svn commit: r349123 - stable/12/usr.sbin/mountd

[Rick Macklem]

Author: rmacklem
Date: Mon Jun 17 00:00:12 2019
New Revision: 349123
URL: https://svnweb.freebsd.org/changeset/base/349123

Log:
  MFC: r347476
  Factor out some exportlist list operations into separate functions.
  
  This patch moves the code that removes and frees all exportlist elements
  out into a separate function called free_exports().
  It does the same for the insertion of a new exportlist entry into a list.
  It also adds a second argument to ex_search() for the list to use.
  None of these changes have any semantic effect. They are being done to
  prepare the code for future patches that convert the single linked list
  for the exportlist to a hash table of lists and a patch that will do
  incremental changes of exports in the kernel.
  And it fixes the argument for SLIST_HEAD_INITIALIZER() to a pointer,
  which doesn't really matter, since SLIST_HEAD_INITIALIZER() doesn't use
  the argument.
  
  PR:		237860

Modified:
  stable/12/usr.sbin/mountd/mountd.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/usr.sbin/mountd/mountd.c
==============================================================================
--- stable/12/usr.sbin/mountd/mountd.c	Sun Jun 16 22:13:27 2019	(r349122)
+++ stable/12/usr.sbin/mountd/mountd.c	Mon Jun 17 00:00:12 2019	(r349123)
@@ -128,6 +128,8 @@ struct exportlist {
 /* ex_flag bits */
 #define	EX_LINKED	0x1
 
+SLIST_HEAD(exportlisthead, exportlist);
+
 struct netmsk {
 	struct sockaddr_storage nt_net;
 	struct sockaddr_storage nt_mask;
@@ -189,13 +191,15 @@ static int	do_mount(struct exportlist *, struct groupl
 		    struct xucred *, char *, int, struct statfs *);
 static int	do_opt(char **, char **, struct exportlist *,
 		    struct grouplist *, int *, int *, struct xucred *);
-static struct exportlist	*ex_search(fsid_t *);
+static struct exportlist	*ex_search(fsid_t *, struct exportlisthead *);
 static struct exportlist	*get_exp(void);
 static void	free_dir(struct dirlist *);
 static void	free_exp(struct exportlist *);
 static void	free_grp(struct grouplist *);
 static void	free_host(struct hostlist *);
 static void	get_exportlist(void);
+static void	insert_exports(struct exportlist *, struct exportlisthead *);
+static void	free_exports(struct exportlisthead *);
 static int	get_host(char *, struct grouplist *, struct grouplist *);
 static struct hostlist *get_ht(void);
 static int	get_line(void);
@@ -227,8 +231,8 @@ static int	xdr_fhs(XDR *, caddr_t);
 static int	xdr_mlist(XDR *, caddr_t);
 static void	terminate(int);
 
-static SLIST_HEAD(, exportlist) exphead = SLIST_HEAD_INITIALIZER(exphead);
-static SLIST_HEAD(, mountlist) mlhead = SLIST_HEAD_INITIALIZER(mlhead);
+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;
@@ -1087,7 +1091,7 @@ mntsrv(struct svc_req *rqstp, SVCXPRT *transp)
 		if (bad)
 			ep = NULL;
 		else
-			ep = ex_search(&fsb.f_fsid);
+			ep = ex_search(&fsb.f_fsid, &exphead);
 		hostset = defset = 0;
 		if (ep && (chk_host(ep->ex_defdir, saddr, &defset, &hostset,
 		    &numsecflavors, &secflavorsp) ||
@@ -1540,7 +1544,7 @@ get_exportlist_one(void)
 					 * See if this directory is already
 					 * in the list.
 					 */
-					ep = ex_search(&fsb.f_fsid);
+					ep = ex_search(&fsb.f_fsid, &exphead);
 					if (ep == (struct exportlist *)NULL) {
 					    ep = get_exp();
 					    ep->ex_fs = fsb.f_fsid;
@@ -1695,7 +1699,7 @@ get_exportlist_one(void)
 		}
 		dirhead = (struct dirlist *)NULL;
 		if ((ep->ex_flag & EX_LINKED) == 0) {
-			SLIST_INSERT_HEAD(&exphead, ep, entries);
+			insert_exports(ep, &exphead);
 
 			ep->ex_flag |= EX_LINKED;
 		}
@@ -1714,7 +1718,6 @@ nextline:
 static void
 get_exportlist(void)
 {
-	struct exportlist *ep, *ep2;
 	struct grouplist *grp, *tgrp;
 	struct export_args export;
 	struct iovec *iov;
@@ -1738,10 +1741,7 @@ get_exportlist(void)
 	/*
 	 * First, get rid of the old list
 	 */
-	SLIST_FOREACH_SAFE(ep, &exphead, entries, ep2) {
-		SLIST_REMOVE(&exphead, ep, exportlist, entries);
-		free_exp(ep);
-	}
+	free_exports(&exphead);
 
 	grp = grphead;
 	while (grp) {
@@ -1869,6 +1869,31 @@ get_exportlist(void)
 }
 
 /*
+ * Insert an export entry in the appropriate list.
+ */
+static void
+insert_exports(struct exportlist *ep, struct exportlisthead *exhp)
+{
+
+	SLIST_INSERT_HEAD(exhp, ep, entries);
+}
+
+/*
+ * Free up the exports lists passed in as arguments.
+ */
+static void
+free_exports(struct exportlisthead *exhp)
+{
+	struct exportlist *ep, *ep2;
+
+	SLIST_FOREACH_SAFE(ep, exhp, entries, ep2) {
+		SLIST_REMOVE(exhp, ep, exportlist, entries);
+		free_exp(ep);
+	}
+	SLIST_INIT(exhp);
+}
+
+/*
  * Allocate an export list element
  */
 static struct exportlist *
@@ -1924,11 +1949,11 @@ getexp_err(struct exportlist *ep, struct grouplist *gr
  * Search the export list for a matching fs.
  */
 static struct exportlist *
-ex_search(fsid_t *fsid)
+ex_search(fsid_t *fsid, struct exportlisthead *exhp)
 {
 	struct exportlist *ep;
 
-	SLIST_FOREACH(ep, &exphead, entries) {
+	SLIST_FOREACH(ep, exhp, entries) {
 		if (ep->ex_fs.val[0] == fsid->val[0] &&
 		    ep->ex_fs.val[1] == fsid->val[1])
 			return (ep);