From mboxrd@z Thu Jan  1 00:00:00 1970
From: Trond Myklebust <trond.myklebust@fys.uio.no>
Subject: Re: 2 questions concerning vfs_rmdir() (2.4.x and 2.5.x)
Date: 23 Aug 2002 11:24:32 +0200
Sender: linux-fsdevel-owner@vger.kernel.org
Message-ID: <shsbs7uudv3.fsf@charged.uio.no>
References: <200208221548.01237.trond.myklebust@fys.uio.no>
	<20020822150511.GB1666@ravel.coda.cs.cmu.edu>
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Cc: Alexander Viro <viro@math.psu.edu>, linux-fsdevel@vger.kernel.org
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To: Jan Harkes <jaharkes@cs.cmu.edu>
In-Reply-To: <20020822150511.GB1666@ravel.coda.cs.cmu.edu>
List-Id: linux-fsdevel.vger.kernel.org

>>>>> " " == Jan Harkes <jaharkes@cs.cmu.edu> writes:

     > Worst case scenario is that the underlying FS receives a new
     > lookup for the entry. Probably very useful when the dcache is
     > slightly out of sync.

But severely fscked up if the dentry is a mountpoint.

     > The rmdir might have failed because the directory doesn't exist
     > in the filesystem, so rehashing the dentry would be wrong.

Where's the big deal?

Either the dentry wasn't hashed in the first place (in which case a
simple test before you call d_unhash() can be used to tell you not to
rehash) or you will in any case need to have code in
lookup_revalidate() to cope with the alternative case "I've got a
hashed dentry that doesn't exist in the filesystem and I didn't call
rmdir()".

Cheers,
  Trond