[Cluster-devel] [PATCH 0 of 5]Bz #248176: GFS2: invalid metadata block, gfs2_meta_indirect_buffer
Steven Whitehouse
swhiteho at redhat.com
Tue Jul 24 13:21:52 UTC 2007
Hi,
None of these patches apply due to whitespace breakage.
On Tue, 2007-07-24 at 00:07 -0500, Bob Peterson wrote:
> Here is a set of five patches designed to fix the "invalid metadata
> block" and hang problems encountered when running the revolver test.
>
> In order, the five patches are:
>
> 1. There were still some critical variables being manipulated outside
> the log_lock spinlock. That usually resulted in more hangs.
The BUG_ON(!buffer_mapped()) line in this patch can be removed as its
only debugging.
> 2. The list_move code previously concocted in log.c for bug #238162
> (see https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=238162#c23)
> seems to be causing a problem. That section was reverted. HOWEVER,
> I need to rerun the test cases listed in that bug to make sure
> removing it doesn't cause anything to break. I haven't had time yet.
Moving the assignment head = &sdp->sd_ail1_list; doesn't give us
anything since head is a pointer and will be constant whether we have
the lock or not.
> 3. The try_rgrp_unlink code in rgrp.c had an infinite loop. This was
> caused because the bitmap function rgblk_search can return a block
> less than the "goal" block, in which case it was looping. The fix is
> to make it always march forward as needed.
Ok.
> 4. There was metadata corruption caused because the clone bitmaps weren't
> being kept in synch with the regular bitmaps in some cases.
> Code was added to keep them in synch.
I need to look at this in more detail. You might be right, but its worth
being rather careful in this part of the code.
> 5. Metadata corruption was occurring because page references weren't
> being removed in all cases. I previously added a function called
> detach_bufdata, but I discovered there already WAS a function out
> there to do the job. It's called gfs2_meta_cache_flush. So I added
> a call to that to remove the page references.
> Recently I had been thinking that this was entirely unnecessary, but
> when I removed the code, the metadata corruption problem returned
> immediately. It might be that there is a timing window where the
> pages can be referenced before gfs2_meta_cache_flush is called and
> my patch cleans them up sooner.
Yes, this looks good,
Steve.
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