Move c_src dirs back to toplevel

We just wanted c sourcefiles out of the top level, not c source
directories.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 0 insertions, 2496 deletions

diff --git a/c_src/libbcachefs/btree_update_interior.c b/c_src/libbcachefs/btree_update_interior.c
deleted file mode 100644
index 44f9dfa2..00000000
--- a/c_src/libbcachefs/btree_update_interior.c
+++ /dev/null
@@ -1,2496 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-#include "bcachefs.h"
-#include "alloc_foreground.h"
-#include "bkey_methods.h"
-#include "btree_cache.h"
-#include "btree_gc.h"
-#include "btree_journal_iter.h"
-#include "btree_update.h"
-#include "btree_update_interior.h"
-#include "btree_io.h"
-#include "btree_iter.h"
-#include "btree_locking.h"
-#include "buckets.h"
-#include "clock.h"
-#include "error.h"
-#include "extents.h"
-#include "journal.h"
-#include "journal_reclaim.h"
-#include "keylist.h"
-#include "replicas.h"
-#include "super-io.h"
-#include "trace.h"
-
-#include <linux/random.h>
-
-static int bch2_btree_insert_node(struct btree_update *, struct btree_trans *,
-				  btree_path_idx_t, struct btree *,
-				  struct keylist *, unsigned);
-static void bch2_btree_update_add_new_node(struct btree_update *, struct btree *);
-
-static btree_path_idx_t get_unlocked_mut_path(struct btree_trans *trans,
-					      enum btree_id btree_id,
-					      unsigned level,
-					      struct bpos pos)
-{
-	btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level,
-			     BTREE_ITER_NOPRESERVE|
-			     BTREE_ITER_INTENT, _RET_IP_);
-	path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_);
-
-	struct btree_path *path = trans->paths + path_idx;
-	bch2_btree_path_downgrade(trans, path);
-	__bch2_btree_path_unlock(trans, path);
-	return path_idx;
-}
-
-/* Debug code: */
-
-/*
- * Verify that child nodes correctly span parent node's range:
- */
-static void btree_node_interior_verify(struct bch_fs *c, struct btree *b)
-{
-#ifdef CONFIG_BCACHEFS_DEBUG
-	struct bpos next_node = b->data->min_key;
-	struct btree_node_iter iter;
-	struct bkey_s_c k;
-	struct bkey_s_c_btree_ptr_v2 bp;
-	struct bkey unpacked;
-	struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
-
-	BUG_ON(!b->c.level);
-
-	if (!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags))
-		return;
-
-	bch2_btree_node_iter_init_from_start(&iter, b);
-
-	while (1) {
-		k = bch2_btree_node_iter_peek_unpack(&iter, b, &unpacked);
-		if (k.k->type != KEY_TYPE_btree_ptr_v2)
-			break;
-		bp = bkey_s_c_to_btree_ptr_v2(k);
-
-		if (!bpos_eq(next_node, bp.v->min_key)) {
-			bch2_dump_btree_node(c, b);
-			bch2_bpos_to_text(&buf1, next_node);
-			bch2_bpos_to_text(&buf2, bp.v->min_key);
-			panic("expected next min_key %s got %s\n", buf1.buf, buf2.buf);
-		}
-
-		bch2_btree_node_iter_advance(&iter, b);
-
-		if (bch2_btree_node_iter_end(&iter)) {
-			if (!bpos_eq(k.k->p, b->key.k.p)) {
-				bch2_dump_btree_node(c, b);
-				bch2_bpos_to_text(&buf1, b->key.k.p);
-				bch2_bpos_to_text(&buf2, k.k->p);
-				panic("expected end %s got %s\n", buf1.buf, buf2.buf);
-			}
-			break;
-		}
-
-		next_node = bpos_successor(k.k->p);
-	}
-#endif
-}
-
-/* Calculate ideal packed bkey format for new btree nodes: */
-
-static void __bch2_btree_calc_format(struct bkey_format_state *s, struct btree *b)
-{
-	struct bkey_packed *k;
-	struct bset_tree *t;
-	struct bkey uk;
-
-	for_each_bset(b, t)
-		bset_tree_for_each_key(b, t, k)
-			if (!bkey_deleted(k)) {
-				uk = bkey_unpack_key(b, k);
-				bch2_bkey_format_add_key(s, &uk);
-			}
-}
-
-static struct bkey_format bch2_btree_calc_format(struct btree *b)
-{
-	struct bkey_format_state s;
-
-	bch2_bkey_format_init(&s);
-	bch2_bkey_format_add_pos(&s, b->data->min_key);
-	bch2_bkey_format_add_pos(&s, b->data->max_key);
-	__bch2_btree_calc_format(&s, b);
-
-	return bch2_bkey_format_done(&s);
-}
-
-static size_t btree_node_u64s_with_format(struct btree_nr_keys nr,
-					  struct bkey_format *old_f,
-					  struct bkey_format *new_f)
-{
-	/* stupid integer promotion rules */
-	ssize_t delta =
-	    (((int) new_f->key_u64s - old_f->key_u64s) *
-	     (int) nr.packed_keys) +
-	    (((int) new_f->key_u64s - BKEY_U64s) *
-	     (int) nr.unpacked_keys);
-
-	BUG_ON(delta + nr.live_u64s < 0);
-
-	return nr.live_u64s + delta;
-}
-
-/**
- * bch2_btree_node_format_fits - check if we could rewrite node with a new format
- *
- * @c:		filesystem handle
- * @b:		btree node to rewrite
- * @nr:		number of keys for new node (i.e. b->nr)
- * @new_f:	bkey format to translate keys to
- *
- * Returns: true if all re-packed keys will be able to fit in a new node.
- *
- * Assumes all keys will successfully pack with the new format.
- */
-static bool bch2_btree_node_format_fits(struct bch_fs *c, struct btree *b,
-				 struct btree_nr_keys nr,
-				 struct bkey_format *new_f)
-{
-	size_t u64s = btree_node_u64s_with_format(nr, &b->format, new_f);
-
-	return __vstruct_bytes(struct btree_node, u64s) < btree_bytes(c);
-}
-
-/* Btree node freeing/allocation: */
-
-static void __btree_node_free(struct btree_trans *trans, struct btree *b)
-{
-	struct bch_fs *c = trans->c;
-
-	trace_and_count(c, btree_node_free, trans, b);
-
-	BUG_ON(btree_node_write_blocked(b));
-	BUG_ON(btree_node_dirty(b));
-	BUG_ON(btree_node_need_write(b));
-	BUG_ON(b == btree_node_root(c, b));
-	BUG_ON(b->ob.nr);
-	BUG_ON(!list_empty(&b->write_blocked));
-	BUG_ON(b->will_make_reachable);
-
-	clear_btree_node_noevict(b);
-
-	mutex_lock(&c->btree_cache.lock);
-	list_move(&b->list, &c->btree_cache.freeable);
-	mutex_unlock(&c->btree_cache.lock);
-}
-
-static void bch2_btree_node_free_inmem(struct btree_trans *trans,
-				       struct btree_path *path,
-				       struct btree *b)
-{
-	struct bch_fs *c = trans->c;
-	unsigned i, level = b->c.level;
-
-	bch2_btree_node_lock_write_nofail(trans, path, &b->c);
-	bch2_btree_node_hash_remove(&c->btree_cache, b);
-	__btree_node_free(trans, b);
-	six_unlock_write(&b->c.lock);
-	mark_btree_node_locked_noreset(path, level, BTREE_NODE_INTENT_LOCKED);
-
-	trans_for_each_path(trans, path, i)
-		if (path->l[level].b == b) {
-			btree_node_unlock(trans, path, level);
-			path->l[level].b = ERR_PTR(-BCH_ERR_no_btree_node_init);
-		}
-}
-
-static void bch2_btree_node_free_never_used(struct btree_update *as,
-					    struct btree_trans *trans,
-					    struct btree *b)
-{
-	struct bch_fs *c = as->c;
-	struct prealloc_nodes *p = &as->prealloc_nodes[b->c.lock.readers != NULL];
-	struct btree_path *path;
-	unsigned i, level = b->c.level;
-
-	BUG_ON(!list_empty(&b->write_blocked));
-	BUG_ON(b->will_make_reachable != (1UL|(unsigned long) as));
-
-	b->will_make_reachable = 0;
-	closure_put(&as->cl);
-
-	clear_btree_node_will_make_reachable(b);
-	clear_btree_node_accessed(b);
-	clear_btree_node_dirty_acct(c, b);
-	clear_btree_node_need_write(b);
-
-	mutex_lock(&c->btree_cache.lock);
-	list_del_init(&b->list);
-	bch2_btree_node_hash_remove(&c->btree_cache, b);
-	mutex_unlock(&c->btree_cache.lock);
-
-	BUG_ON(p->nr >= ARRAY_SIZE(p->b));
-	p->b[p->nr++] = b;
-
-	six_unlock_intent(&b->c.lock);
-
-	trans_for_each_path(trans, path, i)
-		if (path->l[level].b == b) {
-			btree_node_unlock(trans, path, level);
-			path->l[level].b = ERR_PTR(-BCH_ERR_no_btree_node_init);
-		}
-}
-
-static struct btree *__bch2_btree_node_alloc(struct btree_trans *trans,
-					     struct disk_reservation *res,
-					     struct closure *cl,
-					     bool interior_node,
-					     unsigned flags)
-{
-	struct bch_fs *c = trans->c;
-	struct write_point *wp;
-	struct btree *b;
-	BKEY_PADDED_ONSTACK(k, BKEY_BTREE_PTR_VAL_U64s_MAX) tmp;
-	struct open_buckets obs = { .nr = 0 };
-	struct bch_devs_list devs_have = (struct bch_devs_list) { 0 };
-	enum bch_watermark watermark = flags & BCH_WATERMARK_MASK;
-	unsigned nr_reserve = watermark > BCH_WATERMARK_reclaim
-		? BTREE_NODE_RESERVE
-		: 0;
-	int ret;
-
-	mutex_lock(&c->btree_reserve_cache_lock);
-	if (c->btree_reserve_cache_nr > nr_reserve) {
-		struct btree_alloc *a =
-			&c->btree_reserve_cache[--c->btree_reserve_cache_nr];
-
-		obs = a->ob;
-		bkey_copy(&tmp.k, &a->k);
-		mutex_unlock(&c->btree_reserve_cache_lock);
-		goto mem_alloc;
-	}
-	mutex_unlock(&c->btree_reserve_cache_lock);
-
-retry:
-	ret = bch2_alloc_sectors_start_trans(trans,
-				      c->opts.metadata_target ?:
-				      c->opts.foreground_target,
-				      0,
-				      writepoint_ptr(&c->btree_write_point),
-				      &devs_have,
-				      res->nr_replicas,
-				      c->opts.metadata_replicas_required,
-				      watermark, 0, cl, &wp);
-	if (unlikely(ret))
-		return ERR_PTR(ret);
-
-	if (wp->sectors_free < btree_sectors(c)) {
-		struct open_bucket *ob;
-		unsigned i;
-
-		open_bucket_for_each(c, &wp->ptrs, ob, i)
-			if (ob->sectors_free < btree_sectors(c))
-				ob->sectors_free = 0;
-
-		bch2_alloc_sectors_done(c, wp);
-		goto retry;
-	}
-
-	bkey_btree_ptr_v2_init(&tmp.k);
-	bch2_alloc_sectors_append_ptrs(c, wp, &tmp.k, btree_sectors(c), false);
-
-	bch2_open_bucket_get(c, wp, &obs);
-	bch2_alloc_sectors_done(c, wp);
-mem_alloc:
-	b = bch2_btree_node_mem_alloc(trans, interior_node);
