1 #ifndef _BCACHE_WRITEBACK_H 2 #define _BCACHE_WRITEBACK_H 3 4 #define CUTOFF_WRITEBACK 40 5 #define CUTOFF_WRITEBACK_SYNC 70 6 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 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 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 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 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 (op_is_sync(bio->bi_opf) || 80 bio->bi_opf & (REQ_META|REQ_PRIO) || 81 in_use <= CUTOFF_WRITEBACK); 82 } 83 84 static inline void bch_writeback_queue(struct cached_dev *dc) 85 { 86 if (!IS_ERR_OR_NULL(dc->writeback_thread)) 87 wake_up_process(dc->writeback_thread); 88 } 89 90 static inline void bch_writeback_add(struct cached_dev *dc) 91 { 92 if (!atomic_read(&dc->has_dirty) && 93 !atomic_xchg(&dc->has_dirty, 1)) { 94 refcount_inc(&dc->count); 95 96 if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) { 97 SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY); 98 /* XXX: should do this synchronously */ 99 bch_write_bdev_super(dc, NULL); 100 } 101 102 bch_writeback_queue(dc); 103 } 104 } 105 106 void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int); 107 108 void bch_sectors_dirty_init(struct bcache_device *); 109 void bch_cached_dev_writeback_init(struct cached_dev *); 110 int bch_cached_dev_writeback_start(struct cached_dev *); 111 112 #endif 113