1 files changed, 271 insertions, 213 deletions

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 1fec0e67891f..a09b9d00226a 100644
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -261,10 +261,8 @@ int bch2_alloc_v4_invalid(struct bch_fs *c, struct bkey_s_c k,
 	case BCH_DATA_free:
 	case BCH_DATA_need_gc_gens:
 	case BCH_DATA_need_discard:
-		bkey_fsck_err_on(a.v->dirty_sectors ||
-				 a.v->cached_sectors ||
-				 a.v->stripe, c, err,
-				 alloc_key_empty_but_have_data,
+		bkey_fsck_err_on(bch2_bucket_sectors(*a.v) || a.v->stripe,
+				 c, err, alloc_key_empty_but_have_data,
 				 "empty data type free but have data");
 		break;
 	case BCH_DATA_sb:
@@ -272,22 +270,21 @@ int bch2_alloc_v4_invalid(struct bch_fs *c, struct bkey_s_c k,
 	case BCH_DATA_btree:
 	case BCH_DATA_user:
 	case BCH_DATA_parity:
-		bkey_fsck_err_on(!a.v->dirty_sectors, c, err,
-				 alloc_key_dirty_sectors_0,
+		bkey_fsck_err_on(!bch2_bucket_sectors_dirty(*a.v),
+				 c, err, alloc_key_dirty_sectors_0,
 				 "data_type %s but dirty_sectors==0",
 				 bch2_data_types[a.v->data_type]);
 		break;
 	case BCH_DATA_cached:
 		bkey_fsck_err_on(!a.v->cached_sectors ||
-				 a.v->dirty_sectors ||
-				 a.v->stripe, c, err,
-				 alloc_key_cached_inconsistency,
+				 bch2_bucket_sectors_dirty(*a.v) ||
+				 a.v->stripe,
+				 c, err, alloc_key_cached_inconsistency,
 				 "data type inconsistency");
 
 		bkey_fsck_err_on(!a.v->io_time[READ] &&
 				 c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_to_lru_refs,
-				 c, err,
-				 alloc_key_cached_but_read_time_zero,
+				 c, err, alloc_key_cached_but_read_time_zero,
 				 "cached bucket with read_time == 0");
 		break;
 	case BCH_DATA_stripe:
@@ -537,18 +534,12 @@ void bch2_bucket_gens_to_text(struct printbuf *out, struct bch_fs *c, struct bke
 int bch2_bucket_gens_init(struct bch_fs *c)
 {
 	struct btree_trans *trans = bch2_trans_get(c);
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	struct bch_alloc_v4 a;
 	struct bkey_i_bucket_gens g;
 	bool have_bucket_gens_key = false;
-	unsigned offset;
-	struct bpos pos;
-	u8 gen;
 	int ret;
 
-	for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
-			   BTREE_ITER_PREFETCH, k, ret) {
+	ret = for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
+				 BTREE_ITER_PREFETCH, k, ({
 		/*
 		 * Not a fsck error because this is checked/repaired by
 		 * bch2_check_alloc_key() which runs later:
@@ -556,13 +547,14 @@ int bch2_bucket_gens_init(struct bch_fs *c)
 		if (!bch2_dev_bucket_exists(c, k.k->p))
 			continue;
 
-		gen = bch2_alloc_to_v4(k, &a)->gen;
-		pos = alloc_gens_pos(iter.pos, &offset);
+		struct bch_alloc_v4 a;
+		u8 gen = bch2_alloc_to_v4(k, &a)->gen;
+		unsigned offset;
+		struct bpos pos = alloc_gens_pos(iter.pos, &offset);
 
 		if (have_bucket_gens_key && bkey_cmp(iter.pos, pos)) {
 			ret = commit_do(trans, NULL, NULL,
-					BTREE_INSERT_NOFAIL|
-					BTREE_INSERT_LAZY_RW,
+					BCH_TRANS_COMMIT_no_enospc,
 				bch2_btree_insert_trans(trans, BTREE_ID_bucket_gens, &g.k_i, 0));
 			if (ret)
 				break;
@@ -576,45 +568,37 @@ int bch2_bucket_gens_init(struct bch_fs *c)
 		}
 
 		g.v.gens[offset] = gen;
-	}
-	bch2_trans_iter_exit(trans, &iter);
+		0;
+	}));
 
 	if (have_bucket_gens_key && !ret)
 		ret = commit_do(trans, NULL, NULL,
-				BTREE_INSERT_NOFAIL|
-				BTREE_INSERT_LAZY_RW,
+				BCH_TRANS_COMMIT_no_enospc,
 			bch2_btree_insert_trans(trans, BTREE_ID_bucket_gens, &g.k_i, 0));
 
 	bch2_trans_put(trans);
 
