Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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 unsigned int offset_to_stripe(struct bcache_device *d,
56 uint64_t offset)
57{
58 do_div(offset, d->stripe_size);
59 return offset;
60}
61
62static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
63 uint64_t offset,
64 unsigned int nr_sectors)
65{
66 unsigned int stripe = offset_to_stripe(&dc->disk, offset);
67
68 while (1) {
69 if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
70 return true;
71
72 if (nr_sectors <= dc->disk.stripe_size)
73 return false;
74
75 nr_sectors -= dc->disk.stripe_size;
76 stripe++;
77 }
78}
79
80extern unsigned int bch_cutoff_writeback;
81extern unsigned int bch_cutoff_writeback_sync;
82
83static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
84 unsigned int cache_mode, bool would_skip)
85{
86 unsigned int in_use = dc->disk.c->gc_stats.in_use;
87
88 if (cache_mode != CACHE_MODE_WRITEBACK ||
89 test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
90 in_use > bch_cutoff_writeback_sync)
91 return false;
92
93 if (bio_op(bio) == REQ_OP_DISCARD)
94 return false;
95
96 if (dc->partial_stripes_expensive &&
97 bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
98 bio_sectors(bio)))
99 return true;
100
101 if (would_skip)
102 return false;
103
104 return (op_is_sync(bio->bi_opf) ||
105 bio->bi_opf & (REQ_META|REQ_PRIO) ||
106 in_use <= bch_cutoff_writeback);
107}
108
109static inline void bch_writeback_queue(struct cached_dev *dc)
110{
111 if (!IS_ERR_OR_NULL(dc->writeback_thread))
112 wake_up_process(dc->writeback_thread);
113}
114
115static inline void bch_writeback_add(struct cached_dev *dc)
116{
117 if (!atomic_read(&dc->has_dirty) &&
118 !atomic_xchg(&dc->has_dirty, 1)) {
119 if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
120 SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
121 /* XXX: should do this synchronously */
122 bch_write_bdev_super(dc, NULL);
123 }
124
125 bch_writeback_queue(dc);
126 }
127}
128
129void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,
130 uint64_t offset, int nr_sectors);
131
132void bch_sectors_dirty_init(struct bcache_device *d);
133void bch_cached_dev_writeback_init(struct cached_dev *dc);
134int bch_cached_dev_writeback_start(struct cached_dev *dc);
135
136#endif