From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7202882899; Fri, 22 May 2026 04:02:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779422528; cv=none; b=o3sq0PEw2p/DW7vmgPEOHPRkuMJZh3PVLAPnkNmU8KbemH6zcgaKBt8mWppjXC7x3iOXgOSC5Yxd6wA7X5Je/Xi3C6zh8Ioqsp2jpK+dzAUEGpmmbQIRoF8cQmlcrvVSrD2HyrhqjRqT0yTAB5n8Ex/mNQAECFS0YCoNISrNOiM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779422528; c=relaxed/simple; bh=a1dlM8iJuJM1TSh53Q3cSojpGU+Vmv7z09jD7VTe34g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FyB33F6zIZYOlY851nvcvWoideQJAhOOG3Le0Bdg9ysBlMZsxWskVaqutIKwaK+z+siHqksF1mPN0uaZOT21NCH/Sssl364CnTTEQKmFS6jyfSsAEeO3LWzHEtQbvZNILWmDFL5BlbTKUQIc7BIMhy3GfexYTxnTDgr3qjAX2b8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V5U8pIq9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V5U8pIq9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A80681F000E9; Fri, 22 May 2026 04:02:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779422527; bh=GFwLqtBegPrYOeSN0ye6SbCQz3TQv1Qmus2tJiQyxPs=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=V5U8pIq9CYVjKN1M26c9b9NKyxbKNnsst43BpYHw1DsITUIVizoffTmheov44CS5q RC4YKVuVcJV1HeIny7fKMAPNUaVudn/uTOVvE44fxeitC4tGQLrVW5VFS7IbGno+H+ cT2aATaZRzZsglm4rt0Y9AF1jrW8fI5GyXvQw0rIyoOyDQW+I92HQ7KEz4K8PpOoiP 83HyHOFnC80JpiUmO6zQ2C4JY4DUjKUow0IeN7OzXJfPEspGNm+1XkSkX6RsNMyFZx hWGUUq+V+NminNRePBFveQW0fsFFOrqS7G+6Qjvo70M6y6660opAlN7QRmJHAlwatb Ezhvlm7T0Nwlg== Date: Fri, 22 May 2026 04:02:05 +0000 From: Jaegeuk Kim To: Eric Biggers Cc: Theodore Tso , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, Christoph Hellwig , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Akilesh Kailash , Christian Brauner Subject: Re: [f2fs-dev] [PATCH v2] f2fs: another way to set large folio by remembering inode number Message-ID: References: <20260409134538.3692605-1-jaegeuk@kernel.org> <20260521155748.GA79343@macsyma-wired.lan> <20260522035331.GE5937@quark> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260522035331.GE5937@quark> On 05/21, Eric Biggers via Linux-f2fs-devel wrote: > On Fri, May 22, 2026 at 03:32:39AM +0000, Jaegeuk Kim wrote: > > On 05/21, Theodore Tso wrote: > > > On Thu, May 21, 2026 at 01:51:08AM -0700, Christoph Hellwig wrote: > > > > > You haven't sent a proposal. This is a reply to a reply to a reply of a > > > > > patch. There's no justification for why f2fs is so special that it > > > > > needs this. What the hell is going on? You know this is not the way to > > > > > get code merged into Linux. > > > > > > > > None of this got properly answers, and this broken interface now landed > > > > in linux-next. IT is offloading a user.* xattr which is free-form > > > > user data with semantics that are weird to say it very nicely. > > > > > > > > All this was done against the advice in the mailing list discussion. > > > > > > So let me get this straight. This is a magic xattr interface which is > > > not even persisted in the file system, but instead sets a 32-bit > > > bitmask in the struct inode which disappears once the inode gets > > > flushed from the inode stack. And it uses a generic xattr name, > > > "user.fadvise". > > > > > > There's no way in *hell* any other file system is likely to adopt such > > > a broken interface, so why didn't you just use an ioctl to set this > > > magic f2fs-specific flag? > > > > I went this route because Android heavily restricts ioctl() permissions > > and we needed broader access for this to work within the framework. > > It's straightforward (2 lines I think) to update Android's SELinux > policy to allow an ioctl in all domains. So that doesn't seem like a > reason to not use an ioctl. In fact this is actually a reason *to* use > an ioctl, as it shows that ioctls can be allowed/denied independently as > needed, whereas xattrs just use the file write permission. Ok, that's also great news to me. > > - Eric > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel