Re: [PATCH 23/24] NFS: return delegations from the end of a LRU when over the watermark

[Christoph Hellwig <hch@lst.de>]

This was caused by a delegation already on the LRU not getting moved
to the return list.  The patch below fixes it and passes the xfstests
quick group with 4.0.  I'll fold it in after a little more testing.

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 776020bdf8f3..6497fdbd9516 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -93,11 +93,9 @@ static void nfs_mark_return_delegation(struct nfs_server *server,
 				       struct nfs_delegation *delegation)
 {
 	spin_lock(&server->delegations_lock);
-	if (list_empty(&delegation->entry)) {
-		list_add_tail(&delegation->entry,
-				&server->delegations_return);
+	if (list_empty(&delegation->entry))
 		refcount_inc(&delegation->refcount);
-	}
+	list_move_tail(&delegation->entry, &server->delegations_return);
 	spin_unlock(&server->delegations_lock);
 
 	set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);