Update bcachefs sources to 6a25f7a00d bcachefs: fix ioctl code

1 files changed, 0 insertions, 2670 deletions

diff --git a/libbcachefs/btree_update.c b/libbcachefs/btree_update.c
deleted file mode 100644
index c7b20184..00000000
--- a/libbcachefs/btree_update.c
+++ /dev/null
@@ -1,2670 +0,0 @@
-
-#include "bcachefs.h"
-#include "alloc.h"
-#include "bkey_methods.h"
-#include "btree_cache.h"
-#include "btree_gc.h"
-#include "btree_update.h"
-#include "btree_io.h"
-#include "btree_iter.h"
-#include "btree_locking.h"
-#include "buckets.h"
-#include "extents.h"
-#include "journal.h"
-#include "keylist.h"
-#include "super-io.h"
-
-#include <linux/random.h>
-#include <linux/sort.h>
-#include <trace/events/bcachefs.h>
-
-static void btree_interior_update_updated_root(struct bch_fs *,
-					       struct btree_interior_update *,
-					       enum btree_id);
-static void btree_interior_update_will_make_reachable(struct bch_fs *,
-				struct btree_interior_update *,
-				struct btree *);
-static void btree_interior_update_drop_new_node(struct bch_fs *,
-						struct btree *);
-
-/* Calculate ideal packed bkey format for new btree nodes: */
-
-void __bch2_btree_calc_format(struct bkey_format_state *s, struct btree *b)
-{
-	struct bkey_packed *k;
-	struct bset_tree *t;
-	struct bkey uk;
-
-	bch2_bkey_format_add_pos(s, b->data->min_key);
-
-	for_each_bset(b, t)
-		for (k = btree_bkey_first(b, t);
-		     k != btree_bkey_last(b, t);
-		     k = bkey_next(k))
-			if (!bkey_whiteout(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_btree_calc_format(&s, b);
-
-	return bch2_bkey_format_done(&s);
-}
-
-static size_t btree_node_u64s_with_format(struct btree *b,
-					  struct bkey_format *new_f)
-{
-	struct bkey_format *old_f = &b->format;
-
-	/* stupid integer promotion rules */
-	ssize_t delta =
-	    (((int) new_f->key_u64s - old_f->key_u64s) *
-	     (int) b->nr.packed_keys) +
-	    (((int) new_f->key_u64s - BKEY_U64s) *
-	     (int) b->nr.unpacked_keys);
-
-	BUG_ON(delta + b->nr.live_u64s < 0);
-
-	return b->nr.live_u64s + delta;
-}
-
-/**
- * btree_node_format_fits - check if we could rewrite node with a new format
- *
- * This assumes all keys can pack with the new format -- it just checks if
- * the re-packed keys would fit inside the node itself.
- */
-bool bch2_btree_node_format_fits(struct bch_fs *c, struct btree *b,
-				struct bkey_format *new_f)
-{
-	size_t u64s = btree_node_u64s_with_format(b, new_f);
-
-	return __vstruct_bytes(struct btree_node, u64s) < btree_bytes(c);
-}
-
-/* Btree node freeing/allocation: */
-
-/*
- * We're doing the index update that makes @b unreachable, update stuff to
- * reflect that:
- *
- * Must be called _before_ btree_interior_update_updated_root() or
- * btree_interior_update_updated_btree:
- */
-static void bch2_btree_node_free_index(struct bch_fs *c, struct btree *b,
-				      enum btree_id id, struct bkey_s_c k,
-				      struct bch_fs_usage *stats)
-{
-	struct btree_interior_update *as;
-	struct pending_btree_node_free *d;
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	for_each_pending_btree_node_free(c, as, d)
-		if (!bkey_cmp(k.k->p, d->key.k.p) &&
-		    bkey_val_bytes(k.k) == bkey_val_bytes(&d->key.k) &&
-		    !memcmp(k.v, &d->key.v, bkey_val_bytes(k.k)))
-			goto found;
-
-	BUG();
-found:
-	d->index_update_done = true;
-
-	/*
-	 * Btree nodes are accounted as freed in bch_alloc_stats when they're
-	 * freed from the index:
-	 */
-	stats->s[S_COMPRESSED][S_META]	 -= c->sb.btree_node_size;
-	stats->s[S_UNCOMPRESSED][S_META] -= c->sb.btree_node_size;
-
-	/*
-	 * We're dropping @k from the btree, but it's still live until the
-	 * index update is persistent so we need to keep a reference around for
-	 * mark and sweep to find - that's primarily what the
-	 * btree_node_pending_free list is for.
-	 *
-	 * So here (when we set index_update_done = true), we're moving an
-	 * existing reference to a different part of the larger "gc keyspace" -
-	 * and the new position comes after the old position, since GC marks
-	 * the pending free list after it walks the btree.
-	 *
-	 * If we move the reference while mark and sweep is _between_ the old
-	 * and the new position, mark and sweep will see the reference twice
-	 * and it'll get double accounted - so check for that here and subtract
-	 * to cancel out one of mark and sweep's markings if necessary:
-	 */
-
-	/*
-	 * bch2_mark_key() compares the current gc pos to the pos we're
-	 * moving this reference from, hence one comparison here:
-	 */
-	if (gc_pos_cmp(c->gc_pos, gc_phase(GC_PHASE_PENDING_DELETE)) < 0) {
-		struct bch_fs_usage tmp = { 0 };
-
-		bch2_mark_key(c, bkey_i_to_s_c(&d->key),
-			     -c->sb.btree_node_size, true, b
-			     ? gc_pos_btree_node(b)
-			     : gc_pos_btree_root(id),
-			     &tmp, 0);
-		/*
-		 * Don't apply tmp - pending deletes aren't tracked in
-		 * bch_alloc_stats:
-		 */
-	}
-
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static void __btree_node_free(struct bch_fs *c, struct btree *b,
-			      struct btree_iter *iter)
-{
-	trace_btree_node_free(c, 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);
-	BUG_ON(!list_empty(&b->write_blocked));
-	BUG_ON(b->will_make_reachable);
-
-	clear_btree_node_noevict(b);
-
-	six_lock_write(&b->lock);
-
-	bch2_btree_node_hash_remove(c, b);
-
-	mutex_lock(&c->btree_cache_lock);
-	list_move(&b->list, &c->btree_cache_freeable);
-	mutex_unlock(&c->btree_cache_lock);
-
-	/*
-	 * By using six_unlock_write() directly instead of
-	 * bch2_btree_node_unlock_write(), we don't update the iterator's
-	 * sequence numbers and cause future bch2_btree_node_relock() calls to
-	 * fail:
-	 */
-	six_unlock_write(&b->lock);
-}
-
-void bch2_btree_node_free_never_inserted(struct bch_fs *c, struct btree *b)
-{
-	struct open_bucket *ob = b->ob;
-
-	btree_interior_update_drop_new_node(c, b);
-
-	b->ob = NULL;
-
-	clear_btree_node_dirty(b);
-
-	__btree_node_free(c, b, NULL);
-
-	bch2_open_bucket_put(c, ob);
-}
-
-void bch2_btree_node_free_inmem(struct btree_iter *iter, struct btree *b)
-{
-	bch2_btree_iter_node_drop_linked(iter, b);
-
-	__btree_node_free(iter->c, b, iter);
-
-	bch2_btree_iter_node_drop(iter, b);
-}
-
-static void bch2_btree_node_free_ondisk(struct bch_fs *c,
-				       struct pending_btree_node_free *pending)
-{
-	struct bch_fs_usage stats = { 0 };
-
-	BUG_ON(!pending->index_update_done);
-
-	bch2_mark_key(c, bkey_i_to_s_c(&pending->key),
-		     -c->sb.btree_node_size, true,
-		     gc_phase(GC_PHASE_PENDING_DELETE),
-		     &stats, 0);
-	/*
-	 * Don't apply stats - pending deletes aren't tracked in
-	 * bch_alloc_stats:
-	 */
-}
-
-void bch2_btree_open_bucket_put(struct bch_fs *c, struct btree *b)
-{
-	bch2_open_bucket_put(c, b->ob);
-	b->ob = NULL;
-}
-
-static struct btree *__bch2_btree_node_alloc(struct bch_fs *c,
-					     struct disk_reservation *res,
-					     struct closure *cl,
-					     unsigned flags)
-{
-	BKEY_PADDED(k) tmp;
-	struct open_bucket *ob;
-	struct btree *b;
-	unsigned nr_reserve;
-	enum alloc_reserve alloc_reserve;
-
-	if (flags & BTREE_INSERT_USE_ALLOC_RESERVE) {
-		nr_reserve	= 0;
-		alloc_reserve	= RESERVE_ALLOC;
-	} else if (flags & BTREE_INSERT_USE_RESERVE) {
-		nr_reserve	= BTREE_NODE_RESERVE / 2;
-		alloc_reserve	= RESERVE_BTREE;
-	} else {
-		nr_reserve	= BTREE_NODE_RESERVE;
-		alloc_reserve	= RESERVE_NONE;
-	}
-
-	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];
-
-		ob = 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:
-	/* alloc_sectors is weird, I suppose */
-	bkey_extent_init(&tmp.k);
-	tmp.k.k.size = c->sb.btree_node_size,
-
-	ob = bch2_alloc_sectors(c, &c->btree_write_point,
-			       bkey_i_to_extent(&tmp.k),
-			       res->nr_replicas,
-			       c->opts.metadata_replicas_required,
-			       alloc_reserve, cl);
-	if (IS_ERR(ob))
-		return ERR_CAST(ob);
-
-	if (tmp.k.k.size < c->sb.btree_node_size) {
-		bch2_open_bucket_put(c, ob);
-		goto retry;
-	}
-mem_alloc:
-	b = bch2_btree_node_mem_alloc(c);
-
-	/* we hold cannibalize_lock: */
-	BUG_ON(IS_ERR(b));
-	BUG_ON(b->ob);
-
-	bkey_copy(&b->key, &tmp.k);
-	b->key.k.size = 0;
-	b->ob = ob;
-
-	return b;
-}
-
-static struct btree *bch2_btree_node_alloc(struct bch_fs *c,
-					  unsigned level, enum btree_id id,
-					  struct btree_interior_update *as,
-					  struct btree_reserve *reserve)
-{
-	struct btree *b;
-
-	BUG_ON(!reserve->nr);
-
-	b = reserve->b[--reserve->nr];
-
-	BUG_ON(bch2_btree_node_hash_insert(c, b, level, id));
-
-	set_btree_node_accessed(b);
-	set_btree_node_dirty(b);
-
-	bch2_bset_init_first(b, &b->data->keys);
-	memset(&b->nr, 0, sizeof(b->nr));
-	b->data->magic = cpu_to_le64(bset_magic(c));
