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>
diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c
index a202e5b..2b978dc 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c
@@ -265,6 +265,9 @@
case RDS_GET_MR:
ret = rds_get_mr(rs, optval, optlen);
break;
+ case RDS_GET_MR_FOR_DEST:
+ ret = rds_get_mr_for_dest(rs, optval, optlen);
+ break;
case RDS_FREE_MR:
ret = rds_free_mr(rs, optval, optlen);
break;
diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 8dc83d2..971b5a6 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -317,6 +317,30 @@
return __rds_rdma_map(rs, &args, NULL, NULL);
}
+int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen)
+{
+ struct rds_get_mr_for_dest_args args;
+ struct rds_get_mr_args new_args;
+
+ if (optlen != sizeof(struct rds_get_mr_for_dest_args))
+ return -EINVAL;
+
+ if (copy_from_user(&args, (struct rds_get_mr_for_dest_args __user *)optval,
+ sizeof(struct rds_get_mr_for_dest_args)))
+ return -EFAULT;
+
+ /*
+ * Initially, just behave like get_mr().
+ * TODO: Implement get_mr as wrapper around this
+ * and deprecate it.
+ */
+ new_args.vec = args.vec;
+ new_args.cookie_addr = args.cookie_addr;
+ new_args.flags = args.flags;
+
+ return __rds_rdma_map(rs, &new_args, NULL, NULL);
+}
+
/*
* Free the MR indicated by the given R_Key
*/
diff --git a/net/rds/rdma.h b/net/rds/rdma.h
index 4255120..909c398 100644
--- a/net/rds/rdma.h
+++ b/net/rds/rdma.h
@@ -61,6 +61,7 @@
}
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,