1 files changed, 28 insertions, 41 deletions

diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index fd5fec989e39..45bd18f68541 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -485,19 +485,11 @@ static void blkcg_iolatency_throttle(struct rq_qos *rqos, struct bio *bio)
 		mod_timer(&blkiolat->timer, jiffies + HZ);
 }
 
-static void iolatency_record_time(struct iolatency_grp *iolat,
-				  struct bio_issue *issue, u64 now,
-				  bool issue_as_root)
+static void iolatency_record_time(struct iolatency_grp *iolat, u64 start,
+				  u64 now, bool issue_as_root)
 {
-	u64 start = bio_issue_time(issue);
 	u64 req_time;
 
-	/*
-	 * Have to do this so we are truncated to the correct time that our
-	 * issue is truncated to.
-	 */
-	now = __bio_issue_time(now);
-
 	if (now <= start)
 		return;
 
@@ -609,7 +601,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 	if (!iolat->blkiolat->enabled)
 		return;
 
-	now = ktime_to_ns(ktime_get());
+	now = blk_time_get_ns();
 	while (blkg && blkg->parent) {
 		iolat = blkg_to_lat(blkg);
 		if (!iolat) {
@@ -625,7 +617,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 		 * submitted, so do not account for it.
 		 */
 		if (iolat->min_lat_nsec && bio->bi_status != BLK_STS_AGAIN) {
-			iolatency_record_time(iolat, &bio->bi_issue, now,
+			iolatency_record_time(iolat, bio->issue_time_ns, now,
 					      issue_as_root);
 			window_start = atomic64_read(&iolat->window_start);
 			if (now > window_start &&
@@ -658,10 +650,11 @@ static const struct rq_qos_ops blkcg_iolatency_ops = {
 
 static void blkiolatency_timer_fn(struct timer_list *t)
 {
-	struct blk_iolatency *blkiolat = from_timer(blkiolat, t, timer);
+	struct blk_iolatency *blkiolat = timer_container_of(blkiolat, t,
+							    timer);
 	struct blkcg_gq *blkg;
 	struct cgroup_subsys_state *pos_css;
-	u64 now = ktime_to_ns(ktime_get());
+	u64 now = blk_time_get_ns();
 
 	rcu_read_lock();
 	blkg_for_each_descendant_pre(blkg, pos_css,
@@ -749,9 +742,16 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
 	 */
 	enabled = atomic_read(&blkiolat->enable_cnt);
 	if (enabled != blkiolat->enabled) {
-		blk_mq_freeze_queue(blkiolat->rqos.disk->queue);
+		struct request_queue *q = blkiolat->rqos.disk->queue;
+		unsigned int memflags;
+
+		memflags = blk_mq_freeze_queue(blkiolat->rqos.disk->queue);
 		blkiolat->enabled = enabled;
-		blk_mq_unfreeze_queue(blkiolat->rqos.disk->queue);
+		if (enabled)
+			blk_queue_flag_set(QUEUE_FLAG_BIO_ISSUE_TIME, q);
+		else
+			blk_queue_flag_clear(QUEUE_FLAG_BIO_ISSUE_TIME, q);
+		blk_mq_unfreeze_queue(blkiolat->rqos.disk->queue, memflags);
 	}
 }
 
@@ -824,29 +824,6 @@ static void iolatency_clear_scaling(struct blkcg_gq *blkg)
 	}
 }
 
-static int blk_iolatency_try_init(struct blkg_conf_ctx *ctx)
-{
-	static DEFINE_MUTEX(init_mutex);
-	int ret;
-
-	ret = blkg_conf_open_bdev(ctx);
-	if (ret)
-		return ret;
-
-	/*
-	 * blk_iolatency_init() may fail after rq_qos_add() succeeds which can
-	 * confuse iolat_rq_qos() test. Make the test and init atomic.
-	 */
-	mutex_lock(&init_mutex);
-
-	if (!iolat_rq_qos(ctx->bdev->bd_queue))
-		ret = blk_iolatency_init(ctx->bdev->bd_disk);
-
-	mutex_unlock(&init_mutex);
-
-	return ret;
-}
-
 static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
 			     size_t nbytes, loff_t off)
 {
@@ -861,7 +838,17 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
 
 	blkg_conf_init(&ctx, buf);
 
-	ret = blk_iolatency_try_init(&ctx);
+	ret = blkg_conf_open_bdev(&ctx);
+	if (ret)
+		goto out;
+
+	/*
+	 * blk_iolatency_init() may fail after rq_qos_add() succeeds which can
+	 * confuse iolat_rq_qos() test. Make the test and init atomic.
+	 */
+	lockdep_assert_held(&ctx.bdev->bd_queue->rq_qos_mutex);
+	if (!iolat_rq_qos(ctx.bdev->bd_queue))
+		ret = blk_iolatency_init(ctx.bdev->bd_disk);
 	if (ret)
 		goto out;
 
@@ -998,7 +985,7 @@ static void iolatency_pd_init(struct blkg_policy_data *pd)
 	struct blkcg_gq *blkg = lat_to_blkg(iolat);
 	struct rq_qos *rqos = iolat_rq_qos(blkg->q);
 	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
-	u64 now = ktime_to_ns(ktime_get());
+	u64 now = blk_time_get_ns();
 	int cpu;
 
 	if (blk_queue_nonrot(blkg->q))