On 10/8/26 6:27 AM, Anuj Gupta/Anuj Gupta wrote:
> On 10/7/2026 7:12 AM, Pavel Begunkov wrote:
>> +static int blkdev_init_dma_buf_io_ctx(struct file *file,
>> + struct dma_buf_io_ctx *ctx)
>> +{
>> + struct block_device *bdev = file_bdev(file);
>> + struct gendisk *disk = bdev->bd_disk;
>> +
>> + if (!(file->f_flags & O_DIRECT))
>> + return -EINVAL;
>> + if (!disk->fops->init_dma_buf_io_ctx)
>> + return -EOPNOTSUPP;
>
> dma-buf doesn't work with PI: bi_dmabuf_map aliases bi_io_vec, and
> blk_integrity_iterate() walks it as bvecs to generate/verify the
> checksum. rw-dmabuf liburing test hangs on a PI enabled NVMe. Something
> like below is needed:
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index e929f94b25c7..1b7f8cbbda8b 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -3150,6 +3150,12 @@ void blk_mq_submit_bio(struct bio *bio)
> goto queue_exit;
> }
>
> + if (unlikely(op_is_dmabuf(bio->bi_opf) &&
> + bdev_has_integrity_csum(bio->bi_bdev))) {
> + bio_endio_status(bio, BLK_STS_NOTSUPP);
> + goto queue_exit;
> + }
> +
> if ((bio->bi_opf & REQ_POLLED) && !blk_mq_can_poll(q)) {
> bio_endio_status(bio, BLK_STS_NOTSUPP);
> goto queue_exit;
> diff --git a/block/fops.c b/block/fops.c
> index e9da48ab73be..6c6700df943c 100644
> --- a/block/fops.c
> +++ b/block/fops.c
> @@ -976,6 +976,8 @@ static int blkdev_init_dma_buf_io_ctx(struct file *file,
> return -EINVAL;
> if (!disk->fops->init_dma_buf_io_ctx)
> return -EOPNOTSUPP;
> + if (bdev_has_integrity_csum(bdev))
> + return -EOPNOTSUPP;
> return disk->fops->init_dma_buf_io_ctx(bdev, ctx);
> }
Can you send a separate patch? I've queued this series up for some
testing.
--
Jens Axboe
