On Tue, May 14, 2024 at 1:25 PM Chenliang Li <cliang01.li@xxxxxxxxxxx> wrote:
>
> Store the folio shift and folio mask into imu struct and use it in
> iov_iter adjust, as we will have non PAGE_SIZE'd chunks if a
> multi-hugepage buffer get coalesced.
>
> Signed-off-by: Chenliang Li <cliang01.li@xxxxxxxxxxx>
> ---
> io_uring/rsrc.c | 6 ++++--
> io_uring/rsrc.h | 2 ++
> 2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
> index d08224c0c5b0..578d382ca9bc 100644
> --- a/io_uring/rsrc.c
> +++ b/io_uring/rsrc.c
> @@ -1015,6 +1015,8 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
> imu->ubuf = (unsigned long) iov->iov_base;
> imu->ubuf_end = imu->ubuf + iov->iov_len;
> imu->nr_bvecs = nr_pages;
> + imu->folio_shift = PAGE_SHIFT;
> + imu->folio_mask = PAGE_MASK;
> *pimu = imu;
> ret = 0;
>
> @@ -1153,12 +1155,12 @@ int io_import_fixed(int ddir, struct iov_iter *iter,
>
> /* skip first vec */
> offset -= bvec->bv_len;
> - seg_skip = 1 + (offset >> PAGE_SHIFT);
> + seg_skip = 1 + (offset >> imu->folio_shift);
>
> iter->bvec = bvec + seg_skip;
> iter->nr_segs -= seg_skip;
> iter->count -= bvec->bv_len + offset;
> - iter->iov_offset = offset & ~PAGE_MASK;
> + iter->iov_offset = offset & ~imu->folio_mask;
> }
> }
>
> diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
> index b2a9d66b76dd..93da02e652bc 100644
> --- a/io_uring/rsrc.h
> +++ b/io_uring/rsrc.h
> @@ -46,7 +46,9 @@ struct io_mapped_ubuf {
> u64 ubuf;
> u64 ubuf_end;
> unsigned int nr_bvecs;
> + unsigned int folio_shift;
> unsigned long acct_pages;
> + unsigned long folio_mask;
> struct bio_vec bvec[] __counted_by(nr_bvecs);
> };
>
> --
> 2.34.1
>
>
Looks good.
Reviewed-by: Anuj Gupta <anuj20.g@xxxxxxxxxxx>
--
Anuj Gupta
