Support --ha-callout for high-availability callouts

3 files changed, 43 insertions, 4 deletions

diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index 8f6f9cb..7cc1b1b 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -36,6 +36,11 @@ static struct nfs_fh_len *get_rootfh(struct svc_req *, dirpath *, int *, int v3)
 
 int new_cache = 0;
 
+/* PRC: a high-availability callout program can be specified with -H
+ * When this is done, the program will receive callouts whenever clients
+ * send mount or unmount requests -- the callout is not needed for 2.6 kernel */
+char *ha_callout_prog = NULL;
+
 static struct option longopts[] =
 {
 	{ "foreground", 0, 0, 'F' },
@@ -48,6 +53,7 @@ static struct option longopts[] =
 	{ "version", 0, 0, 'v' },
 	{ "port", 1, 0, 'p' },
 	{ "no-tcp", 0, 0, 'n' },
+	{ "ha-callout", 1, 0, 'H' },
 	{ NULL, 0, 0, 0 }
 };
 
@@ -444,7 +450,7 @@ main(int argc, char **argv)
 
 	/* Parse the command line options and arguments. */
 	opterr = 0;
-	while ((c = getopt_long(argc, argv, "o:n:Fd:f:p:P:hN:V:v", longopts, NULL)) != EOF)
+	while ((c = getopt_long(argc, argv, "o:n:Fd:f:p:P:hH:N:V:v", longopts, NULL)) != EOF)
 		switch (c) {
 		case 'o':
 			descriptors = atoi(optarg);
@@ -463,6 +469,9 @@ main(int argc, char **argv)
 		case 'f':
 			export_file = optarg;
 			break;
+		case 'H': /* PRC: specify a high-availability callout program */
+			ha_callout_prog = optarg;
+			break;
 		case 'h':
 			usage(argv [0], 0);
 			break;
@@ -596,6 +605,7 @@ usage(const char *prog, int n)
 "Usage: %s [-F|--foreground] [-h|--help] [-v|--version] [-d kind|--debug kind]\n"
 "	[-o num|--descriptors num] [-f exports-file|--exports-file=file]\n"
 "	[-p|--port port] [-V version|--nfs-version version]\n"
-"	[-N version|--no-nfs-version version] [-n|--no-tcp]\n", prog);
+"	[-N version|--no-nfs-version version] [-n|--no-tcp]\n"
+"	[-H ha-callout-prog]\n", prog);
 	exit(n);
 }
diff --git a/utils/mountd/mountd.man b/utils/mountd/mountd.man
index 3d2b1a8..64e508a 100644
--- a/utils/mountd/mountd.man
+++ b/utils/mountd/mountd.man
@@ -2,7 +2,8 @@
 .\" mountd(8)
 .\"
 .\" Copyright (C) 1999 Olaf Kirch <okir@monad.swb.de>
-.TH rpc.mountd 8 "25 Aug 2000"
+.\" Modified by Paul Clements, 2004.
+.TH rpc.mountd 8 "31 Aug 2004"
 .SH NAME
 rpc.mountd \- NFS mount daemon
 .SH SYNOPSIS
@@ -98,6 +99,26 @@ Force
 to bind to the specified port num, instead of using the random port
 number assigned by the portmapper.
 .TP
+.B \-H " or " \-\-ha-callout prog
+Specify a high availability callout program, which will receive callouts
+for all client mount and unmount requests. This allows 
+.B rpc.mountd
+to be used in a High Availability NFS (HA-NFS) environment. This callout is not
+needed (and should not be used) with 2.6 and later kernels (instead,
+mount the nfsd filesystem on
+.B /proc/fs/nfsd
+).
+The program will be called with 4 arguments.
+The first will be
+.B mount
+or
+.B unmount
+depending on the reason for the callout.
+The second will be the name of the client performing the mount.
+The third will be the path that the client is mounting.
+The last is the number of concurrent mounts that we believe the client
+has of that path.
+.TP
 .B \-V " or " \-\-nfs-version
 This option can be used to request that
 .B rpc.mountd
diff --git a/utils/mountd/rmtab.c b/utils/mountd/rmtab.c
index 844de51..90fbef4 100644
--- a/utils/mountd/rmtab.c
+++ b/utils/mountd/rmtab.c
@@ -19,6 +19,7 @@
 #include "exportfs.h"
 #include "xio.h"
 #include "mountd.h"
+#include "ha-callout.h"
 
 #include <limits.h> /* PATH_MAX */
 
@@ -61,6 +62,8 @@ mountlist_add(char *host, const char *path)
 			    host) == 0
 		    && strcmp(rep->r_path, path) == 0) {
 			rep->r_count++;
+			/* PRC: do the HA callout: */
+			ha_callout("mount", rep->r_client, rep->r_path, rep->r_count);
 			putrmtabent(rep, &pos);
 			endrmtabent();
 			xfunlock(lockid);
@@ -75,6 +78,8 @@ mountlist_add(char *host, const char *path)
 	xe.r_path [sizeof (xe.r_path) - 1] = '\0';
 	xe.r_count = 1;
 	if (setrmtabent("a")) {
+		/* PRC: do the HA callout: */
+		ha_callout("mount", xe.r_client, xe.r_path, xe.r_count);
 		putrmtabent(&xe, NULL);
 		endrmtabent();
 	}
@@ -103,8 +108,11 @@ mountlist_del(char *hname, const char *path)
 	while ((rep = getrmtabent(1, NULL)) != NULL) {
 		match = !strcmp (rep->r_client, hname)
 			&& !strcmp(rep->r_path, path);
-		if (match)
+		if (match) {
 			rep->r_count--;
+			/* PRC: do the HA callout: */
+			ha_callout("unmount", rep->r_client, rep->r_path, rep->r_count);
+		}
 		if (!match || rep->r_count)
 			fputrmtabent(fp, rep, NULL);
 	}