From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:46657 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754101AbeENHCN (ORCPT ); Mon, 14 May 2018 03:02:13 -0400 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 57033AE35 for ; Mon, 14 May 2018 07:02:12 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: inode: Don't compress if NODATASUM or NODATACOW set Date: Mon, 14 May 2018 15:02:10 +0800 Message-Id: <20180514070210.27047-1-wqu@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: As btrfs(5) specified: Note If nodatacow or nodatasum are enabled, compression is disabled. If NODATASUM or NODATACOW set, we should not compress the extent. And in fact, we have bug report about corrupted compressed extent leading to memory corruption in mail list. Although it's mostly buggy lzo implementation causing the problem, btrfs still needs to be fixed to meet the specification. Reported-by: James Harvey Signed-off-by: Qu Wenruo --- fs/btrfs/inode.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index d241285a0d2a..dbef3f404559 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -396,6 +396,14 @@ static inline int inode_need_compress(struct inode *inode, u64 start, u64 end) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + /* + * Btrfs doesn't support compression without csum or CoW. + * This should have the highest priority. + */ + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW || + BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) + return 0; + /* force compress */ if (btrfs_test_opt(fs_info, FORCE_COMPRESS)) return 1; -- 2.17.0