d_path: Make d_path() use a struct path

d_path() is used on a <dentry,vfsmount> pair.  Lets use a struct path to
reflect this.

[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index c2c153f..6bd6460 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -10,6 +10,7 @@
 #include <linux/rcupdate.h>
 
 struct nameidata;
+struct path;
 struct vfsmount;
 
 /*
@@ -300,8 +301,8 @@
  */
 extern char *dynamic_dname(struct dentry *, char *, int, const char *, ...);
 
-extern char * d_path(struct dentry *, struct vfsmount *, char *, int);
-  
+extern char *d_path(struct path *, char *, int);
+
 /* Allocation counts.. */
 
 /**