From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36148 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933767AbeALOKk (ORCPT ); Fri, 12 Jan 2018 09:10:40 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0CE9eMv063862 for ; Fri, 12 Jan 2018 09:10:39 -0500 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0b-001b2d01.pphosted.com with ESMTP id 2fexcb8t8m-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 12 Jan 2018 09:10:39 -0500 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 12 Jan 2018 07:10:38 -0700 From: Chandan Rajendra To: linux-ext4@vger.kernel.org Cc: Chandan Rajendra , linux-fsdevel@vger.kernel.org, tytso@mit.edu Subject: [RFC PATCH 4/8] ext4: decrypt all boundary blocks when doing buffered write Date: Fri, 12 Jan 2018 19:41:25 +0530 In-Reply-To: <20180112141129.27507-1-chandan@linux.vnet.ibm.com> References: <20180112141129.27507-1-chandan@linux.vnet.ibm.com> Message-Id: <20180112141129.27507-5-chandan@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: With block size < page size, ext4_block_write_begin() may have two blocks to decrypt. Hence this commit invokes fscrypt_decrypt_page() for those blocks. Signed-off-by: Chandan Rajendra --- fs/ext4/inode.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 6f6589e..d3baa15 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1158,12 +1158,13 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, unsigned to = from + len; struct inode *inode = page->mapping->host; unsigned block_start, block_end; - sector_t block; + sector_t block, page_blk_nr; int err = 0; unsigned blocksize = inode->i_sb->s_blocksize; unsigned bbits; struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; bool decrypt = false; + int i; BUG_ON(!PageLocked(page)); BUG_ON(from > PAGE_SIZE); @@ -1224,16 +1225,28 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, /* * If we issued read requests, let them complete. */ - while (wait_bh > wait) { - wait_on_buffer(*--wait_bh); - if (!buffer_uptodate(*wait_bh)) + for (i = 0; (wait + i) < wait_bh; i++) { + wait_on_buffer(wait[i]); + if (!buffer_uptodate(wait[i])) err = -EIO; } - if (unlikely(err)) + if (unlikely(err)) { page_zero_new_buffers(page, from, to); - else if (decrypt) - err = fscrypt_decrypt_page(page->mapping->host, page, - PAGE_SIZE, 0, page->index); + } else if (decrypt) { + page_blk_nr = (sector_t)page->index << (PAGE_SHIFT - bbits); + + while (wait_bh > wait) { + --wait_bh; + block = page_blk_nr + (bh_offset(*wait_bh) >> bbits); + err = fscrypt_decrypt_page(page->mapping->host, page, + (*wait_bh)->b_size, + bh_offset(*wait_bh), + block); + if (err) + break; + } + } + return err; } #endif -- 2.9.5