Rename from bcache-tools to bcachefs-tools

1 files changed, 0 insertions, 2498 deletions

diff --git a/libbcache/extents.c b/libbcache/extents.c
deleted file mode 100644
index 4b422fb1..00000000
--- a/libbcache/extents.c
+++ /dev/null
@@ -1,2498 +0,0 @@
-/*
- * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com>
- *
- * Code for managing the extent btree and dynamically updating the writeback
- * dirty sector count.
- */
-
-#include "bcache.h"
-#include "bkey_methods.h"
-#include "btree_gc.h"
-#include "btree_update.h"
-#include "checksum.h"
-#include "debug.h"
-#include "dirent.h"
-#include "error.h"
-#include "extents.h"
-#include "inode.h"
-#include "journal.h"
-#include "super-io.h"
-#include "writeback.h"
-#include "xattr.h"
-
-#include <trace/events/bcache.h>
-
-static enum merge_result bch_extent_merge(struct bch_fs *, struct btree *,
-					  struct bkey_i *, struct bkey_i *);
-
-static void sort_key_next(struct btree_node_iter *iter,
-			  struct btree *b,
-			  struct btree_node_iter_set *i)
-{
-	i->k += __btree_node_offset_to_key(b, i->k)->u64s;
-
-	if (i->k == i->end)
-		*i = iter->data[--iter->used];
-}
-
-/*
- * Returns true if l > r - unless l == r, in which case returns true if l is
- * older than r.
- *
- * Necessary for btree_sort_fixup() - if there are multiple keys that compare
- * equal in different sets, we have to process them newest to oldest.
- */
-#define key_sort_cmp(l, r)						\
-({									\
-	int _c = bkey_cmp_packed(b,					\
-				 __btree_node_offset_to_key(b, (l).k),	\
-				 __btree_node_offset_to_key(b, (r).k));	\
-									\
-	_c ? _c > 0 : (l).k > (r).k;					\
-})
-
-static inline bool should_drop_next_key(struct btree_node_iter *iter,
-					struct btree *b)
-{
-	struct btree_node_iter_set *l = iter->data, *r = iter->data + 1;
-	struct bkey_packed *k = __btree_node_offset_to_key(b, l->k);
-
-	if (bkey_whiteout(k))
-		return true;
-
-	if (iter->used < 2)
-		return false;
-
-	if (iter->used > 2 &&
-	    key_sort_cmp(r[0], r[1]))
-		r++;
-
-	/*
-	 * key_sort_cmp() ensures that when keys compare equal the older key
-	 * comes first; so if l->k compares equal to r->k then l->k is older and
-	 * should be dropped.
-	 */
-	return !bkey_cmp_packed(b,
-				__btree_node_offset_to_key(b, l->k),
-				__btree_node_offset_to_key(b, r->k));
-}
-
-struct btree_nr_keys bch_key_sort_fix_overlapping(struct bset *dst,
-						  struct btree *b,
-						  struct btree_node_iter *iter)
-{
-	struct bkey_packed *out = dst->start;
-	struct btree_nr_keys nr;
-
-	memset(&nr, 0, sizeof(nr));
-
-	heap_resort(iter, key_sort_cmp);
-
-	while (!bch_btree_node_iter_end(iter)) {
-		if (!should_drop_next_key(iter, b)) {
-			struct bkey_packed *k =
-				__btree_node_offset_to_key(b, iter->data->k);
-
-			bkey_copy(out, k);
-			btree_keys_account_key_add(&nr, 0, out);
-			out = bkey_next(out);
-		}
-
-		sort_key_next(iter, b, iter->data);
-		heap_sift(iter, 0, key_sort_cmp);
-	}
-
-	dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
-	return nr;
-}
-
-/* Common among btree and extent ptrs */
-
-const struct bch_extent_ptr *
-bch_extent_has_device(struct bkey_s_c_extent e, unsigned dev)
-{
-	const struct bch_extent_ptr *ptr;
-
-	extent_for_each_ptr(e, ptr)
-		if (ptr->dev == dev)
-			return ptr;
-
-	return NULL;
-}
-
-unsigned bch_extent_nr_ptrs(struct bkey_s_c_extent e)
-{
-	const struct bch_extent_ptr *ptr;
-	unsigned nr_ptrs = 0;
-
-	extent_for_each_ptr(e, ptr)
-		nr_ptrs++;
-
-	return nr_ptrs;
-}
-
-unsigned bch_extent_nr_dirty_ptrs(struct bkey_s_c k)
-{
-	struct bkey_s_c_extent e;
-	const struct bch_extent_ptr *ptr;
-	unsigned nr_ptrs = 0;
-
-	switch (k.k->type) {
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED:
-		e = bkey_s_c_to_extent(k);
-
-		extent_for_each_ptr(e, ptr)
-			nr_ptrs += !ptr->cached;
-		break;
-
-	case BCH_RESERVATION:
-		nr_ptrs = bkey_s_c_to_reservation(k).v->nr_replicas;
-		break;
-	}
-
-	return nr_ptrs;
-}
-
-/* returns true if equal */
-static bool crc_cmp(union bch_extent_crc *l, union bch_extent_crc *r)
-{
-	return extent_crc_type(l) == extent_crc_type(r) &&
-		!memcmp(l, r, extent_entry_bytes(to_entry(l)));
-}
-
-/* Increment pointers after @crc by crc's offset until the next crc entry: */
-void bch_extent_crc_narrow_pointers(struct bkey_s_extent e, union bch_extent_crc *crc)
-{
-	union bch_extent_entry *entry;
-
-	extent_for_each_entry_from(e, entry, extent_entry_next(to_entry(crc))) {
-		if (!extent_entry_is_ptr(entry))
-			return;
-
-		entry->ptr.offset += crc_offset(crc);
-	}
-}
-
-/*
- * We're writing another replica for this extent, so while we've got the data in
- * memory we'll be computing a new checksum for the currently live data.
- *
- * If there are other replicas we aren't moving, and they are checksummed but
- * not compressed, we can modify them to point to only the data that is
- * currently live (so that readers won't have to bounce) while we've got the
- * checksum we need:
- *
- * XXX: to guard against data being corrupted while in memory, instead of
- * recomputing the checksum here, it would be better in the read path to instead
- * of computing the checksum of the entire extent:
- *
- * | extent                              |
- *
- * compute the checksums of the live and dead data separately
- * | dead data || live data || dead data |
- *
- * and then verify that crc_dead1 + crc_live + crc_dead2 == orig_crc, and then
- * use crc_live here (that we verified was correct earlier)
- *
- * note: doesn't work with encryption
- */
-void bch_extent_narrow_crcs(struct bkey_s_extent e)
-{
-	union bch_extent_crc *crc;
-	bool have_wide = false, have_narrow = false;
-	struct bch_csum csum = { 0 };
-	unsigned csum_type = 0;
-
-	extent_for_each_crc(e, crc) {
-		if (crc_compression_type(crc) ||
-		    bch_csum_type_is_encryption(crc_csum_type(crc)))
-			continue;
-
-		if (crc_uncompressed_size(e.k, crc) != e.k->size) {
-			have_wide = true;
-		} else {
-			have_narrow = true;
-			csum = crc_csum(crc);
-			csum_type = crc_csum_type(crc);
-		}
-	}
-
-	if (!have_wide || !have_narrow)
-		return;
-
-	extent_for_each_crc(e, crc) {
-		if (crc_compression_type(crc))
-			continue;
-
-		if (crc_uncompressed_size(e.k, crc) != e.k->size) {
-			switch (extent_crc_type(crc)) {
-			case BCH_EXTENT_CRC_NONE:
-				BUG();
-			case BCH_EXTENT_CRC32:
-				if (bch_crc_bytes[csum_type] > 4)
-					continue;
-
-				bch_extent_crc_narrow_pointers(e, crc);
-				crc->crc32._compressed_size	= e.k->size - 1;
-				crc->crc32._uncompressed_size	= e.k->size - 1;
-				crc->crc32.offset		= 0;
-				crc->crc32.csum_type		= csum_type;
-				crc->crc32.csum			= csum.lo;
-				break;
-			case BCH_EXTENT_CRC64:
-				if (bch_crc_bytes[csum_type] > 10)
-					continue;
-
-				bch_extent_crc_narrow_pointers(e, crc);
-				crc->crc64._compressed_size	= e.k->size - 1;
-				crc->crc64._uncompressed_size	= e.k->size - 1;
-				crc->crc64.offset		= 0;
-				crc->crc64.csum_type		= csum_type;
-				crc->crc64.csum_lo		= csum.lo;
-				crc->crc64.csum_hi		= csum.hi;
-				break;
-			case BCH_EXTENT_CRC128:
-				if (bch_crc_bytes[csum_type] > 16)
-					continue;
-
-				bch_extent_crc_narrow_pointers(e, crc);
-				crc->crc128._compressed_size	= e.k->size - 1;
-				crc->crc128._uncompressed_size	= e.k->size - 1;
-				crc->crc128.offset		= 0;
-				crc->crc128.csum_type		= csum_type;
-				crc->crc128.csum		= csum;
-				break;
-			}
-		}
-	}
-}
-
-void bch_extent_drop_redundant_crcs(struct bkey_s_extent e)
-{
-	union bch_extent_entry *entry = e.v->start;
-	union bch_extent_crc *crc, *prev = NULL;
-
-	while (entry != extent_entry_last(e)) {
-		union bch_extent_entry *next = extent_entry_next(entry);
-		size_t crc_u64s = extent_entry_u64s(entry);
-
-		if (!extent_entry_is_crc(entry))
-			goto next;
-
-		crc = entry_to_crc(entry);
-
-		if (next == extent_entry_last(e)) {
-			/* crc entry with no pointers after it: */
-			goto drop;
-		}
-
-		if (extent_entry_is_crc(next)) {
-			/* no pointers before next crc entry: */
-			goto drop;
-		}
-
-		if (prev && crc_cmp(crc, prev)) {
-			/* identical to previous crc entry: */
-			goto drop;
-		}
-
-		if (!prev &&
-		    !crc_csum_type(crc) &&
-		    !crc_compression_type(crc)) {
-			/* null crc entry: */
-			bch_extent_crc_narrow_pointers(e, crc);
-			goto drop;
-		}
-
-		prev = crc;
-next:
-		entry = next;
-		continue;
-drop:
-		memmove_u64s_down(crc, next,
-				  (u64 *) extent_entry_last(e) - (u64 *) next);
-		e.k->u64s -= crc_u64s;
-	}
-
-	EBUG_ON(bkey_val_u64s(e.k) && !bch_extent_nr_ptrs(e.c));
-}
-
-static bool should_drop_ptr(const struct bch_fs *c,
-			    struct bkey_s_c_extent e,
-			    const struct bch_extent_ptr *ptr)
-{
-	return ptr->cached && ptr_stale(c->devs[ptr->dev], ptr);
-}
-
-static void bch_extent_drop_stale(struct bch_fs *c, struct bkey_s_extent e)
-{
-	struct bch_extent_ptr *ptr = &e.v->start->ptr;
-	bool dropped = false;
-
-	while ((ptr = extent_ptr_next(e, ptr)))
-		if (should_drop_ptr(c, e.c, ptr)) {
-			__bch_extent_drop_ptr(e, ptr);
-			dropped = true;
-		} else
-			ptr++;
-
-	if (dropped)
-		bch_extent_drop_redundant_crcs(e);
-}
-
-static bool bch_ptr_normalize(struct bch_fs *c, struct btree *bk,
-			      struct bkey_s k)
-{
-	return bch_extent_normalize(c, k);
-}
-
-static void bch_ptr_swab(const struct bkey_format *f, struct bkey_packed *k)
-{
-	switch (k->type) {
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED: {
-		union bch_extent_entry *entry;
-		u64 *d = (u64 *) bkeyp_val(f, k);
