[Ocfs2-devel] ext3/4, btrfs, ocfs2: How to assure that cleancache_invalidate_fs is called on every superblock free

[Jan Kara]

  Hello,

On Fri 09-03-12 14:40:22, Andor Daam wrote:
> Is it ever possible for a superblock for a mounted filesystem to be
> free'd without a previous call to unmount the filesystem?
  No, I don't think so (well, except for cases where we do not manage to
fully setup the superblock). But be aware that mount/umount need not be
really the entry points you are looking for since filesystem can be mounted
several times. Rather deactivate_locked_supers() is the place you are
looking for...

> I need to be certain that the function cleancache_invalidate_fs, which is
> at the moment called by deactivate_locked_super (fs/super.c) [1], is
> called before every free on a superblock of cleancache-enabled
> filesystems.  Is this already the case or are there situations in which
> this does not happen?
> 
> It would be interesting to know this, as we are planning to have
> cleancache save pointers to superblocks of every mounted
> cleancache-enabled filesystem [2] and it would be fatal if a
> superblock is free'd without cleancache being notified.

								Honza
-- 
Jan Kara <jack at suse.cz>
SUSE Labs, CR