-	if (ret)
-		bch_err_fn(c, ret);
+	bch_err_fn(c, ret);
 	return ret;
 }
 
 int bch2_alloc_read(struct bch_fs *c)
 {
 	struct btree_trans *trans = bch2_trans_get(c);
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	struct bch_dev *ca;
 	int ret;
 
 	down_read(&c->gc_lock);
 
 	if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_bucket_gens) {
-		const struct bch_bucket_gens *g;
-		u64 b;
-
-		for_each_btree_key(trans, iter, BTREE_ID_bucket_gens, POS_MIN,
-				   BTREE_ITER_PREFETCH, k, ret) {
+		ret = for_each_btree_key(trans, iter, BTREE_ID_bucket_gens, POS_MIN,
+					 BTREE_ITER_PREFETCH, k, ({
 			u64 start = bucket_gens_pos_to_alloc(k.k->p, 0).offset;
 			u64 end = bucket_gens_pos_to_alloc(bpos_nosnap_successor(k.k->p), 0).offset;
 
 			if (k.k->type != KEY_TYPE_bucket_gens)
 				continue;
 
-			g = bkey_s_c_to_bucket_gens(k).v;
+			const struct bch_bucket_gens *g = bkey_s_c_to_bucket_gens(k).v;
 
 			/*
 			 * Not a fsck error because this is checked/repaired by
@@ -623,19 +607,17 @@ int bch2_alloc_read(struct bch_fs *c)
 			if (!bch2_dev_exists2(c, k.k->p.inode))
 				continue;
 
-			ca = bch_dev_bkey_exists(c, k.k->p.inode);
+			struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
 
-			for (b = max_t(u64, ca->mi.first_bucket, start);
+			for (u64 b = max_t(u64, ca->mi.first_bucket, start);
 			     b < min_t(u64, ca->mi.nbuckets, end);
 			     b++)
 				*bucket_gen(ca, b) = g->gens[b & KEY_TYPE_BUCKET_GENS_MASK];
-		}
-		bch2_trans_iter_exit(trans, &iter);
+			0;
+		}));
 	} else {
-		struct bch_alloc_v4 a;
-
-		for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
-				   BTREE_ITER_PREFETCH, k, ret) {
+		ret = for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
+					 BTREE_ITER_PREFETCH, k, ({
 			/*
 			 * Not a fsck error because this is checked/repaired by
 			 * bch2_check_alloc_key() which runs later:
@@ -643,19 +625,18 @@ int bch2_alloc_read(struct bch_fs *c)
 			if (!bch2_dev_bucket_exists(c, k.k->p))
 				continue;
 
-			ca = bch_dev_bkey_exists(c, k.k->p.inode);
+			struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
 
+			struct bch_alloc_v4 a;
 			*bucket_gen(ca, k.k->p.offset) = bch2_alloc_to_v4(k, &a)->gen;
-		}
-		bch2_trans_iter_exit(trans, &iter);
+			0;
+		}));
 	}
 
 	bch2_trans_put(trans);
 	up_read(&c->gc_lock);
 
-	if (ret)
-		bch_err_fn(c, ret);
-
+	bch_err_fn(c, ret);
 	return ret;
 }
 
@@ -768,83 +749,177 @@ static noinline int bch2_bucket_gen_update(struct btree_trans *trans,
 	return ret;
 }
 
-int bch2_trans_mark_alloc(struct btree_trans *trans,
-			  enum btree_id btree_id, unsigned level,
-			  struct bkey_s_c old, struct bkey_i *new,
-			  unsigned flags)
+int bch2_trigger_alloc(struct btree_trans *trans,
+		       enum btree_id btree, unsigned level,
+		       struct bkey_s_c old, struct bkey_s new,
+		       unsigned flags)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_alloc_v4 old_a_convert, *new_a;
-	const struct bch_alloc_v4 *old_a;
-	u64 old_lru, new_lru;
 	int ret = 0;
 
