[linux-2.6-block.git] / drivers / md / dm-core.h

/*
 * Internal header file _only_ for device mapper core
 *
 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the LGPL.
 */

#ifndef DM_CORE_INTERNAL_H
#define DM_CORE_INTERNAL_H

#include <linux/kthread.h>
#include <linux/ktime.h>
#include <linux/blk-mq.h>

#include <trace/events/block.h>

#include "dm.h"

#define DM_RESERVED_MAX_IOS		1024

struct dm_kobject_holder {
	struct kobject kobj;
	struct completion completion;
};

/*
 * DM core internal structure that used directly by dm.c and dm-rq.c
 * DM targets must _not_ deference a mapped_device to directly access its members!
 */
struct mapped_device {
	struct mutex suspend_lock;

	/*
	 * The current mapping (struct dm_table *).
	 * Use dm_get_live_table{_fast} or take suspend_lock for
	 * dereference.
	 */
	void __rcu *map;

	struct list_head table_devices;
	struct mutex table_devices_lock;

	unsigned long flags;

	struct request_queue *queue;
	int numa_node_id;

	enum dm_queue_mode type;
	/* Protect queue and type against concurrent access. */
	struct mutex type_lock;

	atomic_t holders;
	atomic_t open_count;

	struct dm_target *immutable_target;
	struct target_type *immutable_target_type;

	struct gendisk *disk;
	struct dax_device *dax_dev;
	char name[16];

	void *interface_ptr;

	/*
	 * A list of ios that arrived while we were suspended.
	 */
	atomic_t pending[2];
	wait_queue_head_t wait;
	struct work_struct work;
	spinlock_t deferred_lock;
	struct bio_list deferred;

	/*
	 * Event handling.
	 */
	wait_queue_head_t eventq;
	atomic_t event_nr;
	atomic_t uevent_seq;
	struct list_head uevent_list;
	spinlock_t uevent_lock; /* Protect access to uevent_list */

	/* the number of internal suspends */
	unsigned internal_suspend_count;

	/*
	 * Processing queue (flush)
	 */
	struct workqueue_struct *wq;

	/*
	 * io objects are allocated from here.
	 */
	struct bio_set *io_bs;
	struct bio_set *bs;

	/*
	 * freeze/thaw support require holding onto a super block
	 */
	struct super_block *frozen_sb;

	/* forced geometry settings */
	struct hd_geometry geometry;

	struct block_device *bdev;

	/* kobject and completion */
	struct dm_kobject_holder kobj_holder;

	/* zero-length flush that will be cloned and submitted to targets */
	struct bio flush_bio;

	struct dm_stats stats;

	struct kthread_worker kworker;
	struct task_struct *kworker_task;

	/* for request-based merge heuristic in dm_request_fn() */
	unsigned seq_rq_merge_deadline_usecs;
	int last_rq_rw;
	sector_t last_rq_pos;
	ktime_t last_rq_start_time;

	/* for blk-mq request-based DM support */
	struct blk_mq_tag_set *tag_set;
	bool use_blk_mq:1;
	bool init_tio_pdu:1;

	struct srcu_struct io_barrier;
};

int md_in_flight(struct mapped_device *md);
void disable_write_same(struct mapped_device *md);
void disable_write_zeroes(struct mapped_device *md);

static inline struct completion *dm_get_completion_from_kobject(struct kobject *kobj)
{
	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
}

unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);

static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
{
	return !maxlen || strlen(result) + 1 >= maxlen;
}

extern atomic_t dm_global_event_nr;
extern wait_queue_head_t dm_global_eventq;
void dm_issue_global_event(void);

