Description of problem:

Potential deadlocks can occur when tasks are added to the Directory Server.  Where the task itself creates new thread and makes database updates, and the task add operation also triggers post plugins to fire off.

Version-Release number of selected component (if applicable):


How reproducible:

Sometimes

Steps to Reproduce:
1. Install FreeIPA server:
# ipa-server-install

2. Authenticate as admin:
# kinit admin

3. Add a hostgroup:
# ipa hostgroup-add --desc="Web Servers" webservers

4. Add a host:
# ipa host-add web1.example.com --force

5. Add an automember rule:
# ipa automember-add --type=hostgroup webservers
# ipa automember-add-condition --key=fqdn --type=hostgroup --inclusive-regex=^web[1-9]+\.example\.com webservers

6. Try to rebuild membership:
# cat rebuild.ldif 
dn: cn=rt,cn=automember rebuild membership,cn=tasks,cn=config
changetype: add
objectClass: top
objectClass: extensibleObject
cn: rt
basedn: cn=computers,cn=accounts,dc=idm,dc=lab,dc=eng,dc=brq,dc=redhat,dc=com
filter: (fqdn=*)
scope: sub

7. ldapmodify -x -D 'cn=directory manager' -w password -f rebuild.ldif
adding new entry "cn=rt,cn=automember rebuild membership,cn=tasks,cn=config"

Actual results:

The ldapmodify in step 7 hangs

Expected results:

ldapmodify does not hang the Directory Server