Re: [PATCH 2/2] dm-raid1: don't fail the mirror for invalid I/O errors

[Keith Busch <kbusch@kernel.org>]

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/20260624170905.3972095-1-kbusch@meta.com/

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.
 
> 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.