From: Chris Mason <chris.mason@oracle.com>
To: "Yan, Zheng" <yanzheng@21cn.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>,
Tsutomu Itoh <t-itoh@jp.fujitsu.com>,
liubo <liubo2009@cn.fujitsu.com>,
Linux Btrfs <linux-btrfs@vger.kernel.org>,
Josef Bacik <josef@redhat.com>
Subject: Re: bug caused by removal of trans_mutex? (Was: Re: kernel BUG at fs/btrfs/extent-tree.c:6164!)
Date: Mon, 13 Jun 2011 15:55:51 -0400 [thread overview]
Message-ID: <1307994828-sup-6461@shiny> (raw)
In-Reply-To: <BANLkTi=m2CkcSQNPNja=A7eG62vLstM1sw@mail.gmail.com>
Excerpts from Yan, Zheng's message of 2011-06-13 10:58:35 -0400:
> The usage of trans_mutex in relocation code is subtle. It controls
> interaction of relocation
> with transaction start, transaction commit and snapshot creation.
> Simple replacing
> trans_mutex with trans_lock is wrong.
So, I've got a mutex around the reloc_root here and that was almost but
not quite enough. It looks like the biggest problem is that we need to
wait in btrfs_record_root_in_trans for anyone inside merge_reloc_roots.
I'm surviving much longer with a patch in place that synchronizes
btrfs_record_root_in_trans better.
Zheng if you have other comments on the locking please let me know.
-chris
next prev parent reply other threads:[~2011-06-13 19:55 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-06 8:33 kernel BUG at fs/btrfs/extent-tree.c:6164! Tsutomu Itoh
2011-06-07 5:31 ` liubo
2011-06-07 5:59 ` Tsutomu Itoh
2011-06-07 6:17 ` Tsutomu Itoh
2011-06-07 8:24 ` Tsutomu Itoh
2011-06-07 8:36 ` liubo
2011-06-07 15:46 ` Chris Mason
2011-06-08 5:12 ` Tsutomu Itoh
2011-06-13 7:13 ` bug caused by removal of trans_mutex? (Was: Re: kernel BUG at fs/btrfs/extent-tree.c:6164!) Li Zefan
2011-06-13 7:49 ` Yan, Zheng
2011-06-13 8:26 ` Li Zefan
2011-06-13 13:12 ` Chris Mason
2011-06-13 15:18 ` Chris Mason
2011-06-13 14:58 ` Yan, Zheng
2011-06-13 15:09 ` Chris Mason
2011-06-13 19:55 ` Chris Mason [this message]
2011-06-14 3:24 ` Yan, Zheng
2011-06-14 5:44 ` Li Zefan
2011-06-14 6:53 ` Yan, Zheng
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