From: Pavel Begunkov Date: Wed, 23 Nov 2022 11:33:36 +0000 (+0000) Subject: io_uring: add completion locking for iopoll X-Git-Tag: v6.2-rc1~131^2~18 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2ccc92f4effcfa1c51c4fcf1e34d769099d3cad4;p=thirdparty%2Flinux.git io_uring: add completion locking for iopoll There are pieces of code that may allow iopoll to race filling cqes, temporarily add spinlocking around posting events. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/84d86b5c117feda075471c5c9e65208e0dccf5d0.1669203009.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/io_uring/rw.c b/io_uring/rw.c index 1ce065709724b..61c3268319493 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -1049,6 +1049,7 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) else if (!pos) return 0; + spin_lock(&ctx->completion_lock); prev = start; wq_list_for_each_resume(pos, prev) { struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); @@ -1063,11 +1064,11 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) req->cqe.flags = io_put_kbuf(req, 0); __io_fill_cqe_req(req->ctx, req); } - + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); if (unlikely(!nr_events)) return 0; - io_commit_cqring(ctx); io_cqring_ev_posted_iopoll(ctx); pos = start ? start->next : ctx->iopoll_list.first; wq_list_cut(&ctx->iopoll_list, prev, start);