Merge mulgrave.(none):/home/jejb/BK/scsi-new-tag-2.5

into mulgrave.(none):/home/jejb/BK/scsi-for-linus-2.5

22 files changed, 293 insertions, 162 deletions

diff --git a/drivers/scsi/aha1542.c b/drivers/scsi/aha1542.c
index 865a02c08711..ad1af6379ffb 100644
--- a/drivers/scsi/aha1542.c
+++ b/drivers/scsi/aha1542.c
@@ -1635,14 +1635,14 @@ static int aha1542_old_abort(Scsi_Cmnd * SCpnt)
 		if (HOSTDATA(SCpnt->host)->SCint[i]) {
 			if (HOSTDATA(SCpnt->host)->SCint[i] == SCpnt) {
 				printk(KERN_ERR "Timed out command pending for %s\n",
-				       kdevname(SCpnt->request.rq_dev));
+				       kdevname(SCpnt->request->rq_dev));
 				if (HOSTDATA(SCpnt->host)->mb[i].status) {
 					printk(KERN_ERR "OGMB still full - restarting\n");
 					aha1542_out(SCpnt->host->io_port, &ahacmd, 1);
 				};
 			} else
 				printk(KERN_ERR "Other pending command %s\n",
-				       kdevname(SCpnt->request.rq_dev));
+				       kdevname(SCpnt->request->rq_dev));
 		}
 #endif
 
diff --git a/drivers/scsi/constants.c b/drivers/scsi/constants.c
index 57d3f82b80c4..530247392207 100644
--- a/drivers/scsi/constants.c
+++ b/drivers/scsi/constants.c
@@ -1006,13 +1006,13 @@ print_sense_internal(const char * devclass,
 void print_sense(const char * devclass, Scsi_Cmnd * SCpnt)
 {
 	print_sense_internal(devclass, SCpnt->sense_buffer,
-			     SCpnt->request.rq_dev);
+			     SCpnt->request->rq_dev);
 }
 
 void print_req_sense(const char * devclass, Scsi_Request * SRpnt)
 {
 	print_sense_internal(devclass, SRpnt->sr_sense_buffer,
-			     SRpnt->sr_request.rq_dev);
+			     SRpnt->sr_request->rq_dev);
 }
 
 #if (CONSTANTS & CONST_MSG) 
diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c
index 5a84221d5d5c..cc73354accc6 100644
--- a/drivers/scsi/eata.c
+++ b/drivers/scsi/eata.c
@@ -1563,7 +1563,7 @@ static inline int do_qcomm(Scsi_Cmnd *SCpnt, void (*done)(Scsi_Cmnd *)) {
    if (linked_comm && SCpnt->device->queue_depth > 2
                                      && TLDEV(SCpnt->device->type)) {
       HD(j)->cp_stat[i] = READY;
-      flush_dev(SCpnt->device, SCpnt->request.sector, j, FALSE);
+      flush_dev(SCpnt->device, SCpnt->request->sector, j, FALSE);
       return 0;
       }
 
@@ -1875,11 +1875,11 @@ static inline int reorder(unsigned int j, unsigned long cursec,
 
       if (!cpp->din) input_only = FALSE;
 
-      if (SCpnt->request.sector < minsec) minsec = SCpnt->request.sector;
-      if (SCpnt->request.sector > maxsec) maxsec = SCpnt->request.sector;
+      if (SCpnt->request->sector < minsec) minsec = SCpnt->request->sector;
+      if (SCpnt->request->sector > maxsec) maxsec = SCpnt->request->sector;
 
-      sl[n] = SCpnt->request.sector;
-      ioseek += SCpnt->request.nr_sectors;
+      sl[n] = SCpnt->request->sector;
+      ioseek += SCpnt->request->nr_sectors;
 
       if (!n) continue;
 
@@ -1907,7 +1907,7 @@ static inline int reorder(unsigned int j, unsigned long cursec,
 
    if (!input_only) for (n = 0; n < n_ready; n++) {
       k = il[n]; cpp = &HD(j)->cp[k]; SCpnt = cpp->SCpnt;
-      ll[n] = SCpnt->request.nr_sectors; pl[n] = SCpnt->pid;
+      ll[n] = SCpnt->request->nr_sectors; pl[n] = SCpnt->pid;
 
       if (!n) continue;
 
@@ -1935,7 +1935,7 @@ static inline int reorder(unsigned int j, unsigned long cursec,
                 " cur %ld s:%c r:%c rev:%c in:%c ov:%c xd %d.\n",
                 (ihdlr ? "ihdlr" : "qcomm"), SCpnt->channel, SCpnt->target,
                 SCpnt->lun, SCpnt->pid, k, flushcount, n_ready,
-                SCpnt->request.sector, SCpnt->request.nr_sectors, cursec,
+                SCpnt->request->sector, SCpnt->request->nr_sectors, cursec,
                 YESNO(s), YESNO(r), YESNO(rev), YESNO(input_only),
                 YESNO(overlap), cpp->din);
          }
@@ -2073,7 +2073,7 @@ static inline void ihdlr(int irq, unsigned int j) {
 
    if (linked_comm && SCpnt->device->queue_depth > 2
                                      && TLDEV(SCpnt->device->type))
-      flush_dev(SCpnt->device, SCpnt->request.sector, j, TRUE);
+      flush_dev(SCpnt->device, SCpnt->request->sector, j, TRUE);
 
    tstatus = status_byte(spp->target_status);
 
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index e276376771ae..2b0ab4e4e0b4 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -230,6 +230,7 @@ struct Scsi_Host * scsi_register(Scsi_Host_Template * tpnt, int j)
 
     retval->select_queue_depths = tpnt->select_queue_depths;
     retval->max_sectors = tpnt->max_sectors;
+    retval->use_blk_tcq = tpnt->use_blk_tcq;
 
     if(!scsi_hostlist)
 	scsi_hostlist = retval;
diff --git a/drivers/scsi/hosts.h b/drivers/scsi/hosts.h
index 8604eb35140a..95edfbd10ccd 100644
--- a/drivers/scsi/hosts.h
+++ b/drivers/scsi/hosts.h
@@ -286,6 +286,12 @@ typedef struct	SHT
 
     unsigned highmem_io:1;
 
+    /* 
+     * True if the driver wishes to use the generic block layer
+     * tag queueing functions
+     */
+    unsigned use_blk_tcq:1;
+
     /*
      * Name of proc directory
      */
@@ -386,6 +392,7 @@ struct Scsi_Host
     unsigned unchecked_isa_dma:1;
     unsigned use_clustering:1;
     unsigned highmem_io:1;
+    unsigned use_blk_tcq:1;
 
     /*
      * Host has rejected a command because it was busy.
@@ -555,6 +562,26 @@ extern int scsi_unregister_host(Scsi_Host_Template *);
 #define SD_EXTRA_DEVS CONFIG_SD_EXTRA_DEVS
 #define SR_EXTRA_DEVS CONFIG_SR_EXTRA_DEVS
 
+
+/**
+ * scsi_find_device - find a device given the host
+ * @channel:	SCSI channel (zero if only one channel)
+ * @pun:	SCSI target number (physical unit number)
+ * @lun:	SCSI Logical Unit Number
+ **/
+static inline Scsi_Device *scsi_find_device(struct Scsi_Host *host,
+                                            int channel, int pun, int lun) {
+        Scsi_Device *SDpnt;
+
+        for(SDpnt = host->host_queue;
+            SDpnt != NULL;
+            SDpnt = SDpnt->next)
+                if(SDpnt->channel == channel && SDpnt->id == pun
+                   && SDpnt->lun ==lun)
+                        break;
+        return SDpnt;
+}
+    
 #endif
 /*
  * Overrides for Emacs so that we follow Linus's tabbing style.
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index 9652a0f71616..14960822b3e6 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -668,7 +668,7 @@ static inline int should_transform(struct ata_device *drive, Scsi_Cmnd *cmd)
 	struct Scsi_Host *host = drive->driver_data;
 	idescsi_scsi_t *scsi = idescsi_private(host);
 
