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 0FEF4175A6E; Sun, 5 Jul 2026 20:15:33 +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=1783282535; cv=none; b=CKmbdHl3DQjikZyjoepdxGm0D7/bdQLmkfcPpm6aUdtgYRX+7O0WB8aSt71dfXe+BWqhXtuE5ggdqZtEWa3Sv2Ap4xZLUi+mhhgWNxAK7Sf5eixBGA20zE9bKLsj6MLA8xLpGD9Ir5rUe6va5bEQVAwUJubuv38VwMoVAM9J4lg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783282535; c=relaxed/simple; bh=yDS3uFJa8pynG2mdfI80dCmBQ5u2U43X2AnUSZBV4vo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RqfT+N+4f/1rmLdGbzAnc4FCHLbx7E1oZ7AWuvc1lkY/sCaOdgrq4o17czsh26Epn8sy86TX8mInYrvP/uuhoZEl74De3x62yfSIBKF1Dd3Ix7KGRRJ9SYOSFKLQfwy++22JPkyQyOFmgWwL23RgV7yzyCXn7IJRmT1WhvhrDj8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FrPSMO9A; 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="FrPSMO9A" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D97D1F000E9; Sun, 5 Jul 2026 20:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783282533; bh=Jlw6RKgO5cyFNzF+9MdF+LGV8eC96x7LPuun++dRWdk=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=FrPSMO9AwY3lL0nuFdbSh3HSNChkX4F+SJ49Vg+msdirBdIz7T8pHZa4LlF60iS/T rk9cQ55SOdy8FZUOkt/CJR6FdKEgTHp7vPUgchC5dy0vAA8uRad0Wz+U6cvv79pycI h8pTbey/lpMxSwDUazOiA0hH/8nPc5RiJuIJ+BDC6jYMCubJhgZCoEge8cajx27R6k s4hzPkpaMYFLXpVOzS16i/RQacoh9L7tQk2qXY7gAtoh11luqRNvRVAGfGwisVerqT sxspH0U+dgY6R8ZJVJWTnt3TP/2YiB0Jc29iDKSr85odkmnfUwqexp2T0M7ILxIboL kPVIUNplZHHNg== Date: Sun, 5 Jul 2026 13:15:27 -0700 From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-block@vger.kernel.org, Christoph Hellwig , Theodore Ts'o , Andreas Dilger , Baokun Li , Jan Kara , Ojaswin Mujoo , Ritesh Harjani , Zhang Yi , Jaegeuk Kim , Chao Yu Subject: Re: [PATCH v2 04/17] fscrypt: Fully disallow IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE Message-ID: <20260705201527.GH41916@quark> References: <20260705194555.75030-1-ebiggers@kernel.org> <20260705194555.75030-5-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260705194555.75030-5-ebiggers@kernel.org> On Sun, Jul 05, 2026 at 12:45:41PM -0700, Eric Biggers wrote: > FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE works > only with the fs-layer implementation of file contents encryption, not > blk-crypto. This is a problem for standardizing on blk-crypto. > > Fortunately, no one should be using this combination anyway. It doesn't > make sense because the entire point of IV_INO_LBLK_32 is to support > inline encryption hardware that is limited to 32-bit DUNs. > > Thus, fully disallow IV_INO_LBLK_32 with s_blocksize != PAGE_SIZE. > > Reviewed-by: Christoph Hellwig > Signed-off-by: Eric Biggers Sashiko doesn't like that this would break compatibility of existing directories using FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32 if someone updates their kernel to use a different page size. I think we'll just have to take the risk here. I'm pretty confident this scenario isn't being relied on in practice, for various reasons including the one mentioned. - Eric