From: Phillip Susi <psusi@cfl.rr.com>
To: Josef Bacik <josef@redhat.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>, WuBo <wu.bo@cn.fujitsu.com>,
linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] Btrfs: don't panic if orphan item already exists
Date: Wed, 14 Dec 2011 10:41:05 -0500 [thread overview]
Message-ID: <4EE8C391.9090501@cfl.rr.com> (raw)
In-Reply-To: <20111214152638.GB1925@localhost.localdomain>
On 12/14/2011 10:27 AM, Josef Bacik wrote:
> Except consider the case that the program was written intelligently and checks
> for errors on truncate. So he writes 100G, truncates to 50M, and the truncate
> fails and he closes the file and exits. Then somewhere down the road the inode
> is evicted from cache and we reboot the box. Next time the box comes up it only
> looks like a 50M file, except we're still taking up 100G of disk space, and we
> have no idea there's space there and it's still taken up in the allocator so it
> will just look like we've lost ~100G of space. This is why it's left there, so
> everything can be cleaned up.
I'm a little confused here. Is there a commit somewhere in there? How
can the 100g allocation be committed, but not the i_size of the inode?
Shouldn't either both or neither be committed? If both are committed,
and then the truncate fails, then I would expect the system to come back
up after a crash with the file still at 100g. That is, as long as the
orphan item is not left in place after the failed truncate.
next prev parent reply other threads:[~2011-12-14 15:41 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-13 17:55 [PATCH] Btrfs: don't panic if orphan item already exists Josef Bacik
2011-12-13 19:03 ` Phillip Susi
2011-12-13 19:09 ` Josef Bacik
2011-12-14 2:07 ` WuBo
2011-12-14 9:46 ` Miao Xie
2011-12-14 14:58 ` Josef Bacik
2011-12-14 15:14 ` Phillip Susi
2011-12-14 15:27 ` Josef Bacik
2011-12-14 15:41 ` Phillip Susi [this message]
2011-12-14 15:46 ` Josef Bacik
2011-12-14 19:59 ` Phillip Susi
2011-12-14 15:34 ` Josef Bacik
2011-12-14 15:35 ` Josef Bacik
2011-12-14 16:45 ` Chris Mason
2011-12-14 16:47 ` Josef Bacik
2011-12-15 1:42 ` Miao Xie
2011-12-15 1:56 ` WuBo
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