build: fix rdma configure logic

Problem: when --enable-rdmatrans is explicitly requested, failure to
configure it is non-fatal.

Make it fatal if the feature cannot be enabled.

Also rename "rdmatrans" to "rdma" and label it experimental in the
configure help output since it is not production ready.  For example,
if configured, it unconditionally tries to listen on a hard wired
address.

config/x_ac_rdma.m4

@@ -0,0 +1,27 @@
+AC_DEFUN([X_AC_RDMA], [
+
+got_rdma=no
+AC_ARG_ENABLE([rdma],
+  [AS_HELP_STRING([--enable-rdma],
+      [build Infiniband RDMA transport (experimental)])],
+  [want_rdma=yes], [want_rdma=no])
+
+if test x$want_rdma == xyes; then
+  X_AC_CHECK_COND_LIB(rdmacm, rdma_accept)
+  X_AC_CHECK_COND_LIB(ibverbs, ibv_alloc_pd)
+  AC_CHECK_HEADER([infiniband/verbs.h])
+  AC_CHECK_HEADER([rdma/rdma_cma.h])
+  if test x$ac_cv_lib_rdmacm_rdma_accept == xyes -a \
+      x$ac_cv_lib_ibverbs_ibv_alloc_pd == xyes -a \
+      x$ac_cv_header_infiniband_verbs_h == xyes -a \
+      x$ac_cv_header_rdma_rdma_cma_h == xyes; then
+    got_rdma=yes
+    AC_DEFINE([WITH_RDMA], [1], [build Infiniband RDMA transport])
+  else
+    AC_MSG_ERROR([Could not configure RDMA: missing ibverbs/rdmacm packages])
+  fi
+fi
+
+AM_CONDITIONAL([RDMA], [test "x$got_rdma" != xno])
+
+])

configure.ac

@@ -78,7 +78,7 @@ X_AC_CHECK_PTHREADS
 X_AC_CHECK_COND_LIB(munge, munge_ctx_create)
 X_AC_CHECK_COND_LIB(cap, cap_get_proc)
 X_AC_TCMALLOC
-X_AC_RDMATRANS
+X_AC_RDMA
 
 ##
 # For list.c, hostlist.c, hash.c

src/cmd/diod.c

@@ -42,7 +42,7 @@
 #include "src/libdiod/diod_log.h"
 #include "src/libdiod/diod_conf.h"
 #include "src/libdiod/diod_sock.h"
-#if WITH_RDMATRANS
+#if WITH_RDMA
 #include "src/libdiod/diod_rdma.h"
 #endif
 
@@ -344,7 +344,7 @@ struct svc_struct {
     pthread_t t;
     int shutdown;
     int reload;
-#if WITH_RDMATRANS
+#if WITH_RDMA
     diod_rdma_t rdma;
     pthread_t rdma_t;
 #endif
@@ -421,7 +421,7 @@ _service_loop (void *arg)
     return NULL;
 }
 
-#if WITH_RDMATRANS
+#if WITH_RDMA
 static void *
 _service_loop_rdma (void *arg)
 {
@@ -541,7 +541,7 @@ _service_run (srvmode_t mode, int rfdno, int wfdno)
         case SRV_SOCKTEST:
             if (!diod_sock_listen (l, &ss.fds, &ss.nfds))
                 msg_exit ("failed to set up listener");
-#if WITH_RDMATRANS
+#if WITH_RDMA
             ss.rdma = diod_rdma_create ();
             diod_rdma_listen (ss.rdma);
 #endif
@@ -621,7 +621,7 @@ _service_run (srvmode_t mode, int rfdno, int wfdno)
 
     if ((n = pthread_create (&ss.t, NULL, _service_loop, NULL)))
         errn_exit (n, "pthread_create _service_loop");
-#if WITH_RDMATRANS
+#if WITH_RDMA
     if ((n = pthread_create (&ss.rdma_t, NULL, _service_loop_rdma, NULL)))
         errn_exit (n, "pthread_create _service_loop_rdma");
 #endif
@@ -636,7 +636,7 @@ _service_run (srvmode_t mode, int rfdno, int wfdno)
     }
     if ((n = pthread_join (ss.t, NULL)))
         errn_exit (n, "pthread_join _service_loop");
-#if WITH_RDMATRANS
+#if WITH_RDMA
     if ((n = pthread_join (ss.rdma_t, NULL)))
         errn_exit (n, "pthread_join _service_loop_rdma");
 #endif

src/libdiod/Makefile.am

@@ -27,7 +27,7 @@ libdiod_a_SOURCES = \
 	diod_ops.h \
 	lsderr.c
 
-if RDMATRANS
+if RDMA
 libdiod_a_SOURCES += diod_rdma.c diod_rdma.h
 endif
 

src/libnpfs/Makefile.am

@@ -34,7 +34,7 @@ libnpfs_a_SOURCES += user-stub.c
 endif
 endif
 
-if RDMATRANS
+if RDMA
 libnpfs_a_SOURCES += rdmatrans.c
 endif