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 E61873D7D80 for ; Wed, 16 Sep 2026 09:42:26 +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=1789551756; cv=none; b=HBcpbmVkCR117bbJooHQx+w22NgQ3EGubUWoIpO1EjgybLnp8GxkVmkgGUVlCYeTXOjXoTsf+i5w+D5w/SSoWLP9WcUH5CsHZ/JDhpFRUWeDEbWeV9cV4/2yDkIgPiRIKzdDjGh/5Mv86RxpGyjIHAvNVPwGbqnFVOInk+RYh+4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789551756; c=relaxed/simple; bh=RYGypZkvHAPSoTnSEHGuD7Zf1CWfm+jT+OFsEBjBzis=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=AWuBiPPtivjpNXSwzxlm9ItSpLn/4ABT730ZPJyfJ6XySZ6ABlyrcAuRTsQxL/HJaR054uI6W2+RI10bIaibvztzevDZQ+ojzmgkvHcr8BiMtPh9fZG75wNNHAVtv6WNR4HHU/IwjDjxeRj8Lnb10dITgH8LF3YMlp7ddEXEhFI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XBxbYwMg; 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="XBxbYwMg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A24D81F000FF; Wed, 16 Sep 2026 09:42:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789551743; bh=MN3Y6Y13J0+bW8SY2ZNycMgr4/HI/LIg08+gs2mPR9c=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=XBxbYwMgLtNxNyMBpaxVZRt/Bpv3f8oAaUq5JGbI7D+x7zsKpISA0910zABlIx8cr SScNvr9yWD5jZ5R1WgTGyng1K59EwUbVAo+AXn3V3s+FdvpMDJOFdDs6xxBzxFFgE+ jq5yfXHh3G+6VvI/+o48zwO6XbKhHO/S2e8yLAnn3mf1h6wDMhCjSpdmyn/FWJ8g8T 8igcVfVLWYNfh4v/Do0TfrSwCsgEgrxCpX2dceNz3Rpsw68VmoRf98IMFUj9ReKxcj uAyH5NzOVQACk/BQ11FGwiqlq0mWUDjbZAAFq44AeRLZAN8b0zO6k1NmAdDYcQDGhx XecjmtaiBZ9hA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 2/3] mm/truncate: align truncation boundaries to mapping minimum folio order Reply-To: sashiko-reviews@lists.linux.dev To: "Zhang Yi" Cc: linux-ext4@vger.kernel.org, tytso@mit.edu In-Reply-To: <20260916092450.654408-3-yi.zhang@huaweicloud.com> References: <20260916092450.654408-1-yi.zhang@huaweicloud.com> <20260916092450.654408-3-yi.zhang@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 16 Sep 2026 09:42:23 +0000 Message-Id: <20260916094223.A24D81F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Zhang Yi >=20 > When the mapping has a non-zero minimum folio order (min_order), > folio_split() stops at min_order instead of order 0, so the sub-folio > containing a split point stays aligned to 1 << min_order rather than to > a single page. The original boundaries were based on page granularity, > so either boundary could land inside the min_order chunk at its edge, > and the truncation loop would drop that whole chunk, valid out-of-range > tail included. >=20 > For example, a 64K (order-4) folio with min_order =3D 2 (16K) punched from > offset 0 to 36K: >=20 > split @p0 -> [p0-p3, p4-p7, p8-p15] # non-uniform, min_order > folio2 =3D p8-p15 # straddles: p8 in range, p9-p15 tail valid > [ ... ] >=20 > Reported-by: Joanne Koong > Link: https://lore.kernel.org/linux-mm/CAJnrk1bQYUe6+1ryyJur5EEnZYrC+_5AY= sy=3DOWzVRgD4202y1g@mail.gmail.com/ > Fixes: e220917fa5077 ("mm: split a folio in minimum folio order chunks") > Signed-off-by: Zhang Yi Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260916092450.6544= 08-1-yi.zhang@huaweicloud.com?part=3D2