qa: failfast mount for better performance

During teuthology tests, the tearing down of the cluster between two
tests causes the config to be reset and a config_notify generated. This
leads to a race to create a new mount using the old fscid. But by the
time the mount is attempted the new fs gets created with a new fscid.
This situation leads to the client mount waiting for a connection
completion notification from the mds for 5 minutes (default timeout)
and eventually giving up.
However, the default teuthology command timeout is 2 minutes. So,
teuthology fails the command and declares the job as failed way before
the mount can timeout.

The resolution to this case is to lower the client mount timeout to 30
seconds so that the config_notify fails fast paving the way for
successive commands to get executed with the new fs.

An unhandled cluster warning about an unresponsive client also gets
emitted later during qa job termination which leads to teuthology
declaring the job as failed. As of now this warning seems harmless since
it is emitted during cluster cleanup phase.
So, this warning is added to the log-ignorelist section in the
snap-schedule YAML.

Fixes: https://tracker.ceph.com/issues/66009
Signed-off-by: Milind Changire <[email protected]>

Author: mchangir

qa/cephfs/conf/mgr.yaml

@@ -2,6 +2,7 @@ overrides:
   ceph:
     conf:
       mgr:
+        client mount timeout: 30
         debug client: 20
         debug mgr: 20
         debug ms: 1

qa/suites/fs/functional/tasks/snap-schedule.yaml

@@ -15,6 +15,7 @@ overrides:
       - is full \(reached quota
       - POOL_FULL
       - POOL_BACKFILLFULL
+      - cluster \[WRN\] evicting unresponsive client
 
 tasks:
   - cephfs_test_runner: