block: move the policy field to struct block_device

Move the policy field to struct block_device and rename it to the
more descriptive bd_read_only.  Also turn the field into a bool as it
is used as such.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -696,7 +696,7 @@ static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
 {
 	const int op = bio_op(bio);
 
-	if (part->policy && op_is_write(op)) {
+	if (part->bdev->bd_read_only && op_is_write(op)) {
 		char b[BDEVNAME_SIZE];
 
 		if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))

block/genhd.c

@@ -1687,14 +1687,14 @@ void set_disk_ro(struct gendisk *disk, int flag)
 	struct disk_part_iter piter;
 	struct hd_struct *part;
 
-	if (disk->part0.policy != flag) {
+	if (disk->part0.bdev->bd_read_only != flag) {
 		set_disk_ro_uevent(disk, flag);
-		disk->part0.policy = flag;
+		disk->part0.bdev->bd_read_only = flag;
 	}
 
 	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
 	while ((part = disk_part_iter_next(&piter)))
-		part->policy = flag;
+		part->bdev->bd_read_only = flag;
 	disk_part_iter_exit(&piter);
 }
 
@@ -1704,7 +1704,7 @@ int bdev_read_only(struct block_device *bdev)
 {
 	if (!bdev)
 		return 0;
-	return bdev->bd_part->policy;
+	return bdev->bd_read_only;
 }
 
 EXPORT_SYMBOL(bdev_read_only);

block/ioctl.c

@@ -345,7 +345,7 @@ static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 		if (ret)
 			return ret;
 	}
-	bdev->bd_part->policy = n;
+	bdev->bd_read_only = n;
 	return 0;
 }
 

block/partitions/core.c

@@ -199,7 +199,7 @@ static ssize_t part_ro_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
-	return sprintf(buf, "%d\n", p->policy ? 1 : 0);
+	return sprintf(buf, "%d\n", p->bdev->bd_read_only);
 }
 
 static ssize_t part_alignment_offset_show(struct device *dev,
@@ -420,7 +420,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno,
 	bdev->bd_start_sect = start;
 	bdev_set_nr_sectors(bdev, len);
 	p->partno = partno;
-	p->policy = get_disk_ro(disk);
+	bdev->bd_read_only = get_disk_ro(disk);
 
 	if (info) {
 		err = -ENOMEM;

include/linux/blk_types.h

@@ -23,6 +23,7 @@ struct block_device {
 	sector_t		bd_start_sect;
 	struct disk_stats __percpu *bd_stats;
 	unsigned long		bd_stamp;
+	bool			bd_read_only;	/* read-only policy */
 	dev_t			bd_dev;
 	int			bd_openers;
 	struct inode *		bd_inode;	/* will die */

include/linux/genhd.h

@@ -55,7 +55,7 @@ struct hd_struct {
 
 	struct block_device *bdev;
 	struct device __dev;
-	int policy, partno;
+	int partno;
 	struct rcu_work rcu_work;
 };
 
@@ -278,7 +278,7 @@ extern void set_disk_ro(struct gendisk *disk, int flag);
 
 static inline int get_disk_ro(struct gendisk *disk)
 {
-	return disk->part0.policy;
+	return disk->part0.bdev->bd_read_only;
 }
 
 extern void disk_block_events(struct gendisk *disk);