On Mon, Mar 3, 2025 at 7:50 AM Pavel Begunkov <asml.silence@xxxxxxxxx> wrote:
>
> I need a convenient way to pass around and work with iovec+size pair,
> put them into a structure and makes use of it in rw.c
>
> Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
> ---
> include/linux/io_uring_types.h | 5 +++++
> io_uring/rsrc.c | 9 +++++++++
> io_uring/rsrc.h | 17 +++++++++++++++++
> io_uring/rw.c | 17 +++++++----------
> io_uring/rw.h | 6 ++++--
> 5 files changed, 42 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
> index 35fc241c4672..9101f12d21ef 100644
> --- a/include/linux/io_uring_types.h
> +++ b/include/linux/io_uring_types.h
> @@ -110,6 +110,11 @@ struct io_uring_task {
> } ____cacheline_aligned_in_smp;
> };
>
> +struct iou_vec {
> + struct iovec *iovec;
> + unsigned nr;
> +};
> +
> struct io_uring {
> u32 head;
> u32 tail;
> diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
> index d6ac41840900..9b05e614819e 100644
> --- a/io_uring/rsrc.c
> +++ b/io_uring/rsrc.c
> @@ -1264,3 +1264,12 @@ int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg)
> fput(file);
> return ret;
> }
> +
> +void io_vec_free(struct iou_vec *iv)
> +{
> + if (!iv->iovec)
> + return;
> + kfree(iv->iovec);
> + iv->iovec = NULL;
> + iv->nr = 0;
> +}
> diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
> index 662244282b2c..e3f1cfb2ff7b 100644
> --- a/io_uring/rsrc.h
> +++ b/io_uring/rsrc.h
> @@ -3,6 +3,7 @@
> #define IOU_RSRC_H
>
> #include <linux/lockdep.h>
> +#include <linux/io_uring_types.h>
I sent out a separate patch for this a couple days ago:
https://lore.kernel.org/io-uring/20250301183612.937529-1-csander@xxxxxxxxxxxxxxx/T/#u
>
> enum {
> IORING_RSRC_FILE = 0,
> @@ -144,4 +145,20 @@ static inline void __io_unaccount_mem(struct user_struct *user,
> atomic_long_sub(nr_pages, &user->locked_vm);
> }
>
> +void io_vec_free(struct iou_vec *iv);
> +
> +static inline void io_vec_reset_iovec(struct iou_vec *iv,
> + struct iovec *iovec, unsigned nr)
> +{
> + io_vec_free(iv);
> + iv->iovec = iovec;
> + iv->nr = nr;
> +}
> +
> +static inline void io_alloc_cache_vec_kasan(struct iou_vec *iv)
> +{
> + if (IS_ENABLED(CONFIG_KASAN))
> + io_vec_free(iv);
> +}
> +
> #endif
> diff --git a/io_uring/rw.c b/io_uring/rw.c
> index 5ee9f8949e8b..ad7f647d48e9 100644
> --- a/io_uring/rw.c
> +++ b/io_uring/rw.c
> @@ -87,9 +87,9 @@ static int io_import_vec(int ddir, struct io_kiocb *req,
> int ret, nr_segs;
> struct iovec *iov;
>
> - if (io->free_iovec) {
> - nr_segs = io->free_iov_nr;
> - iov = io->free_iovec;
> + if (io->vec.iovec) {
> + nr_segs = io->vec.nr;
> + iov = io->vec.iovec;
> } else {
> nr_segs = 1;
> iov = &io->fast_iov;
> @@ -101,9 +101,7 @@ static int io_import_vec(int ddir, struct io_kiocb *req,
> return ret;
> if (iov) {
> req->flags |= REQ_F_NEED_CLEANUP;
> - io->free_iov_nr = io->iter.nr_segs;
> - kfree(io->free_iovec);
> - io->free_iovec = iov;
> + io_vec_reset_iovec(&io->vec, iov, io->iter.nr_segs);
> }
> return 0;
> }
> @@ -151,7 +149,7 @@ static void io_rw_recycle(struct io_kiocb *req, unsigned int issue_flags)
> if (unlikely(issue_flags & IO_URING_F_UNLOCKED))
> return;
>
> - io_alloc_cache_kasan(&rw->free_iovec, &rw->free_iov_nr);
> + io_alloc_cache_vec_kasan(&rw->vec);
> if (io_alloc_cache_put(&req->ctx->rw_cache, rw)) {
> req->async_data = NULL;
> req->flags &= ~REQ_F_ASYNC_DATA;
> @@ -201,7 +199,7 @@ static int io_rw_alloc_async(struct io_kiocb *req)
> rw = io_uring_alloc_async_data(&ctx->rw_cache, req);
> if (!rw)
> return -ENOMEM;
> - if (rw->free_iovec)
> + if (rw->vec.iovec)
> req->flags |= REQ_F_NEED_CLEANUP;
> rw->bytes_done = 0;
> return 0;
> @@ -1327,7 +1325,6 @@ void io_rw_cache_free(const void *entry)
> {
> struct io_async_rw *rw = (struct io_async_rw *) entry;
>
> - if (rw->free_iovec)
> - kfree(rw->free_iovec);
> + io_vec_free(&rw->vec);
> kfree(rw);
> }
> diff --git a/io_uring/rw.h b/io_uring/rw.h
> index bf121b81ebe8..e86a3858f48b 100644
> --- a/io_uring/rw.h
> +++ b/io_uring/rw.h
> @@ -3,19 +3,21 @@
> #include <linux/io_uring_types.h>
> #include <linux/pagemap.h>
>
> +#include "rsrc.h"
Why is this include necessary? struct iou_vec is defined in
io_uring_types.h. Seems like the include would make more sense in
rw.c.
Best,
Caleb
> +
> struct io_meta_state {
> u32 seed;
> struct iov_iter_state iter_meta;
> };
>
> struct io_async_rw {
> + struct iou_vec vec;
> size_t bytes_done;
> - struct iovec *free_iovec;
> +
> struct_group(clear,
> struct iov_iter iter;
> struct iov_iter_state iter_state;
> struct iovec fast_iov;
> - int free_iov_nr;
> /*
> * wpq is for buffered io, while meta fields are used with
> * direct io
> --
> 2.48.1
>
>