-	b->data->flags = 0;
-	SET_BTREE_NODE_ID(b->data, id);
-	SET_BTREE_NODE_LEVEL(b->data, level);
-	b->data->ptr = bkey_i_to_extent(&b->key)->v.start->ptr;
-
-	bch2_btree_build_aux_trees(b);
-
-	btree_interior_update_will_make_reachable(c, as, b);
-
-	trace_btree_node_alloc(c, b);
-	return b;
-}
-
-struct btree *__bch2_btree_node_alloc_replacement(struct bch_fs *c,
-						  struct btree *b,
-						  struct bkey_format format,
-						  struct btree_interior_update *as,
-						  struct btree_reserve *reserve)
-{
-	struct btree *n;
-
-	n = bch2_btree_node_alloc(c, b->level, b->btree_id, as, reserve);
-
-	n->data->min_key	= b->data->min_key;
-	n->data->max_key	= b->data->max_key;
-	n->data->format		= format;
-
-	btree_node_set_format(n, format);
-
-	bch2_btree_sort_into(c, n, b);
-
-	btree_node_reset_sib_u64s(n);
-
-	n->key.k.p = b->key.k.p;
-	return n;
-}
-
-static struct btree *bch2_btree_node_alloc_replacement(struct bch_fs *c,
-						struct btree *b,
-						struct btree_interior_update *as,
-						struct btree_reserve *reserve)
-{
-	struct bkey_format new_f = 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(c, b, &new_f))
-		new_f = b->format;
-
-	return __bch2_btree_node_alloc_replacement(c, b, new_f, as, reserve);
-}
-
-static void bch2_btree_set_root_inmem(struct bch_fs *c, struct btree *b,
-				     struct btree_reserve *btree_reserve)
-{
-	struct btree *old = btree_node_root(c, 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);
-	btree_node_root(c, b) = b;
-	mutex_unlock(&c->btree_root_lock);
-
-	if (btree_reserve) {
-		/*
-		 * New allocation (we're not being called because we're in
-		 * bch2_btree_root_read()) - do marking while holding
-		 * btree_root_lock:
-		 */
-		struct bch_fs_usage stats = { 0 };
-
-		bch2_mark_key(c, bkey_i_to_s_c(&b->key),
-			     c->sb.btree_node_size, true,
-			     gc_pos_btree_root(b->btree_id),
-			     &stats, 0);
-
-		if (old)
-			bch2_btree_node_free_index(c, NULL, old->btree_id,
-						  bkey_i_to_s_c(&old->key),
-						  &stats);
-		bch2_fs_usage_apply(c, &stats, &btree_reserve->disk_res,
-				   gc_pos_btree_root(b->btree_id));
-	}
-
-	bch2_recalc_btree_reserve(c);
-}
-
-static void bch2_btree_set_root_ondisk(struct bch_fs *c, struct btree *b)
-{
-	struct btree_root *r = &c->btree_roots[b->btree_id];
-
-	mutex_lock(&c->btree_root_lock);
-
-	BUG_ON(b != r->b);
-	bkey_copy(&r->key, &b->key);
-	r->level = b->level;
-	r->alive = true;
-
-	mutex_unlock(&c->btree_root_lock);
-}
-
-/*
- * Only for filesystem bringup, when first reading the btree roots or allocating
- * btree roots when initializing a new filesystem:
- */
-void bch2_btree_set_root_initial(struct bch_fs *c, struct btree *b,
-				struct btree_reserve *btree_reserve)
-{
-	BUG_ON(btree_node_root(c, b));
-
-	bch2_btree_set_root_inmem(c, b, btree_reserve);
-	bch2_btree_set_root_ondisk(c, b);
-}
-
-/**
- * bch_btree_set_root - update the root in memory and on disk
- *
- * To ensure forward progress, the current task must not be holding any
- * btree node write locks. However, you must hold an intent lock on the
- * old root.
- *
- * Note: This allocates a journal entry but doesn't add any keys to
- * it.  All the btree roots are part of every journal write, so there
- * is nothing new to be done.  This just guarantees that there is a
- * journal write.
- */
-static void bch2_btree_set_root(struct btree_iter *iter, struct btree *b,
-			       struct btree_interior_update *as,
-			       struct btree_reserve *btree_reserve)
-{
-	struct bch_fs *c = iter->c;
-	struct btree *old;
-
-	trace_btree_set_root(c, b);
-	BUG_ON(!b->written);
-
-	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(old, iter);
-
-	bch2_btree_set_root_inmem(c, b, btree_reserve);
-
-	btree_interior_update_updated_root(c, as, iter->btree_id);
-
-	/*
-	 * 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(old, iter);
-}
-
-static struct btree *__btree_root_alloc(struct bch_fs *c, unsigned level,
-					enum btree_id id,
-					struct btree_interior_update *as,
-					struct btree_reserve *reserve)
-{
-	struct btree *b = bch2_btree_node_alloc(c, level, id, as, reserve);
-
-	b->data->min_key = POS_MIN;
-	b->data->max_key = POS_MAX;
-	b->data->format = bch2_btree_calc_format(b);
-	b->key.k.p = POS_MAX;
-
-	btree_node_set_format(b, b->data->format);
-	bch2_btree_build_aux_trees(b);
-
-	six_unlock_write(&b->lock);
-
-	return b;
-}
-
-void bch2_btree_reserve_put(struct bch_fs *c, struct btree_reserve *reserve)
-{
-	bch2_disk_reservation_put(c, &reserve->disk_res);
-
-	mutex_lock(&c->btree_reserve_cache_lock);
-
-	while (reserve->nr) {
-		struct btree *b = reserve->b[--reserve->nr];
-
-		six_unlock_write(&b->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 = NULL;
-			bkey_copy(&a->k, &b->key);
-		} else {
-			bch2_open_bucket_put(c, b->ob);
-			b->ob = NULL;
-		}
-
-		__btree_node_free(c, b, NULL);
-
-		six_unlock_intent(&b->lock);
-	}
-
-	mutex_unlock(&c->btree_reserve_cache_lock);
-
-	mempool_free(reserve, &c->btree_reserve_pool);
-}
-
-static struct btree_reserve *__bch2_btree_reserve_get(struct bch_fs *c,
-						     unsigned nr_nodes,
-						     unsigned flags,
-						     struct closure *cl)
-{
-	struct btree_reserve *reserve;
-	struct btree *b;
-	struct disk_reservation disk_res = { 0, 0 };
-	unsigned sectors = nr_nodes * c->sb.btree_node_size;
-	int ret, disk_res_flags = BCH_DISK_RESERVATION_GC_LOCK_HELD|
-		BCH_DISK_RESERVATION_METADATA;
-
-	if (flags & BTREE_INSERT_NOFAIL)
-		disk_res_flags |= BCH_DISK_RESERVATION_NOFAIL;
-
-	/*
-	 * This check isn't necessary for correctness - it's just to potentially
-	 * prevent us from doing a lot of work that'll end up being wasted:
-	 */
-	ret = bch2_journal_error(&c->journal);
-	if (ret)
-		return ERR_PTR(ret);
-
-	if (bch2_disk_reservation_get(c, &disk_res, sectors, disk_res_flags))
-		return ERR_PTR(-ENOSPC);
-
-	BUG_ON(nr_nodes > BTREE_RESERVE_MAX);
-
-	/*
-	 * Protects reaping from the btree node cache and using the btree node
-	 * open bucket reserve:
-	 */
-	ret = bch2_btree_node_cannibalize_lock(c, cl);
-	if (ret) {
-		bch2_disk_reservation_put(c, &disk_res);
-		return ERR_PTR(ret);
-	}
-
-	reserve = mempool_alloc(&c->btree_reserve_pool, GFP_NOIO);
-
-	reserve->disk_res = disk_res;
-	reserve->nr = 0;
-
-	while (reserve->nr < nr_nodes) {
-		b = __bch2_btree_node_alloc(c, &disk_res,
-					    flags & BTREE_INSERT_NOWAIT
-					    ? NULL : cl, flags);
-		if (IS_ERR(b)) {
-			ret = PTR_ERR(b);
-			goto err_free;
-		}
-
-		ret = bch2_check_mark_super(c, bkey_i_to_s_c_extent(&b->key),
-					    BCH_DATA_BTREE);
-		if (ret)
-			goto err_free;
-
-		reserve->b[reserve->nr++] = b;
-	}
-
-	bch2_btree_node_cannibalize_unlock(c);
-	return reserve;
-err_free:
-	bch2_btree_reserve_put(c, reserve);
-	bch2_btree_node_cannibalize_unlock(c);
-	trace_btree_reserve_get_fail(c, nr_nodes, cl);
-	return ERR_PTR(ret);
-}
-
-struct btree_reserve *bch2_btree_reserve_get(struct bch_fs *c,
-					    struct btree *b,
-					    unsigned extra_nodes,
-					    unsigned flags,
-					    struct closure *cl)
-{
-	unsigned depth = btree_node_root(c, b)->level - b->level;
-	unsigned nr_nodes = btree_reserve_required_nodes(depth) + extra_nodes;
-
-	return __bch2_btree_reserve_get(c, nr_nodes, flags, cl);
-}
-
-int bch2_btree_root_alloc(struct bch_fs *c, enum btree_id id,
-			 struct closure *writes)
-{
-	struct btree_interior_update as;
-	struct btree_reserve *reserve;
-	struct closure cl;
-	struct btree *b;
-
-	memset(&as, 0, sizeof(as));
-	closure_init_stack(&cl);
-
-	while (1) {
-		/* XXX haven't calculated capacity yet :/ */
-		reserve = __bch2_btree_reserve_get(c, 1, 0, &cl);
-		if (!IS_ERR(reserve))
-			break;
-
-		if (PTR_ERR(reserve) == -ENOSPC)
-			return PTR_ERR(reserve);
-
-		closure_sync(&cl);
-	}
-
-	b = __btree_root_alloc(c, 0, id, &as, reserve);
-
-	bch2_btree_node_write(c, b, writes, SIX_LOCK_intent);
-
-	bch2_btree_set_root_initial(c, b, reserve);
-
-	btree_interior_update_drop_new_node(c, b);
-	bch2_btree_open_bucket_put(c, b);
-	six_unlock_intent(&b->lock);
-
-	bch2_btree_reserve_put(c, reserve);
-
-	return 0;
-}
-
-static void bch2_insert_fixup_btree_ptr(struct btree_iter *iter,
-				       struct btree *b,
-				       struct bkey_i *insert,
-				       struct btree_node_iter *node_iter,
-				       struct disk_reservation *disk_res)
-{
-	struct bch_fs *c = iter->c;
-	struct bch_fs_usage stats = { 0 };
-	struct bkey_packed *k;
-	struct bkey tmp;
-
-	if (bkey_extent_is_data(&insert->k))
-		bch2_mark_key(c, bkey_i_to_s_c(insert),
-			     c->sb.btree_node_size, true,
-			     gc_pos_btree_node(b), &stats, 0);
-
-	while ((k = bch2_btree_node_iter_peek_all(node_iter, b)) &&
