Re: [PATCHv6 11/11] iomap: add support for dma aligned direct-io

Keith Busch
2022-06-29T03:52:18Z

On Tue, Jun 28, 2022 at 11:18:34PM -0400, Eric Farman wrote:
> Sort of. In the working case, I see a set of iovecs come through with
> different counts:
>
> base count
> 0000 0001
> 0000 0200
> 0000 0400
> 0000 0800
> 0000 1000
> 0001 1000
> 0200 1000 << Change occurs here
> 0400 1000
> 0800 1000
> 1000 1000
>
> EINVAL was being returned for any of these iovecs except the page-
> aligned ones. Once the x200 request returns 0, the remainder of the
> above list was skipped and the requests continue elsewhere on the file.
>
> Still not sure how our request is getting us into this process. We're
> simply asking to read a single block, but that's somewhere within an
> image file.

I thought this was sounding like some kind of corruption. I tested ext4 on
various qemu devices with 4k logical block sizes, and it all looks okay there.

What block driver are you observing this with?