Re: git: 2612f1b8649b - main - deadfs: Return ENXIO instead of EIO when the device is gone.

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Konstantin Belousov writes:

> On Fri, Oct 24, 2025 at 10:12:30AM +0000, Poul-Henning Kamp wrote:

> I do not think that DRM really affects the code path for io.

100% agreement.

But it can change the order of thread/interrupt/event-handling
scheduling.

When I tested the ENXIO patch, I started booting an unmodified
kernel in single-user and immediately got ENXIO when I pulled
the USB stick - quite to my surprise.

Then I kldloaded i915kms, still in single-user, and now I got
the observed bad EIO behaviour.

With a fixed kernel and i915kms loaded, I saw four or five reads
return EIO before one got ENXIO and terminated recoverdisk.

Getting a handful of EIO's before the ENXIO finally appears
strongly suggests that some of the eventhandling related to
the disappearing USB stick is being held up by something.

As soon as I can, I'll try to gather more data.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.