| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Fri, 5 Feb 2016 12:17:14 +0100 |
| Subject: mm: backing-dev: don't disable IRQs in wb_congested_put() |
| |
| it triggers: |
| |BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:930 |
| |in_atomic(): 0, irqs_disabled(): 1, pid: 12, name: rcuc/0 |
| |1 lock held by rcuc/0/12: |
| | #0: (rcu_callback){......}, at: [<ffffffff810ce1a6>] rcu_cpu_kthread+0x376/0xb10 |
| |irq event stamp: 23636 |
| |hardirqs last enabled at (23635): [<ffffffff8173524c>] _raw_spin_unlock_irqrestore+0x6c/0x80 |
| |hardirqs last disabled at (23636): [<ffffffff81173918>] wb_congested_put+0x18/0x90 |
| | [<ffffffff81735434>] rt_spin_lock+0x24/0x60 |
| | [<ffffffff810afed2>] atomic_dec_and_spin_lock+0x52/0x90 |
| | [<ffffffff81173928>] wb_congested_put+0x28/0x90 |
| | [<ffffffff813b833e>] __blkg_release_rcu+0x5e/0x1e0 |
| | [<ffffffff813b8367>] ? __blkg_release_rcu+0x87/0x1e0 |
| | [<ffffffff813b82e0>] ? blkg_conf_finish+0x90/0x90 |
| | [<ffffffff810ce1e7>] rcu_cpu_kthread+0x3b7/0xb10 |
| |
| due to cgwb_lock beeing taken with spin_lock_irqsave() usually. |
| |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| mm/backing-dev.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/mm/backing-dev.c |
| +++ b/mm/backing-dev.c |
| @@ -459,9 +459,9 @@ void wb_congested_put(struct bdi_writeba |
| { |
| unsigned long flags; |
| |
| - local_irq_save(flags); |
| + local_irq_save_nort(flags); |
| if (!atomic_dec_and_lock(&congested->refcnt, &cgwb_lock)) { |
| - local_irq_restore(flags); |
| + local_irq_restore_nort(flags); |
| return; |
| } |
| |
