diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b32a0f8..8b9a594 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -434,7 +434,6 @@
 	 */
 	struct cgroup_subsys *ss;
 
-	int (*open)(struct inode *inode, struct file *file);
 	/*
 	 * read_u64() is a shortcut for the common case of returning a
 	 * single integer. Use it in place of read()
@@ -448,6 +447,11 @@
 	/* generic seq_file read interface */
 	int (*seq_show)(struct seq_file *sf, void *v);
 
+	/* optional ops, implement all or none */
+	void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
+	void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
+	void (*seq_stop)(struct seq_file *sf, void *v);
+
 	/*
 	 * write_u64() is a shortcut for the common case of accepting
 	 * a single integer (as parsed by simple_strtoull) from
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 39fdf75..13a3d3ba 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2286,6 +2286,45 @@
  * supports string->u64 maps, but can be extended in future.
  */
 
+static void *cgroup_seqfile_start(struct seq_file *seq, loff_t *ppos)
+{
+	struct cftype *cft = seq_cft(seq);
+
+	if (cft->seq_start) {
+		return cft->seq_start(seq, ppos);
+	} else {
+		/*
+		 * The same behavior and code as single_open().  Returns
+		 * !NULL if pos is at the beginning; otherwise, NULL.
+		 */
+		return NULL + !*ppos;
+	}
+}
+
+static void *cgroup_seqfile_next(struct seq_file *seq, void *v, loff_t *ppos)
+{
+	struct cftype *cft = seq_cft(seq);
+
+	if (cft->seq_next) {
+		return cft->seq_next(seq, v, ppos);
+	} else {
+		/*
+		 * The same behavior and code as single_open(), always
+		 * terminate after the initial read.
+		 */
+		++*ppos;
+		return NULL;
+	}
+}
+
+static void cgroup_seqfile_stop(struct seq_file *seq, void *v)
+{
+	struct cftype *cft = seq_cft(seq);
+
+	if (cft->seq_stop)
+		cft->seq_stop(seq, v);
+}
+
 static int cgroup_seqfile_show(struct seq_file *m, void *arg)
 {
 	struct cftype *cft = seq_cft(m);
@@ -2303,6 +2342,13 @@
 	return 0;
 }
 
+static struct seq_operations cgroup_seq_operations = {
+	.start		= cgroup_seqfile_start,
+	.next		= cgroup_seqfile_next,
+	.stop		= cgroup_seqfile_stop,
+	.show		= cgroup_seqfile_show,
+};
+
 static int cgroup_file_open(struct inode *inode, struct file *file)
 {
 	struct cfent *cfe = __d_cfe(file->f_dentry);
@@ -2338,20 +2384,17 @@
 	WARN_ON_ONCE(cfe->css && cfe->css != css);
 	cfe->css = css;
 
-	if (cft->open) {
-		err = cft->open(inode, file);
-	} else {
-		err = single_open_size(file, cgroup_seqfile_show, cfe,
-				       sizeof(struct cgroup_open_file));
-		if (!err) {
-			struct seq_file *sf = file->private_data;
-			struct cgroup_open_file *of = sf->private;
+	err = seq_open_private(file, &cgroup_seq_operations,
+			       sizeof(struct cgroup_open_file));
+	if (!err) {
+		struct seq_file *sf = file->private_data;
+		struct cgroup_open_file *of = sf->private;
 
-			of->cfe = cfe;
-		}
+		of->cfe = cfe;
+		return 0;
 	}
 
-	if (css->ss && err)
+	if (css->ss)
 		css_put(css);
 	return err;
 }
@@ -2363,7 +2406,7 @@
 
 	if (css->ss)
 		css_put(css);
-	return single_release(inode, file);
+	return seq_release_private(inode, file);
 }
 
 /*
@@ -3774,38 +3817,6 @@
 	.show = cgroup_pidlist_show,
 };
 
-static const struct file_operations cgroup_pidlist_operations = {
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.write = cgroup_file_write,
-	.release = seq_release_private,
-};
-
-/*
- * The following functions handle opens on a file that displays a pidlist
- * (tasks or procs). Prepare an array of the process/thread IDs of whoever's
- * in the cgroup.
- */
-/* helper function for the two below it */
-static int cgroup_pidlist_open(struct inode *unused, struct file *file)
-{
-	struct cfent *cfe = __d_cfe(file->f_dentry);
-	struct cgroup_open_file *of;
-	int retval;
-
-	/* configure file information */
-	file->f_op = &cgroup_pidlist_operations;
-
-	retval = seq_open_private(file, &cgroup_pidlist_seq_operations,
-				  sizeof(*of));
-	if (retval)
-		return retval;
-
-	of = ((struct seq_file *)file->private_data)->private;
-	of->cfe = cfe;
-	return 0;
-}
-
 static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
 					 struct cftype *cft)
 {
@@ -3859,7 +3870,10 @@
 static struct cftype cgroup_base_files[] = {
 	{
 		.name = "cgroup.procs",
-		.open = cgroup_pidlist_open,
+		.seq_start = cgroup_pidlist_start,
+		.seq_next = cgroup_pidlist_next,
+		.seq_stop = cgroup_pidlist_stop,
+		.seq_show = cgroup_pidlist_show,
 		.private = CGROUP_FILE_PROCS,
 		.write_u64 = cgroup_procs_write,
 		.mode = S_IRUGO | S_IWUSR,
@@ -3884,7 +3898,10 @@
 	{
 		.name = "tasks",
 		.flags = CFTYPE_INSANE,		/* use "procs" instead */
-		.open = cgroup_pidlist_open,
+		.seq_start = cgroup_pidlist_start,
+		.seq_next = cgroup_pidlist_next,
+		.seq_stop = cgroup_pidlist_stop,
+		.seq_show = cgroup_pidlist_show,
 		.private = CGROUP_FILE_TASKS,
 		.write_u64 = cgroup_tasks_write,
 		.mode = S_IRUGO | S_IWUSR,