From patchwork Sun Dec 11 07:06:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13070510 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C432C4332F for ; Sun, 11 Dec 2022 07:07:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230150AbiLKHHz (ORCPT ); Sun, 11 Dec 2022 02:07:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229775AbiLKHHx (ORCPT ); Sun, 11 Dec 2022 02:07:53 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71433328; Sat, 10 Dec 2022 23:07:46 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C7EC860CF2; Sun, 11 Dec 2022 07:07:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06B2EC433F1; Sun, 11 Dec 2022 07:07:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670742465; bh=psO0ZX6nJ2FtuYgmtkGSazEI/UfM/vdZQtAlmPfn/fs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=inJU8Cb+PgiWi/tm9t6otqAd3//7B+h56IfSSBx4FswQdf4mGTVDWWzVhQl1UC/13 DvDHei/manfGaCURh+AemGutOLweE6XCgPEpI/llpAiSjXb3p09KmoCB2QLeHgBPG6 y+pur9nMRFaKScGqKlc9ZJUafTCBDtc9TYzmNA1x36IB2qsR9IMefNtrF4BXjWTJLi KzPFH8Yk6q6ZmRopNCJTZx1vqWA1guDCro3CpsbZ2J3CFov2o93/vnDQ9MKODBtNnG 62YWxIMOY/xriaEt9gdsxGZHzX4JYSY6RsqxC4N7JZmISjiVOi4KJbNvkcoRuHIsNR w7r1ZgszjtS0g== From: Eric Biggers To: fstests@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org Subject: [PATCH 02/10] common/verity: set FSV_BLOCK_SIZE to an appropriate value Date: Sat, 10 Dec 2022 23:06:55 -0800 Message-Id: <20221211070704.341481-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221211070704.341481-1-ebiggers@kernel.org> References: <20221211070704.341481-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org From: Eric Biggers In order to maximize the chance that the verity tests can actually be run, FSV_BLOCK_SIZE (the default Merkle tree size for the verity tests) needs to be min(fs_block_size, page_size), not simply page_size. The only reason that page_size was okay before was because the kernel only supported merkle_tree_block_size == fs_block_size == page_size anyway. But that is changing. Signed-off-by: Eric Biggers --- common/verity | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) diff --git a/common/verity b/common/verity index 1a53a7ea..a94ebf8e 100644 --- a/common/verity +++ b/common/verity @@ -13,6 +13,11 @@ if [ "$FSTYP" == "btrfs" ]; then fi fi +# Require fs-verity support on the scratch filesystem. +# +# FSV_BLOCK_SIZE will be set to a Merkle tree block size that is supported by +# the filesystem. Other sizes may be supported too, but FSV_BLOCK_SIZE is the +# only size that is guaranteed to work without any additional checks. _require_scratch_verity() { _require_scratch @@ -27,7 +32,7 @@ _require_scratch_verity() # Try to mount the filesystem. If this fails then either the kernel # isn't aware of fs-verity, or the mkfs options were not compatible with - # verity (e.g. ext4 with block size != PAGE_SIZE). + # verity (e.g. ext4 with block size != PAGE_SIZE on old kernels). if ! _try_scratch_mount &>>$seqres.full; then _notrun "kernel is unaware of $FSTYP verity feature," \ "or mkfs options are not compatible with verity" @@ -39,6 +44,27 @@ _require_scratch_verity() _notrun "kernel $FSTYP isn't configured with verity support" fi + # Select a default Merkle tree block size for when tests don't + # explicitly specify one. + # + # For consistency reasons, all 'fsverity' subcommands, including + # 'fsverity enable', default to 4K Merkle tree blocks. That's generally + # not ideal for tests, since it's possible that the filesystem doesn't + # support 4K blocks but does support another size. Specifically, the + # kernel originally supported only merkle_tree_block_size == + # fs_block_size == page_size, and later it was updated to support + # merkle_tree_block_size <= min(fs_block_size, page_size). + # + # Therefore, we default to merkle_tree_block_size == min(fs_block_size, + # page_size). That maximizes the chance of verity actually working. + local fs_block_size=$(_get_block_size $SCRATCH_MNT) + local page_size=$(get_page_size) + if (( fs_block_size <= page_size )); then + FSV_BLOCK_SIZE=$fs_block_size + else + FSV_BLOCK_SIZE=$page_size + fi + # The filesystem may have fs-verity enabled but not actually usable by # default. E.g., ext4 only supports verity on extent-based files, so it # doesn't work on ext3-style filesystems. So, try actually using it. @@ -47,10 +73,6 @@ _require_scratch_verity() fi _scratch_unmount - - # Merkle tree block size. Currently all filesystems only support - # PAGE_SIZE for this. This is also the default for 'fsverity enable'. - FSV_BLOCK_SIZE=$(get_page_size) } # Check for CONFIG_FS_VERITY_BUILTIN_SIGNATURES=y, as well as the userspace