-	/*
-	 * Deletion only happens in the device removal path, with
-	 * BTREE_TRIGGER_NORUN:
-	 */
-	BUG_ON(new->k.type != KEY_TYPE_alloc_v4);
+	if (bch2_trans_inconsistent_on(!bch2_dev_bucket_exists(c, new.k->p), trans,
+				       "alloc key for invalid device or bucket"))
+		return -EIO;
 
-	old_a = bch2_alloc_to_v4(old, &old_a_convert);
-	new_a = &bkey_i_to_alloc_v4(new)->v;
+	struct bch_dev *ca = bch_dev_bkey_exists(c, new.k->p.inode);
 
-	new_a->data_type = alloc_data_type(*new_a, new_a->data_type);
+	struct bch_alloc_v4 old_a_convert;
+	const struct bch_alloc_v4 *old_a = bch2_alloc_to_v4(old, &old_a_convert);
 
-	if (new_a->dirty_sectors > old_a->dirty_sectors ||
-	    new_a->cached_sectors > old_a->cached_sectors) {
-		new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
-		new_a->io_time[WRITE]= max_t(u64, 1, atomic64_read(&c->io_clock[WRITE].now));
-		SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, true);
-		SET_BCH_ALLOC_V4_NEED_DISCARD(new_a, true);
-	}
+	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+		struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
 
-	if (data_type_is_empty(new_a->data_type) &&
-	    BCH_ALLOC_V4_NEED_INC_GEN(new_a) &&
-	    !bch2_bucket_is_open_safe(c, new->k.p.inode, new->k.p.offset)) {
-		new_a->gen++;
-		SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, false);
-	}
+		new_a->data_type = alloc_data_type(*new_a, new_a->data_type);
 
-	if (old_a->data_type != new_a->data_type ||
-	    (new_a->data_type == BCH_DATA_free &&
-	     alloc_freespace_genbits(*old_a) != alloc_freespace_genbits(*new_a))) {
-		ret =   bch2_bucket_do_index(trans, old, old_a, false) ?:
-			bch2_bucket_do_index(trans, bkey_i_to_s_c(new), new_a, true);
-		if (ret)
-			return ret;
-	}
+		if (bch2_bucket_sectors(*new_a) > bch2_bucket_sectors(*old_a)) {
+			new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
+			new_a->io_time[WRITE]= max_t(u64, 1, atomic64_read(&c->io_clock[WRITE].now));
+			SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, true);
+			SET_BCH_ALLOC_V4_NEED_DISCARD(new_a, true);
+		}
+
+		if (data_type_is_empty(new_a->data_type) &&
+		    BCH_ALLOC_V4_NEED_INC_GEN(new_a) &&
+		    !bch2_bucket_is_open_safe(c, new.k->p.inode, new.k->p.offset)) {
+			new_a->gen++;
+			SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, false);
+		}
 
-	if (new_a->data_type == BCH_DATA_cached &&
-	    !new_a->io_time[READ])
-		new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
+		if (old_a->data_type != new_a->data_type ||
+		    (new_a->data_type == BCH_DATA_free &&
+		     alloc_freespace_genbits(*old_a) != alloc_freespace_genbits(*new_a))) {
+			ret =   bch2_bucket_do_index(trans, old, old_a, false) ?:
+				bch2_bucket_do_index(trans, new.s_c, new_a, true);
+			if (ret)
+				return ret;
+		}
 
-	old_lru = alloc_lru_idx_read(*old_a);
-	new_lru = alloc_lru_idx_read(*new_a);
+		if (new_a->data_type == BCH_DATA_cached &&
+		    !new_a->io_time[READ])
+			new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
 
