Move c_src dirs back to toplevel

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

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

1 files changed, 0 insertions, 1662 deletions

diff --git a/c_src/libbcachefs/io_write.c b/c_src/libbcachefs/io_write.c
deleted file mode 100644
index 33c0e783..00000000
--- a/c_src/libbcachefs/io_write.c
+++ /dev/null
@@ -1,1662 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
- * Copyright 2012 Google, Inc.
- */
-
-#include "bcachefs.h"
-#include "alloc_foreground.h"
-#include "bkey_buf.h"
-#include "bset.h"
-#include "btree_update.h"
-#include "buckets.h"
-#include "checksum.h"
-#include "clock.h"
-#include "compress.h"
-#include "debug.h"
-#include "ec.h"
-#include "error.h"
-#include "extent_update.h"
-#include "inode.h"
-#include "io_write.h"
-#include "journal.h"
-#include "keylist.h"
-#include "move.h"
-#include "nocow_locking.h"
-#include "rebalance.h"
-#include "subvolume.h"
-#include "super.h"
-#include "super-io.h"
-#include "trace.h"
-
-#include <linux/blkdev.h>
-#include <linux/prefetch.h>
-#include <linux/random.h>
-#include <linux/sched/mm.h>
-
-#ifndef CONFIG_BCACHEFS_NO_LATENCY_ACCT
-
-static inline void bch2_congested_acct(struct bch_dev *ca, u64 io_latency,
-				       u64 now, int rw)
-{
-	u64 latency_capable =
-		ca->io_latency[rw].quantiles.entries[QUANTILE_IDX(1)].m;
-	/* ideally we'd be taking into account the device's variance here: */
-	u64 latency_threshold = latency_capable << (rw == READ ? 2 : 3);
-	s64 latency_over = io_latency - latency_threshold;
-
-	if (latency_threshold && latency_over > 0) {
-		/*
-		 * bump up congested by approximately latency_over * 4 /
-		 * latency_threshold - we don't need much accuracy here so don't
-		 * bother with the divide:
-		 */
-		if (atomic_read(&ca->congested) < CONGESTED_MAX)
-			atomic_add(latency_over >>
-				   max_t(int, ilog2(latency_threshold) - 2, 0),
-				   &ca->congested);
-
-		ca->congested_last = now;
-	} else if (atomic_read(&ca->congested) > 0) {
-		atomic_dec(&ca->congested);
-	}
-}
-
-void bch2_latency_acct(struct bch_dev *ca, u64 submit_time, int rw)
-{
-	atomic64_t *latency = &ca->cur_latency[rw];
-	u64 now = local_clock();
-	u64 io_latency = time_after64(now, submit_time)
-		? now - submit_time
-		: 0;
-	u64 old, new, v = atomic64_read(latency);
-
-	do {
-		old = v;
-
-		/*
-		 * If the io latency was reasonably close to the current
-		 * latency, skip doing the update and atomic operation - most of
-		 * the time:
-		 */
-		if (abs((int) (old - io_latency)) < (old >> 1) &&
-		    now & ~(~0U << 5))
-			break;
-
-		new = ewma_add(old, io_latency, 5);
-	} while ((v = atomic64_cmpxchg(latency, old, new)) != old);
-
-	bch2_congested_acct(ca, io_latency, now, rw);
-
-	__bch2_time_stats_update(&ca->io_latency[rw], submit_time, now);
-}
-
-#endif
-
-/* Allocate, free from mempool: */
-
-void bch2_bio_free_pages_pool(struct bch_fs *c, struct bio *bio)
-{
-	struct bvec_iter_all iter;
-	struct bio_vec *bv;
-
-	bio_for_each_segment_all(bv, bio, iter)
-		if (bv->bv_page != ZERO_PAGE(0))
-			mempool_free(bv->bv_page, &c->bio_bounce_pages);
