NFS: Don't immediately return directory delegations when disabled

The function nfs_inode_evict_delegation() immediately and synchronously
returns a delegation when called. This means we can't call it from
nfs4_have_delegation(), since that function could be called under a
lock. Instead we should mark the delegation for return and let the state
manager handle it for us.

Fixes: b6d2a52 ("NFS: Add a module option to disable directory delegations")
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Author: Anna Schumaker

fs/nfs/delegation.c

@@ -149,7 +149,7 @@ static int nfs4_do_check_delegation(struct inode *inode, fmode_t type,
 int nfs4_have_delegation(struct inode *inode, fmode_t type, int flags)
 {
 	if (S_ISDIR(inode->i_mode) && !directory_delegations)
-		nfs_inode_evict_delegation(inode);
+		nfs4_inode_set_return_delegation_on_close(inode);
 	return nfs4_do_check_delegation(inode, type, flags, true);
 }