io_uring: add end-of-bits marker and build time verify it
Not easy to tell if we're going over the size of bits we can shove
in req->flags, so add an end-of-bits marker and a BUILD_BUG_ON()
check for it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index f131105..4bbad2ed 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -511,6 +511,9 @@
REQ_F_OVERFLOW_BIT,
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
+
+ /* not a real bit, just to check we're not overflowing the space */
+ __REQ_F_LAST_BIT,
};
enum {
@@ -7998,6 +8001,7 @@
BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
+ BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
return 0;
};
