X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Falloc_background.c;h=48971fcf2d5bb393c818732e3b0f1be50c179ebc;hb=ce906d661e63d4318b9f26ec145f2ff5fddf5162;hp=b2d1b8f9c9b8e86d477fe2b219ad77aa854d3ff8;hpb=ac0d08877aa87a9cdf493bc6f336c391fb4e04a0;p=bcachefs-tools-debian

diff --git a/libbcachefs/alloc_background.c b/libbcachefs/alloc_background.c
index b2d1b8f..48971fc 100644
--- a/libbcachefs/alloc_background.c
+++ b/libbcachefs/alloc_background.c
@@ -4,6 +4,7 @@
 #include "alloc_foreground.h"
 #include "btree_cache.h"
 #include "btree_io.h"
+#include "btree_key_cache.h"
 #include "btree_update.h"
 #include "btree_update_interior.h"
 #include "btree_gc.h"
@@ -13,6 +14,7 @@
 #include "ec.h"
 #include "error.h"
 #include "recovery.h"
+#include "varint.h"
 
 #include <linux/kthread.h>
 #include <linux/math64.h>
@@ -23,15 +25,12 @@
 #include <linux/sort.h>
 #include <trace/events/bcachefs.h>
 
-static const char * const bch2_alloc_field_names[] = {
-#define x(name, bytes) #name,
-	BCH_ALLOC_FIELDS()
+static const unsigned BCH_ALLOC_V1_FIELD_BYTES[] = {
+#define x(name, bits) [BCH_ALLOC_FIELD_V1_##name] = bits / 8,
+	BCH_ALLOC_FIELDS_V1()
 #undef x
-	NULL
 };
 
-static void bch2_recalc_oldest_io(struct bch_fs *, struct bch_dev *, int);
-
 /* Ratelimiting/PD controllers */
 
 static void pd_controllers_update(struct work_struct *work)
@@ -40,39 +39,36 @@ static void pd_controllers_update(struct work_struct *work)
 					   struct bch_fs,
 					   pd_controllers_update);
 	struct bch_dev *ca;
+	s64 free = 0, fragmented = 0;
 	unsigned i;
 
 	for_each_member_device(ca, c, i) {
-		struct bch_dev_usage stats = bch2_dev_usage_read(c, ca);
+		struct bch_dev_usage stats = bch2_dev_usage_read(ca);
 
-		u64 free = bucket_to_sector(ca,
+		free += bucket_to_sector(ca,
 				__dev_buckets_free(ca, stats)) << 9;
 		/*
 		 * Bytes of internal fragmentation, which can be
 		 * reclaimed by copy GC
 		 */
-		s64 fragmented = (bucket_to_sector(ca,
-					stats.buckets[BCH_DATA_USER] +
-					stats.buckets[BCH_DATA_CACHED]) -
-				  (stats.sectors[BCH_DATA_USER] +
-				   stats.sectors[BCH_DATA_CACHED])) << 9;
-
-		fragmented = max(0LL, fragmented);
-
-		bch2_pd_controller_update(&ca->copygc_pd,
-					 free, fragmented, -1);
+		fragmented += max_t(s64, 0, (bucket_to_sector(ca,
+					stats.d[BCH_DATA_user].buckets +
+					stats.d[BCH_DATA_cached].buckets) -
+				  (stats.d[BCH_DATA_user].sectors +
+				   stats.d[BCH_DATA_cached].sectors)) << 9);
 	}
 
+	bch2_pd_controller_update(&c->copygc_pd, free, fragmented, -1);
 	schedule_delayed_work(&c->pd_controllers_update,
 			      c->pd_controllers_update_seconds * HZ);
 }
 
 /* Persistent alloc info: */
 
-static inline u64 get_alloc_field(const struct bch_alloc *a,
-				  const void **p, unsigned field)
+static inline u64 alloc_field_v1_get(const struct bch_alloc *a,
+				     const void **p, unsigned field)
 {
-	unsigned bytes = BCH_ALLOC_FIELD_BYTES[field];
+	unsigned bytes = BCH_ALLOC_V1_FIELD_BYTES[field];
 	u64 v;
 
 	if (!(a->fields & (1 << field)))
@@ -99,10 +95,10 @@ static inline u64 get_alloc_field(const struct bch_alloc *a,
 	return v;
 }
 
-static inline void put_alloc_field(struct bkey_i_alloc *a, void **p,
-				   unsigned field, u64 v)
+static inline void alloc_field_v1_put(struct bkey_i_alloc *a, void **p,
+				      unsigned field, u64 v)
 {
-	unsigned bytes = BCH_ALLOC_FIELD_BYTES[field];
+	unsigned bytes = BCH_ALLOC_V1_FIELD_BYTES[field];
 
 	if (!v)
 		return;
@@ -129,55 +125,127 @@ static inline void put_alloc_field(struct bkey_i_alloc *a, void **p,
 	*p += bytes;
 }
 
-struct bkey_alloc_unpacked bch2_alloc_unpack(struct bkey_s_c k)
+static void bch2_alloc_unpack_v1(struct bkey_alloc_unpacked *out,
+				 struct bkey_s_c k)
 {
-	struct bkey_alloc_unpacked ret = { .gen = 0 };
+	const struct bch_alloc *in = bkey_s_c_to_alloc(k).v;
+	const void *d = in->data;
+	unsigned idx = 0;
+
+	out->gen = in->gen;
 
-	if (k.k->type == KEY_TYPE_alloc) {
-		const struct bch_alloc *a = bkey_s_c_to_alloc(k).v;
-		const void *d = a->data;
-		unsigned idx = 0;
+#define x(_name, _bits) out->_name = alloc_field_v1_get(in, &d, idx++);
+	BCH_ALLOC_FIELDS_V1()
+#undef  x
+}
 
-		ret.gen = a->gen;
+static int bch2_alloc_unpack_v2(struct bkey_alloc_unpacked *out,
+				struct bkey_s_c k)
+{
+	struct bkey_s_c_alloc_v2 a = bkey_s_c_to_alloc_v2(k);
+	const u8 *in = a.v->data;
+	const u8 *end = bkey_val_end(a);
+	unsigned fieldnr = 0;
+	int ret;
+	u64 v;
 
-#define x(_name, _bits)	ret._name = get_alloc_field(a, &d, idx++);
-		BCH_ALLOC_FIELDS()
+	out->gen	= a.v->gen;
+	out->oldest_gen	= a.v->oldest_gen;
+	out->data_type	= a.v->data_type;
+
+#define x(_name, _bits)							\
+	if (fieldnr < a.v->nr_fields) {					\
+		ret = bch2_varint_decode(in, end, &v);			\
+		if (ret < 0)						\
+			return ret;					\
+		in += ret;						\
+	} else {							\
+		v = 0;							\
+	}								\
+	out->_name = v;							\
+	if (v != out->_name)						\
+		return -1;						\
+	fieldnr++;
+
+	BCH_ALLOC_FIELDS_V2()
 #undef  x
-	}
-	return ret;
+	return 0;
 }
 
