[SCSI] osst: changes required to move forward to block request

On 02/07/2006 04:12:55 AM, Christoph Hellwig wrote:
> On Mon, Feb 06, 2006 at 08:02:21PM -0500, Willem Riede wrote:
>
> > But I will certainly help retire scsi_request. And anything else that is
> > needed to keep up with proper kernel style. Let me know what those are, if
> > you  would? I'll start looking at how st has changed, and will be back with
> > any  questions I may have.
>
> right now the above is the most urgent bit.  What would be nice but not
> required is a conversion to the sense handling helpers, similar to what
> st got (aka using the *normalize_sense functions and then dealing with the
> parsed sense buffer instead of the raw sense data)

Ok, so here is my first take at satisfying this request.
Be warned, that beyond compiling, and checking that the new module
doesn't immediately blow up, there hasn't yet been a lot of testing.

But this should allow you to comment on the changes, and move forward
with dropping scsi_request from the kernel code.

Signed-off-by: Willem Riede <osst@riede.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 290 insertions, 225 deletions

diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index b9f6084fdd9e..00f3edc2417f 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -13,7 +13,7 @@
   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
+  Copyright 1992 - 2002 Kai Makisara / 2000 - 2006 Willem Riede
          email osst@riede.org
 
   $Header: /cvsroot/osst/Driver/osst.c,v 1.73 2005/01/01 21:13:34 wriede Exp $
@@ -24,7 +24,7 @@
 */
 
 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";
+static const char * osst_version = "0.99.4";
 
 /* The "failure to reconnect" firmware bug */
 #define OSST_FW_NEED_POLL_MIN 10601 /*(107A)*/
@@ -69,7 +69,6 @@ static const char * osst_version = "0.99.3";
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_ioctl.h>
-#include <scsi/scsi_request.h>
 
 #define ST_KILOBYTE 1024
 
@@ -176,16 +175,16 @@ static struct scsi_driver osst_template = {
         }
 };
 
-static int osst_int_ioctl(struct osst_tape *STp, struct scsi_request ** aSRpnt,
+static int osst_int_ioctl(struct osst_tape *STp, struct osst_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_set_frame_position(struct osst_tape *STp, struct osst_request ** aSRpnt, int frame, int skip);
 
-static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt);
+static int osst_get_frame_position(struct osst_tape *STp, struct osst_request ** aSRpnt);
 
-static int osst_flush_write_buffer(struct osst_tape *STp, struct scsi_request ** aSRpnt);
+static int osst_flush_write_buffer(struct osst_tape *STp, struct osst_request ** aSRpnt);
 
-static int osst_write_error_recovery(struct osst_tape * STp, struct scsi_request ** aSRpnt, int pending);
+static int osst_write_error_recovery(struct osst_tape * STp, struct osst_request ** aSRpnt, int pending);
 
 static inline char *tape_name(struct osst_tape *tape)
 {
@@ -194,52 +193,84 @@ static inline char *tape_name(struct osst_tape *tape)
 
 /* Routines that handle the interaction with mid-layer SCSI routines */
 
+
+/* Normalize Sense */
+static void osst_analyze_sense(struct osst_request *SRpnt, struct st_cmdstatus *s)
+{
+        const u8 *ucp;
+        const u8 *sense = SRpnt->sense;
+
+        s->have_sense = scsi_normalize_sense(SRpnt->sense,
+                                SCSI_SENSE_BUFFERSIZE, &s->sense_hdr);
+        s->flags = 0;
+
+        if (s->have_sense) {
+                s->deferred = 0;
+                s->remainder_valid =
+                        scsi_get_sense_info_fld(sense, SCSI_SENSE_BUFFERSIZE, &s->uremainder64);
+                switch (sense[0] & 0x7f) {
+                case 0x71:
+                        s->deferred = 1;
+                case 0x70:
+                        s->fixed_format = 1;
+                        s->flags = sense[2] & 0xe0;
+                        break;
+                case 0x73:
+                        s->deferred = 1;
+                case 0x72:
+                        s->fixed_format = 0;
+                        ucp = scsi_sense_desc_find(sense, SCSI_SENSE_BUFFERSIZE, 4);
+                        s->flags = ucp ? (ucp[3] & 0xe0) : 0;
+                        break;
+                }
+        }
+}
+
 /* Convert the result to success code */
-static int osst_chk_result(struct osst_tape * STp, struct scsi_request * SRpnt)
+static int osst_chk_result(struct osst_tape * STp, struct osst_request * SRpnt)
 {
         char *name = tape_name(STp);
-        int result = SRpnt->sr_result;
-        unsigned char * sense = SRpnt->sr_sense_buffer, scode;
+        int result = SRpnt->result;
+        u8 * sense = SRpnt->sense, scode;
 #if DEBUG
         const char *stp;
 #endif
+        struct st_cmdstatus *cmdstatp;
 
-        if (!result) {
-                sense[0] = 0;    /* We don't have sense data if this byte is zero */
+        if (!result)
                 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 */
+
+        cmdstatp = &STp->buffer->cmdstat;
+        osst_analyze_sense(SRpnt, cmdstatp);
+
+        if (cmdstatp->have_sense)
+                scode = STp->buffer->cmdstat.sense_hdr.sense_key;
+        else
                 scode = 0;
-        }
 #if DEBUG
         if (debugging) {
-                printk(OSST_DEB_MSG "%s:D: Error: %x, cmd: %x %x %x %x %x %x Len: %d\n",
+                printk(OSST_DEB_MSG "%s:D: Error: %x, cmd: %x %x %x %x %x %x\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);
+                   SRpnt->cmd[0], SRpnt->cmd[1], SRpnt->cmd[2],
+                   SRpnt->cmd[3], SRpnt->cmd[4], SRpnt->cmd[5]);
                 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);
+                if (cmdstatp->have_sense)
+                        __scsi_print_sense("osst ", SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
         }
         else
 #endif
-        if (!(driver_byte(result) & DRIVER_SENSE) ||
-                ((sense[0] & 0x70) == 0x70 &&
+        if (cmdstatp->have_sense && (
                  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) {
+                 SRpnt->cmd[0] != MODE_SENSE &&
+                 SRpnt->cmd[0] != TEST_UNIT_READY)) { /* Abnormal conditions for tape */
+                if (cmdstatp->have_sense) {
                         printk(KERN_WARNING "%s:W: Command with sense data:\n", name);
-                        scsi_print_req_sense("osst:", SRpnt);
+                        __scsi_print_sense("osst ", SRpnt->sense, SCSI_SENSE_BUFFERSIZE);
                 }
                 else {
                         static  int     notyetprinted = 1;
@@ -259,15 +290,14 @@ static int osst_chk_result(struct osst_tape * STp, struct scsi_request * SRpnt)
         }
         STp->pos_unknown |= STp->device->was_reset;
 
