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 7CE1C4D0CC4 for ; Fri, 9 Oct 2026 11:01:20 +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=1791543686; cv=none; b=IhT9vQWsAqhiuDnaoLUUtJ2VrcaQMvI6x6y5xCPPvPObtHLtByVm9qMJN9OZ0GgYPjnX8wr0dbNk3N76B4CK7Cs7UFQ2LcIS4m27Xv34qYQ3LT8GXwnCCmTdiZpGKWkDWGxTwUv0RmHX5WvQ6DPcbr+5A3Nrs7v/HJ8q0+HQU8c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791543686; c=relaxed/simple; bh=WMwG//0d1cXpGHvwFHY/dwwvHa+llPzRWDWSbjcVrIM=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=s0YFiH+bNnZ+Uzc9OIJrmMmJUoEJH5wY1z7cEQxQb+EhiH/EhSKFAN+loMPXWn3Hqjt+97XT3SD4toCS/nHIQ4S/GuRrialnKcyAB1e2V/KEQgbTv0FHdOX7dYbUy6FqsvmsW0yxYoR1BfgsdxLXWmvOxLXfJCXwWtgzCfR4edE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SlcWKbo6; 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="SlcWKbo6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDA4A1F000FF; Fri, 9 Oct 2026 11:01:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791543680; bh=TCvUsPEY+QLzSBc4F/BeCKTG8E1nXt4loK+NBCX1Fss=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=SlcWKbo6eRyUkxraAfRHFINaU6cky4dPkYQZTk7I84yfnSPaoDWgyhr5A5ovLfOJp BoPw6x+LMhwuGvhMkm0Cg0l/dNFjMCgCL5Zlh87fPpjhDpoLttMbuZI6c7fjV9UC73 ict8W+W668v/oYbOSHuOv0zPgHKNqKd6tQCJ560Y1BTrjhBHyasngtBQBCtDVzutOX LLO/bGtzQff9nIExyhGcm0031Y2ux4ur7eslnWDQWXBUt5X6qKON40MgKvlfZhKax+ Fwl6P7hBzvI9sm24rfBXsXeUbXEHqKOSVpPJRZ6l3Ut4hCcMjScwkR3gDrejorn+tO ZCL6WVAA3qsPA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v7 12/31] 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: <20261009103033.2920530-13-yi.zhang@huaweicloud.com> References: <20261009103033.2920530-1-yi.zhang@huaweicloud.com> <20261009103033.2920530-13-yi.zhang@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 09 Oct 2026 11:01:19 +0000 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/20261009103033.2920= 530-1-yi.zhang@huaweicloud.com?part=3D12