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authorThomas Gleixner <tglx@linutronix.de>2020-05-11 22:54:30 +0200
committerThomas Gleixner <tglx@linutronix.de>2020-05-11 22:54:30 +0200
commit68f0f2690e183306b52671a9ad09fb31808b0500 (patch)
treeed86c9a38d307f609ccaab0baac367df3e7e5e39 /block/bfq-iosched.c
parentbaf5fe761846815164753d1bd0638fd3696db8fd (diff)
parentf736e0f1a55a88cb258b73da77463573739e9ac9 (diff)
downloadlinux-68f0f2690e183306b52671a9ad09fb31808b0500.tar.gz
Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul McKenney:

  1. Miscellaneous fixes.
  2. kfree_rcu() updates.
  3. Remove scheduler locking restriction
  4. RCU-tasks update, including addition of RCU Tasks Trace for
     BPF use and RCU Tasks Rude.  (This branch is on top of #3 due
     to overlap of changed code.)
  5. RCU CPU stall warning updates.
  6. Torture-test updates.
Diffstat (limited to 'block/bfq-iosched.c')
-rw-r--r--block/bfq-iosched.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 8c436abfaf14..78ba57efd16b 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -2716,8 +2716,6 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq)
 	}
 }
 
-
-static
 void bfq_release_process_ref(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 {
 	/*
@@ -6215,20 +6213,28 @@ static struct bfq_queue *bfq_init_rq(struct request *rq)
 	return bfqq;
 }
 
-static void bfq_idle_slice_timer_body(struct bfq_queue *bfqq)
+static void
+bfq_idle_slice_timer_body(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 {
-	struct bfq_data *bfqd = bfqq->bfqd;
 	enum bfqq_expiration reason;
 	unsigned long flags;
 
 	spin_lock_irqsave(&bfqd->lock, flags);
-	bfq_clear_bfqq_wait_request(bfqq);
 
+	/*
+	 * Considering that bfqq may be in race, we should firstly check
+	 * whether bfqq is in service before doing something on it. If
+	 * the bfqq in race is not in service, it has already been expired
+	 * through __bfq_bfqq_expire func and its wait_request flags has
+	 * been cleared in __bfq_bfqd_reset_in_service func.
+	 */
 	if (bfqq != bfqd->in_service_queue) {
 		spin_unlock_irqrestore(&bfqd->lock, flags);
 		return;
 	}
 
+	bfq_clear_bfqq_wait_request(bfqq);
+
 	if (bfq_bfqq_budget_timeout(bfqq))
 		/*
 		 * Also here the queue can be safely expired
@@ -6273,7 +6279,7 @@ static enum hrtimer_restart bfq_idle_slice_timer(struct hrtimer *timer)
 	 * early.
 	 */
 	if (bfqq)
-		bfq_idle_slice_timer_body(bfqq);
+		bfq_idle_slice_timer_body(bfqd, bfqq);
 
 	return HRTIMER_NORESTART;
 }