-	if (old_lru != new_lru) {
-		ret = bch2_lru_change(trans, new->k.p.inode,
-				      bucket_to_u64(new->k.p),
-				      old_lru, new_lru);
-		if (ret)
-			return ret;
+		u64 old_lru = alloc_lru_idx_read(*old_a);
+		u64 new_lru = alloc_lru_idx_read(*new_a);
+		if (old_lru != new_lru) {
+			ret = bch2_lru_change(trans, new.k->p.inode,
+					      bucket_to_u64(new.k->p),
+					      old_lru, new_lru);
+			if (ret)
+				return ret;
+		}
+
+		new_a->fragmentation_lru = alloc_lru_idx_fragmentation(*new_a,
+						bch_dev_bkey_exists(c, new.k->p.inode));
+		if (old_a->fragmentation_lru != new_a->fragmentation_lru) {
+			ret = bch2_lru_change(trans,
+					BCH_LRU_FRAGMENTATION_START,
+					bucket_to_u64(new.k->p),
+					old_a->fragmentation_lru, new_a->fragmentation_lru);
+			if (ret)
+				return ret;
+		}
+
+		if (old_a->gen != new_a->gen) {
+			ret = bch2_bucket_gen_update(trans, new.k->p, new_a->gen);
+			if (ret)
+				return ret;
+		}
+
+		/*
+		 * need to know if we're getting called from the invalidate path or
+		 * not:
+		 */
+
+		if ((flags & BTREE_TRIGGER_BUCKET_INVALIDATE) &&
+		    old_a->cached_sectors) {
+			ret = bch2_update_cached_sectors_list(trans, new.k->p.inode,
+							      -((s64) old_a->cached_sectors));
+			if (ret)
+				return ret;
+		}
 	}
 
-	new_a->fragmentation_lru = alloc_lru_idx_fragmentation(*new_a,
-					bch_dev_bkey_exists(c, new->k.p.inode));
+	if (!(flags & BTREE_TRIGGER_TRANSACTIONAL) && (flags & BTREE_TRIGGER_INSERT)) {
+		struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
+		u64 journal_seq = trans->journal_res.seq;
+		u64 bucket_journal_seq = new_a->journal_seq;
 
-	if (old_a->fragmentation_lru != new_a->fragmentation_lru) {
-		ret = bch2_lru_change(trans,
-				BCH_LRU_FRAGMENTATION_START,
-				bucket_to_u64(new->k.p),
-				old_a->fragmentation_lru, new_a->fragmentation_lru);
-		if (ret)
-			return ret;
+		if ((flags & BTREE_TRIGGER_INSERT) &&
+		    data_type_is_empty(old_a->data_type) !=
+		    data_type_is_empty(new_a->data_type) &&
+		    new.k->type == KEY_TYPE_alloc_v4) {
+			struct bch_alloc_v4 *v = bkey_s_to_alloc_v4(new).v;
+
+			/*
+			 * If the btree updates referring to a bucket weren't flushed
+			 * before the bucket became empty again, then the we don't have
+			 * to wait on a journal flush before we can reuse the bucket:
+			 */
+			v->journal_seq = bucket_journal_seq =
+				data_type_is_empty(new_a->data_type) &&
+				(journal_seq == v->journal_seq ||
+				 bch2_journal_noflush_seq(&c->journal, v->journal_seq))
+				? 0 : journal_seq;
+		}
+
+		if (!data_type_is_empty(old_a->data_type) &&
+		    data_type_is_empty(new_a->data_type) &&
+		    bucket_journal_seq) {
+			ret = bch2_set_bucket_needs_journal_commit(&c->buckets_waiting_for_journal,
+					c->journal.flushed_seq_ondisk,
+					new.k->p.inode, new.k->p.offset,
+					bucket_journal_seq);
+			if (ret) {
+				bch2_fs_fatal_error(c,
+					"error setting bucket_needs_journal_commit: %i", ret);
+				return ret;
+			}
+		}
+
+		percpu_down_read(&c->mark_lock);
+		if (new_a->gen != old_a->gen)
+			*bucket_gen(ca, new.k->p.offset) = new_a->gen;
+
+		bch2_dev_usage_update(c, ca, old_a, new_a, journal_seq, false);
+
+		if (new_a->data_type == BCH_DATA_free &&
+		    (!new_a->journal_seq || new_a->journal_seq < c->journal.flushed_seq_ondisk))
+			closure_wake_up(&c->freelist_wait);
+
+		if (new_a->data_type == BCH_DATA_need_discard &&
+		    (!bucket_journal_seq || bucket_journal_seq < c->journal.flushed_seq_ondisk))
+			bch2_do_discards(c);
+
+		if (old_a->data_type != BCH_DATA_cached &&
+		    new_a->data_type == BCH_DATA_cached &&
+		    should_invalidate_buckets(ca, bch2_dev_usage_read(ca)))
+			bch2_do_invalidates(c);
+
+		if (new_a->data_type == BCH_DATA_need_gc_gens)
+			bch2_do_gc_gens(c);
+		percpu_up_read(&c->mark_lock);
 	}
 
