panic on zpool set cachefile=none

[Andriy Gapon]

Unfortunately no dump.
cachefile may have pointed to a wrong (non-existent) file before the command.
System: stable/7 (after ZFS MFC), amd64

Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address   = 0x20
fault code              = supervisor read data, page not present
instruction pointer     = 0x8:0xffffffff80323bf3
stack pointer           = 0x10:0xffffff80783ff850
frame pointer           = 0x10:0xffffff80783ff8f0
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 26403 (solthread 0xfffffff)
trap number             = 12
panic: page fault
cpuid = 1
KDB: stack backtrace:
db_trace_self_wrapper() at 0xffffffff8018d8b5 = db_trace_self_wrapper+0x2a
kdb_backtrace() at 0xffffffff802da5b7 = kdb_backtrace+0x32
panic() at 0xffffffff802adecc = panic+0x1b0
trap_fatal() at 0xffffffff8044a07b = trap_fatal+0x3b0
trap_pfault() at 0xffffffff8044a2eb = trap_pfault+0x252
trap() at 0xffffffff8044ac70 = trap+0x368
calltrap() at 0xffffffff8042f59e = calltrap+0x8
--- trap 0xc, rip = 0xffffffff80323bf3, rsp = 0xffffff80783ff850, rbp =
0xffffff80783ff8f0 ---
namei() at 0xffffffff80323bf3 = namei+0x174
kern_unlink() at 0xffffffff80334841 = kern_unlink+0x66
spa_config_sync() at 0xffffffff807c0653 = spa_config_sync+0x1a2
spa_config_update_common() at 0xffffffff807c0cf4 = spa_config_update_common+0xdd
spa_config_update() at 0xffffffff807c0d27 = spa_config_update+0xe
spa_async_thread() at 0xffffffff807ba72a = spa_async_thread+0x89
fork_exit() at 0xffffffff8028cb79 = fork_exit+0x12b
fork_trampoline() at 0xffffffff8042f95e = fork_trampoline+0xe
--- trap 0, rip = 0, rsp = 0xffffff80783ffd30, rbp = 0 ---

-- 
Andriy Gapon