From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:15564 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751521Ab3BDCir (ORCPT ); Sun, 3 Feb 2013 21:38:47 -0500 Message-ID: <510F1F63.8000203@cn.fujitsu.com> Date: Mon, 04 Feb 2013 10:39:31 +0800 From: Miao Xie Reply-To: miaox@cn.fujitsu.com MIME-Version: 1.0 To: Eric Sandeen CC: Tsutomu Itoh , Linux Btrfs Subject: Re: [BUG] kernel BUG at fs/btrfs/async-thread.c:605! References: <5109E70D.3010005@jp.fujitsu.com> <510A0756.40206@redhat.com> <510A243C.3010508@cn.fujitsu.com> <510B0CE5.9090601@jp.fujitsu.com> <510B3B4B.6070607@cn.fujitsu.com> <510B5845.2020602@jp.fujitsu.com> In-Reply-To: <510B5845.2020602@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, Eric I want to send out my fix patch, but Could I add your Signed-off-by? because you found the key to solving the problem. Thanks Miao On Fri, 01 Feb 2013 14:53:09 +0900, Tsutomu Itoh wrote: >>> Can you please explain similar problems, Miao? >> >> Before missing device check, there are several places where we read the metadata, >> such as reading chunk tree root, btrfs_read_chunk_tree, those functions may fail >> after submit a bio. If we don't wait until the bio end, and just stop the workers, >> the same problem will happen. >> >> (invalidate_inode_pages2() will wait until the bio end, because it need lock the pages >> which are going to be invalidated, and the page is locked if it is under disk read IO) > > I understood. > > My reproducer is not reproduce this problem yet. But the following messages were > displayed when 'rmmod btrfs' command was executed. > > [76378.723481] ============================================================================= > [76378.723901] BUG btrfs_extent_buffer (Tainted: G B ): Objects remaining in btrfs_extent_buffer on kmem_cache_close() > [76378.724333] ----------------------------------------------------------------------------- > [76378.724333] > [76378.724959] INFO: Slab 0xffffea00065c3280 objects=23 used=2 fp=0xffff8801970caac0 flags=0x8000000000004080 > [76378.725391] Pid: 9156, comm: rmmod Tainted: G B 3.8.0-rc5 #1 > [76378.725397] Call Trace: > [76378.725403] [] slab_err+0xb0/0xd2 > > I think that this message means there is a possibility that I/O did not end > normally. > and, after Miao's patch applied, this message is not displayed when rmmod was > executed. > > So, Miao's patch seems to fix the problem for me. [SNIP] >>>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c >>>> index 0c31d07..d8fd711 100644 >>>> --- a/fs/btrfs/disk-io.c >>>> +++ b/fs/btrfs/disk-io.c >>>> @@ -2728,13 +2728,13 @@ fail_cleaner: >>>> * kthreads >>>> */ >>>> filemap_write_and_wait(fs_info->btree_inode->i_mapping); >>>> - invalidate_inode_pages2(fs_info->btree_inode->i_mapping); >>>> >>>> fail_block_groups: >>>> btrfs_free_block_groups(fs_info); >>>> >>>> fail_tree_roots: >>>> free_root_pointers(fs_info, 1); >>>> + invalidate_inode_pages2(fs_info->btree_inode->i_mapping); >>>> >>>> fail_sb_buffer: >>>> btrfs_stop_workers(&fs_info->generic_worker); >>>> @@ -2755,7 +2755,6 @@ fail_alloc: >>>> fail_iput: >>>> btrfs_mapping_tree_free(&fs_info->mapping_tree); >>>> >>>> - invalidate_inode_pages2(fs_info->btree_inode->i_mapping); >>>> iput(fs_info->btree_inode); >>>> fail_bdi: >>>> bdi_destroy(&fs_info->bdi); >>>> > > >