io_uring: don't store bgid in req->buf_index

Pass buffer group id into the rest of helpers via struct buf_sel_arg
and remove all reassignments of req->buf_index back to bgid. Now, it
only stores buffer indexes, and the group is provided by callers.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3ea9fa08113ecb4d9224b943e7806e80a324bdf9.1743437358.git.asml.silence@gmail.com
Link: https://lore.kernel.org/io-uring/0c01d76ff12986c2f48614db8610caff8f78c869.1743500909.git.asml.silence@gmail.com/
[axboe: fold in patch from second link]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index b44d201520d85780bbe7e4dfbfeaf43f3b51e55b..3b467879bca8962b19ce035f9f9f65e76abaa959 100644 (file)
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -653,8 +653,7 @@ struct io_kiocb {
        u8                              iopoll_completed;
        /*
         * Can be either a fixed buffer index, or used with provided buffers.
-        * For the latter, before issue it points to the buffer group ID,
-        * and after selection it points to the buffer ID itself.
+        * For the latter, it points to the selected buffer ID.
         */
        u16                             buf_index;
 

diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index f195876732be4bf50e14718b1dd082700f5e6817..1cf0d2c01287fb563bebb16bbab7ed0a4f12c738 100644 (file)
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -92,7 +92,6 @@ void io_kbuf_drop_legacy(struct io_kiocb *req)
 {
        if (WARN_ON_ONCE(!(req->flags & REQ_F_BUFFER_SELECTED)))
                return;
-       req->buf_index = req->kbuf->bgid;
        req->flags &= ~REQ_F_BUFFER_SELECTED;
        kfree(req->kbuf);
        req->kbuf = NULL;
@@ -110,7 +109,6 @@ bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags)
        bl = io_buffer_get_list(ctx, buf->bgid);
        list_add(&buf->list, &bl->buf_list);
        req->flags &= ~REQ_F_BUFFER_SELECTED;
-       req->buf_index = buf->bgid;
 
        io_ring_submit_unlock(ctx, issue_flags);
        return true;
@@ -302,7 +300,7 @@ int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg,
        int ret = -ENOENT;
 
        io_ring_submit_lock(ctx, issue_flags);
-       bl = io_buffer_get_list(ctx, req->buf_index);
+       bl = io_buffer_get_list(ctx, arg->buf_group);
        if (unlikely(!bl))
                goto out_unlock;
 
@@ -335,7 +333,7 @@ int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg)
 
        lockdep_assert_held(&ctx->uring_lock);
 
-       bl = io_buffer_get_list(ctx, req->buf_index);
+       bl = io_buffer_get_list(ctx, arg->buf_group);
        if (unlikely(!bl))
                return -ENOENT;
 
@@ -355,10 +353,9 @@ static inline bool __io_put_kbuf_ring(struct io_kiocb *req, int len, int nr)
        struct io_buffer_list *bl = req->buf_list;
        bool ret = true;
 
-       if (bl) {
+       if (bl)
                ret = io_kbuf_commit(req, bl, len, nr);
-               req->buf_index = bl->bgid;
-       }
+
        req->flags &= ~REQ_F_BUFFER_RING;
        return ret;
 }

diff --git a/io_uring/kbuf.h b/io_uring/kbuf.h
index 09129115f3efd59dc46e0ab7e4aa269a49f2f9ee..0798a732e6cb0de925f6357789346ebe2cc30b57 100644 (file)
--- a/io_uring/kbuf.h
+++ b/io_uring/kbuf.h
@@ -55,6 +55,7 @@ struct buf_sel_arg {
        size_t max_len;
        unsigned short nr_iovs;
        unsigned short mode;
+       unsigned buf_group;
 };
 
 void __user *io_buffer_select(struct io_kiocb *req, size_t *len,
@@ -94,7 +95,6 @@ static inline bool io_kbuf_recycle_ring(struct io_kiocb *req)
         * to monopolize the buffer.
         */
        if (req->buf_list) {
-               req->buf_index = req->buf_list->bgid;
                req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT);
                return true;
        }

diff --git a/io_uring/net.c b/io_uring/net.c
index 6314b1583c8c476b8530a9f8cca8eb58a69df863..5f1a519d1fc6eec1e450575814537eca4e7eff6f 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -190,7 +190,6 @@ static inline void io_mshot_prep_retry(struct io_kiocb *req,
        sr->done_io = 0;
        sr->retry = false;
        sr->len = 0; /* get from the provided buffer */
-       req->buf_index = sr->buf_group;
 }
 
 static int io_net_import_vec(struct io_kiocb *req, struct io_async_msghdr *iomsg,
@@ -568,6 +567,7 @@ static int io_send_select_buffer(struct io_kiocb *req, unsigned int issue_flags,
                .iovs = &kmsg->fast_iov,
                .max_len = min_not_zero(sr->len, INT_MAX),
                .nr_iovs = 1,
+               .buf_group = sr->buf_group,
        };
 
        if (kmsg->vec.iovec) {
@@ -1056,6 +1056,7 @@ static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg
                        .iovs = &kmsg->fast_iov,
                        .nr_iovs = 1,
                        .mode = KBUF_MODE_EXPAND,
+                       .buf_group = sr->buf_group,
                };
 
                if (kmsg->vec.iovec) {