/* SPDX-License-Identifier: GPL-2.0 */#ifndef _BCACHE_WRITEBACK_H#define _BCACHE_WRITEBACK_H #define CUTOFF_WRITEBACK	40#define CUTOFF_WRITEBACK_SYNC	70 #define CUTOFF_WRITEBACK_MAX		70#define CUTOFF_WRITEBACK_SYNC_MAX	90 #define MAX_WRITEBACKS_IN_PASS  5#define MAX_WRITESIZE_IN_PASS   5000	/* *512b */ #define WRITEBACK_RATE_UPDATE_SECS_MAX		60#define WRITEBACK_RATE_UPDATE_SECS_DEFAULT	5 #define BCH_AUTO_GC_DIRTY_THRESHOLD	50 /* * 14 (16384ths) is chosen here as something that each backing device * should be a reasonable fraction of the share, and not to blow up * until individual backing devices are a petabyte. */#define WRITEBACK_SHARE_SHIFT   14 static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d){	uint64_t i, ret = 0; 	for (i = 0; i < d->nr_stripes; i++)		ret += atomic_read(d->stripe_sectors_dirty + i); 	return ret;} static inline unsigned int offset_to_stripe(struct bcache_device *d,					uint64_t offset){	do_div(offset, d->stripe_size);	return offset;} static inline bool bcache_dev_stripe_dirty(struct cached_dev *dc,					   uint64_t offset,					   unsigned int nr_sectors){	unsigned int stripe = offset_to_stripe(&dc->disk, offset); 	while (1) {		if (atomic_read(dc->disk.stripe_sectors_dirty + stripe))			return true; 		if (nr_sectors <= dc->disk.stripe_size)			return false; 		nr_sectors -= dc->disk.stripe_size;		stripe++;	}} extern unsigned int bch_cutoff_writeback;extern unsigned int bch_cutoff_writeback_sync; static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,				    unsigned int cache_mode, bool would_skip){	unsigned int in_use = dc->disk.c->gc_stats.in_use; 	if (cache_mode != CACHE_MODE_WRITEBACK ||	    test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||	    in_use > bch_cutoff_writeback_sync)		return false; 	if (bio_op(bio) == REQ_OP_DISCARD)		return false; 	if (dc->partial_stripes_expensive &&	    bcache_dev_stripe_dirty(dc, bio->bi_iter.bi_sector,				    bio_sectors(bio)))		return true; 	if (would_skip)		return false; 	return (op_is_sync(bio->bi_opf) ||		bio->bi_opf & (REQ_META|REQ_PRIO) ||		in_use <= bch_cutoff_writeback);} static inline void bch_writeback_queue(struct cached_dev *dc){	if (!IS_ERR_OR_NULL(dc->writeback_thread))		wake_up_process(dc->writeback_thread);} static inline void bch_writeback_add(struct cached_dev *dc){	if (!atomic_read(&dc->has_dirty) &&	    !atomic_xchg(&dc->has_dirty, 1)) {		if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {			SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);			/* XXX: should do this synchronously */			bch_write_bdev_super(dc, NULL);		} 		bch_writeback_queue(dc);	}} void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,				  uint64_t offset, int nr_sectors); void bch_sectors_dirty_init(struct bcache_device *d);void bch_cached_dev_writeback_init(struct cached_dev *dc);int bch_cached_dev_writeback_start(struct cached_dev *dc); #endif