-	six_unlock_write(&b->c.lock);
-	six_unlock_intent(&b->c.lock);
-
-	/* we hold cannibalize_lock: */
-	BUG_ON(IS_ERR(b));
-	BUG_ON(b->ob.nr);
-
-	bkey_copy(&b->key, &tmp.k);
-	b->ob = obs;
-
-	return b;
-}
-
-static struct btree *bch2_btree_node_alloc(struct btree_update *as,
-					   struct btree_trans *trans,
-					   unsigned level)
-{
-	struct bch_fs *c = as->c;
-	struct btree *b;
-	struct prealloc_nodes *p = &as->prealloc_nodes[!!level];
-	int ret;
-
-	BUG_ON(level >= BTREE_MAX_DEPTH);
-	BUG_ON(!p->nr);
-
-	b = p->b[--p->nr];
-
-	btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_intent);
-	btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_write);
-
-	set_btree_node_accessed(b);
-	set_btree_node_dirty_acct(c, b);
-	set_btree_node_need_write(b);
-
-	bch2_bset_init_first(b, &b->data->keys);
-	b->c.level	= level;
-	b->c.btree_id	= as->btree_id;
-	b->version_ondisk = c->sb.version;
-
-	memset(&b->nr, 0, sizeof(b->nr));
-	b->data->magic = cpu_to_le64(bset_magic(c));
-	memset(&b->data->_ptr, 0, sizeof(b->data->_ptr));
-	b->data->flags = 0;
-	SET_BTREE_NODE_ID(b->data, as->btree_id);
-	SET_BTREE_NODE_LEVEL(b->data, level);
-
-	if (b->key.k.type == KEY_TYPE_btree_ptr_v2) {
-		struct bkey_i_btree_ptr_v2 *bp = bkey_i_to_btree_ptr_v2(&b->key);
-
-		bp->v.mem_ptr		= 0;
-		bp->v.seq		= b->data->keys.seq;
-		bp->v.sectors_written	= 0;
-	}
-
-	SET_BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data, true);
-
-	bch2_btree_build_aux_trees(b);
-
-	ret = bch2_btree_node_hash_insert(&c->btree_cache, b, level, as->btree_id);
-	BUG_ON(ret);
-
-	trace_and_count(c, btree_node_alloc, trans, b);
-	bch2_increment_clock(c, btree_sectors(c), WRITE);
-	return b;
-}
-
-static void btree_set_min(struct btree *b, struct bpos pos)
-{
-	if (b->key.k.type == KEY_TYPE_btree_ptr_v2)
-		bkey_i_to_btree_ptr_v2(&b->key)->v.min_key = pos;
-	b->data->min_key = pos;
-}
-
-static void btree_set_max(struct btree *b, struct bpos pos)
-{
-	b->key.k.p = pos;
-	b->data->max_key = pos;
-}
-
-static struct btree *bch2_btree_node_alloc_replacement(struct btree_update *as,
-						       struct btree_trans *trans,
-						       struct btree *b)
-{
-	struct btree *n = bch2_btree_node_alloc(as, trans, b->c.level);
-	struct bkey_format format = bch2_btree_calc_format(b);
-
-	/*
-	 * The keys might expand with the new format - if they wouldn't fit in
-	 * the btree node anymore, use the old format for now:
-	 */
-	if (!bch2_btree_node_format_fits(as->c, b, b->nr, &format))
-		format = b->format;
-
-	SET_BTREE_NODE_SEQ(n->data, BTREE_NODE_SEQ(b->data) + 1);
-
-	btree_set_min(n, b->data->min_key);
-	btree_set_max(n, b->data->max_key);
-
-	n->data->format		= format;
-	btree_node_set_format(n, format);
-
-	bch2_btree_sort_into(as->c, n, b);
-
-	btree_node_reset_sib_u64s(n);
-	return n;
-}
-
-static struct btree *__btree_root_alloc(struct btree_update *as,
-				struct btree_trans *trans, unsigned level)
-{
-	struct btree *b = bch2_btree_node_alloc(as, trans, level);
-
-	btree_set_min(b, POS_MIN);
-	btree_set_max(b, SPOS_MAX);
-	b->data->format = bch2_btree_calc_format(b);
-
-	btree_node_set_format(b, b->data->format);
-	bch2_btree_build_aux_trees(b);
-
-	return b;
-}
-
-static void bch2_btree_reserve_put(struct btree_update *as, struct btree_trans *trans)
-{
-	struct bch_fs *c = as->c;
-	struct prealloc_nodes *p;
-
-	for (p = as->prealloc_nodes;
-	     p < as->prealloc_nodes + ARRAY_SIZE(as->prealloc_nodes);
-	     p++) {
-		while (p->nr) {
-			struct btree *b = p->b[--p->nr];
-
-			mutex_lock(&c->btree_reserve_cache_lock);
-
-			if (c->btree_reserve_cache_nr <
-			    ARRAY_SIZE(c->btree_reserve_cache)) {
-				struct btree_alloc *a =
-					&c->btree_reserve_cache[c->btree_reserve_cache_nr++];
-
-				a->ob = b->ob;
-				b->ob.nr = 0;
-				bkey_copy(&a->k, &b->key);
-			} else {
-				bch2_open_buckets_put(c, &b->ob);
-			}
-
-			mutex_unlock(&c->btree_reserve_cache_lock);
-
-			btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_intent);
-			btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_write);
-			__btree_node_free(trans, b);
-			six_unlock_write(&b->c.lock);
-			six_unlock_intent(&b->c.lock);
-		}
-	}
-}
-
-static int bch2_btree_reserve_get(struct btree_trans *trans,
-				  struct btree_update *as,
-				  unsigned nr_nodes[2],
-				  unsigned flags,
-				  struct closure *cl)
-{
-	struct btree *b;
-	unsigned interior;
-	int ret = 0;
-
-	BUG_ON(nr_nodes[0] + nr_nodes[1] > BTREE_RESERVE_MAX);
-
-	/*
-	 * Protects reaping from the btree node cache and using the btree node
-	 * open bucket reserve:
-	 */
-	ret = bch2_btree_cache_cannibalize_lock(trans, cl);
-	if (ret)
-		return ret;
-
-	for (interior = 0; interior < 2; interior++) {
-		struct prealloc_nodes *p = as->prealloc_nodes + interior;
-
-		while (p->nr < nr_nodes[interior]) {
-			b = __bch2_btree_node_alloc(trans, &as->disk_res, cl,
-						    interior, flags);
-			if (IS_ERR(b)) {
-				ret = PTR_ERR(b);
-				goto err;
-			}
-
-			p->b[p->nr++] = b;
-		}
-	}
-err:
-	bch2_btree_cache_cannibalize_unlock(trans);
-	return ret;
-}
-
-/* Asynchronous interior node update machinery */
-
-static void bch2_btree_update_free(struct btree_update *as, struct btree_trans *trans)
-{
-	struct bch_fs *c = as->c;
-
-	if (as->took_gc_lock)
-		up_read(&c->gc_lock);
-	as->took_gc_lock = false;
-
-	bch2_journal_pin_drop(&c->journal, &as->journal);
-	bch2_journal_pin_flush(&c->journal, &as->journal);
-	bch2_disk_reservation_put(c, &as->disk_res);
-	bch2_btree_reserve_put(as, trans);
-
-	bch2_time_stats_update(&c->times[BCH_TIME_btree_interior_update_total],
-			       as->start_time);
-
-	mutex_lock(&c->btree_interior_update_lock);
-	list_del(&as->unwritten_list);
-	list_del(&as->list);
-
-	closure_debug_destroy(&as->cl);
-	mempool_free(as, &c->btree_interior_update_pool);
-
-	/*
-	 * Have to do the wakeup with btree_interior_update_lock still held,
-	 * since being on btree_interior_update_list is our ref on @c:
-	 */
-	closure_wake_up(&c->btree_interior_update_wait);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static void btree_update_add_key(struct btree_update *as,
-				 struct keylist *keys, struct btree *b)
-{
-	struct bkey_i *k = &b->key;
-
-	BUG_ON(bch2_keylist_u64s(keys) + k->k.u64s >
-	       ARRAY_SIZE(as->_old_keys));
-
-	bkey_copy(keys->top, k);
-	bkey_i_to_btree_ptr_v2(keys->top)->v.mem_ptr = b->c.level + 1;
-
-	bch2_keylist_push(keys);
-}
-
-/*
- * The transactional part of an interior btree node update, where we journal the
- * update we did to the interior node and update alloc info:
- */
-static int btree_update_nodes_written_trans(struct btree_trans *trans,
-					    struct btree_update *as)
-{
-	struct jset_entry *e = bch2_trans_jset_entry_alloc(trans, as->journal_u64s);
-	int ret = PTR_ERR_OR_ZERO(e);
-	if (ret)
-		return ret;
-
-	memcpy(e, as->journal_entries, as->journal_u64s * sizeof(u64));
-
-	trans->journal_pin = &as->journal;
-
-	for_each_keylist_key(&as->old_keys, k) {
-		unsigned level = bkey_i_to_btree_ptr_v2(k)->v.mem_ptr;
-
-		ret = bch2_key_trigger_old(trans, as->btree_id, level, bkey_i_to_s_c(k),
-					   BTREE_TRIGGER_TRANSACTIONAL);
-		if (ret)
-			return ret;
-	}
-
-	for_each_keylist_key(&as->new_keys, k) {
-		unsigned level = bkey_i_to_btree_ptr_v2(k)->v.mem_ptr;
-
-		ret = bch2_key_trigger_new(trans, as->btree_id, level, bkey_i_to_s(k),
-					   BTREE_TRIGGER_TRANSACTIONAL);
-		if (ret)
-			return ret;
-	}
-
-	return 0;
-}
-
-static void btree_update_nodes_written(struct btree_update *as)
-{
-	struct bch_fs *c = as->c;
-	struct btree *b;
-	struct btree_trans *trans = bch2_trans_get(c);
-	u64 journal_seq = 0;
-	unsigned i;
-	int ret;
-
-	/*
-	 * If we're already in an error state, it might be because a btree node
-	 * was never written, and we might be trying to free that same btree
-	 * node here, but it won't have been marked as allocated and we'll see
-	 * spurious disk usage inconsistencies in the transactional part below
-	 * if we don't skip it:
-	 */
-	ret = bch2_journal_error(&c->journal);
-	if (ret)
-		goto err;
-
-	/*
-	 * Wait for any in flight writes to finish before we free the old nodes
-	 * on disk:
-	 */
-	for (i = 0; i < as->nr_old_nodes; i++) {
-		__le64 seq;
-
-		b = as->old_nodes[i];
-
-		btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_read);
-		seq = b->data ? b->data->keys.seq : 0;
-		six_unlock_read(&b->c.lock);
-
-		if (seq == as->old_nodes_seq[i])
-			wait_on_bit_io(&b->flags, BTREE_NODE_write_in_flight_inner,
-				       TASK_UNINTERRUPTIBLE);
-	}
-
-	/*
-	 * We did an update to a parent node where the pointers we added pointed
-	 * to child nodes that weren't written yet: now, the child nodes have
-	 * been written so we can write out the update to the interior node.
-	 */
-
-	/*
-	 * We can't call into journal reclaim here: we'd block on the journal
-	 * reclaim lock, but we may need to release the open buckets we have
-	 * pinned in order for other btree updates to make forward progress, and
-	 * journal reclaim does btree updates when flushing bkey_cached entries,
-	 * which may require allocations as well.
