[PATCH] disk->minor_shift cleanup

	new field - disk->minors (1 << disk->minor_shift).  Almost all uses
of ->minor_shift had that form and thus had been replaced.

drivers/block/acsi.c

@@ -1739,7 +1739,10 @@ int acsi_init( void )
 		sprintf(disk->disk_name, "ad%c", 'a'+i);
 		disk->major = MAJOR_NR;
 		disk->first_minor = i << 4;
-		disk->minor_shift = (acsi_info[i].type==HARDDISK)?4:0;
+		if (acsi_info[i].type != HARDDISK) {
+			disk->minor_shift = 0;
+			disk->minors = 1;
+		}
 		disk->fops = &acsi_fops;
 		set_capacity(disk, acsi_info[i].size);
 		add_disk(disk);

drivers/block/blkpg.c

@@ -97,7 +97,7 @@ int add_partition(struct block_device *bdev, struct blkpg_partition *p)
 		return -EINVAL;
 	if (part)
 		BUG();
-	if (p->pno <= 0 || p->pno >= (1 << g->minor_shift))
+	if (p->pno <= 0 || p->pno >= g->minors)
 		return -EINVAL;
 
 	/* partition number in use? */
@@ -105,7 +105,7 @@ int add_partition(struct block_device *bdev, struct blkpg_partition *p)
 		return -EBUSY;
 
 	/* overlap? */
-	for (i = 0; i < (1<<g->minor_shift) - 1; i++)
+	for (i = 0; i < g->minors - 1; i++)
 		if (!(ppstart+pplength <= g->part[i].start_sect ||
 		      ppstart >= g->part[i].start_sect + g->part[i].nr_sects))
 			return -EBUSY;
@@ -142,7 +142,7 @@ int del_partition(struct block_device *bdev, struct blkpg_partition *p)
 		return -EINVAL;
 	if (part)
 		BUG();
-	if (p->pno <= 0 || p->pno >= (1 << g->minor_shift))
+	if (p->pno <= 0 || p->pno >= g->minors)
   		return -EINVAL;
 
 	/* existing drive and partition? */

drivers/block/genhd.c

@@ -61,7 +61,7 @@ void add_disk(struct gendisk *disk)
 {
 	write_lock(&gendisk_lock);
 	list_add(&disk->list, &gendisks[disk->major].list);
-	if (disk->minor_shift)
+	if (disk->minors > 1)
 		list_add_tail(&disk->full_list, &gendisk_list);
 	else
 		INIT_LIST_HEAD(&disk->full_list);
@@ -107,7 +107,7 @@ get_gendisk(dev_t dev, int *part)
 		disk = list_entry(p, struct gendisk, list);
 		if (disk->first_minor > minor)
 			continue;
-		if (disk->first_minor + (1<<disk->minor_shift) <= minor)
+		if (disk->first_minor + disk->minors <= minor)
 			continue;
 		read_unlock(&gendisk_lock);
 		*part = minor - disk->first_minor;
@@ -163,7 +163,7 @@ static int show_partition(struct seq_file *part, void *v)
 		sgp->major, sgp->first_minor,
 		(unsigned long long)get_capacity(sgp) >> 1,
 		disk_name(sgp, 0, buf));
-	for (n = 0; n < (1<<sgp->minor_shift) - 1; n++) {
+	for (n = 0; n < sgp->minors - 1; n++) {
 		if (sgp->part[n].nr_sects == 0)
 			continue;
 		seq_printf(part, "%4d  %4d %10llu %s\n",

drivers/ide/ide-cd.c

@@ -3193,6 +3193,7 @@ static int ide_cdrom_attach (ide_drive_t *drive)
 	memset(info, 0, sizeof (struct cdrom_info));
 	drive->driver_data = info;
 	DRIVER(drive)->busy++;
+	g->minors = 1;
 	g->minor_shift = 0;
 	g->de = drive->de;
 	g->flags = GENHD_FL_CD;

drivers/ide/ide-disk.c

@@ -1871,6 +1871,7 @@ static int idedisk_attach(ide_drive_t *drive)
 		goto failed;
 	}
 	DRIVER(drive)->busy--;
+	g->minors = 1 << PARTN_BITS;
 	g->minor_shift = PARTN_BITS;
 	g->de = drive->de;
 	g->flags = drive->removable ? GENHD_FL_REMOVABLE : 0;

drivers/ide/ide-floppy.c

@@ -2108,6 +2108,7 @@ static int idefloppy_attach (ide_drive_t *drive)
 	DRIVER(drive)->busy++;
 	idefloppy_setup (drive, floppy);
 	DRIVER(drive)->busy--;
+	g->minors = 1 << PARTN_BITS;
 	g->minor_shift = PARTN_BITS;
 	g->de = drive->de;
 	g->flags = drive->removable ? GENHD_FL_REMOVABLE : 0;

