From patchwork Mon Apr 16 02:02:27 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 10341973 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 771326016D for ; Mon, 16 Apr 2018 02:03:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5740228471 for ; Mon, 16 Apr 2018 02:03:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4BD852847B; Mon, 16 Apr 2018 02:03:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1AAB428471 for ; Mon, 16 Apr 2018 02:03:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752630AbeDPCCg (ORCPT ); Sun, 15 Apr 2018 22:02:36 -0400 Received: from prv3-mh.provo.novell.com ([137.65.250.26]:46636 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752212AbeDPCCf (ORCPT ); Sun, 15 Apr 2018 22:02:35 -0400 Received: from adam-pc.lan (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by prv3-mh.provo.novell.com with ESMTP (NOT encrypted); Sun, 15 Apr 2018 20:02:31 -0600 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: Do super block verification before writing it to disk Date: Mon, 16 Apr 2018 10:02:27 +0800 Message-Id: <20180416020227.18528-1-wqu@suse.com> X-Mailer: git-send-email 2.17.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There are already 2 reports about strangely corrupted super blocks, where csum type and incompat flags get some obvious garbage, but csum still matches and all other vitals are correct. This normally means some kernel memory corruption happens, although the cause is unknown, at least detect it and prevent further corruption. Signed-off-by: Qu Wenruo --- fs/btrfs/disk-io.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 23803102aa0d..10d814f03f13 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -68,7 +68,8 @@ static const struct extent_io_ops btree_extent_io_ops; static void end_workqueue_fn(struct btrfs_work *work); static void free_fs_root(struct btrfs_root *root); -static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info); +static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, + struct btrfs_super_block *sb); static void btrfs_destroy_ordered_extents(struct btrfs_root *root); static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans, struct btrfs_fs_info *fs_info); @@ -2680,7 +2681,7 @@ int open_ctree(struct super_block *sb, memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE); - ret = btrfs_check_super_valid(fs_info); + ret = btrfs_check_super_valid(fs_info, fs_info->super_copy); if (ret) { btrfs_err(fs_info, "superblock contains fatal errors"); err = -EINVAL; @@ -3575,6 +3576,21 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) sb = fs_info->super_for_commit; dev_item = &sb->dev_item; + /* Do extra check on the sb to be written */ + ret = btrfs_check_super_valid(fs_info, sb); + if (ret) { + btrfs_err(fs_info, "fatal superblock corrupted detected"); + return -EUCLEAN; + } + /* + * Unknown incompat flags can't be mounted, so newly developed flags + * means corruption + */ + if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) { + btrfs_err(fs_info, "fatal superblock corrupted detected"); + return -EUCLEAN; + } + mutex_lock(&fs_info->fs_devices->device_list_mutex); head = &fs_info->fs_devices->devices; max_errors = btrfs_super_num_devices(fs_info->super_copy) - 1; @@ -3985,9 +4001,9 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level, level, first_key); } -static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info) +static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, + struct btrfs_super_block *sb) { - struct btrfs_super_block *sb = fs_info->super_copy; u64 nodesize = btrfs_super_nodesize(sb); u64 sectorsize = btrfs_super_sectorsize(sb); int ret = 0;