illumos gate

A hotfix for oi_148:

echo 'nfs4_trigger_domount_args_create+0x34/v 0' | mdb -kw

This flags all calls to nfs4_trigger_ping_server as nointr.

It's a little bit difficult to provoke this bug but here is what I did to reproduce this bug:

I used two openindiana 151a machines.

host1: I used dtrace to see if it works:

dtrace -n 'nfs4_trigger_domount_args_create:* { trace(arg1); }' -n 'nfs4_trigger_ping_server:* { trace(arg1); }'  and/or
dtrace -n 'nfs4*:return {trace(arg1);}'

host1: I mounted a filesystem via nfs from host2
host2: Typed "uadmin 1 1" to reboot
host1: I moved with cd as fast as possible(!) into a deeper filesystem from host2
host1: After some time I saw a few calls for nfs4_trigger_ping_server() in my dtrace output and I sent my cd process a SIGINTR with a ctrl+c. (If you can't see the call it's time to start over.) cd hung and I was able to see a pending interrupt signal from nfs4_trigger_ping_server() with dtrace.

With my latest patch (http://cr.illumos.org/view/e4qg2vxm/nfs-webrev/) dtrace looks like the following:

  3  65386  nfs4_ephemeral_tree_hold:return                 0
  2  65416   nfs4_ping_server_common:return                 5
  2  65402  nfs4_trigger_ping_server:return                 5
  2  65416   nfs4_ping_server_common:return                 5
  2  65402  nfs4_trigger_ping_server:return                 5
  2  65416   nfs4_ping_server_common:return                18
  2  65402  nfs4_trigger_ping_server:return                18
  2  65408  nfs4_trigger_esi_destroy:return                 2
  2  65396 nfs4_trigger_domount_args_create:return                 4
  2  65388  nfs4_ephemeral_tree_decr:return                 8
  2  65392        nfs4_trigger_mount:return                 4
  2  65364       nfs4_trigger_access:return                 4
  2  65921 nfs4_waitfor_purge_complete:return                 0
  2  65921 nfs4_waitfor_purge_complete:return                 0
  2  66129      nfs4_validate_caches:return                 0
  2  65921 nfs4_waitfor_purge_complete:return                 0

...and cd aborts.