Merge tag 'configfs-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/leitao/linux

Pull configfs updates from Breno Leitao:

 - Attribute structures can now be const (Thomas Weißschuh)

 - The first selftests for the configfs userspace interface, plus a
   sample subsystem that accepts symlinks to test against. They include
   a race of symlink(2) against rmdir of the target, which exercises the
   use-after-free fixed in v7.3-rc3.

 - Rust bindings, merged from Andreas Hindborg's signed tag: fix the
   data offset calculation in subsystem callbacks (marked for stable),
   add the missing Send and Sync bounds, and correct a safety comment.

* tag 'configfs-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/leitao/linux:
  samples: configfs: constify the configfs_attribute structures
  configfs: Allow the registration of const struct configfs_attribute
  configfs: Constify configfs_bin_attribute
  configfs: Treat attribute structures as const internally
  configfs: Constify is_visible/is_visible_bin in configfs_group_operations
  rust: configfs: remove mutability from some field initializers
  selftests/configfs: race symlink against rmdir of the target
  selftests/configfs: cover symlink and unlink
  samples/configfs: add a subsystem that accepts symlinks
  selftests/configfs: add tests for the userspace interface
  rust: configfs: fix data offset calculation for subsystem callbacks
  rust: configfs: require thread-safe callback data
  rust: configfs: fix release safety documentation

1 files changed, 38 insertions, 35 deletions

diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index ef65c75beeaa..5bead9173ec1 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -66,8 +66,11 @@ struct config_item_type {
 	struct module				*ct_owner;
 	const struct configfs_item_operations	*ct_item_ops;
 	const struct configfs_group_operations	*ct_group_ops;
-	struct configfs_attribute		**ct_attrs;
-	struct configfs_bin_attribute		**ct_bin_attrs;
+	union {
+		struct configfs_attribute		**ct_attrs;
+		const struct configfs_attribute		*const *ct_attrs_const;
+	};
+	const struct configfs_bin_attribute	*const *ct_bin_attrs;
 };
 
 /**
@@ -160,41 +163,41 @@ struct configfs_bin_attribute {
 	ssize_t (*write)(struct config_item *, const void *, size_t);
 };
 
-#define CONFIGFS_BIN_ATTR(_pfx, _name, _priv, _maxsz)		\
-static struct configfs_bin_attribute _pfx##attr_##_name = {	\
-	.cb_attr = {						\
-		.ca_name	= __stringify(_name),		\
-		.ca_mode	= S_IRUGO | S_IWUSR,		\
-		.ca_owner	= THIS_MODULE,			\
-	},							\
-	.cb_private	= _priv,				\
-	.cb_max_size	= _maxsz,				\
-	.read		= _pfx##_name##_read,			\
-	.write		= _pfx##_name##_write,			\
+#define CONFIGFS_BIN_ATTR(_pfx, _name, _priv, _maxsz)			\
+static const struct configfs_bin_attribute _pfx##attr_##_name = {	\
+	.cb_attr = {							\
+		.ca_name	= __stringify(_name),			\
+		.ca_mode	= S_IRUGO | S_IWUSR,			\
+		.ca_owner	= THIS_MODULE,				\
+	},								\
+	.cb_private	= _priv,					\
+	.cb_max_size	= _maxsz,					\
+	.read		= _pfx##_name##_read,				\
+	.write		= _pfx##_name##_write,				\
 }
 
-#define CONFIGFS_BIN_ATTR_RO(_pfx, _name, _priv, _maxsz)	\
-static struct configfs_bin_attribute _pfx##attr_##_name = {	\
-	.cb_attr = {						\
-		.ca_name	= __stringify(_name),		\
-		.ca_mode	= S_IRUGO,			\
-		.ca_owner	= THIS_MODULE,			\
-	},							\
-	.cb_private	= _priv,				\
-	.cb_max_size	= _maxsz,				\
-	.read		= _pfx##_name##_read,			\
+#define CONFIGFS_BIN_ATTR_RO(_pfx, _name, _priv, _maxsz)		\
+static const struct configfs_bin_attribute _pfx##attr_##_name = {	\
+	.cb_attr = {							\
+		.ca_name	= __stringify(_name),			\
+		.ca_mode	= S_IRUGO,				\
+		.ca_owner	= THIS_MODULE,				\
+	},								\
+	.cb_private	= _priv,					\
+	.cb_max_size	= _maxsz,					\
+	.read		= _pfx##_name##_read,				\
 }
 
-#define CONFIGFS_BIN_ATTR_WO(_pfx, _name, _priv, _maxsz)	\
-static struct configfs_bin_attribute _pfx##attr_##_name = {	\
-	.cb_attr = {						\
-		.ca_name	= __stringify(_name),		\
-		.ca_mode	= S_IWUSR,			\
-		.ca_owner	= THIS_MODULE,			\
-	},							\
-	.cb_private	= _priv,				\
-	.cb_max_size	= _maxsz,				\
-	.write		= _pfx##_name##_write,			\
+#define CONFIGFS_BIN_ATTR_WO(_pfx, _name, _priv, _maxsz)		\
+static const struct configfs_bin_attribute _pfx##attr_##_name = {	\
+	.cb_attr = {							\
+		.ca_name	= __stringify(_name),			\
+		.ca_mode	= S_IWUSR,				\
+		.ca_owner	= THIS_MODULE,				\
+	},								\
+	.cb_private	= _priv,					\
+	.cb_max_size	= _maxsz,					\
+	.write		= _pfx##_name##_write,				\
 }
 
 /*
@@ -220,8 +223,8 @@ struct configfs_group_operations {
 	struct config_group *(*make_group)(struct config_group *group, const char *name);
 	void (*disconnect_notify)(struct config_group *group, struct config_item *item);
 	void (*drop_item)(struct config_group *group, struct config_item *item);
-	bool (*is_visible)(struct config_item *item, struct configfs_attribute *attr, int n);
-	bool (*is_bin_visible)(struct config_item *item, struct configfs_bin_attribute *attr,
+	bool (*is_visible)(struct config_item *item, const struct configfs_attribute *attr, int n);
+	bool (*is_bin_visible)(struct config_item *item, const struct configfs_bin_attribute *attr,
 			       int n);
 };