-		unsigned i;
-
-		for (i = 0; i < bkeyp_val_u64s(f, k); i++)
-			d[i] = swab64(d[i]);
-
-		for (entry = (union bch_extent_entry *) d;
-		     entry < (union bch_extent_entry *) (d + bkeyp_val_u64s(f, k));
-		     entry = extent_entry_next(entry)) {
-			switch (extent_entry_type(entry)) {
-			case BCH_EXTENT_ENTRY_crc32:
-				entry->crc32.csum = swab32(entry->crc32.csum);
-				break;
-			case BCH_EXTENT_ENTRY_crc64:
-				entry->crc64.csum_hi = swab16(entry->crc64.csum_hi);
-				entry->crc64.csum_lo = swab64(entry->crc64.csum_lo);
-				break;
-			case BCH_EXTENT_ENTRY_crc128:
-				entry->crc128.csum.hi = swab64(entry->crc64.csum_hi);
-				entry->crc128.csum.lo = swab64(entry->crc64.csum_lo);
-				break;
-			case BCH_EXTENT_ENTRY_ptr:
-				break;
-			}
-		}
-		break;
-	}
-	}
-}
-
-static const char *extent_ptr_invalid(const struct bch_fs *c,
-				      struct bkey_s_c_extent e,
-				      const struct bch_extent_ptr *ptr,
-				      unsigned size_ondisk,
-				      bool metadata)
-{
-	const struct bch_extent_ptr *ptr2;
-	struct bch_dev *ca;
-
-	if (ptr->dev >= c->sb.nr_devices)
-		return "pointer to invalid device";
-
-	ca = c->devs[ptr->dev];
-	if (!ca)
-		return "pointer to invalid device";
-
-	extent_for_each_ptr(e, ptr2)
-		if (ptr != ptr2 && ptr->dev == ptr2->dev)
-			return "multiple pointers to same device";
-
-	if (ptr->offset + size_ondisk > ca->mi.bucket_size * ca->mi.nbuckets)
-		return "offset past end of device";
-
-	if (ptr->offset < ca->mi.bucket_size * ca->mi.first_bucket)
-		return "offset before first bucket";
-
-	if ((ptr->offset & (ca->mi.bucket_size - 1)) +
-	    size_ondisk > ca->mi.bucket_size)
-		return "spans multiple buckets";
-
-	if (!(metadata ? ca->mi.has_metadata : ca->mi.has_data))
-		return "device not marked as containing data";
-
-	return NULL;
-}
-
-static size_t extent_print_ptrs(struct bch_fs *c, char *buf,
-				size_t size, struct bkey_s_c_extent e)
-{
-	char *out = buf, *end = buf + size;
-	const union bch_extent_entry *entry;
-	const union bch_extent_crc *crc;
-	const struct bch_extent_ptr *ptr;
-	struct bch_dev *ca;
-	bool first = true;
-
-#define p(...)	(out += scnprintf(out, end - out, __VA_ARGS__))
-
-	extent_for_each_entry(e, entry) {
-		if (!first)
-			p(" ");
-
-		switch (__extent_entry_type(entry)) {
-		case BCH_EXTENT_ENTRY_crc32:
-		case BCH_EXTENT_ENTRY_crc64:
-		case BCH_EXTENT_ENTRY_crc128:
-			crc = entry_to_crc(entry);
-
-			p("crc: c_size %u size %u offset %u csum %u compress %u",
-			  crc_compressed_size(e.k, crc),
-			  crc_uncompressed_size(e.k, crc),
-			  crc_offset(crc), crc_csum_type(crc),
-			  crc_compression_type(crc));
-			break;
-		case BCH_EXTENT_ENTRY_ptr:
-			ptr = entry_to_ptr(entry);
-			ca = c->devs[ptr->dev];
-
-			p("ptr: %u:%llu gen %u%s", ptr->dev,
-			  (u64) ptr->offset, ptr->gen,
-			  ca && ptr_stale(ca, ptr)
-			  ? " stale" : "");
-			break;
-		default:
-			p("(invalid extent entry %.16llx)", *((u64 *) entry));
-			goto out;
-		}
-
-		first = false;
-	}
-out:
-	if (bkey_extent_is_cached(e.k))
-		p(" cached");
-#undef p
-	return out - buf;
-}
-
-/* Btree ptrs */
-
-static const char *bch_btree_ptr_invalid(const struct bch_fs *c,
-					 struct bkey_s_c k)
-{
-	if (bkey_extent_is_cached(k.k))
-		return "cached";
-
-	if (k.k->size)
-		return "nonzero key size";
-
-	if (bkey_val_u64s(k.k) > BKEY_BTREE_PTR_VAL_U64s_MAX)
-		return "value too big";
-
-	switch (k.k->type) {
-	case BCH_EXTENT: {
-		struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
-		const union bch_extent_entry *entry;
-		const struct bch_extent_ptr *ptr;
-		const union bch_extent_crc *crc;
-		const char *reason;
-
-		extent_for_each_entry(e, entry)
-			if (__extent_entry_type(entry) >= BCH_EXTENT_ENTRY_MAX)
-				return "invalid extent entry type";
-
-		extent_for_each_ptr_crc(e, ptr, crc) {
-			reason = extent_ptr_invalid(c, e, ptr,
-						    c->sb.btree_node_size,
-						    true);
-			if (reason)
-				return reason;
-		}
-
-		if (crc)
-			return "has crc field";
-
-		return NULL;
-	}
-
-	default:
-		return "invalid value type";
-	}
-}
-
-static void btree_ptr_debugcheck(struct bch_fs *c, struct btree *b,
-				 struct bkey_s_c k)
-{
-	struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
-	const struct bch_extent_ptr *ptr;
-	unsigned seq;
-	const char *err;
-	char buf[160];
-	struct bucket *g;
-	struct bch_dev *ca;
-	unsigned replicas = 0;
-	bool bad;
-
-	extent_for_each_ptr(e, ptr) {
-		ca = c->devs[ptr->dev];
-		g = PTR_BUCKET(ca, ptr);
-		replicas++;
-
-		err = "stale";
-		if (ptr_stale(ca, ptr))
-			goto err;
-
-		do {
-			seq = read_seqcount_begin(&c->gc_pos_lock);
-			bad = gc_pos_cmp(c->gc_pos, gc_pos_btree_node(b)) > 0 &&
-				g->mark.data_type != BUCKET_BTREE;
-		} while (read_seqcount_retry(&c->gc_pos_lock, seq));
-
-		err = "inconsistent";
-		if (bad)
-			goto err;
-	}
-
-	if (replicas < c->sb.meta_replicas_have) {
-		bch_bkey_val_to_text(c, btree_node_type(b),
-				     buf, sizeof(buf), k);
-		bch_fs_bug(c,
-			"btree key bad (too few replicas, %u < %u): %s",
-			replicas, c->sb.meta_replicas_have, buf);
-		return;
-	}
-
-	return;
-err:
-	bch_bkey_val_to_text(c, btree_node_type(b), buf, sizeof(buf), k);
-	bch_fs_bug(c, "%s btree pointer %s: bucket %zi prio %i "
-		      "gen %i last_gc %i mark %08x",
-		      err, buf, PTR_BUCKET_NR(ca, ptr),
-		      g->read_prio, PTR_BUCKET(ca, ptr)->mark.gen,
-		      ca->oldest_gens[PTR_BUCKET_NR(ca, ptr)],
-		      (unsigned) g->mark.counter);
-}
-
-static void bch_btree_ptr_to_text(struct bch_fs *c, char *buf,
-				  size_t size, struct bkey_s_c k)
-{
-	char *out = buf, *end = buf + size;
-	const char *invalid;
-
-#define p(...)	(out += scnprintf(out, end - out, __VA_ARGS__))
-
-	if (bkey_extent_is_data(k.k))
-		out += extent_print_ptrs(c, buf, size, bkey_s_c_to_extent(k));
-
-	invalid = bch_btree_ptr_invalid(c, k);
-	if (invalid)
-		p(" invalid: %s", invalid);
-#undef p
-}
-
-struct extent_pick_ptr
-bch_btree_pick_ptr(struct bch_fs *c, const struct btree *b)
-{
-	struct bkey_s_c_extent e = bkey_i_to_s_c_extent(&b->key);
-	const union bch_extent_crc *crc;
-	const struct bch_extent_ptr *ptr;
-	struct extent_pick_ptr pick = { .ca = NULL };
-
-	extent_for_each_ptr_crc(e, ptr, crc) {
-		struct bch_dev *ca = c->devs[ptr->dev];
-		struct btree *root = btree_node_root(c, b);
-
-		if (bch_fs_inconsistent_on(crc, c,
-				"btree node pointer with crc at btree %u level %u/%u bucket %zu",
-				b->btree_id, b->level, root ? root->level : -1,
-				PTR_BUCKET_NR(ca, ptr)))
-			break;
-
-		if (bch_dev_inconsistent_on(ptr_stale(ca, ptr), ca,
-				"stale btree node pointer at btree %u level %u/%u bucket %zu",
-				b->btree_id, b->level, root ? root->level : -1,
-				PTR_BUCKET_NR(ca, ptr)))
-			continue;
-
-		if (ca->mi.state == BCH_MEMBER_STATE_FAILED)
-			continue;
-
-		if (pick.ca && pick.ca->mi.tier < ca->mi.tier)
-			continue;
-
-		if (!percpu_ref_tryget(&ca->io_ref))
-			continue;
-
-		if (pick.ca)
-			percpu_ref_put(&pick.ca->io_ref);
-
-		pick.ca		= ca;
-		pick.ptr	= *ptr;
-	}
-
-	return pick;
-}
-
-const struct bkey_ops bch_bkey_btree_ops = {
-	.key_invalid	= bch_btree_ptr_invalid,
-	.key_debugcheck	= btree_ptr_debugcheck,
-	.val_to_text	= bch_btree_ptr_to_text,
-	.swab		= bch_ptr_swab,
-};
-
-/* Extents */
-
-static bool __bch_cut_front(struct bpos where, struct bkey_s k)
-{
-	u64 len = 0;
-
-	if (bkey_cmp(where, bkey_start_pos(k.k)) <= 0)
-		return false;
-
-	EBUG_ON(bkey_cmp(where, k.k->p) > 0);
-
-	len = k.k->p.offset - where.offset;
-
-	BUG_ON(len > k.k->size);
-
-	/*
-	 * Don't readjust offset if the key size is now 0, because that could
-	 * cause offset to point to the next bucket:
-	 */
-	if (!len)
-		__set_bkey_deleted(k.k);
-	else if (bkey_extent_is_data(k.k)) {
-		struct bkey_s_extent e = bkey_s_to_extent(k);
-		struct bch_extent_ptr *ptr;
-		union bch_extent_crc *crc, *prev_crc = NULL;
-
-		extent_for_each_ptr_crc(e, ptr, crc) {
-			switch (extent_crc_type(crc)) {
-			case BCH_EXTENT_CRC_NONE:
-				ptr->offset += e.k->size - len;
-				break;
-			case BCH_EXTENT_CRC32:
-				if (prev_crc != crc)
-					crc->crc32.offset += e.k->size - len;
-				break;
-			case BCH_EXTENT_CRC64:
-				if (prev_crc != crc)
-					crc->crc64.offset += e.k->size - len;
-				break;
-			case BCH_EXTENT_CRC128:
-				if (prev_crc != crc)
-					crc->crc128.offset += e.k->size - len;
-				break;
-			}
-			prev_crc = crc;
-		}
-	}
-
-	k.k->size = len;
-
-	return true;
-}
-
-bool bch_cut_front(struct bpos where, struct bkey_i *k)
-{
-	return __bch_cut_front(where, bkey_i_to_s(k));
-}
-
-bool bch_cut_back(struct bpos where, struct bkey *k)
-{
-	u64 len = 0;
-
-	if (bkey_cmp(where, k->p) >= 0)
-		return false;
-
-	EBUG_ON(bkey_cmp(where, bkey_start_pos(k)) < 0);
-
-	len = where.offset - bkey_start_offset(k);
-
-	BUG_ON(len > k->size);
-
-	k->p = where;
-	k->size = len;
-
-	if (!len)
-		__set_bkey_deleted(k);
-
-	return true;
-}
-
-/**
- * bch_key_resize - adjust size of @k
- *
- * bkey_start_offset(k) will be preserved, modifies where the extent ends
- */
-void bch_key_resize(struct bkey *k,
-		    unsigned new_size)
-{
-	k->p.offset -= k->size;
-	k->p.offset += new_size;
-	k->size = new_size;
-}
-
-/*
- * In extent_sort_fix_overlapping(), insert_fixup_extent(),
- * extent_merge_inline() - we're modifying keys in place that are packed. To do
- * that we have to unpack the key, modify the unpacked key - then this
- * copies/repacks the unpacked to the original as necessary.
- */
-static bool __extent_save(struct btree *b, struct btree_node_iter *iter,
-			  struct bkey_packed *dst, struct bkey *src)
-{
-	struct bkey_format *f = &b->format;
-	struct bkey_i *dst_unpacked;
-	bool ret;
-
-	if ((dst_unpacked = packed_to_bkey(dst))) {
-		dst_unpacked->k = *src;
-		ret = true;
-	} else {
-		ret = bkey_pack_key(dst, src, f);
-	}
-
-	if (ret && iter)
-		bch_verify_key_order(b, iter, dst);
-
-	return ret;
-}
-
-static void extent_save(struct btree *b, struct btree_node_iter *iter,
-			struct bkey_packed *dst, struct bkey *src)
-{
-	BUG_ON(!__extent_save(b, iter, dst, src));
-}
-
-/*
- * Returns true if l > r - unless l == r, in which case returns true if l is
- * older than r.
- *
- * Necessary for sort_fix_overlapping() - if there are multiple keys that
- * compare equal in different sets, we have to process them newest to oldest.
- */
-#define extent_sort_cmp(l, r)						\
-({									\
-	struct bkey _ul = bkey_unpack_key(b,				\
-				__btree_node_offset_to_key(b, (l).k));	\
-	struct bkey _ur = bkey_unpack_key(b,				\
-				__btree_node_offset_to_key(b, (r).k));	\
-									\
-	int _c = bkey_cmp(bkey_start_pos(&_ul), bkey_start_pos(&_ur));	\
-	_c ? _c > 0 : (l).k < (r).k;					\
-})
-
-static inline void extent_sort_sift(struct btree_node_iter *iter,
-				    struct btree *b, size_t i)
-{
-	heap_sift(iter, i, extent_sort_cmp);
-}
-
-static inline void extent_sort_next(struct btree_node_iter *iter,
-				    struct btree *b,
-				    struct btree_node_iter_set *i)
-{
-	sort_key_next(iter, b, i);
-	heap_sift(iter, i - iter->data, extent_sort_cmp);
-}
-
-static void extent_sort_append(struct bch_fs *c,
-			       struct btree *b,
-			       struct btree_nr_keys *nr,
-			       struct bkey_packed *start,
-			       struct bkey_packed **prev,
-			       struct bkey_packed *k)
-{
-	struct bkey_format *f = &b->format;
-	BKEY_PADDED(k) tmp;
-
-	if (bkey_whiteout(k))
-		return;
-
-	bkey_unpack(b, &tmp.k, k);
-
-	if (*prev &&
-	    bch_extent_merge(c, b, (void *) *prev, &tmp.k))
-		return;
-
-	if (*prev) {
-		bkey_pack(*prev, (void *) *prev, f);
-
-		btree_keys_account_key_add(nr, 0, *prev);
-		*prev = bkey_next(*prev);
-	} else {
-		*prev = start;
-	}
-
-	bkey_copy(*prev, &tmp.k);
-}
-
-struct btree_nr_keys bch_extent_sort_fix_overlapping(struct bch_fs *c,
-					struct bset *dst,
-					struct btree *b,
-					struct btree_node_iter *iter)
-{
-	struct bkey_format *f = &b->format;
-	struct btree_node_iter_set *_l = iter->data, *_r;
-	struct bkey_packed *prev = NULL, *out, *lk, *rk;
-	struct bkey l_unpacked, r_unpacked;
-	struct bkey_s l, r;
-	struct btree_nr_keys nr;
-
-	memset(&nr, 0, sizeof(nr));
-
-	heap_resort(iter, extent_sort_cmp);
-
-	while (!bch_btree_node_iter_end(iter)) {
-		lk = __btree_node_offset_to_key(b, _l->k);
-
-		if (iter->used == 1) {
-			extent_sort_append(c, b, &nr, dst->start, &prev, lk);
-			extent_sort_next(iter, b, _l);
-			continue;
-		}
-
-		_r = iter->data + 1;
-		if (iter->used > 2 &&
-		    extent_sort_cmp(_r[0], _r[1]))
-			_r++;
-
-		rk = __btree_node_offset_to_key(b, _r->k);
-
-		l = __bkey_disassemble(b, lk, &l_unpacked);
-		r = __bkey_disassemble(b, rk, &r_unpacked);
-
-		/* If current key and next key don't overlap, just append */
-		if (bkey_cmp(l.k->p, bkey_start_pos(r.k)) <= 0) {
-			extent_sort_append(c, b, &nr, dst->start, &prev, lk);
-			extent_sort_next(iter, b, _l);
-			continue;
-		}
-
-		/* Skip 0 size keys */
-		if (!r.k->size) {
-			extent_sort_next(iter, b, _r);
-			continue;
-		}
-
-		/*
-		 * overlap: keep the newer key and trim the older key so they
-		 * don't overlap. comparing pointers tells us which one is
-		 * newer, since the bsets are appended one after the other.
-		 */
-
-		/* can't happen because of comparison func */
-		BUG_ON(_l->k < _r->k &&
-		       !bkey_cmp(bkey_start_pos(l.k), bkey_start_pos(r.k)));
-
-		if (_l->k > _r->k) {
-			/* l wins, trim r */
-			if (bkey_cmp(l.k->p, r.k->p) >= 0) {
-				sort_key_next(iter, b, _r);
-			} else {
-				__bch_cut_front(l.k->p, r);
-				extent_save(b, NULL, rk, r.k);
-			}
-
-			extent_sort_sift(iter, b, _r - iter->data);
-		} else if (bkey_cmp(l.k->p, r.k->p) > 0) {
-			BKEY_PADDED(k) tmp;
-
-			/*
-			 * r wins, but it overlaps in the middle of l - split l:
-			 */
-			bkey_reassemble(&tmp.k, l.s_c);
-			bch_cut_back(bkey_start_pos(r.k), &tmp.k.k);
-
-			__bch_cut_front(r.k->p, l);
-			extent_save(b, NULL, lk, l.k);
-
-			extent_sort_sift(iter, b, 0);
-
-			extent_sort_append(c, b, &nr, dst->start, &prev,
-					   bkey_to_packed(&tmp.k));
-		} else {
-			bch_cut_back(bkey_start_pos(r.k), l.k);
-			extent_save(b, NULL, lk, l.k);
-		}
-	}
-
-	if (prev) {
-		bkey_pack(prev, (void *) prev, f);
-		btree_keys_account_key_add(&nr, 0, prev);
-		out = bkey_next(prev);
-	} else {
-		out = dst->start;
-	}
-
-	dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
-	return nr;
-}
-
-struct extent_insert_state {
-	struct btree_insert		*trans;
-	struct btree_insert_entry	*insert;
-	struct bpos			committed;
-	struct bch_fs_usage		stats;
-
-	/* for deleting: */
-	struct bkey_i			whiteout;
-	bool				do_journal;
-	bool				deleting;
-};
-
-static void bch_add_sectors(struct extent_insert_state *s,
-			    struct bkey_s_c k, u64 offset, s64 sectors)
-{
-	struct bch_fs *c = s->trans->c;
-	struct btree *b = s->insert->iter->nodes[0];
-
-	EBUG_ON(bkey_cmp(bkey_start_pos(k.k), b->data->min_key) < 0);
-
-	if (!sectors)
-		return;
-
-	bch_mark_key(c, k, sectors, false, gc_pos_btree_node(b),
-		     &s->stats, s->trans->journal_res.seq);
-
-	if (bkey_extent_is_data(k.k) &&
-	    !bkey_extent_is_cached(k.k))
-		bcache_dev_sectors_dirty_add(c, k.k->p.inode, offset, sectors);
-}
-
-static void bch_subtract_sectors(struct extent_insert_state *s,
-				 struct bkey_s_c k, u64 offset, s64 sectors)
-{
-	bch_add_sectors(s, k, offset, -sectors);
-}
-
-/* These wrappers subtract exactly the sectors that we're removing from @k */
-static void bch_cut_subtract_back(struct extent_insert_state *s,
-				  struct bpos where, struct bkey_s k)
-{
-	bch_subtract_sectors(s, k.s_c, where.offset,
-			     k.k->p.offset - where.offset);
-	bch_cut_back(where, k.k);
-}
-
-static void bch_cut_subtract_front(struct extent_insert_state *s,
-				   struct bpos where, struct bkey_s k)
-{
-	bch_subtract_sectors(s, k.s_c, bkey_start_offset(k.k),
-			     where.offset - bkey_start_offset(k.k));
-	__bch_cut_front(where, k);
-}
-
-static void bch_drop_subtract(struct extent_insert_state *s, struct bkey_s k)
-{
-	if (k.k->size)
-		bch_subtract_sectors(s, k.s_c,
-				     bkey_start_offset(k.k), k.k->size);
-	k.k->size = 0;
-	__set_bkey_deleted(k.k);
-}
-
-/*
- * Note: If this returns true because only some pointers matched,
- * we can lose some caching that had happened in the interim.
