[linux-block.git] / drivers / md / bcache / writeback.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHE_WRITEBACK_H
#define _BCACHE_WRITEBACK_H

#define CUTOFF_WRITEBACK	40
#define CUTOFF_WRITEBACK_SYNC	70

#define CUTOFF_WRITEBACK_MAX		70
#define CUTOFF_WRITEBACK_SYNC_MAX	90

#define MAX_WRITEBACKS_IN_PASS  5
#define MAX_WRITESIZE_IN_PASS   5000	/* *512b */

#define WRITEBACK_RATE_UPDATE_SECS_MAX		60
#define WRITEBACK_RATE_UPDATE_SECS_DEFAULT	5

#define BCH_AUTO_GC_DIRTY_THRESHOLD	50

#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW 50
#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID 57
#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH 64

#define BCH_DIRTY_INIT_THRD_MAX	12
/*
 * 14 (16384ths) is chosen here as something that each backing device
 * should be a reasonable fraction of the share, and not to blow up
 * until individual backing devices are a petabyte.
 */
#define WRITEBACK_SHARE_SHIFT   14

struct bch_dirty_init_state;
struct dirty_init_thrd_info {
	struct bch_dirty_init_state	*state;
	struct task_struct		*thread;
};

struct bch_dirty_init_state {
	struct cache_set		*c;
	struct bcache_device		*d;
	int				total_threads;
	int				key_idx;
	spinlock_t			idx_lock;
	atomic_t			started;
	atomic_t			enough;
	wait_queue_head_t		wait;
	struct dirty_init_thrd_info	infos[BCH_DIRTY_INIT_THRD_MAX];
};

static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
{
	uint64_t i, ret = 0;

	for (i = 0; i < d->nr_stripes; i++)
		ret += atomic_read(d->stripe_sectors_dirty + i);

	return ret;
}

static inline int offset_to_stripe(struct bcache_device *d,
					uint64_t offset)
{
	do_div(offset, d->stripe_size);

	/* d->nr_stripes is in range [1, INT_MAX] */
	if (unlikely(offset >= d->nr_stripes)) {
		pr_err("Invalid stripe %llu (>= nr_stripes %d).\n",
			offset, d->nr_stripes);
		return -EINVAL;
	}

	/*
	 * Here offset is definitly smaller than INT_MAX,
	 * return it as int will never overflow.
	 */
	return offset;
}

static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
					   uint64_t offset,
					   unsigned int nr_sectors)
{
	int stripe = offset_to_stripe(&dc->disk, offset);

	if (stripe < 0)
		return false;

	while (1) {
		if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
			return true;

		if (nr_sectors <= dc->disk.stripe_size)
			return false;

		nr_sectors -= dc->disk.stripe_size;
		stripe++;
	}
}

extern unsigned int bch_cutoff_writeback;
extern unsigned int bch_cutoff_writeback_sync;

static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
				    unsigned int cache_mode, bool would_skip)
{
	unsigned int in_use = dc->disk.c->gc_stats.in_use;

	if (cache_mode != CACHE_MODE_WRITEBACK ||
	    test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
	    in_use > bch_cutoff_writeback_sync)
		return false;

	if (bio_op(bio) == REQ_OP_DISCARD)
		return false;

	if (dc->partial_stripes_expensive &&
	    bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
				    bio_sectors(bio)))
		return true;

	if (would_skip)
		return false;

	return (op_is_sync(bio->bi_opf) ||
		bio->bi_opf & (REQ_META|REQ_PRIO) ||
		in_use <= bch_cutoff_writeback);
}

static inline void bch_writeback_queue(struct cached_dev *dc)
{
	if (!IS_ERR_OR_NULL(dc->writeback_thread))
		wake_up_process(dc->writeback_thread);
}

static inline void bch_writeback_add(struct cached_dev *dc)
{
	if (!atomic_read(&dc->has_dirty) &&
	    !atomic_xchg(&dc->has_dirty, 1)) {
		if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
			SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
			/* XXX: should do this synchronously */
			bch_write_bdev_super(dc, NULL);
		}

		bch_writeback_queue(dc);
	}
}

void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,
				  uint64_t offset, int nr_sectors);

void bch_sectors_dirty_init(struct bcache_device *d);
void bch_cached_dev_writeback_init(struct cached_dev *dc);
int bch_cached_dev_writeback_start(struct cached_dev *dc);

