io_uring: optimise fixed rw rsrc node setting

Move fixed rw io_req_set_rsrc_node() from rw prep into
io_import_fixed(), if we're using fixed buffers it will always be called
during submission as we save the state in advance,

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/68c06f66d5aa9661f1e4b88d08c52d23528297ec.1634314022.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d97545e..014363a 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2871,12 +2871,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                kiocb->ki_complete = io_complete_rw;
        }
 
-       if (req->opcode == IORING_OP_READ_FIXED ||
-           req->opcode == IORING_OP_WRITE_FIXED) {
-               req->imu = NULL;
-               io_req_set_rsrc_node(req, ctx);
-       }
-
+       req->imu = NULL;
        req->rw.addr = READ_ONCE(sqe->addr);
        req->rw.len = READ_ONCE(sqe->len);
        req->buf_index = READ_ONCE(sqe->buf_index);
@@ -3005,13 +3000,15 @@ static int __io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter
 
 static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter)
 {
-       struct io_ring_ctx *ctx = req->ctx;
        struct io_mapped_ubuf *imu = req->imu;
        u16 index, buf_index = req->buf_index;
 
        if (likely(!imu)) {
+               struct io_ring_ctx *ctx = req->ctx;
+
                if (unlikely(buf_index >= ctx->nr_user_bufs))
                        return -EFAULT;
+               io_req_set_rsrc_node(req, ctx);
                index = array_index_nospec(buf_index, ctx->nr_user_bufs);
                imu = READ_ONCE(ctx->user_bufs[index]);
                req->imu = imu;