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| author | Jens Axboe <axboe@fb.com> | 2017-02-16 07:57:33 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-02-16 08:02:06 -0700 |
| commit | 5d7f5ce15156af205e175e8fa5c669ba40bf0c5e (patch) | |
| tree | 1fc9ab7169aeb6527fac23de6ba16b1e677c2236 | |
| parent | eeeefd41843218c55a8782a6920f044d9bf6207a (diff) | |
| download | linux-0-day-5d7f5ce15156af205e175e8fa5c669ba40bf0c5e.tar.gz linux-0-day-5d7f5ce15156af205e175e8fa5c669ba40bf0c5e.tar.xz | |
cfq-iosched: don't call wbt_disable_default() with IRQs disabled
wbt_disable_default() calls del_timer_sync() to wait for the wbt
timer to finish before disabling throttling. We can't do this with
IRQs disable. This fixes a lockdep splat on boot, if non-root
cgroups are used.
Reported-by: Gabriel C <nix.or.die@gmail.com>
Fixes: 87760e5eef35 ("block: hook up writeback throttling")
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/cfq-iosched.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index c73a6fcaeb9d5..838f07e2b64a2 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3758,7 +3758,7 @@ static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, } #ifdef CONFIG_CFQ_GROUP_IOSCHED -static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) +static bool check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { struct cfq_data *cfqd = cic_to_cfqd(cic); struct cfq_queue *cfqq; @@ -3775,15 +3775,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) * spuriously on a newly created cic but there's no harm. */ if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr)) - return; - - /* - * If we have a non-root cgroup, we can depend on that to - * do proper throttling of writes. Turn off wbt for that - * case, if it was enabled by default. - */ - if (nonroot_cg) - wbt_disable_default(cfqd->queue); + return nonroot_cg; /* * Drop reference to queues. New queues will be assigned in new @@ -3804,9 +3796,13 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) } cic->blkcg_serial_nr = serial_nr; + return nonroot_cg; } #else -static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { } +static inline bool check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) +{ + return false; +} #endif /* CONFIG_CFQ_GROUP_IOSCHED */ static struct cfq_queue ** @@ -4448,11 +4444,12 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, const int rw = rq_data_dir(rq); const bool is_sync = rq_is_sync(rq); struct cfq_queue *cfqq; + bool disable_wbt; spin_lock_irq(q->queue_lock); check_ioprio_changed(cic, bio); - check_blkcg_changed(cic, bio); + disable_wbt = check_blkcg_changed(cic, bio); new_queue: cfqq = cic_to_cfqq(cic, is_sync); if (!cfqq || cfqq == &cfqd->oom_cfqq) { @@ -4488,6 +4485,10 @@ new_queue: rq->elv.priv[0] = cfqq; rq->elv.priv[1] = cfqq->cfqg; spin_unlock_irq(q->queue_lock); + + if (disable_wbt) + wbt_disable_default(q); + return 0; } |