From owner-freebsd-stable@FreeBSD.ORG Fri Aug 17 20:02:40 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C170416A417 for ; Fri, 17 Aug 2007 20:02:40 +0000 (UTC) (envelope-from fbsdlists@gmail.com) Received: from nz-out-0506.google.com (nz-out-0506.google.com [64.233.162.236]) by mx1.freebsd.org (Postfix) with ESMTP id 7B5CB13C4A6 for ; Fri, 17 Aug 2007 20:02:40 +0000 (UTC) (envelope-from fbsdlists@gmail.com) Received: by nz-out-0506.google.com with SMTP id l8so290629nzf for ; Fri, 17 Aug 2007 13:02:39 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=gk2hO5ARbyzBfqsdv+WSj5nZ7J1KK4bZTj2Dg6XReE61WJox9Z5iP6QhLfRh9olWYKzZSEssa7mJmoL2wJou1eeZDSgHncAqkHaVRqJ5pKqlddF7blg9tjF2gKO7SWgFx7fq5swGXC54wx+7lBZNFV3wvICrcxfBVhV0vTPrMK8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=H2OxlVJtgyC2UikuebJcpJbl8QKKkZF/sKg+cCJgkWHp1f8mutCD0Lg3QNF6OK3Fjw2bVTIwcGgLK3uk/FXyMxwLz03KK+OeK9s+tUwG6MLNv8IPNiqNI63Vw+5YiAvpAI/lHsyaGtJ1qdbYigqWVUH7+HaatYOEZe4f0E3Arxs= Received: by 10.142.237.20 with SMTP id k20mr206466wfh.1187379416401; Fri, 17 Aug 2007 12:36:56 -0700 (PDT) Received: by 10.142.80.8 with HTTP; Fri, 17 Aug 2007 12:36:54 -0700 (PDT) Message-ID: <54db43990708171236x4366f78av6fb76eca1fee6688@mail.gmail.com> Date: Fri, 17 Aug 2007 15:36:54 -0400 From: "Bob Johnson" To: "Svein Halvor Halvorsen" In-Reply-To: <46C552C7.70101@lvor.halvorsen.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200708161437.l7GEb2KV006533@lurza.secnetix.de> <46C552C7.70101@lvor.halvorsen.cc> Cc: freebsd-stable@freebsd.org Subject: Re: panic after removing usb flash disk X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Aug 2007 20:02:40 -0000 On 8/17/07, Svein Halvor Halvorsen wrote: > Oliver Fromme wrote: > > Roman Bogorodskiy wrote: > > > Artem Kuchin wrote: > > > > [FreeBSD crashes when a mounted device disappears] > > > > > > It's not a bug, it's a feature. > > > > I certainly wouldn't call it a feature. As others have > > noted, it is a known shortcoming in FreeBSD, and fixing > > it is non-trivial. > > Could someone point me in some general direction, as to where I > could learn more about the path a read/write request will take > through all the different kernel layers? I doubt I will be able to > fix anything, but it would be interesting to learn. Aside from the general "RTFS", there are probably two (or three) good places to look: "The Design and Implementation of the FreeBSD Operating System" by McKusick and Neville-Neil, or its predecessor which may be much more affordable, "The Design and Implementation of the 4.4 BSD Operating System" by McKusick, Bostic, Karels, and Quarterman. Chapter 2 of the latter is available at http://www.freebsd.org/doc/en_US.ISO8859-1/books/design-44bsd/book.html . It will give you some hints, but probably not as much detail as you want. And, of course, reading the archived threads on the topic, already referenced by others, will provide a quick education in the issues involved. I think that would be the best place to start. - Bob