From patchwork Fri Jul 15 17:45:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Michal_Koutn=C3=BD?= X-Patchwork-Id: 12919545 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E79B4C433EF for ; Fri, 15 Jul 2022 17:45:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230234AbiGORpN (ORCPT ); Fri, 15 Jul 2022 13:45:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230186AbiGORpK (ORCPT ); Fri, 15 Jul 2022 13:45:10 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C496A2F3B6; Fri, 15 Jul 2022 10:45:09 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 68A301FA60; Fri, 15 Jul 2022 17:45:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1657907108; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZSHoQpScjMUzWiSKG0olhRxQb1JkMonLtUYiuDkfb4M=; b=U3AZUrNSgwy7DUCVJYyAITp2ZfBei/B/ktxAG/snKJgOhteOF5+tkPKXsOwZ6ekWnnOEwF 2efyWw2j3/HHJdjK49dMX4TZ5LZrCpCiNtwaB2gNCnSPIWp8lbBgQbooSKaPUH+kH8wJ4n MGHHawrABmMUTjNg5b3LknkJu/IG2ic= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3C3D913AC3; Fri, 15 Jul 2022 17:45:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 6rOtDaSn0WKPDAAAMHmgww (envelope-from ); Fri, 15 Jul 2022 17:45:08 +0000 From: =?utf-8?q?Michal_Koutn=C3=BD?= To: axboe@kernel.dk Cc: asml.silence@gmail.com, fam.zheng@bytedance.com, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, roman.gushchin@linux.dev, usama.arif@bytedance.com Subject: [PATCH] io_uring: Don't require reinitable percpu_ref Date: Fri, 15 Jul 2022 19:45:01 +0200 Message-Id: <20220715174501.25216-1-mkoutny@suse.com> X-Mailer: git-send-email 2.37.0 In-Reply-To: <8a9adb78-d9bb-a511-e4c1-c94cca392c9b@kernel.dk> References: <8a9adb78-d9bb-a511-e4c1-c94cca392c9b@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org The commit 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register") removed the worklow relying on reinit/resurrection of the percpu_ref, hence, initialization with that requested is a relic. This is based on code review, this causes no real bug (and theoretically can't). Technically it's a revert of commit 214828962dea ("io_uring: initialize percpu refcounters using PERCU_REF_ALLOW_REINIT") but since the flag omission is now justified, I'm not making this a revert. Fixes: 8bb649ee1da3 ("io_uring: remove ring quiesce for io_uring_register") Signed-off-by: Michal Koutný Acked-by: Roman Gushchin --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index a01ea49f3017..563f2266c674 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1911,7 +1911,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) ctx->dummy_ubuf->ubuf = -1UL; if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, - PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) + 0, GFP_KERNEL)) goto err; ctx->flags = p->flags;