X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Fbtree_update_leaf.c;h=0195b13de1523ade6f91b528ad77a0b88ca013c8;hb=1b2d60826974e31b9894b6d5aa59b0e7e62823cd;hp=b166ab4b4a3b53fdfbc99b3a5a34ad940e73a5e2;hpb=e66011cd2c8aa1c1e78085704a9a2514c6b7ccd1;p=bcachefs-tools-debian

diff --git a/libbcachefs/btree_update_leaf.c b/libbcachefs/btree_update_leaf.c
index b166ab4..0195b13 100644
--- a/libbcachefs/btree_update_leaf.c
+++ b/libbcachefs/btree_update_leaf.c
@@ -8,6 +8,7 @@
 #include "btree_iter.h"
 #include "btree_key_cache.h"
 #include "btree_locking.h"
+#include "btree_write_buffer.h"
 #include "buckets.h"
 #include "debug.h"
 #include "errcode.h"
@@ -24,6 +25,44 @@
 #include <linux/sort.h>
 #include <trace/events/bcachefs.h>
 
+/*
+ * bch2_btree_path_peek_slot() for a cached iterator might return a key in a
+ * different snapshot:
+ */
+struct bkey_s_c bch2_btree_path_peek_slot_exact(struct btree_path *path, struct bkey *u)
+{
+	struct bkey_s_c k = bch2_btree_path_peek_slot(path, u);
+
+	if (k.k && bpos_eq(path->pos, k.k->p))
+		return k;
+
+	bkey_init(u);
+	u->p = path->pos;
+	return (struct bkey_s_c) { u, NULL };
+}
+
+static void verify_update_old_key(struct btree_trans *trans, struct btree_insert_entry *i)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+	struct bch_fs *c = trans->c;
+	struct bkey u;
+	struct bkey_s_c k = bch2_btree_path_peek_slot_exact(i->path, &u);
+
+	if (unlikely(trans->journal_replay_not_finished)) {
+		struct bkey_i *j_k =
+			bch2_journal_keys_peek_slot(c, i->btree_id, i->level, i->k->k.p);
+
+		if (j_k)
+			k = bkey_i_to_s_c(j_k);
+	}
+
+	i->old_k.needs_whiteout = k.k->needs_whiteout;
+
+	BUG_ON(memcmp(&i->old_k, k.k, sizeof(struct bkey)));
+	BUG_ON(i->old_v != k.v);
+#endif
+}
+
 static int __must_check
 bch2_trans_update_by_path(struct btree_trans *, struct btree_path *,
 			  struct bkey_i *, enum btree_update_flags);
@@ -62,9 +101,6 @@ inline void bch2_btree_node_prep_for_write(struct btree_trans *trans,
 {
 	struct bch_fs *c = trans->c;
 
-	if (path->cached)
-		return;
-
 	if (unlikely(btree_node_just_written(b)) &&
 	    bch2_btree_post_write_cleanup(c, b))
 		bch2_trans_node_reinit_iter(trans, b);
@@ -92,8 +128,8 @@ bool bch2_btree_bset_insert_key(struct btree_trans *trans,
 	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(bpos_cmp(insert->k.p, b->data->min_key) < 0);
-	EBUG_ON(bpos_cmp(insert->k.p, b->data->max_key) > 0);
+	EBUG_ON(bpos_lt(insert->k.p, b->data->min_key));
+	EBUG_ON(bpos_gt(insert->k.p, b->data->max_key));
 	EBUG_ON(insert->k.u64s >
 		bch_btree_keys_u64s_remaining(trans->c, b));
 
@@ -178,6 +214,8 @@ static int __btree_node_flush(struct journal *j, struct journal_entry_pin *pin,
 		    w->journal.seq != seq)
 			break;
 
+		new &= ~BTREE_WRITE_TYPE_MASK;
+		new |= BTREE_WRITE_journal_reclaim;
 		new |= 1 << BTREE_NODE_need_write;
 	} while ((v = cmpxchg(&b->flags, old, new)) != old);
 
@@ -212,25 +250,26 @@ inline void bch2_btree_add_journal_pin(struct bch_fs *c,
 /**
  * btree_insert_key - insert a key one key into a leaf node
  */
-static void btree_insert_key_leaf(struct btree_trans *trans,
-				  struct btree_insert_entry *insert)
+inline void bch2_btree_insert_key_leaf(struct btree_trans *trans,
+				       struct btree_path *path,
+				       struct bkey_i *insert,
+				       u64 journal_seq)
 {
 	struct bch_fs *c = trans->c;
-	struct btree *b = insert_l(insert)->b;
+	struct btree *b = path_l(path)->b;
 	struct bset_tree *t = bset_tree_last(b);
 	struct bset *i = bset(b, t);
 	int old_u64s = bset_u64s(t);
 	int old_live_u64s = b->nr.live_u64s;
 	int live_u64s_added, u64s_added;
 
-	if (unlikely(!bch2_btree_bset_insert_key(trans, insert->path, b,
-					&insert_l(insert)->iter, insert->k)))
+	if (unlikely(!bch2_btree_bset_insert_key(trans, path, b,
+					&path_l(path)->iter, insert)))
 		return;
 
-	i->journal_seq = cpu_to_le64(max(trans->journal_res.seq,
-					 le64_to_cpu(i->journal_seq)));
+	i->journal_seq = cpu_to_le64(max(journal_seq, le64_to_cpu(i->journal_seq)));
 
-	bch2_btree_add_journal_pin(c, b, trans->journal_res.seq);
+	bch2_btree_add_journal_pin(c, b, journal_seq);
 
 	if (unlikely(!btree_node_dirty(b)))
 		set_btree_node_dirty_acct(c, b);
@@ -248,6 +287,12 @@ static void btree_insert_key_leaf(struct btree_trans *trans,
 		bch2_trans_node_reinit_iter(trans, b);
 }
 
+static void btree_insert_key_leaf(struct btree_trans *trans,
+				  struct btree_insert_entry *insert)
+{
+	bch2_btree_insert_key_leaf(trans, insert->path, insert->k, trans->journal_res.seq);
+}
+
 /* Cached btree updates: */
 
 /* Normal update interface: */
@@ -255,7 +300,7 @@ static void btree_insert_key_leaf(struct btree_trans *trans,
 static inline void btree_insert_entry_checks(struct btree_trans *trans,
 					     struct btree_insert_entry *i)
 {
-	BUG_ON(bpos_cmp(i->k->k.p, i->path->pos));
+	BUG_ON(!bpos_eq(i->k->k.p, i->path->pos));
 	BUG_ON(i->cached	!= i->path->cached);
 	BUG_ON(i->level		!= i->path->level);
 	BUG_ON(i->btree_id	!= i->path->btree_id);
@@ -267,7 +312,7 @@ static inline void btree_insert_entry_checks(struct btree_trans *trans,
 }
 
 static noinline int
-bch2_trans_journal_preres_get_cold(struct btree_trans *trans, unsigned u64s,
+bch2_trans_journal_preres_get_cold(struct btree_trans *trans, unsigned flags,
 				   unsigned long trace_ip)
 {
 	struct bch_fs *c = trans->c;
@@ -276,7 +321,9 @@ bch2_trans_journal_preres_get_cold(struct btree_trans *trans, unsigned u64s,
 	bch2_trans_unlock(trans);
 
 	ret = bch2_journal_preres_get(&c->journal,
-			&trans->journal_preres, u64s, 0);
+			&trans->journal_preres,
+			trans->journal_preres_u64s,
+			(flags & JOURNAL_WATERMARK_MASK));
 	if (ret)
 		return ret;
 
@@ -289,23 +336,16 @@ bch2_trans_journal_preres_get_cold(struct btree_trans *trans, unsigned u64s,
 	return 0;
 }
 
