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 8F8BC4AC145 for ; Thu, 3 Sep 2026 13:13:53 +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=1788441276; cv=none; b=HJfrCuOrTdiaSB07DlQMD/SwSFgy1qrfPIJw+RHGgt/dztGAYDYGYsaLJ9D2N8hpg+CkmSejMP0uIEddEVjmMKBa080j5C11yiizxnKanOYONydHKyjtn6Zwjy6HTOUU+6rGQTgmHfIQW03LGe+2rI6uJ/mb3feJofRZ3PxFIq8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788441276; c=relaxed/simple; bh=OPqoHvF+b1l6e3DkvbNLBLHs/GEArrpR49ap64KcWZE=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=UTdmQi5PjtRShD1Hdo92P4xEiDaeyTUBe5TNLvCjFayEW2OwXLtxNzOi4Ln6lK2ElJ5KZ+T7EctyO+E8NeIuSY2dZ8rp2Dk998MEdKEgJVDxIx3ijpZDrzJRfv/AILuNoft+x7fG5r0UpQo8s5ZnCbb7lv/J0buU8iic/lWhANA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ULv0GS7q; 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="ULv0GS7q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D12E1F00ACA; Thu, 3 Sep 2026 13:13:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788441231; bh=t1RgXYWpko1tcobvLVZ6WQu502G5fRMq9UwhscRG6nA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=ULv0GS7q4OJ8pDj6daHyOKhCF2rWmIFz+MrLKiKfUGaekczGYWbM4/jX4289zRQk+ 0rG7Ft7L3ZskQyjHkjRLXhQfTjYD/dBJfyUQblOxseqsJNUc5gwp3XyxNRGUPFdpzv ZkiQvKw1w/XzVu9NwptXP1TQy4zdqjvipymUcnbRw6rKWwlTEKYaK2XbIAge+4lfKh kL5cVcGcA5kkF5PhKYyb6mIeHiyQbgdpoE8uJBg1mptpMOTyQQAdJVzhDnI45PHoi7 yfI6davOBKuaOVxlaaclhIqftuBtO94RNZUvzyUVYT9pKRlkNuFIa8GZagV0dfp+Gz 4X5tJdlwjqdaw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 13/31] ext4: do not use data=ordered mode for inodes using buffered iomap path Reply-To: sashiko-reviews@lists.linux.dev To: "Zhang Yi" Cc: tytso@mit.edu, linux-ext4@vger.kernel.org In-Reply-To: <20260903123543.2302999-14-yi.zhang@huaweicloud.com> References: <20260903123543.2302999-1-yi.zhang@huaweicloud.com> <20260903123543.2302999-14-yi.zhang@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 03 Sep 2026 13:13:51 +0000 Message-Id: <20260903131351.9D12E1F00ACA@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Zhang Yi >=20 > The data=3Dordered mode introduces two fundamental conflicts with the > iomap buffered write path, leading to potential deadlocks. >=20 > 1) Lock ordering conflict > In the iomap writeback path, each folio is processed sequentially: > the folio lock is acquired first, followed by starting a transaction > to create block mappings. >=20 > In data=3Dordered mode, writeback triggered by the journal commit > process may attempt to acquire a folio lock that is already held by > iomap background writeback process. Meanwhile, iomap, under that same > folio lock, may start a new transaction to map other blocks on this > folio and wait for the currently committing transaction to finish, > [ ... ] >=20 > Online defragmentation does not yet support iomap; this can be resolved > separately in the future. >=20 > 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/20260903123543.2302= 999-1-yi.zhang@huaweicloud.com?part=3D13