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[23.128.96.35]) by mx.google.com with ESMTPS id e18-20020a17090301d200b001b8c824e826si5754770plh.533.2023.10.07.00.40.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Oct 2023 00:40:56 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by groat.vger.email (Postfix) with ESMTP id 267C0826316F; Sat, 7 Oct 2023 00:40:49 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at groat.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343712AbjJGHkL (ORCPT + 18 others); Sat, 7 Oct 2023 03:40:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343700AbjJGHkK (ORCPT ); Sat, 7 Oct 2023 03:40:10 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0549ECE; Sat, 7 Oct 2023 00:40:09 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.169]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4S2cdb5bQHz4f3kkj; Sat, 7 Oct 2023 15:40:03 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP3 (Coremail) with SMTP id _Ch0CgB3uzpTCyFlgqLRCA--.24202S2; Sat, 07 Oct 2023 15:40:05 +0800 (CST) From: Kemeng Shi To: miklos@szeredi.hu, bernd.schubert@fastmail.fm Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] fuse: remove unneeded lock which protecting update of congestion_threshold Date: Sat, 7 Oct 2023 23:39:56 +0800 Message-Id: <20231007153956.344794-1-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 MIME-Version: 1.0 X-CM-TRANSID: _Ch0CgB3uzpTCyFlgqLRCA--.24202S2 X-Coremail-Antispam: 1UD129KBjvdXoWrZw4kJF4UJF1xur43XrW8Zwb_yoWkurb_WF Z8XFs7C3W5trWF9asrZw1Fqryvgry0yr1jv398JryYvFy5trsIvF9rurn5ury7ZF4jq3s8 C3sYgFW3WwnFgjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb7AYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l87I20VAvwVAaII0Ic2I_JFv_Gryl8c AvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWD JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Gc CE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxI r21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87 Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IY c2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s 026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF 0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0x vE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2 jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU0miiDUUUUU== X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=2.8 required=5.0 tests=DATE_IN_FUTURE_06_12, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_SBL_CSS, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on groat.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (groat.vger.email [0.0.0.0]); Sat, 07 Oct 2023 00:40:49 -0700 (PDT) X-Spam-Level: ** X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1779081628493920514 X-GMAIL-MSGID: 1779081628493920514 Commit 670d21c6e17f6 ("fuse: remove reliance on bdi congestion") change how congestion_threshold is used and lock in fuse_conn_congestion_threshold_write is not needed anymore. 1. Access to supe_block is removed along with removing of bdi congestion. Then down_read(&fc->killsb) which protecting access to super_block is no needed. 2. Compare num_background and congestion_threshold without holding bg_lock. Then there is no need to hold bg_lock to update congestion_threshold. Signed-off-by: Kemeng Shi --- fs/fuse/control.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/fs/fuse/control.c b/fs/fuse/control.c index ab62e4624256..1bf928e277fe 100644 --- a/fs/fuse/control.c +++ b/fs/fuse/control.c @@ -174,11 +174,7 @@ static ssize_t fuse_conn_congestion_threshold_write(struct file *file, if (!fc) goto out; - down_read(&fc->killsb); - spin_lock(&fc->bg_lock); - fc->congestion_threshold = val; - spin_unlock(&fc->bg_lock); - up_read(&fc->killsb); + WRITE_ONCE(fc->congestion_threshold, val); fuse_conn_put(fc); out: return ret;