From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B4C3C55186 for ; Thu, 23 Apr 2020 23:23:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1361420CC7 for ; Thu, 23 Apr 2020 23:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728822AbgDWXXx (ORCPT ); Thu, 23 Apr 2020 19:23:53 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:48332 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728156AbgDWXGa (ORCPT ); Thu, 23 Apr 2020 19:06:30 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jRkvK-0004ah-04; Fri, 24 Apr 2020 00:06:26 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvJ-00E6hB-0d; Fri, 24 Apr 2020 00:06:25 +0100 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, Denis Kirjanov , "Greg Kroah-Hartman" , "David Sterba" , "Qu Wenruo" , "Ben Hutchings" , "Nikolay Borisov" Date: Fri, 24 Apr 2020 00:04:25 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 038/245] btrfs: Refactor check_leaf function for later expansion In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.83-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Qu Wenruo commit c3267bbaa9cae09b62960eafe33ad19196803285 upstream. Current check_leaf() function does a good job checking key order and item offset/size. However it only checks from slot 0 to the last but one slot, this is good but makes later expansion hard. So this refactoring iterates from slot 0 to the last slot. For key comparison, it uses a key with all 0 as initial key, so all valid keys should be larger than that. And for item size/offset checks, it compares current item end with previous item offset. For slot 0, use leaf end as a special case. This makes later item/key offset checks and item size checks easier to be implemented. Also, makes check_leaf() to return -EUCLEAN other than -EIO to indicate error. Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba [bwh: Backported to 4.4: - BTRFS_LEAF_DATA_SIZE() takes a root rather than an fs_info - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- fs/btrfs/disk-io.c | 50 +++++++++++++++++++++++++--------------------- 1 file changed, 27 insertions(+), 23 deletions(-) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -516,8 +516,9 @@ static int check_tree_block_fsid(struct static noinline int check_leaf(struct btrfs_root *root, struct extent_buffer *leaf) { + /* No valid key type is 0, so all key should be larger than this key */ + struct btrfs_key prev_key = {0, 0, 0}; struct btrfs_key key; - struct btrfs_key leaf_key; u32 nritems = btrfs_header_nritems(leaf); int slot; @@ -550,7 +551,7 @@ static noinline int check_leaf(struct bt CORRUPT("non-root leaf's nritems is 0", leaf, check_root, 0); free_extent_buffer(eb); - return -EIO; + return -EUCLEAN; } free_extent_buffer(eb); } @@ -560,28 +561,23 @@ static noinline int check_leaf(struct bt if (nritems == 0) return 0; - /* Check the 0 item */ - if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) != - BTRFS_LEAF_DATA_SIZE(root)) { - CORRUPT("invalid item offset size pair", leaf, root, 0); - return -EIO; - } - /* - * Check to make sure each items keys are in the correct order and their - * offsets make sense. We only have to loop through nritems-1 because - * we check the current slot against the next slot, which verifies the - * next slot's offset+size makes sense and that the current's slot - * offset is correct. + * Check the following things to make sure this is a good leaf, and + * leaf users won't need to bother with similar sanity checks: + * + * 1) key order + * 2) item offset and size + * No overlap, no hole, all inside the leaf. */ - for (slot = 0; slot < nritems - 1; slot++) { - btrfs_item_key_to_cpu(leaf, &leaf_key, slot); - btrfs_item_key_to_cpu(leaf, &key, slot + 1); + for (slot = 0; slot < nritems; slot++) { + u32 item_end_expected; + + btrfs_item_key_to_cpu(leaf, &key, slot); /* Make sure the keys are in the right order */ - if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) { + if (btrfs_comp_cpu_keys(&prev_key, &key) >= 0) { CORRUPT("bad key order", leaf, root, slot); - return -EIO; + return -EUCLEAN; } /* @@ -589,10 +585,14 @@ static noinline int check_leaf(struct bt * item data starts at the end of the leaf and grows towards the * front. */ - if (btrfs_item_offset_nr(leaf, slot) != - btrfs_item_end_nr(leaf, slot + 1)) { + if (slot == 0) + item_end_expected = BTRFS_LEAF_DATA_SIZE(root); + else + item_end_expected = btrfs_item_offset_nr(leaf, + slot - 1); + if (btrfs_item_end_nr(leaf, slot) != item_end_expected) { CORRUPT("slot offset bad", leaf, root, slot); - return -EIO; + return -EUCLEAN; } /* @@ -603,8 +603,12 @@ static noinline int check_leaf(struct bt if (btrfs_item_end_nr(leaf, slot) > BTRFS_LEAF_DATA_SIZE(root)) { CORRUPT("slot end outside of leaf", leaf, root, slot); - return -EIO; + return -EUCLEAN; } + + prev_key.objectid = key.objectid; + prev_key.type = key.type; + prev_key.offset = key.offset; } return 0;