[PATCH] 2.5.17 IDE 66

 - Move ll_10byte_cmd_build to the only place where it's used: ide-cd.  The SCSI
   layer does have it's own implementation which additionally it's messing
   around with the hard_nr_sectors struct request value.  One should *not*
   provide "infrastructure" until its really used as such.

   If anywhere this should reside in a file called ATAPI.

 - Unfold the INIT_REQUEST macro from blk.h. This showed up plenty of duplicate
   checks for QUEUE_EMPTY. Clean them as well. Remove the over cautious
   major(CURRENT->rq_dev != MAJOR_NR) checks. During the last several years I
   never saw any report about it. Looking at the !CURRENT->bio it is clear that
   dereferencing NULL will provide the same kind of panic as the check.  Some
   comments around the code in question show nicely that indeed INIT_REQUEST
   was a good example of code obfuscation.

 - A short look at RQ_INACTIVE shows that it is only used inside the scsi.c file
   and during the removal of devices. This shows that the many checks for
   RQ_INACTIVE are not necessary. Looking closer even shows that some of them
   did happen before checks for an empty queue. Plenty of drivers didn't care
   about it and the CD-ROM ones should be handled properly, because the
   most common drivers would fail as well. Comments indicate that this
   was an leftover from 1.3 days...

arch/m68k/atari/stram.c

@@ -984,7 +984,10 @@ static void do_stram_request(request_queue_t *q)
 	unsigned long len;
 
 	while (1) {
-		INIT_REQUEST;
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
+			return;
+		}
 
 		start = swap_start + (CURRENT->sector << 9);
 		len   = CURRENT->current_nr_sectors << 9;

drivers/acorn/block/mfmhd.c

@@ -889,17 +889,6 @@ static void mfm_request(void)
 {
 	DBG("mfm_request CURRENT=%p Busy=%d\n", CURRENT, Busy);
 
-	if (QUEUE_EMPTY) {
-		DBG("mfm_request: Exited due to NULL Current 1\n");
-		return;
-	}
-
-	if (CURRENT->rq_status == RQ_INACTIVE) {
-		/* Hmm - seems to be happening a lot on 1.3.45 */
-		/*console_printf("mfm_request: Exited due to INACTIVE Current\n"); */
-		return;
-	}
-
 	/* If we are still processing then return; we will get called again */
 	if (Busy) {
 		/* Again seems to be common in 1.3.45 */
@@ -914,16 +903,14 @@ static void mfm_request(void)
 		DBG("mfm_request: loop start\n");
 		sti();
 
-		DBG("mfm_request: before INIT_REQUEST\n");
+		DBG("mfm_request: before blk_queue_empty\n");
 
-		if (QUEUE_EMPTY) {
-			printk("mfm_request: Exiting due to !CURRENT (pre)\n");
+		if (blk_queue_empty(QUEUE)) {
+			printk("mfm_request: Exiting due to empty queue (pre)\n");
 			CLEAR_INTR;
 			Busy = 0;
 			return;
-		};
-
-		INIT_REQUEST;
+		}
 
 		DBG("mfm_request:                 before arg extraction\n");
 

drivers/block/ll_rw_blk.c

@@ -523,42 +523,6 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
 	printk("\n");
 }
 
-/*
- * standard prep_rq_fn that builds 10 byte cmds
- */
-int ll_10byte_cmd_build(request_queue_t *q, struct request *rq)
-{
-	int hard_sect = queue_hardsect_size(q);
-	sector_t block = rq->hard_sector / (hard_sect >> 9);
-	unsigned long blocks = rq->hard_nr_sectors / (hard_sect >> 9);
-
-	if (!(rq->flags & REQ_CMD))
-		return 0;
-
-	memset(rq->cmd, 0, sizeof(rq->cmd));
-
-	if (rq_data_dir(rq) == READ)
-		rq->cmd[0] = READ_10;
-	else 
-		rq->cmd[0] = WRITE_10;
-
-	/*
-	 * fill in lba
-	 */
-	rq->cmd[2] = (block >> 24) & 0xff;
-	rq->cmd[3] = (block >> 16) & 0xff;
-	rq->cmd[4] = (block >>  8) & 0xff;
-	rq->cmd[5] = block & 0xff;
-
-	/*
-	 * and transfer length
-	 */
-	rq->cmd[7] = (blocks >> 8) & 0xff;
-	rq->cmd[8] = blocks & 0xff;
-
-	return 0;
-}
-
 void blk_recount_segments(request_queue_t *q, struct bio *bio)
 {
 	struct bio_vec *bv, *bvprv = NULL;
@@ -1765,9 +1729,8 @@ inline void blk_recalc_rq_sectors(struct request *rq, int nsect)
 {
 	if (rq->flags & REQ_CMD) {
 		rq->hard_sector += nsect;
-		rq->hard_nr_sectors -= nsect;
+		rq->nr_sectors = rq->hard_nr_sectors -= nsect;
 		rq->sector = rq->hard_sector;
-		rq->nr_sectors = rq->hard_nr_sectors;
 
