From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:36736 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753704AbbEKLVk (ORCPT ); Mon, 11 May 2015 07:21:40 -0400 From: Sasha Levin To: stable@vger.kernel.org, stable-commits@vger.kernel.org Cc: Filipe Manana , Chris Mason , Greg Kroah-Hartman , Sasha Levin Subject: [added to the 3.18 stable tree] Btrfs: fix inode eviction infinite loop after extent_same ioctl Date: Mon, 11 May 2015 07:17:01 -0400 Message-Id: <1431343152-19437-40-git-send-email-sasha.levin@oracle.com> In-Reply-To: <1431343152-19437-1-git-send-email-sasha.levin@oracle.com> References: <1431343152-19437-1-git-send-email-sasha.levin@oracle.com> Sender: stable-owner@vger.kernel.org List-ID: From: Filipe Manana This patch has been added to the 3.18 stable tree. If you have any objections, please let us know. =============== [ Upstream commit HEAD ] commit 113e8283869b9855c8b999796aadd506bbac155f upstream. If we pass a length of 0 to the extent_same ioctl, we end up locking an extent range with a start offset greater then its end offset (if the destination file's offset is greater than zero). This results in a warning from extent_io.c:insert_state through the following call chain: btrfs_extent_same() btrfs_double_lock() lock_extent_range() lock_extent(inode->io_tree, offset, offset + len - 1) lock_extent_bits() __set_extent_bit() insert_state() --> WARN_ON(end < start) This leads to an infinite loop when evicting the inode. This is the same problem that my previous patch titled "Btrfs: fix inode eviction infinite loop after cloning into it" addressed but for the extent_same ioctl instead of the clone ioctl. Signed-off-by: Filipe Manana Reviewed-by: Omar Sandoval Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 9dc106617d5669a6f8d86e08f620dc2fb0413e21) Signed-off-by: Sasha Levin --- fs/btrfs/ioctl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 96ea36f..5c414fe 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2925,6 +2925,9 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 len, if (src == dst) return -EINVAL; + if (len == 0) + return 0; + btrfs_double_lock(src, loff, dst, dst_loff, len); ret = extent_same_check_offsets(src, loff, len); -- 2.1.0