Update bcachefs sources to 9b77e72c47 bcachefs: Extents may now cross btree node boundaries

16 files changed, 210 insertions, 812 deletions

diff --git a/.bcachefs_revision b/.bcachefs_revision
index 65ec86e9..26286584 100644
--- a/.bcachefs_revision
+++ b/.bcachefs_revision
@@ -1 +1 @@
-dfb7dc100d4bb9c13caa289e6dedd4d0a12f1ecb
+9b77e72c474e11130b514abd41a3c06e3f67c2ab
diff --git a/libbcachefs/bcachefs_format.h b/libbcachefs/bcachefs_format.h
index 30e77190..618f49ac 100644
--- a/libbcachefs/bcachefs_format.h
+++ b/libbcachefs/bcachefs_format.h
@@ -1342,13 +1342,19 @@ LE64_BITMASK(BCH_SB_METADATA_TARGET,	struct bch_sb, flags[3], 16, 28);
 	x(reflink_inline_data,		14)	\
 	x(new_varint,			15)	\
 	x(journal_no_flush,		16)	\
-	x(alloc_v2,			17)
+	x(alloc_v2,			17)	\
+	x(extents_across_btree_nodes,	18)
+
+#define BCH_SB_FEATURES_ALWAYS				\
+	((1ULL << BCH_FEATURE_new_extent_overwrite)|	\
+	 (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
+	 (1ULL << BCH_FEATURE_btree_updates_journalled)|\
+	 (1ULL << BCH_FEATURE_extents_across_btree_nodes))
 
 #define BCH_SB_FEATURES_ALL				\
-	((1ULL << BCH_FEATURE_new_siphash)|		\
-	 (1ULL << BCH_FEATURE_new_extent_overwrite)|	\
+	(BCH_SB_FEATURES_ALWAYS|			\
+	 (1ULL << BCH_FEATURE_new_siphash)|		\
 	 (1ULL << BCH_FEATURE_btree_ptr_v2)|		\
-	 (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
 	 (1ULL << BCH_FEATURE_new_varint)|		\
 	 (1ULL << BCH_FEATURE_journal_no_flush)|	\
 	 (1ULL << BCH_FEATURE_alloc_v2))
diff --git a/libbcachefs/bkey_sort.c b/libbcachefs/bkey_sort.c
index 2e1d9cd6..f2507079 100644
--- a/libbcachefs/bkey_sort.c
+++ b/libbcachefs/bkey_sort.c
@@ -14,9 +14,8 @@ static inline bool sort_iter_end(struct sort_iter *iter)
 	return !iter->used;
 }
 
-static inline void __sort_iter_sift(struct sort_iter *iter,
-				    unsigned from,
-				    sort_cmp_fn cmp)
+static inline void sort_iter_sift(struct sort_iter *iter, unsigned from,
+				  sort_cmp_fn cmp)
 {
 	unsigned i;
 
@@ -27,18 +26,12 @@ static inline void __sort_iter_sift(struct sort_iter *iter,
 		swap(iter->data[i], iter->data[i + 1]);
 }
 
-static inline void sort_iter_sift(struct sort_iter *iter, sort_cmp_fn cmp)
-{
-
-	__sort_iter_sift(iter, 0, cmp);
-}
-
 static inline void sort_iter_sort(struct sort_iter *iter, sort_cmp_fn cmp)
 {
 	unsigned i = iter->used;
 
 	while (i--)
-		__sort_iter_sift(iter, i, cmp);
+		sort_iter_sift(iter, i, cmp);
 }
 
 static inline struct bkey_packed *sort_iter_peek(struct sort_iter *iter)
@@ -46,26 +39,20 @@ static inline struct bkey_packed *sort_iter_peek(struct sort_iter *iter)
 	return !sort_iter_end(iter) ? iter->data->k : NULL;
 }
 
-static inline void __sort_iter_advance(struct sort_iter *iter,
-				       unsigned idx, sort_cmp_fn cmp)
+static inline void sort_iter_advance(struct sort_iter *iter, sort_cmp_fn cmp)
 {
-	struct sort_iter_set *i = iter->data + idx;
+	struct sort_iter_set *i = iter->data;
 
-	BUG_ON(idx >= iter->used);
+	BUG_ON(!iter->used);
 
 	i->k = bkey_next_skip_noops(i->k, i->end);
 
 	BUG_ON(i->k > i->end);
 
 	if (i->k == i->end)
-		array_remove_item(iter->data, iter->used, idx);
+		array_remove_item(iter->data, iter->used, 0);
 	else
-		__sort_iter_sift(iter, idx, cmp);
-}
-
-static inline void sort_iter_advance(struct sort_iter *iter, sort_cmp_fn cmp)
-{
-	__sort_iter_advance(iter, 0, cmp);
+		sort_iter_sift(iter, 0, cmp);
 }
 
 static inline struct bkey_packed *sort_iter_next(struct sort_iter *iter,
@@ -116,7 +103,7 @@ bch2_key_sort_fix_overlapping(struct bch_fs *c, struct bset *dst,
 	sort_iter_sort(iter, key_sort_fix_overlapping_cmp);
 
 	while ((k = sort_iter_peek(iter))) {
-		if (!bkey_whiteout(k) &&
+		if (!bkey_deleted(k) &&
 		    !should_drop_next_key(iter)) {
 			bkey_copy(out, k);
 			btree_keys_account_key_add(&nr, 0, out);
@@ -136,7 +123,7 @@ static void extent_sort_append(struct bch_fs *c,
 			       struct bkey_packed **out,
 			       struct bkey_s k)
 {
-	if (!bkey_whiteout(k.k)) {
+	if (!bkey_deleted(k.k)) {
 		if (!bch2_bkey_pack_key(*out, k.k, f))
 			memcpy_u64s_small(*out, k.k, BKEY_U64s);
 
@@ -161,7 +148,7 @@ bch2_sort_repack(struct bset *dst, struct btree *src,
 	memset(&nr, 0, sizeof(nr));
 
 	while ((in = bch2_btree_node_iter_next_all(src_iter, src))) {
-		if (filter_whiteouts && bkey_whiteout(in))
+		if (filter_whiteouts && bkey_deleted(in))
 			continue;
 
 		if (bch2_bkey_transform(out_f, out, bkey_packed(in)
@@ -194,7 +181,7 @@ bch2_sort_repack_merge(struct bch_fs *c,
 	bch2_bkey_buf_init(&k);
 
 	while ((k_packed = bch2_btree_node_iter_next_all(iter, src))) {
-		if (filter_whiteouts && bkey_whiteout(k_packed))
+		if (filter_whiteouts && bkey_deleted(k_packed))
 			continue;
 
 		/*
@@ -240,7 +227,7 @@ unsigned bch2_sort_keys(struct bkey_packed *dst,
 	while ((in = sort_iter_next(iter, sort_keys_cmp))) {
 		bool needs_whiteout = false;
 
-		if (bkey_whiteout(in) &&
+		if (bkey_deleted(in) &&
 		    (filter_whiteouts || !in->needs_whiteout))
 			continue;
 
@@ -252,7 +239,7 @@ unsigned bch2_sort_keys(struct bkey_packed *dst,
 			in = sort_iter_next(iter, sort_keys_cmp);
 		}
 
-		if (bkey_whiteout(in)) {
+		if (bkey_deleted(in)) {
 			memcpy_u64s(out, in, bkeyp_key_u64s(f, in));
 			set_bkeyp_val_u64s(f, out, 0);
 		} else {
@@ -264,252 +251,3 @@ unsigned bch2_sort_keys(struct bkey_packed *dst,
 
