diff options
| author | Tejun Heo <tj@kernel.org> | 2020-09-01 14:52:31 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-09-01 16:48:44 -0600 |
| commit | 5aeac7c4b16069aae49005f0a8d4526baa83341b (patch) | |
| tree | d380ddce8bf1e1a8d2e043e1491ba3da588ef89f | |
| parent | 08fc1ab6d748ab1a690fd483f41e2938984ce353 (diff) | |
| download | linux-5aeac7c4b16069aae49005f0a8d4526baa83341b.tar.bz2 | |
blk-iocost: ioc_pd_free() shouldn't assume irq disabled
ioc_pd_free() grabs irq-safe ioc->lock without ensuring that irq is disabled
when it can be called with irq disabled or enabled. This has a small chance
of causing A-A deadlocks and triggers lockdep splats. Use irqsave operations
instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-iocost.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 413e0b5c8e6b..d37b55db2409 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2092,14 +2092,15 @@ static void ioc_pd_free(struct blkg_policy_data *pd) { struct ioc_gq *iocg = pd_to_iocg(pd); struct ioc *ioc = iocg->ioc; + unsigned long flags; if (ioc) { - spin_lock(&ioc->lock); + spin_lock_irqsave(&ioc->lock, flags); if (!list_empty(&iocg->active_list)) { propagate_active_weight(iocg, 0, 0); list_del_init(&iocg->active_list); } - spin_unlock(&ioc->lock); + spin_unlock_irqrestore(&ioc->lock, flags); hrtimer_cancel(&iocg->waitq_timer); hrtimer_cancel(&iocg->delay_timer); |