cifs: define inode-level cache object and register them

Define inode-level data storage objects (managed by cifsInodeInfo structs).
Each inode-level object is created in a super-block level object and is itself
a data storage object in to which pages from the inode are stored.

The inode object is keyed by UniqueId. The coherency data being used is
LastWriteTime, LastChangeTime and end of file reported by the server.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index f884cb5..5a68b92 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -29,6 +29,7 @@
 #include "cifsproto.h"
 #include "cifs_debug.h"
 #include "cifs_fs_sb.h"
+#include "fscache.h"
 
 
 static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral)
@@ -776,6 +777,8 @@
 			inode->i_flags |= S_NOATIME | S_NOCMTIME;
 		if (inode->i_state & I_NEW) {
 			inode->i_ino = hash;
+			/* initialize per-inode cache cookie pointer */
+			CIFS_I(inode)->fscache = NULL;
 			unlock_new_inode(inode);
 		}
 	}
@@ -1571,6 +1574,7 @@
 			cifs_i->write_behind_rc = rc;
 	}
 	invalidate_remote_inode(inode);
+	cifs_fscache_reset_inode_cookie(inode);
 }
 
 int cifs_revalidate_file(struct file *filp)