diff options
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 6063c4482b8..0f7a81fc7c7 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); |