>Number:         9480
>Category:       kern
>Synopsis:       64K block/16K Frag filesystem causes panic at mount time
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Feb 24 12:39:00 2000
>Last-Modified:
>Originator:     
>Organization:
	NASA Ames Research Center
>Release:        Feb 23, 2000
>Environment:
	
System: NetBSD poseur 1.4T NetBSD 1.4T (ALPHA) #0: Wed Feb 23 10:20:39 PST 2000 mjacob@poseur:/usr/src/sys/arch/alpha/compile/ALPHA alpha


>Description:
System panics at mount time with a MMU (bad pointer) fault:


fatal kernel trap:

    trap entry = 0x2 (memory management fault)
    a0         = 0xfffffe00108d0000
    a1         = 0x1
    a2         = 0x0
    pc         = 0xfffffc00004bfd1c
    ra         = 0xfffffc00004459e8
    curproc    = 0xfffffc0006f4e9b8
        pid = 334, comm = mount_ffs

panic: trap
Stopped in mount_ffs at cpu_Debugger+0x4:       ret     zero,(ra)
db> t
cpu_Debugger() at cpu_Debugger+0x4
panic() at panic+0xe4
trap() at trap+0x518
XentMM() at XentMM+0x20
--- memory management fault (from ipl 0) ---
memcpy() at memcpy+0x5c
ffs_mountfs() at ffs_mountfs+0x2c8
ffs_mount() at ffs_mount+0x4ac
sys_mount() at sys_mount+0x53c
syscall() at syscall+0x1c0
XentSys() at XentSys+0x50
--- syscall (21, netbsd.sys_mount) ---
--- user mode ---



>How-To-Repeat:
Compile a kernel with MAXPHYS set to 1024KB and MAXBSIZE set to 64KB.
Create a filesystem on a large CCD (2 x 150GB) with 64KB blocks and
16KB frags:
brunner > root newfs -b 65536 -f 16384 /dev/rccd0c >/tmp/x

Mount it.

brunner > root mount /dev/ccd0c /storage 

Panic.


>Fix:
	
>Audit-Trail:
>Unformatted: