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 65605509F18 for ; Mon, 7 Sep 2026 15:55:29 +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=1788796530; cv=none; b=IR5IM+mk9t2AfpX9PxDgs5tTbzgaixa2Lk3VTz+iBZWk09oPEIW24xa9SebbawbyRZND4qZPP4oX3b1w+0o8FyqxKtmzWJgmOJBLdL6DFI0kBRHOxEowad8PGOBFVBKFwtl4wbrNEgC7jONREq/pz3gJEObjKvuLZjM7/+TXCWY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788796530; c=relaxed/simple; bh=PqZBFuAuEhMuRQJWtL+VRj3CL51UJ8kO4D+GTBhYRls=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=CAIC0YnO+SuPwtMm/CbCINbUooRErC+TgPRJeck8tCp6U+cEfbUMYlfSvWHyABjQsIUUI8L5yT2aEBIH0roDd1u4SGszJTJajHu84bNRr/6h5We8f0zph3PQ7EYxC7fIiw4McYcVoJhHElksQwClgTJjfYBVD4mcvX8njrW6Ais= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iiQQG8Pm; 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="iiQQG8Pm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DBF7F1F00A3A; Mon, 7 Sep 2026 15:55:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788796529; bh=QHyft5VhwVcRbnncAggxvLynus7GgxG7yGf72ddUyAA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=iiQQG8PmHfwq+3mdxYq+O4UKylQdrxq3aR1oLTeThS7N0gChOdoatBc1337qDevys qnU72oRVymHTKPQpjIlK1UBTh5bkPXsnqdKS1svRkDA/myfCHOyQXFrRml83H+bei0 +gcCC4InS9uygb9V2I0i+nvx5gjQscaxz6RVfEPvt7bW4xyih1jZkoccjuv+Bd58CR xIbH4Qkk+oBdAVRHi57XV4KaTSu68rmTiwmdUhuD7HpZCARfdtayWaoW4B9/yP1263 rvEYAWXMF57NJ1akctOLPaDWaYUPW4WeC5DC05KAptt2z0I51O3wRRbHw6+cGngm8a y0fE7s7WBeuFA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 v2] ext4: avoid buffer/folio lock inversion in __ext4_get_inode_loc() Reply-To: sashiko-reviews@lists.linux.dev To: ThangNN99 Cc: tytso@mit.edu, linux-ext4@vger.kernel.org In-Reply-To: <20260907155017.75543-1-ngocthang2710.1999@gmail.com> References: <20260906104841.56075-1-ngocthang2710.1999@gmail.com> <20260907155017.75543-1-ngocthang2710.1999@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 07 Sep 2026 15:55:28 +0000 Message-Id: <20260907155528.DBF7F1F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > __ext4_get_inode_loc() looks up the inode bitmap bh while holding the > lock on the inode table bh: >=20 > __ext4_get_inode_loc() > lock_buffer(itable block) > sb_getblk(inode bitmap block) > __find_get_block_nonatomic() > folio_lock(bdev folio for bitmap block) >=20 > whereas block_read_full_folio() (e.g. userspace reading the bdev inode > directly) takes the same two locks in the opposite order: >=20 > block_read_full_folio() > folio_lock(some folio) > lock_buffer(bh in folio) > [ ... ] >=20 > Reported-by: syzbot+03afbb29537f0336b7ad@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=3D03afbb29537f0336b7ad > Reviewed-by: Jan Kara > Signed-off-by: ThangNN99 Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260907155017.7554= 3-1-ngocthang2710.1999@gmail.com?part=3D1