-void bch2_alloc_pack(struct bkey_i_alloc *dst,
-		     const struct bkey_alloc_unpacked src)
+static void bch2_alloc_pack_v2(struct bkey_alloc_buf *dst,
+			       const struct bkey_alloc_unpacked src)
 {
-	unsigned idx = 0;
-	void *d = dst->v.data;
+	struct bkey_i_alloc_v2 *a = bkey_alloc_v2_init(&dst->k);
+	unsigned nr_fields = 0, last_nonzero_fieldnr = 0;
+	u8 *out = a->v.data;
+	u8 *end = (void *) &dst[1];
+	u8 *last_nonzero_field = out;
 	unsigned bytes;
 
-	dst->v.fields	= 0;
-	dst->v.gen	= src.gen;
+	a->k.p		= POS(src.dev, src.bucket);
+	a->v.gen	= src.gen;
+	a->v.oldest_gen	= src.oldest_gen;
+	a->v.data_type	= src.data_type;
+
+#define x(_name, _bits)							\
+	nr_fields++;							\
+									\
+	if (src._name) {						\
+		out += bch2_varint_encode(out, src._name);		\
+									\
+		last_nonzero_field = out;				\
+		last_nonzero_fieldnr = nr_fields;			\
+	} else {							\
+		*out++ = 0;						\
+	}
 
-#define x(_name, _bits)	put_alloc_field(dst, &d, idx++, src._name);
-	BCH_ALLOC_FIELDS()
+	BCH_ALLOC_FIELDS_V2()
 #undef  x
+	BUG_ON(out > end);
+
+	out = last_nonzero_field;
+	a->v.nr_fields = last_nonzero_fieldnr;
 
-	bytes = (void *) d - (void *) &dst->v;
-	set_bkey_val_bytes(&dst->k, bytes);
-	memset_u64s_tail(&dst->v, 0, bytes);
+	bytes = (u8 *) out - (u8 *) &a->v;
+	set_bkey_val_bytes(&a->k, bytes);
+	memset_u64s_tail(&a->v, 0, bytes);
+}
+
+struct bkey_alloc_unpacked bch2_alloc_unpack(struct bkey_s_c k)
+{
+	struct bkey_alloc_unpacked ret = {
+		.dev	= k.k->p.inode,
+		.bucket	= k.k->p.offset,
+		.gen	= 0,
+	};
+
+	if (k.k->type == KEY_TYPE_alloc_v2)
+		bch2_alloc_unpack_v2(&ret, k);
+	else if (k.k->type == KEY_TYPE_alloc)
+		bch2_alloc_unpack_v1(&ret, k);
+
+	return ret;
+}
+
+void bch2_alloc_pack(struct bch_fs *c,
+		     struct bkey_alloc_buf *dst,
+		     const struct bkey_alloc_unpacked src)
+{
+	bch2_alloc_pack_v2(dst, src);
 }
 
 static unsigned bch_alloc_val_u64s(const struct bch_alloc *a)
 {
 	unsigned i, bytes = offsetof(struct bch_alloc, data);
 
-	for (i = 0; i < ARRAY_SIZE(BCH_ALLOC_FIELD_BYTES); i++)
+	for (i = 0; i < ARRAY_SIZE(BCH_ALLOC_V1_FIELD_BYTES); i++)
 		if (a->fields & (1 << i))
-			bytes += BCH_ALLOC_FIELD_BYTES[i];
+			bytes += BCH_ALLOC_V1_FIELD_BYTES[i];
 
 	return DIV_ROUND_UP(bytes, sizeof(u64));
 }
 
-const char *bch2_alloc_invalid(const struct bch_fs *c, struct bkey_s_c k)
+const char *bch2_alloc_v1_invalid(const struct bch_fs *c, struct bkey_s_c k)
 {
 	struct bkey_s_c_alloc a = bkey_s_c_to_alloc(k);
 
@@ -192,79 +260,77 @@ const char *bch2_alloc_invalid(const struct bch_fs *c, struct bkey_s_c k)
 	return NULL;
 }
 
-void bch2_alloc_to_text(struct printbuf *out, struct bch_fs *c,
-			struct bkey_s_c k)
+const char *bch2_alloc_v2_invalid(const struct bch_fs *c, struct bkey_s_c k)
 {
-	struct bkey_s_c_alloc a = bkey_s_c_to_alloc(k);
-	const void *d = a.v->data;
-	unsigned i;
+	struct bkey_alloc_unpacked u;
+
+	if (k.k->p.inode >= c->sb.nr_devices ||
+	    !c->devs[k.k->p.inode])
+		return "invalid device";
 
-	pr_buf(out, "gen %u", a.v->gen);
+	if (bch2_alloc_unpack_v2(&u, k))
+		return "unpack error";
 
-	for (i = 0; i < BCH_ALLOC_FIELD_NR; i++)
-		if (a.v->fields & (1 << i))
-			pr_buf(out, " %s %llu",
-			       bch2_alloc_field_names[i],
-			       get_alloc_field(a.v, &d, i));
+	return NULL;
 }
 
-int bch2_alloc_read(struct bch_fs *c, struct journal_keys *journal_keys)
+void bch2_alloc_to_text(struct printbuf *out, struct bch_fs *c,
+			   struct bkey_s_c k)
+{
+	struct bkey_alloc_unpacked u = bch2_alloc_unpack(k);
+
+	pr_buf(out, "gen %u oldest_gen %u data_type %u",
+	       u.gen, u.oldest_gen, u.data_type);
+#define x(_name, ...)	pr_buf(out, #_name " %llu ", (u64) u._name);
+	BCH_ALLOC_FIELDS_V2()
+#undef  x
+}
+
+static int bch2_alloc_read_fn(struct bch_fs *c, enum btree_id id,
+			      unsigned level, struct bkey_s_c k)
 {
-	struct btree_trans trans;
-	struct btree_and_journal_iter iter;
-	struct bkey_s_c k;
 	struct bch_dev *ca;
-	unsigned i;
-	int ret = 0;
+	struct bucket *g;
+	struct bkey_alloc_unpacked u;
 
-	bch2_trans_init(&trans, c, 0, 0);
+	if (level ||
+	    (k.k->type != KEY_TYPE_alloc &&
+	     k.k->type != KEY_TYPE_alloc_v2))
+		return 0;
 
-	bch2_btree_and_journal_iter_init(&iter, &trans, journal_keys,
-					 BTREE_ID_ALLOC, POS_MIN);
+	ca = bch_dev_bkey_exists(c, k.k->p.inode);
+	g = bucket(ca, k.k->p.offset);
+	u = bch2_alloc_unpack(k);
 
