pass a struct path to vfs_statfs

We'll need the path to implement the flags field for statvfs support.
We do have it available in all callers except:

 - ecryptfs_statfs.  This one doesn't actually need vfs_statfs but just
   needs to do a caller to the lower filesystem statfs method.
 - sys_ustat.  Add a non-exported statfs_by_dentry helper for it which
   doesn't won't be able to fill out the flags field later on.

In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
of the misleading vfs prefix.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/parisc/hpux/sys_hpux.c b/arch/parisc/hpux/sys_hpux.c
index 92343bd..ba430a0 100644
--- a/arch/parisc/hpux/sys_hpux.c
+++ b/arch/parisc/hpux/sys_hpux.c
@@ -145,7 +145,7 @@
 	s = user_get_super(dev);
 	if (s == NULL)
 		goto out;
-	err = vfs_statfs(s->s_root, &sbuf);
+	err = statfs_by_dentry(s->s_root, &sbuf);
 	drop_super(s);
 	if (err)
 		goto out;
@@ -186,12 +186,12 @@
      int16_t f_pad;
 };
 
-static int vfs_statfs_hpux(struct dentry *dentry, struct hpux_statfs *buf)
+static int do_statfs_hpux(struct path *path, struct hpux_statfs *buf)
 {
 	struct kstatfs st;
 	int retval;
 	
-	retval = vfs_statfs(dentry, &st);
+	retval = vfs_statfs(path, &st);
 	if (retval)
 		return retval;
 
@@ -219,7 +219,7 @@
 	error = user_path(pathname, &path);
 	if (!error) {
 		struct hpux_statfs tmp;
-		error = vfs_statfs_hpux(path.dentry, &tmp);
+		error = do_statfs_hpux(&path, &tmp);
 		if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
 			error = -EFAULT;
 		path_put(&path);
@@ -237,7 +237,7 @@
 	file = fget(fd);
 	if (!file)
 		goto out;
-	error = vfs_statfs_hpux(file->f_path.dentry, &tmp);
+	error = do_statfs_hpux(&file->f_path, &tmp);
 	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
 		error = -EFAULT;
 	fput(file);