nfsd4: delay session removal till free_client

Have unhash_client_locked() remove client and associated sessions from
global hashes, but delay further dismantling till free_client().

(After unhash_client_locked(), the only remaining references outside the
destroying thread are from any connections which have xpt_user callbacks
registered.)

This will simplify locking on session destruction.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 2327a8c0086257cae3475709c64f7722a4b63e3e..0f2643dac22a70569e2dc0e598da1e2459bd5e9a 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -883,6 +883,13 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
 static inline void
 free_client(struct nfs4_client *clp)
 {
+       while (!list_empty(&clp->cl_sessions)) {
+               struct nfsd4_session *ses;
+               ses = list_entry(clp->cl_sessions.next, struct nfsd4_session,
+                               se_perclnt);
+               list_del(&ses->se_perclnt);
+               nfsd4_put_session(ses);
+       }
        if (clp->cl_cred.cr_group_info)
                put_group_info(clp->cl_cred.cr_group_info);
        kfree(clp->cl_principal);
@@ -909,15 +916,12 @@ release_session_client(struct nfsd4_session *session)
 static inline void
 unhash_client_locked(struct nfs4_client *clp)
 {
+       struct nfsd4_session *ses;
+
        mark_client_expired(clp);
        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,
-                                se_perclnt);
-               unhash_session(ses);
-               nfsd4_put_session(ses);
-       }
+       list_for_each_entry(ses, &clp->cl_sessions, se_perclnt)
+               list_del_init(&ses->se_hash);
 }
 
 static void
@@ -1031,6 +1035,8 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
        if (clp == NULL)
                return NULL;
 
+       INIT_LIST_HEAD(&clp->cl_sessions);
+
        princ = svc_gss_principal(rqstp);
        if (princ) {
                clp->cl_principal = kstrdup(princ, GFP_KERNEL);
@@ -1047,7 +1053,6 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
        INIT_LIST_HEAD(&clp->cl_strhash);
        INIT_LIST_HEAD(&clp->cl_openowners);
        INIT_LIST_HEAD(&clp->cl_delegations);
-       INIT_LIST_HEAD(&clp->cl_sessions);
        INIT_LIST_HEAD(&clp->cl_lru);
        spin_lock_init(&clp->cl_lock);
        INIT_WORK(&clp->cl_cb_null.cb_work, nfsd4_do_callback_rpc);