From patchwork Wed Aug 9 07:08:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 13347492 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC59FEB64DD for ; Wed, 9 Aug 2023 07:08:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231474AbjHIHIw (ORCPT ); Wed, 9 Aug 2023 03:08:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231426AbjHIHIh (ORCPT ); Wed, 9 Aug 2023 03:08:37 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4ECF91BCF for ; Wed, 9 Aug 2023 00:08:36 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 070251F383 for ; Wed, 9 Aug 2023 07:08:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1691564915; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=ENuvkMliLYhYxKcCxUMKqHojxC94yVTkmQqkxcP0RN0=; b=JLoU8HLnafeMYKV9/v0rvUc+F8h1Sgi+LHAXs/M8x8dwOro6J8LimBd9+Q6bI42eK43Kix banCvDVmZqmufaac+EeZ39TK6gj8QHVoffnT/QNgGwqLiW1y5X25+BssNAKfvUNQY6QTix 7axBwtNf9fJC5Q+StzwEA2kFI+nCpms= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 58FEC1377F for ; Wed, 9 Aug 2023 07:08:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id Gq3UCHI702SiSwAAMHmgww (envelope-from ) for ; Wed, 09 Aug 2023 07:08:34 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: handle errors properly in update_inline_extent_backref() Date: Wed, 9 Aug 2023 15:08:21 +0800 Message-ID: <7a56e967d536bbb3d40c90def6e59e9970ef3445.1691564698.git.wqu@suse.com> X-Mailer: git-send-email 2.41.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org [PROBLEM] Inside function update_inline_extent_backref(), we have several BUG_ON()s along with some ASSERT()s which can be triggered by corrupted filesystem. [ANAYLYSE] Most of those BUG_ON()s and ASSERT()s are just a way of handling unexpected on-disk data. Although we have tree-checker to rule out obviously incorrect extent tree blocks, it's not enough for those ones. Thus we need proper error handling for them. [FIX] Thankfully all the callers of update_inline_extent_backref() would eventually handle the errror by aborting the current transaction. So this patch would do the proper error handling by: - Make update_inline_extent_backref() to return int The return value would be either 0 or -EUCLEAN. - Replace BUG_ON()s and ASSERT()s with proper error handling This includes: * Dump the bad extent tree leaf * Output an error message for the cause This would include the extent bytenr, num_bytes (if needed), the bad values and expected good values. * Return -EUCLEAN Note here we remove all the WARN_ON()s, as eventually the transaction would be aborted, thus a backtrace would be triggered anyway. - Better comments on why we expect refs == 1 and refs_to_mode == -1 for tree blocks Signed-off-by: Qu Wenruo Reviewed-by: Josef Bacik --- fs/btrfs/extent-tree.c | 80 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 65 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 3cae798499e2..45e325523e81 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -381,11 +381,11 @@ int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb, } } + WARN_ON(1); btrfs_print_leaf(eb); btrfs_err(eb->fs_info, "eb %llu iref 0x%lx invalid extent inline ref type %d", eb->start, (unsigned long)iref, type); - WARN_ON(1); return BTRFS_REF_TYPE_INVALID; } @@ -1059,12 +1059,13 @@ static int lookup_extent_backref(struct btrfs_trans_handle *trans, * helper to update/remove inline back ref */ static noinline_for_stack -void update_inline_extent_backref(struct btrfs_path *path, - struct btrfs_extent_inline_ref *iref, - int refs_to_mod, - struct btrfs_delayed_extent_op *extent_op) +int update_inline_extent_backref(struct btrfs_path *path, + struct btrfs_extent_inline_ref *iref, + int refs_to_mod, + struct btrfs_delayed_extent_op *extent_op) { struct extent_buffer *leaf = path->nodes[0]; + struct