mm: add vzalloc() and vzalloc_node() helpers

Add vzalloc() and vzalloc_node() to encapsulate the
vmalloc-then-memset-zero operation.

Use __GFP_ZERO to zero fill the allocated memory.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 63a4fe6..a03dcf6 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -53,8 +53,10 @@
 #endif
 
 extern void *vmalloc(unsigned long size);
+extern void *vzalloc(unsigned long size);
 extern void *vmalloc_user(unsigned long size);
 extern void *vmalloc_node(unsigned long size, int node);
+extern void *vzalloc_node(unsigned long size, int node);
 extern void *vmalloc_exec(unsigned long size);
 extern void *vmalloc_32(unsigned long size);
 extern void *vmalloc_32_user(unsigned long size);