-	if (major(cmd->request.rq_dev) == SCSI_GENERIC_MAJOR)
+	if (major(cmd->request->rq_dev) == SCSI_GENERIC_MAJOR)
 		return test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
 	return test_bit(IDESCSI_TRANSFORM, &scsi->transform);
 }
diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 8c91af6f7900..9ea4f1b68ca7 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -270,7 +270,7 @@ static int osst_chk_result(OS_Scsi_Tape * STp, Scsi_Request * SRpnt)
 /* Wakeup from interrupt */
 static void osst_sleep_done (Scsi_Cmnd * SCpnt)
 {
-	unsigned int dev = TAPE_NR(SCpnt->request.rq_dev);
+	unsigned int dev = TAPE_NR(SCpnt->request->rq_dev);
 	OS_Scsi_Tape * STp;
 
 	if (os_scsi_tapes && (STp = os_scsi_tapes[dev])) {
@@ -285,13 +285,13 @@ static void osst_sleep_done (Scsi_Cmnd * SCpnt)
 		}
 		else
 			(STp->buffer)->midlevel_result = SCpnt->result;
-		SCpnt->request.rq_status = RQ_SCSI_DONE;
+		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);
+		complete(SCpnt->request->waiting);
 	}
 #if DEBUG
 	else if (debugging)
@@ -313,7 +313,7 @@ static	Scsi_Request * osst_do_scsi(Scsi_Request *SRpnt, OS_Scsi_Tape *STp,
 #endif
 	if (SRpnt == NULL) {
 		if ((SRpnt = scsi_allocate_request(STp->device)) == NULL) {
-			printk(KERN_ERR "osst%d:E: Can't get SCSI request.\n", TAPE_NR(STp->devt));
+			printk(KERN_ERR "osst%d:E: Can't get SCSI request->\n", TAPE_NR(STp->devt));
 			if (signal_pending(current))
 				(STp->buffer)->syscall_result = (-EINTR);
 			else
@@ -336,15 +336,15 @@ static	Scsi_Request * osst_do_scsi(Scsi_Request *SRpnt, OS_Scsi_Tape *STp,
 		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_dev = STp->devt;
+	SRpnt->sr_request->waiting = &(STp->wait);
+	SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
+	SRpnt->sr_request->rq_dev = STp->devt;
 
 	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;
+		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 &&
@@ -377,7 +377,7 @@ static void osst_write_behind_check(OS_Scsi_Tape *STp)
 		STp->nbr_finished++;
 #endif
 	wait_for_completion(&(STp->wait));
-	(STp->buffer)->last_SRpnt->sr_request.waiting = NULL;
+	(STp->buffer)->last_SRpnt->sr_request->waiting = NULL;
 
 	STp->buffer->syscall_result = osst_chk_result(STp, STp->buffer->last_SRpnt);
 
diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index a008f3dd87b0..9debb242fe73 100644
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -4236,7 +4236,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, srb_t * sp)
 				/* Set transfer direction (READ and WRITE) */
 				/* Linux doesn't tell us                   */
 				/*
-				 * For block devices, cmd->request.cmd has the operation
+				 * For block devices, cmd->request->cmd has the operation
 				 * For character devices, this isn't always set properly, so
 				 * we need to check data_cmnd[0].  This catches the conditions
 				 * for st.c, but not sg. Generic commands are pass down to us.
@@ -6241,7 +6241,7 @@ qla1280_print_scsi_cmd(Scsi_Cmnd * cmd)
 	       cmd->tag, cmd->flags, cmd->transfersize);
 	printk("  Pid=%li, SP=0x%p\n", cmd->pid, CMD_SP(cmd));
 	printk(" underflow size = 0x%x, direction=0x%x, req.cmd=0x%x \n",
-	       cmd->underflow, sp->dir, cmd->request.cmd);
+	       cmd->underflow, sp->dir, cmd->request->cmd);
 }
 
 /**************************************************************************
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 0215c45cbd37..8e9df60cecaa 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -253,11 +253,20 @@ __setup("scsi_logging=", scsi_logging_setup);
  
 static void scsi_wait_done(Scsi_Cmnd * SCpnt)
 {
-	struct request *req;
+	struct request *req = SCpnt->request;
+        struct request_queue *q = &SCpnt->device->request_queue;
+        unsigned long flags;
 
-	req = &SCpnt->request;
+        ASSERT_LOCK(q->queue_lock, 0);
 	req->rq_status = RQ_SCSI_DONE;	/* Busy, but indicate request done */
 
+        spin_lock_irqsave(q->queue_lock, flags);
+
+        if(blk_rq_tagged(req))
+                blk_queue_end_tag(q, req);
+
+        spin_unlock_irqrestore(q->queue_lock, flags);
+
 	if (req->waiting)
 		complete(req->waiting);
 }
@@ -296,17 +305,19 @@ static spinlock_t scsi_bhqueue_lock = SPIN_LOCK_UNLOCKED;
 Scsi_Request *scsi_allocate_request(Scsi_Device * device)
 {
   	Scsi_Request *SRpnt = NULL;
+        const int offset = ALIGN(sizeof(Scsi_Request), 4);
+        const int size = offset + sizeof(struct request);
   
   	if (!device)
   		panic("No device passed to scsi_allocate_request().\n");
   
-	SRpnt = (Scsi_Request *) kmalloc(sizeof(Scsi_Request), GFP_ATOMIC);
+        SRpnt = (Scsi_Request *) kmalloc(size, GFP_ATOMIC);
 	if( SRpnt == NULL )
 	{
 		return NULL;
 	}
-
-	memset(SRpnt, 0, sizeof(Scsi_Request));
+	memset(SRpnt, 0, size);
+        SRpnt->sr_request = (struct request *)(((char *)SRpnt) + offset);
 	SRpnt->sr_device = device;
 	SRpnt->sr_host = device->host;
 	SRpnt->sr_magic = SCSI_REQ_MAGIC;
@@ -434,7 +445,7 @@ Scsi_Cmnd *scsi_allocate_device(Scsi_Device * device, int wait,
 			 * Now we can check for a free command block for this device.
 			 */
 			for (SCpnt = device->device_queue; SCpnt; SCpnt = SCpnt->next) {
-				if (SCpnt->request.rq_status == RQ_INACTIVE)
+				if (SCpnt->request == NULL)
 					break;
 			}
 		}
@@ -503,9 +514,7 @@ Scsi_Cmnd *scsi_allocate_device(Scsi_Device * device, int wait,
 		}
 	}
 
-	SCpnt->request.rq_status = RQ_SCSI_BUSY;
-	SCpnt->request.waiting = NULL;	/* And no one is waiting for this
-					 * to complete */
+	SCpnt->request = NULL;
 	atomic_inc(&SCpnt->host->host_active);
 	atomic_inc(&SCpnt->device->device_active);
 
@@ -548,7 +557,7 @@ inline void __scsi_release_command(Scsi_Cmnd * SCpnt)
 
         SDpnt = SCpnt->device;
 
