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