Commit 3793c65c authored by Jens Axboe's avatar Jens Axboe Committed by Linus Torvalds
Browse files

[PATCH] cfq-iosched: fixup locking and ->queue_list list management 



- Drop cic from the list when seen as dead.
- Fixup the locking, just use a simple spinlock.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e60a48f5

block/cfq-iosched.c

+13 −12
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ static int cfq_slice_idle = HZ / 70; 


#define CFQ_KEY_ASYNC		(0)



static DEFINE_RWLOCK(cfq_exit_lock);

static DEFINE_SPINLOCK(cfq_exit_lock);



/*

 * for the hash of cfqq inside the cfqd
@@ -1284,7 +1284,7 @@ static void cfq_exit_io_context(struct io_context *ioc) 
	/*

	 * put the reference this task is holding to the various queues

	 */

	read_lock_irqsave(&cfq_exit_lock, flags);

	spin_lock_irqsave(&cfq_exit_lock, flags);



	n = rb_first(&ioc->cic_root);

	while (n != NULL) {
@@ -1294,7 +1294,7 @@ static void cfq_exit_io_context(struct io_context *ioc) 
		n = rb_next(n);

	}



	read_unlock_irqrestore(&cfq_exit_lock, flags);

	spin_unlock_irqrestore(&cfq_exit_lock, flags);

}



static struct cfq_io_context *
@@ -1400,7 +1400,7 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio) 
	struct cfq_io_context *cic;

	struct rb_node *n;



	write_lock(&cfq_exit_lock);

	spin_lock(&cfq_exit_lock);



	n = rb_first(&ioc->cic_root);

	while (n != NULL) {
@@ -1410,7 +1410,7 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio) 
		n = rb_next(n);

	}



	write_unlock(&cfq_exit_lock);

	spin_unlock(&cfq_exit_lock);



	return 0;

}
@@ -1475,9 +1475,10 @@ cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, 
static void

cfq_drop_dead_cic(struct io_context *ioc, struct cfq_io_context *cic)

{

	read_lock(&cfq_exit_lock);

	spin_lock(&cfq_exit_lock);

	rb_erase(&cic->rb_node, &ioc->cic_root);

	read_unlock(&cfq_exit_lock);

	list_del_init(&cic->queue_list);

	spin_unlock(&cfq_exit_lock);

	kmem_cache_free(cfq_ioc_pool, cic);

	atomic_dec(&ioc_count);

}
@@ -1545,11 +1546,11 @@ cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, 
			BUG();

	}



	read_lock(&cfq_exit_lock);

	spin_lock(&cfq_exit_lock);

	rb_link_node(&cic->rb_node, parent, p);

	rb_insert_color(&cic->rb_node, &ioc->cic_root);

	list_add(&cic->queue_list, &cfqd->cic_list);

	read_unlock(&cfq_exit_lock);

	spin_unlock(&cfq_exit_lock);

}



/*
@@ -2187,7 +2188,7 @@ static void cfq_exit_queue(elevator_t *e) 


	cfq_shutdown_timer_wq(cfqd);



	write_lock(&cfq_exit_lock);

	spin_lock(&cfq_exit_lock);

	spin_lock_irq(q->queue_lock);



	if (cfqd->active_queue)
@@ -2210,7 +2211,7 @@ static void cfq_exit_queue(elevator_t *e) 
	}



	spin_unlock_irq(q->queue_lock);

	write_unlock(&cfq_exit_lock);

	spin_unlock(&cfq_exit_lock);



	cfq_shutdown_timer_wq(cfqd);