-	       !btree_iter_pos_cmp_packed(b, &insert->k.p, k, false))
-		bch2_btree_node_iter_advance(node_iter, b);
-
-	/*
-	 * If we're overwriting, look up pending delete and mark so that gc
-	 * marks it on the pending delete list:
-	 */
-	if (k && !bkey_cmp_packed(b, k, &insert->k))
-		bch2_btree_node_free_index(c, b, iter->btree_id,
-					  bkey_disassemble(b, k, &tmp),
-					  &stats);
-
-	bch2_fs_usage_apply(c, &stats, disk_res, gc_pos_btree_node(b));
-
-	bch2_btree_bset_insert_key(iter, b, node_iter, insert);
-	set_btree_node_dirty(b);
-	set_btree_node_need_write(b);
-}
-
-/* Inserting into a given leaf node (last stage of insert): */
-
-/* Handle overwrites and do insert, for non extents: */
-bool bch2_btree_bset_insert_key(struct btree_iter *iter,
-			       struct btree *b,
-			       struct btree_node_iter *node_iter,
-			       struct bkey_i *insert)
-{
-	const struct bkey_format *f = &b->format;
-	struct bkey_packed *k;
-	struct bset_tree *t;
-	unsigned clobber_u64s;
-
-	EBUG_ON(btree_node_just_written(b));
-	EBUG_ON(bset_written(b, btree_bset_last(b)));
-	EBUG_ON(bkey_deleted(&insert->k) && bkey_val_u64s(&insert->k));
-	EBUG_ON(bkey_cmp(bkey_start_pos(&insert->k), b->data->min_key) < 0 ||
-		bkey_cmp(insert->k.p, b->data->max_key) > 0);
-	BUG_ON(insert->k.u64s > bch_btree_keys_u64s_remaining(iter->c, b));
-
-	k = bch2_btree_node_iter_peek_all(node_iter, b);
-	if (k && !bkey_cmp_packed(b, k, &insert->k)) {
-		BUG_ON(bkey_whiteout(k));
-
-		t = bch2_bkey_to_bset(b, k);
-
-		if (bset_unwritten(b, bset(b, t)) &&
-		    bkey_val_u64s(&insert->k) == bkeyp_val_u64s(f, k)) {
-			BUG_ON(bkey_whiteout(k) != bkey_whiteout(&insert->k));
-
-			k->type = insert->k.type;
-			memcpy_u64s(bkeyp_val(f, k), &insert->v,
-				    bkey_val_u64s(&insert->k));
-			return true;
-		}
-
-		insert->k.needs_whiteout = k->needs_whiteout;
-
-		btree_keys_account_key_drop(&b->nr, t - b->set, k);
-
-		if (t == bset_tree_last(b)) {
-			clobber_u64s = k->u64s;
-
-			/*
-			 * If we're deleting, and the key we're deleting doesn't
-			 * need a whiteout (it wasn't overwriting a key that had
-			 * been written to disk) - just delete it:
-			 */
-			if (bkey_whiteout(&insert->k) && !k->needs_whiteout) {
-				bch2_bset_delete(b, k, clobber_u64s);
-				bch2_btree_node_iter_fix(iter, b, node_iter, t,
-							k, clobber_u64s, 0);
-				return true;
-			}
-
-			goto overwrite;
-		}
-
-		k->type = KEY_TYPE_DELETED;
-		bch2_btree_node_iter_fix(iter, b, node_iter, t, k,
-					k->u64s, k->u64s);
-
-		if (bkey_whiteout(&insert->k)) {
-			reserve_whiteout(b, t, k);
-			return true;
-		} else {
-			k->needs_whiteout = false;
-		}
-	} else {
-		/*
-		 * Deleting, but the key to delete wasn't found - nothing to do:
-		 */
-		if (bkey_whiteout(&insert->k))
-			return false;
-
-		insert->k.needs_whiteout = false;
-	}
-
-	t = bset_tree_last(b);
-	k = bch2_btree_node_iter_bset_pos(node_iter, b, t);
-	clobber_u64s = 0;
-overwrite:
-	bch2_bset_insert(b, node_iter, k, insert, clobber_u64s);
-	if (k->u64s != clobber_u64s || bkey_whiteout(&insert->k))
-		bch2_btree_node_iter_fix(iter, b, node_iter, t, k,
-					clobber_u64s, k->u64s);
-	return true;
-}
-
-static void __btree_node_flush(struct journal *j, struct journal_entry_pin *pin,
-			       unsigned i, u64 seq)
-{
-	struct bch_fs *c = container_of(j, struct bch_fs, journal);
-	struct btree_write *w = container_of(pin, struct btree_write, journal);
-	struct btree *b = container_of(w, struct btree, writes[i]);
-
-	six_lock_read(&b->lock);
-	bch2_btree_node_write_dirty(c, b, NULL,
-			(btree_current_write(b) == w &&
-			 w->journal.pin_list == journal_seq_pin(j, seq)));
-	six_unlock_read(&b->lock);
-}
-
-static void btree_node_flush0(struct journal *j, struct journal_entry_pin *pin, u64 seq)
-{
-	return __btree_node_flush(j, pin, 0, seq);
-}
-
-static void btree_node_flush1(struct journal *j, struct journal_entry_pin *pin, u64 seq)
-{
-	return __btree_node_flush(j, pin, 1, seq);
-}
-
-void bch2_btree_journal_key(struct btree_insert *trans,
-			   struct btree_iter *iter,
-			   struct bkey_i *insert)
-{
-	struct bch_fs *c = trans->c;
-	struct journal *j = &c->journal;
-	struct btree *b = iter->nodes[0];
-	struct btree_write *w = btree_current_write(b);
-
-	EBUG_ON(iter->level || b->level);
-	EBUG_ON(trans->journal_res.ref !=
-		!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY));
-
-	if (!journal_pin_active(&w->journal))
-		bch2_journal_pin_add(j, &trans->journal_res,
-				     &w->journal,
-				     btree_node_write_idx(b) == 0
-				     ? btree_node_flush0
-				     : btree_node_flush1);
-
-	if (trans->journal_res.ref) {
-		u64 seq = trans->journal_res.seq;
-		bool needs_whiteout = insert->k.needs_whiteout;
-
-		/* ick */
-		insert->k.needs_whiteout = false;
-		bch2_journal_add_keys(j, &trans->journal_res,
-				      b->btree_id, insert);
-		insert->k.needs_whiteout = needs_whiteout;
-
-		bch2_journal_set_has_inode(j, &trans->journal_res,
-					   insert->k.p.inode);
-
-		if (trans->journal_seq)
-			*trans->journal_seq = seq;
-		btree_bset_last(b)->journal_seq = cpu_to_le64(seq);
-	}
-
-	if (!btree_node_dirty(b))
-		set_btree_node_dirty(b);
-}
-
-static enum btree_insert_ret
-bch2_insert_fixup_key(struct btree_insert *trans,
-		     struct btree_insert_entry *insert)
-{
-	struct btree_iter *iter = insert->iter;
-
-	BUG_ON(iter->level);
-
-	if (bch2_btree_bset_insert_key(iter,
-				      iter->nodes[0],
-				      &iter->node_iters[0],
-				      insert->k))
-		bch2_btree_journal_key(trans, iter, insert->k);
-
-	trans->did_work = true;
-	return BTREE_INSERT_OK;
-}
-
-static void verify_keys_sorted(struct keylist *l)
-{
-#ifdef CONFIG_BCACHEFS_DEBUG
-	struct bkey_i *k;
-
-	for_each_keylist_key(l, k)
-		BUG_ON(bkey_next(k) != l->top &&
-		       bkey_cmp(k->k.p, bkey_next(k)->k.p) >= 0);
-#endif
-}
-
-static void btree_node_lock_for_insert(struct btree *b, struct btree_iter *iter)
-{
-	struct bch_fs *c = iter->c;
-
-	bch2_btree_node_lock_write(b, iter);
-
-	if (btree_node_just_written(b) &&
-	    bch2_btree_post_write_cleanup(c, b))
-		bch2_btree_iter_reinit_node(iter, b);
-
-	/*
-	 * If the last bset has been written, or if it's gotten too big - start
-	 * a new bset to insert into:
-	 */
-	if (want_new_bset(c, b))
-		bch2_btree_init_next(c, b, iter);
-}
-
-/* Asynchronous interior node update machinery */
-
-struct btree_interior_update *
-bch2_btree_interior_update_alloc(struct bch_fs *c)
-{
-	struct btree_interior_update *as;
-
-	as = mempool_alloc(&c->btree_interior_update_pool, GFP_NOIO);
-	memset(as, 0, sizeof(*as));
-	closure_init(&as->cl, &c->cl);
-	as->c		= c;
-	as->mode	= BTREE_INTERIOR_NO_UPDATE;
-	INIT_LIST_HEAD(&as->write_blocked_list);
-
-	bch2_keylist_init(&as->parent_keys, as->inline_keys,
-			 ARRAY_SIZE(as->inline_keys));
-
-	mutex_lock(&c->btree_interior_update_lock);
-	list_add(&as->list, &c->btree_interior_update_list);
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	return as;
-}
-
-static void btree_interior_update_free(struct closure *cl)
-{
-	struct btree_interior_update *as =
-		container_of(cl, struct btree_interior_update, cl);
-
-	mempool_free(as, &as->c->btree_interior_update_pool);
-}
-
-static void btree_interior_update_nodes_reachable(struct closure *cl)
-{
-	struct btree_interior_update *as =
-		container_of(cl, struct btree_interior_update, cl);
-	struct bch_fs *c = as->c;
-
-	bch2_journal_pin_drop(&c->journal, &as->journal);
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	while (as->nr_new_nodes) {
-		struct btree *b = as->new_nodes[--as->nr_new_nodes];
-
-		BUG_ON(b->will_make_reachable != as);
-		b->will_make_reachable = NULL;
-		mutex_unlock(&c->btree_interior_update_lock);
-
-		six_lock_read(&b->lock);
-		bch2_btree_node_write_dirty(c, b, NULL, btree_node_need_write(b));
-		six_unlock_read(&b->lock);
-		mutex_lock(&c->btree_interior_update_lock);
-	}
-
-	while (as->nr_pending)
-		bch2_btree_node_free_ondisk(c, &as->pending[--as->nr_pending]);
-
-	list_del(&as->list);
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	closure_wake_up(&as->wait);
-
-	closure_return_with_destructor(cl, btree_interior_update_free);
-}
-
-static void btree_interior_update_nodes_written(struct closure *cl)
-{
-	struct btree_interior_update *as =
-		container_of(cl, struct btree_interior_update, cl);
-	struct bch_fs *c = as->c;
-	struct btree *b;
-
-	if (bch2_journal_error(&c->journal)) {
-		/* XXX what? */
-		/* we don't want to free the nodes on disk, that's what */
-	}
-
-	/* XXX: missing error handling, damnit */
-
-	/* check for journal error, bail out if we flushed */
-
-	/*
-	 * 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.
