block: misc ioc cleanups (42ec57a8) · Commits · 戴 / test

block/blk-ioc.c

+36 −36

Original line number	Diff line number	Diff line
		@@ -27,26 +27,28 @@ static void cfq_dtor(struct io_context *ioc)
		}
		}

		/*
		* IO Context helper functions. put_io_context() returns 1 if there are no
		* more users of this io context, 0 otherwise.
		/**
		* put_io_context - put a reference of io_context
		* @ioc: io_context to put
		*
		* Decrement reference count of @ioc and release it if the count reaches
		* zero.
		*/
		int put_io_context(struct io_context *ioc)
		void put_io_context(struct io_context *ioc)
		{
		if (ioc == NULL)
		return 1;
		return;

		BUG_ON(atomic_long_read(&ioc->refcount) <= 0);

		BUG_ON(atomic_long_read(&ioc->refcount) == 0);
		if (!atomic_long_dec_and_test(&ioc->refcount))
		return;

		if (atomic_long_dec_and_test(&ioc->refcount)) {
		rcu_read_lock();
		cfq_dtor(ioc);
		rcu_read_unlock();

		kmem_cache_free(iocontext_cachep, ioc);
		return 1;
		}
		return 0;
		}
		EXPORT_SYMBOL(put_io_context);

		@@ -84,33 +86,31 @@ struct io_context *alloc_io_context(gfp_t gfp_flags, int node)
		{
		struct io_context *ioc;

		ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags, node);
		if (ioc) {
		ioc = kmem_cache_alloc_node(iocontext_cachep, gfp_flags \| __GFP_ZERO,
		node);
		if (unlikely(!ioc))
		return NULL;

		/* initialize */
		atomic_long_set(&ioc->refcount, 1);
		atomic_set(&ioc->nr_tasks, 1);
		spin_lock_init(&ioc->lock);
		ioc->ioprio_changed = 0;
		ioc->ioprio = 0;
		ioc->last_waited = 0; /* doesn't matter... */
		ioc->nr_batch_requests = 0; /* because this is 0 */
		INIT_RADIX_TREE(&ioc->radix_root, GFP_ATOMIC \| __GFP_HIGH);
		INIT_HLIST_HEAD(&ioc->cic_list);
		ioc->ioc_data = NULL;
		#if defined(CONFIG_BLK_CGROUP) \|\| defined(CONFIG_BLK_CGROUP_MODULE)
		ioc->cgroup_changed = 0;
		#endif
		}

		return ioc;
		}

		/*
		* If the current task has no IO context then create one and initialise it.
		* Otherwise, return its existing IO context.
		/**
		* current_io_context - get io_context of %current
		* @gfp_flags: allocation flags, used if allocation is necessary
		* @node: allocation node, used if allocation is necessary
		*
		* This returned IO context doesn't have a specifically elevated refcount,
		* but since the current task itself holds a reference, the context can be
		* used in general code, so long as it stays within `current` context.
		* Return io_context of %current. If it doesn't exist, it is created with
		* @gfp_flags and @node. The returned io_context does NOT have its
		* reference count incremented. Because io_context is exited only on task
		* exit, %current can be sure that the returned io_context is valid and
		* alive as long as it is executing.
		*/
		struct io_context *current_io_context(gfp_t gfp_flags, int node)
		{

include/linux/iocontext.h

+3 −9

Original line number	Diff line number	Diff line
		@@ -76,20 +76,14 @@ static inline struct io_context ioc_task_link(struct io_context ioc)

		struct task_struct;
		#ifdef CONFIG_BLOCK
		int put_io_context(struct io_context *ioc);
		void put_io_context(struct io_context *ioc);
		void exit_io_context(struct task_struct *task);
		struct io_context *get_io_context(gfp_t gfp_flags, int node);
		struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
		#else
		static inline void exit_io_context(struct task_struct *task)
		{
		}

		struct io_context;
		static inline int put_io_context(struct io_context *ioc)
		{
		return 1;
		}
		static inline void put_io_context(struct io_context *ioc) { }
		static inline void exit_io_context(struct task_struct *task) { }
		#endif

		#endif

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