fs/block_dev.c

@@ -540,7 +540,7 @@ int check_disk_change(struct block_device *bdev)
 	disk = get_gendisk(bdev->bd_dev, &part);
 	if (bdops->revalidate)
 		bdops->revalidate(dev);
-	if (disk && disk->minor_shift)
+	if (disk && disk->minors > 1)
 		bdev->bd_invalidated = 1;
 	return 1;
 }
@@ -799,7 +799,7 @@ static int blkdev_reread_part(struct block_device *bdev)
 	struct gendisk *disk = get_gendisk(bdev->bd_dev, &part);
 	int res = 0;
 
-	if (!disk || !disk->minor_shift || bdev != bdev->bd_contains)
+	if (!disk || disk->minors == 1 || bdev != bdev->bd_contains)
 		return -EINVAL;
 	if (part)
 		BUG();

fs/partitions/check.c

@@ -130,7 +130,7 @@ static DEVICE_ATTR(type,S_IRUGO,partition_device_type_read,NULL);
 
 static void driverfs_create_partitions(struct gendisk *hd)
 {
-	int max_p = 1<<hd->minor_shift;
+	int max_p = hd->minors;
 	struct hd_struct *p = hd->part;
 	char name[DEVICE_NAME_SIZE];
 	char bus_id[BUS_ID_SIZE];
@@ -187,7 +187,7 @@ static void driverfs_create_partitions(struct gendisk *hd)
 
 static void driverfs_remove_partitions(struct gendisk *hd)
 {
-	int max_p = 1<<hd->minor_shift;
+	int max_p = hd->minors;
 	struct device *dev;
 	struct hd_struct *p;
 	int part;
@@ -233,7 +233,7 @@ static void check_partition(struct gendisk *hd, struct block_device *bdev)
 		if (isdigit(state->name[strlen(state->name)-1]))
 			sprintf(state->name, "p");
 	}
-	state->limit = 1<<hd->minor_shift;
+	state->limit = hd->minors;
 	for (i = 0; check_part[i]; i++) {
 		int res, j;
 		struct hd_struct *p;
@@ -298,7 +298,7 @@ static void devfs_create_partitions(struct gendisk *dev)
 	unsigned int devfs_flags = DEVFS_FL_DEFAULT;
 	char dirname[64], symlink[16];
 	static devfs_handle_t devfs_handle;
-	int part, max_p = 1<<dev->minor_shift;
+	int part, max_p = dev->minors;
 	struct hd_struct *p = dev->part;
 
 	if (dev->flags & GENHD_FL_REMOVABLE)
@@ -380,7 +380,7 @@ static void devfs_remove_partitions(struct gendisk *dev)
 {
 #ifdef CONFIG_DEVFS_FS
 	int part;
-	for (part = (1<<dev->minor_shift)-1; part--; ) {
+	for (part = dev->minors-1; part--; ) {
 		devfs_unregister(dev->part[part].de);
 		dev->part[part].de = NULL;
 	}
@@ -401,7 +401,7 @@ void register_disk(struct gendisk *disk)
 		devfs_create_cdrom(disk);
 
 	/* No minors to use for partitions */
-	if (!disk->minor_shift)
+	if (disk->minors == 1)
 		return;
 
 	/* No such device (e.g., media were just removed) */
@@ -458,7 +458,7 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 	if (res)
 		return res;
 	bdev->bd_invalidated = 0;
-	for (p = 0; p < (1<<disk->minor_shift) - 1; p++) {
+	for (p = 0; p < disk->minors - 1; p++) {
 		disk->part[p].start_sect = 0;
 		disk->part[p].nr_sects = 0;
 	}
@@ -466,7 +466,7 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 		bdev->bd_op->revalidate(dev);
 	if (get_capacity(disk))
 		check_partition(disk, bdev);
-	for (p = 1; p < (1<<disk->minor_shift); p++)
+	for (p = 1; p < disk->minors; p++)
 		update_partition(disk, p);
 	return res;
 }
@@ -495,7 +495,7 @@ unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
 
 static int wipe_partitions(struct gendisk *disk)
 {
-	int max_p = 1 << disk->minor_shift;
+	int max_p = disk->minors;
 	kdev_t devp;
 	int res;
 	int p;

include/linux/genhd.h

@@ -74,6 +74,7 @@ struct hd_struct {
 struct gendisk {
 	int major;			/* major number of driver */
 	int first_minor;
+	int minors;
 	int minor_shift;		/* number of times minor is shifted to
 					   get real minor */
 	char disk_name[16];		/* name of major driver */