 		rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
 		rq->hard_cur_sectors = rq->current_nr_sectors;
@@ -1944,7 +1907,6 @@ EXPORT_SYMBOL(blk_queue_assign_lock);
 EXPORT_SYMBOL(blk_phys_contig_segment);
 EXPORT_SYMBOL(blk_hw_contig_segment);
 
-EXPORT_SYMBOL(ll_10byte_cmd_build);
 EXPORT_SYMBOL(blk_queue_prep_rq);
 
 EXPORT_SYMBOL(blk_queue_init_tags);

drivers/block/paride/pcd.c

@@ -760,8 +760,11 @@ static void do_pcd_request (request_queue_t * q)
 
 	if (pcd_busy) return;
         while (1) {
-	    if (QUEUE_EMPTY || (CURRENT->rq_status == RQ_INACTIVE)) return;
-	    INIT_REQUEST;
+	    if (blk_queue_empty(QUEUE)) {
+		    CLEAR_INTR;
+		    return;
+	    }
+
 	    if (rq_data_dir(CURRENT) == READ) {
 		unit = minor(CURRENT->rq_dev);
 		if (unit != pcd_unit) {

drivers/block/paride/pd.c

@@ -835,8 +835,10 @@ static void do_pd_request (request_queue_t * q)
 
         if (pd_busy) return;
 repeat:
-        if (QUEUE_EMPTY || (CURRENT->rq_status == RQ_INACTIVE)) return;
-        INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
 
         pd_dev = minor(CURRENT->rq_dev);
 	pd_unit = unit = DEVICE_NR(CURRENT->rq_dev);

drivers/block/paride/pf.c

@@ -841,8 +841,10 @@ static void do_pf_request (request_queue_t * q)
 
         if (pf_busy) return;
 repeat:
-        if (QUEUE_EMPTY || (CURRENT->rq_status == RQ_INACTIVE)) return;
-        INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
 
         pf_unit = unit = DEVICE_NR(CURRENT->rq_dev);
         pf_block = CURRENT->sector;

drivers/block/ps2esdi.c

@@ -471,9 +471,12 @@ static void do_ps2esdi_request(request_queue_t * q)
 	       CURRENT->current_nr_sectors, CURRENT->buffer);
 #endif
 
-	/* standard macro that ensures that requests are really on the
+	/* standard procedure to ensure that requests are really on the
 	   list + sanity checks.                     */
-	INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
 
 	if (isa_virt_to_bus(CURRENT->buffer + CURRENT->current_nr_sectors * 512) > 16 * MB) {
 		printk("%s: DMA above 16MB not supported\n", DEVICE_NAME);

drivers/block/xd.c

@@ -279,8 +279,13 @@ static void do_xd_request (request_queue_t * q)
 	sti();
 	if (xdc_busy)
 		return;
-	while (code = 0, !QUEUE_EMPTY) {
-		INIT_REQUEST;	/* do some checking on the request structure */
+	while (1) {
+		code = 0;
+		/* do some checking on the request structure */
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
+			return;
+		}
 
 		if (CURRENT_DEV < xd_drives
 		    && (CURRENT->flags & REQ_CMD)

drivers/block/z2ram.c

@@ -76,7 +76,10 @@ do_z2_request( request_queue_t * q )
 
     while ( TRUE )
     {
-	INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
 
 	start = CURRENT->sector << 9;
 	len  = CURRENT->current_nr_sectors << 9;

drivers/cdrom/cdu31a.c

@@ -1598,7 +1598,8 @@ static void do_cdu31a_request(request_queue_t * q)
 		 * The beginning here is stolen from the hard disk driver.  I hope
 		 * it's right.
 		 */
-		if (QUEUE_EMPTY || CURRENT->rq_status == RQ_INACTIVE) {
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
 			goto end_do_cdu31a_request;
 		}
 
@@ -1606,8 +1607,6 @@ static void do_cdu31a_request(request_queue_t * q)
 			scd_spinup();
 		}
 