-	if (old_a->gen != new_a->gen) {
-		ret = bch2_bucket_gen_update(trans, new->k.p, new_a->gen);
-		if (ret)
-			return ret;
+	if ((flags & BTREE_TRIGGER_GC) &&
+	    (flags & BTREE_TRIGGER_BUCKET_INVALIDATE)) {
+		struct bch_alloc_v4 new_a_convert;
+		const struct bch_alloc_v4 *new_a = bch2_alloc_to_v4(new.s_c, &new_a_convert);
+
+		percpu_down_read(&c->mark_lock);
+		struct bucket *g = gc_bucket(ca, new.k->p.offset);
+
+		bucket_lock(g);
+
+		g->gen_valid		= 1;
+		g->gen			= new_a->gen;
+		g->data_type		= new_a->data_type;
+		g->stripe		= new_a->stripe;
+		g->stripe_redundancy	= new_a->stripe_redundancy;
+		g->dirty_sectors	= new_a->dirty_sectors;
+		g->cached_sectors	= new_a->cached_sectors;
+
+		bucket_unlock(g);
+		percpu_up_read(&c->mark_lock);
 	}
 
 	return 0;
@@ -869,8 +944,9 @@ static struct bkey_s_c bch2_get_key_or_hole(struct btree_iter *iter, struct bpos
 
 		bch2_trans_copy_iter(&iter2, iter);
 
-		if (!bpos_eq(iter->path->l[0].b->key.k.p, SPOS_MAX))
-			end = bkey_min(end, bpos_nosnap_successor(iter->path->l[0].b->key.k.p));
+		struct btree_path *path = btree_iter_path(iter->trans, iter);
+		if (!bpos_eq(path->l[0].b->key.k.p, SPOS_MAX))
+			end = bkey_min(end, bpos_nosnap_successor(path->l[0].b->key.k.p));
 
 		end = bkey_min(end, POS(iter->pos.inode, iter->pos.offset + U32_MAX - 1));
 
@@ -898,7 +974,6 @@ static struct bkey_s_c bch2_get_key_or_hole(struct btree_iter *iter, struct bpos
 static bool next_bucket(struct bch_fs *c, struct bpos *bucket)
 {
 	struct bch_dev *ca;
-	unsigned iter;
 
 	if (bch2_dev_bucket_exists(c, *bucket))
 		return true;
@@ -916,8 +991,7 @@ static bool next_bucket(struct bch_fs *c, struct bpos *bucket)
 	}
 
 	rcu_read_lock();
-	iter = bucket->inode;
-	ca = __bch2_next_dev(c, &iter, NULL);
+	ca = __bch2_next_dev_idx(c, bucket->inode, NULL);
 	if (ca)
 		*bucket = POS(ca->dev_idx, ca->mi.first_bucket);
 	rcu_read_unlock();
@@ -1158,9 +1232,6 @@ int bch2_check_alloc_hole_bucket_gens(struct btree_trans *trans,
 	unsigned i, gens_offset, gens_end_offset;
 	int ret;
 
-	if (c->sb.version < bcachefs_metadata_version_bucket_gens)
-		return 0;
-
 	bch2_btree_iter_set_pos(bucket_gens_iter, alloc_gens_pos(start, &gens_offset));
 
 	k = bch2_btree_iter_peek_slot(bucket_gens_iter);
@@ -1212,7 +1283,7 @@ fsck_err:
 	return ret;
 }
 
-static noinline_for_stack int __bch2_check_discard_freespace_key(struct btree_trans *trans,
+static noinline_for_stack int bch2_check_discard_freespace_key(struct btree_trans *trans,
 					      struct btree_iter *iter)
 {
 	struct bch_fs *c = trans->c;
@@ -1267,28 +1338,10 @@ delete:
 	ret =   bch2_btree_delete_extent_at(trans, iter,
 			iter->btree_id == BTREE_ID_freespace ? 1 : 0, 0) ?:
 		bch2_trans_commit(trans, NULL, NULL,
-			BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW);
+			BCH_TRANS_COMMIT_no_enospc);
 	goto out;
 }
 