-	 */
-retry:
-	mutex_lock(&c->btree_interior_update_lock);
-	switch (as->mode) {
-	case BTREE_INTERIOR_NO_UPDATE:
-		BUG();
-	case BTREE_INTERIOR_UPDATING_NODE:
-		/* The usual case: */
-		b = READ_ONCE(as->b);
-
-		if (!six_trylock_read(&b->lock)) {
-			mutex_unlock(&c->btree_interior_update_lock);
-			six_lock_read(&b->lock);
-			six_unlock_read(&b->lock);
-			goto retry;
-		}
-
-		BUG_ON(!btree_node_dirty(b));
-		closure_wait(&btree_current_write(b)->wait, cl);
-
-		list_del(&as->write_blocked_list);
-		mutex_unlock(&c->btree_interior_update_lock);
-
-		bch2_btree_node_write_dirty(c, b, NULL,
-					    btree_node_need_write(b));
-		six_unlock_read(&b->lock);
-		break;
-
-	case BTREE_INTERIOR_UPDATING_AS:
-		/*
-		 * The btree node we originally updated has been freed and is
-		 * being rewritten - so we need to write anything here, we just
-		 * need to signal to that btree_interior_update that it's ok to make the
-		 * new replacement node visible:
-		 */
-		closure_put(&as->parent_as->cl);
-
-		/*
-		 * and then we have to wait on that btree_interior_update to finish:
-		 */
-		closure_wait(&as->parent_as->wait, cl);
-		mutex_unlock(&c->btree_interior_update_lock);
-		break;
-
-	case BTREE_INTERIOR_UPDATING_ROOT:
-		/* b is the new btree root: */
-		b = READ_ONCE(as->b);
-
-		if (!six_trylock_read(&b->lock)) {
-			mutex_unlock(&c->btree_interior_update_lock);
-			six_lock_read(&b->lock);
-			six_unlock_read(&b->lock);
-			goto retry;
-		}
-
-		BUG_ON(c->btree_roots[b->btree_id].as != as);
-		c->btree_roots[b->btree_id].as = NULL;
-
-		bch2_btree_set_root_ondisk(c, b);
-
-		/*
-		 * We don't have to wait anything anything here (before
-		 * btree_interior_update_nodes_reachable frees the old nodes
-		 * ondisk) - we've ensured that the very next journal write will
-		 * have the pointer to the new root, and before the allocator
-		 * can reuse the old nodes it'll have to do a journal commit:
-		 */
-		six_unlock_read(&b->lock);
-		mutex_unlock(&c->btree_interior_update_lock);
-
-		/*
-		 * Bit of funny circularity going on here we have to break:
-		 *
-		 * We have to drop our journal pin before writing the journal
-		 * entry that points to the new btree root: else, we could
-		 * deadlock if the journal currently happens to be full.
-		 *
-		 * This mean we're dropping the journal pin _before_ the new
-		 * nodes are technically reachable - but this is safe, because
-		 * after the bch2_btree_set_root_ondisk() call above they will
-		 * be reachable as of the very next journal write:
-		 */
-		bch2_journal_pin_drop(&c->journal, &as->journal);
-
-		/*
-		 * And, do a journal write to write the pointer to the new root,
-		 * then wait for it to complete before freeing the nodes we
-		 * replaced:
-		 */
-		bch2_journal_meta_async(&c->journal, cl);
-		break;
-	}
-
-	continue_at(cl, btree_interior_update_nodes_reachable, system_wq);
-}
-
-/*
- * 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_interior_update_updated_btree(struct bch_fs *c,
-						struct btree_interior_update *as,
-						struct btree *b)
-{
-	mutex_lock(&c->btree_interior_update_lock);
-
-	BUG_ON(as->mode != BTREE_INTERIOR_NO_UPDATE);
-	BUG_ON(!btree_node_dirty(b));
-
-	as->mode = BTREE_INTERIOR_UPDATING_NODE;
-	as->b = b;
-	list_add(&as->write_blocked_list, &b->write_blocked);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	/*
-	 * In general, when you're staging things in a journal that will later
-	 * be written elsewhere, and you also want to guarantee ordering: that
-	 * is, if you have updates a, b, c, after a crash you should never see c
-	 * and not a or b - there's a problem:
-	 *
-	 * If the final destination of the update(s) (i.e. btree node) can be
-	 * written/flushed _before_ the relevant journal entry - oops, that
-	 * breaks ordering, since the various leaf nodes can be written in any
-	 * order.
-	 *
-	 * Normally we use bset->journal_seq to deal with this - if during
-	 * recovery we find a btree node write that's newer than the newest
-	 * journal entry, we just ignore it - we don't need it, anything we're
-	 * supposed to have (that we reported as completed via fsync()) will
-	 * still be in the journal, and as far as the state of the journal is
-	 * concerned that btree node write never happened.
-	 *
-	 * That breaks when we're rewriting/splitting/merging nodes, since we're
-	 * mixing btree node writes that haven't happened yet with previously
-	 * written data that has been reported as completed to the journal.
-	 *
-	 * Thus, before making the new nodes reachable, we have to wait the
-	 * newest journal sequence number we have data for to be written (if it
-	 * hasn't been yet).
-	 */
-	bch2_journal_wait_on_seq(&c->journal, as->journal_seq, &as->cl);
-
-	continue_at(&as->cl, btree_interior_update_nodes_written,
-		    system_freezable_wq);
-}
-
-static void interior_update_flush(struct journal *j,
-			struct journal_entry_pin *pin, u64 seq)
-{
-	struct btree_interior_update *as =
-		container_of(pin, struct btree_interior_update, journal);
-
-	bch2_journal_flush_seq_async(j, as->journal_seq, NULL);
-}
-
-static void btree_interior_update_reparent(struct bch_fs *c,
-					   struct btree_interior_update *as,
-					   struct btree_interior_update *child)
-{
-	child->b = NULL;
-	child->mode = BTREE_INTERIOR_UPDATING_AS;
-	child->parent_as = as;
-	closure_get(&as->cl);
-
-	/*
-	 * When we write a new btree root, we have to drop our journal pin
-	 * _before_ the new nodes are technically reachable; see
-	 * btree_interior_update_nodes_written().
-	 *
-	 * This goes for journal pins that are recursively blocked on us - so,
-	 * just transfer the journal pin to the new interior update so
-	 * btree_interior_update_nodes_written() can drop it.
-	 */
-	bch2_journal_pin_add_if_older(&c->journal, &child->journal,
-				      &as->journal, interior_update_flush);
-	bch2_journal_pin_drop(&c->journal, &child->journal);
-
-	as->journal_seq = max(as->journal_seq, child->journal_seq);
-}
-
-static void btree_interior_update_updated_root(struct bch_fs *c,
-					       struct btree_interior_update *as,
-					       enum btree_id btree_id)
-{
-	struct btree_root *r = &c->btree_roots[btree_id];
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	BUG_ON(as->mode != BTREE_INTERIOR_NO_UPDATE);
-
-	/*
-	 * Old root might not be persistent yet - if so, redirect its
-	 * btree_interior_update operation to point to us:
-	 */
-	if (r->as)
-		btree_interior_update_reparent(c, as, r->as);
-
-	as->mode = BTREE_INTERIOR_UPDATING_ROOT;
-	as->b = r->b;
-	r->as = as;
-
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	/*
-	 * When we're rewriting nodes and updating interior nodes, there's an
-	 * issue with updates that haven't been written in the journal getting
-	 * mixed together with older data - see * btree_interior_update_updated_btree()
-	 * for the explanation.
-	 *
-	 * However, this doesn't affect us when we're writing a new btree root -
-	 * because to make that new root reachable we have to write out a new
-	 * journal entry, which must necessarily be newer than as->journal_seq.
-	 */
-
-	continue_at(&as->cl, btree_interior_update_nodes_written,
-		    system_freezable_wq);
-}
-
-static void btree_interior_update_will_make_reachable(struct bch_fs *c,
-				struct btree_interior_update *as,
-				struct btree *b)
-{
-	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 = as;
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static void __btree_interior_update_drop_new_node(struct btree *b)
-{
-	struct btree_interior_update *as = b->will_make_reachable;
-	unsigned i;
-
-	BUG_ON(!as);
-
-	for (i = 0; i < as->nr_new_nodes; i++)
-		if (as->new_nodes[i] == b)
-			goto found;
-
-	BUG();
-found:
-	as->nr_new_nodes--;
-	memmove(&as->new_nodes[i],
-		&as->new_nodes[i + 1],
-		sizeof(struct btree *) * (as->nr_new_nodes - i));
-	b->will_make_reachable = NULL;
-}
-
-static void btree_interior_update_drop_new_node(struct bch_fs *c,
-						struct btree *b)
-{
-	mutex_lock(&c->btree_interior_update_lock);
-	__btree_interior_update_drop_new_node(b);
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static void bch2_btree_interior_update_add_node_reference(struct bch_fs *c,
-						   struct btree_interior_update *as,
-						   struct btree *b)
-{
-	struct pending_btree_node_free *d;
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	/* Add this node to the list of nodes being freed: */
-	BUG_ON(as->nr_pending >= ARRAY_SIZE(as->pending));
-
-	d = &as->pending[as->nr_pending++];
-	d->index_update_done	= false;
-	d->seq			= b->data->keys.seq;
-	d->btree_id		= b->btree_id;
-	d->level		= b->level;
-	bkey_copy(&d->key, &b->key);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-/*
- * @b is being split/rewritten: it may have pointers to not-yet-written btree
- * nodes and thus outstanding btree_interior_updates - redirect @b's
- * btree_interior_updates to point to this btree_interior_update:
- */
-void bch2_btree_interior_update_will_free_node(struct bch_fs *c,
-					      struct btree_interior_update *as,
-					      struct btree *b)
-{
-	struct closure *cl, *cl_n;
-	struct btree_interior_update *p, *n;
-	struct btree_write *w;
-	struct bset_tree *t;
-
-	bch2_btree_interior_update_add_node_reference(c, as, b);
-
-	/*
-	 * Does this node have data that hasn't been written in the journal?
-	 *
-	 * If so, we have to wait for the corresponding journal entry to be
-	 * written before making the new nodes reachable - we can't just carry
-	 * over the bset->journal_seq tracking, since we'll be mixing those keys
-	 * in with keys that aren't in the journal anymore:
-	 */
-	for_each_bset(b, t)
-		as->journal_seq = max(as->journal_seq, bset(b, t)->journal_seq);
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	/*
-	 * Does this node have any btree_interior_update operations preventing
-	 * it from being written?
-	 *
-	 * If so, redirect them to point to this btree_interior_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(&p->write_blocked_list);
-		btree_interior_update_reparent(c, as, p);
-	}
-
-	clear_btree_node_dirty(b);
-	clear_btree_node_need_write(b);
-	w = btree_current_write(b);
-
-	llist_for_each_entry_safe(cl, cl_n, llist_del_all(&w->wait.list), list)
-		llist_add(&cl->list, &as->wait.list);
-
-	/*
-	 * Does this node have unwritten data that has a pin on the journal?