-static inline int bch2_trans_journal_res_get(struct btree_trans *trans,
-					     unsigned flags)
+static __always_inline int bch2_trans_journal_res_get(struct btree_trans *trans,
+						      unsigned flags)
 {
-	struct bch_fs *c = trans->c;
-	int ret;
-
-	ret = bch2_journal_res_get(&c->journal, &trans->journal_res,
-				   trans->journal_u64s,
-				   flags|
-				   (trans->flags & JOURNAL_WATERMARK_MASK));
-
-	return ret == -EAGAIN ? BTREE_INSERT_NEED_JOURNAL_RES : ret;
+	return bch2_journal_res_get(&trans->c->journal, &trans->journal_res,
+				    trans->journal_u64s, flags);
 }
 
 #define JSET_ENTRY_LOG_U64s		4
 
-static void journal_transaction_name(struct btree_trans *trans)
+static noinline void journal_transaction_name(struct btree_trans *trans)
 {
 	struct bch_fs *c = trans->c;
 	struct journal *j = &c->journal;
@@ -319,35 +359,32 @@ static void journal_transaction_name(struct btree_trans *trans)
 	strncpy(l->d, trans->fn, JSET_ENTRY_LOG_U64s * sizeof(u64));
 }
 
-static inline enum btree_insert_ret
-btree_key_can_insert(struct btree_trans *trans,
-		     struct btree *b,
-		     unsigned u64s)
+static inline int btree_key_can_insert(struct btree_trans *trans,
+				       struct btree *b, unsigned u64s)
 {
 	struct bch_fs *c = trans->c;
 
 	if (!bch2_btree_node_insert_fits(c, b, u64s))
-		return BTREE_INSERT_BTREE_NODE_FULL;
+		return -BCH_ERR_btree_insert_btree_node_full;
 
-	return BTREE_INSERT_OK;
+	return 0;
 }
 
-static enum btree_insert_ret
-btree_key_can_insert_cached(struct btree_trans *trans,
-			    struct btree_path *path,
-			    unsigned u64s)
+static int btree_key_can_insert_cached(struct btree_trans *trans, unsigned flags,
+				       struct btree_path *path, unsigned u64s)
 {
 	struct bch_fs *c = trans->c;
 	struct bkey_cached *ck = (void *) path->l[0].b;
-	unsigned old_u64s = ck->u64s, new_u64s;
+	struct btree_insert_entry *i;
+	unsigned new_u64s;
 	struct bkey_i *new_k;
 
 	EBUG_ON(path->level);
 
 	if (!test_bit(BKEY_CACHED_DIRTY, &ck->flags) &&
 	    bch2_btree_key_cache_must_wait(c) &&
-	    !(trans->flags & BTREE_INSERT_JOURNAL_RECLAIM))
-		return BTREE_INSERT_NEED_JOURNAL_RECLAIM;
+	    !(flags & BTREE_INSERT_JOURNAL_RECLAIM))
+		return -BCH_ERR_btree_insert_need_journal_reclaim;
 
 	/*
 	 * bch2_varint_decode can read past the end of the buffer by at most 7
@@ -356,7 +393,7 @@ btree_key_can_insert_cached(struct btree_trans *trans,
 	u64s += 1;
 
 	if (u64s <= ck->u64s)
-		return BTREE_INSERT_OK;
+		return 0;
 
 	new_u64s	= roundup_pow_of_two(u64s);
 	new_k		= krealloc(ck->k, new_u64s * sizeof(u64), GFP_NOFS);
@@ -366,14 +403,13 @@ btree_key_can_insert_cached(struct btree_trans *trans,
 		return -ENOMEM;
 	}
 
+	trans_for_each_update(trans, i)
+		if (i->old_v == &ck->k->v)
+			i->old_v = &new_k->v;
+
 	ck->u64s	= new_u64s;
 	ck->k		= new_k;
-	/*
-	 * Keys returned by peek() are no longer valid pointers, so we need a
-	 * transaction restart:
-	 */
-	trace_and_count(c, trans_restart_key_cache_key_realloced, trans, _RET_IP_, path, old_u64s, new_u64s);
-	return btree_trans_restart_nounlock(trans, BCH_ERR_transaction_restart_key_cache_realloced);
+	return 0;
 }
 
 /* Triggers: */
@@ -386,6 +422,8 @@ static int run_one_mem_trigger(struct btree_trans *trans,
 	struct bkey_i *new = i->k;
 	int ret;
 
+	verify_update_old_key(trans, i);
+
 	if (unlikely(flags & BTREE_TRIGGER_NORUN))
 		return 0;
 
@@ -423,6 +461,8 @@ static int run_one_trans_trigger(struct btree_trans *trans, struct btree_insert_
 	struct bkey old_k = i->old_k;
 	struct bkey_s_c old = { &old_k, i->old_v };
 
+	verify_update_old_key(trans, i);
+
 	if ((i->flags & BTREE_TRIGGER_NORUN) ||
 	    !(BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS & (1U << i->bkey_type)))
 		return 0;
@@ -520,11 +560,12 @@ static int bch2_trans_commit_run_triggers(struct btree_trans *trans)
 		}
 	}
 
+#ifdef CONFIG_BCACHEFS_DEBUG
 	trans_for_each_update(trans, i)
 		BUG_ON(!(i->flags & BTREE_TRIGGER_NORUN) &&
 		       (BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS & (1U << i->bkey_type)) &&
 		       (!i->insert_trigger_run || !i->overwrite_trigger_run));
-
+#endif
 	return 0;
 }
 
@@ -552,12 +593,13 @@ static noinline int bch2_trans_commit_run_gc_triggers(struct btree_trans *trans)
 }
 
 static inline int
-bch2_trans_commit_write_locked(struct btree_trans *trans,
+bch2_trans_commit_write_locked(struct btree_trans *trans, unsigned flags,
 			       struct btree_insert_entry **stopped_at,
 			       unsigned long trace_ip)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_insert_entry *i;
+	struct btree_write_buffered_key *wb;
 	struct btree_trans_commit_hook *h;
 	unsigned u64s = 0;
 	bool marking = false;
@@ -592,7 +634,7 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 		u64s += i->k->k.u64s;
 		ret = !i->cached
 			? btree_key_can_insert(trans, insert_l(i)->b, u64s)
-			: btree_key_can_insert_cached(trans, i->path, u64s);
+			: btree_key_can_insert_cached(trans, flags, i->path, u64s);
 		if (ret) {
 			*stopped_at = i;
 			return ret;
@@ -600,65 +642,36 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 
 		if (btree_node_type_needs_gc(i->bkey_type))
 			marking = true;
-
-		/*
-		 * Revalidate before calling mem triggers - XXX, ugly:
-		 *
-		 * - successful btree node splits don't cause transaction
-		 *   restarts and will have invalidated the pointer to the bkey
-		 *   value
-		 * - btree_node_lock_for_insert() -> btree_node_prep_for_write()
-		 *   when it has to resort
-		 * - btree_key_can_insert_cached() when it has to reallocate
-		 *
-		 *   Ugly because we currently have no way to tell if the
-		 *   pointer's been invalidated, which means it's debatabale
-		 *   whether we should be stashing the old key at all.
-		 */
-		i->old_v = bch2_btree_path_peek_slot(i->path, &i->old_k).v;
-
-		if (unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags))) {
-			struct bkey_i *j_k =
-				bch2_journal_keys_peek_slot(c, i->btree_id, i->level,
-							    i->k->k.p);
-
-			if (j_k) {
-				i->old_k = j_k->k;
-				i->old_v = &j_k->v;
-			}
-		}
 	}
 
