From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384AbbHBAMt (ORCPT ); Sat, 1 Aug 2015 20:12:49 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36051 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752063AbbHBAKE (ORCPT ); Sat, 1 Aug 2015 20:10:04 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Davide Italiano" , "Theodore Ts'o" Date: Sun, 02 Aug 2015 01:02:37 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 071/164] ext4: move check under lock scope to close a race. In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.70-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Davide Italiano commit 280227a75b56ab5d35854f3a77ef74a7ad56a203 upstream. fallocate() checks that the file is extent-based and returns EOPNOTSUPP in case is not. Other tasks can convert from and to indirect and extent so it's safe to check only after grabbing the inode mutex. Signed-off-by: Davide Italiano Signed-off-by: Theodore Ts'o [bwh: Backported to 3.2: - Adjust context - Add the 'out' label] Signed-off-by: Ben Hutchings --- fs/ext4/extents.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4470,13 +4470,6 @@ long ext4_fallocate(struct file *file, i struct ext4_map_blocks map; unsigned int credits, blkbits = inode->i_blkbits; - /* - * currently supporting (pre)allocate mode for extent-based - * files _only_ - */ - if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) - return -EOPNOTSUPP; - /* Return error if mode is not supported */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) return -EOPNOTSUPP; @@ -4497,6 +4490,15 @@ long ext4_fallocate(struct file *file, i */ credits = ext4_chunk_trans_blocks(inode, max_blocks); mutex_lock(&inode->i_mutex); + + /* + * We only support preallocation for extent-based files only + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + ret = -EOPNOTSUPP; + goto out; + } + ret = inode_newsize_ok(inode, (len + offset)); if (ret) { mutex_unlock(&inode->i_mutex); @@ -4553,6 +4555,7 @@ retry: ret = 0; goto retry; } +out: mutex_unlock(&inode->i_mutex); trace_ext4_fallocate_exit(inode, offset, max_blocks, ret > 0 ? ret2 : ret);