-	 *
-	 * If so, transfer that pin to the btree_interior_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:
-	 */
-	bch2_journal_pin_add_if_older(&c->journal, &w->journal,
-				      &as->journal, interior_update_flush);
-	bch2_journal_pin_drop(&c->journal, &w->journal);
-
-	w = btree_prev_write(b);
-	bch2_journal_pin_add_if_older(&c->journal, &w->journal,
-				      &as->journal, interior_update_flush);
-	bch2_journal_pin_drop(&c->journal, &w->journal);
-
-	if (b->will_make_reachable)
-		__btree_interior_update_drop_new_node(b);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-
-static void btree_node_interior_verify(struct btree *b)
-{
-	struct btree_node_iter iter;
-	struct bkey_packed *k;
-
-	BUG_ON(!b->level);
-
-	bch2_btree_node_iter_init(&iter, b, b->key.k.p, false, false);
-#if 1
-	BUG_ON(!(k = bch2_btree_node_iter_peek(&iter, b)) ||
-	       bkey_cmp_left_packed(b, k, &b->key.k.p));
-
-	BUG_ON((bch2_btree_node_iter_advance(&iter, b),
-		!bch2_btree_node_iter_end(&iter)));
-#else
-	const char *msg;
-
-	msg = "not found";
-	k = bch2_btree_node_iter_peek(&iter, b);
-	if (!k)
-		goto err;
-
-	msg = "isn't what it should be";
-	if (bkey_cmp_left_packed(b, k, &b->key.k.p))
-		goto err;
-
-	bch2_btree_node_iter_advance(&iter, b);
-
-	msg = "isn't last key";
-	if (!bch2_btree_node_iter_end(&iter))
-		goto err;
-	return;
-err:
-	bch2_dump_btree_node(b);
-	printk(KERN_ERR "last key %llu:%llu %s\n", b->key.k.p.inode,
-	       b->key.k.p.offset, msg);
-	BUG();
-#endif
-}
-
-static int
-bch2_btree_insert_keys_interior(struct btree *b,
-			       struct btree_iter *iter,
-			       struct keylist *insert_keys,
-			       struct btree_interior_update *as,
-			       struct btree_reserve *res)
-{
-	struct bch_fs *c = iter->c;
-	struct btree_iter *linked;
-	struct btree_node_iter node_iter;
-	struct bkey_i *insert = bch2_keylist_front(insert_keys);
-	struct bkey_packed *k;
-
-	BUG_ON(!btree_node_intent_locked(iter, btree_node_root(c, b)->level));
-	BUG_ON(!b->level);
-	BUG_ON(!as || as->b);
-	verify_keys_sorted(insert_keys);
-
-	btree_node_lock_for_insert(b, iter);
-
-	if (bch_keylist_u64s(insert_keys) >
-	    bch_btree_keys_u64s_remaining(c, b)) {
-		bch2_btree_node_unlock_write(b, iter);
-		return -1;
-	}
-
-	/* Don't screw up @iter's position: */
-	node_iter = iter->node_iters[b->level];
-
-	/*
-	 * btree_split(), btree_gc_coalesce() will insert keys before
-	 * the iterator's current position - they know the keys go in
-	 * the node the iterator points to:
-	 */
-	while ((k = bch2_btree_node_iter_prev_all(&node_iter, b)) &&
-	       (bkey_cmp_packed(b, k, &insert->k) >= 0))
-		;
-
-	while (!bch2_keylist_empty(insert_keys)) {
-		insert = bch2_keylist_front(insert_keys);
-
-		bch2_insert_fixup_btree_ptr(iter, b, insert,
-					   &node_iter, &res->disk_res);
-		bch2_keylist_pop_front(insert_keys);
-	}
-
-	btree_interior_update_updated_btree(c, as, b);
-
-	for_each_linked_btree_node(iter, b, linked)
-		bch2_btree_node_iter_peek(&linked->node_iters[b->level],
-					 b);
-	bch2_btree_node_iter_peek(&iter->node_iters[b->level], b);
-
-	bch2_btree_iter_verify(iter, b);
-
-	if (bch2_maybe_compact_whiteouts(c, b))
-		bch2_btree_iter_reinit_node(iter, b);
-
-	bch2_btree_node_unlock_write(b, iter);
-
-	btree_node_interior_verify(b);
-	return 0;
-}
-
-/*
- * Move keys from n1 (original replacement node, now lower node) to n2 (higher
- * node)
- */
-static struct btree *__btree_split_node(struct btree_iter *iter, struct btree *n1,
-					struct btree_reserve *reserve,
-					struct btree_interior_update *as)
-{
-	struct bch_fs *c = iter->c;
-	size_t nr_packed = 0, nr_unpacked = 0;
-	struct btree *n2;
-	struct bset *set1, *set2;
-	struct bkey_packed *k, *prev = NULL;
-
-	n2 = bch2_btree_node_alloc(c, n1->level, iter->btree_id, as, reserve);
-
-	n2->data->max_key	= n1->data->max_key;
-	n2->data->format	= n1->format;
-	n2->key.k.p = n1->key.k.p;
-
-	btree_node_set_format(n2, n2->data->format);
-
-	set1 = btree_bset_first(n1);
-	set2 = btree_bset_first(n2);
-
-	/*
-	 * Has to be a linear search because we don't have an auxiliary
-	 * search tree yet
-	 */
-	k = set1->start;
-	while (1) {
-		if (bkey_next(k) == vstruct_last(set1))
-			break;
-		if (k->_data - set1->_data >= (le16_to_cpu(set1->u64s) * 3) / 5)
-			break;
-
-		if (bkey_packed(k))
-			nr_packed++;
-		else
-			nr_unpacked++;
-
-		prev = k;
-		k = bkey_next(k);
-	}
-
-	BUG_ON(!prev);
-
-	n1->key.k.p = bkey_unpack_pos(n1, prev);
-	n1->data->max_key = n1->key.k.p;
-	n2->data->min_key =
-		btree_type_successor(n1->btree_id, n1->key.k.p);
-
-	set2->u64s = cpu_to_le16((u64 *) vstruct_end(set1) - (u64 *) k);
-	set1->u64s = cpu_to_le16(le16_to_cpu(set1->u64s) - le16_to_cpu(set2->u64s));
-
-	set_btree_bset_end(n1, n1->set);
-	set_btree_bset_end(n2, n2->set);
-
-	n2->nr.live_u64s	= le16_to_cpu(set2->u64s);
-	n2->nr.bset_u64s[0]	= le16_to_cpu(set2->u64s);
-	n2->nr.packed_keys	= n1->nr.packed_keys - nr_packed;
-	n2->nr.unpacked_keys	= n1->nr.unpacked_keys - nr_unpacked;
-
-	n1->nr.live_u64s	= le16_to_cpu(set1->u64s);
-	n1->nr.bset_u64s[0]	= le16_to_cpu(set1->u64s);
-	n1->nr.packed_keys	= nr_packed;
-	n1->nr.unpacked_keys	= nr_unpacked;
-
-	BUG_ON(!set1->u64s);
-	BUG_ON(!set2->u64s);
-
-	memcpy_u64s(set2->start,
-		    vstruct_end(set1),
-		    le16_to_cpu(set2->u64s));
-
-	btree_node_reset_sib_u64s(n1);
-	btree_node_reset_sib_u64s(n2);
-
-	bch2_verify_btree_nr_keys(n1);
-	bch2_verify_btree_nr_keys(n2);
-
-	if (n1->level) {
-		btree_node_interior_verify(n1);
-		btree_node_interior_verify(n2);
-	}
-
-	return n2;
-}
-
-/*
- * 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_iter *iter, struct btree *b,
-				    struct keylist *keys,
-				    struct btree_reserve *res)
-{
-	struct btree_node_iter node_iter;
-	struct bkey_i *k = bch2_keylist_front(keys);
-	struct bkey_packed *p;
-	struct bset *i;
-
-	BUG_ON(btree_node_type(b) != BKEY_TYPE_BTREE);
-
-	bch2_btree_node_iter_init(&node_iter, b, k->k.p, false, false);
-
-	while (!bch2_keylist_empty(keys)) {
-		k = bch2_keylist_front(keys);
-
-		BUG_ON(bch_keylist_u64s(keys) >
-		       bch_btree_keys_u64s_remaining(iter->c, b));
-		BUG_ON(bkey_cmp(k->k.p, b->data->min_key) < 0);
-		BUG_ON(bkey_cmp(k->k.p, b->data->max_key) > 0);
-
-		bch2_insert_fixup_btree_ptr(iter, b, k, &node_iter, &res->disk_res);
-		bch2_keylist_pop_front(keys);
-	}
-
-	/*
-	 * We can't tolerate whiteouts here - with whiteouts there can be
-	 * duplicate keys, and it would be rather bad if we picked a duplicate
-	 * for the pivot:
-	 */
-	i = btree_bset_first(b);
-	p = i->start;
-	while (p != vstruct_last(i))
-		if (bkey_deleted(p)) {
-			le16_add_cpu(&i->u64s, -p->u64s);
-			set_btree_bset_end(b, b->set);
-			memmove_u64s_down(p, bkey_next(p),
-					  (u64 *) vstruct_last(i) -
-					  (u64 *) p);
-		} else
-			p = bkey_next(p);
-
-	BUG_ON(b->nsets != 1 ||
-	       b->nr.live_u64s != le16_to_cpu(btree_bset_first(b)->u64s));
-
-	btree_node_interior_verify(b);
-}
-
-static void btree_split(struct btree *b, struct btree_iter *iter,
-			struct keylist *insert_keys,
-			struct btree_reserve *reserve,
-			struct btree_interior_update *as)
-{
-	struct bch_fs *c = iter->c;
-	struct btree *parent = iter->nodes[b->level + 1];
-	struct btree *n1, *n2 = NULL, *n3 = NULL;
-	u64 start_time = local_clock();
-
-	BUG_ON(!parent && (b != btree_node_root(c, b)));
-	BUG_ON(!btree_node_intent_locked(iter, btree_node_root(c, b)->level));
-
-	bch2_btree_interior_update_will_free_node(c, as, b);
-
-	n1 = bch2_btree_node_alloc_replacement(c, b, as, reserve);
-
-	if (b->level)
-		btree_split_insert_keys(iter, n1, insert_keys, reserve);
-
-	if (vstruct_blocks(n1->data, c->block_bits) > BTREE_SPLIT_THRESHOLD(c)) {
-		trace_btree_node_split(c, b, b->nr.live_u64s);
-
-		n2 = __btree_split_node(iter, n1, reserve, as);
-
-		bch2_btree_build_aux_trees(n2);
-		bch2_btree_build_aux_trees(n1);
-		six_unlock_write(&n2->lock);
-		six_unlock_write(&n1->lock);
-
-		bch2_btree_node_write(c, n2, &as->cl, SIX_LOCK_intent);
-
-		/*
-		 * Note that on recursive parent_keys == insert_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(c, b->level + 1,
-						iter->btree_id,
-						as, reserve);
-
-			n3->sib_u64s[0] = U16_MAX;
-			n3->sib_u64s[1] = U16_MAX;
-
-			btree_split_insert_keys(iter, n3, &as->parent_keys,
-						reserve);
-			bch2_btree_node_write(c, n3, &as->cl, SIX_LOCK_intent);
-		}
-	} else {
-		trace_btree_node_compact(c, b, b->nr.live_u64s);
-
-		bch2_btree_build_aux_trees(n1);
-		six_unlock_write(&n1->lock);
-
-		bch2_keylist_add(&as->parent_keys, &n1->key);
-	}
-
-	bch2_btree_node_write(c, n1, &as->cl, SIX_LOCK_intent);
-
-	/* New nodes all written, now make them visible: */
-
-	if (parent) {
-		/* Split a non root node */
-		bch2_btree_insert_node(parent, iter, &as->parent_keys,
-				      reserve, as);
-	} else if (n3) {
-		bch2_btree_set_root(iter, n3, as, reserve);
-	} else {
-		/* Root filled up but didn't need to be split */
-		bch2_btree_set_root(iter, n1, as, reserve);
-	}
-
-	bch2_btree_open_bucket_put(c, n1);
-	if (n2)
-		bch2_btree_open_bucket_put(c, n2);
-	if (n3)
-		bch2_btree_open_bucket_put(c, n3);
-
-	/*
-	 * Note - at this point other linked iterators could still have @b read
-	 * locked; we're depending on the bch2_btree_iter_node_replace() calls
-	 * below removing all references to @b so we don't return with other
-	 * iterators pointing to a node they have locked that's been freed.
