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]/
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.
