[dm-devel] dm-bufio

Kasatkin, Dmitry dmitry.kasatkin at intel.com
Fri Mar 23 14:12:39 UTC 2012

On Fri, Mar 23, 2012 at 1:26 PM, Kasatkin, Dmitry
<dmitry.kasatkin at intel.com> wrote:
> On Fri, Mar 23, 2012 at 1:10 PM, Zdenek Kabelac <zkabelac at redhat.com> wrote:
>> Dne 23.3.2012 12:01, Kasatkin, Dmitry napsal(a):
>>> Hello,
>>> When using dm-bufio and dm-io in general, how to ensure that all dirty
>>> buffers are written to the storage when machine reboots?
>>> suspend hooks could be used, but they are not called on reboot, only
>>> when suspending/removing the target...
>> You mean you reboot without running  'sync' command?
>> And yes - on reboot you should properly unmount devices - so you should
>> see removal of target on your shutdown sequence -  I believe Fedora currently
>> tries to support switch to some shutdown ramdisk, so all filesystem and
>> devices might be properly unmounted and destroyed.
> Hello,
> Thanks for response.
> I use bufio to store some data on block device.
> It is not mounted in anyway. My target just use it to load/store data.
> When machine reboots, I want to be sure that bufio written all dirty buffers...
> - Dmitry

At the moment, I have reboot notifier which does the following

	blkdev_issue_flush(d->dev->bdev, GFP_KERNEL, NULL);

without first line on the next boot I got corrupted/not updated blocks.
and I am not sure if I need last 2 lines...

- Dmitry

>> Zdenek

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