-		INIT_REQUEST;
-
 		block = CURRENT->sector;
 		nblock = CURRENT->nr_sectors;
 

drivers/cdrom/cm206.c

@@ -856,9 +856,11 @@ static void do_cm206_request(request_queue_t * q)
 	uch *source, *dest;
 
 	while (1) {		/* repeat until all requests have been satisfied */
-		INIT_REQUEST;
-		if (QUEUE_EMPTY || CURRENT->rq_status == RQ_INACTIVE)
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
 			return;
+		}
+
 		if (CURRENT->cmd != READ) {
 			debug(("Non-read command %d on cdrom\n",
 			       CURRENT->cmd));

drivers/cdrom/gscd.c

@@ -279,9 +279,11 @@ static void __do_gscd_request(unsigned long dummy)
 	unsigned int nsect;
 
       repeat:
-	if (QUEUE_EMPTY || CURRENT->rq_status == RQ_INACTIVE)
-		goto out;
-	INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
+
 	dev = minor(CURRENT->rq_dev);
 	block = CURRENT->sector;
 	nsect = CURRENT->nr_sectors;

drivers/cdrom/mcdx.c

@@ -562,19 +562,11 @@ void do_mcdx_request(request_queue_t * q)
 
       again:
 
-	if (QUEUE_EMPTY) {
-		xtrace(REQUEST, "end_request(0): CURRENT == NULL\n");
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
 		return;
 	}
 
-	if (CURRENT->rq_status == RQ_INACTIVE) {
-		xtrace(REQUEST,
-		       "end_request(0): rq_status == RQ_INACTIVE\n");
-		return;
-	}
-
-	INIT_REQUEST;
-
 	dev = minor(CURRENT->rq_dev);
 	stuffp = mcdx_stuffp[dev];
 

drivers/cdrom/sbpcd.c

@@ -4915,12 +4915,15 @@ static void DO_SBPCD_REQUEST(request_queue_t * q)
 	printk(" do_sbpcd_request[%di](%p:%ld+%ld), Pid:%d, Time:%li\n",
 		xnr, CURRENT, CURRENT->sector, CURRENT->nr_sectors, current->pid, jiffies);
 #endif
-	INIT_REQUEST;
+
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
+
 	req=CURRENT;		/* take out our request so no other */
 	blkdev_dequeue_request(req);	/* task can fuck it up         GTL  */
 
-	if (req->rq_status == RQ_INACTIVE)
-		sbpcd_end_request(req, 0);
 	if (req -> sector == -1)
 		sbpcd_end_request(req, 0);
 	spin_unlock_irq(q->queue_lock);

drivers/cdrom/sonycd535.c

@@ -806,10 +806,11 @@ do_cdu535_request(request_queue_t * q)
 		 * The beginning here is stolen from the hard disk driver.  I hope
 		 * it's right.
 		 */
-		if (QUEUE_EMPTY || CURRENT->rq_status == RQ_INACTIVE) {
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
 			return;
 		}
-		INIT_REQUEST;
+
 		dev = minor(CURRENT->rq_dev);
 		block = CURRENT->sector;
 		nsect = CURRENT->nr_sectors;

drivers/ide/hd.c

@@ -544,13 +544,17 @@ static void hd_request(void)
 {
 	unsigned int dev, block, nsect, sec, track, head, cyl;
 
-	if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE) return;
 	if (DEVICE_INTR)
 		return;
 repeat:
 	del_timer(&device_timer);
 	sti();
-	INIT_REQUEST;
+
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
+
 	if (reset) {
 		cli();
 		reset_hd();

drivers/ide/ide-cd.c

@@ -2658,6 +2658,47 @@ int ide_cdrom_probe_capabilities(struct ata_device *drive)
 	return nslots;
 }
 
+
+/*
+ * standard prep_rq_fn that builds 10 byte cmds
+ */
+static int ll_10byte_cmd_build(request_queue_t *q, struct request *rq)
+{
+	int hard_sect = queue_hardsect_size(q);
+	sector_t block = rq->hard_sector / (hard_sect >> 9);
+	unsigned long blocks = rq->hard_nr_sectors / (hard_sect >> 9);
+
+	if (!(rq->flags & REQ_CMD))
+		return 0;
+
+	if (rq->hard_nr_sectors != rq->nr_sectors) {
+		printk(KERN_ERR "ide-cd: hard_nr_sectors differs from nr_sectors! %lu %lu\n",
+				rq->nr_sectors, rq->hard_nr_sectors);
+	}
+	memset(rq->cmd, 0, sizeof(rq->cmd));
+
+	if (rq_data_dir(rq) == READ)
+		rq->cmd[0] = GPCMD_READ_10;
+	else
+		rq->cmd[0] = GPCMD_WRITE_10;
+
+	/*
+	 * fill in lba
+	 */
+	rq->cmd[2] = (block >> 24) & 0xff;
+	rq->cmd[3] = (block >> 16) & 0xff;
+	rq->cmd[4] = (block >>  8) & 0xff;
+	rq->cmd[5] = block & 0xff;
+
+	/*
+	 * and transfer length
+	 */
+	rq->cmd[7] = (blocks >> 8) & 0xff;
+	rq->cmd[8] = blocks & 0xff;
+
+	return 0;
+}
+
 static int ide_cdrom_setup(struct ata_device *drive)
 {
 	struct cdrom_info *info = drive->driver_data;

