Re: [PATCH 2/4] fs: return writeback errors for IOCB_DONTCACHE in generic_write_sync

Christoph Hellwig
2025-10-29T16:37:12Z

On Wed, Oct 29, 2025 at 09:01:01AM -0700, Darrick J. Wong wrote:
> Hum. So we kick writeback but don't wait for any of it to start, and
> immediately sample wberr. Does that mean that in the "bdev died" case,
> the newly initiated writeback will have failed so quickly that
> file_check_and_advance_wb_err will see that?

Yes, this is primarily about catching errors in the submission path
before it reaches the device, which are returned synchronously.

> Or are we only reflecting
> past write failures back to userspace on the *second* write after the
> device dies?
>
> It would be helpful to know which fstests break, btw.

generic/252 generic/329 xfs/237