autofs-5.1.7 - add tree_mapent_cleanup_offsets()

From: Ian Kent <raven@themaw.net>

Add function tree_mapent_cleanup_offsets() to the mapent tree handling
implementation.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 CHANGELOG        |    1 +
 include/mounts.h |    1 +
 lib/mounts.c     |   45 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index e2fd532c..89d4cfa0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -37,6 +37,7 @@
 - add tree_mapent_delete_offsets().
 - add tree_mapent_traverse_subtree().
 - fix mount_fullpath().
+- add tree_mapent_cleanup_offsets().
 
 25/01/2021 autofs-5.1.7
 - make bind mounts propagation slave by default.
diff --git a/include/mounts.h b/include/mounts.h
index b5a1193b..5441ee0e 100644
--- a/include/mounts.h
+++ b/include/mounts.h
@@ -171,6 +171,7 @@ void mnts_set_mounted_mount(struct autofs_point *ap, const char *name, unsigned
 struct tree_node *tree_mapent_root(struct mapent *me);
 int tree_mapent_add_node(struct mapent_cache *mc, const char *base, const char *key);
 int tree_mapent_delete_offsets(struct mapent_cache *mc, const char *key);
+void tree_mapent_cleanup_offsets(struct mapent *oe);
 int unlink_mount_tree(struct autofs_point *ap, const char *mp);
 void free_mnt_list(struct mnt_list *list);
 int is_mounted(const char *mp, unsigned int type);
diff --git a/lib/mounts.c b/lib/mounts.c
index 497c28c9..ba573b9a 100644
--- a/lib/mounts.c
+++ b/lib/mounts.c
@@ -1647,6 +1647,51 @@ int tree_mapent_delete_offsets(struct mapent_cache *mc, const char *key)
 	return 1;
 }
 
+static void tree_mapent_umount_mount(struct autofs_point *ap, const char *mp)
+{
+	if (is_mounted(mp, MNTS_ALL)) {
+		if (umount(mp)) {
+			error(ap->logopt, "error recovering from mount fail");
+			error(ap->logopt, "cannot umount %s", mp);
+		}
+	}
+}
+
+static int tree_mapent_cleanup_offsets_work(struct tree_node *n, void *ptr)
+{
+	struct mapent *oe = MAPENT(n);
+	struct traverse_subtree_context *ctxt = ptr;
+
+	tree_mapent_umount_mount(ctxt->ap, oe->key);
+
+	return 1;
+}
+
+void tree_mapent_cleanup_offsets(struct mapent *oe)
+{
+	struct tree_node *base = MAPENT_NODE(oe);
+	struct traverse_subtree_context ctxt = {
+		.ap = oe->mc->ap,
+		.base = base,
+		.strict = 0,
+	};
+	struct autofs_point *ap = oe->mc->ap;
+
+	tree_mapent_traverse_subtree(base, tree_mapent_cleanup_offsets_work, &ctxt);
+
+	/* Cleanup base mount after offsets have been cleaned up */
+	if (*oe->key == '/')
+		tree_mapent_umount_mount(ap, oe->key);
+	else {
+		char mp[PATH_MAX + 1];
+
+		if (!mount_fullpath(mp, PATH_MAX, ap->path, oe->key))
+			error(ap->logopt, "mount path is too long");
+		else
+			tree_mapent_umount_mount(ap, mp);
+	}
+}
+
 /* From glibc decode_name() */
 /* Since the values in a line are separated by spaces, a name cannot
  * contain a space.  Therefore some programs encode spaces in names