Return-Path: Received: from fieldses.org ([174.143.236.118]:45177 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150Ab0I3Vi7 (ORCPT ); Thu, 30 Sep 2010 17:38:59 -0400 Date: Thu, 30 Sep 2010 17:38:45 -0400 From: "J. Bruce Fields" To: Benny Halevy Cc: "J. Bruce Fields" , linux-nfs@vger.kernel.org Subject: Re: [PATCH 11/16] nfsd4: keep per-session list of connections Message-ID: <20100930213845.GF15207@fieldses.org> References: <1285863553-8945-1-git-send-email-bfields@redhat.com> <1285863553-8945-12-git-send-email-bfields@redhat.com> <4CA4FF6E.3030907@panasas.com> Content-Type: text/plain; charset=us-ascii In-Reply-To: <4CA4FF6E.3030907@panasas.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Thu, Sep 30, 2010 at 11:21:50PM +0200, Benny Halevy wrote: > On 2010-09-30 18:19, J. Bruce Fields wrote: > > From: J. Bruce Fields > > > > The spec requires us in various places to keep track of the connections > > associated with each session. > > > > Signed-off-by: J. Bruce Fields > > --- > > fs/nfsd/nfs4state.c | 69 +++++++++++++++++++++++++++++++++++++++----------- > > fs/nfsd/state.h | 8 ++++++ > > include/linux/nfs4.h | 3 ++ > > 3 files changed, 65 insertions(+), 15 deletions(-) > > > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > > index f86476c..c7c1a7a 100644 > > --- a/fs/nfsd/nfs4state.c > > +++ b/fs/nfsd/nfs4state.c > > @@ -625,11 +625,58 @@ static void init_forechannel_attrs(struct nfsd4_channel_attrs *new, struct nfsd4 > > new->maxops = min_t(u32, req->maxops, NFSD_MAX_OPS_PER_COMPOUND); > > } > > > > + > > +static void free_conn(struct nfsd4_conn *c) > > +{ > > + svc_xprt_put(c->cn_xprt); > > + kfree(c); > > +} > > + > > +void free_session(struct kref *kref) > > +{ > > + struct nfsd4_session *ses; > > + int mem; > > + > > + ses = container_of(kref, struct nfsd4_session, se_ref); > > + while (!list_empty(&ses->se_conns)) { > > + struct nfsd4_conn *c; > > + c = list_first_entry(&ses->se_conns, struct nfsd4_conn, cn_persession); > > + list_del(&c->cn_persession); > > + free_conn(c); > > + } > > + spin_lock(&nfsd_drc_lock); > > + mem = ses->se_fchannel.maxreqs * slot_bytes(&ses->se_fchannel); > > + nfsd_drc_mem_used -= mem; > > + spin_unlock(&nfsd_drc_lock); > > + free_session_slots(ses); > > + kfree(ses); > > +} > > + > > + > > static __be32 alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp, struct nfsd4_create_session *cses) > > { > > struct nfsd4_session *new; > > struct nfsd4_channel_attrs *fchan = &cses->fore_channel; > > int numslots, slotsize; > > + int status; > > int idx; > > > > /* > > @@ -654,6 +701,8 @@ static __be32 alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp > > memcpy(clp->cl_sessionid.data, new->se_sessionid.data, > > NFS4_MAX_SESSIONID_LEN); > > > > + INIT_LIST_HEAD(&new->se_conns); > > + > > new->se_flags = cses->flags; > > kref_init(&new->se_ref); > > idx = hash_sessionid(&new->se_sessionid); > > @@ -662,6 +711,11 @@ static __be32 alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp > > list_add(&new->se_perclnt, &clp->cl_sessions); > > spin_unlock(&client_lock); > > > > + status = nfsd4_new_conn(rqstp, new); > > + if (status) { > > + free_session(&new->se_ref); > > + return nfserr_jukebox; > > why not return status? The status is sort of bogus; all that can really happen is an allocation failure: > > +static __be32 nfsd4_new_conn(struct svc_rqst *rqstp, struct nfsd4_session *ses) > > +{ > > + struct nfs4_client *clp = ses->se_client; > > + struct nfsd4_conn *conn; > > + > > + conn = kmalloc(sizeof(struct nfsd4_conn), GFP_KERNEL); > > + if (!conn) > > + return nfserr_jukebox; > > + conn->cn_flags = NFS4_CDFC4_FORE; > > + svc_xprt_get(rqstp->rq_xprt); > > + conn->cn_xprt = rqstp->rq_xprt; > > + > > + spin_lock(&clp->cl_lock); > > + list_add(&conn->cn_persession, &ses->se_conns); > > + spin_unlock(&clp->cl_lock); > > + > > + return nfs_ok; > > +} I'd actually rather change alloc_init_session() to return NULL or the new session. But, yeah, it grates a bit to have a status return that's ignored. Hm. > > diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h > > index 07e40c6..79b15fb 100644 > > --- a/include/linux/nfs4.h > > +++ b/include/linux/nfs4.h > > @@ -61,6 +61,9 @@ > > #define NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL 0x10000 > > #define NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED 0x20000 > > > > +#define NFS4_CDFC4_FORE 0x1 > > +#define NFS4_CDFC4_BACK 0x2 > > + > > nit: I think that defining flags shifted bits is clearer, e.g.: > > enum nfsd4_channel_dir { > NFS4_CDFC4_FORE = 1 << 0, > NFS4_CDFC4_BACK = 1 << 1, I see what you mean. I was just taking the definitions from the spec. And I should add FORE_OR_BOTH and BACK_OR_BOTH some time, neither powers of two. I dunno. --b. > }; > > Benny > > > #define NFS4_SET_TO_SERVER_TIME 0 > > #define NFS4_SET_TO_CLIENT_TIME 1 > > >