1 files changed, 27 insertions, 383 deletions

diff --git a/libbcachefs/extent_update.c b/libbcachefs/extent_update.c
index 846d77dc..fa6c0698 100644
--- a/libbcachefs/extent_update.c
+++ b/libbcachefs/extent_update.c
@@ -39,6 +39,12 @@ static int count_iters_for_insert(struct btree_trans *trans,
 {
 	int ret = 0;
 
+	/*
+	 * The extent update path requires an _additional_ iterator for each
+	 * extent we're inserting and overwriting:
+	 */
+	*nr_iters += 1;
+
 	switch (k.k->type) {
 	case KEY_TYPE_extent:
 	case KEY_TYPE_reflink_v:
@@ -167,402 +173,40 @@ int bch2_extent_is_atomic(struct bkey_i *k, struct btree_iter *iter)
 enum btree_insert_ret
 bch2_extent_can_insert(struct btree_trans *trans,
 		       struct btree_iter *iter,
-		       struct bkey_i *insert,
-		       unsigned *u64s)
+		       struct bkey_i *insert)
 {
 	struct btree_iter_level *l = &iter->l[0];
 	struct btree_node_iter node_iter = l->iter;
 	struct bkey_packed *_k;
+	struct bkey_s_c k;
 	struct bkey unpacked;
 	int sectors;
 