-	while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
-		bch2_mark_key(c, k, 0, 0, NULL, 0,
-			      BTREE_TRIGGER_ALLOC_READ|
-			      BTREE_TRIGGER_NOATOMIC);
+	g->_mark.gen		= u.gen;
+	g->_mark.data_type	= u.data_type;
+	g->_mark.dirty_sectors	= u.dirty_sectors;
+	g->_mark.cached_sectors	= u.cached_sectors;
+	g->io_time[READ]	= u.read_time;
+	g->io_time[WRITE]	= u.write_time;
+	g->oldest_gen		= u.oldest_gen;
+	g->gen_valid		= 1;
 
-		bch2_btree_and_journal_iter_advance(&iter);
-	}
+	return 0;
+}
+
+int bch2_alloc_read(struct bch_fs *c, struct journal_keys *journal_keys)
+{
+	int ret;
+
+	down_read(&c->gc_lock);
+	ret = bch2_btree_and_journal_walk(c, journal_keys, BTREE_ID_alloc,
+					  NULL, bch2_alloc_read_fn);
+	up_read(&c->gc_lock);
 
-	ret = bch2_trans_exit(&trans) ?: ret;
 	if (ret) {
 		bch_err(c, "error reading alloc info: %i", ret);
 		return ret;
 	}
 
-	percpu_down_write(&c->mark_lock);
-	bch2_dev_usage_from_buckets(c);
-	percpu_up_write(&c->mark_lock);
-
-	mutex_lock(&c->bucket_clock[READ].lock);
-	for_each_member_device(ca, c, i) {
-		down_read(&ca->bucket_lock);
-		bch2_recalc_oldest_io(c, ca, READ);
-		up_read(&ca->bucket_lock);
-	}
-	mutex_unlock(&c->bucket_clock[READ].lock);
-
-	mutex_lock(&c->bucket_clock[WRITE].lock);
-	for_each_member_device(ca, c, i) {
-		down_read(&ca->bucket_lock);
-		bch2_recalc_oldest_io(c, ca, WRITE);
-		up_read(&ca->bucket_lock);
-	}
-	mutex_unlock(&c->bucket_clock[WRITE].lock);
-
 	return 0;
 }
 
-enum alloc_write_ret {
-	ALLOC_WROTE,
-	ALLOC_NOWROTE,
-	ALLOC_END,
-};
-
 static int bch2_alloc_write_key(struct btree_trans *trans,
 				struct btree_iter *iter,
 				unsigned flags)
@@ -272,14 +338,19 @@ static int bch2_alloc_write_key(struct btree_trans *trans,
 	struct bch_fs *c = trans->c;
 	struct bkey_s_c k;
 	struct bch_dev *ca;
-	struct bucket_array *ba;
 	struct bucket *g;
 	struct bucket_mark m;
 	struct bkey_alloc_unpacked old_u, new_u;
-	__BKEY_PADDED(k, 8) alloc_key; /* hack: */
-	struct bkey_i_alloc *a;
+	struct bkey_alloc_buf a;
 	int ret;
 retry:
+	bch2_trans_begin(trans);
+
+	ret = bch2_btree_key_cache_flush(trans,
+			BTREE_ID_alloc, iter->pos);
+	if (ret)
+		goto err;
+
 	k = bch2_btree_iter_peek_slot(iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -287,32 +358,18 @@ retry:
 
 	old_u = bch2_alloc_unpack(k);
 
-	if (iter->pos.inode >= c->sb.nr_devices ||
-	    !c->devs[iter->pos.inode])
-		return ALLOC_END;
-
 	percpu_down_read(&c->mark_lock);
 	ca	= bch_dev_bkey_exists(c, iter->pos.inode);
-	ba	= bucket_array(ca);
-
-	if (iter->pos.offset >= ba->nbuckets) {
-		percpu_up_read(&c->mark_lock);
-		return ALLOC_END;
-	}
-
-	g	= &ba->b[iter->pos.offset];
+	g	= bucket(ca, iter->pos.offset);
 	m	= READ_ONCE(g->mark);
-	new_u	= alloc_mem_to_key(g, m);
+	new_u	= alloc_mem_to_key(iter, g, m);
 	percpu_up_read(&c->mark_lock);
 
 	if (!bkey_alloc_unpacked_cmp(old_u, new_u))
-		return ALLOC_NOWROTE;
-
-	a = bkey_alloc_init(&alloc_key.k);
-	a->k.p = iter->pos;
-	bch2_alloc_pack(a, new_u);
+		return 0;
 
-	bch2_trans_update(trans, iter, &a->k_i,
+	bch2_alloc_pack(c, &a, new_u);
+	bch2_trans_update(trans, iter, &a.k,
 			  BTREE_TRIGGER_NORUN);
 	ret = bch2_trans_commit(trans, NULL, NULL,
 				BTREE_INSERT_NOFAIL|flags);
@@ -322,7 +379,7 @@ err:
 	return ret;
 }
 
-int bch2_alloc_write(struct bch_fs *c, unsigned flags, bool *wrote)
+int bch2_alloc_write(struct bch_fs *c, unsigned flags)
 {
 	struct btree_trans trans;
 	struct btree_iter *iter;
@@ -330,169 +387,76 @@ int bch2_alloc_write(struct bch_fs *c, unsigned flags, bool *wrote)
 	unsigned i;
 	int ret = 0;
 
-	BUG_ON(BKEY_ALLOC_VAL_U64s_MAX > 8);
-
-	bch2_trans_init(&trans, c, 0, 0);
-
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_ALLOC, POS_MIN,
+	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
+	iter = bch2_trans_get_iter(&trans, BTREE_ID_alloc, POS_MIN,
 				   BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
 
-	for_each_rw_member(ca, c, i) {
-		unsigned first_bucket;
-
-		percpu_down_read(&c->mark_lock);
-		first_bucket = bucket_array(ca)->first_bucket;
-		percpu_up_read(&c->mark_lock);
+	for_each_member_device(ca, c, i) {
+		bch2_btree_iter_set_pos(iter,
+			POS(ca->dev_idx, ca->mi.first_bucket));
 
-		bch2_btree_iter_set_pos(iter, POS(i, first_bucket));
+		while (iter->pos.offset < ca->mi.nbuckets) {
+			bch2_trans_cond_resched(&trans);
 
-		while (1) {
 			ret = bch2_alloc_write_key(&trans, iter, flags);
-			if (ret < 0 || ret == ALLOC_END)
-				break;
-			if (ret == ALLOC_WROTE)
-				*wrote = true;
+			if (ret) {
+				percpu_ref_put(&ca->io_ref);
+				goto err;
+			}
 			bch2_btree_iter_next_slot(iter);
 		}
-
-		if (ret < 0) {
-			percpu_ref_put(&ca->io_ref);
-			break;
-		}
 	}
-
-	bch2_trans_exit(&trans);
-
-	return ret < 0 ? ret : 0;
-}
-
-int bch2_alloc_replay_key(struct bch_fs *c, struct bkey_i *k)
-{
-	struct btree_trans trans;
-	struct btree_iter *iter;
-	int ret;
-
-	bch2_trans_init(&trans, c, 0, 0);
-
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_ALLOC, k->k.p,
-				   BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-
-	ret = bch2_alloc_write_key(&trans, iter,
-				   BTREE_INSERT_NOFAIL|
-				   BTREE_INSERT_LAZY_RW|
-				   BTREE_INSERT_JOURNAL_REPLAY);
+err:
+	bch2_trans_iter_put(&trans, iter);
 	bch2_trans_exit(&trans);
-	return ret < 0 ? ret : 0;
+	return ret;
 }
 
