diff --git a/.bcachefs_revision b/.bcachefs_revision
index b5f30cd3..610413ad 100644
--- a/.bcachefs_revision
+++ b/.bcachefs_revision
@@ -1 +1 @@
-43a464c9dd38b50c1a89845366f838fe70fbb743
+c8aa081de3a61efdabaf70cbfb1e92c6c1d92e76
diff --git a/libbcachefs/btree_iter.c b/libbcachefs/btree_iter.c
index 263cd18f..ac23a251 100644
--- a/libbcachefs/btree_iter.c
+++ b/libbcachefs/btree_iter.c
@@ -1635,16 +1635,6 @@ static void bch2_btree_iter_link(struct btree_iter *iter, struct btree_iter *new
 
 	new->next = iter->next;
 	iter->next = new;
-
-	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
-		unsigned nr_iters = 0;
-
-		for_each_btree_iter(new, iter)
-			if (iter->btree_id == new->btree_id)
-				nr_iters++;
-
-		BUG_ON(nr_iters > SIX_LOCK_MAX_RECURSE);
-	}
 }
 
 void bch2_btree_iter_copy(struct btree_iter *dst, struct btree_iter *src)
@@ -1681,7 +1671,7 @@ static inline unsigned btree_trans_iter_idx(struct btree_trans *trans,
 	ssize_t idx = iter - trans->iters;
 
 	BUG_ON(idx < 0 || idx >= trans->nr_iters);
-	BUG_ON(!(trans->iters_live & (1U << idx)));
+	BUG_ON(!(trans->iters_live & (1ULL << idx)));
 
 	return idx;
 }
@@ -1691,7 +1681,7 @@ void bch2_trans_iter_put(struct btree_trans *trans,
 {
 	ssize_t idx = btree_trans_iter_idx(trans, iter);
 
-	trans->iters_live	&= ~(1U << idx);
+	trans->iters_live	&= ~(1ULL << idx);
 }
 
 void bch2_trans_iter_free(struct btree_trans *trans,
@@ -1699,23 +1689,50 @@ void bch2_trans_iter_free(struct btree_trans *trans,
 {
 	ssize_t idx = btree_trans_iter_idx(trans, iter);
 
-	trans->iters_live	&= ~(1U << idx);
-	trans->iters_linked	&= ~(1U << idx);
+	trans->iters_live	&= ~(1ULL << idx);
+	trans->iters_linked	&= ~(1ULL << idx);
 	bch2_btree_iter_unlink(iter);
 }
 
-static int btree_trans_realloc_iters(struct btree_trans *trans)
+static int btree_trans_realloc_iters(struct btree_trans *trans,
+				     unsigned new_size)
 {
-	struct btree_iter *new_iters;
+	void *new_iters, *new_updates;
 	unsigned i;
 
+	BUG_ON(new_size > BTREE_ITER_MAX);
+
+	if (new_size <= trans->size)
+		return 0;
+
+	BUG_ON(trans->used_mempool);
+
 	bch2_trans_unlock(trans);
 
+	new_iters = kmalloc(sizeof(struct btree_iter) * new_size +
+			    sizeof(struct btree_insert_entry) * (new_size + 4),
+			    GFP_NOFS);
+	if (new_iters)
+		goto success;
+
 	new_iters = mempool_alloc(&trans->c->btree_iters_pool, GFP_NOFS);
+	new_size = BTREE_ITER_MAX;
+
+	trans->used_mempool = true;
+success:
+	new_updates = new_iters + sizeof(struct btree_iter) * new_size;
 
 	memcpy(new_iters, trans->iters,
 	       sizeof(struct btree_iter) * trans->nr_iters);
-	trans->iters = new_iters;
+	memcpy(new_updates, trans->updates,
+	       sizeof(struct btree_insert_entry) * trans->nr_updates);
+
+	if (trans->iters != trans->iters_onstack)
+		kfree(trans->iters);
+
+	trans->iters	= new_iters;
+	trans->updates	= new_updates;
+	trans->size	= new_size;
 
 	for (i = 0; i < trans->nr_iters; i++)
 		trans->iters[i].next = &trans->iters[i];
@@ -1741,8 +1758,7 @@ static int btree_trans_realloc_iters(struct btree_trans *trans)
 
 void bch2_trans_preload_iters(struct btree_trans *trans)
 {
-	if (trans->iters == trans->iters_onstack)
-		btree_trans_realloc_iters(trans);
+	btree_trans_realloc_iters(trans, 16);
 }
 
 static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
@@ -1755,7 +1771,7 @@ static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
 	BUG_ON(trans->nr_iters > BTREE_ITER_MAX);
 
 	for (idx = 0; idx < trans->nr_iters; idx++)
-		if (trans->iter_ids[idx] == iter_id)
+		if (trans->iters[idx].id == iter_id)
 			goto found;
 	idx = -1;
 found:
@@ -1764,19 +1780,20 @@ found:
 		if (idx < trans->nr_iters)
 			goto got_slot;
 
