Hi!

Proposed solution:

Instead of fixing such semantics and trying to get all filesystems to do it
right, we can easily do away with all freezing calls if the filesystem
implements a proper freeze_fs() callback. The following 9 filesystems have
freeze_fs() implemented as such we can let the kernel issue the callback upon
suspend and thaw on resume automatically on our behalf.

  o xfs
  o reiserfs
  o nilfs2
  o jfs
  o f2fs
  o ext4
  o ext2
  o btrfs

Of these, the following have freezer helpers, which can then be removed
after the kernel automaticaly calls freeze_fs for us on suspend:

  o xfs
  o nilfs2
  o jfs
  o f2fs
  o ext4

I've tested this on a system with ext4 and XFS, and have let 0-day go at
without issues. I have branches availabe for linux-next [3] and Linus'
latest tree [4].

Was hibernation tested? uswsusp?

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html