[Ocfs2-devel] A patch to fix bug 45 in bugzilla

[Ocfs2-devel] A patch to fix bug 45 in bugzilla

[Sonic Zhang]

Hi,

I think I found the root cause of the bug 45 in the bugzilla.

Actually, it is not an OCFS bug. It is caused in the Linux journaling
routine(JBD) journal_create(). In kernel 2.6.x, buffer_head state
BH_Uptodate is checked in mark_buffer_dirty(), while kernel 2.4.x
doesn't do. If this state doesn't exist in the buffer_head, buffer error
information is reported. But, in routine journal_create(), the state
BH_Uptodate is set after the call to mark_buffer_dirty(). This works 
well in kernel 2.4.x, but fails in kernel 2.6.x.

I attach a patch to fix this bug in kernel 2.6.x. Could you please put it 
into the subfolder "patches" in ocfs2 source tree?

Thank you.

---------------------------------------
--- linux-2.6.1.old/fs/jbd/journal.c	2004-03-18 15:55:47.591428104 +0800
+++ linux-2.6.1/fs/jbd/journal.c	2004-03-18 15:56:25.609648456 +0800
@@ -832,10 +832,10 @@
 		bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
 		lock_buffer(bh);
 		memset (bh->b_data, 0, journal->j_blocksize);
-		BUFFER_TRACE(bh, "marking dirty");
-		mark_buffer_dirty(bh);
 		BUFFER_TRACE(bh, "marking uptodate");
 		set_buffer_uptodate(bh);
+		BUFFER_TRACE(bh, "marking dirty");
+		mark_buffer_dirty(bh);

 		unlock_buffer(bh);
 		__brelse(bh);
 	}

[Ocfs2-devel] A patch to fix bug 45 in bugzilla

[Rusty Lynch]

On Thu, Mar 18, 2004 at 05:29:20PM +0800, Sonic Zhang wrote:
> Hi,
> 
> I think I found the root cause of the bug 45 in the bugzilla.
> 
> Actually, it is not an OCFS bug. It is caused in the Linux journaling
> routine(JBD) journal_create(). In kernel 2.6.x, buffer_head state
> BH_Uptodate is checked in mark_buffer_dirty(), while kernel 2.4.x
> doesn't do. If this state doesn't exist in the buffer_head, buffer error
> information is reported. But, in routine journal_create(), the state
> BH_Uptodate is set after the call to mark_buffer_dirty(). This works 
> well in kernel 2.4.x, but fails in kernel 2.6.x.

If this is jbd bug, then how come ext3 doesn't trigger buffer_error()?

> 
> I attach a patch to fix this bug in kernel 2.6.x. Could you please put it 
> into the subfolder "patches" in ocfs2 source tree?
> 
> Thank you.
> 
> ---------------------------------------
> --- linux-2.6.1.old/fs/jbd/journal.c	2004-03-18 15:55:47.591428104 +0800
> +++ linux-2.6.1/fs/jbd/journal.c	2004-03-18 15:56:25.609648456 +0800
> @@ -832,10 +832,10 @@
> 		bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
> 		lock_buffer(bh);
> 		memset (bh->b_data, 0, journal->j_blocksize);
> -		BUFFER_TRACE(bh, "marking dirty");
> -		mark_buffer_dirty(bh);
> 		BUFFER_TRACE(bh, "marking uptodate");
> 		set_buffer_uptodate(bh);
> +		BUFFER_TRACE(bh, "marking dirty");
> +		mark_buffer_dirty(bh);
> 
> 		unlock_buffer(bh);
> 		__brelse(bh);
> 	}
> 
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel@oss.oracle.com
> http://oss.oracle.com/mailman/listinfo/ocfs2-devel

[Ocfs2-devel] A patch to fix bug 45 in bugzilla

[Mark Fasheh]

On Thu, Mar 18, 2004 at 07:10:45AM -0800, Rusty Lynch wrote:
> If this is jbd bug, then how come ext3 doesn't trigger buffer_error()?
Ext3 almost never uses journal_create. They have their mkfs make the
journals for them. (journal_create is used to format a new journal)
	--Mark

--
Mark Fasheh
Software Developer, Oracle Corp
mark.fasheh@oracle.com

[Ocfs2-devel] A patch to fix bug 45 in bugzilla

[Mark Fasheh]

On Thu, Mar 18, 2004 at 05:29:20PM +0800, Sonic Zhang wrote:
> Hi,
> 
> I think I found the root cause of the bug 45 in the bugzilla.
> 
> Actually, it is not an OCFS bug. It is caused in the Linux journaling
> routine(JBD) journal_create(). In kernel 2.6.x, buffer_head state
> BH_Uptodate is checked in mark_buffer_dirty(), while kernel 2.4.x
> doesn't do. If this state doesn't exist in the buffer_head, buffer error
> information is reported. But, in routine journal_create(), the state
> BH_Uptodate is set after the call to mark_buffer_dirty(). This works 
> well in kernel 2.4.x, but fails in kernel 2.6.x.
> 
> I attach a patch to fix this bug in kernel 2.6.x. Could you please put it 
> into the subfolder "patches" in ocfs2 source tree?
Cool! For some reason, this doesn't seem to patch against my 2.6.4 tree.
Would you mind regenerating it against a more recent 2.6 kernel? Also, you
should forward it to Stephen Tweedie (sct@redhat.com), the JBD maintainer.
	--Mark

--
Mark Fasheh
Software Developer, Oracle Corp
mark.fasheh@oracle.com