Date: Fri, 16 Nov 2007 10:54:21 -0700 From: Scott Long <scottl@samsco.org> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: cvs-src@FreeBSD.ORG, src-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG, =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@deepcore.dk>, Nate Lawson <nate@root.org> Subject: Re: cvs commit: src/sys/dev/ata atapi-cd.c atapi-cd.h Message-ID: <473DD94D.8050605@samsco.org> In-Reply-To: <29576.1195233852@critter.freebsd.dk>
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Poul-Henning Kamp wrote: > In message <473DCF61.6010107@samsco.org>, Scott Long writes: > >>> What I've sortof talked phk into is that if I return the "right" error >>> code in the "start" function, it will back off and not retry nor chatter. >>> We still need the "access" function to return OK if HW present or we >>> cannot send ioctl calls to an empty drive. >>> >> IMHO, overloading g_start just adds more cruft to the problem. > > The fundamental problem is that the CDROM ioctls don't distinguish > between drive and media. > > In a nutshell: we are forced to let the open succeed, so the ioctl > to close the tray can be issued, before we can get at the media. > > The problem with letting the open (aka g_access) succeed, is that > the GEOM tasting starts. > > Redefining the ioctls is not a realistic option at this point, so > the task is to find a workaround for the API-deficiency. > > What sos@ and I talked about is that we need to have an error return > that says "The drive is here, but there is no media", to fail the > tasting without GEOM reporting I/O errors on the console. > > The simplest way to do this, is probably to overload ENOENT or some > other currently undefined errno for this effect. > But then why not have g_access be able to communicate the ability to access the device independent from the ability to access the media? Seems like both of these questions are "access" questions. Scotthome | help
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