-		BUG_ON(trans->nr_iters == BTREE_ITER_MAX);
+		BUG_ON(trans->nr_iters > trans->size);
 
-		if (trans->iters == trans->iters_onstack &&
-		    trans->nr_iters == ARRAY_SIZE(trans->iters_onstack)) {
-			int ret = btree_trans_realloc_iters(trans);
+		if (trans->nr_iters == trans->size) {
+			int ret = btree_trans_realloc_iters(trans,
+							trans->size * 2);
 			if (ret)
 				return ERR_PTR(ret);
 		}
 
 		idx = trans->nr_iters++;
+		BUG_ON(trans->nr_iters > trans->size);
 got_slot:
-		trans->iter_ids[idx] = iter_id;
 		iter = &trans->iters[idx];
+		iter->id = iter_id;
 
 		bch2_btree_iter_init(iter, trans->c, btree_id, POS_MIN, flags);
 	} else {
@@ -1786,15 +1803,15 @@ got_slot:
 		iter->flags |= flags & (BTREE_ITER_INTENT|BTREE_ITER_PREFETCH);
 	}
 
-	BUG_ON(trans->iters_live & (1 << idx));
-	trans->iters_live |= 1 << idx;
+	BUG_ON(trans->iters_live & (1ULL << idx));
+	trans->iters_live |= 1ULL << idx;
 
 	if (trans->iters_linked &&
 	    !(trans->iters_linked & (1 << idx)))
 		bch2_btree_iter_link(&trans->iters[__ffs(trans->iters_linked)],
 				     iter);
 
-	trans->iters_linked |= 1 << idx;
+	trans->iters_linked |= 1ULL << idx;
 
 	btree_trans_verify(trans);
 
@@ -1878,6 +1895,7 @@ int bch2_trans_unlock(struct btree_trans *trans)
 
 void __bch2_trans_begin(struct btree_trans *trans)
 {
+	u64 linked_not_live;
 	unsigned idx;
 
 	btree_trans_verify(trans);
@@ -1890,10 +1908,15 @@ void __bch2_trans_begin(struct btree_trans *trans)
 	 * further (allocated an iter with a higher idx) than where the iter
 	 * was originally allocated:
 	 */
-	while (trans->iters_linked &&
-	       trans->iters_live &&
-	       (idx = __fls(trans->iters_linked)) >
-	       __fls(trans->iters_live)) {
+	while (1) {
+		linked_not_live = trans->iters_linked & ~trans->iters_live;
+		if (!linked_not_live)
+			break;
+
+		idx = __ffs64(linked_not_live);
+		if (1ULL << idx > trans->iters_live)
+			break;
+
 		trans->iters_linked ^= 1 << idx;
 		bch2_btree_iter_unlink(&trans->iters[idx]);
 	}
@@ -1907,16 +1930,12 @@ void __bch2_trans_begin(struct btree_trans *trans)
 
 void bch2_trans_init(struct btree_trans *trans, struct bch_fs *c)
 {
+	memset(trans, 0, offsetof(struct btree_trans, iters_onstack));
+
 	trans->c		= c;
-	trans->nr_restarts	= 0;
-	trans->nr_iters		= 0;
-	trans->iters_live	= 0;
-	trans->iters_linked	= 0;
-	trans->nr_updates	= 0;
-	trans->mem_top		= 0;
-	trans->mem_bytes	= 0;
-	trans->mem		= NULL;
+	trans->size		= ARRAY_SIZE(trans->iters_onstack);
 	trans->iters		= trans->iters_onstack;
+	trans->updates		= trans->updates_onstack;
 }
 
 int bch2_trans_exit(struct btree_trans *trans)
@@ -1924,8 +1943,10 @@ int bch2_trans_exit(struct btree_trans *trans)
 	int ret = bch2_trans_unlock(trans);
 
 	kfree(trans->mem);
-	if (trans->iters != trans->iters_onstack)
+	if (trans->used_mempool)
 		mempool_free(trans->iters, &trans->c->btree_iters_pool);
+	else if (trans->iters != trans->iters_onstack)
+		kfree(trans->iters);
 	trans->mem	= (void *) 0x1;
 	trans->iters	= (void *) 0x1;
 	return ret;
diff --git a/libbcachefs/btree_types.h b/libbcachefs/btree_types.h
index 15a4d382..a6aea023 100644
--- a/libbcachefs/btree_types.h
+++ b/libbcachefs/btree_types.h
@@ -231,19 +231,18 @@ struct btree_iter {
 	 */
 	struct bkey		k;
 