-        if ((sense[0] & 0x70) == 0x70 &&
-             scode == RECOVERED_ERROR) {
+        if (cmdstatp->have_sense && scode == RECOVERED_ERROR) {
                 STp->recover_count++;
                 STp->recover_erreg++;
 #if DEBUG
                 if (debugging) {
-                        if (SRpnt->sr_cmnd[0] == READ_6)
+                        if (SRpnt->cmd[0] == READ_6)
                                 stp = "read";
-                        else if (SRpnt->sr_cmnd[0] == WRITE_6)
+                        else if (SRpnt->cmd[0] == WRITE_6)
                                 stp = "write";
                         else
                                 stp = "ioctl";
@@ -283,74 +313,99 @@ static int osst_chk_result(struct osst_tape * STp, struct scsi_request * SRpnt)
 
 
 /* Wakeup from interrupt */
-static void osst_sleep_done (struct scsi_cmnd * SCpnt)
+static void osst_sleep_done(void *data, char *sense, int result, int resid)
 {
-        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;
+        struct osst_request *SRpnt = data;
+        struct osst_tape *STp = SRpnt->stp;
 
+        memcpy(SRpnt->sense, sense, SCSI_SENSE_BUFFERSIZE);
+        STp->buffer->cmdstat.midlevel_result = SRpnt->result = result;
 #if DEBUG
         STp->write_pending = 0;
 #endif
-        complete(SCpnt->request->waiting);
+        if (SRpnt->waiting)
+                complete(SRpnt->waiting);
+}
+
+/* osst_request memory management */
+static struct osst_request *osst_allocate_request(void)
+{
+        return kzalloc(sizeof(struct osst_request), GFP_KERNEL);
 }
 
+static void osst_release_request(struct osst_request *streq)
+{
+        kfree(streq);
+}
 
 /* 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, 
+static  struct osst_request * osst_do_scsi(struct osst_request *SRpnt, struct osst_tape *STp, 
         unsigned char *cmd, int bytes, int direction, int timeout, int retries, int do_wait)
 {
         unsigned char *bp;
+        unsigned short use_sg;
 #ifdef OSST_INJECT_ERRORS
         static   int   inject = 0;
         static   int   repeat = 0;
 #endif
+        struct completion *waiting;
+
+        /* if async, make sure there's no command outstanding */
+        if (!do_wait && ((STp->buffer)->last_SRpnt)) {
+                printk(KERN_ERR "%s: Async command already active.\n",
+                       tape_name(STp));
+                if (signal_pending(current))
+                        (STp->buffer)->syscall_result = (-EINTR);
+                else
+                        (STp->buffer)->syscall_result = (-EBUSY);
+                return NULL;
+        }
+
         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));
+                SRpnt = osst_allocate_request();
+                if (SRpnt == NULL) {
+                        printk(KERN_ERR "%s: Can't allocate SCSI request.\n",
+                                     tape_name(STp));
                         if (signal_pending(current))
                                 (STp->buffer)->syscall_result = (-EINTR);
                         else
                                 (STp->buffer)->syscall_result = (-EBUSY);
                         return NULL;
                 }
+                SRpnt->stp = STp;
         }
 
-        init_completion(&STp->wait);
-        SRpnt->sr_use_sg = (bytes > (STp->buffer)->sg[0].length) ?
-                                    (STp->buffer)->use_sg : 0;
-        if (SRpnt->sr_use_sg) {
+        /* If async IO, set last_SRpnt. This ptr tells write_behind_check
+           which IO is outstanding. It's nulled out when the IO completes. */
+        if (!do_wait)
+                (STp->buffer)->last_SRpnt = SRpnt;
+
+        waiting = &STp->wait;
+        init_completion(waiting);
+        SRpnt->waiting = waiting;
+
+        use_sg = (bytes > STp->buffer->sg[0].length) ? STp->buffer->use_sg : 0;
+        if (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;
+                if (STp->buffer->sg_segs < use_sg)
+                        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);
+        memcpy(SRpnt->cmd, cmd, sizeof(SRpnt->cmd));
+        STp->buffer->cmdstat.have_sense = 0;
+        STp->buffer->syscall_result = 0;
 
-        if (do_wait) {
-                wait_for_completion(SRpnt->sr_request->waiting);
-                SRpnt->sr_request->waiting = NULL;
+        if (scsi_execute_async(STp->device, cmd, COMMAND_SIZE(cmd[0]), direction, bp, bytes,
+                        use_sg, timeout, retries, SRpnt, osst_sleep_done, GFP_KERNEL))
+                /* could not allocate the buffer or request was too large */
+                (STp->buffer)->syscall_result = (-EBUSY);
+        else if (do_wait) {
+                wait_for_completion(waiting);
+                SRpnt->waiting = NULL;
                 STp->buffer->syscall_result = osst_chk_result(STp, SRpnt);
 #ifdef OSST_INJECT_ERRORS
                 if (STp->buffer->syscall_result == 0 &&
@@ -383,21 +438,22 @@ static void osst_write_behind_check(struct osst_tape *STp)
                 STp->nbr_finished++;
 #endif
         wait_for_completion(&(STp->wait));
-        (STp->buffer)->last_SRpnt->sr_request->waiting = NULL;
+        STp->buffer->last_SRpnt->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);
+        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);
+        osst_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->last_SRpnt = NULL;
         STbuffer->buffer_bytes -= STbuffer->writing;
         STbuffer->writing = 0;
 
