fs/bcachefs/buckets.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Code for manipulating bucket marks for garbage collection.
  *
  * Copyright 2014 Datera, Inc.
  */

 #ifndef _BUCKETS_H
 #define _BUCKETS_H

 #include "buckets_types.h"
 #include "extents.h"
 #include "sb-members.h"

 static inline size_t sector_to_bucket(const struct bch_dev *ca, sector_t s)
 {
 	return div_u64(s, ca->mi.bucket_size);
 }

 static inline sector_t bucket_to_sector(const struct bch_dev *ca, size_t b)
 {
 	return ((sector_t) b) * ca->mi.bucket_size;
 }

 static inline sector_t bucket_remainder(const struct bch_dev *ca, sector_t s)
 {
 	u32 remainder;

 	div_u64_rem(s, ca->mi.bucket_size, &remainder);
 	return remainder;
 }

 static inline size_t sector_to_bucket_and_offset(const struct bch_dev *ca, sector_t s,
 						 u32 *offset)
 {
 	return div_u64_rem(s, ca->mi.bucket_size, offset);
 }

 #define for_each_bucket(_b, _buckets)				\
 	for (_b = (_buckets)->b + (_buckets)->first_bucket;	\
 	     _b < (_buckets)->b + (_buckets)->nbuckets; _b++)

 /*
  * Ugly hack alert:
  *
  * We need to cram a spinlock in a single byte, because that's what we have left
  * in struct bucket, and we care about the size of these - during fsck, we need
  * in memory state for every single bucket on every device.
  *
  * We used to do
  *   while (xchg(&b->lock, 1) cpu_relax();
  * but, it turns out not all architectures support xchg on a single byte.
  *
  * So now we use bit_spin_lock(), with fun games since we can't burn a whole
  * ulong for this - we just need to make sure the lock bit always ends up in the
  * first byte.
  */

 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define BUCKET_LOCK_BITNR	0
 #else
 #define BUCKET_LOCK_BITNR	(BITS_PER_LONG - 1)
 #endif

 union ulong_byte_assert {
 	ulong	ulong;
 	u8	byte;
 };

 static inline void bucket_unlock(struct bucket *b)
 {
 	BUILD_BUG_ON(!((union ulong_byte_assert) { .ulong = 1UL << BUCKET_LOCK_BITNR }).byte);

 	clear_bit_unlock(BUCKET_LOCK_BITNR, (void *) &b->lock);
 	wake_up_bit((void *) &b->lock, BUCKET_LOCK_BITNR);
 }

 static inline void bucket_lock(struct bucket *b)
 {
 	wait_on_bit_lock((void *) &b->lock, BUCKET_LOCK_BITNR,
 			 TASK_UNINTERRUPTIBLE);
 }

 static inline struct bucket_array *gc_bucket_array(struct bch_dev *ca)
 {
 	return rcu_dereference_check(ca->buckets_gc,
 				     !ca->fs ||
 				     percpu_rwsem_is_held(&ca->fs->mark_lock) ||
 				     lockdep_is_held(&ca->fs->gc_lock) ||
 				     lockdep_is_held(&ca->bucket_lock));
 }

 static inline struct bucket *gc_bucket(struct bch_dev *ca, size_t b)
 {
 	struct bucket_array *buckets = gc_bucket_array(ca);

 	BUG_ON(b < buckets->first_bucket || b >= buckets->nbuckets);
 	return buckets->b + b;
 }

 static inline struct bucket_gens *bucket_gens(struct bch_dev *ca)
 {
 	return rcu_dereference_check(ca->bucket_gens,
 				     !ca->fs ||
 				     percpu_rwsem_is_held(&ca->fs->mark_lock) ||
 				     lockdep_is_held(&ca->fs->gc_lock) ||
 				     lockdep_is_held(&ca->bucket_lock));
 }

 static inline u8 *bucket_gen(struct bch_dev *ca, size_t b)
 {
 	struct bucket_gens *gens = bucket_gens(ca);

 	BUG_ON(b < gens->first_bucket || b >= gens->nbuckets);
 	return gens->b + b;
 }

 static inline size_t PTR_BUCKET_NR(const struct bch_dev *ca,
 				   const struct bch_extent_ptr *ptr)
 {
 	return sector_to_bucket(ca, ptr->offset);
 }

 static inline struct bpos PTR_BUCKET_POS(const struct bch_fs *c,
 				   const struct bch_extent_ptr *ptr)
 {
 	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);

 	return POS(ptr->dev, PTR_BUCKET_NR(ca, ptr));
 }

 static inline struct bpos PTR_BUCKET_POS_OFFSET(const struct bch_fs *c,
 						const struct bch_extent_ptr *ptr,
 						u32 *bucket_offset)
 {
 	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);

 	return POS(ptr->dev, sector_to_bucket_and_offset(ca, ptr->offset, bucket_offset));
 }

 static inline struct bucket *PTR_GC_BUCKET(struct bch_dev *ca,
 					   const struct bch_extent_ptr *ptr)
 {
 	return gc_bucket(ca, PTR_BUCKET_NR(ca, ptr));
 }

 static inline enum bch_data_type ptr_data_type(const struct bkey *k,
 					       const struct bch_extent_ptr *ptr)
 {
 	if (bkey_is_btree_ptr(k))
 		return BCH_DATA_btree;

 	return ptr->cached ? BCH_DATA_cached : BCH_DATA_user;
 }

 static inline s64 ptr_disk_sectors(s64 sectors, struct extent_ptr_decoded p)
 {
 	EBUG_ON(sectors < 0);

 	return crc_is_compressed(p.crc)
 		? DIV_ROUND_UP_ULL(sectors * p.crc.compressed_size,
 				   p.crc.uncompressed_size)
 		: sectors;
 }

 static inline int gen_cmp(u8 a, u8 b)
 {
 	return (s8) (a - b);
 }

 static inline int gen_after(u8 a, u8 b)
 {
 	int r = gen_cmp(a, b);

 	return r > 0 ? r : 0;
 }

 /**
  * ptr_stale() - check if a pointer points into a bucket that has been
  * invalidated.
  */
 static inline u8 ptr_stale(struct bch_dev *ca,
 			   const struct bch_extent_ptr *ptr)
 {
 	u8 ret;

 	rcu_read_lock();
 	ret = gen_after(*bucket_gen(ca, PTR_BUCKET_NR(ca, ptr)), ptr->gen);
 	rcu_read_unlock();

 	return ret;
 }

 /* Device usage: */

 void bch2_dev_usage_read_fast(struct bch_dev *, struct bch_dev_usage *);
 static inline struct bch_dev_usage bch2_dev_usage_read(struct bch_dev *ca)
 {
 	struct bch_dev_usage ret;

 	bch2_dev_usage_read_fast(ca, &ret);
 	return ret;
 }

 void bch2_dev_usage_init(struct bch_dev *);
 void bch2_dev_usage_to_text(struct printbuf *, struct bch_dev_usage *);

 static inline u64 bch2_dev_buckets_reserved(struct bch_dev *ca, enum bch_watermark watermark)
 {
 	s64 reserved = 0;

 	switch (watermark) {
 	case BCH_WATERMARK_NR:
 		BUG();
 	case BCH_WATERMARK_stripe:
 		reserved += ca->mi.nbuckets >> 6;
 		fallthrough;
 	case BCH_WATERMARK_normal:
 		reserved += ca->mi.nbuckets >> 6;
 		fallthrough;
 	case BCH_WATERMARK_copygc:
 		reserved += ca->nr_btree_reserve;
 		fallthrough;
 	case BCH_WATERMARK_btree:
 		reserved += ca->nr_btree_reserve;
 		fallthrough;
 	case BCH_WATERMARK_btree_copygc:
 	case BCH_WATERMARK_reclaim:
 		break;
 	}

 	return reserved;
 }

 static inline u64 dev_buckets_free(struct bch_dev *ca,
 				   struct bch_dev_usage usage,
 				   enum bch_watermark watermark)
 {
 	return max_t(s64, 0,
 		     usage.d[BCH_DATA_free].buckets -
 		     ca->nr_open_buckets -
 		     bch2_dev_buckets_reserved(ca, watermark));
 }

 static inline u64 __dev_buckets_available(struct bch_dev *ca,
 					  struct bch_dev_usage usage,
 					  enum bch_watermark watermark)
 {
 	return max_t(s64, 0,
 		       usage.d[BCH_DATA_free].buckets
 		     + usage.d[BCH_DATA_cached].buckets
 		     + usage.d[BCH_DATA_need_gc_gens].buckets
 		     + usage.d[BCH_DATA_need_discard].buckets
 		     - ca->nr_open_buckets
 		     - bch2_dev_buckets_reserved(ca, watermark));
 }

 static inline u64 dev_buckets_available(struct bch_dev *ca,
 					enum bch_watermark watermark)
 {
 	return __dev_buckets_available(ca, bch2_dev_usage_read(ca), watermark);
 }

 /* Filesystem usage: */

 static inline unsigned __fs_usage_u64s(unsigned nr_replicas)
 {
 	return sizeof(struct bch_fs_usage) / sizeof(u64) + nr_replicas;
 }

 static inline unsigned fs_usage_u64s(struct bch_fs *c)
 {
 	return __fs_usage_u64s(READ_ONCE(c->replicas.nr));
 }

 static inline unsigned __fs_usage_online_u64s(unsigned nr_replicas)
 {
 	return sizeof(struct bch_fs_usage_online) / sizeof(u64) + nr_replicas;
 }

 static inline unsigned fs_usage_online_u64s(struct bch_fs *c)
 {
 	return __fs_usage_online_u64s(READ_ONCE(c->replicas.nr));
 }

 static inline unsigned dev_usage_u64s(void)
 {
 	return sizeof(struct bch_dev_usage) / sizeof(u64);
 }

 u64 bch2_fs_usage_read_one(struct bch_fs *, u64 *);

 struct bch_fs_usage_online *bch2_fs_usage_read(struct bch_fs *);

 void bch2_fs_usage_acc_to_base(struct bch_fs *, unsigned);

 void bch2_fs_usage_to_text(struct printbuf *,
 			   struct bch_fs *, struct bch_fs_usage_online *);

 u64 bch2_fs_sectors_used(struct bch_fs *, struct bch_fs_usage_online *);

 struct bch_fs_usage_short
 bch2_fs_usage_read_short(struct bch_fs *);

 void bch2_dev_usage_update(struct bch_fs *, struct bch_dev *,
 			   const struct bch_alloc_v4 *,
 			   const struct bch_alloc_v4 *, u64, bool);
 void bch2_dev_usage_update_m(struct bch_fs *, struct bch_dev *,
 			     struct bucket *, struct bucket *);

 /* key/bucket marking: */

 static inline struct bch_fs_usage *fs_usage_ptr(struct bch_fs *c,
 						unsigned journal_seq,
 						bool gc)
 {
 	percpu_rwsem_assert_held(&c->mark_lock);
 	BUG_ON(!gc && !journal_seq);

 	return this_cpu_ptr(gc
 			    ? c->usage_gc
 			    : c->usage[journal_seq & JOURNAL_BUF_MASK]);
 }

 int bch2_update_replicas(struct bch_fs *, struct bkey_s_c,
 			 struct bch_replicas_entry_v1 *, s64,
 			 unsigned, bool);
 int bch2_update_replicas_list(struct btree_trans *,
 			 struct bch_replicas_entry_v1 *, s64);
 int bch2_update_cached_sectors_list(struct btree_trans *, unsigned, s64);
 int bch2_replicas_deltas_realloc(struct btree_trans *, unsigned);

 void bch2_fs_usage_initialize(struct bch_fs *);

 int bch2_check_bucket_ref(struct btree_trans *, struct bkey_s_c,
 			  const struct bch_extent_ptr *,
 			  s64, enum bch_data_type, u8, u8, u32);

 int bch2_mark_metadata_bucket(struct bch_fs *, struct bch_dev *,
 			      size_t, enum bch_data_type, unsigned,
 			      struct gc_pos, unsigned);

 int bch2_trigger_extent(struct btree_trans *, enum btree_id, unsigned,
 			struct bkey_s_c, struct bkey_s, unsigned);
 int bch2_trigger_reservation(struct btree_trans *, enum btree_id, unsigned,
 			  struct bkey_s_c, struct bkey_s, unsigned);