+	u64			id;
+
 	/*
 	 * Circular linked list of linked iterators: linked iterators share
 	 * locks (e.g. two linked iterators may have the same node intent
 	 * locked, or read and write locked, at the same time), and insertions
 	 * through one iterator won't invalidate the other linked iterators.
 	 */
-
 	/* Must come last: */
 	struct btree_iter	*next;
 };
 
-#define BTREE_ITER_MAX		8
-
 struct deferred_update {
 	struct journal_preres	res;
 	struct journal_entry_pin journal;
@@ -269,25 +268,29 @@ struct btree_insert_entry {
 	bool			deferred;
 };
 
+#define BTREE_ITER_MAX		64
+
 struct btree_trans {
 	struct bch_fs		*c;
 	size_t			nr_restarts;
 
+	u64			iters_live;
+	u64			iters_linked;
+
 	u8			nr_iters;
-	u8			iters_live;
-	u8			iters_linked;
 	u8			nr_updates;
+	u8			size;
+	unsigned		used_mempool:1;
 
 	unsigned		mem_top;
 	unsigned		mem_bytes;
 	void			*mem;
 
 	struct btree_iter	*iters;
-	u64			iter_ids[BTREE_ITER_MAX];
-
-	struct btree_insert_entry updates[BTREE_ITER_MAX];
+	struct btree_insert_entry *updates;
 
 	struct btree_iter	iters_onstack[2];
+	struct btree_insert_entry updates_onstack[6];
 };
 
 #define BTREE_FLAG(flag)						\
diff --git a/libbcachefs/btree_update.h b/libbcachefs/btree_update.h
index 7545f4f1..1f371b5a 100644
--- a/libbcachefs/btree_update.h
+++ b/libbcachefs/btree_update.h
@@ -147,7 +147,7 @@ static inline void
 bch2_trans_update(struct btree_trans *trans,
 		  struct btree_insert_entry entry)
 {
-	BUG_ON(trans->nr_updates >= ARRAY_SIZE(trans->updates));
+	BUG_ON(trans->nr_updates >= trans->nr_iters + 4);
 
 	trans->updates[trans->nr_updates++] = entry;
 }
diff --git a/libbcachefs/fs-io.c b/libbcachefs/fs-io.c
index ce46d0ef..cabd3e08 100644
--- a/libbcachefs/fs-io.c
+++ b/libbcachefs/fs-io.c
@@ -232,12 +232,14 @@ static void i_sectors_acct(struct bch_fs *c, struct bch_inode_info *inode,
 static int sum_sector_overwrites(struct btree_trans *trans,
 				 struct btree_iter *extent_iter,
 				 struct bkey_i *new, bool *allocating,
-				 s64 *i_sectors_delta)
+				 s64 *delta)
 {
-	struct btree_iter *iter = bch2_trans_copy_iter(trans, extent_iter);
+	struct btree_iter *iter;
 	struct bkey_s_c old;
-	s64 delta = 0;
 
+	*delta = 0;
+
+	iter = bch2_trans_copy_iter(trans, extent_iter);
 	if (IS_ERR(iter))
 		return PTR_ERR(iter);
 
@@ -257,7 +259,7 @@ static int sum_sector_overwrites(struct btree_trans *trans,
 		    bch2_bkey_nr_dirty_ptrs(bkey_i_to_s_c(new)))
 			*allocating = true;
 
-		delta += (min(new->k.p.offset,
+		*delta += (min(new->k.p.offset,
 			      old.k->p.offset) -
 			  max(bkey_start_offset(&new->k),
 			      bkey_start_offset(old.k))) *
@@ -271,8 +273,6 @@ static int sum_sector_overwrites(struct btree_trans *trans,
 	}
 
 	bch2_trans_iter_free(trans, iter);
-
-	*i_sectors_delta = delta;
 	return 0;
 }
 
diff --git a/libbcachefs/journal.c b/libbcachefs/journal.c
index e2386bb7..a58a1fb6 100644
--- a/libbcachefs/journal.c
+++ b/libbcachefs/journal.c
@@ -248,13 +248,13 @@ static int journal_entry_open(struct journal *j)
 	do {
 		old.v = new.v = v;
 
