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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 1040EC433E6 for ; Wed, 24 Feb 2021 14:17:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB6C964E7A for ; Wed, 24 Feb 2021 14:17:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235809AbhBXOOL (ORCPT ); Wed, 24 Feb 2021 09:14:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:59160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234365AbhBXNKj (ORCPT ); Wed, 24 Feb 2021 08:10:39 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 38B2B64F9B; Wed, 24 Feb 2021 12:55:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614171304; bh=YVFZtCS13rLWVOsj1afugY2qk29ygE76ymbfvutD12A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MED/IwSWJRg/M46cricB+KK7gq6vUCf+ri5Dwf8/V5z1Uhyqo6xGTGg3HTPHIBt3+ 63sUDZyoN+V2B48Y7eLIDCGi/9eX+Nq5LzkoCF81txrjUMY6TS0CYTJ4yHA7lMvHDl EebkJ9oLllN8PZGTVIXA9uv+TMG6uZBCHCOikIipaBgha4UYYJsVBnFgwsIPH0Gk5Q 5gc/A0236jjobWR4ic4HKADX7xUzaqqHxKA2Vj1zW3y92/ZzGUeMBw/RaEVY/5G38n nXucItXB9ngbyq+vC2JGQgDB76gCzhhbBH0BOE9YsI99HaMenb5EMTg0aFAGh44g+k Cxf/pqWYcV4Sg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Josef Bacik , David Sterba , Sasha Levin , linux-btrfs@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 22/26] btrfs: fix error handling in commit_fs_roots Date: Wed, 24 Feb 2021 07:54:30 -0500 Message-Id: <20210224125435.483539-22-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210224125435.483539-1-sashal@kernel.org> References: <20210224125435.483539-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Josef Bacik [ Upstream commit 4f4317c13a40194940acf4a71670179c4faca2b5 ] While doing error injection I would sometimes get a corrupt file system. This is because I was injecting errors at btrfs_search_slot, but would only do it one time per stack. This uncovered a problem in commit_fs_roots, where if we get an error we would just break. However we're in a nested loop, the first loop being a loop to find all the dirty fs roots, and then subsequent root updates would succeed clearing the error value. This isn't likely to happen in real scenarios, however we could potentially get a random ENOMEM once and then not again, and we'd end up with a corrupted file system. Fix this by moving the error checking around a bit to the main loop, as this is the only place where something will fail, and return the error as soon as it occurs. With this patch my reproducer no longer corrupts the file system. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/transaction.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 8829d89eb4aff..1b52c960682d6 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1249,7 +1249,6 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) struct btrfs_root *gang[8]; int i; int ret; - int err = 0; spin_lock(&fs_info->fs_roots_radix_lock); while (1) { @@ -1261,6 +1260,8 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) break; for (i = 0; i < ret; i++) { struct btrfs_root *root = gang[i]; + int ret2; + radix_tree_tag_clear(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, BTRFS_ROOT_TRANS_TAG); @@ -1282,17 +1283,17 @@ static noinline int commit_fs_roots(struct btrfs_trans_handle *trans) root->node); } - err = btrfs_update_root(trans, fs_info->tree_root, + ret2 = btrfs_update_root(trans, fs_info->tree_root, &root->root_key, &root->root_item); + if (ret2) + return ret2; spin_lock(&fs_info->fs_roots_radix_lock); - if (err) - break; btrfs_qgroup_free_meta_all_pertrans(root); } } spin_unlock(&fs_info->fs_roots_radix_lock); - return err; + return 0; } /* -- 2.27.0