 	return (u64 *) out - (u64 *) dst;
 }
-
-/* Compat code for btree_node_old_extent_overwrite: */
-
-/*
- * If keys compare equal, compare by pointer order:
- *
- * Necessary for sort_fix_overlapping() - if there are multiple keys that
- * compare equal in different sets, we have to process them newest to oldest.
- */
-static inline int extent_sort_fix_overlapping_cmp(struct btree *b,
-						  struct bkey_packed *l,
-						  struct bkey_packed *r)
-{
-	struct bkey ul = bkey_unpack_key(b, l);
-	struct bkey ur = bkey_unpack_key(b, r);
-
-	return bkey_cmp(bkey_start_pos(&ul),
-			bkey_start_pos(&ur)) ?:
-		cmp_int((unsigned long) r, (unsigned long) l);
-}
-
-/*
- * The algorithm in extent_sort_fix_overlapping() relies on keys in the same
- * bset being ordered by start offset - but 0 size whiteouts (which are always
- * KEY_TYPE_deleted) break this ordering, so we need to skip over them:
- */
-static void extent_iter_advance(struct sort_iter *iter, unsigned idx)
-{
-	struct sort_iter_set *i = iter->data + idx;
-
-	do {
-		i->k = bkey_next_skip_noops(i->k, i->end);
-	} while (i->k != i->end && bkey_deleted(i->k));
-
-	if (i->k == i->end)
-		array_remove_item(iter->data, iter->used, idx);
-	else
-		__sort_iter_sift(iter, idx, extent_sort_fix_overlapping_cmp);
-}
-
-struct btree_nr_keys
-bch2_extent_sort_fix_overlapping(struct bch_fs *c, struct bset *dst,
-				 struct sort_iter *iter)
-{
-	struct btree *b = iter->b;
-	struct bkey_format *f = &b->format;
-	struct sort_iter_set *_l = iter->data, *_r = iter->data + 1;
-	struct bkey_packed *out = dst->start;
-	struct bkey l_unpacked, r_unpacked;
-	struct bkey_s l, r;
-	struct btree_nr_keys nr;
-	struct bkey_buf split;
-	unsigned i;
-
-	memset(&nr, 0, sizeof(nr));
-	bch2_bkey_buf_init(&split);
-
-	sort_iter_sort(iter, extent_sort_fix_overlapping_cmp);
-	for (i = 0; i < iter->used;) {
-		if (bkey_deleted(iter->data[i].k))
-			__sort_iter_advance(iter, i,
-					    extent_sort_fix_overlapping_cmp);
-		else
-			i++;
-	}
-
-	while (!sort_iter_end(iter)) {
-		l = __bkey_disassemble(b, _l->k, &l_unpacked);
-
-		if (iter->used == 1) {
-			extent_sort_append(c, f, &nr, &out, l);
-			extent_iter_advance(iter, 0);
-			continue;
-		}
-
-		r = __bkey_disassemble(b, _r->k, &r_unpacked);
-
-		/* If current key and next key don't overlap, just append */
-		if (bkey_cmp(l.k->p, bkey_start_pos(r.k)) <= 0) {
-			extent_sort_append(c, f, &nr, &out, l);
-			extent_iter_advance(iter, 0);
-			continue;
-		}
-
-		/* Skip 0 size keys */
-		if (!r.k->size) {
-			extent_iter_advance(iter, 1);
-			continue;
-		}
-
-		/*
-		 * overlap: keep the newer key and trim the older key so they
-		 * don't overlap. comparing pointers tells us which one is
-		 * newer, since the bsets are appended one after the other.
-		 */
-
-		/* can't happen because of comparison func */
-		BUG_ON(_l->k < _r->k &&
-		       !bkey_cmp(bkey_start_pos(l.k), bkey_start_pos(r.k)));
-
-		if (_l->k > _r->k) {
-			/* l wins, trim r */
-			if (bkey_cmp(l.k->p, r.k->p) >= 0) {
-				extent_iter_advance(iter, 1);
-			} else {
-				bch2_cut_front_s(l.k->p, r);
-				extent_save(b, _r->k, r.k);
-				__sort_iter_sift(iter, 1,
-					 extent_sort_fix_overlapping_cmp);
-			}
-		} else if (bkey_cmp(l.k->p, r.k->p) > 0) {
-
-			/*
-			 * r wins, but it overlaps in the middle of l - split l:
-			 */
-			bch2_bkey_buf_reassemble(&split, c, l.s_c);
-			bch2_cut_back(bkey_start_pos(r.k), split.k);
-
-			bch2_cut_front_s(r.k->p, l);
-			extent_save(b, _l->k, l.k);
-
-			__sort_iter_sift(iter, 0,
-					 extent_sort_fix_overlapping_cmp);
-
-			extent_sort_append(c, f, &nr, &out,
-					   bkey_i_to_s(split.k));
-		} else {
-			bch2_cut_back_s(bkey_start_pos(r.k), l);
-			extent_save(b, _l->k, l.k);
-		}
-	}
-
-	dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
-
-	bch2_bkey_buf_exit(&split, c);
-	return nr;
-}
-
-static inline int sort_extents_cmp(struct btree *b,
-				   struct bkey_packed *l,
-				   struct bkey_packed *r)
-{
-	return bch2_bkey_cmp_packed(b, l, r) ?:
-		(int) bkey_deleted(l) - (int) bkey_deleted(r);
-}
-
-unsigned bch2_sort_extents(struct bkey_packed *dst,
-			   struct sort_iter *iter,
-			   bool filter_whiteouts)
-{
-	struct bkey_packed *in, *out = dst;
-
-	sort_iter_sort(iter, sort_extents_cmp);
-
-	while ((in = sort_iter_next(iter, sort_extents_cmp))) {
-		if (bkey_deleted(in))
-			continue;
-
-		if (bkey_whiteout(in) &&
-		    (filter_whiteouts || !in->needs_whiteout))
-			continue;
-
-		bkey_copy(out, in);
-		out = bkey_next(out);
-	}
-
-	return (u64 *) out - (u64 *) dst;
-}
-
-static inline int sort_extent_whiteouts_cmp(struct btree *b,
-					    struct bkey_packed *l,
-					    struct bkey_packed *r)
-{
-	struct bkey ul = bkey_unpack_key(b, l);
-	struct bkey ur = bkey_unpack_key(b, r);
-
-	return bkey_cmp(bkey_start_pos(&ul), bkey_start_pos(&ur));
-}
-
-unsigned bch2_sort_extent_whiteouts(struct bkey_packed *dst,
-				    struct sort_iter *iter)
-{
-	const struct bkey_format *f = &iter->b->format;
-	struct bkey_packed *in, *out = dst;
-	struct bkey_i l, r;
-	bool prev = false, l_packed = false;
-	u64 max_packed_size	= bkey_field_max(f, BKEY_FIELD_SIZE);
-	u64 max_packed_offset	= bkey_field_max(f, BKEY_FIELD_OFFSET);
-	u64 new_size;
-
-	max_packed_size = min_t(u64, max_packed_size, KEY_SIZE_MAX);
-
-	sort_iter_sort(iter, sort_extent_whiteouts_cmp);
-
-	while ((in = sort_iter_next(iter, sort_extent_whiteouts_cmp))) {
-		if (bkey_deleted(in))
-			continue;
-
-		EBUG_ON(bkeyp_val_u64s(f, in));
-		EBUG_ON(in->type != KEY_TYPE_discard);
-
-		r.k = bkey_unpack_key(iter->b, in);
-
-		if (prev &&
-		    bkey_cmp(l.k.p, bkey_start_pos(&r.k)) >= 0) {
-			if (bkey_cmp(l.k.p, r.k.p) >= 0)
-				continue;
-
-			new_size = l_packed
-				? min(max_packed_size, max_packed_offset -
-				      bkey_start_offset(&l.k))
-				: KEY_SIZE_MAX;
-
-			new_size = min(new_size, r.k.p.offset -
-				       bkey_start_offset(&l.k));
-
-			BUG_ON(new_size < l.k.size);
-
-			bch2_key_resize(&l.k, new_size);
-
-			if (bkey_cmp(l.k.p, r.k.p) >= 0)
-				continue;
-
-			bch2_cut_front(l.k.p, &r);
-		}
-
-		if (prev) {
-			if (!bch2_bkey_pack(out, &l, f)) {
-				BUG_ON(l_packed);
-				bkey_copy(out, &l);
-			}
-			out = bkey_next(out);
-		}
-
-		l = r;
-		prev = true;
-		l_packed = bkey_packed(in);
-	}
-
-	if (prev) {
-		if (!bch2_bkey_pack(out, &l, f)) {
-			BUG_ON(l_packed);
-			bkey_copy(out, &l);
-		}
-		out = bkey_next(out);
-	}
-
-	return (u64 *) out - (u64 *) dst;
-}
diff --git a/libbcachefs/bkey_sort.h b/libbcachefs/bkey_sort.h
index 458a051f..1059996d 100644
--- a/libbcachefs/bkey_sort.h
+++ b/libbcachefs/bkey_sort.h
@@ -32,9 +32,6 @@ static inline void sort_iter_add(struct sort_iter *iter,
 struct btree_nr_keys
 bch2_key_sort_fix_overlapping(struct bch_fs *, struct bset *,
 			      struct sort_iter *);
-struct btree_nr_keys
-bch2_extent_sort_fix_overlapping(struct bch_fs *, struct bset *,
-				 struct sort_iter *);
 
 struct btree_nr_keys
 bch2_sort_repack(struct bset *, struct btree *,
@@ -48,10 +45,5 @@ bch2_sort_repack_merge(struct bch_fs *,
 
 unsigned bch2_sort_keys(struct bkey_packed *,
 			struct sort_iter *, bool);
-unsigned bch2_sort_extents(struct bkey_packed *,
-			   struct sort_iter *, bool);
-
-unsigned bch2_sort_extent_whiteouts(struct bkey_packed *,
-				    struct sort_iter *);
 
 #endif /* _BCACHEFS_BKEY_SORT_H */
diff --git a/libbcachefs/bset.c b/libbcachefs/bset.c
index 1c7318c6..756cbae6 100644
--- a/libbcachefs/bset.c
+++ b/libbcachefs/bset.c
@@ -144,7 +144,7 @@ void __bch2_verify_btree_nr_keys(struct btree *b)
 
 	for_each_bset(b, t)
 		bset_tree_for_each_key(b, t, k)
-			if (!bkey_whiteout(k))
+			if (!bkey_deleted(k))
 				btree_keys_account_key_add(&nr, t - b->set, k);
 
 	BUG_ON(memcmp(&nr, &b->nr, sizeof(nr)));
@@ -1120,7 +1120,7 @@ void bch2_bset_insert(struct btree *b,
 	if (bch2_bkey_pack_key(&packed, &insert->k, f))
 		src = &packed;
 
-	if (!bkey_whiteout(&insert->k))
+	if (!bkey_deleted(&insert->k))
 		btree_keys_account_key_add(&b->nr, t - b->set, src);
 
 	if (src->u64s != clobber_u64s) {
@@ -1657,15 +1657,14 @@ found:
 	return prev;
 }
 
-struct bkey_packed *bch2_btree_node_iter_prev_filter(struct btree_node_iter *iter,
-						     struct btree *b,
-						     unsigned min_key_type)
+struct bkey_packed *bch2_btree_node_iter_prev(struct btree_node_iter *iter,
+					      struct btree *b)
 {
 	struct bkey_packed *prev;
 
 	do {
 		prev = bch2_btree_node_iter_prev_all(iter, b);
-	} while (prev && prev->type < min_key_type);
+	} while (prev && bkey_deleted(prev));
 
 	return prev;
 }
diff --git a/libbcachefs/bset.h b/libbcachefs/bset.h
index 469294cc..54b364c8 100644
--- a/libbcachefs/bset.h
+++ b/libbcachefs/bset.h
@@ -400,7 +400,7 @@ bch2_bkey_prev_all(struct btree *b, struct bset_tree *t, struct bkey_packed *k)
 static inline struct bkey_packed *
 bch2_bkey_prev(struct btree *b, struct bset_tree *t, struct bkey_packed *k)
 {
-	return bch2_bkey_prev_filter(b, t, k, KEY_TYPE_discard + 1);
+	return bch2_bkey_prev_filter(b, t, k, 1);
 }
 
 enum bch_extent_overlap {
@@ -506,33 +506,23 @@ __bch2_btree_node_iter_peek_all(struct btree_node_iter *iter,
 }
 
 static inline struct bkey_packed *
-bch2_btree_node_iter_peek_filter(struct btree_node_iter *iter,
-				 struct btree *b,
-				 unsigned min_key_type)
+bch2_btree_node_iter_peek_all(struct btree_node_iter *iter, struct btree *b)
 {
-	while (!bch2_btree_node_iter_end(iter)) {
-		struct bkey_packed *k = __bch2_btree_node_iter_peek_all(iter, b);
-
-		if (k->type >= min_key_type)
-			return k;
-
-		bch2_btree_node_iter_advance(iter, b);
-	}
-
-	return NULL;
-}
-
-static inline struct bkey_packed *
-bch2_btree_node_iter_peek_all(struct btree_node_iter *iter,
-			      struct btree *b)
-{
-	return bch2_btree_node_iter_peek_filter(iter, b, 0);
+	return !bch2_btree_node_iter_end(iter)
+		? __btree_node_offset_to_key(b, iter->data->k)
+		: NULL;
 }
 
 static inline struct bkey_packed *
 bch2_btree_node_iter_peek(struct btree_node_iter *iter, struct btree *b)
 {
-	return bch2_btree_node_iter_peek_filter(iter, b, KEY_TYPE_discard + 1);
+	struct bkey_packed *k;
+
+	while ((k = bch2_btree_node_iter_peek_all(iter, b)) &&
+	       bkey_deleted(k))
+		bch2_btree_node_iter_advance(iter, b);
+
+	return k;
 }
 
 static inline struct bkey_packed *
@@ -548,14 +538,8 @@ bch2_btree_node_iter_next_all(struct btree_node_iter *iter, struct btree *b)
 
 struct bkey_packed *bch2_btree_node_iter_prev_all(struct btree_node_iter *,
 						  struct btree *);
-struct bkey_packed *bch2_btree_node_iter_prev_filter(struct btree_node_iter *,
-						     struct btree *, unsigned);
-
-static inline struct bkey_packed *
-bch2_btree_node_iter_prev(struct btree_node_iter *iter, struct btree *b)
-{
-	return bch2_btree_node_iter_prev_filter(iter, b, KEY_TYPE_discard + 1);
-}
+struct bkey_packed *bch2_btree_node_iter_prev(struct btree_node_iter *,
+					      struct btree *);
 
 struct bkey_s_c bch2_btree_node_iter_peek_unpack(struct btree_node_iter *,
 						struct btree *,
diff --git a/libbcachefs/btree_io.c b/libbcachefs/btree_io.c
index 8a4fbdf4..b5c602a1 100644
--- a/libbcachefs/btree_io.c
+++ b/libbcachefs/btree_io.c
@@ -24,8 +24,7 @@
 
 static void verify_no_dups(struct btree *b,
 			   struct bkey_packed *start,
-			   struct bkey_packed *end,
-			   bool extents)
+			   struct bkey_packed *end)
 {
 #ifdef CONFIG_BCACHEFS_DEBUG
 	struct bkey_packed *k, *p;
@@ -39,10 +38,7 @@ static void verify_no_dups(struct btree *b,
 		struct bkey l = bkey_unpack_key(b, p);
 		struct bkey r = bkey_unpack_key(b, k);
 
-		BUG_ON(extents
-		       ? bkey_cmp(l.p, bkey_start_pos(&r)) > 0
-		       : bkey_cmp(l.p, bkey_start_pos(&r)) >= 0);
-		//BUG_ON(bch2_bkey_cmp_packed(&b->format, p, k) >= 0);
+		BUG_ON(bkey_cmp(l.p, bkey_start_pos(&r)) >= 0);
 	}
 #endif
 }
@@ -150,8 +146,7 @@ static void bch2_sort_whiteouts(struct bch_fs *c, struct btree *b)
 	}
 
 	verify_no_dups(b, new_whiteouts,
-		       (void *) ((u64 *) new_whiteouts + b->whiteout_u64s),
-		       btree_node_old_extent_overwrite(b));
+		       (void *) ((u64 *) new_whiteouts + b->whiteout_u64s));
 
 	memcpy_u64s(unwritten_whiteouts_start(c, b),
 		    new_whiteouts, b->whiteout_u64s);
@@ -176,144 +171,6 @@ static bool should_compact_bset(struct btree *b, struct bset_tree *t,
 	}
 }
 
-static bool bch2_compact_extent_whiteouts(struct bch_fs *c,
-					  struct btree *b,
-					  enum compact_mode mode)
-{
-	const struct bkey_format *f = &b->format;
-	struct bset_tree *t;
-	struct bkey_packed *whiteouts = NULL;
-	struct bkey_packed *u_start, *u_pos;
-	struct sort_iter sort_iter;
-	unsigned bytes, whiteout_u64s = 0, u64s;
-	bool used_mempool, compacting = false;
-
-	BUG_ON(!btree_node_is_extents(b));
-
-	for_each_bset(b, t)
-		if (should_compact_bset(b, t, whiteout_u64s != 0, mode))
-			whiteout_u64s += bset_dead_u64s(b, t);
-
-	if (!whiteout_u64s)
-		return false;
-
-	bch2_sort_whiteouts(c, b);
-
-	sort_iter_init(&sort_iter, b);
-
-	whiteout_u64s += b->whiteout_u64s;
-	bytes = whiteout_u64s * sizeof(u64);
-
-	whiteouts = btree_bounce_alloc(c, bytes, &used_mempool);
-	u_start = u_pos = whiteouts;
-
-	memcpy_u64s(u_pos, unwritten_whiteouts_start(c, b),
-		    b->whiteout_u64s);
-	u_pos = (void *) u_pos + b->whiteout_u64s * sizeof(u64);
-
-	sort_iter_add(&sort_iter, u_start, u_pos);
-
-	for_each_bset(b, t) {
-		struct bset *i = bset(b, t);
-		struct bkey_packed *k, *n, *out, *start, *end;
-		struct btree_node_entry *src = NULL, *dst = NULL;
-
-		if (t != b->set && !bset_written(b, i)) {
-			src = container_of(i, struct btree_node_entry, keys);
-			dst = max(write_block(b),
-				  (void *) btree_bkey_last(b, t - 1));
-		}
-
-		if (src != dst)
-			compacting = true;
-
-		if (!should_compact_bset(b, t, compacting, mode)) {
-			if (src != dst) {
-				memmove(dst, src, sizeof(*src) +
-					le16_to_cpu(src->keys.u64s) *
-					sizeof(u64));
-				i = &dst->keys;
-				set_btree_bset(b, t, i);
-			}
-			continue;
-		}
-
-		compacting = true;
-		u_start = u_pos;
-		start = i->start;
-		end = vstruct_last(i);
-
-		if (src != dst) {
-			memmove(dst, src, sizeof(*src));
-			i = &dst->keys;
-			set_btree_bset(b, t, i);
-		}
-
-		out = i->start;
-
-		for (k = start; k != end; k = n) {
-			n = bkey_next_skip_noops(k, end);
-
-			if (bkey_deleted(k))
-				continue;
-
-			BUG_ON(bkey_whiteout(k) &&
-			       k->needs_whiteout &&
-			       bkey_written(b, k));
-
-			if (bkey_whiteout(k) && !k->needs_whiteout)
-				continue;
-
-			if (bkey_whiteout(k)) {
-				memcpy_u64s(u_pos, k, bkeyp_key_u64s(f, k));
-				set_bkeyp_val_u64s(f, u_pos, 0);
-				u_pos = bkey_next(u_pos);
-			} else {
-				bkey_copy(out, k);
-				out = bkey_next(out);
-			}
-		}
-
-		sort_iter_add(&sort_iter, u_start, u_pos);
-
-		i->u64s = cpu_to_le16((u64 *) out - i->_data);
-		set_btree_bset_end(b, t);
-		bch2_bset_set_no_aux_tree(b, t);
-	}
-
-	b->whiteout_u64s = (u64 *) u_pos - (u64 *) whiteouts;
-
-	BUG_ON((void *) unwritten_whiteouts_start(c, b) <
-	       (void *) btree_bkey_last(b, bset_tree_last(b)));
-
-	u64s = bch2_sort_extent_whiteouts(unwritten_whiteouts_start(c, b),
-					  &sort_iter);
-
-	BUG_ON(u64s > b->whiteout_u64s);
-	BUG_ON(u_pos != whiteouts && !u64s);
-
-	if (u64s != b->whiteout_u64s) {
-		void *src = unwritten_whiteouts_start(c, b);
-
-		b->whiteout_u64s = u64s;
-		memmove_u64s_up(unwritten_whiteouts_start(c, b), src, u64s);
-	}
-
-	verify_no_dups(b,
-		       unwritten_whiteouts_start(c, b),
-		       unwritten_whiteouts_end(c, b),
-		       true);
-
-	btree_bounce_free(c, bytes, used_mempool, whiteouts);
-
-	bch2_btree_build_aux_trees(b);
-
-	bch_btree_keys_u64s_remaining(c, b);
-	bch2_verify_btree_nr_keys(b);
-
-	return true;
-}
-
 static bool bch2_drop_whiteouts(struct btree *b, enum compact_mode mode)
 {
 	struct bset_tree *t;
@@ -358,7 +215,7 @@ static bool bch2_drop_whiteouts(struct btree *b, enum compact_mode mode)
 		for (k = start; k != end; k = n) {
 			n = bkey_next_skip_noops(k, end);
 