-	 *
-	 * We have to free the node first because the bch2_iter_node_replace()
-	 * calls will drop _our_ iterator's reference - and intent lock - to @b.
-	 */
-	bch2_btree_node_free_inmem(iter, b);
-
-	/* Successful split, update the iterator to point to the new nodes: */
-
-	if (n3)
-		bch2_btree_iter_node_replace(iter, n3);
-	if (n2)
-		bch2_btree_iter_node_replace(iter, n2);
-	bch2_btree_iter_node_replace(iter, n1);
-
-	bch2_time_stats_update(&c->btree_split_time, start_time);
-}
-
-/**
- * bch_btree_insert_node - insert bkeys into a given btree node
- *
- * @iter:		btree iterator
- * @insert_keys:	list of keys to insert
- * @hook:		insert callback
- * @persistent:		if not null, @persistent will wait on journal write
- *
- * 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.
- */
-void bch2_btree_insert_node(struct btree *b,
-			   struct btree_iter *iter,
-			   struct keylist *insert_keys,
-			   struct btree_reserve *reserve,
-			   struct btree_interior_update *as)
-{
-	BUG_ON(!b->level);
-	BUG_ON(!reserve || !as);
-
-	if ((as->flags & BTREE_INTERIOR_UPDATE_MUST_REWRITE) ||
-	    bch2_btree_insert_keys_interior(b, iter, insert_keys,
-					    as, reserve))
-		btree_split(b, iter, insert_keys, reserve, as);
-}
-
-static int bch2_btree_split_leaf(struct btree_iter *iter, unsigned flags)
-{
-	struct bch_fs *c = iter->c;
-	struct btree *b = iter->nodes[0];
-	struct btree_reserve *reserve;
-	struct btree_interior_update *as;
-	struct closure cl;
-	int ret = 0;
-
-	closure_init_stack(&cl);
-
-	/* Hack, because gc and splitting nodes doesn't mix yet: */
-	if (!down_read_trylock(&c->gc_lock)) {
-		bch2_btree_iter_unlock(iter);
-		down_read(&c->gc_lock);
-	}
-
-	/*
-	 * XXX: figure out how far we might need to split,
-	 * instead of locking/reserving all the way to the root:
-	 */
-	if (!bch2_btree_iter_set_locks_want(iter, U8_MAX)) {
-		ret = -EINTR;
-		goto out;
-	}
-
-	reserve = bch2_btree_reserve_get(c, b, 0, flags, &cl);
-	if (IS_ERR(reserve)) {
-		ret = PTR_ERR(reserve);
-		if (ret == -EAGAIN) {
-			bch2_btree_iter_unlock(iter);
-			up_read(&c->gc_lock);
-			closure_sync(&cl);
-			return -EINTR;
-		}
-		goto out;
-	}
-
-	as = bch2_btree_interior_update_alloc(c);
-
-	btree_split(b, iter, NULL, reserve, as);
-	bch2_btree_reserve_put(c, reserve);
-
-	bch2_btree_iter_set_locks_want(iter, 1);
-out:
-	up_read(&c->gc_lock);
-	return ret;
-}
-
-enum btree_node_sibling {
-	btree_prev_sib,
-	btree_next_sib,
-};
-
-static struct btree *btree_node_get_sibling(struct btree_iter *iter,
-					    struct btree *b,
-					    enum btree_node_sibling sib)
-{
-	struct btree *parent;
-	struct btree_node_iter node_iter;
-	struct bkey_packed *k;
-	BKEY_PADDED(k) tmp;
-	struct btree *ret;
-	unsigned level = b->level;
-
-	parent = iter->nodes[level + 1];
-	if (!parent)
-		return NULL;
-
-	if (!bch2_btree_node_relock(iter, level + 1)) {
-		bch2_btree_iter_set_locks_want(iter, level + 2);
-		return ERR_PTR(-EINTR);
-	}
-
-	node_iter = iter->node_iters[parent->level];
-
-	k = bch2_btree_node_iter_peek_all(&node_iter, parent);
-	BUG_ON(bkey_cmp_left_packed(parent, k, &b->key.k.p));
-
-	do {
-		k = sib == btree_prev_sib
-			? bch2_btree_node_iter_prev_all(&node_iter, parent)
-			: (bch2_btree_node_iter_advance(&node_iter, parent),
-			   bch2_btree_node_iter_peek_all(&node_iter, parent));
-		if (!k)
-			return NULL;
-	} while (bkey_deleted(k));
-
-	bch2_bkey_unpack(parent, &tmp.k, k);
-
-	ret = bch2_btree_node_get(iter, &tmp.k, level, SIX_LOCK_intent);
-
-	if (IS_ERR(ret) && PTR_ERR(ret) == -EINTR) {
-		btree_node_unlock(iter, level);
-		ret = bch2_btree_node_get(iter, &tmp.k, level, SIX_LOCK_intent);
-	}
-
-	if (!IS_ERR(ret) && !bch2_btree_node_relock(iter, level)) {
-		six_unlock_intent(&ret->lock);
-		ret = ERR_PTR(-EINTR);
-	}
-
-	return ret;
-}
-
-static int __foreground_maybe_merge(struct btree_iter *iter,
-				    enum btree_node_sibling sib)
-{
-	struct bch_fs *c = iter->c;
-	struct btree_reserve *reserve;
-	struct btree_interior_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 closure cl;
-	size_t sib_u64s;
-	int ret = 0;
-
-	closure_init_stack(&cl);
-retry:
-	if (!bch2_btree_node_relock(iter, iter->level))
-		return 0;
-
-	b = iter->nodes[iter->level];
-
-	parent = iter->nodes[b->level + 1];
-	if (!parent)
-		return 0;
-
-	if (b->sib_u64s[sib] > BTREE_FOREGROUND_MERGE_THRESHOLD(c))
-		return 0;
-
-	/* XXX: can't be holding read locks */
-	m = btree_node_get_sibling(iter, b, sib);
-	if (IS_ERR(m)) {
-		ret = PTR_ERR(m);
-		goto out;
-	}
-
-	/* NULL means no sibling: */
-	if (!m) {
-		b->sib_u64s[sib] = U16_MAX;
-		return 0;
-	}
-
-	if (sib == btree_prev_sib) {
-		prev = m;
-		next = b;
-	} else {
-		prev = b;
-		next = m;
-	}
-
-	bch2_bkey_format_init(&new_s);
-	__bch2_btree_calc_format(&new_s, b);
-	__bch2_btree_calc_format(&new_s, m);
-	new_f = bch2_bkey_format_done(&new_s);
-
-	sib_u64s = btree_node_u64s_with_format(b, &new_f) +
-		btree_node_u64s_with_format(m, &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));
-	b->sib_u64s[sib] = sib_u64s;
-
-	if (b->sib_u64s[sib] > BTREE_FOREGROUND_MERGE_THRESHOLD(c)) {
-		six_unlock_intent(&m->lock);
-		return 0;
-	}
-
-	/* We're changing btree topology, doesn't mix with gc: */
-	if (!down_read_trylock(&c->gc_lock)) {
-		six_unlock_intent(&m->lock);
-		bch2_btree_iter_unlock(iter);
-
-		down_read(&c->gc_lock);
-		up_read(&c->gc_lock);
-		ret = -EINTR;
-		goto out;
-	}
-
-	if (!bch2_btree_iter_set_locks_want(iter, U8_MAX)) {
-		ret = -EINTR;
-		goto out_unlock;
-	}
-
-	reserve = bch2_btree_reserve_get(c, b, 0,
-					BTREE_INSERT_NOFAIL|
-					BTREE_INSERT_USE_RESERVE,
-					&cl);
-	if (IS_ERR(reserve)) {
-		ret = PTR_ERR(reserve);
-		goto out_unlock;
-	}
-
-	as = bch2_btree_interior_update_alloc(c);
-
-	bch2_btree_interior_update_will_free_node(c, as, b);
-	bch2_btree_interior_update_will_free_node(c, as, m);
-
-	n = bch2_btree_node_alloc(c, b->level, b->btree_id, as, reserve);
-
-	n->data->min_key	= prev->data->min_key;
-	n->data->max_key	= next->data->max_key;
-	n->data->format		= new_f;
-	n->key.k.p		= next->key.k.p;
-
-	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);
-	six_unlock_write(&n->lock);
-
-	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_btree_node_write(c, n, &as->cl, SIX_LOCK_intent);
-
-	bch2_btree_insert_node(parent, iter, &as->parent_keys, reserve, as);
-
-	bch2_btree_open_bucket_put(c, n);
-	bch2_btree_node_free_inmem(iter, b);
-	bch2_btree_node_free_inmem(iter, m);
-	bch2_btree_iter_node_replace(iter, n);
-
-	bch2_btree_iter_verify(iter, n);
-
-	bch2_btree_reserve_put(c, reserve);
-out_unlock:
-	if (ret != -EINTR && ret != -EAGAIN)
-		bch2_btree_iter_set_locks_want(iter, 1);
-	six_unlock_intent(&m->lock);
-	up_read(&c->gc_lock);
-out:
-	if (ret == -EAGAIN || ret == -EINTR) {
-		bch2_btree_iter_unlock(iter);
-		ret = -EINTR;
-	}
-
-	closure_sync(&cl);
-
-	if (ret == -EINTR) {
-		ret = bch2_btree_iter_traverse(iter);
-		if (!ret)
-			goto retry;
-	}
-
-	return ret;
-}
-
-static int inline foreground_maybe_merge(struct btree_iter *iter,
-					 enum btree_node_sibling sib)
-{
-	struct bch_fs *c = iter->c;
-	struct btree *b;
-
-	if (!btree_node_locked(iter, iter->level))
-		return 0;
-
-	b = iter->nodes[iter->level];
-	if (b->sib_u64s[sib] > BTREE_FOREGROUND_MERGE_THRESHOLD(c))
-		return 0;
-
-	return __foreground_maybe_merge(iter, sib);
-}
-
-/**
- * btree_insert_key - insert a key one key into a leaf node
- */
-static enum btree_insert_ret
-btree_insert_key(struct btree_insert *trans,
-		 struct btree_insert_entry *insert)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_iter *iter = insert->iter;
-	struct btree *b = iter->nodes[0];
-	enum btree_insert_ret ret;
-	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;
-
-	iter->flags &= ~BTREE_ITER_UPTODATE;
-
-	ret = !btree_node_is_extents(b)
-		? bch2_insert_fixup_key(trans, insert)
-		: bch2_insert_fixup_extent(trans, insert);
-
-	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(iter->c, b))
-		bch2_btree_iter_reinit_node(iter, b);
-
-	trace_btree_insert_key(c, b, insert->k);
-	return ret;
-}
-
-static bool same_leaf_as_prev(struct btree_insert *trans,
-			      struct btree_insert_entry *i)
-{
-	/*
-	 * Because we sorted the transaction entries, if multiple iterators
-	 * point to the same leaf node they'll always be adjacent now:
-	 */
-	return i != trans->entries &&
-		i[0].iter->nodes[0] == i[-1].iter->nodes[0];
-}
-
-#define trans_for_each_entry(trans, i)					\
-	for ((i) = (trans)->entries; (i) < (trans)->entries + (trans)->nr; (i)++)
-
-static void multi_lock_write(struct btree_insert *trans)
-{
-	struct btree_insert_entry *i;
-
-	trans_for_each_entry(trans, i)
-		if (!same_leaf_as_prev(trans, i))
-			btree_node_lock_for_insert(i->iter->nodes[0], i->iter);
-}
-
-static void multi_unlock_write(struct btree_insert *trans)
-{
-	struct btree_insert_entry *i;
-
-	trans_for_each_entry(trans, i)
-		if (!same_leaf_as_prev(trans, i))
-			bch2_btree_node_unlock_write(i->iter->nodes[0], i->iter);
-}
-
-static int btree_trans_entry_cmp(const void *_l, const void *_r)
-{
-	const struct btree_insert_entry *l = _l;
-	const struct btree_insert_entry *r = _r;
-
-	return btree_iter_cmp(l->iter, r->iter);
-}
-
-/* Normal update interface: */
-
-/**
- * __bch_btree_insert_at - insert keys at given iterator positions
- *
- * This is main entry point for btree updates.
