panic: ffs_reallocblk: start == end

[Scott Long]

Kostik Belousov wrote:
> On Thu, Nov 15, 2007 at 11:16:02PM +0100, Kris Kennaway wrote:
>> Kris Kennaway wrote:
>>> I got this panic on an 8 core amd64 running 8.0 when writing to a ufs on 
>>> a md device:
>>>
>>> panic: ffs_reallocblk: start == end
>>>
>>> db> wh
>>> Tracing pid 59911 tid 100115 td 0xffffff0003b90000
>>> kdb_enter() at kdb_enter+0x31
>>> panic() at panic+0x1c0
>>> ffs_reallocblks() at ffs_reallocblks+0xb11
>>> VOP_REALLOCBLKS_APV() at VOP_REALLOCBLKS_APV+0xb9
>>> cluster_write() at cluster_write+0x38a
>>> ffs_write() at ffs_write+0x575
>>> VOP_WRITE_APV() at VOP_WRITE_APV+0x147
>>> vn_write() at vn_write+0x213
>>> dofilewrite() at dofilewrite+0x9a
>>> kern_writev() at kern_writev+0x4f
>>> write() at write+0x4b
>>> syscall() at syscall+0x301
>>> Xfast_syscall() at Xfast_syscall+0xab
>>> --- syscall (4, FreeBSD ELF64, write), rip = 0x800a65d0c, rsp = 
>>> 0x7fffffffd268, rbp = 0x2800 ---
>>>
>>> Kris
>>>
>> Another one of these on a different machine.  Looks like something is 
>> definitely broken.
>>
> Kris,
> this is consequence of the checks moved from DIAGNOSTIC to INVARIANTS
> ifdef for ffs, and actually being compiled as result. Peter Holm reported
> the "ffs_truncate3" panic.

So does this check identify a real problem that needs to be fixed?

Scott