On Mon, Mar 3, 2025 at 7:52 AM Pavel Begunkov <asml.silence@xxxxxxxxx> wrote:
>
> Import registered buffers for vectored reads and writes later at issue
> time as we now do for other fixed ops.
>
> Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
> ---
> include/linux/io_uring_types.h | 3 +++
> io_uring/rw.c | 36 +++++++++++++++++++++++++++++-----
> 2 files changed, 34 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
> index b770a2b12da6..d36fccda754b 100644
> --- a/include/linux/io_uring_types.h
> +++ b/include/linux/io_uring_types.h
> @@ -502,6 +502,7 @@ enum {
> REQ_F_BUFFERS_COMMIT_BIT,
> REQ_F_BUF_NODE_BIT,
> REQ_F_HAS_METADATA_BIT,
> + REQ_F_IMPORT_BUFFER_BIT,
>
> /* not a real bit, just to check we're not overflowing the space */
> __REQ_F_LAST_BIT,
> @@ -584,6 +585,8 @@ enum {
> REQ_F_BUF_NODE = IO_REQ_FLAG(REQ_F_BUF_NODE_BIT),
> /* request has read/write metadata assigned */
> REQ_F_HAS_METADATA = IO_REQ_FLAG(REQ_F_HAS_METADATA_BIT),
> + /* resolve padded iovec to registered buffers */
> + REQ_F_IMPORT_BUFFER = IO_REQ_FLAG(REQ_F_IMPORT_BUFFER_BIT),
> };
>
> typedef void (*io_req_tw_func_t)(struct io_kiocb *req, io_tw_token_t tw);
> diff --git a/io_uring/rw.c b/io_uring/rw.c
> index 4c4229f41aaa..33a7ab2a8664 100644
> --- a/io_uring/rw.c
> +++ b/io_uring/rw.c
> @@ -381,6 +381,24 @@ int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> return __io_prep_rw(req, sqe, ITER_SOURCE);
> }
>
> +static int io_rw_import_reg_vec(struct io_kiocb *req,
> + struct io_async_rw *io,
> + int ddir, unsigned int issue_flags)
> +{
> + struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
> + unsigned uvec_segs = rw->len;
> + unsigned iovec_off = io->vec.nr - uvec_segs;
> + int ret;
> +
> + ret = io_import_reg_vec(ddir, &io->iter, req, &io->vec,
> + uvec_segs, iovec_off, issue_flags);
> + if (unlikely(ret))
> + return ret;
> + iov_iter_save_state(&io->iter, &io->iter_state);
> + req->flags &= ~REQ_F_IMPORT_BUFFER;
> + return 0;
> +}
> +
> static int io_rw_prep_reg_vec(struct io_kiocb *req, int ddir)
> {
> struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
> @@ -406,10 +424,8 @@ static int io_rw_prep_reg_vec(struct io_kiocb *req, int ddir)
> if (IS_ERR(res))
> return PTR_ERR(res);
>
> - ret = io_import_reg_vec(ddir, &io->iter, req, &io->vec,
> - uvec_segs, iovec_off, 0);
> - iov_iter_save_state(&io->iter, &io->iter_state);
> - return ret;
> + req->flags |= REQ_F_IMPORT_BUFFER;
> + return 0;
Looks like ddir is now unused in this function?
Best,
Caleb
> }
>
> int io_prep_readv_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> @@ -906,7 +922,11 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags)
> ssize_t ret;
> loff_t *ppos;
>
> - if (io_do_buffer_select(req)) {
> + if (req->flags & REQ_F_IMPORT_BUFFER) {
> + ret = io_rw_import_reg_vec(req, io, ITER_DEST, issue_flags);
> + if (unlikely(ret))
> + return ret;
> + } else if (io_do_buffer_select(req)) {
> ret = io_import_rw_buffer(ITER_DEST, req, io, issue_flags);
> if (unlikely(ret < 0))
> return ret;
> @@ -1117,6 +1137,12 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
> ssize_t ret, ret2;
> loff_t *ppos;
>
> + if (req->flags & REQ_F_IMPORT_BUFFER) {
> + ret = io_rw_import_reg_vec(req, io, ITER_SOURCE, issue_flags);
> + if (unlikely(ret))
> + return ret;
> + }
> +
> ret = io_rw_init_file(req, FMODE_WRITE, WRITE);
> if (unlikely(ret))
> return ret;
> --
> 2.48.1
>
>
