Dmitry Monakhov df4bb5d128 quota: Check that quota is not dirty before release
There is a race window where quota was redirted once we drop dq_list_lock inside dqput(),
but before we grab dquot->dq_lock inside dquot_release()

TASK1                                                       TASK2 (chowner)
->dqput()
  we_slept:
    spin_lock(&dq_list_lock)
    if (dquot_dirty(dquot)) {
          spin_unlock(&dq_list_lock);
          dquot->dq_sb->dq_op->write_dquot(dquot);
          goto we_slept
    if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) {
          spin_unlock(&dq_list_lock);
          dquot->dq_sb->dq_op->release_dquot(dquot);
                                                            dqget()
							    mark_dquot_dirty()
							    dqput()
          goto we_slept;
        }
So dquot dirty quota will be released by TASK1, but on next we_sleept loop
we detect this and call ->write_dquot() for it.
XFSTEST: 440a80d4cb

Link: https://lore.kernel.org/r/20191031103920.3919-2-dmonakhov@openvz.org
CC: stable@vger.kernel.org
Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
Signed-off-by: Jan Kara <jack@suse.cz>
2019-10-31 19:07:42 +01:00
..
2019-09-27 15:10:34 -07:00
2019-09-30 10:25:24 -07:00
2019-09-25 10:21:13 -07:00
2019-09-19 09:42:37 -07:00
2019-09-19 13:09:28 -07:00
2019-07-12 17:37:53 -07:00
2019-09-29 19:25:39 -07:00
2019-09-21 14:26:33 -07:00
2019-09-27 15:54:24 -07:00
2019-09-19 09:42:37 -07:00
2019-09-19 09:42:37 -07:00
2019-07-03 17:52:09 -04:00
2019-09-26 12:20:14 -07:00
2019-09-27 17:00:27 -07:00
2019-09-27 17:00:27 -07:00
2019-09-19 10:21:35 -07:00
2019-08-30 08:11:25 -07:00
2019-09-19 09:42:37 -07:00
2019-09-26 11:36:20 -07:00
2019-09-18 17:35:20 -07:00
2019-07-15 21:20:52 -07:00
2019-04-08 18:21:02 -05:00
2019-08-07 21:51:47 -04:00
2019-03-08 14:48:40 -08:00
2019-09-27 12:08:24 -07:00
2019-09-18 16:59:14 -07:00
2019-09-27 17:00:27 -07:00
2019-09-18 16:59:14 -07:00
2019-09-25 09:55:59 -07:00
2019-08-01 20:51:23 +02:00
2019-09-25 17:51:41 -07:00