misc/118160: unable to mount / rw while booting 7.0-BETA3

[Yuri]

The following reply was made to PR bin/118160; it has been noted by GNATS.

From: Yuri <yuri at rawbw.com>
To: Bruce Evans <brde at optusnet.com.au>
Cc: Yuri <yuri at tsoft.com>, freebsd-gnats-submit at freebsd.org,
        freebsd-bugs at freebsd.org
Subject: Re: misc/118160: unable to mount / rw while booting 7.0-BETA3
Date: Tue, 27 Nov 2007 19:11:52 -0800

 > > While booting log says:
 > > Starting file system checks:
 > > <here goes the list of file systems that it reports, this is ok>
 > > mount:  : Operation not permitted.
 > 
 > This is probably a secondary problem.  You apparently have the root device
 > mounted on "" or something like that.
 > What does mount shouw for the root device?
 > 
 No, when I get to shell after this failure during the normal boot process
 mount shows:
 /dev/ad12s1c    /   (ufs,local,read-only)
 swapinfo shows that swap volume is /dev/ad12s1b
 
 > > The major bug seems to be in the 'mount' system call. 'man mount' says that
 > EPERM is returned if "The caller is neither the super-user nor the owner of
 > dir." I am root.
 > 
 > You are apparently attempting to mount the same device twice (even though
 > -u specifies an already-mounted device, the kernel is apparently confused
 > about where it is mounted).
 > 
 I thought that mount command is supposed to pick up the locations correctly,
 so that when I say 'mount -uw /' device should be picked up from the already
 mounted list.
 
 Also I found that swapon and mount are related in my case. Once swapon is done
 I can't remount root as r/w. And vice versa, when mount -uw is done swapon
 returns EPERM.
 
 This happens when I boot as single user. When I do swapon consecutive
 'mount -uw ' fails. When I do 'mount -uw' consecutive swapon fails.
 So I don't have swap at all since this command failed during boot.
 
 I guess 'nmount' and 'swapon' system calls are similar and somehow interfere
 with each other.
 
 So I still can't boot normally, only through single user mode and I don't
 have swap at all after this.
 
 Yuri