Problem:

After an

{fsync: 1, lock: 1}

a "show dbs" in another connections hangs with

> db.currentOp()
{
"inprog" : [
{
"opid" : 205,
"active" : true,
"lockType" : "write",
"waitingForLock" : true,
"secs_running" : 6991,
"op" : "query",
"ns" : "admin",
"query" :

{ "listDatabases" : 1 }

,
"client" : "127.0.0.1:55521",
"desc" : "conn"
}
],
"fsyncLock" : 1,
"info" : "use db.$cmd.sys.unlock.findOne() to terminate the fsync write/snapshot lock"
}

This block a mongodump, since this appears to execute the listDatabases command.

Reproduce:
1. shell 1 - execute

{fsync: 1, lock: 1}

2. shell 2 - execute "show dbs" ... command does not return

Business Case:

• Usability
  Need to ensure that a mongodump will execute after an {fsync: 1, lock: 1}

  and it does issue any blocking calls.