From patchwork Tue Sep 5 00:58:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13374573 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 82E46CA0FFC for ; Tue, 5 Sep 2023 15:59:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232306AbjIEP7Z (ORCPT ); Tue, 5 Sep 2023 11:59:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243925AbjIEBEe (ORCPT ); Mon, 4 Sep 2023 21:04:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E278CC3; Mon, 4 Sep 2023 18:04:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B3E65B80EF6; Tue, 5 Sep 2023 01:04:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53823C433CC; Tue, 5 Sep 2023 01:04:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693875867; bh=ZD+Z0ymC6v+NTgD8Io2pUOkKRPb7xF1w6LxtCKdRREU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k5Ywg0BWZ9QNcRcFSQLFqhYxn6yBSHXSk/gg6rAoBOoiF9PYiOSNYl6NPK0GJFPTh cvv6WlnIsA8NJ4Au0a19Ya4r/lzv64+t9HxEr/59HiggwZNKodlpiblrPqFstn+kxm eYyUDqdfvmfqMcg4udD+EfYRwEhHuZ+tqE3fH15R352YL78Nr59OaA2m0JwcVFJyZK 8xTUQrCj6mEY3yjt9OVUsbbPPLzuY9vo+ATi40uLljMAW/nvicYPMi+RdJYBRK5e6s j1LaPmAljyIHEVI0N63gDH9AQlt37u+ZIh+TH2HHYg7P7I8q1Qdmrrd6PE7uPmUFhD Uk1NTiFUTF+/Q== 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-btrfs@vger.kernel.org Subject: [PATCH 4/5] fscrypt: replace get_ino_and_lblk_bits with just has_32bit_inodes Date: Mon, 4 Sep 2023 17:58:29 -0700 Message-ID: <20230905005830.365985-5-ebiggers@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230905005830.365985-1-ebiggers@kernel.org> References: <20230905005830.365985-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org From: Eric Biggers Now that fs/crypto/ computes the filesystem's lblk_bits from its maximum file size, it is no longer necessary for filesystems to provide lblk_bits via fscrypt_operations::get_ino_and_lblk_bits. It is still necessary for fs/crypto/ to retrieve ino_bits from the filesystem. However, this is used only to decide whether inode numbers fit in 32 bits. Also, ino_bits is static for all relevant filesystems, i.e. it doesn't depend on the filesystem instance. Therefore, in the interest of keeping things as simple as possible, replace 'get_ino_and_lblk_bits' with a flag 'has_32bit_inodes'. This can always be changed back to a function if a filesystem needs it to be dynamic, but for now a static flag is all that's needed. Signed-off-by: Eric Biggers --- fs/crypto/policy.c | 33 +++++++++++++++------------------ fs/ext4/crypto.c | 9 +-------- fs/f2fs/super.c | 9 +-------- include/linux/fscrypt.h | 26 +++++++++++--------------- 4 files changed, 28 insertions(+), 49 deletions(-) diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 36bffc4d6228d..c8072a634af8f 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -118,11 +118,11 @@ static bool supported_direct_key_modes(const struct inode *inode, } static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy, - const struct inode *inode, - const char *type, int max_ino_bits) + const struct inode *inode) { + const char *type = (policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) + ? "IV_INO_LBLK_64" : "IV_INO_LBLK_32"; struct super_block *sb = inode->i_sb; - int ino_bits = 64, lblk_bits = 64; /* * IV_INO_LBLK_* exist only because of hardware limitations, and @@ -149,9 +149,15 @@ static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy, type, sb->s_id); return false; } - if (sb->s_cop->get_ino_and_lblk_bits) - sb->s_cop->get_ino_and_lblk_bits(sb, &ino_bits, &lblk_bits); - if (ino_bits > max_ino_bits) { + + /* + * IV_INO_LBLK_64 requires that inode numbers fit in 32 bits. + * IV_INO_LBLK_32 hashes the inode number, so in principle it can + * support any length; however, currently the inode number is gotten + * from inode::i_ino which is 'unsigned long'. So for now the + * implementation limit is 32 bits, the same as IV_INO_LBLK_64. + */ + if (!sb->s_cop->has_32bit_inodes) { fscrypt_warn(inode, "Can't use %s policy on filesystem '%s' because its maximum inode number is too large", type, sb->s_id); @@ -242,18 +248,9 @@ static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy, policy->filenames_encryption_mode)) return false; - if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) && - !