diff options
| author | Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> | 2019-10-31 10:39:20 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-17 20:39:43 +0100 |
| commit | f780a35182bf0c37668f734d2bbf8e5dd63d8713 (patch) | |
| tree | 0722de9b84231465e0c32f94cf27bfd606cb017c /fs | |
| parent | 772098e8b6999656b9b28d78f52f80b224556c06 (diff) | |
quota: Check that quota is not dirty before release
commit df4bb5d128e2c44848aeb36b7ceceba3ac85080d upstream.
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: https://github.com/dmonakhov/xfstests/commit/440a80d4cbb39e9234df4d7240aee1d551c36107
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ocfs2/quota_global.c | 2 | ||||
| -rw-r--r-- | fs/quota/dquot.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c index b39d14cbfa34..d212d09c00b1 100644 --- a/fs/ocfs2/quota_global.c +++ b/fs/ocfs2/quota_global.c @@ -727,7 +727,7 @@ static int ocfs2_release_dquot(struct dquot *dquot) mutex_lock(&dquot->dq_lock); /* Check whether we are not racing with some other dqget() */ - if (atomic_read(&dquot->dq_count) > 1) + if (dquot_is_busy(dquot)) goto out; /* Running from downconvert thread? Postpone quota processing to wq */ if (current == osb->dc_task) { diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 9c81fd973418..9d40265ccd7d 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -491,7 +491,7 @@ int dquot_release(struct dquot *dquot) mutex_lock(&dquot->dq_lock); /* Check whether we are not racing with some other dqget() */ - if (atomic_read(&dquot->dq_count) > 1) + if (dquot_is_busy(dquot)) goto out_dqlock; if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); |