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

[Keith Busch]

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?