 #define trigger_run_overwrite_then_insert(_fn, _trans, _btree_id, _level, _old, _new, _flags)\
 ({												\
 	int ret = 0;										\
 												\
 	if (_old.k->type)									\
 		ret = _fn(_trans, _btree_id, _level, _old, _flags & ~BTREE_TRIGGER_INSERT);	\
 	if (!ret && _new.k->type)								\
 		ret = _fn(_trans, _btree_id, _level, _new.s_c, _flags & ~BTREE_TRIGGER_OVERWRITE);\
 	ret;											\
 })

 void bch2_trans_account_disk_usage_change(struct btree_trans *);

 void bch2_trans_fs_usage_revert(struct btree_trans *, struct replicas_delta_list *);
 int bch2_trans_fs_usage_apply(struct btree_trans *, struct replicas_delta_list *);

 int bch2_trans_mark_metadata_bucket(struct btree_trans *, struct bch_dev *,
 				    size_t, enum bch_data_type, unsigned);
 int bch2_trans_mark_dev_sb(struct bch_fs *, struct bch_dev *);
 int bch2_trans_mark_dev_sbs(struct bch_fs *);

 static inline bool is_superblock_bucket(struct bch_dev *ca, u64 b)
 {
 	struct bch_sb_layout *layout = &ca->disk_sb.sb->layout;
 	u64 b_offset	= bucket_to_sector(ca, b);
 	u64 b_end	= bucket_to_sector(ca, b + 1);
 	unsigned i;

 	if (!b)
 		return true;

 	for (i = 0; i < layout->nr_superblocks; i++) {
 		u64 offset = le64_to_cpu(layout->sb_offset[i]);
 		u64 end = offset + (1 << layout->sb_max_size_bits);

 		if (!(offset >= b_end || end <= b_offset))
 			return true;
 	}

 	return false;
 }

 static inline const char *bch2_data_type_str(enum bch_data_type type)
 {
 	return type < BCH_DATA_NR
 		? __bch2_data_types[type]
 		: "(invalid data type)";
 }

 static inline void bch2_prt_data_type(struct printbuf *out, enum bch_data_type type)
 {
 	if (type < BCH_DATA_NR)
 		prt_str(out, __bch2_data_types[type]);
 	else
 		prt_printf(out, "(invalid data type %u)", type);
 }

 /* disk reservations: */

 static inline void bch2_disk_reservation_put(struct bch_fs *c,
 					     struct disk_reservation *res)
 {
 	if (res->sectors) {
 		this_cpu_sub(*c->online_reserved, res->sectors);
 		res->sectors = 0;
 	}
 }

 #define BCH_DISK_RESERVATION_NOFAIL		(1 << 0)

 int __bch2_disk_reservation_add(struct bch_fs *,
 				struct disk_reservation *,
 				u64, int);

 static inline int bch2_disk_reservation_add(struct bch_fs *c, struct disk_reservation *res,
 					    u64 sectors, int flags)
 {
 #ifdef __KERNEL__
 	u64 old, new;

 	do {
 		old = this_cpu_read(c->pcpu->sectors_available);
 		if (sectors > old)
 			return __bch2_disk_reservation_add(c, res, sectors, flags);

 		new = old - sectors;
 	} while (this_cpu_cmpxchg(c->pcpu->sectors_available, old, new) != old);

 	this_cpu_add(*c->online_reserved, sectors);
 	res->sectors			+= sectors;
 	return 0;
 #else
 	return __bch2_disk_reservation_add(c, res, sectors, flags);
 #endif
 }

 static inline struct disk_reservation
 bch2_disk_reservation_init(struct bch_fs *c, unsigned nr_replicas)
 {
 	return (struct disk_reservation) {
 		.sectors	= 0,
 #if 0
 		/* not used yet: */
 		.gen		= c->capacity_gen,
 #endif
 		.nr_replicas	= nr_replicas,
 	};
 }

 static inline int bch2_disk_reservation_get(struct bch_fs *c,
 					    struct disk_reservation *res,
 					    u64 sectors, unsigned nr_replicas,
 					    int flags)
 {
 	*res = bch2_disk_reservation_init(c, nr_replicas);

 	return bch2_disk_reservation_add(c, res, sectors * nr_replicas, flags);
 }

 #define RESERVE_FACTOR	6

 static inline u64 avail_factor(u64 r)
 {
 	return div_u64(r << RESERVE_FACTOR, (1 << RESERVE_FACTOR) + 1);
 }

 int bch2_dev_buckets_resize(struct bch_fs *, struct bch_dev *, u64);
 void bch2_dev_buckets_free(struct bch_dev *);
 int bch2_dev_buckets_alloc(struct bch_fs *, struct bch_dev *);

