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 1AA8544C4E2 for ; Fri, 14 Aug 2026 10:12:40 +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=1786702371; cv=none; b=jrKEI/Mi+DKBo4LBDl4rudoaXzGtJa/THawG0FJJATkGAlBkQdlfxeSKOWHINuqi78oL+kmXn0et+79oU+mBfF8iJEKibGmXXN7eF1UDs/szhiheJszo6AoK532LczTRBTAN1n0hID/dHQ9wS+SwU02acasW0MQXrzqi3ysuURA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786702371; c=relaxed/simple; bh=YSAsSntQLRZuNkqKoqf8Uidp6JLYp0LmTcy3gRAT05Y=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=MWByprvbKD9bjiHEGgmmcghYTLZG9EMkJoqt/hQUlUFvJqQHTu7G7us5jg78k5Pz+CQ5iyEI0i8hMmQhADqGZORVw6E1qaNwakYfFHfdNTc63jNBQX0j9ACoq+FEGqgiSQxNa0Y3qSBNUwHbM2iVp1rQ0GdnGUG8SkQcKyToL3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YoWXFQAC; 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="YoWXFQAC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 168181F00A3D; Fri, 14 Aug 2026 10:12:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786702356; bh=DJBahq80iToO8ECFsMFPTcAIVihdpXXJ+4e4ZCto8KU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=YoWXFQACqohVT2Db+xOjRgRsgv8WtACyDkxpF1ZLIBVhMYpOWpQRVD/JhiZ7YIAuM CVQh+EATbTzfHuCZY0bC42C0jcUs80A8HknUKqKgwWHfpo2JTrD07J1fmn76tMsy4E e9Acr+6hza/gyDWxuUXlvwxS5SJ9tAJ1LztBbPC+J8yQUYpn1ebRagFLiOu4gPqut8 HMpEGx5idF+aUWIbJuhr8G5LOt7V/ROtuEYNUrsTTphv7n9u+I5mJyX5x/Fqle3S9w DnPQRLLKcsCZkln/C32Yr4r+QxLvdoarFzuiWtsMjkOWZ1Ii/OMrBCCb4s8nbLGH7A p83A0plnJT3cA== From: sashiko-bot@kernel.org Subject: Re: [PATCH -next v5 14/32] 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: <20260814093331.1703882-15-yi.zhang@huaweicloud.com> References: <20260814093331.1703882-1-yi.zhang@huaweicloud.com> <20260814093331.1703882-15-yi.zhang@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 14 Aug 2026 10:12:35 +0000 Message-Id: <20260814101236.168181F00A3D@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/20260814093331.1703= 882-1-yi.zhang@huaweicloud.com?part=3D14