-	bio->bi_vcnt = 0;
-}
-
-static struct page *__bio_alloc_page_pool(struct bch_fs *c, bool *using_mempool)
-{
-	struct page *page;
-
-	if (likely(!*using_mempool)) {
-		page = alloc_page(GFP_NOFS);
-		if (unlikely(!page)) {
-			mutex_lock(&c->bio_bounce_pages_lock);
-			*using_mempool = true;
-			goto pool_alloc;
-
-		}
-	} else {
-pool_alloc:
-		page = mempool_alloc(&c->bio_bounce_pages, GFP_NOFS);
-	}
-
-	return page;
-}
-
-void bch2_bio_alloc_pages_pool(struct bch_fs *c, struct bio *bio,
-			       size_t size)
-{
-	bool using_mempool = false;
-
-	while (size) {
-		struct page *page = __bio_alloc_page_pool(c, &using_mempool);
-		unsigned len = min_t(size_t, PAGE_SIZE, size);
-
-		BUG_ON(!bio_add_page(bio, page, len, 0));
-		size -= len;
-	}
-
-	if (using_mempool)
-		mutex_unlock(&c->bio_bounce_pages_lock);
-}
-
-/* Extent update path: */
-
-int bch2_sum_sector_overwrites(struct btree_trans *trans,
-			       struct btree_iter *extent_iter,
-			       struct bkey_i *new,
-			       bool *usage_increasing,
-			       s64 *i_sectors_delta,
-			       s64 *disk_sectors_delta)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_iter iter;
-	struct bkey_s_c old;
-	unsigned new_replicas = bch2_bkey_replicas(c, bkey_i_to_s_c(new));
-	bool new_compressed = bch2_bkey_sectors_compressed(bkey_i_to_s_c(new));
-	int ret = 0;
-
-	*usage_increasing	= false;
-	*i_sectors_delta	= 0;
-	*disk_sectors_delta	= 0;
-
-	bch2_trans_copy_iter(&iter, extent_iter);
-
-	for_each_btree_key_upto_continue_norestart(iter,
-				new->k.p, BTREE_ITER_SLOTS, old, ret) {
-		s64 sectors = min(new->k.p.offset, old.k->p.offset) -
-			max(bkey_start_offset(&new->k),
-			    bkey_start_offset(old.k));
-
-		*i_sectors_delta += sectors *
-			(bkey_extent_is_allocation(&new->k) -
-			 bkey_extent_is_allocation(old.k));
-
-		*disk_sectors_delta += sectors * bch2_bkey_nr_ptrs_allocated(bkey_i_to_s_c(new));
-		*disk_sectors_delta -= new->k.p.snapshot == old.k->p.snapshot
-			? sectors * bch2_bkey_nr_ptrs_fully_allocated(old)
-			: 0;
-
-		if (!*usage_increasing &&
-		    (new->k.p.snapshot != old.k->p.snapshot ||
-		     new_replicas > bch2_bkey_replicas(c, old) ||
-		     (!new_compressed && bch2_bkey_sectors_compressed(old))))
-			*usage_increasing = true;
-
-		if (bkey_ge(old.k->p, new->k.p))
-			break;
-	}
-
-	bch2_trans_iter_exit(trans, &iter);
-	return ret;
-}
-
-static inline int bch2_extent_update_i_size_sectors(struct btree_trans *trans,
-						    struct btree_iter *extent_iter,
-						    u64 new_i_size,
-						    s64 i_sectors_delta)
-{
-	struct btree_iter iter;
-	struct bkey_i *k;
-	struct bkey_i_inode_v3 *inode;
-	/*
-	 * Crazy performance optimization:
-	 * Every extent update needs to also update the inode: the inode trigger
-	 * will set bi->journal_seq to the journal sequence number of this
-	 * transaction - for fsync.
-	 *
-	 * But if that's the only reason we're updating the inode (we're not
-	 * updating bi_size or bi_sectors), then we don't need the inode update
-	 * to be journalled - if we crash, the bi_journal_seq update will be
-	 * lost, but that's fine.
