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From: bfields@fieldses.org (J. Bruce Fields)
To: David Howells <dhowells@redhat.com>
Cc: "J. Bruce Fields" <bfields@redhat.com>,
	linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 10/10] nfsd: clients don't need to break their own delegations
Date: Tue, 20 Mar 2018 10:52:54 -0400	[thread overview]
Message-ID: <20180320145254.GB4288@fieldses.org> (raw)
In-Reply-To: <29167.1521552951@warthog.procyon.org.uk>

On Tue, Mar 20, 2018 at 01:35:51PM +0000, David Howells wrote:
> J. Bruce Fields <bfields@redhat.com> wrote:
> 
> > @@ -139,6 +139,9 @@ struct cred {
> >  	struct key	*thread_keyring; /* keyring private to this thread */
> >  	struct key	*request_key_auth; /* assumed request_key authority */
> >  #endif
> > +#ifdef CONFIG_FILE_LOCKING
> > +	void		*lease_breaker; /* identify NFS client breaking a delegation */
> > +#endif
> >  #ifdef CONFIG_SECURITY
> >  	void		*security;	/* subjective LSM security */
> >  #endif
> 
> Sorry, but ewww.

I'm sure you're right, but, to make sure I understand:

> Two reasons for that comment:
> 
>  (1) The cred struct may get retained long past where you expect if it gets
>      attached to another process or a file descriptor.

How would that happen in the case of a knfsd thread?

>  (2) The ->lease_breaker pointer needs lifetime management in cred.c.  It will
>      potentially get copied around and may need cleaning up.

Hm, OK.

> Can you stick your breaker identity in a key struct as Jeff suggested?

Probably so.  I'm unfamiliar with the keyring code.  How would you
recommend doing that?

--b.

      parent reply	other threads:[~2018-03-20 14:52 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-19 14:36 [PATCH 00/10] Eliminate delegation self-conflicts v2 J. Bruce Fields
2018-03-19 14:36 ` [PATCH 01/10] vfs: remove unnecessary fl_owner_t typedef J. Bruce Fields
2018-03-19 14:36 ` [PATCH 02/10] nfsd: simplify put of fi_deleg_file J. Bruce Fields
2018-03-19 14:36 ` [PATCH 03/10] nfsd: simplify nfs4_put_deleg_lease calls J. Bruce Fields
2018-03-19 14:36 ` [PATCH 04/10] nfsd4: set fl_owner to delegation, not file pointer J. Bruce Fields
2018-03-19 14:36 ` [PATCH 05/10] nfsd4: dp->dl_stid.sc_file doesn't need locking J. Bruce Fields
2018-03-19 14:36 ` [PATCH 06/10] nfsd: make nfs4_get_existing_delegation less confusing J. Bruce Fields
2018-03-19 14:36 ` [PATCH 07/10] nfsd: factor out common delegation-destruction code J. Bruce Fields
2018-03-19 14:36 ` [PATCH 08/10] nfsd: move sc_file assignment into alloc_init_deleg J. Bruce Fields
2018-03-19 14:36 ` [PATCH 09/10] nfsd: create a separate lease for each delegation J. Bruce Fields
2018-03-19 14:36 ` [PATCH 10/10] nfsd: clients don't need to break their own delegations J. Bruce Fields
2018-03-20 13:10 ` [PATCH 00/10] Eliminate delegation self-conflicts v2 Jeff Layton
2018-03-20 13:35 ` [PATCH 10/10] nfsd: clients don't need to break their own delegations David Howells
2018-03-20 13:46   ` Trond Myklebust
2018-03-20 14:49     ` J. Bruce Fields
2018-03-20 15:13       ` Trond Myklebust
2018-03-20 16:02         ` bfields
2018-09-06 19:40           ` bfields
2018-03-20 14:52   ` J. Bruce Fields [this message]

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