btrfs_fs_info *fs_info = leaf->fs_info; struct btrfs_extent_item *ei; struct btrfs_extent_data_ref *dref = NULL; struct btrfs_shared_data_ref *sref = NULL; @@ -1077,18 +1078,33 @@ void update_inline_extent_backref(struct btrfs_path *path, ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); refs = btrfs_extent_refs(leaf, ei); - WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0); + if (unlikely(refs_to_mod < 0 && refs + refs_to_mod <= 0)) { + struct btrfs_key key; + u32 extent_size; + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.type == BTRFS_METADATA_ITEM_KEY) + extent_size = fs_info->nodesize; + else + extent_size = key.offset; + btrfs_print_leaf(leaf); + btrfs_err(fs_info, +"invalid refs_to_mod for extent %llu num_bytes %u, has %d expect >= -%llu", + key.objectid, extent_size, refs_to_mod, refs); + return -EUCLEAN; + } refs += refs_to_mod; btrfs_set_extent_refs(leaf, ei, refs); if (extent_op) __run_delayed_extent_op(extent_op, leaf, ei); - /* - * If type is invalid, we should have bailed out after - * lookup_inline_extent_backref(). - */ type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY); - ASSERT(type != BTRFS_REF_TYPE_INVALID); + /* + * Function btrfs_get_extent_inline_ref_type() has already output + * error messages. + */ + if (unlikely(type == BTRFS_REF_TYPE_INVALID)) + return -EUCLEAN; if (type == BTRFS_EXTENT_DATA_REF_KEY) { dref = (struct btrfs_extent_data_ref *)(&iref->offset); @@ -1098,10 +1114,43 @@ void update_inline_extent_backref(struct btrfs_path *path, refs = btrfs_shared_data_ref_count(leaf, sref); } else { refs = 1; - BUG_ON(refs_to_mod != -1); + /* + * For tree blocks we can only drop one ref for it, and + * tree blocks should not have refs > 1. + * + * Furthermore if we're inserting a new inline backref, + * we won't reach this path either. + * (that would be setup_inline_extent_backref()) + */ + if (unlikely(refs_to_mod != -1)) { + struct btrfs_key key; + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + btrfs_print_leaf(leaf); + btrfs_err(fs_info, + "invalid refs_to_mod for tree block %llu, has %d expect -1", + key.objectid, refs_to_mod); + return -EUCLEAN; + } } - BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod); + if (unlikely(refs_to_mod < 0 && refs < -refs_to_mod)) { + struct btrfs_key key; + u32 extent_size; + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.type == BTRFS_METADATA_ITEM_KEY) + extent_size = fs_info->nodesize; + else + extent_size = key.offset; + btrfs_print_leaf(leaf); + btrfs_err(fs_info, +"invalid refs_to_mod for backref entry, iref %lu extent %llu num_bytes %u, has %d expect >= -%llu", + (unsigned long)iref, key.objectid, extent_size, + refs_to_mod, refs); + return -EUCLEAN; + } refs += refs_to_mod; if (refs > 0) { @@ -1121,6 +1170,7 @@ void update_inline_extent_backref(struct btrfs_path *path, btrfs_truncate_item(path, item_size, 1); } btrfs_mark_buffer_dirty(leaf); + return 0; } static noinline_for_stack @@ -1149,7 +1199,7 @@ int insert_inline_extent_backref(struct btrfs_trans_handle *trans, bytenr, num_bytes, root_objectid, path->slots[0]); return -EUCLEAN; } - update_inline_extent_backref(path, iref, refs_to_add, extent_op); + ret = update_inline_extent_backref(path, iref, refs_to_add, extent_op); } else if (ret == -ENOENT) { setup_inline_extent_backref(trans->fs_info, path, iref, parent, root_objectid, owner, offset, @@ -1169,7 +1219,7 @@ static int remove_extent_backref(struct btrfs_trans_handle *trans, BUG_ON(!is_data && refs_to_drop != 1); if (iref) - update_inline_extent_backref(path, iref, -refs_to_drop, NULL); + ret = update_inline_extent_backref(path, iref, -refs_to_drop, NULL); else if (is_data) ret = remove_extent_data_ref(trans, root, path, refs_to_drop); else