1 files changed, 737 insertions, 0 deletions

diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c
new file mode 100644
index 000000000000..4d1d0954efbf
--- /dev/null
+++ b/fs/bcachefs/btree_update_leaf.c
@@ -0,0 +1,737 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "btree_update.h"
+#include "btree_update_interior.h"
+#include "btree_io.h"
+#include "btree_iter.h"
+#include "btree_locking.h"
+#include "debug.h"
+#include "extents.h"
+#include "journal.h"
+#include "journal_reclaim.h"
+#include "keylist.h"
+#include "trace.h"
+
+#include <linux/sort.h>
+
+/* 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);
+
+	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) &&
+		    !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]);
+
+	btree_node_lock_type(c, b, SIX_LOCK_read);
+	bch2_btree_node_write_cond(c, b,
+			(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->l[0].b;
+	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 (likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))) {
+		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,
+				      iter->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 (unlikely(!journal_pin_active(&w->journal))) {
+		u64 seq = likely(!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))
+			? trans->journal_res.seq
+			: j->replay_journal_seq;
+
+		bch2_journal_pin_add(j, seq, &w->journal,
+				     btree_node_write_idx(b) == 0
+				     ? btree_node_flush0
+				     : btree_node_flush1);
+	}
+
+	if (unlikely(!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;
+	struct btree_iter_level *l = &iter->l[0];
+
+	EBUG_ON(iter->level);
+	EBUG_ON(insert->k->k.u64s >
+		bch_btree_keys_u64s_remaining(trans->c, l->b));
+
+	if (bch2_btree_bset_insert_key(iter, l->b, &l->iter,
+				       insert->k))
+		bch2_btree_journal_key(trans, iter, insert->k);
+
+	trans->did_work = true;
+	return BTREE_INSERT_OK;
+}
+
+/**
+ * btree_insert_key - insert a key one key into a leaf node
+ */
+static enum btree_insert_ret
+btree_insert_key_leaf(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->l[0].b;
+	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;
+
+	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(c, b))
+		bch2_btree_iter_reinit_node(iter, b);
+
+	trace_btree_insert_key(c, b, insert->k);
+	return ret;
+}
+
+#define trans_for_each_entry(trans, i)					\
+	for ((i) = (trans)->entries; (i) < (trans)->entries + (trans)->nr; (i)++)
+
+/*
+ * We sort transaction entries so that if multiple iterators point to the same
+ * leaf node they'll be adjacent:
+ */
+static bool same_leaf_as_prev(struct btree_insert *trans,
+			      struct btree_insert_entry *i)
+{
+	return i != trans->entries &&
+		i[0].iter->l[0].b == i[-1].iter->l[0].b;
+}
+
+static inline struct btree_insert_entry *trans_next_leaf(struct btree_insert *trans,
+							 struct btree_insert_entry *i)
+{
+	struct btree *b = i->iter->l[0].b;
+
+	do {
+		i++;
+	} while (i < trans->entries + trans->nr && b == i->iter->l[0].b);
+
+	return i;
+}
+
+#define trans_for_each_leaf(trans, i)					\
+	for ((i) = (trans)->entries;					\
+	     (i) < (trans)->entries + (trans)->nr;			\
+	     (i) = trans_next_leaf(trans, i))
+
+inline void bch2_btree_node_lock_for_insert(struct bch_fs *c, struct btree *b,
+					    struct btree_iter *iter)
+{
+	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);
+}
+
+static void multi_lock_write(struct bch_fs *c, struct btree_insert *trans)
+{
+	struct btree_insert_entry *i;
+
+	trans_for_each_leaf(trans, i)
+		bch2_btree_node_lock_for_insert(c, i->iter->l[0].b, i->iter);
+}
+
+static void multi_unlock_write(struct btree_insert *trans)
+{
+	struct btree_insert_entry *i;
+
