mountd: Convert mountlist to SLIST

Use SLIST from sys/queue.h instead of homebrew linked list for mountlist.

Reviewed by:	bapt, rmacklem
MFC after:	1 week
Sponsored by:	Gandi.net
Differential Revision:	https://reviews.freebsd.org/D12504

1 files changed, 16 insertions, 33 deletions

diff --git a/usr.sbin/mountd/mountd.c b/usr.sbin/mountd/mountd.c
index 1501f5c7c3f1..4431f881581b 100644
--- a/usr.sbin/mountd/mountd.c
+++ b/usr.sbin/mountd/mountd.c
@@ -92,9 +92,10 @@ __FBSDID("$FreeBSD$");
  * Structures for keeping the mount list and export list
  */
 struct mountlist {
-	struct mountlist *ml_next;
 	char	ml_host[MNTNAMLEN+1];
 	char	ml_dirp[MNTPATHLEN+1];
+
+	SLIST_ENTRY(mountlist)	next;
 };
 
 struct dirlist {
@@ -225,7 +226,7 @@ static int	xdr_mlist(XDR *, caddr_t);
 static void	terminate(int);
 
 static SLIST_HEAD(, exportlist) exphead = SLIST_HEAD_INITIALIZER(exphead);
-static struct mountlist *mlhead;
+static SLIST_HEAD(, mountlist) mlhead = SLIST_HEAD_INITIALIZER(mlhead);
 static struct grouplist *grphead;
 static char *exnames_default[2] = { _PATH_EXPORTS, NULL };
 static char **exnames;
@@ -447,7 +448,6 @@ main(int argc, char **argv)
 	argc -= optind;
 	argv += optind;
 	grphead = (struct grouplist *)NULL;
-	mlhead = (struct mountlist *)NULL;
 	if (argc > 0)
 		exnames = argv;
 	else
@@ -1254,8 +1254,7 @@ xdr_mlist(XDR *xdrsp, caddr_t cp __unused)
 	int false = 0;
 	char *strp;
 
-	mlp = mlhead;
-	while (mlp) {
+	SLIST_FOREACH(mlp, &mlhead, next) {
 		if (!xdr_bool(xdrsp, &true))
 			return (0);
 		strp = &mlp->ml_host[0];
@@ -1264,7 +1263,6 @@ xdr_mlist(XDR *xdrsp, caddr_t cp __unused)
 		strp = &mlp->ml_dirp[0];
 		if (!xdr_string(xdrsp, &strp, MNTPATHLEN))
 			return (0);
-		mlp = mlp->ml_next;
 	}
 	if (!xdr_bool(xdrsp, &false))
 		return (0);
@@ -2946,7 +2944,7 @@ parsecred(char *namelist, struct xucred *cr)
 static void
 get_mountlist(void)
 {
-	struct mountlist *mlp, **mlpp;
+	struct mountlist *mlp;
 	char *host, *dirp, *cp;
 	char str[STRSIZ];
 	FILE *mlfile;
@@ -2959,7 +2957,6 @@ get_mountlist(void)
 			return;
 		}
 	}
-	mlpp = &mlhead;
 	while (fgets(str, STRSIZ, mlfile) != NULL) {
 		cp = str;
 		host = strsep(&cp, " \t\n");
@@ -2973,9 +2970,8 @@ get_mountlist(void)
 		mlp->ml_host[MNTNAMLEN] = '\0';
 		strncpy(mlp->ml_dirp, dirp, MNTPATHLEN);
 		mlp->ml_dirp[MNTPATHLEN] = '\0';
-		mlp->ml_next = (struct mountlist *)NULL;
-		*mlpp = mlp;
-		mlpp = &mlp->ml_next;
+
+		SLIST_INSERT_HEAD(&mlhead, mlp, next);
 	}
 	fclose(mlfile);
 }
@@ -2983,23 +2979,16 @@ get_mountlist(void)
 static void
 del_mlist(char *hostp, char *dirp)
 {
-	struct mountlist *mlp, **mlpp;
-	struct mountlist *mlp2;
+	struct mountlist *mlp, *mlp2;
 	FILE *mlfile;
 	int fnd = 0;
 
-	mlpp = &mlhead;
-	mlp = mlhead;
-	while (mlp) {
+	SLIST_FOREACH_SAFE(mlp, &mlhead, next, mlp2) {
 		if (!strcmp(mlp->ml_host, hostp) &&
 		    (!dirp || !strcmp(mlp->ml_dirp, dirp))) {
 			fnd = 1;
-			mlp2 = mlp;
-			*mlpp = mlp = mlp->ml_next;
-			free((caddr_t)mlp2);
-		} else {
-			mlpp = &mlp->ml_next;
-			mlp = mlp->ml_next;
+			SLIST_REMOVE(&mlhead, mlp, mountlist, next);
+			free((caddr_t)mlp);
 		}
 	}
 	if (fnd) {
@@ -3007,10 +2996,8 @@ del_mlist(char *hostp, char *dirp)
 			syslog(LOG_ERR,"can't update %s", _PATH_RMOUNTLIST);
 			return;
 		}
-		mlp = mlhead;
-		while (mlp) {
+		SLIST_FOREACH(mlp, &mlhead, next) {
 			fprintf(mlfile, "%s %s\n", mlp->ml_host, mlp->ml_dirp);
-			mlp = mlp->ml_next;
 		}
 		fclose(mlfile);
 	}
@@ -3019,17 +3006,14 @@ del_mlist(char *hostp, char *dirp)
 static void
 add_mlist(char *hostp, char *dirp)
 {
-	struct mountlist *mlp, **mlpp;
+	struct mountlist *mlp;
 	FILE *mlfile;
 
-	mlpp = &mlhead;
-	mlp = mlhead;
-	while (mlp) {
+	SLIST_FOREACH(mlp, &mlhead, next) {
 		if (!strcmp(mlp->ml_host, hostp) && !strcmp(mlp->ml_dirp, dirp))
 			return;
-		mlpp = &mlp->ml_next;
-		mlp = mlp->ml_next;
 	}
+
 	mlp = (struct mountlist *)malloc(sizeof (*mlp));
 	if (mlp == (struct mountlist *)NULL)
 		out_of_mem();
@@ -3037,8 +3021,7 @@ add_mlist(char *hostp, char *dirp)
 	mlp->ml_host[MNTNAMLEN] = '\0';
 	strncpy(mlp->ml_dirp, dirp, MNTPATHLEN);
 	mlp->ml_dirp[MNTPATHLEN] = '\0';
-	mlp->ml_next = (struct mountlist *)NULL;
-	*mlpp = mlp;
+	SLIST_INSERT_HEAD(&mlhead, mlp, next);
 	if ((mlfile = fopen(_PATH_RMOUNTLIST, "a")) == NULL) {
 		syslog(LOG_ERR, "can't update %s", _PATH_RMOUNTLIST);
 		return;