fsidd: don't use assert() on expr with side-effect.

assert() is not guaranteed to evaluate its arg.  When compiled with
-DNDEBUG, the evaluation is skipped.  We don't currently compile with
-DNDEBUG, but relying on that is poor form, particularly as this is
described as "sample code" in the git log.

So introduce assert_safe() and use that when there are side-effects.

Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>

2 files changed, 69 insertions, 13 deletions

diff --git a/support/include/version.h b/support/include/version.h
index b7db0bb..d7cf680 120000..100644
--- a/support/include/version.h
+++ b/support/include/version.h
@@ -1 +1,53 @@
-../../utils/mount/version.h
\ No newline at end of file
+/*
+ * version.h -- get running kernel version
+ *
+ * Copyright (C) 2008 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 0211-1301 USA
+ *
+ */
+
+#ifndef _NFS_UTILS_MOUNT_VERSION_H
+#define _NFS_UTILS_MOUNT_VERSION_H
+
+#include <stdio.h>
+#include <limits.h>
+
+#include <sys/utsname.h>
+
+static inline unsigned int MAKE_VERSION(unsigned int p, unsigned int q,
+					unsigned int r)
+{
+	return (65536 * p) + (256 * q) + r;
+}
+
+static inline unsigned int linux_version_code(void)
+{
+	struct utsname my_utsname;
+	unsigned int p, q = 0, r = 0;
+
+	/* UINT_MAX as backward compatibility code should not be run */
+	if (uname(&my_utsname))
+		return UINT_MAX;
+
+	/* UINT_MAX as future versions might not start with an integer */
+	if (sscanf(my_utsname.release, "%u.%u.%u", &p, &q, &r) < 1)
+		return UINT_MAX;
+	
+	return MAKE_VERSION(p, q, r);
+}
+
+#endif	/* _NFS_UTILS_MOUNT_VERSION_H */
diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
index 410b3a3..3fef1ef 100644
--- a/support/reexport/fsidd.c
+++ b/support/reexport/fsidd.c
@@ -26,6 +26,11 @@
 static struct event_base *evbase;
 static struct reexpdb_backend_plugin *dbbackend = &sqlite_plug_ops;
 
+/* assert_safe() always evalutes it argument, as it might have
+ * a side-effect.  assert() won't if compiled with NDEBUG
+ */
+#define assert_safe(__sideeffect) (__sideeffect ? 0 : ({assert(0) ; 0;}))
+
 static void client_cb(evutil_socket_t cl, short ev, void *d)
 {
 	struct event *me = d;
@@ -56,12 +61,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 
 		if (dbbackend->fsidnum_by_path(req_path, &fsidnum, false, &found)) {
 			if (found)
-				assert(asprintf(&answer, "+ %u", fsidnum) != -1);
+				assert_safe(asprintf(&answer, "+ %u", fsidnum) != -1);
 			else
-				assert(asprintf(&answer, "+ ") != -1);
-		
+				assert_safe(asprintf(&answer, "+ ") != -1);
 		} else {
-			assert(asprintf(&answer, "- %s", "Command failed") != -1);
+			assert_safe(asprintf(&answer, "- %s", "Command failed") != -1);
 		}
 
 		(void)send(cl, answer, strlen(answer), 0);
@@ -78,13 +82,13 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 
 		if (dbbackend->fsidnum_by_path(req_path, &fsidnum, true, &found)) {
 			if (found) {
-				assert(asprintf(&answer, "+ %u", fsidnum) != -1);
+				assert_safe(asprintf(&answer, "+ %u", fsidnum) != -1);
 			} else {
-				assert(asprintf(&answer, "+ ") != -1);
+				assert_safe(asprintf(&answer, "+ ") != -1);
 			}
 		
 		} else {
-			assert(asprintf(&answer, "- %s", "Command failed") != -1);
+			assert_safe(asprintf(&answer, "- %s", "Command failed") != -1);
 		}
 
 		(void)send(cl, answer, strlen(answer), 0);
@@ -106,15 +110,15 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 		}
 
 		if (bad_input) {
-			assert(asprintf(&answer, "- %s", "Command failed: Bad input") != -1);
+			assert_safe(asprintf(&answer, "- %s", "Command failed: Bad input") != -1);
 		} else {
 			if (dbbackend->path_by_fsidnum(fsidnum, &path, &found)) {
 				if (found)
-					assert(asprintf(&answer, "+ %s", path) != -1);
+					assert_safe(asprintf(&answer, "+ %s", path) != -1);
 				else
-					assert(asprintf(&answer, "+ ") != -1);
+					assert_safe(asprintf(&answer, "+ ") != -1);
 			} else {
-				assert(asprintf(&answer, "+ ") != -1);
+				assert_safe(asprintf(&answer, "+ ") != -1);
 			}
 		}
 
@@ -129,7 +133,7 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 	} else {
 		char *answer = NULL;
 
-		assert(asprintf(&answer, "- bad command") != -1);
+		assert_safe(asprintf(&answer, "- bad command") != -1);
 		(void)send(cl, answer, strlen(answer), 0);
 
 		free(answer);