zfs get all command hung

[a.smith at ukgrid.net]

Quoting Andriy Gapon <avg at FreeBSD.org>:
>
> procstat -kk <pid>
>

# procstat -kk 37975
   PID    TID COMM             TDNAME           KSTACK
37975 100669 zfs              -                mi_switch+0x176  
sleepq_catch_signals+0x29e sleepq_wait_sig+0x16 _sleep+0x269  
clnt_vc_create+0x153 clnt_reconnect_call+0x64d nfs_request+0x215  
nfs_statfs+0x194 __vfs_statfs+0x28 kern_getfsstat+0x3fc  
syscallenter+0x1e5 syscall+0x4b Xfast_syscall+0xe2

And actually I was thinking, as the all zfs get commands are hanging,  
I can run others and truss them of course. Here is the tail of a truss:


NAME  PROPERTY              VALUE                  SOURCE
write(1,"NAME  PROPERTY              VALU"...,58) = 58 (0x3a)
mx1   type                  filesystem             -
write(1,"mx1   type                  file"...,53) = 53 (0x35)
mx1   creation              Mon Jan 17 12:08 2011  -
write(1,"mx1   creation              Mon "...,53) = 53 (0x35)
mx1   used                  78.2G                  -
write(1,"mx1   used                  78.2"...,53) = 53 (0x35)
mx1   available             195G                   -
write(1,"mx1   available             195G"...,53) = 53 (0x35)
mx1   referenced            22K                    -
write(1,"mx1   referenced            22K "...,53) = 53 (0x35)
mx1   compressratio         1.27x                  -
write(1,"mx1   compressratio         1.27"...,53) = 53 (0x35)
fstat(4,{ mode=crw-rw-rw- ,inode=32,size=0,blksize=4096 }) = 0 (0x0)
ioctl(4,TIOCGETA,0xffffc8c0)                     ERR#19 'Operation not  
supported by device'
lseek(4,0x0,SEEK_SET)                            = 0 (0x0)
lseek(4,0x0,SEEK_CUR)                            = 0 (0x0)
getfsstat(0x0,0x0,0x1,0x0,0x80,0xa008)           = 443 (0x1bb)

Andy.