On Mon, Jul 06, 2026 at 02:52:33PM -0600, Keith Busch wrote:
> On Wed, Jun 24, 2026 at 01:14:03PM +0200, Mikulas Patocka wrote:
> > This approach is OK, I will stage the patches when 7.2-rc1 comes out and
> > when I'll fork the dm git branches.
> >
> > I suggest one change - it is kind of hacky when multiple I/O completion
> > callbacks write into io->orig_bio->bi_status concurrently - so it would be
> > better to not do it and maintain and return separate bit mask for
> > non-retryable errors.
> >
> > For example:
> >
> > static void complete_io(struct io *io)
> > {
> > unsigned long error_bits = io->error_bits;
> > unsigned long nonretryable_error_bits = io->nonretryable_error_bits;
> > io_notify_fn fn = io->callback;
> > void *context = io->context;
> >
> > if (io->vma_invalidate_size)
> > invalidate_kernel_vmap_range(io->vma_invalidate_address,
> > io->vma_invalidate_size);
> >
> > mempool_free(io, &io->client->pool);
> > fn(error_bits, nonretryable_error_bits, context);
> > }
> >
> > static void dec_count(struct io *io, unsigned int region, blk_status_t
> > error)
> > {
> > if (unlikely(error == BLK_STS_NOTSUPP) || unlikely(error ==
> > BLK_STS_INVAL))
> > set_bit(region, &io->nonretryable_error_bits);
> > else if (unlikely(error != BLK_STS_OK))
> > set_bit(region, &io->error_bits);
> >
> > if (atomic_dec_and_test(&io->count))
> > complete_io(io);
> > }
> >
> > Please send the updated patch that uses this approach.
>
> Sure thing, I can get started on that. Though I think it's largely
> obviated if we get the block layer to handle things early rather than
> submit malformed bio's, and this will accomplish that:
>
> https://lore.kernel.org/dm-devel/[email protected]/
Jens hasn't picked that series up yet. Jens?
> But I can certainly respin this series as it provides a more indepth
> defence.
>
> I also owe an update on the relaxed dm-crypt direct-io memory alignment
> as well, as that series fell through the cracks on me for the previous
> merge window.
So where does dm-raid1 and dm-crypt stand relative to these DIO memory
alignment changes? Inferring they are pretty exposed.
> > BTW. I think that blk_path_error should also test for BLK_STS_INVAL and
> > return false, otherwise, dm-multipath would be suffering from this bug
> > too. Ben, could you test it?
>
> Good point.
Would appreciate knowing if multipath exposed too.
Thanks,
Mike
