io_uring: defer msg-ring file validity check until command issue

In preparation for not using the file at prep time, defer checking if this
file refers to a valid io_uring instance until issue time.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9234109..3d0dbcd 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4473,9 +4473,6 @@ static int io_msg_ring_prep(struct io_kiocb *req,
                     sqe->splice_fd_in || sqe->buf_index || sqe->personality))
                return -EINVAL;
 
-       if (req->file->f_op != &io_uring_fops)
-               return -EBADFD;
-
        req->msg.user_data = READ_ONCE(sqe->off);
        req->msg.len = READ_ONCE(sqe->len);
        return 0;
@@ -4485,9 +4482,14 @@ static int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_ring_ctx *target_ctx;
        struct io_msg *msg = &req->msg;
-       int ret = -EOVERFLOW;
        bool filled;
+       int ret;
 
+       ret = -EBADFD;
+       if (req->file->f_op != &io_uring_fops)
+               goto done;
+
+       ret = -EOVERFLOW;
        target_ctx = req->file->private_data;
 
        spin_lock(&target_ctx->completion_lock);
@@ -4500,6 +4502,7 @@ static int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags)
                ret = 0;
        }
 
+done:
        if (ret < 0)
                req_set_fail(req);
        __io_req_complete(req, issue_flags, ret, 0);