[dm-devel] Re: [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex

[David Chinner <dgc sgi com>]

On Sun, Nov 12, 2006 at 11:43:05PM +0100, Rafael J. Wysocki wrote:
> On Sunday, 12 November 2006 23:30, David Chinner wrote:
> > And how does freezing them at that point in time guarantee consistent
> > filesystem state?
> 
> If the work queues are frozen, there won't be any fs-related activity _after_
> we create the suspend image. 

fs-related activity before or after the suspend image is captured is
not a problem - it's fs-related activity _during_ the suspend that
is an issue here. If we have async I/O completing during the suspend
image capture, we've got problems....

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group