-	SCpnt->request.rq_status = RQ_INACTIVE;
+	SCpnt->request = NULL;
 	SCpnt->state = SCSI_STATE_UNUSED;
 	SCpnt->owner = SCSI_OWNER_NOBODY;
 	atomic_dec(&SCpnt->host->host_active);
@@ -771,13 +780,13 @@ void scsi_wait_req (Scsi_Request * SRpnt, const void *cmnd ,
 	DECLARE_COMPLETION(wait);
 	request_queue_t *q = &SRpnt->sr_device->request_queue;
 	
-	SRpnt->sr_request.waiting = &wait;
-	SRpnt->sr_request.rq_status = RQ_SCSI_BUSY;
+	SRpnt->sr_request->waiting = &wait;
+	SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
 	scsi_do_req (SRpnt, (void *) cmnd,
 		buffer, bufflen, scsi_wait_done, timeout, retries);
 	generic_unplug_device(q);
 	wait_for_completion(&wait);
-	SRpnt->sr_request.waiting = NULL;
+	SRpnt->sr_request->waiting = NULL;
 	if( SRpnt->sr_command != NULL )
 	{
 		scsi_release_command(SRpnt->sr_command);
@@ -928,8 +937,7 @@ void scsi_init_cmd_from_req(Scsi_Cmnd * SCpnt, Scsi_Request * SRpnt)
 	SCpnt->cmd_len = SRpnt->sr_cmd_len;
 	SCpnt->use_sg = SRpnt->sr_use_sg;
 
-	memcpy((void *) &SCpnt->request, (const void *) &SRpnt->sr_request,
-	       sizeof(SRpnt->sr_request));
+        SCpnt->request = SRpnt->sr_request;
 	memcpy((void *) SCpnt->data_cmnd, (const void *) SRpnt->sr_cmnd, 
 	       sizeof(SCpnt->data_cmnd));
 	SCpnt->reset_chain = NULL;
@@ -1490,7 +1498,7 @@ void scsi_build_commandblocks(Scsi_Device * SDpnt)
 		SCpnt->target = SDpnt->id;
 		SCpnt->lun = SDpnt->lun;
 		SCpnt->channel = SDpnt->channel;
-		SCpnt->request.rq_status = RQ_INACTIVE;
+		SCpnt->request = NULL;
 		SCpnt->use_sg = 0;
 		SCpnt->old_use_sg = 0;
 		SCpnt->old_cmd_len = 0;
@@ -2062,16 +2070,16 @@ int scsi_unregister_host(Scsi_Host_Template * tpnt)
 			     SCpnt = SCpnt->next) {
 				online_status = SDpnt->online;
 				SDpnt->online = FALSE;
-				if (SCpnt->request.rq_status != RQ_INACTIVE) {
+				if (SCpnt->request && SCpnt->request->rq_status != RQ_INACTIVE) {
 					printk(KERN_ERR "SCSI device not inactive - rq_status=%d, target=%d, pid=%ld, state=%d, owner=%d.\n",
-					       SCpnt->request.rq_status, SCpnt->target, SCpnt->pid,
+					       SCpnt->request->rq_status, SCpnt->target, SCpnt->pid,
 					     SCpnt->state, SCpnt->owner);
 					for (SDpnt1 = shpnt->host_queue; SDpnt1;
 					     SDpnt1 = SDpnt1->next) {
 						for (SCpnt = SDpnt1->device_queue; SCpnt;
 						     SCpnt = SCpnt->next)
-							if (SCpnt->request.rq_status == RQ_SCSI_DISCONNECTING)
-								SCpnt->request.rq_status = RQ_INACTIVE;
+							if (SCpnt->request->rq_status == RQ_SCSI_DISCONNECTING)
+								SCpnt->request->rq_status = RQ_INACTIVE;
 					}
 					SDpnt->online = online_status;
 					printk(KERN_ERR "Device busy???\n");
@@ -2082,7 +2090,8 @@ int scsi_unregister_host(Scsi_Host_Template * tpnt)
 				 * continue on.
 				 */
 				SCpnt->state = SCSI_STATE_DISCONNECTING;
-				SCpnt->request.rq_status = RQ_SCSI_DISCONNECTING;	/* Mark as busy */
+                                if(SCpnt->request)
+                                        SCpnt->request->rq_status = RQ_SCSI_DISCONNECTING;	/* Mark as busy */
 			}
 		}
 	}
@@ -2392,11 +2401,11 @@ static void scsi_dump_status(int level)
 				       SCpnt->target,
 				       SCpnt->lun,
 
-				       kdevname(SCpnt->request.rq_dev),
-				       SCpnt->request.sector,
-				       SCpnt->request.nr_sectors,
-				       (long)SCpnt->request.current_nr_sectors,
-				       SCpnt->request.rq_status,
+				       kdevname(SCpnt->request->rq_dev),
+				       SCpnt->request->sector,
+				       SCpnt->request->nr_sectors,
+				       (long)SCpnt->request->current_nr_sectors,
+				       SCpnt->request->rq_status,
 				       SCpnt->use_sg,
 
 				       SCpnt->retries,
@@ -2708,16 +2717,18 @@ int
 scsi_reset_provider(Scsi_Device *dev, int flag)
 {
 	Scsi_Cmnd SC, *SCpnt = &SC;
+        struct request req;
 	int rtn;
 
+        SCpnt->request = &req;
 	memset(&SCpnt->eh_timeout, 0, sizeof(SCpnt->eh_timeout));
 	SCpnt->host                    	= dev->host;
 	SCpnt->device                  	= dev;
 	SCpnt->target                  	= dev->id;
 	SCpnt->lun                     	= dev->lun;
 	SCpnt->channel                 	= dev->channel;
-	SCpnt->request.rq_status       	= RQ_SCSI_BUSY;
-	SCpnt->request.waiting        	= NULL;
+	SCpnt->request->rq_status      	= RQ_SCSI_BUSY;
+	SCpnt->request->waiting        	= NULL;
 	SCpnt->use_sg                  	= 0;
 	SCpnt->old_use_sg              	= 0;
 	SCpnt->old_cmd_len             	= 0;
diff --git a/drivers/scsi/scsi.h b/drivers/scsi/scsi.h
index cd1df44e19a6..c14b1c497a0a 100644
--- a/drivers/scsi/scsi.h
+++ b/drivers/scsi/scsi.h
@@ -566,6 +566,7 @@ struct scsi_device {
         atomic_t                device_active; /* commands checked out for device */
 	volatile unsigned short device_busy;	/* commands actually active on low-level */
 	Scsi_Cmnd *device_queue;	/* queue of SCSI Command structures */
+        Scsi_Cmnd *current_cmnd;	/* currently active command */
 
 	unsigned int id, lun, channel;
 
@@ -662,7 +663,7 @@ struct scsi_request {
 	struct Scsi_Host *sr_host;
 	Scsi_Device *sr_device;
 	Scsi_Cmnd *sr_command;
-	struct request sr_request;	/* A copy of the command we are
+	struct request *sr_request;	/* A copy of the command we are
 				   working on */
 	unsigned sr_bufflen;	/* Size of data buffer */
 	void *sr_buffer;		/* Data buffer */
@@ -773,8 +774,8 @@ struct scsi_cmnd {
 				   transferred less actual number
 				   transferred (0 if not supported) */
 
-	struct request request;	/* A copy of the command we are
-				   working on */
+	struct request *request;	/* The command we are
+				   	   working on */
 
 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];		/* obtained by REQUEST SENSE
 						 * when CHECK CONDITION is
@@ -856,4 +857,87 @@ struct scsi_cmnd {
 
 extern int scsi_reset_provider(Scsi_Device *, int);
 