@@ -606,11 +662,11 @@ err_out:
 /*
  * Wait for the unit to become Ready
  */
-static int osst_wait_ready(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_wait_ready(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                  unsigned timeout, int initial_delay)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         unsigned long           startwait = jiffies;
 #if DEBUG
         int                     dbg  = debugging;
@@ -630,10 +686,10 @@ static int osst_wait_ready(struct osst_tape * STp, struct scsi_request ** aSRpnt
         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                                        )  )) {
+               (( SRpnt->sense[2]  == 2 && SRpnt->sense[12] == 4    &&
+                 (SRpnt->sense[13] == 1 || SRpnt->sense[13] == 8)    ) ||
+                ( SRpnt->sense[2]  == 6 && SRpnt->sense[12] == 0x28 &&
+                  SRpnt->sense[13] == 0                                        )  )) {
 #if DEBUG
             if (debugging) {
                 printk(OSST_DEB_MSG "%s:D: Sleeping in onstream wait ready\n", name);
@@ -657,8 +713,8 @@ static int osst_wait_ready(struct osst_tape * STp, struct scsi_request ** aSRpnt
 #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]);
+                        STp->buffer->syscall_result, SRpnt->sense[0], SRpnt->sense[2],
+                        SRpnt->sense[12], SRpnt->sense[13]);
 #endif
             return (-EIO);
         }
@@ -671,10 +727,10 @@ static int osst_wait_ready(struct osst_tape * STp, struct scsi_request ** aSRpnt
 /*
  * 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)
+static int osst_wait_for_medium(struct osst_tape * STp, struct osst_request ** aSRpnt, unsigned timeout)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         unsigned long           startwait = jiffies;
 #if DEBUG
         int                     dbg = debugging;
@@ -691,8 +747,7 @@ static int osst_wait_for_medium(struct osst_tape * STp, struct scsi_request ** a
         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                                             ) {
+                SRpnt->sense[2] == 2 && SRpnt->sense[12] == 0x3a && SRpnt->sense[13] == 0  ) {
 #if DEBUG
             if (debugging) {
                 printk(OSST_DEB_MSG "%s:D: Sleeping in onstream wait medium\n", name);
@@ -711,13 +766,13 @@ static int osst_wait_for_medium(struct osst_tape * STp, struct scsi_request ** a
 #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 ( STp->buffer->syscall_result     && SRpnt->sense[2]  != 2 &&
+             SRpnt->sense[12] != 4 && SRpnt->sense[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]);
+                        STp->buffer->syscall_result, SRpnt->sense[0], SRpnt->sense[2],
+                        SRpnt->sense[12], SRpnt->sense[13]);
 #endif
             return 0;
         }
@@ -727,7 +782,7 @@ static int osst_wait_for_medium(struct osst_tape * STp, struct scsi_request ** a
         return 1;
 }
 
-static int osst_position_tape_and_confirm(struct osst_tape * STp, struct scsi_request ** aSRpnt, int frame)
+static int osst_position_tape_and_confirm(struct osst_tape * STp, struct osst_request ** aSRpnt, int frame)
 {
         int     retval;
 
@@ -741,10 +796,10 @@ static int osst_position_tape_and_confirm(struct osst_tape * STp, struct scsi_re
 /*
  * Wait for write(s) to complete
  */
-static int osst_flush_drive_buffer(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_flush_drive_buffer(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         int                     result = 0;
         int                     delay  = OSST_WAIT_WRITE_COMPLETE;
 #if DEBUG
@@ -761,8 +816,8 @@ static int osst_flush_drive_buffer(struct osst_tape * STp, struct scsi_request *
         *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) {
+                if ((SRpnt->sense[2] & 0x0f) == 2 && SRpnt->sense[12] == 4) {
+                        if (SRpnt->sense[13] == 8) {
                                 delay = OSST_WAIT_LONG_WRITE_COMPLETE;
                         }
                 } else
@@ -775,7 +830,7 @@ static int osst_flush_drive_buffer(struct osst_tape * STp, struct scsi_request *
 }
 
 #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)
+static int osst_wait_frame(struct osst_tape * STp, struct osst_request ** aSRpnt, int curr, int minlast, int to)
 {
         unsigned long   startwait = jiffies;
         char          * name      = tape_name(STp);
@@ -830,9 +885,9 @@ static int osst_wait_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt
         return -EBUSY;
 }
 
-static int osst_recover_wait_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt, int writing)
+static int osst_recover_wait_frame(struct osst_tape * STp, struct osst_request ** aSRpnt, int writing)
 {
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         unsigned char           cmd[MAX_COMMAND_SIZE];
         unsigned long           startwait = jiffies;
         int                     retval    = 1;
@@ -853,7 +908,7 @@ static int osst_recover_wait_frame(struct osst_tape * STp, struct scsi_request *
 
                 while (retval && time_before (jiffies, startwait + 5*60*HZ)) {
 
-                        if (STp->buffer->syscall_result && (SRpnt->sr_sense_buffer[2] & 0x0f) != 2) {
+                        if (STp->buffer->syscall_result && (SRpnt->sense[2] & 0x0f) != 2) {
 
                                 /* some failure - not just not-ready */
                                 retval = osst_write_error_recovery(STp, aSRpnt, 0);
@@ -878,9 +933,9 @@ static int osst_recover_wait_frame(struct osst_tape * STp, struct scsi_request *
                 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]);
+                                        (*aSRpnt)->sense[ 2] & 0x0f,
+                                        (*aSRpnt)->sense[12],
+                                        (*aSRpnt)->sense[13]);
 
         return retval;
 }
@@ -888,10 +943,10 @@ static int osst_recover_wait_frame(struct osst_tape * STp, struct scsi_request *
 /*
  * 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)
+static int osst_read_frame(struct osst_tape * STp, struct osst_request ** aSRpnt, int timeout)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         int                     retval = 0;
 #if DEBUG
         os_aux_t              * aux    = STp->buffer->aux;
@@ -929,10 +984,10 @@ static int osst_read_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt
             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]);
+                   SRpnt->sense[0], SRpnt->sense[1],
+                   SRpnt->sense[2], SRpnt->sense[3],
+                   SRpnt->sense[4], SRpnt->sense[5],
+                   SRpnt->sense[6], SRpnt->sense[7]);
 #endif
         }
         else
@@ -959,10 +1014,10 @@ static int osst_read_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt
         return (retval);
 }
 