 /* Bucket IO clocks: */
 
-static void bch2_recalc_oldest_io(struct bch_fs *c, struct bch_dev *ca, int rw)
-{
-	struct bucket_clock *clock = &c->bucket_clock[rw];
-	struct bucket_array *buckets = bucket_array(ca);
-	struct bucket *g;
-	u16 max_last_io = 0;
-	unsigned i;
-
-	lockdep_assert_held(&c->bucket_clock[rw].lock);
-
-	/* Recalculate max_last_io for this device: */
-	for_each_bucket(g, buckets)
-		max_last_io = max(max_last_io, bucket_last_io(c, g, rw));
-
-	ca->max_last_bucket_io[rw] = max_last_io;
-
-	/* Recalculate global max_last_io: */
-	max_last_io = 0;
-
-	for_each_member_device(ca, c, i)
-		max_last_io = max(max_last_io, ca->max_last_bucket_io[rw]);
-
-	clock->max_last_io = max_last_io;
-}
-
-static void bch2_rescale_bucket_io_times(struct bch_fs *c, int rw)
+int bch2_bucket_io_time_reset(struct btree_trans *trans, unsigned dev,
+			      size_t bucket_nr, int rw)
 {
-	struct bucket_clock *clock = &c->bucket_clock[rw];
-	struct bucket_array *buckets;
-	struct bch_dev *ca;
+	struct bch_fs *c = trans->c;
+	struct bch_dev *ca = bch_dev_bkey_exists(c, dev);
+	struct btree_iter *iter;
 	struct bucket *g;
-	unsigned i;
-
-	trace_rescale_prios(c);
-
-	for_each_member_device(ca, c, i) {
-		down_read(&ca->bucket_lock);
-		buckets = bucket_array(ca);
-
-		for_each_bucket(g, buckets)
-			g->io_time[rw] = clock->hand -
-			bucket_last_io(c, g, rw) / 2;
-
-		bch2_recalc_oldest_io(c, ca, rw);
-
-		up_read(&ca->bucket_lock);
-	}
-}
-
-static inline u64 bucket_clock_freq(u64 capacity)
-{
-	return max(capacity >> 10, 2028ULL);
-}
-
-static void bch2_inc_clock_hand(struct io_timer *timer)
-{
-	struct bucket_clock *clock = container_of(timer,
-						struct bucket_clock, rescale);
-	struct bch_fs *c = container_of(clock,
-					struct bch_fs, bucket_clock[clock->rw]);
-	struct bch_dev *ca;
-	u64 capacity;
-	unsigned i;
-
-	mutex_lock(&clock->lock);
-
-	/* if clock cannot be advanced more, rescale prio */
-	if (clock->max_last_io >= U16_MAX - 2)
-		bch2_rescale_bucket_io_times(c, clock->rw);
-
-	BUG_ON(clock->max_last_io >= U16_MAX - 2);
-
-	for_each_member_device(ca, c, i)
-		ca->max_last_bucket_io[clock->rw]++;
-	clock->max_last_io++;
-	clock->hand++;
-
-	mutex_unlock(&clock->lock);
+	struct bkey_alloc_buf *a;
+	struct bkey_alloc_unpacked u;
+	u64 *time, now;
+	int ret = 0;
 
-	capacity = READ_ONCE(c->capacity);
+	iter = bch2_trans_get_iter(trans, BTREE_ID_alloc, POS(dev, bucket_nr),
+				   BTREE_ITER_CACHED|
+				   BTREE_ITER_CACHED_NOFILL|
+				   BTREE_ITER_INTENT);
+	ret = bch2_btree_iter_traverse(iter);
+	if (ret)
+		goto out;
 
-	if (!capacity)
-		return;
+	a = bch2_trans_kmalloc(trans, sizeof(struct bkey_alloc_buf));
+	ret = PTR_ERR_OR_ZERO(a);
+	if (ret)
+		goto out;
 
-	/*
-	 * we only increment when 0.1% of the filesystem capacity has been read
-	 * or written too, this determines if it's time
-	 *
-	 * XXX: we shouldn't really be going off of the capacity of devices in
-	 * RW mode (that will be 0 when we're RO, yet we can still service
-	 * reads)
-	 */
-	timer->expire += bucket_clock_freq(capacity);
+	percpu_down_read(&c->mark_lock);
+	g = bucket(ca, bucket_nr);
+	u = alloc_mem_to_key(iter, g, READ_ONCE(g->mark));
+	percpu_up_read(&c->mark_lock);
 
-	bch2_io_timer_add(&c->io_clock[clock->rw], timer);
-}
+	time = rw == READ ? &u.read_time : &u.write_time;
+	now = atomic64_read(&c->io_clock[rw].now);
+	if (*time == now)
+		goto out;
 
-static void bch2_bucket_clock_init(struct bch_fs *c, int rw)
-{
-	struct bucket_clock *clock = &c->bucket_clock[rw];
+	*time = now;
 
-	clock->hand		= 1;
-	clock->rw		= rw;
-	clock->rescale.fn	= bch2_inc_clock_hand;
-	clock->rescale.expire	= bucket_clock_freq(c->capacity);
-	mutex_init(&clock->lock);
+	bch2_alloc_pack(c, a, u);
+	ret   = bch2_trans_update(trans, iter, &a->k, 0) ?:
+		bch2_trans_commit(trans, NULL, NULL, 0);
+out:
+	bch2_trans_iter_put(trans, iter);
+	return ret;
 }
 
 /* Background allocator thread: */
@@ -503,8 +467,6 @@ static void bch2_bucket_clock_init(struct bch_fs *c, int rw)
  * commands to the newly free buckets, then puts them on the various freelists.
  */
 
-#define BUCKET_GC_GEN_MAX	96U
-
 /**
  * wait_buckets_available - wait on reclaimable buckets
  *
@@ -514,6 +476,8 @@ static void bch2_bucket_clock_init(struct bch_fs *c, int rw)
 static int wait_buckets_available(struct bch_fs *c, struct bch_dev *ca)
 {
 	unsigned long gc_count = c->gc_count;
+	s64 available;
+	unsigned i;
 	int ret = 0;
 
 	ca->allocator_state = ALLOCATOR_BLOCKED;
@@ -529,9 +493,19 @@ static int wait_buckets_available(struct bch_fs *c, struct bch_dev *ca)
 		if (gc_count != c->gc_count)
 			ca->inc_gen_really_needs_gc = 0;
 