+/**
+ * scsi_activate_tcq - turn on tag command queueing
+ * @SDpnt:	device to turn on TCQ for
+ * @depth:	queue depth
+ *
+ * Notes:
+ *	Eventually, I hope depth would be the maximum depth
+ *	the device could cope with and the real queue depth
+ *	would be adjustable from 0 to depth.
+ **/
+static inline void scsi_activate_tcq(Scsi_Device *SDpnt, int depth) {
+        request_queue_t *q = &SDpnt->request_queue;
+
+        if(SDpnt->tagged_supported && !blk_queue_tagged(q)) {
+                blk_queue_init_tags(q, depth);
+                SDpnt->tagged_queue = 1;
+        }
+}
+
+/**
+ * scsi_deactivate_tcq - turn off tag command queueing
+ * @SDpnt:	device to turn off TCQ for
+ **/
+static inline void scsi_deactivate_tcq(Scsi_Device *SDpnt) {
+        blk_queue_free_tags(&SDpnt->request_queue);
+        SDpnt->tagged_queue = 0;
+}
+#define MSG_SIMPLE_TAG	0x20
+#define MSG_HEAD_TAG	0x21
+#define MSG_ORDERED_TAG	0x22
+
+#define SCSI_NO_TAG	(-1)    /* identify no tag in use */
+
+/**
+ * scsi_populate_tag_msg - place a tag message in a buffer
+ * @SCpnt:	pointer to the Scsi_Cmnd for the tag
+ * @msg:	pointer to the area to place the tag
+ *
+ * Notes:
+ *	designed to create the correct type of tag message for the 
+ *	particular request.  Returns the size of the tag message.
+ *	May return 0 if TCQ is disabled for this device.
+ **/
+static inline int scsi_populate_tag_msg(Scsi_Cmnd *SCpnt, char *msg) {
+        struct request *req = SCpnt->request;
+
+        if(!blk_rq_tagged(req))
+                return 0;
+    
+        if(req->flags & REQ_BARRIER)
+                *msg++ = MSG_ORDERED_TAG;
+        else
+                *msg++ = MSG_SIMPLE_TAG;
+
+        *msg++ = SCpnt->request->tag;
+
+        return 2;
+}
+
+/**
+ * scsi_find_tag - find a tagged command by device
+ * @SDpnt:	pointer to the ScSI device
+ * @tag:	the tag number
+ *
+ * Notes:
+ *	Only works with tags allocated by the generic blk layer.
+ **/
+static inline Scsi_Cmnd *scsi_find_tag(Scsi_Device *SDpnt, int tag) {
+
+        struct request *req;
+
+        if(tag == SCSI_NO_TAG)
+                /* single command, look in space */
+                return SDpnt->current_cmnd;
+
+        req = blk_queue_find_tag(&SDpnt->request_queue, tag);
+
+        if(req == NULL)
+                return NULL;
+
+        return (Scsi_Cmnd *)req->special;
+}
+
 #endif
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 328875a71815..058688349f5d 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -694,7 +694,7 @@ static int scsi_debug_read(Scsi_Cmnd * SCpnt, int upper_blk, int block,
 	{
 		int delay = SCSI_SETUP_LATENCY;
 
-		delay += SCpnt->request.nr_sectors * SCSI_DATARATE;
+		delay += SCpnt->request->nr_sectors * SCSI_DATARATE;
 		if (delay)
 			usleep(delay);
 	}
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 311f4a6fd149..11d9307d20f0 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -319,7 +319,7 @@ void scsi_eh_done(Scsi_Cmnd * SCpnt)
 		return;
 	}
 
-	SCpnt->request.rq_status = RQ_SCSI_DONE;
+	SCpnt->request->rq_status = RQ_SCSI_DONE;
 
 	SCpnt->owner = SCSI_OWNER_ERROR_HANDLER;
 	SCpnt->eh_state = SUCCESS;
@@ -346,7 +346,7 @@ void scsi_eh_done(Scsi_Cmnd * SCpnt)
 STATIC
 void scsi_eh_action_done(Scsi_Cmnd * SCpnt, int answer)
 {
-	SCpnt->request.rq_status = RQ_SCSI_DONE;
+	SCpnt->request->rq_status = RQ_SCSI_DONE;
 
 	SCpnt->owner = SCSI_OWNER_ERROR_HANDLER;
 	SCpnt->eh_state = (answer ? SUCCESS : FAILED);
@@ -601,7 +601,7 @@ retry:
 		 * Set up the semaphore so we wait for the command to complete.
 		 */
 		SCpnt->host->eh_action = &sem;
-		SCpnt->request.rq_status = RQ_SCSI_BUSY;
+		SCpnt->request->rq_status = RQ_SCSI_BUSY;
 
 		spin_lock_irqsave(SCpnt->host->host_lock, flags);
 		host->hostt->queuecommand(SCpnt, scsi_eh_done);
@@ -633,7 +633,7 @@ retry:
 				SCpnt->host->hostt->eh_abort_handler(SCpnt);
 			spin_unlock_irqrestore(SCpnt->host->host_lock, flags);
 			
-			SCpnt->request.rq_status = RQ_SCSI_DONE;
+			SCpnt->request->rq_status = RQ_SCSI_DONE;
 			SCpnt->owner = SCSI_OWNER_ERROR_HANDLER;
 			
 			SCpnt->eh_state = FAILED;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index bede96547efb..5fbe664e65ea 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -76,12 +76,10 @@ static void __scsi_insert_special(request_queue_t *q, struct request *rq,
 	 * must not attempt merges on this) and that it acts as a soft
 	 * barrier
 	 */
-	rq->flags = REQ_SPECIAL | REQ_BARRIER;
+	rq->flags &= REQ_QUEUED;
+	rq->flags |= REQ_SPECIAL | REQ_BARRIER;
 
 	rq->special = data;
-	rq->q = NULL;
-	rq->bio = rq->biotail = NULL;
-	rq->nr_phys_segments = 0;
 
 	/*
 	 * We have the option of inserting the head or the tail of the queue.
@@ -90,6 +88,9 @@ static void __scsi_insert_special(request_queue_t *q, struct request *rq,
 	 * device, or a host that is unable to accept a particular command.
 	 */
 	spin_lock_irqsave(q->queue_lock, flags);
+	/* If command is tagged, release the tag */
+	if(blk_rq_tagged(rq))
+		blk_queue_end_tag(q, rq);
 	_elv_add_request(q, rq, !at_head, 0);
 	q->request_fn(q);
 	spin_unlock_irqrestore(q->queue_lock, flags);
@@ -120,7 +121,7 @@ int scsi_insert_special_cmd(Scsi_Cmnd * SCpnt, int at_head)
 {
 	request_queue_t *q = &SCpnt->device->request_queue;
 
-	__scsi_insert_special(q, &SCpnt->request, SCpnt, at_head);
+	__scsi_insert_special(q, SCpnt->request, SCpnt, at_head);
 	return 0;
 }
 
@@ -148,7 +149,7 @@ int scsi_insert_special_req(Scsi_Request * SRpnt, int at_head)
 {
 	request_queue_t *q = &SRpnt->sr_device->request_queue;
 
-	__scsi_insert_special(q, &SRpnt->sr_request, SRpnt, at_head);
+	__scsi_insert_special(q, SRpnt->sr_request, SRpnt, at_head);
 	return 0;
 }
 
