bcachefs: Inline more of bch2_trans_commit hot path

The main optimization here is that if we let
bch2_replicas_delta_list_apply() fail, we can completely skip calling
bch2_bkey_replicas_marked_locked().

And assorted other small optimizations.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.c

@@ -64,21 +64,9 @@ static inline int btree_iter_pos_cmp(struct btree_iter *iter,
 
 /* Btree node locking: */
 
-/*
- * Updates the saved lock sequence number, so that bch2_btree_node_relock() will
- * succeed:
- */
 void bch2_btree_node_unlock_write(struct btree *b, struct btree_iter *iter)
 {
-	struct btree_iter *linked;
-
-	EBUG_ON(iter->l[b->c.level].b != b);
-	EBUG_ON(iter->l[b->c.level].lock_seq + 1 != b->c.lock.state.seq);
-
-	trans_for_each_iter_with_node(iter->trans, b, linked)
-		linked->l[b->c.level].lock_seq += 2;
-
-	six_unlock_write(&b->c.lock);
+	bch2_btree_node_unlock_write_inlined(b, iter);
 }
 
 void __bch2_btree_node_lock_write(struct btree *b, struct btree_iter *iter)

fs/bcachefs/btree_locking.h

@@ -202,6 +202,24 @@ static inline bool bch2_btree_node_relock(struct btree_iter *iter,
 		__bch2_btree_node_relock(iter, level);
 }
 
+/*
+ * Updates the saved lock sequence number, so that bch2_btree_node_relock() will
+ * succeed:
+ */
+static inline void
+bch2_btree_node_unlock_write_inlined(struct btree *b, struct btree_iter *iter)
+{
+	struct btree_iter *linked;
+
+	EBUG_ON(iter->l[b->c.level].b != b);
+	EBUG_ON(iter->l[b->c.level].lock_seq + 1 != b->c.lock.state.seq);
+
+	trans_for_each_iter_with_node(iter->trans, b, linked)
+		linked->l[b->c.level].lock_seq += 2;
+
+	six_unlock_write(&b->c.lock);
+}
+
 void bch2_btree_node_unlock_write(struct btree *, struct btree_iter *);
 
 void __bch2_btree_node_lock_write(struct btree *, struct btree_iter *);

fs/bcachefs/btree_update_interior.h

@@ -284,17 +284,17 @@ static inline unsigned btree_write_set_buffer(struct btree *b)
 static inline struct btree_node_entry *want_new_bset(struct bch_fs *c,
 						     struct btree *b)
 {
-	struct bset *i = btree_bset_last(b);
+	struct bset_tree *t = bset_tree_last(b);
 	struct btree_node_entry *bne = max(write_block(b),
 			(void *) btree_bkey_last(b, bset_tree_last(b)));
 	ssize_t remaining_space =
 		__bch_btree_u64s_remaining(c, b, &bne->keys.start[0]);
 
-	if (unlikely(bset_written(b, i))) {
+	if (unlikely(bset_written(b, bset(b, t)))) {
 		if (remaining_space > (ssize_t) (block_bytes(c) >> 3))
 			return bne;
 	} else {
-		if (unlikely(vstruct_bytes(i) > btree_write_set_buffer(b)) &&
+		if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) &&
 		    remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3))
 			return bne;
 	}

fs/bcachefs/btree_update_leaf.c

@@ -17,6 +17,7 @@
 #include "replicas.h"
 #include "trace.h"
 
+#include <linux/prefetch.h>
 #include <linux/sort.h>
 
 static inline bool same_leaf_as_prev(struct btree_trans *trans,
@@ -50,23 +51,6 @@ inline void bch2_btree_node_lock_for_insert(struct bch_fs *c, struct btree *b,
 		bch2_btree_init_next(c, b, iter);
 }
 
-static void btree_trans_lock_write(struct btree_trans *trans, bool lock)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_insert_entry *i;
-	unsigned iter;
-
-	trans_for_each_update_sorted(trans, i, iter) {
-		if (same_leaf_as_prev(trans, iter))
-			continue;
-
-		if (lock)
-			bch2_btree_node_lock_for_insert(c, i->iter->l[0].b, i->iter);
-		else
-			bch2_btree_node_unlock_write(i->iter->l[0].b, i->iter);
-	}
-}
-
 static inline void btree_trans_sort_updates(struct btree_trans *trans)
 {
 	struct btree_insert_entry *l, *r;
@@ -377,29 +361,6 @@ btree_key_can_insert(struct btree_trans *trans,
 	return BTREE_INSERT_OK;
 }
 
