From e0eb71dcfc4b862261d99f7f90169142867beb0a Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 1 Oct 2021 18:07:01 +0100 Subject: [PATCH] io_uring: don't return from io_drain_req() Never return from io_drain_req() but punt to tw if we've got there but it's a false positive and we shouldn't actually drain. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/93583cee51b8783706b76c73196c155b28d9e762.1633107393.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 36 ++++++++++++++---------------------- 1 file changed, 14 insertions(+), 22 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index fb073915fa5c..b0b4c5b00f37 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6428,46 +6428,39 @@ static u32 io_get_sequence(struct io_kiocb *req) return seq; } -static bool io_drain_req(struct io_kiocb *req) +static void io_drain_req(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; struct io_defer_entry *de; int ret; - u32 seq; + u32 seq = io_get_sequence(req); /* Still need defer if there is pending req in defer list. */ - if (likely(list_empty_careful(&ctx->defer_list) && - !(req->flags & REQ_F_IO_DRAIN))) { - ctx->drain_active = false; - return false; - } - - seq = io_get_sequence(req); - /* Still a chance to pass the sequence check */ if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) { +queue: ctx->drain_active = false; - return false; + io_req_task_queue(req); + return; } ret = io_req_prep_async(req); - if (ret) - goto fail; + if (ret) { +fail: + io_req_complete_failed(req, ret); + return; + } io_prep_async_link(req); de = kmalloc(sizeof(*de), GFP_KERNEL); if (!de) { ret = -ENOMEM; -fail: - io_req_complete_failed(req, ret); - return true; + goto fail; } spin_lock(&ctx->completion_lock); if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) { spin_unlock(&ctx->completion_lock); kfree(de); - io_queue_async_work(req, NULL); - ctx->drain_active = false; - return true; + goto queue; } trace_io_uring_defer(ctx, req, req->user_data); @@ -6475,7 +6468,6 @@ fail: de->seq = seq; list_add_tail(&de->list, &ctx->defer_list); spin_unlock(&ctx->completion_lock); - return true; } static void io_clean_op(struct io_kiocb *req) @@ -6931,8 +6923,8 @@ static void io_queue_sqe_fallback(struct io_kiocb *req) { if (req->flags & REQ_F_FAIL) { io_req_complete_fail_submit(req); - } else if (unlikely(req->ctx->drain_active) && io_drain_req(req)) { - return; + } else if (unlikely(req->ctx->drain_active)) { + io_drain_req(req); } else { int ret = io_req_prep_async(req);