devfs related panic

[Sepherosa Ziehau <sepherosa@xxxxxxxxx>]

Hi all,

#12 0xffffffff802e8a1f in dssetmask (dev=0xffffffe085418f50,
mode=<value optimized out>, flags=<value optimized out>,
    sspp=<value optimized out>, info=<value optimized out>) at
/usr/src/sys/sys/diskslice.h:349
#13 dsopen (dev=0xffffffe085418f50, mode=<value optimized out>,
flags=<value optimized out>, sspp=<value optimized out>,
    info=<value optimized out>) at /usr/src/sys/kern/subr_diskslice.c:741
#14 0xffffffff802e45ff in diskopen (ap=0xffffffe0ba9c3798) at
/usr/src/sys/kern/subr_disk.c:956
#15 0xffffffff802a3e1c in dev_dopen (dev=0xffffffe085418f50,
oflags=8192, devtype=195, cred=0x1f) at
/usr/src/sys/kern/kern_device.c:151
#16 0xffffffff803e9c02 in devfs_spec_open (ap=0xffffffe0ba9c3838) at
/usr/src/sys/vfs/devfs/devfs_vnops.c:919
#17 0xffffffff8033c61c in vop_open (ops=0xffffffe0ad0d2e00,
vp=0xffffffe0bb1d6c48, mode=1, cred=0xffffffe0ae317868,
fp=0xffffffe08518ad58)
    at /usr/src/sys/kern/vfs_vopops.c:289
#18 0xffffffff80339ec6 in vn_open (nd=0xffffffe0ba9c3a98, fp=<value
optimized out>, fmode=1, cmode=<value optimized out>)
    at /usr/src/sys/kern/vfs_vnops.c:284
#19 0xffffffff80336c5d in kern_open (nd=0xffffffe0ba9c3a98,
oflags=<value optimized out>, mode=<value optimized out>,
    res=<value optimized out>) at /usr/src/sys/kern/vfs_syscalls.c:1836
#20 0xffffffff80336eb6 in sys_open (uap=0xffffffe0ba9c3b58) at
/usr/src/sys/kern/vfs_syscalls.c:1946
#21 0xffffffff8048f652 in syscall2 (frame=0xffffffe0ba9c3c08) at
/usr/src/sys/platform/pc64/x86_64/trap.c:1188
#22 0xffffffff80487c1f in Xfast_syscall () at
/usr/src/sys/platform/pc64/x86_64/exception.S:320

core dump is uploaded to sephe@leaf:crash/vmcore0.tbz

It happened after following stuffs were done by my friend:
- a sata disk was plugged into the esata port, and the disk was detected as da1
- dd if=/dev/zero of=/dev/da1, something like that
- unplug the sata disk
- after a short while, another sata disk was plugged in the same esata port
- this time no message showed about anything related to /dev/da1
- run the above dd command again, panic

Best Regards,
sephe

-- 
Tomorrow Will Never Die