Re: [PATCH] libata, freezer: avoid block device removal while systemis frozen

From: Tejun Heo
Date: Sat Dec 14 2013 - 15:31:29 EST


Hello, Nigel.

On Sat, Dec 14, 2013 at 10:15:21AM +1100, Nigel Cunningham wrote:
> My understanding is that the point is ensuring that - particularly
> in the case of hibernation - we don't cause filesystem corruption by
> writing one thing while writing the image and then doing something
> else (without knowledge of what happened while the image was being
> written) while reading the image or after restoring it.

So, all this is about hibernation? Does that mean that it's safe to
unfreeze before invoking resume? ie. we currently do,

freeze
suspend devs
resume devs
unfreeze

If we can just do,

freeze
suspend devs
unfreeze
resume devs

it should be a lot better and would remove all locking dependency
chains in the resume path.

Thanks.

--
tejun
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