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 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 24 static 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 42 static 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 64 static inline void bch_writeback_queue(struct cached_dev *dc) 65 { 66 wake_up_process(dc->writeback_thread); 67 } 68 69 static 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 85 void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int); 86 87 void bch_sectors_dirty_init(struct cached_dev *dc); 88 void bch_cached_dev_writeback_init(struct cached_dev *); 89 int bch_cached_dev_writeback_start(struct cached_dev *); 90 91 #endif 92