSST_BUFFER_SIZE;
+static int osst_write_threshold   = OSST_WRITE_THRESHOLD;
+static int osst_max_sg_segs       = OSST_MAX_SG;
+static int osst_max_dev           = OSST_MAX_TAPES;
+static int osst_nr_dev;
+
+static struct osst_tape **os_scsi_tapes = NULL;
+static DEFINE_RWLOCK(os_scsi_tapes_lock);
+
+static int modes_defined = 0;
+
+static struct osst_buffer *new_tape_buffer(int, int, int);
+static int enlarge_buffer(struct osst_buffer *, int);
+static void normalize_buffer(struct osst_buffer *);
+static int append_to_buffer(const char __user *, struct osst_buffer *, int);
+static int from_buffer(struct osst_buffer *, char __user *, int);
+static int osst_zero_buffer_tail(struct osst_buffer *);
+static int osst_copy_to_buffer(struct osst_buffer *, unsigned char *);
+static int osst_copy_from_buffer(struct osst_buffer *, unsigned char *);
+
+static int osst_probe(struct device *);
+static int osst_remove(struct device *);
+
+static struct scsi_driver osst_template = {
+	.owner			= THIS_MODULE,
+	.gendrv = {
+		.name		=  "osst",
+		.probe		= osst_probe,
+		.remove		= osst_remove,
+	}
+};
+
+static int osst_int_ioctl(struct osst_tape *STp, struct scsi_request ** aSRpnt,
+			    unsigned int cmd_in, unsigned long arg);
+
+static int osst_set_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt, int frame, int skip);
+
+static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt);
+
+static int osst_flush_write_buffer(struct osst_tape *STp, struct scsi_request ** aSRpnt);
+
+static int osst_write_error_recovery(struct osst_tape * STp, struct scsi_request ** aSRpnt, int pending);
+
+static inline char *tape_name(struct osst_tape *tape)
+{
+	return tape->drive->disk_name;
+}
+
+/* Routines that handle the interaction with mid-layer SCSI routines */
+
+/* Convert the result to success code */
+static int osst_chk_result(struct osst_tape * STp, struct scsi_request * SRpnt)
+{
+	char *name = tape_name(STp);
+	int result = SRpnt->sr_result;
+	unsigned char * sense = SRpnt->sr_sense_buffer, scode;
+#if DEBUG
+	const char *stp;
+#endif
+
+	if (!result) {
+		sense[0] = 0;    /* We don't have sense data if this byte is zero */
+		return 0;
+	}
+	if ((driver_byte(result) & DRIVER_MASK) == DRIVER_SENSE)
+		scode = sense[2] & 0x0f;
+	else {
+		sense[0] = 0;    /* We don't have sense data if this byte is zero */
+		scode = 0;
+	}
+#if DEBUG
+	if (debugging) {
+		printk(OSST_DEB_MSG "%s:D: Error: %x, cmd: %x %x %x %x %x %x Len: %d\n",
+		   name, result,
+		   SRpnt->sr_cmnd[0], SRpnt->sr_cmnd[1], SRpnt->sr_cmnd[2],
+		   SRpnt->sr_cmnd[3], SRpnt->sr_cmnd[4], SRpnt->sr_cmnd[5],
+		   SRpnt->sr_bufflen);
+		if (scode) printk(OSST_DEB_MSG "%s:D: Sense: %02x, ASC: %02x, ASCQ: %02x\n",
+			       	name, scode, sense[12], sense[13]);
+		if (driver_byte(result) & DRIVER_SENSE)
+			scsi_print_req_sense("osst ", SRpnt);
+	}
+	else
+#endif
+	if (!(driver_byte(result) & DRIVER_SENSE) ||
+		((sense[0] & 0x70) == 0x70 &&
+		 scode != NO_SENSE &&
+		 scode != RECOVERED_ERROR &&
+/*      	 scode != UNIT_ATTENTION && */
+		 scode != BLANK_CHECK &&
+		 scode != VOLUME_OVERFLOW &&
+		 SRpnt->sr_cmnd[0] != MODE_SENSE &&
+		 SRpnt->sr_cmnd[0] != TEST_UNIT_READY)) { /* Abnormal conditions for tape */
+		if (driver_byte(result) & DRIVER_SENSE) {
+			printk(KERN_WARNING "%s:W: Command with sense data:\n", name);
+			scsi_print_req_sense("osst:", SRpnt);
+		}
+		else {
+			static	int	notyetprinted = 1;
+
+			printk(KERN_WARNING
+			     "%s:W: Warning %x (sugg. bt 0x%x, driver bt 0x%x, host bt 0x%x).\n",
+			     name, result, suggestion(result), driver_byte(result) & DRIVER_MASK,
+			     host_byte(result));
+			if (notyetprinted) {
+				notyetprinted = 0;
+				printk(KERN_INFO
+					"%s:I: This warning may be caused by your scsi controller,\n", name);
+				printk(KERN_INFO
+					"%s:I: it has been reported with some Buslogic cards.\n", name);
+			}
+		}
+	}
+	STp->pos_unknown |= STp->device->was_reset;
+
+	if ((sense[0] & 0x70) == 0x70 &&
+	     scode == RECOVERED_ERROR) {
+		STp->recover_count++;
+		STp->recover_erreg++;
+#if DEBUG
+		if (debugging) {
+			if (SRpnt->sr_cmnd[0] == READ_6)
+				stp = "read";
+			else if (SRpnt->sr_cmnd[0] == WRITE_6)
+				stp = "write";
+			else
+				stp = "ioctl";
+			printk(OSST_DEB_MSG "%s:D: Recovered %s error (%d).\n", name, stp,
+					     STp->recover_count);
+		}
+#endif
+		if ((sense[2] & 0xe0) == 0)
+			return 0;
+	}
+	return (-EIO);
+}
+
+
+/* Wakeup from interrupt */
+static void osst_sleep_done (struct scsi_cmnd * SCpnt)
+{
+	struct osst_tape * STp = container_of(SCpnt->request->rq_disk->private_data, struct osst_tape, driver);
+
+	if ((STp->buffer)->writing &&
+	    (SCpnt->sense_buffer[0] & 0x70) == 0x70 &&
+	    (SCpnt->sense_buffer[2] & 0x40)) {
+		/* EOM at write-behind, has all been written? */
+		if ((SCpnt->sense_buffer[2] & 0x0f) == VOLUME_OVERFLOW)
+			STp->buffer->midlevel_result = SCpnt->result; /* Error */
+		else
+			STp->buffer->midlevel_result = INT_MAX;       /* OK */
+	}
+	else
+		STp->buffer->midlevel_result = SCpnt->result;
+	SCpnt->request->rq_status = RQ_SCSI_DONE;
+	STp->buffer->last_SRpnt = SCpnt->sc_request;
+
+#if DEBUG
+	STp->write_pending = 0;
+#endif
+	complete(SCpnt->request->waiting);
+}
+
+
+/* Do the scsi command. Waits until command performed if do_wait is true.
+   Otherwise osst_write_behind_check() is used to check that the command
+   has finished. */
+static	struct scsi_request * osst_do_scsi(struct scsi_request *SRpnt, struct osst_tape *STp, 
+	unsigned char *cmd, int bytes, int direction, int timeout, int retries, int do_wait)
+{
+	unsigned char *bp;
+#ifdef OSST_INJECT_ERRORS
+	static   int   inject = 0;
+	static   int   repeat = 0;
+#endif
+	if (SRpnt == NULL) {
+		if ((SRpnt = scsi_allocate_request(STp->device, GFP_ATOMIC)) == NULL) {
+			printk(KERN_ERR "%s:E: Can't get SCSI request.\n", tape_name(STp));
+			if (signal_pending(current))
+				(STp->buffer)->syscall_result = (-EINTR);
+			else
+				(STp->buffer)->syscall_result = (-EBUSY);
+			return NULL;
+		}
+	}
+
+        init_completion(&STp->wait);
+	SRpnt->sr_use_sg = (bytes > (STp->buffer)->sg[0].length) ?
+				    (STp->buffer)->use_sg : 0;
+	if (SRpnt->sr_use_sg) {
+		bp = (char *)&(STp->buffer->sg[0]);
+		if (STp->buffer->sg_segs < SRpnt->sr_use_sg)
+			SRpnt->sr_use_sg = STp->buffer->sg_segs;
+	}
+	else
+		bp = (STp->buffer)->b_data;
+	SRpnt->sr_data_direction = direction;
+	SRpnt->sr_cmd_len = 0;
+	SRpnt->sr_request->waiting = &(STp->wait);
+	SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
+	SRpnt->sr_request->rq_disk = STp->drive;
+
+	scsi_do_req(SRpnt, (void *)cmd, bp, bytes, osst_sleep_done, timeout, retries);
+
+	if (do_wait) {
+		wait_for_completion(SRpnt->sr_request->waiting);
+		SRpnt->sr_request->waiting = NULL;
+		STp->buffer->syscall_result = osst_chk_result(STp, SRpnt);
+#ifdef OSST_INJECT_ERRORS
+		if (STp->buffer->syscall_result == 0 &&
+		    cmd[0] == READ_6 &&
+		    cmd[4] && 
+		    ( (++ inject % 83) == 29  ||
+		      (STp->first_frame_position == 240 
+			         /* or STp->read_error_frame to fail again on the block calculated above */ &&
+				 ++repeat < 3))) {
+			printk(OSST_DEB_MSG "%s:D: Injecting read error\n", tape_name(STp));
+			STp->buffer->last_result_fatal = 1;
+		}
+#endif
+	}
+	return SRpnt;
+}
+
+
+/* Handle the write-behind checking (downs the semaphore) */
+static void osst_write_behind_check(struct osst_tape *STp)
+{
+	struct osst_buffer * STbuffer;
+
+	STbuffer = STp->buffer;
+
+#if DEBUG
+	if (STp->write_pending)
+		STp->nbr_waits++;
+	else
+		STp->nbr_finished++;
+#endif
+	wait_for_completion(&(STp->wait));
+	(STp->buffer)->last_SRpnt->sr_request->waiting = NULL;
+
+	STp->buffer->syscall_result = osst_chk_result(STp, STp->buffer->last_SRpnt);
+
+	if ((STp->buffer)->syscall_result)
+		(STp->buffer)->syscall_result =
+			osst_write_error_recovery(STp, &((STp->buffer)->last_SRpnt), 1);
+	else
+		STp->first_frame_position++;
+
+	scsi_release_request((STp->buffer)->last_SRpnt);
+
+	if (STbuffer->writing < STbuffer->buffer_bytes)
+		printk(KERN_WARNING "osst :A: write_behind_check: something left in buffer!\n");
+
+	STbuffer->buffer_bytes -= STbuffer->writing;
+	STbuffer->writing = 0;
+
+	return;
+}
+
+
+
+/* Onstream specific Routines */
+/*
+ * Initialize the OnStream AUX
+ */
+static void osst_init_aux(struct osst_tape * STp, int frame_type, int frame_seq_number,
+					 int logical_blk_num, int blk_sz, int blk_cnt)
+{
+	os_aux_t       *aux = STp->buffer->aux;
+	os_partition_t *par = &aux->partition;
+	os_dat_t       *dat = &aux->dat;
+
+	if (STp->raw) return;
+
+	memset(aux, 0, sizeof(*aux));
+	aux->format_id = htonl(0);
+	memcpy(aux->application_sig, "LIN4", 4);
+	aux->hdwr = htonl(0);
+	aux->frame_type = frame_type;
+
+	switch (frame_type) {
+	  case	OS_FRAME_TYPE_HEADER:
+		aux->update_frame_cntr    = htonl(STp->update_frame_cntr);
+		par->partition_num        = OS_CONFIG_PARTITION;
+		par->par_desc_ver         = OS_PARTITION_VERSION;
+		par->wrt_pass_cntr        = htons(0xffff);
+		/* 0-4 = reserved, 5-9 = header, 2990-2994 = header, 2995-2999 = reserved */
+		par->first_frame_ppos     = htonl(0);
+		par->last_frame_ppos      = htonl(0xbb7);
+		aux->frame_seq_num        = htonl(0);
+		aux->logical_blk_num_high = htonl(0);
+		aux->logical_blk_num      = htonl(0);
+		aux->next_mark_ppos       = htonl(STp->first_mark_ppos);
+		break;
+	  case	OS_FRAME_TYPE_DATA:
+	  case	OS_FRAME_TYPE_MARKER:
+		dat->dat_sz = 8;
+		dat->reserved1 = 0;
+		dat->entry_cnt = 1;
+		dat->reserved3 = 0;
+		dat->dat_list[0].blk_sz   = htonl(blk_sz);
+		dat->dat_list[0].blk_cnt  = htons(blk_cnt);
+		dat->dat_list[0].flags    = frame_type==OS_FRAME_TYPE_MARKER?
+							OS_DAT_FLAGS_MARK:OS_DAT_FLAGS_DATA;
+		dat->dat_list[0].reserved = 0;
+	  case	OS_FRAME_TYPE_EOD:
+		aux->update_frame_cntr    = htonl(0);
+		par->partition_num        = OS_DATA_PARTITION;
+		par->par_desc_ver         = OS_PARTITION_VERSION;
+		par->wrt_pass_cntr        = htons(STp->wrt_pass_cntr);
+		par->first_frame_ppos     = htonl(STp->first_data_ppos);
+		par->last_frame_ppos      = htonl(STp->capacity);
+		aux->frame_seq_num        = htonl(frame_seq_number);
+		aux->logical_blk_num_high = htonl(0);
+		aux->logical_blk_num      = htonl(logical_blk_num);
+		break;
+	  default: ; /* probably FILL */
+	}
+	aux->filemark_cnt = ntohl(STp->filemark_cnt);
+	aux->phys_fm = ntohl(0xffffffff);
+	aux->last_mark_ppos = ntohl(STp->last_mark_ppos);
+	aux->last_mark_lbn  = ntohl(STp->last_mark_lbn);
+}
+
+/*
+ * Verify that we have the correct tape frame
+ */
+static int osst_verify_frame(struct osst_tape * STp, int frame_seq_number, int quiet)
+{
+	char               * name = tape_name(STp);
+	os_aux_t           * aux  = STp->buffer->aux;
+	os_partition_t     * par  = &(aux->partition);
+	struct st_partstat * STps = &(STp->ps[STp->partition]);
+	int		     blk_cnt, blk_sz, i;
+
+	if (STp->raw) {
+		if (STp->buffer->syscall_result) {
+			for (i=0; i < STp->buffer->sg_segs; i++)
+				memset(page_address(STp->buffer->sg[i].page),
+				       0, STp->buffer->sg[i].length);
+			strcpy(STp->buffer->b_data, "READ ERROR ON FRAME");
+                } else
+			STp->buffer->buffer_bytes = OS_FRAME_SIZE;
+		return 1;
+	}
+	if (STp->buffer->syscall_result) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame, read error\n", name);
+#endif
+		return 0;
+	}
+	if (ntohl(aux->format_id) != 0) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame, format_id %u\n", name, ntohl(aux->format_id));
+#endif
+		goto err_out;
+	}
+	if (memcmp(aux->application_sig, STp->application_sig, 4) != 0 &&
+	    (memcmp(aux->application_sig, "LIN3", 4) != 0 || STp->linux_media_version != 4)) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame, incorrect application signature\n", name);
+#endif
+		goto err_out;
+	}
+	if (par->partition_num != OS_DATA_PARTITION) {
+		if (!STp->linux_media || STp->linux_media_version != 2) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Skipping frame, partition num %d\n",
+					    name, par->partition_num);
+#endif
+			goto err_out;
+		}
+	}
+	if (par->par_desc_ver != OS_PARTITION_VERSION) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame, partition version %d\n", name, par->par_desc_ver);
+#endif
+		goto err_out;
+	}
+	if (ntohs(par->wrt_pass_cntr) != STp->wrt_pass_cntr) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame, wrt_pass_cntr %d (expected %d)\n", 
+				    name, ntohs(par->wrt_pass_cntr), STp->wrt_pass_cntr);
+#endif
+		goto err_out;
+	}
+	if (aux->frame_type != OS_FRAME_TYPE_DATA &&
+	    aux->frame_type != OS_FRAME_TYPE_EOD &&
+	    aux->frame_type != OS_FRAME_TYPE_MARKER) {
+		if (!quiet)
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Skipping frame, frame type %x\n", name, aux->frame_type);
+#endif
+		goto err_out;
+	}
+	if (aux->frame_type == OS_FRAME_TYPE_EOD &&
+	    STp->first_frame_position < STp->eod_frame_ppos) {
+		printk(KERN_INFO "%s:I: Skipping premature EOD frame %d\n", name,
+				 STp->first_frame_position);
+		goto err_out;
+	}
+        if (frame_seq_number != -1 && ntohl(aux->frame_seq_num) != frame_seq_number) {
+		if (!quiet)
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Skipping frame, sequence number %u (expected %d)\n", 
+					    name, ntohl(aux->frame_seq_num), frame_seq_number);
+#endif
+		goto err_out;
+	}
+	if (aux->frame_type == OS_FRAME_TYPE_MARKER) {
+		STps->eof = ST_FM_HIT;
+
+		i = ntohl(aux->filemark_cnt);
+		if (STp->header_cache != NULL && i < OS_FM_TAB_MAX && (i > STp->filemark_cnt ||
+		    STp->first_frame_position - 1 != ntohl(STp->header_cache->dat_fm_tab.fm_tab_ent[i]))) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: %s filemark %d at frame pos %d\n", name,
+				  STp->header_cache->dat_fm_tab.fm_tab_ent[i] == 0?"Learned":"Corrected",
+				  i, STp->first_frame_position - 1);
+#endif
+			STp->header_cache->dat_fm_tab.fm_tab_ent[i] = htonl(STp->first_frame_position - 1);
+			if (i >= STp->filemark_cnt)
+				 STp->filemark_cnt = i+1;
+		}
+	}
+	if (aux->frame_type == OS_FRAME_TYPE_EOD) {
+		STps->eof = ST_EOD_1;
+		STp->frame_in_buffer = 1;
+	}
+	if (aux->frame_type == OS_FRAME_TYPE_DATA) {
+                blk_cnt = ntohs(aux->dat.dat_list[0].blk_cnt);
+		blk_sz  = ntohl(aux->dat.dat_list[0].blk_sz);
+		STp->buffer->buffer_bytes = blk_cnt * blk_sz;
+		STp->buffer->read_pointer = 0;
+		STp->frame_in_buffer = 1;
+
+		/* See what block size was used to write file */
+		if (STp->block_size != blk_sz && blk_sz > 0) {
+			printk(KERN_INFO
+	    	"%s:I: File was written with block size %d%c, currently %d%c, adjusted to match.\n",
+       				name, blk_sz<1024?blk_sz:blk_sz/1024,blk_sz<1024?'b':'k',
+				STp->block_size<1024?STp->block_size:STp->block_size/1024,
+				STp->block_size<1024?'b':'k');
+			STp->block_size            = blk_sz;
+			STp->buffer->buffer_blocks = OS_DATA_SIZE / blk_sz;
+		}
+		STps->eof = ST_NOEOF;
+	}
+        STp->frame_seq_number = ntohl(aux->frame_seq_num);
+	STp->logical_blk_num  = ntohl(aux->logical_blk_num);
+	return 1;
+
+err_out:
+	if (STp->read_error_frame == 0)
+		STp->read_error_frame = STp->first_frame_position - 1;
+	return 0;
+}
+
+/*
+ * Wait for the unit to become Ready
+ */
+static int osst_wait_ready(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+				 unsigned timeout, int initial_delay)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	unsigned long		startwait = jiffies;
+#if DEBUG
+	int			dbg  = debugging;
+	char    	      * name = tape_name(STp);
+
+	printk(OSST_DEB_MSG "%s:D: Reached onstream wait ready\n", name);
+#endif
+
+	if (initial_delay > 0)
+		msleep(jiffies_to_msecs(initial_delay));
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = TEST_UNIT_READY;
+
+	SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+	*aSRpnt = SRpnt;
+	if (!SRpnt) return (-EBUSY);
+
+	while ( STp->buffer->syscall_result && time_before(jiffies, startwait + timeout*HZ) &&
+	       (( SRpnt->sr_sense_buffer[2]  == 2 && SRpnt->sr_sense_buffer[12] == 4    &&
+		 (SRpnt->sr_sense_buffer[13] == 1 || SRpnt->sr_sense_buffer[13] == 8)    ) ||
+		( SRpnt->sr_sense_buffer[2]  == 6 && SRpnt->sr_sense_buffer[12] == 0x28 &&
+		  SRpnt->sr_sense_buffer[13] == 0                                        )  )) {
+#if DEBUG
+	    if (debugging) {
+		printk(OSST_DEB_MSG "%s:D: Sleeping in onstream wait ready\n", name);
+		printk(OSST_DEB_MSG "%s:D: Turning off debugging for a while\n", name);
+		debugging = 0;
+	    }
+#endif
+	    msleep(100);
+
+	    memset(cmd, 0, MAX_COMMAND_SIZE);
+	    cmd[0] = TEST_UNIT_READY;
+
+	    SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+	}
+	*aSRpnt = SRpnt;
+#if DEBUG
+	debugging = dbg;
+#endif
+	if ( STp->buffer->syscall_result &&
+	     osst_write_error_recovery(STp, aSRpnt, 0) ) {
+#if DEBUG
+	    printk(OSST_DEB_MSG "%s:D: Abnormal exit from onstream wait ready\n", name);
+	    printk(OSST_DEB_MSG "%s:D: Result = %d, Sense: 0=%02x, 2=%02x, 12=%02x, 13=%02x\n", name,
+			STp->buffer->syscall_result, SRpnt->sr_sense_buffer[0], SRpnt->sr_sense_buffer[2],
+			SRpnt->sr_sense_buffer[12], SRpnt->sr_sense_buffer[13]);
+#endif
+	    return (-EIO);
+	}
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Normal exit from onstream wait ready\n", name);
+#endif
+	return 0;
+}
+
+/*
+ * Wait for a tape to be inserted in the unit
+ */
+static int osst_wait_for_medium(struct osst_tape * STp, struct scsi_request ** aSRpnt, unsigned timeout)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	unsigned long		startwait = jiffies;
+#if DEBUG
+	int			dbg = debugging;
+	char    	      * name = tape_name(STp);
+
+	printk(OSST_DEB_MSG "%s:D: Reached onstream wait for medium\n", name);
+#endif
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = TEST_UNIT_READY;
+
+	SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+	*aSRpnt = SRpnt;
+	if (!SRpnt) return (-EBUSY);
+
+	while ( STp->buffer->syscall_result && time_before(jiffies, startwait + timeout*HZ) &&
+		SRpnt->sr_sense_buffer[2]  == 2 && SRpnt->sr_sense_buffer[12] == 0x3a       &&
+	        SRpnt->sr_sense_buffer[13] == 0                                             ) {
+#if DEBUG
+	    if (debugging) {
+		printk(OSST_DEB_MSG "%s:D: Sleeping in onstream wait medium\n", name);
+		printk(OSST_DEB_MSG "%s:D: Turning off debugging for a while\n", name);
+		debugging = 0;
+	    }
+#endif
+	    msleep(100);
+
+	    memset(cmd, 0, MAX_COMMAND_SIZE);
+	    cmd[0] = TEST_UNIT_READY;
+
+	    SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+	}
+	*aSRpnt = SRpnt;
+#if DEBUG
+	debugging = dbg;
+#endif
+	if ( STp->buffer->syscall_result     && SRpnt->sr_sense_buffer[2]  != 2 &&
+	     SRpnt->sr_sense_buffer[12] != 4 && SRpnt->sr_sense_buffer[13] == 1) {
+#if DEBUG
+	    printk(OSST_DEB_MSG "%s:D: Abnormal exit from onstream wait medium\n", name);
+	    printk(OSST_DEB_MSG "%s:D: Result = %d, Sense: 0=%02x, 2=%02x, 12=%02x, 13=%02x\n", name,
+			STp->buffer->syscall_result, SRpnt->sr_sense_buffer[0], SRpnt->sr_sense_buffer[2],
+			SRpnt->sr_sense_buffer[12], SRpnt->sr_sense_buffer[13]);
+#endif
+	    return 0;
+	}
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Normal exit from onstream wait medium\n", name);
+#endif
+	return 1;
+}
+
+static int osst_position_tape_and_confirm(struct osst_tape * STp, struct scsi_request ** aSRpnt, int frame)
+{
+	int	retval;
+
+	osst_wait_ready(STp, aSRpnt, 15 * 60, 0);			/* TODO - can this catch a write error? */
+	retval = osst_set_frame_position(STp, aSRpnt, frame, 0);
+	if (retval) return (retval);
+	osst_wait_ready(STp, aSRpnt, 15 * 60, OSST_WAIT_POSITION_COMPLETE);
+	return (osst_get_frame_position(STp, aSRpnt));
+}
+
+/*
+ * Wait for write(s) to complete
+ */
+static int osst_flush_drive_buffer(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	int			result = 0;
+	int			delay  = OSST_WAIT_WRITE_COMPLETE;
+#if DEBUG
+	char		      * name = tape_name(STp);
+
+	printk(OSST_DEB_MSG "%s:D: Reached onstream flush drive buffer (write filemark)\n", name);
+#endif
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = WRITE_FILEMARKS;
+	cmd[1] = 1;
+
+	SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+	*aSRpnt = SRpnt;
+	if (!SRpnt) return (-EBUSY);
+	if (STp->buffer->syscall_result) {
+		if ((SRpnt->sr_sense_buffer[2] & 0x0f) == 2 && SRpnt->sr_sense_buffer[12] == 4) {
+			if (SRpnt->sr_sense_buffer[13] == 8) {
+				delay = OSST_WAIT_LONG_WRITE_COMPLETE;
+			}
+		} else
+			result = osst_write_error_recovery(STp, aSRpnt, 0);
+	}
+	result |= osst_wait_ready(STp, aSRpnt, 5 * 60, delay);
+	STp->ps[STp->partition].rw = OS_WRITING_COMPLETE;
+
+	return (result);
+}
+
+#define OSST_POLL_PER_SEC 10
+static int osst_wait_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt, int curr, int minlast, int to)
+{
+	unsigned long	startwait = jiffies;
+	char	      * name      = tape_name(STp);
+#if DEBUG
+	char	   notyetprinted  = 1;
+#endif
+	if (minlast >= 0 && STp->ps[STp->partition].rw != ST_READING)
+		printk(KERN_ERR "%s:A: Waiting for frame without having initialized read!\n", name);
+
+	while (time_before (jiffies, startwait + to*HZ))
+	{ 
+		int result;
+		result = osst_get_frame_position(STp, aSRpnt);
+		if (result == -EIO)
+			if ((result = osst_write_error_recovery(STp, aSRpnt, 0)) == 0)
+				return 0;	/* successful recovery leaves drive ready for frame */
+		if (result < 0) break;
+		if (STp->first_frame_position == curr &&
+		    ((minlast < 0 &&
+		      (signed)STp->last_frame_position > (signed)curr + minlast) ||
+		     (minlast >= 0 && STp->cur_frames > minlast)
+		    ) && result >= 0)
+		{
+#if DEBUG			
+			if (debugging || jiffies - startwait >= 2*HZ/OSST_POLL_PER_SEC)
+				printk (OSST_DEB_MSG
+					"%s:D: Succ wait f fr %i (>%i): %i-%i %i (%i): %3li.%li s\n",
+					name, curr, curr+minlast, STp->first_frame_position,
+					STp->last_frame_position, STp->cur_frames,
+					result, (jiffies-startwait)/HZ, 
+					(((jiffies-startwait)%HZ)*10)/HZ);
+#endif
+			return 0;
+		}
+#if DEBUG
+		if (jiffies - startwait >= 2*HZ/OSST_POLL_PER_SEC && notyetprinted)
+		{
+			printk (OSST_DEB_MSG "%s:D: Wait for frame %i (>%i): %i-%i %i (%i)\n",
+				name, curr, curr+minlast, STp->first_frame_position,
+				STp->last_frame_position, STp->cur_frames, result);
+			notyetprinted--;
+		}
+#endif
+		msleep(1000 / OSST_POLL_PER_SEC);
+	}
+#if DEBUG
+	printk (OSST_DEB_MSG "%s:D: Fail wait f fr %i (>%i): %i-%i %i: %3li.%li s\n",
+		name, curr, curr+minlast, STp->first_frame_position,
+		STp->last_frame_position, STp->cur_frames,
+		(jiffies-startwait)/HZ, (((jiffies-startwait)%HZ)*10)/HZ);
+#endif	
+	return -EBUSY;
+}
+
+static int osst_recover_wait_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt, int writing)
+{
+	struct scsi_request   * SRpnt;
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	unsigned long   	startwait = jiffies;
+	int			retval    = 1;
+        char		      * name      = tape_name(STp);
+                                                                                                                                
+	if (writing) {
+		char	mybuf[24];
+		char  * olddata = STp->buffer->b_data;
+		int	oldsize = STp->buffer->buffer_size;
+
+		/* write zero fm then read pos - if shows write error, try to recover - if no progress, wait */
+
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = WRITE_FILEMARKS;
+		cmd[1] = 1;
+		SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, 0, DMA_NONE, STp->timeout,
+								MAX_RETRIES, 1);
+
+		while (retval && time_before (jiffies, startwait + 5*60*HZ)) {
+
+			if (STp->buffer->syscall_result && (SRpnt->sr_sense_buffer[2] & 0x0f) != 2) {
+
+				/* some failure - not just not-ready */
+				retval = osst_write_error_recovery(STp, aSRpnt, 0);
+				break;
+			}
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout (HZ / OSST_POLL_PER_SEC);
+
+			STp->buffer->b_data = mybuf; STp->buffer->buffer_size = 24;
+			memset(cmd, 0, MAX_COMMAND_SIZE);
+			cmd[0] = READ_POSITION;
+
+			SRpnt = osst_do_scsi(SRpnt, STp, cmd, 20, DMA_FROM_DEVICE, STp->timeout,
+										MAX_RETRIES, 1);
+
+			retval = ( STp->buffer->syscall_result || (STp->buffer)->b_data[15] > 25 );
+			STp->buffer->b_data = olddata; STp->buffer->buffer_size = oldsize;
+		}
+		if (retval)
+			printk(KERN_ERR "%s:E: Device did not succeed to write buffered data\n", name);
+	} else
+		/* TODO - figure out which error conditions can be handled */
+		if (STp->buffer->syscall_result)
+			printk(KERN_WARNING
+				"%s:W: Recover_wait_frame(read) cannot handle %02x:%02x:%02x\n", name,
+					(*aSRpnt)->sr_sense_buffer[ 2] & 0x0f,
+					(*aSRpnt)->sr_sense_buffer[12],
+					(*aSRpnt)->sr_sense_buffer[13]);
+
+	return retval;
+}
+
+/*
+ * Read the next OnStream tape frame at the current location
+ */
+static int osst_read_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt, int timeout)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	int			retval = 0;
+#if DEBUG
+	os_aux_t	      * aux    = STp->buffer->aux;
+	char		      * name   = tape_name(STp);
+#endif
+
+	if (STp->poll)
+		if (osst_wait_frame (STp, aSRpnt, STp->first_frame_position, 0, timeout))
+			retval = osst_recover_wait_frame(STp, aSRpnt, 0);
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = READ_6;
+	cmd[1] = 1;
+	cmd[4] = 1;
+
+#if DEBUG
+	if (debugging)
+		printk(OSST_DEB_MSG "%s:D: Reading frame from OnStream tape\n", name);
+#endif
+	SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, OS_FRAME_SIZE, DMA_FROM_DEVICE,
+				      STp->timeout, MAX_RETRIES, 1);
+	*aSRpnt = SRpnt;
+	if (!SRpnt)
+		return (-EBUSY);
+
+	if ((STp->buffer)->syscall_result) {
+	    retval = 1;
+	    if (STp->read_error_frame == 0) {
+		STp->read_error_frame = STp->first_frame_position;
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Recording read error at %d\n", name, STp->read_error_frame);
+#endif
+	    }
+#if DEBUG
+	    if (debugging)
+		printk(OSST_DEB_MSG "%s:D: Sense: %2x %2x %2x %2x %2x %2x %2x %2x\n",
+		   name,
+		   SRpnt->sr_sense_buffer[0], SRpnt->sr_sense_buffer[1],
+		   SRpnt->sr_sense_buffer[2], SRpnt->sr_sense_buffer[3],
+		   SRpnt->sr_sense_buffer[4], SRpnt->sr_sense_buffer[5],
+		   SRpnt->sr_sense_buffer[6], SRpnt->sr_sense_buffer[7]);
+#endif
+	}
+	else
+	    STp->first_frame_position++;
+#if DEBUG
+	if (debugging) {
+	   char sig[8]; int i;
+	   for (i=0;i<4;i++)
+		   sig[i] = aux->application_sig[i]<32?'^':aux->application_sig[i];
+	   sig[4] = '\0';
+	   printk(OSST_DEB_MSG 
+		"%s:D: AUX: %s UpdFrCt#%d Wpass#%d %s FrSeq#%d LogBlk#%d Qty=%d Sz=%d\n", name, sig,
+			ntohl(aux->update_frame_cntr), ntohs(aux->partition.wrt_pass_cntr),
+			aux->frame_type==1?"EOD":aux->frame_type==2?"MARK":
+			aux->frame_type==8?"HEADR":aux->frame_type==0x80?"DATA":"FILL", 
+			ntohl(aux->frame_seq_num), ntohl(aux->logical_blk_num),
+			ntohs(aux->dat.dat_list[0].blk_cnt), ntohl(aux->dat.dat_list[0].blk_sz) );
+	   if (aux->frame_type==2)
+		printk(OSST_DEB_MSG "%s:D: mark_cnt=%d, last_mark_ppos=%d, last_mark_lbn=%d\n", name,
+			ntohl(aux->filemark_cnt), ntohl(aux->last_mark_ppos), ntohl(aux->last_mark_lbn));
+	   printk(OSST_DEB_MSG "%s:D: Exit read frame from OnStream tape with code %d\n", name, retval);
+	}
+#endif
+	return (retval);
+}
+
+static int osst_initiate_read(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	struct st_partstat    * STps   = &(STp->ps[STp->partition]);
+	struct scsi_request   * SRpnt  ;
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	int			retval = 0;
+	char		      * name   = tape_name(STp);
+
+	if (STps->rw != ST_READING) {         /* Initialize read operation */
+		if (STps->rw == ST_WRITING || STp->dirty) {
+			STp->write_type = OS_WRITE_DATA;
+                        osst_flush_write_buffer(STp, aSRpnt);
+			osst_flush_drive_buffer(STp, aSRpnt);
+		}
+		STps->rw = ST_READING;
+		STp->frame_in_buffer = 0;
+
+		/*
+		 *      Issue a read 0 command to get the OnStream drive
+                 *      read frames into its buffer.