-	 */
-	unsigned inode_update_flags = BTREE_UPDATE_NOJOURNAL;
-	int ret;
-
-	k = bch2_bkey_get_mut_noupdate(trans, &iter, BTREE_ID_inodes,
-			      SPOS(0,
-				   extent_iter->pos.inode,
-				   extent_iter->snapshot),
-			      BTREE_ITER_CACHED);
-	ret = PTR_ERR_OR_ZERO(k);
-	if (unlikely(ret))
-		return ret;
-
-	if (unlikely(k->k.type != KEY_TYPE_inode_v3)) {
-		k = bch2_inode_to_v3(trans, k);
-		ret = PTR_ERR_OR_ZERO(k);
-		if (unlikely(ret))
-			goto err;
-	}
-
-	inode = bkey_i_to_inode_v3(k);
-
-	if (!(le64_to_cpu(inode->v.bi_flags) & BCH_INODE_i_size_dirty) &&
-	    new_i_size > le64_to_cpu(inode->v.bi_size)) {
-		inode->v.bi_size = cpu_to_le64(new_i_size);
-		inode_update_flags = 0;
-	}
-
-	if (i_sectors_delta) {
-		le64_add_cpu(&inode->v.bi_sectors, i_sectors_delta);
-		inode_update_flags = 0;
-	}
-
-	if (inode->k.p.snapshot != iter.snapshot) {
-		inode->k.p.snapshot = iter.snapshot;
-		inode_update_flags = 0;
-	}
-
-	ret = bch2_trans_update(trans, &iter, &inode->k_i,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
-				inode_update_flags);
-err:
-	bch2_trans_iter_exit(trans, &iter);
-	return ret;
-}
-
-int bch2_extent_update(struct btree_trans *trans,
-		       subvol_inum inum,
-		       struct btree_iter *iter,
-		       struct bkey_i *k,
-		       struct disk_reservation *disk_res,
-		       u64 new_i_size,
-		       s64 *i_sectors_delta_total,
-		       bool check_enospc)
-{
-	struct bpos next_pos;
-	bool usage_increasing;
-	s64 i_sectors_delta = 0, disk_sectors_delta = 0;
-	int ret;
-
-	/*
-	 * This traverses us the iterator without changing iter->path->pos to
-	 * search_key() (which is pos + 1 for extents): we want there to be a
-	 * path already traversed at iter->pos because
-	 * bch2_trans_extent_update() will use it to attempt extent merging
-	 */
-	ret = __bch2_btree_iter_traverse(iter);
-	if (ret)
-		return ret;
-
-	ret = bch2_extent_trim_atomic(trans, iter, k);
-	if (ret)
-		return ret;
-
-	next_pos = k->k.p;
-
-	ret = bch2_sum_sector_overwrites(trans, iter, k,
-			&usage_increasing,
-			&i_sectors_delta,
-			&disk_sectors_delta);
-	if (ret)
-		return ret;
-
-	if (disk_res &&
-	    disk_sectors_delta > (s64) disk_res->sectors) {
-		ret = bch2_disk_reservation_add(trans->c, disk_res,
-					disk_sectors_delta - disk_res->sectors,
-					!check_enospc || !usage_increasing
-					? BCH_DISK_RESERVATION_NOFAIL : 0);
-		if (ret)
-			return ret;
-	}
-
-	/*
-	 * Note:
-	 * We always have to do an inode update - even when i_size/i_sectors
-	 * aren't changing - for fsync to work properly; fsync relies on
-	 * inode->bi_journal_seq which is updated by the trigger code:
-	 */
-	ret =   bch2_extent_update_i_size_sectors(trans, iter,
-						  min(k->k.p.offset << 9, new_i_size),
-						  i_sectors_delta) ?:
-		bch2_trans_update(trans, iter, k, 0) ?:
-		bch2_trans_commit(trans, disk_res, NULL,
-				BCH_TRANS_COMMIT_no_check_rw|
-				BCH_TRANS_COMMIT_no_enospc);
-	if (unlikely(ret))
-		return ret;
-
-	if (i_sectors_delta_total)
-		*i_sectors_delta_total += i_sectors_delta;
-	bch2_btree_iter_set_pos(iter, next_pos);
-	return 0;
-}
-
-static int bch2_write_index_default(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct bkey_buf sk;
-	struct keylist *keys = &op->insert_keys;
-	struct bkey_i *k = bch2_keylist_front(keys);
-	struct btree_trans *trans = bch2_trans_get(c);
-	struct btree_iter iter;
-	subvol_inum inum = {
-		.subvol = op->subvol,
-		.inum	= k->k.p.inode,
-	};
-	int ret;
-
-	BUG_ON(!inum.subvol);
-
-	bch2_bkey_buf_init(&sk);
-