- *
- * Return values:
- * -EINTR: locking changed, this function should be called again. Only returned
- *  if passed BTREE_INSERT_ATOMIC.
- * -EROFS: filesystem read only
- * -EIO: journal or btree node IO error
- */
-int __bch2_btree_insert_at(struct btree_insert *trans)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_insert_entry *i;
-	struct btree_iter *split = NULL;
-	bool cycle_gc_lock = false;
-	unsigned u64s;
-	int ret;
-
-	trans_for_each_entry(trans, i) {
-		BUG_ON(i->iter->level);
-		BUG_ON(bkey_cmp(bkey_start_pos(&i->k->k), i->iter->pos));
-	}
-
-	sort(trans->entries, trans->nr, sizeof(trans->entries[0]),
-	     btree_trans_entry_cmp, NULL);
-
-	if (unlikely(!percpu_ref_tryget(&c->writes)))
-		return -EROFS;
-retry_locks:
-	ret = -EINTR;
-	trans_for_each_entry(trans, i)
-		if (!bch2_btree_iter_set_locks_want(i->iter, 1))
-			goto err;
-retry:
-	trans->did_work = false;
-	u64s = 0;
-	trans_for_each_entry(trans, i)
-		if (!i->done)
-			u64s += jset_u64s(i->k->k.u64s + i->extra_res);
-
-	memset(&trans->journal_res, 0, sizeof(trans->journal_res));
-
-	ret = !(trans->flags & BTREE_INSERT_JOURNAL_REPLAY)
-		? bch2_journal_res_get(&c->journal,
-				      &trans->journal_res,
-				      u64s, u64s)
-		: 0;
-	if (ret)
-		goto err;
-
-	multi_lock_write(trans);
-
-	u64s = 0;
-	trans_for_each_entry(trans, i) {
-		/* Multiple inserts might go to same leaf: */
-		if (!same_leaf_as_prev(trans, i))
-			u64s = 0;
-
-		/*
-		 * bch2_btree_node_insert_fits() must be called under write lock:
-		 * with only an intent lock, another thread can still call
-		 * bch2_btree_node_write(), converting an unwritten bset to a
-		 * written one
-		 */
-		if (!i->done) {
-			u64s += i->k->k.u64s + i->extra_res;
-			if (!bch2_btree_node_insert_fits(c,
-					i->iter->nodes[0], u64s)) {
-				split = i->iter;
-				goto unlock;
-			}
-		}
-	}
-
-	ret = 0;
-	split = NULL;
-	cycle_gc_lock = false;
-
-	trans_for_each_entry(trans, i) {
-		if (i->done)
-			continue;
-
-		switch (btree_insert_key(trans, i)) {
-		case BTREE_INSERT_OK:
-			i->done = true;
-			break;
-		case BTREE_INSERT_JOURNAL_RES_FULL:
-		case BTREE_INSERT_NEED_TRAVERSE:
-			ret = -EINTR;
-			break;
-		case BTREE_INSERT_NEED_RESCHED:
-			ret = -EAGAIN;
-			break;
-		case BTREE_INSERT_BTREE_NODE_FULL:
-			split = i->iter;
-			break;
-		case BTREE_INSERT_ENOSPC:
-			ret = -ENOSPC;
-			break;
-		case BTREE_INSERT_NEED_GC_LOCK:
-			cycle_gc_lock = true;
-			ret = -EINTR;
-			break;
-		default:
-			BUG();
-		}
-
-		if (!trans->did_work && (ret || split))
-			break;
-	}
-unlock:
-	multi_unlock_write(trans);
-	bch2_journal_res_put(&c->journal, &trans->journal_res);
-
-	if (split)
-		goto split;
-	if (ret)
-		goto err;
-
-	/*
-	 * hack: iterators are inconsistent when they hit end of leaf, until
-	 * traversed again
-	 */
-	trans_for_each_entry(trans, i)
-		if (i->iter->flags & BTREE_ITER_AT_END_OF_LEAF)
-			goto out;
-
-	trans_for_each_entry(trans, i)
-		if (!same_leaf_as_prev(trans, i)) {
-			foreground_maybe_merge(i->iter, btree_prev_sib);
-			foreground_maybe_merge(i->iter, btree_next_sib);
-		}
-out:
-	/* make sure we didn't lose an error: */
-	if (!ret && IS_ENABLED(CONFIG_BCACHEFS_DEBUG))
-		trans_for_each_entry(trans, i)
-			BUG_ON(!i->done);
-
-	percpu_ref_put(&c->writes);
-	return ret;
-split:
-	/*
-	 * have to drop journal res before splitting, because splitting means
-	 * allocating new btree nodes, and holding a journal reservation
-	 * potentially blocks the allocator:
-	 */
-	ret = bch2_btree_split_leaf(split, trans->flags);
-	if (ret)
-		goto err;
-	/*
-	 * if the split didn't have to drop locks the insert will still be
-	 * atomic (in the BTREE_INSERT_ATOMIC sense, what the caller peeked()
-	 * and is overwriting won't have changed)
-	 */
-	goto retry_locks;
-err:
-	if (cycle_gc_lock) {
-		down_read(&c->gc_lock);
-		up_read(&c->gc_lock);
-	}
-
-	if (ret == -EINTR) {
-		trans_for_each_entry(trans, i) {
-			int ret2 = bch2_btree_iter_traverse(i->iter);
-			if (ret2) {
-				ret = ret2;
-				goto out;
-			}
-		}
-
-		/*
-		 * BTREE_ITER_ATOMIC means we have to return -EINTR if we
-		 * dropped locks:
-		 */
-		if (!(trans->flags & BTREE_INSERT_ATOMIC))
-			goto retry;
-	}
-
-	goto out;
-}
-
-int bch2_btree_delete_at(struct btree_iter *iter, unsigned flags)
-{
-	struct bkey_i k;
-
-	bkey_init(&k.k);
-	k.k.p = iter->pos;
-
-	return bch2_btree_insert_at(iter->c, NULL, NULL, NULL,
-				    BTREE_INSERT_NOFAIL|
-				    BTREE_INSERT_USE_RESERVE|flags,
-				    BTREE_INSERT_ENTRY(iter, &k));
-}
-
-int bch2_btree_insert_list_at(struct btree_iter *iter,
-			     struct keylist *keys,
-			     struct disk_reservation *disk_res,
-			     struct extent_insert_hook *hook,
-			     u64 *journal_seq, unsigned flags)
-{
-	BUG_ON(flags & BTREE_INSERT_ATOMIC);
-	BUG_ON(bch2_keylist_empty(keys));
-	verify_keys_sorted(keys);
-
-	while (!bch2_keylist_empty(keys)) {
-		/* need to traverse between each insert */
-		int ret = bch2_btree_iter_traverse(iter);
-		if (ret)
-			return ret;
-
-		ret = bch2_btree_insert_at(iter->c, disk_res, hook,
-				journal_seq, flags,
-				BTREE_INSERT_ENTRY(iter, bch2_keylist_front(keys)));
-		if (ret)
-			return ret;
-
-		bch2_keylist_pop_front(keys);
-	}
-
-	return 0;
-}
-
-/**
- * bch_btree_insert - insert keys into the extent btree
- * @c:			pointer to struct bch_fs
- * @id:			btree to insert into
- * @insert_keys:	list of keys to insert
- * @hook:		insert callback
- */
-int bch2_btree_insert(struct bch_fs *c, enum btree_id id,
-		     struct bkey_i *k,
-		     struct disk_reservation *disk_res,
-		     struct extent_insert_hook *hook,
-		     u64 *journal_seq, int flags)
-{
-	struct btree_iter iter;
-	int ret, ret2;
-
-	bch2_btree_iter_init(&iter, c, id, bkey_start_pos(&k->k),
-			     BTREE_ITER_INTENT);
-
-	ret = bch2_btree_iter_traverse(&iter);
-	if (unlikely(ret))
-		goto out;
-
-	ret = bch2_btree_insert_at(c, disk_res, hook, journal_seq, flags,
-				  BTREE_INSERT_ENTRY(&iter, k));
-out:	ret2 = bch2_btree_iter_unlock(&iter);
-
-	return ret ?: ret2;
-}
-
-/**
- * bch_btree_update - like bch2_btree_insert(), but asserts that we're
- * overwriting an existing key
- */
-int bch2_btree_update(struct bch_fs *c, enum btree_id id,
-		     struct bkey_i *k, u64 *journal_seq)
-{
-	struct btree_iter iter;
-	struct bkey_s_c u;
-	int ret;
-
-	EBUG_ON(id == BTREE_ID_EXTENTS);
-
-	bch2_btree_iter_init(&iter, c, id, k->k.p,
-			     BTREE_ITER_INTENT);
-
-	u = bch2_btree_iter_peek_with_holes(&iter);
-	ret = btree_iter_err(u);
-	if (ret)
-		return ret;
-
-	if (bkey_deleted(u.k)) {
-		bch2_btree_iter_unlock(&iter);
-		return -ENOENT;
-	}
-
-	ret = bch2_btree_insert_at(c, NULL, NULL, journal_seq, 0,
-				  BTREE_INSERT_ENTRY(&iter, k));
-	bch2_btree_iter_unlock(&iter);
-	return ret;
-}
-
-/*
- * bch_btree_delete_range - delete everything within a given range
- *
- * Range is a half open interval - [start, end)
- */
-int bch2_btree_delete_range(struct bch_fs *c, enum btree_id id,
-			   struct bpos start,
-			   struct bpos end,
-			   struct bversion version,
-			   struct disk_reservation *disk_res,
-			   struct extent_insert_hook *hook,
-			   u64 *journal_seq)
-{
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	int ret = 0;
-
-	bch2_btree_iter_init(&iter, c, id, start,
-			     BTREE_ITER_INTENT);
-
-	while ((k = bch2_btree_iter_peek(&iter)).k &&
-	       !(ret = btree_iter_err(k))) {
-		unsigned max_sectors = KEY_SIZE_MAX & (~0 << c->block_bits);
-		/* really shouldn't be using a bare, unpadded bkey_i */
-		struct bkey_i delete;
-
-		if (bkey_cmp(iter.pos, end) >= 0)
-			break;
-
-		bkey_init(&delete.k);
-
-		/*
-		 * For extents, iter.pos won't necessarily be the same as
-		 * bkey_start_pos(k.k) (for non extents they always will be the
-		 * same). It's important that we delete starting from iter.pos
-		 * because the range we want to delete could start in the middle
-		 * of k.
