NFSv4: Fix up another delegation related race

When we can update_open_stateid(), we need to be certain that we don't
race with a delegation return. While we could do this by grabbing the
nfs_client->cl_lock, a dedicated spin lock in the delegation structure
will scale better.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
index f1c5e2a5d88e..8299c6220e95 100644
--- a/fs/nfs/delegation.h
+++ b/fs/nfs/delegation.h
@@ -22,6 +22,7 @@ struct nfs_delegation {
         long flags;
         loff_t maxsize;
         __u64 change_attr;
+        spinlock_t lock;
         struct rcu_head rcu;
 };