From: " J. Bruce Fields" Subject: Re: [RFC 04/11] nfsd: mark client for renew Date: Wed, 16 Dec 2009 15:48:39 -0500 Message-ID: <20091216204839.GA28822@fieldses.org> References: <4B291B4C.3060603@panasas.com> <1260985272-21481-1-git-send-email-bhalevy@panasas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-nfs@vger.kernel.org, pnfs@linux-nfs.org To: Benny Halevy Return-path: Received: from fieldses.org ([174.143.236.118]:50647 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751499AbZLPUse (ORCPT ); Wed, 16 Dec 2009 15:48:34 -0500 In-Reply-To: <1260985272-21481-1-git-send-email-bhalevy@panasas.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Dec 16, 2009 at 07:41:12PM +0200, Benny Halevy wrote: > Mark the nfs4_client for renew on operations holding a stateid (or nfs41 > OP_SEQUENCE). > Do the actual lru list update when the compound processing is complete. > This will prevents the client from being expired by the laundromat while > the compound is in progress. > > Signed-off-by: Benny Halevy > --- > fs/nfsd/nfs4proc.c | 5 +++++ > fs/nfsd/nfs4state.c | 39 +++++++++++++++++++++++++++++++++++---- > fs/nfsd/state.h | 1 + > fs/nfsd/xdr4.h | 1 + > 4 files changed, 42 insertions(+), 4 deletions(-) > > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > index 37514c4..a8e9731 100644 > --- a/fs/nfsd/nfs4proc.c > +++ b/fs/nfsd/nfs4proc.c > @@ -1010,6 +1010,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp, > resp->opcnt = 0; > resp->rqstp = rqstp; > resp->cstate.minorversion = args->minorversion; > + resp->cstate.renew_client = NULL; > resp->cstate.replay_owner = NULL; > fh_init(&resp->cstate.current_fh, NFS4_FHSIZE); > fh_init(&resp->cstate.save_fh, NFS4_FHSIZE); > @@ -1114,6 +1115,10 @@ encode_op: > fh_put(&resp->cstate.current_fh); > fh_put(&resp->cstate.save_fh); > BUG_ON(resp->cstate.replay_owner); > + if (resp->cstate.renew_client) { > + renew_client(resp->cstate.renew_client); > + put_nfs4_client(resp->cstate.renew_client); > + } > out: > nfsd4_release_compoundargs(args); > /* Reset deferral mechanism for RPC deferrals */ > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index c456551..16ccab3 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -634,8 +634,39 @@ free_session(struct kref *kref) > } > > static inline void > +mark_client_for_renew(struct nfsd4_compound_state *cstate, > + struct nfs4_client *clp) > +{ > + int old_state = atomic_cmpxchg(&clp->cl_state, CL_STATE_NORMAL, > + CL_STATE_RENEW); > + > + if (old_state != CL_STATE_EXPIRED) { > + cstate->renew_client = clp; > + get_nfs4_client(clp); If cstate->renew_client is already set, then we may leak a reference count here, right? Also: at least in the v4 case, I don't think there's anything preventing cstate->renew_client being already set to a different client. (With sessions hopefully that's not possible.) This patch doesn't appear to stand alone as it removes the client renewals without yet replacing them by anything. --b. > + } > + > + dprintk("%s: client (clientid %08x/%08x) %s\n", > + __func__, > + clp->cl_clientid.cl_boot, > + clp->cl_clientid.cl_id, > + old_state == CL_STATE_EXPIRED ? "already expired" : > + "marked for renew"); > +} > + > +void > renew_client(struct nfs4_client *clp) > { > + int old_state = atomic_cmpxchg(&clp->cl_state, CL_STATE_RENEW, > + CL_STATE_NORMAL); > + > + if (old_state == CL_STATE_EXPIRED) { > + dprintk("%s: client (clientid %08x/%08x) already expired\n", > + __func__, > + clp->cl_clientid.cl_boot, > + clp->cl_clientid.cl_id); > + return; > + } > + > /* > * Move client to the end to the LRU list. > */ > @@ -1471,7 +1502,7 @@ out: > /* Renew the clientid on success and on replay */ > if (cstate->session) { > nfs4_lock_state(); > - renew_client(session->se_client); > + mark_client_for_renew(cstate, session->se_client); > nfs4_unlock_state(); > } > dprintk("%s: return %d\n", __func__, ntohl(status)); > @@ -2830,7 +2861,7 @@ nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate, > status = nfs4_check_delegmode(dp, flags); > if (status) > goto out; > - renew_client(dp->dl_client); > + mark_client_for_renew(cstate, dp->dl_client); > if (filpp) > *filpp = dp->dl_vfs_file; > } else { /* open or lock stateid */ > @@ -2850,7 +2881,7 @@ nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate, > status = nfs4_check_openmode(stp, flags); > if (status) > goto out; > - renew_client(stp->st_stateowner->so_client); > + mark_client_for_renew(cstate, stp->st_stateowner->so_client); > if (filpp) > *filpp = stp->st_vfs_file; > } > @@ -2970,7 +3001,7 @@ nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid, > status = check_stateid_generation(stateid, &stp->st_stateid, flags); > if (status) > return status; > - renew_client(sop->so_client); > + mark_client_for_renew(cstate, sop->so_client); > return nfs_ok; > > check_replay: > diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h > index 21109d4..b684c84 100644 > --- a/fs/nfsd/state.h > +++ b/fs/nfsd/state.h > @@ -385,6 +385,7 @@ extern void nfs4_lock_state(void); > extern void nfs4_unlock_state(void); > extern int nfs4_in_grace(void); > extern __be32 nfs4_check_open_reclaim(clientid_t *clid); > +extern void renew_client(struct nfs4_client *); > extern void get_nfs4_client(struct nfs4_client *); > extern void put_nfs4_client(struct nfs4_client *clp); > extern void nfs4_free_stateowner(struct kref *kref); > diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h > index efa3377..e48d5c7 100644 > --- a/fs/nfsd/xdr4.h > +++ b/fs/nfsd/xdr4.h > @@ -46,6 +46,7 @@ > struct nfsd4_compound_state { > struct svc_fh current_fh; > struct svc_fh save_fh; > + struct nfs4_client *renew_client; > struct nfs4_stateowner *replay_owner; > /* For sessions DRC */ > struct nfsd4_session *session; > -- > 1.6.5.1 >