It's hard to implement cloning if the internal structure needs to be mutable and/or relies on other ring resources. In preparation to such buffer types, add a flag indicating that the buffer can't be cloned. It might be possible to add cloning in the future for them, but that would likely need reallocating the structure and reacquiring resources in case by case manner. Signed-off-by: Pavel Begunkov --- io_uring/rsrc.c | 5 +++++ io_uring/rsrc.h | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 83a7ad9f5bc7..0b526b094dc9 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -1434,6 +1434,11 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx if (!src_node) { dst_node = NULL; } else { + if (src_node->buf->flags & IO_REGBUF_F_UNCLONEABLE) { + io_rsrc_data_free(ctx, &data); + return -ENOMEM; + } + dst_node = io_rsrc_node_alloc(ctx, IORING_RSRC_BUFFER); if (!dst_node) { io_rsrc_data_free(ctx, &data); diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h index 9ef88383b363..73d7b1ebf0b6 100644 --- a/io_uring/rsrc.h +++ b/io_uring/rsrc.h @@ -26,7 +26,8 @@ struct io_rsrc_node { }; enum { - IO_REGBUF_F_KBUF = 1, + IO_REGBUF_F_KBUF = 1 << 0, + IO_REGBUF_F_UNCLONEABLE = 1 << 1, }; struct io_mapped_ubuf { -- 2.54.0