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/drivers/md/bitmap.c b/drivers/md/bitmap.c
index a0585fb..7aeceed 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -206,16 +206,10 @@
 /* copy the pathname of a file to a buffer */
 char *file_path(struct file *file, char *buf, int count)
 {
-	struct dentry *d;
-	struct vfsmount *v;
-
 	if (!buf)
 		return NULL;
 
-	d = file->f_path.dentry;
-	v = file->f_path.mnt;
-
-	buf = d_path(d, v, buf, count);
+	buf = d_path(&file->f_path, buf, count);
 
 	return IS_ERR(buf) ? NULL : buf;
 }