+		 */
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = READ_6;
+		cmd[1] = 1;
+
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Start Read Ahead on OnStream tape\n", name);
+#endif
+		SRpnt   = osst_do_scsi(*aSRpnt, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+		*aSRpnt = SRpnt;
+		if ((retval = STp->buffer->syscall_result))
+			printk(KERN_WARNING "%s:W: Error starting read ahead\n", name);
+	}
+
+	return retval;
+}
+
+static int osst_get_logical_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+						int frame_seq_number, int quiet)
+{
+	struct st_partstat * STps  = &(STp->ps[STp->partition]);
+	char		   * name  = tape_name(STp);
+	int		     cnt   = 0,
+			     bad   = 0,
+			     past  = 0,
+			     x,
+			     position;
+
+	/*
+	 * If we want just any frame (-1) and there is a frame in the buffer, return it
+	 */
+	if (frame_seq_number == -1 && STp->frame_in_buffer) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Frame %d still in buffer\n", name, STp->frame_seq_number);
+#endif
+		return (STps->eof);
+	}
+	/*
+         * Search and wait for the next logical tape frame
+	 */
+	while (1) {
+		if (cnt++ > 400) {
+                        printk(KERN_ERR "%s:E: Couldn't find logical frame %d, aborting\n",
+					    name, frame_seq_number);
+			if (STp->read_error_frame) {
+				osst_set_frame_position(STp, aSRpnt, STp->read_error_frame, 0);
+#if DEBUG
+                        	printk(OSST_DEB_MSG "%s:D: Repositioning tape to bad frame %d\n",
+						    name, STp->read_error_frame);
+#endif
+				STp->read_error_frame = 0;
+				STp->abort_count++;
+			}
+			return (-EIO);
+		}
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Looking for frame %d, attempt %d\n",
+					  name, frame_seq_number, cnt);
+#endif
+		if ( osst_initiate_read(STp, aSRpnt)
+                || ( (!STp->frame_in_buffer) && osst_read_frame(STp, aSRpnt, 30) ) ) {
+			if (STp->raw)
+				return (-EIO);
+			position = osst_get_frame_position(STp, aSRpnt);
+			if (position >= 0xbae && position < 0xbb8)
+				position = 0xbb8;
+			else if (position > STp->eod_frame_ppos || ++bad == 10) {
+				position = STp->read_error_frame - 1;
+				bad = 0;
+			}
+			else {
+				position += 29;
+				cnt      += 19;
+			}
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Bad frame detected, positioning tape to block %d\n",
+					 name, position);
+#endif
+			osst_set_frame_position(STp, aSRpnt, position, 0);
+			continue;
+		}
+		if (osst_verify_frame(STp, frame_seq_number, quiet))
+			break;
+		if (osst_verify_frame(STp, -1, quiet)) {
+			x = ntohl(STp->buffer->aux->frame_seq_num);
+			if (STp->fast_open) {
+				printk(KERN_WARNING
+				       "%s:W: Found logical frame %d instead of %d after fast open\n",
+				       name, x, frame_seq_number);
+				STp->header_ok = 0;
+				STp->read_error_frame = 0;
+				return (-EIO);
+			}
+			if (x > frame_seq_number) {
+				if (++past > 3) {
+					/* positioning backwards did not bring us to the desired frame */
+					position = STp->read_error_frame - 1;
+				}
+				else {
+			        	position = osst_get_frame_position(STp, aSRpnt)
+					         + frame_seq_number - x - 1;
+
+					if (STp->first_frame_position >= 3000 && position < 3000)
+						position -= 10;
+				}
+#if DEBUG
+                                printk(OSST_DEB_MSG
+				       "%s:D: Found logical frame %d while looking for %d: back up %d\n",
+						name, x, frame_seq_number,
+					       	STp->first_frame_position - position);
+#endif
+                        	osst_set_frame_position(STp, aSRpnt, position, 0);
+				cnt += 10;
+			}
+			else
+				past = 0;
+		}
+		if (osst_get_frame_position(STp, aSRpnt) == 0xbaf) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Skipping config partition\n", name);
+#endif
+			osst_set_frame_position(STp, aSRpnt, 0xbb8, 0);
+			cnt--;
+		}
+		STp->frame_in_buffer = 0;
+	}
+	if (cnt > 1) {
+		STp->recover_count++;
+		STp->recover_erreg++;
+		printk(KERN_WARNING "%s:I: Don't worry, Read error at position %d recovered\n", 
+					name, STp->read_error_frame);
+ 	}
+	STp->read_count++;
+
+#if DEBUG
+	if (debugging || STps->eof)
+		printk(OSST_DEB_MSG
+			"%s:D: Exit get logical frame (%d=>%d) from OnStream tape with code %d\n",
+			name, frame_seq_number, STp->frame_seq_number, STps->eof);
+#endif
+	STp->fast_open = 0;
+	STp->read_error_frame = 0;
+	return (STps->eof);
+}
+
+static int osst_seek_logical_blk(struct osst_tape * STp, struct scsi_request ** aSRpnt, int logical_blk_num)
+{
+        struct st_partstat * STps = &(STp->ps[STp->partition]);
+	char		   * name = tape_name(STp);
+	int	retries    = 0;
+	int	frame_seq_estimate, ppos_estimate, move;
+	
+	if (logical_blk_num < 0) logical_blk_num = 0;
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Seeking logical block %d (now at %d, size %d%c)\n",
+				name, logical_blk_num, STp->logical_blk_num, 
+				STp->block_size<1024?STp->block_size:STp->block_size/1024,
+				STp->block_size<1024?'b':'k');
+#endif
+	/* Do we know where we are? */
+	if (STps->drv_block >= 0) {
+		move                = logical_blk_num - STp->logical_blk_num;
+		if (move < 0) move -= (OS_DATA_SIZE / STp->block_size) - 1;
+		move               /= (OS_DATA_SIZE / STp->block_size);
+		frame_seq_estimate  = STp->frame_seq_number + move;
+	} else
+		frame_seq_estimate  = logical_blk_num * STp->block_size / OS_DATA_SIZE;
+
+	if (frame_seq_estimate < 2980) ppos_estimate = frame_seq_estimate + 10;
+	else			       ppos_estimate = frame_seq_estimate + 20;
+	while (++retries < 10) {
+	   if (ppos_estimate > STp->eod_frame_ppos-2) {
+	       frame_seq_estimate += STp->eod_frame_ppos - 2 - ppos_estimate;
+	       ppos_estimate       = STp->eod_frame_ppos - 2;
+	   }
+	   if (frame_seq_estimate < 0) {
+	       frame_seq_estimate = 0;
+	       ppos_estimate      = 10;
+	   }
+	   osst_set_frame_position(STp, aSRpnt, ppos_estimate, 0);
+	   if (osst_get_logical_frame(STp, aSRpnt, frame_seq_estimate, 1) >= 0) {
+	      /* we've located the estimated frame, now does it have our block? */
+	      if (logical_blk_num <  STp->logical_blk_num ||
+	          logical_blk_num >= STp->logical_blk_num + ntohs(STp->buffer->aux->dat.dat_list[0].blk_cnt)) {
+		 if (STps->eof == ST_FM_HIT)
+		    move = logical_blk_num < STp->logical_blk_num? -2 : 1;
+		 else {
+		    move                = logical_blk_num - STp->logical_blk_num;
+		    if (move < 0) move -= (OS_DATA_SIZE / STp->block_size) - 1;
+		    move               /= (OS_DATA_SIZE / STp->block_size);
+		 }
+		 if (!move) move = logical_blk_num > STp->logical_blk_num ? 1 : -1;
+#if DEBUG
+		 printk(OSST_DEB_MSG
+			"%s:D: Seek retry %d at ppos %d fsq %d (est %d) lbn %d (need %d) move %d\n",
+				name, retries, ppos_estimate, STp->frame_seq_number, frame_seq_estimate, 
+				STp->logical_blk_num, logical_blk_num, move);
+#endif
+		 frame_seq_estimate += move;
+		 ppos_estimate      += move;
+		 continue;
+	      } else {
+		 STp->buffer->read_pointer  = (logical_blk_num - STp->logical_blk_num) * STp->block_size;
+		 STp->buffer->buffer_bytes -= STp->buffer->read_pointer;
+		 STp->logical_blk_num       =  logical_blk_num;
+#if DEBUG
+		 printk(OSST_DEB_MSG 
+			"%s:D: Seek success at ppos %d fsq %d in_buf %d, bytes %d, ptr %d*%d\n",
+				name, ppos_estimate, STp->frame_seq_number, STp->frame_in_buffer, 
+				STp->buffer->buffer_bytes, STp->buffer->read_pointer / STp->block_size, 
+				STp->block_size);
+#endif
+		 STps->drv_file = ntohl(STp->buffer->aux->filemark_cnt);
+		 if (STps->eof == ST_FM_HIT) {
+		     STps->drv_file++;
+		     STps->drv_block = 0;
+		 } else {
+		     STps->drv_block = ntohl(STp->buffer->aux->last_mark_lbn)?
+					  STp->logical_blk_num -
+					     (STps->drv_file ? ntohl(STp->buffer->aux->last_mark_lbn) + 1 : 0):
+					-1;
+		 }
+		 STps->eof = (STp->first_frame_position >= STp->eod_frame_ppos)?ST_EOD:ST_NOEOF;
+		 return 0;
+	      }
+	   }
+	   if (osst_get_logical_frame(STp, aSRpnt, -1, 1) < 0)
+	      goto error;
+	   /* we are not yet at the estimated frame, adjust our estimate of its physical position */
+#if DEBUG
+	   printk(OSST_DEB_MSG "%s:D: Seek retry %d at ppos %d fsq %d (est %d) lbn %d (need %d)\n", 
+			   name, retries, ppos_estimate, STp->frame_seq_number, frame_seq_estimate, 
+			   STp->logical_blk_num, logical_blk_num);
+#endif
+	   if (frame_seq_estimate != STp->frame_seq_number)
+	      ppos_estimate += frame_seq_estimate - STp->frame_seq_number;
+	   else
+	      break;
+	}
+error:
+	printk(KERN_ERR "%s:E: Couldn't seek to logical block %d (at %d), %d retries\n", 
+			    name, logical_blk_num, STp->logical_blk_num, retries);
+	return (-EIO);
+}
+
+/* The values below are based on the OnStream frame payload size of 32K == 2**15,
+ * that is, OSST_FRAME_SHIFT + OSST_SECTOR_SHIFT must be 15. With a minimum block
+ * size of 512 bytes, we need to be able to resolve 32K/512 == 64 == 2**6 positions
+ * inside each frame. Finaly, OSST_SECTOR_MASK == 2**OSST_FRAME_SHIFT - 1.
+ */
+#define OSST_FRAME_SHIFT  6
+#define OSST_SECTOR_SHIFT 9
+#define OSST_SECTOR_MASK  0x03F
+
+static int osst_get_sector(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	int	sector;
+#if DEBUG
+	char  * name = tape_name(STp);
+	
+	printk(OSST_DEB_MSG 
+		"%s:D: Positioned at ppos %d, frame %d, lbn %d, file %d, blk %d, %cptr %d, eof %d\n",
+		name, STp->first_frame_position, STp->frame_seq_number, STp->logical_blk_num,
+		STp->ps[STp->partition].drv_file, STp->ps[STp->partition].drv_block, 
+		STp->ps[STp->partition].rw == ST_WRITING?'w':'r',
+		STp->ps[STp->partition].rw == ST_WRITING?STp->buffer->buffer_bytes:
+		STp->buffer->read_pointer, STp->ps[STp->partition].eof);
+#endif
+	/* do we know where we are inside a file? */
+	if (STp->ps[STp->partition].drv_block >= 0) {
+		sector = (STp->frame_in_buffer ? STp->first_frame_position-1 :
+				STp->first_frame_position) << OSST_FRAME_SHIFT;
+		if (STp->ps[STp->partition].rw == ST_WRITING)
+		       	sector |= (STp->buffer->buffer_bytes >> OSST_SECTOR_SHIFT) & OSST_SECTOR_MASK;
+		else
+	       		sector |= (STp->buffer->read_pointer >> OSST_SECTOR_SHIFT) & OSST_SECTOR_MASK;
+	} else {
+		sector = osst_get_frame_position(STp, aSRpnt);
+		if (sector > 0)
+			sector <<= OSST_FRAME_SHIFT;
+	}
+	return sector;
+}
+
+static int osst_seek_sector(struct osst_tape * STp, struct scsi_request ** aSRpnt, int sector)
+{
+        struct st_partstat * STps   = &(STp->ps[STp->partition]);
+	int		     frame  = sector >> OSST_FRAME_SHIFT,
+			     offset = (sector & OSST_SECTOR_MASK) << OSST_SECTOR_SHIFT, 
+			     r;
+#if DEBUG
+	char          * name = tape_name(STp);
+
+	printk(OSST_DEB_MSG "%s:D: Seeking sector %d in frame %d at offset %d\n",
+				name, sector, frame, offset);
+#endif
+	if (frame < 0 || frame >= STp->capacity) return (-ENXIO);
+
+	if (frame <= STp->first_data_ppos) {
+		STp->frame_seq_number = STp->logical_blk_num = STps->drv_file = STps->drv_block = 0;
+		return (osst_set_frame_position(STp, aSRpnt, frame, 0));
+	}
+	r = osst_set_frame_position(STp, aSRpnt, offset?frame:frame-1, 0);
+	if (r < 0) return r;
+
+	r = osst_get_logical_frame(STp, aSRpnt, -1, 1);
+	if (r < 0) return r;
+
+	if (osst_get_frame_position(STp, aSRpnt) != (offset?frame+1:frame)) return (-EIO);
+
+	if (offset) {
+		STp->logical_blk_num      += offset / STp->block_size;
+		STp->buffer->read_pointer  = offset;
+		STp->buffer->buffer_bytes -= offset;
+	} else {
+		STp->frame_seq_number++;
+		STp->frame_in_buffer       = 0;
+		STp->logical_blk_num      += ntohs(STp->buffer->aux->dat.dat_list[0].blk_cnt);
+		STp->buffer->buffer_bytes  = STp->buffer->read_pointer = 0;
+	}
+	STps->drv_file = ntohl(STp->buffer->aux->filemark_cnt);
+	if (STps->eof == ST_FM_HIT) {
+		STps->drv_file++;
+		STps->drv_block = 0;
+	} else {
+		STps->drv_block = ntohl(STp->buffer->aux->last_mark_lbn)?
+				    STp->logical_blk_num -
+					(STps->drv_file ? ntohl(STp->buffer->aux->last_mark_lbn) + 1 : 0):
+				  -1;
+	}
+	STps->eof       = (STp->first_frame_position >= STp->eod_frame_ppos)?ST_EOD:ST_NOEOF;
+#if DEBUG
+	printk(OSST_DEB_MSG 
+		"%s:D: Now positioned at ppos %d, frame %d, lbn %d, file %d, blk %d, rptr %d, eof %d\n",
+		name, STp->first_frame_position, STp->frame_seq_number, STp->logical_blk_num,
+		STps->drv_file, STps->drv_block, STp->buffer->read_pointer, STps->eof);
+#endif
+	return 0;
+}
+
+/*
+ * Read back the drive's internal buffer contents, as a part
+ * of the write error recovery mechanism for old OnStream
+ * firmware revisions.
+ * Precondition for this function to work: all frames in the
+ * drive's buffer must be of one type (DATA, MARK or EOD)!
+ */
+static int osst_read_back_buffer_and_rewrite(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+						unsigned int frame, unsigned int skip, int pending)
+{
+	struct scsi_request   * SRpnt = * aSRpnt;
+	unsigned char	      * buffer, * p;
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	int			flag, new_frame, i;
+	int			nframes          = STp->cur_frames;
+	int			blks_per_frame   = ntohs(STp->buffer->aux->dat.dat_list[0].blk_cnt);
+	int			frame_seq_number = ntohl(STp->buffer->aux->frame_seq_num)
+						- (nframes + pending - 1);
+	int			logical_blk_num  = ntohl(STp->buffer->aux->logical_blk_num) 
+						- (nframes + pending - 1) * blks_per_frame;
+	char		      * name             = tape_name(STp);
+	unsigned long		startwait        = jiffies;
+#if DEBUG
+	int			dbg              = debugging;
+#endif
+
+	if ((buffer = (unsigned char *)vmalloc((nframes + 1) * OS_DATA_SIZE)) == NULL)
+		return (-EIO);
+
+	printk(KERN_INFO "%s:I: Reading back %d frames from drive buffer%s\n",
+			 name, nframes, pending?" and one that was pending":"");
+
+	osst_copy_from_buffer(STp->buffer, (p = &buffer[nframes * OS_DATA_SIZE]));
+#if DEBUG
+	if (pending && debugging)
+		printk(OSST_DEB_MSG "%s:D: Pending frame %d (lblk %d), data %02x %02x %02x %02x\n",
+				name, frame_seq_number + nframes,
+			       	logical_blk_num + nframes * blks_per_frame,
+			       	p[0], p[1], p[2], p[3]);
+#endif
+	for (i = 0, p = buffer; i < nframes; i++, p += OS_DATA_SIZE) {
+
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = 0x3C;		/* Buffer Read           */
+		cmd[1] = 6;		/* Retrieve Faulty Block */
+		cmd[7] = 32768 >> 8;
+		cmd[8] = 32768 & 0xff;
+
+		SRpnt = osst_do_scsi(SRpnt, STp, cmd, OS_FRAME_SIZE, DMA_FROM_DEVICE,
+					    STp->timeout, MAX_RETRIES, 1);
+	
+		if ((STp->buffer)->syscall_result || !SRpnt) {
+			printk(KERN_ERR "%s:E: Failed to read frame back from OnStream buffer\n", name);
+			vfree((void *)buffer);
+			*aSRpnt = SRpnt;
+			return (-EIO);
+		}
+		osst_copy_from_buffer(STp->buffer, p);
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Read back logical frame %d, data %02x %02x %02x %02x\n",
+					  name, frame_seq_number + i, p[0], p[1], p[2], p[3]);
+#endif
+	}
+	*aSRpnt = SRpnt;
+	osst_get_frame_position(STp, aSRpnt);
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Frames left in buffer: %d\n", name, STp->cur_frames);
+#endif
+	/* Write synchronously so we can be sure we're OK again and don't have to recover recursively */
+	/* In the header we don't actually re-write the frames that fail, just the ones after them */
+
+	for (flag=1, new_frame=frame, p=buffer, i=0; i < nframes + pending; ) {
+
+		if (flag) {
+			if (STp->write_type == OS_WRITE_HEADER) {
+				i += skip;
+				p += skip * OS_DATA_SIZE;
+			}
+			else if (new_frame < 2990 && new_frame+skip+nframes+pending >= 2990)
+				new_frame = 3000-i;
+			else
+				new_frame += skip;
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Position to frame %d, write fseq %d\n",
+						name, new_frame+i, frame_seq_number+i);
+#endif
+			osst_set_frame_position(STp, aSRpnt, new_frame + i, 0);
+			osst_wait_ready(STp, aSRpnt, 60, OSST_WAIT_POSITION_COMPLETE);
+			osst_get_frame_position(STp, aSRpnt);
+			SRpnt = * aSRpnt;
+
+			if (new_frame > frame + 1000) {
+				printk(KERN_ERR "%s:E: Failed to find writable tape media\n", name);
+				vfree((void *)buffer);
+				return (-EIO);
+			}
+			if ( i >= nframes + pending ) break;
+			flag = 0;
+		}
+		osst_copy_to_buffer(STp->buffer, p);
+		/*
+		 * IMPORTANT: for error recovery to work, _never_ queue frames with mixed frame type!
+		 */
+		osst_init_aux(STp, STp->buffer->aux->frame_type, frame_seq_number+i,
+			       	logical_blk_num + i*blks_per_frame,
+			       	ntohl(STp->buffer->aux->dat.dat_list[0].blk_sz), blks_per_frame);
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = WRITE_6;
+		cmd[1] = 1;
+		cmd[4] = 1;
+
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG
+				"%s:D: About to write frame %d, seq %d, lbn %d, data %02x %02x %02x %02x\n",
+				name, new_frame+i, frame_seq_number+i, logical_blk_num + i*blks_per_frame,
+				p[0], p[1], p[2], p[3]);
+#endif
+		SRpnt = osst_do_scsi(SRpnt, STp, cmd, OS_FRAME_SIZE, DMA_TO_DEVICE,
+					    STp->timeout, MAX_RETRIES, 1);
+
+		if (STp->buffer->syscall_result)
+			flag = 1;
+		else {
+			p += OS_DATA_SIZE; i++;
+
+			/* if we just sent the last frame, wait till all successfully written */
+			if ( i == nframes + pending ) {
+#if DEBUG
+				printk(OSST_DEB_MSG "%s:D: Check re-write successful\n", name);
+#endif
+				memset(cmd, 0, MAX_COMMAND_SIZE);
+				cmd[0] = WRITE_FILEMARKS;
+				cmd[1] = 1;
+				SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
+							    STp->timeout, MAX_RETRIES, 1);
+#if DEBUG
+				if (debugging) {
+					printk(OSST_DEB_MSG "%s:D: Sleeping in re-write wait ready\n", name);
+					printk(OSST_DEB_MSG "%s:D: Turning off debugging for a while\n", name);
+					debugging = 0;
+				}
+#endif
+				flag = STp->buffer->syscall_result;
+				while ( !flag && time_before(jiffies, startwait + 60*HZ) ) {
+
+					memset(cmd, 0, MAX_COMMAND_SIZE);
+					cmd[0] = TEST_UNIT_READY;
+
+					SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE, STp->timeout,
+												MAX_RETRIES, 1);
+
+					if (SRpnt->sr_sense_buffer[2] == 2 && SRpnt->sr_sense_buffer[12] == 4 &&
+					    (SRpnt->sr_sense_buffer[13] == 1 || SRpnt->sr_sense_buffer[13] == 8)) {
+						/* in the process of becoming ready */
+						msleep(100);
+						continue;
+					}
+					if (STp->buffer->syscall_result)
+						flag = 1;
+					break;
+				}
+#if DEBUG
+				debugging = dbg;
+				printk(OSST_DEB_MSG "%s:D: Wait re-write finished\n", name);
+#endif
+			}
+		}
+		*aSRpnt = SRpnt;
+		if (flag) {
+			if ((SRpnt->sr_sense_buffer[ 2] & 0x0f) == 13 &&
+			     SRpnt->sr_sense_buffer[12]         ==  0 &&
+			     SRpnt->sr_sense_buffer[13]         ==  2) {
+				printk(KERN_ERR "%s:E: Volume overflow in write error recovery\n", name);
+				vfree((void *)buffer);
+				return (-EIO);			/* hit end of tape = fail */
+			}
+			i = ((SRpnt->sr_sense_buffer[3] << 24) |
+			     (SRpnt->sr_sense_buffer[4] << 16) |
+			     (SRpnt->sr_sense_buffer[5] <<  8) |
+			      SRpnt->sr_sense_buffer[6]        ) - new_frame;
+			p = &buffer[i * OS_DATA_SIZE];
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Additional write error at %d\n", name, new_frame+i);
+#endif
+			osst_get_frame_position(STp, aSRpnt);
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: reported frame positions: host = %d, tape = %d, buffer = %d\n",
+					  name, STp->first_frame_position, STp->last_frame_position, STp->cur_frames);
+#endif
+		}
+	}
+	if (flag) {
+		/* error recovery did not successfully complete */
+		printk(KERN_ERR "%s:D: Write error recovery failed in %s\n", name,
+				STp->write_type == OS_WRITE_HEADER?"header":"body");
+	}
+	if (!pending)
+		osst_copy_to_buffer(STp->buffer, p);	/* so buffer content == at entry in all cases */
+	vfree((void *)buffer);
+	return 0;
+}
+
+static int osst_reposition_and_retry(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+					unsigned int frame, unsigned int skip, int pending)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	char		      * name      = tape_name(STp);
+	int			expected  = 0;
+	int			attempts  = 1000 / skip;
+	int			flag      = 1;
+	unsigned long		startwait = jiffies;
+#if DEBUG
+	int			dbg       = debugging;
+#endif
+
+	while (attempts && time_before(jiffies, startwait + 60*HZ)) {
+		if (flag) {
+#if DEBUG
+			debugging = dbg;
+#endif
+			if (frame < 2990 && frame+skip+STp->cur_frames+pending >= 2990)
+				frame = 3000-skip;
+			expected = frame+skip+STp->cur_frames+pending;
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Position to fppos %d, re-write from fseq %d\n",
+					  name, frame+skip, STp->frame_seq_number-STp->cur_frames-pending);
+#endif
+			osst_set_frame_position(STp, aSRpnt, frame + skip, 1);
+			flag = 0;
+			attempts--;
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(HZ / 10);
+		}
+		if (osst_get_frame_position(STp, aSRpnt) < 0) {		/* additional write error */
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Addl error, host %d, tape %d, buffer %d\n",
+					  name, STp->first_frame_position,
+					  STp->last_frame_position, STp->cur_frames);
+#endif
+			frame = STp->last_frame_position;
+			flag = 1;
+			continue;
+		}
+		if (pending && STp->cur_frames < 50) {
+
+			memset(cmd, 0, MAX_COMMAND_SIZE);
+			cmd[0] = WRITE_6;
+			cmd[1] = 1;
+			cmd[4] = 1;
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: About to write pending fseq %d at fppos %d\n",
+					  name, STp->frame_seq_number-1, STp->first_frame_position);
+#endif
+			SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, OS_FRAME_SIZE, DMA_TO_DEVICE,
+						      STp->timeout, MAX_RETRIES, 1);
+			*aSRpnt = SRpnt;
+
+			if (STp->buffer->syscall_result) {		/* additional write error */
+				if ((SRpnt->sr_sense_buffer[ 2] & 0x0f) == 13 &&
+				     SRpnt->sr_sense_buffer[12]         ==  0 &&
+				     SRpnt->sr_sense_buffer[13]         ==  2) {
+					printk(KERN_ERR
+					       "%s:E: Volume overflow in write error recovery\n",
+					       name);
+					break;				/* hit end of tape = fail */
+				}
+				flag = 1;
+			}
+			else
+				pending = 0;
+
+			continue;
+		}
+		if (STp->cur_frames == 0) {
+#if DEBUG
+			debugging = dbg;
+			printk(OSST_DEB_MSG "%s:D: Wait re-write finished\n", name);
+#endif
+			if (STp->first_frame_position != expected) {
+				printk(KERN_ERR "%s:A: Actual position %d - expected %d\n", 
+						name, STp->first_frame_position, expected);
+				return (-EIO);
+			}
+			return 0;
+		}
+#if DEBUG
+		if (debugging) {
+			printk(OSST_DEB_MSG "%s:D: Sleeping in re-write wait ready\n", name);
+			printk(OSST_DEB_MSG "%s:D: Turning off debugging for a while\n", name);
+			debugging = 0;
+		}
+#endif
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(HZ / 10);
+	}
+	printk(KERN_ERR "%s:E: Failed to find valid tape media\n", name);
+#if DEBUG
+	debugging = dbg;
+#endif
+	return (-EIO);
+}
+
+/*
+ * Error recovery algorithm for the OnStream tape.