-		if ((ssize_t) (dev_buckets_available(c, ca) -
-			       ca->inc_gen_really_needs_gc) >=
-		    (ssize_t) fifo_free(&ca->free_inc))
+		available  = dev_buckets_available(ca);
+		available -= ca->inc_gen_really_needs_gc;
+
+		spin_lock(&c->freelist_lock);
+		for (i = 0; i < RESERVE_NR; i++)
+			available -= fifo_used(&ca->free[i]);
+		spin_unlock(&c->freelist_lock);
+
+		available = max(available, 0LL);
+
+		if (available > fifo_free(&ca->free_inc) ||
+		    (available &&
+		     !fifo_full(&ca->free[RESERVE_MOVINGGC])))
 			break;
 
 		up_read(&c->gc_lock);
@@ -547,20 +521,22 @@ static int wait_buckets_available(struct bch_fs *c, struct bch_dev *ca)
 	return ret;
 }
 
-static bool bch2_can_invalidate_bucket(struct bch_dev *ca,
-				       size_t bucket,
-				       struct bucket_mark mark)
+static bool bch2_can_invalidate_bucket(struct bch_dev *ca, size_t b,
+				       struct bucket_mark m)
 {
 	u8 gc_gen;
 
-	if (!is_available_bucket(mark))
+	if (!is_available_bucket(m))
+		return false;
+
+	if (m.owned_by_allocator)
 		return false;
 
 	if (ca->buckets_nouse &&
-	    test_bit(bucket, ca->buckets_nouse))
+	    test_bit(b, ca->buckets_nouse))
 		return false;
 
-	gc_gen = bucket_gc_gen(ca, bucket);
+	gc_gen = bucket_gc_gen(bucket(ca, b));
 
 	if (gc_gen >= BUCKET_GC_GEN_MAX / 2)
 		ca->inc_gen_needs_gc++;
@@ -574,43 +550,33 @@ static bool bch2_can_invalidate_bucket(struct bch_dev *ca,
 /*
  * Determines what order we're going to reuse buckets, smallest bucket_key()
  * first.
- *
- *
- * - We take into account the read prio of the bucket, which gives us an
- *   indication of how hot the data is -- we scale the prio so that the prio
- *   farthest from the clock is worth 1/8th of the closest.
- *
- * - The number of sectors of cached data in the bucket, which gives us an
- *   indication of the cost in cache misses this eviction will cause.
- *
- * - If hotness * sectors used compares equal, we pick the bucket with the
- *   smallest bucket_gc_gen() - since incrementing the same bucket's generation
- *   number repeatedly forces us to run mark and sweep gc to avoid generation
- *   number wraparound.
  */
 
-static unsigned long bucket_sort_key(struct bch_fs *c, struct bch_dev *ca,
-				     size_t b, struct bucket_mark m)
+static unsigned bucket_sort_key(struct bucket *g, struct bucket_mark m,
+				u64 now, u64 last_seq_ondisk)
 {
-	unsigned last_io = bucket_last_io(c, bucket(ca, b), READ);
-	unsigned max_last_io = ca->max_last_bucket_io[READ];
-
-	/*
-	 * Time since last read, scaled to [0, 8) where larger value indicates
-	 * more recently read data:
-	 */
-	unsigned long hotness = (max_last_io - last_io) * 7 / max_last_io;
-
-	/* How much we want to keep the data in this bucket: */
-	unsigned long data_wantness =
-		(hotness + 1) * bucket_sectors_used(m);
+	unsigned used = bucket_sectors_used(m);
 
-	unsigned long needs_journal_commit =
-		bucket_needs_journal_commit(m, c->journal.last_seq_ondisk);
+	if (used) {
+		/*
+		 * Prefer to keep buckets that have been read more recently, and
+		 * buckets that have more data in them:
+		 */
+		u64 last_read = max_t(s64, 0, now - g->io_time[READ]);
+		u32 last_read_scaled = max_t(u64, U32_MAX, div_u64(last_read, used));
 
-	return  (data_wantness << 9) |
-		(needs_journal_commit << 8) |
-		(bucket_gc_gen(ca, b) / 16);
+		return -last_read_scaled;
+	} else {
+		/*
+		 * Prefer to use buckets with smaller gc_gen so that we don't
+		 * have to walk the btree and recalculate oldest_gen - but shift
+		 * off the low bits so that buckets will still have equal sort
+		 * keys when there's only a small difference, so that we can
+		 * keep sequential buckets together:
+		 */
+		return  (bucket_needs_journal_commit(m, last_seq_ondisk) << 4)|
+			(bucket_gc_gen(g) >> 4);
+	}
 }
 
 static inline int bucket_alloc_cmp(alloc_heap *h,
@@ -633,16 +599,15 @@ static void find_reclaimable_buckets_lru(struct bch_fs *c, struct bch_dev *ca)
 {
 	struct bucket_array *buckets;
 	struct alloc_heap_entry e = { 0 };
+	u64 now, last_seq_ondisk;
 	size_t b, i, nr = 0;
 
-	ca->alloc_heap.used = 0;
-
-	mutex_lock(&c->bucket_clock[READ].lock);
 	down_read(&ca->bucket_lock);
 
 	buckets = bucket_array(ca);
-
-	bch2_recalc_oldest_io(c, ca, READ);
+	ca->alloc_heap.used = 0;
+	now = atomic64_read(&c->io_clock[READ].now);
+	last_seq_ondisk = c->journal.last_seq_ondisk;
 
 	/*
 	 * Find buckets with lowest read priority, by building a maxheap sorted
@@ -650,8 +615,9 @@ static void find_reclaimable_buckets_lru(struct bch_fs *c, struct bch_dev *ca)
 	 * all buckets have been visited.
 	 */
 	for (b = ca->mi.first_bucket; b < ca->mi.nbuckets; b++) {
-		struct bucket_mark m = READ_ONCE(buckets->b[b].mark);
-		unsigned long key = bucket_sort_key(c, ca, b, m);
+		struct bucket *g = &buckets->b[b];
+		struct bucket_mark m = READ_ONCE(g->mark);
+		unsigned key = bucket_sort_key(g, m, now, last_seq_ondisk);
 
 		if (!bch2_can_invalidate_bucket(ca, b, m))
 			continue;
@@ -686,7 +652,6 @@ static void find_reclaimable_buckets_lru(struct bch_fs *c, struct bch_dev *ca)
 	}
 
 	up_read(&ca->bucket_lock);
-	mutex_unlock(&c->bucket_clock[READ].lock);
 }
 
 static void find_reclaimable_buckets_fifo(struct bch_fs *c, struct bch_dev *ca)
@@ -766,13 +731,13 @@ static size_t find_reclaimable_buckets(struct bch_fs *c, struct bch_dev *ca)
 	ca->inc_gen_needs_gc			= 0;
 
