io_uring: add a dummy -EOPNOTSUPP prep handler

Add it and use it for the epoll handling, if epoll isn't configured.

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

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 469d89f..15d0377 100644 (file)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -4034,10 +4034,16 @@ err:
        return IOU_ISSUE_SKIP_COMPLETE;
 }
 
+static __maybe_unused int io_eopnotsupp_prep(struct io_kiocb *kiocb,
+                                            const struct io_uring_sqe *sqe)
+{
+       return -EOPNOTSUPP;
+}
+
+#if defined(CONFIG_EPOLL)
 static int io_epoll_ctl_prep(struct io_kiocb *req,
                             const struct io_uring_sqe *sqe)
 {
-#if defined(CONFIG_EPOLL)
        struct io_epoll *epoll = io_kiocb_to_cmd(req);
 
        if (sqe->buf_index || sqe->splice_fd_in)
@@ -4056,14 +4062,10 @@ static int io_epoll_ctl_prep(struct io_kiocb *req,
        }
 
        return 0;
-#else
-       return -EOPNOTSUPP;
-#endif
 }
 
 static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
 {
-#if defined(CONFIG_EPOLL)
        struct io_epoll *ie = io_kiocb_to_cmd(req);
        int ret;
        bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -4076,10 +4078,8 @@ static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
                req_set_fail(req);
        io_req_set_res(req, ret, 0);
        return IOU_OK;
-#else
-       return -EOPNOTSUPP;
-#endif
 }
+#endif
 
 static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
@@ -11246,8 +11246,12 @@ static const struct io_op_def io_op_defs[] = {
        [IORING_OP_EPOLL_CTL] = {
                .unbound_nonreg_file    = 1,
                .audit_skip             = 1,
+#if defined(CONFIG_EPOLL)
                .prep                   = io_epoll_ctl_prep,
                .issue                  = io_epoll_ctl,
+#else
+               .prep                   = io_eopnotsupp_prep,
+#endif
        },
        [IORING_OP_SPLICE] = {
                .needs_file             = 1,
@@ -11418,7 +11422,8 @@ static int __init io_uring_init(void)
 
        for (i = 0; i < ARRAY_SIZE(io_op_defs); i++) {
                BUG_ON(!io_op_defs[i].prep);
-               BUG_ON(!io_op_defs[i].issue);
+               if (io_op_defs[i].prep != io_eopnotsupp_prep)
+                       BUG_ON(!io_op_defs[i].issue);
        }
 
        req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC |