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_WRITEBACK_FRAGMENT_THRESHOLD_LOW 50 20 #define BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID 57 21 #define BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH 64 22 23 #define BCH_DIRTY_INIT_THRD_MAX 12 24 /* 25 * 14 (16384ths) is chosen here as something that each backing device 26 * should be a reasonable fraction of the share, and not to blow up 27 * until individual backing devices are a petabyte. 28 */ 29 #define WRITEBACK_SHARE_SHIFT 14 30 31 struct bch_dirty_init_state; 32 struct dirty_init_thrd_info { 33 struct bch_dirty_init_state *state; 34 struct task_struct *thread; 35 }; 36 37 struct bch_dirty_init_state { 38 struct cache_set *c; 39 struct bcache_device *d; 40 int total_threads; 41 int key_idx; 42 spinlock_t idx_lock; 43 atomic_t started; 44 atomic_t enough; 45 wait_queue_head_t wait; 46 struct dirty_init_thrd_info infos[BCH_DIRTY_INIT_THRD_MAX]; 47 }; 48 49 static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d) 50 { 51 uint64_t i, ret = 0; 52 53 for (i = 0; i < d->nr_stripes; i++) 54 ret += atomic_read(d->stripe_sectors_dirty + i); 55 56 return ret; 57 } 58 59 static inline int offset_to_stripe(struct bcache_device *d, 60 uint64_t offset) 61 { 62 do_div(offset, d->stripe_size); 63 64 /* d->nr_stripes is in range [1, INT_MAX] */ 65 if (unlikely(offset >= d->nr_stripes)) { 66 pr_err("Invalid stripe %llu (>= nr_stripes %d).\n", 67 offset, d->nr_stripes); 68 return -EINVAL; 69 } 70 71 /* 72 * Here offset is definitly smaller than INT_MAX, 73 * return it as int will never overflow. 74 */ 75 return offset; 76 } 77 78 static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc, 79 uint64_t offset, 80 unsigned int nr_sectors) 81 { 82 int stripe = offset_to_stripe(&dc->disk, offset); 83 84 if (stripe < 0) 85 return false; 86 87 while (1) { 88 if (atomic_read(dc->disk.stripe_sectors_dirty + stripe)) 89 return true; 90 91 if (nr_sectors <= dc->disk.stripe_size) 92 return false; 93 94 nr_sectors -= dc->disk.stripe_size; 95 stripe++; 96 } 97 } 98 99 extern unsigned int bch_cutoff_writeback; 100 extern unsigned int bch_cutoff_writeback_sync; 101 102 static inline bool should_writeback(struct cached_dev *dc, struct bio *bio, 103 unsigned int cache_mode, bool would_skip) 104 { 105 unsigned int in_use = dc->disk.c->gc_stats.in_use; 106 107 if (cache_mode != CACHE_MODE_WRITEBACK || 108 test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) || 109 in_use > bch_cutoff_writeback_sync) 110 return false; 111 112 if (bio_op(bio) == REQ_OP_DISCARD) 113 return false; 114 115 if (dc->partial_stripes_expensive && 116 bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector, 117 bio_sectors(bio))) 118 return true; 119 120 if (would_skip) 121 return false; 122 123 return (op_is_sync(bio->bi_opf) || 124 bio->bi_opf & (REQ_META|REQ_PRIO) || 125 in_use <= bch_cutoff_writeback); 126 } 127 128 static inline void bch_writeback_queue(struct cached_dev *dc) 129 { 130 if (!IS_ERR_OR_NULL(dc->writeback_thread)) 131 wake_up_process(dc->writeback_thread); 132 } 133 134 static inline void bch_writeback_add(struct cached_dev *dc) 135 { 136 if (!atomic_read(&dc->has_dirty) && 137 !atomic_xchg(&dc->has_dirty, 1)) { 138 if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) { 139 SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY); 140 /* XXX: should do this synchronously */ 141 bch_write_bdev_super(dc, NULL); 142 } 143 144 bch_writeback_queue(dc); 145 } 146 } 147 148 void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode, 149 uint64_t offset, int nr_sectors); 150 151 void bch_sectors_dirty_init(struct bcache_device *d); 152 void bch_cached_dev_writeback_init(struct cached_dev *dc); 153 int bch_cached_dev_writeback_start(struct cached_dev *dc); 154 155 #endif 156