From: Jan Hudec <bulb@ucw.cz>
To: Nir Tzachar <tzachar@cs.bgu.ac.il>
Cc: Jan Hudec <bulb@ucw.cz>, linux-fsdevel@vger.kernel.org
Subject: Re: a problem with dget
Date: Wed, 26 Mar 2003 10:57:20 +0100 [thread overview]
Message-ID: <20030326095720.GF24147@vagabond> (raw)
In-Reply-To: <Pine.LNX.4.44_heb2.09.0303261143140.2215-100000@ruby>
On Wed, Mar 26, 2003 at 11:45:22AM +0200, Nir Tzachar wrote:
> > Isn't that the little confusing semanticsof lookup that's biting you?
> > When ->lookup returns non-NULL, real_lookup (the caller) puts the dentry
> > passed to ->lookup. So if you fill it in, you must return NULL and *NOT*
> > the dentry you recieved!
> >
> > > the problem happens every time i try to do a dget an any dentry.
> >
> > Yes, because you need to hold a reference to do dget.
> >
>
> thanks, this was my problem exactly.
>
> anyway, who uses these semantics? which f/s needs to reallocate a dentry
> and discards the one supplied to it? and why?
I think NFS may cause any filesystem to need this. The problem is, that
when a partition is exported, disconnected entries may appear (created
by fh_to_dentry). When/if these entries are then looked up, they should
be connected. This semantics migh be used to do the connecting (it's not
necessary, but it's a useful optimization).
-------------------------------------------------------------------------------
Jan 'Bulb' Hudec <bulb@ucw.cz>
next prev parent reply other threads:[~2003-03-26 9:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-03-25 16:47 a problem with dget Nir Tzachar
2003-03-26 9:23 ` Jan Hudec
2003-03-26 9:45 ` Nir Tzachar
2003-03-26 9:57 ` Jan Hudec [this message]
2003-03-26 20:43 ` [FiST] " Jerome de Vivie
2003-03-27 8:17 ` Nir Tzachar
2003-03-28 2:01 ` Erez Zadok
2003-03-30 4:29 ` Nir Tzachar
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