Date: Thu, 7 May 2015 07:47:27 +0100 From: Doug Rabson <dfr@rabson.org> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: freebsd current <freebsd-current@freebsd.org>, =?UTF-8?Q?Edward_Tomasz_Napiera=C5=82a?= <trasz@freebsd.org>, David.Boyd49@twc.com Subject: Re: nmount, mountd drops high order MNT_xx flags during a mount update Message-ID: <CACA0VUj=ZEK3PCxaaus_ZjmSMdCXJ=67ppc_HjY53D8LH2JZmg@mail.gmail.com> In-Reply-To: <1588878108.33116674.1430961004678.JavaMail.root@uoguelph.ca> References: <1588878108.33116674.1430961004678.JavaMail.root@uoguelph.ca>
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You could add a single integer-valued vfsopt which holds the high-order bits of f_flags? On 7 May 2015 at 02:10, Rick Macklem <rmacklem@uoguelph.ca> 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" >
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