-			if (!bkey_whiteout(k)) {
+			if (!bkey_deleted(k)) {
 				bkey_copy(out, k);
 				out = bkey_next(out);
 			} else {
@@ -382,9 +239,7 @@ static bool bch2_drop_whiteouts(struct btree *b, enum compact_mode mode)
 bool bch2_compact_whiteouts(struct bch_fs *c, struct btree *b,
 			    enum compact_mode mode)
 {
-	return !btree_node_old_extent_overwrite(b)
-		? bch2_drop_whiteouts(b, mode)
-		: bch2_compact_extent_whiteouts(c, b, mode);
+	return bch2_drop_whiteouts(b, mode);
 }
 
 static void btree_node_sort(struct bch_fs *c, struct btree *b,
@@ -422,14 +277,7 @@ static void btree_node_sort(struct bch_fs *c, struct btree *b,
 
 	start_time = local_clock();
 
-	if (btree_node_old_extent_overwrite(b))
-		filter_whiteouts = bset_written(b, start_bset);
-
-	u64s = (btree_node_old_extent_overwrite(b)
-		? bch2_sort_extents
-		: bch2_sort_keys)(out->keys.start,
-				  &sort_iter,
-				  filter_whiteouts);
+	u64s = bch2_sort_keys(out->keys.start, &sort_iter, filter_whiteouts);
 
 	out->keys.u64s = cpu_to_le16(u64s);
 
@@ -877,11 +725,11 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
 		/*
 		 * with the separate whiteouts thing (used for extents), the
 		 * second set of keys actually can have whiteouts too, so we
-		 * can't solely go off bkey_whiteout()...
+		 * can't solely go off bkey_deleted()...
 		 */
 
 		if (!seen_non_whiteout &&
-		    (!bkey_whiteout(k) ||
+		    (!bkey_deleted(k) ||
 		     (prev && bkey_iter_cmp(b, prev, k) > 0))) {
 			*whiteout_u64s = k->_data - i->_data;
 			seen_non_whiteout = true;
@@ -969,11 +817,10 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 			bset_encrypt(c, i, b->written << 9);
 
-			if (btree_node_is_extents(b) &&
-			    !BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data)) {
-				set_btree_node_old_extent_overwrite(b);
-				set_btree_node_need_rewrite(b);
-			}
+			btree_err_on(btree_node_is_extents(b) &&
+				     !BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data),
+				     BTREE_ERR_FATAL, c, NULL, b, NULL,
+				     "btree node does not have NEW_EXTENT_OVERWRITE set");
 
 			sectors = vstruct_sectors(b->data, c->block_bits);
 		} else {
@@ -1047,9 +894,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 	set_btree_bset(b, b->set, &b->data->keys);
 
-	b->nr = (btree_node_old_extent_overwrite(b)
-		 ? bch2_extent_sort_fix_overlapping
-		 : bch2_key_sort_fix_overlapping)(c, &sorted->keys, iter);
+	b->nr = bch2_key_sort_fix_overlapping(c, &sorted->keys, iter);
 
 	u64s = le16_to_cpu(sorted->keys.u64s);
 	*sorted = *b->data;
@@ -1590,24 +1435,14 @@ void __bch2_btree_node_write(struct bch_fs *c, struct btree *b,
 	i->journal_seq	= cpu_to_le64(seq);
 	i->u64s		= 0;
 
-	if (!btree_node_old_extent_overwrite(b)) {
-		sort_iter_add(&sort_iter,
-			      unwritten_whiteouts_start(c, b),
-			      unwritten_whiteouts_end(c, b));
-		SET_BSET_SEPARATE_WHITEOUTS(i, false);
-	} else {
-		memcpy_u64s(i->start,
-			    unwritten_whiteouts_start(c, b),
-			    b->whiteout_u64s);
-		i->u64s = cpu_to_le16(b->whiteout_u64s);
-		SET_BSET_SEPARATE_WHITEOUTS(i, true);
-	}
+	sort_iter_add(&sort_iter,
+		      unwritten_whiteouts_start(c, b),
+		      unwritten_whiteouts_end(c, b));
+	SET_BSET_SEPARATE_WHITEOUTS(i, false);
 
 	b->whiteout_u64s = 0;
 
-	u64s = btree_node_old_extent_overwrite(b)
-		? bch2_sort_extents(vstruct_last(i), &sort_iter, false)
-		: bch2_sort_keys(i->start, &sort_iter, false);
+	u64s = bch2_sort_keys(i->start, &sort_iter, false);
 	le16_add_cpu(&i->u64s, u64s);
 
 	set_needs_whiteout(i, false);
diff --git a/libbcachefs/btree_iter.c b/libbcachefs/btree_iter.c
index 146ad2f5..303e6d3a 100644
--- a/libbcachefs/btree_iter.c
+++ b/libbcachefs/btree_iter.c
@@ -34,13 +34,13 @@ static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
 static inline bool btree_iter_pos_before_node(struct btree_iter *iter,
 					      struct btree *b)
 {
-	return bkey_cmp(btree_iter_search_key(iter), b->data->min_key) < 0;
+	return bkey_cmp(iter->real_pos, b->data->min_key) < 0;
 }
 
 static inline bool btree_iter_pos_after_node(struct btree_iter *iter,
 					     struct btree *b)
 {
-	return bkey_cmp(b->key.k.p, btree_iter_search_key(iter)) < 0;
+	return bkey_cmp(b->key.k.p, iter->real_pos) < 0;
 }
 
 static inline bool btree_iter_pos_in_node(struct btree_iter *iter,
@@ -491,7 +491,6 @@ static void bch2_btree_iter_verify_cached(struct btree_iter *iter)
 static void bch2_btree_iter_verify_level(struct btree_iter *iter,
 					 unsigned level)
 {
-	struct bpos pos = btree_iter_search_key(iter);
 	struct btree_iter_level *l = &iter->l[level];
 	struct btree_node_iter tmp = l->iter;
 	bool locked = btree_node_locked(iter, level);
@@ -535,16 +534,16 @@ static void bch2_btree_iter_verify_level(struct btree_iter *iter,
 	 * whiteouts)
 	 */
 	p = level || btree_node_type_is_extents(iter->btree_id)
-		? bch2_btree_node_iter_prev_filter(&tmp, l->b, KEY_TYPE_discard)
+		? bch2_btree_node_iter_prev(&tmp, l->b)
 		: bch2_btree_node_iter_prev_all(&tmp, l->b);
 	k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
 
-	if (p && bkey_iter_pos_cmp(l->b, p, &pos) >= 0) {
+	if (p && bkey_iter_pos_cmp(l->b, p, &iter->real_pos) >= 0) {
 		msg = "before";
 		goto err;
 	}
 
-	if (k && bkey_iter_pos_cmp(l->b, k, &pos) < 0) {
+	if (k && bkey_iter_pos_cmp(l->b, k, &iter->real_pos) < 0) {
 		msg = "after";
 		goto err;
 	}
@@ -567,12 +566,11 @@ err:
 	}
 
 	panic("iterator should be %s key at level %u:\n"
-	      "iter pos %s %llu:%llu\n"
+	      "iter pos %llu:%llu\n"
 	      "prev key %s\n"
 	      "cur  key %s\n",
 	      msg, level,
-	      iter->flags & BTREE_ITER_IS_EXTENTS ? ">" : "=>",
-	      iter->pos.inode, iter->pos.offset,
+	      iter->real_pos.inode, iter->real_pos.offset,
 	      buf1, buf2);
 }
 
@@ -626,12 +624,11 @@ static void __bch2_btree_iter_fix_key_modified(struct btree_iter *iter,
 					       struct bkey_packed *where)
 {
 	struct btree_iter_level *l = &iter->l[b->c.level];
-	struct bpos pos = btree_iter_search_key(iter);
 
 	if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b))
 		return;
 
-	if (bkey_iter_pos_cmp(l->b, where, &pos) < 0)
+	if (bkey_iter_pos_cmp(l->b, where, &iter->real_pos) < 0)
 		bch2_btree_node_iter_advance(&l->iter, l->b);
 
 	btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
@@ -666,7 +663,6 @@ static void __bch2_btree_node_iter_fix(struct btree_iter *iter,
 	bool iter_current_key_modified =
 		orig_iter_pos >= offset &&
 		orig_iter_pos <= offset + clobber_u64s;
-	struct bpos iter_pos = btree_iter_search_key(iter);
 
 	btree_node_iter_for_each(node_iter, set)
 		if (set->end == old_end)
@@ -674,7 +670,7 @@ static void __bch2_btree_node_iter_fix(struct btree_iter *iter,
 