 	switch (ca->mi.replacement) {
-	case CACHE_REPLACEMENT_LRU:
+	case BCH_CACHE_REPLACEMENT_lru:
 		find_reclaimable_buckets_lru(c, ca);
 		break;
-	case CACHE_REPLACEMENT_FIFO:
+	case BCH_CACHE_REPLACEMENT_fifo:
 		find_reclaimable_buckets_fifo(c, ca);
 		break;
-	case CACHE_REPLACEMENT_RANDOM:
+	case BCH_CACHE_REPLACEMENT_random:
 		find_reclaimable_buckets_random(c, ca);
 		break;
 	}
@@ -831,21 +796,14 @@ static int bch2_invalidate_one_bucket2(struct btree_trans *trans,
 				       struct btree_iter *iter,
 				       u64 *journal_seq, unsigned flags)
 {
-#if 0
-	__BKEY_PADDED(k, BKEY_ALLOC_VAL_U64s_MAX) alloc_key;
-#else
-	/* hack: */
-	__BKEY_PADDED(k, 8) alloc_key;
-#endif
 	struct bch_fs *c = trans->c;
-	struct bkey_i_alloc *a;
+	struct bkey_alloc_buf a;
 	struct bkey_alloc_unpacked u;
 	struct bucket *g;
 	struct bucket_mark m;
-	struct bkey_s_c k;
 	bool invalidating_cached_data;
 	size_t b;
-	int ret;
+	int ret = 0;
 
 	BUG_ON(!ca->alloc_heap.used ||
 	       !ca->alloc_heap.data[0].nr);
@@ -853,51 +811,66 @@ static int bch2_invalidate_one_bucket2(struct btree_trans *trans,
 
 	/* first, put on free_inc and mark as owned by allocator: */
 	percpu_down_read(&c->mark_lock);
-	spin_lock(&c->freelist_lock);
+	g = bucket(ca, b);
+	m = READ_ONCE(g->mark);
 
-	verify_not_on_freelist(c, ca, b);
-
-	BUG_ON(!fifo_push(&ca->free_inc, b));
+	BUG_ON(m.dirty_sectors);
 
 	bch2_mark_alloc_bucket(c, ca, b, true, gc_pos_alloc(c, NULL), 0);
 
+	spin_lock(&c->freelist_lock);
+	verify_not_on_freelist(c, ca, b);
+	BUG_ON(!fifo_push(&ca->free_inc, b));
 	spin_unlock(&c->freelist_lock);
+
+	/*
+	 * If we're not invalidating cached data, we only increment the bucket
+	 * gen in memory here, the incremented gen will be updated in the btree
+	 * by bch2_trans_mark_pointer():
+	 */
+	if (!m.cached_sectors &&
+	    !bucket_needs_journal_commit(m, c->journal.last_seq_ondisk)) {
+		BUG_ON(m.data_type);
+		bucket_cmpxchg(g, m, m.gen++);
+		percpu_up_read(&c->mark_lock);
+		goto out;
+	}
+
 	percpu_up_read(&c->mark_lock);
 
-	BUG_ON(BKEY_ALLOC_VAL_U64s_MAX > 8);
+	/*
+	 * If the read-only path is trying to shut down, we can't be generating
+	 * new btree updates:
+	 */
+	if (test_bit(BCH_FS_ALLOCATOR_STOPPING, &c->flags)) {
+		ret = 1;
+		goto out;
+	}
 
 	bch2_btree_iter_set_pos(iter, POS(ca->dev_idx, b));
 retry:
-	k = bch2_btree_iter_peek_slot(iter);
-	ret = bkey_err(k);
+	ret = bch2_btree_iter_traverse(iter);
 	if (ret)
 		return ret;
 
-	/*
-	 * The allocator has to start before journal replay is finished - thus,
-	 * we have to trust the in memory bucket @m, not the version in the
-	 * btree:
-	 */
 	percpu_down_read(&c->mark_lock);
-	g = bucket(ca, b);
+	g = bucket(ca, iter->pos.offset);
 	m = READ_ONCE(g->mark);
-	u = alloc_mem_to_key(g, m);
+	u = alloc_mem_to_key(iter, g, m);
+
 	percpu_up_read(&c->mark_lock);
 
-	invalidating_cached_data = m.cached_sectors != 0;
+	invalidating_cached_data = u.cached_sectors != 0;
 
 	u.gen++;
 	u.data_type	= 0;
 	u.dirty_sectors	= 0;
 	u.cached_sectors = 0;
-	u.read_time	= c->bucket_clock[READ].hand;
-	u.write_time	= c->bucket_clock[WRITE].hand;
-
-	a = bkey_alloc_init(&alloc_key.k);
-	a->k.p = iter->pos;
-	bch2_alloc_pack(a, u);
+	u.read_time	= atomic64_read(&c->io_clock[READ].now);
+	u.write_time	= atomic64_read(&c->io_clock[WRITE].now);
 
-	bch2_trans_update(trans, iter, &a->k_i,
+	bch2_alloc_pack(c, &a, u);
+	bch2_trans_update(trans, iter, &a.k,
 			  BTREE_TRIGGER_BUCKET_INVALIDATE);
 
 	/*
@@ -912,12 +885,11 @@ retry:
 				BTREE_INSERT_NOUNLOCK|
 				BTREE_INSERT_NOCHECK_RW|
 				BTREE_INSERT_NOFAIL|
-				BTREE_INSERT_USE_RESERVE|
-				BTREE_INSERT_USE_ALLOC_RESERVE|
+				BTREE_INSERT_JOURNAL_RESERVED|
 				flags);
 	if (ret == -EINTR)
 		goto retry;
-
+out:
 	if (!ret) {
 		/* remove from alloc_heap: */
 		struct alloc_heap_entry e, *top = ca->alloc_heap.data;
@@ -951,32 +923,7 @@ retry:
 		percpu_up_read(&c->mark_lock);
 	}
 
-	return ret;
-}
-
-static bool bch2_invalidate_one_bucket(struct bch_fs *c, struct bch_dev *ca,
-				       size_t bucket, u64 *flush_seq)
-{
-	struct bucket_mark m;
-
-	percpu_down_read(&c->mark_lock);
-	spin_lock(&c->freelist_lock);
-
-	bch2_invalidate_bucket(c, ca, bucket, &m);
-
-	verify_not_on_freelist(c, ca, bucket);
-	BUG_ON(!fifo_push(&ca->free_inc, bucket));
-
-	spin_unlock(&c->freelist_lock);
-
-	bucket_io_clock_reset(c, ca, bucket, READ);
-	bucket_io_clock_reset(c, ca, bucket, WRITE);
-
-	percpu_up_read(&c->mark_lock);
-
-	*flush_seq = max(*flush_seq, bucket_journal_seq(c, m));
-
-	return m.cached_sectors != 0;
+	return ret < 0 ? ret : 0;
 }
 