-	 */
-	ret = commit_do(trans, &as->disk_res, &journal_seq,
-			BCH_WATERMARK_reclaim|
-			BCH_TRANS_COMMIT_no_enospc|
-			BCH_TRANS_COMMIT_no_check_rw|
-			BCH_TRANS_COMMIT_journal_reclaim,
-			btree_update_nodes_written_trans(trans, as));
-	bch2_trans_unlock(trans);
-
-	bch2_fs_fatal_err_on(ret && !bch2_journal_error(&c->journal), c,
-			     "%s(): error %s", __func__, bch2_err_str(ret));
-err:
-	if (as->b) {
-
-		b = as->b;
-		btree_path_idx_t path_idx = get_unlocked_mut_path(trans,
-						as->btree_id, b->c.level, b->key.k.p);
-		struct btree_path *path = trans->paths + path_idx;
-		/*
-		 * @b is the node we did the final insert into:
-		 *
-		 * On failure to get a journal reservation, we still have to
-		 * unblock the write and allow most of the write path to happen
-		 * so that shutdown works, but the i->journal_seq mechanism
-		 * won't work to prevent the btree write from being visible (we
-		 * didn't get a journal sequence number) - instead
-		 * __bch2_btree_node_write() doesn't do the actual write if
-		 * we're in journal error state:
-		 */
-
-		/*
-		 * Ensure transaction is unlocked before using
-		 * btree_node_lock_nopath() (the use of which is always suspect,
-		 * we need to work on removing this in the future)
-		 *
-		 * It should be, but get_unlocked_mut_path() -> bch2_path_get()
-		 * calls bch2_path_upgrade(), before we call path_make_mut(), so
-		 * we may rarely end up with a locked path besides the one we
-		 * have here:
-		 */
-		bch2_trans_unlock(trans);
-		btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_intent);
-		mark_btree_node_locked(trans, path, b->c.level, BTREE_NODE_INTENT_LOCKED);
-		path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock);
-		path->l[b->c.level].b = b;
-
-		bch2_btree_node_lock_write_nofail(trans, path, &b->c);
-
-		mutex_lock(&c->btree_interior_update_lock);
-
-		list_del(&as->write_blocked_list);
-		if (list_empty(&b->write_blocked))
-			clear_btree_node_write_blocked(b);
-
-		/*
-		 * Node might have been freed, recheck under
-		 * btree_interior_update_lock:
-		 */
-		if (as->b == b) {
-			BUG_ON(!b->c.level);
-			BUG_ON(!btree_node_dirty(b));
-
-			if (!ret) {
-				struct bset *last = btree_bset_last(b);
-
-				last->journal_seq = cpu_to_le64(
-							     max(journal_seq,
-								 le64_to_cpu(last->journal_seq)));
-
-				bch2_btree_add_journal_pin(c, b, journal_seq);
-			} else {
-				/*
-				 * If we didn't get a journal sequence number we
-				 * can't write this btree node, because recovery
-				 * won't know to ignore this write:
-				 */
-				set_btree_node_never_write(b);
-			}
-		}
-
-		mutex_unlock(&c->btree_interior_update_lock);
-
-		mark_btree_node_locked_noreset(path, b->c.level, BTREE_NODE_INTENT_LOCKED);
-		six_unlock_write(&b->c.lock);
-
-		btree_node_write_if_need(c, b, SIX_LOCK_intent);
-		btree_node_unlock(trans, path, b->c.level);
-		bch2_path_put(trans, path_idx, true);
-	}
-
-	bch2_journal_pin_drop(&c->journal, &as->journal);
-
-	mutex_lock(&c->btree_interior_update_lock);
-	for (i = 0; i < as->nr_new_nodes; i++) {
-		b = as->new_nodes[i];
-
-		BUG_ON(b->will_make_reachable != (unsigned long) as);
-		b->will_make_reachable = 0;
-		clear_btree_node_will_make_reachable(b);
-	}
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	for (i = 0; i < as->nr_new_nodes; i++) {
-		b = as->new_nodes[i];
-
-		btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_read);
-		btree_node_write_if_need(c, b, SIX_LOCK_read);
-		six_unlock_read(&b->c.lock);
-	}
-
-	for (i = 0; i < as->nr_open_buckets; i++)
-		bch2_open_bucket_put(c, c->open_buckets + as->open_buckets[i]);
-
-	bch2_btree_update_free(as, trans);
-	bch2_trans_put(trans);
-}
-
-static void btree_interior_update_work(struct work_struct *work)
-{
-	struct bch_fs *c =
-		container_of(work, struct bch_fs, btree_interior_update_work);
-	struct btree_update *as;
-
-	while (1) {
-		mutex_lock(&c->btree_interior_update_lock);
-		as = list_first_entry_or_null(&c->btree_interior_updates_unwritten,
-					      struct btree_update, unwritten_list);
-		if (as && !as->nodes_written)
-			as = NULL;
-		mutex_unlock(&c->btree_interior_update_lock);
-
-		if (!as)
-			break;
-
-		btree_update_nodes_written(as);
-	}
-}
-
-static CLOSURE_CALLBACK(btree_update_set_nodes_written)
-{
-	closure_type(as, struct btree_update, cl);
-	struct bch_fs *c = as->c;
-
-	mutex_lock(&c->btree_interior_update_lock);
-	as->nodes_written = true;
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	queue_work(c->btree_interior_update_worker, &c->btree_interior_update_work);
-}
-
-/*
- * We're updating @b with pointers to nodes that haven't finished writing yet:
- * block @b from being written until @as completes
- */
-static void btree_update_updated_node(struct btree_update *as, struct btree *b)
-{
-	struct bch_fs *c = as->c;
-
-	mutex_lock(&c->btree_interior_update_lock);
-	list_add_tail(&as->unwritten_list, &c->btree_interior_updates_unwritten);
-
-	BUG_ON(as->mode != BTREE_INTERIOR_NO_UPDATE);
-	BUG_ON(!btree_node_dirty(b));
-	BUG_ON(!b->c.level);
-
-	as->mode	= BTREE_INTERIOR_UPDATING_NODE;
-	as->b		= b;
-
-	set_btree_node_write_blocked(b);
-	list_add(&as->write_blocked_list, &b->write_blocked);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static int bch2_update_reparent_journal_pin_flush(struct journal *j,
-				struct journal_entry_pin *_pin, u64 seq)
-{
-	return 0;
-}
-
-static void btree_update_reparent(struct btree_update *as,
-				  struct btree_update *child)
-{
-	struct bch_fs *c = as->c;
-
-	lockdep_assert_held(&c->btree_interior_update_lock);
-
-	child->b = NULL;
-	child->mode = BTREE_INTERIOR_UPDATING_AS;
-
-	bch2_journal_pin_copy(&c->journal, &as->journal, &child->journal,
-			      bch2_update_reparent_journal_pin_flush);
-}
-
-static void btree_update_updated_root(struct btree_update *as, struct btree *b)
-{
-	struct bkey_i *insert = &b->key;
-	struct bch_fs *c = as->c;
-
-	BUG_ON(as->mode != BTREE_INTERIOR_NO_UPDATE);
-
-	BUG_ON(as->journal_u64s + jset_u64s(insert->k.u64s) >
-	       ARRAY_SIZE(as->journal_entries));
-
-	as->journal_u64s +=
-		journal_entry_set((void *) &as->journal_entries[as->journal_u64s],
-				  BCH_JSET_ENTRY_btree_root,
-				  b->c.btree_id, b->c.level,
-				  insert, insert->k.u64s);
-
-	mutex_lock(&c->btree_interior_update_lock);
-	list_add_tail(&as->unwritten_list, &c->btree_interior_updates_unwritten);
-
-	as->mode	= BTREE_INTERIOR_UPDATING_ROOT;
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-/*
- * bch2_btree_update_add_new_node:
- *
- * This causes @as to wait on @b to be written, before it gets to
- * bch2_btree_update_nodes_written
- *
- * Additionally, it sets b->will_make_reachable to prevent any additional writes
- * to @b from happening besides the first until @b is reachable on disk
- *
- * And it adds @b to the list of @as's new nodes, so that we can update sector
- * counts in bch2_btree_update_nodes_written:
- */
-static void bch2_btree_update_add_new_node(struct btree_update *as, struct btree *b)
-{
-	struct bch_fs *c = as->c;
-
-	closure_get(&as->cl);
-
-	mutex_lock(&c->btree_interior_update_lock);
-	BUG_ON(as->nr_new_nodes >= ARRAY_SIZE(as->new_nodes));
-	BUG_ON(b->will_make_reachable);
-
-	as->new_nodes[as->nr_new_nodes++] = b;
-	b->will_make_reachable = 1UL|(unsigned long) as;
-	set_btree_node_will_make_reachable(b);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	btree_update_add_key(as, &as->new_keys, b);
-
-	if (b->key.k.type == KEY_TYPE_btree_ptr_v2) {
-		unsigned bytes = vstruct_end(&b->data->keys) - (void *) b->data;
-		unsigned sectors = round_up(bytes, block_bytes(c)) >> 9;
-
-		bkey_i_to_btree_ptr_v2(&b->key)->v.sectors_written =
-			cpu_to_le16(sectors);
-	}
-}
-
-/*
- * returns true if @b was a new node
- */
-static void btree_update_drop_new_node(struct bch_fs *c, struct btree *b)
-{
-	struct btree_update *as;
-	unsigned long v;
-	unsigned i;
-
-	mutex_lock(&c->btree_interior_update_lock);
-	/*
-	 * When b->will_make_reachable != 0, it owns a ref on as->cl that's
-	 * dropped when it gets written by bch2_btree_complete_write - the
-	 * xchg() is for synchronization with bch2_btree_complete_write:
-	 */
-	v = xchg(&b->will_make_reachable, 0);
-	clear_btree_node_will_make_reachable(b);
-	as = (struct btree_update *) (v & ~1UL);
-
-	if (!as) {
-		mutex_unlock(&c->btree_interior_update_lock);
-		return;
-	}
-
-	for (i = 0; i < as->nr_new_nodes; i++)
-		if (as->new_nodes[i] == b)
-			goto found;
-
-	BUG();
-found:
-	array_remove_item(as->new_nodes, as->nr_new_nodes, i);
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	if (v & 1)
-		closure_put(&as->cl);
-}
-
-static void bch2_btree_update_get_open_buckets(struct btree_update *as, struct btree *b)
-{
-	while (b->ob.nr)
-		as->open_buckets[as->nr_open_buckets++] =
-			b->ob.v[--b->ob.nr];
-}
-
-static int bch2_btree_update_will_free_node_journal_pin_flush(struct journal *j,
-				struct journal_entry_pin *_pin, u64 seq)
-{
-	return 0;
-}
-
-/*
- * @b is being split/rewritten: it may have pointers to not-yet-written btree
- * nodes and thus outstanding btree_updates - redirect @b's
- * btree_updates to point to this btree_update:
- */
-static void bch2_btree_interior_update_will_free_node(struct btree_update *as,
-						      struct btree *b)
-{
-	struct bch_fs *c = as->c;
-	struct btree_update *p, *n;
-	struct btree_write *w;
-
-	set_btree_node_dying(b);
-
-	if (btree_node_fake(b))
-		return;
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	/*
-	 * Does this node have any btree_update operations preventing
-	 * it from being written?
