On Fri, Aug 22, 2025 at 04:26:06PM +0800, Fengnan Chang wrote:
> When use io_uring with direct IO, we could use per-cpu bio cache
> from bio_alloc_bioset, So pass IOCB_ALLOC_CACHE flag to alloc
> bio helper.
>
> Signed-off-by: Fengnan Chang <changfengnan@xxxxxxxxxxxxx>
> ---
> fs/iomap/direct-io.c | 6 ++++++
> include/linux/iomap.h | 1 +
> 2 files changed, 7 insertions(+)
>
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 6f25d4cfea9f..85cc092a4004 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -341,6 +341,9 @@ static int iomap_dio_bio_iter(struct iomap_iter *iter, struct iomap_dio *dio)
> !bdev_iter_is_aligned(iomap->bdev, dio->submit.iter))
> return -EINVAL;
>
> + if (iter->flags & IOMAP_ALLOC_CACHE)
> + bio_opf |= REQ_ALLOC_CACHE;
Is there a reason /not/ to use the per-cpu bio cache unconditionally?
--D
> +
> if (dio->flags & IOMAP_DIO_WRITE) {
> bio_opf |= REQ_OP_WRITE;
>
> @@ -636,6 +639,9 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> if (iocb->ki_flags & IOCB_NOWAIT)
> iomi.flags |= IOMAP_NOWAIT;
>
> + if (iocb->ki_flags & IOCB_ALLOC_CACHE)
> + iomi.flags |= IOMAP_ALLOC_CACHE;
> +
> if (iov_iter_rw(iter) == READ) {
> /* reads can always complete inline */
> dio->flags |= IOMAP_DIO_INLINE_COMP;
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 73dceabc21c8..6cba9b1753ca 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -196,6 +196,7 @@ struct iomap_write_ops {
> #endif /* CONFIG_FS_DAX */
> #define IOMAP_ATOMIC (1 << 9) /* torn-write protection */
> #define IOMAP_DONTCACHE (1 << 10)
> +#define IOMAP_ALLOC_CACHE (1 << 11)
>
> struct iomap_ops {
> /*
> --
> 2.20.1
>
>