-static int bch2_check_discard_freespace_key(struct btree_trans *trans,
-					    struct btree_iter *iter,
-					    struct bpos end)
-{
-	if (!btree_id_is_extents(iter->btree_id)) {
-		return __bch2_check_discard_freespace_key(trans, iter);
-	} else {
-		int ret = 0;
-
-		while (!bkey_eq(iter->pos, end) &&
-		       !(ret = btree_trans_too_many_iters(trans) ?:
-			       __bch2_check_discard_freespace_key(trans, iter)))
-			bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
-
-		return ret;
-	}
-}
-
 /*
  * We've already checked that generation numbers in the bucket_gens btree are
  * valid for buckets that exist; this just checks for keys for nonexistent
@@ -1422,8 +1475,7 @@ int bch2_check_alloc_info(struct bch_fs *c)
 		}
 
 		ret = bch2_trans_commit(trans, NULL, NULL,
-					BTREE_INSERT_NOFAIL|
-					BTREE_INSERT_LAZY_RW);
+					BCH_TRANS_COMMIT_no_enospc);
 		if (ret)
 			goto bkey_err;
 
@@ -1442,23 +1494,50 @@ bkey_err:
 	if (ret < 0)
 		goto err;
 
-	ret = for_each_btree_key2(trans, iter,
+	ret = for_each_btree_key(trans, iter,
 			BTREE_ID_need_discard, POS_MIN,
 			BTREE_ITER_PREFETCH, k,
-		bch2_check_discard_freespace_key(trans, &iter, k.k->p)) ?:
-	      for_each_btree_key2(trans, iter,
-			BTREE_ID_freespace, POS_MIN,
-			BTREE_ITER_PREFETCH, k,
-		bch2_check_discard_freespace_key(trans, &iter, k.k->p)) ?:
-	      for_each_btree_key_commit(trans, iter,
+		bch2_check_discard_freespace_key(trans, &iter));
+	if (ret)
+		goto err;
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_freespace, POS_MIN,
+			     BTREE_ITER_PREFETCH);
+	while (1) {
+		bch2_trans_begin(trans);
+		k = bch2_btree_iter_peek(&iter);
+		if (!k.k)
+			break;
+
+		ret = bkey_err(k) ?:
+			bch2_check_discard_freespace_key(trans, &iter);
+		if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
+			ret = 0;
+			continue;
+		}
+		if (ret) {
+			struct printbuf buf = PRINTBUF;
+			bch2_bkey_val_to_text(&buf, c, k);
+
+			bch_err(c, "while checking %s", buf.buf);
+			printbuf_exit(&buf);
+			break;
+		}
+
+		bch2_btree_iter_set_pos(&iter, bpos_nosnap_successor(iter.pos));
+	}
+	bch2_trans_iter_exit(trans, &iter);
+	if (ret)
+		goto err;
+
+	ret = for_each_btree_key_commit(trans, iter,
 			BTREE_ID_bucket_gens, POS_MIN,
 			BTREE_ITER_PREFETCH, k,
-			NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
+			NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 		bch2_check_bucket_gens_key(trans, &iter, k));
 err:
 	bch2_trans_put(trans);
-	if (ret)
-		bch_err_fn(c, ret);
+	bch_err_fn(c, ret);
 	return ret;
 }
 
@@ -1486,6 +1565,27 @@ static int bch2_check_alloc_to_lru_ref(struct btree_trans *trans,
 	if (a->data_type != BCH_DATA_cached)
 		return 0;
 
+	if (fsck_err_on(!a->io_time[READ], c,
+			alloc_key_cached_but_read_time_zero,
+			"cached bucket with read_time 0\n"
+			"  %s",
+		(printbuf_reset(&buf),
+		 bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
+		struct bkey_i_alloc_v4 *a_mut =
+			bch2_alloc_to_v4_mut(trans, alloc_k);
+		ret = PTR_ERR_OR_ZERO(a_mut);
+		if (ret)
+			goto err;
+
+		a_mut->v.io_time[READ] = atomic64_read(&c->io_clock[READ].now);
+		ret = bch2_trans_update(trans, alloc_iter,
+					&a_mut->k_i, BTREE_TRIGGER_NORUN);
+		if (ret)
+			goto err;
+
+		a = &a_mut->v;
+	}
+
 	lru_k = bch2_bkey_get_iter(trans, &lru_iter, BTREE_ID_lru,
 			     lru_pos(alloc_k.k->p.inode,
 				     bucket_to_u64(alloc_k.k->p),
@@ -1494,41 +1594,18 @@ static int bch2_check_alloc_to_lru_ref(struct btree_trans *trans,
 	if (ret)
 		return ret;
 
