From: Christoph Hellwig <hch@infradead.org>
To: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>,
Surbhi Palande <surbhi.palande@ubuntu.com>,
Dave Chinner <david@fromorbit.com>,
Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>,
Ted Ts'o <tytso@mit.edu>,
Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>,
Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [RFC][PATCH] Re: [BUG] ext4: cannot unfreeze a filesystem due to a deadlock
Date: Mon, 2 May 2011 10:41:55 -0400 [thread overview]
Message-ID: <20110502144155.GA8045@infradead.org> (raw)
In-Reply-To: <20110502142055.GF4556@quack.suse.cz>
On Mon, May 02, 2011 at 04:20:55PM +0200, Jan Kara wrote:
> Hmm, but what prevents the following race?
>
> Thread 1 Thread 2
> ..
> xfs_trans_alloc()
> xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
> freeze_super()
sb->s_frozen = SB_FREEZE_TRANS;
> ...
> xfs_fs_freeze()
> ...
> xfs_quiesce_attr()
waits for all active
transactions
> ...
xfs_trans_alloc
-> blocks in xfs_wait_for_freeze
(thus doesn't get to _xfs_trans_alloc)
> _xfs_trans_alloc()
> atomic_inc(&mp->m_active_trans);
> ... goes on modifying the filesystem
>
> It seems to be a similar problem as in ext4 - the atomic_inc() and
> vfs_check_frozen() are in the wrong order...
I can't see the problem in this scheme. Note that we want
_xfs_trans_alloc to be able to create a transaction for
xfs_fs_log_dummy, so that we can write the dummy log record after
freezing out all other transactions, so that one is special cased
and doesn't do the xfs_wait_for_freeze.
next prev parent reply other threads:[~2011-05-02 14:41 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-07 11:53 [BUG] ext4: cannot unfreeze a filesystem due to a deadlock Masayoshi MIZUMA
2011-02-15 16:06 ` Jan Kara
2011-02-15 17:03 ` Ted Ts'o
2011-02-15 17:29 ` Jan Kara
2011-02-15 18:04 ` Ted Ts'o
2011-02-15 19:11 ` Jan Kara
2011-02-15 23:17 ` Toshiyuki Okajima
2011-02-16 14:56 ` Jan Kara
2011-02-17 3:50 ` Toshiyuki Okajima
2011-02-17 5:13 ` Andreas Dilger
2011-02-17 10:41 ` Jan Kara
2011-02-17 10:45 ` Jan Kara
2011-03-28 8:06 ` [RFC][PATCH] " Toshiyuki Okajima
2011-03-30 14:12 ` Jan Kara
2011-03-31 8:37 ` Yongqiang Yang
2011-03-31 8:48 ` Yongqiang Yang
2011-03-31 14:04 ` Eric Sandeen
2011-03-31 14:36 ` Yongqiang Yang
2011-03-31 15:25 ` Eric Sandeen
2011-03-31 16:28 ` Jan Kara
2011-03-31 12:03 ` Toshiyuki Okajima
2011-04-05 10:25 ` Toshiyuki Okajima
2011-04-05 22:54 ` Jan Kara
2011-04-06 5:09 ` Toshiyuki Okajima
2011-04-06 5:57 ` Jan Kara
2011-04-06 7:40 ` Toshiyuki Okajima
2011-04-06 17:46 ` Jan Kara
2011-04-15 13:39 ` Toshiyuki Okajima
2011-04-15 17:13 ` Jan Kara
2011-04-15 17:17 ` Eric Sandeen
2011-04-15 17:37 ` Jan Kara
2011-04-18 9:05 ` Toshiyuki Okajima
2011-04-18 10:51 ` Jan Kara
2011-04-19 9:43 ` Toshiyuki Okajima
2011-04-22 6:58 ` Toshiyuki Okajima
2011-04-22 21:26 ` Peter M. Petrakis
2011-04-22 21:40 ` Jan Kara
2011-04-22 22:57 ` Peter M. Petrakis
2011-04-22 22:10 ` Jan Kara
2011-04-25 6:28 ` Toshiyuki Okajima
2011-05-03 8:06 ` Surbhi Palande
2011-05-03 11:01 ` Surbhi Palande
