From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756346Ab2ATWfu (ORCPT ); Fri, 20 Jan 2012 17:35:50 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:33962 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755877Ab2ATWfr (ORCPT ); Fri, 20 Jan 2012 17:35:47 -0500 From: Tyler Hicks To: ecryptfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , john.johansen@canonical.com, dustin.kirkland@gazzang.com, Cong Wang , Li Wang Subject: [PATCH 1/3] eCryptfs: Make truncate path killable Date: Fri, 20 Jan 2012 16:35:05 -0600 Message-Id: <1327098907-28963-2-git-send-email-tyhicks@canonical.com> X-Mailer: git-send-email 1.7.8.3 In-Reply-To: <1327098907-28963-1-git-send-email-tyhicks@canonical.com> References: <1327098907-28963-1-git-send-email-tyhicks@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: --- fs/ecryptfs/read_write.c | 19 ++++++++++++++----- 1 files changed, 14 insertions(+), 5 deletions(-) diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c index ec3d936..608c1c3 100644 --- a/fs/ecryptfs/read_write.c +++ b/fs/ecryptfs/read_write.c @@ -132,6 +132,11 @@ int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset, size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page); loff_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 *ecryptfs_inode, char *data, loff_t offset, } 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; } } -- 1.7.8.3