 #endif /* _BUCKETS_H */
	/* SPDX-License-Identifier: GPL-2.0 */
	/*
	* Code for manipulating bucket marks for garbage collection.
	*
	* Copyright 2014 Datera, Inc.
	*/

	#ifndef _BUCKETS_H
	#define _BUCKETS_H

	#include "buckets_types.h"
	#include "extents.h"
	#include "sb-members.h"

	static inline size_t sector_to_bucket(const struct bch_dev *ca, sector_t s)
	{
	return div_u64(s, ca->mi.bucket_size);
	}

	static inline sector_t bucket_to_sector(const struct bch_dev *ca, size_t b)
	{
	return ((sector_t) b) * ca->mi.bucket_size;
	}

	static inline sector_t bucket_remainder(const struct bch_dev *ca, sector_t s)
	{
	u32 remainder;

	div_u64_rem(s, ca->mi.bucket_size, &remainder);
	return remainder;
	}

	static inline size_t sector_to_bucket_and_offset(const struct bch_dev *ca, sector_t s,
	u32 *offset)
	{
	return div_u64_rem(s, ca->mi.bucket_size, offset);
	}

	#define for_each_bucket(_b, _buckets) \
	for (_b = (_buckets)->b + (_buckets)->first_bucket; \
	_b < (_buckets)->b + (_buckets)->nbuckets; _b++)

	/*
	* Ugly hack alert:
	*
	* We need to cram a spinlock in a single byte, because that's what we have left
	* in struct bucket, and we care about the size of these - during fsck, we need
	* in memory state for every single bucket on every device.
	*
	* We used to do
	* while (xchg(&b->lock, 1) cpu_relax();
	* but, it turns out not all architectures support xchg on a single byte.
	*
	* So now we use bit_spin_lock(), with fun games since we can't burn a whole
	* ulong for this - we just need to make sure the lock bit always ends up in the
	* first byte.
	*/

	#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
	#define BUCKET_LOCK_BITNR 0
	#else
	#define BUCKET_LOCK_BITNR (BITS_PER_LONG - 1)
	#endif

	union ulong_byte_assert {
	ulong ulong;
	u8 byte;
	};

	static inline void bucket_unlock(struct bucket *b)
	{
	BUILD_BUG_ON(!((union ulong_byte_assert) { .ulong = 1UL << BUCKET_LOCK_BITNR }).byte);

	clear_bit_unlock(BUCKET_LOCK_BITNR, (void *) &b->lock);
	wake_up_bit((void *) &b->lock, BUCKET_LOCK_BITNR);
	}

	static inline void bucket_lock(struct bucket *b)
	{
	wait_on_bit_lock((void *) &b->lock, BUCKET_LOCK_BITNR,
	TASK_UNINTERRUPTIBLE);
	}

	static inline struct bucket_array gc_bucket_array(struct bch_dev ca)
	{
	return rcu_dereference_check(ca->buckets_gc,
	!ca->fs \|\|
	percpu_rwsem_is_held(&ca->fs->mark_lock) \|\|
	lockdep_is_held(&ca->fs->gc_lock) \|\|
	lockdep_is_held(&ca->bucket_lock));
	}

	static inline struct bucket gc_bucket(struct bch_dev ca, size_t b)
	{
	struct bucket_array *buckets = gc_bucket_array(ca);

	BUG_ON(b < buckets->first_bucket \|\| b >= buckets->nbuckets);
	return buckets->b + b;
	}

	static inline struct bucket_gens bucket_gens(struct bch_dev ca)
	{
	return rcu_dereference_check(ca->bucket_gens,
	!ca->fs \|\|
	percpu_rwsem_is_held(&ca->fs->mark_lock) \|\|
	lockdep_is_held(&ca->fs->gc_lock) \|\|
	lockdep_is_held(&ca->bucket_lock));
	}

	static inline u8 bucket_gen(struct bch_dev ca, size_t b)
	{
	struct bucket_gens *gens = bucket_gens(ca);