-static int osst_initiate_read(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_initiate_read(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         struct st_partstat    * STps   = &(STp->ps[STp->partition]);
-        struct scsi_request   * SRpnt  ;
+        struct osst_request   * SRpnt  ;
         unsigned char           cmd[MAX_COMMAND_SIZE];
         int                     retval = 0;
         char                  * name   = tape_name(STp);
@@ -996,7 +1051,7 @@ static int osst_initiate_read(struct osst_tape * STp, struct scsi_request ** aSR
         return retval;
 }
 
-static int osst_get_logical_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_get_logical_frame(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                                 int frame_seq_number, int quiet)
 {
         struct st_partstat * STps  = &(STp->ps[STp->partition]);
@@ -1125,7 +1180,7 @@ static int osst_get_logical_frame(struct osst_tape * STp, struct scsi_request **
         return (STps->eof);
 }
 
-static int osst_seek_logical_blk(struct osst_tape * STp, struct scsi_request ** aSRpnt, int logical_blk_num)
+static int osst_seek_logical_blk(struct osst_tape * STp, struct osst_request ** aSRpnt, int logical_blk_num)
 {
         struct st_partstat * STps = &(STp->ps[STp->partition]);
         char               * name = tape_name(STp);
@@ -1234,7 +1289,7 @@ error:
 #define OSST_SECTOR_SHIFT 9
 #define OSST_SECTOR_MASK  0x03F
 
-static int osst_get_sector(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_get_sector(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         int     sector;
 #if DEBUG
@@ -1264,7 +1319,7 @@ static int osst_get_sector(struct osst_tape * STp, struct scsi_request ** aSRpnt
         return sector;
 }
 
-static int osst_seek_sector(struct osst_tape * STp, struct scsi_request ** aSRpnt, int sector)
+static int osst_seek_sector(struct osst_tape * STp, struct osst_request ** aSRpnt, int sector)
 {
         struct st_partstat * STps   = &(STp->ps[STp->partition]);
         int                  frame  = sector >> OSST_FRAME_SHIFT,
@@ -1327,10 +1382,10 @@ static int osst_seek_sector(struct osst_tape * STp, struct scsi_request ** aSRpn
  * 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,
+static int osst_read_back_buffer_and_rewrite(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                                 unsigned int frame, unsigned int skip, int pending)
 {
-        struct scsi_request   * SRpnt = * aSRpnt;
+        struct osst_request   * SRpnt = * aSRpnt;
         unsigned char         * buffer, * p;
         unsigned char           cmd[MAX_COMMAND_SIZE];
         int                     flag, new_frame, i;
@@ -1474,8 +1529,8 @@ static int osst_read_back_buffer_and_rewrite(struct osst_tape * STp, struct scsi
                                         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)) {
+                                        if (SRpnt->sense[2] == 2 && SRpnt->sense[12] == 4 &&
+                                            (SRpnt->sense[13] == 1 || SRpnt->sense[13] == 8)) {
                                                 /* in the process of becoming ready */
                                                 msleep(100);
                                                 continue;
@@ -1492,17 +1547,17 @@ static int osst_read_back_buffer_and_rewrite(struct osst_tape * STp, struct scsi
                 }
                 *aSRpnt = SRpnt;
                 if (flag) {
-                        if ((SRpnt->sr_sense_buffer[ 2] & 0x0f) == 13 &&
-                             SRpnt->sr_sense_buffer[12]         ==  0 &&
-                             SRpnt->sr_sense_buffer[13]         ==  2) {
+                        if ((SRpnt->sense[ 2] & 0x0f) == 13 &&
+                             SRpnt->sense[12]         ==  0 &&
+                             SRpnt->sense[13]         ==  2) {
                                 printk(KERN_ERR "%s:E: Volume overflow in write error recovery\n", name);
                                 vfree(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;
+                        i = ((SRpnt->sense[3] << 24) |
+                             (SRpnt->sense[4] << 16) |
+                             (SRpnt->sense[5] <<  8) |
+                              SRpnt->sense[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);
@@ -1525,11 +1580,11 @@ static int osst_read_back_buffer_and_rewrite(struct osst_tape * STp, struct scsi
         return 0;
 }
 
-static int osst_reposition_and_retry(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_reposition_and_retry(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                         unsigned int frame, unsigned int skip, int pending)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         char                  * name      = tape_name(STp);
         int                     expected  = 0;
         int                     attempts  = 1000 / skip;
@@ -1581,9 +1636,9 @@ static int osst_reposition_and_retry(struct osst_tape * STp, struct scsi_request
                         *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) {
+                                if ((SRpnt->sense[ 2] & 0x0f) == 13 &&
+                                     SRpnt->sense[12]         ==  0 &&
+                                     SRpnt->sense[13]         ==  2) {
                                         printk(KERN_ERR
                                                "%s:E: Volume overflow in write error recovery\n",
                                                name);
@@ -1628,9 +1683,9 @@ static int osst_reposition_and_retry(struct osst_tape * STp, struct scsi_request
  * Error recovery algorithm for the OnStream tape.
  */
 
-static int osst_write_error_recovery(struct osst_tape * STp, struct scsi_request ** aSRpnt, int pending)
+static int osst_write_error_recovery(struct osst_tape * STp, struct osst_request ** aSRpnt, int pending)
 {
-        struct scsi_request * SRpnt  = * aSRpnt;
+        struct osst_request * SRpnt  = * aSRpnt;
         struct st_partstat  * STps   = & STp->ps[STp->partition];
         char                * name   = tape_name(STp);
         int                   retval = 0;
@@ -1639,20 +1694,20 @@ static int osst_write_error_recovery(struct osst_tape * STp, struct scsi_request
 
