From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757058Ab2BAVIN (ORCPT ); Wed, 1 Feb 2012 16:08:13 -0500 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:55592 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755984Ab2BAVIL (ORCPT ); Wed, 1 Feb 2012 16:08:11 -0500 X-Sasl-enc: O9DOBJJXRQDGMxtR/AIRW9h3YFfFamc6NCAKGkssbzD6 1328130490 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Feb 1 12:57:37 2012 Message-Id: <20120201205737.822818760@clark.kroah.org> User-Agent: quilt/0.51-15.1 Date: Wed, 01 Feb 2012 12:55:44 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Tyler Hicks Subject: [04/65] eCryptfs: Make truncate path killable In-Reply-To: <20120201210236.GA25966@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tyler Hicks commit 5e6f0d769017cc49207ef56996e42363ec26c1f0 upstream. ecryptfs_write() handles the truncation of eCryptfs inodes. It grabs a page, zeroes out the appropriate portions, and then encrypts the page before writing it to the lower filesystem. It was unkillable and due to the lack of sparse file support could result in tying up a large portion of system resources, while encrypting pages of zeros, with no way for the truncate operation to be stopped from userspace. This patch adds the ability for ecryptfs_write() to detect a pending fatal signal and return as gracefully as possible. The intent is to leave the lower file in a useable state, while still allowing a user to break out of the encryption loop. If a pending fatal signal is detected, the eCryptfs inode size is updated to reflect the modified inode size and then -EINTR is returned. Signed-off-by: Tyler Hicks Signed-off-by: Greg Kroah-Hartman --- fs/ecryptfs/read_write.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) --- a/fs/ecryptfs/read_write.c +++ b/fs/ecryptfs/read_write.c @@ -132,6 +132,11 @@ int ecryptfs_write(struct inode *ecryptf size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page); size_t total_remaining_bytes = ((offset + size) - pos); + if (fatal_signal_pending(current)) { + rc = -EINTR; + break; + } + if (num_bytes > total_remaining_bytes) num_bytes = total_remaining_bytes; if (pos < offset) { @@ -193,15 +198,19 @@ int ecryptfs_write(struct inode *ecryptf } pos += num_bytes; } - if ((offset + size) > ecryptfs_file_size) { - i_size_write(ecryptfs_inode, (offset + size)); + if (pos > ecryptfs_file_size) { + i_size_write(ecryptfs_inode, pos); if (crypt_stat->flags & ECRYPTFS_ENCRYPTED) { - rc = ecryptfs_write_inode_size_to_metadata( + int rc2; + + rc2 = ecryptfs_write_inode_size_to_metadata( ecryptfs_inode); - if (rc) { + if (rc2) { printk(KERN_ERR "Problem with " "ecryptfs_write_inode_size_to_metadata; " - "rc = [%d]\n", rc); + "rc = [%d]\n", rc2); + if (!rc) + rc = rc2; goto out; } }