+	if (trans->nr_wb_updates &&
+	    trans->nr_wb_updates + c->btree_write_buffer.state.nr > c->btree_write_buffer.size)
+		return -BCH_ERR_btree_insert_need_flush_buffer;
+
 	/*
 	 * Don't get journal reservation until after we know insert will
 	 * succeed:
 	 */
-	if (likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))) {
+	if (likely(!(flags & BTREE_INSERT_JOURNAL_REPLAY))) {
 		ret = bch2_trans_journal_res_get(trans,
+				(flags & JOURNAL_WATERMARK_MASK)|
 				JOURNAL_RES_GET_NONBLOCK);
 		if (ret)
 			return ret;
 
-		journal_transaction_name(trans);
+		if (unlikely(trans->journal_transaction_names))
+			journal_transaction_name(trans);
 	} else {
 		trans->journal_res.seq = c->journal.replay_journal_seq;
 	}
 
-	if (unlikely(trans->extra_journal_entries.nr)) {
-		memcpy_u64s_small(journal_res_entry(&c->journal, &trans->journal_res),
-				  trans->extra_journal_entries.data,
-				  trans->extra_journal_entries.nr);
-
-		trans->journal_res.offset	+= trans->extra_journal_entries.nr;
-		trans->journal_res.u64s		-= trans->extra_journal_entries.nr;
-	}
-
 	/*
 	 * Not allowed to fail after we've gotten our journal reservation - we
 	 * have to use it:
 	 */
 
-	if (!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY)) {
+	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
+	    !(flags & BTREE_INSERT_JOURNAL_REPLAY)) {
 		if (bch2_journal_seq_verify)
 			trans_for_each_update(trans, i)
 				i->k->k.version.lo = trans->journal_res.seq;
@@ -669,35 +682,59 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 
 	if (trans->fs_usage_deltas &&
 	    bch2_trans_fs_usage_apply(trans, trans->fs_usage_deltas))
-		return BTREE_INSERT_NEED_MARK_REPLICAS;
+		return -BCH_ERR_btree_insert_need_mark_replicas;
+
+	if (trans->nr_wb_updates) {
+		EBUG_ON(flags & BTREE_INSERT_JOURNAL_REPLAY);
+
+		ret = bch2_btree_insert_keys_write_buffer(trans);
+		if (ret)
+			goto revert_fs_usage;
+	}
 
 	trans_for_each_update(trans, i)
 		if (BTREE_NODE_TYPE_HAS_MEM_TRIGGERS & (1U << i->bkey_type)) {
 			ret = run_one_mem_trigger(trans, i, i->flags);
 			if (ret)
-				return ret;
+				goto fatal_err;
 		}
 
 	if (unlikely(c->gc_pos.phase)) {
 		ret = bch2_trans_commit_run_gc_triggers(trans);
 		if  (ret)
-			return ret;
+			goto fatal_err;
 	}
 
-	if (likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))) {
-		trans_for_each_update(trans, i) {
-			struct journal *j = &c->journal;
-			struct jset_entry *entry;
+	if (unlikely(trans->extra_journal_entries.nr)) {
+		memcpy_u64s_small(journal_res_entry(&c->journal, &trans->journal_res),
+				  trans->extra_journal_entries.data,
+				  trans->extra_journal_entries.nr);
 
+		trans->journal_res.offset	+= trans->extra_journal_entries.nr;
+		trans->journal_res.u64s		-= trans->extra_journal_entries.nr;
+	}
+
+	if (likely(!(flags & BTREE_INSERT_JOURNAL_REPLAY))) {
+		struct journal *j = &c->journal;
+		struct jset_entry *entry;
+
+		trans_for_each_update(trans, i) {
 			if (i->key_cache_already_flushed)
 				continue;
 
-			entry = bch2_journal_add_entry(j, &trans->journal_res,
-					       BCH_JSET_ENTRY_overwrite,
-					       i->btree_id, i->level,
-					       i->old_k.u64s);
-			bkey_reassemble(&entry->start[0],
-					(struct bkey_s_c) { &i->old_k, i->old_v });
+			if (i->flags & BTREE_UPDATE_NOJOURNAL)
+				continue;
+
+			verify_update_old_key(trans, i);
+
+			if (trans->journal_transaction_names) {
+				entry = bch2_journal_add_entry(j, &trans->journal_res,
+						       BCH_JSET_ENTRY_overwrite,
+						       i->btree_id, i->level,
+						       i->old_k.u64s);
+				bkey_reassemble(&entry->start[0],
+						(struct bkey_s_c) { &i->old_k, i->old_v });
+			}
 
 			entry = bch2_journal_add_entry(j, &trans->journal_res,
 					       BCH_JSET_ENTRY_btree_keys,
@@ -706,6 +743,14 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 			bkey_copy(&entry->start[0], i->k);
 		}
 
+		trans_for_each_wb_update(trans, wb) {
+			entry = bch2_journal_add_entry(j, &trans->journal_res,
+					       BCH_JSET_ENTRY_btree_keys,
+					       wb->btree, 0,
+					       wb->k.k.u64s);
+			bkey_copy(&entry->start[0], &wb->k);
+		}
+
 		if (trans->journal_seq)
 			*trans->journal_seq = trans->journal_res.seq;
 	}
@@ -716,89 +761,118 @@ bch2_trans_commit_write_locked(struct btree_trans *trans,
 		if (!i->cached)
 			btree_insert_key_leaf(trans, i);
 		else if (!i->key_cache_already_flushed)
-			bch2_btree_insert_key_cached(trans, i->path, i->k);
+			bch2_btree_insert_key_cached(trans, flags, i->path, i->k);
 		else {
 			bch2_btree_key_cache_drop(trans, i->path);
 			btree_path_set_dirty(i->path, BTREE_ITER_NEED_TRAVERSE);
 		}
 	}
 
+	return 0;
+fatal_err:
+	bch2_fatal_error(c);
+revert_fs_usage:
+	if (trans->fs_usage_deltas)
+		bch2_trans_fs_usage_revert(trans, trans->fs_usage_deltas);
 	return ret;
 }
 
+static noinline int trans_lock_write_fail(struct btree_trans *trans, struct btree_insert_entry *i)
+{
+	while (--i >= trans->updates) {
+		if (same_leaf_as_prev(trans, i))
+			continue;
+
+		bch2_btree_node_unlock_write(trans, i->path, insert_l(i)->b);
+	}
+
+	trace_and_count(trans->c, trans_restart_would_deadlock_write, trans);
+	return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock_write);
+}
+
 static inline int trans_lock_write(struct btree_trans *trans)
 {
 	struct btree_insert_entry *i;
-	int ret;
 
 	trans_for_each_update(trans, i) {
 		if (same_leaf_as_prev(trans, i))
 			continue;
 
-		ret = bch2_btree_node_lock_write(trans, i->path, &insert_l(i)->b->c);
-		if (ret)
-			goto fail;
+		if (bch2_btree_node_lock_write(trans, i->path, &insert_l(i)->b->c))
+			return trans_lock_write_fail(trans, i);
 
