5.2-BETA panic: page fault

[Don Lewis]

Can you reproduce this problem without bktr?

> #6  0xc06743d8 in calltrap () at {standard input}:94
> #7  0xc0505b53 in _mtx_lock_flags (m=0x0, opts=0, 
>     file=0xc06bfc1d "/usr/src/sys/kern/kern_lock.c", line=228)
>     at /usr/src/sys/kern/kern_mutex.c:214
> #8  0xc0502b54 in lockmgr (lkp=0xc3b2e028, flags=0, interlkp=0xe4, 
>     td=0xc06bfc1d) at /usr/src/sys/kern/kern_lock.c:228
> #9  0xc0566d87 in vfs_busy (mp=0x0, flags=16, interlkp=0xc075d0e0,
> td=0x0)
>     at /usr/src/sys/kern/vfs_subr.c:527
> #10 0xc056cfff in sync (td=0xc0730dc0, uap=0x0)

> #16 0xc06743d8 in calltrap () at {standard input}:94
> #17 0xc0505b53 in _mtx_lock_flags (m=0x0, opts=0, 
>     file=0xc06bfc1d "/usr/src/sys/kern/kern_lock.c", line=228)
>     at /usr/src/sys/kern/kern_mutex.c:214
> #18 0xc0502b54 in lockmgr (lkp=0xc3b2e028, flags=0, interlkp=0xe4, 
>     td=0xc06bfc1d) at /usr/src/sys/kern/kern_lock.c:228
> #19 0xc0566d87 in vfs_busy (mp=0x0, flags=0, interlkp=0x0, td=0x0)
>     at /usr/src/sys/kern/vfs_subr.c:527
> #20 0xc056374c in lookup (ndp=0xd7f2ec00) at
> /usr/src/sys/kern/vfs_lookup.c:559

You are getting a double panic, with the second happening during the
file system sync.  The code seems to be be tripping over the same mount
list entry each time.  Maybe the mount list is getting corrupted.  Are
you using amd?  Print *lkp in the lockmgr() stack frame.


You might want to add
	KASSERT(mp->mnt_lock.lk_interlock !=NULL, "vfs_busy: NULL mount
        pointer interlock");
at the top of vfs_busy() and right before the lockmgr() call.