-		 *
-		 * (bch2_btree_iter_peek() does guarantee that iter.pos >=
-		 * bkey_start_pos(k.k)).
-		 */
-		delete.k.p = iter.pos;
-		delete.k.version = version;
-
-		if (iter.flags & BTREE_ITER_IS_EXTENTS) {
-			/*
-			 * The extents btree is special - KEY_TYPE_DISCARD is
-			 * used for deletions, not KEY_TYPE_DELETED. This is an
-			 * internal implementation detail that probably
-			 * shouldn't be exposed (internally, KEY_TYPE_DELETED is
-			 * used as a proxy for k->size == 0):
-			 */
-			delete.k.type = KEY_TYPE_DISCARD;
-
-			/* create the biggest key we can */
-			bch2_key_resize(&delete.k, max_sectors);
-			bch2_cut_back(end, &delete.k);
-		}
-
-		ret = bch2_btree_insert_at(c, disk_res, hook, journal_seq,
-					  BTREE_INSERT_NOFAIL,
-					  BTREE_INSERT_ENTRY(&iter, &delete));
-		if (ret)
-			break;
-
-		bch2_btree_iter_cond_resched(&iter);
-	}
-
-	bch2_btree_iter_unlock(&iter);
-	return ret;
-}
-
-static int __btree_node_rewrite(struct bch_fs *c, struct btree_iter *iter,
-				struct btree *b, unsigned flags,
-				struct closure *cl)
-{
-	struct btree *n, *parent = iter->nodes[b->level + 1];
-	struct btree_reserve *reserve;
-	struct btree_interior_update *as;
-
-	reserve = bch2_btree_reserve_get(c, b, 0, flags, cl);
-	if (IS_ERR(reserve)) {
-		trace_btree_gc_rewrite_node_fail(c, b);
-		return PTR_ERR(reserve);
-	}
-
-	as = bch2_btree_interior_update_alloc(c);
-
-	bch2_btree_interior_update_will_free_node(c, as, b);
-
-	n = bch2_btree_node_alloc_replacement(c, b, as, reserve);
-
-	bch2_btree_build_aux_trees(n);
-	six_unlock_write(&n->lock);
-
-	trace_btree_gc_rewrite_node(c, b);
-
-	bch2_btree_node_write(c, n, &as->cl, SIX_LOCK_intent);
-
-	if (parent) {
-		bch2_btree_insert_node(parent, iter,
-				      &keylist_single(&n->key),
-				      reserve, as);
-	} else {
-		bch2_btree_set_root(iter, n, as, reserve);
-	}
-
-	bch2_btree_open_bucket_put(c, n);
-
-	bch2_btree_node_free_inmem(iter, b);
-
-	BUG_ON(!bch2_btree_iter_node_replace(iter, n));
-
-	bch2_btree_reserve_put(c, reserve);
-	return 0;
-}
-
-/**
- * bch_btree_node_rewrite - Rewrite/move a btree node
- *
- * Returns 0 on success, -EINTR or -EAGAIN on failure (i.e.
- * btree_check_reserve() has to wait)
- */
-int bch2_btree_node_rewrite(struct bch_fs *c, struct btree_iter *iter,
-			    __le64 seq, unsigned flags)
-{
-	unsigned locks_want = iter->locks_want;
-	struct closure cl;
-	struct btree *b;
-	int ret;
-
-	flags |= BTREE_INSERT_NOFAIL;
-
-	closure_init_stack(&cl);
-
-	bch2_btree_iter_set_locks_want(iter, U8_MAX);
-
-	if (!(flags & BTREE_INSERT_GC_LOCK_HELD)) {
-		if (!down_read_trylock(&c->gc_lock)) {
-			bch2_btree_iter_unlock(iter);
-			down_read(&c->gc_lock);
-		}
-	}
-
-	while (1) {
-		ret = bch2_btree_iter_traverse(iter);
-		if (ret)
-			break;
-
-		b = bch2_btree_iter_peek_node(iter);
-		if (!b || b->data->keys.seq != seq)
-			break;
-
-		ret = __btree_node_rewrite(c, iter, b, flags, &cl);
-		if (ret != -EAGAIN &&
-		    ret != -EINTR)
-			break;
-
-		bch2_btree_iter_unlock(iter);
-		closure_sync(&cl);
-	}
-
-	bch2_btree_iter_set_locks_want(iter, locks_want);
-
-	if (!(flags & BTREE_INSERT_GC_LOCK_HELD))
-		up_read(&c->gc_lock);
-
-	closure_sync(&cl);
-	return ret;
-}
-
-int bch2_btree_node_update_key(struct bch_fs *c, struct btree *b,
-			       struct bkey_i_extent *new_key)
-{
-	struct btree_interior_update *as;
-	struct btree_reserve *reserve = NULL;
-	struct btree *parent, *new_hash = NULL;
-	struct btree_iter iter;
-	struct closure cl;
-	bool must_rewrite_parent = false;
-	int ret;
-
-	__bch2_btree_iter_init(&iter, c, b->btree_id, b->key.k.p,
-			       BTREE_MAX_DEPTH,
-			       b->level, 0);
-	closure_init_stack(&cl);
-
-	if (PTR_HASH(&new_key->k_i) != PTR_HASH(&b->key)) {
-		/* bch2_btree_reserve_get will unlock */
-		do {
-			ret = bch2_btree_node_cannibalize_lock(c, &cl);
-			closure_sync(&cl);
-		} while (ret == -EAGAIN);
-
-		BUG_ON(ret);
-
-		new_hash = bch2_btree_node_mem_alloc(c);
-	}
-retry:
-	reserve = bch2_btree_reserve_get(c, b, 0,
-				BTREE_INSERT_NOFAIL|
-				BTREE_INSERT_USE_RESERVE|
-				BTREE_INSERT_USE_ALLOC_RESERVE,
-				&cl);
-	closure_sync(&cl);
-	if (IS_ERR(reserve)) {
-		ret = PTR_ERR(reserve);
-		if (ret == -EAGAIN || ret == -EINTR)
-			goto retry;
-		goto err;
-	}
-
-	down_read(&c->gc_lock);
-
-	ret = bch2_btree_iter_traverse(&iter);
-	if (ret)
-		goto err;
-
-	mutex_lock(&c->btree_interior_update_lock);
-
-	/*
-	 * Two corner cases that need to be thought about here:
-	 *
-	 * @b may not be reachable yet - there might be another interior update
-	 * operation waiting on @b to be written, and we're gonna deliver the
-	 * write completion to that interior update operation _before_
-	 * persisting the new_key update
-	 *
-	 * That ends up working without us having to do anything special here:
-	 * the reason is, we do kick off (and do the in memory updates) for the
-	 * update for @new_key before we return, creating a new interior_update
-	 * operation here.
-	 *
-	 * The new interior update operation here will in effect override the
-	 * previous one. The previous one was going to terminate - make @b
-	 * reachable - in one of two ways:
-	 * - updating the btree root pointer
-	 *   In that case,
-	 *   no, this doesn't work. argh.
-	 */
-
-	if (b->will_make_reachable)
-		must_rewrite_parent = true;
-
-	/* other case: btree node being freed */
-	if (iter.nodes[b->level] != b) {
-		/* node has been freed: */
-		BUG_ON(btree_node_hashed(b));
-		mutex_unlock(&c->btree_interior_update_lock);
-		goto err;
-	}
-
-	mutex_unlock(&c->btree_interior_update_lock);
-
-	ret = bch2_check_mark_super(c, extent_i_to_s_c(new_key), BCH_DATA_BTREE);
-	if (ret)
-		goto err;
-
-	as = bch2_btree_interior_update_alloc(c);
-
-	if (must_rewrite_parent)
-		as->flags |= BTREE_INTERIOR_UPDATE_MUST_REWRITE;
-
-	bch2_btree_interior_update_add_node_reference(c, as, b);
-
-	if (new_hash) {
-		bkey_copy(&new_hash->key, &new_key->k_i);
-		BUG_ON(bch2_btree_node_hash_insert(c, new_hash,
-					b->level, b->btree_id));
-	}
-
-	parent = iter.nodes[b->level + 1];
-	if (parent) {
-		bch2_btree_insert_node(parent, &iter,
-				       &keylist_single(&b->key),
-				       reserve, as);
-	} else {
-		bch2_btree_set_root(&iter, b, as, reserve);
-	}
-
-	if (new_hash) {
-		mutex_lock(&c->btree_cache_lock);
-		bch2_btree_node_hash_remove(c, b);
-
-		bkey_copy(&b->key, &new_key->k_i);
-		__bch2_btree_node_hash_insert(c, b);
-
-		bch2_btree_node_hash_remove(c, new_hash);
-		mutex_unlock(&c->btree_cache_lock);
-	} else {
-		bkey_copy(&b->key, &new_key->k_i);
-	}
-err:
-	if (!IS_ERR_OR_NULL(reserve))
-		bch2_btree_reserve_put(c, reserve);
-	if (new_hash) {
-		mutex_lock(&c->btree_cache_lock);
-		list_move(&b->list, &c->btree_cache_freeable);
-		mutex_unlock(&c->btree_cache_lock);
-
-		six_unlock_write(&new_hash->lock);
-		six_unlock_intent(&new_hash->lock);
-	}
-	bch2_btree_iter_unlock(&iter);
-	up_read(&c->gc_lock);
-	return ret;
-}