Re: [PATCH] io_uring: rename "copy buffers" to "clone buffers"

[Jens Axboe <axboe@kernel.dk>]

On 10/15/24 8:27 PM, Jens Axboe wrote:
> Thanks, I'll take a look! A vmlinux would be handy to have, in terms of
> looking up where it's fauling without spending too much time on it. But
> if you don't have it, no worries, I'll give this a spin tomorrow.

Ah, it was just missing the dummy_ubuf check. The below should fix it,
I'll queue it up and add a test case to liburing too.

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 33a3d156a85b..6f3b6de230bd 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1176,7 +1176,8 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx
 	for (i = 0; i < nbufs; i++) {
 		struct io_mapped_ubuf *src = src_ctx->user_bufs[i];
 
-		refcount_inc(&src->refs);
+		if (src != &dummy_ubuf)
+			refcount_inc(&src->refs);
 		user_bufs[i] = src;
 	}
 

-- 
Jens Axboe