[PATCH 4/8] nfsd4: extend the client_lock to cover cl_lru

Benny Halevy
2010-05-04T22:44:20Z

To be used later on to hold a reference count on the client while in use by a
nfsv4.1 compound.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
---
fs/nfsd/nfs4state.c | 38 ++++++++++++++++++++++++--------------
1 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 53cb5e4..6720081 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -249,7 +249,7 @@ unhash_delegation(struct nfs4_delegation *dp)
* SETCLIENTID state
*/

-/* client_lock protects the session hash table */
+/* client_lock protects the client lru list and session hash table */
static DEFINE_SPINLOCK(client_lock);

/* Hash tables for nfs4_clientid state */
@@ -627,8 +627,9 @@ free_session(struct kref *kref)
kfree(ses);
}

+/* must be called under the client_lock */
static inline void
-renew_client(struct nfs4_client *clp)
+renew_client_locked(struct nfs4_client *clp)
{
/*
* Move client to the end to the LRU list.
@@ -640,6 +641,14 @@ renew_client(struct nfs4_client *clp)
clp->cl_time = get_seconds();
}

+static inline void
+renew_client(struct nfs4_client *clp)
+{
+ spin_lock(&client_lock);
+ renew_client_locked(clp);
+ spin_unlock(&client_lock);
+}
+
/* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */
static int
STALE_CLIENTID(clientid_t *clid)
@@ -705,14 +714,14 @@ expire_client(struct nfs4_client *clp)
list_del_init(&dp->dl_recall_lru);
unhash_delegation(dp);
}
- list_del(&clp->cl_idhash);
- list_del(&clp->cl_strhash);
- list_del(&clp->cl_lru);
while (!list_empty(&clp->cl_openowners)) {
sop = list_entry(clp->cl_openowners.next, struct nfs4_stateowner, so_perclient);
release_openowner(sop);
}
+ list_del(&clp->cl_idhash);
+ list_del(&clp->cl_strhash);
spin_lock(&client_lock);
+ list_del(&clp->cl_lru);
while (!list_empty(&clp->cl_sessions)) {
struct nfsd4_session *ses;
ses = list_entry(clp->cl_sessions.next, struct nfsd4_session,
@@ -847,8 +856,7 @@ add_to_unconfirmed(struct nfs4_client *clp, unsigned int strhashval)
list_add(&clp->cl_strhash, &unconf_str_hashtbl[strhashval]);
idhashval = clientid_hashval(clp->cl_clientid.cl_id);
list_add(&clp->cl_idhash, &unconf_id_hashtbl[idhashval]);
- list_add_tail(&clp->cl_lru, &client_lru);
- clp->cl_time = get_seconds();
+ renew_client(clp);
}

static void
@@ -1440,15 +1448,12 @@ nfsd4_sequence(struct svc_rqst *rqstp,

out:
/* Hold a session reference until done processing the compound. */
- if (cstate->session)
- nfsd4_get_session(cstate->session);
- spin_unlock(&client_lock);
- /* Renew the clientid on success and on replay */
if (cstate->session) {
- nfs4_lock_state();
- renew_client(session->se_client);
- nfs4_unlock_state();
+ nfsd4_get_session(cstate->session);
+ /* Renew the clientid on success and on replay */
+ renew_client_locked(session->se_client);
}
+ spin_unlock(&client_lock);
dprintk("%s: return %d\n", __func__, ntohl(status));
return status;
}
@@ -2557,6 +2562,7 @@ nfs4_laundromat(void)
dprintk("NFSD: laundromat service - starting\n");
if (locks_in_grace())
nfsd4_end_grace();
+ spin_lock(&client_lock);
list_for_each_safe(pos, next, &client_lru) {
clp = list_entry(pos, struct nfs4_client, cl_lru);
if (time_after((unsigned long)clp->cl_time, (unsigned long)cutoff)) {
@@ -2565,11 +2571,15 @@ nfs4_laundromat(void)
clientid_val = t;
break;
}
+ list_del_init(&clp->cl_lru);
+ spin_unlock(&client_lock);
dprintk("NFSD: purging unused client (clientid %08x)\n",
clp->cl_clientid.cl_id);
nfsd4_remove_clid_dir(clp);
expire_client(clp);
+ spin_lock(&client_lock);
}
+ spin_unlock(&client_lock);
INIT_LIST_HEAD(&reaplist);
spin_lock(&recall_lock);
list_for_each_safe(pos, next, &del_recall_lru) {
--
1.6.5.1