bcachefs: move "ptrs not changing" optimization to bch2_trigger_extent()

This is useful for btree ptrs as well, when we're just updating
sectors_written.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/buckets.c

@@ -1023,6 +1023,18 @@ int bch2_trigger_extent(struct btree_trans *trans,
 			struct bkey_s_c old, struct bkey_s new,
 			unsigned flags)
 {
+	struct bkey_ptrs_c new_ptrs = bch2_bkey_ptrs_c(new.s_c);
+	struct bkey_ptrs_c old_ptrs = bch2_bkey_ptrs_c(old);
+	unsigned new_ptrs_bytes = (void *) new_ptrs.end - (void *) new_ptrs.start;
+	unsigned old_ptrs_bytes = (void *) old_ptrs.end - (void *) old_ptrs.start;
+
+	/* if pointers aren't changing - nothing to do: */
+	if (new_ptrs_bytes == old_ptrs_bytes &&
+	    !memcmp(new_ptrs.start,
+		    old_ptrs.start,
+		    new_ptrs_bytes))
+		return 0;
+
 	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
 		struct bch_fs *c = trans->c;
 		int mod = (int) bch2_bkey_needs_rebalance(c, new.s_c) -

fs/bcachefs/reflink.c

@@ -301,14 +301,6 @@ int bch2_trans_mark_reflink_v(struct btree_trans *trans,
 	    (flags & BTREE_TRIGGER_INSERT))
 		check_indirect_extent_deleting(new, &flags);
 
-	if (old.k->type == KEY_TYPE_reflink_v &&
-	    new.k->type == KEY_TYPE_reflink_v &&
-	    old.k->u64s == new.k->u64s &&
-	    !memcmp(bkey_s_c_to_reflink_v(old).v->start,
-		    bkey_s_to_reflink_v(new).v->start,
-		    bkey_val_bytes(new.k) - 8))
-		return 0;
-
 	return bch2_trigger_extent(trans, btree_id, level, old, new, flags);
 }