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_64", 32)) - return false; - - /* - * IV_INO_LBLK_32 hashes the inode number, so in principle it can - * support any ino_bits. However, currently the inode number is gotten - * from inode::i_ino which is 'unsigned long'. So for now the - * implementation limit is 32 bits. - */ - if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) && - !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_32", 32)) + if ((policy->flags & (FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 | + FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) && + !supported_iv_ino_lblk_policy(policy, inode)) return false; if (memchr_inv(policy->__reserved, 0, sizeof(policy->__reserved))) { diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index a9221be67f2a7..2859d9569aa74 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -232,20 +232,13 @@ static bool ext4_has_stable_inodes(struct super_block *sb) return ext4_has_feature_stable_inodes(sb); } -static void ext4_get_ino_and_lblk_bits(struct super_block *sb, - int *ino_bits_ret, int *lblk_bits_ret) -{ - *ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count); - *lblk_bits_ret = 8 * sizeof(ext4_lblk_t); -} - const struct fscrypt_operations ext4_cryptops = { .needs_bounce_pages = 1, + .has_32bit_inodes = 1, .legacy_key_prefix_for_backcompat = "ext4:", .get_context = ext4_get_context, .set_context = ext4_set_context, .get_dummy_policy = ext4_get_dummy_policy, .empty_dir = ext4_empty_dir, .has_stable_inodes = ext4_has_stable_inodes, - .get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits, }; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 276535af5bf3c..7e8e510ef77af 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -3203,13 +3203,6 @@ static bool f2fs_has_stable_inodes(struct super_block *sb) return true; } -static void f2fs_get_ino_and_lblk_bits(struct super_block *sb, - int *ino_bits_ret, int *lblk_bits_ret) -{ - *ino_bits_ret = 8 * sizeof(nid_t); - *lblk_bits_ret = 8 * sizeof(block_t); -} - static struct block_device **f2fs_get_devices(struct super_block *sb, unsigned int *num_devs) { @@ -3232,13 +3225,13 @@ static struct block_device **f2fs_get_devices(struct super_block *sb, static const struct fscrypt_operations f2fs_cryptops = { .needs_bounce_pages = 1, + .has_32bit_inodes = 1, .legacy_key_prefix_for_backcompat = "f2fs:", .get_context = f2fs_get_context, .set_context = f2fs_set_context, .get_dummy_policy = f2fs_get_dummy_policy, .empty_dir = f2fs_empty_dir, .has_stable_inodes = f2fs_has_stable_inodes, - .get_ino_and_lblk_bits = f2fs_get_ino_and_lblk_bits, .get_devices = f2fs_get_devices, }; #endif diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index ac684f688d488..fb2a74e618a11 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -73,6 +73,17 @@ struct fscrypt_operations { */ unsigned int needs_bounce_pages : 1; + /* + * If set, then fs/crypto/ will allow the use of encryption settings + * that assume inode numbers fit in 32 bits (i.e. + * FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64}), provided that the other + * prerequisites for these settings are also met. This is only useful + * if the filesystem wants to support inline encryption hardware that is + * limited to 32-bit or 64-bit data unit numbers and where programming + * keyslots is very slow. + */ + unsigned int has_32bit_inodes : 1; + /* * This field exists only for backwards compatibility reasons and should * only be set by the filesystems that are setting it already. It @@ -150,21 +161,6 @@ struct fscrypt_operations { */ bool (*has_stable_inodes)(struct super_block *sb); - /* - * Get the number of bits that the filesystem uses to represent inode - * numbers and file logical block numbers. - * - * By default, both of these are assumed to be 64-bit. This function - * can be implemented to declare that either or both of these numbers is - * shorter, which may allow the use of the - * FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags and/or the use of - * inline crypto hardware whose maximum DUN length is less than 64 bits - * (e.g., eMMC v5.2 spec compliant hardware). This function only needs - * to be implemented if support for one of these features is needed. - */ - void (*get_ino_and_lblk_bits)(struct super_block *sb, - int *ino_bits_ret, int *lblk_bits_ret); - /* * Return an array of pointers to the block devices to which the * filesystem may write encrypted file contents, NULL if the filesystem