-	 *
-	 * If so, redirect them to point to this btree_update: we can
-	 * write out our new nodes, but we won't make them visible until those
-	 * operations complete
-	 */
-	list_for_each_entry_safe(p, n, &b->write_blocked, write_blocked_list) {
-		list_del_init(&p->write_blocked_list);
-		btree_update_reparent(as, p);
-
-		/*
-		 * for flush_held_btree_writes() waiting on updates to flush or
-		 * nodes to be writeable:
-		 */
-		closure_wake_up(&c->btree_interior_update_wait);
-	}
-
-	clear_btree_node_dirty_acct(c, b);
-	clear_btree_node_need_write(b);
-	clear_btree_node_write_blocked(b);
-
-	/*
-	 * Does this node have unwritten data that has a pin on the journal?
-	 *
-	 * If so, transfer that pin to the btree_update operation -
-	 * note that if we're freeing multiple nodes, we only need to keep the
-	 * oldest pin of any of the nodes we're freeing. We'll release the pin
-	 * when the new nodes are persistent and reachable on disk:
-	 */
-	w = btree_current_write(b);
-	bch2_journal_pin_copy(&c->journal, &as->journal, &w->journal,
-			      bch2_btree_update_will_free_node_journal_pin_flush);
-	bch2_journal_pin_drop(&c->journal, &w->journal);
-
-	w = btree_prev_write(b);
-	bch2_journal_pin_copy(&c->journal, &as->journal, &w->journal,
-			      bch2_btree_update_will_free_node_journal_pin_flush);
-	bch2_journal_pin_drop(&c->journal, &w->journal);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	/*
-	 * Is this a node that isn't reachable on disk yet?
-	 *
-	 * Nodes that aren't reachable yet have writes blocked until they're
-	 * reachable - now that we've cancelled any pending writes and moved
-	 * things waiting on that write to wait on this update, we can drop this
-	 * node from the list of nodes that the other update is making
-	 * reachable, prior to freeing it:
-	 */
-	btree_update_drop_new_node(c, b);
-
-	btree_update_add_key(as, &as->old_keys, b);
-
-	as->old_nodes[as->nr_old_nodes] = b;
-	as->old_nodes_seq[as->nr_old_nodes] = b->data->keys.seq;
-	as->nr_old_nodes++;
-}
-
-static void bch2_btree_update_done(struct btree_update *as, struct btree_trans *trans)
-{
-	struct bch_fs *c = as->c;
-	u64 start_time = as->start_time;
-
-	BUG_ON(as->mode == BTREE_INTERIOR_NO_UPDATE);
-
-	if (as->took_gc_lock)
-		up_read(&as->c->gc_lock);
-	as->took_gc_lock = false;
-
-	bch2_btree_reserve_put(as, trans);
-
-	continue_at(&as->cl, btree_update_set_nodes_written,
-		    as->c->btree_interior_update_worker);
-
-	bch2_time_stats_update(&c->times[BCH_TIME_btree_interior_update_foreground],
-			       start_time);
-}
-
-static struct btree_update *
-bch2_btree_update_start(struct btree_trans *trans, struct btree_path *path,
-			unsigned level, bool split, unsigned flags)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_update *as;
-	u64 start_time = local_clock();
-	int disk_res_flags = (flags & BCH_TRANS_COMMIT_no_enospc)
-		? BCH_DISK_RESERVATION_NOFAIL : 0;
-	unsigned nr_nodes[2] = { 0, 0 };
-	unsigned update_level = level;
-	enum bch_watermark watermark = flags & BCH_WATERMARK_MASK;
-	int ret = 0;
-	u32 restart_count = trans->restart_count;
-
-	BUG_ON(!path->should_be_locked);
-
-	if (watermark == BCH_WATERMARK_copygc)
-		watermark = BCH_WATERMARK_btree_copygc;
-	if (watermark < BCH_WATERMARK_btree)
-		watermark = BCH_WATERMARK_btree;
-
-	flags &= ~BCH_WATERMARK_MASK;
-	flags |= watermark;
-
-	if (!(flags & BCH_TRANS_COMMIT_journal_reclaim) &&
-	    watermark < c->journal.watermark) {
-		struct journal_res res = { 0 };
-
-		ret = drop_locks_do(trans,
-			bch2_journal_res_get(&c->journal, &res, 1,
-					     watermark|JOURNAL_RES_GET_CHECK));
-		if (ret)
-			return ERR_PTR(ret);
-	}
-
-	while (1) {
-		nr_nodes[!!update_level] += 1 + split;
-		update_level++;
-
-		ret = bch2_btree_path_upgrade(trans, path, update_level + 1);
-		if (ret)
-			return ERR_PTR(ret);
-
-		if (!btree_path_node(path, update_level)) {
-			/* Allocating new root? */
-			nr_nodes[1] += split;
-			update_level = BTREE_MAX_DEPTH;
-			break;
-		}
-
-		/*
-		 * Always check for space for two keys, even if we won't have to
-		 * split at prior level - it might have been a merge instead:
-		 */
-		if (bch2_btree_node_insert_fits(c, path->l[update_level].b,
-						BKEY_BTREE_PTR_U64s_MAX * 2))
-			break;
-
-		split = path->l[update_level].b->nr.live_u64s > BTREE_SPLIT_THRESHOLD(c);
-	}
-
-	if (!down_read_trylock(&c->gc_lock)) {
-		ret = drop_locks_do(trans, (down_read(&c->gc_lock), 0));
-		if (ret) {
-			up_read(&c->gc_lock);
-			return ERR_PTR(ret);
-		}
-	}
-
-	as = mempool_alloc(&c->btree_interior_update_pool, GFP_NOFS);
-	memset(as, 0, sizeof(*as));
-	closure_init(&as->cl, NULL);
-	as->c		= c;
-	as->start_time	= start_time;
-	as->mode	= BTREE_INTERIOR_NO_UPDATE;
-	as->took_gc_lock = true;
-	as->btree_id	= path->btree_id;
-	as->update_level = update_level;
-	INIT_LIST_HEAD(&as->list);
-	INIT_LIST_HEAD(&as->unwritten_list);
-	INIT_LIST_HEAD(&as->write_blocked_list);
-	bch2_keylist_init(&as->old_keys, as->_old_keys);
-	bch2_keylist_init(&as->new_keys, as->_new_keys);
-	bch2_keylist_init(&as->parent_keys, as->inline_keys);
-
-	mutex_lock(&c->btree_interior_update_lock);
-	list_add_tail(&as->list, &c->btree_interior_update_list);
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	/*
-	 * We don't want to allocate if we're in an error state, that can cause
-	 * deadlock on emergency shutdown due to open buckets getting stuck in
-	 * the btree_reserve_cache after allocator shutdown has cleared it out.
-	 * This check needs to come after adding us to the btree_interior_update
-	 * list but before calling bch2_btree_reserve_get, to synchronize with
-	 * __bch2_fs_read_only().
-	 */
-	ret = bch2_journal_error(&c->journal);
-	if (ret)
-		goto err;
-
-	ret = bch2_disk_reservation_get(c, &as->disk_res,
-			(nr_nodes[0] + nr_nodes[1]) * btree_sectors(c),
-			c->opts.metadata_replicas,
-			disk_res_flags);
-	if (ret)
-		goto err;
-
-	ret = bch2_btree_reserve_get(trans, as, nr_nodes, flags, NULL);
-	if (bch2_err_matches(ret, ENOSPC) ||
-	    bch2_err_matches(ret, ENOMEM)) {
-		struct closure cl;
-
-		/*
-		 * XXX: this should probably be a separate BTREE_INSERT_NONBLOCK
-		 * flag
-		 */
-		if (bch2_err_matches(ret, ENOSPC) &&
-		    (flags & BCH_TRANS_COMMIT_journal_reclaim) &&
-		    watermark != BCH_WATERMARK_reclaim) {
-			ret = -BCH_ERR_journal_reclaim_would_deadlock;
-			goto err;
-		}
-
-		closure_init_stack(&cl);
-
-		do {
-			ret = bch2_btree_reserve_get(trans, as, nr_nodes, flags, &cl);
-
-			bch2_trans_unlock(trans);
-			closure_sync(&cl);
-		} while (bch2_err_matches(ret, BCH_ERR_operation_blocked));
-	}
-
-	if (ret) {
-		trace_and_count(c, btree_reserve_get_fail, trans->fn,
-				_RET_IP_, nr_nodes[0] + nr_nodes[1], ret);
-		goto err;
-	}
-
-	ret = bch2_trans_relock(trans);
-	if (ret)
-		goto err;
-
-	bch2_trans_verify_not_restarted(trans, restart_count);
-	return as;
-err:
-	bch2_btree_update_free(as, trans);
-	if (!bch2_err_matches(ret, ENOSPC) &&
-	    !bch2_err_matches(ret, EROFS))
-		bch_err_fn_ratelimited(c, ret);
-	return ERR_PTR(ret);
-}
-
-/* Btree root updates: */
-
-static void bch2_btree_set_root_inmem(struct bch_fs *c, struct btree *b)
-{
-	/* Root nodes cannot be reaped */
-	mutex_lock(&c->btree_cache.lock);
-	list_del_init(&b->list);
-	mutex_unlock(&c->btree_cache.lock);
-
-	mutex_lock(&c->btree_root_lock);
-	BUG_ON(btree_node_root(c, b) &&
-	       (b->c.level < btree_node_root(c, b)->c.level ||
-		!btree_node_dying(btree_node_root(c, b))));
-
-	bch2_btree_id_root(c, b->c.btree_id)->b = b;
-	mutex_unlock(&c->btree_root_lock);
-
-	bch2_recalc_btree_reserve(c);
-}
-
-static void bch2_btree_set_root(struct btree_update *as,
-				struct btree_trans *trans,
-				struct btree_path *path,
-				struct btree *b)
-{
-	struct bch_fs *c = as->c;
-	struct btree *old;
-
-	trace_and_count(c, btree_node_set_root, trans, b);
-
-	old = btree_node_root(c, b);
-
-	/*
-	 * Ensure no one is using the old root while we switch to the
-	 * new root:
-	 */
-	bch2_btree_node_lock_write_nofail(trans, path, &old->c);
-
-	bch2_btree_set_root_inmem(c, b);
-
-	btree_update_updated_root(as, b);
-
-	/*
-	 * Unlock old root after new root is visible:
-	 *
-	 * The new root isn't persistent, but that's ok: we still have
-	 * an intent lock on the new root, and any updates that would
-	 * depend on the new root would have to update the new root.
