Re: dentry bloat.

[Manfred Spraul]

Dipankar Sarma wrote:

> On Sat, May 08, 2004 at 12:27:50PM -0700, Linus Torvalds wrote:
>  
>
> > And yes, removing d_movecount would be ok by then, as long as we re-test
> > the parent inside d_lock (we don't need to re-test "hash", since if we
> > tested the full name inside the lock, the hash had better match too ;)
> >    
What's the prupose of d_move_count?
AFAICS it protects against a double rename: first to different bucket, 
then back to original bucket. This changes the position of the dentry in 
the hash chain and a concurrent lookup would skip entries.
d_lock wouldn't prevent that.

But I think d_bucket could be removed: for __d_lookup the test appears 
to be redundant with the d_move_count test. The remaining users are not 
performance critical, they could recalculate the bucket from d_parent 
and d_name.hash.

--
   Manfred

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