nfs + msdosfs = crashes & panics

[Jeffrey Hsu]

Chris Pressey wrote:

Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x34
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xc01c0009
stack pointer	        = 0x10:0xc927486c
frame pointer	        = 0x10:0xc92748b8
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 456 (nfsd)
current thread          = pri 10 
interrupt mask		= none
panic: from debugger

#0  0xc017937e in dumpsys ()
(kgdb) bt
#0  0xc017937e in dumpsys ()
#1  0xc0179173 in boot ()
#2  0xc01795a4 in poweroff_wait ()
#3  0xc0129989 in db_panic ()
#4  0xc0129927 in db_command ()
#5  0xc01299f3 in db_command_loop ()
#6  0xc012bfb1 in db_trap ()
#7  0xc02aea66 in kdb_trap ()
#8  0xc02bfe8e in trap_fatal ()
#9  0xc02bf90f in trap ()
#10 0xc01c0009 in msdosfs_write ()
#11 0xc0209488 in nfsrv_write ()
#12 0xc021da8a in nfssvc_nfsd ()
#13 0xc021d385 in nfssvc ()
#14 0xc02c01d6 in syscall2 ()
#15 0xc02afa6a in Xint0x80_syscall ()
You're probably indirecting though a non-existent proc-related structure.
The protocol threads don't have a proc structure associated with
them.  Before, there were a bunch of places which incorrectly used
curproc to check things like credentials.   All the places
are going to core dump now.  I've fixed a bunch of places which
incorrectly used curthread, but there are still some left.