-		bch2_btree_node_prep_for_write(trans, i->path, insert_l(i)->b);
+		if (!i->cached)
+			bch2_btree_node_prep_for_write(trans, i->path, insert_l(i)->b);
 	}
 
 	return 0;
-fail:
-	while (--i >= trans->updates) {
-		if (same_leaf_as_prev(trans, i))
-			continue;
-
-		bch2_btree_node_unlock_write_inlined(trans, i->path, insert_l(i)->b);
-	}
-
-	trace_and_count(trans->c, trans_restart_would_deadlock_write, trans);
-	return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock_write);
 }
 
 static noinline void bch2_drop_overwrites_from_journal(struct btree_trans *trans)
 {
 	struct btree_insert_entry *i;
+	struct btree_write_buffered_key *wb;
 
 	trans_for_each_update(trans, i)
 		bch2_journal_key_overwritten(trans->c, i->btree_id, i->level, i->k->k.p);
+
+	trans_for_each_wb_update(trans, wb)
+		bch2_journal_key_overwritten(trans->c, wb->btree, 0, wb->k.k.p);
+}
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+static noinline int bch2_trans_commit_bkey_invalid(struct btree_trans *trans, unsigned flags,
+						   struct btree_insert_entry *i,
+						   struct printbuf *err)
+{
+	struct bch_fs *c = trans->c;
+	int rw = (flags & BTREE_INSERT_JOURNAL_REPLAY) ? READ : WRITE;
+
+	printbuf_reset(err);
+	prt_printf(err, "invalid bkey on insert from %s -> %ps",
+		   trans->fn, (void *) i->ip_allocated);
+	prt_newline(err);
+	printbuf_indent_add(err, 2);
+
+	bch2_bkey_val_to_text(err, c, bkey_i_to_s_c(i->k));
+	prt_newline(err);
+
+	bch2_bkey_invalid(c, bkey_i_to_s_c(i->k),
+			  i->bkey_type, rw, err);
+	bch2_print_string_as_lines(KERN_ERR, err->buf);
+
+	bch2_inconsistent_error(c);
+	bch2_dump_trans_updates(trans);
+	printbuf_exit(err);
+
+	return -EINVAL;
 }
+#endif
 
 /*
  * Get journal reservation, take write locks, and attempt to do btree update(s):
  */
-static inline int do_bch2_trans_commit(struct btree_trans *trans,
+static inline int do_bch2_trans_commit(struct btree_trans *trans, unsigned flags,
 				       struct btree_insert_entry **stopped_at,
 				       unsigned long trace_ip)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_insert_entry *i;
-	struct printbuf buf = PRINTBUF;
 	int ret, u64s_delta = 0;
-	int rw = (trans->flags & BTREE_INSERT_JOURNAL_REPLAY) ? READ : WRITE;
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+	struct printbuf buf = PRINTBUF;
 
 	trans_for_each_update(trans, i) {
-		if (bch2_bkey_invalid(c, bkey_i_to_s_c(i->k),
-				      i->bkey_type, rw, &buf)) {
-			printbuf_reset(&buf);
-			prt_printf(&buf, "invalid bkey on insert from %s -> %ps",
-			       trans->fn, (void *) i->ip_allocated);
-			prt_newline(&buf);
-			printbuf_indent_add(&buf, 2);
-
-			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(i->k));
-			prt_newline(&buf);
-
-			bch2_bkey_invalid(c, bkey_i_to_s_c(i->k),
-					  i->bkey_type, rw, &buf);
-
-			bch2_trans_inconsistent(trans, "%s", buf.buf);
-			printbuf_exit(&buf);
-			return -EINVAL;
-		}
+		int rw = (flags & BTREE_INSERT_JOURNAL_REPLAY) ? READ : WRITE;
+
+		if (unlikely(bch2_bkey_invalid(c, bkey_i_to_s_c(i->k),
+					       i->bkey_type, rw, &buf)))
+			return bch2_trans_commit_bkey_invalid(trans, flags, i, &buf);
 		btree_insert_entry_checks(trans, i);
 	}
-
 	printbuf_exit(&buf);
+#endif
 
 	trans_for_each_update(trans, i) {
 		if (i->cached)
@@ -810,7 +884,7 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans,
 		if (!same_leaf_as_next(trans, i)) {
 			if (u64s_delta <= 0) {
 				ret = bch2_foreground_maybe_merge(trans, i->path,
-							i->level, trans->flags);
+							i->level, flags);
 				if (unlikely(ret))
 					return ret;
 			}
@@ -821,11 +895,9 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans,
 
 	ret = bch2_journal_preres_get(&c->journal,
 			&trans->journal_preres, trans->journal_preres_u64s,
-			JOURNAL_RES_GET_NONBLOCK|
-			(trans->flags & JOURNAL_WATERMARK_MASK));
-	if (unlikely(ret == -EAGAIN))
-		ret = bch2_trans_journal_preres_get_cold(trans,
-						trans->journal_preres_u64s, trace_ip);
+			(flags & JOURNAL_WATERMARK_MASK)|JOURNAL_RES_GET_NONBLOCK);
+	if (unlikely(ret == -BCH_ERR_journal_preres_get_blocked))
+		ret = bch2_trans_journal_preres_get_cold(trans, flags, trace_ip);
 	if (unlikely(ret))
 		return ret;
 
@@ -833,9 +905,9 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans,
 	if (unlikely(ret))
 		return ret;
 
-	ret = bch2_trans_commit_write_locked(trans, stopped_at, trace_ip);
+	ret = bch2_trans_commit_write_locked(trans, flags, stopped_at, trace_ip);
 
-	if (!ret && unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)))
+	if (!ret && unlikely(trans->journal_replay_not_finished))
 		bch2_drop_overwrites_from_journal(trans);
 
 	trans_for_each_update(trans, i)
@@ -872,19 +944,19 @@ static int journal_reclaim_wait_done(struct bch_fs *c)
 }
 
 static noinline
-int bch2_trans_commit_error(struct btree_trans *trans,
+int bch2_trans_commit_error(struct btree_trans *trans, unsigned flags,
 			    struct btree_insert_entry *i,
 			    int ret, unsigned long trace_ip)
 {
 	struct bch_fs *c = trans->c;
 
 	switch (ret) {
-	case BTREE_INSERT_BTREE_NODE_FULL:
-		ret = bch2_btree_split_leaf(trans, i->path, trans->flags);
+	case -BCH_ERR_btree_insert_btree_node_full:
+		ret = bch2_btree_split_leaf(trans, i->path, flags);
 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 			trace_and_count(c, trans_restart_btree_node_split, trans, trace_ip, i->path);
 		break;
-	case BTREE_INSERT_NEED_MARK_REPLICAS:
+	case -BCH_ERR_btree_insert_need_mark_replicas:
 		bch2_trans_unlock(trans);
 
 		ret = bch2_replicas_delta_list_mark(c, trans->fs_usage_deltas);
@@ -895,16 +967,18 @@ int bch2_trans_commit_error(struct btree_trans *trans,
 		if (ret)
 			trace_and_count(c, trans_restart_mark_replicas, trans, trace_ip);
 		break;
-	case BTREE_INSERT_NEED_JOURNAL_RES:
+	case -BCH_ERR_journal_res_get_blocked:
 		bch2_trans_unlock(trans);
 
-		if ((trans->flags & BTREE_INSERT_JOURNAL_RECLAIM) &&
-		    !(trans->flags & JOURNAL_WATERMARK_reserved)) {
+		if ((flags & BTREE_INSERT_JOURNAL_RECLAIM) &&
+		    !(flags & JOURNAL_WATERMARK_reserved)) {
 			ret = -BCH_ERR_journal_reclaim_would_deadlock;
 			break;
 		}
 
-		ret = bch2_trans_journal_res_get(trans, JOURNAL_RES_GET_CHECK);
+		ret = bch2_trans_journal_res_get(trans,
+					(flags & JOURNAL_WATERMARK_MASK)|
+					JOURNAL_RES_GET_CHECK);
 		if (ret)
 			break;
 