-	 */
-	bch2_btree_node_unlock_write(trans, path, old);
-}
-
-/* Interior node updates: */
-
-static void bch2_insert_fixup_btree_ptr(struct btree_update *as,
-					struct btree_trans *trans,
-					struct btree_path *path,
-					struct btree *b,
-					struct btree_node_iter *node_iter,
-					struct bkey_i *insert)
-{
-	struct bch_fs *c = as->c;
-	struct bkey_packed *k;
-	struct printbuf buf = PRINTBUF;
-	unsigned long old, new, v;
-
-	BUG_ON(insert->k.type == KEY_TYPE_btree_ptr_v2 &&
-	       !btree_ptr_sectors_written(insert));
-
-	if (unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)))
-		bch2_journal_key_overwritten(c, b->c.btree_id, b->c.level, insert->k.p);
-
-	if (bch2_bkey_invalid(c, bkey_i_to_s_c(insert),
-			      btree_node_type(b), WRITE, &buf) ?:
-	    bch2_bkey_in_btree_node(c, b, bkey_i_to_s_c(insert), &buf)) {
-		printbuf_reset(&buf);
-		prt_printf(&buf, "inserting invalid bkey\n  ");
-		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(insert));
-		prt_printf(&buf, "\n  ");
-		bch2_bkey_invalid(c, bkey_i_to_s_c(insert),
-				  btree_node_type(b), WRITE, &buf);
-		bch2_bkey_in_btree_node(c, b, bkey_i_to_s_c(insert), &buf);
-
-		bch2_fs_inconsistent(c, "%s", buf.buf);
-		dump_stack();
-	}
-
-	BUG_ON(as->journal_u64s + jset_u64s(insert->k.u64s) >
-	       ARRAY_SIZE(as->journal_entries));
-
-	as->journal_u64s +=
-		journal_entry_set((void *) &as->journal_entries[as->journal_u64s],
-				  BCH_JSET_ENTRY_btree_keys,
-				  b->c.btree_id, b->c.level,
-				  insert, insert->k.u64s);
-
-	while ((k = bch2_btree_node_iter_peek_all(node_iter, b)) &&
-	       bkey_iter_pos_cmp(b, k, &insert->k.p) < 0)
-		bch2_btree_node_iter_advance(node_iter, b);
-
-	bch2_btree_bset_insert_key(trans, path, b, node_iter, insert);
-	set_btree_node_dirty_acct(c, b);
-
-	v = READ_ONCE(b->flags);
-	do {
-		old = new = v;
-
-		new &= ~BTREE_WRITE_TYPE_MASK;
-		new |= BTREE_WRITE_interior;
-		new |= 1 << BTREE_NODE_need_write;
-	} while ((v = cmpxchg(&b->flags, old, new)) != old);
-
-	printbuf_exit(&buf);
-}
-
-static void
-__bch2_btree_insert_keys_interior(struct btree_update *as,
-				  struct btree_trans *trans,
-				  struct btree_path *path,
-				  struct btree *b,
-				  struct btree_node_iter node_iter,
-				  struct keylist *keys)
-{
-	struct bkey_i *insert = bch2_keylist_front(keys);
-	struct bkey_packed *k;
-
-	BUG_ON(btree_node_type(b) != BKEY_TYPE_btree);
-
-	while ((k = bch2_btree_node_iter_prev_all(&node_iter, b)) &&
-	       (bkey_cmp_left_packed(b, k, &insert->k.p) >= 0))
-		;
-
-	while (!bch2_keylist_empty(keys)) {
-		insert = bch2_keylist_front(keys);
-
-		if (bpos_gt(insert->k.p, b->key.k.p))
-			break;
-
-		bch2_insert_fixup_btree_ptr(as, trans, path, b, &node_iter, insert);
-		bch2_keylist_pop_front(keys);
-	}
-}
-
-/*
- * Move keys from n1 (original replacement node, now lower node) to n2 (higher
- * node)
- */
-static void __btree_split_node(struct btree_update *as,
-			       struct btree_trans *trans,
-			       struct btree *b,
-			       struct btree *n[2])
-{
-	struct bkey_packed *k;
-	struct bpos n1_pos = POS_MIN;
-	struct btree_node_iter iter;
-	struct bset *bsets[2];
-	struct bkey_format_state format[2];
-	struct bkey_packed *out[2];
-	struct bkey uk;
-	unsigned u64s, n1_u64s = (b->nr.live_u64s * 3) / 5;
-	struct { unsigned nr_keys, val_u64s; } nr_keys[2];
-	int i;
-
-	memset(&nr_keys, 0, sizeof(nr_keys));
-
-	for (i = 0; i < 2; i++) {
-		BUG_ON(n[i]->nsets != 1);
-
-		bsets[i] = btree_bset_first(n[i]);
-		out[i] = bsets[i]->start;
-
-		SET_BTREE_NODE_SEQ(n[i]->data, BTREE_NODE_SEQ(b->data) + 1);
-		bch2_bkey_format_init(&format[i]);
-	}
-
-	u64s = 0;
-	for_each_btree_node_key(b, k, &iter) {
-		if (bkey_deleted(k))
-			continue;
-
-		i = u64s >= n1_u64s;
-		u64s += k->u64s;
-		uk = bkey_unpack_key(b, k);
-		if (!i)
-			n1_pos = uk.p;
-		bch2_bkey_format_add_key(&format[i], &uk);
-
-		nr_keys[i].nr_keys++;
-		nr_keys[i].val_u64s += bkeyp_val_u64s(&b->format, k);
-	}
-
-	btree_set_min(n[0], b->data->min_key);
-	btree_set_max(n[0], n1_pos);
-	btree_set_min(n[1], bpos_successor(n1_pos));
-	btree_set_max(n[1], b->data->max_key);
-
-	for (i = 0; i < 2; i++) {
-		bch2_bkey_format_add_pos(&format[i], n[i]->data->min_key);
-		bch2_bkey_format_add_pos(&format[i], n[i]->data->max_key);
-
-		n[i]->data->format = bch2_bkey_format_done(&format[i]);
-
-		unsigned u64s = nr_keys[i].nr_keys * n[i]->data->format.key_u64s +
-			nr_keys[i].val_u64s;
-		if (__vstruct_bytes(struct btree_node, u64s) > btree_bytes(as->c))
-			n[i]->data->format = b->format;
-
-		btree_node_set_format(n[i], n[i]->data->format);
-	}
-
-	u64s = 0;
-	for_each_btree_node_key(b, k, &iter) {
-		if (bkey_deleted(k))
-			continue;
-
-		i = u64s >= n1_u64s;
-		u64s += k->u64s;
-
-		if (bch2_bkey_transform(&n[i]->format, out[i], bkey_packed(k)
-					? &b->format: &bch2_bkey_format_current, k))
-			out[i]->format = KEY_FORMAT_LOCAL_BTREE;
-		else
-			bch2_bkey_unpack(b, (void *) out[i], k);
-
-		out[i]->needs_whiteout = false;
-
-		btree_keys_account_key_add(&n[i]->nr, 0, out[i]);
-		out[i] = bkey_p_next(out[i]);
-	}
-
-	for (i = 0; i < 2; i++) {
-		bsets[i]->u64s = cpu_to_le16((u64 *) out[i] - bsets[i]->_data);
-
-		BUG_ON(!bsets[i]->u64s);
-
-		set_btree_bset_end(n[i], n[i]->set);
-
-		btree_node_reset_sib_u64s(n[i]);
-
-		bch2_verify_btree_nr_keys(n[i]);
-
-		if (b->c.level)
-			btree_node_interior_verify(as->c, n[i]);
-	}
-}
-
-/*
- * For updates to interior nodes, we've got to do the insert before we split
- * because the stuff we're inserting has to be inserted atomically. Post split,
- * the keys might have to go in different nodes and the split would no longer be
- * atomic.
- *
- * Worse, if the insert is from btree node coalescing, if we do the insert after
- * we do the split (and pick the pivot) - the pivot we pick might be between
- * nodes that were coalesced, and thus in the middle of a child node post
- * coalescing:
- */
-static void btree_split_insert_keys(struct btree_update *as,
-				    struct btree_trans *trans,
-				    btree_path_idx_t path_idx,
-				    struct btree *b,
-				    struct keylist *keys)
-{
-	struct btree_path *path = trans->paths + path_idx;
-
-	if (!bch2_keylist_empty(keys) &&
-	    bpos_le(bch2_keylist_front(keys)->k.p, b->data->max_key)) {
-		struct btree_node_iter node_iter;
-
-		bch2_btree_node_iter_init(&node_iter, b, &bch2_keylist_front(keys)->k.p);
-
-		__bch2_btree_insert_keys_interior(as, trans, path, b, node_iter, keys);
-
-		btree_node_interior_verify(as->c, b);
-	}
-}
-
-static int btree_split(struct btree_update *as, struct btree_trans *trans,
-		       btree_path_idx_t path, struct btree *b,
-		       struct keylist *keys, unsigned flags)
-{
-	struct bch_fs *c = as->c;
-	struct btree *parent = btree_node_parent(trans->paths + path, b);
-	struct btree *n1, *n2 = NULL, *n3 = NULL;
-	btree_path_idx_t path1 = 0, path2 = 0;
-	u64 start_time = local_clock();
-	int ret = 0;
-
-	BUG_ON(!parent && (b != btree_node_root(c, b)));
-	BUG_ON(parent && !btree_node_intent_locked(trans->paths + path, b->c.level + 1));
-
-	bch2_btree_interior_update_will_free_node(as, b);
-
-	if (b->nr.live_u64s > BTREE_SPLIT_THRESHOLD(c)) {
-		struct btree *n[2];
-
-		trace_and_count(c, btree_node_split, trans, b);
-
-		n[0] = n1 = bch2_btree_node_alloc(as, trans, b->c.level);
-		n[1] = n2 = bch2_btree_node_alloc(as, trans, b->c.level);
-
-		__btree_split_node(as, trans, b, n);
-
-		if (keys) {
-			btree_split_insert_keys(as, trans, path, n1, keys);
-			btree_split_insert_keys(as, trans, path, n2, keys);
-			BUG_ON(!bch2_keylist_empty(keys));
-		}
-
-		bch2_btree_build_aux_trees(n2);
-		bch2_btree_build_aux_trees(n1);
-
-		bch2_btree_update_add_new_node(as, n1);
-		bch2_btree_update_add_new_node(as, n2);
-		six_unlock_write(&n2->c.lock);
-		six_unlock_write(&n1->c.lock);
-
-		path1 = get_unlocked_mut_path(trans, as->btree_id, n1->c.level, n1->key.k.p);
-		six_lock_increment(&n1->c.lock, SIX_LOCK_intent);
-		mark_btree_node_locked(trans, trans->paths + path1, n1->c.level, BTREE_NODE_INTENT_LOCKED);
-		bch2_btree_path_level_init(trans, trans->paths + path1, n1);
-
-		path2 = get_unlocked_mut_path(trans, as->btree_id, n2->c.level, n2->key.k.p);
-		six_lock_increment(&n2->c.lock, SIX_LOCK_intent);
-		mark_btree_node_locked(trans, trans->paths + path2, n2->c.level, BTREE_NODE_INTENT_LOCKED);
-		bch2_btree_path_level_init(trans, trans->paths + path2, n2);
-
-		/*
-		 * Note that on recursive parent_keys == keys, so we
-		 * can't start adding new keys to parent_keys before emptying it
-		 * out (which we did with btree_split_insert_keys() above)
-		 */
-		bch2_keylist_add(&as->parent_keys, &n1->key);
-		bch2_keylist_add(&as->parent_keys, &n2->key);
-
-		if (!parent) {
-			/* Depth increases, make a new root */
-			n3 = __btree_root_alloc(as, trans, b->c.level + 1);
-
-			bch2_btree_update_add_new_node(as, n3);
-			six_unlock_write(&n3->c.lock);
-
