Re: FAQ updated (was Re: XFS breakage...)

[David Greaves <david@dgreaves.com>]

Nathan Scott wrote:
> Correction there - no -stable exists with this yet, I guess that'll
> be 2.6.17.7 once its out though.
> 
>> what action do you suggest i do now?
> 
> I've captured the state of this issue here, with options and ways
> to correct the problem:
> 	http://oss.sgi.com/projects/xfs/faq.html#dir2
> 
> Hope this helps.

It does, thanks :)


Does this problem exist in 2.16.6.x??

>From various comments like:
  Unless 2.6.16.x is a dead-end could we please also have this patch put
  into there?
and
  a result (I believe) of the corruption bug that was in 2.6.16/17.
and
  I just want to confirm this bug as well and unfortunately it was my
  system disk too who had to take the hit. Im running 2.6.16
I assume it does.

But the FAQ says:
Q: What is the issue with directory corruption in Linux 2.6.17?
In the Linux kernel 2.6.17 release a subtle bug...

which implies it's not...

HELP

So given this is from 2.6.16.9:
                        /*
                         * One less used entry in the free table.
                         */
                        INT_MOD(free->hdr.nused, ARCH_CONVERT, -1);
                        xfs_dir2_free_log_header(tp, fbp);

and it looks awfully similar to the patch which says:

--- linux-2.6.17.2.orig/fs/xfs/xfs_dir2_node.c
+++ linux-2.6.17.2/fs/xfs/xfs_dir2_node.c
@@ -970,7 +970,7 @@ xfs_dir2_leafn_remove(
 			/*
 			 * One less used entry in the free table.
 			 */
-			free->hdr.nused = cpu_to_be32(-1);
+			be32_add(&free->hdr.nused, -1);
 			xfs_dir2_free_log_header(tp, fbp);

Should 2.6.16.x replace
  INT_MOD(free->hdr.nused, ARCH_CONVERT, -1);
with
  be32_add(&free->hdr.nused, -1);

I hope so because I assumed there simply wasn't a patch for 2.6.16 and
applied this 'best guess' to my servers and rebooted/remounted successfully.

David


--