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From: Avi Kivity <avi@qumranet.com>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] qcow2 - safe on kill?  safe on power fail?
Date: Tue, 22 Jul 2008 09:07:34 +0300	[thread overview]
Message-ID: <48857926.5020708@qumranet.com> (raw)
In-Reply-To: <48850A99.7070005@codemonkey.ws>

Anthony Liguori wrote:
> Andreas Schwab wrote:
>> Anthony Liguori <anthony@codemonkey.ws> writes:
>>
>>  
>>> The only ways that you can cause corruption is if the QCOW2 sector
>>> allocation code is faulty (and you would be screwed no matter what 
>>> here)
>>> or if you issue a SIGTERM/SIGKILL that interrupts the code while it's
>>> allocating a new sector.
>>>     
>>
>> Blocking SIGTERM until the allocation is finished could close that hole.
>>   
>
> Seems like a band-aid to me as SIGKILL is still an issue.  Plus it 
> would involve modifying all disk formats, not just QCOW2.  I'd rather 
> see proper journal support added to QCOW2 myself.

Journalling is so out of fashion.  It's better to sequence the 
operations so that failure results in a leak instead of corruption.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

  parent reply	other threads:[~2008-07-22  6:07 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-05 21:18 [Qemu-devel] Signal handling and qcow2 image corruption David Barrett
2008-03-05 21:55 ` Anthony Liguori
2008-03-05 23:48   ` David Barrett
2008-03-06  6:57   ` Avi Kivity
2008-07-21 18:10   ` [Qemu-devel] qcow2 - safe on kill? safe on power fail? Jamie Lokier
2008-07-21 19:43     ` Anthony Liguori
2008-07-21 21:26       ` Jamie Lokier
2008-07-21 22:14         ` Anthony Liguori
2008-07-21 23:47           ` Jamie Lokier
2008-07-22  6:06           ` Avi Kivity
2008-07-22 14:08             ` Anthony Liguori
2008-07-22 14:46               ` Jamie Lokier
2008-07-22 19:11               ` Avi Kivity
2008-07-22 14:32             ` Jamie Lokier
2008-07-21 22:00       ` Andreas Schwab
2008-07-21 22:15         ` Anthony Liguori
2008-07-21 22:22           ` David Barrett
2008-07-21 22:50             ` Anthony Liguori
2008-07-22  6:07           ` Avi Kivity [this message]
2008-07-22 14:11             ` Anthony Liguori
2008-07-22 14:36               ` Avi Kivity
2008-07-22 16:16                 ` Jamie Lokier
2008-07-22 19:13                   ` Avi Kivity
2008-07-22 20:04                     ` Jamie Lokier
2008-07-22 21:25                       ` Avi Kivity
2008-07-22 14:22             ` Jamie Lokier

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