bdev: move ->bd_read_only to ->__bd_flags

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

block/ioctl.c

@@ -402,7 +402,10 @@ static int blkdev_roset(struct block_device *bdev, unsigned cmd,
 		if (ret)
 			return ret;
 	}
-	bdev->bd_read_only = n;
+	if (n)
+		bdev_set_flag(bdev, BD_READ_ONLY);
+	else
+		bdev_clear_flag(bdev, BD_READ_ONLY);
 	return 0;
 }
 

include/linux/blk_types.h

@@ -47,7 +47,7 @@ struct block_device {
 	unsigned long		bd_stamp;
 	atomic_t		__bd_flags;	// partition number + flags
 #define BD_PARTNO		255	// lower 8 bits; assign-once
-	bool			bd_read_only;	/* read-only policy */
+#define BD_READ_ONLY		(1u<<8) // read-only policy
 	bool			bd_write_holder;
 	bool			bd_has_submit_bio;
 	dev_t			bd_dev;

include/linux/blkdev.h

@@ -742,13 +742,13 @@ static inline void bdev_clear_flag(struct block_device *bdev, unsigned flag)
 
 static inline int get_disk_ro(struct gendisk *disk)
 {
-	return disk->part0->bd_read_only ||
+	return bdev_test_flag(disk->part0, BD_READ_ONLY) ||
 		test_bit(GD_READ_ONLY, &disk->state);
 }
 
 static inline int bdev_read_only(struct block_device *bdev)
 {
-	return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
+	return bdev_test_flag(bdev, BD_READ_ONLY) || get_disk_ro(bdev->bd_disk);
 }
 
 bool set_capacity_and_notify(struct gendisk *disk, sector_t size);