From 390e67de5d9fe919d1894359536f0c5527fa2331 Mon Sep 17 00:00:00 2001
From: Neil Brown <neilb@suse.de>
Date: Tue, 20 Mar 2007 11:13:42 +1100
Subject: [PATCH] Handle -o remount better

On -o remount, we need to update the entry in mtab rather than
add a new one.  update_mtab does this so use that.
However it might free some strings that shouldn't be freed, so
stop it from calling free - the program will exit soon anyway
so no exit is needed.
---
 support/nfs/fstab.c | 13 +++++++++++--
 utils/mount/mount.c |  5 +++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/support/nfs/fstab.c b/support/nfs/fstab.c
index ba72a53..aee8e53 100644
--- a/support/nfs/fstab.c
+++ b/support/nfs/fstab.c
@@ -101,6 +101,7 @@ fstab_head()
 	return &fstab;
 }
 
+#if 0
 static void
 my_free(const void *s) {
 	if (s)
@@ -120,6 +121,7 @@ discard_mntentchn(struct mntentchn *mc0) {
 		free(mc);
 	}
 }
+#endif
 
 static void
 read_mntentchn(mntFILE *mfp, const char *fnam, struct mntentchn *mc0) {
@@ -444,7 +446,8 @@ lock_mtab (void) {
  */
 
 void
-update_mtab (const char *dir, struct mntent *instead) {
+update_mtab (const char *dir, struct mntent *instead)
+{
 	mntFILE *mfp, *mftmp;
 	const char *fnam = MOUNTED;
 	struct mntentchn mtabhead;	/* dummy */
@@ -513,8 +516,14 @@ update_mtab (const char *dir, struct mntent *instead) {
 		}
 	}
 
+#if 0
+	/* the chain might have strings copied from 'instead',
+	 * so we cannot safely free it.
+	 * And there is no need anyway because we are going to exit
+	 * shortly.  So just don't call discard_mntentchn....
+	 */
 	discard_mntentchn(mc0);
-
+#endif
 	if (fchmod (fileno (mftmp->mntent_fp),
 		    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) < 0) {
 		int errsv = errno;
diff --git a/utils/mount/mount.c b/utils/mount/mount.c
index 55d60aa..4da9002 100644
--- a/utils/mount/mount.c
+++ b/utils/mount/mount.c
@@ -179,6 +179,11 @@ int add_mtab(char *fsname, char *mount_point, char *fstype, int flags, char *opt
 	ment.mnt_freq = 0;
 	ment.mnt_passno= 0;
 
+	if(flags & MS_REMOUNT) {
+		update_mtab(ment.mnt_dir, &ment);
+		return 0;
+	}
+
 	lock_mtab();
 
         if ((mtab = setmntent(MOUNTED, "a+")) == NULL) {
-- 
2.39.2