sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv

A directory sysfs_dirent points to the associated kobj.  A regular or
bin file points to the associated [bin_]attribute.  This patch
replaces sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with void *
->priv.

This is to prepare for kernfs interface so that sysfs can specify the
private data in the same way for directories and files.  This lower
debuggability but not by much - the whole thing was overlaid in a
union anyway.  If debuggability becomes an issue, we can later add
->priv accessors which explicitly check for the sysfs_dirent type and
performs casting.

This patch doesn't introduce any behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 8 deletions

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 2abccfdd932e..a6f3fa3f02fe 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -17,8 +17,6 @@ struct sysfs_open_dirent;
 
 /* type-specific structures for sysfs_dirent->s_* union members */
 struct sysfs_elem_dir {
-	struct kobject		*kobj;
-
 	unsigned long		subdirs;
 	/* children rbtree starts here and goes through sd->s_rb */
 	struct rb_root		children;
@@ -29,10 +27,6 @@ struct sysfs_elem_symlink {
 };
 
 struct sysfs_elem_attr {
-	union {
-		struct attribute	*attr;
-		struct bin_attribute	*bin_attr;
-	};
 	struct sysfs_open_dirent *open;
 };
 
@@ -74,6 +68,8 @@ struct sysfs_dirent {
 		struct sysfs_elem_attr		s_attr;
 	};
 
+	void			*priv;
+
 	unsigned short		s_flags;
 	umode_t			s_mode;
 	unsigned int		s_ino;
@@ -103,7 +99,7 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 
 #define sysfs_dirent_init_lockdep(sd)				\
 do {								\
-	struct attribute *attr = sd->s_attr.attr;		\
+	struct attribute *attr = sd->priv;			\
 	struct lock_class_key *key = attr->key;			\
 	if (!key)						\
 		key = &attr->skey;				\
@@ -114,10 +110,11 @@ do {								\
 /* Test for attributes that want to ignore lockdep for read-locking */
 static inline bool sysfs_ignore_lockdep(struct sysfs_dirent *sd)
 {
+	struct attribute *attr = sd->priv;
 	int type = sysfs_type(sd);
 
 	return (type == SYSFS_KOBJ_ATTR || type == SYSFS_KOBJ_BIN_ATTR) &&
-		sd->s_attr.attr->ignore_lockdep;
+		attr->ignore_lockdep;
 }
 
 #else