 /*
@@ -990,10 +937,11 @@ static int bch2_invalidate_buckets(struct bch_fs *c, struct bch_dev *ca)
 	int ret = 0;
 
 	bch2_trans_init(&trans, c, 0, 0);
-
-	iter = bch2_trans_get_iter(&trans, BTREE_ID_ALLOC,
+	iter = bch2_trans_get_iter(&trans, BTREE_ID_alloc,
 				   POS(ca->dev_idx, 0),
-				   BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+				   BTREE_ITER_CACHED|
+				   BTREE_ITER_CACHED_NOFILL|
+				   BTREE_ITER_INTENT);
 
 	/* Only use nowait if we've already invalidated at least one bucket: */
 	while (!ret &&
@@ -1004,6 +952,7 @@ static int bch2_invalidate_buckets(struct bch_fs *c, struct bch_dev *ca)
 				(!fifo_empty(&ca->free_inc)
 				 ? BTREE_INSERT_NOWAIT : 0));
 
+	bch2_trans_iter_put(&trans, iter);
 	bch2_trans_exit(&trans);
 
 	/* If we used NOWAIT, don't return the error: */
@@ -1033,7 +982,16 @@ static int push_invalidated_bucket(struct bch_fs *c, struct bch_dev *ca, size_t
 		set_current_state(TASK_INTERRUPTIBLE);
 
 		spin_lock(&c->freelist_lock);
-		for (i = 0; i < RESERVE_NR; i++)
+		for (i = 0; i < RESERVE_NR; i++) {
+
+			/*
+			 * Don't strand buckets on the copygc freelist until
+			 * after recovery is finished:
+			 */
+			if (!test_bit(BCH_FS_STARTED, &c->flags) &&
+			    i == RESERVE_MOVINGGC)
+				continue;
+
 			if (fifo_push(&ca->free[i], bucket)) {
 				fifo_pop(&ca->free_inc, bucket);
 
@@ -1043,6 +1001,7 @@ static int push_invalidated_bucket(struct bch_fs *c, struct bch_dev *ca, size_t
 				spin_unlock(&c->freelist_lock);
 				goto out;
 			}
+		}
 
 		if (ca->allocator_state != ALLOCATOR_BLOCKED_FULL) {
 			ca->allocator_state = ALLOCATOR_BLOCKED_FULL;
@@ -1087,6 +1046,12 @@ static int discard_invalidated_buckets(struct bch_fs *c, struct bch_dev *ca)
 	return 0;
 }
 
+static inline bool allocator_thread_running(struct bch_dev *ca)
+{
+	return ca->mi.state == BCH_MEMBER_STATE_rw &&
+		test_bit(BCH_FS_ALLOCATOR_RUNNING, &ca->fs->flags);
+}
+
 /**
  * bch_allocator_thread - move buckets from free_inc to reserves
  *
@@ -1103,10 +1068,19 @@ static int bch2_allocator_thread(void *arg)
 	int ret;
 
 	set_freezable();
-	ca->allocator_state = ALLOCATOR_RUNNING;
 
 	while (1) {
+		if (!allocator_thread_running(ca)) {
+			ca->allocator_state = ALLOCATOR_STOPPED;
+			if (kthread_wait_freezable(allocator_thread_running(ca)))
+				break;
+		}
+
+		ca->allocator_state = ALLOCATOR_RUNNING;
+
 		cond_resched();
+		if (kthread_should_stop())
+			break;
 
 		pr_debug("discarding %zu invalidated buckets",
 			 fifo_used(&ca->free_inc));
@@ -1192,7 +1166,7 @@ stop:
 void bch2_recalc_capacity(struct bch_fs *c)
 {
 	struct bch_dev *ca;
-	u64 capacity = 0, reserved_sectors = 0, gc_reserve;
+	u64 capacity = 0, reserved_sectors = 0, gc_reserve, copygc_threshold = 0;
 	unsigned bucket_size_max = 0;
 	unsigned long ra_pages = 0;
 	unsigned i, j;
@@ -1235,7 +1209,7 @@ void bch2_recalc_capacity(struct bch_fs *c)
 
 		dev_reserve *= ca->mi.bucket_size;
 
-		ca->copygc_threshold = dev_reserve;
+		copygc_threshold += dev_reserve;
 
 		capacity += bucket_to_sector(ca, ca->mi.nbuckets -
 					     ca->mi.first_bucket);
@@ -1254,22 +1228,11 @@ void bch2_recalc_capacity(struct bch_fs *c)
 
 	reserved_sectors = min(reserved_sectors, capacity);
 
+	c->copygc_threshold = copygc_threshold;
 	c->capacity = capacity - reserved_sectors;
 
 	c->bucket_size_max = bucket_size_max;
 
-	if (c->capacity) {
-		bch2_io_timer_add(&c->io_clock[READ],
-				 &c->bucket_clock[READ].rescale);
-		bch2_io_timer_add(&c->io_clock[WRITE],
-				 &c->bucket_clock[WRITE].rescale);
-	} else {
-		bch2_io_timer_del(&c->io_clock[READ],
-				 &c->bucket_clock[READ].rescale);
-		bch2_io_timer_del(&c->io_clock[WRITE],
-				 &c->bucket_clock[WRITE].rescale);
-	}
-
 	/* Wake up case someone was waiting for buckets */
 	closure_wake_up(&c->freelist_wait);
 }
@@ -1313,7 +1276,7 @@ void bch2_dev_allocator_remove(struct bch_fs *c, struct bch_dev *ca)
 	for (i = 0; i < ARRAY_SIZE(c->write_points); i++)
 		bch2_writepoint_stop(c, ca, &c->write_points[i]);
 
-	bch2_writepoint_stop(c, ca, &ca->copygc_write_point);
+	bch2_writepoint_stop(c, ca, &c->copygc_write_point);
 	bch2_writepoint_stop(c, ca, &c->rebalance_write_point);
 	bch2_writepoint_stop(c, ca, &c->btree_write_point);
 
@@ -1414,9 +1377,12 @@ int bch2_dev_allocator_start(struct bch_dev *ca)
 		return 0;
 
 	p = kthread_create(bch2_allocator_thread, ca,
-			   "bch_alloc[%s]", ca->name);
-	if (IS_ERR(p))
+			   "bch-alloc/%s", ca->name);
+	if (IS_ERR(p)) {
+		bch_err(ca->fs, "error creating allocator thread: %li",
+			PTR_ERR(p));
 		return PTR_ERR(p);
+	}
 
 	get_task_struct(p);
 	rcu_assign_pointer(ca->alloc_thread, p);
@@ -1424,226 +1390,9 @@ int bch2_dev_allocator_start(struct bch_dev *ca)
 	return 0;
 }
 