+	trans_for_each_leaf(trans, i)
+		bch2_btree_node_unlock_write(i->iter->l[0].b, i->iter);
+}
+
+static inline int btree_trans_cmp(struct btree_insert_entry l,
+				  struct btree_insert_entry r)
+{
+	return btree_iter_cmp(l.iter, r.iter);
+}
+
+/* Normal update interface: */
+
+/*
+ * Get journal reservation, take write locks, and attempt to do btree update(s):
+ */
+static inline int do_btree_insert_at(struct btree_insert *trans,
+				     struct btree_iter **split,
+				     bool *cycle_gc_lock)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_insert_entry *i;
+	unsigned u64s;
+	int ret;
+
+	trans_for_each_entry(trans, i) {
+		BUG_ON(i->done);
+		BUG_ON(i->iter->uptodate >= BTREE_ITER_NEED_RELOCK);
+	}
+
+	u64s = 0;
+	trans_for_each_entry(trans, i)
+		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)
+		return ret;
+
+	multi_lock_write(c, trans);
+
+	if (race_fault()) {
+		ret = -EINTR;
+		goto out;
+	}
+
+	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
+		 */
+		u64s += i->k->k.u64s + i->extra_res;
+		if (!bch2_btree_node_insert_fits(c,
+				i->iter->l[0].b, u64s)) {
+			ret = -EINTR;
+			*split = i->iter;
+			goto out;
+		}
+	}
+
+	if (!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY)) {
+		if (journal_seq_verify(c))
+			trans_for_each_entry(trans, i)
+				i->k->k.version.lo = trans->journal_res.seq;
+		else if (inject_invalid_keys(c))
+			trans_for_each_entry(trans, i)
+				i->k->k.version = MAX_VERSION;
+	}
+
+	trans_for_each_entry(trans, i) {
+		switch (btree_insert_key_leaf(trans, i)) {
+		case BTREE_INSERT_OK:
+			i->done = true;
+			break;
+		case BTREE_INSERT_JOURNAL_RES_FULL:
+		case BTREE_INSERT_NEED_TRAVERSE:
+		case BTREE_INSERT_NEED_RESCHED:
+			ret = -EINTR;
+			break;
+		case BTREE_INSERT_BTREE_NODE_FULL:
+			ret = -EINTR;
+			*split = i->iter;
+			break;
+		case BTREE_INSERT_ENOSPC:
+			ret = -ENOSPC;
+			break;
+		case BTREE_INSERT_NEED_GC_LOCK:
+			ret = -EINTR;
+			*cycle_gc_lock = true;
+			break;
+		default:
+			BUG();
+		}
+
+		/*
+		 * If we did some work (i.e. inserted part of an extent),
+		 * we have to do all the other updates as well:
+		 */
+		if (!trans->did_work && (ret || *split))
+			break;
+	}
+out:
+	multi_unlock_write(trans);
+	bch2_journal_res_put(&c->journal, &trans->journal_res);
+
+	return ret;
+}
+
+static inline void btree_insert_entry_checks(struct bch_fs *c,
+					     struct btree_insert_entry *i)
+{
+	BUG_ON(i->iter->level);
+	BUG_ON(bkey_cmp(bkey_start_pos(&i->k->k), i->iter->pos));
+	BUG_ON(debug_check_bkeys(c) &&
+	       !bkey_deleted(&i->k->k) &&
+	       bch2_bkey_invalid(c, (enum bkey_type) i->iter->btree_id,
+				 bkey_i_to_s_c(i->k)));
+}
+
+/**
+ * __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 *linked, *split = NULL;
+	bool cycle_gc_lock = false;
+	unsigned flags;
+	int ret;
+
+	BUG_ON(!trans->nr);
+
+	for_each_btree_iter(trans->entries[0].iter, linked)
+		bch2_btree_iter_verify_locks(linked);
+
+	/* for the sake of sanity: */
+	BUG_ON(trans->nr > 1 && !(trans->flags & BTREE_INSERT_ATOMIC));
+
+	trans_for_each_entry(trans, i)
+		btree_insert_entry_checks(c, i);
+
+	bubble_sort(trans->entries, trans->nr, btree_trans_cmp);
+
+	if (unlikely(!percpu_ref_tryget(&c->writes)))
+		return -EROFS;
+retry:
+	split = NULL;
+	cycle_gc_lock = false;
+
+	trans_for_each_entry(trans, i) {
+		if (!bch2_btree_iter_upgrade(i->iter, 1, true)) {
+			ret = -EINTR;
+			goto err;
+		}
+
+		if (i->iter->flags & BTREE_ITER_ERROR) {
+			ret = -EIO;
+			goto err;
+		}
+	}
+
+	ret = do_btree_insert_at(trans, &split, &cycle_gc_lock);
+	if (unlikely(ret))
+		goto err;
+
+	trans_for_each_leaf(trans, i)
+		bch2_foreground_maybe_merge(c, i->iter, 0, trans->flags);
+
