From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2C91336E498 for ; Tue, 23 Jun 2026 10:12:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.113 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782209526; cv=none; b=Z1JvxJLjG7aHmkOBAoVQ8G/oXBBmGLFI4KlUsk514h+9WHdCUfrqWIURFUfV1vQQn9smhYYOrO7I4aLishcTtvin9iFAUhY8vkbYn2TZqOaXcZ9yYu0XUuLNU5YxjnGqGEUQrmzb6Zg1v8Y0Uv+CvPGotaQ3ZozsBsqQf28QB1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782209526; c=relaxed/simple; bh=GKWhxnmin9C8KXDCB0s8f8XY1VjFSulvTHn1/woT5fU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=n8aBCdSb51OCN1rcckytit9IbdFVE5aOgyydNhiTvJ3M0ToLVWRadQIw48+9HD+FG+93GE9xpKYoPOmmPmxmAISQZZm/m74mesgOLv3dcIqPc2bWYE88raGCywD4R1QUqZqHQ1iSWzVEAwlY3n0pqmxqFzrh4S+s/hXw5QD2tVE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=pR5meXF2; arc=none smtp.client-ip=115.124.30.113 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="pR5meXF2" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1782209522; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=gbhjrVUba6vrOJZoU2T57dkDjF3VKrHb52fpIyBFEf0=; b=pR5meXF2kJ+t6tlu5J8Yj/c3X4tdBFcrx6Ii6lyFXs54rmwfSa/PJNe+bfprBRkrlJO7sPlwpdog5SRboR7Gg0VY3zSb+Uz8fFtUFo7Tee8AR+PBxRfPZfDr418n2F1sHTJQB6L3Lg6gI2X55SQ8K6i2rWJsACOLhuF2zvAV0XY= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033045133197;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0X5TqL7-_1782209520; Received: from 30.221.132.85(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0X5TqL7-_1782209520 cluster:ay36) by smtp.aliyun-inc.com; Tue, 23 Jun 2026 18:12:01 +0800 Message-ID: Date: Tue, 23 Jun 2026 18:12:00 +0800 Precedence: bulk X-Mailing-List: linux-unionfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ovl: Allow changing default fsync_mode To: Yafang Shao Cc: miklos@szeredi.hu, amir73il@gmail.com, linux-unionfs@vger.kernel.org, fuweid89@gmail.com References: <20260623084337.54344-1-laoar.shao@gmail.com> <7c986c19-75d5-4092-a08a-4f865947e7ca@linux.alibaba.com> <80869b29-0791-4f63-8fa4-24bc039ce701@linux.alibaba.com> <7f9e379c-186d-41de-926d-bfc020e6c87c@linux.alibaba.com> From: Gao Xiang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2026/6/23 17:59, Yafang Shao wrote: > On Tue, Jun 23, 2026 at 5:49 PM Gao Xiang wrote: >> >> >> >> On 2026/6/23 17:34, Yafang Shao wrote: >>> On Tue, Jun 23, 2026 at 5:25 PM Gao Xiang wrote: >>>> >>>> >>>> >>>> On 2026/6/23 17:15, Yafang Shao wrote: >>>>> On Tue, Jun 23, 2026 at 5:00 PM Gao Xiang wrote: >>>>>> >>>>>> >>>>>> >>>>>> On 2026/6/23 16:43, Yafang Shao wrote: >>>>>>> We have enabled "volatile" fsync_mode on our Kubernetes production >>>>>>> environment to prevent container exit from being blocked when there >>>>>>> are many dirty pages to flush. This has worked well without introducing >>>>>>> any issues. >>>>>>> >>>>>>> However, on some of our production servers, upgrading the container >>>>>>> runtime to support the "volatile" mount option is not straightforward [0]. >>>>>>> To address this, we want to enable it by default within the kernel. >>>>>> >>>>>> Just a side note: "upgrade the container runtime is not >>>>>> straightforward", how? it seems that issue is already resolved and >>>>>> there is no more discussion. >>>>> >>>>> We still have many production servers running Docker, while the >>>>> "volatile" mount option is only supported by containerd. Upgrading >>>>> from Docker to containerd is a difficult process. >>>> >>>> But docker can be patched too: if upgrading the userspace is >>>> hard, why upgrading the linux kernel is easy? >>> >>> It is quite easy since the kernel can be livepatched without >>> rebooting. My employer is a heavy livepatch user. [1] >>> >>> [1]. https://lore.kernel.org/live-patching/ >> >> It's just a generic opinion, in general, docker can be live >> upgraded without pausing the containers, and upgrading >> userspace is easier / safer than patching the kernel. > > Are you sure? How would one change an already mounted overlayfs that > was not enabled with "volatile"? > I don't see how your patch can apply to already mounted overlayfs. Again, I don't want such customized messy breaks userspace again; with that patch, container runtime needs to consider if `volatile` is the default which just breaks the existing containerd versions. Thanks, Gao Xiang