From nobody Fri Oct 24 10:12:30 2025 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4ctJcJ5B3yz6F2hL; Fri, 24 Oct 2025 10:12:32 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: from phk.freebsd.dk (phk.freebsd.dk [130.225.244.222]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4ctJcJ2qz1z3fG3; Fri, 24 Oct 2025 10:12:32 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Authentication-Results: mx1.freebsd.org; none Received: from critter.freebsd.dk (unknown [192.168.55.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by phk.freebsd.dk (Postfix) with ESMTPS id B3C19C3F3D; Fri, 24 Oct 2025 10:12:30 +0000 (UTC) Received: (from phk@localhost) by critter.freebsd.dk (8.18.1/8.16.1/Submit) id 59OACUDA002781; Fri, 24 Oct 2025 10:12:30 GMT (envelope-from phk) Message-Id: <202510241012.59OACUDA002781@critter.freebsd.dk> To: Konstantin Belousov cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 2612f1b8649b - main - deadfs: Return ENXIO instead of EIO when the device is gone. In-reply-to: From: "Poul-Henning Kamp" References: <202510240741.59O7fBAe041995@gitrepo.freebsd.org> List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2779.1761300750.1@critter.freebsd.dk> Date: Fri, 24 Oct 2025 10:12:30 +0000 X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:1835, ipnet:130.225.0.0/16, country:EU] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Queue-Id: 4ctJcJ2qz1z3fG3 -------- Konstantin Belousov writes: > On Fri, Oct 24, 2025 at 07:41:11AM +0000, Poul-Henning Kamp wrote: > > Something changed recently, and while testing this fix, I noticed > Nothing changed WRT code, it is just a race that causes the behavior. That is why I wrote "something", because I agree that it is not code in our tree which has changed. > > that drm-kmod-66/i915kms may be the condition which trigger > > the different code-path. It worries me if loading drm-kmod-66/i915kms can cause this kind of change of behaviour. Even with the fix, I see 2-4 read(2) operations return EIO before the ENXIO manifests. The only hypothesis I have, is that something in DRM-world hogs some kind of HW resource, but I do not have time (nor drm-skillz) to look into that this morning, and I wanted to get the ENXIO fix in for RELENG-15 purposes[1]. I'm also seeing two other "hmm, that's odd" things on -current these days, but they are very specialized so I do not think they should hold up 15: A) When using a GreazeWeazle USB device, the USB connection will get stuck. B) When using a Professional Canon document scanner, the USB connection will get stuck even before the first page is been received. When I next get a chance, I am going to retry both of those scenarios without loading drm-kmod-66/i915kms, to see if makes any difference. Poul-Henning [1]: As I remarked to re@: Measured in years, that is probably the oldest bug I have ever fixed in FreeBSD: According to dds' amazing UNIX history it goes back to 4.4BSD, which means it's probably John Heidemann's mistake. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.