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Date: Fri, 10 May 2024 06:44:29 +0800
From: Kuan-Wei Chiu <visitorckw@gmail.com>
To: Kent Overstreet <kent.overstreet@linux.dev>, Coly Li <colyli@suse.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>, Jens Axboe <axboe@kernel.dk>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Next Mailing List <linux-next@vger.kernel.org>,
	Matthew Mirvish <matthew@mm12.xyz>
Subject: Re: linux-next: manual merge of the refactor-heap tree with the
 block tree
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References: <20240509152745.08af752f@canb.auug.org.au>
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On Thu, May 09, 2024 at 03:58:57PM -0400, Kent Overstreet wrote:
> On Thu, May 09, 2024 at 03:27:45PM +1000, Stephen Rothwell wrote:
> > Hi all,
> > 
> > Today's linux-next merge of the refactor-heap tree got conflicts in:
> > 
> >   drivers/md/bcache/bset.c
> >   drivers/md/bcache/bset.h
> >   drivers/md/bcache/btree.c
> >   drivers/md/bcache/writeback.c
> > 
> > between commit:
> > 
> >   3a861560ccb3 ("bcache: fix variable length array abuse in btree_iter")
> > 
> > from the block tree and commit:
> > 
> >   afa5721abaaa ("bcache: Remove heap-related macros and switch to generic min_heap")
> > 
> > from the refactor-heap tree.
> > 
> > Ok, these conflicts are too extensive, so I am dropping the refactor-heap
> > tree for today.  I suggest you all get together and sort something out.
> 
> Coli and Kuan, you guys will need to get this sorted out quick if we
> want refactor-heap to make the merge window

Hi Coli and Kent,

If I understand correctly, the reported bug is because we attempted to
point (heap)->data to a dynamically allocated memory , but at that time
(heap)->data was not a regular pointer but a fixed size array with a
length of MAX_BSETS.

In my refactor heap patch series, I introduced a preallocated array and
decided in min_heap_init() whether the data pointer should point to an
incoming pointer or to the preallocated array. Therefore, I am
wondering if my patch might have unintentionally fixed this bug?

I am unsure how to reproduce the reported issue. Could you assist me in
verifying whether my assumption is correct?

Regards,
Kuan-Wei