From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8B5C02367B0; Mon, 23 Jun 2025 10:26:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750674414; cv=none; b=mExKaEeVRFvNhYFOIVmJQ+qPdF9QcSHUdO7RurFPgcTM6XxyNZ06tdbqigYIYwoFtoRqCri02Kh4sw/yLRVyCTXHHZjPHmHsTDgRnLn32N26mdP/F4y6PUSJ1HAUzRllF6D3QF6TBehvmUrKhUWFzrgDYpbtI/PnXuXrTcvFDUU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750674414; c=relaxed/simple; bh=7Xubnx5PrszaDkFPcdQn0yJvFNKRnBtRBZljZ8eV87Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fUieGWBYosZ8BR+HTN8sELcH916Em7MAzbP1wxAX6NjLHcxGqDd23FryP81HdnyCyZqJ/TPj5DLU0jtuAv2v951AaIN2lk7jzQU/dt+n6oNYFqj+XlkblUKCJcIh/r/EruUdniy5AFBCNT2smUIJ5vg48MPx0nolbxAvDCb/VjA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CfnB+mjo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CfnB+mjo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B929DC4CEF0; Mon, 23 Jun 2025 10:26:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750674414; bh=7Xubnx5PrszaDkFPcdQn0yJvFNKRnBtRBZljZ8eV87Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CfnB+mjogCAFWsxEZGWCYMGFf+mYwiYYOVggLuWsLuewkGioyV2kdsS55h8h/9A1v f97TmJeIXm0KZaamPOoVTaM2eC+27mCUn1ien3aTvUshy2QdDa/BTMZ/hmbqskwJyl YSMD+WvUa5f+1/kqbVXj2ko7eKql88rlr0xucnhPs6czPP3InALEi0VKhyxTddE4F8 ooEUdk2odGnkyCef8GXSxSkStCNnXAkCLxttHqWunbn6t/vUIIN3Htq2EumT4r4MFe 9npy1dOYhJIc0zkhPai9Hc/LCvAat4naHaBW0F8gxRuwqfFJX+ABkb7q+fVt6vHAYn CMOAjnJGtJ0OA== Date: Mon, 23 Jun 2025 12:26:49 +0200 From: Christian Brauner To: Amir Goldstein Cc: Miklos Szeredi , linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, Kent Overstreet Subject: Re: [PATCH v3] ovl: support layers on case-folding capable filesystems Message-ID: <20250623-analog-kolossal-4eee589ebb08@brauner> References: <20250602171702.1941891-1-amir73il@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Sun, Jun 22, 2025 at 09:20:24AM +0200, Amir Goldstein wrote: > On Mon, Jun 16, 2025 at 10:06 AM Amir Goldstein wrote: > > > > On Sun, Jun 15, 2025 at 9:20 PM Kent Overstreet > > wrote: > > > > > > On Mon, Jun 02, 2025 at 07:17:02PM +0200, Amir Goldstein wrote: > > > > Case folding is often applied to subtrees and not on an entire > > > > filesystem. > > > > > > > > Disallowing layers from filesystems that support case folding is over > > > > limiting. > > > > > > > > Replace the rule that case-folding capable are not allowed as layers > > > > with a rule that case folded directories are not allowed in a merged > > > > directory stack. > > > > > > > > Should case folding be enabled on an underlying directory while > > > > overlayfs is mounted the outcome is generally undefined. > > > > > > > > Specifically in ovl_lookup(), we check the base underlying directory > > > > and fail with -ESTALE and write a warning to kmsg if an underlying > > > > directory case folding is enabled. > > > > > > > > Suggested-by: Kent Overstreet > > > > Link: https://lore.kernel.org/linux-fsdevel/20250520051600.1903319-1-kent.overstreet@linux.dev/ > > > > Signed-off-by: Amir Goldstein > > > > --- > > > > > > > > Miklos, > > > > > > > > This is my solution to Kent's request to allow overlayfs mount on > > > > bcachefs subtrees that do not have casefolding enabled, while other > > > > subtrees do have casefolding enabled. > > > > > > > > I have written a test to cover the change of behavior [1]. > > > > This test does not run on old kernel's where the mount always fails > > > > with casefold capable layers. > > > > > > > > Let me know what you think. > > > > > > > > Kent, > > > > > > > > I have tested this on ext4. > > > > Please test on bcachefs. > > > > > > Where are we at with getting this in? I've got users who keep asking, so > > > hoping we can get it backported to 6.15 > > > > I'm planning to queue this for 6.17, but hoping to get an ACK from Miklos first. > > > > Hi Christian, > > I would like to let this change soak in next for 6.17. > I can push to overlayfs-next, but since you have some changes on vfs.file, > I wanted to consult with you first. > > The changes are independent so they could go through different trees, > but I don't like that so much, so I propose a few options. > > 1. make vfs.file a stable branch, so I can base overlayfs-next on it > 2. rename to vfs.backing_file and make stable > 3. take this single ovl patch via your tree, as I don't currently have > any other ovl patches queued to 6.17 Let's start with 3. and switch to a stable branch on demand?