From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chandan Rajendra Subject: [PATCH V2 08/13] ext4: Decrypt all boundary blocks when doing buffered write Date: Sun, 28 Apr 2019 10:01:16 +0530 Message-ID: <20190428043121.30925-9-chandan@linux.ibm.com> References: <20190428043121.30925-1-chandan@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1hKbTJ-0001tC-Jh for linux-f2fs-devel@lists.sourceforge.net; Sun, 28 Apr 2019 04:31:25 +0000 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) id 1hKbTG-00HGai-9y for linux-f2fs-devel@lists.sourceforge.net; Sun, 28 Apr 2019 04:31:25 +0000 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3S4TZWs106028 for ; Sun, 28 Apr 2019 00:31:13 -0400 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0a-001b2d01.pphosted.com with ESMTP id 2s54cf96rb-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Sun, 28 Apr 2019 00:31:13 -0400 Received: from localhost by e12.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 28 Apr 2019 05:31:12 +0100 In-Reply-To: <20190428043121.30925-1-chandan@linux.ibm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org Cc: hch@infradead.org, tytso@mit.edu, ebiggers@kernel.org, Chandan Rajendra , adilger.kernel@dilger.ca, jaegeuk@kernel.org With subpage sized blocks, ext4_block_write_begin() can have up to two blocks to decrypt. Hence this commit invokes fscrypt_decrypt_page() for each of those blocks. Signed-off-by: Chandan Rajendra --- fs/ext4/inode.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 1327e04334df..51744a3c3964 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1156,12 +1156,14 @@ 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; + struct buffer_head *bh, *head, *wait[2]; + int nr_wait = 0; bool decrypt = false; + int i; BUG_ON(!PageLocked(page)); BUG_ON(from > PAGE_SIZE); @@ -1213,25 +1215,36 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, !buffer_unwritten(bh) && (block_start < from || block_end > to)) { ll_rw_block(REQ_OP_READ, 0, 1, &bh); - *wait_bh++ = bh; + wait[nr_wait++] = bh; decrypt = IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode); } } /* * 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; i < nr_wait; i++) { + wait_on_buffer(wait[i]); + if (!buffer_uptodate(wait[i])) err = -EIO; } 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); - if (err) - clear_buffer_uptodate(*wait_bh); + page_blk_nr = (sector_t)page->index << (PAGE_SHIFT - bbits); + + for (i = 0; i < nr_wait; i++) { + int err2; + + block = page_blk_nr + (bh_offset(wait[i]) >> bbits); + err2 = fscrypt_decrypt_page(page->mapping->host, page, + wait[i]->b_size, + bh_offset(wait[i]), + block); + if (err2) { + clear_buffer_uptodate(wait[i]); + err = err2; + } + } } return err; -- 2.19.1