+ */
+
+static int osst_write_error_recovery(struct osst_tape * STp, struct scsi_request ** aSRpnt, int pending)
+{
+	struct scsi_request * SRpnt  = * aSRpnt;
+	struct st_partstat  * STps   = & STp->ps[STp->partition];
+	char		    * name   = tape_name(STp);
+	int		      retval = 0;
+	int		      rw_state;
+	unsigned int	      frame, skip;
+
+	rw_state = STps->rw;
+
+	if ((SRpnt->sr_sense_buffer[ 2] & 0x0f) != 3
+	  || SRpnt->sr_sense_buffer[12]         != 12
+	  || SRpnt->sr_sense_buffer[13]         != 0) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Write error recovery cannot handle %02x:%02x:%02x\n", name,
+			SRpnt->sr_sense_buffer[2], SRpnt->sr_sense_buffer[12], SRpnt->sr_sense_buffer[13]);
+#endif
+		return (-EIO);
+	}
+	frame =	(SRpnt->sr_sense_buffer[3] << 24) |
+		(SRpnt->sr_sense_buffer[4] << 16) |
+		(SRpnt->sr_sense_buffer[5] <<  8) |
+		 SRpnt->sr_sense_buffer[6];
+	skip  =  SRpnt->sr_sense_buffer[9];
+ 
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Detected physical bad frame at %u, advised to skip %d\n", name, frame, skip);
+#endif
+	osst_get_frame_position(STp, aSRpnt);
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: reported frame positions: host = %d, tape = %d\n",
+			name, STp->first_frame_position, STp->last_frame_position);
+#endif
+	switch (STp->write_type) {
+	   case OS_WRITE_DATA:
+	   case OS_WRITE_EOD:
+	   case OS_WRITE_NEW_MARK:
+		printk(KERN_WARNING 
+			"%s:I: Relocating %d buffered logical frames from position %u to %u\n",
+			name, STp->cur_frames, frame, (frame + skip > 3000 && frame < 3000)?3000:frame + skip);
+		if (STp->os_fw_rev >= 10600)
+			retval = osst_reposition_and_retry(STp, aSRpnt, frame, skip, pending);
+		else
+			retval = osst_read_back_buffer_and_rewrite(STp, aSRpnt, frame, skip, pending);
+		printk(KERN_WARNING "%s:%s: %sWrite error%srecovered\n", name,
+			       	retval?"E"    :"I",
+			       	retval?""     :"Don't worry, ",
+			       	retval?" not ":" ");
+		break;
+	   case OS_WRITE_LAST_MARK:
+		printk(KERN_ERR "%s:E: Bad frame in update last marker, fatal\n", name);
+		osst_set_frame_position(STp, aSRpnt, frame + STp->cur_frames + pending, 0);
+		retval = -EIO;
+		break;
+	   case OS_WRITE_HEADER:
+		printk(KERN_WARNING "%s:I: Bad frame in header partition, skipped\n", name);
+		retval = osst_read_back_buffer_and_rewrite(STp, aSRpnt, frame, 1, pending);
+		break;
+	   default:
+		printk(KERN_INFO "%s:I: Bad frame in filler, ignored\n", name);
+		osst_set_frame_position(STp, aSRpnt, frame + STp->cur_frames + pending, 0);
+	}
+	osst_get_frame_position(STp, aSRpnt);
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Positioning complete, cur_frames %d, pos %d, tape pos %d\n", 
+			name, STp->cur_frames, STp->first_frame_position, STp->last_frame_position);
+	printk(OSST_DEB_MSG "%s:D: next logical frame to write: %d\n", name, STp->logical_blk_num);
+#endif
+	if (retval == 0) {
+		STp->recover_count++;
+		STp->recover_erreg++;
+	} else
+		STp->abort_count++;
+
+	STps->rw = rw_state;
+	return retval;
+}
+
+static int osst_space_over_filemarks_backward(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+								 int mt_op, int mt_count)
+{
+	char  * name = tape_name(STp);
+	int     cnt;
+	int     last_mark_ppos = -1;
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Reached space_over_filemarks_backwards %d %d\n", name, mt_op, mt_count);
+#endif
+	if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks_bwd\n", name);
+#endif
+		return -EIO;
+	}
+	if (STp->linux_media_version >= 4) {
+		/*
+		 * direct lookup in header filemark list
+		 */
+		cnt = ntohl(STp->buffer->aux->filemark_cnt);
+		if (STp->header_ok                         && 
+		    STp->header_cache != NULL              &&
+		    (cnt - mt_count)  >= 0                 &&
+		    (cnt - mt_count)   < OS_FM_TAB_MAX     &&
+		    (cnt - mt_count)   < STp->filemark_cnt &&
+		    STp->header_cache->dat_fm_tab.fm_tab_ent[cnt-1] == STp->buffer->aux->last_mark_ppos)
+
+			last_mark_ppos = ntohl(STp->header_cache->dat_fm_tab.fm_tab_ent[cnt - mt_count]);
+#if DEBUG
+		if (STp->header_cache == NULL || (cnt - mt_count) < 0 || (cnt - mt_count) >= OS_FM_TAB_MAX)
+			printk(OSST_DEB_MSG "%s:D: Filemark lookup fail due to %s\n", name,
+			       STp->header_cache == NULL?"lack of header cache":"count out of range");
+		else
+			printk(OSST_DEB_MSG "%s:D: Filemark lookup: prev mark %d (%s), skip %d to %d\n",
+				name, cnt,
+				((cnt == -1 && ntohl(STp->buffer->aux->last_mark_ppos) == -1) ||
+				 (STp->header_cache->dat_fm_tab.fm_tab_ent[cnt-1] ==
+					 STp->buffer->aux->last_mark_ppos))?"match":"error",
+			       mt_count, last_mark_ppos);
+#endif
+		if (last_mark_ppos > 10 && last_mark_ppos < STp->eod_frame_ppos) {
+			osst_position_tape_and_confirm(STp, aSRpnt, last_mark_ppos);
+			if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+				printk(OSST_DEB_MSG 
+					"%s:D: Couldn't get logical blk num in space_filemarks\n", name);
+#endif
+				return (-EIO);
+			}
+			if (STp->buffer->aux->frame_type != OS_FRAME_TYPE_MARKER) {
+				printk(KERN_WARNING "%s:W: Expected to find marker at ppos %d, not found\n",
+						 name, last_mark_ppos);
+				return (-EIO);
+			}
+			goto found;
+		}
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Reverting to scan filemark backwards\n", name);
+#endif
+	}
+	cnt = 0;
+	while (cnt != mt_count) {
+		last_mark_ppos = ntohl(STp->buffer->aux->last_mark_ppos);
+		if (last_mark_ppos == -1)
+			return (-EIO);
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Positioning to last mark at %d\n", name, last_mark_ppos);
+#endif
+		osst_position_tape_and_confirm(STp, aSRpnt, last_mark_ppos);
+		cnt++;
+		if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks\n", name);
+#endif
+			return (-EIO);
+		}
+		if (STp->buffer->aux->frame_type != OS_FRAME_TYPE_MARKER) {
+			printk(KERN_WARNING "%s:W: Expected to find marker at ppos %d, not found\n",
+					 name, last_mark_ppos);
+			return (-EIO);
+		}
+	}
+found:
+	if (mt_op == MTBSFM) {
+		STp->frame_seq_number++;
+		STp->frame_in_buffer      = 0;
+		STp->buffer->buffer_bytes = 0;
+		STp->buffer->read_pointer = 0;
+		STp->logical_blk_num     += ntohs(STp->buffer->aux->dat.dat_list[0].blk_cnt);
+	}
+	return 0;
+}
+
+/*
+ * ADRL 1.1 compatible "slow" space filemarks fwd version
+ *
+ * Just scans for the filemark sequentially.
+ */
+static int osst_space_over_filemarks_forward_slow(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+								     int mt_op, int mt_count)
+{
+	int	cnt = 0;
+#if DEBUG
+	char  * name = tape_name(STp);
+
+	printk(OSST_DEB_MSG "%s:D: Reached space_over_filemarks_forward_slow %d %d\n", name, mt_op, mt_count);
+#endif
+	if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks_fwd\n", name);
+#endif
+		return (-EIO);
+	}
+	while (1) {
+		if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks\n", name);
+#endif
+			return (-EIO);
+		}
+		if (STp->buffer->aux->frame_type == OS_FRAME_TYPE_MARKER)
+			cnt++;
+		if (STp->buffer->aux->frame_type == OS_FRAME_TYPE_EOD) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: space_fwd: EOD reached\n", name);
+#endif
+			if (STp->first_frame_position > STp->eod_frame_ppos+1) {
+#if DEBUG
+				printk(OSST_DEB_MSG "%s:D: EOD position corrected (%d=>%d)\n",
+					       	name, STp->eod_frame_ppos, STp->first_frame_position-1);
+#endif
+				STp->eod_frame_ppos = STp->first_frame_position-1;
+			}
+			return (-EIO);
+		}
+		if (cnt == mt_count)
+			break;
+		STp->frame_in_buffer = 0;
+	}
+	if (mt_op == MTFSF) {
+		STp->frame_seq_number++;
+		STp->frame_in_buffer      = 0;
+		STp->buffer->buffer_bytes = 0;
+		STp->buffer->read_pointer = 0;
+		STp->logical_blk_num     += ntohs(STp->buffer->aux->dat.dat_list[0].blk_cnt);
+	}
+	return 0;
+}
+
+/*
+ * Fast linux specific version of OnStream FSF
+ */
+static int osst_space_over_filemarks_forward_fast(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+								     int mt_op, int mt_count)
+{
+	char  * name = tape_name(STp);
+	int	cnt  = 0,
+		next_mark_ppos = -1;
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Reached space_over_filemarks_forward_fast %d %d\n", name, mt_op, mt_count);
+#endif
+	if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks_fwd\n", name);
+#endif
+		return (-EIO);
+	}
+
+	if (STp->linux_media_version >= 4) {
+		/*
+		 * direct lookup in header filemark list
+		 */
+		cnt = ntohl(STp->buffer->aux->filemark_cnt) - 1;
+		if (STp->header_ok                         && 
+		    STp->header_cache != NULL              &&
+		    (cnt + mt_count)   < OS_FM_TAB_MAX     &&
+		    (cnt + mt_count)   < STp->filemark_cnt &&
+		    ((cnt == -1 && ntohl(STp->buffer->aux->last_mark_ppos) == -1) ||
+		     (STp->header_cache->dat_fm_tab.fm_tab_ent[cnt] == STp->buffer->aux->last_mark_ppos)))
+
+			next_mark_ppos = ntohl(STp->header_cache->dat_fm_tab.fm_tab_ent[cnt + mt_count]);
+#if DEBUG
+		if (STp->header_cache == NULL || (cnt + mt_count) >= OS_FM_TAB_MAX)
+			printk(OSST_DEB_MSG "%s:D: Filemark lookup fail due to %s\n", name,
+			       STp->header_cache == NULL?"lack of header cache":"count out of range");
+		else
+			printk(OSST_DEB_MSG "%s:D: Filemark lookup: prev mark %d (%s), skip %d to %d\n",
+			       name, cnt,
+			       ((cnt == -1 && ntohl(STp->buffer->aux->last_mark_ppos) == -1) ||
+				(STp->header_cache->dat_fm_tab.fm_tab_ent[cnt] ==
+					 STp->buffer->aux->last_mark_ppos))?"match":"error",
+			       mt_count, next_mark_ppos);
+#endif
+		if (next_mark_ppos <= 10 || next_mark_ppos > STp->eod_frame_ppos) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Reverting to slow filemark space\n", name);
+#endif
+			return osst_space_over_filemarks_forward_slow(STp, aSRpnt, mt_op, mt_count);
+		} else {
+			osst_position_tape_and_confirm(STp, aSRpnt, next_mark_ppos);
+			if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+				printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks\n",
+						 name);
+#endif
+				return (-EIO);
+			}
+			if (STp->buffer->aux->frame_type != OS_FRAME_TYPE_MARKER) {
+				printk(KERN_WARNING "%s:W: Expected to find marker at ppos %d, not found\n",
+						 name, next_mark_ppos);
+				return (-EIO);
+			}
+			if (ntohl(STp->buffer->aux->filemark_cnt) != cnt + mt_count) {
+				printk(KERN_WARNING "%s:W: Expected to find marker %d at ppos %d, not %d\n",
+						 name, cnt+mt_count, next_mark_ppos,
+						 ntohl(STp->buffer->aux->filemark_cnt));
+       				return (-EIO);
+			}
+		}
+	} else {
+		/*
+		 * Find nearest (usually previous) marker, then jump from marker to marker
+		 */
+		while (1) {
+			if (STp->buffer->aux->frame_type == OS_FRAME_TYPE_MARKER)
+				break;
+			if (STp->buffer->aux->frame_type == OS_FRAME_TYPE_EOD) {
+#if DEBUG
+				printk(OSST_DEB_MSG "%s:D: space_fwd: EOD reached\n", name);
+#endif
+				return (-EIO);
+			}
+			if (ntohl(STp->buffer->aux->filemark_cnt) == 0) {
+				if (STp->first_mark_ppos == -1) {
+#if DEBUG
+					printk(OSST_DEB_MSG "%s:D: Reverting to slow filemark space\n", name);
+#endif
+					return osst_space_over_filemarks_forward_slow(STp, aSRpnt, mt_op, mt_count);
+				}
+				osst_position_tape_and_confirm(STp, aSRpnt, STp->first_mark_ppos);
+				if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+					printk(OSST_DEB_MSG
+					       "%s:D: Couldn't get logical blk num in space_filemarks_fwd_fast\n",
+					       name);
+#endif
+					return (-EIO);
+				}
+				if (STp->buffer->aux->frame_type != OS_FRAME_TYPE_MARKER) {
+					printk(KERN_WARNING "%s:W: Expected to find filemark at %d\n",
+							 name, STp->first_mark_ppos);
+					return (-EIO);
+				}
+			} else {
+				if (osst_space_over_filemarks_backward(STp, aSRpnt, MTBSF, 1) < 0)
+					return (-EIO);
+				mt_count++;
+			}
+		}
+		cnt++;
+		while (cnt != mt_count) {
+			next_mark_ppos = ntohl(STp->buffer->aux->next_mark_ppos);
+			if (!next_mark_ppos || next_mark_ppos > STp->eod_frame_ppos) {
+#if DEBUG
+				printk(OSST_DEB_MSG "%s:D: Reverting to slow filemark space\n", name);
+#endif
+				return osst_space_over_filemarks_forward_slow(STp, aSRpnt, mt_op, mt_count - cnt);
+			}
+#if DEBUG
+			else printk(OSST_DEB_MSG "%s:D: Positioning to next mark at %d\n", name, next_mark_ppos);
+#endif
+			osst_position_tape_and_confirm(STp, aSRpnt, next_mark_ppos);
+			cnt++;
+			if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+				printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in space_filemarks\n",
+						 name);
+#endif
+				return (-EIO);
+			}
+			if (STp->buffer->aux->frame_type != OS_FRAME_TYPE_MARKER) {
+				printk(KERN_WARNING "%s:W: Expected to find marker at ppos %d, not found\n",
+						 name, next_mark_ppos);
+				return (-EIO);
+			}
+		}
+	}
+	if (mt_op == MTFSF) {
+		STp->frame_seq_number++;
+		STp->frame_in_buffer      = 0;
+		STp->buffer->buffer_bytes = 0;
+		STp->buffer->read_pointer = 0;
+		STp->logical_blk_num     += ntohs(STp->buffer->aux->dat.dat_list[0].blk_cnt);
+	}
+	return 0;
+}
+
+/*
+ * In debug mode, we want to see as many errors as possible
+ * to test the error recovery mechanism.
+ */
+#if DEBUG
+static void osst_set_retries(struct osst_tape * STp, struct scsi_request ** aSRpnt, int retries)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt  = * aSRpnt;
+	char		      * name   = tape_name(STp);
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = MODE_SELECT;
+	cmd[1] = 0x10;
+	cmd[4] = NUMBER_RETRIES_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+	(STp->buffer)->b_data[0] = cmd[4] - 1;
+	(STp->buffer)->b_data[1] = 0;			/* Medium Type - ignoring */
+	(STp->buffer)->b_data[2] = 0;			/* Reserved */
+	(STp->buffer)->b_data[3] = 0;			/* Block Descriptor Length */
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 0] = NUMBER_RETRIES_PAGE | (1 << 7);
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 1] = 2;
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 2] = 4;
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 3] = retries;
+
+	if (debugging)
+	    printk(OSST_DEB_MSG "%s:D: Setting number of retries on OnStream tape to %d\n", name, retries);
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_TO_DEVICE, STp->timeout, 0, 1);
+	*aSRpnt = SRpnt;
+
+	if ((STp->buffer)->syscall_result)
+	    printk (KERN_ERR "%s:D: Couldn't set retries to %d\n", name, retries);
+}
+#endif
+
+
+static int osst_write_filemark(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	int	result;
+	int	this_mark_ppos = STp->first_frame_position;
+	int	this_mark_lbn  = STp->logical_blk_num;
+#if DEBUG
+	char  * name = tape_name(STp);
+#endif
+
+	if (STp->raw) return 0;
+
+	STp->write_type = OS_WRITE_NEW_MARK;
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Writing Filemark %i at fppos %d (fseq %d, lblk %d)\n", 
+	       name, STp->filemark_cnt, this_mark_ppos, STp->frame_seq_number, this_mark_lbn);
+#endif
+	STp->dirty = 1;
+	result  = osst_flush_write_buffer(STp, aSRpnt);
+	result |= osst_flush_drive_buffer(STp, aSRpnt);
+	STp->last_mark_ppos = this_mark_ppos;
+	STp->last_mark_lbn  = this_mark_lbn;
+	if (STp->header_cache != NULL && STp->filemark_cnt < OS_FM_TAB_MAX)
+		STp->header_cache->dat_fm_tab.fm_tab_ent[STp->filemark_cnt] = htonl(this_mark_ppos);
+	if (STp->filemark_cnt++ == 0)
+		STp->first_mark_ppos = this_mark_ppos;
+	return result;
+}
+
+static int osst_write_eod(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	int	result;
+#if DEBUG
+	char  * name = tape_name(STp);
+#endif
+
+	if (STp->raw) return 0;
+
+	STp->write_type = OS_WRITE_EOD;
+	STp->eod_frame_ppos = STp->first_frame_position;
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Writing EOD at fppos %d (fseq %d, lblk %d)\n", name,
+			STp->eod_frame_ppos, STp->frame_seq_number, STp->logical_blk_num);
+#endif
+	STp->dirty = 1;
+
+	result  = osst_flush_write_buffer(STp, aSRpnt);	
+	result |= osst_flush_drive_buffer(STp, aSRpnt);
+	STp->eod_frame_lfa = --(STp->frame_seq_number);
+	return result;
+}
+
+static int osst_write_filler(struct osst_tape * STp, struct scsi_request ** aSRpnt, int where, int count)
+{
+	char * name = tape_name(STp);
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Reached onstream write filler group %d\n", name, where);
+#endif
+	osst_wait_ready(STp, aSRpnt, 60 * 5, 0);
+	osst_set_frame_position(STp, aSRpnt, where, 0);
+	STp->write_type = OS_WRITE_FILLER;
+	while (count--) {
+		memcpy(STp->buffer->b_data, "Filler", 6);
+		STp->buffer->buffer_bytes = 6;
+		STp->dirty = 1;
+		if (osst_flush_write_buffer(STp, aSRpnt)) {
+			printk(KERN_INFO "%s:I: Couldn't write filler frame\n", name);
+			return (-EIO);
+		}
+	}
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Exiting onstream write filler group\n", name);
+#endif
+	return osst_flush_drive_buffer(STp, aSRpnt);
+}
+
+static int __osst_write_header(struct osst_tape * STp, struct scsi_request ** aSRpnt, int where, int count)
+{
+	char * name = tape_name(STp);
+	int     result;
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Reached onstream write header group %d\n", name, where);
+#endif
+	osst_wait_ready(STp, aSRpnt, 60 * 5, 0);
+	osst_set_frame_position(STp, aSRpnt, where, 0);
+	STp->write_type = OS_WRITE_HEADER;
+	while (count--) {
+		osst_copy_to_buffer(STp->buffer, (unsigned char *)STp->header_cache);
+		STp->buffer->buffer_bytes = sizeof(os_header_t);
+		STp->dirty = 1;
+		if (osst_flush_write_buffer(STp, aSRpnt)) {
+			printk(KERN_INFO "%s:I: Couldn't write header frame\n", name);
+			return (-EIO);
+		}
+	}
+	result = osst_flush_drive_buffer(STp, aSRpnt);
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Write onstream header group %s\n", name, result?"failed":"done");
+#endif
+	return result;
+}
+
+static int osst_write_header(struct osst_tape * STp, struct scsi_request ** aSRpnt, int locate_eod)
+{
+	os_header_t * header;
+	int	      result;
+	char        * name = tape_name(STp);
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Writing tape header\n", name);
+#endif
+	if (STp->raw) return 0;
+
+	if (STp->header_cache == NULL) {
+		if ((STp->header_cache = (os_header_t *)vmalloc(sizeof(os_header_t))) == NULL) {
+			printk(KERN_ERR "%s:E: Failed to allocate header cache\n", name);
+			return (-ENOMEM);
+		}
+		memset(STp->header_cache, 0, sizeof(os_header_t));
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Allocated and cleared memory for header cache\n", name);
+#endif
+	}
+	if (STp->header_ok) STp->update_frame_cntr++;
+	else                STp->update_frame_cntr = 0;
+
+	header = STp->header_cache;
+	strcpy(header->ident_str, "ADR_SEQ");
+	header->major_rev      = 1;
+	header->minor_rev      = 4;
+	header->ext_trk_tb_off = htons(17192);
+	header->pt_par_num     = 1;
+	header->partition[0].partition_num              = OS_DATA_PARTITION;
+	header->partition[0].par_desc_ver               = OS_PARTITION_VERSION;
+	header->partition[0].wrt_pass_cntr              = htons(STp->wrt_pass_cntr);
+	header->partition[0].first_frame_ppos           = htonl(STp->first_data_ppos);
+	header->partition[0].last_frame_ppos            = htonl(STp->capacity);
+	header->partition[0].eod_frame_ppos             = htonl(STp->eod_frame_ppos);
+	header->cfg_col_width                           = htonl(20);
+	header->dat_col_width                           = htonl(1500);
+	header->qfa_col_width                           = htonl(0);
+	header->ext_track_tb.nr_stream_part             = 1;
+	header->ext_track_tb.et_ent_sz                  = 32;
+	header->ext_track_tb.dat_ext_trk_ey.et_part_num = 0;
+	header->ext_track_tb.dat_ext_trk_ey.fmt         = 1;
+	header->ext_track_tb.dat_ext_trk_ey.fm_tab_off  = htons(17736);
+	header->ext_track_tb.dat_ext_trk_ey.last_hlb_hi = 0;
+	header->ext_track_tb.dat_ext_trk_ey.last_hlb    = htonl(STp->eod_frame_lfa);
+	header->ext_track_tb.dat_ext_trk_ey.last_pp	= htonl(STp->eod_frame_ppos);
+	header->dat_fm_tab.fm_part_num                  = 0;
+	header->dat_fm_tab.fm_tab_ent_sz                = 4;
+	header->dat_fm_tab.fm_tab_ent_cnt               = htons(STp->filemark_cnt<OS_FM_TAB_MAX?
