Subject: kern/8964: panic on reboot(2) if an LFS is mounted read-only
To: None <gnats-bugs@gnats.netbsd.org>
From: None <itohy@netbsd.org>
List: netbsd-bugs
Date: 12/06/1999 22:48:46
>Number: 8964
>Category: kern
>Synopsis: panic on reboot(2) if an LFS is mounted read-only
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: kern-bug-people (Kernel Bug People)
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Mon Dec 6 22:48:00 1999
>Last-Modified:
>Originator: ITOH Yasufumi
>Organization:
>Release: 1.4P (Dec. 3, 1999)
>Environment:
System: NetBSD 1.4P NetBSD 1.4P (ACHA.elf) #20: Sun Dec 5 14:55:44 JST 1999 itohy@pino.my.domain:/usr/src/sys/arch/x68k/compile/ACHA.elf x68k
no SOFTDEP in the kernel config.
>Description:
The system panic()s on reboot if
1. an LFS is mounted, and
2. the filesystem is read-only.
This problem seems to be introduced by the softdep merge.
>How-To-Repeat:
Mount an LFS in read-only mode and reboot the system.
Here's an example when the root filesystem is an LFS.
# mount
root_device on / type lfs (local, read-only)
# reboot
Dec 6 08:29:42 init: kernel security level changed from 0 to 1
syncing disks... panic: bawrite LFS buffer
Stopped in reboot at cpu_Debugger+0x6: unlk a6
db> trace
cpu_Debugger(2004,1,2710,519c00,54fc54) + 6
panic(116d2c,54fe68,45bd8,54fe60,12abd4) + 56
lfs_bwrite(54fe60,12abd4,519c00,54fe9c,4bd16) + 1c
bawrite(519c00) + 36
vfs_shutdown(54ff3c,300e0,0,0,0) + be
cpu_reboot(0,0,0,530640,1) + 3c
sys_reboot(530640,54ff88,54ff80) + 52
syscall(d0) + 196
trap0() + e
db>
>Fix:
Unknown.
LFS buffers should not be marked asynchronous.
>Audit-Trail:
>Unformatted: