From patchwork Wed May 1 22:45:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 1093877 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="gilxO/Pq"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44vYQx0rkRz9sD4 for ; Thu, 2 May 2019 08:46:17 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726404AbfEAWqP (ORCPT ); Wed, 1 May 2019 18:46:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:47246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726126AbfEAWqJ (ORCPT ); Wed, 1 May 2019 18:46:09 -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 C1E92217D7; Wed, 1 May 2019 22:46:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556750768; bh=xD7PqOfhddvE9okJKFAirf34SL4fz8KKEtN16Qy6Kso=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gilxO/PqfpEGq5c0zQGIqQZrLC3gFUWqXtIObS+nLMp9ZEEI5orwUg2BzcJT9mUB0 THM/ewxak22G9gQkbw7qJvZ7zyBtX1k20tFJtJctGjT8wJLhM8WiB18YU5BunF+PRW GFG0+lcuMb/OEg+KZIGOYNlpwWk/GuCg7qsQ78Zk= 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, linux-fsdevel@vger.kernel.org, Chandan Rajendra Subject: [PATCH 13/13] ext4: encrypt only up to last block in ext4_bio_write_page() Date: Wed, 1 May 2019 15:45:15 -0700 Message-Id: <20190501224515.43059-14-ebiggers@kernel.org> X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog In-Reply-To: <20190501224515.43059-1-ebiggers@kernel.org> References: <20190501224515.43059-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Eric Biggers As an optimization, don't encrypt blocks fully beyond i_size, since those definitely won't need to be written out. Also add a comment. This is in preparation for allowing encryption on ext4 filesystems with blocksize != PAGE_SIZE. This is based on work by Chandan Rajendra. Signed-off-by: Eric Biggers Reviewed-by: Chandan Rajendra --- fs/ext4/page-io.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 457ddf051608f..ab843ad89df2f 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -468,11 +468,19 @@ int ext4_bio_write_page(struct ext4_io_submit *io, bh = head = page_buffers(page); + /* + * If any blocks are being written to an encrypted file, encrypt them + * into a bounce page. For simplicity, just encrypt until the last + * block which might be needed. This may cause some unneeded blocks + * (e.g. holes) to be unnecessarily encrypted, but this is rare and + * can't happen in the common case of blocksize == PAGE_SIZE. + */ if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode) && nr_to_submit) { gfp_t gfp_flags = GFP_NOFS; + unsigned int enc_bytes = round_up(len, i_blocksize(inode)); retry_encrypt: - bounce_page = fscrypt_encrypt_pagecache_blocks(page, PAGE_SIZE, + bounce_page = fscrypt_encrypt_pagecache_blocks(page, enc_bytes, 0, gfp_flags); if (IS_ERR(bounce_page)) { ret = PTR_ERR(bounce_page);