block: add docs for gendisk / request_queue refcount helpers (b5bd357c) · Commits · EulixOS / Software / Kernel

block/blk-core.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -321,6 +321,13 @@ void blk_clear_pm_only(struct request_queue *q)
		}
		EXPORT_SYMBOL_GPL(blk_clear_pm_only);

		/**
		* blk_put_queue - decrement the request_queue refcount
		* @q: the request_queue structure to decrement the refcount for
		*
		* Decrements the refcount of the request_queue kobject. When this reaches 0
		* we'll have blk_release_queue() called.
		*/
		void blk_put_queue(struct request_queue *q)
		{
		kobject_put(&q->kobj);
		@@ -598,6 +605,12 @@ struct request_queue *blk_alloc_queue(make_request_fn make_request, int node_id)
		}
		EXPORT_SYMBOL(blk_alloc_queue);

		/**
		* blk_get_queue - increment the request_queue refcount
		* @q: the request_queue structure to increment the refcount for
		*
		* Increment the refcount of the request_queue kobject.
		*/
		bool blk_get_queue(struct request_queue *q)
		{
		if (likely(!blk_queue_dying(q))) {

block/genhd.c

+49 −1

Original line number	Diff line number	Diff line
		@@ -876,6 +876,20 @@ static void invalidate_partition(struct gendisk *disk, int partno)
		bdput(bdev);
		}

		/**
		* del_gendisk - remove the gendisk
		* @disk: the struct gendisk to remove
		*
		* Removes the gendisk and all its associated resources. This deletes the
		* partitions associated with the gendisk, and unregisters the associated
		* request_queue.
		*
		* This is the counter to the respective __device_add_disk() call.
		*
		* The final removal of the struct gendisk happens when its refcount reaches 0
		* with put_disk(), which should be called after del_gendisk(), if
		* __device_add_disk() was used.
		*/
		void del_gendisk(struct gendisk *disk)
		{
		struct disk_part_iter piter;
		@@ -1514,6 +1528,23 @@ int disk_expand_part_tbl(struct gendisk *disk, int partno)
		return 0;
		}

		/**
		* disk_release - releases all allocated resources of the gendisk
		* @dev: the device representing this disk
		*
		* This function releases all allocated resources of the gendisk.
		*
		* The struct gendisk refcount is incremented with get_gendisk() or
		* get_disk_and_module(), and its refcount is decremented with
		* put_disk_and_module() or put_disk(). Once the refcount reaches 0 this
		* function is called.
		*
		* Drivers which used __device_add_disk() have a gendisk with a request_queue
		* assigned. Since the request_queue sits on top of the gendisk for these
		* drivers we also call blk_put_queue() for them, and we expect the
		* request_queue refcount to reach 0 at this point, and so the request_queue
		* will also be freed prior to the disk.
		*/
		static void disk_release(struct device *dev)
		{
		struct gendisk *disk = dev_to_disk(dev);
		@@ -1727,6 +1758,13 @@ struct gendisk *__alloc_disk_node(int minors, int node_id)
		}
		EXPORT_SYMBOL(__alloc_disk_node);

		/**
		* get_disk_and_module - increments the gendisk and gendisk fops module refcount
		* @disk: the struct gendisk to to increment the refcount for
		*
		* This increments the refcount for the struct gendisk, and the gendisk's
		* fops module owner.
		*/
		struct kobject get_disk_and_module(struct gendisk disk)
		{
		struct module *owner;
		@@ -1747,6 +1785,13 @@ struct kobject get_disk_and_module(struct gendisk disk)
		}
		EXPORT_SYMBOL(get_disk_and_module);

		/**
		* put_disk - decrements the gendisk refcount
		* @disk: the struct gendisk to to decrement the refcount for
		*
		* This decrements the refcount for the struct gendisk. When this reaches 0
		* we'll have disk_release() called.
		*/
		void put_disk(struct gendisk *disk)
		{
		if (disk)
		@@ -1754,7 +1799,10 @@ void put_disk(struct gendisk *disk)
		}
		EXPORT_SYMBOL(put_disk);

		/*
		/**
		* put_disk_and_module - decrements the module and gendisk refcount
		* @disk: the struct gendisk to to decrement the refcount for
		*
		* This is a counterpart of get_disk_and_module() and thus also of
		* get_gendisk().
		*/