@@ -912,7 +986,7 @@ int bch2_trans_commit_error(struct btree_trans *trans,
 		if (ret)
 			trace_and_count(c, trans_restart_journal_res_get, trans, trace_ip);
 		break;
-	case BTREE_INSERT_NEED_JOURNAL_RECLAIM:
+	case -BCH_ERR_btree_insert_need_journal_reclaim:
 		bch2_trans_unlock(trans);
 
 		trace_and_count(c, trans_blocked_journal_reclaim, trans, trace_ip);
@@ -926,6 +1000,30 @@ int bch2_trans_commit_error(struct btree_trans *trans,
 		if (ret)
 			trace_and_count(c, trans_restart_journal_reclaim, trans, trace_ip);
 		break;
+	case -BCH_ERR_btree_insert_need_flush_buffer: {
+		struct btree_write_buffer *wb = &c->btree_write_buffer;
+
+		ret = 0;
+
+		if (wb->state.nr > wb->size * 3 / 4) {
+			bch2_trans_reset_updates(trans);
+			bch2_trans_unlock(trans);
+
+			mutex_lock(&wb->flush_lock);
+
+			if (wb->state.nr > wb->size * 3 / 4)
+				ret = __bch2_btree_write_buffer_flush(trans,
+						flags|BTREE_INSERT_NOCHECK_RW, true);
+			else
+				mutex_unlock(&wb->flush_lock);
+
+			if (!ret) {
+				trace_and_count(c, trans_restart_write_buffer_flush, trans, _THIS_IP_);
+				ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_write_buffer_flush);
+			}
+		}
+		break;
+	}
 	default:
 		BUG_ON(ret >= 0);
 		break;
@@ -934,22 +1032,22 @@ int bch2_trans_commit_error(struct btree_trans *trans,
 	BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted);
 
 	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOSPC) &&
-				!(trans->flags & BTREE_INSERT_NOWAIT) &&
-				(trans->flags & BTREE_INSERT_NOFAIL), c,
+				!(flags & BTREE_INSERT_NOWAIT) &&
+				(flags & BTREE_INSERT_NOFAIL), c,
 		"%s: incorrectly got %s\n", __func__, bch2_err_str(ret));
 
 	return ret;
 }
 
 static noinline int
-bch2_trans_commit_get_rw_cold(struct btree_trans *trans)
+bch2_trans_commit_get_rw_cold(struct btree_trans *trans, unsigned flags)
 {
 	struct bch_fs *c = trans->c;
 	int ret;
 
-	if (likely(!(trans->flags & BTREE_INSERT_LAZY_RW)) ||
+	if (likely(!(flags & BTREE_INSERT_LAZY_RW)) ||
 	    test_bit(BCH_FS_STARTED, &c->flags))
-		return -EROFS;
+		return -BCH_ERR_erofs_trans_commit;
 
 	bch2_trans_unlock(trans);
 
@@ -958,7 +1056,7 @@ bch2_trans_commit_get_rw_cold(struct btree_trans *trans)
 	if (ret)
 		return ret;
 
-	percpu_ref_get(&c->writes);
+	bch2_write_ref_get(c, BCH_WRITE_REF_trans);
 	return 0;
 }
 
@@ -983,18 +1081,20 @@ do_bch2_trans_commit_to_journal_replay(struct btree_trans *trans)
 	return ret;
 }
 
-int __bch2_trans_commit(struct btree_trans *trans)
+int __bch2_trans_commit(struct btree_trans *trans, unsigned flags)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_insert_entry *i = NULL;
+	struct btree_write_buffered_key *wb;
 	unsigned u64s;
 	int ret = 0;
 
 	if (!trans->nr_updates &&
+	    !trans->nr_wb_updates &&
 	    !trans->extra_journal_entries.nr)
 		goto out_reset;
 
-	if (trans->flags & BTREE_INSERT_GC_LOCK_HELD)
+	if (flags & BTREE_INSERT_GC_LOCK_HELD)
 		lockdep_assert_held(&c->gc_lock);
 
 	ret = bch2_trans_commit_run_triggers(trans);
@@ -1006,13 +1106,27 @@ int __bch2_trans_commit(struct btree_trans *trans)
 		goto out_reset;
 	}
 
-	if (!(trans->flags & BTREE_INSERT_NOCHECK_RW) &&
-	    unlikely(!percpu_ref_tryget_live(&c->writes))) {
-		ret = bch2_trans_commit_get_rw_cold(trans);
+	if (!(flags & BTREE_INSERT_NOCHECK_RW) &&
+	    unlikely(!bch2_write_ref_tryget(c, BCH_WRITE_REF_trans))) {
+		ret = bch2_trans_commit_get_rw_cold(trans, flags);
 		if (ret)
 			goto out_reset;
 	}
 
+	if (c->btree_write_buffer.state.nr > c->btree_write_buffer.size / 2 &&
+	    mutex_trylock(&c->btree_write_buffer.flush_lock)) {
+		bch2_trans_begin(trans);
+		bch2_trans_unlock(trans);
+
+		ret = __bch2_btree_write_buffer_flush(trans,
+					flags|BTREE_INSERT_NOCHECK_RW, true);
+		if (!ret) {
+			trace_and_count(c, trans_restart_write_buffer_flush, trans, _THIS_IP_);
+			ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_write_buffer_flush);
+		}
+		goto out;
+	}
+
 	EBUG_ON(test_bit(BCH_FS_CLEAN_SHUTDOWN, &c->flags));
 
 	memset(&trans->journal_preres, 0, sizeof(trans->journal_preres));
@@ -1020,17 +1134,19 @@ int __bch2_trans_commit(struct btree_trans *trans)
 	trans->journal_u64s		= trans->extra_journal_entries.nr;
 	trans->journal_preres_u64s	= 0;
 
-	/* For journalling transaction name: */
-	trans->journal_u64s += jset_u64s(JSET_ENTRY_LOG_U64s);
+	trans->journal_transaction_names = READ_ONCE(c->opts.journal_transaction_names);
+
+	if (trans->journal_transaction_names)
+		trans->journal_u64s += jset_u64s(JSET_ENTRY_LOG_U64s);
 
 	trans_for_each_update(trans, i) {
-		BUG_ON(!i->path->should_be_locked);
+		EBUG_ON(!i->path->should_be_locked);
 
 		ret = bch2_btree_path_upgrade(trans, i->path, i->level + 1);
 		if (unlikely(ret))
 			goto out;
 
-		BUG_ON(!btree_node_intent_locked(i->path, i->level));
+		EBUG_ON(!btree_node_intent_locked(i->path, i->level));
 
 		if (i->key_cache_already_flushed)
 			continue;
@@ -1038,27 +1154,35 @@ int __bch2_trans_commit(struct btree_trans *trans)
 		/* we're going to journal the key being updated: */
 		u64s = jset_u64s(i->k->k.u64s);
 		if (i->cached &&
-		    likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY)))
+		    likely(!(flags & BTREE_INSERT_JOURNAL_REPLAY)))
 			trans->journal_preres_u64s += u64s;
+
+		if (i->flags & BTREE_UPDATE_NOJOURNAL)
+			continue;
+
 		trans->journal_u64s += u64s;
 
 		/* and we're also going to log the overwrite: */
-		trans->journal_u64s += jset_u64s(i->old_k.u64s);
+		if (trans->journal_transaction_names)
+			trans->journal_u64s += jset_u64s(i->old_k.u64s);
 	}
 
+	trans_for_each_wb_update(trans, wb)
+		trans->journal_u64s += jset_u64s(wb->k.k.u64s);
+
 	if (trans->extra_journal_res) {
 		ret = bch2_disk_reservation_add(c, trans->disk_res,
 				trans->extra_journal_res,
-				(trans->flags & BTREE_INSERT_NOFAIL)
+				(flags & BTREE_INSERT_NOFAIL)
 				? BCH_DISK_RESERVATION_NOFAIL : 0);
 		if (ret)
 			goto err;
 	}
 retry:
-	BUG_ON(trans->restarted);
+	bch2_trans_verify_not_in_restart(trans);
 	memset(&trans->journal_res, 0, sizeof(trans->journal_res));
 
-	ret = do_bch2_trans_commit(trans, &i, _RET_IP_);
+	ret = do_bch2_trans_commit(trans, flags, &i, _RET_IP_);
 
 	/* make sure we didn't drop or screw up locks: */
 	bch2_trans_verify_locks(trans);
@@ -1070,22 +1194,14 @@ retry:
 out:
 	bch2_journal_preres_put(&c->journal, &trans->journal_preres);
 
-	if (likely(!(trans->flags & BTREE_INSERT_NOCHECK_RW)))
-		percpu_ref_put(&c->writes);
+	if (likely(!(flags & BTREE_INSERT_NOCHECK_RW)))
+		bch2_write_ref_put(c, BCH_WRITE_REF_trans);
 out_reset:
 	bch2_trans_reset_updates(trans);
 
-	if (trans->fs_usage_deltas) {
-		trans->fs_usage_deltas->used = 0;
-		memset((void *) trans->fs_usage_deltas +
-		       offsetof(struct replicas_delta_list, memset_start), 0,
-		       (void *) &trans->fs_usage_deltas->memset_end -
-		       (void *) &trans->fs_usage_deltas->memset_start);
-	}
-
 	return ret;
 err:
-	ret = bch2_trans_commit_error(trans, i, ret, _RET_IP_);
+	ret = bch2_trans_commit_error(trans, flags, i, ret, _RET_IP_);
 	if (ret)
 		goto out;
 
@@ -1113,7 +1229,7 @@ static noinline int __check_pos_snapshot_overwritten(struct btree_trans *trans,
 		if (!k.k)
 			break;
 
-		if (bkey_cmp(pos, k.k->p))
+		if (!bkey_eq(pos, k.k->p))
 			break;
 
 		if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, pos.snapshot)) {
@@ -1138,12 +1254,63 @@ static inline int check_pos_snapshot_overwritten(struct btree_trans *trans,
 	return __check_pos_snapshot_overwritten(trans, id, pos);
 }
 
+static noinline int extent_front_merge(struct btree_trans *trans,
+				       struct btree_iter *iter,
+				       struct bkey_s_c k,
+				       struct bkey_i **insert,
+				       enum btree_update_flags flags)
+{
+	struct bch_fs *c = trans->c;
+	struct bkey_i *update;
+	int ret;
+
+	update = bch2_bkey_make_mut(trans, k);
+	ret = PTR_ERR_OR_ZERO(update);
+	if (ret)
+		return ret;
+
+	if (!bch2_bkey_merge(c, bkey_i_to_s(update), bkey_i_to_s_c(*insert)))
+		return 0;
+
+	ret =   check_pos_snapshot_overwritten(trans, iter->btree_id, k.k->p) ?:
+		check_pos_snapshot_overwritten(trans, iter->btree_id, (*insert)->k.p);
+	if (ret < 0)
+		return ret;
+	if (ret)
+		return 0;
+
+	ret = bch2_btree_delete_at(trans, iter, flags);
+	if (ret)
+		return ret;
+
+	*insert = update;
+	return 0;
+}
+
+static noinline int extent_back_merge(struct btree_trans *trans,
+				      struct btree_iter *iter,
+				      struct bkey_i *insert,
+				      struct bkey_s_c k)
+{
+	struct bch_fs *c = trans->c;
+	int ret;
+
+	ret =   check_pos_snapshot_overwritten(trans, iter->btree_id, insert->k.p) ?:
+		check_pos_snapshot_overwritten(trans, iter->btree_id, k.k->p);
+	if (ret < 0)
+		return ret;
+	if (ret)
+		return 0;
+
+	bch2_bkey_merge(c, bkey_i_to_s(insert), k);
+	return 0;
+}
+
 int bch2_trans_update_extent(struct btree_trans *trans,
 			     struct btree_iter *orig_iter,
 			     struct bkey_i *insert,
 			     enum btree_update_flags flags)
 {
-	struct bch_fs *c = trans->c;
 	struct btree_iter iter, update_iter;
 	struct bpos start = bkey_start_pos(&insert->k);
 	struct bkey_i *update;
@@ -1161,52 +1328,19 @@ int bch2_trans_update_extent(struct btree_trans *trans,
 	if (!k.k)
 		goto out;
 
-	if (bch2_bkey_maybe_mergable(k.k, &insert->k)) {
-		/*
-		 * We can't merge extents if they belong to interior snapshot
-		 * tree nodes, and there's a snapshot in which one extent is
-		 * visible and the other is not - i.e. if visibility is
-		 * different.
-		 *
-		 * Instead of checking if visibilitiy of the two extents is
-		 * different, for now we just check if either has been
-		 * overwritten:
-		 */
-		ret = check_pos_snapshot_overwritten(trans, btree_id, insert->k.p);
-		if (ret < 0)
-			goto err;
-		if (ret)
-			goto nomerge1;
-
-		ret = check_pos_snapshot_overwritten(trans, btree_id, k.k->p);
-		if (ret < 0)
-			goto err;
-		if (ret)
-			goto nomerge1;
-
-		update = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
-		if ((ret = PTR_ERR_OR_ZERO(update)))
-			goto err;
-
-		bkey_reassemble(update, k);
-
-		if (bch2_bkey_merge(c, bkey_i_to_s(update), bkey_i_to_s_c(insert))) {
-			ret = bch2_btree_delete_at(trans, &iter, flags);
+	if (bkey_eq(k.k->p, bkey_start_pos(&insert->k))) {
+		if (bch2_bkey_maybe_mergable(k.k, &insert->k)) {
+			ret = extent_front_merge(trans, &iter, k, &insert, flags);
 			if (ret)
 				goto err;
-
-			insert = update;
-			goto next;
 		}
-	}
-nomerge1:
-	ret = 0;
-	if (!bkey_cmp(k.k->p, start))
+
 		goto next;
+	}
 
-	while (bkey_cmp(insert->k.p, bkey_start_pos(k.k)) > 0) {
-		bool front_split = bkey_cmp(bkey_start_pos(k.k), start) < 0;
-		bool back_split  = bkey_cmp(k.k->p, insert->k.p) > 0;
+	while (bkey_gt(insert->k.p, bkey_start_pos(k.k))) {
+		bool front_split = bkey_lt(bkey_start_pos(k.k), start);
+		bool back_split  = bkey_gt(k.k->p, insert->k.p);
 
 		/*
 		 * If we're going to be splitting a compressed extent, note it
@@ -1219,12 +1353,10 @@ nomerge1:
 			trans->extra_journal_res += compressed_sectors;
 
 		if (front_split) {
-			update = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
+			update = bch2_bkey_make_mut(trans, k);
 			if ((ret = PTR_ERR_OR_ZERO(update)))
 				goto err;
 
-			bkey_reassemble(update, k);
-
 			bch2_cut_back(start, update);
 
 			bch2_trans_iter_init(trans, &update_iter, btree_id, update->k.p,
@@ -1243,12 +1375,10 @@ nomerge1:
 
 		if (k.k->p.snapshot != insert->k.p.snapshot &&
 		    (front_split || back_split)) {
-			update = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
+			update = bch2_bkey_make_mut(trans, k);
 			if ((ret = PTR_ERR_OR_ZERO(update)))
 				goto err;
 
-			bkey_reassemble(update, k);
-
 			bch2_cut_front(start, update);
 			bch2_cut_back(insert->k.p, update);
 
@@ -1265,7 +1395,7 @@ nomerge1:
 				goto err;
 		}
 
-		if (bkey_cmp(k.k->p, insert->k.p) <= 0) {
+		if (bkey_le(k.k->p, insert->k.p)) {
 			update = bch2_trans_kmalloc(trans, sizeof(*update));
 			if ((ret = PTR_ERR_OR_ZERO(update)))
 				goto err;
@@ -1292,11 +1422,10 @@ nomerge1:
 		}
 
 		if (back_split) {
-			update = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
+			update = bch2_bkey_make_mut(trans, k);
 			if ((ret = PTR_ERR_OR_ZERO(update)))
 				goto err;
 
