Currently we only increment opcounters for bulk insert if one of the inserts fails

In [8]: db.command('serverStatus')['opcounters']['insert']
Out[8]: 0

In [9]: db.foo.insert([{}])
Out[9]: [ObjectId('4e6e698f7b98300f2b000003')]

In [10]: db.command('serverStatus')['opcounters']['insert']
Out[10]: 1

In [11]: db.foo.insert([{},{}])
Out[11]: [ObjectId('4e6e699f7b98300f2b000004'), ObjectId('4e6e699f7b98300f2b000005')]

In [12]: db.command('serverStatus')['opcounters']['insert']
Out[12]: 1

In [14]: db.foo.insert([

,

,

])
Out[14]: [1, 1, 1]

In [15]: db.command('serverStatus')['opcounters']['insert']
Out[15]: 2