         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 ((SRpnt->sense[ 2] & 0x0f) != 3
+          || SRpnt->sense[12]         != 12
+          || SRpnt->sense[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]);
+                        SRpnt->sense[2], SRpnt->sense[12], SRpnt->sense[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];
+        frame = (SRpnt->sense[3] << 24) |
+                (SRpnt->sense[4] << 16) |
+                (SRpnt->sense[5] <<  8) |
+                 SRpnt->sense[6];
+        skip  =  SRpnt->sense[9];
  
 #if DEBUG
         printk(OSST_DEB_MSG "%s:D: Detected physical bad frame at %u, advised to skip %d\n", name, frame, skip);
@@ -1707,7 +1762,7 @@ static int osst_write_error_recovery(struct osst_tape * STp, struct scsi_request
         return retval;
 }
 
-static int osst_space_over_filemarks_backward(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_space_over_filemarks_backward(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                                                  int mt_op, int mt_count)
 {
         char  * name = tape_name(STp);
@@ -1806,7 +1861,7 @@ found:
  *
  * Just scans for the filemark sequentially.
  */
-static int osst_space_over_filemarks_forward_slow(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_space_over_filemarks_forward_slow(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                                                      int mt_op, int mt_count)
 {
         int     cnt = 0;
@@ -1860,7 +1915,7 @@ static int osst_space_over_filemarks_forward_slow(struct osst_tape * STp, struct
 /*
  * Fast linux specific version of OnStream FSF
  */
-static int osst_space_over_filemarks_forward_fast(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_space_over_filemarks_forward_fast(struct osst_tape * STp, struct osst_request ** aSRpnt,
                                                                      int mt_op, int mt_count)
 {
         char  * name = tape_name(STp);
@@ -2011,10 +2066,10 @@ static int osst_space_over_filemarks_forward_fast(struct osst_tape * STp, struct
  * to test the error recovery mechanism.
  */
 #if DEBUG
-static void osst_set_retries(struct osst_tape * STp, struct scsi_request ** aSRpnt, int retries)
+static void osst_set_retries(struct osst_tape * STp, struct osst_request ** aSRpnt, int retries)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt  = * aSRpnt;
+        struct osst_request   * SRpnt  = * aSRpnt;
         char                  * name   = tape_name(STp);
 
         memset(cmd, 0, MAX_COMMAND_SIZE);
@@ -2043,7 +2098,7 @@ static void osst_set_retries(struct osst_tape * STp, struct scsi_request ** aSRp
 #endif
 
 
-static int osst_write_filemark(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_write_filemark(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         int     result;
         int     this_mark_ppos = STp->first_frame_position;
@@ -2071,7 +2126,7 @@ static int osst_write_filemark(struct osst_tape * STp, struct scsi_request ** aS
         return result;
 }
 
-static int osst_write_eod(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_write_eod(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         int     result;
 #if DEBUG
@@ -2094,7 +2149,7 @@ static int osst_write_eod(struct osst_tape * STp, struct scsi_request ** aSRpnt)
         return result;
 }
 
-static int osst_write_filler(struct osst_tape * STp, struct scsi_request ** aSRpnt, int where, int count)
+static int osst_write_filler(struct osst_tape * STp, struct osst_request ** aSRpnt, int where, int count)
 {
         char * name = tape_name(STp);
 
@@ -2119,7 +2174,7 @@ static int osst_write_filler(struct osst_tape * STp, struct scsi_request ** aSRp
         return osst_flush_drive_buffer(STp, aSRpnt);
 }
 
-static int __osst_write_header(struct osst_tape * STp, struct scsi_request ** aSRpnt, int where, int count)
+static int __osst_write_header(struct osst_tape * STp, struct osst_request ** aSRpnt, int where, int count)
 {
         char * name = tape_name(STp);
         int     result;
@@ -2146,7 +2201,7 @@ static int __osst_write_header(struct osst_tape * STp, struct scsi_request ** aS
         return result;
 }
 
-static int osst_write_header(struct osst_tape * STp, struct scsi_request ** aSRpnt, int locate_eod)
+static int osst_write_header(struct osst_tape * STp, struct osst_request ** aSRpnt, int locate_eod)
 {
         os_header_t * header;
         int           result;
@@ -2220,7 +2275,7 @@ static int osst_write_header(struct osst_tape * STp, struct scsi_request ** aSRp
         return result;
 }
 
-static int osst_reset_header(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_reset_header(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         if (STp->header_cache != NULL)
                 memset(STp->header_cache, 0, sizeof(os_header_t));
@@ -2233,7 +2288,7 @@ static int osst_reset_header(struct osst_tape * STp, struct scsi_request ** aSRp
         return osst_write_header(STp, aSRpnt, 1);
 }
 
-static int __osst_analyze_headers(struct osst_tape * STp, struct scsi_request ** aSRpnt, int ppos)
+static int __osst_analyze_headers(struct osst_tape * STp, struct osst_request ** aSRpnt, int ppos)
 {
         char        * name = tape_name(STp);
         os_header_t * header;
@@ -2410,7 +2465,7 @@ static int __osst_analyze_headers(struct osst_tape * STp, struct scsi_request **
         return 1;
 }
 
-static int osst_analyze_headers(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_analyze_headers(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         int     position, ppos;
         int     first, last;
@@ -2465,7 +2520,7 @@ static int osst_analyze_headers(struct osst_tape * STp, struct scsi_request ** a
         return 1;
 }
 
-static int osst_verify_position(struct osst_tape * STp, struct scsi_request ** aSRpnt)
+static int osst_verify_position(struct osst_tape * STp, struct osst_request ** aSRpnt)
 {
         int     frame_position  = STp->first_frame_position;
         int     frame_seq_numbr = STp->frame_seq_number;
@@ -2541,11 +2596,11 @@ static unsigned int osst_parse_firmware_rev (const char * str)
 /*
  * Configure the OnStream SCII tape drive for default operation
  */
-static int osst_configure_onstream(struct osst_tape *STp, struct scsi_request ** aSRpnt)
+static int osst_configure_onstream(struct osst_tape *STp, struct osst_request ** aSRpnt)
 {
         unsigned char                  cmd[MAX_COMMAND_SIZE];
         char                         * name = tape_name(STp);
-        struct scsi_request                 * SRpnt = * aSRpnt;
+        struct osst_request          * SRpnt = * aSRpnt;
         osst_mode_parameter_header_t * header;
         osst_block_size_page_t       * bs;
         osst_capabilities_page_t     * cp;
@@ -2712,7 +2767,7 @@ static int osst_configure_onstream(struct osst_tape *STp, struct scsi_request **
 
