Merge tag 'block-6.4-2023-06-23' of git://git.kernel.dk/linux

Pull block fix from Jens Axboe:
 "It's apparently the week of 'fixup something from last week', because
  the same is true for this block pull request.

  Fix up a lock grab that needs to be IRQ saving, rather than just IRQ
  disabling, in the block cgroup code"

* tag 'block-6.4-2023-06-23' of git://git.kernel.dk/linux:
  block: make sure local irq is disabled when calling __blkcg_rstat_flush

Author: torvalds

block/blk-cgroup.c

@@ -970,6 +970,7 @@ static void __blkcg_rstat_flush(struct blkcg *blkcg, int cpu)
 	struct llist_head *lhead = per_cpu_ptr(blkcg->lhead, cpu);
 	struct llist_node *lnode;
 	struct blkg_iostat_set *bisc, *next_bisc;
+	unsigned long flags;
 
 	rcu_read_lock();
 
@@ -983,7 +984,7 @@ static void __blkcg_rstat_flush(struct blkcg *blkcg, int cpu)
 	 * When flushing from cgroup, cgroup_rstat_lock is always held, so
 	 * this lock won't cause contention most of time.
 	 */
-	raw_spin_lock(&blkg_stat_lock);
+	raw_spin_lock_irqsave(&blkg_stat_lock, flags);
 
 	/*
 	 * Iterate only the iostat_cpu's queued in the lockless list.
@@ -1009,7 +1010,7 @@ static void __blkcg_rstat_flush(struct blkcg *blkcg, int cpu)
 			blkcg_iostat_update(parent, &blkg->iostat.cur,
 					    &blkg->iostat.last);
 	}
-	raw_spin_unlock(&blkg_stat_lock);
+	raw_spin_unlock_irqrestore(&blkg_stat_lock, flags);
 out:
 	rcu_read_unlock();
 }