- * Because cache promotion only promotes the part of the extent
- * actually read, and not the whole extent, and due to the key
- * splitting done in bch_extent_insert_fixup, preserving such
- * caching is difficult.
- */
-static bool bch_extent_cmpxchg_cmp(struct bkey_s_c l, struct bkey_s_c r)
-{
-	struct bkey_s_c_extent le, re;
-	const struct bch_extent_ptr *lp, *rp;
-	s64 offset;
-
-	BUG_ON(!l.k->size || !r.k->size);
-
-	if (l.k->type != r.k->type ||
-	    bversion_cmp(l.k->version, r.k->version))
-		return false;
-
-	switch (l.k->type) {
-	case KEY_TYPE_COOKIE:
-		return !memcmp(bkey_s_c_to_cookie(l).v,
-			       bkey_s_c_to_cookie(r).v,
-			       sizeof(struct bch_cookie));
-
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED:
-		le = bkey_s_c_to_extent(l);
-		re = bkey_s_c_to_extent(r);
-
-		/*
-		 * bkey_cmpxchg() handles partial matches - when either l or r
-		 * has been trimmed - so we need just to handle l or r not
-		 * starting at the same place when checking for a match here.
-		 *
-		 * If the starts of the keys are different, we just apply that
-		 * offset to the device pointer offsets when checking those -
-		 * matching how bch_cut_front() adjusts device pointer offsets
-		 * when adjusting the start of a key:
-		 */
-		offset = bkey_start_offset(l.k) - bkey_start_offset(r.k);
-
-		/*
-		 * XXX: perhaps we only raced with copygc or tiering replacing
-		 * one of the pointers: it should suffice to find _any_ matching
-		 * pointer
-		 */
-
-		if (bkey_val_u64s(le.k) != bkey_val_u64s(re.k))
-			return false;
-
-		extent_for_each_ptr(le, lp) {
-			const union bch_extent_entry *entry =
-				vstruct_idx(re.v, (u64 *) lp - le.v->_data);
-
-			if (!extent_entry_is_ptr(entry))
-				return false;
-
-			rp = &entry->ptr;
-
-			if (lp->offset	!= rp->offset + offset ||
-			    lp->dev	!= rp->dev ||
-			    lp->gen	!= rp->gen)
-				return false;
-		}
-
-		return true;
-	default:
-		return false;
-	}
-
-}
-
-/*
- * Returns true on success, false on failure (and false means @new no longer
- * overlaps with @k)
- *
- * If returned true, we may have inserted up to one key in @b.
- * If returned false, we may have inserted up to two keys in @b.
- *
- * On return, there is room in @res for at least one more key of the same size
- * as @new.
- */
-enum extent_insert_hook_ret bch_extent_cmpxchg(struct extent_insert_hook *hook,
-					       struct bpos committed_pos,
-					       struct bpos next_pos,
-					       struct bkey_s_c k,
-					       const struct bkey_i *new)
-{
-	struct bch_replace_info *replace = container_of(hook,
-					struct bch_replace_info, hook);
-	struct bkey_i *old = &replace->key;
-
-	EBUG_ON(bkey_cmp(committed_pos, bkey_start_pos(&new->k)) < 0);
-
-	/* must have something to compare against */
-	EBUG_ON(!bkey_val_u64s(&old->k));
-
-	/* new must be a subset of old */
-	EBUG_ON(bkey_cmp(new->k.p, old->k.p) > 0 ||
-		bkey_cmp(bkey_start_pos(&new->k), bkey_start_pos(&old->k)) < 0);
-
-	if (k.k && bch_extent_cmpxchg_cmp(k, bkey_i_to_s_c(old))) {
-		replace->successes++;
-		return BTREE_HOOK_DO_INSERT;
-	} else {
-		replace->failures++;
-		return BTREE_HOOK_NO_INSERT;
-	}
-}
-
-static bool bch_extent_merge_inline(struct bch_fs *,
-				    struct btree_iter *,
-				    struct bkey_packed *,
-				    struct bkey_packed *,
-				    bool);
-
-#define MAX_LOCK_HOLD_TIME	(5 * NSEC_PER_MSEC)
-
-static enum btree_insert_ret
-extent_insert_should_stop(struct extent_insert_state *s)
-{
-	struct btree *b = s->insert->iter->nodes[0];
-
-	/*
-	 * Check if we have sufficient space in both the btree node and the
-	 * journal reservation:
-	 *
-	 * Each insert checks for room in the journal entry, but we check for
-	 * room in the btree node up-front. In the worst case, bkey_cmpxchg()
-	 * will insert two keys, and one iteration of this room will insert one
-	 * key, so we need room for three keys.
-	 */
-	if (!bch_btree_node_insert_fits(s->trans->c, b, s->insert->k->k.u64s))
-		return BTREE_INSERT_BTREE_NODE_FULL;
-	else if (!journal_res_insert_fits(s->trans, s->insert))
-		return BTREE_INSERT_JOURNAL_RES_FULL; /* XXX worth tracing */
-	else
-		return BTREE_INSERT_OK;
-}
-
-static void extent_bset_insert(struct bch_fs *c, struct btree_iter *iter,
-			       struct bkey_i *insert)
-{
-	struct btree *b = iter->nodes[0];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-	struct bset_tree *t = bset_tree_last(b);
-	struct bkey_packed *where =
-		bch_btree_node_iter_bset_pos(node_iter, b, t);
-	struct bkey_packed *prev = bkey_prev(b, t, where);
-	struct bkey_packed *next_live_key = where;
-	unsigned clobber_u64s;
-
-	if (prev)
-		where = bkey_next(prev);
-
-	while (next_live_key != btree_bkey_last(b, t) &&
-	       bkey_deleted(next_live_key))
-		next_live_key = bkey_next(next_live_key);
-
-	/*
-	 * Everything between where and next_live_key is now deleted keys, and
-	 * is overwritten:
-	 */
-	clobber_u64s = (u64 *) next_live_key - (u64 *) where;
-
-	if (prev &&
-	    bch_extent_merge_inline(c, iter, prev, bkey_to_packed(insert), true))
-		goto drop_deleted_keys;
-
-	if (next_live_key != btree_bkey_last(b, t) &&
-	    bch_extent_merge_inline(c, iter, bkey_to_packed(insert),
-				    next_live_key, false))
-		goto drop_deleted_keys;
-
-	bch_bset_insert(b, node_iter, where, insert, clobber_u64s);
-	bch_btree_node_iter_fix(iter, b, node_iter, t, where,
-				clobber_u64s, where->u64s);
-	return;
-drop_deleted_keys:
-	bch_bset_delete(b, where, clobber_u64s);
-	bch_btree_node_iter_fix(iter, b, node_iter, t, where, clobber_u64s, 0);
-}
-
-static void extent_insert_committed(struct extent_insert_state *s)
-{
-	struct bch_fs *c = s->trans->c;
-	struct btree_iter *iter = s->insert->iter;
-	struct bkey_i *insert = !s->deleting
-		? s->insert->k
-		: &s->whiteout;
-	BKEY_PADDED(k) split;
-
-	EBUG_ON(bkey_cmp(insert->k.p, s->committed) < 0);
-	EBUG_ON(bkey_cmp(s->committed, bkey_start_pos(&insert->k)) < 0);
-
-	if (!bkey_cmp(s->committed, bkey_start_pos(&insert->k)))
-		return;
-
-	if (s->deleting && !s->do_journal) {
-		bch_cut_front(s->committed, insert);
-		goto done;
-	}
-
-	EBUG_ON(bkey_deleted(&insert->k) || !insert->k.size);
-
-	bkey_copy(&split.k, insert);
-
-	if (!(s->trans->flags & BTREE_INSERT_JOURNAL_REPLAY) &&
-	    bkey_cmp(s->committed, insert->k.p) &&
-	    bkey_extent_is_compressed(bkey_i_to_s_c(insert))) {
-		/* XXX: possibly need to increase our reservation? */
-		bch_cut_subtract_back(s, s->committed,
-				      bkey_i_to_s(&split.k));
-		bch_cut_front(s->committed, insert);
-		bch_add_sectors(s, bkey_i_to_s_c(insert),
-				bkey_start_offset(&insert->k),
-				insert->k.size);
-	} else {
-		bch_cut_back(s->committed, &split.k.k);
-		bch_cut_front(s->committed, insert);
-	}
-
-	if (debug_check_bkeys(c))
-		bkey_debugcheck(c, iter->nodes[iter->level],
-				bkey_i_to_s_c(&split.k));
-
-	bch_btree_journal_key(s->trans, iter, &split.k);
-
-	if (!s->deleting)
-		extent_bset_insert(c, iter, &split.k);
-done:
-	bch_btree_iter_set_pos_same_leaf(iter, s->committed);
-
-	insert->k.needs_whiteout	= false;
-	s->do_journal			= false;
-	s->trans->did_work		= true;
-}
-
-static enum extent_insert_hook_ret
-__extent_insert_advance_pos(struct extent_insert_state *s,
-			    struct bpos next_pos,
-			    struct bkey_s_c k)
-{
-	struct extent_insert_hook *hook = s->trans->hook;
-	enum extent_insert_hook_ret ret;
-#if 0
-	/*
-	 * Currently disabled for encryption - broken with fcollapse. Will have
-	 * to reenable when versions are exposed for send/receive - versions
-	 * will have to be monotonic then:
-	 */
-	if (k.k && k.k->size &&
-	    !bversion_zero(s->insert->k->k.version) &&
-	    bversion_cmp(k.k->version, s->insert->k->k.version) > 0) {
-		ret = BTREE_HOOK_NO_INSERT;
-	} else
-#endif
-	if (hook)
-		ret = hook->fn(hook, s->committed, next_pos, k, s->insert->k);
-	else
-		ret = BTREE_HOOK_DO_INSERT;
-
-	EBUG_ON(bkey_deleted(&s->insert->k->k) || !s->insert->k->k.size);
-
-	switch (ret) {
-	case BTREE_HOOK_DO_INSERT:
-		break;
-	case BTREE_HOOK_NO_INSERT:
-		extent_insert_committed(s);
-		bch_cut_subtract_front(s, next_pos, bkey_i_to_s(s->insert->k));
-
-		bch_btree_iter_set_pos_same_leaf(s->insert->iter, next_pos);
-		break;
-	case BTREE_HOOK_RESTART_TRANS:
-		return ret;
-	}
-
-	s->committed = next_pos;
-	return ret;
-}
-
-/*
- * Update iter->pos, marking how much of @insert we've processed, and call hook
- * fn:
- */
-static enum extent_insert_hook_ret
-extent_insert_advance_pos(struct extent_insert_state *s, struct bkey_s_c k)
