Almost forgot these last few unimportant files...

Documentation/filesystems/Locking

@@ -62,6 +62,7 @@ ata *);
 	int (*removexattr) (struct dentry *, const char *);
 	void (*truncate_range)(struct inode *, loff_t, loff_t);
 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len);
+	struct file *(*open)(struct dentry *,struct file *,const struct cred *);
 
 locking rules:
 	all may block
@@ -89,6 +90,7 @@ listxattr:	no
 removexattr:	yes
 truncate_range:	yes
 fiemap:		no
+open:		no
 	Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
 victim.
 	cross-directory ->rename() has (per-superblock) ->s_vfs_rename_sem.

Documentation/filesystems/vfs.txt

@@ -364,6 +364,8 @@ struct inode_operations {
 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
 	int (*removexattr) (struct dentry *, const char *);
 	void (*truncate_range)(struct inode *, loff_t, loff_t);
+	struct file *(*open) (struct dentry *, struct file *,
+			      const struct cred *);
 };
 
 Again, all methods are called without any locks being held, unless
@@ -475,6 +477,12 @@ otherwise noted.
   truncate_range: a method provided by the underlying filesystem to truncate a
   	range of blocks , i.e. punch a hole somewhere in a file.
 
+  open: this is an alternative to f_op->open(), the difference is that this
+	method may return any open file, not necessarily originating from the
+	same filesystem as the one i_op->open() was called on.  It may be useful
+	for stacking filesystems which want to allow native I/O directly on
+	underlying files.
+
 
 The Address Space Object
 ========================

MAINTAINERS

@@ -4998,6 +4998,13 @@ F:	drivers/scsi/osd/
 F:	include/scsi/osd_*
 F:	fs/exofs/
 
+OVERLAYFS FILESYSTEM
+M:	Miklos Szeredi <miklos@szeredi.hu>
+L:	linux-fsdevel@vger.kernel.org
+S:	Supported
+F:	fs/overlayfs/*
+F:	Documentation/filesystems/overlayfs.txt
+
 P54 WIRELESS DRIVER
 M:	Christian Lamparter <chunkeey@googlemail.com>
 L:	linux-wireless@vger.kernel.org