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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _BCACHE_WRITEBACK_H3#define _BCACHE_WRITEBACK_H4 5#define CUTOFF_WRITEBACK 406#define CUTOFF_WRITEBACK_SYNC 707 8#define CUTOFF_WRITEBACK_MAX 709#define CUTOFF_WRITEBACK_SYNC_MAX 9010 11#define MAX_WRITEBACKS_IN_PASS 512#define MAX_WRITESIZE_IN_PASS 5000 /* *512b */13 14#define WRITEBACK_RATE_UPDATE_SECS_MAX 6015#define WRITEBACK_RATE_UPDATE_SECS_DEFAULT 516 17#define BCH_AUTO_GC_DIRTY_THRESHOLD 5018 19#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW 5020#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID 5721#define BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH 6422 23#define BCH_DIRTY_INIT_THRD_MAX 1224/*25 * 14 (16384ths) is chosen here as something that each backing device26 * should be a reasonable fraction of the share, and not to blow up27 * until individual backing devices are a petabyte.28 */29#define WRITEBACK_SHARE_SHIFT 1430 31struct bch_dirty_init_state;32struct dirty_init_thrd_info {33 struct bch_dirty_init_state *state;34 struct task_struct *thread;35};36 37struct 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 49static 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 59static 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 78static 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 99extern unsigned int bch_cutoff_writeback;100extern unsigned int bch_cutoff_writeback_sync;101 102static 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 128static 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 134static 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 148void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,149 uint64_t offset, int nr_sectors);150 151void bch_sectors_dirty_init(struct bcache_device *d);152void bch_cached_dev_writeback_init(struct cached_dev *dc);153int bch_cached_dev_writeback_start(struct cached_dev *dc);154 155#endif156