-static bool flush_held_btree_writes(struct bch_fs *c)
-{
-	struct bucket_table *tbl;
-	struct rhash_head *pos;
-	struct btree *b;
-	bool nodes_unwritten;
-	size_t i;
-again:
-	cond_resched();
-	nodes_unwritten = false;
-
-	if (bch2_journal_error(&c->journal))
-		return true;
-
-	rcu_read_lock();
-	for_each_cached_btree(b, c, tbl, i, pos)
-		if (btree_node_need_write(b)) {
-			if (btree_node_may_write(b)) {
-				rcu_read_unlock();
-				btree_node_lock_type(c, b, SIX_LOCK_read);
-				bch2_btree_node_write(c, b, SIX_LOCK_read);
-				six_unlock_read(&b->lock);
-				goto again;
-			} else {
-				nodes_unwritten = true;
-			}
-		}
-	rcu_read_unlock();
-
-	if (c->btree_roots_dirty) {
-		bch2_journal_meta(&c->journal);
-		goto again;
-	}
-
-	return !nodes_unwritten &&
-		!bch2_btree_interior_updates_nr_pending(c);
-}
-
-static void allocator_start_issue_discards(struct bch_fs *c)
-{
-	struct bch_dev *ca;
-	unsigned dev_iter;
-	size_t bu;
-
-	for_each_rw_member(ca, c, dev_iter)
-		while (fifo_pop(&ca->free_inc, bu))
-			blkdev_issue_discard(ca->disk_sb.bdev,
-					     bucket_to_sector(ca, bu),
-					     ca->mi.bucket_size, GFP_NOIO, 0);
-}
-
-static int resize_free_inc(struct bch_dev *ca)
-{
-	alloc_fifo free_inc;
-
-	if (!fifo_full(&ca->free_inc))
-		return 0;
-
-	if (!init_fifo(&free_inc,
-		       ca->free_inc.size * 2,
-		       GFP_KERNEL))
-		return -ENOMEM;
-
-	fifo_move(&free_inc, &ca->free_inc);
-	swap(free_inc, ca->free_inc);
-	free_fifo(&free_inc);
-	return 0;
-}
-
-static bool bch2_fs_allocator_start_fast(struct bch_fs *c)
-{
-	struct bch_dev *ca;
-	unsigned dev_iter;
-	bool ret = true;
-
-	if (test_alloc_startup(c))
-		return false;
-
-	down_read(&c->gc_lock);
-
-	/* Scan for buckets that are already invalidated: */
-	for_each_rw_member(ca, c, dev_iter) {
-		struct bucket_array *buckets;
-		struct bucket_mark m;
-		long bu;
-
-		down_read(&ca->bucket_lock);
-		buckets = bucket_array(ca);
-
-		for (bu = buckets->first_bucket;
-		     bu < buckets->nbuckets; bu++) {
-			m = READ_ONCE(buckets->b[bu].mark);
-
-			if (!buckets->b[bu].gen_valid ||
-			    !is_available_bucket(m) ||
-			    m.cached_sectors ||
-			    (ca->buckets_nouse &&
-			     test_bit(bu, ca->buckets_nouse)))
-				continue;
-
-			percpu_down_read(&c->mark_lock);
-			bch2_mark_alloc_bucket(c, ca, bu, true,
-					gc_pos_alloc(c, NULL), 0);
-			percpu_up_read(&c->mark_lock);
-
-			fifo_push(&ca->free_inc, bu);
-
-			discard_invalidated_buckets(c, ca);
-
-			if (fifo_full(&ca->free[RESERVE_BTREE]))
-				break;
-		}
-		up_read(&ca->bucket_lock);
-	}
-
-	up_read(&c->gc_lock);
-
-	/* did we find enough buckets? */
-	for_each_rw_member(ca, c, dev_iter)
-		if (!fifo_full(&ca->free[RESERVE_BTREE]))
-			ret = false;
-
-	return ret;
-}
-
-int bch2_fs_allocator_start(struct bch_fs *c)
-{
-	struct bch_dev *ca;
-	unsigned dev_iter;
-	u64 journal_seq = 0;
-	bool wrote;
-	long bu;
-	int ret = 0;
-
-	if (!test_alloc_startup(c) &&
-	    bch2_fs_allocator_start_fast(c))
-		return 0;
-
-	pr_debug("not enough empty buckets; scanning for reclaimable buckets");
-
-	/*
-	 * We're moving buckets to freelists _before_ they've been marked as
-	 * invalidated on disk - we have to so that we can allocate new btree
-	 * nodes to mark them as invalidated on disk.
-	 *
-	 * However, we can't _write_ to any of these buckets yet - they might
-	 * have cached data in them, which is live until they're marked as
-	 * invalidated on disk:
-	 */
-	set_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags);
-
-	down_read(&c->gc_lock);
-	do {
-		wrote = false;
-
-		for_each_rw_member(ca, c, dev_iter) {
-			find_reclaimable_buckets(c, ca);
-
-			while (!fifo_full(&ca->free[RESERVE_BTREE]) &&
-			       (bu = next_alloc_bucket(ca)) >= 0) {
-				ret = resize_free_inc(ca);
-				if (ret) {
-					percpu_ref_put(&ca->io_ref);
-					up_read(&c->gc_lock);
-					goto err;
-				}
-
-				bch2_invalidate_one_bucket(c, ca, bu,
-							   &journal_seq);
-
-				fifo_push(&ca->free[RESERVE_BTREE], bu);
-			}
-		}
-
-		pr_debug("done scanning for reclaimable buckets");
-
-		/*
-		 * XXX: it's possible for this to deadlock waiting on journal reclaim,
-		 * since we're holding btree writes. What then?
-		 */
-		ret = bch2_alloc_write(c,
-				       BTREE_INSERT_NOCHECK_RW|
-				       BTREE_INSERT_USE_ALLOC_RESERVE|
-				       BTREE_INSERT_NOWAIT, &wrote);
-
-		/*
-		 * If bch2_alloc_write() did anything, it may have used some
-		 * buckets, and we need the RESERVE_BTREE freelist full - so we
-		 * need to loop and scan again.
-		 * And if it errored, it may have been because there weren't
-		 * enough buckets, so just scan and loop again as long as it
-		 * made some progress:
-		 */
-	} while (wrote);
-	up_read(&c->gc_lock);
-
-	if (ret)
-		goto err;
-
-	pr_debug("flushing journal");
-
-	ret = bch2_journal_flush(&c->journal);
-	if (ret)
-		goto err;
-
-	pr_debug("issuing discards");
-	allocator_start_issue_discards(c);
-err:
-	clear_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags);
-	closure_wait_event(&c->btree_interior_update_wait,
-			   flush_held_btree_writes(c));
-
-	return ret;
-}
-
 void bch2_fs_allocator_background_init(struct bch_fs *c)
 {
 	spin_lock_init(&c->freelist_lock);
-	bch2_bucket_clock_init(c, READ);
-	bch2_bucket_clock_init(c, WRITE);
 
 	c->pd_controllers_update_seconds = 5;
 	INIT_DELAYED_WORK(&c->pd_controllers_update, pd_controllers_update);