[PATCH 21/21] nvme: Support atomic writes

[Pankaj Raghav]

> +++ b/drivers/nvme/host/core.c
> @@ -1926,6 +1926,35 @@ static void nvme_update_disk_info(struct gendisk *disk,
>  	blk_queue_io_min(disk->queue, phys_bs);
>  	blk_queue_io_opt(disk->queue, io_opt);
>  
> +	atomic_bs = rounddown_pow_of_two(atomic_bs);
> +	if (id->nsfeat & NVME_NS_FEAT_ATOMICS && id->nawupf) {
> +		if (id->nabo) {
> +			dev_err(ns->ctrl->device, "Support atomic NABO=%x\n",
> +				id->nabo);
> +		} else {
> +			u32 boundary = 0;
> +
> +			if (le16_to_cpu(id->nabspf))
> +				boundary = (le16_to_cpu(id->nabspf) + 1) * bs;
> +
> +			if (is_power_of_2(boundary) || !boundary) {
> +				blk_queue_atomic_write_max_bytes(disk->queue, atomic_bs);
> +				blk_queue_atomic_write_unit_min_sectors(disk->queue, 1);
> +				blk_queue_atomic_write_unit_max_sectors(disk->queue,
> +									atomic_bs / bs);
blk_queue_atomic_write_unit_[min| max]_sectors expects sectors (512 bytes unit)
as input but no conversion is done here from device logical block size
to SECTORs.
> +				blk_queue_atomic_write_boundary_bytes(disk->queue, boundary);
> +			} else {
> +				dev_err(ns->ctrl->device, "Unsupported atomic boundary=0x%x\n",
> +					boundary);
> +			}
>