-			trans->paths[path2].locks_want++;
-			BUG_ON(btree_node_locked(trans->paths + path2, n3->c.level));
-			six_lock_increment(&n3->c.lock, SIX_LOCK_intent);
-			mark_btree_node_locked(trans, trans->paths + path2, n3->c.level, BTREE_NODE_INTENT_LOCKED);
-			bch2_btree_path_level_init(trans, trans->paths + path2, n3);
-
-			n3->sib_u64s[0] = U16_MAX;
-			n3->sib_u64s[1] = U16_MAX;
-
-			btree_split_insert_keys(as, trans, path, n3, &as->parent_keys);
-		}
-	} else {
-		trace_and_count(c, btree_node_compact, trans, b);
-
-		n1 = bch2_btree_node_alloc_replacement(as, trans, b);
-
-		if (keys) {
-			btree_split_insert_keys(as, trans, path, n1, keys);
-			BUG_ON(!bch2_keylist_empty(keys));
-		}
-
-		bch2_btree_build_aux_trees(n1);
-		bch2_btree_update_add_new_node(as, n1);
-		six_unlock_write(&n1->c.lock);
-
-		path1 = get_unlocked_mut_path(trans, as->btree_id, n1->c.level, n1->key.k.p);
-		six_lock_increment(&n1->c.lock, SIX_LOCK_intent);
-		mark_btree_node_locked(trans, trans->paths + path1, n1->c.level, BTREE_NODE_INTENT_LOCKED);
-		bch2_btree_path_level_init(trans, trans->paths + path1, n1);
-
-		if (parent)
-			bch2_keylist_add(&as->parent_keys, &n1->key);
-	}
-
-	/* New nodes all written, now make them visible: */
-
-	if (parent) {
-		/* Split a non root node */
-		ret = bch2_btree_insert_node(as, trans, path, parent, &as->parent_keys, flags);
-		if (ret)
-			goto err;
-	} else if (n3) {
-		bch2_btree_set_root(as, trans, trans->paths + path, n3);
-	} else {
-		/* Root filled up but didn't need to be split */
-		bch2_btree_set_root(as, trans, trans->paths + path, n1);
-	}
-
-	if (n3) {
-		bch2_btree_update_get_open_buckets(as, n3);
-		bch2_btree_node_write(c, n3, SIX_LOCK_intent, 0);
-	}
-	if (n2) {
-		bch2_btree_update_get_open_buckets(as, n2);
-		bch2_btree_node_write(c, n2, SIX_LOCK_intent, 0);
-	}
-	bch2_btree_update_get_open_buckets(as, n1);
-	bch2_btree_node_write(c, n1, SIX_LOCK_intent, 0);
-
-	/*
-	 * The old node must be freed (in memory) _before_ unlocking the new
-	 * nodes - else another thread could re-acquire a read lock on the old
-	 * node after another thread has locked and updated the new node, thus
-	 * seeing stale data:
-	 */
-	bch2_btree_node_free_inmem(trans, trans->paths + path, b);
-
-	if (n3)
-		bch2_trans_node_add(trans, trans->paths + path, n3);
-	if (n2)
-		bch2_trans_node_add(trans, trans->paths + path2, n2);
-	bch2_trans_node_add(trans, trans->paths + path1, n1);
-
-	if (n3)
-		six_unlock_intent(&n3->c.lock);
-	if (n2)
-		six_unlock_intent(&n2->c.lock);
-	six_unlock_intent(&n1->c.lock);
-out:
-	if (path2) {
-		__bch2_btree_path_unlock(trans, trans->paths + path2);
-		bch2_path_put(trans, path2, true);
-	}
-	if (path1) {
-		__bch2_btree_path_unlock(trans, trans->paths + path1);
-		bch2_path_put(trans, path1, true);
-	}
-
-	bch2_trans_verify_locks(trans);
-
-	bch2_time_stats_update(&c->times[n2
-			       ? BCH_TIME_btree_node_split
-			       : BCH_TIME_btree_node_compact],
-			       start_time);
-	return ret;
-err:
-	if (n3)
-		bch2_btree_node_free_never_used(as, trans, n3);
-	if (n2)
-		bch2_btree_node_free_never_used(as, trans, n2);
-	bch2_btree_node_free_never_used(as, trans, n1);
-	goto out;
-}
-
-static void
-bch2_btree_insert_keys_interior(struct btree_update *as,
-				struct btree_trans *trans,
-				struct btree_path *path,
-				struct btree *b,
-				struct keylist *keys)
-{
-	struct btree_path *linked;
-	unsigned i;
-
-	__bch2_btree_insert_keys_interior(as, trans, path, b,
-					  path->l[b->c.level].iter, keys);
-
-	btree_update_updated_node(as, b);
-
-	trans_for_each_path_with_node(trans, b, linked, i)
-		bch2_btree_node_iter_peek(&linked->l[b->c.level].iter, b);
-
-	bch2_trans_verify_paths(trans);
-}
-
-/**
- * bch2_btree_insert_node - insert bkeys into a given btree node
- *
- * @as:			btree_update object
- * @trans:		btree_trans object
- * @path_idx:		path that points to current node
- * @b:			node to insert keys into
- * @keys:		list of keys to insert
- * @flags:		transaction commit flags
- *
- * Returns: 0 on success, typically transaction restart error on failure
- *
- * Inserts as many keys as it can into a given btree node, splitting it if full.
- * If a split occurred, this function will return early. This can only happen
- * for leaf nodes -- inserts into interior nodes have to be atomic.
- */
-static int bch2_btree_insert_node(struct btree_update *as, struct btree_trans *trans,
-				  btree_path_idx_t path_idx, struct btree *b,
-				  struct keylist *keys, unsigned flags)
-{
-	struct bch_fs *c = as->c;
-	struct btree_path *path = trans->paths + path_idx;
-	int old_u64s = le16_to_cpu(btree_bset_last(b)->u64s);
-	int old_live_u64s = b->nr.live_u64s;
-	int live_u64s_added, u64s_added;
-	int ret;
-
-	lockdep_assert_held(&c->gc_lock);
-	BUG_ON(!btree_node_intent_locked(path, b->c.level));
-	BUG_ON(!b->c.level);
-	BUG_ON(!as || as->b);
-	bch2_verify_keylist_sorted(keys);
-
-	ret = bch2_btree_node_lock_write(trans, path, &b->c);
-	if (ret)
-		return ret;
-
-	bch2_btree_node_prep_for_write(trans, path, b);
-
-	if (!bch2_btree_node_insert_fits(c, b, bch2_keylist_u64s(keys))) {
-		bch2_btree_node_unlock_write(trans, path, b);
-		goto split;
-	}
-
-	btree_node_interior_verify(c, b);
-
-	bch2_btree_insert_keys_interior(as, trans, path, b, keys);
-
-	live_u64s_added = (int) b->nr.live_u64s - old_live_u64s;
-	u64s_added = (int) le16_to_cpu(btree_bset_last(b)->u64s) - old_u64s;
-
-	if (b->sib_u64s[0] != U16_MAX && live_u64s_added < 0)
-		b->sib_u64s[0] = max(0, (int) b->sib_u64s[0] + live_u64s_added);
-	if (b->sib_u64s[1] != U16_MAX && live_u64s_added < 0)
-		b->sib_u64s[1] = max(0, (int) b->sib_u64s[1] + live_u64s_added);
-
-	if (u64s_added > live_u64s_added &&
-	    bch2_maybe_compact_whiteouts(c, b))
-		bch2_trans_node_reinit_iter(trans, b);
-
-	bch2_btree_node_unlock_write(trans, path, b);
-
-	btree_node_interior_verify(c, b);
-	return 0;
-split:
-	/*
-	 * We could attempt to avoid the transaction restart, by calling
-	 * bch2_btree_path_upgrade() and allocating more nodes:
-	 */
-	if (b->c.level >= as->update_level) {
-		trace_and_count(c, trans_restart_split_race, trans, _THIS_IP_, b);
-		return btree_trans_restart(trans, BCH_ERR_transaction_restart_split_race);
-	}
-
-	return btree_split(as, trans, path_idx, b, keys, flags);
-}
-
-int bch2_btree_split_leaf(struct btree_trans *trans,
-			  btree_path_idx_t path,
-			  unsigned flags)
-{
-	/* btree_split & merge may both cause paths array to be reallocated */
-
-	struct btree *b = path_l(trans->paths + path)->b;
-	struct btree_update *as;
-	unsigned l;
-	int ret = 0;
-
-	as = bch2_btree_update_start(trans, trans->paths + path,
-				     trans->paths[path].level,
-				     true, flags);
-	if (IS_ERR(as))
-		return PTR_ERR(as);
-
-	ret = btree_split(as, trans, path, b, NULL, flags);
-	if (ret) {
-		bch2_btree_update_free(as, trans);
-		return ret;
-	}
-
-	bch2_btree_update_done(as, trans);
-
-	for (l = trans->paths[path].level + 1;
-	     btree_node_intent_locked(&trans->paths[path], l) && !ret;
-	     l++)
-		ret = bch2_foreground_maybe_merge(trans, path, l, flags);
-
-	return ret;
-}
-
-int __bch2_foreground_maybe_merge(struct btree_trans *trans,
-				  btree_path_idx_t path,
-				  unsigned level,
-				  unsigned flags,
-				  enum btree_node_sibling sib)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_update *as;
-	struct bkey_format_state new_s;
-	struct bkey_format new_f;
-	struct bkey_i delete;
-	struct btree *b, *m, *n, *prev, *next, *parent;
-	struct bpos sib_pos;
-	size_t sib_u64s;
-	enum btree_id btree = trans->paths[path].btree_id;
-	btree_path_idx_t sib_path = 0, new_path = 0;
-	u64 start_time = local_clock();
-	int ret = 0;
-
-	BUG_ON(!trans->paths[path].should_be_locked);
-	BUG_ON(!btree_node_locked(&trans->paths[path], level));
-
-	b = trans->paths[path].l[level].b;
-
-	if ((sib == btree_prev_sib && bpos_eq(b->data->min_key, POS_MIN)) ||
-	    (sib == btree_next_sib && bpos_eq(b->data->max_key, SPOS_MAX))) {
-		b->sib_u64s[sib] = U16_MAX;
-		return 0;
-	}
-
-	sib_pos = sib == btree_prev_sib
-		? bpos_predecessor(b->data->min_key)
-		: bpos_successor(b->data->max_key);
-
-	sib_path = bch2_path_get(trans, btree, sib_pos,
-				 U8_MAX, level, BTREE_ITER_INTENT, _THIS_IP_);
-	ret = bch2_btree_path_traverse(trans, sib_path, false);
-	if (ret)
-		goto err;
-
-	btree_path_set_should_be_locked(trans->paths + sib_path);
-
-	m = trans->paths[sib_path].l[level].b;
-
-	if (btree_node_parent(trans->paths + path, b) !=
-	    btree_node_parent(trans->paths + sib_path, m)) {
-		b->sib_u64s[sib] = U16_MAX;
-		goto out;
-	}
-
-	if (sib == btree_prev_sib) {
-		prev = m;
-		next = b;
-	} else {
-		prev = b;
-		next = m;
-	}
-
-	if (!bpos_eq(bpos_successor(prev->data->max_key), next->data->min_key)) {
-		struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
-
-		bch2_bpos_to_text(&buf1, prev->data->max_key);
-		bch2_bpos_to_text(&buf2, next->data->min_key);