#endif
Commit	Line	Data
4cc96131 MS	1	/*
	2	* Internal header file _only_ for device mapper core
	3	*
	4	* Copyright (C) 2016 Red Hat, Inc. All rights reserved.
	5	*
	6	* This file is released under the LGPL.
	7	*/
	8
	9	#ifndef DM_CORE_INTERNAL_H
	10	#define DM_CORE_INTERNAL_H
	11
	12	#include <linux/kthread.h>
	13	#include <linux/ktime.h>
	14	#include <linux/blk-mq.h>
	15
	16	#include <trace/events/block.h>
	17
	18	#include "dm.h"
	19
	20	#define DM_RESERVED_MAX_IOS 1024
	21
	22	struct dm_kobject_holder {
	23	struct kobject kobj;
	24	struct completion completion;
	25	};
	26
	27	/*
	28	* DM core internal structure that used directly by dm.c and dm-rq.c
	29	* DM targets must _not_ deference a mapped_device to directly access its members!
	30	*/
	31	struct mapped_device {
4cc96131 MS	32	struct mutex suspend_lock;
	33
	34	/*
	35	* The current mapping (struct dm_table *).
	36	* Use dm_get_live_table{_fast} or take suspend_lock for
	37	* dereference.
	38	*/
	39	void __rcu *map;
	40
	41	struct list_head table_devices;
	42	struct mutex table_devices_lock;
	43
	44	unsigned long flags;
	45
	46	struct request_queue *queue;
	47	int numa_node_id;
	48
7e0d574f	49	enum dm_queue_mode type;
4cc96131 MS	50	/* Protect queue and type against concurrent access. */
	51	struct mutex type_lock;
	52
	53	atomic_t holders;
	54	atomic_t open_count;
	55
	56	struct dm_target *immutable_target;
	57	struct target_type *immutable_target_type;
	58
	59	struct gendisk *disk;
f26c5719	60	struct dax_device *dax_dev;
4cc96131 MS	61	char name[16];
	62
	63	void *interface_ptr;
	64
	65	/*
	66	* A list of ios that arrived while we were suspended.
	67	*/
	68	atomic_t pending[2];
	69	wait_queue_head_t wait;
	70	struct work_struct work;
	71	spinlock_t deferred_lock;
	72	struct bio_list deferred;
	73
	74	/*
	75	* Event handling.
	76	*/
	77	wait_queue_head_t eventq;
	78	atomic_t event_nr;
	79	atomic_t uevent_seq;
	80	struct list_head uevent_list;
	81	spinlock_t uevent_lock; /* Protect access to uevent_list */
	82
	83	/* the number of internal suspends */
	84	unsigned internal_suspend_count;
	85
	86	/*
	87	* Processing queue (flush)
	88	*/
	89	struct workqueue_struct *wq;
	90
	91	/*
	92	* io objects are allocated from here.
	93	*/
64f52b0e	94	struct bio_set *io_bs;
4cc96131 MS	95	struct bio_set *bs;
	96
	97	/*
	98	* freeze/thaw support require holding onto a super block
	99	*/
	100	struct super_block *frozen_sb;
	101
	102	/* forced geometry settings */
	103	struct hd_geometry geometry;
	104
	105	struct block_device *bdev;
	106
	107	/* kobject and completion */
	108	struct dm_kobject_holder kobj_holder;
	109
	110	/* zero-length flush that will be cloned and submitted to targets */
	111	struct bio flush_bio;
	112
	113	struct dm_stats stats;
	114
	115	struct kthread_worker kworker;
	116	struct task_struct *kworker_task;
	117
	118	/* for request-based merge heuristic in dm_request_fn() */
	119	unsigned seq_rq_merge_deadline_usecs;
	120	int last_rq_rw;
	121	sector_t last_rq_pos;
	122	ktime_t last_rq_start_time;
	123
	124	/* for blk-mq request-based DM support */
	125	struct blk_mq_tag_set *tag_set;
	126	bool use_blk_mq:1;
	127	bool init_tio_pdu:1;
856eb091 MP	128
856eb091 MP	129	struct srcu_struct io_barrier;
4cc96131 MS	130	};
4cc96131 MS	131
4cc96131 MS	132	int md_in_flight(struct mapped_device *md);
4cc96131 MS	133	void disable_write_same(struct mapped_device *md);
ac62d620	134	void disable_write_zeroes(struct mapped_device *md);
4cc96131 MS	135
	136	static inline struct completion dm_get_completion_from_kobject(struct kobject kobj)
	137	{
	138	return &container_of(kobj, struct dm_kobject_holder, kobj)->completion;
	139	}
	140
	141	unsigned __dm_get_module_param(unsigned *module_param, unsigned def, unsigned max);
	142
	143	static inline bool dm_message_test_buffer_overflow(char *result, unsigned maxlen)
	144	{
	145	return !maxlen \|\| strlen(result) + 1 >= maxlen;
	146	}
	147
93e6442c MP	148	extern atomic_t dm_global_event_nr;
93e6442c MP	149	extern wait_queue_head_t dm_global_eventq;
62e08243	150	void dm_issue_global_event(void);
93e6442c	151
4cc96131	152	#endif