[PATCH] deal with rmmod/put_io_context() races (334e94de) · Commits · e / devices / android_kernel_teracube_2e

block/as-iosched.c

+14 −1

Original line number	Original line	Diff line number	Diff line
	@@ -182,6 +182,9 @@ struct as_rq {

	static kmem_cache_t *arq_pool;		static kmem_cache_t *arq_pool;

			static atomic_t ioc_count = ATOMIC_INIT(0);
			static struct completion *ioc_gone;

	static void as_move_to_dispatch(struct as_data ad, struct as_rq arq);		static void as_move_to_dispatch(struct as_data ad, struct as_rq arq);
	static void as_antic_stop(struct as_data *ad);		static void as_antic_stop(struct as_data *ad);

	@@ -193,11 +196,14 @@ static void as_antic_stop(struct as_data *ad);
	static void free_as_io_context(struct as_io_context *aic)		static void free_as_io_context(struct as_io_context *aic)
	{		{
	kfree(aic);		kfree(aic);
			if (atomic_dec_and_test(&ioc_count) && ioc_gone)
			complete(ioc_gone);
	}		}

	static void as_trim(struct io_context *ioc)		static void as_trim(struct io_context *ioc)
	{		{
	kfree(ioc->aic);		if (ioc->aic)
			free_as_io_context(ioc->aic);
	ioc->aic = NULL;		ioc->aic = NULL;
	}		}

	@@ -226,6 +232,7 @@ static struct as_io_context *alloc_as_io_context(void)
	ret->seek_total = 0;		ret->seek_total = 0;
	ret->seek_samples = 0;		ret->seek_samples = 0;
	ret->seek_mean = 0;		ret->seek_mean = 0;
			atomic_inc(&ioc_count);
	}		}

	return ret;		return ret;
	@@ -1900,7 +1907,13 @@ static int __init as_init(void)

	static void __exit as_exit(void)		static void __exit as_exit(void)
	{		{
			DECLARE_COMPLETION(all_gone);
	elv_unregister(&iosched_as);		elv_unregister(&iosched_as);
			ioc_gone = &all_gone;
			barrier();
			if (atomic_read(&ioc_count))
			complete(ioc_gone);
			synchronize_rcu();
	kmem_cache_destroy(arq_pool);		kmem_cache_destroy(arq_pool);
	}		}

block/cfq-iosched.c

+16 −0

Original line number	Original line	Diff line number	Diff line
	@@ -91,6 +91,9 @@ static kmem_cache_t *crq_pool;
	static kmem_cache_t *cfq_pool;		static kmem_cache_t *cfq_pool;
	static kmem_cache_t *cfq_ioc_pool;		static kmem_cache_t *cfq_ioc_pool;

			static atomic_t ioc_count = ATOMIC_INIT(0);
			static struct completion *ioc_gone;

	#define CFQ_PRIO_LISTS IOPRIO_BE_NR		#define CFQ_PRIO_LISTS IOPRIO_BE_NR
	#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)		#define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
	#define cfq_class_be(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_BE)		#define cfq_class_be(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_BE)
	@@ -1202,13 +1205,17 @@ static void cfq_free_io_context(struct cfq_io_context *cic)
	{		{
	struct cfq_io_context *__cic;		struct cfq_io_context *__cic;
	struct list_head entry, next;		struct list_head entry, next;
			int freed = 1;

	list_for_each_safe(entry, next, &cic->list) {		list_for_each_safe(entry, next, &cic->list) {
	__cic = list_entry(entry, struct cfq_io_context, list);		__cic = list_entry(entry, struct cfq_io_context, list);
	kmem_cache_free(cfq_ioc_pool, __cic);		kmem_cache_free(cfq_ioc_pool, __cic);
			freed++;
	}		}

	kmem_cache_free(cfq_ioc_pool, cic);		kmem_cache_free(cfq_ioc_pool, cic);
			if (atomic_sub_and_test(freed, &ioc_count) && ioc_gone)
			complete(ioc_gone);
	}		}

	static void cfq_trim(struct io_context *ioc)		static void cfq_trim(struct io_context *ioc)
	@@ -1297,6 +1304,7 @@ cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask)
	cic->dtor = cfq_free_io_context;		cic->dtor = cfq_free_io_context;
	cic->exit = cfq_exit_io_context;		cic->exit = cfq_exit_io_context;
	INIT_LIST_HEAD(&cic->queue_list);		INIT_LIST_HEAD(&cic->queue_list);
			atomic_inc(&ioc_count);
	}		}

	return cic;		return cic;
	@@ -1501,6 +1509,7 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
	list);		list);
	read_unlock(&cfq_exit_lock);		read_unlock(&cfq_exit_lock);
	kmem_cache_free(cfq_ioc_pool, cic);		kmem_cache_free(cfq_ioc_pool, cic);
			atomic_dec(&ioc_count);
	goto restart;		goto restart;
	}		}

	@@ -1523,6 +1532,7 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
	list_del(&__cic->list);		list_del(&__cic->list);
	read_unlock(&cfq_exit_lock);		read_unlock(&cfq_exit_lock);
	kmem_cache_free(cfq_ioc_pool, __cic);		kmem_cache_free(cfq_ioc_pool, __cic);
			atomic_dec(&ioc_count);
	goto restart;		goto restart;
	}		}
	}		}
	@@ -2510,7 +2520,13 @@ static int __init cfq_init(void)

	static void __exit cfq_exit(void)		static void __exit cfq_exit(void)
	{		{
			DECLARE_COMPLETION(all_gone);
	elv_unregister(&iosched_cfq);		elv_unregister(&iosched_cfq);
			ioc_gone = &all_gone;
			barrier();
			if (atomic_read(&ioc_count))
			complete(ioc_gone);
			synchronize_rcu();
	cfq_slab_kill();		cfq_slab_kill();
	}		}

block/ll_rw_blk.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -3477,10 +3477,12 @@ void put_io_context(struct io_context *ioc)
	BUG_ON(atomic_read(&ioc->refcount) == 0);		BUG_ON(atomic_read(&ioc->refcount) == 0);

	if (atomic_dec_and_test(&ioc->refcount)) {		if (atomic_dec_and_test(&ioc->refcount)) {
			rcu_read_lock();
	if (ioc->aic && ioc->aic->dtor)		if (ioc->aic && ioc->aic->dtor)
	ioc->aic->dtor(ioc->aic);		ioc->aic->dtor(ioc->aic);
	if (ioc->cic && ioc->cic->dtor)		if (ioc->cic && ioc->cic->dtor)
	ioc->cic->dtor(ioc->cic);		ioc->cic->dtor(ioc->cic);
			rcu_read_unlock();

	kmem_cache_free(iocontext_cachep, ioc);		kmem_cache_free(iocontext_cachep, ioc);
	}		}