On Mon, Feb 24, 2025 at 1:31 PM Keith Busch <kbusch@xxxxxxxx> wrote:
>
> From: Keith Busch <kbusch@xxxxxxxxxx>
>
> Registered buffers may depend on a linked command, which makes the prep
> path too early to import. Move to the issue path when the node is
> actually needed like all the other users of fixed buffers.
>
> Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
> ---
> io_uring/opdef.c | 8 ++++----
> io_uring/rw.c | 43 ++++++++++++++++++++++++++-----------------
> io_uring/rw.h | 4 ++--
> 3 files changed, 32 insertions(+), 23 deletions(-)
>
> diff --git a/io_uring/opdef.c b/io_uring/opdef.c
> index 9344534780a02..5369ae33b5ad9 100644
> --- a/io_uring/opdef.c
> +++ b/io_uring/opdef.c
> @@ -104,8 +104,8 @@ const struct io_issue_def io_issue_defs[] = {
> .iopoll = 1,
> .iopoll_queue = 1,
> .async_size = sizeof(struct io_async_rw),
> - .prep = io_prep_read_fixed,
> - .issue = io_read,
> + .prep = io_prep_read,
> + .issue = io_read_fixed,
> },
> [IORING_OP_WRITE_FIXED] = {
> .needs_file = 1,
> @@ -118,8 +118,8 @@ const struct io_issue_def io_issue_defs[] = {
> .iopoll = 1,
> .iopoll_queue = 1,
> .async_size = sizeof(struct io_async_rw),
> - .prep = io_prep_write_fixed,
> - .issue = io_write,
> + .prep = io_prep_write,
> + .issue = io_write_fixed,
> },
> [IORING_OP_POLL_ADD] = {
> .needs_file = 1,
> diff --git a/io_uring/rw.c b/io_uring/rw.c
> index db24bcd4c6335..5f37fa48fdd9b 100644
> --- a/io_uring/rw.c
> +++ b/io_uring/rw.c
> @@ -348,33 +348,20 @@ int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> return io_prep_rwv(req, sqe, ITER_SOURCE);
> }
>
> -static int io_prep_rw_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe,
> - int ddir)
> +static int io_init_rw_fixed(struct io_kiocb *req, unsigned int issue_flags, int ddir)
> {
> struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
> - struct io_async_rw *io;
> + struct io_async_rw *io = req->async_data;
> int ret;
>
> - ret = io_prep_rw(req, sqe, ddir, false);
> - if (unlikely(ret))
> - return ret;
> + if (io->bytes_done)
> + return 0;
>
> - io = req->async_data;
> ret = io_import_reg_buf(req, &io->iter, rw->addr, rw->len, ddir, 0);
Shouldn't this be passing issue_flags here?
Best,
Caleb
> iov_iter_save_state(&io->iter, &io->iter_state);
> return ret;
> }
>
> -int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> -{
> - return io_prep_rw_fixed(req, sqe, ITER_DEST);
> -}
> -
> -int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> -{
> - return io_prep_rw_fixed(req, sqe, ITER_SOURCE);
> -}
> -
> /*
> * Multishot read is prepared just like a normal read/write request, only
> * difference is that we set the MULTISHOT flag.
> @@ -1138,6 +1125,28 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
> }
> }
>
> +int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags)
> +{
> + int ret;
> +
> + ret = io_init_rw_fixed(req, issue_flags, ITER_DEST);
> + if (ret)
> + return ret;
> +
> + return io_read(req, issue_flags);
> +}
> +
> +int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags)
> +{
> + int ret;
> +
> + ret = io_init_rw_fixed(req, issue_flags, ITER_SOURCE);
> + if (ret)
> + return ret;
> +
> + return io_write(req, issue_flags);
> +}
> +
> void io_rw_fail(struct io_kiocb *req)
> {
> int res;
> diff --git a/io_uring/rw.h b/io_uring/rw.h
> index a45e0c71b59d6..42a491d277273 100644
> --- a/io_uring/rw.h
> +++ b/io_uring/rw.h
> @@ -30,14 +30,14 @@ struct io_async_rw {
> );
> };
>
> -int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> -int io_prep_write_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> int io_prep_readv(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> int io_prep_writev(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> int io_read(struct io_kiocb *req, unsigned int issue_flags);
> int io_write(struct io_kiocb *req, unsigned int issue_flags);
> +int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags);
> +int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags);
> void io_readv_writev_cleanup(struct io_kiocb *req);
> void io_rw_fail(struct io_kiocb *req);
> void io_req_rw_complete(struct io_kiocb *req, io_tw_token_t tw);
> --
> 2.43.5
>
