Re: [PATCH v2 6/8] fuse: add user_ prefix to userspace headers and payload fields

[Caleb Sander Mateos <csander@purestorage.com>]

On Mon, Oct 27, 2025 at 3:29 PM Joanne Koong <joannelkoong@gmail.com> wrote:
>
> Rename the headers and payload fields to user_headers and user_payload.
> This makes it explicit that these pointers reference userspace addresses
> and prepares for upcoming fixed buffer support, where there will be
> separate fields for kernel-space pointers to the payload and headers.
>
> Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
> ---
>  fs/fuse/dev_uring.c   | 17 ++++++++---------
>  fs/fuse/dev_uring_i.h |  4 ++--
>  2 files changed, 10 insertions(+), 11 deletions(-)
>
> diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
> index d96368e93e8d..c814b571494f 100644
> --- a/fs/fuse/dev_uring.c
> +++ b/fs/fuse/dev_uring.c
> @@ -585,11 +585,11 @@ static void __user *get_user_ring_header(struct fuse_ring_ent *ent,
>  {
>         switch (type) {
>         case FUSE_URING_HEADER_IN_OUT:
> -               return &ent->headers->in_out;
> +               return &ent->user_headers->in_out;
>         case FUSE_URING_HEADER_OP:
> -               return &ent->headers->op_in;
> +               return &ent->user_headers->op_in;
>         case FUSE_URING_HEADER_RING_ENT:
> -               return &ent->headers->ring_ent_in_out;
> +               return &ent->user_headers->ring_ent_in_out;
>         }
>
>         WARN_ON_ONCE(1);
> @@ -645,7 +645,7 @@ static int fuse_uring_copy_from_ring(struct fuse_ring *ring,
>         if (err)
>                 return err;
>
> -       err = import_ubuf(ITER_SOURCE, ent->payload, ring->max_payload_sz,
> +       err = import_ubuf(ITER_SOURCE, ent->user_payload, ring->max_payload_sz,
>                           &iter);
>         if (err)
>                 return err;
> @@ -674,7 +674,7 @@ static int fuse_uring_args_to_ring(struct fuse_ring *ring, struct fuse_req *req,
>                 .commit_id = req->in.h.unique,
>         };
>
> -       err = import_ubuf(ITER_DEST, ent->payload, ring->max_payload_sz, &iter);
> +       err = import_ubuf(ITER_DEST, ent->user_payload, ring->max_payload_sz, &iter);
>         if (err) {
>                 pr_info_ratelimited("fuse: Import of user buffer failed\n");
>                 return err;
> @@ -710,8 +710,7 @@ static int fuse_uring_args_to_ring(struct fuse_ring *ring, struct fuse_req *req,
>
>         ent_in_out.payload_sz = cs.ring.copied_sz;
>         return copy_header_to_ring(ent, FUSE_URING_HEADER_RING_ENT,
> -                                  &ent_in_out,
> -                                  sizeof(ent_in_out));
> +                                  &ent_in_out, sizeof(ent_in_out));

nit: looks like an unnecessary formatting change here. Either drop it
or move it to the earlier commit that added these lines?

Best,
Caleb

>  }
>
>  static int fuse_uring_copy_to_ring(struct fuse_ring_ent *ent,
> @@ -1104,8 +1103,8 @@ fuse_uring_create_ring_ent(struct io_uring_cmd *cmd,
>         INIT_LIST_HEAD(&ent->list);
>
>         ent->queue = queue;
> -       ent->headers = iov[0].iov_base;
> -       ent->payload = iov[1].iov_base;
> +       ent->user_headers = iov[0].iov_base;
> +       ent->user_payload = iov[1].iov_base;
>
>         atomic_inc(&ring->queue_refs);
>         return ent;
> diff --git a/fs/fuse/dev_uring_i.h b/fs/fuse/dev_uring_i.h
> index 51a563922ce1..381fd0b8156a 100644
> --- a/fs/fuse/dev_uring_i.h
> +++ b/fs/fuse/dev_uring_i.h
> @@ -39,8 +39,8 @@ enum fuse_ring_req_state {
>  /** A fuse ring entry, part of the ring queue */
>  struct fuse_ring_ent {
>         /* userspace buffer */
> -       struct fuse_uring_req_header __user *headers;
> -       void __user *payload;
> +       struct fuse_uring_req_header __user *user_headers;
> +       void __user *user_payload;
>
>         /* the ring queue that owns the request */
>         struct fuse_ring_queue *queue;
> --
> 2.47.3
>