fuse: improve utimes support

Add two new flags for setattr: FATTR_ATIME_NOW and FATTR_MTIME_NOW.  These
mean, that atime or mtime should be changed to the current time.

Also it is now possible to update atime or mtime individually, not just
together.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index a50d0d9..43a77d7 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -83,6 +83,8 @@
 #define FATTR_ATIME	(1 << 4)
 #define FATTR_MTIME	(1 << 5)
 #define FATTR_FH	(1 << 6)
+#define FATTR_ATIME_NOW	(1 << 7)
+#define FATTR_MTIME_NOW	(1 << 8)
 
 /**
  * Flags returned by the OPEN request