@@ -259,8 +260,10 @@ void scsi_queue_next_request(request_queue_t * q, Scsi_Cmnd * SCpnt)
 		 * in which case we need to request the blocks that come after
 		 * the bad sector.
 		 */
-		SCpnt->request.special = (void *) SCpnt;
-		_elv_add_request(q, &SCpnt->request, 0, 0);
+		SCpnt->request->special = (void *) SCpnt;
+		if(blk_rq_tagged(SCpnt->request))
+			blk_queue_end_tag(q, SCpnt->request);
+		_elv_add_request(q, SCpnt->request, 0, 0);
 	}
 
 	/*
@@ -356,15 +359,18 @@ static Scsi_Cmnd *__scsi_end_request(Scsi_Cmnd * SCpnt,
 				     int frequeue)
 {
 	request_queue_t *q = &SCpnt->device->request_queue;
-	struct request *req = &SCpnt->request;
+	struct request *req = SCpnt->request;
+	int flags;
 
 	ASSERT_LOCK(q->queue_lock, 0);
 
+	spin_lock_irqsave(q->queue_lock, flags);
 	/*
 	 * If there are blocks left over at the end, set up the command
 	 * to queue the remainder of them.
 	 */
 	if (end_that_request_first(req, uptodate, sectors)) {
+		spin_unlock_irqrestore(q->queue_lock, flags);
 		if (!requeue)
 			return SCpnt;
 
@@ -376,15 +382,15 @@ static Scsi_Cmnd *__scsi_end_request(Scsi_Cmnd * SCpnt,
 		return SCpnt;
 	}
 
-	/*
-	 * This request is done.  If there is someone blocked waiting for this
-	 * request, wake them up.
-	 */
-	if (req->waiting)
-		complete(req->waiting);
-
 	add_blkdev_randomness(major(req->rq_dev));
 
+	if(blk_rq_tagged(req))
+		blk_queue_end_tag(q, req);
+
+	end_that_request_last(req);
+
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
 	/*
 	 * This will goose the queue request function at the end, so we don't
 	 * need to worry about launching another command.
@@ -441,7 +447,7 @@ Scsi_Cmnd *scsi_end_request(Scsi_Cmnd * SCpnt, int uptodate, int sectors)
  */
 static void scsi_release_buffers(Scsi_Cmnd * SCpnt)
 {
-	struct request *req = &SCpnt->request;
+	struct request *req = SCpnt->request;
 
 	ASSERT_LOCK(SCpnt->host->host_lock, 0);
 
@@ -491,7 +497,7 @@ void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
 	int result = SCpnt->result;
 	int this_count = SCpnt->bufflen >> 9;
 	request_queue_t *q = &SCpnt->device->request_queue;
-	struct request *req = &SCpnt->request;
+	struct request *req = SCpnt->request;
 
 	/*
 	 * We must do one of several things here:
@@ -675,7 +681,7 @@ void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
 	if (result) {
 		struct Scsi_Device_Template *STpnt;
 
-		STpnt = scsi_get_request_dev(&SCpnt->request);
+		STpnt = scsi_get_request_dev(SCpnt->request);
 		printk("SCSI %s error : host %d channel %d id %d lun %d return code = %x\n",
 		       (STpnt ? STpnt->name : "device"),
 		       SCpnt->device->host->host_no,
@@ -868,7 +874,7 @@ void scsi_request_fn(request_queue_t * q)
 		 * the remainder of a partially fulfilled request that can 
 		 * come up when there is a medium error.  We have to treat
 		 * these two cases differently.  We differentiate by looking
-		 * at request.cmd, as this tells us the real story.
+		 * at request->cmd, as this tells us the real story.
 		 */
 		if (req->flags & REQ_SPECIAL) {
 			STpnt = NULL;
@@ -904,6 +910,9 @@ void scsi_request_fn(request_queue_t * q)
 			 */
 			if (!SCpnt)
 				break;
+
+			/* pull a tag out of the request if we have one */
+			SCpnt->tag = req->tag;
 		} else {
 			blk_dump_rq_flags(req, "SCSI bad req");
 			break;
@@ -924,18 +933,15 @@ void scsi_request_fn(request_queue_t * q)
 		 * reason to search the list, because all of the commands
 		 * in this queue are for the same device.
 		 */
-		blkdev_dequeue_request(req);
+		if(!(blk_queue_tagged(q) && (blk_queue_start_tag(q, req) == 0)))
+			blkdev_dequeue_request(req);
 
-		if (req != &SCpnt->request && req != &SRpnt->sr_request ) {
-			memcpy(&SCpnt->request, req, sizeof(struct request));
+		/* note the overloading of req->special.  When the tag
+		 * is active it always means SCpnt.  If the tag goes
+		 * back for re-queueing, it may be reset */
+		req->special = SCpnt;
+		SCpnt->request = req;
 
-			/*
-			 * We have copied the data out of the request block -
-			 * it is now in a field in SCpnt.  Release the request
-			 * block.
-			 */
-			blkdev_release_request(req);
-		}
 		/*
 		 * Now it is finally safe to release the lock.  We are
 		 * not going to noodle the request list until this
@@ -945,7 +951,7 @@ void scsi_request_fn(request_queue_t * q)
 		req = NULL;
 		spin_unlock_irq(q->queue_lock);
 
-		if (SCpnt->request.flags & REQ_CMD) {
+		if (SCpnt->request->flags & REQ_CMD) {
 			/*
 			 * This will do a couple of things:
 			 *  1) Fill in the actual SCSI command.
@@ -959,7 +965,7 @@ void scsi_request_fn(request_queue_t * q)
 			 * request to be rejected immediately.
 			 */
 			if (STpnt == NULL)
-				STpnt = scsi_get_request_dev(&SCpnt->request);
+				STpnt = scsi_get_request_dev(SCpnt->request);
 
 			/* 
 			 * This sets up the scatter-gather table (allocating if
@@ -973,9 +979,11 @@ void scsi_request_fn(request_queue_t * q)
 					SDpnt->starved = 1;
 					SHpnt->some_device_starved = 1;
 				}
-				SCpnt->request.special = SCpnt;
-				SCpnt->request.flags |= REQ_SPECIAL;
-				_elv_add_request(q, &SCpnt->request, 0, 0);
+				SCpnt->request->special = SCpnt;
+				SCpnt->request->flags |= REQ_SPECIAL;
+				if(blk_rq_tagged(SCpnt->request))
+					blk_queue_end_tag(q, SCpnt->request);
+				_elv_add_request(q, SCpnt->request, 0, 0);
 				break;
 			}
 
@@ -985,7 +993,7 @@ void scsi_request_fn(request_queue_t * q)
 			if (!STpnt->init_command(SCpnt)) {
 				scsi_release_buffers(SCpnt);
 				SCpnt = __scsi_end_request(SCpnt, 0, 
-							   SCpnt->request.nr_sectors, 0, 0);
+							   SCpnt->request->nr_sectors, 0, 0);
 				if( SCpnt != NULL )
 				{
 					panic("Should not have leftover blocks\n");
diff --git a/drivers/scsi/scsi_merge.c b/drivers/scsi/scsi_merge.c
index 82c3a17235bc..b29b763bd38a 100644
--- a/drivers/scsi/scsi_merge.c
+++ b/drivers/scsi/scsi_merge.c
@@ -57,7 +57,7 @@
  */
 int scsi_init_io(Scsi_Cmnd *SCpnt)
 {
-	struct request     *req = &SCpnt->request;
+	struct request     *req = SCpnt->request;
 	struct scatterlist *sgpnt;
 	int count, gfp_mask;
 
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 63fe305e4342..e350a3292ed2 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -327,13 +327,13 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 	/*
 	 * don't support specials for nwo
 	 */
-	if (!(SCpnt->request.flags & REQ_CMD))
+	if (!(SCpnt->request->flags & REQ_CMD))
 		return 0;
 
