From patchwork Mon May 20 16:29:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 10951833 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 067CD76 for ; Mon, 20 May 2019 16:30:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E937F2880B for ; Mon, 20 May 2019 16:30:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DB51128704; Mon, 20 May 2019 16:30:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SUSPICIOUS_RECIPS autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4A6FC28704 for ; Mon, 20 May 2019 16:30:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392217AbfETQaY (ORCPT ); Mon, 20 May 2019 12:30:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:44922 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389633AbfETQaX (ORCPT ); Mon, 20 May 2019 12:30:23 -0400 Received: from ebiggers-linuxstation.mtv.corp.google.com (unknown [104.132.1.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 75E952173C; Mon, 20 May 2019 16:30:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558369822; bh=YFNzSvg/+MDLitcd1QNpcVpA4+wyTUZ+/r0vkLTqq0k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O7pAok8IEBV5OA3zUbAW5iySnocSDF3dhyW8Rs8LYjILJ5FvABSYFGTSBZ58+cDGu S2zJ0aE0WC89S1owYpzQSV3tpJLo9BPKDbwRstlx76JVH15V5vHz1XPlsSn65NzymM 1eqHXVBf5ot+HAmebVIHFTRF/zGf3VEA+tAXaVQg= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, Chandan Rajendra Subject: [PATCH v2 05/14] fscrypt: introduce fscrypt_encrypt_block_inplace() Date: Mon, 20 May 2019 09:29:43 -0700 Message-Id: <20190520162952.156212-6-ebiggers@kernel.org> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog In-Reply-To: <20190520162952.156212-1-ebiggers@kernel.org> References: <20190520162952.156212-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Biggers fscrypt_encrypt_page() behaves very differently depending on whether the filesystem set FS_CFLG_OWN_PAGES in its fscrypt_operations. This makes the function difficult to understand and document. It also makes it so that all callers have to provide inode and lblk_num, when fscrypt could determine these itself for pagecache pages. Therefore, move the FS_CFLG_OWN_PAGES behavior into a new function fscrypt_encrypt_block_inplace(). This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. Reviewed-by: Chandan Rajendra Signed-off-by: Eric Biggers --- fs/crypto/crypto.c | 50 +++++++++++++++++++++++++---------------- fs/ubifs/crypto.c | 12 +++++----- include/linux/fscrypt.h | 13 +++++++++++ 3 files changed, 50 insertions(+), 25 deletions(-) diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 9cda0147fca95..6877b7c6165de 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -199,8 +199,7 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, /** * fscypt_encrypt_page() - Encrypts a page * @inode: The inode for which the encryption should take place - * @page: The page to encrypt. Must be locked for bounce-page - * encryption. + * @page: The page to encrypt. Must be locked. * @len: Length of data to encrypt in @page and encrypted * data in returned page. * @offs: Offset of data within @page and returned @@ -210,10 +209,9 @@ int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw, * previously written data. * @gfp_flags: The gfp flag for memory allocation * - * Encrypts @page. If the filesystem set FS_CFLG_OWN_PAGES, then the data is - * encrypted in-place and @page is returned. Else, a bounce page is allocated, - * the data is encrypted into the bounce page, and the bounce page is returned. - * The caller is responsible for calling fscrypt_free_bounce_page(). + * Encrypts @page. A bounce page is allocated, the data is encrypted into the + * bounce page, and the bounce page is returned. The caller is responsible for + * calling fscrypt_free_bounce_page(). * * Return: A page containing the encrypted data on success, else an ERR_PTR() */ @@ -224,24 +222,12 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, u64 lblk_num, gfp_t gfp_flags) { - struct page *ciphertext_page = page; + struct page *ciphertext_page; int err; - if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) { - /* with inplace-encryption we just encrypt the page */ - err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num, page, - ciphertext_page, len, offs, - gfp_flags); - if (err) - return ERR_PTR(err); - - return ciphertext_page; - } - if (WARN_ON_ONCE(!PageLocked(page))) return ERR_PTR(-EINVAL); - /* The encryption operation will require a bounce page. */ ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags); if (!ciphertext_page) return ERR_PTR(-ENOMEM); @@ -258,6 +244,32 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, } EXPORT_SYMBOL(fscrypt_encrypt_page); +/** + * fscrypt_encrypt_block_inplace() - Encrypt a filesystem block in-place + * @inode: The inode to which this block belongs + * @page: The page containing the block to encrypt + * @len: Size of block to encrypt. Doesn't need to be a multiple of the + * fs block size, but must be a multiple of FS_CRYPTO_BLOCK_SIZE. + * @offs: Byte offset within @page at which the block to encrypt begins + * @lblk_num: Filesystem logical block number of the block, i.e. the 0-based + * number of the block within the file + * @gfp_flags: Memory allocation flags + * + * Encrypt a possibly-compressed filesystem block that is located in an + * arbitrary page, not necessarily in the original pagecache page. The @inode + * and @lblk_num must be specified, as they can't be determined from @page. + * + * Return: 0 on success; -errno on failure + */ +int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page, + unsigned int len, unsigned int offs, + u64 lblk_num, gfp_t gfp_flags) +{ + return fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num, page, page, + len, offs, gfp_flags); +} +EXPORT_SYMBOL(fscrypt_encrypt_block_inplace); + /** * fscrypt_decrypt_page() - Decrypts a page in-place * @inode: The corresponding inode for the page to decrypt. diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c index 4aaedf2d7f442..032efdad2e668 100644 --- a/fs/ubifs/crypto.c +++ b/fs/ubifs/crypto.c @@ -29,8 +29,8 @@ int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, { struct ubifs_info *c = inode->i_sb->s_fs_info; void *p = &dn->data; - struct page *ret; unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); + int err; ubifs_assert(c, pad_len <= *out_len); dn->compr_size = cpu_to_le16(in_len); @@ -39,11 +39,11 @@ int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, if (pad_len != in_len) memset(p + in_len, 0, pad_len - in_len); - ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len, - offset_in_page(&dn->data), block, GFP_NOFS); - if (IS_ERR(ret)) { - ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret)); - return PTR_ERR(ret); + err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len, + offset_in_page(p), block, GFP_NOFS); + if (err) { + ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err); + return err; } *out_len = pad_len; diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 1c7287f146a98..a9b2d26e615d5 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -106,6 +106,10 @@ extern void fscrypt_release_ctx(struct fscrypt_ctx *); extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, u64, gfp_t); +extern int fscrypt_encrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num, + gfp_t gfp_flags); extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, u64); @@ -293,6 +297,15 @@ static inline struct page *fscrypt_encrypt_page(const struct inode *inode, return ERR_PTR(-EOPNOTSUPP); } +static inline int fscrypt_encrypt_block_inplace(const struct inode *inode, + struct page *page, + unsigned int len, + unsigned int offs, u64 lblk_num, + gfp_t gfp_flags) +{ + return -EOPNOTSUPP; +} + static inline int fscrypt_decrypt_page(const struct inode *inode, struct page *page, unsigned int len, unsigned int offs,