+	trans_for_each_entry(trans, i)
+		bch2_btree_iter_downgrade(i->iter);
+out:
+	percpu_ref_put(&c->writes);
+
+	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
+		/* make sure we didn't drop or screw up locks: */
+		for_each_btree_iter(trans->entries[0].iter, linked) {
+			bch2_btree_iter_verify_locks(linked);
+			BUG_ON((trans->flags & BTREE_INSERT_NOUNLOCK) &&
+			       trans->did_work &&
+			       linked->uptodate >= BTREE_ITER_NEED_RELOCK);
+		}
+
+		/* make sure we didn't lose an error: */
+		if (!ret)
+			trans_for_each_entry(trans, i)
+				BUG_ON(!i->done);
+	}
+
+	BUG_ON(!(trans->flags & BTREE_INSERT_ATOMIC) && ret == -EINTR);
+
+	return ret;
+err:
+	flags = trans->flags;
+
+	/*
+	 * BTREE_INSERT_NOUNLOCK means don't unlock _after_ successful btree
+	 * update; if we haven't done anything yet it doesn't apply
+	 */
+	if (!trans->did_work)
+		flags &= ~BTREE_INSERT_NOUNLOCK;
+
+	if (split) {
+		ret = bch2_btree_split_leaf(c, split, flags);
+
+		/*
+		 * if the split succeeded without dropping locks the insert will
+		 * still be atomic (in the BTREE_INSERT_ATOMIC sense, what the
+		 * caller peeked() and is overwriting won't have changed)
+		 */
+#if 0
+		/*
+		 * XXX:
+		 * split -> btree node merging (of parent node) might still drop
+		 * locks when we're not passing it BTREE_INSERT_NOUNLOCK
+		 */
+		if (!ret && !trans->did_work)
+			goto retry;
+#endif
+
+		/*
+		 * don't care if we got ENOSPC because we told split it
+		 * couldn't block:
+		 */
+		if (!ret || (flags & BTREE_INSERT_NOUNLOCK))
+			ret = -EINTR;
+	}
+
+	if (cycle_gc_lock) {
+		if (!down_read_trylock(&c->gc_lock)) {
+			if (flags & BTREE_INSERT_NOUNLOCK)
+				goto out;
+
+			bch2_btree_iter_unlock(trans->entries[0].iter);
+			down_read(&c->gc_lock);
+		}
+		up_read(&c->gc_lock);
+	}
+
+	if (ret == -EINTR) {
+		if (flags & BTREE_INSERT_NOUNLOCK)
+			goto out;
+
+		trans_for_each_entry(trans, i) {
+			int ret2 = bch2_btree_iter_traverse(i->iter);
+			if (ret2) {
+				ret = ret2;
+				goto out;
+			}
+
+			BUG_ON(i->iter->uptodate > BTREE_ITER_NEED_PEEK);
+		}
+
+		/*
+		 * BTREE_ITER_ATOMIC means we have to return -EINTR if we
+		 * dropped locks:
+		 */
+		if (!(flags & BTREE_INSERT_ATOMIC))
+			goto retry;
+	}
+
+	goto out;
+}
+
+void bch2_trans_update(struct btree_trans *trans,
+		       struct btree_iter *iter,
+		       struct bkey_i *k,
+		       unsigned extra_journal_res)
+{
+	struct btree_insert_entry *i;
+
+	BUG_ON(trans->nr_updates >= ARRAY_SIZE(trans->updates));
+
+	i = &trans->updates[trans->nr_updates++];
+
+	*i = (struct btree_insert_entry) {
+		.iter	= iter,
+		.k		= k,
+		.extra_res	= extra_journal_res,
+	};
+
+	btree_insert_entry_checks(trans->c, i);
+}
+
+int bch2_trans_commit(struct btree_trans *trans,
+		      struct disk_reservation *disk_res,
+		      struct extent_insert_hook *hook,
+		      u64 *journal_seq,
+		      unsigned flags)
+{
+	struct btree_insert insert = {
+		.c		= trans->c,
+		.disk_res	= disk_res,
+		.journal_seq	= journal_seq,
+		.flags		= flags,
+		.nr		= trans->nr_updates,
+		.entries	= trans->updates,
+	};
+
+	if (!trans->nr_updates)
+		return 0;
+
+	trans->nr_updates = 0;
+
+	return __bch2_btree_insert_at(&insert);
+}
+
+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));
+	bch2_verify_keylist_sorted(keys);
+
+	while (!bch2_keylist_empty(keys)) {
+		int 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;
+
+	bch2_btree_iter_init(&iter, c, id, bkey_start_pos(&k->k),
+			     BTREE_ITER_INTENT);
+	ret = bch2_btree_insert_at(c, disk_res, hook, journal_seq, flags,
+				   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) {
+			/* 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;
+}