Date: Fri, 24 Oct 2025 09:12:18 -0400 From: Warner Losh <imp@bsdimp.com> To: Konstantin Belousov <kostikbel@gmail.com> Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, src-committers <src-committers@freebsd.org>, "<dev-commits-src-all@freebsd.org>" <dev-commits-src-all@freebsd.org>, "<dev-commits-src-main@freebsd.org>" <dev-commits-src-main@freebsd.org> Subject: Re: git: 2612f1b8649b - main - deadfs: Return ENXIO instead of EIO when the device is gone. Message-ID: <CANCZdfrCa7PXtXEPU-O5Lgn3CkY86u-%2BP=pxVz%2BszAVxij9Hgw@mail.gmail.com> In-Reply-To: <aPtnt9siqT5R_32l@kib.kiev.ua> References: <202510240741.59O7fBAe041995@gitrepo.freebsd.org> <aPs27Dc_w10t3ENH@kib.kiev.ua> <202510241012.59OACUDA002781@critter.freebsd.dk> <aPtWo1UP-UpPdsVf@kib.kiev.ua> <202510241116.59OBG1ii003074@critter.freebsd.dk> <aPtnt9siqT5R_32l@kib.kiev.ua>
index | next in thread | previous in thread | raw e-mail
[-- Attachment #1 --] On Fri, Oct 24, 2025, 7:49 AM Konstantin Belousov <kostikbel@gmail.com> wrote: > On Fri, Oct 24, 2025 at 11:16:01AM +0000, Poul-Henning Kamp wrote: > > -------- > > 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. > > It might make sense to annotate CAM EIOs with EXTERROR(). > But then, we probably need to add something to copy that > extended data between threads and possibly extend struct buf/bio > witg the place for exterror data besides b_error. > Given the contexts cam runs in, managing the storage for that can be hard. Warner > [-- Attachment #2 --] <div dir="auto"><div><br><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Fri, Oct 24, 2025, 7:49 AM Konstantin Belousov <<a href="mailto:kostikbel@gmail.com">kostikbel@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Fri, Oct 24, 2025 at 11:16:01AM +0000, Poul-Henning Kamp wrote:<br> > --------<br> > Konstantin Belousov writes:<br> > <br> > > On Fri, Oct 24, 2025 at 10:12:30AM +0000, Poul-Henning Kamp wrote:<br> > <br> > > I do not think that DRM really affects the code path for io.<br> > <br> > 100% agreement.<br> > <br> > But it can change the order of thread/interrupt/event-handling<br> > scheduling.<br> > <br> > When I tested the ENXIO patch, I started booting an unmodified<br> > kernel in single-user and immediately got ENXIO when I pulled<br> > the USB stick - quite to my surprise.<br> > <br> > Then I kldloaded i915kms, still in single-user, and now I got<br> > the observed bad EIO behaviour.<br> > <br> > With a fixed kernel and i915kms loaded, I saw four or five reads<br> > return EIO before one got ENXIO and terminated recoverdisk.<br> > <br> > Getting a handful of EIO's before the ENXIO finally appears<br> > strongly suggests that some of the eventhandling related to<br> > the disappearing USB stick is being held up by something.<br> > <br> > As soon as I can, I'll try to gather more data.<br> <br> It might make sense to annotate CAM EIOs with EXTERROR().<br> But then, we probably need to add something to copy that<br> extended data between threads and possibly extend struct buf/bio<br> witg the place for exterror data besides b_error.<br></blockquote></div></div><div dir="auto"><br></div><div dir="auto">Given the contexts cam runs in, managing the storage for that can be hard.</div><div dir="auto"><br></div><div dir="auto">Warner</div><div dir="auto"><div class="gmail_quote gmail_quote_container"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> </blockquote></div></div></div>home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CANCZdfrCa7PXtXEPU-O5Lgn3CkY86u-%2BP=pxVz%2BszAVxij9Hgw>