@@ -719,6 +719,12 @@ int nfs_revalidate_mapping_nolock(struct
 	struct nfs_inode *nfsi = NFS_I(inode);
 	int ret = 0;
 
+	/*
+	 * swapfiles are not supposed to be shared.
+	 */
+	if (IS_SWAPFILE(inode))
+		goto out;
+
 	if ((nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
 			|| nfs_attribute_timeout(inode) || NFS_STALE(inode)) {
 		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);

@@ -107,7 +107,7 @@ void nfs_writedata_release(void *wdata)
 	nfs_writedata_free(wdata);
 }
 
-static struct nfs_page *nfs_page_find_request_locked(struct page *page)
+static struct nfs_page *nfs_page_find_request_locked(struct nfs_inode *nfsi, struct page *page)
 {
 	struct nfs_page *req = NULL;
 

@@ -115,6 +115,10 @@ static struct nfs_page *nfs_page_find_re
 		req = (struct nfs_page *)page_private(page);
 		if (req != NULL)
 			atomic_inc(&req->wb_count);
+	} else if (unlikely(PageSwapCache(page))) {
+		req = radix_tree_lookup(&nfsi->nfs_page_tree, page_file_index(page));
+		if (req != NULL)
+			atomic_inc(&req->wb_count);
 	}
 	return req;
 }

@@ -122,10 +126,11 @@ static struct nfs_page *nfs_page_find_re
 static struct nfs_page *nfs_page_find_request(struct page *page)
 {
 	struct nfs_page *req = NULL;
-	spinlock_t *req_lock = &NFS_I(page_file_mapping(page)->host)->req_lock;
+	struct nfs_inode *nfsi = NFS_I(page_file_mapping(page)->host);
+	spinlock_t *req_lock = &nfsi->req_lock;
 
 	spin_lock(req_lock);
-	req = nfs_page_find_request_locked(page);
+	req = nfs_page_find_request_locked(nfsi, page);
 	spin_unlock(req_lock);
 	return req;
 }

@@ -248,12 +253,13 @@ static void nfs_end_page_writeback(struc
 static int nfs_page_mark_flush(struct page *page)
 {
 	struct nfs_page *req;
-	spinlock_t *req_lock = &NFS_I(page_file_mapping(page)->host)->req_lock;
+	struct nfs_inode *nfsi = NFS_I(page_file_mapping(page)->host);
+	spinlock_t *req_lock = &nfsi->req_lock;
 	int ret;
 
 	spin_lock(req_lock);
 	for(;;) {
-		req = nfs_page_find_request_locked(page);
+		req = nfs_page_find_request_locked(nfsi, page);
 		if (req == NULL) {
 			spin_unlock(req_lock);
 			return 1;

@@ -368,8 +374,14 @@ static int nfs_inode_add_request(struct 
 		if (nfs_have_delegation(inode, FMODE_WRITE))
 			nfsi->change_attr++;
 	}
-	SetPagePrivate(req->wb_page);
-	set_page_private(req->wb_page, (unsigned long)req);
+	/*
+	 * Swap-space should not get truncated. Hence no need to plug the race
+	 * with invalidate/truncate.
+	 */
+	if (likely(!PageSwapCache(req->wb_page))) {
+		SetPagePrivate(req->wb_page);
+		set_page_private(req->wb_page, (unsigned long)req);
+	}
 	nfsi->npages++;
 	atomic_inc(&req->wb_count);
 	return 0;

@@ -386,8 +398,10 @@ static void nfs_inode_remove_request(str
 	BUG_ON (!NFS_WBACK_BUSY(req));
 
 	spin_lock(&nfsi->req_lock);
-	set_page_private(req->wb_page, 0);
-	ClearPagePrivate(req->wb_page);
+	if (likely(!PageSwapCache(req->wb_page))) {
+		set_page_private(req->wb_page, 0);
+		ClearPagePrivate(req->wb_page);
+	}
 	radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index);
 	nfsi->npages--;
 	if (!nfsi->npages) {

@@ -600,7 +614,7 @@ static struct nfs_page * nfs_update_requ
 		 * A request for the page we wish to update
 		 */
 		spin_lock(&nfsi->req_lock);
-		req = nfs_page_find_request_locked(page);
+		req = nfs_page_find_request_locked(nfsi, page);
 		if (req) {
 			if (!nfs_lock_request_dontget(req)) {
 				int error;

@@ -1472,8 +1486,6 @@ int nfs_wb_page_priority(struct inode *i
 		if (ret < 0)
 			goto out;
 	}
-	if (!PagePrivate(page))
-		return 0;
 	ret = nfs_sync_mapping_wait(page_file_mapping(page), &wbc, how);
 	if (ret >= 0)
 		return 0;