 	/* didn't find the bset in the iterator - might have to readd it: */
 	if (new_u64s &&
-	    bkey_iter_pos_cmp(b, where, &iter_pos) >= 0) {
+	    bkey_iter_pos_cmp(b, where, &iter->real_pos) >= 0) {
 		bch2_btree_node_iter_push(node_iter, b, where, end);
 		goto fixup_done;
 	} else {
@@ -689,7 +685,7 @@ found:
 		return;
 
 	if (new_u64s &&
-	    bkey_iter_pos_cmp(b, where, &iter_pos) >= 0) {
+	    bkey_iter_pos_cmp(b, where, &iter->real_pos) >= 0) {
 		set->k = offset;
 	} else if (set->k < offset + clobber_u64s) {
 		set->k = offset + new_u64s;
@@ -825,12 +821,11 @@ static inline bool btree_iter_advance_to_pos(struct btree_iter *iter,
 					     struct btree_iter_level *l,
 					     int max_advance)
 {
-	struct bpos pos = btree_iter_search_key(iter);
 	struct bkey_packed *k;
 	int nr_advanced = 0;
 
 	while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) &&
-	       bkey_iter_pos_cmp(l->b, k, &pos) < 0) {
+	       bkey_iter_pos_cmp(l->b, k, &iter->real_pos) < 0) {
 		if (max_advance > 0 && nr_advanced >= max_advance)
 			return false;
 
@@ -893,10 +888,9 @@ static void btree_iter_verify_new_node(struct btree_iter *iter, struct btree *b)
 static inline void __btree_iter_init(struct btree_iter *iter,
 				     unsigned level)
 {
-	struct bpos pos = btree_iter_search_key(iter);
 	struct btree_iter_level *l = &iter->l[level];
 
-	bch2_btree_node_iter_init(&l->iter, l->b, &pos);
+	bch2_btree_node_iter_init(&l->iter, l->b, &iter->real_pos);
 
 	/*
 	 * Iterators to interior nodes should always be pointed at the first non
@@ -1380,7 +1374,7 @@ struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
 
 	BUG_ON(bkey_cmp(b->key.k.p, iter->pos) < 0);
 
-	iter->pos = b->key.k.p;
+	iter->pos = iter->real_pos = b->key.k.p;
 	iter->uptodate = BTREE_ITER_UPTODATE;
 
 	bch2_btree_iter_verify(iter);
@@ -1442,7 +1436,7 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 		b = iter->l[iter->level].b;
 	}
 
-	iter->pos = b->key.k.p;
+	iter->pos = iter->real_pos = b->key.k.p;
 	iter->uptodate = BTREE_ITER_UPTODATE;
 
 	bch2_btree_iter_verify(iter);
@@ -1490,57 +1484,53 @@ out:
 		btree_iter_set_dirty(iter, BTREE_ITER_NEED_PEEK);
 }
 
-void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos,
-			       bool strictly_greater)
+static void btree_iter_set_search_pos(struct btree_iter *iter, struct bpos new_pos)
 {
-	struct bpos old = btree_iter_search_key(iter);
-	int cmp;
+	int cmp = bkey_cmp(new_pos, iter->real_pos);
 
-	iter->flags &= ~BTREE_ITER_IS_EXTENTS;
-	iter->flags |= strictly_greater ? BTREE_ITER_IS_EXTENTS : 0;
+	iter->real_pos = new_pos;
 
+	btree_iter_pos_changed(iter, cmp);
+}
+
+void __bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos,
+			       bool strictly_greater)
+{
 	bkey_init(&iter->k);
 	iter->k.p = iter->pos = new_pos;
 
-	cmp = bkey_cmp(btree_iter_search_key(iter), old);
+	iter->flags &= ~BTREE_ITER_IS_EXTENTS;
+	iter->flags |= strictly_greater ? BTREE_ITER_IS_EXTENTS : 0;
 
-	btree_iter_pos_changed(iter, cmp);
+	btree_iter_set_search_pos(iter, btree_iter_search_key(iter));
 }
 
 void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos new_pos)
 {
-	int cmp = bkey_cmp(new_pos, iter->pos);
-
-	bkey_init(&iter->k);
-	iter->k.p = iter->pos = new_pos;
-
-	btree_iter_pos_changed(iter, cmp);
+	__bch2_btree_iter_set_pos(iter, new_pos,
+			(iter->flags & BTREE_ITER_IS_EXTENTS) != 0);
 }
 
 static inline bool bch2_btree_iter_advance_pos(struct btree_iter *iter)
 {
 	struct bpos pos = iter->k.p;
+	bool ret = bkey_cmp(pos, POS_MAX) != 0;
 
-	if (unlikely(!bkey_cmp(pos, POS_MAX)))
-		return false;
-
-	if (!(iter->flags & BTREE_ITER_IS_EXTENTS))
+	if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
 		pos = bkey_successor(pos);
 	bch2_btree_iter_set_pos(iter, pos);
-	return true;
+	return ret;
 }
 
 static inline bool bch2_btree_iter_rewind_pos(struct btree_iter *iter)
 {
 	struct bpos pos = bkey_start_pos(&iter->k);
+	bool ret = bkey_cmp(pos, POS_MIN) != 0;
 
-	if (unlikely(!bkey_cmp(pos, POS_MIN)))
-		return false;
-
-	if (!(iter->flags & BTREE_ITER_IS_EXTENTS))
+	if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
 		pos = bkey_predecessor(pos);
 	bch2_btree_iter_set_pos(iter, pos);
-	return true;
+	return ret;
 }
 
 static inline bool btree_iter_set_pos_to_next_leaf(struct btree_iter *iter)
@@ -1548,10 +1538,16 @@ static inline bool btree_iter_set_pos_to_next_leaf(struct btree_iter *iter)
 	struct bpos next_pos = iter->l[0].b->key.k.p;
 	bool ret = bkey_cmp(next_pos, POS_MAX) != 0;
 
-	if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
-		next_pos = bkey_successor(next_pos);
+	/*
+	 * Typically, we don't want to modify iter->pos here, since that
+	 * indicates where we searched from - unless we got to the end of the
+	 * btree, in that case we want iter->pos to reflect that:
+	 */
+	if (ret)
+		btree_iter_set_search_pos(iter, bkey_successor(next_pos));
+	else
+		bch2_btree_iter_set_pos(iter, POS_MAX);
 
-	bch2_btree_iter_set_pos(iter, next_pos);
 	return ret;
 }
 
@@ -1560,14 +1556,11 @@ static inline bool btree_iter_set_pos_to_prev_leaf(struct btree_iter *iter)
 	struct bpos next_pos = iter->l[0].b->data->min_key;
 	bool ret = bkey_cmp(next_pos, POS_MIN) != 0;
 
-	if (ret) {
-		next_pos = bkey_predecessor(next_pos);
-
-		if (iter->flags & BTREE_ITER_IS_EXTENTS)
-			next_pos = bkey_predecessor(next_pos);
-	}
+	if (ret)
+		btree_iter_set_search_pos(iter, bkey_predecessor(next_pos));
+	else
+		bch2_btree_iter_set_pos(iter, POS_MIN);
 
-	bch2_btree_iter_set_pos(iter, next_pos);
 	return ret;
 }
 
@@ -1636,6 +1629,8 @@ struct bkey_s_c bch2_btree_iter_peek(struct btree_iter *iter)
 	if (bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0)
 		iter->pos = bkey_start_pos(k.k);
 
+	iter->real_pos = k.k->p;
+
 	iter->uptodate = BTREE_ITER_UPTODATE;
 
 	bch2_btree_iter_verify_level(iter, 0);
@@ -1714,8 +1709,8 @@ struct bkey_s_c bch2_btree_iter_peek_with_updates(struct btree_iter *iter)
 	}
 
 	/*
-	 * iter->pos should always be equal to the key we just
-	 * returned - except extents can straddle iter->pos:
+	 * iter->pos should be mononotically increasing, and always be equal to
+	 * the key we just returned - except extents can straddle iter->pos:
 	 */
 	if (bkey_cmp(bkey_start_pos(k.k), iter->pos) > 0)
 		iter->pos = bkey_start_pos(k.k);
@@ -1774,6 +1769,9 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 	/* Extents can straddle iter->pos: */
 	if (bkey_cmp(k.k->p, pos) < 0)
 		iter->pos = k.k->p;
+
+	iter->real_pos = k.k->p;
+
 	iter->uptodate	= BTREE_ITER_UPTODATE;
 
 	bch2_btree_iter_verify_level(iter, 0);
@@ -1795,11 +1793,8 @@ struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter)
 static inline struct bkey_s_c
 __bch2_btree_iter_peek_slot_extents(struct btree_iter *iter)
 {
-	struct btree_iter_level *l = &iter->l[0];
-	struct btree_node_iter node_iter;
 	struct bkey_s_c k;
-	struct bkey n;
-	int ret;
+	struct bpos pos, next_start;
 