-	if (fsck_err_on(!a->io_time[READ], c,
-			alloc_key_cached_but_read_time_zero,
-			"cached bucket with read_time 0\n"
-			"  %s",
-		(printbuf_reset(&buf),
-		 bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf)) ||
-	    fsck_err_on(lru_k.k->type != KEY_TYPE_set, c,
+	if (fsck_err_on(lru_k.k->type != KEY_TYPE_set, c,
 			alloc_key_to_missing_lru_entry,
 			"missing lru entry\n"
 			"  %s",
 			(printbuf_reset(&buf),
 			 bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) {
-		u64 read_time = a->io_time[READ] ?:
-			atomic64_read(&c->io_clock[READ].now);
-
 		ret = bch2_lru_set(trans,
 				   alloc_k.k->p.inode,
 				   bucket_to_u64(alloc_k.k->p),
-				   read_time);
+				   a->io_time[READ]);
 		if (ret)
 			goto err;
-
-		if (a->io_time[READ] != read_time) {
-			struct bkey_i_alloc_v4 *a_mut =
-				bch2_alloc_to_v4_mut(trans, alloc_k);
-			ret = PTR_ERR_OR_ZERO(a_mut);
-			if (ret)
-				goto err;
-
-			a_mut->v.io_time[READ] = read_time;
-			ret = bch2_trans_update(trans, alloc_iter,
-						&a_mut->k_i, BTREE_TRIGGER_NORUN);
-			if (ret)
-				goto err;
-		}
 	}
 err:
 fsck_err:
@@ -1539,17 +1616,12 @@ fsck_err:
 
 int bch2_check_alloc_to_lru_refs(struct bch_fs *c)
 {
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	int ret = 0;
-
-	ret = bch2_trans_run(c,
+	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_alloc,
 				POS_MIN, BTREE_ITER_PREFETCH, k,
-				NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
+				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			bch2_check_alloc_to_lru_ref(trans, &iter)));
-	if (ret)
-		bch_err_fn(c, ret);
+	bch_err_fn(c, ret);
 	return ret;
 }
 
@@ -1655,11 +1727,11 @@ write:
 	ret =   bch2_trans_update(trans, &iter, &a->k_i, 0) ?:
 		bch2_trans_commit(trans, NULL, NULL,
 				  BCH_WATERMARK_btree|
-				  BTREE_INSERT_NOFAIL);
+				  BCH_TRANS_COMMIT_no_enospc);
 	if (ret)
 		goto out;
 
-	this_cpu_inc(c->counters[BCH_COUNTER_bucket_discard]);
+	count_event(c, bucket_discard);
 	(*discarded)++;
 out:
 	(*seen)++;
@@ -1672,8 +1744,6 @@ out:
 static void bch2_do_discards_work(struct work_struct *work)
 {
 	struct bch_fs *c = container_of(work, struct bch_fs, discard_work);
-	struct btree_iter iter;
-	struct bkey_s_c k;
 	u64 seen = 0, open = 0, need_journal_commit = 0, discarded = 0;
 	struct bpos discard_pos_done = POS_MAX;
 	int ret;
@@ -1684,8 +1754,8 @@ static void bch2_do_discards_work(struct work_struct *work)
 	 * successful commit:
 	 */
 	ret = bch2_trans_run(c,
-		for_each_btree_key2(trans, iter,
-				BTREE_ID_need_discard, POS_MIN, 0, k,
+		for_each_btree_key(trans, iter,
+				   BTREE_ID_need_discard, POS_MIN, 0, k,
 			bch2_discard_one_bucket(trans, &iter, &discard_pos_done,
 						&seen,
 						&open,
@@ -1760,7 +1830,7 @@ static int invalidate_one_bucket(struct btree_trans *trans,
 				BTREE_TRIGGER_BUCKET_INVALIDATE) ?:
 		bch2_trans_commit(trans, NULL, NULL,
 				  BCH_WATERMARK_btree|
-				  BTREE_INSERT_NOFAIL);
+				  BCH_TRANS_COMMIT_no_enospc);
 	if (ret)
 		goto out;
 
