From patchwork Tue Apr 26 08:21:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 566652 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 0337BC43217 for ; Tue, 26 Apr 2022 08:38:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345434AbiDZIlF (ORCPT ); Tue, 26 Apr 2022 04:41:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345789AbiDZIjb (ORCPT ); Tue, 26 Apr 2022 04:39:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F6A66D864; Tue, 26 Apr 2022 01:31:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AF66B6189A; Tue, 26 Apr 2022 08:31:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B13DCC385A4; Tue, 26 Apr 2022 08:31:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650961867; bh=cAHJHvv5OO7Wdml7C5cnVYBlU08Dp1ge/HrmNel2wYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XxgTQ157zKyXhXp75zzpFTek9Ude9VQzqxPFAOKm8ua55yu+XwbhdZpUubRoL4opt HSCBm81QnS3+iDLRL/PUdhlfNIxCi4ysQR7x7KFKwxKoZLDEHPgKwqLBmQrDxHxVgh yklgu9KxC1ODd2yxaeobxE5r1MJDHayields5nVM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ye Bin , Jan Kara , Theodore Tso Subject: [PATCH 5.4 58/62] jbd2: fix a potential race while discarding reserved buffers after an abort Date: Tue, 26 Apr 2022 10:21:38 +0200 Message-Id: <20220426081738.884850289@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081737.209637816@linuxfoundation.org> References: <20220426081737.209637816@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ye Bin commit 23e3d7f7061f8682c751c46512718f47580ad8f0 upstream. we got issue as follows: [ 72.796117] EXT4-fs error (device sda): ext4_journal_check_start:83: comm fallocate: Detected aborted journal [ 72.826847] EXT4-fs (sda): Remounting filesystem read-only fallocate: fallocate failed: Read-only file system [ 74.791830] jbd2_journal_commit_transaction: jh=0xffff9cfefe725d90 bh=0x0000000000000000 end delay [ 74.793597] ------------[ cut here ]------------ [ 74.794203] kernel BUG at fs/jbd2/transaction.c:2063! [ 74.794886] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 74.795533] CPU: 4 PID: 2260 Comm: jbd2/sda-8 Not tainted 5.17.0-rc8-next-20220315-dirty #150 [ 74.798327] RIP: 0010:__jbd2_journal_unfile_buffer+0x3e/0x60 [ 74.801971] RSP: 0018:ffffa828c24a3cb8 EFLAGS: 00010202 [ 74.802694] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 74.803601] RDX: 0000000000000001 RSI: ffff9cfefe725d90 RDI: ffff9cfefe725d90 [ 74.804554] RBP: ffff9cfefe725d90 R08: 0000000000000000 R09: ffffa828c24a3b20 [ 74.805471] R10: 0000000000000001 R11: 0000000000000001 R12: ffff9cfefe725d90 [ 74.806385] R13: ffff9cfefe725d98 R14: 0000000000000000 R15: ffff9cfe833a4d00 [ 74.807301] FS: 0000000000000000(0000) GS:ffff9d01afb00000(0000) knlGS:0000000000000000 [ 74.808338] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 74.809084] CR2: 00007f2b81bf4000 CR3: 0000000100056000 CR4: 00000000000006e0 [ 74.810047] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 74.810981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 74.811897] Call Trace: [ 74.812241] [ 74.812566] __jbd2_journal_refile_buffer+0x12f/0x180 [ 74.813246] jbd2_journal_refile_buffer+0x4c/0xa0 [ 74.813869] jbd2_journal_commit_transaction.cold+0xa1/0x148 [ 74.817550] kjournald2+0xf8/0x3e0 [ 74.819056] kthread+0x153/0x1c0 [ 74.819963] ret_from_fork+0x22/0x30 Above issue may happen as follows: write truncate kjournald2 generic_perform_write ext4_write_begin ext4_walk_page_buffers do_journal_get_write_access ->add BJ_Reserved list ext4_journalled_write_end ext4_walk_page_buffers write_end_fn ext4_handle_dirty_metadata ***************JBD2 ABORT************** jbd2_journal_dirty_metadata -> return -EROFS, jh in reserved_list jbd2_journal_commit_transaction while (commit_transaction->t_reserved_list) jh = commit_transaction->t_reserved_list; truncate_pagecache_range do_invalidatepage ext4_journalled_invalidatepage jbd2_journal_invalidatepage journal_unmap_buffer __dispose_buffer __jbd2_journal_unfile_buffer jbd2_journal_put_journal_head ->put last ref_count __journal_remove_journal_head bh->b_private = NULL; jh->b_bh = NULL; jbd2_journal_refile_buffer(journal, jh); bh = jh2bh(jh); ->bh is NULL, later will trigger null-ptr-deref journal_free_journal_head(jh); After commit 96f1e0974575, we no longer hold the j_state_lock while iterating over the list of reserved handles in jbd2_journal_commit_transaction(). This potentially allows the journal_head to be freed by journal_unmap_buffer while the commit codepath is also trying to free the BJ_Reserved buffers. Keeping j_state_lock held while trying extends hold time of the lock minimally, and solves this issue. Fixes: 96f1e0974575("jbd2: avoid long hold times of j_state_lock while committing a transaction") Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20220317142137.1821590-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/commit.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -451,7 +451,6 @@ void jbd2_journal_commit_transaction(jou } spin_unlock(&commit_transaction->t_handle_lock); commit_transaction->t_state = T_SWITCH; - write_unlock(&journal->j_state_lock); J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <= journal->j_max_transaction_buffers); @@ -471,6 +470,8 @@ void jbd2_journal_commit_transaction(jou * has reserved. This is consistent with the existing behaviour * that multiple jbd2_journal_get_write_access() calls to the same * buffer are perfectly permissible. + * We use journal->j_state_lock here to serialize processing of + * t_reserved_list with eviction of buffers from journal_unmap_buffer(). */ while (commit_transaction->t_reserved_list) { jh = commit_transaction->t_reserved_list; @@ -490,6 +491,7 @@ void jbd2_journal_commit_transaction(jou jbd2_journal_refile_buffer(journal, jh); } + write_unlock(&journal->j_state_lock); /* * Now try to drop any written-back buffers from the journal's * checkpoint lists. We do this *before* commit because it potentially