 	/* keys & holes can't span inode numbers: */
 	if (iter->pos.offset == KEY_OFFSET_MAX) {
@@ -1807,50 +1802,31 @@ __bch2_btree_iter_peek_slot_extents(struct btree_iter *iter)
 			return bkey_s_c_null;
 
 		bch2_btree_iter_set_pos(iter, bkey_successor(iter->pos));
-
-		ret = bch2_btree_iter_traverse(iter);
-		if (unlikely(ret))
-			return bkey_s_c_err(ret);
 	}
 
-	/*
-	 * iterator is now at the correct position for inserting at iter->pos,
-	 * but we need to keep iterating until we find the first non whiteout so
-	 * we know how big a hole we have, if any:
-	 */
-
-	node_iter = l->iter;
-	k = __btree_iter_unpack(iter, l, &iter->k,
-		bch2_btree_node_iter_peek(&node_iter, l->b));
+	pos = iter->pos;
+	k = bch2_btree_iter_peek(iter);
+	iter->pos = pos;
 
-	if (k.k && bkey_cmp(bkey_start_pos(k.k), iter->pos) <= 0) {
-		/*
-		 * We're not setting iter->uptodate because the node iterator
-		 * doesn't necessarily point at the key we're returning:
-		 */
-
-		EBUG_ON(bkey_cmp(k.k->p, iter->pos) <= 0);
-		bch2_btree_iter_verify_level(iter, 0);
+	if (bkey_err(k))
 		return k;
-	}
 
-	/* hole */
+	if (k.k && bkey_cmp(bkey_start_pos(k.k), iter->pos) <= 0)
+		return k;
 
-	if (!k.k)
-		k.k = &l->b->key.k;
+	next_start = k.k ? bkey_start_pos(k.k) : POS_MAX;
 
-	bkey_init(&n);
-	n.p = iter->pos;
-	bch2_key_resize(&n,
+	bkey_init(&iter->k);
+	iter->k.p = iter->pos;
+	bch2_key_resize(&iter->k,
 			min_t(u64, KEY_SIZE_MAX,
-			      (k.k->p.inode == n.p.inode
-			       ? bkey_start_offset(k.k)
+			      (next_start.inode == iter->pos.inode
+			       ? next_start.offset
 			       : KEY_OFFSET_MAX) -
-			      n.p.offset));
+			      iter->pos.offset));
 
-	EBUG_ON(!n.size);
+	EBUG_ON(!iter->k.size);
 
-	iter->k	= n;
 	iter->uptodate = BTREE_ITER_UPTODATE;
 
 	bch2_btree_iter_verify_level(iter, 0);
@@ -1869,13 +1845,13 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 	if (iter->uptodate == BTREE_ITER_UPTODATE)
 		return btree_iter_peek_uptodate(iter);
 
+	if (iter->flags & BTREE_ITER_IS_EXTENTS)
+		return __bch2_btree_iter_peek_slot_extents(iter);
+
 	ret = bch2_btree_iter_traverse(iter);
 	if (unlikely(ret))
 		return bkey_s_c_err(ret);
 
-	if (iter->flags & BTREE_ITER_IS_EXTENTS)
-		return __bch2_btree_iter_peek_slot_extents(iter);
-
 	k = __btree_iter_peek_all(iter, l, &iter->k);
 
 	EBUG_ON(k.k && bkey_deleted(k.k) && bkey_cmp(k.k->p, iter->pos) == 0);
@@ -1937,6 +1913,7 @@ static inline void bch2_btree_iter_init(struct btree_trans *trans,
 	bkey_init(&iter->k);
 	iter->k.p			= pos;
 	iter->flags			= flags;
+	iter->real_pos			= btree_iter_search_key(iter);
 	iter->uptodate			= BTREE_ITER_NEED_TRAVERSE;
 	iter->btree_id			= btree_id;
 	iter->level			= 0;
diff --git a/libbcachefs/btree_types.h b/libbcachefs/btree_types.h
index 631bf469..be91f489 100644
--- a/libbcachefs/btree_types.h
+++ b/libbcachefs/btree_types.h
@@ -247,6 +247,8 @@ enum btree_iter_uptodate {
 struct btree_iter {
 	struct btree_trans	*trans;
 	struct bpos		pos;
+	/* what we're searching for/what the iterator actually points to: */
+	struct bpos		real_pos;
 	struct bpos		pos_after_commit;
 
 	u16			flags;
@@ -413,7 +415,6 @@ enum btree_flags {
 	BTREE_NODE_just_written,
 	BTREE_NODE_dying,
 	BTREE_NODE_fake,
-	BTREE_NODE_old_extent_overwrite,
 	BTREE_NODE_need_rewrite,
 	BTREE_NODE_never_write,
 };
@@ -428,7 +429,6 @@ BTREE_FLAG(write_in_flight);
 BTREE_FLAG(just_written);
 BTREE_FLAG(dying);
 BTREE_FLAG(fake);
-BTREE_FLAG(old_extent_overwrite);
 BTREE_FLAG(need_rewrite);
 BTREE_FLAG(never_write);
 
diff --git a/libbcachefs/btree_update_interior.c b/libbcachefs/btree_update_interior.c
index dd1b8f6e..fff062b5 100644
--- a/libbcachefs/btree_update_interior.c
+++ b/libbcachefs/btree_update_interior.c
@@ -90,7 +90,7 @@ void __bch2_btree_calc_format(struct bkey_format_state *s, struct btree *b)
 
 	for_each_bset(b, t)
 		bset_tree_for_each_key(b, t, k)
-			if (!bkey_whiteout(k)) {
+			if (!bkey_deleted(k)) {
 				uk = bkey_unpack_key(b, k);
 				bch2_bkey_format_add_key(s, &uk);
 			}
@@ -302,14 +302,7 @@ static struct btree *bch2_btree_node_alloc(struct btree_update *as, unsigned lev
 		bp->v.sectors_written	= 0;
 	}
 
-	if (c->sb.features & (1ULL << BCH_FEATURE_new_extent_overwrite))
-		SET_BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data, true);
-
-	if (btree_node_is_extents(b) &&
-	    !BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data)) {
-		set_btree_node_old_extent_overwrite(b);
-		set_btree_node_need_rewrite(b);
-	}
+	SET_BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data, true);
 
 	bch2_btree_build_aux_trees(b);
 
diff --git a/libbcachefs/btree_update_leaf.c b/libbcachefs/btree_update_leaf.c
index d09124fc..4d283a38 100644
--- a/libbcachefs/btree_update_leaf.c
+++ b/libbcachefs/btree_update_leaf.c
@@ -62,9 +62,6 @@ bool bch2_btree_bset_insert_key(struct btree_iter *iter,
 	EBUG_ON(btree_node_just_written(b));
 	EBUG_ON(bset_written(b, btree_bset_last(b)));
 	EBUG_ON(bkey_deleted(&insert->k) && bkey_val_u64s(&insert->k));
-	EBUG_ON(bkey_cmp(b->data->min_key, POS_MIN) &&
-		bkey_cmp(bkey_start_pos(&insert->k),
-			 bkey_predecessor(b->data->min_key)) < 0);
 	EBUG_ON(bkey_cmp(insert->k.p, b->data->min_key) < 0);
 	EBUG_ON(bkey_cmp(insert->k.p, b->data->max_key) > 0);
 	EBUG_ON(insert->k.u64s >
@@ -76,13 +73,13 @@ bool bch2_btree_bset_insert_key(struct btree_iter *iter,
 		k = NULL;
 
 	/* @k is the key being overwritten/deleted, if any: */
-	EBUG_ON(k && bkey_whiteout(k));
+	EBUG_ON(k && bkey_deleted(k));
 
 	/* Deleting, but not found? nothing to do: */
-	if (bkey_whiteout(&insert->k) && !k)
+	if (bkey_deleted(&insert->k) && !k)
 		return false;
 
-	if (bkey_whiteout(&insert->k)) {
+	if (bkey_deleted(&insert->k)) {
 		/* Deleting: */
 		btree_account_key_drop(b, k);
 		k->type = KEY_TYPE_deleted;
@@ -219,7 +216,7 @@ static inline void btree_insert_entry_checks(struct btree_trans *trans,
 {
 	struct bch_fs *c = trans->c;
 
-	BUG_ON(bkey_cmp(insert->k.p, iter->pos));
+	BUG_ON(bkey_cmp(insert->k.p, iter->real_pos));
 	BUG_ON(bch2_debug_check_bkeys &&
 	       bch2_bkey_invalid(c, bkey_i_to_s_c(insert),
 				 __btree_node_type(iter->level, iter->btree_id)));
@@ -705,26 +702,31 @@ static inline int btree_iter_pos_cmp(const struct btree_iter *l,
 		 bkey_cmp(l->pos, r->pos);
 }
 
-static void bch2_trans_update2(struct btree_trans *trans,
+static int bch2_trans_update2(struct btree_trans *trans,
 			       struct btree_iter *iter,
 			       struct bkey_i *insert)
 {
 	struct btree_insert_entry *i, n = (struct btree_insert_entry) {
 		.iter = iter, .k = insert
 	};
+	int ret;
 
 	btree_insert_entry_checks(trans, n.iter, n.k);
 
-	BUG_ON(iter->uptodate > BTREE_ITER_NEED_PEEK);
-
 	EBUG_ON(trans->nr_updates2 >= BTREE_ITER_MAX);
 
