[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry

Give the statfs superblock operation a dentry pointer rather than a superblock
pointer.

This complements the get_sb() patch.  That reduced the significance of
sb->s_root, allowing NFS to place a fake root there.  However, NFS does
require a dentry to use as a target for the statfs operation.  This permits
the root in the vfsmount to be used instead.

linux/mount.h has been added where necessary to make allyesconfig build
successfully.

Interest has also been expressed for use with the FUSE and XFS filesystems.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mount.h b/include/linux/mount.h
index b7472ae..60718f1 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -17,6 +17,11 @@
 #include <linux/spinlock.h>
 #include <asm/atomic.h>
 
+struct super_block;
+struct vfsmount;
+struct dentry;
+struct namespace;
+
 #define MNT_NOSUID	0x01
 #define MNT_NODEV	0x02
 #define MNT_NOEXEC	0x04