-	while ((_k = bch2_btree_node_iter_peek_filter(&node_iter, l->b,
-						      KEY_TYPE_discard))) {
-		struct bkey_s_c k = bkey_disassemble(l->b, _k, &unpacked);
-		enum bch_extent_overlap overlap =
-			bch2_extent_overlap(&insert->k, k.k);
-
-		if (bkey_cmp(bkey_start_pos(k.k), insert->k.p) >= 0)
-			break;
-
-		overlap = bch2_extent_overlap(&insert->k, k.k);
-
-		/*
-		 * If we're overwriting an existing extent, we may need to emit
-		 * a whiteout - unless we're inserting a new extent at the same
-		 * position:
-		 */
-		if (k.k->needs_whiteout &&
-		    (!bkey_whiteout(&insert->k) ||
-		     bkey_cmp(k.k->p, insert->k.p)))
-			*u64s += BKEY_U64s;
-
-		/*
-		 * If we're partially overwriting an existing extent which has
-		 * been written out to disk, we'll need to emit a new version of
-		 * that extent:
-		 */
-		if (bkey_written(l->b, _k) &&
-		    overlap != BCH_EXTENT_OVERLAP_ALL)
-			*u64s += _k->u64s;
-
-		/* And we may be splitting an existing extent: */
-		if (overlap == BCH_EXTENT_OVERLAP_MIDDLE)
-			*u64s += _k->u64s;
-
-		if (overlap == BCH_EXTENT_OVERLAP_MIDDLE &&
-		    (sectors = bch2_bkey_sectors_compressed(k))) {
-			int flags = trans->flags & BTREE_INSERT_NOFAIL
-				? BCH_DISK_RESERVATION_NOFAIL : 0;
-
-			switch (bch2_disk_reservation_add(trans->c,
-					trans->disk_res,
-					sectors, flags)) {
-			case 0:
-				break;
-			case -ENOSPC:
-				return BTREE_INSERT_ENOSPC;
-			default:
-				BUG();
-			}
-		}
-
-		if (overlap == BCH_EXTENT_OVERLAP_FRONT ||
-		    overlap == BCH_EXTENT_OVERLAP_MIDDLE)
-			break;
-
-		bch2_btree_node_iter_advance(&node_iter, l->b);
-	}
-
-	return BTREE_INSERT_OK;
-}
-
-static void verify_extent_nonoverlapping(struct bch_fs *c,
-					 struct btree *b,
-					 struct btree_node_iter *_iter,
-					 struct bkey_i *insert)
-{
-#ifdef CONFIG_BCACHEFS_DEBUG
-	struct btree_node_iter iter;
-	struct bkey_packed *k;
-	struct bkey uk;
-
-	if (!expensive_debug_checks(c))
-		return;
-
-	iter = *_iter;
-	k = bch2_btree_node_iter_prev_filter(&iter, b, KEY_TYPE_discard);
-	BUG_ON(k &&
-	       (uk = bkey_unpack_key(b, k),
-		bkey_cmp(uk.p, bkey_start_pos(&insert->k)) > 0));
-
-	iter = *_iter;
-	k = bch2_btree_node_iter_peek_filter(&iter, b, KEY_TYPE_discard);
-#if 0
-	BUG_ON(k &&
-	       (uk = bkey_unpack_key(b, k),
-		bkey_cmp(insert->k.p, bkey_start_pos(&uk))) > 0);
-#else
-	if (k &&
-	    (uk = bkey_unpack_key(b, k),
-	     bkey_cmp(insert->k.p, bkey_start_pos(&uk))) > 0) {
-		char buf1[100];
-		char buf2[100];
-
-		bch2_bkey_to_text(&PBUF(buf1), &insert->k);
-		bch2_bkey_to_text(&PBUF(buf2), &uk);
-
-		bch2_dump_btree_node(b);
-		panic("insert > next :\n"
-		      "insert %s\n"
-		      "next   %s\n",
-		      buf1, buf2);
-	}
-#endif
-
-#endif
-}
-
-static void extent_bset_insert(struct bch_fs *c, struct btree_iter *iter,
-			       struct bkey_i *insert)
-{
-	struct btree_iter_level *l = &iter->l[0];
-	struct bkey_packed *k =
-		bch2_btree_node_iter_bset_pos(&l->iter, l->b, bset_tree_last(l->b));
-
-	BUG_ON(insert->k.u64s > bch_btree_keys_u64s_remaining(c, l->b));
-
-	EBUG_ON(bkey_deleted(&insert->k) || !insert->k.size);
-	verify_extent_nonoverlapping(c, l->b, &l->iter, insert);
-
-	if (debug_check_bkeys(c))
-		bch2_bkey_debugcheck(c, l->b, bkey_i_to_s_c(insert));
-
-	bch2_bset_insert(l->b, &l->iter, k, insert, 0);
-	bch2_btree_node_iter_fix(iter, l->b, &l->iter, k, 0, k->u64s);
-}
-
-static void pack_push_whiteout(struct bch_fs *c, struct btree *b,
-			       struct bpos pos)
-{
-	struct bkey_packed k;
-
-	if (!bkey_pack_pos(&k, pos, b)) {
-		struct bkey_i tmp;
-
-		bkey_init(&tmp.k);
-		tmp.k.p = pos;
-		bkey_copy(&k, &tmp);
-	}
-
-	k.needs_whiteout = true;
-	push_whiteout(c, b, &k);
-}
-
-static void
-extent_drop(struct bch_fs *c, struct btree_iter *iter,
-	    struct bkey_packed *_k, struct bkey_s k)
-{
-	struct btree_iter_level *l = &iter->l[0];
-
-	if (!bkey_whiteout(k.k))
-		btree_account_key_drop(l->b, _k);
-
-	k.k->size = 0;
-	k.k->type = KEY_TYPE_deleted;
-
-	if (!btree_node_old_extent_overwrite(l->b) &&
-	    k.k->needs_whiteout) {
-		pack_push_whiteout(c, l->b, k.k->p);
-		k.k->needs_whiteout = false;
-	}
-
-	if (_k >= btree_bset_last(l->b)->start) {
-		unsigned u64s = _k->u64s;
-
-		bch2_bset_delete(l->b, _k, _k->u64s);
-		bch2_btree_node_iter_fix(iter, l->b, &l->iter, _k, u64s, 0);
-	} else {
-		extent_save(l->b, _k, k.k);
-		bch2_btree_iter_fix_key_modified(iter, l->b, _k);
-	}
-}
-
-static void
-extent_squash(struct bch_fs *c, struct btree_iter *iter,
-	      struct bkey_i *insert,
-	      struct bkey_packed *_k, struct bkey_s k,
-	      enum bch_extent_overlap overlap)
-{
-	struct btree_iter_level *l = &iter->l[0];
-	struct bkey_on_stack tmp, split;
-
-	bkey_on_stack_init(&tmp);
-	bkey_on_stack_init(&split);
-
-	if (!btree_node_old_extent_overwrite(l->b)) {
-		if (!bkey_whiteout(&insert->k) &&
-		    !bkey_cmp(k.k->p, insert->k.p)) {
-			insert->k.needs_whiteout = k.k->needs_whiteout;
-			k.k->needs_whiteout = false;
-		}
-	} else {
-		insert->k.needs_whiteout |= k.k->needs_whiteout;
-	}
-
-	switch (overlap) {
-	case BCH_EXTENT_OVERLAP_FRONT:
-		if (bkey_written(l->b, _k)) {
-			bkey_on_stack_reassemble(&tmp, c, k.s_c);
-			bch2_cut_front(insert->k.p, tmp.k);
-
-			/*
-			 * needs_whiteout was propagated to new version of @k,
-			 * @tmp:
-			 */
-			if (!btree_node_old_extent_overwrite(l->b))
-				k.k->needs_whiteout = false;
-
-			extent_drop(c, iter, _k, k);
-			extent_bset_insert(c, iter, tmp.k);
-		} else {
-			btree_keys_account_val_delta(l->b, _k,
-				bch2_cut_front_s(insert->k.p, k));
-
-			extent_save(l->b, _k, k.k);
-			/*
-			 * No need to call bset_fix_invalidated_key, start of
-			 * extent changed but extents are indexed by where they
-			 * end
-			 */
-			bch2_btree_iter_fix_key_modified(iter, l->b, _k);
-		}
-		break;
-	case BCH_EXTENT_OVERLAP_BACK:
-		if (bkey_written(l->b, _k)) {
-			bkey_on_stack_reassemble(&tmp, c, k.s_c);
-			bch2_cut_back(bkey_start_pos(&insert->k), tmp.k);
-
-			/*
-			 * @tmp has different position than @k, needs_whiteout
-			 * should not be propagated:
-			 */
-			if (!btree_node_old_extent_overwrite(l->b))
-				tmp.k->k.needs_whiteout = false;
-
-			extent_drop(c, iter, _k, k);
-			extent_bset_insert(c, iter, tmp.k);
-		} else {
-			/*
-			 * position of @k is changing, emit a whiteout if
-			 * needs_whiteout is set:
-			 */
-			if (!btree_node_old_extent_overwrite(l->b) &&
-			    k.k->needs_whiteout) {
-				pack_push_whiteout(c, l->b, k.k->p);
-				k.k->needs_whiteout = false;
-			}
-
-			btree_keys_account_val_delta(l->b, _k,
-				bch2_cut_back_s(bkey_start_pos(&insert->k), k));
-			extent_save(l->b, _k, k.k);
-
-			bch2_bset_fix_invalidated_key(l->b, _k);
-			bch2_btree_node_iter_fix(iter, l->b, &l->iter,
-						 _k, _k->u64s, _k->u64s);
-		}
-		break;
-	case BCH_EXTENT_OVERLAP_ALL:
-		extent_drop(c, iter, _k, k);
-		break;
-	case BCH_EXTENT_OVERLAP_MIDDLE:
-		bkey_on_stack_reassemble(&split, c, k.s_c);
-		bch2_cut_back(bkey_start_pos(&insert->k), split.k);
-
-		if (!btree_node_old_extent_overwrite(l->b))
-			split.k->k.needs_whiteout = false;
-
-		/* this is identical to BCH_EXTENT_OVERLAP_FRONT: */
-		if (bkey_written(l->b, _k)) {
-			bkey_on_stack_reassemble(&tmp, c, k.s_c);
-			bch2_cut_front(insert->k.p, tmp.k);
-
-			if (!btree_node_old_extent_overwrite(l->b))
-				k.k->needs_whiteout = false;
-
-			extent_drop(c, iter, _k, k);
-			extent_bset_insert(c, iter, tmp.k);
-		} else {
-			btree_keys_account_val_delta(l->b, _k,
-				bch2_cut_front_s(insert->k.p, k));
-
-			extent_save(l->b, _k, k.k);
-			bch2_btree_iter_fix_key_modified(iter, l->b, _k);
-		}
-
-		extent_bset_insert(c, iter, split.k);
-		break;
-	}
-
-	bkey_on_stack_exit(&split, c);
-	bkey_on_stack_exit(&tmp, c);
-}
+	_k = bch2_btree_node_iter_peek_filter(&node_iter, l->b,
+					      KEY_TYPE_discard);
+	if (!_k)
+		return BTREE_INSERT_OK;
 
