[Devel] [PATCH VZ9 v3] fs/fuse kio: skip looking into response to request from userspace

[Alexey Kuznetsov]

Ack

On Tue, Jul 30, 2024 at 12:42 PM Liu Kui <kui.liu at virtuozzo.com> wrote:
>
> Response to userspace requests should not be analyzed and translated
> to msg->errors. Instead the entire response message should be just
> passed to userspace and let userspace handle it.
>
> Fix the issue that userspace krpcio getting aborted by PCS_RPC_ERROR_RESP
> response.
>
> Signed-off-by: Liu Kui <kui.liu at virtuozzo.com>
> ---
>  fs/fuse/kio/pcs/pcs_krpc.c | 11 ++++++-----
>  fs/fuse/kio/pcs/pcs_krpc.h |  3 ++-
>  fs/fuse/kio/pcs/pcs_rpc.c  |  7 +++++++
>  3 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/fs/fuse/kio/pcs/pcs_krpc.c b/fs/fuse/kio/pcs/pcs_krpc.c
> index 567d8a0c884f..f61e8e2c813f 100644
> --- a/fs/fuse/kio/pcs/pcs_krpc.c
> +++ b/fs/fuse/kio/pcs/pcs_krpc.c
> @@ -105,7 +105,8 @@ static void krpc_msg_get_response_iter(struct pcs_msg *msg, int offset,
>         struct pcs_msg *req = msg->private;
>         struct krpc_req *kreq = req->private2;
>
> -       if (!(kreq->flags & KRPC_REQ_F_RESP_BUFF)) {
> +       if (!(kreq->flags & KRPC_REQ_F_RESP_BUFF) ||
> +               (kreq->flags & KRPC_REQ_F_ERR_RESP)) {
>                 /* No data payload */
>                 BUG_ON(msg->size > PAGE_SIZE);
>
> @@ -148,16 +149,16 @@ struct pcs_msg *krpc_get_hdr(struct pcs_rpc *ep, struct pcs_rpc_hdr *h)
>         if (msg == NULL)
>                 return NULL;
>
> -       req_h = (struct pcs_rpc_hdr *)msg_inline_head(msg);
> -       if (req_h->type != (h->type & ~PCS_RPC_DIRECTION))
> -               return NULL;
> -
>         kreq = msg->private2;
>
>         resp = pcs_rpc_alloc_input_msg(ep, sizeof(struct pcs_rpc_hdr));
>         if (!resp)
>                 return NULL;
>
> +       req_h = (struct pcs_rpc_hdr *)msg_inline_head(msg);
> +       if (req_h->type != (h->type & ~PCS_RPC_DIRECTION))
> +               kreq->flags |= KRPC_REQ_F_ERR_RESP;
> +
>         memcpy(resp->_inline_buffer, h, sizeof(struct pcs_rpc_hdr));
>         memcpy(kreq->hdr_buf, h, sizeof(struct pcs_rpc_hdr));
>         resp->size = h->len;
> diff --git a/fs/fuse/kio/pcs/pcs_krpc.h b/fs/fuse/kio/pcs/pcs_krpc.h
> index 6c0ef20ebc99..8100dfb2629d 100644
> --- a/fs/fuse/kio/pcs/pcs_krpc.h
> +++ b/fs/fuse/kio/pcs/pcs_krpc.h
> @@ -93,7 +93,8 @@ struct krpc_req {
>
>  #define KRPC_REQ_F_ALIGNMENT   PCS_KRPC_MSG_F_ALIGNMENT
>  #define KRPC_REQ_F_RESP_BUFF   PCS_KRPC_MSG_F_RESP_BUFF        /* data buff is for read response */
> -#define KRPC_REQ_F_ABORTED             0x10000
> +#define KRPC_REQ_F_ABORTED     0x10000
> +#define KRPC_REQ_F_ERR_RESP    0x20000
>         int flags;
>
>         struct pcs_msg          msg;
> diff --git a/fs/fuse/kio/pcs/pcs_rpc.c b/fs/fuse/kio/pcs/pcs_rpc.c
> index deebc1dddf1b..f990f0f30609 100644
> --- a/fs/fuse/kio/pcs/pcs_rpc.c
> +++ b/fs/fuse/kio/pcs/pcs_rpc.c
> @@ -484,6 +484,12 @@ static void handle_response(struct pcs_rpc * ep, struct pcs_msg * msg)
>         pcs_msg_del_calendar(req);
>         list_del(&req->list);
>
> +       /* don't try to interpret response to request from userspace */
> +       if (!(h->xid.origin.val & PCS_NODE_ALT_MASK)) {
> +               req->response = msg;
> +               goto skip;
> +       }
> +
>         if (h->type == PCS_RPC_ERROR_RESP) {
>                 struct pcs_rpc_error_resp * eh = (struct pcs_rpc_error_resp *)msg->_inline_buffer;
>
> @@ -502,6 +508,7 @@ static void handle_response(struct pcs_rpc * ep, struct pcs_msg * msg)
>                         req->response = msg;
>         }
>
> +skip:
>         if (ep->ops->hook_response)
>                 ep->ops->hook_response(ep, req);
>
> --
> 2.39.3 (Apple Git-146)