file system deadlock in RELENG_11

[Mike Tancsa]

On 8/24/2017 4:01 PM, Mike Tancsa wrote:
> OK, this is fairly easy to repeat. If I start a sync of a snapshot via
> zrep, it hangs the box.  CTRL+T shows
> 
> 
> DEBUG: overiding stale lock on zroot/chyves from pid 19378
> sending zroot/chyves at zrep_000010 to 10.151.9.2:zroot/chyves
> cannot receive new filesystem stream: destination
> 'zroot/chyves/guests/resi/disk1' exists
> must specify -F to overwrite it
> ^C
> load: 0.48  cmd: zfs 29690 [tx->tx_sync_done_cv] 358.94r 0.00u 0.00s 0%
> 3476k
> load: 0.48  cmd: zfs 29690 [tx->tx_sync_done_cv] 360.42r 0.00u 0.00s 0%

I was able to get ps to run and not sure if its helpful or not, but
these are the two unkillable zfs processes


root         5   0.0  0.0       0    128  -  DL   10:09      0:05.58
[zfskern]
root     29683   0.0  0.0    7752   3824  5  DE+  15:53      0:00.32 zfs
send -R -I zroot/chyves at zrep_00000d zroot/chyves at zrep_000010
root     29690   0.0  0.0    7752   3492  5  D+   15:53      0:00.00 zfs
rename zroot/chyves at zrep_000010 zroot/chyves at zrep_000010_unsent


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-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada   http://www.tancsa.com/