drivers/block/null_blk/null_blk.h

Source file repositories/reference/linux-study-clean/drivers/block/null_blk/null_blk.h

File Facts

System
Linux kernel
Corpus path
drivers/block/null_blk/null_blk.h
Extension
.h
Size
6273 bytes
Lines
186
Domain
Driver Families
Bucket
drivers/block
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct nullb_cmd {
	blk_status_t error;
	bool fake_timeout;
	struct nullb_queue *nq;
	struct hrtimer timer;
};

struct nullb_queue {
	struct nullb_device *dev;
	unsigned int requeue_selection;

	struct list_head poll_list;
	spinlock_t poll_lock;
};

struct nullb_zone {
	/*
	 * Zone lock to prevent concurrent modification of a zone write
	 * pointer position and condition: with memory backing, a write
	 * command execution may sleep on memory allocation. For this case,
	 * use mutex as the zone lock. Otherwise, use the spinlock for
	 * locking the zone.
	 */
	union {
		spinlock_t spinlock;
		struct mutex mutex;
	};
	enum blk_zone_type type;
	enum blk_zone_cond cond;
	sector_t start;
	sector_t wp;
	unsigned int len;
	unsigned int capacity;
};

struct nullb_device {
	struct nullb *nullb;
	struct config_group group;
#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
	struct fault_config timeout_config;
	struct fault_config requeue_config;
	struct fault_config init_hctx_fault_config;
#endif
	struct radix_tree_root data; /* data stored in the disk */
	struct radix_tree_root cache; /* disk cache data */
	unsigned long flags; /* device flags */
	unsigned int curr_cache;
	struct badblocks badblocks;
	bool badblocks_once;
	bool badblocks_partial_io;

	unsigned int nr_zones;
	unsigned int nr_zones_imp_open;
	unsigned int nr_zones_exp_open;
	unsigned int nr_zones_closed;
	unsigned int imp_close_zone_no;
	struct nullb_zone *zones;
	sector_t zone_size_sects;
	bool need_zone_res_mgmt;
	spinlock_t zone_res_lock;

	unsigned long size; /* device size in MB */
	unsigned long completion_nsec; /* time in ns to complete a request */
	unsigned long cache_size; /* disk cache size in MB */
	unsigned long zone_size; /* zone size in MB if device is zoned */
	unsigned long zone_capacity; /* zone capacity in MB if device is zoned */
	unsigned int zone_nr_conv; /* number of conventional zones */
	unsigned int zone_max_open; /* max number of open zones */
	unsigned int zone_max_active; /* max number of active zones */
	unsigned int zone_append_max_sectors; /* Max sectors per zone append command */
	unsigned int submit_queues; /* number of submission queues */
	unsigned int prev_submit_queues; /* number of submission queues before change */
	unsigned int poll_queues; /* number of IOPOLL submission queues */
	unsigned int prev_poll_queues; /* number of IOPOLL submission queues before change */
	unsigned int home_node; /* home node for the device */
	unsigned int queue_mode; /* block interface */
	unsigned int blocksize; /* block size */
	unsigned int max_sectors; /* Max sectors per command */
	unsigned int irqmode; /* IRQ completion handler */
	unsigned int hw_queue_depth; /* queue depth */
	unsigned int index; /* index of the disk, only valid with a disk */
	unsigned int mbps; /* Bandwidth throttle cap (in MB/s) */
	bool blocking; /* blocking blk-mq device */
	bool use_per_node_hctx; /* use per-node allocation for hardware context */
	bool power; /* power on/off the device */
	bool memory_backed; /* if data is stored in memory */
	bool discard; /* if support discard */
	bool zoned; /* if device is zoned */
	bool zone_full; /* Initialize zones to be full */
	bool virt_boundary; /* virtual boundary on/off for the device */

Annotation

Implementation Notes