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
279afbad KO	2	#ifndef _BCACHE_WRITEBACK_H
	3	#define _BCACHE_WRITEBACK_H
	4
72c27061 KO	5	#define CUTOFF_WRITEBACK 40
	6	#define CUTOFF_WRITEBACK_SYNC 70
	7
9aaf5165 CL	8	#define CUTOFF_WRITEBACK_MAX 70
	9	#define CUTOFF_WRITEBACK_SYNC_MAX 90
	10
539d39eb TJ	11	#define MAX_WRITEBACKS_IN_PASS 5
	12	#define MAX_WRITESIZE_IN_PASS 5000 /* 512b /
	13
7a5e3ecb CL	14	#define WRITEBACK_RATE_UPDATE_SECS_MAX 60
	15	#define WRITEBACK_RATE_UPDATE_SECS_DEFAULT 5
	16
7a671d8e CL	17	#define BCH_AUTO_GC_DIRTY_THRESHOLD 50
7a671d8e CL	18
71dda2a5	19	#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW 50
	20	#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID 57
	21	#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH 64
	22
4dc34ae1	23	#define BCH_DIRTY_INIT_THRD_MAX 12
616486ab ML	24	/*
	25	* 14 (16384ths) is chosen here as something that each backing device
	26	* should be a reasonable fraction of the share, and not to blow up
	27	* until individual backing devices are a petabyte.
	28	*/
	29	#define WRITEBACK_SHARE_SHIFT 14
	30
b144e45f CL	31	struct bch_dirty_init_state;
	32	struct dirty_init_thrd_info {
	33	struct bch_dirty_init_state *state;
	34	struct task_struct *thread;
	35	};
	36
	37	struct bch_dirty_init_state {
	38	struct cache_set *c;
	39	struct bcache_device *d;
	40	int total_threads;
	41	int key_idx;
	42	spinlock_t idx_lock;
	43	atomic_t started;
	44	atomic_t enough;
	45	wait_queue_head_t wait;
	46	struct dirty_init_thrd_info infos[BCH_DIRTY_INIT_THRD_MAX];
	47	};
	48
279afbad KO	49	static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
	50	{
	51	uint64_t i, ret = 0;
	52
	53	for (i = 0; i < d->nr_stripes; i++)
	54	ret += atomic_read(d->stripe_sectors_dirty + i);
	55
	56	return ret;
	57	}
	58
7a148126	59	static inline int offset_to_stripe(struct bcache_device *d,
48a915a8 KO	60	uint64_t offset)
	61	{
	62	do_div(offset, d->stripe_size);
7a148126 CL	63
	64	/* d->nr_stripes is in range [1, INT_MAX] */
	65	if (unlikely(offset >= d->nr_stripes)) {
	66	pr_err("Invalid stripe %llu (>= nr_stripes %d).\n",
	67	offset, d->nr_stripes);
	68	return -EINVAL;
	69	}
	70
	71	/*
	72	* Here offset is definitly smaller than INT_MAX,
	73	* return it as int will never overflow.
	74	*/
48a915a8 KO	75	return offset;
	76	}
	77
	78	static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
72c27061	79	uint64_t offset,
6f10f7d1	80	unsigned int nr_sectors)
72c27061	81	{
7a148126 CL	82	int stripe = offset_to_stripe(&dc->disk, offset);
	83
	84	if (stripe < 0)
	85	return false;
72c27061 KO	86
72c27061 KO	87	while (1) {
48a915a8	88	if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
72c27061 KO	89	return true;
72c27061 KO	90
48a915a8	91	if (nr_sectors <= dc->disk.stripe_size)
72c27061 KO	92	return false;
72c27061 KO	93
48a915a8	94	nr_sectors -= dc->disk.stripe_size;
72c27061 KO	95	stripe++;
	96	}
	97	}
	98
9aaf5165 CL	99	extern unsigned int bch_cutoff_writeback;
	100	extern unsigned int bch_cutoff_writeback_sync;
	101
72c27061	102	static inline bool should_writeback(struct cached_dev dc, struct bio bio,
6f10f7d1	103	unsigned int cache_mode, bool would_skip)
72c27061	104	{
6f10f7d1	105	unsigned int in_use = dc->disk.c->gc_stats.in_use;
72c27061 KO	106
72c27061 KO	107	if (cache_mode != CACHE_MODE_WRITEBACK \|\|
c4d951dd	108	test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) \|\|
9aaf5165	109	in_use > bch_cutoff_writeback_sync)
72c27061 KO	110	return false;
72c27061 KO	111
9951379b DA	112	if (bio_op(bio) == REQ_OP_DISCARD)
	113	return false;
	114
72c27061	115	if (dc->partial_stripes_expensive &&
4f024f37	116	bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
72c27061 KO	117	bio_sectors(bio)))
	118	return true;
	119
	120	if (would_skip)
	121	return false;
	122
b41c9b02 EW	123	return (op_is_sync(bio->bi_opf) \|\|
b41c9b02 EW	124	bio->bi_opf & (REQ_META\|REQ_PRIO) \|\|
9aaf5165	125	in_use <= bch_cutoff_writeback);
72c27061 KO	126	}
72c27061 KO	127
5e6926da KO	128	static inline void bch_writeback_queue(struct cached_dev *dc)
5e6926da KO	129	{
8d16ce54 SB	130	if (!IS_ERR_OR_NULL(dc->writeback_thread))
8d16ce54 SB	131	wake_up_process(dc->writeback_thread);
5e6926da KO	132	}
	133
	134	static inline void bch_writeback_add(struct cached_dev *dc)
	135	{
	136	if (!atomic_read(&dc->has_dirty) &&
	137	!atomic_xchg(&dc->has_dirty, 1)) {
5e6926da KO	138	if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
	139	SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
	140	/* XXX: should do this synchronously */
	141	bch_write_bdev_super(dc, NULL);
	142	}
	143
	144	bch_writeback_queue(dc);
	145	}
	146	}
	147
fc2d5988 CL	148	void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,
fc2d5988 CL	149	uint64_t offset, int nr_sectors);
279afbad	150
fc2d5988 CL	151	void bch_sectors_dirty_init(struct bcache_device *d);
	152	void bch_cached_dev_writeback_init(struct cached_dev *dc);
	153	int bch_cached_dev_writeback_start(struct cached_dev *dc);
279afbad KO	154
279afbad KO	155	#endif