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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0E6CC4321E for ; Mon, 1 Nov 2021 09:42:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B85360EBC for ; Mon, 1 Nov 2021 09:42:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232288AbhKAJow (ORCPT ); Mon, 1 Nov 2021 05:44:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:47858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232936AbhKAJls (ORCPT ); Mon, 1 Nov 2021 05:41:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6128D61372; Mon, 1 Nov 2021 09:28:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635758894; bh=x7YBmrPO1ZMwjfGRA3C/Q5JQWAl/WZTWzeN97tpkKqg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j+Rh3Qy2YVZLnjjjMlWt8VXZNVnTVeH05Ihh+8yJtP6Wk6cVC/GsYR1rvsfpIsa5b 702tu0qiC3Gb+cJ2wUkr24TUmajJXzd536kIDVtxEzE12+7fdt6ykIyy+Y59qOmJKy X/c4gG2m2Tah55f1rYiE8+Y+V6Ynpil6Vw3jZntg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gautham Ananthakrishna , Joseph Qi , rajesh.sivaramasubramaniom@oracle.com, Mark Fasheh , Joel Becker , Junxiao Bi , Changwei Ge , Gang He , Jun Piao , Andrew Morton , Linus Torvalds Subject: [PATCH 5.14 026/125] ocfs2: fix race between searching chunks and release journal_head from buffer_head Date: Mon, 1 Nov 2021 10:16:39 +0100 Message-Id: <20211101082538.390315965@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211101082533.618411490@linuxfoundation.org> References: <20211101082533.618411490@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Gautham Ananthakrishna commit 6f1b228529ae49b0f85ab89bcdb6c365df401558 upstream. Encountered a race between ocfs2_test_bg_bit_allocatable() and jbd2_journal_put_journal_head() resulting in the below vmcore. PID: 106879 TASK: ffff880244ba9c00 CPU: 2 COMMAND: "loop3" Call trace: panic oops_end no_context __bad_area_nosemaphore bad_area_nosemaphore __do_page_fault do_page_fault page_fault [exception RIP: ocfs2_block_group_find_clear_bits+316] ocfs2_block_group_find_clear_bits [ocfs2] ocfs2_cluster_group_search [ocfs2] ocfs2_search_chain [ocfs2] ocfs2_claim_suballoc_bits [ocfs2] __ocfs2_claim_clusters [ocfs2] ocfs2_claim_clusters [ocfs2] ocfs2_local_alloc_slide_window [ocfs2] ocfs2_reserve_local_alloc_bits [ocfs2] ocfs2_reserve_clusters_with_limit [ocfs2] ocfs2_reserve_clusters [ocfs2] ocfs2_lock_refcount_allocators [ocfs2] ocfs2_make_clusters_writable [ocfs2] ocfs2_replace_cow [ocfs2] ocfs2_refcount_cow [ocfs2] ocfs2_file_write_iter [ocfs2] lo_rw_aio loop_queue_work kthread_worker_fn kthread ret_from_fork When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and released the jounal head from the buffer head. Needed to take bit lock for the bit 'BH_JournalHead' to fix this race. Link: https://lkml.kernel.org/r/1634820718-6043-1-git-send-email-gautham.ananthakrishna@oracle.com Signed-off-by: Gautham Ananthakrishna Reviewed-by: Joseph Qi Cc: Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/suballoc.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -1251,7 +1251,7 @@ static int ocfs2_test_bg_bit_allocatable { struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data; struct journal_head *jh; - int ret; + int ret = 1; if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap)) return 0; @@ -1259,14 +1259,18 @@ static int ocfs2_test_bg_bit_allocatable if (!buffer_jbd(bg_bh)) return 1; - jh = bh2jh(bg_bh); - spin_lock(&jh->b_state_lock); - bg = (struct ocfs2_group_desc *) jh->b_committed_data; - if (bg) - ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap); - else - ret = 1; - spin_unlock(&jh->b_state_lock); + jbd_lock_bh_journal_head(bg_bh); + if (buffer_jbd(bg_bh)) { + jh = bh2jh(bg_bh); + spin_lock(&jh->b_state_lock); + bg = (struct ocfs2_group_desc *) jh->b_committed_data; + if (bg) + ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap); + else + ret = 1; + spin_unlock(&jh->b_state_lock); + } + jbd_unlock_bh_journal_head(bg_bh); return ret; }