+	ret = bch2_btree_iter_traverse(iter);
+	if (unlikely(ret))
+		return ret;
+
+	BUG_ON(iter->uptodate > BTREE_ITER_NEED_PEEK);
+
 	iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
 
 	trans_for_each_update2(trans, i) {
 		if (btree_iter_pos_cmp(n.iter, i->iter) == 0) {
 			*i = n;
-			return;
+			return 0;
 		}
 
 		if (btree_iter_pos_cmp(n.iter, i->iter) <= 0)
@@ -733,6 +735,7 @@ static void bch2_trans_update2(struct btree_trans *trans,
 
 	array_insert_item(trans->updates2, trans->nr_updates2,
 			  i - trans->updates2, n);
+	return 0;
 }
 
 static int extent_update_to_keys(struct btree_trans *trans,
@@ -753,9 +756,9 @@ static int extent_update_to_keys(struct btree_trans *trans,
 
 	iter->flags |= BTREE_ITER_INTENT;
 	__bch2_btree_iter_set_pos(iter, insert->k.p, false);
-	bch2_trans_update2(trans, iter, insert);
+	ret = bch2_trans_update2(trans, iter, insert);
 	bch2_trans_iter_put(trans, iter);
-	return 0;
+	return ret;
 }
 
 static int extent_handle_overwrites(struct btree_trans *trans,
@@ -785,8 +788,10 @@ static int extent_handle_overwrites(struct btree_trans *trans,
 			bch2_cut_back(start, update);
 
 			__bch2_btree_iter_set_pos(update_iter, update->k.p, false);
-			bch2_trans_update2(trans, update_iter, update);
+			ret = bch2_trans_update2(trans, update_iter, update);
 			bch2_trans_iter_put(trans, update_iter);
+			if (ret)
+				goto err;
 		}
 
 		if (bkey_cmp(k.k->p, end) > 0) {
@@ -800,8 +805,10 @@ static int extent_handle_overwrites(struct btree_trans *trans,
 			bch2_cut_front(end, update);
 
 			__bch2_btree_iter_set_pos(update_iter, update->k.p, false);
-			bch2_trans_update2(trans, update_iter, update);
+			ret = bch2_trans_update2(trans, update_iter, update);
 			bch2_trans_iter_put(trans, update_iter);
+			if (ret)
+				goto err;
 		} else {
 			update_iter = bch2_trans_copy_iter(trans, iter);
 
@@ -815,8 +822,10 @@ static int extent_handle_overwrites(struct btree_trans *trans,
 			update->k.size = 0;
 
 			__bch2_btree_iter_set_pos(update_iter, update->k.p, false);
-			bch2_trans_update2(trans, update_iter, update);
+			ret = bch2_trans_update2(trans, update_iter, update);
 			bch2_trans_iter_put(trans, update_iter);
+			if (ret)
+				goto err;
 		}
 
 		k = bch2_btree_iter_next_with_updates(iter);
@@ -921,11 +930,11 @@ int __bch2_trans_commit(struct btree_trans *trans)
 	trans_for_each_update(trans, i) {
 		if (i->iter->flags & BTREE_ITER_IS_EXTENTS) {
 			ret = extent_update_to_keys(trans, i->iter, i->k);
-			if (ret)
-				goto out;
 		} else {
-			bch2_trans_update2(trans, i->iter, i->k);
+			ret = bch2_trans_update2(trans, i->iter, i->k);
 		}
+		if (ret)
+			goto out;
 	}
 
 	trans_for_each_update2(trans, i) {
diff --git a/libbcachefs/buckets.c b/libbcachefs/buckets.c
index ef79f5ca..c559070b 100644
--- a/libbcachefs/buckets.c
+++ b/libbcachefs/buckets.c
@@ -1318,9 +1318,6 @@ int bch2_mark_update(struct btree_trans *trans,
 		     unsigned flags)
 {
 	struct bch_fs		*c = trans->c;
-	struct btree		*b = iter_l(iter)->b;
-	struct btree_node_iter	node_iter = iter_l(iter)->iter;
-	struct bkey_packed	*_old;
 	struct bkey_s_c		old;
 	struct bkey		unpacked;
 	int ret = 0;
@@ -1360,23 +1357,24 @@ int bch2_mark_update(struct btree_trans *trans,
 				BTREE_TRIGGER_OVERWRITE|flags);
 		}
 	} else {
+		struct btree_iter *copy;
+
 		BUG_ON(btree_iter_type(iter) == BTREE_ITER_CACHED);
 		bch2_mark_key_locked(c, old, bkey_i_to_s_c(new),
 			0, new->k.size,
 			fs_usage, trans->journal_res.seq,
 			BTREE_TRIGGER_INSERT|flags);
 
-		while ((_old = bch2_btree_node_iter_peek(&node_iter, b))) {
-			unsigned offset = 0;
-			s64 sectors;
+		copy = bch2_trans_copy_iter(trans, iter);
 
-			old = bkey_disassemble(b, _old, &unpacked);
-			sectors = -((s64) old.k->size);
+		for_each_btree_key_continue(copy, 0, old, ret) {
+			unsigned offset = 0;
+			s64 sectors = -((s64) old.k->size);
 
 			flags |= BTREE_TRIGGER_OVERWRITE;
 
 			if (bkey_cmp(new->k.p, bkey_start_pos(old.k)) <= 0)
-				return 0;
+				break;
 
 			switch (bch2_extent_overlap(&new->k, old.k)) {
 			case BCH_EXTENT_OVERLAP_ALL:
@@ -1409,9 +1407,8 @@ int bch2_mark_update(struct btree_trans *trans,
 					trans->journal_res.seq, flags) ?: 1;
 			if (ret <= 0)
 				break;
-
-			bch2_btree_node_iter_advance(&node_iter, b);
 		}
+		bch2_trans_iter_put(trans, copy);
 	}
 
 	return ret;
@@ -1442,27 +1439,20 @@ void bch2_trans_fs_usage_apply(struct btree_trans *trans,
 		pr_err("overlapping with");
 
 		if (btree_iter_type(i->iter) != BTREE_ITER_CACHED) {
-			struct btree		*b = iter_l(i->iter)->b;
-			struct btree_node_iter	node_iter = iter_l(i->iter)->iter;
-			struct bkey_packed	*_k;
-
-			while ((_k = bch2_btree_node_iter_peek(&node_iter, b))) {
-				struct bkey		unpacked;
-				struct bkey_s_c		k;
-
-				pr_info("_k %px format %u", _k, _k->format);
-				k = bkey_disassemble(b, _k, &unpacked);
+			struct btree_iter *copy = bch2_trans_copy_iter(trans, i->iter);
+			struct bkey_s_c k;
+			int ret;
 
-				if (btree_node_is_extents(b)
+			for_each_btree_key_continue(copy, 0, k, ret) {
+				if (btree_node_type_is_extents(i->iter->btree_id)
 				    ? bkey_cmp(i->k->k.p, bkey_start_pos(k.k)) <= 0
 				    : bkey_cmp(i->k->k.p, k.k->p))
 					break;
 
 				bch2_bkey_val_to_text(&PBUF(buf), c, k);
 				pr_err("%s", buf);
-
-				bch2_btree_node_iter_advance(&node_iter, b);
 			}
+			bch2_trans_iter_put(trans, copy);
 		} else {
 			struct bkey_cached *ck = (void *) i->iter->l[0].b;
 
@@ -1984,15 +1974,13 @@ int bch2_trans_mark_update(struct btree_trans *trans,
 					BTREE_TRIGGER_OVERWRITE|flags);
 		}
 	} else {
-		struct btree		*b = iter_l(iter)->b;
-		struct btree_node_iter	node_iter = iter_l(iter)->iter;
-		struct bkey_packed	*_old;
-		struct bkey		unpacked;
+		struct btree_iter *copy;
+		struct bkey _old;
 
 		EBUG_ON(btree_iter_type(iter) == BTREE_ITER_CACHED);
 
-		bkey_init(&unpacked);
-		old = (struct bkey_s_c) { &unpacked, NULL };
+		bkey_init(&_old);
+		old = (struct bkey_s_c) { &_old, NULL };
 
 		ret = bch2_trans_mark_key(trans, old, bkey_i_to_s_c(new),
 					  0, new->k.size,
@@ -2000,18 +1988,16 @@ int bch2_trans_mark_update(struct btree_trans *trans,
 		if (ret)
 			return ret;
 
-		while ((_old = bch2_btree_node_iter_peek(&node_iter, b))) {
-			unsigned flags = BTREE_TRIGGER_OVERWRITE;
-			unsigned offset = 0;
-			s64 sectors;
+		copy = bch2_trans_copy_iter(trans, iter);
 
-			old = bkey_disassemble(b, _old, &unpacked);
-			sectors = -((s64) old.k->size);
+		for_each_btree_key_continue(copy, 0, old, ret) {
+			unsigned offset = 0;
+			s64 sectors = -((s64) old.k->size);
 
 			flags |= BTREE_TRIGGER_OVERWRITE;
 
 			if (bkey_cmp(new->k.p, bkey_start_pos(old.k)) <= 0)
-				return 0;
+				break;
 
 			switch (bch2_extent_overlap(&new->k, old.k)) {
 			case BCH_EXTENT_OVERLAP_ALL:
@@ -2042,10 +2028,9 @@ int bch2_trans_mark_update(struct btree_trans *trans,
 			ret = bch2_trans_mark_key(trans, old, bkey_i_to_s_c(new),
 					offset, sectors, flags);
 			if (ret)
-				return ret;
-
-			bch2_btree_node_iter_advance(&node_iter, b);
+				break;
 		}
+		bch2_trans_iter_put(trans, copy);
 	}
 
 	return ret;
diff --git a/libbcachefs/extent_update.c b/libbcachefs/extent_update.c
index 5c43678e..16d2bca8 100644
--- a/libbcachefs/extent_update.c
+++ b/libbcachefs/extent_update.c
@@ -99,24 +99,12 @@ int bch2_extent_atomic_end(struct btree_iter *iter,
 			   struct bpos *end)
 {
 	struct btree_trans *trans = iter->trans;
-	struct btree *b;
-	struct btree_node_iter	node_iter;
-	struct bkey_packed	*_k;
-	unsigned		nr_iters = 0;
+	struct btree_iter *copy;
+	struct bkey_s_c k;
+	unsigned nr_iters = 0;
 	int ret;
 
