nfsd: don't use locks_in_grace to determine whether to call nfs4_grace_end

It's possible that lockd or another lock manager might still be on the
list after we call nfsd4_end_grace. If the laundromat thread runs
again at that point, then we could end up calling nfsd4_end_grace more
than once.

That's not only inefficient, but calling nfsd4_recdir_purge_old more
than once could be problematic. Fix this by adding a new global
"grace_ended" flag and use that to determine whether we've already
called nfsd4_grace_end.

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

1 files changed, 9 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a822e31de4f8..277c989e7f7b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3155,10 +3155,17 @@ out:
 static struct lock_manager nfsd4_manager = {
 };
 
+static bool grace_ended;
+
 static void
 nfsd4_end_grace(void)
 {
+        /* do nothing if grace period already ended */
+        if (grace_ended)
+                return;
+
         dprintk("NFSD: end of grace period\n");
+        grace_ended = true;
         nfsd4_record_grace_done(&init_net, boot_time);
         locks_end_grace(&nfsd4_manager);
         /*
@@ -3183,8 +3190,7 @@ nfs4_laundromat(void)
         nfs4_lock_state();
 
         dprintk("NFSD: laundromat service - starting\n");
-        if (locks_in_grace())
-                nfsd4_end_grace();
+        nfsd4_end_grace();
         INIT_LIST_HEAD(&reaplist);
         spin_lock(&client_lock);
         list_for_each_safe(pos, next, &client_lru) {
@@ -4718,6 +4724,7 @@ nfs4_state_start(void)
         nfsd4_client_tracking_init(&init_net);
         boot_time = get_seconds();
         locks_start_grace(&nfsd4_manager);
+        grace_ended = false;
         printk(KERN_INFO "NFSD: starting %ld-second grace period\n",
                nfsd4_grace);
         ret = set_callback_cred();