-	part_nr = SD_PARTITION(SCpnt->request.rq_dev);
-	dsk_nr = DEVICE_NR(SCpnt->request.rq_dev);
+	part_nr = SD_PARTITION(SCpnt->request->rq_dev);
+	dsk_nr = DEVICE_NR(SCpnt->request->rq_dev);
 
-	block = SCpnt->request.sector;
+	block = SCpnt->request->sector;
 	this_count = SCpnt->request_bufflen >> 9;
 
 	SCSI_LOG_HLQUEUE(1, printk("sd_command_init: dsk_nr=%d, block=%d, "
@@ -344,9 +344,9 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 	/* >>>>> this change is not in the lk 2.5 series */
 	if (part_nr >= (sd_template.dev_max << 4) || (part_nr & 0xf) ||
 	    !sdp || !sdp->online ||
- 	    block + SCpnt->request.nr_sectors > sd[part_nr].nr_sects) {
+ 	    block + SCpnt->request->nr_sectors > sd[part_nr].nr_sects) {
 		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", 
-				 SCpnt->request.nr_sectors));
+				 SCpnt->request->nr_sectors));
 		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
 		return 0;
 	}
@@ -375,7 +375,7 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 	 * for this.
 	 */
 	if (sdp->sector_size == 1024) {
-		if ((block & 1) || (SCpnt->request.nr_sectors & 1)) {
+		if ((block & 1) || (SCpnt->request->nr_sectors & 1)) {
 			printk(KERN_ERR "sd: Bad block number requested");
 			return 0;
 		} else {
@@ -384,7 +384,7 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 		}
 	}
 	if (sdp->sector_size == 2048) {
-		if ((block & 3) || (SCpnt->request.nr_sectors & 3)) {
+		if ((block & 3) || (SCpnt->request->nr_sectors & 3)) {
 			printk(KERN_ERR "sd: Bad block number requested");
 			return 0;
 		} else {
@@ -393,7 +393,7 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 		}
 	}
 	if (sdp->sector_size == 4096) {
-		if ((block & 7) || (SCpnt->request.nr_sectors & 7)) {
+		if ((block & 7) || (SCpnt->request->nr_sectors & 7)) {
 			printk(KERN_ERR "sd: Bad block number requested");
 			return 0;
 		} else {
@@ -401,25 +401,25 @@ static int sd_init_command(Scsi_Cmnd * SCpnt)
 			this_count = this_count >> 3;
 		}
 	}
-	if (rq_data_dir(&SCpnt->request) == WRITE) {
+	if (rq_data_dir(SCpnt->request) == WRITE) {
 		if (!sdp->writeable) {
 			return 0;
 		}
 		SCpnt->cmnd[0] = WRITE_6;
 		SCpnt->sc_data_direction = SCSI_DATA_WRITE;
-	} else if (rq_data_dir(&SCpnt->request) == READ) {
+	} else if (rq_data_dir(SCpnt->request) == READ) {
 		SCpnt->cmnd[0] = READ_6;
 		SCpnt->sc_data_direction = SCSI_DATA_READ;
 	} else {
 		printk(KERN_ERR "sd: Unknown command %lx\n", 
-		       SCpnt->request.flags);
-/* overkill 	panic("Unknown sd command %lx\n", SCpnt->request.flags); */
+		       SCpnt->request->flags);
+/* overkill 	panic("Unknown sd command %lx\n", SCpnt->request->flags); */
 		return 0;
 	}
 
 	SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n", 
-		nbuff, (rq_data_dir(&SCpnt->request) == WRITE) ? 
-		"writing" : "reading", this_count, SCpnt->request.nr_sectors));
+		nbuff, (rq_data_dir(SCpnt->request) == WRITE) ? 
+		"writing" : "reading", this_count, SCpnt->request->nr_sectors));
 
 	SCpnt->cmnd[1] = (SCpnt->device->scsi_level <= SCSI_2) ?
 			 ((SCpnt->lun << 5) & 0xe0) : 0;
@@ -664,7 +664,7 @@ static void sd_rw_intr(Scsi_Cmnd * SCpnt)
 #if CONFIG_SCSI_LOGGING
 	char nbuff[6];
 
-	SCSI_LOG_HLCOMPLETE(1, sd_dskname(DEVICE_NR(SCpnt->request.rq_dev), 
+	SCSI_LOG_HLCOMPLETE(1, sd_dskname(DEVICE_NR(SCpnt->request->rq_dev), 
 			    nbuff));
 	SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n", 
 				      nbuff, result));
@@ -690,8 +690,8 @@ static void sd_rw_intr(Scsi_Cmnd * SCpnt)
 			(SCpnt->sense_buffer[4] << 16) |
 			(SCpnt->sense_buffer[5] << 8) |
 			SCpnt->sense_buffer[6];
-			if (SCpnt->request.bio != NULL)
-				block_sectors = bio_sectors(SCpnt->request.bio);
+			if (SCpnt->request->bio != NULL)
+				block_sectors = bio_sectors(SCpnt->request->bio);
 			switch (SCpnt->device->sector_size) {
 			case 1024:
 				error_sector <<= 1;
@@ -716,7 +716,7 @@ static void sd_rw_intr(Scsi_Cmnd * SCpnt)
 			}
 
 			error_sector &= ~(block_sectors - 1);
-			good_sectors = error_sector - SCpnt->request.sector;
+			good_sectors = error_sector - SCpnt->request->sector;
 			if (good_sectors < 0 || good_sectors >= this_count)
 				good_sectors = 0;
 			break;
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 9b5e51229c09..0d052876234a 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -695,7 +695,7 @@ static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 
     srp->my_cmdp = SRpnt;
     q = &SRpnt->sr_device->request_queue;
-    SRpnt->sr_request.rq_dev = sdp->i_rdev;
+    SRpnt->sr_request->rq_dev = sdp->i_rdev;
     SRpnt->sr_sense_buffer[0] = 0;
     SRpnt->sr_cmd_len = hp->cmd_len;
     if (! (hp->flags & SG_FLAG_LUN_INHIBIT)) {
@@ -1222,7 +1222,7 @@ static void sg_cmd_done_bh(Scsi_Cmnd * SCpnt)
     SRpnt->sr_bufflen = 0;
     SRpnt->sr_buffer = NULL;
     SRpnt->sr_underflow = 0;
-    SRpnt->sr_request.rq_dev = mk_kdev(0, 0);  /* "sg" _disowns_ request blk */
+    SRpnt->sr_request->rq_dev = mk_kdev(0, 0);  /* "sg" _disowns_ request blk */
 
     srp->my_cmdp = NULL;
     srp->done = 1;
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 0e28dc69652b..2fb8f0fe0f6a 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -197,11 +197,11 @@ static void rw_intr(Scsi_Cmnd * SCpnt)
 	int this_count = SCpnt->bufflen >> 9;
 	int good_sectors = (result == 0 ? this_count : 0);
 	int block_sectors = 0;
-	int device_nr = DEVICE_NR(SCpnt->request.rq_dev);
+	int device_nr = DEVICE_NR(SCpnt->request->rq_dev);
 	Scsi_CD *SCp = &scsi_CDs[device_nr];
 