-{
-	struct btree *b = s->insert->iter->nodes[0];
-	struct bpos next_pos = bpos_min(s->insert->k->k.p,
-					k.k ? k.k->p : b->key.k.p);
-
-	/* hole? */
-	if (k.k && bkey_cmp(s->committed, bkey_start_pos(k.k)) < 0) {
-		bool have_uncommitted = bkey_cmp(s->committed,
-				bkey_start_pos(&s->insert->k->k)) > 0;
-
-		switch (__extent_insert_advance_pos(s, bkey_start_pos(k.k),
-						    bkey_s_c_null)) {
-		case BTREE_HOOK_DO_INSERT:
-			break;
-		case BTREE_HOOK_NO_INSERT:
-			/*
-			 * we had to split @insert and insert the committed
-			 * part - need to bail out and recheck journal
-			 * reservation/btree node before we advance pos past @k:
-			 */
-			if (have_uncommitted)
-				return BTREE_HOOK_NO_INSERT;
-			break;
-		case BTREE_HOOK_RESTART_TRANS:
-			return BTREE_HOOK_RESTART_TRANS;
-		}
-	}
-
-	/* avoid redundant calls to hook fn: */
-	if (!bkey_cmp(s->committed, next_pos))
-		return BTREE_HOOK_DO_INSERT;
-
-	return __extent_insert_advance_pos(s, next_pos, k);
-}
-
-static enum btree_insert_ret
-extent_insert_check_split_compressed(struct extent_insert_state *s,
-				     struct bkey_s_c k,
-				     enum bch_extent_overlap overlap)
-{
-	struct bch_fs *c = s->trans->c;
-	unsigned sectors;
-
-	if (overlap == BCH_EXTENT_OVERLAP_MIDDLE &&
-	    (sectors = bkey_extent_is_compressed(k))) {
-		int flags = BCH_DISK_RESERVATION_BTREE_LOCKS_HELD;
-
-		if (s->trans->flags & BTREE_INSERT_NOFAIL)
-			flags |= BCH_DISK_RESERVATION_NOFAIL;
-
-		switch (bch_disk_reservation_add(c,
-				s->trans->disk_res,
-				sectors, flags)) {
-		case 0:
-			break;
-		case -ENOSPC:
-			return BTREE_INSERT_ENOSPC;
-		case -EINTR:
-			return BTREE_INSERT_NEED_GC_LOCK;
-		default:
-			BUG();
-		}
-	}
-
-	return BTREE_INSERT_OK;
-}
-
-static enum btree_insert_ret
-extent_squash(struct extent_insert_state *s, struct bkey_i *insert,
-	      struct bset_tree *t, struct bkey_packed *_k, struct bkey_s k,
-	      enum bch_extent_overlap overlap)
-{
-	struct bch_fs *c = s->trans->c;
-	struct btree_iter *iter = s->insert->iter;
-	struct btree *b = iter->nodes[0];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-
-	switch (overlap) {
-	case BCH_EXTENT_OVERLAP_FRONT:
-		/* insert overlaps with start of k: */
-		bch_cut_subtract_front(s, insert->k.p, k);
-		BUG_ON(bkey_deleted(k.k));
-		extent_save(b, node_iter, _k, k.k);
-		break;
-
-	case BCH_EXTENT_OVERLAP_BACK:
-		/* insert overlaps with end of k: */
-		bch_cut_subtract_back(s, bkey_start_pos(&insert->k), k);
-		BUG_ON(bkey_deleted(k.k));
-		extent_save(b, node_iter, _k, k.k);
-
-		/*
-		 * As the auxiliary tree is indexed by the end of the
-		 * key and we've just changed the end, update the
-		 * auxiliary tree.
-		 */
-		bch_bset_fix_invalidated_key(b, t, _k);
-		bch_btree_node_iter_fix(iter, b, node_iter, t,
-					_k, _k->u64s, _k->u64s);
-		break;
-
-	case BCH_EXTENT_OVERLAP_ALL: {
-		struct bpos orig_pos = k.k->p;
-
-		/* The insert key completely covers k, invalidate k */
-		if (!bkey_whiteout(k.k))
-			btree_keys_account_key_drop(&b->nr,
-						t - b->set, _k);
-
-		bch_drop_subtract(s, k);
-		k.k->p = bkey_start_pos(&insert->k);
-		if (!__extent_save(b, node_iter, _k, k.k)) {
-			/*
-			 * Couldn't repack: we aren't necessarily able
-			 * to repack if the new key is outside the range
-			 * of the old extent, so we have to split
-			 * @insert:
-			 */
-			k.k->p = orig_pos;
-			extent_save(b, node_iter, _k, k.k);
-
-			if (extent_insert_advance_pos(s, k.s_c) ==
-			    BTREE_HOOK_RESTART_TRANS)
-				return BTREE_INSERT_NEED_TRAVERSE;
-
-			extent_insert_committed(s);
-			/*
-			 * We split and inserted upto at k.k->p - that
-			 * has to coincide with iter->pos, so that we
-			 * don't have anything more we have to insert
-			 * until we recheck our journal reservation:
-			 */
-			EBUG_ON(bkey_cmp(s->committed, k.k->p));
-		} else {
-			bch_bset_fix_invalidated_key(b, t, _k);
-			bch_btree_node_iter_fix(iter, b, node_iter, t,
-						_k, _k->u64s, _k->u64s);
-		}
-
-		break;
-	}
-	case BCH_EXTENT_OVERLAP_MIDDLE: {
-		BKEY_PADDED(k) split;
-		/*
-		 * The insert key falls 'in the middle' of k
-		 * The insert key splits k in 3:
-		 * - start only in k, preserve
-		 * - middle common section, invalidate in k
-		 * - end only in k, preserve
-		 *
-		 * We update the old key to preserve the start,
-		 * insert will be the new common section,
-		 * we manually insert the end that we are preserving.
-		 *
-		 * modify k _before_ doing the insert (which will move
-		 * what k points to)
-		 */
-		bkey_reassemble(&split.k, k.s_c);
-		split.k.k.needs_whiteout |= bset_written(b, bset(b, t));
-
-		bch_cut_back(bkey_start_pos(&insert->k), &split.k.k);
-		BUG_ON(bkey_deleted(&split.k.k));
-
-		bch_cut_subtract_front(s, insert->k.p, k);
-		BUG_ON(bkey_deleted(k.k));
-		extent_save(b, node_iter, _k, k.k);
-
-		bch_add_sectors(s, bkey_i_to_s_c(&split.k),
-				bkey_start_offset(&split.k.k),
-				split.k.k.size);
-		extent_bset_insert(c, iter, &split.k);
-		break;
-	}
-	}
-
-	return BTREE_INSERT_OK;
-}
-
-static enum btree_insert_ret
-bch_delete_fixup_extent(struct extent_insert_state *s)
-{
-	struct bch_fs *c = s->trans->c;
-	struct btree_iter *iter = s->insert->iter;
-	struct btree *b = iter->nodes[0];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-	struct bkey_packed *_k;
-	struct bkey unpacked;
-	struct bkey_i *insert = s->insert->k;
-	enum btree_insert_ret ret = BTREE_INSERT_OK;
-
-	EBUG_ON(bkey_cmp(iter->pos, bkey_start_pos(&insert->k)));
-
-	s->whiteout	= *insert;
-	s->do_journal	= false;
-
-	while (bkey_cmp(s->committed, insert->k.p) < 0 &&
-	       (ret = extent_insert_should_stop(s)) == BTREE_INSERT_OK &&
-	       (_k = bch_btree_node_iter_peek_all(node_iter, b))) {
-		struct bset_tree *t = bch_bkey_to_bset(b, _k);
-		struct bkey_s k = __bkey_disassemble(b, _k, &unpacked);
-		enum bch_extent_overlap overlap;
-
-		EBUG_ON(bkey_cmp(iter->pos, bkey_start_pos(&insert->k)));
-		EBUG_ON(bkey_cmp(iter->pos, k.k->p) >= 0);
-
-		if (bkey_cmp(bkey_start_pos(k.k), insert->k.p) >= 0)
-			break;
-
-		if (bkey_whiteout(k.k)) {
-			s->committed = bpos_min(insert->k.p, k.k->p);
-			goto next;
-		}
-
-		overlap = bch_extent_overlap(&insert->k, k.k);
-
-		ret = extent_insert_check_split_compressed(s, k.s_c, overlap);
-		if (ret != BTREE_INSERT_OK)
-			goto stop;
-
-		switch (extent_insert_advance_pos(s, k.s_c)) {
-		case BTREE_HOOK_DO_INSERT:
-			break;
-		case BTREE_HOOK_NO_INSERT:
-			continue;
-		case BTREE_HOOK_RESTART_TRANS:
-			ret = BTREE_INSERT_NEED_TRAVERSE;
-			goto stop;
-		}
-
-		s->do_journal = true;
-
-		if (overlap == BCH_EXTENT_OVERLAP_ALL) {
-			btree_keys_account_key_drop(&b->nr,
-						t - b->set, _k);
-			bch_subtract_sectors(s, k.s_c,
-					     bkey_start_offset(k.k), k.k->size);
-			_k->type = KEY_TYPE_DISCARD;
-			reserve_whiteout(b, t, _k);
-		} else if (k.k->needs_whiteout ||
-			   bset_written(b, bset(b, t))) {
-			struct bkey_i discard = *insert;
-
-			switch (overlap) {
-			case BCH_EXTENT_OVERLAP_FRONT:
-				bch_cut_front(bkey_start_pos(k.k), &discard);
-				break;
-			case BCH_EXTENT_OVERLAP_BACK:
-				bch_cut_back(k.k->p, &discard.k);
-				break;
-			default:
-				break;
-			}
-
-			discard.k.needs_whiteout = true;
-
-			ret = extent_squash(s, insert, t, _k, k, overlap);
-			BUG_ON(ret != BTREE_INSERT_OK);
-
-			extent_bset_insert(c, iter, &discard);
-		} else {
-			ret = extent_squash(s, insert, t, _k, k, overlap);
-			BUG_ON(ret != BTREE_INSERT_OK);
-		}
-next:
-		bch_cut_front(s->committed, insert);
-		bch_btree_iter_set_pos_same_leaf(iter, s->committed);
-	}
-
-	if (bkey_cmp(s->committed, insert->k.p) < 0 &&
-	    ret == BTREE_INSERT_OK &&
-	    extent_insert_advance_pos(s, bkey_s_c_null) == BTREE_HOOK_RESTART_TRANS)
-		ret = BTREE_INSERT_NEED_TRAVERSE;
-stop:
-	extent_insert_committed(s);
-
-	bch_fs_usage_apply(c, &s->stats, s->trans->disk_res,
-			   gc_pos_btree_node(b));
-
-	EBUG_ON(bkey_cmp(iter->pos, s->committed));
-	EBUG_ON((bkey_cmp(iter->pos, b->key.k.p) == 0) != iter->at_end_of_leaf);
-
-	bch_cut_front(iter->pos, insert);
-
-	if (insert->k.size && iter->at_end_of_leaf)
-		ret = BTREE_INSERT_NEED_TRAVERSE;
-
-	EBUG_ON(insert->k.size && ret == BTREE_INSERT_OK);
-
-	return ret;
-}
-
-/**
- * bch_extent_insert_fixup - insert a new extent and deal with overlaps
- *
- * this may result in not actually doing the insert, or inserting some subset
- * of the insert key. For cmpxchg operations this is where that logic lives.
