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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#ifndef _BCACHE_WRITEBACK_H
2#define _BCACHE_WRITEBACK_H
3
4#define CUTOFF_WRITEBACK 40
5#define CUTOFF_WRITEBACK_SYNC 70
6
7static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
8{
9 uint64_t i, ret = 0;
10
11 for (i = 0; i < d->nr_stripes; i++)
12 ret += atomic_read(d->stripe_sectors_dirty + i);
13
14 return ret;
15}
16
17static inline unsigned offset_to_stripe(struct bcache_device *d,
18 uint64_t offset)
19{
20 do_div(offset, d->stripe_size);
21 return offset;
22}
23
24static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
25 uint64_t offset,
26 unsigned nr_sectors)
27{
28 unsigned stripe = offset_to_stripe(&dc->disk, offset);
29
30 while (1) {
31 if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
32 return true;
33
34 if (nr_sectors <= dc->disk.stripe_size)
35 return false;
36
37 nr_sectors -= dc->disk.stripe_size;
38 stripe++;
39 }
40}
41
42static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
43 unsigned cache_mode, bool would_skip)
44{
45 unsigned in_use = dc->disk.c->gc_stats.in_use;
46
47 if (cache_mode != CACHE_MODE_WRITEBACK ||
48 test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
49 in_use > CUTOFF_WRITEBACK_SYNC)
50 return false;
51
52 if (dc->partial_stripes_expensive &&
53 bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
54 bio_sectors(bio)))
55 return true;
56
57 if (would_skip)
58 return false;
59
60 return bio->bi_rw & REQ_SYNC ||
61 in_use <= CUTOFF_WRITEBACK;
62}
63
64static inline void bch_writeback_queue(struct cached_dev *dc)
65{
66 wake_up_process(dc->writeback_thread);
67}
68
69static inline void bch_writeback_add(struct cached_dev *dc)
70{
71 if (!atomic_read(&dc->has_dirty) &&
72 !atomic_xchg(&dc->has_dirty, 1)) {
73 atomic_inc(&dc->count);
74
75 if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
76 SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
77 /* XXX: should do this synchronously */
78 bch_write_bdev_super(dc, NULL);
79 }
80
81 bch_writeback_queue(dc);
82 }
83}
84
85void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
86
87void bch_sectors_dirty_init(struct cached_dev *dc);
88int bch_cached_dev_writeback_init(struct cached_dev *);
89
90#endif