Re: [PATCH v4 3/7] md/raid10: consistently fail atomic writes that require splitting

From: John Garry

Date: Wed Jul 15 2026 - 06:50:04 EST


On 15/07/2026 11:05, Abd-Alrhman Masalkhi wrote:
On Wed, Jul 15, 2026 at 10:25 +0100, John Garry wrote:
On 10/07/2026 11:15, Abd-Alrhman Masalkhi wrote:
RAID10 currently handles one badblock path explicitly by failing atomic
writes with EIO. However, another badblock path can also reduce the
writable range and force the bio through bio_submit_split_bioset(),

What is this other badblock path which you are referring to?

The other path is when the requested write overlaps a bad-block region
from the beginning, but the intended write extends beyond the bad-block
region. In that case, the current code silently reduces max_sectors.
As a result, we end up calling bio_submit_split_bioset(), which
completes the bio with -EINVAL rather than -EIO. This is the same issue
that existed in raid1 and was fixed by patch 2.

OK, it would be nice to add a concise version of that info to the commit log.

Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>