sysfs: make sysfs_root a regular directory dirent

sysfs_root is different from a regular directory dirent in that it's
of type SYSFS_ROOT and doesn't have a name.  These differences aren't
used by anybody and only adds to complexity.  Make sysfs_root a
regular directory dirent.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

fs/sysfs/inode.c

@@ -157,11 +157,6 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
 
 	/* initialize inode according to type */
 	switch (sysfs_type(sd)) {
-	case SYSFS_ROOT:
-		inode->i_op = &sysfs_dir_inode_operations;
-		inode->i_fop = &sysfs_dir_operations;
-		inc_nlink(inode); /* directory, account for "." */
-		break;
 	case SYSFS_DIR:
 		inode->i_op = &sysfs_dir_inode_operations;
 		inode->i_fop = &sysfs_dir_operations;

fs/sysfs/mount.c

@@ -24,8 +24,9 @@ static const struct super_operations sysfs_ops = {
 };
 
 struct sysfs_dirent sysfs_root = {
+	.s_name		= "",
 	.s_count	= ATOMIC_INIT(1),
-	.s_flags	= SYSFS_ROOT,
+	.s_flags	= SYSFS_DIR,
 	.s_mode		= S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
 	.s_ino		= 1,
 };

fs/sysfs/sysfs.h

@@ -48,11 +48,10 @@ struct sysfs_dirent {
 #define SD_DEACTIVATED_BIAS		INT_MIN
 
 #define SYSFS_TYPE_MASK			0x00ff
-#define SYSFS_ROOT			0x0001
-#define SYSFS_DIR			0x0002
-#define SYSFS_KOBJ_ATTR			0x0004
-#define SYSFS_KOBJ_BIN_ATTR		0x0008
-#define SYSFS_KOBJ_LINK			0x0020
+#define SYSFS_DIR			0x0001
+#define SYSFS_KOBJ_ATTR			0x0002
+#define SYSFS_KOBJ_BIN_ATTR		0x0004
+#define SYSFS_KOBJ_LINK			0x0008
 #define SYSFS_COPY_NAME			(SYSFS_DIR | SYSFS_KOBJ_LINK)
 
 #define SYSFS_FLAG_MASK			~SYSFS_TYPE_MASK