kern/185734: panic on stable/10 when writing to ZFS disk

[R Tyler Croy]

>Number:         185734
>Category:       kern
>Synopsis:       panic on stable/10 when writing to ZFS disk
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jan 13 06:50:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     R Tyler Croy
>Release:        10.0-PRERELEASE (r260356)
>Organization:
>Environment:
FreeBSD kiwi 10.0-PRERELEASE FreeBSD 10.0-PRERELEASE #2 209885b(stable/10): Sun Jan  5 20:38:07 PST 2014     root at kiwi:/usr/home/tyler/scratch/obj/usr/home/tyler/source/github/freebsd/sys/KIWI  amd64
>Description:
Was attempting to pull a big update from the FreeBSD git mirror, which usually downloads large-ish pack files and writes them to disk.

After fetching the object files, and attempting to write them to my encrypted ZFS-based disk, the machine panicked as you can see below.

Jan 12 22:24:43 kiwi dhclient[36674]: send_packet: Network is down
Jan 12 22:25:09 kiwi last message repeated 3 times
Jan 12 22:25:33 kiwi last message repeated 2 times
Jan 12 22:30:55 kiwi syslogd: kernel boot file is /boot/kernel/kernel
Jan 12 22:30:55 kiwi kernel: 
Jan 12 22:30:55 kiwi kernel: 
Jan 12 22:30:55 kiwi kernel: Fatal trap 12: page fault while in kernel mode
Jan 12 22:30:55 kiwi kernel: cpuid = 1; apic id = 01
Jan 12 22:30:55 kiwi kernel: fault virtual address      = 0x34f80125
Jan 12 22:30:55 kiwi kernel: fault code         = supervisor write data, page not present
Jan 12 22:30:55 kiwi kernel: instruction pointer        = 0x20:0xffffffff80685341
Jan 12 22:30:55 kiwi kernel: stack pointer              = 0x28:0xfffffe0234f888e0
Jan 12 22:30:55 kiwi kernel: frame pointer              = 0x28:0xfffffe0234f889b0
Jan 12 22:30:55 kiwi kernel: code segment               = base 0x0, limit 0xfffff, type 0x1b
Jan 12 22:30:55 kiwi kernel: = DPL 0, pres 1, long 1, def32 0, gran 1
Jan 12 22:30:55 kiwi kernel: processor eflags   = interrupt enabled, resume, IOPL = 0
Jan 12 22:30:55 kiwi kernel: current process            = 22137 (git)
Jan 12 22:30:55 kiwi kernel: trap number                = 12
Jan 12 22:30:55 kiwi kernel: panic: page fault
Jan 12 22:30:55 kiwi kernel: cpuid = 1
Jan 12 22:30:55 kiwi kernel: KDB: stack backtrace:
Jan 12 22:30:55 kiwi kernel: #0 0xffffffff8066c750 at kdb_backtrace+0x60
Jan 12 22:30:55 kiwi kernel: #1 0xffffffff806341a5 at panic+0x155
Jan 12 22:30:55 kiwi kernel: #2 0xffffffff808cf752 at trap_fatal+0x3a2
Jan 12 22:30:55 kiwi kernel: #3 0xffffffff808cfa29 at trap_pfault+0x2c9
Jan 12 22:30:55 kiwi kernel: #4 0xffffffff808cf1b6 at trap+0x5e6
Jan 12 22:30:55 kiwi kernel: #5 0xffffffff808b6452 at calltrap+0x8
Jan 12 22:30:55 kiwi kernel: #6 0xffffffff8068231a at dofilewrite+0x8a
Jan 12 22:30:55 kiwi kernel: #7 0xffffffff80682045 at kern_writev+0x65
Jan 12 22:30:55 kiwi kernel: #8 0xffffffff80681fd3 at sys_write+0x63
Jan 12 22:30:55 kiwi kernel: #9 0xffffffff808d0047 at amd64_syscall+0x357
Jan 12 22:30:55 kiwi kernel: #10 0xffffffff808b673b at Xfast_syscall+0xfb
Jan 12 22:30:55 kiwi kernel: Uptime: 5d2h27m4s
Jan 12 22:30:55 kiwi kernel: Automatic reboot in 15 seconds - press a key on the console to abort
Jan 12 22:30:55 kiwi kernel: Rebooting...
Jan 12 22:30:55 kiwi kernel: cpu_reset: Restarting BSP
Jan 12 22:30:55 kiwi kernel: cpu_reset_proxy: Stopped CPU 1

>How-To-Repeat:
Unable to reproduce unfortunately :(
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: