From d76829889ac4250a18cfcc1a606bb256bb9c570c Mon Sep 17 00:00:00 2001 From: Benny Halevy Date: Wed, 12 May 2010 00:13:54 +0300 Subject: [PATCH] nfsd4: keep a reference count on client while in use Get a refcount on the client on SEQUENCE, Release the refcount and renew the client when all respective compounds completed. Do not expire the client by the laundromat while in use. If the client was expired via another path, free it when the compounds complete and the refcount reaches 0. Note that unhash_client_locked must call list_del_init on cl_lru as it may be called twice for the same client (once from nfs4_laundromat and then from expire_client) Signed-off-by: Benny Halevy Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 27 ++++++++++++++++++++++++--- fs/nfsd/nfs4xdr.c | 3 ++- fs/nfsd/state.h | 1 + 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 98aa7e8827b9..cc0e9117dd16 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -701,6 +701,22 @@ free_client(struct nfs4_client *clp) kfree(clp); } +void +release_session_client(struct nfsd4_session *session) +{ + struct nfs4_client *clp = session->se_client; + + if (!atomic_dec_and_lock(&clp->cl_refcount, &client_lock)) + return; + if (is_client_expired(clp)) { + free_client(clp); + session->se_client = NULL; + } else + renew_client_locked(clp); + spin_unlock(&client_lock); + nfsd4_put_session(session); +} + /* must be called under the client_lock */ static inline void unhash_client_locked(struct nfs4_client *clp) @@ -1476,8 +1492,7 @@ out: /* Hold a session reference until done processing the compound. */ if (cstate->session) { nfsd4_get_session(cstate->session); - /* Renew the clientid on success and on replay */ - renew_client_locked(session->se_client); + atomic_inc(&session->se_client->cl_refcount); } spin_unlock(&client_lock); dprintk("%s: return %d\n", __func__, ntohl(status)); @@ -2598,7 +2613,13 @@ nfs4_laundromat(void) clientid_val = t; break; } - list_move(&clp->cl_lru, &reaplist); + if (atomic_read(&clp->cl_refcount)) { + dprintk("NFSD: client in use (clientid %08x)\n", + clp->cl_clientid.cl_id); + continue; + } + unhash_client_locked(clp); + list_add(&clp->cl_lru, &reaplist); } spin_unlock(&client_lock); list_for_each_safe(pos, next, &reaplist) { diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 5c2de471329a..126d0caabb3c 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -3313,7 +3313,8 @@ nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p, struct nfsd4_compo dprintk("%s: SET SLOT STATE TO AVAILABLE\n", __func__); cs->slot->sl_inuse = false; } - nfsd4_put_session(cs->session); + /* Renew the clientid on success and on replay */ + release_session_client(cs->session); } return 1; } diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index cfd743ea4b79..006c84230c7c 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -420,6 +420,7 @@ extern int nfs4_has_reclaimed_state(const char *name, bool use_exchange_id); extern void nfsd4_recdir_purge_old(void); extern int nfsd4_create_clid_dir(struct nfs4_client *clp); extern void nfsd4_remove_clid_dir(struct nfs4_client *clp); +extern void release_session_client(struct nfsd4_session *); static inline void nfs4_put_stateowner(struct nfs4_stateowner *so) -- 2.39.2