Date: Fri, 21 Jun 2013 14:37:04 GMT From: Hugo Silva <hugo@barafranca.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/179814: mountroot fails with error=19 under Xen on 9-STABLE Message-ID: <201306211437.r5LEb4Uo043458@oldred.freebsd.org> Resent-Message-ID: <201306211440.r5LEe0hY039556@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 179814
>Category: kern
>Synopsis: mountroot fails with error=19 under Xen on 9-STABLE
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Jun 21 14:40:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator: Hugo Silva
>Release: 9.1-STABLE
>Organization:
>Environment:
>Description:
Somewhere between r250634 and now there appears to have been a change that prevents a HVM+PV domU from mounting root:
xn0: <Virtual Network Interface> at device/vif/0 on xenbusb_front0
xn0: Ethernet address: 00:16:3e:b4:bf:05
xenbusb_back0: <Xen Backend Devices> on xenstore0
xctrl0: <Xen Control Device> on xenstore0
xbd0: 32768MB <Virtual Block Device> at device/vbd/768 on xenbusb_front0
xbd0: attaching as ada0
xbd1: 2048MB <Virtual Block Device> at device/vbd/832 on xenbusb_front0
xbd1: attaching as ada1
xbd2: 49152MB <Virtual Block Device> at device/vbd/5632 on xenbusb_front0
xbd2: attaching as ada2
xn0: backend features:
SMP: AP CPU #1 Launched!
Trying to mount root from ufs:/dev/ad0p2 [rw,noatime]...
mountroot: waiting for device /dev/ad0p2 ...
Mounting from ufs:/dev/ad0p2 failed with error 19.
Loader variables:
vfs.root.mountfrom=ufs:/dev/ad0p2
vfs.root.mountfrom.options=rw,noatime
Manual root filesystem specification:
<fstype>:<device> [options]
Mount <device> using filesystem <fstype>
and with the specified (optional) option list.
eg. ufs:/dev/da0s1a
zfs:tank
cd9660:/dev/acd0 ro
(which is equivalent to: mount -t cd9660 -o ro /dev/acd0 /)
? List valid disk boot devices
. Yield 1 second (for background tasks)
<empty line> Abort manual input
mountroot>
I ran into this issue when updating the kernel+userland to mitigate against the new mmap exploit.
Reverting to the old (r250634) kernel makes the problem go away.
I tried to compile XENHVM instead of my custom HVMPV kernel just to rule out some custom option being the culprit, however unlikely in this scenario. The same thing happened (mountroot prompt)
Somehow, this seems to be a xen specific problem, as a physical server was also updated to the same revision that caused the mountroot problem on the virtual machine, and it booted without problems.
For the time being we're running with a patched r250634 kernel.
>How-To-Repeat:
Update your HVM+PV VM to today's -STABLE and reboot.
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201306211437.r5LEb4Uo043458>