>+static bool blkdev_atomic_write_valid(struct block_device *bdev, loff_t pos,
>+ struct iov_iter *iter)
>+{
>+ struct request_queue *q = bdev_get_queue(bdev);
>+ unsigned int min_bytes = queue_atomic_write_unit_min_bytes(q);
>+ unsigned int max_bytes = queue_atomic_write_unit_max_bytes(q);
>+
>+ if (!iter_is_ubuf(iter))
>+ return false;
>+ if (iov_iter_count(iter) & (min_bytes - 1))
>+ return false;
>+ if (!is_power_of_2(iov_iter_count(iter)))
>+ return false;
>+ if (pos & (iov_iter_count(iter) - 1))
>+ return false;
>+ if (iov_iter_count(iter) > max_bytes)
>+ return false;
>+ return true;
>+}
Here do we need to also validate whether the IO doesn't straddle
the atmic bondary limit (if it's non-zero)? We do check that IO
doesn't straddle the atomic boundary limit but that happens very
late in the IO code path either during blk-merge or in NVMe driver
code.
Thanks,
--Nilay
