RDS: Add GET_MR_FOR_DEST sockopt

RDS currently supports a GET_MR sockopt to establish a
memory region (MR) for a chunk of memory. However, the fastreg
method ties a MR to a particular destination. The GET_MR_FOR_DEST
sockopt allows the remote machine to be specified, and thus
support for fastreg (aka FRWRs).

Note that this patch does *not* do all of this - it simply
implements the new sockopt in terms of the old one, so applications
can begin to use the new sockopt in preparation for cutover to
FRWRs.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/net/rds/rdma.h b/net/rds/rdma.h
index 425512098b0b..909c39835a5d 100644
--- a/net/rds/rdma.h
+++ b/net/rds/rdma.h
@@ -61,6 +61,7 @@ static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie)
 }
 
 int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen);
+int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen);
 int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen);
 void rds_rdma_drop_keys(struct rds_sock *rs);
 int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,