 #ifdef DEBUG
-	printk("sr.c done: %x %p\n", result, SCpnt->request.bh->b_data);
+	printk("sr.c done: %x %p\n", result, SCpnt->request->bh->b_data);
 #endif
 	/*
 	   Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial success.
@@ -219,14 +219,14 @@ static void rw_intr(Scsi_Cmnd * SCpnt)
 		(SCpnt->sense_buffer[4] << 16) |
 		(SCpnt->sense_buffer[5] << 8) |
 		SCpnt->sense_buffer[6];
-		if (SCpnt->request.bio != NULL)
-			block_sectors = bio_sectors(SCpnt->request.bio);
+		if (SCpnt->request->bio != NULL)
+			block_sectors = bio_sectors(SCpnt->request->bio);
 		if (block_sectors < 4)
 			block_sectors = 4;
 		if (SCp->device->sector_size == 2048)
 			error_sector <<= 2;
 		error_sector &= ~(block_sectors - 1);
-		good_sectors = error_sector - SCpnt->request.sector;
+		good_sectors = error_sector - SCpnt->request->sector;
 		if (good_sectors < 0 || good_sectors >= this_count)
 			good_sectors = 0;
 		/*
@@ -266,14 +266,14 @@ static int sr_init_command(Scsi_Cmnd * SCpnt)
 	int dev, devm, block=0, this_count, s_size;
 	Scsi_CD *SCp;
 
-	devm = minor(SCpnt->request.rq_dev);
-	dev = DEVICE_NR(SCpnt->request.rq_dev);
+	devm = minor(SCpnt->request->rq_dev);
+	dev = DEVICE_NR(SCpnt->request->rq_dev);
 	SCp = &scsi_CDs[dev];
 
 	SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %d, block = %d\n", devm, block));
 
 	if (dev >= sr_template.nr_dev || !SCp->device || !SCp->device->online) {
-		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", SCpnt->request.nr_sectors));
+		SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n", SCpnt->request->nr_sectors));
 		SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
 		return 0;
 	}
@@ -286,8 +286,8 @@ static int sr_init_command(Scsi_Cmnd * SCpnt)
 		return 0;
 	}
 
-	if (!(SCpnt->request.flags & REQ_CMD)) {
-		blk_dump_rq_flags(&SCpnt->request, "sr unsup command");
+	if (!(SCpnt->request->flags & REQ_CMD)) {
+		blk_dump_rq_flags(SCpnt->request, "sr unsup command");
 		return 0;
 	}
 
@@ -308,23 +308,23 @@ static int sr_init_command(Scsi_Cmnd * SCpnt)
 		return 0;
 	}
 
-	if (rq_data_dir(&SCpnt->request) == WRITE) {
+	if (rq_data_dir(SCpnt->request) == WRITE) {
 		if (!SCp->device->writeable)
 			return 0;
 		SCpnt->cmnd[0] = WRITE_10;
 		SCpnt->sc_data_direction = SCSI_DATA_WRITE;
-	} else if (rq_data_dir(&SCpnt->request) == READ) {
+	} else if (rq_data_dir(SCpnt->request) == READ) {
 		SCpnt->cmnd[0] = READ_10;
 		SCpnt->sc_data_direction = SCSI_DATA_READ;
 	} else {
-		blk_dump_rq_flags(&SCpnt->request, "Unknown sr command");
+		blk_dump_rq_flags(SCpnt->request, "Unknown sr command");
 		return 0;
 	}
 
 	/*
 	 * request doesn't start on hw block boundary, add scatter pads
 	 */
-	if ((SCpnt->request.sector % (s_size >> 9)) || (SCpnt->request_bufflen % s_size)) {
+	if ((SCpnt->request->sector % (s_size >> 9)) || (SCpnt->request_bufflen % s_size)) {
 		printk("sr: unaligned transfer\n");
 		return 0;
 	}
@@ -334,13 +334,13 @@ static int sr_init_command(Scsi_Cmnd * SCpnt)
 
 	SCSI_LOG_HLQUEUE(2, printk("sr%d : %s %d/%ld 512 byte blocks.\n",
                                    devm,
-		   (rq_data_dir(&SCpnt->request) == WRITE) ? "writing" : "reading",
-				 this_count, SCpnt->request.nr_sectors));
+		   (rq_data_dir(SCpnt->request) == WRITE) ? "writing" : "reading",
+				 this_count, SCpnt->request->nr_sectors));
 
 	SCpnt->cmnd[1] = (SCpnt->device->scsi_level <= SCSI_2) ?
 			 ((SCpnt->lun << 5) & 0xe0) : 0;
 
-	block = SCpnt->request.sector / (s_size >> 9);
+	block = SCpnt->request->sector / (s_size >> 9);
 
 	if (this_count > 0xffff)
 		this_count = 0xffff;
@@ -496,7 +496,7 @@ void get_sectorsize(int i)
 		cmd[1] = (SCp->device->scsi_level <= SCSI_2) ?
 			 ((SCp->device->lun << 5) & 0xe0) : 0;
 		memset((void *) &cmd[2], 0, 8);
-		SRpnt->sr_request.rq_status = RQ_SCSI_BUSY;	/* Mark as really busy */
+		SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;	/* Mark as really busy */
 		SRpnt->sr_cmd_len = 0;
 
 		memset(buffer, 0, 8);
diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c
index ebf2474d7067..85ba7a66a237 100644
--- a/drivers/scsi/sr_ioctl.c
+++ b/drivers/scsi/sr_ioctl.c
@@ -93,7 +93,7 @@ int sr_do_ioctl(int target, unsigned char *sr_cmd, void *buffer, unsigned buflen
 	SRpnt->sr_data_direction = readwrite;
 
 	/* use ISA DMA buffer if necessary */
-	SRpnt->sr_request.buffer = buffer;
+	SRpnt->sr_request->buffer = buffer;
 	if (buffer && SRpnt->sr_host->unchecked_isa_dma &&
 	    (virt_to_phys(buffer) + buflength - 1 > ISA_DMA_THRESHOLD)) {
 		bounce_buffer = (char *) kmalloc(buflength, GFP_DMA);
@@ -112,7 +112,7 @@ int sr_do_ioctl(int target, unsigned char *sr_cmd, void *buffer, unsigned buflen
 	scsi_wait_req(SRpnt, (void *) sr_cmd, (void *) buffer, buflength,
 		      IOCTL_TIMEOUT, IOCTL_RETRIES);
 
-	req = &SRpnt->sr_request;
+	req = SRpnt->sr_request;
 	if (SRpnt->sr_buffer && req->buffer && SRpnt->sr_buffer != req->buffer) {
 		memcpy(req->buffer, SRpnt->sr_buffer, SRpnt->sr_bufflen);
 		kfree(SRpnt->sr_buffer);
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 7342c3e661f3..087aa6f3fe48 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -229,7 +229,7 @@ static int st_chk_result(Scsi_Tape *STp, Scsi_Request * SRpnt)
 		scode = 0;
 	}
 
-	dev = TAPE_NR(SRpnt->sr_request.rq_dev);
+	dev = TAPE_NR(SRpnt->sr_request->rq_dev);
         DEB(
         if (debugging) {
                 printk(ST_DEB_MSG "st%d: Error: %x, cmd: %x %x %x %x %x %x Len: %d\n",
@@ -306,7 +306,7 @@ static void st_sleep_done(Scsi_Cmnd * SCpnt)
 	int remainder;
 	Scsi_Tape *STp;
 
-	st_nbr = TAPE_NR(SCpnt->request.rq_dev);
+	st_nbr = TAPE_NR(SCpnt->request->rq_dev);
 	read_lock(&st_dev_arr_lock);
 	STp = scsi_tapes[st_nbr];
 	read_unlock(&st_dev_arr_lock);
@@ -328,11 +328,11 @@ static void st_sleep_done(Scsi_Cmnd * SCpnt)
 			(STp->buffer)->midlevel_result = INT_MAX;	/* OK */
 	} else
 		(STp->buffer)->midlevel_result = SCpnt->result;
-	SCpnt->request.rq_status = RQ_SCSI_DONE;
+	SCpnt->request->rq_status = RQ_SCSI_DONE;
 	(STp->buffer)->last_SRpnt = SCpnt->sc_request;
 	DEB( STp->write_pending = 0; )
 
