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 <hans.westgaard.ry@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 916f5ec..eb23c38 100644 (file)
--- 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]);