Re: [PATCH 6/6] audit: Point to fsnotify mark instead of embedding it

[Jan Kara <jack@suse.cz>]

On Fri 29-06-18 16:20:12, Amir Goldstein wrote:
> On Thu, Jun 28, 2018 at 7:40 PM, Jan Kara <jack@suse.cz> wrote:
> > Audit tree code currently embeds fsnotify mark in audit_chunk. As chunk
> > attached to an inode is replace when new tag is added / removed, we also
> > need to remove old fsnotify mark and add a new one on such occasion.
> > This is cumbersome and makes locking rules somewhat difficult to follow.
> >
> > Fix these problems by allocating fsnotify mark independently and keeping
> > it all the time while there is some chunk attached to an inode. Also add
> > documentation about the locking rules so that things are easier to
> > follow.
> >
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> 
> Wow! this patch is a lot to take in at once.
> I wonder if it would be possible to split it to:
> - make mark not embedded and take chunk reference
> - replace_mark_chunk() and rid of cumbersome code

OK, I'll try something.

> Or any other simplification that would help me survive this review.
> 
> In the mean while just one nit below...
> 
> [...]
> > +       mutex_lock(&entry->group->mark_mutex);
> > +       spin_lock(&hash_lock);
> > +       chunk = AUDIT_M(entry)->chunk;
> > +       replace_mark_chunk(entry, NULL);
> > +       spin_unlock(&hash_lock);
> > +       if (chunk) {
> > +               mutex_unlock(&entry->group->mark_mutex);
> > +               evict_chunk(chunk);
> > +               audit_mark_put_chunk(chunk);
> > +       } else {
> > +               mutex_unlock(&entry->group->mark_mutex);
> > +       }
> 
> else case seems like a leftover or something.

Fixed. Thanks.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR