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 791254AE113 for ; Thu, 3 Sep 2026 13:19:11 +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=1788441554; cv=none; b=UWBrJEag04QK1SvkkV2NgPqrTmg43nfsvzVMxqyq91M+OfmdBPFLuD0eyUnL+o8WPkVdMu0yvRsQK9qusplpR1lvU0a+/39y+bV3tETCkAgRemU8pLsosg0qBy2HkiuUlQiBRVkjJgjNem/yHT1MKShFIv+kpbRKTALiyXUMYSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788441554; c=relaxed/simple; bh=TQNoDhX6hnz9OPbCgiJ0qnhqMGgeMN50efh6KjcOV+U=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=cLJ6oxvAsfh+gWWWBvQhUildW9Mwk0R8zoePt6yFagWy7Oc+MtfeyZVMyW8DsS2NS4b2l+CW4cCmdduzltTj5wOSx5rr48+t5vnF9gyJQymt7h07LnamlhUcYKVJc6JicVkdUGcKyrayRvadzWHapJjpGmmjRZko2odT0863/PM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j+YppW85; 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="j+YppW85" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA49E1F00A3A; Thu, 3 Sep 2026 13:19:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788441550; bh=a8Y9/aFYWjXsybv4TLmgyJfdKS9eRixgzRKCoX098Nc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=j+YppW85RdSlITGOhzbCEGCkCe1w6Noeu2pzQEoskCeQRo+FFWjAGiud7PbCRSrSP hvLrp5wxDLOi8H2aKTm8cWWaLUWeZ88pUHgMWxc7c3N0Fv/zSuuMGNtaJL14ofeLUp 9Im2/NBXZ+5W3ZObJ0kL2Kd8vgFyqIfqr+qwTkwczUEi3TicBTAuFX/rPPf69smhOs FXwKEGcV0i4xT+hnr++n9iXNq/OUJou8MMFnwKT+c0e+dLZR9MILLVSDi84hdxcvBC InIODYXgBtfrLmHguIRClFGXip7yrGcED8HQRy2nD3932p2021yq5y5A/+/Bn25/kX rKteUmQVZmfSQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 18/31] ext4: drain writeback before removing extents on the iomap path Reply-To: sashiko-reviews@lists.linux.dev To: "Zhang Yi" Cc: tytso@mit.edu, linux-ext4@vger.kernel.org In-Reply-To: <20260903123543.2302999-19-yi.zhang@huaweicloud.com> References: <20260903123543.2302999-1-yi.zhang@huaweicloud.com> <20260903123543.2302999-19-yi.zhang@huaweicloud.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 03 Sep 2026 13:19:10 +0000 Message-Id: <20260903131910.BA49E1F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Zhang Yi >=20 > Because the iomap infrastructure does not always create an ifs to > manage sub-folio state when folio size is larger than blocksize, > invalidating a partial dirty folio during punch hole may fail to > clear the dirty state of the affected range. As a result, writeback > of that folio may observe a hole. At writeback submit time, > ext4_map_blocks() already handles this case and will not allocate > blocks. However, when punch hole races with writeback, the > following scenario can cause I/O completion to encounter a hole. >=20 > punch hole writeback > ---------- --------- > ext4_punch_hole() > ext4_truncate_page_cache_block_range() > [ ... ] > always maintain an ifs when folio size is larger than blocksize, so that > partial invalidate reliably clears sub-block dirty bits and no draining > is needed. >=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=3D18