From owner-freebsd-stable@FreeBSD.ORG Thu Jul 19 16:39:16 2007 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6006E16A400 for ; Thu, 19 Jul 2007 16:39:16 +0000 (UTC) (envelope-from josh@tcbug.org) Received: from conn-smtp.mc.mpls.visi.com (conn.mc.mpls.visi.com [208.42.156.2]) by mx1.freebsd.org (Postfix) with ESMTP id 2ED0113C4A5 for ; Thu, 19 Jul 2007 16:39:16 +0000 (UTC) (envelope-from josh@tcbug.org) Received: from mail.tcbug.org (mail.tcbug.org [208.42.70.163]) by conn-smtp.mc.mpls.visi.com (Postfix) with ESMTP id 4069F8179; Thu, 19 Jul 2007 11:39:15 -0500 (CDT) Received: from [192.168.1.5] (unknown [192.168.2.1]) by mail.tcbug.org (Postfix) with ESMTP id B571D341C0C; Thu, 19 Jul 2007 11:39:14 -0500 (CDT) From: Josh Paetzel To: "M. Warner Losh" Date: Thu, 19 Jul 2007 11:39:10 -0500 User-Agent: KMail/1.9.6 References: <200707181541.l6IFf4ht051775@lurza.secnetix.de> <20070718170559.GA11915@eos.sc1.parodius.com> <20070719.084821.-202614780.imp@bsdimp.com> In-Reply-To: <20070719.084821.-202614780.imp@bsdimp.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4576160.1lHOmQfbd2"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200707191139.14063.josh@tcbug.org> Cc: LoN_Kamikaze@gmx.de, koitsu@freebsd.org, freebsd-stable@freebsd.org, idiotbg@gmail.com Subject: Re: removing external usb hdd without unmounting causes reboot? 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: Thu, 19 Jul 2007 16:39:16 -0000 --nextPart4576160.1lHOmQfbd2 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Thursday 19 July 2007, M. Warner Losh wrote: > In message: <20070718170559.GA11915@eos.sc1.parodius.com> > > Jeremy Chadwick writes: > : If someone wants to work on this and needs devices/toys (thumb > : drives, external enclosures + hard disks), let me know, I will be > : more than happy to buy them the hardware needed. > > Willing to fund the work on it too? This is a volunteer project, > and you have to motivate people to work on this. Tirades in > mailing lists has proven to be ineffective in the past. > > I've looked at the issue, and generically, if a device goes away, > it is *HARD* to not panic. The same thing happens if you eject a > CF card in a PC Card adapter in a PC Card slot. > > The best one can do without massive buffer cache work is what > firewire does: it has one attachment to handle all umass devices.=20 > When the device goes away, it pauses all operations to that device. > If the device comes back, it resumes the I/O . If the device > never comes back, then the I/O never finishes. > > Warner > Just curious, but what, if any, is the performance hit with this=20 strategy? I could care less about performance on a usb stick, but if=20 we are talking about changes that are going to affect all filesystems=20 regardless of storage device implimentation then I'm sort of=20 interested. eg: I wouldn't be happy trading filesystem performance for avoiding a=20 panic that is trivial to avoid in the first place. =2D-=20 Thanks, Josh Paetzel --nextPart4576160.1lHOmQfbd2 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQBGn5OyJvkB8SevrssRAsqXAJ98RETmGzxIBmt2SiBB5zt0S3dnSACfXHkp ci5jccivyKEhONXAHppH+4Y= =bgmg -----END PGP SIGNATURE----- --nextPart4576160.1lHOmQfbd2--