+								STp->filemark_cnt:OS_FM_TAB_MAX);
+
+	result  = __osst_write_header(STp, aSRpnt, 0xbae, 5);
+	if (STp->update_frame_cntr == 0)
+		    osst_write_filler(STp, aSRpnt, 0xbb3, 5);
+	result &= __osst_write_header(STp, aSRpnt,     5, 5);
+
+	if (locate_eod) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Locating back to eod frame addr %d\n", name, STp->eod_frame_ppos);
+#endif
+		osst_set_frame_position(STp, aSRpnt, STp->eod_frame_ppos, 0);
+	}
+	if (result)
+		printk(KERN_ERR "%s:E: Write header failed\n", name);
+	else {
+		memcpy(STp->application_sig, "LIN4", 4);
+		STp->linux_media         = 1;
+		STp->linux_media_version = 4;
+		STp->header_ok           = 1;
+	}
+	return result;
+}
+
+static int osst_reset_header(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	if (STp->header_cache != NULL)
+		memset(STp->header_cache, 0, sizeof(os_header_t));
+
+	STp->logical_blk_num = STp->frame_seq_number = 0;
+	STp->frame_in_buffer = 0;
+	STp->eod_frame_ppos = STp->first_data_ppos = 0x0000000A;
+	STp->filemark_cnt = 0;
+	STp->first_mark_ppos = STp->last_mark_ppos = STp->last_mark_lbn = -1;
+	return osst_write_header(STp, aSRpnt, 1);
+}
+
+static int __osst_analyze_headers(struct osst_tape * STp, struct scsi_request ** aSRpnt, int ppos)
+{
+	char        * name = tape_name(STp);
+	os_header_t * header;
+	os_aux_t    * aux;
+	char          id_string[8];
+	int	      linux_media_version,
+		      update_frame_cntr;
+
+	if (STp->raw)
+		return 1;
+
+	if (ppos == 5 || ppos == 0xbae || STp->buffer->syscall_result) {
+		if (osst_set_frame_position(STp, aSRpnt, ppos, 0))
+			printk(KERN_WARNING "%s:W: Couldn't position tape\n", name);
+		osst_wait_ready(STp, aSRpnt, 60 * 15, 0);
+		if (osst_initiate_read (STp, aSRpnt)) {
+			printk(KERN_WARNING "%s:W: Couldn't initiate read\n", name);
+			return 0;
+		}
+	}
+	if (osst_read_frame(STp, aSRpnt, 180)) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Couldn't read header frame\n", name);
+#endif
+		return 0;
+	}
+	header = (os_header_t *) STp->buffer->b_data;	/* warning: only first segment addressable */
+	aux = STp->buffer->aux;
+	if (aux->frame_type != OS_FRAME_TYPE_HEADER) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping non-header frame (%d)\n", name, ppos);
+#endif
+		return 0;
+	}
+	if (ntohl(aux->frame_seq_num)              != 0                   ||
+	    ntohl(aux->logical_blk_num)            != 0                   ||
+	          aux->partition.partition_num     != OS_CONFIG_PARTITION ||
+	    ntohl(aux->partition.first_frame_ppos) != 0                   ||
+	    ntohl(aux->partition.last_frame_ppos)  != 0xbb7               ) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Invalid header frame (%d,%d,%d,%d,%d)\n", name,
+				ntohl(aux->frame_seq_num), ntohl(aux->logical_blk_num),
+			       	aux->partition.partition_num, ntohl(aux->partition.first_frame_ppos),
+			       	ntohl(aux->partition.last_frame_ppos));
+#endif
+		return 0;
+	}
+	if (strncmp(header->ident_str, "ADR_SEQ", 7) != 0 &&
+	    strncmp(header->ident_str, "ADR-SEQ", 7) != 0) {
+		strlcpy(id_string, header->ident_str, 8);
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Invalid header identification string %s\n", name, id_string);
+#endif
+		return 0;
+	}
+	update_frame_cntr = ntohl(aux->update_frame_cntr);
+	if (update_frame_cntr < STp->update_frame_cntr) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame %d with update_frame_counter %d<%d\n",
+				   name, ppos, update_frame_cntr, STp->update_frame_cntr);
+#endif
+		return 0;
+	}
+	if (header->major_rev != 1 || header->minor_rev != 4 ) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: %s revision %d.%d detected (1.4 supported)\n", 
+				 name, (header->major_rev != 1 || header->minor_rev < 2 || 
+				       header->minor_rev  > 4 )? "Invalid" : "Warning:",
+				 header->major_rev, header->minor_rev);
+#endif
+		if (header->major_rev != 1 || header->minor_rev < 2 || header->minor_rev > 4)
+			return 0;
+	}
+#if DEBUG
+	if (header->pt_par_num != 1)
+		printk(KERN_INFO "%s:W: %d partitions defined, only one supported\n", 
+				 name, header->pt_par_num);
+#endif
+	memcpy(id_string, aux->application_sig, 4);
+	id_string[4] = 0;
+	if (memcmp(id_string, "LIN", 3) == 0) {
+		STp->linux_media = 1;
+		linux_media_version = id_string[3] - '0';
+		if (linux_media_version != 4)
+			printk(KERN_INFO "%s:I: Linux media version %d detected (current 4)\n",
+					 name, linux_media_version);
+	} else {
+		printk(KERN_WARNING "%s:W: Non Linux media detected (%s)\n", name, id_string);
+		return 0;
+	}
+	if (linux_media_version < STp->linux_media_version) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Skipping frame %d with linux_media_version %d\n",
+				  name, ppos, linux_media_version);
+#endif
+		return 0;
+	}
+	if (linux_media_version > STp->linux_media_version) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Frame %d sets linux_media_version to %d\n",
+				   name, ppos, linux_media_version);
+#endif
+		memcpy(STp->application_sig, id_string, 5);
+		STp->linux_media_version = linux_media_version;
+		STp->update_frame_cntr = -1;
+	}
+	if (update_frame_cntr > STp->update_frame_cntr) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Frame %d sets update_frame_counter to %d\n",
+				   name, ppos, update_frame_cntr);
+#endif
+		if (STp->header_cache == NULL) {
+			if ((STp->header_cache = (os_header_t *)vmalloc(sizeof(os_header_t))) == NULL) {
+				printk(KERN_ERR "%s:E: Failed to allocate header cache\n", name);
+				return 0;
+			}
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Allocated memory for header cache\n", name);
+#endif
+		}
+		osst_copy_from_buffer(STp->buffer, (unsigned char *)STp->header_cache);
+		header = STp->header_cache;	/* further accesses from cached (full) copy */
+
+		STp->wrt_pass_cntr     = ntohs(header->partition[0].wrt_pass_cntr);
+		STp->first_data_ppos   = ntohl(header->partition[0].first_frame_ppos);
+		STp->eod_frame_ppos    = ntohl(header->partition[0].eod_frame_ppos);
+		STp->eod_frame_lfa     = ntohl(header->ext_track_tb.dat_ext_trk_ey.last_hlb);
+		STp->filemark_cnt      = ntohl(aux->filemark_cnt);
+		STp->first_mark_ppos   = ntohl(aux->next_mark_ppos);
+		STp->last_mark_ppos    = ntohl(aux->last_mark_ppos);
+		STp->last_mark_lbn     = ntohl(aux->last_mark_lbn);
+		STp->update_frame_cntr = update_frame_cntr;
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Detected write pass %d, update frame counter %d, filemark counter %d\n",
+			  name, STp->wrt_pass_cntr, STp->update_frame_cntr, STp->filemark_cnt);
+	printk(OSST_DEB_MSG "%s:D: first data frame on tape = %d, last = %d, eod frame = %d\n", name,
+			  STp->first_data_ppos,
+			  ntohl(header->partition[0].last_frame_ppos),
+			  ntohl(header->partition[0].eod_frame_ppos));
+	printk(OSST_DEB_MSG "%s:D: first mark on tape = %d, last = %d, eod frame = %d\n", 
+			  name, STp->first_mark_ppos, STp->last_mark_ppos, STp->eod_frame_ppos);
+#endif
+		if (header->minor_rev < 4 && STp->linux_media_version == 4) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Moving filemark list to ADR 1.4 location\n", name);
+#endif
+			memcpy((void *)header->dat_fm_tab.fm_tab_ent, 
+			       (void *)header->old_filemark_list, sizeof(header->dat_fm_tab.fm_tab_ent));
+			memset((void *)header->old_filemark_list, 0, sizeof(header->old_filemark_list));
+		}
+		if (header->minor_rev == 4   &&
+		    (header->ext_trk_tb_off                          != htons(17192)               ||
+		     header->partition[0].partition_num              != OS_DATA_PARTITION          ||
+		     header->partition[0].par_desc_ver               != OS_PARTITION_VERSION       ||
+		     header->partition[0].last_frame_ppos            != htonl(STp->capacity)       ||
+		     header->cfg_col_width                           != htonl(20)                  ||
+		     header->dat_col_width                           != htonl(1500)                ||
+		     header->qfa_col_width                           != htonl(0)                   ||
+		     header->ext_track_tb.nr_stream_part             != 1                          ||
+		     header->ext_track_tb.et_ent_sz                  != 32                         ||
+		     header->ext_track_tb.dat_ext_trk_ey.et_part_num != OS_DATA_PARTITION          ||
+		     header->ext_track_tb.dat_ext_trk_ey.fmt         != 1                          ||
+		     header->ext_track_tb.dat_ext_trk_ey.fm_tab_off  != htons(17736)               ||
+		     header->ext_track_tb.dat_ext_trk_ey.last_hlb_hi != 0                          ||
+		     header->ext_track_tb.dat_ext_trk_ey.last_pp     != htonl(STp->eod_frame_ppos) ||
+		     header->dat_fm_tab.fm_part_num                  != OS_DATA_PARTITION          ||
+		     header->dat_fm_tab.fm_tab_ent_sz                != 4                          ||
+		     header->dat_fm_tab.fm_tab_ent_cnt               !=
+			     htons(STp->filemark_cnt<OS_FM_TAB_MAX?STp->filemark_cnt:OS_FM_TAB_MAX)))
+			printk(KERN_WARNING "%s:W: Failed consistency check ADR 1.4 format\n", name);
+
+	}
+
+	return 1;
+}
+
+static int osst_analyze_headers(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	int	position, ppos;
+	int	first, last;
+	int	valid = 0;
+	char  * name  = tape_name(STp);
+
+	position = osst_get_frame_position(STp, aSRpnt);
+
+	if (STp->raw) {
+		STp->header_ok = STp->linux_media = 1;
+		STp->linux_media_version = 0;
+		return 1;
+	}
+	STp->header_ok = STp->linux_media = STp->linux_media_version = 0;
+	STp->wrt_pass_cntr = STp->update_frame_cntr = -1;
+	STp->eod_frame_ppos = STp->first_data_ppos = -1;
+	STp->first_mark_ppos = STp->last_mark_ppos = STp->last_mark_lbn = -1;
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Reading header\n", name);
+#endif
+
+	/* optimization for speed - if we are positioned at ppos 10, read second group first  */	
+	/* TODO try the ADR 1.1 locations for the second group if we have no valid one yet... */
+
+	first = position==10?0xbae: 5;
+	last  = position==10?0xbb3:10;
+
+	for (ppos = first; ppos < last; ppos++)
+		if (__osst_analyze_headers(STp, aSRpnt, ppos))
+			valid = 1;
+
+	first = position==10? 5:0xbae;
+	last  = position==10?10:0xbb3;
+
+	for (ppos = first; ppos < last; ppos++)
+		if (__osst_analyze_headers(STp, aSRpnt, ppos))
+			valid = 1;
+
+	if (!valid) {
+		printk(KERN_ERR "%s:E: Failed to find valid ADRL header, new media?\n", name);
+		STp->eod_frame_ppos = STp->first_data_ppos = 0;
+		osst_set_frame_position(STp, aSRpnt, 10, 0);
+		return 0;
+	}
+	if (position <= STp->first_data_ppos) {
+		position = STp->first_data_ppos;
+		STp->ps[0].drv_file = STp->ps[0].drv_block = STp->frame_seq_number = STp->logical_blk_num = 0;
+	}
+	osst_set_frame_position(STp, aSRpnt, position, 0);
+	STp->header_ok = 1;
+
+	return 1;
+}
+
+static int osst_verify_position(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+{
+	int	frame_position  = STp->first_frame_position;
+	int	frame_seq_numbr = STp->frame_seq_number;
+	int	logical_blk_num = STp->logical_blk_num;
+       	int	halfway_frame   = STp->frame_in_buffer;
+	int	read_pointer    = STp->buffer->read_pointer;
+	int	prev_mark_ppos  = -1;
+	int	actual_mark_ppos, i, n;
+#if DEBUG
+	char  * name = tape_name(STp);
+
+	printk(OSST_DEB_MSG "%s:D: Verify that the tape is really the one we think before writing\n", name);
+#endif
+	osst_set_frame_position(STp, aSRpnt, frame_position - 1, 0);
+	if (osst_get_logical_frame(STp, aSRpnt, -1, 0) < 0) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Couldn't get logical blk num in verify_position\n", name);
+#endif
+		return (-EIO);
+	}
+	if (STp->linux_media_version >= 4) {
+		for (i=0; i<STp->filemark_cnt; i++)
+			if ((n=ntohl(STp->header_cache->dat_fm_tab.fm_tab_ent[i])) < frame_position)
+				prev_mark_ppos = n;
+	} else
+		prev_mark_ppos = frame_position - 1;  /* usually - we don't really know */
+	actual_mark_ppos = STp->buffer->aux->frame_type == OS_FRAME_TYPE_MARKER ?
+				frame_position - 1 : ntohl(STp->buffer->aux->last_mark_ppos);
+	if (frame_position  != STp->first_frame_position                   ||
+	    frame_seq_numbr != STp->frame_seq_number + (halfway_frame?0:1) ||
+	    prev_mark_ppos  != actual_mark_ppos                            ) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Block mismatch: fppos %d-%d, fseq %d-%d, mark %d-%d\n", name,
+				  STp->first_frame_position, frame_position, 
+				  STp->frame_seq_number + (halfway_frame?0:1),
+				  frame_seq_numbr, actual_mark_ppos, prev_mark_ppos);
+#endif
+		return (-EIO);
+	}
+	if (halfway_frame) {
+		/* prepare buffer for append and rewrite on top of original */
+		osst_set_frame_position(STp, aSRpnt, frame_position - 1, 0);
+		STp->buffer->buffer_bytes  = read_pointer;
+		STp->ps[STp->partition].rw = ST_WRITING;
+		STp->dirty                 = 1;
+	}
+	STp->frame_in_buffer  = halfway_frame;
+	STp->frame_seq_number = frame_seq_numbr;
+	STp->logical_blk_num  = logical_blk_num;
+	return 0;
+}
+
+/* Acc. to OnStream, the vers. numbering is the following:
+ * X.XX for released versions (X=digit), 
+ * XXXY for unreleased versions (Y=letter)
+ * Ordering 1.05 < 106A < 106B < ...  < 106a < ... < 1.06
+ * This fn makes monoton numbers out of this scheme ...
+ */
+static unsigned int osst_parse_firmware_rev (const char * str)
+{
+	if (str[1] == '.') {
+		return (str[0]-'0')*10000
+			+(str[2]-'0')*1000
+			+(str[3]-'0')*100;
+	} else {
+		return (str[0]-'0')*10000
+			+(str[1]-'0')*1000
+			+(str[2]-'0')*100 - 100
+			+(str[3]-'@');
+	}
+}
+
+/*
+ * Configure the OnStream SCII tape drive for default operation
+ */
+static int osst_configure_onstream(struct osst_tape *STp, struct scsi_request ** aSRpnt)
+{
+	unsigned char                  cmd[MAX_COMMAND_SIZE];
+	char                         * name = tape_name(STp);
+	struct scsi_request                 * SRpnt = * aSRpnt;
+	osst_mode_parameter_header_t * header;
+	osst_block_size_page_t       * bs;
+	osst_capabilities_page_t     * cp;
+	osst_tape_paramtr_page_t     * prm;
+	int                            drive_buffer_size;
+
+	if (STp->ready != ST_READY) {
+#if DEBUG
+	    printk(OSST_DEB_MSG "%s:D: Not Ready\n", name);
+#endif
+	    return (-EIO);
+	}
+	
+	if (STp->os_fw_rev < 10600) {
+	    printk(KERN_INFO "%s:I: Old OnStream firmware revision detected (%s),\n", name, STp->device->rev);
+	    printk(KERN_INFO "%s:I: an upgrade to version 1.06 or above is recommended\n", name);
+	}
+
+	/*
+	 * Configure 32.5KB (data+aux) frame size.
+         * Get the current frame size from the block size mode page
+	 */
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = MODE_SENSE;
+	cmd[1] = 8;
+	cmd[2] = BLOCK_SIZE_PAGE;
+	cmd[4] = BLOCK_SIZE_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_FROM_DEVICE, STp->timeout, 0, 1);
+	if (SRpnt == NULL) {
+#if DEBUG
+ 	    printk(OSST_DEB_MSG "osst :D: Busy\n");
+#endif
+	    return (-EBUSY);
+	}
+	*aSRpnt = SRpnt;
+	if ((STp->buffer)->syscall_result != 0) {
+	    printk (KERN_ERR "%s:E: Can't get tape block size mode page\n", name);
+	    return (-EIO);
+	}
+
+	header = (osst_mode_parameter_header_t *) (STp->buffer)->b_data;
+	bs = (osst_block_size_page_t *) ((STp->buffer)->b_data + sizeof(osst_mode_parameter_header_t) + header->bdl);
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: 32KB play back: %s\n",   name, bs->play32     ? "Yes" : "No");
+	printk(OSST_DEB_MSG "%s:D: 32.5KB play back: %s\n", name, bs->play32_5   ? "Yes" : "No");
+	printk(OSST_DEB_MSG "%s:D: 32KB record: %s\n",      name, bs->record32   ? "Yes" : "No");
+	printk(OSST_DEB_MSG "%s:D: 32.5KB record: %s\n",    name, bs->record32_5 ? "Yes" : "No");
+#endif
+
+	/*
+	 * Configure default auto columns mode, 32.5KB transfer mode
+	 */ 
+	bs->one = 1;
+	bs->play32 = 0;
+	bs->play32_5 = 1;
+	bs->record32 = 0;
+	bs->record32_5 = 1;
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = MODE_SELECT;
+	cmd[1] = 0x10;
+	cmd[4] = BLOCK_SIZE_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_TO_DEVICE, STp->timeout, 0, 1);
+	*aSRpnt = SRpnt;
+	if ((STp->buffer)->syscall_result != 0) {
+	    printk (KERN_ERR "%s:E: Couldn't set tape block size mode page\n", name);
+	    return (-EIO);
+	}
+
+#if DEBUG
+	printk(KERN_INFO "%s:D: Drive Block Size changed to 32.5K\n", name);
+	 /*
+	 * In debug mode, we want to see as many errors as possible
+	 * to test the error recovery mechanism.
+	 */
+	osst_set_retries(STp, aSRpnt, 0);
+	SRpnt = * aSRpnt;
+#endif
+
+	/*
+	 * Set vendor name to 'LIN4' for "Linux support version 4".
+	 */
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = MODE_SELECT;
+	cmd[1] = 0x10;
+	cmd[4] = VENDOR_IDENT_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+	header->mode_data_length = VENDOR_IDENT_PAGE_LENGTH + MODE_HEADER_LENGTH - 1;
+	header->medium_type      = 0;	/* Medium Type - ignoring */
+	header->dsp              = 0;	/* Reserved */
+	header->bdl              = 0;	/* Block Descriptor Length */
+	
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 0] = VENDOR_IDENT_PAGE | (1 << 7);
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 1] = 6;
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 2] = 'L';
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 3] = 'I';
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 4] = 'N';
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 5] = '4';
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 6] = 0;
+	(STp->buffer)->b_data[MODE_HEADER_LENGTH + 7] = 0;
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_TO_DEVICE, STp->timeout, 0, 1);
+	*aSRpnt = SRpnt;
+
+	if ((STp->buffer)->syscall_result != 0) {
+	    printk (KERN_ERR "%s:E: Couldn't set vendor name to %s\n", name, 
+			(char *) ((STp->buffer)->b_data + MODE_HEADER_LENGTH + 2));
+	    return (-EIO);
+	}
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = MODE_SENSE;
+	cmd[1] = 8;
+	cmd[2] = CAPABILITIES_PAGE;
+	cmd[4] = CAPABILITIES_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_FROM_DEVICE, STp->timeout, 0, 1);
+	*aSRpnt = SRpnt;
+
+	if ((STp->buffer)->syscall_result != 0) {
+	    printk (KERN_ERR "%s:E: Can't get capabilities page\n", name);
+	    return (-EIO);
+	}
+
+	header = (osst_mode_parameter_header_t *) (STp->buffer)->b_data;
+	cp     = (osst_capabilities_page_t    *) ((STp->buffer)->b_data +
+		 sizeof(osst_mode_parameter_header_t) + header->bdl);
+
+	drive_buffer_size = ntohs(cp->buffer_size) / 2;
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = MODE_SENSE;
+	cmd[1] = 8;
+	cmd[2] = TAPE_PARAMTR_PAGE;
+	cmd[4] = TAPE_PARAMTR_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_FROM_DEVICE, STp->timeout, 0, 1);
+	*aSRpnt = SRpnt;
+
+	if ((STp->buffer)->syscall_result != 0) {
+	    printk (KERN_ERR "%s:E: Can't get tape parameter page\n", name);
+	    return (-EIO);
+	}
+
+	header = (osst_mode_parameter_header_t *) (STp->buffer)->b_data;
+	prm    = (osst_tape_paramtr_page_t    *) ((STp->buffer)->b_data +
+		 sizeof(osst_mode_parameter_header_t) + header->bdl);
+
+	STp->density  = prm->density;
+	STp->capacity = ntohs(prm->segtrk) * ntohs(prm->trks);
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Density %d, tape length: %dMB, drive buffer size: %dKB\n",
+			  name, STp->density, STp->capacity / 32, drive_buffer_size);
+#endif
+
+	return 0;
+	
+}
+
+
+/* Step over EOF if it has been inadvertently crossed (ioctl not used because
+   it messes up the block number). */
+static int cross_eof(struct osst_tape *STp, struct scsi_request ** aSRpnt, int forward)
+{
+	int	result;
+	char  * name = tape_name(STp);
+
+#if DEBUG
+	if (debugging)
+		printk(OSST_DEB_MSG "%s:D: Stepping over filemark %s.\n",
+	   			  name, forward ? "forward" : "backward");
+#endif
+
+	if (forward) {
+	   /* assumes that the filemark is already read by the drive, so this is low cost */
+	   result = osst_space_over_filemarks_forward_slow(STp, aSRpnt, MTFSF, 1);
+	}
+	else
+	   /* assumes this is only called if we just read the filemark! */
+	   result = osst_seek_logical_blk(STp, aSRpnt, STp->logical_blk_num - 1);
+
+	if (result < 0)
+	   printk(KERN_WARNING "%s:W: Stepping over filemark %s failed.\n",
+				name, forward ? "forward" : "backward");
+
+	return result;
+}
+
+
+/* Get the tape position. */
+
+static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt)
+{
+	unsigned char		scmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	int			result = 0;
+	char    	      * name   = tape_name(STp);
+
+	/* KG: We want to be able to use it for checking Write Buffer availability
+	 *  and thus don't want to risk to overwrite anything. Exchange buffers ... */
+	char		mybuf[24];
+	char	      * olddata = STp->buffer->b_data;
+	int		oldsize = STp->buffer->buffer_size;
+
+	if (STp->ready != ST_READY) return (-EIO);
+
+	memset (scmd, 0, MAX_COMMAND_SIZE);
+	scmd[0] = READ_POSITION;
+
+	STp->buffer->b_data = mybuf; STp->buffer->buffer_size = 24;
+	SRpnt = osst_do_scsi(*aSRpnt, STp, scmd, 20, DMA_FROM_DEVICE,
+				      STp->timeout, MAX_RETRIES, 1);
+	if (!SRpnt) {
+		STp->buffer->b_data = olddata; STp->buffer->buffer_size = oldsize;
+		return (-EBUSY);
+	}
+	*aSRpnt = SRpnt;
+
+	if (STp->buffer->syscall_result)
+		result = ((SRpnt->sr_sense_buffer[2] & 0x0f) == 3) ? -EIO : -EINVAL;	/* 3: Write Error */
+
+	if (result == -EINVAL)
+		printk(KERN_ERR "%s:E: Can't read tape position.\n", name);
+	else {
+		if (result == -EIO) {	/* re-read position - this needs to preserve media errors */
+			unsigned char mysense[16];
+			memcpy (mysense, SRpnt->sr_sense_buffer, 16);
+			memset (scmd, 0, MAX_COMMAND_SIZE);
+			scmd[0] = READ_POSITION;
+			STp->buffer->b_data = mybuf; STp->buffer->buffer_size = 24;
+			SRpnt = osst_do_scsi(SRpnt, STp, scmd, 20, DMA_FROM_DEVICE,
+						    STp->timeout, MAX_RETRIES, 1);
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Reread position, reason=[%02x:%02x:%02x], result=[%s%02x:%02x:%02x]\n",
+					name, mysense[2], mysense[12], mysense[13], STp->buffer->syscall_result?"":"ok:",
+					SRpnt->sr_sense_buffer[2],SRpnt->sr_sense_buffer[12],SRpnt->sr_sense_buffer[13]);
+#endif
+			if (!STp->buffer->syscall_result)
+				memcpy (SRpnt->sr_sense_buffer, mysense, 16);
+			else
+				printk(KERN_WARNING "%s:W: Double error in get position\n", name);
+		}
+		STp->first_frame_position = ((STp->buffer)->b_data[4] << 24)
+					  + ((STp->buffer)->b_data[5] << 16)
+					  + ((STp->buffer)->b_data[6] << 8)
+					  +  (STp->buffer)->b_data[7];
+		STp->last_frame_position  = ((STp->buffer)->b_data[ 8] << 24)
+					  + ((STp->buffer)->b_data[ 9] << 16)
+					  + ((STp->buffer)->b_data[10] <<  8)
+					  +  (STp->buffer)->b_data[11];
+		STp->cur_frames           =  (STp->buffer)->b_data[15];
+#if DEBUG
+		if (debugging) {
+			printk(OSST_DEB_MSG "%s:D: Drive Positions: host %d, tape %d%s, buffer %d\n", name,
+					    STp->first_frame_position, STp->last_frame_position,
+					    ((STp->buffer)->b_data[0]&0x80)?" (BOP)":
+					    ((STp->buffer)->b_data[0]&0x40)?" (EOP)":"",
+					    STp->cur_frames);
+		}
+#endif
+		if (STp->cur_frames == 0 && STp->first_frame_position != STp->last_frame_position) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Correcting read position %d, %d, %d\n", name,
+					STp->first_frame_position, STp->last_frame_position, STp->cur_frames);
+#endif
+			STp->first_frame_position = STp->last_frame_position;
+		}
+	}
+	STp->buffer->b_data = olddata; STp->buffer->buffer_size = oldsize;
+
+	return (result == 0 ? STp->first_frame_position : result);
+}
+
+
+/* Set the tape block */
+static int osst_set_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt, int ppos, int skip)
+{
+	unsigned char		scmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	struct st_partstat    * STps;
+	int			result = 0;
+	int			pp     = (ppos == 3000 && !skip)? 0 : ppos;
+	char		      * name   = tape_name(STp);
+
+	if (STp->ready != ST_READY) return (-EIO);
+
+	STps = &(STp->ps[STp->partition]);
+
+	if (ppos < 0 || ppos > STp->capacity) {
+		printk(KERN_WARNING "%s:W: Reposition request %d out of range\n", name, ppos);
+		pp = ppos = ppos < 0 ? 0 : (STp->capacity - 1);
+		result = (-EINVAL);
+	}
+
+	do {
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Setting ppos to %d.\n", name, pp);
+#endif
+		memset (scmd, 0, MAX_COMMAND_SIZE);
+		scmd[0] = SEEK_10;
+		scmd[1] = 1;
+		scmd[3] = (pp >> 24);
+		scmd[4] = (pp >> 16);
+		scmd[5] = (pp >> 8);
+		scmd[6] =  pp;
+		if (skip)
+			scmd[9] = 0x80;
+
+		SRpnt = osst_do_scsi(*aSRpnt, STp, scmd, 0, DMA_NONE, STp->long_timeout,
+								MAX_RETRIES, 1);
+		if (!SRpnt)
+			return (-EBUSY);
+		*aSRpnt  = SRpnt;
+
+		if ((STp->buffer)->syscall_result != 0) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: SEEK command from %d to %d failed.\n",
+					name, STp->first_frame_position, pp);
+#endif
+			result = (-EIO);
+		}
+		if (pp != ppos)
+			osst_wait_ready(STp, aSRpnt, 5 * 60, OSST_WAIT_POSITION_COMPLETE);
+	} while ((pp != ppos) && (pp = ppos));
+	STp->first_frame_position = STp->last_frame_position = ppos;
+	STps->eof = ST_NOEOF;
+	STps->at_sm = 0;
+	STps->rw = ST_IDLE;
+	STp->frame_in_buffer = 0;
+	return result;
+}
+
+static int osst_write_trailer(struct osst_tape *STp, struct scsi_request ** aSRpnt, int leave_at_EOT)
+{
+	struct st_partstat * STps = &(STp->ps[STp->partition]);
+	int result = 0;
+
+	if (STp->write_type != OS_WRITE_NEW_MARK) {
+		/* true unless the user wrote the filemark for us */
+		result = osst_flush_drive_buffer(STp, aSRpnt);
+		if (result < 0) goto out;
+		result = osst_write_filemark(STp, aSRpnt);
+		if (result < 0) goto out;
+
+		if (STps->drv_file >= 0)
+			STps->drv_file++ ;
+		STps->drv_block = 0;
+	}
+	result = osst_write_eod(STp, aSRpnt);
+	osst_write_header(STp, aSRpnt, leave_at_EOT);
+
+	STps->eof = ST_FM;
+out:
+	return result;
+}
+
+/* osst versions of st functions - augmented and stripped to suit OnStream only */
+
+/* Flush the write buffer (never need to write if variable blocksize). */
+static int osst_flush_write_buffer(struct osst_tape *STp, struct scsi_request ** aSRpnt)
+{
+	int			offset, transfer, blks = 0;
+	int			result = 0;
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt = *aSRpnt;
+	struct st_partstat    * STps;
+	char		      * name = tape_name(STp);
+
+	if ((STp->buffer)->writing) {
+		if (SRpnt == (STp->buffer)->last_SRpnt)
+#if DEBUG
+			{ printk(OSST_DEB_MSG
+	 "%s:D: aSRpnt points to scsi_request that write_behind_check will release -- cleared\n", name);
+#endif
+			*aSRpnt = SRpnt = NULL;
+#if DEBUG
+			} else if (SRpnt)
+				printk(OSST_DEB_MSG
+	 "%s:D: aSRpnt does not point to scsi_request that write_behind_check will release -- strange\n", name);
+#endif	
+		osst_write_behind_check(STp);
+		if ((STp->buffer)->syscall_result) {
+#if DEBUG
+			if (debugging)
+				printk(OSST_DEB_MSG "%s:D: Async write error (flush) %x.\n",
+				       name, (STp->buffer)->midlevel_result);
+#endif
+			if ((STp->buffer)->midlevel_result == INT_MAX)
+				return (-ENOSPC);
+			return (-EIO);
+		}
+	}
+
+	result = 0;
+	if (STp->dirty == 1) {
+
+		STp->write_count++;
+		STps     = &(STp->ps[STp->partition]);
+		STps->rw = ST_WRITING;
+		offset   = STp->buffer->buffer_bytes;
+		blks     = (offset + STp->block_size - 1) / STp->block_size;
+		transfer = OS_FRAME_SIZE;
+		
+		if (offset < OS_DATA_SIZE)
+			osst_zero_buffer_tail(STp->buffer);
+
+		if (STp->poll)
+			if (osst_wait_frame (STp, aSRpnt, STp->first_frame_position, -50, 120))
+				result = osst_recover_wait_frame(STp, aSRpnt, 1);
+
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = WRITE_6;
+		cmd[1] = 1;
+		cmd[4] = 1;
+
+		switch	(STp->write_type) {
+		   case OS_WRITE_DATA:
+#if DEBUG
+   			if (debugging)
+				printk(OSST_DEB_MSG "%s:D: Writing %d blocks to frame %d, lblks %d-%d\n",
+					name, blks, STp->frame_seq_number, 
+					STp->logical_blk_num - blks, STp->logical_blk_num - 1);
+#endif
+			osst_init_aux(STp, OS_FRAME_TYPE_DATA, STp->frame_seq_number++,
+				      STp->logical_blk_num - blks, STp->block_size, blks);
+			break;
+		   case OS_WRITE_EOD:
+			osst_init_aux(STp, OS_FRAME_TYPE_EOD, STp->frame_seq_number++,
+				      STp->logical_blk_num, 0, 0);
+			break;
+		   case OS_WRITE_NEW_MARK:
+			osst_init_aux(STp, OS_FRAME_TYPE_MARKER, STp->frame_seq_number++,
+				      STp->logical_blk_num++, 0, blks=1);
+			break;
+		   case OS_WRITE_HEADER:
+			osst_init_aux(STp, OS_FRAME_TYPE_HEADER, 0, 0, 0, blks=0);
+			break;
+		default: /* probably FILLER */
+			osst_init_aux(STp, OS_FRAME_TYPE_FILL, 0, 0, 0, 0);
+		}
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Flushing %d bytes, Transfering %d bytes in %d lblocks.\n",
+			  			 name, offset, transfer, blks);
+#endif
+
+		SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, transfer, DMA_TO_DEVICE,
+					      STp->timeout, MAX_RETRIES, 1);
+		*aSRpnt = SRpnt;
+		if (!SRpnt)
+			return (-EBUSY);
+
+		if ((STp->buffer)->syscall_result != 0) {
+#if DEBUG
+			printk(OSST_DEB_MSG
+				"%s:D: write sense [0]=0x%02x [2]=%02x [12]=%02x [13]=%02x\n",
+				name, SRpnt->sr_sense_buffer[0], SRpnt->sr_sense_buffer[2],
+				SRpnt->sr_sense_buffer[12], SRpnt->sr_sense_buffer[13]);
+#endif
+			if ((SRpnt->sr_sense_buffer[0] & 0x70) == 0x70 &&
+			    (SRpnt->sr_sense_buffer[2] & 0x40) && /* FIXME - SC-30 drive doesn't assert EOM bit */
+			    (SRpnt->sr_sense_buffer[2] & 0x0f) == NO_SENSE) {
+				STp->dirty = 0;
+				(STp->buffer)->buffer_bytes = 0;
+				result = (-ENOSPC);
+			}
+			else {
+				if (osst_write_error_recovery(STp, aSRpnt, 1)) {
+					printk(KERN_ERR "%s:E: Error on flush write.\n", name);
+					result = (-EIO);
+				}
+			}
+			STps->drv_block = (-1);		/* FIXME - even if write recovery succeeds? */
+		}
+		else {
+			STp->first_frame_position++;
+			STp->dirty = 0;
+			(STp->buffer)->buffer_bytes = 0;
+		}
+	}
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Exit flush write buffer with code %d\n", name, result);
+#endif
+	return result;
+}
+
+
+/* Flush the tape buffer. The tape will be positioned correctly unless
+   seek_next is true. */
+static int osst_flush_buffer(struct osst_tape * STp, struct scsi_request ** aSRpnt, int seek_next)
+{
+	struct st_partstat * STps;
+	int    backspace = 0, result = 0;
+#if DEBUG
+	char * name = tape_name(STp);
+#endif
+
+	/*
+	 * If there was a bus reset, block further access
+	 * to this device.
