diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index acd542625fd8a645772f7a91dedf3e4fa0e62d4f..fa323589704f828c808127304af1615ca0f3f6df 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -16,6 +16,7 @@
 #include <linux/pagemap.h>
 #include <linux/namei.h>
 #include <linux/seq_file.h>
+#include <linux/exportfs.h>
 
 #include "kernfs-internal.h"
 
@@ -64,6 +65,59 @@ const struct super_operations kernfs_sops = {
 	.show_path	= kernfs_sop_show_path,
 };
 
+static struct inode *kernfs_fh_get_inode(struct super_block *sb,
+		u64 ino, u32 generation)
+{
+	struct kernfs_super_info *info = kernfs_info(sb);
+	struct inode *inode;
+	struct kernfs_node *kn;
+
+	if (ino == 0)
+		return ERR_PTR(-ESTALE);
+
+	kn = kernfs_find_and_get_node_by_ino(info->root, ino);
+	if (!kn)
+		return ERR_PTR(-ESTALE);
+	inode = kernfs_get_inode(sb, kn);
+	kernfs_put(kn);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	if (generation && inode->i_generation != generation) {
+		/* we didn't find the right inode.. */
+		iput(inode);
+		return ERR_PTR(-ESTALE);
+	}
+	return inode;
+}
+
+static struct dentry *kernfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    kernfs_fh_get_inode);
+}
+
+static struct dentry *kernfs_fh_to_parent(struct super_block *sb, struct fid *fid,
+		int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    kernfs_fh_get_inode);
+}
+
+static struct dentry *kernfs_get_parent_dentry(struct dentry *child)
+{
+	struct kernfs_node *kn = kernfs_dentry_node(child);
+
+	return d_obtain_alias(kernfs_get_inode(child->d_sb, kn->parent));
+}
+
+static const struct export_operations kernfs_export_ops = {
+	.fh_to_dentry	= kernfs_fh_to_dentry,
+	.fh_to_parent	= kernfs_fh_to_parent,
+	.get_parent	= kernfs_get_parent_dentry,
+};
+
 /**
  * kernfs_root_from_sb - determine kernfs_root associated with a super_block
  * @sb: the super_block in question
@@ -159,6 +213,8 @@ static int kernfs_fill_super(struct super_block *sb, unsigned long magic)
 	sb->s_magic = magic;
 	sb->s_op = &kernfs_sops;
 	sb->s_xattr = kernfs_xattr_handlers;
+	if (info->root->flags & KERNFS_ROOT_SUPPORT_EXPORTOP)
+		sb->s_export_op = &kernfs_export_ops;
 	sb->s_time_gran = 1;
 
 	/* get root inode, initialize and unlock it */
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 06a0c5913e1dbf7367bdb2dc47cb2d3e1a91e7bb..d149361e58756d0ea93deb014121e965a3fe8097 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -69,6 +69,12 @@ enum kernfs_root_flag {
 	 * following flag enables that behavior.
 	 */
 	KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK	= 0x0002,
+
+	/*
+	 * The filesystem supports exportfs operation, so userspace can use
+	 * fhandle to access nodes of the fs.
+	 */
+	KERNFS_ROOT_SUPPORT_EXPORTOP		= 0x0004,
 };
 
 /* type-specific structures for kernfs_node union members */
@@ -98,6 +104,12 @@ struct kernfs_elem_attr {
 /* represent a kernfs node */
 union kernfs_node_id {
 	struct {
+		/*
+		 * blktrace will export this struct as a simplified 'struct
+		 * fid' (which is a big data struction), so userspace can use
+		 * it to find kernfs node. The layout must match the first two
+		 * fields of 'struct fid' exactly.
+		 */
 		u32		ino;
 		u32		generation;
 	};
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 620794a20a339c7e10948da829fae5a6818e598b..6cefa277f39c61b3ad1004bec9331bd2e883f317 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1737,7 +1737,8 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask, int ref_flags)
 		&cgroup_kf_syscall_ops : &cgroup1_kf_syscall_ops;
 
 	root->kf_root = kernfs_create_root(kf_sops,
-					   KERNFS_ROOT_CREATE_DEACTIVATED,
+					   KERNFS_ROOT_CREATE_DEACTIVATED |
+					   KERNFS_ROOT_SUPPORT_EXPORTOP,
 					   root_cgrp);
 	if (IS_ERR(root->kf_root)) {
 		ret = PTR_ERR(root->kf_root);