From 711d44ee5644d5bd4e57b6e27d0e20421fff4632 Mon Sep 17 00:00:00 2001
From: Rick Macklem <rmacklem@FreeBSD.org>
Date: Tue, 14 May 2019 22:00:47 +0000
Subject: [PATCH] Replace global list for grouplist with list(s) for each
 exportlist element.

In mountd.c, the grouplist structures are linked into a single global
linked list headed by "grphead". The only use of this linked list is
to free all list elements when the exportlist elements are also all being
free'd at the time the exports are being reloaded.
This patch replaces this one global linked list head with a list head in
each exportlist structure, where the grouplist elements for that exported
file system are linked.
The only change is that now the grouplist elements are free'd with the
associated exportlist element as they are free'd instead of all grouplist
elements being free'd after the exportlist elements are free'd. This
change should have no effect in practice.
This is being done, since a future patch that will add a "-I" option for
incrementally updating the exports in the kernel needs to know which
grouplist elements are associated with each exported file system and
having them linked into a list headed by the exportlist element does that.

MFC after:	1 month
---
 usr.sbin/mountd/mountd.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/usr.sbin/mountd/mountd.c b/usr.sbin/mountd/mountd.c
index 291a0f5f8404..ae143ade5ae4 100644
--- a/usr.sbin/mountd/mountd.c
+++ b/usr.sbin/mountd/mountd.c
@@ -114,6 +114,7 @@ struct dirlist {
 struct exportlist {
 	struct dirlist	*ex_dirl;
 	struct dirlist	*ex_defdir;
+	struct grouplist *ex_grphead;
 	int		ex_flag;
 	fsid_t		ex_fs;
 	char		*ex_fsdir;
@@ -235,7 +236,6 @@ static void	terminate(int);
 
 static struct exportlisthead exphead = SLIST_HEAD_INITIALIZER(&exphead);
 static SLIST_HEAD(, mountlist) mlhead = SLIST_HEAD_INITIALIZER(&mlhead);
-static struct grouplist *grphead;
 static char *exnames_default[2] = { _PATH_EXPORTS, NULL };
 static char **exnames;
 static char **hosts = NULL;
@@ -455,7 +455,6 @@ main(int argc, char **argv)
 
 	argc -= optind;
 	argv += optind;
-	grphead = (struct grouplist *)NULL;
 	if (argc > 0)
 		exnames = argv;
 	else
@@ -1692,8 +1691,8 @@ get_exportlist_one(void)
 		 */
 		if (has_host) {
 			hang_dirp(dirhead, tgrp, ep, opt_flags);
-			grp->gr_next = grphead;
-			grphead = tgrp;
+			grp->gr_next = ep->ex_grphead;
+			ep->ex_grphead = tgrp;
 		} else {
 			hang_dirp(dirhead, (struct grouplist *)NULL, ep,
 				opt_flags);
@@ -1720,7 +1719,6 @@ get_exportlist_one(void)
 static void
 get_exportlist(void)
 {
-	struct grouplist *grp, *tgrp;
 	struct export_args export;
 	struct iovec *iov;
 	struct statfs *mntbufp;
@@ -1743,14 +1741,6 @@ get_exportlist(void)
 	 */
 	free_exports(&exphead);
 
-	grp = grphead;
-	while (grp) {
-		tgrp = grp;
-		grp = grp->gr_next;
-		free_grp(tgrp);
-	}
-	grphead = (struct grouplist *)NULL;
-
 	/*
 	 * and the old V4 root dir.
 	 */
@@ -2448,6 +2438,7 @@ get_host(char *cp, struct grouplist *grp, struct grouplist *tgrp)
 static void
 free_exp(struct exportlist *ep)
 {
+	struct grouplist *grp, *tgrp;
 
 	if (ep->ex_defdir) {
 		free_host(ep->ex_defdir->dp_hosts);
@@ -2458,6 +2449,12 @@ free_exp(struct exportlist *ep)
 	if (ep->ex_indexfile)
 		free(ep->ex_indexfile);
 	free_dir(ep->ex_dirl);
+	grp = ep->ex_grphead;
+	while (grp) {
+		tgrp = grp;
+		grp = grp->gr_next;
+		free_grp(tgrp);
+	}
 	free((caddr_t)ep);
 }