[FS] seq_file: Introduce the seq_open_private()

This function allocates the zeroed chunk of memory and
call seq_open(). The __seq_open_private() helper returns
the allocated memory to make it possible for the caller
to initialize it.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 83783ab..8bf1e05 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -46,6 +46,8 @@
 
 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
 int single_release(struct inode *, struct file *);
+void *__seq_open_private(struct file *, const struct seq_operations *, int);
+int seq_open_private(struct file *, const struct seq_operations *, int);
 int seq_release_private(struct inode *, struct file *);
 
 #define SEQ_START_TOKEN ((void *)1)