On Thu, Mar 26, 2020 at 7:53 AM Christoph Hellwig [off-list ref] wrote:

On Tue, Mar 17, 2020 at 05:51:06PM +0100, Andrzej Pietrasiewicz wrote:

quoted

From: Evan Green <redacted>

Properly plumb out EOPNOTSUPP from loop driver operations, which may
get returned when for instance a discard operation is attempted but not
supported by the underlying block device. Before this change, everything
was reported in the log as an I/O error, which is scary and not
helpful in debugging.

This really should be using errno_to_blk_status.

I had that here in v7:
https://lore.kernel.org/lkml/20191114235008.185111-1-evgreen@chromium.org/ (local)