Re: [PATCH 0/3] Transient errors in Direct I/O

[ Please cc the XFS list on XFS and iomap infrastructure changes.]

On Fri, Jun 05, 2020 at 03:48:35PM -0500, Goldwyn Rodrigues wrote:

In current scenarios, for XFS, it would mean that a page invalidation
would end up being a writeback error. So, if iomap returns zero, fall
back to biffered I/O. XFS has never supported fallback to buffered I/O.
I hope it is not "never will" ;)

I wouldn't say "never", but we are not going to change XFS behaviour
because btrfs has a page invalidation vs DIO bug in it...

If you want to make a specific filesystem fall back to buffered IO
in this case, pass a new flag into iomap_dio_rw() to conditionally
abort the DIO on invalidation failure and let filesystem
implementations opt-in to use that flag.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com