- *
- * All subsets of @insert that need to be inserted are inserted using
- * bch_btree_insert_and_journal(). If @b or @res fills up, this function
- * returns false, setting @iter->pos for the prefix of @insert that actually got
- * inserted.
- *
- * BSET INVARIANTS: this function is responsible for maintaining all the
- * invariants for bsets of extents in memory. things get really hairy with 0
- * size extents
- *
- * within one bset:
- *
- * bkey_start_pos(bkey_next(k)) >= k
- * or bkey_start_offset(bkey_next(k)) >= k->offset
- *
- * i.e. strict ordering, no overlapping extents.
- *
- * multiple bsets (i.e. full btree node):
- *
- * ∀ k, j
- *   k.size != 0 ∧ j.size != 0 →
- *     ¬ (k > bkey_start_pos(j) ∧ k < j)
- *
- * i.e. no two overlapping keys _of nonzero size_
- *
- * We can't realistically maintain this invariant for zero size keys because of
- * the key merging done in bch_btree_insert_key() - for two mergeable keys k, j
- * there may be another 0 size key between them in another bset, and it will
- * thus overlap with the merged key.
- *
- * In addition, the end of iter->pos indicates how much has been processed.
- * If the end of iter->pos is not the same as the end of insert, then
- * key insertion needs to continue/be retried.
- */
-enum btree_insert_ret
-bch_insert_fixup_extent(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];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-	struct bkey_packed *_k;
-	struct bkey unpacked;
-	enum btree_insert_ret ret = BTREE_INSERT_OK;
-
-	struct extent_insert_state s = {
-		.trans		= trans,
-		.insert		= insert,
-		.committed	= insert->iter->pos,
-		.deleting	= bkey_whiteout(&insert->k->k),
-	};
-
-	EBUG_ON(iter->level);
-	EBUG_ON(bkey_deleted(&insert->k->k) || !insert->k->k.size);
-
-	if (s.deleting)
-		return bch_delete_fixup_extent(&s);
-
-	/*
-	 * As we process overlapping extents, we advance @iter->pos both to
-	 * signal to our caller (btree_insert_key()) how much of @insert->k has
-	 * been inserted, and also to keep @iter->pos consistent with
-	 * @insert->k and the node iterator that we're advancing:
-	 */
-	EBUG_ON(bkey_cmp(iter->pos, bkey_start_pos(&insert->k->k)));
-
-	if (!(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))
-		bch_add_sectors(&s, bkey_i_to_s_c(insert->k),
-				bkey_start_offset(&insert->k->k),
-				insert->k->k.size);
-
-	while (bkey_cmp(s.committed, insert->k->k.p) < 0 &&
-	       (ret = extent_insert_should_stop(&s)) == BTREE_INSERT_OK &&
-	       (_k = bch_btree_node_iter_peek_all(node_iter, b))) {
-		struct bset_tree *t = bch_bkey_to_bset(b, _k);
-		struct bkey_s k = __bkey_disassemble(b, _k, &unpacked);
-		enum bch_extent_overlap overlap;
-
-		EBUG_ON(bkey_cmp(iter->pos, bkey_start_pos(&insert->k->k)));
-		EBUG_ON(bkey_cmp(iter->pos, k.k->p) >= 0);
-
-		if (bkey_cmp(bkey_start_pos(k.k), insert->k->k.p) >= 0)
-			break;
-
-		overlap = bch_extent_overlap(&insert->k->k, k.k);
-
-		ret = extent_insert_check_split_compressed(&s, k.s_c, overlap);
-		if (ret != BTREE_INSERT_OK)
-			goto stop;
-
-		if (!k.k->size)
-			goto squash;
-
-		/*
-		 * Only call advance pos & call hook for nonzero size extents:
-		 * If hook returned BTREE_HOOK_NO_INSERT, @insert->k no longer
-		 * overlaps with @k:
-		 */
-		switch (extent_insert_advance_pos(&s, k.s_c)) {
-		case BTREE_HOOK_DO_INSERT:
-			break;
-		case BTREE_HOOK_NO_INSERT:
-			continue;
-		case BTREE_HOOK_RESTART_TRANS:
-			ret = BTREE_INSERT_NEED_TRAVERSE;
-			goto stop;
-		}
-
-		if (k.k->size &&
-		    (k.k->needs_whiteout || bset_written(b, bset(b, t))))
-			insert->k->k.needs_whiteout = true;
-
-		if (overlap == BCH_EXTENT_OVERLAP_ALL &&
-		    bkey_whiteout(k.k) &&
-		    k.k->needs_whiteout) {
-			unreserve_whiteout(b, t, _k);
-			_k->needs_whiteout = false;
-		}
-squash:
-		ret = extent_squash(&s, insert->k, t, _k, k, overlap);
-		if (ret != BTREE_INSERT_OK)
-			goto stop;
-	}
-
-	if (bkey_cmp(s.committed, insert->k->k.p) < 0 &&
-	    ret == BTREE_INSERT_OK &&
-	    extent_insert_advance_pos(&s, bkey_s_c_null) == BTREE_HOOK_RESTART_TRANS)
-		ret = BTREE_INSERT_NEED_TRAVERSE;
-stop:
-	extent_insert_committed(&s);
-	/*
-	 * Subtract any remaining sectors from @insert, if we bailed out early
-	 * and didn't fully insert @insert:
-	 */
-	if (insert->k->k.size &&
-	    !(trans->flags & BTREE_INSERT_JOURNAL_REPLAY))
-		bch_subtract_sectors(&s, bkey_i_to_s_c(insert->k),
-				     bkey_start_offset(&insert->k->k),
-				     insert->k->k.size);
-
-	bch_fs_usage_apply(c, &s.stats, trans->disk_res,
-			   gc_pos_btree_node(b));
-
-	EBUG_ON(bkey_cmp(iter->pos, bkey_start_pos(&insert->k->k)));
-	EBUG_ON(bkey_cmp(iter->pos, s.committed));
-	EBUG_ON((bkey_cmp(iter->pos, b->key.k.p) == 0) != iter->at_end_of_leaf);
-
-	if (insert->k->k.size && iter->at_end_of_leaf)
-		ret = BTREE_INSERT_NEED_TRAVERSE;
-
-	EBUG_ON(insert->k->k.size && ret == BTREE_INSERT_OK);
-
-	return ret;
-}
-
-static const char *bch_extent_invalid(const struct bch_fs *c,
-				      struct bkey_s_c k)
-{
-	if (bkey_val_u64s(k.k) > BKEY_EXTENT_VAL_U64s_MAX)
-		return "value too big";
-
-	if (!k.k->size)
-		return "zero key size";
-
-	switch (k.k->type) {
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED: {
-		struct bkey_s_c_extent e = bkey_s_c_to_extent(k);
-		const union bch_extent_entry *entry;
-		const union bch_extent_crc *crc;
-		const struct bch_extent_ptr *ptr;
-		unsigned size_ondisk = e.k->size;
-		const char *reason;
-
-		extent_for_each_entry(e, entry) {
-			if (__extent_entry_type(entry) >= BCH_EXTENT_ENTRY_MAX)
-				return "invalid extent entry type";
-
-			if (extent_entry_is_crc(entry)) {
-				crc = entry_to_crc(entry);
-
-				if (crc_offset(crc) + e.k->size >
-				    crc_uncompressed_size(e.k, crc))
-					return "checksum offset + key size > uncompressed size";
-
-				size_ondisk = crc_compressed_size(e.k, crc);
-
-				if (!bch_checksum_type_valid(c, crc_csum_type(crc)))
-					return "invalid checksum type";
-
-				if (crc_compression_type(crc) >= BCH_COMPRESSION_NR)
-					return "invalid compression type";
-			} else {
-				ptr = entry_to_ptr(entry);
-
-				reason = extent_ptr_invalid(c, e, &entry->ptr,
-							    size_ondisk, false);
-				if (reason)
-					return reason;
-			}
-		}
-
-		return NULL;
-	}
-
-	case BCH_RESERVATION: {
-		struct bkey_s_c_reservation r = bkey_s_c_to_reservation(k);
-
-		if (bkey_val_bytes(k.k) != sizeof(struct bch_reservation))
-			return "incorrect value size";
-
-		if (!r.v->nr_replicas || r.v->nr_replicas > BCH_REPLICAS_MAX)
-			return "invalid nr_replicas";
-
-		return NULL;
-	}
-
-	default:
-		return "invalid value type";
-	}
-}
-
-static void bch_extent_debugcheck_extent(struct bch_fs *c, struct btree *b,
-					 struct bkey_s_c_extent e)
-{
-	const struct bch_extent_ptr *ptr;
-	struct bch_dev *ca;
-	struct bucket *g;
-	unsigned seq, stale;
-	char buf[160];
-	bool bad;
-	unsigned ptrs_per_tier[BCH_TIER_MAX];
-	unsigned replicas = 0;
-
-	/*
-	 * XXX: we should be doing most/all of these checks at startup time,
-	 * where we check bkey_invalid() in btree_node_read_done()
-	 *
-	 * But note that we can't check for stale pointers or incorrect gc marks
-	 * until after journal replay is done (it might be an extent that's
-	 * going to get overwritten during replay)
-	 */
-
-	memset(ptrs_per_tier, 0, sizeof(ptrs_per_tier));
-
-	extent_for_each_ptr(e, ptr) {
-		ca = c->devs[ptr->dev];
-		g = PTR_BUCKET(ca, ptr);
-		replicas++;
-		ptrs_per_tier[ca->mi.tier]++;
-
-		/*
-		 * If journal replay hasn't finished, we might be seeing keys
