integrity: move ima inode integrity data management

Move the inode integrity data(iint) management up to the integrity directory
in order to share the iint among the different integrity models.

Changelog:
- don't define MAX_DIGEST_SIZE
- rename several globally visible 'ima_' prefixed functions, structs,
  locks, etc to 'integrity_'
- replace '20' with SHA1_DIGEST_SIZE
- reflect location change in appropriate Kconfig and Makefiles
- remove unnecessary initialization of iint_initialized to 0
- rebased on current ima_iint.c
- define integrity_iint_store/lock as static

There should be no other functional changes.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>

security/integrity/integrity.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2009-2010 IBM Corporation
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/integrity.h>
+#include <crypto/sha.h>
+
+/* iint cache flags */
+#define IMA_MEASURED		0x01
+
+/* integrity data associated with an inode */
+struct integrity_iint_cache {
+	struct rb_node rb_node; /* rooted in integrity_iint_tree */
+	struct inode *inode;	/* back pointer to inode in question */
+	u64 version;		/* track inode changes */
+	unsigned char flags;
+	u8 digest[SHA1_DIGEST_SIZE];
+	struct mutex mutex;	/* protects: version, flags, digest */
+};
+
+/* rbtree tree calls to lookup, insert, delete
+ * integrity data associated with an inode.
+ */
+struct integrity_iint_cache *integrity_iint_insert(struct inode *inode);
+struct integrity_iint_cache *integrity_iint_find(struct inode *inode);