io_uring: fix ->extra{1,2} misuse

We don't really know the state of req->extra{1,2] fields in
__io_fill_cqe_req(), if an opcode handler is not aware of CQE32 option,
it never sets them up properly. Track the state of those fields with a
request flag.

Fixes: 76c68fbf1a1f9 ("io_uring: enable CQE32")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4b3e5be512fbf4debec7270fd485b8a3b014d464.1655287457.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 10901db..808b7f4 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -844,6 +844,7 @@ enum {
        REQ_F_SINGLE_POLL_BIT,
        REQ_F_DOUBLE_POLL_BIT,
        REQ_F_PARTIAL_IO_BIT,
+       REQ_F_CQE32_INIT_BIT,
        REQ_F_APOLL_MULTISHOT_BIT,
        /* keep async read/write and isreg together and in order */
        REQ_F_SUPPORT_NOWAIT_BIT,
@@ -913,6 +914,8 @@ enum {
        REQ_F_PARTIAL_IO        = BIT(REQ_F_PARTIAL_IO_BIT),
        /* fast poll multishot mode */
        REQ_F_APOLL_MULTISHOT   = BIT(REQ_F_APOLL_MULTISHOT_BIT),
+       /* ->extra1 and ->extra2 are initialised */
+       REQ_F_CQE32_INIT        = BIT(REQ_F_CQE32_INIT_BIT),
 };
 
 struct async_poll {
@@ -2488,8 +2491,12 @@ static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
                                                req->cqe.res, req->cqe.flags,
                                                0, 0);
        } else {
-               u64 extra1 = req->extra1;
-               u64 extra2 = req->extra2;
+               u64 extra1 = 0, extra2 = 0;
+
+               if (req->flags & REQ_F_CQE32_INIT) {
+                       extra1 = req->extra1;
+                       extra2 = req->extra2;
+               }
 
                trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
                                        req->cqe.res, req->cqe.flags, extra1, extra2);
@@ -5019,6 +5026,7 @@ static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
 {
        req->extra1 = extra1;
        req->extra2 = extra2;
+       req->flags |= REQ_F_CQE32_INIT;
 }
 
 /*