NFS: Fix a bogus warning in nfs_generic_pgio

It is OK for pageused == pagecount in the loop, as long as we don't add
another entry to the *pages array. Move the test so that it only triggers
in that case.

Reported-by: Steve Dickson <SteveD@redhat.com>
Fixes: bba5c1887a92 (nfs: disallow duplicate pages in pgio page vectors)
Cc: Weston Andros Adamson <dros@primarydata.com>
Cc: stable@vger.kernel.org # 3.16.x
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 08085de879edd4265343bca39bf9781d63c54e4c..ed0db61f8543f0ee4d68c3b457510cedad2187ca 100644 (file)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -752,12 +752,11 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
                nfs_list_remove_request(req);
                nfs_list_add_request(req, &hdr->pages);
 
-               if (WARN_ON_ONCE(pageused >= pagecount))
-                       return nfs_pgio_error(desc, hdr);
-
                if (!last_page || last_page != req->wb_page) {
-                       *pages++ = last_page = req->wb_page;
                        pageused++;
+                       if (pageused > pagecount)
+                               break;
+                       *pages++ = last_page = req->wb_page;
                }
        }
        if (WARN_ON_ONCE(pageused != pagecount))