net/rds: Detect need of On-Demand-Paging memory registration

Add code to check if memory intended for RDMA is FS-DAX-memory. RDS will fail with error code EOPNOTSUPP if FS-DAX-memory is detected. Signed-off-by: Hans Westgaard Ry <[email protected]> Acked-by: Santosh Shilimkar <[email protected]> Signed-off-by: Leon Romanovsky <[email protected]>
niw · Jan 16, 2020 · c4c86ab · c4c86ab
1 parent 8ffc324
commit c4c86ab
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
@@ -156,11 +156,13 @@ void rds_rdma_drop_keys(struct rds_sock *rs)
 static int rds_pin_pages(unsigned long user_addr, unsigned int nr_pages,
 			struct page **pages, int write)
 {
+	unsigned int gup_flags = FOLL_LONGTERM;
 	int ret;
 
-	ret = get_user_pages_fast(user_addr, nr_pages, write ? FOLL_WRITE : 0,
-				  pages);
+	if (write)
+		gup_flags |= FOLL_WRITE;
 
+	ret = get_user_pages_fast(user_addr, nr_pages, gup_flags, pages);
 	if (ret >= 0 && ret < nr_pages) {
 		while (ret--)
 			put_page(pages[ret]);