commit ec08843916d07c28045398e5b17e7347a8fa0135
Author: Steve Dickson <steved@redhat.com>
Date:   Fri May 11 12:13:06 2007 -0400

    nfs-utils: have mountd hold open etab file to force inode number to change
    
    This patch changes mountd to hold the etab file open so that when it's
    changed by exportfs, the inode number should change. We then change
    auth_reload to reload the file based on whether st_ino is different
    from the last time it was checked. It also changes auth_reload to
    maintain a static counter value and return it instead of a timestamp
    and fixes up get_exportlist accordingly. Finally, it adds some
    comments to xtab_write to warn people about editing the etab in place.
    
    Signed-off-by: Jeff Layton <jlayton@redhat.com>
    Signed-off-by: Steve Dickson <steved@redhat.com>

--- nfs-utils-1.0.10/support/export/xtab.c.orig	2007-05-11 12:07:09.258724000 -0400
+++ nfs-utils-1.0.10/support/export/xtab.c	2007-05-11 12:07:39.720637000 -0400
@@ -80,6 +80,12 @@ xtab_export_read(void)
 	return xtab_read(_PATH_ETAB, 1);
 }
 
+/*
+ * mountd now keeps an open fd for the etab at all times to make sure that the
+ * inode number changes when the xtab_export_write is done. If you change the
+ * routine below such that the files are edited in place, then you'll need to
+ * fix the auth_reload logic as well...
+ */
 static int
 xtab_write(char *xtab, char *xtabtmp, int is_export)
 {
--- nfs-utils-1.0.10/utils/mountd/auth.c.orig	2006-08-07 02:40:50.000000000 -0400
+++ nfs-utils-1.0.10/utils/mountd/auth.c	2007-05-11 12:10:34.081481000 -0400
@@ -14,6 +14,7 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <errno.h>
+#include <unistd.h>
 #include "misc.h"
 #include "nfslib.h"
 #include "exportfs.h"
@@ -46,24 +47,34 @@ auth_init(char *exports)
 	xtab_mount_write();
 }
 
-int
+unsigned int
 auth_reload()
 {
 	struct stat		stb;
-	static time_t		last_modified = 0;
-
-	if (stat(_PATH_ETAB, &stb) < 0)
+	static ino_t		last_inode;
+	static int		last_fd;
+	static unsigned int	counter;
+	int			fd;
+
+	if ((fd = open(_PATH_ETAB, O_RDONLY)) < 0) {
+		xlog(L_FATAL, "couldn't open %s", _PATH_ETAB);
+	} else if (fstat(fd, &stb) < 0) {
 		xlog(L_FATAL, "couldn't stat %s", _PATH_ETAB);
-	if (stb.st_mtime == last_modified)
-		return 0;
-	last_modified = stb.st_mtime;
+	} else if (stb.st_ino == last_inode) {
+		close(fd);
+		return counter;
+	} else {
+		close(last_fd);
+		last_fd = fd;
+		last_inode = stb.st_ino;
+	}
 
 	export_freeall();
 	memset(&my_client, 0, sizeof(my_client));
-	// export_read(export_file);
 	xtab_export_read();
+	++counter;
 
-	return 1;
+	return counter;
 }
 
 static nfs_export *
--- nfs-utils-1.0.10/utils/mountd/mountd.c.orig	2006-08-07 02:40:50.000000000 -0400
+++ nfs-utils-1.0.10/utils/mountd/mountd.c	2007-05-11 12:17:03.512115000 -0400
@@ -463,10 +463,15 @@ get_exportlist(void)
 	struct groupnode	*g, *ng, *c, **cp;
 	nfs_export		*exp;
 	int			i;
+	static unsigned int ecounter;
+	unsigned int        acounter;
 
-	if (!auth_reload() && elist)
+	acounter = auth_reload();
+	if (elist && acounter == ecounter)
 		return elist;
 
+	ecounter = acounter;
+
 	for (e = elist; e != NULL; e = ne) {
 		ne = e->ex_next;
 		for (g = e->ex_groups; g != NULL; g = ng) {
--- nfs-utils-1.0.10/utils/mountd/mountd.h.orig	2006-08-07 02:40:50.000000000 -0400
+++ nfs-utils-1.0.10/utils/mountd/mountd.h	2007-05-11 12:18:21.393183000 -0400
@@ -40,7 +40,7 @@ bool_t		mount_mnt_3_svc(struct svc_req *
 
 void		mount_dispatch(struct svc_req *, SVCXPRT *);
 void		auth_init(char *export_file);
-int		auth_reload(void);
+unsigned int	auth_reload(void);
 nfs_export *	auth_authenticate(char *what, struct sockaddr_in *sin,
 					char *path);
 void		auth_export(nfs_export *exp);