From: Chandan Rajendra Subject: [RFC PATCH V2 07/11] fscrypt_zeroout_range: Encrypt all zeroed out blocks of a page Date: Mon, 12 Feb 2018 15:13:43 +0530 Message-ID: <20180212094347.22071-8-chandan@linux.vnet.ibm.com> References: <20180212094347.22071-1-chandan@linux.vnet.ibm.com> Cc: Chandan Rajendra , linux-fsdevel@vger.kernel.org, ebiggers3@gmail.com, linux-fscrypt@vger.kernel.org, tytso@mit.edu To: linux-ext4@vger.kernel.org Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36004 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753976AbeBLJmy (ORCPT ); Mon, 12 Feb 2018 04:42:54 -0500 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1C9cou1143424 for ; Mon, 12 Feb 2018 04:42:53 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0a-001b2d01.pphosted.com with ESMTP id 2g32cem3u4-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 12 Feb 2018 04:42:53 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 12 Feb 2018 02:42:52 -0700 In-Reply-To: <20180212094347.22071-1-chandan@linux.vnet.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: For block size < page size, This commit adds code to encrypt all zeroed out blocks of a page. Signed-off-by: Chandan Rajendra --- fs/crypto/bio.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-) diff --git a/fs/crypto/bio.c b/fs/crypto/bio.c index 378df08..4d0d14f 100644 --- a/fs/crypto/bio.c +++ b/fs/crypto/bio.c @@ -104,10 +104,12 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, { struct fscrypt_ctx *ctx; struct page *ciphertext_page = NULL; + unsigned int page_nr_blks; + unsigned int offset; + unsigned int page_io_len; struct bio *bio; int ret, err = 0; - - BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE); + int i; ctx = fscrypt_get_ctx(inode, GFP_NOFS); if (IS_ERR(ctx)) @@ -119,12 +121,23 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, goto errout; } - while (len--) { - err = fscrypt_do_block_crypto(inode, FS_ENCRYPT, lblk, - ZERO_PAGE(0), ciphertext_page, - PAGE_SIZE, 0, GFP_NOFS); - if (err) - goto errout; + page_nr_blks = 1 << (PAGE_SHIFT - inode->i_blkbits); + + while (len) { + page_nr_blks = min_t(unsigned int, page_nr_blks, len); + page_io_len = page_nr_blks << inode->i_blkbits; + offset = 0; + + for (i = 0; i < page_nr_blks; i++) { + err = fscrypt_do_block_crypto(inode, FS_ENCRYPT, lblk, + ZERO_PAGE(0), ciphertext_page, + inode->i_sb->s_blocksize, offset, + GFP_NOFS); + if (err) + goto errout; + lblk++; + offset += inode->i_sb->s_blocksize; + } bio = bio_alloc(GFP_NOWAIT, 1); if (!bio) { @@ -135,9 +148,8 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, bio->bi_iter.bi_sector = pblk << (inode->i_sb->s_blocksize_bits - 9); bio_set_op_attrs(bio, REQ_OP_WRITE, 0); - ret = bio_add_page(bio, ciphertext_page, - inode->i_sb->s_blocksize, 0); - if (ret != inode->i_sb->s_blocksize) { + ret = bio_add_page(bio, ciphertext_page, page_io_len, 0); + if (ret != page_io_len) { /* should never happen! */ WARN_ON(1); bio_put(bio); @@ -150,8 +162,8 @@ int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk, bio_put(bio); if (err) goto errout; - lblk++; - pblk++; + pblk += page_nr_blks; + len -= page_nr_blks; } err = 0; errout: -- 2.9.5