summaryrefslogtreecommitdiff
path: root/block
diff options
context:
space:
mode:
authorJens Axboe <axboe@fb.com>2017-05-09 11:39:56 -0600
committerJens Axboe <axboe@fb.com>2017-05-10 07:40:18 -0600
commitd3738123986954ba3abbd96b595f5176b50c3f5d (patch)
tree67770332a697a8496a60c75ca8583dec06b3ceda /block
parent340ff3216799a947fe0b07bed8f0409ffc716be9 (diff)
downloadlinux-sh-d3738123986954ba3abbd96b595f5176b50c3f5d.tar.gz
blk-stat: don't use this_cpu_ptr() in a preemptable section
If PREEMPT_RCU is enabled, rcu_read_lock() isn't strong enough for us to use this_cpu_ptr() in that section. Use the safer get/put_cpu_ptr() variants instead. Reported-by: Mike Galbraith <efault@gmx.de> Fixes: 34dbad5d26e2 ("blk-stat: convert to callback-based statistics reporting") Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
-rw-r--r--block/blk-stat.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/block/blk-stat.c b/block/blk-stat.c
index 6c2f40940439..c52356d90fe3 100644
--- a/block/blk-stat.c
+++ b/block/blk-stat.c
@@ -96,13 +96,16 @@ void blk_stat_add(struct request *rq)
rcu_read_lock();
list_for_each_entry_rcu(cb, &q->stats->callbacks, list) {
- if (blk_stat_is_active(cb)) {
- bucket = cb->bucket_fn(rq);
- if (bucket < 0)
- continue;
- stat = &this_cpu_ptr(cb->cpu_stat)[bucket];
- __blk_stat_add(stat, value);
- }
+ if (!blk_stat_is_active(cb))
+ continue;
+
+ bucket = cb->bucket_fn(rq);
+ if (bucket < 0)
+ continue;
+
+ stat = &get_cpu_ptr(cb->cpu_stat)[bucket];
+ __blk_stat_add(stat, value);
+ put_cpu_ptr(cb->cpu_stat);
}
rcu_read_unlock();
}