-	ret = bch2_btree_iter_traverse(iter);
-	if (ret)
-		return ret;
-
-	b = iter->l[0].b;
-	node_iter = iter->l[0].iter;
-
-	BUG_ON(bkey_cmp(b->data->min_key, POS_MIN) &&
-	       bkey_cmp(bkey_start_pos(&insert->k),
-			bkey_predecessor(b->data->min_key)) < 0);
-
-	*end = bpos_min(insert->k.p, b->key.k.p);
+	*end = insert->k.p;
 
 	/* extent_update_to_keys(): */
 	nr_iters += 1;
@@ -126,9 +114,9 @@ int bch2_extent_atomic_end(struct btree_iter *iter,
 	if (ret < 0)
 		return ret;
 
-	while ((_k = bch2_btree_node_iter_peek(&node_iter, b))) {
-		struct bkey	unpacked;
-		struct bkey_s_c	k = bkey_disassemble(b, _k, &unpacked);
+	copy = bch2_trans_copy_iter(trans, iter);
+
+	for_each_btree_key_continue(copy, 0, k, ret) {
 		unsigned offset = 0;
 
 		if (bkey_cmp(bkey_start_pos(k.k), *end) >= 0)
@@ -155,10 +143,9 @@ int bch2_extent_atomic_end(struct btree_iter *iter,
 					&nr_iters, EXTENT_ITERS_MAX);
 		if (ret)
 			break;
-
-		bch2_btree_node_iter_advance(&node_iter, b);
 	}
 
+	bch2_trans_iter_put(trans, copy);
 	return ret < 0 ? ret : 0;
 }
 
diff --git a/libbcachefs/extents.c b/libbcachefs/extents.c
index ad3e88dd..d1ff0831 100644
--- a/libbcachefs/extents.c
+++ b/libbcachefs/extents.c
@@ -972,9 +972,9 @@ bool bch2_extent_normalize(struct bch_fs *c, struct bkey_s k)
 
 	/* will only happen if all pointers were cached: */
 	if (!bch2_bkey_nr_ptrs(k.s_c))
-		k.k->type = KEY_TYPE_discard;
+		k.k->type = KEY_TYPE_deleted;
 
-	return bkey_whiteout(k.k);
+	return bkey_deleted(k.k);
 }
 
 void bch2_bkey_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
diff --git a/libbcachefs/recovery.c b/libbcachefs/recovery.c
index 8560023b..f86b0418 100644
--- a/libbcachefs/recovery.c
+++ b/libbcachefs/recovery.c
@@ -506,115 +506,6 @@ static void replay_now_at(struct journal *j, u64 seq)
 		bch2_journal_pin_put(j, j->replay_journal_seq++);
 }
 
-static int bch2_extent_replay_key(struct bch_fs *c, enum btree_id btree_id,
-				  struct bkey_i *k)
-{
-	struct btree_trans trans;
-	struct btree_iter *iter, *split_iter;
-	/*
-	 * We might cause compressed extents to be split, so we need to pass in
-	 * a disk_reservation:
-	 */
-	struct disk_reservation disk_res =
-		bch2_disk_reservation_init(c, 0);
-	struct bkey_i *split;
-	struct bpos atomic_end;
-	/*
-	 * Some extents aren't equivalent - w.r.t. what the triggers do
-	 * - if they're split:
-	 */
-	bool remark_if_split = bch2_bkey_sectors_compressed(bkey_i_to_s_c(k)) ||
-		k->k.type == KEY_TYPE_reflink_p;
-	bool remark = false;
-	int ret;
-
-	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
-retry:
-	bch2_trans_begin(&trans);
-
-	iter = bch2_trans_get_iter(&trans, btree_id,
-				   bkey_start_pos(&k->k),
-				   BTREE_ITER_INTENT);
-
-	do {
-		ret = bch2_btree_iter_traverse(iter);
-		if (ret)
-			goto err;
-
-		atomic_end = bpos_min(k->k.p, iter->l[0].b->key.k.p);
-
-		split = bch2_trans_kmalloc(&trans, bkey_bytes(&k->k));
-		ret = PTR_ERR_OR_ZERO(split);
-		if (ret)
-			goto err;
-
-		if (!remark &&
-		    remark_if_split &&
-		    bkey_cmp(atomic_end, k->k.p) < 0) {
-			ret = bch2_disk_reservation_add(c, &disk_res,
-					k->k.size *
-					bch2_bkey_nr_ptrs_allocated(bkey_i_to_s_c(k)),
-					BCH_DISK_RESERVATION_NOFAIL);
-			BUG_ON(ret);
-
-			remark = true;
-		}
-
-		bkey_copy(split, k);
-		bch2_cut_front(iter->pos, split);
-		bch2_cut_back(atomic_end, split);
-
-		split_iter = bch2_trans_copy_iter(&trans, iter);
-
-		/*
-		 * It's important that we don't go through the
-		 * extent_handle_overwrites() and extent_update_to_keys() path
-		 * here: journal replay is supposed to treat extents like
-		 * regular keys
-		 */
-		__bch2_btree_iter_set_pos(split_iter, split->k.p, false);
-		bch2_trans_update(&trans, split_iter, split,
-				  BTREE_TRIGGER_NORUN);
-		bch2_trans_iter_put(&trans, split_iter);
-
-		bch2_btree_iter_set_pos(iter, split->k.p);
-
-		if (remark) {
-			ret = bch2_trans_mark_key(&trans,
-						  bkey_s_c_null,
-						  bkey_i_to_s_c(split),
-						  0, split->k.size,
-						  BTREE_TRIGGER_INSERT);
-			if (ret)
-				goto err;
-		}
-	} while (bkey_cmp(iter->pos, k->k.p) < 0);
-
-	if (remark) {
-		ret = bch2_trans_mark_key(&trans,
-					  bkey_i_to_s_c(k),
-					  bkey_s_c_null,
-					  0, -((s64) k->k.size),
-					  BTREE_TRIGGER_OVERWRITE);
-		if (ret)
-			goto err;
-	}
-
-	ret = bch2_trans_commit(&trans, &disk_res, NULL,
-				BTREE_INSERT_NOFAIL|
-				BTREE_INSERT_LAZY_RW|
-				BTREE_INSERT_JOURNAL_REPLAY);
-err:
-	bch2_trans_iter_put(&trans, iter);
-
-	if (ret == -EINTR)
-		goto retry;
-
-	bch2_disk_reservation_put(c, &disk_res);
-
-	return bch2_trans_exit(&trans) ?: ret;
-}
-
 static int __bch2_journal_replay_key(struct btree_trans *trans,
 				     enum btree_id id, unsigned level,
 				     struct bkey_i *k)
@@ -753,9 +644,7 @@ static int bch2_journal_replay(struct bch_fs *c,
 
 		replay_now_at(j, keys.journal_seq_base + i->journal_seq);
 
-		ret = i->k->k.size
-			? bch2_extent_replay_key(c, i->btree_id, i->k)
-			: bch2_journal_replay_key(c, i);
+		ret = bch2_journal_replay_key(c, i);
 		if (ret)
 			goto err;
 	}
@@ -1088,6 +977,12 @@ int bch2_fs_recovery(struct bch_fs *c)
 		bch_info(c, "recovering from clean shutdown, journal seq %llu",
 			 le64_to_cpu(clean->journal_seq));
 
+	if (!(c->sb.features & (1ULL << BCH_FEATURE_new_extent_overwrite))) {
+		bch_err(c, "feature new_extent_overwrite not set, filesystem no longer supported");
+		ret = -EINVAL;
+		goto err;
+	}
+
 	if (!(c->sb.features & (1ULL << BCH_FEATURE_alloc_v2))) {
 		bch_info(c, "alloc_v2 feature bit not set, fsck required");
 		c->opts.fsck = true;
diff --git a/libbcachefs/super-io.c b/libbcachefs/super-io.c
index 47a0e206..09598ec9 100644
--- a/libbcachefs/super-io.c
+++ b/libbcachefs/super-io.c
@@ -953,9 +953,7 @@ int bch2_fs_mark_dirty(struct bch_fs *c)
 
 	mutex_lock(&c->sb_lock);
 	SET_BCH_SB_CLEAN(c->disk_sb.sb, false);
-	c->disk_sb.sb->features[0] |= 1ULL << BCH_FEATURE_new_extent_overwrite;
-	c->disk_sb.sb->features[0] |= 1ULL << BCH_FEATURE_extents_above_btree_updates;
-	c->disk_sb.sb->features[0] |= 1ULL << BCH_FEATURE_btree_updates_journalled;
+	c->disk_sb.sb->features[0] |= BCH_SB_FEATURES_ALWAYS;
 	ret = bch2_write_super(c);
 	mutex_unlock(&c->sb_lock);