> + if (partno && bdev_flagged(disk->part0, BD_FLAG_HAS_SUBMIT_BIO))
> + bdev_set_flag(bdev, BD_FLAG_HAS_SUBMIT_BIO);
> else
> + bdev_clear_flag(bdev, BD_FLAG_HAS_SUBMIT_BIO);
While the block layer has a bit of history of using wrappers for
testing, setting and clearing flags, I have to say I always find them
rather confusing when reading the code.
> +#define BD_FLAG_READ_ONLY 0 /* read-only-policy */
I know this is copied from the existing field, but can you expand
it a bit?
> +#define BD_FLAG_WRITE_HOLDER 1
> +#define BD_FLAG_HAS_SUBMIT_BIO 2
> +#define BD_FLAG_MAKE_IT_FAIL 3
And also write comments for these.
> +
> struct block_device {
> sector_t bd_start_sect;
> sector_t bd_nr_sectors;
> @@ -44,10 +49,8 @@ struct block_device {
> struct request_queue * bd_queue;
> struct disk_stats __percpu *bd_stats;
> unsigned long bd_stamp;
> - bool bd_read_only; /* read-only policy */
> + unsigned short bd_flags;
I suspect you really need an unsigned long and atomic bit ops here.
Even a lock would probably not work on alpha as it could affect
the other fields in the same 32-bit alignment.