-	do {
-		bch2_trans_begin(trans);
-
-		k = bch2_keylist_front(keys);
-		bch2_bkey_buf_copy(&sk, c, k);
-
-		ret = bch2_subvolume_get_snapshot(trans, inum.subvol,
-						  &sk.k->k.p.snapshot);
-		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
-			continue;
-		if (ret)
-			break;
-
-		bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
-				     bkey_start_pos(&sk.k->k),
-				     BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-
-		ret =   bch2_bkey_set_needs_rebalance(c, sk.k,
-					op->opts.background_target,
-					op->opts.background_compression) ?:
-			bch2_extent_update(trans, inum, &iter, sk.k,
-					&op->res,
-					op->new_i_size, &op->i_sectors_delta,
-					op->flags & BCH_WRITE_CHECK_ENOSPC);
-		bch2_trans_iter_exit(trans, &iter);
-
-		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
-			continue;
-		if (ret)
-			break;
-
-		if (bkey_ge(iter.pos, k->k.p))
-			bch2_keylist_pop_front(&op->insert_keys);
-		else
-			bch2_cut_front(iter.pos, k);
-	} while (!bch2_keylist_empty(keys));
-
-	bch2_trans_put(trans);
-	bch2_bkey_buf_exit(&sk, c);
-
-	return ret;
-}
-
-/* Writes */
-
-void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
-			       enum bch_data_type type,
-			       const struct bkey_i *k,
-			       bool nocow)
-{
-	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
-	struct bch_write_bio *n;
-
-	BUG_ON(c->opts.nochanges);
-
-	bkey_for_each_ptr(ptrs, ptr) {
-		BUG_ON(!bch2_dev_exists2(c, ptr->dev));
-
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-
-		if (to_entry(ptr + 1) < ptrs.end) {
-			n = to_wbio(bio_alloc_clone(NULL, &wbio->bio,
-						GFP_NOFS, &ca->replica_set));
-
-			n->bio.bi_end_io	= wbio->bio.bi_end_io;
-			n->bio.bi_private	= wbio->bio.bi_private;
-			n->parent		= wbio;
-			n->split		= true;
-			n->bounce		= false;
-			n->put_bio		= true;
-			n->bio.bi_opf		= wbio->bio.bi_opf;
-			bio_inc_remaining(&wbio->bio);
-		} else {
-			n = wbio;
-			n->split		= false;
-		}
-
-		n->c			= c;
-		n->dev			= ptr->dev;
-		n->have_ioref		= nocow || bch2_dev_get_ioref(ca,
-					type == BCH_DATA_btree ? READ : WRITE);
-		n->nocow		= nocow;
-		n->submit_time		= local_clock();
-		n->inode_offset		= bkey_start_offset(&k->k);
-		n->bio.bi_iter.bi_sector = ptr->offset;
-
-		if (likely(n->have_ioref)) {
-			this_cpu_add(ca->io_done->sectors[WRITE][type],
-				     bio_sectors(&n->bio));
-
-			bio_set_dev(&n->bio, ca->disk_sb.bdev);
-
-			if (type != BCH_DATA_btree && unlikely(c->opts.no_data_io)) {
-				bio_endio(&n->bio);
-				continue;
-			}
-
-			submit_bio(&n->bio);
-		} else {
-			n->bio.bi_status	= BLK_STS_REMOVED;
-			bio_endio(&n->bio);
-		}
-	}
-}
-
-static void __bch2_write(struct bch_write_op *);
-
-static void bch2_write_done(struct closure *cl)
-{
-	struct bch_write_op *op = container_of(cl, struct bch_write_op, cl);
-	struct bch_fs *c = op->c;
-
-	EBUG_ON(op->open_buckets.nr);
-
-	bch2_time_stats_update(&c->times[BCH_TIME_data_write], op->start_time);
-	bch2_disk_reservation_put(c, &op->res);
-
-	if (!(op->flags & BCH_WRITE_MOVE))
-		bch2_write_ref_put(c, BCH_WRITE_REF_write);
-	bch2_keylist_free(&op->insert_keys, op->inline_keys);
-
-	EBUG_ON(cl->parent);
-	closure_debug_destroy(cl);
-	if (op->end_io)
-		op->end_io(op);
-}
-
-static noinline int bch2_write_drop_io_error_ptrs(struct bch_write_op *op)
-{
-	struct keylist *keys = &op->insert_keys;
-	struct bch_extent_ptr *ptr;
-	struct bkey_i *src, *dst = keys->keys, *n;
-
-	for (src = keys->keys; src != keys->top; src = n) {
-		n = bkey_next(src);
-
