Re: [RFC PATCH v3 1/3] io-uring/cmd: add iou_vec field for io_uring_cmd

[Sidong Yang <sidong.yang@furiosa.ai>]

On Sun, Mar 16, 2025 at 07:24:32AM +0000, Pavel Begunkov wrote:
> On 3/15/25 17:23, Sidong Yang wrote:
> > This patch adds iou_vec field for io_uring_cmd. Also it needs to be
> > cleanup for cache. It could be used in uring cmd api that imports
> > multiple fixed buffers.
> 
> Sidong, I think you accidentially erased my authorship over the
> patch. The only difference I see is that you rebased it and dropped
> prep patches by placing iou_vec into struct io_uring_cmd_data. And
> the prep patch was mandatory, once something is exported there is
> a good chance it gets [ab]used, and iou_vec is not ready for it.

Yes, First I thought it's not mandatory for this function. But it seems that
it's needed. I see that your patch hides all fields in io_uring_cmd_data but
op_data needed to be accessable for btrfs cmd. And I'll take a look for the
code referencing sqes in io_uring_cmd_data. Let me add the commit for next
version v4.

Thanks,
Sidong

> 
> 
> > Signed-off-by: Sidong Yang <sidong.yang@furiosa.ai>
> > ---
> >   include/linux/io_uring/cmd.h |  1 +
> >   io_uring/io_uring.c          |  2 +-
> >   io_uring/opdef.c             |  1 +
> >   io_uring/uring_cmd.c         | 20 ++++++++++++++++++++
> >   io_uring/uring_cmd.h         |  3 +++
> >   5 files changed, 26 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
> > index 598cacda4aa3..74b9f0aec229 100644
> > --- a/include/linux/io_uring/cmd.h
> > +++ b/include/linux/io_uring/cmd.h
> > @@ -22,6 +22,7 @@ struct io_uring_cmd {
> >   struct io_uring_cmd_data {
> >   	void			*op_data;
> >   	struct io_uring_sqe	sqes[2];
> > +	struct iou_vec		iou_vec;
> >   };
> >   static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
> > diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> > index 5ff30a7092ed..55334fa53abf 100644
> > --- a/io_uring/io_uring.c
> > +++ b/io_uring/io_uring.c
> > @@ -289,7 +289,7 @@ static void io_free_alloc_caches(struct io_ring_ctx *ctx)
> >   	io_alloc_cache_free(&ctx->apoll_cache, kfree);
> >   	io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
> >   	io_alloc_cache_free(&ctx->rw_cache, io_rw_cache_free);
> > -	io_alloc_cache_free(&ctx->uring_cache, kfree);
> > +	io_alloc_cache_free(&ctx->uring_cache, io_cmd_cache_free);
> >   	io_alloc_cache_free(&ctx->msg_cache, kfree);
> >   	io_futex_cache_free(ctx);
> >   	io_rsrc_cache_free(ctx);
> > diff --git a/io_uring/opdef.c b/io_uring/opdef.c
> > index 7fd173197b1e..e275180c2077 100644
> > --- a/io_uring/opdef.c
> > +++ b/io_uring/opdef.c
> > @@ -755,6 +755,7 @@ const struct io_cold_def io_cold_defs[] = {
> >   	},
> >   	[IORING_OP_URING_CMD] = {
> >   		.name			= "URING_CMD",
> > +		.cleanup		= io_uring_cmd_cleanup,
> >   	},
> >   	[IORING_OP_SEND_ZC] = {
> >   		.name			= "SEND_ZC",
> > diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> > index de39b602aa82..315c603cfdd4 100644
> > --- a/io_uring/uring_cmd.c
> > +++ b/io_uring/uring_cmd.c
> > @@ -28,6 +28,13 @@ static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags)
> >   	if (issue_flags & IO_URING_F_UNLOCKED)
> >   		return;
> > +
> > +	req->flags &= ~REQ_F_NEED_CLEANUP;
> > +
> > +	io_alloc_cache_vec_kasan(&cache->iou_vec);
> > +	if (cache->iou_vec.nr > IO_VEC_CACHE_SOFT_CAP)
> > +		io_vec_free(&cache->iou_vec);
> > +
> >   	if (io_alloc_cache_put(&req->ctx->uring_cache, cache)) {
> >   		ioucmd->sqe = NULL;
> >   		req->async_data = NULL;
> > @@ -35,6 +42,11 @@ static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags)
> >   	}
> >   }
> > +void io_uring_cmd_cleanup(struct io_kiocb *req)
> > +{
> > +	io_req_uring_cleanup(req, 0);
> > +}
> > +
> >   bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
> >   				   struct io_uring_task *tctx, bool cancel_all)
> >   {
> > @@ -339,3 +351,11 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
> >   }
> >   EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
> >   #endif
> > +
> > +void io_cmd_cache_free(const void *entry)
> > +{
> > +	struct io_uring_cmd_data *cache = (struct io_uring_cmd_data *)entry;
> > +
> > +	io_vec_free(&cache->iou_vec);
> > +	kfree(cache);
> > +}
> > diff --git a/io_uring/uring_cmd.h b/io_uring/uring_cmd.h
> > index f6837ee0955b..d2b9c1522e22 100644
> > --- a/io_uring/uring_cmd.h
> > +++ b/io_uring/uring_cmd.h
> > @@ -1,7 +1,10 @@
> >   // SPDX-License-Identifier: GPL-2.0
> > +#include <linux/io_uring_types.h>
> >   int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags);
> >   int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> > +void io_uring_cmd_cleanup(struct io_kiocb *req);
> >   bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
> >   				   struct io_uring_task *tctx, bool cancel_all);
> > +void io_cmd_cache_free(const void *entry);
> 
> -- 
> Pavel Begunkov
>