kernelcrash during root filesystem recovery

[utz lehmann <xfs@xxxxxxxxxx>]

hi

i found a bug in yesterdays (2000-11-29) kernel (the test11 one).

i had powered off my computer without a clean shutdown. i do this very
often, no problems since month with xfs.

the kernel traped into kdb while recovering the xfs root filesystem. i write
the messages down from the screen, maybe there are typos:


XFS: WARNING: recovery required on readonly filesystem.

XFS: write access will be enabled recovery.

Staring XFS recovery on filesystem: ide0 (3,6) (dev:3/6)
Unable to handle kernel NULL pointer dereference at virtual address 00000008
 printing eip:
c016482b
*pde = 00000000

Entering kdb (currect=0xc125c000, pid1) Panic: Oops
due to panic @ 0xc016482b
eax = 0x00000000 ebx = 0xc12c3460 ecx = 0xc12c3460 edx = 0x00000000
esi = 0xc12c0e60 edi = 0x00000000 esp = 0xc125d940 eip = 0xc016482b
ebp = 0x00000000 xss = 0x00000018 xcs = 0x00000010 eflags = 0x00010246
xds = 0x00000018 xes = 0x00000018 origeax = 0xffffffff &regs = 0xc125d90c


i rebooted the machine with the same result.
rebooting with a kernel from 2000-11-14 works with no problems.

i made some tests with the buggy kernel:

clean shutdown works.
hardreset after "sync" works.
hardreset after booting without sync works.
hardreset during booting works.
hardreset during writing (cp -av /usr/src/linux /tmp) triggers the bug.
4 times it traped into kdb, 1 time the kernel hangs.

booting with the older kernel always works.

my system:
K6-500, 128MB
xfs root filesystem on a ide disk.


hope that helps.


utz