-	complete(SCpnt->request.waiting);
+	complete(SCpnt->request->waiting);
 }
 
 
@@ -371,16 +371,16 @@ static Scsi_Request *
 		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_dev = STp->devt;
+	SRpnt->sr_request->waiting = &(STp->wait);
+	SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
+	SRpnt->sr_request->rq_dev = STp->devt;
 
 	scsi_do_req(SRpnt, (void *) cmd, bp, bytes,
 		    st_sleep_done, timeout, retries);
 
 	if (do_wait) {
-		wait_for_completion(SRpnt->sr_request.waiting);
-		SRpnt->sr_request.waiting = NULL;
+		wait_for_completion(SRpnt->sr_request->waiting);
+		SRpnt->sr_request->waiting = NULL;
 		(STp->buffer)->syscall_result = st_chk_result(STp, SRpnt);
 	}
 	return SRpnt;
@@ -403,7 +403,7 @@ static void write_behind_check(Scsi_Tape * STp)
         ) /* end DEB */
 
 	wait_for_completion(&(STp->wait));
-	(STp->buffer)->last_SRpnt->sr_request.waiting = NULL;
+	(STp->buffer)->last_SRpnt->sr_request->waiting = NULL;
 
 	(STp->buffer)->syscall_result = st_chk_result(STp, (STp->buffer)->last_SRpnt);
 	scsi_release_request((STp->buffer)->last_SRpnt);
diff --git a/drivers/scsi/sun3_NCR5380.c b/drivers/scsi/sun3_NCR5380.c
index 88ecf5d92a56..b4d0903a79a9 100644
--- a/drivers/scsi/sun3_NCR5380.c
+++ b/drivers/scsi/sun3_NCR5380.c
@@ -1217,7 +1217,7 @@ static void NCR5380_dma_complete( struct Scsi_Host *instance )
 	       HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
 	       NCR5380_read(STATUS_REG));
 
-    if((sun3scsi_dma_finish(hostdata->connected->request.cmd))) {
+    if((sun3scsi_dma_finish(hostdata->connected->request->cmd))) {
 	    printk("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n", HOSTNO);
 	    printk("please e-mail sammy@oh.verio.com with a description of how this\n");
 	    printk("error was produced.\n");
@@ -2016,9 +2016,9 @@ static void NCR5380_information_transfer (struct Scsi_Host *instance)
 		if((count > SUN3_DMA_MINSIZE) && (sun3_dma_setup_done
 						  != cmd))
 		{
-			if((cmd->request.cmd == 0) || (cmd->request.cmd == 1)) {
+			if((cmd->request->cmd == 0) || (cmd->request->cmd == 1)) {
 				sun3scsi_dma_setup(d, count,
-						   cmd->request.cmd);
+						   cmd->request->cmd);
 				sun3_dma_setup_done = cmd;
 			}
 		}
@@ -2628,7 +2628,7 @@ static void NCR5380_reselect (struct Scsi_Host *instance)
 						  != tmp))
 		{
 			sun3scsi_dma_setup(d, count,
-					   tmp->request.cmd);
+					   tmp->request->cmd);
 			sun3_dma_setup_done = tmp;
 		}
 #endif
diff --git a/drivers/scsi/sun3_scsi.c b/drivers/scsi/sun3_scsi.c
index 3eae7cee2490..457a5518b34e 100644
--- a/drivers/scsi/sun3_scsi.c
+++ b/drivers/scsi/sun3_scsi.c
@@ -518,7 +518,7 @@ static inline unsigned long sun3scsi_dma_residual(struct Scsi_Host *instance)
 static inline unsigned long sun3scsi_dma_xfer_len(unsigned long wanted, Scsi_Cmnd *cmd,
 				    int write_flag)
 {
-	if((cmd->request.cmd == 0) || (cmd->request.cmd == 1))
+	if((cmd->request->cmd == 0) || (cmd->request->cmd == 1))
  		return wanted;
 	else
 		return 0;
diff --git a/drivers/scsi/u14-34f.c b/drivers/scsi/u14-34f.c
index 5ae088c86547..6de097b8368b 100644
--- a/drivers/scsi/u14-34f.c
+++ b/drivers/scsi/u14-34f.c
@@ -1206,7 +1206,7 @@ static inline int do_qcomm(Scsi_Cmnd *SCpnt, void (*done)(Scsi_Cmnd *)) {
    if (linked_comm && SCpnt->device->queue_depth > 2
                                      && TLDEV(SCpnt->device->type)) {
       HD(j)->cp_stat[i] = READY;
-      flush_dev(SCpnt->device, SCpnt->request.sector, j, FALSE);
+      flush_dev(SCpnt->device, SCpnt->request->sector, j, FALSE);
       return 0;
       }
 
@@ -1529,11 +1529,11 @@ static inline int reorder(unsigned int j, unsigned long cursec,
 
       if (!(cpp->xdir == DTD_IN)) input_only = FALSE;
 
-      if (SCpnt->request.sector < minsec) minsec = SCpnt->request.sector;
-      if (SCpnt->request.sector > maxsec) maxsec = SCpnt->request.sector;
+      if (SCpnt->request->sector < minsec) minsec = SCpnt->request->sector;
+      if (SCpnt->request->sector > maxsec) maxsec = SCpnt->request->sector;
 
-      sl[n] = SCpnt->request.sector;
-      ioseek += SCpnt->request.nr_sectors;
+      sl[n] = SCpnt->request->sector;
+      ioseek += SCpnt->request->nr_sectors;
 
       if (!n) continue;
 
@@ -1561,7 +1561,7 @@ static inline int reorder(unsigned int j, unsigned long cursec,
 
    if (!input_only) for (n = 0; n < n_ready; n++) {
       k = il[n]; cpp = &HD(j)->cp[k]; SCpnt = cpp->SCpnt;
-      ll[n] = SCpnt->request.nr_sectors; pl[n] = SCpnt->pid;
+      ll[n] = SCpnt->request->nr_sectors; pl[n] = SCpnt->pid;
 
       if (!n) continue;
 
@@ -1589,7 +1589,7 @@ static inline int reorder(unsigned int j, unsigned long cursec,
                 " cur %ld s:%c r:%c rev:%c in:%c ov:%c xd %d.\n",
                 (ihdlr ? "ihdlr" : "qcomm"), SCpnt->channel, SCpnt->target,
                 SCpnt->lun, SCpnt->pid, k, flushcount, n_ready,
-                SCpnt->request.sector, SCpnt->request.nr_sectors, cursec,
+                SCpnt->request->sector, SCpnt->request->nr_sectors, cursec,
                 YESNO(s), YESNO(r), YESNO(rev), YESNO(input_only),
                 YESNO(overlap), cpp->xdir);
          }
@@ -1718,7 +1718,7 @@ static inline void ihdlr(int irq, unsigned int j) {
 
    if (linked_comm && SCpnt->device->queue_depth > 2
                                      && TLDEV(SCpnt->device->type))
-      flush_dev(SCpnt->device, SCpnt->request.sector, j, TRUE);
+      flush_dev(SCpnt->device, SCpnt->request->sector, j, TRUE);
 
    tstatus = status_byte(spp->target_status);