2011-05-03 13:08 ` (unknown), Surbhi Palande
2011-05-03 13:46 ` your mail Jan Kara
2011-05-03 13:56 ` Surbhi Palande
2011-05-03 15:26 ` Surbhi Palande
2011-05-03 15:36 ` Jan Kara
2011-05-03 15:43 ` Surbhi Palande
2011-05-04 19:24 ` Jan Kara
2011-05-06 15:20 ` [RFC][PATCH] Do not accept a new handle when the F.S is frozen Surbhi Palande
2011-05-06 15:20 ` [PATCH] Adding support to freeze and unfreeze a journal Surbhi Palande
2011-05-06 20:56 ` Andreas Dilger
2011-05-07 20:04 ` [PATCH v2] " Surbhi Palande
2011-05-08 8:24 ` Marco Stornelli
2011-05-09 9:04 ` Surbhi Palande
2011-05-09 9:24 ` Jan Kara
2011-05-09 9:53 ` Jan Kara
2011-05-09 13:49 ` Surbhi Palande
2011-05-09 14:51 ` [PATCH v3] " Surbhi Palande
2011-05-09 15:08 ` Jan Kara
2011-05-10 15:07 ` [PATCH] " Surbhi Palande
2011-05-10 21:07 ` Andreas Dilger
2011-05-11 7:46 ` Surbhi Palande
2011-05-09 15:23 ` [PATCH v3] " Eric Sandeen
2011-05-11 7:06 ` Surbhi Palande
2011-05-11 7:10 ` [PATCH] Attempt to sync the fsstress writes to a frozen F.S Surbhi Palande
2011-05-12 14:22 ` Eric Sandeen
2011-05-12 14:22 ` Eric Sandeen
2011-05-24 21:42 ` Ted Ts'o
2011-05-25 12:00 ` Surbhi Palande
2011-05-25 12:12 ` Theodore Tso
2011-05-27 16:28 ` Jan Kara
2011-05-11 9:05 ` [PATCH v3] Adding support to freeze and unfreeze a journal Andreas Dilger
2011-05-12 9:40 ` Surbhi Palande
2011-05-03 13:08 ` [PATCH] Prevent dirtying a page when ext4 F.S is frozen Surbhi Palande
2011-05-03 15:19 ` [RFC][PATCH] Re: [BUG] ext4: cannot unfreeze a filesystem due to a deadlock Jan Kara
2011-05-04 12:09 ` Surbhi Palande
2011-05-04 19:19 ` Jan Kara
2011-05-04 21:34 ` Surbhi Palande
2011-05-04 22:48 ` Jan Kara
2011-05-05 6:06 ` Surbhi Palande
2011-05-05 11:18 ` Jan Kara
2011-05-05 14:01 ` Surbhi Palande
2011-03-31 23:40 ` Dave Chinner
2011-03-31 23:53 ` Eric Sandeen
2011-04-01 14:08 ` Jan Kara
2011-04-06 5:40 ` Dave Chinner
2011-04-06 6:18 ` Jan Kara
2011-04-06 11:21 ` Dave Chinner
2011-04-06 13:44 ` Christoph Hellwig
2011-04-06 22:59 ` Dave Chinner
2011-04-06 17:40 ` Jan Kara
2011-04-06 22:54 ` Dave Chinner
2011-04-08 21:33 ` Jan Kara
2011-05-02 9:07 ` Surbhi Palande
2011-05-02 10:56 ` Jan Kara
2011-05-02 11:27 ` Surbhi Palande
2011-05-02 12:06 ` Surbhi Palande
2011-05-02 12:20 ` Jan Kara
2011-05-02 12:30 ` Surbhi Palande
2011-05-02 13:16 ` Jan Kara
2011-05-02 13:22 ` Christoph Hellwig
2011-05-02 14:20 ` Jan Kara
2011-05-02 14:41 ` Christoph Hellwig [this message]
2011-05-02 16:23 ` Jan Kara
2011-05-02 16:38 ` Christoph Hellwig
2011-05-02 13:22 ` Surbhi Palande
2011-05-02 13:24 ` Christoph Hellwig
2011-05-02 13:27 ` Surbhi Palande
2011-05-02 14:26 ` Jan Kara
2011-05-02 14:04 ` Eric Sandeen
2011-05-03 7:27 ` Surbhi Palande
2011-05-03 20:14 ` Eric Sandeen
2011-05-04 8:26 ` Surbhi Palande
2011-05-04 14:30 ` Eric Sandeen
2011-05-02 14:01 ` Eric Sandeen
2011-04-05 10:44 ` Toshiyuki Okajima
2011-12-09 1:56 ` Masayoshi MIZUMA
2011-12-15 12:41 ` Masayoshi MIZUMA
2013-11-29 4:58 ` Yongqiang Yang
2013-11-29 8:00 ` Jan Kara
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