@@ -1795,22 +1865,18 @@ err:
 static void bch2_do_invalidates_work(struct work_struct *work)
 {
 	struct bch_fs *c = container_of(work, struct bch_fs, invalidate_work);
-	struct bch_dev *ca;
 	struct btree_trans *trans = bch2_trans_get(c);
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	unsigned i;
 	int ret = 0;
 
-	ret = bch2_btree_write_buffer_flush(trans);
+	ret = bch2_btree_write_buffer_tryflush(trans);
 	if (ret)
 		goto err;
 
-	for_each_member_device(ca, c, i) {
+	for_each_member_device(c, ca) {
 		s64 nr_to_invalidate =
 			should_invalidate_buckets(ca, bch2_dev_usage_read(ca));
 
-		ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_lru,
+		ret = for_each_btree_key_upto(trans, iter, BTREE_ID_lru,
 				lru_pos(ca->dev_idx, 0, 0),
 				lru_pos(ca->dev_idx, U64_MAX, LRU_TIME_MAX),
 				BTREE_ITER_INTENT, k,
@@ -1884,8 +1950,7 @@ int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
 
 			ret =   bch2_bucket_do_index(trans, k, a, true) ?:
 				bch2_trans_commit(trans, NULL, NULL,
-						  BTREE_INSERT_LAZY_RW|
-						  BTREE_INSERT_NOFAIL);
+						  BCH_TRANS_COMMIT_no_enospc);
 			if (ret)
 				goto bkey_err;
 
@@ -1905,8 +1970,7 @@ int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
 
 			ret = bch2_btree_insert_trans(trans, BTREE_ID_freespace, freespace, 0) ?:
 				bch2_trans_commit(trans, NULL, NULL,
-						  BTREE_INSERT_LAZY_RW|
-						  BTREE_INSERT_NOFAIL);
+						  BCH_TRANS_COMMIT_no_enospc);
 			if (ret)
 				goto bkey_err;
 
@@ -1937,8 +2001,6 @@ bkey_err:
 
 int bch2_fs_freespace_init(struct bch_fs *c)
 {
-	struct bch_dev *ca;
-	unsigned i;
 	int ret = 0;
 	bool doing_init = false;
 
@@ -1947,7 +2009,7 @@ int bch2_fs_freespace_init(struct bch_fs *c)
 	 * every mount:
 	 */
 
-	for_each_member_device(ca, c, i) {
+	for_each_member_device(c, ca) {
 		if (ca->mi.freespace_initialized)
 			continue;
 
@@ -2007,15 +2069,13 @@ out:
 
 void bch2_recalc_capacity(struct bch_fs *c)
 {
-	struct bch_dev *ca;
 	u64 capacity = 0, reserved_sectors = 0, gc_reserve;
 	unsigned bucket_size_max = 0;
 	unsigned long ra_pages = 0;
-	unsigned i;
 
 	lockdep_assert_held(&c->state_lock);
 
-	for_each_online_member(ca, c, i) {
+	for_each_online_member(c, ca) {
 		struct backing_dev_info *bdi = ca->disk_sb.bdev->bd_disk->bdi;
 
 		ra_pages += bdi->ra_pages;
@@ -2023,7 +2083,7 @@ void bch2_recalc_capacity(struct bch_fs *c)
 
 	bch2_set_ra_pages(c, ra_pages);
 
-	for_each_rw_member(ca, c, i) {
+	for_each_rw_member(c, ca) {
 		u64 dev_reserve = 0;
 
 		/*
@@ -2079,11 +2139,9 @@ void bch2_recalc_capacity(struct bch_fs *c)
 
 u64 bch2_min_rw_member_capacity(struct bch_fs *c)
 {
-	struct bch_dev *ca;
-	unsigned i;
 	u64 ret = U64_MAX;
 
-	for_each_rw_member(ca, c, i)
+	for_each_rw_member(c, ca)
 		ret = min(ret, ca->mi.nbuckets * ca->mi.bucket_size);
 	return ret;
 }