	BUG_ON(b < gens->first_bucket \|\| b >= gens->nbuckets);
	return gens->b + b;
	}

	static inline size_t PTR_BUCKET_NR(const struct bch_dev *ca,
	const struct bch_extent_ptr *ptr)
	{
	return sector_to_bucket(ca, ptr->offset);
	}

	static inline struct bpos PTR_BUCKET_POS(const struct bch_fs *c,
	const struct bch_extent_ptr *ptr)
	{
	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);

	return POS(ptr->dev, PTR_BUCKET_NR(ca, ptr));
	}

	static inline struct bpos PTR_BUCKET_POS_OFFSET(const struct bch_fs *c,
	const struct bch_extent_ptr *ptr,
	u32 *bucket_offset)
	{
	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);

	return POS(ptr->dev, sector_to_bucket_and_offset(ca, ptr->offset, bucket_offset));
	}

	static inline struct bucket PTR_GC_BUCKET(struct bch_dev ca,
	const struct bch_extent_ptr *ptr)
	{
	return gc_bucket(ca, PTR_BUCKET_NR(ca, ptr));
	}

	static inline enum bch_data_type ptr_data_type(const struct bkey *k,
	const struct bch_extent_ptr *ptr)
	{
	if (bkey_is_btree_ptr(k))
	return BCH_DATA_btree;

	return ptr->cached ? BCH_DATA_cached : BCH_DATA_user;
	}

	static inline s64 ptr_disk_sectors(s64 sectors, struct extent_ptr_decoded p)
	{
	EBUG_ON(sectors < 0);

	return crc_is_compressed(p.crc)
	? DIV_ROUND_UP_ULL(sectors * p.crc.compressed_size,
	p.crc.uncompressed_size)
	: sectors;
	}

	static inline int gen_cmp(u8 a, u8 b)
	{
	return (s8) (a - b);
	}

	static inline int gen_after(u8 a, u8 b)
	{
	int r = gen_cmp(a, b);

	return r > 0 ? r : 0;
	}

	/**
	* ptr_stale() - check if a pointer points into a bucket that has been
	* invalidated.
	*/
	static inline u8 ptr_stale(struct bch_dev *ca,
	const struct bch_extent_ptr *ptr)
	{
	u8 ret;

	rcu_read_lock();
	ret = gen_after(*bucket_gen(ca, PTR_BUCKET_NR(ca, ptr)), ptr->gen);
	rcu_read_unlock();

	return ret;
	}

	/* Device usage: */

	void bch2_dev_usage_read_fast(struct bch_dev , struct bch_dev_usage );
	static inline struct bch_dev_usage bch2_dev_usage_read(struct bch_dev *ca)
	{
	struct bch_dev_usage ret;

	bch2_dev_usage_read_fast(ca, &ret);
	return ret;
	}

	void bch2_dev_usage_init(struct bch_dev *);
	void bch2_dev_usage_to_text(struct printbuf , struct bch_dev_usage );

	static inline u64 bch2_dev_buckets_reserved(struct bch_dev *ca, enum bch_watermark watermark)
	{
	s64 reserved = 0;

	switch (watermark) {
	case BCH_WATERMARK_NR:
	BUG();
	case BCH_WATERMARK_stripe:
	reserved += ca->mi.nbuckets >> 6;
	fallthrough;
	case BCH_WATERMARK_normal:
	reserved += ca->mi.nbuckets >> 6;
	fallthrough;
	case BCH_WATERMARK_copygc:
	reserved += ca->nr_btree_reserve;
	fallthrough;
	case BCH_WATERMARK_btree:
	reserved += ca->nr_btree_reserve;
	fallthrough;
	case BCH_WATERMARK_btree_copygc:
	case BCH_WATERMARK_reclaim:
	break;
	}

	return reserved;
	}

	static inline u64 dev_buckets_free(struct bch_dev *ca,
	struct bch_dev_usage usage,
	enum bch_watermark watermark)
	{
	return max_t(s64, 0,
	usage.d[BCH_DATA_free].buckets -
	ca->nr_open_buckets -
	bch2_dev_buckets_reserved(ca, watermark));
	}

	static inline u64 __dev_buckets_available(struct bch_dev *ca,
	struct bch_dev_usage usage,
	enum bch_watermark watermark)
	{
	return max_t(s64, 0,
	usage.d[BCH_DATA_free].buckets
	+ usage.d[BCH_DATA_cached].buckets
	+ usage.d[BCH_DATA_need_gc_gens].buckets
	+ usage.d[BCH_DATA_need_discard].buckets
	- ca->nr_open_buckets
	- bch2_dev_buckets_reserved(ca, watermark));
	}

	static inline u64 dev_buckets_available(struct bch_dev *ca,
	enum bch_watermark watermark)
	{
	return __dev_buckets_available(ca, bch2_dev_usage_read(ca), watermark);
	}

