Re: panic: unmount: dangling vnode

On Fri, Mar 25, 2005 at 07:16:20PM -0800, Kris Kennaway wrote:
> HEAD from a few days ago on a SMP machine:
> 
> panic: unmount: dangling vnode
> cpuid = 0
> KDB: enter: panic
> [thread pid 33932 tid 100296 ]
> Stopped at      kdb_enter+0x30: leave
> db> wh
> Tracing pid 33932 tid 100296 td 0xc649a8a0
> kdb_enter(c06f4b02,0,c06fd194,f7e19c78,c649a8a0) at kdb_enter+0x30
> panic(c06fd194,f7e19c8c,c0588d42,c07a34e8,c9ebfb18) at panic+0x13e
> vfs_mount_destroy(c59c4000,c649a8a0,0,3de,0) at vfs_mount_destroy+0x25
> dounmount(c59c4000,8000000,c649a8a0,37d,54fffc6) at dounmount+0x45b
> unmount(c649a8a0,f7e19d14,c070fe19,3ad,2) at unmount+0x26e
> syscall(2f,bfbf002f,bfbf002f,804a619,bfbfe75a) at syscall+0x271
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (22, FreeBSD ELF32, unmount), eip = 0x280bb7af, esp = 0xbfbfe4ec, ebp = 0xbfbfe5a8 ---

db> show lockedvnods
Locked vnodes

0xc952e7c4: tag ufs, type VDIR
    usecount 1, writecount 0, refcount 3 mountedhere 0
    flags ()
    v_object 0xc9e1bd68 ref 0 pages 1
     lock type ufs: EXCL (count 1) by thread 0xc88a5000 (pid 1823)
        ino 1537520, on dev da0s1e

0xc80fac34: tag ufs, type VDIR
    usecount 0, writecount 0, refcount 3 mountedhere 0
    flags ()
    v_object 0xcadc118c ref 0 pages 1
     lock type ufs: EXCL (count 1) by thread 0xc649a8a0 (pid 33932)
        ino 1537587, on dev da0s1e
db> wh 1823
Tracing pid 1823 tid 100370 td 0xc88a5000
sched_switch(c88a5000,0,1,11e,db739c33) at sched_switch+0x195
mi_switch(1,0,c06f76e7,1ab,1) at mi_switch+0x2ad
sleepq_switch(e4b9adc0,c06f3f2e,18a,1,f7f6699c) at sleepq_switch+0x135
sleepq_wait(e4b9adc0,0,c06f5234,da,0) at sleepq_wait+0x42
msleep(e4b9adc0,c07a30e0,4c,c06fc57f,0) at msleep+0x3d2
bwait(e4b9adc0,4c,c06fc57f,f7f66ab0,f7f66a18) at bwait+0x60
bufwait(e4b9adc0,e4b9adc0,0,800,0) at bufwait+0x29
breadn(c952e7c4,0,0,800,0) at breadn+0x2eb
bread(c952e7c4,0,0,800,0) at bread+0x4c
ffs_read(f7f66b34,f7f66af8,c0518c55,f7f66cb8,f7f66b60) at ffs_read+0x25c
VOP_READ_APV(c073e820,f7f66b34,c0754c3c,1dd,c06f2e9a) at VOP_READ_APV+0x9d
ufs_readdir(f7f66c98,c051bdf4,c952e848,1,f7f66b88) at ufs_readdir+0xd3
VOP_READDIR_APV(c073e820,f7f66c98,f7f66c2c,c04e3377,f7f66c98) at VOP_READDIR_APV+0x9d
VOP_READDIR_AP(f7f66c98,c952e848,0,c06fd675,f7f66c9c) at VOP_READDIR_AP+0x1b
null_bypass(f7f66c98,0,0) at null_bypass+0xbb
VOP_READDIR_APV(c07275c0,f7f66c98,c88a5000,e53,1) at VOP_READDIR_APV+0xa5
getdirentries(c88a5000,f7f66d14,10,3ff,4) at getdirentries+0x15e
syscall(805002f,805002f,bfbf002f,8053400,1) at syscall+0x271
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (196, FreeBSD ELF32, getdirentries), eip = 0x280bfbaf, esp = 0xbfbfeb3c, ebp = 0xbfbfeb68 ---

I have to reboot this machine now, but let me know if there's
something else that would have helped for next time.

Kris