From patchwork Mon May 20 16:29:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 10951843 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 960EB16C1 for ; Mon, 20 May 2019 16:30:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 85BBF28824 for ; Mon, 20 May 2019 16:30:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7875F28823; Mon, 20 May 2019 16:30:29 +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 E9D802880B for ; Mon, 20 May 2019 16:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392231AbfETQa1 (ORCPT ); Mon, 20 May 2019 12:30:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:44950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389672AbfETQaY (ORCPT ); Mon, 20 May 2019 12:30:24 -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 7727C21773; Mon, 20 May 2019 16:30:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558369823; bh=GxxBp84liEESrFGEA5Xz5LCPPTKwa7tjP6Dd6snqoFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BcgkoNrbokz9Pfll6PnRDKcSf68YnAWkmjiNV1XOohyU3XaaCLlxx7nY7b+fdROwu 9vxU0iFKqZcUOi+z1FxvEarXhrdy3lQeYkexV4XVkidXKLxdxm9TbDlIvvF7iCypFi Ms5aw6QQvZvZqZPJMJebW6RLpKf3gbMjexba17Hs= 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 08/14] fscrypt: introduce fscrypt_decrypt_block_inplace() Date: Mon, 20 May 2019 09:29:46 -0700 Message-Id: <20190520162952.156212-9-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 Currently fscrypt_decrypt_page() does one of two logically distinct things depending on whether FS_CFLG_OWN_PAGES is set in the filesystem's fscrypt_operations: decrypt a pagecache page in-place, or decrypt a filesystem block in-place in any page. Currently these happen to share the same implementation, but this conflates the notion of blocks and pages. 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_decrypt_block_inplace(). This mirrors 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 | 31 +++++++++++++++++++++++++++---- fs/ubifs/crypto.c | 7 ++++--- include/linux/fscrypt.h | 11 +++++++++++ 3 files changed, 42 insertions(+), 7 deletions(-) diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 7bdb985126d97..2e6fb5e4f7a7f 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -284,8 +284,7 @@ EXPORT_SYMBOL(fscrypt_encrypt_block_inplace); /** * fscrypt_decrypt_page() - Decrypts a page in-place * @inode: The corresponding inode for the page to decrypt. - * @page: The page to decrypt. Must be locked in case - * it is a writeback page (FS_CFLG_OWN_PAGES unset). + * @page: The page to decrypt. Must be locked. * @len: Number of bytes in @page to be decrypted. * @offs: Start of data in @page. * @lblk_num: Logical block number. @@ -299,8 +298,7 @@ EXPORT_SYMBOL(fscrypt_encrypt_block_inplace); int fscrypt_decrypt_page(const struct inode *inode, struct page *page, unsigned int len, unsigned int offs, u64 lblk_num) { - if (WARN_ON_ONCE(!PageLocked(page) && - !(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES))) + if (WARN_ON_ONCE(!PageLocked(page))) return -EINVAL; return fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page, page, @@ -308,6 +306,31 @@ int fscrypt_decrypt_page(const struct inode *inode, struct page *page, } EXPORT_SYMBOL(fscrypt_decrypt_page); +/** + * fscrypt_decrypt_block_inplace() - Decrypt a filesystem block in-place + * @inode: The inode to which this block belongs + * @page: The page containing the block to decrypt + * @len: Size of block to decrypt. 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 decrypt begins + * @lblk_num: Filesystem logical block number of the block, i.e. the 0-based + * number of the block within the file + * + * Decrypt 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_decrypt_block_inplace(const struct inode *inode, struct page *page, + unsigned int len, unsigned int offs, + u64 lblk_num) +{ + return fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page, page, + len, offs, GFP_NOFS); +} +EXPORT_SYMBOL(fscrypt_decrypt_block_inplace); + /* * Validate dentries in encrypted directories to make sure we aren't potentially * caching stale dentries after a key has been added. diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c index 032efdad2e668..22be7aeb96c4f 100644 --- a/fs/ubifs/crypto.c +++ b/fs/ubifs/crypto.c @@ -64,10 +64,11 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, } ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE); - err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen, - offset_in_page(&dn->data), block); + err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data), + dlen, offset_in_page(&dn->data), + block); if (err) { - ubifs_err(c, "fscrypt_decrypt_page failed: %i", err); + ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err); return err; } *out_len = clen; diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index c7e16bd16a6c2..315affc99b050 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -114,6 +114,9 @@ extern int fscrypt_encrypt_block_inplace(const struct inode *inode, gfp_t gfp_flags); extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, u64); +extern int fscrypt_decrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num); static inline bool fscrypt_is_bounce_page(struct page *page) { @@ -315,6 +318,14 @@ static inline int fscrypt_decrypt_page(const struct inode *inode, return -EOPNOTSUPP; } +static inline int fscrypt_decrypt_block_inplace(const struct inode *inode, + struct page *page, + unsigned int len, + unsigned int offs, u64 lblk_num) +{ + return -EOPNOTSUPP; +} + static inline bool fscrypt_is_bounce_page(struct page *page) { return false;