+	 */
+	if( STp->pos_unknown)
+		return (-EIO);
+
+	if (STp->ready != ST_READY)
+		return 0;
+
+	STps = &(STp->ps[STp->partition]);
+	if (STps->rw == ST_WRITING || STp->dirty) {	/* Writing */
+		STp->write_type = OS_WRITE_DATA;
+		return osst_flush_write_buffer(STp, aSRpnt);
+	}
+	if (STp->block_size == 0)
+		return 0;
+
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Reached flush (read) buffer\n", name);
+#endif
+
+	if (!STp->can_bsr) {
+		backspace = ((STp->buffer)->buffer_bytes + (STp->buffer)->read_pointer) / STp->block_size -
+			    ((STp->buffer)->read_pointer + STp->block_size - 1        ) / STp->block_size ;
+		(STp->buffer)->buffer_bytes = 0;
+		(STp->buffer)->read_pointer = 0;
+		STp->frame_in_buffer = 0;		/* FIXME is this relevant w. OSST? */
+	}
+
+	if (!seek_next) {
+		if (STps->eof == ST_FM_HIT) {
+			result = cross_eof(STp, aSRpnt, 0); /* Back over the EOF hit */
+			if (!result)
+				STps->eof = ST_NOEOF;
+			else {
+				if (STps->drv_file >= 0)
+					STps->drv_file++;
+				STps->drv_block = 0;
+			}
+		}
+		if (!result && backspace > 0)	/* TODO -- design and run a test case for this */
+			result = osst_seek_logical_blk(STp, aSRpnt, STp->logical_blk_num - backspace);
+	}
+	else if (STps->eof == ST_FM_HIT) {
+		if (STps->drv_file >= 0)
+			STps->drv_file++;
+		STps->drv_block = 0;
+		STps->eof = ST_NOEOF;
+	}
+
+	return result;
+}
+
+static int osst_write_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt, int synchronous)
+{
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt;
+	int			blks;
+#if DEBUG
+	char		      * name = tape_name(STp);
+#endif
+
+	if ((!STp-> raw) && (STp->first_frame_position == 0xbae)) { /* _must_ preserve buffer! */
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Reaching config partition.\n", name);
+#endif
+		if (osst_flush_drive_buffer(STp, aSRpnt) < 0) {
+			return (-EIO);
+		}
+		/* error recovery may have bumped us past the header partition */
+		if (osst_get_frame_position(STp, aSRpnt) < 0xbb8) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Skipping over config partition.\n", name);
+#endif
+		osst_position_tape_and_confirm(STp, aSRpnt, 0xbb8);
+		}
+	}
+
+	if (STp->poll)
+		if (osst_wait_frame (STp, aSRpnt, STp->first_frame_position, -48, 120))
+			if (osst_recover_wait_frame(STp, aSRpnt, 1))
+				return (-EIO);
+
+//	osst_build_stats(STp, &SRpnt);
+
+	STp->ps[STp->partition].rw = ST_WRITING;
+	STp->write_type            = OS_WRITE_DATA;
+			
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0]   = WRITE_6;
+	cmd[1]   = 1;
+	cmd[4]   = 1;						/* one frame at a time... */
+	blks     = STp->buffer->buffer_bytes / STp->block_size;
+#if DEBUG
+	if (debugging)
+		printk(OSST_DEB_MSG "%s:D: Writing %d blocks to frame %d, lblks %d-%d\n", name, blks, 
+			STp->frame_seq_number, STp->logical_blk_num - blks, STp->logical_blk_num - 1);
+#endif
+	osst_init_aux(STp, OS_FRAME_TYPE_DATA, STp->frame_seq_number++,
+		      STp->logical_blk_num - blks, STp->block_size, blks);
+
+#if DEBUG
+	if (!synchronous)
+		STp->write_pending = 1;
+#endif
+	SRpnt = osst_do_scsi(*aSRpnt, STp, cmd, OS_FRAME_SIZE, DMA_TO_DEVICE, STp->timeout,
+									MAX_RETRIES, synchronous);
+	if (!SRpnt)
+		return (-EBUSY);
+	*aSRpnt = SRpnt;
+
+	if (synchronous) {
+		if (STp->buffer->syscall_result != 0) {
+#if DEBUG
+			if (debugging)
+				printk(OSST_DEB_MSG "%s:D: Error on write:\n", name);
+#endif
+			if ((SRpnt->sr_sense_buffer[0] & 0x70) == 0x70 &&
+			    (SRpnt->sr_sense_buffer[2] & 0x40)) {
+				if ((SRpnt->sr_sense_buffer[2] & 0x0f) == VOLUME_OVERFLOW)
+					return (-ENOSPC);
+			}
+			else {
+				if (osst_write_error_recovery(STp, aSRpnt, 1))
+					return (-EIO);
+			}
+		}
+		else
+			STp->first_frame_position++;
+	}
+
+	STp->write_count++;
+
+	return 0;
+}
+
+/* Lock or unlock the drive door. Don't use when struct scsi_request allocated. */
+static int do_door_lock(struct osst_tape * STp, int do_lock)
+{
+	int retval, cmd;
+
+	cmd = do_lock ? SCSI_IOCTL_DOORLOCK : SCSI_IOCTL_DOORUNLOCK;
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: %socking drive door.\n", tape_name(STp), do_lock ? "L" : "Unl");
+#endif
+	retval = scsi_ioctl(STp->device, cmd, NULL);
+	if (!retval) {
+		STp->door_locked = do_lock ? ST_LOCKED_EXPLICIT : ST_UNLOCKED;
+	}
+	else {
+		STp->door_locked = ST_LOCK_FAILS;
+	}
+	return retval;
+}
+
+/* Set the internal state after reset */
+static void reset_state(struct osst_tape *STp)
+{
+	int i;
+	struct st_partstat *STps;
+
+	STp->pos_unknown = 0;
+	for (i = 0; i < ST_NBR_PARTITIONS; i++) {
+		STps = &(STp->ps[i]);
+		STps->rw = ST_IDLE;
+		STps->eof = ST_NOEOF;
+		STps->at_sm = 0;
+		STps->last_block_valid = 0;
+		STps->drv_block = -1;
+		STps->drv_file = -1;
+	}
+}
+				
+
+/* Entry points to osst */
+
+/* Write command */
+static ssize_t osst_write(struct file * filp, const char __user * buf, size_t count, loff_t *ppos)
+{
+	ssize_t		      total, retval = 0;
+	ssize_t		      i, do_count, blks, transfer;
+	int		      write_threshold;
+	int		      doing_write = 0;
+	const char   __user * b_point;
+	struct scsi_request * SRpnt = NULL;
+	struct st_modedef   * STm;
+	struct st_partstat  * STps;
+	struct osst_tape    * STp  = filp->private_data;
+	char		    * name = tape_name(STp);
+
+
+	if (down_interruptible(&STp->lock))
+		return (-ERESTARTSYS);
+
+	/*
+	 * If we are in the middle of error recovery, don't let anyone
+	 * else try and use this device.  Also, if error recovery fails, it
+	 * may try and take the device offline, in which case all further
+	 * access to the device is prohibited.
+	 */
+	if( !scsi_block_when_processing_errors(STp->device) ) {
+		retval = (-ENXIO);
+		goto out;
+	}
+	
+	if (STp->ready != ST_READY) {
+		if (STp->ready == ST_NO_TAPE)
+			retval = (-ENOMEDIUM);
+		else
+			retval = (-EIO);
+		goto out;
+	}
+	STm = &(STp->modes[STp->current_mode]);
+	if (!STm->defined) {
+		retval = (-ENXIO);
+		goto out;
+	}
+	if (count == 0)
+		goto out;
+
+	/*
+	 * If there was a bus reset, block further access
+	 * to this device.
+	 */
+	if (STp->pos_unknown) {
+		retval = (-EIO);
+		goto out;
+	}
+
+#if DEBUG
+	if (!STp->in_use) {
+		printk(OSST_DEB_MSG "%s:D: Incorrect device.\n", name);
+		retval = (-EIO);
+		goto out;
+	}
+#endif
+
+	if (STp->write_prot) {
+		retval = (-EACCES);
+		goto out;
+	}
+
+	/* Write must be integral number of blocks */
+	if (STp->block_size != 0 && (count % STp->block_size) != 0) {
+		printk(KERN_ERR "%s:E: Write (%Zd bytes) not multiple of tape block size (%d%c).\n",
+				       name, count, STp->block_size<1024?
+				       STp->block_size:STp->block_size/1024, STp->block_size<1024?'b':'k');
+		retval = (-EINVAL);
+		goto out;
+	}
+
+	if (STp->first_frame_position >= STp->capacity - OSST_EOM_RESERVE) {
+		printk(KERN_ERR "%s:E: Write truncated at EOM early warning (frame %d).\n",
+				       name, STp->first_frame_position);
+		retval = (-ENOSPC);
+		goto out;
+	}
+
+	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED && !do_door_lock(STp, 1))
+		STp->door_locked = ST_LOCKED_AUTO;
+
+	STps = &(STp->ps[STp->partition]);
+
+	if (STps->rw == ST_READING) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Switching from read to write at file %d, block %d\n", name, 
+					STps->drv_file, STps->drv_block);
+#endif
+		retval = osst_flush_buffer(STp, &SRpnt, 0);
+		if (retval)
+			goto out;
+		STps->rw = ST_IDLE;
+	}
+	if (STps->rw != ST_WRITING) {
+		/* Are we totally rewriting this tape? */
+		if (!STp->header_ok ||
+		    (STp->first_frame_position == STp->first_data_ppos && STps->drv_block < 0) ||
+		    (STps->drv_file == 0 && STps->drv_block == 0)) {
+			STp->wrt_pass_cntr++;
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Allocating next write pass counter: %d\n",
+						  name, STp->wrt_pass_cntr);
+#endif
+			osst_reset_header(STp, &SRpnt);
+			STps->drv_file = STps->drv_block = 0;
+		}
+		/* Do we know where we'll be writing on the tape? */
+		else {
+			if ((STp->fast_open && osst_verify_position(STp, &SRpnt)) ||
+			  		STps->drv_file < 0 || STps->drv_block < 0) {
+				if (STp->first_frame_position == STp->eod_frame_ppos) {	/* at EOD */
+			  		STps->drv_file = STp->filemark_cnt;
+			  		STps->drv_block = 0;
+				}
+				else {
+					/* We have no idea where the tape is positioned - give up */
+#if DEBUG
+					printk(OSST_DEB_MSG
+						"%s:D: Cannot write at indeterminate position.\n", name);
+#endif
+					retval = (-EIO);
+					goto out;
+				}
+      			}	  
+			if ((STps->drv_file + STps->drv_block) > 0 && STps->drv_file < STp->filemark_cnt) {
+				STp->filemark_cnt = STps->drv_file;
+				STp->last_mark_ppos =
+				       	ntohl(STp->header_cache->dat_fm_tab.fm_tab_ent[STp->filemark_cnt-1]);
+				printk(KERN_WARNING
+					"%s:W: Overwriting file %d with old write pass counter %d\n",
+						name, STps->drv_file, STp->wrt_pass_cntr);
+				printk(KERN_WARNING
+					"%s:W: may lead to stale data being accepted on reading back!\n",
+						name);
+#if DEBUG
+				printk(OSST_DEB_MSG
+				  "%s:D: resetting filemark count to %d and last mark ppos,lbn to %d,%d\n",
+					name, STp->filemark_cnt, STp->last_mark_ppos, STp->last_mark_lbn);
+#endif
+			}
+		}
+		STp->fast_open = 0;
+	}
+	if (!STp->header_ok) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Write cannot proceed without valid headers\n", name);
+#endif
+		retval = (-EIO);
+		goto out;
+	}
+
+	if ((STp->buffer)->writing) {
+if (SRpnt) printk(KERN_ERR "%s:A: Not supposed to have SRpnt at line %d\n", name, __LINE__);
+		osst_write_behind_check(STp);
+		if ((STp->buffer)->syscall_result) {
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Async write error (write) %x.\n", name,
+						 (STp->buffer)->midlevel_result);
+#endif
+		if ((STp->buffer)->midlevel_result == INT_MAX)
+			STps->eof = ST_EOM_OK;
+		else
+			STps->eof = ST_EOM_ERROR;
+		}
+	}
+	if (STps->eof == ST_EOM_OK) {
+		retval = (-ENOSPC);
+		goto out;
+	}
+	else if (STps->eof == ST_EOM_ERROR) {
+		retval = (-EIO);
+		goto out;
+	}
+
+	/* Check the buffer readability in cases where copy_user might catch
+		 the problems after some tape movement. */
+	if ((copy_from_user(&i, buf, 1) != 0 ||
+	     copy_from_user(&i, buf + count - 1, 1) != 0)) {
+		retval = (-EFAULT);
+		goto out;
+	}
+
+	if (!STm->do_buffer_writes) {
+		write_threshold = 1;
+	}
+	else
+		write_threshold = (STp->buffer)->buffer_blocks * STp->block_size;
+	if (!STm->do_async_writes)
+		write_threshold--;
+
+	total = count;
+#if DEBUG
+	if (debugging)
+		printk(OSST_DEB_MSG "%s:D: Writing %d bytes to file %d block %d lblk %d fseq %d fppos %d\n",
+				name, count, STps->drv_file, STps->drv_block,
+				STp->logical_blk_num, STp->frame_seq_number, STp->first_frame_position);
+#endif
+	b_point = buf;
+	while ((STp->buffer)->buffer_bytes + count > write_threshold)
+	{
+		doing_write = 1;
+		do_count = (STp->buffer)->buffer_blocks * STp->block_size -
+			   (STp->buffer)->buffer_bytes;
+		if (do_count > count)
+			do_count = count;
+
+		i = append_to_buffer(b_point, STp->buffer, do_count);
+		if (i) {
+			retval = i;
+			goto out;
+		}
+
+		blks = do_count / STp->block_size;
+		STp->logical_blk_num += blks;  /* logical_blk_num is incremented as data is moved from user */
+  
+		i = osst_write_frame(STp, &SRpnt, 1);
+
+		if (i == (-ENOSPC)) {
+			transfer = STp->buffer->writing;	/* FIXME -- check this logic */
+			if (transfer <= do_count) {
+				filp->f_pos += do_count - transfer;
+				count -= do_count - transfer;
+				if (STps->drv_block >= 0) {
+					STps->drv_block += (do_count - transfer) / STp->block_size;
+				}
+				STps->eof = ST_EOM_OK;
+				retval = (-ENOSPC);		/* EOM within current request */
+#if DEBUG
+				if (debugging)
+				      printk(OSST_DEB_MSG "%s:D: EOM with %d bytes unwritten.\n",
+							     name, transfer);
+#endif
+			}
+			else {
+				STps->eof = ST_EOM_ERROR;
+				STps->drv_block = (-1);		/* Too cautious? */
+				retval = (-EIO);		/* EOM for old data */
+#if DEBUG
+				if (debugging)
+				      printk(OSST_DEB_MSG "%s:D: EOM with lost data.\n", name);
+#endif
+			}
+		}
+		else
+			retval = i;
+			
+		if (retval < 0) {
+			if (SRpnt != NULL) {
+				scsi_release_request(SRpnt);
+				SRpnt = NULL;
+			}
+			STp->buffer->buffer_bytes = 0;
+			STp->dirty = 0;
+			if (count < total)
+				retval = total - count;
+			goto out;
+		}
+
+		filp->f_pos += do_count;
+		b_point += do_count;
+		count -= do_count;
+		if (STps->drv_block >= 0) {
+			STps->drv_block += blks;
+		}
+		STp->buffer->buffer_bytes = 0;
+		STp->dirty = 0;
+	}  /* end while write threshold exceeded */
+
+	if (count != 0) {
+		STp->dirty = 1;
+		i = append_to_buffer(b_point, STp->buffer, count);
+		if (i) {
+			retval = i;
+			goto out;
+		}
+		blks = count / STp->block_size;
+		STp->logical_blk_num += blks;
+		if (STps->drv_block >= 0) {
+			STps->drv_block += blks;
+		}
+		filp->f_pos += count;
+		count = 0;
+	}
+
+	if (doing_write && (STp->buffer)->syscall_result != 0) {
+		retval = (STp->buffer)->syscall_result;
+		goto out;
+	}
+
+	if (STm->do_async_writes && ((STp->buffer)->buffer_bytes >= STp->write_threshold)) { 
+		/* Schedule an asynchronous write */
+		(STp->buffer)->writing = ((STp->buffer)->buffer_bytes /
+					   STp->block_size) * STp->block_size;
+		STp->dirty = !((STp->buffer)->writing ==
+				          (STp->buffer)->buffer_bytes);
+
+		i = osst_write_frame(STp, &SRpnt, 0);
+		if (i < 0) {
+			retval = (-EIO);
+			goto out;
+		}
+		SRpnt = NULL;			/* Prevent releasing this request! */
+	}
+	STps->at_sm &= (total == 0);
+	if (total > 0)
+		STps->eof = ST_NOEOF;
+
+	retval = total;
+
+out:
+	if (SRpnt != NULL) scsi_release_request(SRpnt);
+
+	up(&STp->lock);
+
+	return retval;
+}
+
+
+/* Read command */
+static ssize_t osst_read(struct file * filp, char __user * buf, size_t count, loff_t *ppos)
+{
+	ssize_t		      total, retval = 0;
+	ssize_t		      i, transfer;
+	int		      special;
+	struct st_modedef   * STm;
+	struct st_partstat  * STps;
+	struct scsi_request * SRpnt = NULL;
+	struct osst_tape    * STp   = filp->private_data;
+	char		    * name  = tape_name(STp);
+
+
+	if (down_interruptible(&STp->lock))
+		return (-ERESTARTSYS);
+
+	/*
+	 * If we are in the middle of error recovery, don't let anyone
+	 * else try and use this device.  Also, if error recovery fails, it
+	 * may try and take the device offline, in which case all further
+	 * access to the device is prohibited.
+	 */
+	if( !scsi_block_when_processing_errors(STp->device) ) {
+		retval = (-ENXIO);
+		goto out;
+	}
+	
+	if (STp->ready != ST_READY) {
+		if (STp->ready == ST_NO_TAPE)
+			retval = (-ENOMEDIUM);
+		else
+			retval = (-EIO);
+		goto out;
+	}
+	STm = &(STp->modes[STp->current_mode]);
+	if (!STm->defined) {
+		retval = (-ENXIO);
+		goto out;
+	}
+#if DEBUG
+	if (!STp->in_use) {
+		printk(OSST_DEB_MSG "%s:D: Incorrect device.\n", name);
+		retval = (-EIO);
+		goto out;
+	}
+#endif
+	/* Must have initialized medium */
+	if (!STp->header_ok) {
+		retval = (-EIO);
+		goto out;
+	}
+
+	if (STp->do_auto_lock && STp->door_locked == ST_UNLOCKED && !do_door_lock(STp, 1))
+		STp->door_locked = ST_LOCKED_AUTO;
+
+	STps = &(STp->ps[STp->partition]);
+	if (STps->rw == ST_WRITING) {
+		retval = osst_flush_buffer(STp, &SRpnt, 0);
+		if (retval)
+			goto out;
+		STps->rw = ST_IDLE;
+		/* FIXME -- this may leave the tape without EOD and up2date headers */
+	}
+
+	if ((count % STp->block_size) != 0) {
+		printk(KERN_WARNING
+		    "%s:W: Read (%Zd bytes) not multiple of tape block size (%d%c).\n", name, count,
+		    STp->block_size<1024?STp->block_size:STp->block_size/1024, STp->block_size<1024?'b':'k');
+	}
+
+#if DEBUG
+	if (debugging && STps->eof != ST_NOEOF)
+		printk(OSST_DEB_MSG "%s:D: EOF/EOM flag up (%d). Bytes %d\n", name,
+				     STps->eof, (STp->buffer)->buffer_bytes);
+#endif
+	if ((STp->buffer)->buffer_bytes == 0 &&
+	     STps->eof >= ST_EOD_1) {
+		if (STps->eof < ST_EOD) {
+			STps->eof += 1;
+			retval = 0;
+			goto out;
+		}
+		retval = (-EIO);  /* EOM or Blank Check */
+		goto out;
+	}
+
+	/* Check the buffer writability before any tape movement. Don't alter
+		 buffer data. */
+	if (copy_from_user(&i, buf, 1)             != 0 ||
+	    copy_to_user  (buf, &i, 1)             != 0 ||
+	    copy_from_user(&i, buf + count - 1, 1) != 0 ||
+	    copy_to_user  (buf + count - 1, &i, 1) != 0) {
+		retval = (-EFAULT);
+		goto out;
+	}
+
+	/* Loop until enough data in buffer or a special condition found */
+	for (total = 0, special = 0; total < count - STp->block_size + 1 && !special; ) {
+
+		/* Get new data if the buffer is empty */
+		if ((STp->buffer)->buffer_bytes == 0) {
+			if (STps->eof == ST_FM_HIT)
+				break;
+			special = osst_get_logical_frame(STp, &SRpnt, STp->frame_seq_number, 0);
+			if (special < 0) { 			/* No need to continue read */
+				STp->frame_in_buffer = 0;
+				retval = special;
+				goto out;
+			}
+		}
+
+		/* Move the data from driver buffer to user buffer */
+		if ((STp->buffer)->buffer_bytes > 0) {
+#if DEBUG
+			if (debugging && STps->eof != ST_NOEOF)
+			    printk(OSST_DEB_MSG "%s:D: EOF up (%d). Left %d, needed %d.\n", name,
+						 STps->eof, (STp->buffer)->buffer_bytes, count - total);
+#endif
+		       	/* force multiple of block size, note block_size may have been adjusted */
+			transfer = (((STp->buffer)->buffer_bytes < count - total ?
+				     (STp->buffer)->buffer_bytes : count - total)/
+					STp->block_size) * STp->block_size;
+
+			if (transfer == 0) {
+				printk(KERN_WARNING
+				  "%s:W: Nothing can be transfered, requested %Zd, tape block size (%d%c).\n",
+			   		name, count, STp->block_size < 1024?
