From owner-freebsd-current@FreeBSD.ORG Sun May 10 13:03:43 2015 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 21FE0687; Sun, 10 May 2015 13:03:43 +0000 (UTC) Received: from esa-annu.net.uoguelph.ca (esa-annu.mail.uoguelph.ca [131.104.91.36]) by mx1.freebsd.org (Postfix) with ESMTP id B11EC1BA0; Sun, 10 May 2015 13:03:42 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2D/AwBkVk9V/95baINcg2NeBoMYwUUJgU4KhTdOAoFRFAEBAQEBAQGBCoQgAQEBAwEBAQEgBCcgCwUWDgoCAg0ZAikBCSYGCAcEARwEiAMIDbNZknQBAQEBAQEBAQEBAQEBAQEBAQEBGYEhihiEMwEBHDQHgmiBRQWWW4JGgU2DVj6DHIdqIoIGh0cjggkcgW4iMQEBAQEDgQU5gQEBAQE X-IronPort-AV: E=Sophos;i="5.13,401,1427774400"; d="scan'208";a="211910200" Received: from muskoka.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.222]) by esa-annu.net.uoguelph.ca with ESMTP; 10 May 2015 09:03:25 -0400 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id 192A3B3F04; Sun, 10 May 2015 09:03:25 -0400 (EDT) Date: Sun, 10 May 2015 09:03:25 -0400 (EDT) From: Rick Macklem To: Doug Rabson Cc: freebsd current , Edward Tomasz =?utf-8?Q?Napiera=C5=82a?= , David Boyd49 Message-ID: <581797832.35173877.1431263005089.JavaMail.root@uoguelph.ca> In-Reply-To: Subject: Re: nmount, mountd drops high order MNT_xx flags during a mount update MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.95.11] X-Mailer: Zimbra 7.2.6_GA_2926 (ZimbraWebClient - FF3.0 (Win)/7.2.6_GA_2926) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 May 2015 13:03:43 -0000 Doug Rabson wrote: > You could add a single integer-valued vfsopt which holds the > high-order > bits of f_flags? > I have created a patch that does this. It is on https://reviews.freebsd.org/D2506 (I have also attached it here, for those who don't use Phabricator.) Please review/comment on this. (Feel free to add yourself as a reviewer, etc.) Also, David, if you can test this patch, it would be appreciated. Thanks for the suggestion Doug, rick > On 7 May 2015 at 02:10, Rick Macklem wrote: > > > David Boyd reported a problem to freebsd-current@ w.r.t. the > > MNT_AUTOMOUNTED > > flag getting cleared by mountd. > > http://docs.FreeBSD.org/cgi/mid.cgi?1429477202.29812.38.camel > > I just took a look at this and it's kinda ugly... > > > > mountd acquires a list of mounts via getmntinfo() and then does an > > nmount() for each of them to get rid of any exports. It uses > > f_flags from the statfs returned by getmntinfo() as the 3rd > > argument to nmount(). > > --> Since nmount()s 3rd argument is a "int", it silently drops any > > MNT_xx flag in the high order 32bits of f_flags. At this time, > > it happens that MNT_AUTOMOUNTED is the only one, but... > > > > I can think of a couple of ways to fix this, but I don't like any > > of > > them;-) > > > > 1) I suppose mountd could check for each flag set in f_flags and > > generate > > a vfsopts string for it, but that means that every time a new flag > > that > > can be updated is added to MNT_xx, this mountd.c code would have to > > updated. > > --> Ugly!! > > > > 2) Require that all flags in MNT_UPDATEMASK be in the low order > > 32bits. > > I wouldn`t mind this except in means that the MNT_xx flags must > > be > > redefined > > and I don`t think that could get MFC`d. > > > > 3) Add a new newernmount(2) which has a 64bit flags argument > > instead of > > int. > > > > Hopefully someone can think of a nice way to fix this, rick > > _______________________________________________ > > freebsd-current@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-current > > To unsubscribe, send any mail to > > "freebsd-current-unsubscribe@freebsd.org" > > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to > "freebsd-current-unsubscribe@freebsd.org" >