bcachefs: Make replicas_delta_list smaller

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_update_leaf.c

@@ -587,9 +587,11 @@ static inline int do_btree_insert_at(struct btree_trans *trans,
 	bch2_journal_res_put(&c->journal, &trans->journal_res);
 out_clear_replicas:
 	if (trans->fs_usage_deltas) {
-		memset(&trans->fs_usage_deltas->fs_usage, 0,
-		       sizeof(trans->fs_usage_deltas->fs_usage));
 		trans->fs_usage_deltas->used = 0;
+		memset((void *) trans->fs_usage_deltas +
+		       offsetof(struct replicas_delta_list, memset_start), 0,
+		       (void *) &trans->fs_usage_deltas->memset_end -
+		       (void *) &trans->fs_usage_deltas->memset_start);
 	}
 
 	return ret;

fs/bcachefs/buckets.c

@@ -585,9 +585,14 @@ void bch2_replicas_delta_list_apply(struct bch_fs *c,
 {
 	struct replicas_delta *d = r->d;
 	struct replicas_delta *top = (void *) r->d + r->used;
+	unsigned i;
+
+	fs_usage->nr_inodes += r->nr_inodes;
 
-	acc_u64s((u64 *) fs_usage,
-		 (u64 *) &r->fs_usage, sizeof(*fs_usage) / sizeof(u64));
+	for (i = 0; i < BCH_REPLICAS_MAX; i++) {
+		fs_usage->reserved += r->persistent_reserved[i];
+		fs_usage->persistent_reserved[i] += r->persistent_reserved[i];
+	}
 
 	while (d != top) {
 		BUG_ON((void *) d > (void *) top);
@@ -1739,9 +1744,9 @@ int bch2_trans_mark_key(struct btree_trans *trans, struct bkey_s_c k,
 		d = replicas_deltas_realloc(trans, 0);
 
 		if (!(flags & BCH_BUCKET_MARK_OVERWRITE))
-			d->fs_usage.nr_inodes++;
+			d->nr_inodes++;
 		else
-			d->fs_usage.nr_inodes--;
+			d->nr_inodes--;
 		return 0;
 	case KEY_TYPE_reservation: {
 		unsigned replicas = bkey_s_c_to_reservation(k).v->nr_replicas;
@@ -1750,10 +1755,9 @@ int bch2_trans_mark_key(struct btree_trans *trans, struct bkey_s_c k,
 
 		sectors *= replicas;
 		replicas = clamp_t(unsigned, replicas, 1,
-				   ARRAY_SIZE(d->fs_usage.persistent_reserved));
+				   ARRAY_SIZE(d->persistent_reserved));
 
-		d->fs_usage.reserved				+= sectors;
-		d->fs_usage.persistent_reserved[replicas - 1]	+= sectors;
+		d->persistent_reserved[replicas - 1] += sectors;
 		return 0;
 	}
 	case KEY_TYPE_reflink_p:

fs/bcachefs/buckets_types.h

@@ -100,7 +100,11 @@ struct replicas_delta {
 struct replicas_delta_list {
 	unsigned		size;
 	unsigned		used;
-	struct bch_fs_usage	fs_usage;
+
+	struct			{} memset_start;
+	u64			nr_inodes;
+	u64			persistent_reserved[BCH_REPLICAS_MAX];
+	struct			{} memset_end;
 	struct replicas_delta	d[0];
 };