 /* 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)
+static int cross_eof(struct osst_tape *STp, struct osst_request ** aSRpnt, int forward)
 {
         int     result;
         char  * name = tape_name(STp);
@@ -2741,10 +2796,10 @@ static int cross_eof(struct osst_tape *STp, struct scsi_request ** aSRpnt, int f
 
 /* Get the tape position. */
 
-static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt)
+static int osst_get_frame_position(struct osst_tape *STp, struct osst_request ** aSRpnt)
 {
         unsigned char           scmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         int                     result = 0;
         char                  * name   = tape_name(STp);
 
@@ -2769,14 +2824,14 @@ static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request **
         *aSRpnt = SRpnt;
 
         if (STp->buffer->syscall_result)
-                result = ((SRpnt->sr_sense_buffer[2] & 0x0f) == 3) ? -EIO : -EINVAL;    /* 3: Write Error */
+                result = ((SRpnt->sense[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);
+                        memcpy (mysense, SRpnt->sense, 16);
                         memset (scmd, 0, MAX_COMMAND_SIZE);
                         scmd[0] = READ_POSITION;
                         STp->buffer->b_data = mybuf; STp->buffer->buffer_size = 24;
@@ -2785,10 +2840,10 @@ static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request **
 #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]);
+                                        SRpnt->sense[2],SRpnt->sense[12],SRpnt->sense[13]);
 #endif
                         if (!STp->buffer->syscall_result)
-                                memcpy (SRpnt->sr_sense_buffer, mysense, 16);
+                                memcpy (SRpnt->sense, mysense, 16);
                         else
                                 printk(KERN_WARNING "%s:W: Double error in get position\n", name);
                 }
@@ -2825,10 +2880,10 @@ static int osst_get_frame_position(struct osst_tape *STp, struct scsi_request **
 
 
 /* Set the tape block */
-static int osst_set_frame_position(struct osst_tape *STp, struct scsi_request ** aSRpnt, int ppos, int skip)
+static int osst_set_frame_position(struct osst_tape *STp, struct osst_request ** aSRpnt, int ppos, int skip)
 {
         unsigned char           scmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         struct st_partstat    * STps;
         int                     result = 0;
         int                     pp     = (ppos == 3000 && !skip)? 0 : ppos;
@@ -2883,7 +2938,7 @@ static int osst_set_frame_position(struct osst_tape *STp, struct scsi_request **
         return result;
 }
 
-static int osst_write_trailer(struct osst_tape *STp, struct scsi_request ** aSRpnt, int leave_at_EOT)
+static int osst_write_trailer(struct osst_tape *STp, struct osst_request ** aSRpnt, int leave_at_EOT)
 {
         struct st_partstat * STps = &(STp->ps[STp->partition]);
         int result = 0;
@@ -2910,12 +2965,12 @@ out:
 /* 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)
+static int osst_flush_write_buffer(struct osst_tape *STp, struct osst_request ** aSRpnt)
 {
         int                     offset, transfer, blks = 0;
         int                     result = 0;
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt = *aSRpnt;
+        struct osst_request   * SRpnt = *aSRpnt;
         struct st_partstat    * STps;
         char                  * name = tape_name(STp);
 
@@ -2923,13 +2978,13 @@ static int osst_flush_write_buffer(struct osst_tape *STp, struct scsi_request **
                 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);
+         "%s:D: aSRpnt points to osst_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);
+         "%s:D: aSRpnt does not point to osst_request that write_behind_check will release -- strange\n", name);
 #endif  
                 osst_write_behind_check(STp);
                 if ((STp->buffer)->syscall_result) {
@@ -3007,12 +3062,12 @@ static int osst_flush_write_buffer(struct osst_tape *STp, struct scsi_request **
 #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]);
+                                name, SRpnt->sense[0], SRpnt->sense[2],
+                                SRpnt->sense[12], SRpnt->sense[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) {
+                        if ((SRpnt->sense[0] & 0x70) == 0x70 &&
+                            (SRpnt->sense[2] & 0x40) && /* FIXME - SC-30 drive doesn't assert EOM bit */
+                            (SRpnt->sense[2] & 0x0f) == NO_SENSE) {
                                 STp->dirty = 0;
                                 (STp->buffer)->buffer_bytes = 0;
                                 result = (-ENOSPC);
@@ -3040,7 +3095,7 @@ static int osst_flush_write_buffer(struct osst_tape *STp, struct scsi_request **
 
 /* 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)
+static int osst_flush_buffer(struct osst_tape * STp, struct osst_request ** aSRpnt, int seek_next)
 {
         struct st_partstat * STps;
         int    backspace = 0, result = 0;
@@ -3102,10 +3157,10 @@ static int osst_flush_buffer(struct osst_tape * STp, struct scsi_request ** aSRp
         return result;
 }
 
-static int osst_write_frame(struct osst_tape * STp, struct scsi_request ** aSRpnt, int synchronous)
+static int osst_write_frame(struct osst_tape * STp, struct osst_request ** aSRpnt, int synchronous)
 {
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt;
+        struct osst_request   * SRpnt;
         int                     blks;
 #if DEBUG
         char                  * name = tape_name(STp);
@@ -3166,9 +3221,9 @@ static int osst_write_frame(struct osst_tape * STp, struct scsi_request ** aSRpn
                         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)
+                        if ((SRpnt->sense[0] & 0x70) == 0x70 &&
+                            (SRpnt->sense[2] & 0x40)) {
+                                if ((SRpnt->sense[2] & 0x0f) == VOLUME_OVERFLOW)
                                         return (-ENOSPC);
                         }
                         else {
@@ -3185,7 +3240,7 @@ static int osst_write_frame(struct osst_tape * STp, struct scsi_request ** aSRpn
         return 0;
 }
 
