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

Tejun Heo
2013-12-16T12:45:20Z

Hello,

On Mon, Dec 16, 2013 at 08:12:07PM +0800, Ming Lei wrote:
> Looks we should guarantee that I/O queue is emptied before system sleep,
> otherwise it may be a bug, since battery may be drained up to cause
> data loss or block devices may be disconnected during sleep.

It's a bit beside the point as that's what journaling is for. Power
loss during suspend isn't all that different from power loss while
suspended. Also, the filesystems are already synced before entering
suspend, so it shouldn't be an issue. However, that doesn't guarantee
there aren't no pending bdi work items. We *hope* to control the
sources with freezer but there's no guarantee about the coverage and
no way to verify that either.

Thanks.

--
tejun