+					STp->block_size:STp->block_size/1024,
+				       	STp->block_size<1024?'b':'k');
+				break;
+			}
+			i = from_buffer(STp->buffer, buf, transfer);
+			if (i)  {
+				retval = i;
+				goto out;
+			}
+			STp->logical_blk_num += transfer / STp->block_size;
+			STps->drv_block      += transfer / STp->block_size;
+			filp->f_pos          += transfer;
+			buf                  += transfer;
+			total                += transfer;
+		}
+ 
+		if ((STp->buffer)->buffer_bytes == 0) {
+#if DEBUG
+			if (debugging)
+				printk(OSST_DEB_MSG "%s:D: Finished with frame %d\n",
+					       	name, STp->frame_seq_number);
+#endif
+			STp->frame_in_buffer = 0;
+			STp->frame_seq_number++;              /* frame to look for next time */
+		}
+	} /* for (total = 0, special = 0; total < count && !special; ) */
+
+	/* Change the eof state if no data from tape or buffer */
+	if (total == 0) {
+		if (STps->eof == ST_FM_HIT) {
+			STps->eof = (STp->first_frame_position >= STp->eod_frame_ppos)?ST_EOD_2:ST_FM;
+			STps->drv_block = 0;
+			if (STps->drv_file >= 0)
+				STps->drv_file++;
+		}
+		else if (STps->eof == ST_EOD_1) {
+			STps->eof = ST_EOD_2;
+			if (STps->drv_block > 0 && STps->drv_file >= 0)
+				STps->drv_file++;
+			STps->drv_block = 0;
+		}
+		else if (STps->eof == ST_EOD_2)
+			STps->eof = ST_EOD;
+	}
+	else if (STps->eof == ST_FM)
+		STps->eof = ST_NOEOF;
+
+	retval = total;
+
+out:
+	if (SRpnt != NULL) scsi_release_request(SRpnt);
+
+	up(&STp->lock);
+
+	return retval;
+}
+
+
+/* Set the driver options */
+static void osst_log_options(struct osst_tape *STp, struct st_modedef *STm, char *name)
+{
+  printk(KERN_INFO
+"%s:I: Mode %d options: buffer writes: %d, async writes: %d, read ahead: %d\n",
+	 name, STp->current_mode, STm->do_buffer_writes, STm->do_async_writes,
+	 STm->do_read_ahead);
+  printk(KERN_INFO
+"%s:I:    can bsr: %d, two FMs: %d, fast mteom: %d, auto lock: %d,\n",
+	 name, STp->can_bsr, STp->two_fm, STp->fast_mteom, STp->do_auto_lock);
+  printk(KERN_INFO
+"%s:I:    defs for wr: %d, no block limits: %d, partitions: %d, s2 log: %d\n",
+	 name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions,
+	 STp->scsi2_logical);
+  printk(KERN_INFO
+"%s:I:    sysv: %d\n", name, STm->sysv);
+#if DEBUG
+  printk(KERN_INFO
+	 "%s:D:    debugging: %d\n",
+	 name, debugging);
+#endif
+}
+
+
+static int osst_set_options(struct osst_tape *STp, long options)
+{
+	int		    value;
+	long		    code;
+	struct st_modedef * STm;
+	char		  * name = tape_name(STp);
+
+	STm = &(STp->modes[STp->current_mode]);
+	if (!STm->defined) {
+		memcpy(STm, &(STp->modes[0]), sizeof(*STm));
+		modes_defined = 1;
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Initialized mode %d definition from mode 0\n",
+					     name, STp->current_mode);
+#endif
+	}
+
+	code = options & MT_ST_OPTIONS;
+	if (code == MT_ST_BOOLEANS) {
+		STm->do_buffer_writes = (options & MT_ST_BUFFER_WRITES) != 0;
+		STm->do_async_writes  = (options & MT_ST_ASYNC_WRITES) != 0;
+		STm->defaults_for_writes = (options & MT_ST_DEF_WRITES) != 0;
+		STm->do_read_ahead    = (options & MT_ST_READ_AHEAD) != 0;
+		STp->two_fm	      = (options & MT_ST_TWO_FM) != 0;
+		STp->fast_mteom	      = (options & MT_ST_FAST_MTEOM) != 0;
+		STp->do_auto_lock     = (options & MT_ST_AUTO_LOCK) != 0;
+		STp->can_bsr          = (options & MT_ST_CAN_BSR) != 0;
+		STp->omit_blklims     = (options & MT_ST_NO_BLKLIMS) != 0;
+		if ((STp->device)->scsi_level >= SCSI_2)
+			STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0;
+		STp->scsi2_logical    = (options & MT_ST_SCSI2LOGICAL) != 0;
+		STm->sysv	      = (options & MT_ST_SYSV) != 0;
+#if DEBUG
+		debugging = (options & MT_ST_DEBUGGING) != 0;
+#endif
+		osst_log_options(STp, STm, name);
+	}
+	else if (code == MT_ST_SETBOOLEANS || code == MT_ST_CLEARBOOLEANS) {
+		value = (code == MT_ST_SETBOOLEANS);
+		if ((options & MT_ST_BUFFER_WRITES) != 0)
+			STm->do_buffer_writes = value;
+		if ((options & MT_ST_ASYNC_WRITES) != 0)
+			STm->do_async_writes = value;
+		if ((options & MT_ST_DEF_WRITES) != 0)
+			STm->defaults_for_writes = value;
+		if ((options & MT_ST_READ_AHEAD) != 0)
+			STm->do_read_ahead = value;
+		if ((options & MT_ST_TWO_FM) != 0)
+			STp->two_fm = value;
+		if ((options & MT_ST_FAST_MTEOM) != 0)
+			STp->fast_mteom = value;
+		if ((options & MT_ST_AUTO_LOCK) != 0)
+			STp->do_auto_lock = value;
+		if ((options & MT_ST_CAN_BSR) != 0)
+			STp->can_bsr = value;
+		if ((options & MT_ST_NO_BLKLIMS) != 0)
+			STp->omit_blklims = value;
+		if ((STp->device)->scsi_level >= SCSI_2 &&
+		    (options & MT_ST_CAN_PARTITIONS) != 0)
+			STp->can_partitions = value;
+		if ((options & MT_ST_SCSI2LOGICAL) != 0)
+			STp->scsi2_logical = value;
+		if ((options & MT_ST_SYSV) != 0)
+			STm->sysv = value;
+#if DEBUG
+		if ((options & MT_ST_DEBUGGING) != 0)
+			debugging = value;
+#endif
+		osst_log_options(STp, STm, name);
+	}
+	else if (code == MT_ST_WRITE_THRESHOLD) {
+		value = (options & ~MT_ST_OPTIONS) * ST_KILOBYTE;
+		if (value < 1 || value > osst_buffer_size) {
+			printk(KERN_WARNING "%s:W: Write threshold %d too small or too large.\n",
+					     name, value);
+			return (-EIO);
+		}
+		STp->write_threshold = value;
+		printk(KERN_INFO "%s:I: Write threshold set to %d bytes.\n",
+				  name, value);
+	}
+	else if (code == MT_ST_DEF_BLKSIZE) {
+		value = (options & ~MT_ST_OPTIONS);
+		if (value == ~MT_ST_OPTIONS) {
+			STm->default_blksize = (-1);
+			printk(KERN_INFO "%s:I: Default block size disabled.\n", name);
+		}
+		else {
+			if (value < 512 || value > OS_DATA_SIZE || OS_DATA_SIZE % value) {
+				printk(KERN_WARNING "%s:W: Default block size cannot be set to %d.\n",
+							 name, value);
+				return (-EINVAL);
+			}
+			STm->default_blksize = value;
+			printk(KERN_INFO "%s:I: Default block size set to %d bytes.\n",
+					  name, STm->default_blksize);
+		}
+	}
+	else if (code == MT_ST_TIMEOUTS) {
+		value = (options & ~MT_ST_OPTIONS);
+		if ((value & MT_ST_SET_LONG_TIMEOUT) != 0) {
+			STp->long_timeout = (value & ~MT_ST_SET_LONG_TIMEOUT) * HZ;
+			printk(KERN_INFO "%s:I: Long timeout set to %d seconds.\n", name,
+					     (value & ~MT_ST_SET_LONG_TIMEOUT));
+		}
+		else {
+			STp->timeout = value * HZ;
+			printk(KERN_INFO "%s:I: Normal timeout set to %d seconds.\n", name, value);
+		}
+	}
+	else if (code == MT_ST_DEF_OPTIONS) {
+		code = (options & ~MT_ST_CLEAR_DEFAULT);
+		value = (options & MT_ST_CLEAR_DEFAULT);
+		if (code == MT_ST_DEF_DENSITY) {
+			if (value == MT_ST_CLEAR_DEFAULT) {
+				STm->default_density = (-1);
+				printk(KERN_INFO "%s:I: Density default disabled.\n", name);
+			}
+			else {
+				STm->default_density = value & 0xff;
+				printk(KERN_INFO "%s:I: Density default set to %x\n",
+						  name, STm->default_density);
+			}
+		}
+		else if (code == MT_ST_DEF_DRVBUFFER) {
+			if (value == MT_ST_CLEAR_DEFAULT) {
+				STp->default_drvbuffer = 0xff;
+				printk(KERN_INFO "%s:I: Drive buffer default disabled.\n", name);
+			}
+			else {
+				STp->default_drvbuffer = value & 7;
+				printk(KERN_INFO "%s:I: Drive buffer default set to %x\n",
+						  name, STp->default_drvbuffer);
+			}
+		}
+		else if (code == MT_ST_DEF_COMPRESSION) {
+			if (value == MT_ST_CLEAR_DEFAULT) {
+				STm->default_compression = ST_DONT_TOUCH;
+				printk(KERN_INFO "%s:I: Compression default disabled.\n", name);
+			}
+			else {
+				STm->default_compression = (value & 1 ? ST_YES : ST_NO);
+				printk(KERN_INFO "%s:I: Compression default set to %x\n",
+						  name, (value & 1));
+			}
+		}
+	}
+	else
+		return (-EIO);
+
+	return 0;
+}
+
+
+/* Internal ioctl function */
+static int osst_int_ioctl(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+			     unsigned int cmd_in, unsigned long arg)
+{
+	int			timeout;
+	long			ltmp;
+	int			i, ioctl_result;
+	int			chg_eof = 1;
+	unsigned char		cmd[MAX_COMMAND_SIZE];
+	struct scsi_request   * SRpnt = * aSRpnt;
+	struct st_partstat    * STps;
+	int			fileno, blkno, at_sm, frame_seq_numbr, logical_blk_num;
+	int			datalen = 0, direction = DMA_NONE;
+	char		      * name = tape_name(STp);
+
+	if (STp->ready != ST_READY && cmd_in != MTLOAD) {
+		if (STp->ready == ST_NO_TAPE)
+			return (-ENOMEDIUM);
+		else
+			return (-EIO);
+	}
+	timeout = STp->long_timeout;
+	STps = &(STp->ps[STp->partition]);
+	fileno = STps->drv_file;
+	blkno = STps->drv_block;
+	at_sm = STps->at_sm;
+	frame_seq_numbr = STp->frame_seq_number;
+	logical_blk_num = STp->logical_blk_num;
+
+	memset(cmd, 0, MAX_COMMAND_SIZE);
+	switch (cmd_in) {
+	 case MTFSFM:
+		chg_eof = 0; /* Changed from the FSF after this */
+	 case MTFSF:
+		if (STp->raw)
+		   return (-EIO);
+		if (STp->linux_media)
+		   ioctl_result = osst_space_over_filemarks_forward_fast(STp, &SRpnt, cmd_in, arg);
+		else
+		   ioctl_result = osst_space_over_filemarks_forward_slow(STp, &SRpnt, cmd_in, arg);
+		if (fileno >= 0)
+		   fileno += arg;
+		blkno = 0;
+		at_sm &= (arg == 0);
+		goto os_bypass;
+
+	 case MTBSF:
+		chg_eof = 0; /* Changed from the FSF after this */
+	 case MTBSFM:
+		if (STp->raw)
+		   return (-EIO);
+		ioctl_result = osst_space_over_filemarks_backward(STp, &SRpnt, cmd_in, arg);
+		if (fileno >= 0)
+		   fileno -= arg;
+		blkno = (-1);  /* We can't know the block number */
+		at_sm &= (arg == 0);
+		goto os_bypass;
+
+	 case MTFSR:
+	 case MTBSR:
+#if DEBUG
+		if (debugging)
+		   printk(OSST_DEB_MSG "%s:D: Skipping %lu blocks %s from logical block %d\n",
+				name, arg, cmd_in==MTFSR?"forward":"backward", logical_blk_num);
+#endif
+		if (cmd_in == MTFSR) {
+		   logical_blk_num += arg;
+		   if (blkno >= 0) blkno += arg;
+		}
+		else {
+		   logical_blk_num -= arg;
+		   if (blkno >= 0) blkno -= arg;
+		}
+		ioctl_result = osst_seek_logical_blk(STp, &SRpnt, logical_blk_num);
+		fileno = STps->drv_file;
+		blkno  = STps->drv_block;
+		at_sm &= (arg == 0);
+		goto os_bypass;
+
+	 case MTFSS:
+		cmd[0] = SPACE;
+		cmd[1] = 0x04; /* Space Setmarks */   /* FIXME -- OS can't do this? */
+		cmd[2] = (arg >> 16);
+		cmd[3] = (arg >> 8);
+		cmd[4] = arg;
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Spacing tape forward %d setmarks.\n", name,
+		cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
+#endif
+		if (arg != 0) {
+			blkno = fileno = (-1);
+			at_sm = 1;
+		}
+		break;
+	 case MTBSS:
+		cmd[0] = SPACE;
+		cmd[1] = 0x04; /* Space Setmarks */   /* FIXME -- OS can't do this? */
+		ltmp = (-arg);
+		cmd[2] = (ltmp >> 16);
+		cmd[3] = (ltmp >> 8);
+		cmd[4] = ltmp;
+#if DEBUG
+		if (debugging) {
+			if (cmd[2] & 0x80)
+			   ltmp = 0xff000000;
+			ltmp = ltmp | (cmd[2] << 16) | (cmd[3] << 8) | cmd[4];
+			printk(OSST_DEB_MSG "%s:D: Spacing tape backward %ld setmarks.\n",
+						name, (-ltmp));
+		 }
+#endif
+		 if (arg != 0) {
+			blkno = fileno = (-1);
+			at_sm = 1;
+		 }
+		 break;
+	 case MTWEOF:
+		 if ((STps->rw == ST_WRITING || STp->dirty) && !STp->pos_unknown) {
+			STp->write_type = OS_WRITE_DATA;
+			ioctl_result = osst_flush_write_buffer(STp, &SRpnt);
+		 } else
+			ioctl_result = 0;
+#if DEBUG
+		 if (debugging) 
+			   printk(OSST_DEB_MSG "%s:D: Writing %ld filemark(s).\n", name, arg);
+#endif
+		 for (i=0; i<arg; i++)
+			ioctl_result |= osst_write_filemark(STp, &SRpnt);
+		 if (fileno >= 0) fileno += arg;
+		 if (blkno  >= 0) blkno   = 0;
+		 goto os_bypass;
+
+	 case MTWSM:
+		 if (STp->write_prot)
+			return (-EACCES);
+		 if (!STp->raw)
+			return 0;
+		 cmd[0] = WRITE_FILEMARKS;   /* FIXME -- need OS version */
+		 if (cmd_in == MTWSM)
+			 cmd[1] = 2;
+		 cmd[2] = (arg >> 16);
+		 cmd[3] = (arg >> 8);
+		 cmd[4] = arg;
+		 timeout = STp->timeout;
+#if DEBUG
+		 if (debugging) 
+			   printk(OSST_DEB_MSG "%s:D: Writing %d setmark(s).\n", name,
+				  cmd[2] * 65536 + cmd[3] * 256 + cmd[4]);
+#endif
+		 if (fileno >= 0)
+			fileno += arg;
+		 blkno = 0;
+		 at_sm = (cmd_in == MTWSM);
+		 break;
+	 case MTOFFL:
+	 case MTLOAD:
+	 case MTUNLOAD:
+	 case MTRETEN:
+		 cmd[0] = START_STOP;
+		 cmd[1] = 1;			/* Don't wait for completion */
+		 if (cmd_in == MTLOAD) {
+		     if (STp->ready == ST_NO_TAPE)
+			 cmd[4] = 4;		/* open tray */
+		      else
+			 cmd[4] = 1;		/* load */
+		 }
+		 if (cmd_in == MTRETEN)
+			 cmd[4] = 3;		/* retension then mount */
+		 if (cmd_in == MTOFFL)
+			 cmd[4] = 4;		/* rewind then eject */
+		 timeout = STp->timeout;
+#if DEBUG
+		 if (debugging) {
+			 switch (cmd_in) {
+				 case MTUNLOAD:
+					 printk(OSST_DEB_MSG "%s:D: Unloading tape.\n", name);
+					 break;
+				 case MTLOAD:
+					 printk(OSST_DEB_MSG "%s:D: Loading tape.\n", name);
+					 break;
+				 case MTRETEN:
+					 printk(OSST_DEB_MSG "%s:D: Retensioning tape.\n", name);
+					 break;
+				 case MTOFFL:
+					 printk(OSST_DEB_MSG "%s:D: Ejecting tape.\n", name);
+					 break;
+			 }
+		 }
+#endif
+       fileno = blkno = at_sm = frame_seq_numbr = logical_blk_num = 0 ;
+		 break;
+	 case MTNOP:
+#if DEBUG
+		 if (debugging)
+			 printk(OSST_DEB_MSG "%s:D: No-op on tape.\n", name);
+#endif
+		 return 0;  /* Should do something ? */
+		 break;
+	 case MTEOM:
+#if DEBUG
+		if (debugging)
+		   printk(OSST_DEB_MSG "%s:D: Spacing to end of recorded medium.\n", name);
+#endif
+		if ((osst_position_tape_and_confirm(STp, &SRpnt, STp->eod_frame_ppos) < 0) ||
+			    (osst_get_logical_frame(STp, &SRpnt, -1, 0)               < 0)) {
+		   ioctl_result = -EIO;
+		   goto os_bypass;
+		}
+		if (STp->buffer->aux->frame_type != OS_FRAME_TYPE_EOD) {
+#if DEBUG
+		   printk(OSST_DEB_MSG "%s:D: No EOD frame found where expected.\n", name);
+#endif
+		   ioctl_result = -EIO;
+		   goto os_bypass;
+		}
+		ioctl_result = osst_set_frame_position(STp, &SRpnt, STp->eod_frame_ppos, 0);
+		fileno = STp->filemark_cnt;
+		blkno  = at_sm = 0;
+		goto os_bypass;
+
+	 case MTERASE:
+		if (STp->write_prot)
+		   return (-EACCES);
+		ioctl_result = osst_reset_header(STp, &SRpnt);
+		i = osst_write_eod(STp, &SRpnt);
+		if (i < ioctl_result) ioctl_result = i;
+		i = osst_position_tape_and_confirm(STp, &SRpnt, STp->eod_frame_ppos);
+		if (i < ioctl_result) ioctl_result = i;
+		fileno = blkno = at_sm = 0 ;
+		goto os_bypass;
+
+	 case MTREW:
+		cmd[0] = REZERO_UNIT; /* rewind */
+		cmd[1] = 1;
+#if DEBUG
+		if (debugging)
+		   printk(OSST_DEB_MSG "%s:D: Rewinding tape, Immed=%d.\n", name, cmd[1]);
+#endif
+		fileno = blkno = at_sm = frame_seq_numbr = logical_blk_num = 0 ;
+		break;
+
+	 case MTSETBLK:           /* Set block length */
+		 if ((STps->drv_block == 0 )			  &&
+		     !STp->dirty				  &&
+		     ((STp->buffer)->buffer_bytes == 0)		  &&
+		     ((arg & MT_ST_BLKSIZE_MASK) >= 512 )	  && 
+		     ((arg & MT_ST_BLKSIZE_MASK) <= OS_DATA_SIZE) &&
+		     !(OS_DATA_SIZE % (arg & MT_ST_BLKSIZE_MASK))  ) {
+			 /*
+			  * Only allowed to change the block size if you opened the
+			  * device at the beginning of a file before writing anything.
+			  * Note, that when reading, changing block_size is futile,
+			  * as the size used when writing overrides it.
+			  */
+			 STp->block_size = (arg & MT_ST_BLKSIZE_MASK);
+			 printk(KERN_INFO "%s:I: Block size set to %d bytes.\n",
+					   name, STp->block_size);
+			 return 0;
+		 }
+	 case MTSETDENSITY:       /* Set tape density */
+	 case MTSETDRVBUFFER:     /* Set drive buffering */
+	 case SET_DENS_AND_BLK:   /* Set density and block size */
+		 chg_eof = 0;
+		 if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
+			 return (-EIO);       /* Not allowed if data in buffer */
+		 if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
+		     (arg & MT_ST_BLKSIZE_MASK) != 0                    &&
+		     (arg & MT_ST_BLKSIZE_MASK) != STp->block_size       ) {
+			 printk(KERN_WARNING "%s:W: Illegal to set block size to %d%s.\n",
+						name, (int)(arg & MT_ST_BLKSIZE_MASK),
+						(OS_DATA_SIZE % (arg & MT_ST_BLKSIZE_MASK))?"":" now");
+			 return (-EINVAL);
+		 }
+		 return 0;  /* FIXME silently ignore if block size didn't change */
+
+	 default:
+		return (-ENOSYS);
+	}
+
+	SRpnt = osst_do_scsi(SRpnt, STp, cmd, datalen, direction, timeout, MAX_RETRIES, 1);
+
+	ioctl_result = (STp->buffer)->syscall_result;
+
+	if (!SRpnt) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Couldn't exec scsi cmd for IOCTL\n", name);
+#endif
+		return ioctl_result;
+	}
+
+	if (!ioctl_result) {  /* SCSI command successful */
+		STp->frame_seq_number = frame_seq_numbr;
+		STp->logical_blk_num  = logical_blk_num;
+	}
+
+os_bypass:
+#if DEBUG
+	if (debugging)
+		printk(OSST_DEB_MSG "%s:D: IOCTL (%d) Result=%d\n", name, cmd_in, ioctl_result);
+#endif
+
+	if (!ioctl_result) {				/* success */
+
+		if (cmd_in == MTFSFM) {
+			 fileno--;
+			 blkno--;
+		}
+		if (cmd_in == MTBSFM) {
+			 fileno++;
+			 blkno++;
+		}
+		STps->drv_block = blkno;
+		STps->drv_file = fileno;
+		STps->at_sm = at_sm;
+
+		if (cmd_in == MTEOM)
+			STps->eof = ST_EOD;
+		else if ((cmd_in == MTFSFM || cmd_in == MTBSF) && STps->eof == ST_FM_HIT) {
+			ioctl_result = osst_seek_logical_blk(STp, &SRpnt, STp->logical_blk_num-1);
+			STps->drv_block++;
+			STp->logical_blk_num++;
+			STp->frame_seq_number++;
+			STp->frame_in_buffer = 0;
+			STp->buffer->read_pointer = 0;
+		}
+		else if (cmd_in == MTFSF)
+			STps->eof = (STp->first_frame_position >= STp->eod_frame_ppos)?ST_EOD:ST_FM;
+		else if (chg_eof)
+			STps->eof = ST_NOEOF;
+
+		if (cmd_in == MTOFFL || cmd_in == MTUNLOAD)
+			STp->rew_at_close = 0;
+		else if (cmd_in == MTLOAD) {
+			for (i=0; i < ST_NBR_PARTITIONS; i++) {
+			    STp->ps[i].rw = ST_IDLE;
+			    STp->ps[i].last_block_valid = 0;/* FIXME - where else is this field maintained? */
+			}
+			STp->partition = 0;
+		}
+
+		if (cmd_in == MTREW) {
+			ioctl_result = osst_position_tape_and_confirm(STp, &SRpnt, STp->first_data_ppos); 
+			if (ioctl_result > 0)
+				ioctl_result = 0;
+		}
+
+	} else if (cmd_in == MTBSF || cmd_in == MTBSFM ) {
+		if (osst_position_tape_and_confirm(STp, &SRpnt, STp->first_data_ppos) < 0)
+			STps->drv_file = STps->drv_block = -1;
+		else
+			STps->drv_file = STps->drv_block = 0;
+		STps->eof = ST_NOEOF;
+	} else if (cmd_in == MTFSF || cmd_in == MTFSFM) {
+		if (osst_position_tape_and_confirm(STp, &SRpnt, STp->eod_frame_ppos) < 0)
+			STps->drv_file = STps->drv_block = -1;
+		else {
+			STps->drv_file  = STp->filemark_cnt;
+			STps->drv_block = 0;
+		}
+		STps->eof = ST_EOD;
+	} else if (cmd_in == MTBSR || cmd_in == MTFSR || cmd_in == MTWEOF || cmd_in == MTEOM) {
+		STps->drv_file = STps->drv_block = (-1);
+		STps->eof = ST_NOEOF;
+		STp->header_ok = 0;
+	} else if (cmd_in == MTERASE) {
+		STp->header_ok = 0;
+	} else if (SRpnt) {  /* SCSI command was not completely successful. */
+		if (SRpnt->sr_sense_buffer[2] & 0x40) {
+			STps->eof = ST_EOM_OK;
+			STps->drv_block = 0;
+		}
+		if (chg_eof)
+			STps->eof = ST_NOEOF;
+
+		if ((SRpnt->sr_sense_buffer[2] & 0x0f) == BLANK_CHECK)
+			STps->eof = ST_EOD;
+
+		if (cmd_in == MTLOAD && osst_wait_for_medium(STp, &SRpnt, 60))
+			ioctl_result = osst_wait_ready(STp, &SRpnt, 5 * 60, OSST_WAIT_POSITION_COMPLETE);
+	}
+	*aSRpnt = SRpnt;
+
+	return ioctl_result;
+}
+
+
+/* Open the device */
+static int os_scsi_tape_open(struct inode * inode, struct file * filp)
+{
+	unsigned short	      flags;
+	int		      i, b_size, new_session = 0, retval = 0;
+	unsigned char	      cmd[MAX_COMMAND_SIZE];
+	struct scsi_request * SRpnt = NULL;
+	struct osst_tape    * STp;
+	struct st_modedef   * STm;
+	struct st_partstat  * STps;
+	char		    * name;
+	int		      dev  = TAPE_NR(inode);
+	int		      mode = TAPE_MODE(inode);
+
+	/*
+	 * We really want to do nonseekable_open(inode, filp); here, but some
+	 * versions of tar incorrectly call lseek on tapes and bail out if that
+	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
+	 */
+	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
+
+	write_lock(&os_scsi_tapes_lock);
+	if (dev >= osst_max_dev || os_scsi_tapes == NULL ||
+	    (STp = os_scsi_tapes[dev]) == NULL || !STp->device) {
+		write_unlock(&os_scsi_tapes_lock);
+		return (-ENXIO);
+	}
+
+	name = tape_name(STp);
+
+	if (STp->in_use) {
+		write_unlock(&os_scsi_tapes_lock);
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Device already in use.\n", name);
+#endif
+		return (-EBUSY);
+	}
+	if (scsi_device_get(STp->device)) {
+		write_unlock(&os_scsi_tapes_lock);
+#if DEBUG
+                printk(OSST_DEB_MSG "%s:D: Failed scsi_device_get.\n", name);
+#endif
+		return (-ENXIO);
+	}
+	filp->private_data = STp;
+	STp->in_use = 1;
+	write_unlock(&os_scsi_tapes_lock);
+	STp->rew_at_close = TAPE_REWIND(inode);
+
+	if( !scsi_block_when_processing_errors(STp->device) ) {
+		return -ENXIO;
+	}
+
+	if (mode != STp->current_mode) {
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Mode change from %d to %d.\n",
+					       name, STp->current_mode, mode);
+#endif
+		new_session = 1;
+		STp->current_mode = mode;
+	}
+	STm = &(STp->modes[STp->current_mode]);
+
+	flags = filp->f_flags;
+	STp->write_prot = ((flags & O_ACCMODE) == O_RDONLY);
+
+	STp->raw = TAPE_IS_RAW(inode);
+	if (STp->raw)
+		STp->header_ok = 0;
+
+	/* Allocate data segments for this device's tape buffer */
+	if (!enlarge_buffer(STp->buffer, STp->restr_dma)) {
+		printk(KERN_ERR "%s:E: Unable to allocate memory segments for tape buffer.\n", name);
+		retval = (-EOVERFLOW);
+		goto err_out;
+	}
+	if (STp->buffer->buffer_size >= OS_FRAME_SIZE) {
+		for (i = 0, b_size = 0; 
+		     (i < STp->buffer->sg_segs) && ((b_size + STp->buffer->sg[i].length) <= OS_DATA_SIZE); 
+		     b_size += STp->buffer->sg[i++].length);
+		STp->buffer->aux = (os_aux_t *) (page_address(STp->buffer->sg[i].page) + OS_DATA_SIZE - b_size);
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: b_data points to %p in segment 0 at %p\n", name,
+			STp->buffer->b_data, page_address(STp->buffer->sg[0].page));
+		printk(OSST_DEB_MSG "%s:D: AUX points to %p in segment %d at %p\n", name,
+			 STp->buffer->aux, i, page_address(STp->buffer->sg[i].page));
+#endif
+	} else {
+		STp->buffer->aux = NULL; /* this had better never happen! */
+		printk(KERN_NOTICE "%s:A: Framesize %d too large for buffer.\n", name, OS_FRAME_SIZE);
+		retval = (-EIO);
+		goto err_out;
+	}
+	STp->buffer->writing = 0;
+	STp->buffer->syscall_result = 0;
+	STp->dirty = 0;
+	for (i=0; i < ST_NBR_PARTITIONS; i++) {
+		STps = &(STp->ps[i]);
+		STps->rw = ST_IDLE;
+	}
+	STp->ready = ST_READY;
+#if DEBUG
+	STp->nbr_waits = STp->nbr_finished = 0;
+#endif
+
+	memset (cmd, 0, MAX_COMMAND_SIZE);
+	cmd[0] = TEST_UNIT_READY;
+
+	SRpnt = osst_do_scsi(NULL, STp, cmd, 0, DMA_NONE, STp->timeout, MAX_RETRIES, 1);
+	if (!SRpnt) {
+		retval = (STp->buffer)->syscall_result;		/* FIXME - valid? */
+		goto err_out;
+	}
+	if ((SRpnt->sr_sense_buffer[0] & 0x70) == 0x70      &&
+	    (SRpnt->sr_sense_buffer[2] & 0x0f) == NOT_READY &&
+	     SRpnt->sr_sense_buffer[12]        == 4         ) {
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Unit not ready, cause %x\n", name, SRpnt->sr_sense_buffer[13]);
+#endif
+		if (filp->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto err_out;
+		}
+		if (SRpnt->sr_sense_buffer[13] == 2) {	/* initialize command required (LOAD) */
+			memset (cmd, 0, MAX_COMMAND_SIZE);
+        		cmd[0] = START_STOP;
+			cmd[1] = 1;
+			cmd[4] = 1;
+			SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
+					     STp->timeout, MAX_RETRIES, 1);
+		}
+		osst_wait_ready(STp, &SRpnt, (SRpnt->sr_sense_buffer[13]==1?15:3) * 60, 0);
+	}
+	if ((SRpnt->sr_sense_buffer[0] & 0x70) == 0x70 &&
+	    (SRpnt->sr_sense_buffer[2] & 0x0f) == UNIT_ATTENTION) { /* New media? */
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Unit wants attention\n", name);
+#endif
+		STp->header_ok = 0;
+
+		for (i=0; i < 10; i++) {
+
+			memset (cmd, 0, MAX_COMMAND_SIZE);
+			cmd[0] = TEST_UNIT_READY;
+
+			SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
+					     STp->timeout, MAX_RETRIES, 1);
+			if ((SRpnt->sr_sense_buffer[0] & 0x70) != 0x70 ||
+			    (SRpnt->sr_sense_buffer[2] & 0x0f) != UNIT_ATTENTION)
+				break;
+		}
+
+		STp->pos_unknown = 0;
+		STp->partition = STp->new_partition = 0;
+		if (STp->can_partitions)
+			STp->nbr_partitions = 1;  /* This guess will be updated later if necessary */
+		for (i=0; i < ST_NBR_PARTITIONS; i++) {
+			STps = &(STp->ps[i]);
+			STps->rw = ST_IDLE;		/* FIXME - seems to be redundant... */
+			STps->eof = ST_NOEOF;
+			STps->at_sm = 0;
+			STps->last_block_valid = 0;
+			STps->drv_block = 0;
+			STps->drv_file = 0 ;
+		}
+		new_session = 1;
+		STp->recover_count = 0;
+		STp->abort_count = 0;
+	}
+	/*
+	 * if we have valid headers from before, and the drive/tape seem untouched,
+	 * open without reconfiguring and re-reading the headers
+	 */
+	if (!STp->buffer->syscall_result && STp->header_ok &&
+	    !SRpnt->sr_result && SRpnt->sr_sense_buffer[0] == 0) {
+
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = MODE_SENSE;
+		cmd[1] = 8;
+		cmd[2] = VENDOR_IDENT_PAGE;
+		cmd[4] = VENDOR_IDENT_PAGE_LENGTH + MODE_HEADER_LENGTH;
+
+		SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_FROM_DEVICE, STp->timeout, 0, 1);
+
+		if (STp->buffer->syscall_result                     ||
+		    STp->buffer->b_data[MODE_HEADER_LENGTH + 2] != 'L' ||
+		    STp->buffer->b_data[MODE_HEADER_LENGTH + 3] != 'I' ||
+		    STp->buffer->b_data[MODE_HEADER_LENGTH + 4] != 'N' ||
+		    STp->buffer->b_data[MODE_HEADER_LENGTH + 5] != '4'  ) {
+#if DEBUG
+			printk(OSST_DEB_MSG "%s:D: Signature was changed to %c%c%c%c\n", name,
+			  STp->buffer->b_data[MODE_HEADER_LENGTH + 2],
+			  STp->buffer->b_data[MODE_HEADER_LENGTH + 3],
+			  STp->buffer->b_data[MODE_HEADER_LENGTH + 4],
+			  STp->buffer->b_data[MODE_HEADER_LENGTH + 5]);
+#endif
+			STp->header_ok = 0;
+		}
+		i = STp->first_frame_position;
+		if (STp->header_ok && i == osst_get_frame_position(STp, &SRpnt)) {
+			if (STp->door_locked == ST_UNLOCKED) {
+				if (do_door_lock(STp, 1))
+					printk(KERN_INFO "%s:I: Can't lock drive door\n", name);
+				else
+					STp->door_locked = ST_LOCKED_AUTO;
+			}
+			if (!STp->frame_in_buffer) {
+				STp->block_size = (STm->default_blksize > 0) ?
