Re: dentry bloat.

From: Dipankar Sarma
Date: Mon May 10 2004 - 13:43:40 EST


On Sun, May 09, 2004 at 11:17:12PM +0100, viro@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx wrote:
> On Sun, May 09, 2004 at 09:03:16PM +0530, Dipankar Sarma wrote:
>
> > Actually, what may happen is that since the dentries are added
> > in the front, a double move like that would result in hash chain
> > traversal looping. Timing dependent and unlikely, but d_move_count
> > avoided that theoritical possibility. It is not about skipping
> > dentries which is safe because a miss would result in a real_lookup()
>
> Not really. A miss could result in getting another dentry allocated
> for the same e.g. directory, which is *NOT* harmless at all.

AFAICS, a miss in __d_lookup would result in a repeat lookup
under dcache_lock in which case we are safe or real_lookup()
which in turn does another lookup with dcache_lock. Is there
a path that I am missing here ?

Thanks
Dipankar
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