On 2023-01-12 01:26, Reid Wahl wrote:
On Wed, Jan 11, 2023 at 10:21 PM Madison Kelly <mke...@alteeve.com> wrote:
On 2023-01-12 01:12, Reid Wahl wrote:
On Wed, Jan 11, 2023 at 8:11 PM Madison Kelly <mke...@alteeve.com> wrote:
Hi all,
There was a lot of sub-threads, so I figured it's helpful to start a
new thread with a summary so far. For context; I have a super simple
perl script that pretends to be an RA for the sake of debugging.
https://pastebin.com/9z314TaB
I've had variations log environment variables and confirmed that all
the variables in the direct call that work are in the crm_resource
triggered call. There are no selinux issues logged in audit.log and
selinux is permissive. The script logs the real and effective UID and
GID and it's the same in both instances. Calling other shell programs
(tested with 'hostname') run fine, this is specifically crm_resource ->
test RA -> virsh call.
I ran strace on the virsh call from inside my test script (changing
'virsh.good' to 'virsh.bad' between running directly and via
crm_resource. The strace runs made six files each time. Below are
pastebin links with the outputs of the six runs in one paste, but each
file's output is in it's own block (search for file: to see the
different file outputs)
Good/direct run of the test RA:
- https://pastebin.com/xtqe9NSG
Bad/crm_resource triggered run of the test RA:
- https://pastebin.com/vBiLVejW
Still absolutely stumped.
The strace outputs show that your bad runs are all getting stopped
with SIGTTOU. If you've never heard of that, me either.
The hell?! This is new to me also.
https://www.gnu.org/software/libc/manual/html_node/Job-Control-Signals.html
Macro: int SIGTTOU
This is similar to SIGTTIN, but is generated when a process in a
background job attempts to write to the terminal or set its modes.
Again, the default action is to stop the process. SIGTTOU is only
generated for an attempt to write to the terminal if the TOSTOP output
mode is set; see Output Modes.
Maybe this has something to do with the buffer settings in the perl
script(?). It might be worth trying a version that doesn't fiddle with
the outputs and buffer settings.
I tried removing the $|, and then I changed the script to be entirely a
bash script, still hanging. I tried 'virsh --connect <method> list
--all' where method was qemu:///system, qemu:///session, and
ssh+qemu:///root@localhost/system, all hang. In bash or perl.
I don't know which difference between your environment and mine is
relevant here, such that I can't reproduce the issue using your test
script. It works perfectly fine for me.
Can you run `stty -a | grep tostop`? If there's a minus sign
("-tostop"), it's disabled; if it's present without a minus sign
("tostop"), it's enabled, as best I can tell.
-tostop is there
====
[root@mk-a07n02 ~]# stty -a | grep tostop
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt
[root@mk-a07n02 ~]#
====
I'm just spitballing here. It's disabled by default on my machine...
but even when I enable it, crm_resource --validate works fine. It may
be set differently when running under crm_resource.
How do you enable it?
With `stty tostop`
It's 100% possible that this whole thing is a red herring by the way.
I'm looking for anything that might explain the discrepancy. SIGTTOU
may not be directly tied to the root cause.
Appreciate the stab, didn't stop the hang though :(
--
Madison Kelly
Alteeve's Niche!
Chief Technical Officer
c: +1-647-471-0951
https://alteeve.com/
_______________________________________________
Manage your subscription:
https://lists.clusterlabs.org/mailman/listinfo/users
ClusterLabs home: https://www.clusterlabs.org/