+							STm->default_blksize : OS_DATA_SIZE;
+				STp->buffer->buffer_bytes = STp->buffer->read_pointer = 0;
+			}
+			STp->buffer->buffer_blocks = OS_DATA_SIZE / STp->block_size;
+			STp->fast_open = 1;
+			scsi_release_request(SRpnt);
+			return 0;
+		}
+#if DEBUG
+		if (i != STp->first_frame_position)
+			printk(OSST_DEB_MSG "%s:D: Tape position changed from %d to %d\n",
+						name, i, STp->first_frame_position);
+#endif
+		STp->header_ok = 0;
+	}
+	STp->fast_open = 0;
+
+	if ((STp->buffer)->syscall_result != 0 &&   /* in all error conditions except no medium */ 
+	    (SRpnt->sr_sense_buffer[2] != 2 || SRpnt->sr_sense_buffer[12] != 0x3A) ) {
+
+		memset(cmd, 0, MAX_COMMAND_SIZE);
+		cmd[0] = MODE_SELECT;
+		cmd[1] = 0x10;
+		cmd[4] = 4 + MODE_HEADER_LENGTH;
+
+		(STp->buffer)->b_data[0] = cmd[4] - 1;
+		(STp->buffer)->b_data[1] = 0;			/* Medium Type - ignoring */
+		(STp->buffer)->b_data[2] = 0;			/* Reserved */
+		(STp->buffer)->b_data[3] = 0;			/* Block Descriptor Length */
+		(STp->buffer)->b_data[MODE_HEADER_LENGTH + 0] = 0x3f;
+		(STp->buffer)->b_data[MODE_HEADER_LENGTH + 1] = 1;
+		(STp->buffer)->b_data[MODE_HEADER_LENGTH + 2] = 2;
+		(STp->buffer)->b_data[MODE_HEADER_LENGTH + 3] = 3;
+
+#if DEBUG
+		printk(OSST_DEB_MSG "%s:D: Applying soft reset\n", name);
+#endif
+		SRpnt = osst_do_scsi(SRpnt, STp, cmd, cmd[4], DMA_TO_DEVICE, STp->timeout, 0, 1);
+
+		STp->header_ok = 0;
+
+		for (i=0; i < 10; i++) {
+
+			memset (cmd, 0, MAX_COMMAND_SIZE);
+			cmd[0] = TEST_UNIT_READY;
+
+			SRpnt = osst_do_scsi(SRpnt, STp, cmd, 0, DMA_NONE,
+						    STp->timeout, MAX_RETRIES, 1);
+			if ((SRpnt->sr_sense_buffer[0] & 0x70) != 0x70 ||
+			    (SRpnt->sr_sense_buffer[2] & 0x0f) == NOT_READY)
+			break;
+
+			if ((SRpnt->sr_sense_buffer[2] & 0x0f) == UNIT_ATTENTION) {
+				STp->pos_unknown = 0;
+				STp->partition = STp->new_partition = 0;
+				if (STp->can_partitions)
+					STp->nbr_partitions = 1;  /* This guess will be updated later if necessary */
+				for (i=0; i < ST_NBR_PARTITIONS; i++) {
+					STps = &(STp->ps[i]);
+					STps->rw = ST_IDLE;
+					STps->eof = ST_NOEOF;
+					STps->at_sm = 0;
+					STps->last_block_valid = 0;
+					STps->drv_block = 0;
+					STps->drv_file = 0 ;
+				}
+				new_session = 1;
+			}
+		}
+	}
+
+	if (osst_wait_ready(STp, &SRpnt, 15 * 60, 0))		/* FIXME - not allowed with NOBLOCK */
+		 printk(KERN_INFO "%s:I: Device did not become Ready in open\n", name);
+
+	if ((STp->buffer)->syscall_result != 0) {
+		if ((STp->device)->scsi_level >= SCSI_2 &&
+		    (SRpnt->sr_sense_buffer[0] & 0x70) == 0x70 &&
+		    (SRpnt->sr_sense_buffer[2] & 0x0f) == NOT_READY &&
+		     SRpnt->sr_sense_buffer[12] == 0x3a) { /* Check ASC */
+			STp->ready = ST_NO_TAPE;
+		} else
+			STp->ready = ST_NOT_READY;
+		scsi_release_request(SRpnt);
+		SRpnt = NULL;
+		STp->density = 0;   	/* Clear the erroneous "residue" */
+		STp->write_prot = 0;
+		STp->block_size = 0;
+		STp->ps[0].drv_file = STp->ps[0].drv_block = (-1);
+		STp->partition = STp->new_partition = 0;
+		STp->door_locked = ST_UNLOCKED;
+		return 0;
+	}
+
+	osst_configure_onstream(STp, &SRpnt);
+
+	STp->block_size = STp->raw ? OS_FRAME_SIZE : (
+			     (STm->default_blksize > 0) ? STm->default_blksize : OS_DATA_SIZE);
+	STp->buffer->buffer_blocks = STp->raw ? 1 : OS_DATA_SIZE / STp->block_size;
+	STp->buffer->buffer_bytes  =
+	STp->buffer->read_pointer  =
+	STp->frame_in_buffer       = 0;
+
+#if DEBUG
+	if (debugging)
+		printk(OSST_DEB_MSG "%s:D: Block size: %d, frame size: %d, buffer size: %d (%d blocks).\n",
+		     name, STp->block_size, OS_FRAME_SIZE, (STp->buffer)->buffer_size,
+		     (STp->buffer)->buffer_blocks);
+#endif
+
+	if (STp->drv_write_prot) {
+		STp->write_prot = 1;
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Write protected\n", name);
+#endif
+		if ((flags & O_ACCMODE) == O_WRONLY || (flags & O_ACCMODE) == O_RDWR) {
+			retval = (-EROFS);
+			goto err_out;
+		}
+	}
+
+	if (new_session) {  /* Change the drive parameters for the new mode */
+#if DEBUG
+		if (debugging)
+	printk(OSST_DEB_MSG "%s:D: New Session\n", name);
+#endif
+		STp->density_changed = STp->blksize_changed = 0;
+		STp->compression_changed = 0;
+	}
+
+	/*
+	 * properly position the tape and check the ADR headers
+	 */
+	if (STp->door_locked == ST_UNLOCKED) {
+		 if (do_door_lock(STp, 1))
+			printk(KERN_INFO "%s:I: Can't lock drive door\n", name);
+		 else
+			STp->door_locked = ST_LOCKED_AUTO;
+	}
+
+	osst_analyze_headers(STp, &SRpnt);
+
+	scsi_release_request(SRpnt);
+	SRpnt = NULL;
+
+	return 0;
+
+err_out:
+	if (SRpnt != NULL)
+		scsi_release_request(SRpnt);
+	normalize_buffer(STp->buffer);
+	STp->header_ok = 0;
+	STp->in_use = 0;
+	scsi_device_put(STp->device);
+
+	return retval;
+}
+
+
+/* Flush the tape buffer before close */
+static int os_scsi_tape_flush(struct file * filp)
+{
+	int		      result = 0, result2;
+	struct osst_tape    * STp    = filp->private_data;
+	struct st_modedef   * STm    = &(STp->modes[STp->current_mode]);
+	struct st_partstat  * STps   = &(STp->ps[STp->partition]);
+	struct scsi_request * SRpnt  = NULL;
+	char		    * name   = tape_name(STp);
+
+	if (file_count(filp) > 1)
+		return 0;
+
+	if ((STps->rw == ST_WRITING || STp->dirty) && !STp->pos_unknown) {
+		STp->write_type = OS_WRITE_DATA;
+		result = osst_flush_write_buffer(STp, &SRpnt);
+		if (result != 0 && result != (-ENOSPC))
+			goto out;
+	}
+	if ( STps->rw >= ST_WRITING && !STp->pos_unknown) {
+
+#if DEBUG
+		if (debugging) {
+			printk(OSST_DEB_MSG "%s:D: File length %ld bytes.\n",
+					       name, (long)(filp->f_pos));
+			printk(OSST_DEB_MSG "%s:D: Async write waits %d, finished %d.\n",
+					       name, STp->nbr_waits, STp->nbr_finished);
+		}
+#endif
+		result = osst_write_trailer(STp, &SRpnt, !(STp->rew_at_close));
+#if DEBUG
+		if (debugging)
+			printk(OSST_DEB_MSG "%s:D: Buffer flushed, %d EOF(s) written\n",
+					       name, 1+STp->two_fm);
+#endif
+	}
+	else if (!STp->rew_at_close) {
+		STps = &(STp->ps[STp->partition]);
+		if (!STm->sysv || STps->rw != ST_READING) {
+			if (STp->can_bsr)
+				result = osst_flush_buffer(STp, &SRpnt, 0); /* this is the default path */
+			else if (STps->eof == ST_FM_HIT) {
+				result = cross_eof(STp, &SRpnt, 0);
+					if (result) {
+						if (STps->drv_file >= 0)
+							STps->drv_file++;
+						STps->drv_block = 0;
+						STps->eof = ST_FM;
+					}
+					else
+						STps->eof = ST_NOEOF;
+			}
+		}
+		else if ((STps->eof == ST_NOEOF &&
+			  !(result = cross_eof(STp, &SRpnt, 1))) ||
+			 STps->eof == ST_FM_HIT) {
+			if (STps->drv_file >= 0)
+				STps->drv_file++;
+			STps->drv_block = 0;
+			STps->eof = ST_FM;
+		}
+	}
+
+out:
+	if (STp->rew_at_close) {
+		result2 = osst_position_tape_and_confirm(STp, &SRpnt, STp->first_data_ppos);
+		STps->drv_file = STps->drv_block = STp->frame_seq_number = STp->logical_blk_num = 0;
+		if (result == 0 && result2 < 0)
+			result = result2;
+	}
+	if (SRpnt) scsi_release_request(SRpnt);
+
+	if (STp->abort_count || STp->recover_count) {
+		printk(KERN_INFO "%s:I:", name);
+		if (STp->abort_count)
+			printk(" %d unrecovered errors", STp->abort_count);
+		if (STp->recover_count)
+			printk(" %d recovered errors", STp->recover_count);
+		if (STp->write_count)
+			printk(" in %d frames written", STp->write_count);
+		if (STp->read_count)
+			printk(" in %d frames read", STp->read_count);
+		printk("\n");
+		STp->recover_count = 0;
+		STp->abort_count   = 0;
+	}
+	STp->write_count = 0;
+	STp->read_count  = 0;
+
+	return result;
+}
+
+
+/* Close the device and release it */
+static int os_scsi_tape_close(struct inode * inode, struct file * filp)
+{
+	int		      result = 0;
+	struct osst_tape    * STp    = filp->private_data;
+
+	if (STp->door_locked == ST_LOCKED_AUTO)
+		do_door_lock(STp, 0);
+
+	if (STp->raw)
+		STp->header_ok = 0;
+	
+	normalize_buffer(STp->buffer);
+	write_lock(&os_scsi_tapes_lock);
+	STp->in_use = 0;
+	write_unlock(&os_scsi_tapes_lock);
+
+	scsi_device_put(STp->device);
+
+	return result;
+}
+
+
+/* The ioctl command */
+static int osst_ioctl(struct inode * inode,struct file * file,
+	 unsigned int cmd_in, unsigned long arg)
+{
+	int		      i, cmd_nr, cmd_type, retval = 0;
+	unsigned int	      blk;
+	struct st_modedef   * STm;
+	struct st_partstat  * STps;
+	struct scsi_request * SRpnt = NULL;
+	struct osst_tape    * STp   = file->private_data;
+	char		    * name  = tape_name(STp);
+	void	    __user  * p     = (void __user *)arg;
+
+	if (down_interruptible(&STp->lock))
+		return -ERESTARTSYS;
+
+#if DEBUG
+	if (debugging && !STp->in_use) {
+		printk(OSST_DEB_MSG "%s:D: Incorrect device.\n", name);
+		retval = (-EIO);
+		goto out;
+	}
+#endif
+	STm = &(STp->modes[STp->current_mode]);
+	STps = &(STp->ps[STp->partition]);
+
+	/*
+	 * If we are in the middle of error recovery, don't let anyone
+	 * else try and use this device.  Also, if error recovery fails, it
+	 * may try and take the device offline, in which case all further
+	 * access to the device is prohibited.
+	 */
+	if( !scsi_block_when_processing_errors(STp->device) ) {
+		retval = (-ENXIO);
+		goto out;
+	}
+
+	cmd_type = _IOC_TYPE(cmd_in);
+	cmd_nr   = _IOC_NR(cmd_in);
+#if DEBUG
+	printk(OSST_DEB_MSG "%s:D: Ioctl %d,%d in %s mode\n", name,
+			    cmd_type, cmd_nr, STp->raw?"raw":"normal");
+#endif
+	if (cmd_type == _IOC_TYPE(MTIOCTOP) && cmd_nr == _IOC_NR(MTIOCTOP)) {
+		struct mtop mtc;
+		int    auto_weof = 0;
+
+		if (_IOC_SIZE(cmd_in) != sizeof(mtc)) {
+			retval = (-EINVAL);
+			goto out;
+		}
+
+		i = copy_from_user((char *) &mtc, p, sizeof(struct mtop));
+		if (i) {
+			retval = (-EFAULT);
+			goto out;
+		}
+
+		if (mtc.mt_op == MTSETDRVBUFFER && !capable(CAP_SYS_ADMIN)) {
+			printk(KERN_WARNING "%s:W: MTSETDRVBUFFER only allowed for root.\n", name);
+			retval = (-EPERM);
+			goto out;
+		}
+
+		if (!STm->defined && (mtc.mt_op != MTSETDRVBUFFER && (mtc.mt_count & MT_ST_OPTIONS) == 0)) {
+			retval = (-ENXIO);
+			goto out;
+		}
+
+		if (!STp->pos_unknown) {
+
+			if (STps->eof == ST_FM_HIT) {
+				if (mtc.mt_op == MTFSF || mtc.mt_op == MTFSFM|| mtc.mt_op == MTEOM) {
+					mtc.mt_count -= 1;
+					if (STps->drv_file >= 0)
+						STps->drv_file += 1;
+				}
+				else if (mtc.mt_op == MTBSF || mtc.mt_op == MTBSFM) {
+					mtc.mt_count += 1;
+					if (STps->drv_file >= 0)
+						STps->drv_file += 1;
+				}
+			}
+
+			if (mtc.mt_op == MTSEEK) {
+				/* Old position must be restored if partition will be changed */
+				i = !STp->can_partitions || (STp->new_partition != STp->partition);
+			}
+			else {
+				i = mtc.mt_op == MTREW   || mtc.mt_op == MTOFFL ||
+				    mtc.mt_op == MTRETEN || mtc.mt_op == MTEOM  ||
+				    mtc.mt_op == MTLOCK  || mtc.mt_op == MTLOAD ||
+				    mtc.mt_op == MTFSF   || mtc.mt_op == MTFSFM ||
+				    mtc.mt_op == MTBSF   || mtc.mt_op == MTBSFM ||
+				    mtc.mt_op == MTCOMPRESSION;
+			}
+			i = osst_flush_buffer(STp, &SRpnt, i);
+			if (i < 0) {
+				retval = i;
+				goto out;
+			}
+		}
+		else {
+			/*
+			 * If there was a bus reset, block further access
+			 * to this device.  If the user wants to rewind the tape,
+			 * then reset the flag and allow access again.
+			 */
+			if(mtc.mt_op != MTREW   &&
+			   mtc.mt_op != MTOFFL  &&
+			   mtc.mt_op != MTRETEN &&
+			   mtc.mt_op != MTERASE &&
+			   mtc.mt_op != MTSEEK  &&
+			   mtc.mt_op != MTEOM)   {
+				retval = (-EIO);
+				goto out;
+			}
+			reset_state(STp);
+			/* remove this when the midlevel properly clears was_reset */
+			STp->device->was_reset = 0;
+		}
+
+		if (mtc.mt_op != MTCOMPRESSION  && mtc.mt_op != MTLOCK         &&
+		    mtc.mt_op != MTNOP          && mtc.mt_op != MTSETBLK       &&
+		    mtc.mt_op != MTSETDENSITY   && mtc.mt_op != MTSETDRVBUFFER && 
+		    mtc.mt_op != MTMKPART       && mtc.mt_op != MTSETPART      &&
+		    mtc.mt_op != MTWEOF         && mtc.mt_op != MTWSM           ) {
+
+			/*
+			 * The user tells us to move to another position on the tape.
+			 * If we were appending to the tape content, that would leave
+			 * the tape without proper end, in that case write EOD and
+			 * update the header to reflect its position.
+			 */
+#if DEBUG
+			printk(KERN_WARNING "%s:D: auto_weod %s at ffp=%d,efp=%d,fsn=%d,lbn=%d,fn=%d,bn=%d\n", name,
+					STps->rw >= ST_WRITING ? "write" : STps->rw == ST_READING ? "read" : "idle",
+					STp->first_frame_position, STp->eod_frame_ppos, STp->frame_seq_number,
+					STp->logical_blk_num, STps->drv_file, STps->drv_block );
+#endif
+			if (STps->rw >= ST_WRITING && STp->first_frame_position >= STp->eod_frame_ppos) {
+				auto_weof = ((STp->write_type != OS_WRITE_NEW_MARK) &&
+							!(mtc.mt_op == MTREW || mtc.mt_op == MTOFFL));
+				i = osst_write_trailer(STp, &SRpnt,
+							!(mtc.mt_op == MTREW || mtc.mt_op == MTOFFL));
+#if DEBUG
+				printk(KERN_WARNING "%s:D: post trailer xeof=%d,ffp=%d,efp=%d,fsn=%d,lbn=%d,fn=%d,bn=%d\n",
+						name, auto_weof, STp->first_frame_position, STp->eod_frame_ppos,
+						STp->frame_seq_number, STp->logical_blk_num, STps->drv_file, STps->drv_block );
+#endif
+				if (i < 0) {
+					retval = i;
+					goto out;
+				}
+			}
+			STps->rw = ST_IDLE;
+		}
+
+		if (mtc.mt_op == MTOFFL && STp->door_locked != ST_UNLOCKED)
+			do_door_lock(STp, 0);  /* Ignore result! */
+
+		if (mtc.mt_op == MTSETDRVBUFFER &&
+		   (mtc.mt_count & MT_ST_OPTIONS) != 0) {
+			retval = osst_set_options(STp, mtc.mt_count);
+			goto out;
+		}
+
+		if (mtc.mt_op == MTSETPART) {
+			if (mtc.mt_count >= STp->nbr_partitions)
+				retval = -EINVAL;
+			else {
+				STp->new_partition = mtc.mt_count;
+				retval = 0;
+			}
+			goto out;
+		}
+
+		if (mtc.mt_op == MTMKPART) {
+			if (!STp->can_partitions) {
+				retval = (-EINVAL);
+				goto out;
+			}
+			if ((i = osst_int_ioctl(STp, &SRpnt, MTREW, 0)) < 0 /*||
+			    (i = partition_tape(inode, mtc.mt_count)) < 0*/) {
+				retval = i;
+				goto out;
+			}
+			for (i=0; i < ST_NBR_PARTITIONS; i++) {
+				STp->ps[i].rw = ST_IDLE;
+				STp->ps[i].at_sm = 0;
+				STp->ps[i].last_block_valid = 0;
+			}
+			STp->partition = STp->new_partition = 0;
+			STp->nbr_partitions = 1;  /* Bad guess ?-) */
+			STps->drv_block = STps->drv_file = 0;
+			retval = 0;
+			goto out;
+	 	}
+
+		if (mtc.mt_op == MTSEEK) {
+			if (STp->raw)
+				i = osst_set_frame_position(STp, &SRpnt, mtc.mt_count, 0);
+			else
+				i = osst_seek_sector(STp, &SRpnt, mtc.mt_count);
+			if (!STp->can_partitions)
+				STp->ps[0].rw = ST_IDLE;
+			retval = i;
+			goto out;
+		}
+ 
+		if (mtc.mt_op == MTLOCK || mtc.mt_op == MTUNLOCK) {
+			retval = do_door_lock(STp, (mtc.mt_op == MTLOCK));
+			goto out;
+		}
+
+		if (auto_weof)
+			cross_eof(STp, &SRpnt, 0);
+
+		if (mtc.mt_op == MTCOMPRESSION)
+			retval = -EINVAL;       /* OnStream drives don't have compression hardware */
+		else
+			/* MTBSF MTBSFM MTBSR MTBSS MTEOM MTERASE MTFSF MTFSFB MTFSR MTFSS
+			 * MTLOAD MTOFFL MTRESET MTRETEN MTREW MTUNLOAD MTWEOF MTWSM */
+			retval = osst_int_ioctl(STp, &SRpnt, mtc.mt_op, mtc.mt_count);
+		goto out;
+	}
+
+	if (!STm->defined) {
+		retval = (-ENXIO);
+		goto out;
+	}
+
+	if ((i = osst_flush_buffer(STp, &SRpnt, 0)) < 0) {
+		retval = i;
+		goto out;
+	}
+
+	if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) {
+		struct mtget mt_status;
+
+		if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) {
+			 retval = (-EINVAL);
+			 goto out;
+		}
+
+		mt_status.mt_type = MT_ISONSTREAM_SC;
+		mt_status.mt_erreg = STp->recover_erreg << MT_ST_SOFTERR_SHIFT;
+		mt_status.mt_dsreg =
+			((STp->block_size << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK) |
+			((STp->density    << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK);
+		mt_status.mt_blkno = STps->drv_block;
+		mt_status.mt_fileno = STps->drv_file;
+		if (STp->block_size != 0) {
+			if (STps->rw == ST_WRITING)
+				mt_status.mt_blkno += (STp->buffer)->buffer_bytes / STp->block_size;
+			else if (STps->rw == ST_READING)
+				mt_status.mt_blkno -= ((STp->buffer)->buffer_bytes +
+							STp->block_size - 1) / STp->block_size;
+		}
+
+		mt_status.mt_gstat = 0;
+		if (STp->drv_write_prot)
+			mt_status.mt_gstat |= GMT_WR_PROT(0xffffffff);
+		if (mt_status.mt_blkno == 0) {
+			if (mt_status.mt_fileno == 0)
+				mt_status.mt_gstat |= GMT_BOT(0xffffffff);
+			else
+				mt_status.mt_gstat |= GMT_EOF(0xffffffff);
+		}
+		mt_status.mt_resid = STp->partition;
+		if (STps->eof == ST_EOM_OK || STps->eof == ST_EOM_ERROR)
+			mt_status.mt_gstat |= GMT_EOT(0xffffffff);
+		else if (STps->eof >= ST_EOM_OK)
+			mt_status.mt_gstat |= GMT_EOD(0xffffffff);
+		if (STp->density == 1)
+			mt_status.mt_gstat |= GMT_D_800(0xffffffff);
+		else if (STp->density == 2)
+			mt_status.mt_gstat |= GMT_D_1600(0xffffffff);
+		else if (STp->density == 3)
+			mt_status.mt_gstat |= GMT_D_6250(0xffffffff);
+		if (STp->ready == ST_READY)
+			mt_status.mt_gstat |= GMT_ONLINE(0xffffffff);
+		if (STp->ready == ST_NO_TAPE)
+			mt_status.mt_gstat |= GMT_DR_OPEN(0xffffffff);
+		if (STps->at_sm)
+			mt_status.mt_gstat |= GMT_SM(0xffffffff);
+		if (STm->do_async_writes || (STm->do_buffer_writes && STp->block_size != 0) ||
+		    STp->drv_buffer != 0)
+			mt_status.mt_gstat |= GMT_IM_REP_EN(0xffffffff);
+
+		i = copy_to_user(p, &mt_status, sizeof(struct mtget));
+		if (i) {
+			retval = (-EFAULT);
+			goto out;
+		}
+
+		STp->recover_erreg = 0;  /* Clear after read */
+		retval = 0;
+		goto out;
+	} /* End of MTIOCGET */
+
+	if (cmd_type == _IOC_TYPE(MTIOCPOS) && cmd_nr == _IOC_NR(MTIOCPOS)) {
+		struct mtpos mt_pos;
+
+		if (_IOC_SIZE(cmd_in) != sizeof(struct mtpos)) {
+			retval = (-EINVAL);
+			goto out;
+		}
+		if (STp->raw)
+			blk = osst_get_frame_position(STp, &SRpnt);
+		else
+			blk = osst_get_sector(STp, &SRpnt);
+		if (blk < 0) {
+			retval = blk;
+			goto out;
+		}
+		mt_pos.mt_blkno = blk;
+		i = copy_to_user(p, &mt_pos, sizeof(struct mtpos));
+		if (i)
+			retval = -EFAULT;
+		goto out;
+	}
+	if (SRpnt) scsi_release_request(SRpnt);
+
+	up(&STp->lock);
+
+	return scsi_ioctl(STp->device, cmd_in, p);
+
+out:
+	if (SRpnt) scsi_release_request(SRpnt);
+
+	up(&STp->lock);
+
+	return retval;
+}
+
+#ifdef CONFIG_COMPAT
+static long osst_compat_ioctl(struct file * file, unsigned int cmd_in, unsigned long arg)
+{
+	struct osst_tape *STp = file->private_data;
+	struct scsi_device *sdev = STp->device;
+	int ret = -ENOIOCTLCMD;
+	if (sdev->host->hostt->compat_ioctl) {
+
+		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
+
+	}
+	return ret;
+}
+#endif
+
+
+
+/* Memory handling routines */
+
+/* Try to allocate a new tape buffer skeleton. Caller must not hold os_scsi_tapes_lock */
+static struct osst_buffer * new_tape_buffer( int from_initialization, int need_dma, int max_sg )
+{
+	int i, priority;
+	struct osst_buffer *tb;
+
+	if (from_initialization)
+		priority = GFP_ATOMIC;
+	else
+		priority = GFP_KERNEL;
+
+	i = sizeof(struct osst_buffer) + (osst_max_sg_segs - 1) * sizeof(struct scatterlist);
+	tb = (struct osst_buffer *)kmalloc(i, priority);
+	if (!tb) {
+		printk(KERN_NOTICE "osst :I: Can't allocate new tape buffer.\n");
+		return NULL;
+	}
+	memset(tb, 0, i);
+	tb->sg_segs = tb->orig_sg_segs = 0;
+	tb->use_sg = max_sg;
+	tb->in_use = 1;
+	tb->dma = need_dma;
+	tb->buffer_size = 0;
+#if DEBUG
+	if (debugging) 
+		printk(OSST_DEB_MSG
+			"osst :D: Allocated tape buffer skeleton (%d bytes, %d segments, dma: %d).\n",
+			   i, max_sg, need_dma);
+#endif
+	return tb;
+}
+
+/* Try to allocate a temporary (while a user has the device open) enlarged tape buffer */
+static int enlarge_buffer(struct osst_buffer *STbuffer, int need_dma)
+{
+	int segs, nbr, max_segs, b_size, priority, order, got;
+
+	if (STbuffer->buffer_size >= OS_FRAME_SIZE)
+		return 1;
+
+	if (STbuffer->sg_segs) {
+		printk(KERN_WARNING "osst :A: Buffer not previously normalized.\n");
+		normalize_buffer(STbuffer);
+	}
+	/* See how many segments we can use -- need at least two */
+	nbr = max_segs = STbuffer->use_sg;
+	if (nbr <= 2)
+		return 0;
+
+	priority = GFP_KERNEL /* | __GFP_NOWARN */;
+	if (need_dma)
+		priority |= GFP_DMA;
+
+	/* Try to allocate the first segment up to OS_DATA_SIZE and the others
+	   big enough to reach the goal (code assumes no segments in place) */
+	for (b_size = OS_DATA_SIZE, order = OSST_FIRST_ORDER; b_size >= PAGE_SIZE; order--, b_size /= 2) {
+		STbuffer->sg[0].page = alloc_pages(priority, order);
+		STbuffer->sg[0].offset = 0;
+		if (STbuffer->sg[0].page != NULL) {
+		    STbuffer->sg[0].length = b_size;
+		    STbuffer->b_data = page_address(STbuffer->sg[0].page);
+		    break;
+		}
+	}
+	if (STbuffer->sg[0].page == NULL) {
+		printk(KERN_NOTICE "osst :I: Can't allocate tape buffer main segment.\n");
+		return 0;
+	}
+	/* Got initial segment of 'bsize,order', continue with same size if possible, except for AUX */
+	for (segs=STbuffer->sg_segs=1, got=b_size;
+	     segs < max_segs && got < OS_FRAME_SIZE; ) {
+		STbuffer->sg[segs].page =
+				alloc_pages(priority, (OS_FRAME_SIZE - got <= PAGE_SIZE) ? 0 : order);
+		STbuffer->sg[segs].offset = 0;
+		if (STbuffer->sg[segs].page == NULL) {
+			if (OS_FRAME_SIZE - got <= (max_segs - segs) * b_size / 2 && order) {
+				b_size /= 2;  /* Large enough for the rest of the buffers */
+				order--;
+				continue;
+			}
+			printk(KERN_WARNING "osst :W: Failed to enlarge buffer to %d bytes.\n",
+						OS_FRAME_SIZE);
+#if DEBUG
+			STbuffer->buffer_size = got;
+#endif
+			normalize_buffer(STbuffer);
+			return 0;
+		}
+		STbuffer->sg[segs].length = (OS_FRAME_SIZE - got <= PAGE_SIZE / 2) ? (OS_FRAME_SIZE - got) : b_size;
+		got += STbuffer->sg[segs].length;
+		STbuffer->buffer_size = got;
+		STbuffer->sg_segs = ++segs;
+	}
+#if DEBUG
+	if (debugging) {
+		printk(OSST_DEB_MSG
+			   "osst :D: Expanded tape buffer (%d bytes, %d->%d segments, dma: %d, at: %p).\n",
+			   got, STbuffer->orig_sg_segs, STbuffer->sg_segs, need_dma, STbuffer->b_data);
+		printk(OSST_DEB_MSG
+			   "osst :D: segment sizes: first %d at %p, last %d bytes at %p.\n",
+			   STbuffer->sg[0].length, page_address(STbuffer->sg[0].page),
+			   STbuffer->sg[segs-1].length, page_address(STbuffer->sg[segs-1].page));
+	}
+#endif
+
+	return 1;
+}
+
+
+/* Release the segments */
+static void normalize_buffer(struct osst_buffer *STbuffer)
+{
+  int i, order, b_size;
+
+	for (i=0; i < STbuffer->sg_segs; i++) {
+
+		for (b_size = PAGE_SIZE, order = 0;
+		     b_size < STbuffer->sg[i].length;
+		     b_size *= 2, order++);
+
+		__free_pages(STbuffer->sg[i].page, order);
+		STbuffer->buffer_size -= STbuffer->sg[i].length;
+	}
+#if DEBUG
+	if (debugging && STbuffer->orig_sg_segs < STbuffer->sg_segs)
+		printk(OSST_DEB_MSG "osst :D: Buffer at %p normalized to %d bytes (segs %d).\n",
+			     STbuffer->b_data, STbuffer->buffer_size, STbuffer->sg_segs);
+#endif
+	STbuffer->sg_segs = STbuffer->orig_sg_segs = 0;
+}
+
+
+/* Move data from the user buffer to the tape buffer. Returns zero (success) or
+   negative error code. */
+static int append_to_buffer(const char __user *ubp, struct osst_buffer *st_bp, int do_count)
+{
+	int i, cnt, res, offset;
+
+	for (i=0, offset=st_bp->buffer_bytes;
+	     i < st_bp->sg_segs && offset >= st_bp->sg[i].length; i++)
+	offset -= st_bp->sg[i].length;
+	if (i == st_bp->sg_segs) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: Append_to_buffer offset overflow.\n");
+		return (-EIO);
+	}
+	for ( ; i < st_bp->sg_segs && do_count > 0; i++) {
+		cnt = st_bp->sg[i].length - offset < do_count ?
