From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 819DA70830 for ; Wed, 8 Apr 2026 05:03:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775624623; cv=none; b=VCKuNC1yd0uHqwmYvKPnsg93/peqSLi01wky6aA9BGIfu3aeZ3gYBOTAdzj9afwEAEY9i7M16odsdsQGqK9/elPx0uQBFLiYtpFHGVk92tuMqJysv2cTJnV+OBjF39AzO3OlP13jFTb79vOot4ajPSM1MzfdNbsbq5atxyX4hd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775624623; c=relaxed/simple; bh=UwfkPRAHZKA1fTPJMPuhB/TwI/OKdQosFQ4BiEg+Hec=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Nvv674GDgbzoIYOoove7odI95+edvoRAwUlz2n0q6AypHCntnihle9N0pmAcLDlb3g9qKF25GyfCgyAbQGLKrnmxssAWoJ4LKSbF7aJ0TW765vyfTrI/Ul4SkbQINtSYysS+xMFITdxRngfi1j6L7Jm9Y3VnbSd7YZHZbi8yJlU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=s6ylrp4A; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="s6ylrp4A" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5/qEsbqxOUv5KSzyhq5DLMuZrREUg6mbeIZELe+SUww=; b=s6ylrp4Asy9kfLDQpYmKGUrXLC 89uIj0BTQszIY71WxqqXaqlEOKWSwJMVa5rD8GE5gVB9/eItM5O12CYEKd/uNpxNIQTWh5mPIW6hs 718SAvy03aXJJbOwQYSvpfTJ/9YEU+91O9N6iQ+YmtyTI3rA2675pRjeG2SBhZkFiJvVPhbsE2zSY Moc3JvijJkdGh5ybAJrDeOW/EKbz1c7eYqPhbSsJ1ds8RTgsznD9lzX5PIctU6ttD/vfmnaI/8hF/ j43CoVI48GMFJeL9IXH6DrBNfI+pSythCP6Vk/Kw0TzP5f5/oRxvEWtNCbtNrmTkY7kfkK+ItQMSG W4EiJ7ZQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1wAL4l-00000008GcG-0ubk; Wed, 08 Apr 2026 05:03:39 +0000 Date: Tue, 7 Apr 2026 22:03:39 -0700 From: Christoph Hellwig To: Jaegeuk Kim Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] f2fs: do not support mmap write for large folio Message-ID: References: <20260406154940.2407853-1-jaegeuk@kernel.org> 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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Apr 07, 2026 at 10:58:11PM +0000, Jaegeuk Kim wrote: > On 04/06, Christoph Hellwig wrote: > > On Mon, Apr 06, 2026 at 03:49:40PM +0000, Jaegeuk Kim wrote: > > > Let's check mmmap writes onto the large folio. > > > > Why? And how is this not breaking applications? > > Since we only support the large folio on the read case. In general spelling such basic out in the commit log, and even comments is really helpful. I'm curious how this works, though - by the time you read a large folio you don't know if it will ever be written to.