Support --ha-callout for high-availability callouts

[nfs-utils.git] / support / include / ha-callout.h

diff --git a/support/include/ha-callout.h b/support/include/ha-callout.h
new file mode 100644 (file)
index 0000000..707d51b
--- /dev/null
+++ b/support/include/ha-callout.h
@@ -0,0 +1,52 @@
+/*
+ * support/include/ha-callout.h
+ *
+ * High Availability NFS Callout support routines
+ *
+ * Copyright (c) 2004, Paul Clements, SteelEye Technology
+ *
+ * In order to implement HA NFS, we need several callouts at key
+ * points in statd and mountd. These callouts all come to ha_callout(),
+ * which, in turn, calls out to an ha-callout script (not part of nfs-utils;
+ * defined by -H argument to rpc.statd and rpc.mountd).
+ */
+#ifndef HA_CALLOUT_H
+#define HA_CALLOUT_H
+
+#include <sys/wait.h>
+
+extern char *ha_callout_prog;
+
+static inline void
+ha_callout(char *event, char *arg1, char *arg2, int arg3)
+{
+       char buf[16]; /* should be plenty */
+       pid_t pid;
+       int ret = -1;
+
+       if (!ha_callout_prog) /* HA callout is not enabled */
+               return;
+
+       sprintf(buf, "%d", arg3);
+
+       pid = fork();
+       switch (pid) {
+               case 0: execl(ha_callout_prog, ha_callout_prog,
+                               event, arg1, arg2, 
+                             arg3 < 0 ? NULL : buf,
+                             NULL);
+                       perror("execl");
+                       exit(2);
+               case -1: perror("fork");
+                       break;
+               default: ret = waitpid(pid, NULL, 0);
+       }
+
+#ifdef dprintf
+       dprintf(N_DEBUG, "ha callout returned %d\n", WEXITSTATUS(ret));
+#else
+       xlog(D_GENERAL, "ha callout returned %d\n", WEXITSTATUS(ret));
+#endif
+}
+
+#endif