#include <linux/blkdev.h>
#include <linux/atomic.h>
#include <linux/kthread.h>
+#include <linux/fs.h>
/* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */
#define BLKG_STAT_CPU_BATCH (INT_MAX / 2)
return NULL;
}
+/**
+ * blkg_try_get_closest - try and get a blkg ref on the closet blkg
+ * @blkg: blkg to get
+ *
+ * This walks up the blkg tree to find the closest non-dying blkg and returns
+ * the blkg that it did association with as it may not be the passed in blkg.
+ */
+static inline struct blkcg_gq *blkg_try_get_closest(struct blkcg_gq *blkg)
+{
+ while (!atomic_inc_not_zero(&blkg->refcnt))
+ blkg = blkg->parent;
+
+ return blkg;
+}
void __blkg_release_rcu(struct rcu_head *rcu);
static inline bool blkcg_bio_issue_check(struct request_queue *q,
struct bio *bio)
{
- struct blkcg *blkcg;
struct blkcg_gq *blkg;
bool throtl = false;
- rcu_read_lock();
+ if (!bio->bi_blkg) {
+ char b[BDEVNAME_SIZE];
- /* associate blkcg if bio hasn't attached one */
- bio_associate_blkcg(bio, NULL);
- blkcg = bio_blkcg(bio);
-
- blkg = blkg_lookup(blkcg, q);
- if (unlikely(!blkg)) {
- spin_lock_irq(&q->queue_lock);
- blkg = __blkg_lookup_create(blkcg, q);
- if (IS_ERR(blkg))
- blkg = NULL;
- spin_unlock_irq(&q->queue_lock);
+ WARN_ONCE(1,
+ "no blkg associated for bio on block-device: %s\n",
+ bio_devname(bio, b));
+ bio_associate_blkg(bio);
}
+ blkg = bio->bi_blkg;
+
throtl = blk_throtl_bio(q, blkg, bio);
if (!throtl) {
- blkg = blkg ?: q->root_blkg;
/*
* If the bio is flagged with BIO_QUEUE_ENTERED it means this
* is a split bio and we would have already accounted for the
blkg_rwstat_add(&blkg->stat_ios, bio->bi_opf, 1);
}
- rcu_read_unlock();
return !throtl;
}