-		if (bkey_extent_is_direct_data(&src->k)) {
-			bch2_bkey_drop_ptrs(bkey_i_to_s(src), ptr,
-					    test_bit(ptr->dev, op->failed.d));
-
-			if (!bch2_bkey_nr_ptrs(bkey_i_to_s_c(src)))
-				return -EIO;
-		}
-
-		if (dst != src)
-			memmove_u64s_down(dst, src, src->k.u64s);
-		dst = bkey_next(dst);
-	}
-
-	keys->top = dst;
-	return 0;
-}
-
-/**
- * __bch2_write_index - after a write, update index to point to new data
- * @op:		bch_write_op to process
- */
-static void __bch2_write_index(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct keylist *keys = &op->insert_keys;
-	unsigned dev;
-	int ret = 0;
-
-	if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
-		ret = bch2_write_drop_io_error_ptrs(op);
-		if (ret)
-			goto err;
-	}
-
-	if (!bch2_keylist_empty(keys)) {
-		u64 sectors_start = keylist_sectors(keys);
-
-		ret = !(op->flags & BCH_WRITE_MOVE)
-			? bch2_write_index_default(op)
-			: bch2_data_update_index_update(op);
-
-		BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
-		BUG_ON(keylist_sectors(keys) && !ret);
-
-		op->written += sectors_start - keylist_sectors(keys);
-
-		if (ret && !bch2_err_matches(ret, EROFS)) {
-			struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
-
-			bch_err_inum_offset_ratelimited(c,
-				insert->k.p.inode, insert->k.p.offset << 9,
-				"write error while doing btree update: %s",
-				bch2_err_str(ret));
-		}
-
-		if (ret)
-			goto err;
-	}
-out:
-	/* If some a bucket wasn't written, we can't erasure code it: */
-	for_each_set_bit(dev, op->failed.d, BCH_SB_MEMBERS_MAX)
-		bch2_open_bucket_write_error(c, &op->open_buckets, dev);
-
-	bch2_open_buckets_put(c, &op->open_buckets);
-	return;
-err:
-	keys->top = keys->keys;
-	op->error = ret;
-	op->flags |= BCH_WRITE_DONE;
-	goto out;
-}
-
-static inline void __wp_update_state(struct write_point *wp, enum write_point_state state)
-{
-	if (state != wp->state) {
-		u64 now = ktime_get_ns();
-
-		if (wp->last_state_change &&
-		    time_after64(now, wp->last_state_change))
-			wp->time[wp->state] += now - wp->last_state_change;
-		wp->state = state;
-		wp->last_state_change = now;
-	}
-}
-
-static inline void wp_update_state(struct write_point *wp, bool running)
-{
-	enum write_point_state state;
-
-	state = running			 ? WRITE_POINT_running :
-		!list_empty(&wp->writes) ? WRITE_POINT_waiting_io
-					 : WRITE_POINT_stopped;
-
-	__wp_update_state(wp, state);
-}
-
-static CLOSURE_CALLBACK(bch2_write_index)
-{
-	closure_type(op, struct bch_write_op, cl);
-	struct write_point *wp = op->wp;
-	struct workqueue_struct *wq = index_update_wq(op);
-	unsigned long flags;
-
-	if ((op->flags & BCH_WRITE_DONE) &&
-	    (op->flags & BCH_WRITE_MOVE))
-		bch2_bio_free_pages_pool(op->c, &op->wbio.bio);
-
-	spin_lock_irqsave(&wp->writes_lock, flags);
-	if (wp->state == WRITE_POINT_waiting_io)
-		__wp_update_state(wp, WRITE_POINT_waiting_work);
-	list_add_tail(&op->wp_list, &wp->writes);
-	spin_unlock_irqrestore (&wp->writes_lock, flags);
-
-	queue_work(wq, &wp->index_update_work);
-}
-
-static inline void bch2_write_queue(struct bch_write_op *op, struct write_point *wp)
-{
-	op->wp = wp;
-
-	if (wp->state == WRITE_POINT_stopped) {
-		spin_lock_irq(&wp->writes_lock);
-		__wp_update_state(wp, WRITE_POINT_waiting_io);
-		spin_unlock_irq(&wp->writes_lock);
-	}
-}
-
-void bch2_write_point_do_index_updates(struct work_struct *work)
-{
-	struct write_point *wp =
-		container_of(work, struct write_point, index_update_work);
-	struct bch_write_op *op;
-
-	while (1) {
-		spin_lock_irq(&wp->writes_lock);
