1 files changed, 276 insertions, 0 deletions
diff --git a/fs/bcachefs/buckets.h b/fs/bcachefs/buckets.h
new file mode 100644
index 000000000000..a4ba6d787b0b
--- /dev/null
+++ b/fs/bcachefs/buckets.h
@@ -0,0 +1,276 @@
+/* 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 "super.h"
+
+#define for_each_bucket(_b, _buckets)				\
+	for (_b = (_buckets)->b + (_buckets)->first_bucket;	\
+	     _b < (_buckets)->b + (_buckets)->nbuckets; _b++)
+
+#define bucket_cmpxchg(g, new, expr)				\
+({								\
+	u64 _v = atomic64_read(&(g)->_mark.v);			\
+	struct bucket_mark _old;				\
+								\
+	do {							\
+		(new).v.counter = _old.v.counter = _v;		\
+		expr;						\
+	} while ((_v = atomic64_cmpxchg(&(g)->_mark.v,		\
+			       _old.v.counter,			\
+			       (new).v.counter)) != _old.v.counter);\
+	_old;							\
+})
+
+static inline struct bucket_array *bucket_array(struct bch_dev *ca)
+{
+	return rcu_dereference_check(ca->buckets,
+				     !ca->fs ||
+				     percpu_rwsem_is_held(&ca->fs->usage_lock) ||
+				     lockdep_is_held(&ca->fs->gc_lock) ||
+				     lockdep_is_held(&ca->bucket_lock));
+}
+
+static inline struct bucket *bucket(struct bch_dev *ca, size_t b)
+{
+	struct bucket_array *buckets = bucket_array(ca);
+
+	BUG_ON(b < buckets->first_bucket || b >= buckets->nbuckets);
+	return buckets->b + b;
+}
+
+static inline void bucket_io_clock_reset(struct bch_fs *c, struct bch_dev *ca,
+					 size_t b, int rw)
+{
+	bucket(ca, b)->io_time[rw] = c->bucket_clock[rw].hand;
+}
+
+static inline u16 bucket_last_io(struct bch_fs *c, struct bucket *g, int rw)
+{
+	return c->bucket_clock[rw].hand - g->io_time[rw];
+}
+
+/*
+ * bucket_gc_gen() returns the difference between the bucket's current gen and
+ * the oldest gen of any pointer into that bucket in the btree.
+ */
+
+static inline u8 bucket_gc_gen(struct bch_dev *ca, size_t b)
+{
+	return bucket(ca, b)->mark.gen - ca->oldest_gens[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 bucket *PTR_BUCKET(struct bch_dev *ca,
+					const struct bch_extent_ptr *ptr)
+{
+	return bucket(ca, PTR_BUCKET_NR(ca, ptr));
+}
+
+static inline struct bucket_mark ptr_bucket_mark(struct bch_dev *ca,
+						 const struct bch_extent_ptr *ptr)
+{
+	struct bucket_mark m;
+
+	rcu_read_lock();
+	m = READ_ONCE(bucket(ca, PTR_BUCKET_NR(ca, ptr))->mark);
+	rcu_read_unlock();
+
+	return m;
+}
+
+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)
+{
+	return gen_after(ptr_bucket_mark(ca, ptr).gen, ptr->gen);
+}
+
+/* bucket gc marks */
+
+/* The dirty and cached sector counts saturate. If this occurs,
+ * reference counting alone will not free the bucket, and a btree
+ * GC must be performed. */
+#define GC_MAX_SECTORS_USED ((1U << 15) - 1)
+
+static inline unsigned bucket_sectors_used(struct bucket_mark mark)
+{
+	return mark.dirty_sectors + mark.cached_sectors;
+}
+
+static inline bool bucket_unused(struct bucket_mark mark)
+{
+	return !mark.owned_by_allocator &&
+		!mark.data_type &&
+		!bucket_sectors_used(mark);
+}
+
+/* Device usage: */
+
+struct bch_dev_usage __bch2_dev_usage_read(struct bch_dev *);
+struct bch_dev_usage bch2_dev_usage_read(struct bch_fs *, struct bch_dev *);
+
+static inline u64 __dev_buckets_available(struct bch_dev *ca,
+					  struct bch_dev_usage stats)
+{
+	u64 total = ca->mi.nbuckets - ca->mi.first_bucket;
+
