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[209.132.180.67]) by mx.google.com with ESMTP id y29si408473pgk.376.2018.12.06.06.50.07; Thu, 06 Dec 2018 06:50:22 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=ogFTkL6Y; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730894AbeLFOrU (ORCPT + 99 others); Thu, 6 Dec 2018 09:47:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:52150 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731395AbeLFOrR (ORCPT ); Thu, 6 Dec 2018 09:47:17 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6DB7D20892; Thu, 6 Dec 2018 14:47:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544107636; bh=nq5UpJKFLJWsHvpZCq6DglZsCmGe8MAY6GMiJCtJP0o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ogFTkL6YUSt3vYlAiMRUr9d659N8nLd6b5LESB/owosroaiB4Wa/QVmyq8LR5BhCP gQyaRvyta9Qcw1/z7byvuTp7te5Ks+KO3t+lHvZ9uZdD6RThgR0GV5jr2Lxs06BJCC bNyBVaDPkbzLaPFiAde8BIQgyg8pddaVnxLeISys= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Filipe Manana , "Lakshmipathi.G" , Qu Wenruo , Liu Bo , David Sterba , Ben Hutchings Subject: [PATCH 4.9 074/101] btrfs: tree-checker: Fix false panic for sanity test Date: Thu, 6 Dec 2018 15:39:13 +0100 Message-Id: <20181206143016.307219956@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181206143011.174892052@linuxfoundation.org> References: <20181206143011.174892052@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qu Wenruo commit 69fc6cbbac542c349b3d350d10f6e394c253c81d upstream. [BUG] If we run btrfs with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y, it will instantly cause kernel panic like: ------ ... assertion failed: 0, file: fs/btrfs/disk-io.c, line: 3853 ... Call Trace: btrfs_mark_buffer_dirty+0x187/0x1f0 [btrfs] setup_items_for_insert+0x385/0x650 [btrfs] __btrfs_drop_extents+0x129a/0x1870 [btrfs] ... ----- [Cause] Btrfs will call btrfs_check_leaf() in btrfs_mark_buffer_dirty() to check if the leaf is valid with CONFIG_BTRFS_FS_RUN_SANITY_TESTS=y. However quite some btrfs_mark_buffer_dirty() callers(*) don't really initialize its item data but only initialize its item pointers, leaving item data uninitialized. This makes tree-checker catch uninitialized data as error, causing such panic. *: These callers include but not limited to setup_items_for_insert() btrfs_split_item() btrfs_expand_item() [Fix] Add a new parameter @check_item_data to btrfs_check_leaf(). With @check_item_data set to false, item data check will be skipped and fallback to old btrfs_check_leaf() behavior. So we can still get early warning if we screw up item pointers, and avoid false panic. Cc: Filipe Manana Reported-by: Lakshmipathi.G Signed-off-by: Qu Wenruo Reviewed-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/disk-io.c | 10 ++++++++-- fs/btrfs/tree-checker.c | 27 ++++++++++++++++++++++----- fs/btrfs/tree-checker.h | 14 +++++++++++++- 3 files changed, 43 insertions(+), 8 deletions(-) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -604,7 +604,7 @@ static int btree_readpage_end_io_hook(st * that we don't try and read the other copies of this block, just * return -EIO. */ - if (found_level == 0 && btrfs_check_leaf(root, eb)) { + if (found_level == 0 && btrfs_check_leaf_full(root, eb)) { set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags); ret = -EIO; } @@ -3940,7 +3940,13 @@ void btrfs_mark_buffer_dirty(struct exte buf->len, root->fs_info->dirty_metadata_batch); #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY - if (btrfs_header_level(buf) == 0 && btrfs_check_leaf(root, buf)) { + /* + * Since btrfs_mark_buffer_dirty() can be called with item pointer set + * but item data not updated. + * So here we should only check item pointers, not item data. + */ + if (btrfs_header_level(buf) == 0 && + btrfs_check_leaf_relaxed(root, buf)) { btrfs_print_leaf(root, buf); ASSERT(0); } --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -195,7 +195,8 @@ static int check_leaf_item(struct btrfs_ return ret; } -int btrfs_check_leaf(struct btrfs_root *root, struct extent_buffer *leaf) +static int check_leaf(struct btrfs_root *root, struct extent_buffer *leaf, + bool check_item_data) { struct btrfs_fs_info *fs_info = root->fs_info; /* No valid key type is 0, so all key should be larger than this key */ @@ -299,10 +300,15 @@ int btrfs_check_leaf(struct btrfs_root * return -EUCLEAN; } - /* Check if the item size and content meet other criteria */ - ret = check_leaf_item(root, leaf, &key, slot); - if (ret < 0) - return ret; + if (check_item_data) { + /* + * Check if the item size and content meet other + * criteria + */ + ret = check_leaf_item(root, leaf, &key, slot); + if (ret < 0) + return ret; + } prev_key.objectid = key.objectid; prev_key.type = key.type; @@ -312,6 +318,17 @@ int btrfs_check_leaf(struct btrfs_root * return 0; } +int btrfs_check_leaf_full(struct btrfs_root *root, struct extent_buffer *leaf) +{ + return check_leaf(root, leaf, true); +} + +int btrfs_check_leaf_relaxed(struct btrfs_root *root, + struct extent_buffer *leaf) +{ + return check_leaf(root, leaf, false); +} + int btrfs_check_node(struct btrfs_root *root, struct extent_buffer *node) { unsigned long nr = btrfs_header_nritems(node); --- a/fs/btrfs/tree-checker.h +++ b/fs/btrfs/tree-checker.h @@ -20,7 +20,19 @@ #include "ctree.h" #include "extent_io.h" -int btrfs_check_leaf(struct btrfs_root *root, struct extent_buffer *leaf); +/* + * Comprehensive leaf checker. + * Will check not only the item pointers, but also every possible member + * in item data. + */ +int btrfs_check_leaf_full(struct btrfs_root *root, struct extent_buffer *leaf); + +/* + * Less strict leaf checker. + * Will only check item pointers, not reading item data. + */ +int btrfs_check_leaf_relaxed(struct btrfs_root *root, + struct extent_buffer *leaf); int btrfs_check_node(struct btrfs_root *root, struct extent_buffer *node); #endif