New ZFSv28 patchset for 8-STABLE

[Attila Nagy]

  On 12/16/2010 01:44 PM, Martin Matuska wrote:
> Hi everyone,
>
> following the announcement of Pawel Jakub Dawidek (pjd at FreeBSD.org) I am
> providing a ZFSv28 testing patch for 8-STABLE.
>
> Link to the patch:
>
> http://people.freebsd.org/~mm/patches/zfs/v28/stable-8-zfsv28-20101215.patch.xz
>
I've got an IO hang with dedup enabled (not sure it's related, I've 
started to rewrite all data on pool, which makes a heavy load):

The processes are in various states:
65747   1001      1  54   10 28620K 24360K tx->tx  0   6:58  0.00% cvsup
80383   1001      1  54   10 40616K 30196K select  1   5:38  0.00% rsync
  1501 www         1  44    0  7304K  2504K zio->i  0   2:09  0.00% nginx
  1479 www         1  44    0  7304K  2416K zio->i  1   2:03  0.00% nginx
  1477 www         1  44    0  7304K  2664K zio->i  0   2:02  0.00% nginx
  1487 www         1  44    0  7304K  2376K zio->i  0   1:40  0.00% nginx
  1490 www         1  44    0  7304K  1852K zfs     0   1:30  0.00% nginx
  1486 www         1  44    0  7304K  2400K zfsvfs  1   1:05  0.00% nginx

And everything which wants to touch the pool is/becomes dead.

Procstat says about one process:
# procstat -k 1497
   PID    TID COMM             TDNAME           KSTACK
  1497 100257 nginx            -                mi_switch sleepq_wait 
__lockmgr_args vop_stdlock VOP_LOCK1_APV null_lock VOP_LOCK1_APV 
_vn_lock nullfs_root lookup namei vn_open_cred kern_openat syscallenter 
syscall Xfast_syscall