-		bch_err(c,
-			"%s(): btree topology error:\n"
-			"  prev ends at   %s\n"
-			"  next starts at %s",
-			__func__, buf1.buf, buf2.buf);
-		printbuf_exit(&buf1);
-		printbuf_exit(&buf2);
-		bch2_topology_error(c);
-		ret = -EIO;
-		goto err;
-	}
-
-	bch2_bkey_format_init(&new_s);
-	bch2_bkey_format_add_pos(&new_s, prev->data->min_key);
-	__bch2_btree_calc_format(&new_s, prev);
-	__bch2_btree_calc_format(&new_s, next);
-	bch2_bkey_format_add_pos(&new_s, next->data->max_key);
-	new_f = bch2_bkey_format_done(&new_s);
-
-	sib_u64s = btree_node_u64s_with_format(b->nr, &b->format, &new_f) +
-		btree_node_u64s_with_format(m->nr, &m->format, &new_f);
-
-	if (sib_u64s > BTREE_FOREGROUND_MERGE_HYSTERESIS(c)) {
-		sib_u64s -= BTREE_FOREGROUND_MERGE_HYSTERESIS(c);
-		sib_u64s /= 2;
-		sib_u64s += BTREE_FOREGROUND_MERGE_HYSTERESIS(c);
-	}
-
-	sib_u64s = min(sib_u64s, btree_max_u64s(c));
-	sib_u64s = min(sib_u64s, (size_t) U16_MAX - 1);
-	b->sib_u64s[sib] = sib_u64s;
-
-	if (b->sib_u64s[sib] > c->btree_foreground_merge_threshold)
-		goto out;
-
-	parent = btree_node_parent(trans->paths + path, b);
-	as = bch2_btree_update_start(trans, trans->paths + path, level, false,
-				     BCH_TRANS_COMMIT_no_enospc|flags);
-	ret = PTR_ERR_OR_ZERO(as);
-	if (ret)
-		goto err;
-
-	trace_and_count(c, btree_node_merge, trans, b);
-
-	bch2_btree_interior_update_will_free_node(as, b);
-	bch2_btree_interior_update_will_free_node(as, m);
-
-	n = bch2_btree_node_alloc(as, trans, b->c.level);
-
-	SET_BTREE_NODE_SEQ(n->data,
-			   max(BTREE_NODE_SEQ(b->data),
-			       BTREE_NODE_SEQ(m->data)) + 1);
-
-	btree_set_min(n, prev->data->min_key);
-	btree_set_max(n, next->data->max_key);
-
-	n->data->format	 = new_f;
-	btree_node_set_format(n, new_f);
-
-	bch2_btree_sort_into(c, n, prev);
-	bch2_btree_sort_into(c, n, next);
-
-	bch2_btree_build_aux_trees(n);
-	bch2_btree_update_add_new_node(as, n);
-	six_unlock_write(&n->c.lock);
-
-	new_path = get_unlocked_mut_path(trans, btree, n->c.level, n->key.k.p);
-	six_lock_increment(&n->c.lock, SIX_LOCK_intent);
-	mark_btree_node_locked(trans, trans->paths + new_path, n->c.level, BTREE_NODE_INTENT_LOCKED);
-	bch2_btree_path_level_init(trans, trans->paths + new_path, n);
-
-	bkey_init(&delete.k);
-	delete.k.p = prev->key.k.p;
-	bch2_keylist_add(&as->parent_keys, &delete);
-	bch2_keylist_add(&as->parent_keys, &n->key);
-
-	bch2_trans_verify_paths(trans);
-
-	ret = bch2_btree_insert_node(as, trans, path, parent, &as->parent_keys, flags);
-	if (ret)
-		goto err_free_update;
-
-	bch2_trans_verify_paths(trans);
-
-	bch2_btree_update_get_open_buckets(as, n);
-	bch2_btree_node_write(c, n, SIX_LOCK_intent, 0);
-
-	bch2_btree_node_free_inmem(trans, trans->paths + path, b);
-	bch2_btree_node_free_inmem(trans, trans->paths + sib_path, m);
-
-	bch2_trans_node_add(trans, trans->paths + path, n);
-
-	bch2_trans_verify_paths(trans);
-
-	six_unlock_intent(&n->c.lock);
-
-	bch2_btree_update_done(as, trans);
-
-	bch2_time_stats_update(&c->times[BCH_TIME_btree_node_merge], start_time);
-out:
-err:
-	if (new_path)
-		bch2_path_put(trans, new_path, true);
-	bch2_path_put(trans, sib_path, true);
-	bch2_trans_verify_locks(trans);
-	return ret;
-err_free_update:
-	bch2_btree_node_free_never_used(as, trans, n);
-	bch2_btree_update_free(as, trans);
-	goto out;
-}
-
-int bch2_btree_node_rewrite(struct btree_trans *trans,
-			    struct btree_iter *iter,
-			    struct btree *b,
-			    unsigned flags)
-{
-	struct bch_fs *c = trans->c;
-	struct btree *n, *parent;
-	struct btree_update *as;
-	btree_path_idx_t new_path = 0;
-	int ret;
-
-	flags |= BCH_TRANS_COMMIT_no_enospc;
-
-	struct btree_path *path = btree_iter_path(trans, iter);
-	parent = btree_node_parent(path, b);
-	as = bch2_btree_update_start(trans, path, b->c.level, false, flags);
-	ret = PTR_ERR_OR_ZERO(as);
-	if (ret)
-		goto out;
-
-	bch2_btree_interior_update_will_free_node(as, b);
-
-	n = bch2_btree_node_alloc_replacement(as, trans, b);
-
-	bch2_btree_build_aux_trees(n);
-	bch2_btree_update_add_new_node(as, n);
-	six_unlock_write(&n->c.lock);
-
-	new_path = get_unlocked_mut_path(trans, iter->btree_id, n->c.level, n->key.k.p);
-	six_lock_increment(&n->c.lock, SIX_LOCK_intent);
-	mark_btree_node_locked(trans, trans->paths + new_path, n->c.level, BTREE_NODE_INTENT_LOCKED);
-	bch2_btree_path_level_init(trans, trans->paths + new_path, n);
-
-	trace_and_count(c, btree_node_rewrite, trans, b);
-
-	if (parent) {
-		bch2_keylist_add(&as->parent_keys, &n->key);
-		ret = bch2_btree_insert_node(as, trans, iter->path,
-					     parent, &as->parent_keys, flags);
-		if (ret)
-			goto err;
-	} else {
-		bch2_btree_set_root(as, trans, btree_iter_path(trans, iter), n);
-	}
-
-	bch2_btree_update_get_open_buckets(as, n);
-	bch2_btree_node_write(c, n, SIX_LOCK_intent, 0);
-
-	bch2_btree_node_free_inmem(trans, btree_iter_path(trans, iter), b);
-
-	bch2_trans_node_add(trans, trans->paths + iter->path, n);
-	six_unlock_intent(&n->c.lock);
-
-	bch2_btree_update_done(as, trans);
-out:
-	if (new_path)
-		bch2_path_put(trans, new_path, true);
-	bch2_trans_downgrade(trans);
-	return ret;
-err:
-	bch2_btree_node_free_never_used(as, trans, n);
-	bch2_btree_update_free(as, trans);
-	goto out;
-}
-
-struct async_btree_rewrite {
-	struct bch_fs		*c;
-	struct work_struct	work;
-	struct list_head	list;
-	enum btree_id		btree_id;
-	unsigned		level;
-	struct bpos		pos;
-	__le64			seq;
-};
-
-static int async_btree_node_rewrite_trans(struct btree_trans *trans,
-					  struct async_btree_rewrite *a)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_iter iter;
-	struct btree *b;
-	int ret;
-
-	bch2_trans_node_iter_init(trans, &iter, a->btree_id, a->pos,
-				  BTREE_MAX_DEPTH, a->level, 0);
-	b = bch2_btree_iter_peek_node(&iter);
-	ret = PTR_ERR_OR_ZERO(b);
-	if (ret)
-		goto out;
-
-	if (!b || b->data->keys.seq != a->seq) {
-		struct printbuf buf = PRINTBUF;
-
-		if (b)
-			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&b->key));
-		else
-			prt_str(&buf, "(null");
-		bch_info(c, "%s: node to rewrite not found:, searching for seq %llu, got\n%s",
-			 __func__, a->seq, buf.buf);
-		printbuf_exit(&buf);
-		goto out;
-	}
-
-	ret = bch2_btree_node_rewrite(trans, &iter, b, 0);
-out:
-	bch2_trans_iter_exit(trans, &iter);
-
-	return ret;
-}
-
-static void async_btree_node_rewrite_work(struct work_struct *work)
-{
-	struct async_btree_rewrite *a =
-		container_of(work, struct async_btree_rewrite, work);
-	struct bch_fs *c = a->c;
-	int ret;
-
-	ret = bch2_trans_do(c, NULL, NULL, 0,
-		      async_btree_node_rewrite_trans(trans, a));
-	bch_err_fn(c, ret);
-	bch2_write_ref_put(c, BCH_WRITE_REF_node_rewrite);
-	kfree(a);
-}
-
-void bch2_btree_node_rewrite_async(struct bch_fs *c, struct btree *b)
-{
-	struct async_btree_rewrite *a;
-	int ret;
-
-	a = kmalloc(sizeof(*a), GFP_NOFS);
-	if (!a) {
-		bch_err(c, "%s: error allocating memory", __func__);
-		return;
-	}
-
-	a->c		= c;
-	a->btree_id	= b->c.btree_id;
-	a->level	= b->c.level;
-	a->pos		= b->key.k.p;
-	a->seq		= b->data->keys.seq;
-	INIT_WORK(&a->work, async_btree_node_rewrite_work);
-
-	if (unlikely(!test_bit(BCH_FS_may_go_rw, &c->flags))) {
-		mutex_lock(&c->pending_node_rewrites_lock);
-		list_add(&a->list, &c->pending_node_rewrites);
-		mutex_unlock(&c->pending_node_rewrites_lock);
-		return;
-	}
-
-	if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_node_rewrite)) {
-		if (test_bit(BCH_FS_started, &c->flags)) {
-			bch_err(c, "%s: error getting c->writes ref", __func__);
-			kfree(a);
-			return;
-		}
-
-		ret = bch2_fs_read_write_early(c);
-		bch_err_msg(c, ret, "going read-write");
-		if (ret) {
-			kfree(a);
-			return;
-		}
-
-		bch2_write_ref_get(c, BCH_WRITE_REF_node_rewrite);
-	}
-
-	queue_work(c->btree_interior_update_worker, &a->work);
-}
-
-void bch2_do_pending_node_rewrites(struct bch_fs *c)
-{
-	struct async_btree_rewrite *a, *n;
-
-	mutex_lock(&c->pending_node_rewrites_lock);
-	list_for_each_entry_safe(a, n, &c->pending_node_rewrites, list) {
-		list_del(&a->list);
-
-		bch2_write_ref_get(c, BCH_WRITE_REF_node_rewrite);
-		queue_work(c->btree_interior_update_worker, &a->work);
-	}
-	mutex_unlock(&c->pending_node_rewrites_lock);
-}
-
-void bch2_free_pending_node_rewrites(struct bch_fs *c)
-{
-	struct async_btree_rewrite *a, *n;
-
-	mutex_lock(&c->pending_node_rewrites_lock);
-	list_for_each_entry_safe(a, n, &c->pending_node_rewrites, list) {
-		list_del(&a->list);
-
-		kfree(a);
-	}
-	mutex_unlock(&c->pending_node_rewrites_lock);
-}
-
-static int __bch2_btree_node_update_key(struct btree_trans *trans,
-					struct btree_iter *iter,
-					struct btree *b, struct btree *new_hash,
-					struct bkey_i *new_key,
-					unsigned commit_flags,
-					bool skip_triggers)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_iter iter2 = { NULL };
-	struct btree *parent;
-	int ret;
-
-	if (!skip_triggers) {
-		ret   = bch2_key_trigger_old(trans, b->c.btree_id, b->c.level + 1,