-static int btree_trans_check_can_insert(struct btree_trans *trans,
-					struct btree_insert_entry **stopped_at)
-{
-	struct btree_insert_entry *i;
-	unsigned iter, u64s = 0;
-	int ret;
-
-	trans_for_each_update_sorted(trans, i, iter) {
-		/* Multiple inserts might go to same leaf: */
-		if (!same_leaf_as_prev(trans, iter))
-			u64s = 0;
-
-		u64s += i->k->k.u64s;
-		ret = btree_key_can_insert(trans, i, &u64s);
-		if (ret) {
-			*stopped_at = i;
-			return ret;
-		}
-	}
-
-	return 0;
-}
-
 static inline void do_btree_insert_one(struct btree_trans *trans,
 				       struct btree_insert_entry *insert)
 {
@@ -450,6 +411,8 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 	unsigned mark_flags = trans->flags & BTREE_INSERT_BUCKET_INVALIDATE
 		? BCH_BUCKET_MARK_BUCKET_INVALIDATE
 		: 0;
+	unsigned iter, u64s = 0;
+	bool marking = false;
 	int ret;
 
 	if (race_fault()) {
@@ -462,25 +425,28 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 	 * held, otherwise another thread could write the node changing the
 	 * amount of space available:
 	 */
-	ret = btree_trans_check_can_insert(trans, stopped_at);
-	if (ret)
-		return ret;
 
-	trans_for_each_update(trans, i) {
-		if (!btree_node_type_needs_gc(i->iter->btree_id))
-			continue;
+	prefetch(&trans->c->journal.flags);
 
-		if (!fs_usage) {
-			percpu_down_read(&c->mark_lock);
-			fs_usage = bch2_fs_usage_scratch_get(c);
-		}
+	trans_for_each_update_sorted(trans, i, iter) {
+		/* Multiple inserts might go to same leaf: */
+		if (!same_leaf_as_prev(trans, iter))
+			u64s = 0;
 
-		/* Must be called under mark_lock: */
-		if (!bch2_bkey_replicas_marked_locked(c,
-			bkey_i_to_s_c(i->k), true)) {
-			ret = BTREE_INSERT_NEED_MARK_REPLICAS;
-			goto err;
+		u64s += i->k->k.u64s;
+		ret = btree_key_can_insert(trans, i, &u64s);
+		if (ret) {
+			*stopped_at = i;
+			return ret;
 		}
+
+		if (btree_node_type_needs_gc(i->iter->btree_id))
+			marking = true;
+	}
+
+	if (marking) {
+		percpu_down_read(&c->mark_lock);
+		fs_usage = bch2_fs_usage_scratch_get(c);
 	}
 
 	/*
@@ -508,16 +474,20 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 				i->k->k.version = MAX_VERSION;
 	}
 
+	/* Must be called under mark_lock: */
+	if (marking && trans->fs_usage_deltas &&
+	    bch2_replicas_delta_list_apply(c, &fs_usage->u,
+					   trans->fs_usage_deltas)) {
+		ret = BTREE_INSERT_NEED_MARK_REPLICAS;
+		goto err;
+	}
+
 	trans_for_each_update(trans, i)
 		if (likely(!(trans->flags & BTREE_INSERT_NOMARK)) &&
 		    update_has_nontrans_triggers(i))
 			bch2_mark_update(trans, i, &fs_usage->u, mark_flags);
 
-	if (fs_usage && trans->fs_usage_deltas)
-		bch2_replicas_delta_list_apply(c, &fs_usage->u,
-					       trans->fs_usage_deltas);
-
-	if (fs_usage)
+	if (marking)
 		bch2_trans_fs_usage_apply(trans, fs_usage);
 
 	if (unlikely(c->gc_pos.phase))
@@ -526,7 +496,7 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 	trans_for_each_update(trans, i)
 		do_btree_insert_one(trans, i);
 err:
-	if (fs_usage) {
+	if (marking) {
 		bch2_fs_usage_scratch_put(c, fs_usage);
 		percpu_up_read(&c->mark_lock);
 	}
@@ -609,9 +579,17 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans,
 	 */
 	btree_trans_sort_updates(trans);
 
