[linux-lvm] Question about VFS Locking patch, why is a change needed?

[Steven Dake]

Folks,

I was analyzing the VFS locking patch and I wanted to know if someone 
could explain the purpose of a change in the reiserfs for me:

The change is:
Index: linus.21/fs/reiserfs/super.c
--- linus.21/fs/reiserfs/super.c Fri, 11 Jan 2002 10:14:59 -0500 root 
(linux/41_super.c 1.2.2.1.2.1.1.1 644)
+++ linus.21(w)/fs/reiserfs/super.c Mon, 28 Jan 2002 13:50:56 -0500 root 
(linux/41_super.c 1.2.2.1.2.1.1.1 644)
@@ -66,7 +66,7 @@
     reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
     journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s));
     reiserfs_block_writes(&th) ;
-    journal_end(&th, s, 1) ;
+    journal_end_sync(&th, s, 1) ;
   }
   s->s_dirt = dirty;
   unlock_kernel() ;

I tried LVM with and without this change even under heavy load and LVM 
can still create mountable snapshots of a reiser filesystem without the 
change.  Why is it there?

Thanks
-steve