Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qa0-f68.google.com ([209.85.216.68]:60050 "EHLO mail-qa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348AbaGQSqp (ORCPT ); Thu, 17 Jul 2014 14:46:45 -0400 Received: by mail-qa0-f68.google.com with SMTP id dc16so683629qab.11 for ; Thu, 17 Jul 2014 11:46:44 -0700 (PDT) From: Jeff Layton Date: Thu, 17 Jul 2014 14:46:42 -0400 To: "J. Bruce Fields" Cc: hch@infradead.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH v2 04/10] nfsd: Ensure stateids remain unique until they are freed Message-ID: <20140717144642.5159dea5@tlielax.poochiereds.net> In-Reply-To: <20140717184417.GD30442@fieldses.org> References: <1405521125-2303-1-git-send-email-jlayton@primarydata.com> <1405521125-2303-5-git-send-email-jlayton@primarydata.com> <20140717184417.GD30442@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 17 Jul 2014 14:44:17 -0400 "J. Bruce Fields" wrote: > On Wed, Jul 16, 2014 at 10:31:59AM -0400, Jeff Layton wrote: > > From: Trond Myklebust > > > > Add an extra delegation state to allow the stateid to remain in the idr > > tree until the last reference has been released. This will be necessary > > to ensure uniqueness once the client_mutex is removed. > > Cyclic idr allocation should make reuse extremely unlikely, shouldn't > it? > > Probably needs to be fixed anyway, applying. > > --b. > Yes, for the most part, but reuse is still possible once the counter wraps if you had a long-lived stateid (for instance). Not a likely problem, but we might as well fix it while we're in here. > > > > [jlayton: reset the sc_type under the state_lock in > > unhash_delegation] > > > > Signed-off-by: Trond Myklebust > > Signed-off-by: Jeff Layton > > Reviewed-by: Christoph Hellwig > > --- > > fs/nfsd/nfs4state.c | 8 ++++---- > > fs/nfsd/state.h | 1 + > > 2 files changed, 5 insertions(+), 4 deletions(-) > > > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > > index 1b01a20827ab..fd4deb049ddf 100644 > > --- a/fs/nfsd/nfs4state.c > > +++ b/fs/nfsd/nfs4state.c > > @@ -616,6 +616,7 @@ void > > nfs4_put_delegation(struct nfs4_delegation *dp) > > { > > if (atomic_dec_and_test(&dp->dl_count)) { > > + remove_stid(&dp->dl_stid); > > nfs4_free_stid(deleg_slab, &dp->dl_stid); > > num_delegations--; > > } > > @@ -657,6 +658,7 @@ unhash_delegation(struct nfs4_delegation *dp) > > struct nfs4_file *fp = dp->dl_file; > > > > spin_lock(&state_lock); > > + dp->dl_stid.sc_type = NFS4_CLOSED_DELEG_STID; > > list_del_init(&dp->dl_perclnt); > > list_del_init(&dp->dl_recall_lru); > > spin_lock(&fp->fi_lock); > > @@ -670,19 +672,15 @@ unhash_delegation(struct nfs4_delegation *dp) > > } > > } > > > > - > > - > > static void destroy_revoked_delegation(struct nfs4_delegation *dp) > > { > > list_del_init(&dp->dl_recall_lru); > > - remove_stid(&dp->dl_stid); > > nfs4_put_delegation(dp); > > } > > > > static void destroy_delegation(struct nfs4_delegation *dp) > > { > > unhash_delegation(dp); > > - remove_stid(&dp->dl_stid); > > nfs4_put_delegation(dp); > > } > > > > @@ -4036,7 +4034,9 @@ static __be32 nfsd4_validate_stateid(struct > > nfs4_client *cl, stateid_t *stateid) return nfs_ok; > > default: > > printk("unknown stateid type %x\n", s->sc_type); > > + /* Fallthrough */ > > case NFS4_CLOSED_STID: > > + case NFS4_CLOSED_DELEG_STID: > > return nfserr_bad_stateid; > > } > > } > > diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h > > index 81b7522e3f67..996d61eeb357 100644 > > --- a/fs/nfsd/state.h > > +++ b/fs/nfsd/state.h > > @@ -80,6 +80,7 @@ struct nfs4_stid { > > #define NFS4_CLOSED_STID 8 > > /* For a deleg stateid kept around only to process free_stateid's: > > */ #define NFS4_REVOKED_DELEG_STID 16 > > +#define NFS4_CLOSED_DELEG_STID 32 > > unsigned char sc_type; > > stateid_t sc_stateid; > > struct nfs4_client *sc_client; > > -- > > 1.9.3 > > -- Jeff Layton