-			bkey_reassemble(update, k);
 			bch2_cut_front(insert->k.p, update);
 
 			ret = bch2_trans_update_by_path(trans, iter.path, update,
@@ -1316,22 +1445,10 @@ next:
 	}
 
 	if (bch2_bkey_maybe_mergable(&insert->k, k.k)) {
-		ret = check_pos_snapshot_overwritten(trans, btree_id, insert->k.p);
-		if (ret < 0)
-			goto err;
+		ret = extent_back_merge(trans, &iter, insert, k);
 		if (ret)
-			goto nomerge2;
-
-		ret = check_pos_snapshot_overwritten(trans, btree_id, k.k->p);
-		if (ret < 0)
 			goto err;
-		if (ret)
-			goto nomerge2;
-
-		bch2_bkey_merge(c, bkey_i_to_s(insert), k);
 	}
-nomerge2:
-	ret = 0;
 out:
 	if (!bkey_deleted(&insert->k)) {
 		/*
@@ -1371,7 +1488,7 @@ static int need_whiteout_for_snapshot(struct btree_trans *trans,
 	for_each_btree_key_norestart(trans, iter, btree_id, pos,
 			   BTREE_ITER_ALL_SNAPSHOTS|
 			   BTREE_ITER_NOPRESERVE, k, ret) {
-		if (bkey_cmp(k.k->p, pos))
+		if (!bkey_eq(k.k->p, pos))
 			break;
 
 		if (bch2_snapshot_is_ancestor(trans->c, snapshot,
@@ -1385,6 +1502,37 @@ static int need_whiteout_for_snapshot(struct btree_trans *trans,
 	return ret;
 }
 
+static int __must_check
+bch2_trans_update_by_path_trace(struct btree_trans *trans, struct btree_path *path,
+				struct bkey_i *k, enum btree_update_flags flags,
+				unsigned long ip);
+
+static noinline int flush_new_cached_update(struct btree_trans *trans,
+					    struct btree_path *path,
+					    struct btree_insert_entry *i,
+					    enum btree_update_flags flags,
+					    unsigned long ip)
+{
+	struct btree_path *btree_path;
+	int ret;
+
+	i->key_cache_already_flushed = true;
+	i->flags |= BTREE_TRIGGER_NORUN;
+
+	btree_path = bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
+				   BTREE_ITER_INTENT, _THIS_IP_);
+
+	ret = bch2_btree_path_traverse(trans, btree_path, 0);
+	if (ret)
+		goto err;
+
+	btree_path_set_should_be_locked(btree_path);
+	ret = bch2_trans_update_by_path_trace(trans, btree_path, i->k, flags, ip);
+err:
+	bch2_path_put(trans, btree_path, true);
+	return ret;
+}
+
 static int __must_check
 bch2_trans_update_by_path_trace(struct btree_trans *trans, struct btree_path *path,
 				struct bkey_i *k, enum btree_update_flags flags,
@@ -1392,12 +1540,11 @@ bch2_trans_update_by_path_trace(struct btree_trans *trans, struct btree_path *pa
 {
 	struct bch_fs *c = trans->c;
 	struct btree_insert_entry *i, n;
-	int ret = 0;
+	int cmp;
 
-	BUG_ON(!path->should_be_locked);
-
-	BUG_ON(trans->nr_updates >= BTREE_ITER_MAX);
-	BUG_ON(bpos_cmp(k->k.p, path->pos));
+	EBUG_ON(!path->should_be_locked);
+	EBUG_ON(trans->nr_updates >= BTREE_ITER_MAX);
+	EBUG_ON(!bpos_eq(k->k.p, path->pos));
 
 	n = (struct btree_insert_entry) {
 		.flags		= flags,
@@ -1420,13 +1567,14 @@ bch2_trans_update_by_path_trace(struct btree_trans *trans, struct btree_path *pa
 	 * Pending updates are kept sorted: first, find position of new update,
 	 * then delete/trim any updates the new update overwrites:
 	 */
-	trans_for_each_update(trans, i)
-		if (btree_insert_entry_cmp(&n, i) <= 0)
+	trans_for_each_update(trans, i) {
+		cmp = btree_insert_entry_cmp(&n, i);
+		if (cmp <= 0)
 			break;
+	}
 
-	if (i < trans->updates + trans->nr_updates &&
-	    !btree_insert_entry_cmp(&n, i)) {
-		BUG_ON(i->insert_trigger_run || i->overwrite_trigger_run);
+	if (!cmp && i < trans->updates + trans->nr_updates) {
+		EBUG_ON(i->insert_trigger_run || i->overwrite_trigger_run);
 
 		bch2_path_put(trans, i->path, true);
 		i->flags	= n.flags;
@@ -1438,10 +1586,10 @@ bch2_trans_update_by_path_trace(struct btree_trans *trans, struct btree_path *pa
 		array_insert_item(trans->updates, trans->nr_updates,
 				  i - trans->updates, n);
 
-		i->old_v = bch2_btree_path_peek_slot(path, &i->old_k).v;
+		i->old_v = bch2_btree_path_peek_slot_exact(path, &i->old_k).v;
 		i->old_btree_u64s = !bkey_deleted(&i->old_k) ? i->old_k.u64s : 0;
 
-		if (unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags))) {
+		if (unlikely(trans->journal_replay_not_finished)) {
 			struct bkey_i *j_k =
 				bch2_journal_keys_peek_slot(c, n.btree_id, n.level, k->k.p);
 
@@ -1462,29 +1610,14 @@ bch2_trans_update_by_path_trace(struct btree_trans *trans, struct btree_path *pa
 	 * work:
 	 */
 	if (path->cached &&
-	    bkey_deleted(&i->old_k)) {
-		struct btree_path *btree_path;
-
-		i->key_cache_already_flushed = true;
-		i->flags |= BTREE_TRIGGER_NORUN;
-
-		btree_path = bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
-					   BTREE_ITER_INTENT, _THIS_IP_);
-
-		ret = bch2_btree_path_traverse(trans, btree_path, 0);
-		if (ret)
-			goto err;
-
-		btree_path_set_should_be_locked(btree_path);
-		ret = bch2_trans_update_by_path_trace(trans, btree_path, k, flags, ip);
-err:
-		bch2_path_put(trans, btree_path, true);
-	}
+	    bkey_deleted(&i->old_k) &&
+	    !(flags & BTREE_UPDATE_NO_KEY_CACHE_COHERENCY))
+		return flush_new_cached_update(trans, path, i, flags, ip);
 
-	return ret;
+	return 0;
 }
 
-static int __must_check
+static inline int __must_check
 bch2_trans_update_by_path(struct btree_trans *trans, struct btree_path *path,
 			  struct bkey_i *k, enum btree_update_flags flags)
 {
@@ -1521,7 +1654,7 @@ int __must_check bch2_trans_update(struct btree_trans *trans, struct btree_iter
 	    btree_id_cached(trans->c, path->btree_id)) {
 		if (!iter->key_cache_path ||
 		    !iter->key_cache_path->should_be_locked ||
-		    bpos_cmp(iter->key_cache_path->pos, k->k.p)) {
+		    !bpos_eq(iter->key_cache_path->pos, k->k.p)) {
 			if (!iter->key_cache_path)
 				iter->key_cache_path =
 					bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
@@ -1554,6 +1687,59 @@ int __must_check bch2_trans_update(struct btree_trans *trans, struct btree_iter
 	return bch2_trans_update_by_path(trans, path, k, flags);
 }
 