-/**
- * bch_extent_insert_fixup - insert a new extent and deal with overlaps
- *
- * this may result in not actually doing the insert, or inserting some subset
- * of the insert key. For cmpxchg operations this is where that logic lives.
- *
- * All subsets of @insert that need to be inserted are inserted using
- * bch2_btree_insert_and_journal(). If @b or @res fills up, this function
- * returns false, setting @iter->pos for the prefix of @insert that actually got
- * inserted.
- *
- * BSET INVARIANTS: this function is responsible for maintaining all the
- * invariants for bsets of extents in memory. things get really hairy with 0
- * size extents
- *
- * within one bset:
- *
- * bkey_start_pos(bkey_next(k)) >= k
- * or bkey_start_offset(bkey_next(k)) >= k->offset
- *
- * i.e. strict ordering, no overlapping extents.
- *
- * multiple bsets (i.e. full btree node):
- *
- * ∀ k, j
- *   k.size != 0 ∧ j.size != 0 →
- *     ¬ (k > bkey_start_pos(j) ∧ k < j)
- *
- * i.e. no two overlapping keys _of nonzero size_
- *
- * We can't realistically maintain this invariant for zero size keys because of
- * the key merging done in bch2_btree_insert_key() - for two mergeable keys k, j
- * there may be another 0 size key between them in another bset, and it will
- * thus overlap with the merged key.
- *
- * In addition, the end of iter->pos indicates how much has been processed.
- * If the end of iter->pos is not the same as the end of insert, then
- * key insertion needs to continue/be retried.
- */
-void bch2_insert_fixup_extent(struct btree_trans *trans,
-			      struct btree_iter *iter,
-			      struct bkey_i *insert)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_iter_level *l = &iter->l[0];
-	struct btree_node_iter node_iter = l->iter;
-	bool do_update		= !bkey_whiteout(&insert->k);
-	struct bkey_packed *_k;
-	struct bkey unpacked;
+	k = bkey_disassemble(l->b, _k, &unpacked);
 
