1 #ifndef _BCACHE_WRITEBACK_H
2 #define _BCACHE_WRITEBACK_H
3
4 #define CUTOFF_WRITEBACK 40
5 #define CUTOFF_WRITEBACK_SYNC 70
6
bcache_dev_sectors_dirty(struct bcache_device * d)7 static 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
bcache_flash_devs_sectors_dirty(struct cache_set * c)17 static inline uint64_t bcache_flash_devs_sectors_dirty(struct cache_set *c)
18 {
19 uint64_t i, ret = 0;
20
21 mutex_lock(&bch_register_lock);
22
23 for (i = 0; i < c->nr_uuids; i++) {
24 struct bcache_device *d = c->devices[i];
25
26 if (!d || !UUID_FLASH_ONLY(&c->uuids[i]))
27 continue;
28 ret += bcache_dev_sectors_dirty(d);
29 }
30
31 mutex_unlock(&bch_register_lock);
32
33 return ret;
34 }
35
offset_to_stripe(struct bcache_device * d,uint64_t offset)36 static inline unsigned offset_to_stripe(struct bcache_device *d,
37 uint64_t offset)
38 {
39 do_div(offset, d->stripe_size);
40 return offset;
41 }
42
bcache_dev_stripe_dirty(struct cached_dev * dc,uint64_t offset,unsigned nr_sectors)43 static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,
44 uint64_t offset,
45 unsigned nr_sectors)
46 {
47 unsigned stripe = offset_to_stripe(&dc->disk, offset);
48
49 while (1) {
50 if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))
51 return true;
52
53 if (nr_sectors <= dc->disk.stripe_size)
54 return false;
55
56 nr_sectors -= dc->disk.stripe_size;
57 stripe++;
58 }
59 }
60
should_writeback(struct cached_dev * dc,struct bio * bio,unsigned cache_mode,bool would_skip)61 static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
62 unsigned cache_mode, bool would_skip)
63 {
64 unsigned in_use = dc->disk.c->gc_stats.in_use;
65
66 if (cache_mode != CACHE_MODE_WRITEBACK ||
67 test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
68 in_use > CUTOFF_WRITEBACK_SYNC)
69 return false;
70
71 if (dc->partial_stripes_expensive &&
72 bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,
73 bio_sectors(bio)))
74 return true;
75
76 if (would_skip)
77 return false;
78
79 return bio->bi_rw & REQ_SYNC ||
80 in_use <= CUTOFF_WRITEBACK;
81 }
82
bch_writeback_queue(struct cached_dev * dc)83 static inline void bch_writeback_queue(struct cached_dev *dc)
84 {
85 if (!IS_ERR_OR_NULL(dc->writeback_thread))
86 wake_up_process(dc->writeback_thread);
87 }
88
bch_writeback_add(struct cached_dev * dc)89 static inline void bch_writeback_add(struct cached_dev *dc)
90 {
91 if (!atomic_read(&dc->has_dirty) &&
92 !atomic_xchg(&dc->has_dirty, 1)) {
93 atomic_inc(&dc->count);
94
95 if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
96 SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
97 /* XXX: should do this synchronously */
98 bch_write_bdev_super(dc, NULL);
99 }
100
101 bch_writeback_queue(dc);
102 }
103 }
104
105 void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
106
107 void bch_sectors_dirty_init(struct bcache_device *);
108 void bch_cached_dev_writeback_init(struct cached_dev *);
109 int bch_cached_dev_writeback_start(struct cached_dev *);
110
111 #endif
112