Re: [PATCH v2 3/3] block: fops: handle IOCB_USE_PI in direct IO

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

On 2/10/22 5:08 AM, Alexander V. Buev wrote:
> Check that the size of integrity data correspond to device integrity
> profile and data size. Split integrity data to the different bio's
> in case of to big orginal bio (together with normal data).
> 
> Signed-off-by: Alexander V. Buev <a.buev@yadro.com>
> ---
>   block/fops.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 62 insertions(+)
> 
> diff --git a/block/fops.c b/block/fops.c
> index 4f59e0f5bf30..99c670b9f7d4 100644
> --- a/block/fops.c
> +++ b/block/fops.c
> @@ -16,6 +16,7 @@
>   #include <linux/suspend.h>
>   #include <linux/fs.h>
>   #include <linux/module.h>
> +#include <linux/blk-integrity.h>
>   #include "blk.h"
>   
>   static inline struct inode *bdev_file_inode(struct file *file)
> @@ -44,6 +45,19 @@ static unsigned int dio_bio_write_op(struct kiocb *iocb)
>   
>   #define DIO_INLINE_BIO_VECS 4
>   
> +static int __bio_integrity_add_iovec(struct bio *bio, struct iov_iter *pi_iter)
> +{
> +	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
> +	unsigned int pi_len = bio_integrity_bytes(bi, bio->bi_iter.bi_size >> SECTOR_SHIFT);
> +	size_t iter_count = pi_iter->count-pi_len;
> +	int ret;
> +
> +	iov_iter_truncate(pi_iter, pi_len);
> +	ret = bio_integrity_add_iovec(bio, pi_iter);
> +	pi_iter->count = iter_count;
> +	return ret;
> +}
> +
>   static void blkdev_bio_end_io_simple(struct bio *bio)
>   {
>   	struct task_struct *waiter = bio->bi_private;
> @@ -101,6 +115,14 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
>   	if (iocb->ki_flags & IOCB_HIPRI)
>   		bio_set_polled(&bio, iocb);
>   
> +	if (iocb->ki_flags & IOCB_USE_PI) {
> +		ret = __bio_integrity_add_iovec(&bio, iocb->pi_iter);
> +		if (ret) {
> +			bio_release_pages(&bio, should_dirty);
> +			goto out;
> +		}
> +	}
> +
>   	submit_bio(&bio);
>   	for (;;) {
>   		set_current_state(TASK_UNINTERRUPTIBLE);
> @@ -252,6 +274,16 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
>   		pos += bio->bi_iter.bi_size;
>   
>   		nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
> +
> +		if (iocb->ki_flags & IOCB_USE_PI) {
> +			ret = __bio_integrity_add_iovec(bio, iocb->pi_iter);
> +			if (ret) {
> +				bio->bi_status = BLK_STS_IOERR;
> +				bio_endio(bio);
> +				break;
> +			}
> +		}
> +
>   		if (!nr_pages) {
>   			submit_bio(bio);
>   			break;
> @@ -358,6 +390,15 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
>   		task_io_account_write(bio->bi_iter.bi_size);
>   	}
>   
> +	if (iocb->ki_flags & IOCB_USE_PI) {
> +		ret = __bio_integrity_add_iovec(bio, iocb->pi_iter);
> +		if (ret) {
> +			bio->bi_status = BLK_STS_IOERR;
> +			bio_endio(bio);
> +			return ret;
> +		}
> +	}
> +
>   	if (iocb->ki_flags & IOCB_HIPRI) {
>   		bio->bi_opf |= REQ_POLLED | REQ_NOWAIT;
>   		submit_bio(bio);
> @@ -377,6 +418,27 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
>   	if (!iov_iter_count(iter))
>   		return 0;
>   
> +	if (iocb->ki_flags & IOCB_USE_PI) {
> +		struct block_device *bdev = iocb->ki_filp->private_data;
> +		struct blk_integrity *bi = bdev_get_integrity(bdev);
> +		unsigned int intervals;
> +
> +		if (unlikely(!(bi && bi->tuple_size &&
> +				bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE))) {
> +			pr_err("Device %d:%d is not integrity capable",
> +				MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
> +			return -EINVAL;
> +		}
> +
> +		intervals = bio_integrity_intervals(bi, iter->count >> 9);
> +		if (unlikely(intervals * bi->tuple_size > iocb->pi_iter->count)) {
> +			pr_err("Integrity & data size mismatch data=%zu integrity=%zu intervals=%u tuple=%u",
> +				iter->count, iocb->pi_iter->count,
> +				intervals, bi->tuple_size);
> +				return -EINVAL;
> +		}
> +	}
> +

Is there any reason above code is not moved into inline helper ?

>   	nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
>   	if (likely(nr_pages <= BIO_MAX_VECS)) {
>   		if (is_sync_kiocb(iocb))
>