	/* Filesystem usage: */

	static inline unsigned __fs_usage_u64s(unsigned nr_replicas)
	{
	return sizeof(struct bch_fs_usage) / sizeof(u64) + nr_replicas;
	}

	static inline unsigned fs_usage_u64s(struct bch_fs *c)
	{
	return __fs_usage_u64s(READ_ONCE(c->replicas.nr));
	}

	static inline unsigned __fs_usage_online_u64s(unsigned nr_replicas)
	{
	return sizeof(struct bch_fs_usage_online) / sizeof(u64) + nr_replicas;
	}

	static inline unsigned fs_usage_online_u64s(struct bch_fs *c)
	{
	return __fs_usage_online_u64s(READ_ONCE(c->replicas.nr));
	}

	static inline unsigned dev_usage_u64s(void)
	{
	return sizeof(struct bch_dev_usage) / sizeof(u64);
	}

	u64 bch2_fs_usage_read_one(struct bch_fs , u64 );

	struct bch_fs_usage_online bch2_fs_usage_read(struct bch_fs );

	void bch2_fs_usage_acc_to_base(struct bch_fs *, unsigned);

	void bch2_fs_usage_to_text(struct printbuf *,
	struct bch_fs , struct bch_fs_usage_online );

	u64 bch2_fs_sectors_used(struct bch_fs , struct bch_fs_usage_online );

	struct bch_fs_usage_short
	bch2_fs_usage_read_short(struct bch_fs *);

	void bch2_dev_usage_update(struct bch_fs , struct bch_dev ,
	const struct bch_alloc_v4 *,
	const struct bch_alloc_v4 *, u64, bool);
	void bch2_dev_usage_update_m(struct bch_fs , struct bch_dev ,
	struct bucket , struct bucket );

	/* key/bucket marking: */

	static inline struct bch_fs_usage fs_usage_ptr(struct bch_fs c,
	unsigned journal_seq,
	bool gc)
	{
	percpu_rwsem_assert_held(&c->mark_lock);
	BUG_ON(!gc && !journal_seq);

	return this_cpu_ptr(gc
	? c->usage_gc
	: c->usage[journal_seq & JOURNAL_BUF_MASK]);
	}

	int bch2_update_replicas(struct bch_fs *, struct bkey_s_c,
	struct bch_replicas_entry_v1 *, s64,
	unsigned, bool);
	int bch2_update_replicas_list(struct btree_trans *,
	struct bch_replicas_entry_v1 *, s64);
	int bch2_update_cached_sectors_list(struct btree_trans *, unsigned, s64);
	int bch2_replicas_deltas_realloc(struct btree_trans *, unsigned);

	void bch2_fs_usage_initialize(struct bch_fs *);

	int bch2_check_bucket_ref(struct btree_trans *, struct bkey_s_c,
	const struct bch_extent_ptr *,
	s64, enum bch_data_type, u8, u8, u32);

	int bch2_mark_metadata_bucket(struct bch_fs , struct bch_dev ,
	size_t, enum bch_data_type, unsigned,
	struct gc_pos, unsigned);

	int bch2_trigger_extent(struct btree_trans *, enum btree_id, unsigned,
	struct bkey_s_c, struct bkey_s, unsigned);
	int bch2_trigger_reservation(struct btree_trans *, enum btree_id, unsigned,
	struct bkey_s_c, struct bkey_s, unsigned);

