diff options
Diffstat (limited to 'block/blk-throttle.c')
| -rw-r--r-- | block/blk-throttle.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 9beaac7fb39..c252df9169d 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -303,21 +303,23 @@ throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg) return tg; } -static struct throtl_grp * throtl_get_tg(struct throtl_data *td) +static struct throtl_grp *throtl_get_tg(struct throtl_data *td, + struct blkio_cgroup *blkcg) { struct throtl_grp *tg = NULL, *__tg = NULL; - struct blkio_cgroup *blkcg; struct request_queue *q = td->queue; /* no throttling for dead queue */ if (unlikely(blk_queue_bypass(q))) return NULL; - blkcg = task_blkio_cgroup(current); tg = throtl_find_tg(td, blkcg); if (tg) return tg; + if (!css_tryget(&blkcg->css)) + return NULL; + /* * Need to allocate a group. Allocation of group also needs allocation * of per cpu stats which in-turn takes a mutex() and can block. Hence @@ -331,6 +333,7 @@ static struct throtl_grp * throtl_get_tg(struct throtl_data *td) /* Group allocated and queue is still alive. take the lock */ rcu_read_lock(); spin_lock_irq(q->queue_lock); + css_put(&blkcg->css); /* Make sure @q is still alive */ if (unlikely(blk_queue_bypass(q))) { @@ -339,11 +342,6 @@ static struct throtl_grp * throtl_get_tg(struct throtl_data *td) } /* - * Initialize the new group. After sleeping, read the blkcg again. - */ - blkcg = task_blkio_cgroup(current); - - /* * If some other thread already allocated the group while we were * not holding queue lock, free up the group */ @@ -1163,7 +1161,7 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio) * IO group */ spin_lock_irq(q->queue_lock); - tg = throtl_get_tg(td); + tg = throtl_get_tg(td, blkcg); if (unlikely(!tg)) goto out_unlock; |