AFS: implement statfs

Implement the statfs() op for AFS.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/afs/afs_fs.h b/fs/afs/afs_fs.h
index d963ef4..a18c374 100644
--- a/fs/afs/afs_fs.h
+++ b/fs/afs/afs_fs.h
@@ -28,7 +28,8 @@
 	FSMAKEDIR		= 141,	/* AFS Create a directory */
 	FSREMOVEDIR		= 142,	/* AFS Remove a directory */
 	FSGIVEUPCALLBACKS	= 147,	/* AFS Discard callback promises */
-	FSGETVOLUMEINFO		= 148,	/* AFS Get root volume information */
+	FSGETVOLUMEINFO		= 148,	/* AFS Get information about a volume */
+	FSGETVOLUMESTATUS	= 149,	/* AFS Get volume status information */
 	FSGETROOTVOLUME		= 151,	/* AFS Get root volume name */
 	FSLOOKUP		= 161,	/* AFS lookup file in directory */
 	FSFETCHDATA64		= 65537, /* AFS Fetch file data */