From nobody Sun Feb 8 16:05:48 2026 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4E78C8F6 for ; Thu, 25 Jul 2024 02:40:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721875234; cv=none; b=LhE3DRuABslWHZROeuXi+AQgvbujeIIXe30HC7LJYk+hiwYNILeEFQScXqjUMYNNCI3llPkPwEWFiZmCVhbhbR42yDdpVloFUAcrDbCgjPI012ksTPnUYJLOOO40ohZ7bg2Z7hppqnyPMjY7tG1ZAjJ5saWjJz57FjuSsdPt9F0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721875234; c=relaxed/simple; bh=+Q3gEmDizWp+wVM9J7repNjFwCf88tvXmIhUEt02z3U=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=tnOZqANivFST6MQZdlHqlAH1gdPh2RIAiIwYaU3aoZ0HIZt1YNe650Yw5ahs69qCJS06s2g56xDSOuA5Bnjqz12WK+LEuX/fNFqP7Xqc/blJ3VRkRwA1OoB9mBh1Ah387GA0gmMuKfvNj02MQuEEr3I9ANbjHZZ68v0zisJbaDc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=shopee.com; spf=pass smtp.mailfrom=shopee.com; dkim=pass (2048-bit key) header.d=shopee.com header.i=@shopee.com header.b=Ucj5nsdj; arc=none smtp.client-ip=209.85.214.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=shopee.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shopee.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=shopee.com header.i=@shopee.com header.b="Ucj5nsdj" Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-1fc4fcbb131so3756745ad.3 for ; Wed, 24 Jul 2024 19:40:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shopee.com; s=shopee.com; t=1721875232; x=1722480032; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Q6qGDo/UGEvSr10Mbjrm7JlnAMdeNemkg4xjMy1whgo=; b=Ucj5nsdj/Uhls5WQA73mxy2+GNsBls5GF2CiLS++Ort4R/m9Tzf44U/O2FRP0WAiHc KYWof9/jy4cG0TSySHCgoPvKpFp7F48COnV60NOSrFcqBeLZQLQztZ6zg1XgukOa0OVm wGnl8A3+lVDEfxoIA6aTlNDXNf8AF54ZfO327tMKvEF0tnoKt74lgXbKTRAPY+oOCzpe QC/mH0sBPqFUZlk0IGgdIE3xt0kWUtwqQ4KTIlC+Foqt5FkHOTXTEhBtFkjXmmFFB+AI PK6tlbwtu2mfs56MoqwmWm13d43mNU5A5GFty8nILu4MpbAyBAdHcNwZOJkgMSaeE+RJ XPgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721875232; x=1722480032; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Q6qGDo/UGEvSr10Mbjrm7JlnAMdeNemkg4xjMy1whgo=; b=KhoE07U+A+Hk1I4phbqmR076x/oeCQxbkB1iBrgPq9IMJjg3330Tf5YpXgxWKaXCft 69w7sSZmQvsvVNhutGzFf+QF0I7RH4VXzFhslTp9DSqS595qlFPdUdVQVnduSraQL7Yx vuCvgAVK2KULxMY3qzRkfqLDZd5IYZhkyMJ0fpBGVzgvn40wno9KPt0CDySBrn2SsUsn wyI3Nto0wctch2e/4VqV6s+DdscEcuBiJwqpSiGsSbsY3dLIkiPUhRY+TO7Xrlndbsm6 LRntRxEzyAsF/t9fzq8ts/JG3n0gzJBHbtWGOY/ns6G2t2vekMfyH5Rj6rt2cNa8jMSr UvWQ== X-Forwarded-Encrypted: i=1; AJvYcCWss67r9t0aW3RQudR/533kQoK9OEg+4xh3/+JeMebHvtqQmIxYnUmbGlbNwMZ2InO/C+Nba3ns9c1IRSUKzf3ToN78IuFnPGgLfNsi X-Gm-Message-State: AOJu0Yx/HKYUaPoxidcVR5y44zO0GIR68ezabVNK580eRYhbR/QSzf51 xo7BG3s5Z22UqbnYUXO5cOdx0fCAdjM7JQbOXmLF0I5zKgDzaArnvJbg9giW2/s= X-Google-Smtp-Source: AGHT+IFptWv1W0aKCBfAlsb4iJ8o/+2ZgqQljyVLnF95YGVYKfrsg+wXBhNV7DYReRptmCteiaPr5w== X-Received: by 2002:a17:902:fb0e:b0:1f7:1b08:dda9 with SMTP id d9443c01a7336-1fed924ff52mr4939955ad.8.1721875231899; Wed, 24 Jul 2024 19:40:31 -0700 (PDT) Received: from localhost.localdomain ([143.92.64.18]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1fed7c8c6f4sm2814165ad.24.2024.07.24.19.40.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jul 2024 19:40:31 -0700 (PDT) From: Haifeng Xu To: viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, tj@kernel.org Cc: axboe@kernel.dk, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Haifeng Xu Subject: [PATCH] fs: don't flush in-flight wb switches for superblocks without cgroup writeback Date: Thu, 25 Jul 2024 10:39:58 +0800 Message-Id: <20240725023958.370787-1-haifeng.xu@shopee.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When deactivating any type of superblock, it had to wait for the in-flight wb switches to be completed. wb switches are executed in inode_switch_wbs_w= ork_fn() which needs to acquire the wb_switch_rwsem and races against sync_inodes_sb= (). If there are too much dirty data in the superblock, the waiting time may in= crease significantly. For superblocks without cgroup writeback such as tmpfs, they have nothing to do with the wb swithes, so the flushing can be avoided. Signed-off-by: Haifeng Xu --- fs/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/super.c b/fs/super.c index 095ba793e10c..f846f853e957 100644 --- a/fs/super.c +++ b/fs/super.c @@ -621,7 +621,8 @@ void generic_shutdown_super(struct super_block *sb) sync_filesystem(sb); sb->s_flags &=3D ~SB_ACTIVE; =20 - cgroup_writeback_umount(); + if (sb->s_bdi !=3D &noop_backing_dev_info) + cgroup_writeback_umount(); =20 /* Evict all inodes with zero refcount. */ evict_inodes(sb); --=20 2.25.1