-/* Lock or unlock the drive door. Don't use when struct scsi_request allocated. */
+/* Lock or unlock the drive door. Don't use when struct osst_request allocated. */
 static int do_door_lock(struct osst_tape * STp, int do_lock)
 {
         int retval, cmd;
@@ -3233,7 +3288,7 @@ static ssize_t osst_write(struct file * filp, const char __user * buf, size_t co
         int                   write_threshold;
         int                   doing_write = 0;
         const char   __user * b_point;
-        struct scsi_request * SRpnt = NULL;
+        struct osst_request * SRpnt = NULL;
         struct st_modedef   * STm;
         struct st_partstat  * STps;
         struct osst_tape    * STp  = filp->private_data;
@@ -3424,7 +3479,7 @@ if (SRpnt) printk(KERN_ERR "%s:A: Not supposed to have SRpnt at line %d\n", name
 #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,
+                                name, (int) count, STps->drv_file, STps->drv_block,
                                 STp->logical_blk_num, STp->frame_seq_number, STp->first_frame_position);
 #endif
         b_point = buf;
@@ -3460,7 +3515,7 @@ if (SRpnt) printk(KERN_ERR "%s:A: Not supposed to have SRpnt at line %d\n", name
 #if DEBUG
                                 if (debugging)
                                       printk(OSST_DEB_MSG "%s:D: EOM with %d bytes unwritten.\n",
-                                                             name, transfer);
+                                                             name, (int) transfer);
 #endif
                         }
                         else {
@@ -3478,7 +3533,7 @@ if (SRpnt) printk(KERN_ERR "%s:A: Not supposed to have SRpnt at line %d\n", name
                         
                 if (retval < 0) {
                         if (SRpnt != NULL) {
-                                scsi_release_request(SRpnt);
+                                osst_release_request(SRpnt);
                                 SRpnt = NULL;
                         }
                         STp->buffer->buffer_bytes = 0;
@@ -3540,7 +3595,7 @@ if (SRpnt) printk(KERN_ERR "%s:A: Not supposed to have SRpnt at line %d\n", name
         retval = total;
 
 out:
-        if (SRpnt != NULL) scsi_release_request(SRpnt);
+        if (SRpnt != NULL) osst_release_request(SRpnt);
 
         up(&STp->lock);
 
@@ -3556,7 +3611,7 @@ static ssize_t osst_read(struct file * filp, char __user * buf, size_t count, lo
         int                   special;
         struct st_modedef   * STm;
         struct st_partstat  * STps;
-        struct scsi_request * SRpnt = NULL;
+        struct osst_request * SRpnt = NULL;
         struct osst_tape    * STp   = filp->private_data;
         char                * name  = tape_name(STp);
 
@@ -3664,7 +3719,7 @@ static ssize_t osst_read(struct file * filp, char __user * buf, size_t count, lo
 #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);
+                                                 STps->eof, (STp->buffer)->buffer_bytes, (int) (count - total));
 #endif
                         /* force multiple of block size, note block_size may have been adjusted */
                         transfer = (((STp->buffer)->buffer_bytes < count - total ?
@@ -3725,7 +3780,7 @@ static ssize_t osst_read(struct file * filp, char __user * buf, size_t count, lo
         retval = total;
 
 out:
-        if (SRpnt != NULL) scsi_release_request(SRpnt);
+        if (SRpnt != NULL) osst_release_request(SRpnt);
 
         up(&STp->lock);
 
@@ -3913,7 +3968,7 @@ static int osst_set_options(struct osst_tape *STp, long options)
 
 
 /* Internal ioctl function */
-static int osst_int_ioctl(struct osst_tape * STp, struct scsi_request ** aSRpnt,
+static int osst_int_ioctl(struct osst_tape * STp, struct osst_request ** aSRpnt,
                              unsigned int cmd_in, unsigned long arg)
 {
         int                     timeout;
@@ -3921,7 +3976,7 @@ static int osst_int_ioctl(struct osst_tape * STp, struct scsi_request ** aSRpnt,
         int                     i, ioctl_result;
         int                     chg_eof = 1;
         unsigned char           cmd[MAX_COMMAND_SIZE];
-        struct scsi_request   * SRpnt = * aSRpnt;
+        struct osst_request   * SRpnt = * aSRpnt;
         struct st_partstat    * STps;
         int                     fileno, blkno, at_sm, frame_seq_numbr, logical_blk_num;
         int                     datalen = 0, direction = DMA_NONE;
@@ -4279,14 +4334,14 @@ os_bypass:
         } 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) {
+                if (SRpnt->sense[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)
+                if ((SRpnt->sense[2] & 0x0f) == BLANK_CHECK)
                         STps->eof = ST_EOD;
 
                 if (cmd_in == MTLOAD && osst_wait_for_medium(STp, &SRpnt, 60))
@@ -4304,7 +4359,7 @@ 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_request * SRpnt = NULL;
         struct osst_tape    * STp;
         struct st_modedef   * STm;
         struct st_partstat  * STps;
@@ -4412,17 +4467,17 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
                 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 ((SRpnt->sense[0] & 0x70) == 0x70      &&
+            (SRpnt->sense[2] & 0x0f) == NOT_READY &&
+             SRpnt->sense[12]        == 4         ) {
 #if DEBUG
-                printk(OSST_DEB_MSG "%s:D: Unit not ready, cause %x\n", name, SRpnt->sr_sense_buffer[13]);
+                printk(OSST_DEB_MSG "%s:D: Unit not ready, cause %x\n", name, SRpnt->sense[13]);
 #endif
                 if (filp->f_flags & O_NONBLOCK) {
                         retval = -EAGAIN;
                         goto err_out;
                 }
-                if (SRpnt->sr_sense_buffer[13] == 2) {  /* initialize command required (LOAD) */
+                if (SRpnt->sense[13] == 2) {    /* initialize command required (LOAD) */
                         memset (cmd, 0, MAX_COMMAND_SIZE);
                         cmd[0] = START_STOP;
                         cmd[1] = 1;
@@ -4430,10 +4485,10 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
                         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);
+                osst_wait_ready(STp, &SRpnt, (SRpnt->sense[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 ((SRpnt->sense[0] & 0x70) == 0x70 &&
+            (SRpnt->sense[2] & 0x0f) == UNIT_ATTENTION) { /* New media? */
 #if DEBUG
                 printk(OSST_DEB_MSG "%s:D: Unit wants attention\n", name);
 #endif
@@ -4446,8 +4501,8 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
 