+	if (WARN_ONCE(stats.buckets_unavailable > total,
+		      "buckets_unavailable overflow (%llu > %llu)\n",
+		      stats.buckets_unavailable, total))
+		return 0;
+
+	return total - stats.buckets_unavailable;
+}
+
+/*
+ * Number of reclaimable buckets - only for use by the allocator thread:
+ */
+static inline u64 dev_buckets_available(struct bch_fs *c, struct bch_dev *ca)
+{
+	return __dev_buckets_available(ca, bch2_dev_usage_read(c, ca));
+}
+
+static inline u64 __dev_buckets_free(struct bch_dev *ca,
+				     struct bch_dev_usage stats)
+{
+	return __dev_buckets_available(ca, stats) +
+		fifo_used(&ca->free[RESERVE_NONE]) +
+		fifo_used(&ca->free_inc);
+}
+
+static inline u64 dev_buckets_free(struct bch_fs *c, struct bch_dev *ca)
+{
+	return __dev_buckets_free(ca, bch2_dev_usage_read(c, ca));
+}
+
+/* Filesystem usage: */
+
+static inline enum bch_data_type s_alloc_to_data_type(enum s_alloc s)
+{
+	switch (s) {
+	case S_META:
+		return BCH_DATA_BTREE;
+	case S_DIRTY:
+		return BCH_DATA_USER;
+	default:
+		BUG();
+	}
+}
+
+struct bch_fs_usage __bch2_fs_usage_read(struct bch_fs *);
+struct bch_fs_usage bch2_fs_usage_read(struct bch_fs *);
+void bch2_fs_usage_apply(struct bch_fs *, struct bch_fs_usage *,
+			 struct disk_reservation *, struct gc_pos);
+
+u64 __bch2_fs_sectors_used(struct bch_fs *, struct bch_fs_usage);
+u64 bch2_fs_sectors_used(struct bch_fs *, struct bch_fs_usage);
+u64 bch2_fs_sectors_free(struct bch_fs *, struct bch_fs_usage);
+
+static inline bool is_available_bucket(struct bucket_mark mark)
+{
+	return (!mark.owned_by_allocator &&
+		!mark.dirty_sectors &&
+		!mark.nouse);
+}
+
+static inline bool bucket_needs_journal_commit(struct bucket_mark m,
+					       u16 last_seq_ondisk)
+{
+	return m.journal_seq_valid &&
+		((s16) m.journal_seq - (s16) last_seq_ondisk > 0);
+}
+
+void bch2_bucket_seq_cleanup(struct bch_fs *);
+
+bool bch2_invalidate_bucket(struct bch_fs *, struct bch_dev *,
+			    size_t, struct bucket_mark *);
+void bch2_mark_alloc_bucket(struct bch_fs *, struct bch_dev *,
+			    size_t, bool, struct gc_pos, unsigned);
+void bch2_mark_metadata_bucket(struct bch_fs *, struct bch_dev *,
+			       size_t, enum bch_data_type, unsigned,
+			       struct gc_pos, unsigned);
+
+#define BCH_BUCKET_MARK_NOATOMIC		(1 << 0)
+#define BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE	(1 << 1)
+#define BCH_BUCKET_MARK_GC_WILL_VISIT		(1 << 2)
+#define BCH_BUCKET_MARK_GC_LOCK_HELD		(1 << 3)
+
+void bch2_mark_key(struct bch_fs *, struct bkey_s_c, s64, bool, struct gc_pos,
+		   struct bch_fs_usage *, u64, unsigned);
+
+void bch2_recalc_sectors_available(struct bch_fs *);
+
+void __bch2_disk_reservation_put(struct bch_fs *, struct disk_reservation *);
+
+static inline void bch2_disk_reservation_put(struct bch_fs *c,
+					     struct disk_reservation *res)
+{
+	if (res->sectors)
+		__bch2_disk_reservation_put(c, res);
+}
+
+#define BCH_DISK_RESERVATION_NOFAIL		(1 << 0)
+#define BCH_DISK_RESERVATION_GC_LOCK_HELD	(1 << 1)
+#define BCH_DISK_RESERVATION_BTREE_LOCKS_HELD	(1 << 2)
+
+int bch2_disk_reservation_add(struct bch_fs *,
+			     struct disk_reservation *,
+			     unsigned, int);
+
+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,
+					    unsigned 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);
+}
+
+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 */