-					     bkey_i_to_s_c(&b->key),
-					     BTREE_TRIGGER_TRANSACTIONAL) ?:
-			bch2_key_trigger_new(trans, b->c.btree_id, b->c.level + 1,
-					     bkey_i_to_s(new_key),
-					     BTREE_TRIGGER_TRANSACTIONAL);
-		if (ret)
-			return ret;
-	}
-
-	if (new_hash) {
-		bkey_copy(&new_hash->key, new_key);
-		ret = bch2_btree_node_hash_insert(&c->btree_cache,
-				new_hash, b->c.level, b->c.btree_id);
-		BUG_ON(ret);
-	}
-
-	parent = btree_node_parent(btree_iter_path(trans, iter), b);
-	if (parent) {
-		bch2_trans_copy_iter(&iter2, iter);
-
-		iter2.path = bch2_btree_path_make_mut(trans, iter2.path,
-				iter2.flags & BTREE_ITER_INTENT,
-				_THIS_IP_);
-
-		struct btree_path *path2 = btree_iter_path(trans, &iter2);
-		BUG_ON(path2->level != b->c.level);
-		BUG_ON(!bpos_eq(path2->pos, new_key->k.p));
-
-		btree_path_set_level_up(trans, path2);
-
-		trans->paths_sorted = false;
-
-		ret   = bch2_btree_iter_traverse(&iter2) ?:
-			bch2_trans_update(trans, &iter2, new_key, BTREE_TRIGGER_NORUN);
-		if (ret)
-			goto err;
-	} else {
-		BUG_ON(btree_node_root(c, b) != b);
-
-		struct jset_entry *e = bch2_trans_jset_entry_alloc(trans,
-				       jset_u64s(new_key->k.u64s));
-		ret = PTR_ERR_OR_ZERO(e);
-		if (ret)
-			return ret;
-
-		journal_entry_set(e,
-				  BCH_JSET_ENTRY_btree_root,
-				  b->c.btree_id, b->c.level,
-				  new_key, new_key->k.u64s);
-	}
-
-	ret = bch2_trans_commit(trans, NULL, NULL, commit_flags);
-	if (ret)
-		goto err;
-
-	bch2_btree_node_lock_write_nofail(trans, btree_iter_path(trans, iter), &b->c);
-
-	if (new_hash) {
-		mutex_lock(&c->btree_cache.lock);
-		bch2_btree_node_hash_remove(&c->btree_cache, new_hash);
-		bch2_btree_node_hash_remove(&c->btree_cache, b);
-
-		bkey_copy(&b->key, new_key);
-		ret = __bch2_btree_node_hash_insert(&c->btree_cache, b);
-		BUG_ON(ret);
-		mutex_unlock(&c->btree_cache.lock);
-	} else {
-		bkey_copy(&b->key, new_key);
-	}
-
-	bch2_btree_node_unlock_write(trans, btree_iter_path(trans, iter), b);
-out:
-	bch2_trans_iter_exit(trans, &iter2);
-	return ret;
-err:
-	if (new_hash) {
-		mutex_lock(&c->btree_cache.lock);
-		bch2_btree_node_hash_remove(&c->btree_cache, b);
-		mutex_unlock(&c->btree_cache.lock);
-	}
-	goto out;
-}
-
-int bch2_btree_node_update_key(struct btree_trans *trans, struct btree_iter *iter,
-			       struct btree *b, struct bkey_i *new_key,
-			       unsigned commit_flags, bool skip_triggers)
-{
-	struct bch_fs *c = trans->c;
-	struct btree *new_hash = NULL;
-	struct btree_path *path = btree_iter_path(trans, iter);
-	struct closure cl;
-	int ret = 0;
-
-	ret = bch2_btree_path_upgrade(trans, path, b->c.level + 1);
-	if (ret)
-		return ret;
-
-	closure_init_stack(&cl);
-
-	/*
-	 * check btree_ptr_hash_val() after @b is locked by
-	 * btree_iter_traverse():
-	 */
-	if (btree_ptr_hash_val(new_key) != b->hash_val) {
-		ret = bch2_btree_cache_cannibalize_lock(trans, &cl);
-		if (ret) {
-			ret = drop_locks_do(trans, (closure_sync(&cl), 0));
-			if (ret)
-				return ret;
-		}
-
-		new_hash = bch2_btree_node_mem_alloc(trans, false);
-	}
-
-	path->intent_ref++;
-	ret = __bch2_btree_node_update_key(trans, iter, b, new_hash, new_key,
-					   commit_flags, skip_triggers);
-	--path->intent_ref;
-
-	if (new_hash) {
-		mutex_lock(&c->btree_cache.lock);
-		list_move(&new_hash->list, &c->btree_cache.freeable);
-		mutex_unlock(&c->btree_cache.lock);
-
-		six_unlock_write(&new_hash->c.lock);
-		six_unlock_intent(&new_hash->c.lock);
-	}
-	closure_sync(&cl);
-	bch2_btree_cache_cannibalize_unlock(trans);
-	return ret;
-}
-
-int bch2_btree_node_update_key_get_iter(struct btree_trans *trans,
-					struct btree *b, struct bkey_i *new_key,
-					unsigned commit_flags, bool skip_triggers)
-{
-	struct btree_iter iter;
-	int ret;
-
-	bch2_trans_node_iter_init(trans, &iter, b->c.btree_id, b->key.k.p,
-				  BTREE_MAX_DEPTH, b->c.level,
-				  BTREE_ITER_INTENT);
-	ret = bch2_btree_iter_traverse(&iter);
-	if (ret)
-		goto out;
-
-	/* has node been freed? */
-	if (btree_iter_path(trans, &iter)->l[b->c.level].b != b) {
-		/* node has been freed: */
-		BUG_ON(!btree_node_dying(b));
-		goto out;
-	}
-
-	BUG_ON(!btree_node_hashed(b));
-
-	struct bch_extent_ptr *ptr;
-	bch2_bkey_drop_ptrs(bkey_i_to_s(new_key), ptr,
-			    !bch2_bkey_has_device(bkey_i_to_s(&b->key), ptr->dev));
-
-	ret = bch2_btree_node_update_key(trans, &iter, b, new_key,
-					 commit_flags, skip_triggers);
-out:
-	bch2_trans_iter_exit(trans, &iter);
-	return ret;
-}
-
-/* Init code: */
-
-/*
- * Only for filesystem bringup, when first reading the btree roots or allocating
- * btree roots when initializing a new filesystem:
- */
-void bch2_btree_set_root_for_read(struct bch_fs *c, struct btree *b)
-{
-	BUG_ON(btree_node_root(c, b));
-
-	bch2_btree_set_root_inmem(c, b);
-}
-
-static int __bch2_btree_root_alloc(struct btree_trans *trans, enum btree_id id)
-{
-	struct bch_fs *c = trans->c;
-	struct closure cl;
-	struct btree *b;
-	int ret;
-
-	closure_init_stack(&cl);
-
-	do {
-		ret = bch2_btree_cache_cannibalize_lock(trans, &cl);
-		closure_sync(&cl);
-	} while (ret);
-
-	b = bch2_btree_node_mem_alloc(trans, false);
-	bch2_btree_cache_cannibalize_unlock(trans);
-
-	set_btree_node_fake(b);
-	set_btree_node_need_rewrite(b);
-	b->c.level	= 0;
-	b->c.btree_id	= id;
-
-	bkey_btree_ptr_init(&b->key);
-	b->key.k.p = SPOS_MAX;
-	*((u64 *) bkey_i_to_btree_ptr(&b->key)->v.start) = U64_MAX - id;
-
-	bch2_bset_init_first(b, &b->data->keys);
-	bch2_btree_build_aux_trees(b);
-
-	b->data->flags = 0;
-	btree_set_min(b, POS_MIN);
-	btree_set_max(b, SPOS_MAX);
-	b->data->format = bch2_btree_calc_format(b);
-	btree_node_set_format(b, b->data->format);
-
-	ret = bch2_btree_node_hash_insert(&c->btree_cache, b,
-					  b->c.level, b->c.btree_id);
-	BUG_ON(ret);
-
-	bch2_btree_set_root_inmem(c, b);
-
-	six_unlock_write(&b->c.lock);
-	six_unlock_intent(&b->c.lock);
-	return 0;
-}
-
-void bch2_btree_root_alloc(struct bch_fs *c, enum btree_id id)
-{
-	bch2_trans_run(c, __bch2_btree_root_alloc(trans, id));
-}
-
-void bch2_btree_updates_to_text(struct printbuf *out, struct bch_fs *c)
-{
-	struct btree_update *as;
-
-	mutex_lock(&c->btree_interior_update_lock);
-	list_for_each_entry(as, &c->btree_interior_update_list, list)
-		prt_printf(out, "%p m %u w %u r %u j %llu\n",
-		       as,
-		       as->mode,
-		       as->nodes_written,
-		       closure_nr_remaining(&as->cl),
-		       as->journal.seq);
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static bool bch2_btree_interior_updates_pending(struct bch_fs *c)
-{
-	bool ret;
-
-	mutex_lock(&c->btree_interior_update_lock);
-	ret = !list_empty(&c->btree_interior_update_list);
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	return ret;
-}
-
-bool bch2_btree_interior_updates_flush(struct bch_fs *c)
-{
-	bool ret = bch2_btree_interior_updates_pending(c);
-
-	if (ret)
-		closure_wait_event(&c->btree_interior_update_wait,
-				   !bch2_btree_interior_updates_pending(c));
-	return ret;
-}
-
-void bch2_journal_entry_to_btree_root(struct bch_fs *c, struct jset_entry *entry)
-{
-	struct btree_root *r = bch2_btree_id_root(c, entry->btree_id);
-
-	mutex_lock(&c->btree_root_lock);
-
-	r->level = entry->level;
-	r->alive = true;
-	bkey_copy(&r->key, (struct bkey_i *) entry->start);
-
-	mutex_unlock(&c->btree_root_lock);
-}
-
-struct jset_entry *
-bch2_btree_roots_to_journal_entries(struct bch_fs *c,
-				    struct jset_entry *end,
-				    unsigned long skip)
-{
-	unsigned i;
-
-	mutex_lock(&c->btree_root_lock);
-
-	for (i = 0; i < btree_id_nr_alive(c); i++) {
-		struct btree_root *r = bch2_btree_id_root(c, i);
-
-		if (r->alive && !test_bit(i, &skip)) {
-			journal_entry_set(end, BCH_JSET_ENTRY_btree_root,
-					  i, r->level, &r->key, r->key.k.u64s);
-			end = vstruct_next(end);
-		}
-	}
-
-	mutex_unlock(&c->btree_root_lock);
-
-	return end;
-}
-
-void bch2_fs_btree_interior_update_exit(struct bch_fs *c)
-{
-	if (c->btree_interior_update_worker)
-		destroy_workqueue(c->btree_interior_update_worker);
-	mempool_exit(&c->btree_interior_update_pool);
-}
-
-void bch2_fs_btree_interior_update_init_early(struct bch_fs *c)
-{
-	mutex_init(&c->btree_reserve_cache_lock);
-	INIT_LIST_HEAD(&c->btree_interior_update_list);
-	INIT_LIST_HEAD(&c->btree_interior_updates_unwritten);
-	mutex_init(&c->btree_interior_update_lock);
-	INIT_WORK(&c->btree_interior_update_work, btree_interior_update_work);
-
-	INIT_LIST_HEAD(&c->pending_node_rewrites);
-	mutex_init(&c->pending_node_rewrites_lock);
-}
-
-int bch2_fs_btree_interior_update_init(struct bch_fs *c)
-{
-	c->btree_interior_update_worker =
-		alloc_workqueue("btree_update", WQ_UNBOUND|WQ_MEM_RECLAIM, 1);
-	if (!c->btree_interior_update_worker)
-		return -BCH_ERR_ENOMEM_btree_interior_update_worker_init;
-
-	if (mempool_init_kmalloc_pool(&c->btree_interior_update_pool, 1,
-				      sizeof(struct btree_update)))
-		return -BCH_ERR_ENOMEM_btree_interior_update_pool_init;
-
-	return 0;
-}