f2fs: control the memory footprint used by ino entries

This patch adds to control the memory footprint used by ino entries.
This will conduct best effort, not strictly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index acb71e5..d10b644 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -106,7 +106,8 @@
 enum mem_type {
 	FREE_NIDS,	/* indicates the free nid list */
 	NAT_ENTRIES,	/* indicates the cached nat entry */
-	DIRTY_DENTS	/* indicates dirty dentry pages */
+	DIRTY_DENTS,	/* indicates dirty dentry pages */
+	INO_ENTRIES,	/* indicates inode entries */
 };
 
 struct nat_entry_set {