-		 * that will be overwritten by the time journal replay is done:
-		 */
-		if (!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags))
-			continue;
-
-		stale = 0;
-
-		do {
-			struct bucket_mark mark;
-
-			seq = read_seqcount_begin(&c->gc_pos_lock);
-			mark = READ_ONCE(g->mark);
-
-			/* between mark and bucket gen */
-			smp_rmb();
-
-			stale = ptr_stale(ca, ptr);
-
-			bch_fs_bug_on(stale && !ptr->cached, c,
-					 "stale dirty pointer");
-
-			bch_fs_bug_on(stale > 96, c,
-					 "key too stale: %i",
-					 stale);
-
-			if (stale)
-				break;
-
-			bad = (mark.data_type != BUCKET_DATA ||
-			       (gc_pos_cmp(c->gc_pos, gc_pos_btree_node(b)) > 0 &&
-				!mark.owned_by_allocator &&
-				!(ptr->cached
-				  ? mark.cached_sectors
-				  : mark.dirty_sectors)));
-		} while (read_seqcount_retry(&c->gc_pos_lock, seq));
-
-		if (bad)
-			goto bad_ptr;
-	}
-
-	if (replicas > BCH_REPLICAS_MAX) {
-		bch_bkey_val_to_text(c, btree_node_type(b), buf,
-				     sizeof(buf), e.s_c);
-		bch_fs_bug(c,
-			"extent key bad (too many replicas: %u): %s",
-			replicas, buf);
-		return;
-	}
-
-	if (!bkey_extent_is_cached(e.k) &&
-	    replicas < c->sb.data_replicas_have) {
-		bch_bkey_val_to_text(c, btree_node_type(b), buf,
-				     sizeof(buf), e.s_c);
-		bch_fs_bug(c,
-			"extent key bad (too few replicas, %u < %u): %s",
-			replicas, c->sb.data_replicas_have, buf);
-		return;
-	}
-
-	return;
-
-bad_ptr:
-	bch_bkey_val_to_text(c, btree_node_type(b), buf,
-			     sizeof(buf), e.s_c);
-	bch_fs_bug(c, "extent pointer bad gc mark: %s:\nbucket %zu prio %i "
-		   "gen %i last_gc %i mark 0x%08x",
-		   buf, PTR_BUCKET_NR(ca, ptr),
-		   g->read_prio, PTR_BUCKET(ca, ptr)->mark.gen,
-		   ca->oldest_gens[PTR_BUCKET_NR(ca, ptr)],
-		   (unsigned) g->mark.counter);
-	return;
-}
-
-static void bch_extent_debugcheck(struct bch_fs *c, struct btree *b,
-				  struct bkey_s_c k)
-{
-	switch (k.k->type) {
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED:
-		bch_extent_debugcheck_extent(c, b, bkey_s_c_to_extent(k));
-		break;
-	case BCH_RESERVATION:
-		break;
-	default:
-		BUG();
-	}
-}
-
-static void bch_extent_to_text(struct bch_fs *c, char *buf,
-			       size_t size, struct bkey_s_c k)
-{
-	char *out = buf, *end = buf + size;
-	const char *invalid;
-
-#define p(...)	(out += scnprintf(out, end - out, __VA_ARGS__))
-
-	if (bkey_extent_is_data(k.k))
-		out += extent_print_ptrs(c, buf, size, bkey_s_c_to_extent(k));
-
-	invalid = bch_extent_invalid(c, k);
-	if (invalid)
-		p(" invalid: %s", invalid);
-#undef p
-}
-
-static unsigned PTR_TIER(struct bch_fs *c,
-			 const struct bch_extent_ptr *ptr)
-{
-	return c->devs[ptr->dev]->mi.tier;
-}
-
-static void bch_extent_crc_init(union bch_extent_crc *crc,
-				unsigned compressed_size,
-				unsigned uncompressed_size,
-				unsigned compression_type,
-				unsigned nonce,
-				struct bch_csum csum, unsigned csum_type)
-{
-	if (bch_crc_bytes[csum_type]	<= 4 &&
-	    uncompressed_size		<= CRC32_SIZE_MAX &&
-	    nonce			<= CRC32_NONCE_MAX) {
-		crc->crc32 = (struct bch_extent_crc32) {
-			.type = 1 << BCH_EXTENT_ENTRY_crc32,
-			._compressed_size	= compressed_size - 1,
-			._uncompressed_size	= uncompressed_size - 1,
-			.offset			= 0,
-			.compression_type	= compression_type,
-			.csum_type		= csum_type,
-			.csum			= *((__le32 *) &csum.lo),
-		};
-		return;
-	}
-
-	if (bch_crc_bytes[csum_type]	<= 10 &&
-	    uncompressed_size		<= CRC64_SIZE_MAX &&
-	    nonce			<= CRC64_NONCE_MAX) {
-		crc->crc64 = (struct bch_extent_crc64) {
-			.type = 1 << BCH_EXTENT_ENTRY_crc64,
-			._compressed_size	= compressed_size - 1,
-			._uncompressed_size	= uncompressed_size - 1,
-			.offset			= 0,
-			.nonce			= nonce,
-			.compression_type	= compression_type,
-			.csum_type		= csum_type,
-			.csum_lo		= csum.lo,
-			.csum_hi		= *((__le16 *) &csum.hi),
-		};
-		return;
-	}
-
-	if (bch_crc_bytes[csum_type]	<= 16 &&
-	    uncompressed_size		<= CRC128_SIZE_MAX &&
-	    nonce			<= CRC128_NONCE_MAX) {
-		crc->crc128 = (struct bch_extent_crc128) {
-			.type = 1 << BCH_EXTENT_ENTRY_crc128,
-			._compressed_size	= compressed_size - 1,
-			._uncompressed_size	= uncompressed_size - 1,
-			.offset			= 0,
-			.nonce			= nonce,
-			.compression_type	= compression_type,
-			.csum_type		= csum_type,
-			.csum			= csum,
-		};
-		return;
-	}
-
-	BUG();
-}
-
-void bch_extent_crc_append(struct bkey_i_extent *e,
-			   unsigned compressed_size,
-			   unsigned uncompressed_size,
-			   unsigned compression_type,
-			   unsigned nonce,
-			   struct bch_csum csum, unsigned csum_type)
-{
-	union bch_extent_crc *crc;
-
-	BUG_ON(compressed_size > uncompressed_size);
-	BUG_ON(uncompressed_size != e->k.size);
-	BUG_ON(!compressed_size || !uncompressed_size);
-
-	/*
-	 * Look up the last crc entry, so we can check if we need to add
-	 * another:
-	 */
-	extent_for_each_crc(extent_i_to_s(e), crc)
-		;
-
-	if (!crc && !csum_type && !compression_type)
-		return;
-
-	if (crc &&
-	    crc_compressed_size(&e->k, crc)	== compressed_size &&
-	    crc_uncompressed_size(&e->k, crc)	== uncompressed_size &&
-	    crc_offset(crc)			== 0 &&
-	    crc_nonce(crc)			== nonce &&
-	    crc_csum_type(crc)			== csum_type &&
-	    crc_compression_type(crc)		== compression_type &&
-	    crc_csum(crc).lo			== csum.lo &&
-	    crc_csum(crc).hi			== csum.hi)
-		return;
-
-	bch_extent_crc_init((void *) extent_entry_last(extent_i_to_s(e)),
-			    compressed_size,
-			    uncompressed_size,
-			    compression_type,
-			    nonce, csum, csum_type);
-	__extent_entry_push(e);
-}
-
-/*
- * bch_extent_normalize - clean up an extent, dropping stale pointers etc.
- *
- * Returns true if @k should be dropped entirely
- *
- * For existing keys, only called when btree nodes are being rewritten, not when
- * they're merely being compacted/resorted in memory.
- */
-bool bch_extent_normalize(struct bch_fs *c, struct bkey_s k)
-{
-	struct bkey_s_extent e;
-
-	switch (k.k->type) {
-	case KEY_TYPE_ERROR:
-		return false;
-
-	case KEY_TYPE_DELETED:
-	case KEY_TYPE_COOKIE:
-		return true;
-
-	case KEY_TYPE_DISCARD:
-		return bversion_zero(k.k->version);
-
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED:
-		e = bkey_s_to_extent(k);
-
-		bch_extent_drop_stale(c, e);
-
-		if (!bkey_val_u64s(e.k)) {
-			if (bkey_extent_is_cached(e.k)) {
-				k.k->type = KEY_TYPE_DISCARD;
-				if (bversion_zero(k.k->version))
-					return true;
-			} else {
-				k.k->type = KEY_TYPE_ERROR;
-			}
-		}
-
-		return false;
-	case BCH_RESERVATION:
-		return false;
-	default:
-		BUG();
-	}
-}
-
-void bch_extent_mark_replicas_cached(struct bch_fs *c,
-				     struct bkey_s_extent e,
-				     unsigned nr_cached)
-{
-	struct bch_extent_ptr *ptr;
-	bool have_higher_tier;
-	unsigned tier = 0;
-
-	if (!nr_cached)
-		return;
-
-	do {
-		have_higher_tier = false;
-
-		extent_for_each_ptr(e, ptr) {
-			if (!ptr->cached &&
-			    PTR_TIER(c, ptr) == tier) {
-				ptr->cached = true;
-				nr_cached--;
-				if (!nr_cached)
-					return;
-			}
-
-			if (PTR_TIER(c, ptr) > tier)
-				have_higher_tier = true;
-		}
-
-		tier++;
-	} while (have_higher_tier);
-}
-
-/*
- * This picks a non-stale pointer, preferabbly from a device other than
- * avoid.  Avoid can be NULL, meaning pick any.  If there are no non-stale
- * pointers to other devices, it will still pick a pointer from avoid.
- * Note that it prefers lowered-numbered pointers to higher-numbered pointers
- * as the pointers are sorted by tier, hence preferring pointers to tier 0
- * rather than pointers to tier 1.