-	EBUG_ON(iter->level);
-	EBUG_ON(!insert->k.size);
-	EBUG_ON(bkey_cmp(iter->pos, bkey_start_pos(&insert->k)));
+	/* Check if we're splitting a compressed extent: */
 
-	while ((_k = bch2_btree_node_iter_peek_filter(&l->iter, l->b,
-						      KEY_TYPE_discard))) {
-		struct bkey_s k = __bkey_disassemble(l->b, _k, &unpacked);
-		enum bch_extent_overlap overlap =
-			bch2_extent_overlap(&insert->k, k.k);
+	if (bkey_cmp(bkey_start_pos(&insert->k), bkey_start_pos(k.k)) > 0 &&
+	    bkey_cmp(insert->k.p, k.k->p) < 0 &&
+	    (sectors = bch2_bkey_sectors_compressed(k))) {
+		int flags = trans->flags & BTREE_INSERT_NOFAIL
+			? BCH_DISK_RESERVATION_NOFAIL : 0;
 
-		if (bkey_cmp(bkey_start_pos(k.k), insert->k.p) >= 0)
+		switch (bch2_disk_reservation_add(trans->c, trans->disk_res,
+						  sectors, flags)) {
+		case 0:
 			break;
-
-		if (!bkey_whiteout(k.k))
-			do_update = true;
-
-		if (!do_update) {
-			struct bpos cur_end = bpos_min(insert->k.p, k.k->p);
-
-			bch2_cut_front(cur_end, insert);
-			bch2_btree_iter_set_pos_same_leaf(iter, cur_end);
-		} else {
-			extent_squash(c, iter, insert, _k, k, overlap);
+		case -ENOSPC:
+			return BTREE_INSERT_ENOSPC;
+		default:
+			BUG();
 		}
-
-		node_iter = l->iter;
-
-		if (overlap == BCH_EXTENT_OVERLAP_FRONT ||
-		    overlap == BCH_EXTENT_OVERLAP_MIDDLE)
-			break;
 	}
 
-	l->iter = node_iter;
-	bch2_btree_iter_set_pos_same_leaf(iter, insert->k.p);
-
-	if (do_update) {
-		if (insert->k.type == KEY_TYPE_deleted)
-			insert->k.type = KEY_TYPE_discard;
-
-		if (!bkey_whiteout(&insert->k) ||
-		    btree_node_old_extent_overwrite(l->b))
-			extent_bset_insert(c, iter, insert);
-
-		bch2_btree_journal_key(trans, iter, insert);
-	}
-
-	bch2_cut_front(insert->k.p, insert);
+	return BTREE_INSERT_OK;
 }