NFS: Micro-optimisation for nfs_wb_page()

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

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 966b8db..fab214a 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1516,6 +1516,8 @@ int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
                if (ret < 0)
                        goto out;
        }
+       if (!PagePrivate(page))
+               return 0;
        ret = nfs_sync_mapping_wait(page->mapping, &wbc, how);
        if (ret >= 0)
                return 0;