- */
-void bch_extent_pick_ptr_avoiding(struct bch_fs *c, struct bkey_s_c k,
-				  struct bch_dev *avoid,
-				  struct extent_pick_ptr *ret)
-{
-	struct bkey_s_c_extent e;
-	const union bch_extent_crc *crc;
-	const struct bch_extent_ptr *ptr;
-
-	switch (k.k->type) {
-	case KEY_TYPE_DELETED:
-	case KEY_TYPE_DISCARD:
-	case KEY_TYPE_COOKIE:
-		ret->ca = NULL;
-		return;
-
-	case KEY_TYPE_ERROR:
-		ret->ca = ERR_PTR(-EIO);
-		return;
-
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED:
-		e = bkey_s_c_to_extent(k);
-		ret->ca = NULL;
-
-		extent_for_each_ptr_crc(e, ptr, crc) {
-			struct bch_dev *ca = c->devs[ptr->dev];
-
-			if (ptr->cached && ptr_stale(ca, ptr))
-				continue;
-
-			if (ca->mi.state == BCH_MEMBER_STATE_FAILED)
-				continue;
-
-			if (ret->ca &&
-			    (ca == avoid ||
-			     ret->ca->mi.tier < ca->mi.tier))
-				continue;
-
-			if (!percpu_ref_tryget(&ca->io_ref))
-				continue;
-
-			if (ret->ca)
-				percpu_ref_put(&ret->ca->io_ref);
-
-			*ret = (struct extent_pick_ptr) {
-				.crc = crc_to_128(e.k, crc),
-				.ptr = *ptr,
-				.ca = ca,
-			};
-		}
-
-		if (!ret->ca && !bkey_extent_is_cached(e.k))
-			ret->ca = ERR_PTR(-EIO);
-		return;
-
-	case BCH_RESERVATION:
-		ret->ca = NULL;
-		return;
-
-	default:
-		BUG();
-	}
-}
-
-static enum merge_result bch_extent_merge(struct bch_fs *c,
-					  struct btree *bk,
-					  struct bkey_i *l, struct bkey_i *r)
-{
-	struct bkey_s_extent el, er;
-	union bch_extent_entry *en_l, *en_r;
-
-	if (key_merging_disabled(c))
-		return BCH_MERGE_NOMERGE;
-
-	/*
-	 * Generic header checks
-	 * Assumes left and right are in order
-	 * Left and right must be exactly aligned
-	 */
-
-	if (l->k.u64s		!= r->k.u64s ||
-	    l->k.type		!= r->k.type ||
-	    bversion_cmp(l->k.version, r->k.version) ||
-	    bkey_cmp(l->k.p, bkey_start_pos(&r->k)))
-		return BCH_MERGE_NOMERGE;
-
-	switch (l->k.type) {
-	case KEY_TYPE_DELETED:
-	case KEY_TYPE_DISCARD:
-	case KEY_TYPE_ERROR:
-		/* These types are mergeable, and no val to check */
-		break;
-
-	case BCH_EXTENT:
-	case BCH_EXTENT_CACHED:
-		el = bkey_i_to_s_extent(l);
-		er = bkey_i_to_s_extent(r);
-
-		extent_for_each_entry(el, en_l) {
-			struct bch_extent_ptr *lp, *rp;
-			unsigned bucket_size;
-
-			en_r = vstruct_idx(er.v, (u64 *) en_l - el.v->_data);
-
-			if ((extent_entry_type(en_l) !=
-			     extent_entry_type(en_r)) ||
-			    extent_entry_is_crc(en_l))
-				return BCH_MERGE_NOMERGE;
-
-			lp = &en_l->ptr;
-			rp = &en_r->ptr;
-
-			if (lp->offset + el.k->size	!= rp->offset ||
-			    lp->dev			!= rp->dev ||
-			    lp->gen			!= rp->gen)
-				return BCH_MERGE_NOMERGE;
-
-			/* We don't allow extents to straddle buckets: */
-			bucket_size = c->devs[lp->dev]->mi.bucket_size;
-
-			if ((lp->offset & ~((u64) bucket_size - 1)) !=
-			    (rp->offset & ~((u64) bucket_size - 1)))
-				return BCH_MERGE_NOMERGE;
-		}
-
-		break;
-	case BCH_RESERVATION: {
-		struct bkey_i_reservation *li = bkey_i_to_reservation(l);
-		struct bkey_i_reservation *ri = bkey_i_to_reservation(r);
-
-		if (li->v.generation != ri->v.generation ||
-		    li->v.nr_replicas != ri->v.nr_replicas)
-			return BCH_MERGE_NOMERGE;
-		break;
-	}
-	default:
-		return BCH_MERGE_NOMERGE;
-	}
-
-	l->k.needs_whiteout |= r->k.needs_whiteout;
-
-	/* Keys with no pointers aren't restricted to one bucket and could
-	 * overflow KEY_SIZE
-	 */
-	if ((u64) l->k.size + r->k.size > KEY_SIZE_MAX) {
-		bch_key_resize(&l->k, KEY_SIZE_MAX);
-		bch_cut_front(l->k.p, r);
-		return BCH_MERGE_PARTIAL;
-	}
-
-	bch_key_resize(&l->k, l->k.size + r->k.size);
-
-	return BCH_MERGE_MERGE;
-}
-
-static void extent_i_save(struct btree *b, struct bkey_packed *dst,
-			  struct bkey_i *src)
-{
-	struct bkey_format *f = &b->format;
-	struct bkey_i *dst_unpacked;
-
-	BUG_ON(bkeyp_val_u64s(f, dst) != bkey_val_u64s(&src->k));
-
-	/*
-	 * We don't want the bch_verify_key_order() call in extent_save(),
-	 * because we may be out of order with deleted keys that are about to be
-	 * removed by extent_bset_insert()
-	 */
-
-	if ((dst_unpacked = packed_to_bkey(dst)))
-		bkey_copy(dst_unpacked, src);
-	else
-		BUG_ON(!bkey_pack(dst, src, f));
-}
-
-static bool extent_merge_one_overlapping(struct btree_iter *iter,
-					 struct bpos new_pos,
-					 struct bset_tree *t,
-					 struct bkey_packed *k, struct bkey uk,
-					 bool check, bool could_pack)
-{
-	struct btree *b = iter->nodes[0];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-
-	BUG_ON(!bkey_deleted(k));
-
-	if (check) {
-		return !bkey_packed(k) || could_pack;
-	} else {
-		uk.p = new_pos;
-		extent_save(b, node_iter, k, &uk);
-		bch_bset_fix_invalidated_key(b, t, k);
-		bch_btree_node_iter_fix(iter, b, node_iter, t,
-					k, k->u64s, k->u64s);
-		return true;
-	}
-}
-
-static bool extent_merge_do_overlapping(struct btree_iter *iter,
-					struct bkey *m, bool back_merge)
-{
-	struct btree *b = iter->nodes[0];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-	struct bset_tree *t;
-	struct bkey_packed *k;
-	struct bkey uk;
-	struct bpos new_pos = back_merge ? m->p : bkey_start_pos(m);
-	bool could_pack = bkey_pack_pos((void *) &uk, new_pos, b);
-	bool check = true;
-
-	/*
-	 * @m is the new merged extent:
-	 *
-	 * The merge took place in the last bset; we know there can't be any 0
-	 * size extents overlapping with m there because if so they would have
-	 * been between the two extents we merged.
-	 *
-	 * But in the other bsets, we have to check for and fix such extents:
-	 */
-do_fixup:
-	for_each_bset(b, t) {
-		if (t == bset_tree_last(b))
-			break;
-
-		/*
-		 * if we don't find this bset in the iterator we already got to
-		 * the end of that bset, so start searching from the end.
-		 */
-		k = bch_btree_node_iter_bset_pos(node_iter, b, t);
-
-		if (k == btree_bkey_last(b, t))
-			k = bkey_prev_all(b, t, k);
-		if (!k)
-			continue;
-
-		if (back_merge) {
-			/*
-			 * Back merge: 0 size extents will be before the key
-			 * that was just inserted (and thus the iterator
-			 * position) - walk backwards to find them
-			 */
-			for (;
-			     k &&
-			     (uk = bkey_unpack_key(b, k),
-			      bkey_cmp(uk.p, bkey_start_pos(m)) > 0);
-			     k = bkey_prev_all(b, t, k)) {
-				if (bkey_cmp(uk.p, m->p) >= 0)
-					continue;
-
-				if (!extent_merge_one_overlapping(iter, new_pos,
-						t, k, uk, check, could_pack))
-					return false;
-			}
-		} else {
-			/* Front merge - walk forwards */
-			for (;
-			     k != btree_bkey_last(b, t) &&
-			     (uk = bkey_unpack_key(b, k),
-			      bkey_cmp(uk.p, m->p) < 0);
-			     k = bkey_next(k)) {
-				if (bkey_cmp(uk.p,
-					     bkey_start_pos(m)) <= 0)
-					continue;
-
-				if (!extent_merge_one_overlapping(iter, new_pos,
-						t, k, uk, check, could_pack))
-					return false;
-			}
-		}
-	}
-
-	if (check) {
-		check = false;
-		goto do_fixup;
-	}
-
-	return true;
-}
-
-/*
- * When merging an extent that we're inserting into a btree node, the new merged
- * extent could overlap with an existing 0 size extent - if we don't fix that,
- * it'll break the btree node iterator so this code finds those 0 size extents
- * and shifts them out of the way.
- *
- * Also unpacks and repacks.
- */
-static bool bch_extent_merge_inline(struct bch_fs *c,
-				    struct btree_iter *iter,
-				    struct bkey_packed *l,
-				    struct bkey_packed *r,
-				    bool back_merge)
-{
-	struct btree *b = iter->nodes[0];
-	struct btree_node_iter *node_iter = &iter->node_iters[0];
-	const struct bkey_format *f = &b->format;
-	struct bset_tree *t = bset_tree_last(b);
-	struct bkey_packed *m;
-	BKEY_PADDED(k) li;
-	BKEY_PADDED(k) ri;
-	struct bkey_i *mi;
-	struct bkey tmp;
-
-	/*
-	 * We need to save copies of both l and r, because we might get a
-	 * partial merge (which modifies both) and then fails to repack
-	 */
-	bkey_unpack(b, &li.k, l);
-	bkey_unpack(b, &ri.k, r);
-
-	m = back_merge ? l : r;
-	mi = back_merge ? &li.k : &ri.k;
-
-	/* l & r should be in last bset: */
-	EBUG_ON(bch_bkey_to_bset(b, m) != t);
-
-	switch (bch_extent_merge(c, b, &li.k, &ri.k)) {
-	case BCH_MERGE_NOMERGE:
-		return false;
-	case BCH_MERGE_PARTIAL:
-		if (bkey_packed(m) && !bkey_pack_key((void *) &tmp, &mi->k, f))
-			return false;
-
-		if (!extent_merge_do_overlapping(iter, &li.k.k, back_merge))
-			return false;
-
-		extent_i_save(b, m, mi);
-		bch_bset_fix_invalidated_key(b, t, m);
-
-		/*
-		 * Update iterator to reflect what we just inserted - otherwise,
-		 * the iter_fix() call is going to put us _before_ the key we
-		 * just partially merged with:
-		 */
-		if (back_merge)
-			bch_btree_iter_set_pos_same_leaf(iter, li.k.k.p);
-
-		bch_btree_node_iter_fix(iter, iter->nodes[0], node_iter,
-					t, m, m->u64s, m->u64s);
-
-		if (!back_merge)
-			bkey_copy(packed_to_bkey(l), &li.k);
-		else
-			bkey_copy(packed_to_bkey(r), &ri.k);
-		return false;
-	case BCH_MERGE_MERGE:
-		if (bkey_packed(m) && !bkey_pack_key((void *) &tmp, &li.k.k, f))
-			return false;
-
-		if (!extent_merge_do_overlapping(iter, &li.k.k, back_merge))
-			return false;
-
-		extent_i_save(b, m, &li.k);
-		bch_bset_fix_invalidated_key(b, t, m);
-
-		bch_btree_node_iter_fix(iter, iter->nodes[0], node_iter,
-					t, m, m->u64s, m->u64s);
-		return true;
-	default:
-		BUG();
-	}
-}
-
-const struct bkey_ops bch_bkey_extent_ops = {
-	.key_invalid	= bch_extent_invalid,
-	.key_debugcheck	= bch_extent_debugcheck,
-	.val_to_text	= bch_extent_to_text,
-	.swab		= bch_ptr_swab,
-	.key_normalize	= bch_ptr_normalize,
-	.key_merge	= bch_extent_merge,
-	.is_extents	= true,
-};