PM / hibernate xfs lock up / xfs_reclaim_inodes_ag

[Christoph Hellwig]

On Wed, Jul 27, 2011 at 11:35:13AM +0200, Rafael J. Wysocki wrote:
> The Pavel's objection, if I remember it correctly, was that some
> (or the majority of?) filesystems didn't implement the freezing operation,
> so they would be more vulnerable to data loss in case of a failing hibernation
> after this change.  However, that's better than actively causing pain to XFS
> users.

The objection never made sense and only means he never read the code.
freeze_super (or freeze_bdev back then) always does a sync_filesystem
before even checking if we have a freeze method, and sync_filesystem is
what we iterate over for each superblock in sync().