-	btree_trans_lock_write(trans, true);
+	trans_for_each_update_sorted(trans, i, idx)
+		if (!same_leaf_as_prev(trans, idx))
+			bch2_btree_node_lock_for_insert(trans->c,
+						i->iter->l[0].b, i->iter);
+
 	ret = bch2_trans_commit_write_locked(trans, stopped_at);
-	btree_trans_lock_write(trans, false);
+
+	trans_for_each_update_sorted(trans, i, idx)
+		if (!same_leaf_as_prev(trans, idx))
+			bch2_btree_node_unlock_write_inlined(i->iter->l[0].b,
+							     i->iter);
 
 	/*
 	 * Drop journal reservation after dropping write locks, since dropping

fs/bcachefs/buckets.c

@@ -498,14 +498,18 @@ void bch2_dev_usage_from_buckets(struct bch_fs *c)
 	}
 }
 
-static inline void update_replicas(struct bch_fs *c,
-				   struct bch_fs_usage *fs_usage,
-				   struct bch_replicas_entry *r,
-				   s64 sectors)
+static inline int update_replicas(struct bch_fs *c,
+				  struct bch_fs_usage *fs_usage,
+				  struct bch_replicas_entry *r,
+				  s64 sectors)
 {
 	int idx = bch2_replicas_entry_idx(c, r);
 
-	BUG_ON(idx < 0);
+	if (idx < 0)
+		return -1;
+
+	if (!fs_usage)
+		return 0;
 
 	switch (r->data_type) {
 	case BCH_DATA_BTREE:
@@ -519,6 +523,7 @@ static inline void update_replicas(struct bch_fs *c,
 		break;
 	}
 	fs_usage->replicas[idx]		+= sectors;
+	return 0;
 }
 
 static inline void update_cached_sectors(struct bch_fs *c,
@@ -579,14 +584,29 @@ static inline void update_cached_sectors_list(struct btree_trans *trans,
 	update_replicas_list(trans, &r.e, sectors);
 }
 
-void bch2_replicas_delta_list_apply(struct bch_fs *c,
-				    struct bch_fs_usage *fs_usage,
-				    struct replicas_delta_list *r)
+static inline struct replicas_delta *
+replicas_delta_next(struct replicas_delta *d)
+{
+	return (void *) d + replicas_entry_bytes(&d->r) + 8;
+}
+
+int bch2_replicas_delta_list_apply(struct bch_fs *c,
+				   struct bch_fs_usage *fs_usage,
+				   struct replicas_delta_list *r)
 {
 	struct replicas_delta *d = r->d;
 	struct replicas_delta *top = (void *) r->d + r->used;
 	unsigned i;
 
+	for (d = r->d; d != top; d = replicas_delta_next(d))
+		if (update_replicas(c, fs_usage, &d->r, d->delta)) {
+			top = d;
+			goto unwind;
+		}
+
+	if (!fs_usage)
+		return 0;
+
 	fs_usage->nr_inodes += r->nr_inodes;
 
 	for (i = 0; i < BCH_REPLICAS_MAX; i++) {
@@ -594,13 +614,11 @@ void bch2_replicas_delta_list_apply(struct bch_fs *c,
 		fs_usage->persistent_reserved[i] += r->persistent_reserved[i];
 	}
 
-	while (d != top) {
-		BUG_ON((void *) d > (void *) top);
-
-		update_replicas(c, fs_usage, &d->r, d->delta);
-
-		d = (void *) d + replicas_entry_bytes(&d->r) + 8;
-	}
+	return 0;
+unwind:
+	for (d = r->d; d != top; d = replicas_delta_next(d))
+		update_replicas(c, fs_usage, &d->r, -d->delta);
+	return -1;
 }
 
 #define do_mark_fn(fn, c, pos, flags, ...)				\

fs/bcachefs/buckets.h

@@ -279,9 +279,9 @@ int bch2_mark_overwrite(struct btree_trans *, struct btree_iter *,
 int bch2_mark_update(struct btree_trans *, struct btree_insert_entry *,
 		     struct bch_fs_usage *, unsigned);
 
-void bch2_replicas_delta_list_apply(struct bch_fs *,
-				    struct bch_fs_usage *,
-				    struct replicas_delta_list *);
+int bch2_replicas_delta_list_apply(struct bch_fs *,
+				   struct bch_fs_usage *,
+				   struct replicas_delta_list *);
 int bch2_trans_mark_key(struct btree_trans *, struct bkey_s_c,
 			unsigned, s64, unsigned);
 int bch2_trans_mark_update(struct btree_trans *,