io_uring: hide uring_fd in ctx

req->ring_fd and req->ring_file are used only during the prep stage
during submission, which is is protected by mutex. There is no need
to store them per-request, place them in ctx.

Signed-off-by: Pavel Begunkov <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 771954b..46cc1bc 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -251,6 +251,8 @@ struct io_ring_ctx {
         */
        struct fixed_file_data  *file_data;
        unsigned                nr_user_files;
+       int                     ring_fd;
+       struct file             *ring_file;
 
        /* if used, fixed mapped user buffers */
        unsigned                nr_user_bufs;
@@ -475,15 +477,10 @@ struct io_kiocb {
        };
 
        struct io_async_ctx             *io;
-       union {
-               /*
-                * ring_file is only used in the submission path, and
-                * llist_node is only used for poll deferred completions
-                */
-               struct file             *ring_file;
-               struct llist_node       llist_node;
-       };
-       int                             ring_fd;
+       /*
+        * llist_node is only used for poll deferred completions
+        */
+       struct llist_node               llist_node;
        bool                            has_user;
        bool                            in_async;
        bool                            needs_fixed_file;
@@ -1141,7 +1138,6 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
 
 got_it:
        req->io = NULL;
-       req->ring_file = NULL;
        req->file = NULL;
        req->ctx = ctx;
        req->flags = 0;
@@ -2725,7 +2721,7 @@ static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
        req->close.fd = READ_ONCE(sqe->fd);
        if (req->file->f_op == &io_uring_fops ||
-           req->close.fd == req->ring_fd)
+           req->close.fd == req->ctx->ring_fd)
                return -EBADF;
 
        return 0;
@@ -4395,7 +4391,7 @@ static int io_grab_files(struct io_kiocb *req)
        int ret = -EBADF;
        struct io_ring_ctx *ctx = req->ctx;
 
-       if (!req->ring_file)
+       if (!ctx->ring_file)
                return -EBADF;
 
        rcu_read_lock();
@@ -4406,7 +4402,7 @@ static int io_grab_files(struct io_kiocb *req)
         * the fd has changed since we started down this path, and disallow
         * this operation if it has.
         */
-       if (fcheck(req->ring_fd) == req->ring_file) {
+       if (fcheck(ctx->ring_fd) == ctx->ring_file) {
                list_add(&req->inflight_entry, &ctx->inflight_list);
                req->flags |= REQ_F_INFLIGHT;
                req->work.files = current->files;
@@ -4778,6 +4774,9 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
                statep = &state;
        }
 
+       ctx->ring_fd = ring_fd;
+       ctx->ring_file = ring_file;
+
        for (i = 0; i < nr; i++) {
                const struct io_uring_sqe *sqe;
                struct io_kiocb *req;
@@ -4810,8 +4809,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
                        }
                }
 
-               req->ring_file = ring_file;
-               req->ring_fd = ring_fd;
                req->has_user = *mm != NULL;
                req->in_async = async;
                req->needs_fixed_file = async;