+		      st_bp->sg[i].length - offset : do_count;
+		res = copy_from_user(page_address(st_bp->sg[i].page) + offset, ubp, cnt);
+		if (res)
+			return (-EFAULT);
+		do_count -= cnt;
+		st_bp->buffer_bytes += cnt;
+		ubp += cnt;
+		offset = 0;
+	}
+	if (do_count) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: Append_to_buffer overflow (left %d).\n",
+		       do_count);
+		return (-EIO);
+	}
+	return 0;
+}
+
+
+/* Move data from the tape buffer to the user buffer. Returns zero (success) or
+   negative error code. */
+static int from_buffer(struct osst_buffer *st_bp, char __user *ubp, int do_count)
+{
+	int i, cnt, res, offset;
+
+	for (i=0, offset=st_bp->read_pointer;
+	     i < st_bp->sg_segs && offset >= st_bp->sg[i].length; i++)
+		offset -= st_bp->sg[i].length;
+	if (i == st_bp->sg_segs) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: From_buffer offset overflow.\n");
+		return (-EIO);
+	}
+	for ( ; i < st_bp->sg_segs && do_count > 0; i++) {
+		cnt = st_bp->sg[i].length - offset < do_count ?
+		      st_bp->sg[i].length - offset : do_count;
+		res = copy_to_user(ubp, page_address(st_bp->sg[i].page) + offset, cnt);
+		if (res)
+			return (-EFAULT);
+		do_count -= cnt;
+		st_bp->buffer_bytes -= cnt;
+		st_bp->read_pointer += cnt;
+		ubp += cnt;
+		offset = 0;
+	}
+	if (do_count) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: From_buffer overflow (left %d).\n", do_count);
+		return (-EIO);
+	}
+	return 0;
+}
+
+/* Sets the tail of the buffer after fill point to zero.
+   Returns zero (success) or negative error code.        */
+static int osst_zero_buffer_tail(struct osst_buffer *st_bp)
+{
+	int	i, offset, do_count, cnt;
+
+	for (i = 0, offset = st_bp->buffer_bytes;
+	     i < st_bp->sg_segs && offset >= st_bp->sg[i].length; i++)
+		offset -= st_bp->sg[i].length;
+	if (i == st_bp->sg_segs) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: Zero_buffer offset overflow.\n");
+		return (-EIO);
+	}
+	for (do_count = OS_DATA_SIZE - st_bp->buffer_bytes;
+	     i < st_bp->sg_segs && do_count > 0; i++) {
+		cnt = st_bp->sg[i].length - offset < do_count ?
+		      st_bp->sg[i].length - offset : do_count ;
+		memset(page_address(st_bp->sg[i].page) + offset, 0, cnt);
+		do_count -= cnt;
+		offset = 0;
+	}
+	if (do_count) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: Zero_buffer overflow (left %d).\n", do_count);
+		return (-EIO);
+	}
+	return 0;
+}
+
+/* Copy a osst 32K chunk of memory into the buffer.
+   Returns zero (success) or negative error code.  */
+static int osst_copy_to_buffer(struct osst_buffer *st_bp, unsigned char *ptr)
+{
+	int	i, cnt, do_count = OS_DATA_SIZE;
+
+	for (i = 0; i < st_bp->sg_segs && do_count > 0; i++) {
+		cnt = st_bp->sg[i].length < do_count ?
+		      st_bp->sg[i].length : do_count ;
+		memcpy(page_address(st_bp->sg[i].page), ptr, cnt);
+		do_count -= cnt;
+		ptr      += cnt;
+	}
+	if (do_count || i != st_bp->sg_segs-1) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: Copy_to_buffer overflow (left %d at sg %d).\n",
+					 do_count, i);
+		return (-EIO);
+	}
+	return 0;
+}
+
+/* Copy a osst 32K chunk of memory from the buffer.
+   Returns zero (success) or negative error code.  */
+static int osst_copy_from_buffer(struct osst_buffer *st_bp, unsigned char *ptr)
+{
+	int	i, cnt, do_count = OS_DATA_SIZE;
+
+	for (i = 0; i < st_bp->sg_segs && do_count > 0; i++) {
+		cnt = st_bp->sg[i].length < do_count ?
+		      st_bp->sg[i].length : do_count ;
+		memcpy(ptr, page_address(st_bp->sg[i].page), cnt);
+		do_count -= cnt;
+		ptr      += cnt;
+	}
+	if (do_count || i != st_bp->sg_segs-1) {  /* Should never happen */
+		printk(KERN_WARNING "osst :A: Copy_from_buffer overflow (left %d at sg %d).\n",
+					 do_count, i);
+		return (-EIO);
+	}
+	return 0;
+}
+
+
+/* Module housekeeping */
+
+static void validate_options (void)
+{
+  if (max_dev > 0)
+		osst_max_dev = max_dev;  
+  if (write_threshold_kbs > 0)
+		osst_write_threshold = write_threshold_kbs * ST_KILOBYTE;
+  if (osst_write_threshold > osst_buffer_size)
+		osst_write_threshold = osst_buffer_size;
+  if (max_sg_segs >= OSST_FIRST_SG)
+		osst_max_sg_segs = max_sg_segs;
+#if DEBUG
+  printk(OSST_DEB_MSG "osst :D: max tapes %d, write threshold %d, max s/g segs %d.\n",
+			   osst_max_dev, osst_write_threshold, osst_max_sg_segs);
+#endif
+}
+	
+#ifndef MODULE
+/* Set the boot options. Syntax: osst=xxx,yyy,...
+   where xxx is write threshold in 1024 byte blocks,
+   and   yyy is number of s/g segments to use. */
+static int __init osst_setup (char *str)
+{
+  int i, ints[5];
+  char *stp;
+
+  stp = get_options(str, ARRAY_SIZE(ints), ints);
+	
+  if (ints[0] > 0) {
+	for (i = 0; i < ints[0] && i < ARRAY_SIZE(parms); i++)
+		  *parms[i].val = ints[i + 1];
+  } else {
+	while (stp != NULL) {
+		for (i = 0; i < ARRAY_SIZE(parms); i++) {
+			int len = strlen(parms[i].name);
+			if (!strncmp(stp, parms[i].name, len) &&
+			    (*(stp + len) == ':' || *(stp + len) == '=')) {
+				*parms[i].val =
+					simple_strtoul(stp + len + 1, NULL, 0);
+				break;
+			}
+		}
+		if (i >= sizeof(parms) / sizeof(struct osst_dev_parm))
+			printk(KERN_INFO "osst :I: Illegal parameter in '%s'\n",
+			       stp);
+		stp = strchr(stp, ',');
+		if (stp)
+			stp++;
+	}
+  }
+
+  return 1;
+}
+
+__setup("osst=", osst_setup);
+
+#endif
+
+static struct file_operations osst_fops = {
+	.owner =        THIS_MODULE,
+	.read =         osst_read,
+	.write =        osst_write,
+	.ioctl =        osst_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = osst_compat_ioctl,
+#endif
+	.open =         os_scsi_tape_open,
+	.flush =        os_scsi_tape_flush,
+	.release =      os_scsi_tape_close,
+};
+
+static int osst_supports(struct scsi_device * SDp)
+{
+	struct	osst_support_data {
+		char *vendor;
+		char *model;
+		char *rev;
+		char *driver_hint; /* Name of the correct driver, NULL if unknown */
+	};
+
+static	struct	osst_support_data support_list[] = {
+		/* {"XXX", "Yy-", "", NULL},  example */
+		SIGS_FROM_OSST,
+		{NULL, }};
+
+	struct	osst_support_data *rp;
+
+	/* We are willing to drive OnStream SC-x0 as well as the
+	 * 	 * IDE, ParPort, FireWire, USB variants, if accessible by
+	 * 	 	 * emulation layer (ide-scsi, usb-storage, ...) */
+
+	for (rp=&(support_list[0]); rp->vendor != NULL; rp++)
+		if (!strncmp(rp->vendor, SDp->vendor, strlen(rp->vendor)) &&
+		    !strncmp(rp->model, SDp->model, strlen(rp->model)) &&
+		    !strncmp(rp->rev, SDp->rev, strlen(rp->rev))) 
+			return 1;
+	return 0;
+}
+
+/*
+ * sysfs support for osst driver parameter information
+ */
+
+static ssize_t osst_version_show(struct device_driver *ddd, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%s\n", osst_version);
+}
+
+static DRIVER_ATTR(version, S_IRUGO, osst_version_show, NULL);
+
+static void osst_create_driverfs_files(struct device_driver *driverfs)
+{
+	driver_create_file(driverfs, &driver_attr_version);
+}
+
+static void osst_remove_driverfs_files(struct device_driver *driverfs)
+{
+	driver_remove_file(driverfs, &driver_attr_version);
+}
+
+/*
+ * sysfs support for accessing ADR header information
+ */
+
+static ssize_t osst_adr_rev_show(struct class_device *class_dev, char *buf)
+{
+	struct osst_tape * STp = (struct osst_tape *) class_get_devdata (class_dev);
+	ssize_t l = 0;
+
+	if (STp && STp->header_ok && STp->linux_media)
+		l = snprintf(buf, PAGE_SIZE, "%d.%d\n", STp->header_cache->major_rev, STp->header_cache->minor_rev);
+	return l;
+}
+
+CLASS_DEVICE_ATTR(ADR_rev, S_IRUGO, osst_adr_rev_show, NULL);
+
+static ssize_t osst_linux_media_version_show(struct class_device *class_dev, char *buf)
+{
+	struct osst_tape * STp = (struct osst_tape *) class_get_devdata (class_dev);
+	ssize_t l = 0;
+
+	if (STp && STp->header_ok && STp->linux_media)
+		l = snprintf(buf, PAGE_SIZE, "LIN%d\n", STp->linux_media_version);
+	return l;
+}
+
+CLASS_DEVICE_ATTR(media_version, S_IRUGO, osst_linux_media_version_show, NULL);
+
+static ssize_t osst_capacity_show(struct class_device *class_dev, char *buf)
+{
+	struct osst_tape * STp = (struct osst_tape *) class_get_devdata (class_dev);
+	ssize_t l = 0;
+
+	if (STp && STp->header_ok && STp->linux_media)
+		l = snprintf(buf, PAGE_SIZE, "%d\n", STp->capacity);
+	return l;
+}
+
+CLASS_DEVICE_ATTR(capacity, S_IRUGO, osst_capacity_show, NULL);
+
+static ssize_t osst_first_data_ppos_show(struct class_device *class_dev, char *buf)
+{
+	struct osst_tape * STp = (struct osst_tape *) class_get_devdata (class_dev);
+	ssize_t l = 0;
+
+	if (STp && STp->header_ok && STp->linux_media)
+		l = snprintf(buf, PAGE_SIZE, "%d\n", STp->first_data_ppos);
+	return l;
+}
+
+CLASS_DEVICE_ATTR(BOT_frame, S_IRUGO, osst_first_data_ppos_show, NULL);
+
+static ssize_t osst_eod_frame_ppos_show(struct class_device *class_dev, char *buf)
+{
+	struct osst_tape * STp = (struct osst_tape *) class_get_devdata (class_dev);
+	ssize_t l = 0;
+
+	if (STp && STp->header_ok && STp->linux_media)
+		l = snprintf(buf, PAGE_SIZE, "%d\n", STp->eod_frame_ppos);
+	return l;
+}
+
+CLASS_DEVICE_ATTR(EOD_frame, S_IRUGO, osst_eod_frame_ppos_show, NULL);
+
+static ssize_t osst_filemark_cnt_show(struct class_device *class_dev, char *buf)
+{
+	struct osst_tape * STp = (struct osst_tape *) class_get_devdata (class_dev);
+	ssize_t l = 0;
+
+	if (STp && STp->header_ok && STp->linux_media)
+		l = snprintf(buf, PAGE_SIZE, "%d\n", STp->filemark_cnt);
+	return l;
+}
+
+CLASS_DEVICE_ATTR(file_count, S_IRUGO, osst_filemark_cnt_show, NULL);
+
+static struct class_simple * osst_sysfs_class;
+
+static int osst_sysfs_valid = 0;
+
+static void osst_sysfs_init(void)
+{
+	osst_sysfs_class = class_simple_create(THIS_MODULE, "onstream_tape");
+	if ( IS_ERR(osst_sysfs_class) )
+		printk(KERN_WARNING "osst :W: Unable to register sysfs class\n");
+	else
+		osst_sysfs_valid = 1;
+}
+
+static void osst_sysfs_add(dev_t dev, struct device *device, struct osst_tape * STp, char * name)
+{
+	struct class_device *osst_class_member;
+
+	if (!osst_sysfs_valid) return;
+
+	osst_class_member = class_simple_device_add(osst_sysfs_class, dev, device, "%s", name);
+	if (IS_ERR(osst_class_member)) {
+		printk(KERN_WARNING "osst :W: Unable to add sysfs class member %s\n", name);
+		return;
+	}
+	class_set_devdata(osst_class_member, STp);
+	class_device_create_file(osst_class_member, &class_device_attr_ADR_rev);
+	class_device_create_file(osst_class_member, &class_device_attr_media_version);
+	class_device_create_file(osst_class_member, &class_device_attr_capacity);
+	class_device_create_file(osst_class_member, &class_device_attr_BOT_frame);
+	class_device_create_file(osst_class_member, &class_device_attr_EOD_frame);
+	class_device_create_file(osst_class_member, &class_device_attr_file_count);
+}
+
+static void osst_sysfs_destroy(dev_t dev)
+{
+	if (!osst_sysfs_valid) return; 
+
+	class_simple_device_remove(dev);
+}
+
+static void osst_sysfs_cleanup(void)
+{
+	if (osst_sysfs_valid) {
+		class_simple_destroy(osst_sysfs_class);
+		osst_sysfs_valid = 0;
+	}
+}
+
+/*
+ * osst startup / cleanup code
+ */
+
+static int osst_probe(struct device *dev)
+{
+	struct scsi_device * SDp = to_scsi_device(dev);
+	struct osst_tape   * tpnt;
+	struct st_modedef  * STm;
+	struct st_partstat * STps;
+	struct osst_buffer * buffer;
+	struct gendisk	   * drive;
+	int		     i, mode, dev_num;
+
+	if (SDp->type != TYPE_TAPE || !osst_supports(SDp))
+		return -ENODEV;
+
+	drive = alloc_disk(1);
+	if (!drive) {
+		printk(KERN_ERR "osst :E: Out of memory. Device not attached.\n");
+		return -ENODEV;
+	}
+
+	/* if this is the first attach, build the infrastructure */
+	write_lock(&os_scsi_tapes_lock);
+	if (os_scsi_tapes == NULL) {
+		os_scsi_tapes =
+			(struct osst_tape **)kmalloc(osst_max_dev * sizeof(struct osst_tape *),
+				   GFP_ATOMIC);
+		if (os_scsi_tapes == NULL) {
+			write_unlock(&os_scsi_tapes_lock);
+			printk(KERN_ERR "osst :E: Unable to allocate array for OnStream SCSI tapes.\n");
+			goto out_put_disk;
+		}
+		for (i=0; i < osst_max_dev; ++i) os_scsi_tapes[i] = NULL;
+	}
+	
+	if (osst_nr_dev >= osst_max_dev) {
+		write_unlock(&os_scsi_tapes_lock);
+		printk(KERN_ERR "osst :E: Too many tape devices (max. %d).\n", osst_max_dev);
+		goto out_put_disk;
+	}
+
+	/* find a free minor number */
+	for (i=0; os_scsi_tapes[i] && i<osst_max_dev; i++);
+	if(i >= osst_max_dev) panic ("Scsi_devices corrupt (osst)");
+	dev_num = i;
+
+	/* allocate a struct osst_tape for this device */
+	tpnt = (struct osst_tape *)kmalloc(sizeof(struct osst_tape), GFP_ATOMIC);
+	if (tpnt == NULL) {
+		write_unlock(&os_scsi_tapes_lock);
+		printk(KERN_ERR "osst :E: Can't allocate device descriptor, device not attached.\n");
+		goto out_put_disk;
+	}
+	memset(tpnt, 0, sizeof(struct osst_tape));
+
+	/* allocate a buffer for this device */
+	i = SDp->host->sg_tablesize;
+	if (osst_max_sg_segs < i)
+		i = osst_max_sg_segs;
+	buffer = new_tape_buffer(1, SDp->host->unchecked_isa_dma, i);
+	if (buffer == NULL) {
+		write_unlock(&os_scsi_tapes_lock);
+		printk(KERN_ERR "osst :E: Unable to allocate a tape buffer, device not attached.\n");
+		kfree(tpnt);
+		goto out_put_disk;
+	}
+	os_scsi_tapes[dev_num] = tpnt;
+	tpnt->buffer = buffer;
+	tpnt->device = SDp;
+	drive->private_data = &tpnt->driver;
+	sprintf(drive->disk_name, "osst%d", dev_num);
+	tpnt->driver = &osst_template;
+	tpnt->drive = drive;
+	tpnt->in_use = 0;
+	tpnt->capacity = 0xfffff;
+	tpnt->dirty = 0;
+	tpnt->drv_buffer = 1;  /* Try buffering if no mode sense */
+	tpnt->restr_dma = (SDp->host)->unchecked_isa_dma;
+	tpnt->density = 0;
+	tpnt->do_auto_lock = OSST_AUTO_LOCK;
+	tpnt->can_bsr = OSST_IN_FILE_POS;
+	tpnt->can_partitions = 0;
+	tpnt->two_fm = OSST_TWO_FM;
+	tpnt->fast_mteom = OSST_FAST_MTEOM;
+	tpnt->scsi2_logical = OSST_SCSI2LOGICAL; /* FIXME */
+	tpnt->write_threshold = osst_write_threshold;
+	tpnt->default_drvbuffer = 0xff; /* No forced buffering */
+	tpnt->partition = 0;
+	tpnt->new_partition = 0;
+	tpnt->nbr_partitions = 0;
+	tpnt->min_block = 512;
+	tpnt->max_block = OS_DATA_SIZE;
+	tpnt->timeout = OSST_TIMEOUT;
+	tpnt->long_timeout = OSST_LONG_TIMEOUT;
+
+	/* Recognize OnStream tapes */
+	/* We don't need to test for OnStream, as this has been done in detect () */
+	tpnt->os_fw_rev = osst_parse_firmware_rev (SDp->rev);
+	tpnt->omit_blklims = 1;
+
+	tpnt->poll = (strncmp(SDp->model, "DI-", 3) == 0) || 
+		     (strncmp(SDp->model, "FW-", 3) == 0) || OSST_FW_NEED_POLL(tpnt->os_fw_rev,SDp);
+	tpnt->frame_in_buffer = 0;
+	tpnt->header_ok = 0;
+	tpnt->linux_media = 0;
+	tpnt->header_cache = NULL;
+
+	for (i=0; i < ST_NBR_MODES; i++) {
+		STm = &(tpnt->modes[i]);
+		STm->defined = 0;
+		STm->sysv = OSST_SYSV;
+		STm->defaults_for_writes = 0;
+		STm->do_async_writes = OSST_ASYNC_WRITES;
+		STm->do_buffer_writes = OSST_BUFFER_WRITES;
+		STm->do_read_ahead = OSST_READ_AHEAD;
+		STm->default_compression = ST_DONT_TOUCH;
+		STm->default_blksize = 512;
+		STm->default_density = (-1);  /* No forced density */
+	}
+
+	for (i=0; i < ST_NBR_PARTITIONS; i++) {
+		STps = &(tpnt->ps[i]);
+		STps->rw = ST_IDLE;
+		STps->eof = ST_NOEOF;
+		STps->at_sm = 0;
+		STps->last_block_valid = 0;
+		STps->drv_block = (-1);
+		STps->drv_file = (-1);
+	}
+
+	tpnt->current_mode = 0;
+	tpnt->modes[0].defined = 1;
+	tpnt->modes[2].defined = 1;
+	tpnt->density_changed = tpnt->compression_changed = tpnt->blksize_changed = 0;
+
+	init_MUTEX(&tpnt->lock);
+	osst_nr_dev++;
+	write_unlock(&os_scsi_tapes_lock);
+	{
+		char name[8];
+		/*  Rewind entry  */
+		osst_sysfs_add(MKDEV(OSST_MAJOR, dev_num), dev, tpnt, tape_name(tpnt));
+		/*  No-rewind entry  */
+		snprintf(name, 8, "%s%s", "n", tape_name(tpnt));
+		osst_sysfs_add(MKDEV(OSST_MAJOR, dev_num + 128), dev, tpnt, name);
+	}
+	for (mode = 0; mode < ST_NBR_MODES; ++mode) {
+		/*  Rewind entry  */
+		devfs_mk_cdev(MKDEV(OSST_MAJOR, dev_num + (mode << 5)),
+				S_IFCHR | S_IRUGO | S_IWUGO,
+				"%s/ot%s", SDp->devfs_name, osst_formats[mode]);
+
+		/*  No-rewind entry  */
+		devfs_mk_cdev(MKDEV(OSST_MAJOR, dev_num + (mode << 5) + 128),
+				S_IFCHR | S_IRUGO | S_IWUGO,
+				"%s/ot%sn", SDp->devfs_name, osst_formats[mode]);
+	}
+	drive->number = devfs_register_tape(SDp->devfs_name);
+
+	printk(KERN_INFO
+		"osst :I: Attached OnStream %.5s tape at scsi%d, channel %d, id %d, lun %d as %s\n",
+		SDp->model, SDp->host->host_no, SDp->channel, SDp->id, SDp->lun, tape_name(tpnt));
+
+	return 0;
+
+out_put_disk:
+        put_disk(drive);
+        return -ENODEV;
+};
+
+static int osst_remove(struct device *dev)
+{
+	struct scsi_device * SDp = to_scsi_device(dev);
+	struct osst_tape * tpnt;
+	int i, mode;
+
+	if ((SDp->type != TYPE_TAPE) || (osst_nr_dev <= 0))
+		return 0;
+
+	write_lock(&os_scsi_tapes_lock);
+	for(i=0; i < osst_max_dev; i++) {
+		if((tpnt = os_scsi_tapes[i]) && (tpnt->device == SDp)) {
+			osst_sysfs_destroy(MKDEV(OSST_MAJOR, i));
+			osst_sysfs_destroy(MKDEV(OSST_MAJOR, i+128));
+			tpnt->device = NULL;
+			for (mode = 0; mode < ST_NBR_MODES; ++mode) {
+				devfs_remove("%s/ot%s", SDp->devfs_name, osst_formats[mode]);
+				devfs_remove("%s/ot%sn", SDp->devfs_name, osst_formats[mode]);
+			}
+			devfs_unregister_tape(tpnt->drive->number);
+			put_disk(tpnt->drive);
+			os_scsi_tapes[i] = NULL;
+			osst_nr_dev--;
+			write_unlock(&os_scsi_tapes_lock);
+			if (tpnt->header_cache != NULL) vfree(tpnt->header_cache);
+			if (tpnt->buffer) {
+				normalize_buffer(tpnt->buffer);
+				kfree(tpnt->buffer);
+			}
+			kfree(tpnt);
+			return 0;
+		}
+	}
+	write_unlock(&os_scsi_tapes_lock);
+	return 0;
+}
+
+static int __init init_osst(void) 
+{
+	printk(KERN_INFO "osst :I: Tape driver with OnStream support version %s\nosst :I: %s\n", osst_version, cvsid);
+
+	validate_options();
+	osst_sysfs_init();
+
+	if ((register_chrdev(OSST_MAJOR,"osst", &osst_fops) < 0) || scsi_register_driver(&osst_template.gendrv)) {
+		printk(KERN_ERR "osst :E: Unable to register major %d for OnStream tapes\n", OSST_MAJOR);
+		osst_sysfs_cleanup();
+		return 1;
+	}
+	osst_create_driverfs_files(&osst_template.gendrv);
+
+	return 0;
+}
+
+static void __exit exit_osst (void)
+{
+	int i;
+	struct osst_tape * STp;
+
+	osst_remove_driverfs_files(&osst_template.gendrv);
+	scsi_unregister_driver(&osst_template.gendrv);
+	unregister_chrdev(OSST_MAJOR, "osst");
+	osst_sysfs_cleanup();
+
+	if (os_scsi_tapes) {
+		for (i=0; i < osst_max_dev; ++i) {
+			if (!(STp = os_scsi_tapes[i])) continue;
+			/* This is defensive, supposed to happen during detach */
+			if (STp->header_cache)
+				vfree(STp->header_cache);
+			if (STp->buffer) {
+				normalize_buffer(STp->buffer);
+				kfree(STp->buffer);
+			}
+			put_disk(STp->drive);
+			kfree(STp);
+		}
+		kfree(os_scsi_tapes);
+	}
+	printk(KERN_INFO "osst :I: Unloaded.\n");
+}
+
+module_init(init_osst);
+module_exit(exit_osst);