drivers/mtd/ftl.c

@@ -1192,7 +1192,10 @@ static void do_ftl_request(request_arg_t)
 
     do {
 	//	    sti();
-	INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
 
 	minor = minor(CURRENT->rq_dev);
 

drivers/mtd/mtdblock.c

@@ -405,7 +405,11 @@ static void handle_mtdblock_request(void)
 	unsigned int res;
 
 	for (;;) {
-		INIT_REQUEST;
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
+			return;
+		}
+
 		req = CURRENT;
 		spin_unlock_irq(QUEUE->queue_lock);
 		mtdblk = mtdblks[minor(req->rq_dev)];

drivers/mtd/mtdblock_ro.c

@@ -112,9 +112,13 @@ static void mtdblock_request(RQFUNC_ARG)
 
    while (1)
    {
-      /* Grab the Request and unlink it from the request list, INIT_REQUEST
+      /* Grab the Request and unlink it from the request list, we
 	 will execute a return if we are done. */
-      INIT_REQUEST;
+	if (blk_queue_empty(QUEUE)) {
+		CLEAR_INTR;
+		return;
+	}
+
       current_request = CURRENT;
 
       if (minor(current_request->rq_dev) >= MAX_MTD_DEVICES)

drivers/mtd/nftlcore.c

@@ -837,7 +837,11 @@ void nftl_request(RQFUNC_ARG)
 	int res;
 
 	while (1) {
-		INIT_REQUEST;	/* blk.h */
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
+			return;
+		}
+
 		req = CURRENT;
 		
 		/* We can do this because the generic code knows not to

drivers/s390/block/xpram.c

@@ -747,7 +747,10 @@ void xpram_request(request_queue_t * queue)
 #endif /* V24 */
 
 	while(1) {
-		INIT_REQUEST;
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
+			return;
+		}
 
 		fault=0;
 #if ( XPRAM_VERSION == 24 )

drivers/sbus/char/jsflash.c

@@ -207,7 +207,11 @@ static void jsfd_do_request(request_queue_t *q)
 	size_t len;
 
 	for (;;) {
-		INIT_REQUEST;	/* if (QUEUE_EMPTY) return; */
+		if (blk_queue_empty(QUEUE)) {
+			CLEAR_INTR;
+			return;
+		}
+
 		req = CURRENT;
 
 		dev = MINOR(req->rq_dev);

include/linux/blk.h

@@ -313,22 +313,11 @@ static void (*DEVICE_INTR)(void) = NULL;
 
 #define SET_INTR(x) (DEVICE_INTR = (x))
 
-#ifdef DEVICE_INTR
-#define CLEAR_INTR SET_INTR(NULL)
-#else
-#define CLEAR_INTR
-#endif
-
-#define INIT_REQUEST						\
-	if (QUEUE_EMPTY) {					\
-		CLEAR_INTR;					\
-		return;						\
-	}							\
-	if (major(CURRENT->rq_dev) != MAJOR_NR) 			\
-		panic(DEVICE_NAME ": request list destroyed");	\
-	if (!CURRENT->bio)					\
-		panic(DEVICE_NAME ": no bio");			\
-
+# ifdef DEVICE_INTR
+#  define CLEAR_INTR SET_INTR(NULL)
+# else
+#  define CLEAR_INTR
+# endif
 #endif /* !defined(IDE_DRIVER) */
 
 /*

include/linux/blkdev.h

@@ -303,7 +303,6 @@ extern void blk_recount_segments(request_queue_t *, struct bio *);
 extern inline int blk_phys_contig_segment(request_queue_t *q, struct bio *, struct bio *);
 extern inline int blk_hw_contig_segment(request_queue_t *q, struct bio *, struct bio *);
 extern int block_ioctl(struct block_device *, unsigned int, unsigned long);
-extern int ll_10byte_cmd_build(request_queue_t *, struct request *);
 
 /*
  * get ready for proper ref counting