	#define trigger_run_overwrite_then_insert(_fn, _trans, _btree_id, _level, _old, _new, _flags)\
	({ \
	int ret = 0; \
	\
	if (_old.k->type) \
	ret = _fn(_trans, _btree_id, _level, _old, _flags & ~BTREE_TRIGGER_INSERT); \
	if (!ret && _new.k->type) \
	ret = _fn(_trans, _btree_id, _level, _new.s_c, _flags & ~BTREE_TRIGGER_OVERWRITE);\
	ret; \
	})

	void bch2_trans_account_disk_usage_change(struct btree_trans *);

	void bch2_trans_fs_usage_revert(struct btree_trans , struct replicas_delta_list );
	int bch2_trans_fs_usage_apply(struct btree_trans , struct replicas_delta_list );

	int bch2_trans_mark_metadata_bucket(struct btree_trans , struct bch_dev ,
	size_t, enum bch_data_type, unsigned);
	int bch2_trans_mark_dev_sb(struct bch_fs , struct bch_dev );
	int bch2_trans_mark_dev_sbs(struct bch_fs *);

	static inline bool is_superblock_bucket(struct bch_dev *ca, u64 b)
	{
	struct bch_sb_layout *layout = &ca->disk_sb.sb->layout;
	u64 b_offset = bucket_to_sector(ca, b);
	u64 b_end = bucket_to_sector(ca, b + 1);
	unsigned i;

	if (!b)
	return true;

	for (i = 0; i < layout->nr_superblocks; i++) {
	u64 offset = le64_to_cpu(layout->sb_offset[i]);
	u64 end = offset + (1 << layout->sb_max_size_bits);

	if (!(offset >= b_end \|\| end <= b_offset))
	return true;
	}

	return false;
	}

	static inline const char *bch2_data_type_str(enum bch_data_type type)
	{
	return type < BCH_DATA_NR
	? __bch2_data_types[type]
	: "(invalid data type)";
	}

	static inline void bch2_prt_data_type(struct printbuf *out, enum bch_data_type type)
	{
	if (type < BCH_DATA_NR)
	prt_str(out, __bch2_data_types[type]);
	else
	prt_printf(out, "(invalid data type %u)", type);
	}

	/* disk reservations: */

	static inline void bch2_disk_reservation_put(struct bch_fs *c,
	struct disk_reservation *res)
	{
	if (res->sectors) {
	this_cpu_sub(*c->online_reserved, res->sectors);
	res->sectors = 0;
	}
	}

	#define BCH_DISK_RESERVATION_NOFAIL (1 << 0)

	int __bch2_disk_reservation_add(struct bch_fs *,
	struct disk_reservation *,
	u64, int);

	static inline int bch2_disk_reservation_add(struct bch_fs c, struct disk_reservation res,
	u64 sectors, int flags)
	{
	#ifdef __KERNEL__
	u64 old, new;

	do {
	old = this_cpu_read(c->pcpu->sectors_available);
	if (sectors > old)
	return __bch2_disk_reservation_add(c, res, sectors, flags);

	new = old - sectors;
	} while (this_cpu_cmpxchg(c->pcpu->sectors_available, old, new) != old);

	this_cpu_add(*c->online_reserved, sectors);
	res->sectors += sectors;
	return 0;
	#else
	return __bch2_disk_reservation_add(c, res, sectors, flags);
	#endif
	}

	static inline struct disk_reservation
	bch2_disk_reservation_init(struct bch_fs *c, unsigned nr_replicas)
	{
	return (struct disk_reservation) {
	.sectors = 0,
	#if 0
	/* not used yet: */
	.gen = c->capacity_gen,
	#endif
	.nr_replicas = nr_replicas,
	};
	}

	static inline int bch2_disk_reservation_get(struct bch_fs *c,
	struct disk_reservation *res,
	u64 sectors, unsigned nr_replicas,
	int flags)
	{
	*res = bch2_disk_reservation_init(c, nr_replicas);

	return bch2_disk_reservation_add(c, res, sectors * nr_replicas, flags);
	}

	#define RESERVE_FACTOR 6

	static inline u64 avail_factor(u64 r)
	{
	return div_u64(r << RESERVE_FACTOR, (1 << RESERVE_FACTOR) + 1);
	}

	int bch2_dev_buckets_resize(struct bch_fs , struct bch_dev , u64);
	void bch2_dev_buckets_free(struct bch_dev *);
	int bch2_dev_buckets_alloc(struct bch_fs , struct bch_dev );

	#endif /* _BUCKETS_H */