On Wed, Jun 27, 2007 at 08:49:24PM +0000, Pavel Machek wrote:

Hi!

quoted

FWIW, I'm on record stating that "sync" is not sufficient to quiesce an XFS
filesystem for a suspend/resume to work safely and have argued that the only

Hmm, so XFS writes to disk even when its threads are frozen?

They issue async I/O before they sleep and expects
processing to be done on I/O completion via workqueues.

quoted

safe thing to do is freeze the filesystem before suspend and thaw it after
resume. This is why I originally asked you to test that with the other problem

Could you add that to the XFS threads if it is really required? They
do know that they are being frozen for suspend.

We don't suspend the threads on a filesystem freeze - they continue
run. A filesystem freeze guarantees the filesystem clean and that
the in memory state matches what is on disk. It is not possible for
the filesytem to issue I/O or have outstanding I/O when it is in the
frozen state, so the state of the threads and/or workqueues does not
matter because they will be idle.

Cheers,

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