diff options
| -rw-r--r-- | block/blk-throttle.c | 16 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 20 |
2 files changed, 19 insertions, 17 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 9beaac7fb397..c252df9169db 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; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 6063c4482b86..0f7a81fc7c73 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1122,17 +1122,19 @@ cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg) * Search for the cfq group current task belongs to. request_queue lock must * be held. */ -static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd) +static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, + struct blkio_cgroup *blkcg) { - struct blkio_cgroup *blkcg; struct cfq_group *cfqg = NULL, *__cfqg = NULL; struct request_queue *q = cfqd->queue; - blkcg = task_blkio_cgroup(current); cfqg = cfq_find_cfqg(cfqd, blkcg); if (cfqg) return cfqg; + 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 @@ -1142,16 +1144,14 @@ static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd) * around by the time we return. CFQ queue allocation code does * the same. It might be racy though. */ - rcu_read_unlock(); spin_unlock_irq(q->queue_lock); cfqg = cfq_alloc_cfqg(cfqd); spin_lock_irq(q->queue_lock); - rcu_read_lock(); - blkcg = task_blkio_cgroup(current); + css_put(&blkcg->css); /* * If some other thread already allocated the group while we were @@ -1278,7 +1278,8 @@ static bool cfq_clear_queue(struct request_queue *q) } #else /* GROUP_IOSCHED */ -static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd) +static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, + struct blkio_cgroup *blkcg) { return &cfqd->root_group; } @@ -2860,6 +2861,7 @@ static struct cfq_queue * cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, gfp_t gfp_mask) { + struct blkio_cgroup *blkcg; struct cfq_queue *cfqq, *new_cfqq = NULL; struct cfq_io_cq *cic; struct cfq_group *cfqg; @@ -2867,7 +2869,9 @@ cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, retry: rcu_read_lock(); - cfqg = cfq_get_cfqg(cfqd); + blkcg = task_blkio_cgroup(current); + + cfqg = cfq_get_cfqg(cfqd, blkcg); cic = cfq_cic_lookup(cfqd, ioc); /* cic always exists here */ cfqq = cic_to_cfqq(cic, is_sync); |