+int __must_check bch2_trans_update_buffered(struct btree_trans *trans,
+					    enum btree_id btree,
+					    struct bkey_i *k)
+{
+	struct btree_write_buffered_key *i;
+	int ret;
+
+	EBUG_ON(trans->nr_wb_updates > trans->wb_updates_size);
+	EBUG_ON(k->k.u64s > BTREE_WRITE_BUFERED_U64s_MAX);
+
+	trans_for_each_wb_update(trans, i) {
+		if (i->btree == btree && bpos_eq(i->k.k.p, k->k.p)) {
+			bkey_copy(&i->k, k);
+			return 0;
+		}
+	}
+
+	if (!trans->wb_updates ||
+	    trans->nr_wb_updates == trans->wb_updates_size) {
+		struct btree_write_buffered_key *u;
+
+		if (trans->nr_wb_updates == trans->wb_updates_size) {
+			struct btree_transaction_stats *s = btree_trans_stats(trans);
+
+			BUG_ON(trans->wb_updates_size > U8_MAX / 2);
+			trans->wb_updates_size = max(1, trans->wb_updates_size * 2);
+			if (s)
+				s->wb_updates_size = trans->wb_updates_size;
+		}
+
+		u = bch2_trans_kmalloc_nomemzero(trans,
+					trans->wb_updates_size *
+					sizeof(struct btree_write_buffered_key));
+		ret = PTR_ERR_OR_ZERO(u);
+		if (ret)
+			return ret;
+
+		if (trans->nr_wb_updates)
+			memcpy(u, trans->wb_updates, trans->nr_wb_updates *
+			       sizeof(struct btree_write_buffered_key));
+		trans->wb_updates = u;
+	}
+
+	trans->wb_updates[trans->nr_wb_updates] = (struct btree_write_buffered_key) {
+		.btree	= btree,
+	};
+
+	bkey_copy(&trans->wb_updates[trans->nr_wb_updates].k, k);
+	trans->nr_wb_updates++;
+
+	return 0;
+}
+
 void bch2_trans_commit_hook(struct btree_trans *trans,
 			    struct btree_trans_commit_hook *h)
 {
@@ -1562,7 +1748,8 @@ void bch2_trans_commit_hook(struct btree_trans *trans,
 }
 
 int __bch2_btree_insert(struct btree_trans *trans,
-			enum btree_id id, struct bkey_i *k)
+			enum btree_id id,
+			struct bkey_i *k, enum btree_update_flags flags)
 {
 	struct btree_iter iter;
 	int ret;
@@ -1570,7 +1757,7 @@ int __bch2_btree_insert(struct btree_trans *trans,
 	bch2_trans_iter_init(trans, &iter, id, bkey_start_pos(&k->k),
 			     BTREE_ITER_INTENT);
 	ret   = bch2_btree_iter_traverse(&iter) ?:
-		bch2_trans_update(trans, &iter, k, 0);
+		bch2_trans_update(trans, &iter, k, flags);
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }
@@ -1588,7 +1775,7 @@ int bch2_btree_insert(struct bch_fs *c, enum btree_id id,
 		      u64 *journal_seq, int flags)
 {
 	return bch2_trans_do(c, disk_res, journal_seq, flags,
-			     __bch2_btree_insert(&trans, id, k));
+			     __bch2_btree_insert(&trans, id, k, 0));
 }
 
 int bch2_btree_delete_extent_at(struct btree_trans *trans, struct btree_iter *iter,
@@ -1623,7 +1810,7 @@ int bch2_btree_delete_range_trans(struct btree_trans *trans, enum btree_id id,
 	int ret = 0;
 
 	bch2_trans_iter_init(trans, &iter, id, start, BTREE_ITER_INTENT);
-	while ((k = bch2_btree_iter_peek(&iter)).k) {
+	while ((k = bch2_btree_iter_peek_upto(&iter, end)).k) {
 		struct disk_reservation disk_res =
 			bch2_disk_reservation_init(trans->c, 0);
 		struct bkey_i delete;
@@ -1632,9 +1819,6 @@ int bch2_btree_delete_range_trans(struct btree_trans *trans, enum btree_id id,
 		if (ret)
 			goto err;
 
-		if (bkey_cmp(iter.pos, end) >= 0)
-			break;
-
 		bkey_init(&delete.k);
 
 		/*
@@ -1653,18 +1837,10 @@ int bch2_btree_delete_range_trans(struct btree_trans *trans, enum btree_id id,
 		 */
 		delete.k.p = iter.pos;
 
-		if (iter.flags & BTREE_ITER_IS_EXTENTS) {
-			unsigned max_sectors =
-				KEY_SIZE_MAX & (~0 << trans->c->block_bits);
-
-			/* create the biggest key we can */
-			bch2_key_resize(&delete.k, max_sectors);
-			bch2_cut_back(end, &delete);
-
-			ret = bch2_extent_trim_atomic(trans, &iter, &delete);
-			if (ret)
-				goto err;
-		}
+		if (iter.flags & BTREE_ITER_IS_EXTENTS)
+			bch2_key_resize(&delete.k,
+					bpos_min(end, k.k->p).offset -
+					iter.pos.offset);
 
 		ret   = bch2_trans_update(trans, &iter, &delete, update_flags) ?:
 			bch2_trans_commit(trans, &disk_res, journal_seq,
@@ -1709,18 +1885,25 @@ int bch2_btree_delete_range(struct bch_fs *c, enum btree_id id,
 	return ret;
 }
 
-int bch2_trans_log_msg(struct btree_trans *trans, const char *msg)
+static int __bch2_trans_log_msg(darray_u64 *entries, const char *fmt, va_list args)
 {
-	unsigned len = strlen(msg);
-	unsigned u64s = DIV_ROUND_UP(len, sizeof(u64));
+	struct printbuf buf = PRINTBUF;
 	struct jset_entry_log *l;
+	unsigned u64s;
 	int ret;
 
-	ret = darray_make_room(&trans->extra_journal_entries, jset_u64s(u64s));
+	prt_vprintf(&buf, fmt, args);
+	ret = buf.allocation_failure ? -ENOMEM : 0;
 	if (ret)
-		return ret;
+		goto err;
+
+	u64s = DIV_ROUND_UP(buf.pos, sizeof(u64));
+
+	ret = darray_make_room(entries, jset_u64s(u64s));
+	if (ret)
+		goto err;
 
-	l = (void *) &darray_top(trans->extra_journal_entries);
+	l = (void *) &darray_top(*entries);
 	l->entry.u64s		= cpu_to_le16(u64s);
 	l->entry.btree_id	= 0;
 	l->entry.level		= 1;
@@ -1728,10 +1911,44 @@ int bch2_trans_log_msg(struct btree_trans *trans, const char *msg)
 	l->entry.pad[0]		= 0;
 	l->entry.pad[1]		= 0;
 	l->entry.pad[2]		= 0;
-	memcpy(l->d, msg, len);
-	while (len & 7)
-		l->d[len++] = '\0';
+	memcpy(l->d, buf.buf, buf.pos);
+	while (buf.pos & 7)
+		l->d[buf.pos++] = '\0';
+
+	entries->nr += jset_u64s(u64s);
+err:
+	printbuf_exit(&buf);
+	return ret;
+}
+
+int bch2_trans_log_msg(struct btree_trans *trans, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = __bch2_trans_log_msg(&trans->extra_journal_entries, fmt, args);
+	va_end(args);
+
+	return ret;
+}
+
+int bch2_fs_log_msg(struct bch_fs *c, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+
+	if (!test_bit(JOURNAL_STARTED, &c->journal.flags)) {
+		ret = __bch2_trans_log_msg(&c->journal.early_journal_entries, fmt, args);
+	} else {
+		ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_LAZY_RW,
+			__bch2_trans_log_msg(&trans.extra_journal_entries, fmt, args));
+	}
+
+	va_end(args);
+
+	return ret;
 
-	trans->extra_journal_entries.nr += jset_u64s(u64s);
-	return 0;
 }