LU-4920 quota: always clear lqe_lockh on lock cancel

In the qsd_id_blocking_ast(), lqe_lockh should always be cleared,
otherwise, quota code will mistakenly assume the id lock is still
valid.

Lustre-change: http://review.whamcloud.com/9965/
Lustre-commit: 73ef5dcd8bcf32e4127e0011357b8bc39472cdba

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: Li Xi <lixi@ddn.com>
Change-Id: I2cfcdf19ded66c0ecabc77961a1c9a4d27de1d8c
Revert "LU-4249 quota: lqe reference debug patch"

This reverts commit befd4337b760db3f6390ad2ab8f7b7f317dd5f8c.

The commit befd4337 is from #9833, a debug patch. Since a final patch #11019
is now available, the debug patch should be removed.
LU-4249 quota: race in qsd_upd_thread()

qsd_upd_thread() uses list_for_each_entry_safe() to process
list items one by one, however, it has to drop lock while
processing each item, that'll race with other list processing
thread.

The proper way is to check list head each time when it acquired
lock.

Lustre-commit: f8f7c34a7bbcf22aeca7699ce76254e41e3e95b7
Lustre-change: http://review.whamcloud.com/10988

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: If6228105b2a5895da10bb8293e6738509372eb12
LU-4558 clio: Solve a race in cl_lock_put

It's not atomic to check the last reference and state of cl_lock
in cl_lock_put(). This can cause a problem that an using lock is
freed, if the process is preempted between atomic_dec_and_test()
and (lock->cll_state == CLS_FREEING).

This problem can be solved by holding a refcount by coh_locks. In
this case, it can be sure that if the lock refcount reaches zero,
nobody else can have any chance to use it again.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: I08b81bcd6a4040ea9608db97d60aa6706405ee8c
LU-4422 quota: fix s-q test_6

s-q test_6 should not fail by checking whether the file is
growing, because in most time, the test is waiting for quota
slave reconnecting to quota master.

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I2332febf639bdbe033c588b97a2c7a1e1e2f51e2