1 files changed, 15 insertions, 3 deletions

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 4ec67f8d70aa..a1d1de7b97c5 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -724,10 +724,11 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
                      struct nfs_pgio_header *hdr)
 {
         struct nfs_page         *req;
-        struct page             **pages;
+        struct page             **pages,
+                                *last_page;
         struct list_head *head = &desc->pg_list;
         struct nfs_commit_info cinfo;
-        unsigned int pagecount;
+        unsigned int pagecount, pageused;
 
         pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count);
         if (!nfs_pgarray_set(&hdr->page_array, pagecount))
@@ -735,12 +736,23 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 
         nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
         pages = hdr->page_array.pagevec;
+        last_page = NULL;
+        pageused = 0;
         while (!list_empty(head)) {
                 req = nfs_list_entry(head->next);
                 nfs_list_remove_request(req);
                 nfs_list_add_request(req, &hdr->pages);
-                *pages++ = req->wb_page;
+
+                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 (WARN_ON_ONCE(pageused != pagecount))
+                return nfs_pgio_error(desc, hdr);
 
         if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
             (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))