From owner-freebsd-current Sat Feb 27 4: 5:51 1999 Delivered-To: freebsd-current@freebsd.org Received: from ns1.yes.no (ns1.yes.no [195.204.136.10]) by hub.freebsd.org (Postfix) with ESMTP id 434EC14BE1 for ; Sat, 27 Feb 1999 04:05:47 -0800 (PST) (envelope-from eivind@bitbox.follo.net) Received: from bitbox.follo.net (bitbox.follo.net [195.204.143.218]) by ns1.yes.no (8.9.1a/8.9.1) with ESMTP id NAA28189; Sat, 27 Feb 1999 13:05:27 +0100 (CET) Received: (from eivind@localhost) by bitbox.follo.net (8.8.8/8.8.6) id NAA35911; Sat, 27 Feb 1999 13:05:26 +0100 (MET) Date: Sat, 27 Feb 1999 13:05:26 +0100 From: Eivind Eklund To: Luigi Rizzo Cc: Tony Finch , current@FreeBSD.ORG Subject: Re: mount -o union broken recently? Message-ID: <19990227130525.L19632@bitbox.follo.net> References: <199902262016.VAA26475@labinfo.iet.unipi.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.95.1i In-Reply-To: <199902262016.VAA26475@labinfo.iet.unipi.it>; from Luigi Rizzo on Fri, Feb 26, 1999 at 09:16:44PM +0100 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, Feb 26, 1999 at 09:16:44PM +0100, Luigi Rizzo wrote: > (about union mounts on 3.1 not returning all files with an 'ls' in 3.1 > while it did in 3.0) > > > Is it sorrect that this magic is implemented in sys/kern/vfs_lookup.c? > > The odd thing is that AFAICS no-one has made significant changes to > > this code. > > i just experienced the above today while trying diskless, and while ls > only seems to return the entries for the topmost directory, files are > accessible if you know the name. no idea if this is of any help. > > on a related subject; i noticed that using mount_null on a directory > with device entries (e.g. still in the diskless case, say /foo/dev is > an mfs partition with device entries, and i do a mount_null /foo/dev > /dev ) causes very bad effects such as crashing the system when i > start X. ideas about this as well ? Yes. NULLFS mounts do not work, due to a combination of aliasing problems and locking problems. There is a preliminary patch at http://www.freebsd.org/~eivind/FixNULL.patch that I believe fix the aliasing problems, and some of the locking problems, but not all. Using nullfs with this works somewhat, but sometimes get locks screwed up (which result in access to one file just hanging). Eivind. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message