diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2010-04-06 16:51:31 +0200 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2020-04-03 18:49:53 +0200 |
| commit | 8f3b085a282c3c8eaca0cb50df03f059f1935c74 (patch) | |
| tree | e25d6b5be08b889e7a1ba616aab734c742a92377 | |
| parent | 1830dd0000c63d03a21a396715d352875fdcc004 (diff) | |
| download | linux-rt-8f3b085a282c3c8eaca0cb50df03f059f1935c74.tar.gz | |
md: raid5: Make raid5_percpu handling RT aware
__raid_run_ops() disables preemption with get_cpu() around the access
to the raid5_percpu variables. That causes scheduling while atomic
spews on RT.
Serialize the access to the percpu data with a lock and keep the code
preemptible.
Reported-by: Udo van den Heuvel <udovdh@xs4all.nl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Udo van den Heuvel <udovdh@xs4all.nl>
| -rw-r--r-- | drivers/md/raid5.c | 7 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 1 |
2 files changed, 6 insertions, 2 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index ba00e9877f02..4f5420851da2 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2058,8 +2058,9 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) struct raid5_percpu *percpu; unsigned long cpu; - cpu = get_cpu(); + cpu = get_cpu_light(); percpu = per_cpu_ptr(conf->percpu, cpu); + spin_lock(&percpu->lock); if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { ops_run_biofill(sh); overlap_clear++; @@ -2118,7 +2119,8 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) if (test_and_clear_bit(R5_Overlap, &dev->flags)) wake_up(&sh->raid_conf->wait_for_overlap); } - put_cpu(); + spin_unlock(&percpu->lock); + put_cpu_light(); } static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh) @@ -6815,6 +6817,7 @@ static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) __func__, cpu); return -ENOMEM; } + spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock); return 0; } diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index f90e0704bed9..cca69edd669d 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -634,6 +634,7 @@ struct r5conf { int recovery_disabled; /* per cpu variables */ struct raid5_percpu { + spinlock_t lock; /* Protection for -RT */ struct page *spare_page; /* Used when checking P/Q in raid6 */ void *scribble; /* space for constructing buffer * lists and performing address |