-		EBUG_ON(journal_state_count(new, new.idx));
-
 		if (old.cur_entry_offset == JOURNAL_ENTRY_ERROR_VAL)
 			return -EROFS;
 
 		/* Handle any already added entries */
 		new.cur_entry_offset = le32_to_cpu(buf->data->u64s);
+
+		EBUG_ON(journal_state_count(new, new.idx));
 		journal_state_inc(&new);
 	} while ((v = atomic64_cmpxchg(&j->reservations.counter,
 				       old.v, new.v)) != old.v);
diff --git a/libbcachefs/journal_reclaim.c b/libbcachefs/journal_reclaim.c
index eb989462..5cee6872 100644
--- a/libbcachefs/journal_reclaim.c
+++ b/libbcachefs/journal_reclaim.c
@@ -501,8 +501,8 @@ void bch2_journal_reclaim(struct journal *j)
 		nr_buckets = min(nr_buckets, ja->nr);
 
 		bucket_to_flush = (ja->cur_idx + nr_buckets) % ja->nr;
-		seq_to_flush = max_t(u64, seq_to_flush,
-				     ja->bucket_seq[bucket_to_flush]);
+		seq_to_flush = max(seq_to_flush,
+				   ja->bucket_seq[bucket_to_flush]);
 	}
 
 	/* Also flush if the pin fifo is more than half full */
@@ -519,12 +519,14 @@ void bch2_journal_reclaim(struct journal *j)
 		       msecs_to_jiffies(j->reclaim_delay_ms)))
 		min_nr = 1;
 
-	if (j->prereserved.reserved * 2 > j->prereserved.remaining)
+	if (j->prereserved.reserved * 2 > j->prereserved.remaining) {
+		seq_to_flush = max(seq_to_flush, journal_last_seq(j));
 		min_nr = 1;
+	}
 
 	journal_flush_pins(j, seq_to_flush, min_nr);
 
-	if (!test_bit(BCH_FS_RO, &c->flags))
+	if (!bch2_journal_error(j))
 		queue_delayed_work(c->journal_reclaim_wq, &j->reclaim_work,
 				   msecs_to_jiffies(j->reclaim_delay_ms));
 }
diff --git a/libbcachefs/super-io.c b/libbcachefs/super-io.c
index 71d97c57..ca361424 100644
--- a/libbcachefs/super-io.c
+++ b/libbcachefs/super-io.c
@@ -1019,7 +1019,10 @@ void bch2_fs_mark_clean(struct bch_fs *c, bool clean)
 	sb_clean->flags		= 0;
 	sb_clean->read_clock	= cpu_to_le16(c->bucket_clock[READ].hand);
 	sb_clean->write_clock	= cpu_to_le16(c->bucket_clock[WRITE].hand);
-	sb_clean->journal_seq	= journal_cur_seq(&c->journal) - 1;
+	sb_clean->journal_seq	= cpu_to_le64(journal_cur_seq(&c->journal) - 1);
+
+	/* Trying to catch outstanding bug: */
+	BUG_ON(le64_to_cpu(sb_clean->journal_seq) > S64_MAX);
 
 	entry = sb_clean->start;
 	entry = bch2_journal_super_entries_add_common(c, entry);
diff --git a/libbcachefs/super.c b/libbcachefs/super.c
index 1528f77e..4ec8a0b5 100644
--- a/libbcachefs/super.c
+++ b/libbcachefs/super.c
@@ -681,7 +681,9 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 	    mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
 					btree_bytes(c)) ||
 	    mempool_init_kmalloc_pool(&c->btree_iters_pool, 1,
-			sizeof(struct btree_iter) * BTREE_ITER_MAX) ||
+			sizeof(struct btree_iter) * BTREE_ITER_MAX +
+			sizeof(struct btree_insert_entry) *
+			(BTREE_ITER_MAX + 4)) ||
 	    bch2_io_clock_init(&c->io_clock[READ]) ||
 	    bch2_io_clock_init(&c->io_clock[WRITE]) ||
 	    bch2_fs_journal_init(&c->journal) ||