                         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)
+                        if ((SRpnt->sense[0] & 0x70) != 0x70 ||
+                            (SRpnt->sense[2] & 0x0f) != UNIT_ATTENTION)
                                 break;
                 }
 
@@ -4473,7 +4528,7 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
          * 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) {
+            !SRpnt->result && SRpnt->sense[0] == 0) {
 
                 memset(cmd, 0, MAX_COMMAND_SIZE);
                 cmd[0] = MODE_SENSE;
@@ -4512,7 +4567,7 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
                         }
                         STp->buffer->buffer_blocks = OS_DATA_SIZE / STp->block_size;
                         STp->fast_open = 1;
-                        scsi_release_request(SRpnt);
+                        osst_release_request(SRpnt);
                         return 0;
                 }
 #if DEBUG
@@ -4525,7 +4580,7 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
         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) ) {
+            (SRpnt->sense[2] != 2 || SRpnt->sense[12] != 0x3A) ) {
 
                 memset(cmd, 0, MAX_COMMAND_SIZE);
                 cmd[0] = MODE_SELECT;
@@ -4555,11 +4610,11 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
 
                         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)
+                        if ((SRpnt->sense[0] & 0x70) != 0x70 ||
+                            (SRpnt->sense[2] & 0x0f) == NOT_READY)
                         break;
 
-                        if ((SRpnt->sr_sense_buffer[2] & 0x0f) == UNIT_ATTENTION) {
+                        if ((SRpnt->sense[2] & 0x0f) == UNIT_ATTENTION) {
                                 STp->pos_unknown = 0;
                                 STp->partition = STp->new_partition = 0;
                                 if (STp->can_partitions)
@@ -4583,13 +4638,13 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
 
         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 */
+                    (SRpnt->sense[0] & 0x70) == 0x70 &&
+                    (SRpnt->sense[2] & 0x0f) == NOT_READY &&
+                     SRpnt->sense[12] == 0x3a) { /* Check ASC */
                         STp->ready = ST_NO_TAPE;
                 } else
                         STp->ready = ST_NOT_READY;
-                scsi_release_request(SRpnt);
+                osst_release_request(SRpnt);
                 SRpnt = NULL;
                 STp->density = 0;       /* Clear the erroneous "residue" */
                 STp->write_prot = 0;
@@ -4649,14 +4704,14 @@ static int os_scsi_tape_open(struct inode * inode, struct file * filp)
 
         osst_analyze_headers(STp, &SRpnt);
 
-        scsi_release_request(SRpnt);
+        osst_release_request(SRpnt);
         SRpnt = NULL;
 
         return 0;
 
 err_out:
         if (SRpnt != NULL)
-                scsi_release_request(SRpnt);
+                osst_release_request(SRpnt);
         normalize_buffer(STp->buffer);
         STp->header_ok = 0;
         STp->in_use = 0;
@@ -4673,7 +4728,7 @@ static int os_scsi_tape_flush(struct file * filp)
         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;
+        struct osst_request * SRpnt  = NULL;
         char                * name   = tape_name(STp);
 
         if (file_count(filp) > 1)
@@ -4736,7 +4791,7 @@ out:
                 if (result == 0 && result2 < 0)
                         result = result2;
         }
-        if (SRpnt) scsi_release_request(SRpnt);
+        if (SRpnt) osst_release_request(SRpnt);
 
         if (STp->abort_count || STp->recover_count) {
                 printk(KERN_INFO "%s:I:", name);
@@ -4790,7 +4845,7 @@ static int osst_ioctl(struct inode * inode,struct file * file,
         unsigned int          blk;
         struct st_modedef   * STm;
         struct st_partstat  * STps;
-        struct scsi_request * SRpnt = NULL;
+        struct osst_request * SRpnt = NULL;
         struct osst_tape    * STp   = file->private_data;
         char                * name  = tape_name(STp);
         void        __user  * p     = (void __user *)arg;
@@ -5104,14 +5159,14 @@ static int osst_ioctl(struct inode * inode,struct file * file,
                         retval = -EFAULT;
                 goto out;
         }
-        if (SRpnt) scsi_release_request(SRpnt);
+        if (SRpnt) osst_release_request(SRpnt);
 
         up(&STp->lock);
 
         return scsi_ioctl(STp->device, cmd_in, p);
 
 out:
-        if (SRpnt) scsi_release_request(SRpnt);
+        if (SRpnt) osst_release_request(SRpnt);
 
         up(&STp->lock);
 
diff --git a/drivers/scsi/osst.h b/drivers/scsi/osst.h
index b72e1c76f52c..011d4d6ca9f9 100644
--- a/drivers/scsi/osst.h
+++ b/drivers/scsi/osst.h
@@ -518,7 +518,8 @@ struct osst_buffer {
   int writing;
   int midlevel_result;
   int syscall_result;
-  struct scsi_request *last_SRpnt;
+  struct osst_request *last_SRpnt;
+  struct st_cmdstatus cmdstat;
   unsigned char *b_data;
   os_aux_t *aux;               /* onstream AUX structure at end of each block     */
   unsigned short use_sg;       /* zero or number of s/g segments for this adapter */
@@ -626,6 +627,15 @@ struct osst_tape {
   struct gendisk *drive;
 } ;
 
+/* scsi tape command */
+struct osst_request {
+        unsigned char cmd[MAX_COMMAND_SIZE];
+        unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+        int result;
+        struct osst_tape *stp;
+        struct completion *waiting;
+};
+
 /* Values of write_type */
 #define OS_WRITE_DATA      0
 #define OS_WRITE_EOD       1