-		op = list_first_entry_or_null(&wp->writes, struct bch_write_op, wp_list);
-		if (op)
-			list_del(&op->wp_list);
-		wp_update_state(wp, op != NULL);
-		spin_unlock_irq(&wp->writes_lock);
-
-		if (!op)
-			break;
-
-		op->flags |= BCH_WRITE_IN_WORKER;
-
-		__bch2_write_index(op);
-
-		if (!(op->flags & BCH_WRITE_DONE))
-			__bch2_write(op);
-		else
-			bch2_write_done(&op->cl);
-	}
-}
-
-static void bch2_write_endio(struct bio *bio)
-{
-	struct closure *cl		= bio->bi_private;
-	struct bch_write_op *op		= container_of(cl, struct bch_write_op, cl);
-	struct bch_write_bio *wbio	= to_wbio(bio);
-	struct bch_write_bio *parent	= wbio->split ? wbio->parent : NULL;
-	struct bch_fs *c		= wbio->c;
-	struct bch_dev *ca		= bch_dev_bkey_exists(c, wbio->dev);
-
-	if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_write,
-				    op->pos.inode,
-				    wbio->inode_offset << 9,
-				    "data write error: %s",
-				    bch2_blk_status_to_str(bio->bi_status))) {
-		set_bit(wbio->dev, op->failed.d);
-		op->flags |= BCH_WRITE_IO_ERROR;
-	}
-
-	if (wbio->nocow)
-		set_bit(wbio->dev, op->devs_need_flush->d);
-
-	if (wbio->have_ioref) {
-		bch2_latency_acct(ca, wbio->submit_time, WRITE);
-		percpu_ref_put(&ca->io_ref);
-	}
-
-	if (wbio->bounce)
-		bch2_bio_free_pages_pool(c, bio);
-
-	if (wbio->put_bio)
-		bio_put(bio);
-
-	if (parent)
-		bio_endio(&parent->bio);
-	else
-		closure_put(cl);
-}
-
-static void init_append_extent(struct bch_write_op *op,
-			       struct write_point *wp,
-			       struct bversion version,
-			       struct bch_extent_crc_unpacked crc)
-{
-	struct bkey_i_extent *e;
-
-	op->pos.offset += crc.uncompressed_size;
-
-	e = bkey_extent_init(op->insert_keys.top);
-	e->k.p		= op->pos;
-	e->k.size	= crc.uncompressed_size;
-	e->k.version	= version;
-
-	if (crc.csum_type ||
-	    crc.compression_type ||
-	    crc.nonce)
-		bch2_extent_crc_append(&e->k_i, crc);
-
-	bch2_alloc_sectors_append_ptrs_inlined(op->c, wp, &e->k_i, crc.compressed_size,
-				       op->flags & BCH_WRITE_CACHED);
-
-	bch2_keylist_push(&op->insert_keys);
-}
-
-static struct bio *bch2_write_bio_alloc(struct bch_fs *c,
-					struct write_point *wp,
-					struct bio *src,
-					bool *page_alloc_failed,
-					void *buf)
-{
-	struct bch_write_bio *wbio;
-	struct bio *bio;
-	unsigned output_available =
-		min(wp->sectors_free << 9, src->bi_iter.bi_size);
-	unsigned pages = DIV_ROUND_UP(output_available +
-				      (buf
-				       ? ((unsigned long) buf & (PAGE_SIZE - 1))
-				       : 0), PAGE_SIZE);
-
-	pages = min(pages, BIO_MAX_VECS);
-
-	bio = bio_alloc_bioset(NULL, pages, 0,
-			       GFP_NOFS, &c->bio_write);
-	wbio			= wbio_init(bio);
-	wbio->put_bio		= true;
-	/* copy WRITE_SYNC flag */
-	wbio->bio.bi_opf	= src->bi_opf;
-
-	if (buf) {
-		bch2_bio_map(bio, buf, output_available);
-		return bio;
-	}
-
-	wbio->bounce		= true;
-
-	/*
-	 * We can't use mempool for more than c->sb.encoded_extent_max
-	 * worth of pages, but we'd like to allocate more if we can:
-	 */
-	bch2_bio_alloc_pages_pool(c, bio,
-				  min_t(unsigned, output_available,
-					c->opts.encoded_extent_max));
-
-	if (bio->bi_iter.bi_size < output_available)
-		*page_alloc_failed =
-			bch2_bio_alloc_pages(bio,
-					     output_available -
-					     bio->bi_iter.bi_size,
-					     GFP_NOFS) != 0;
-
-	return bio;
-}
-
-static int bch2_write_rechecksum(struct bch_fs *c,
-				 struct bch_write_op *op,
-				 unsigned new_csum_type)
-{
-	struct bio *bio = &op->wbio.bio;
-	struct bch_extent_crc_unpacked new_crc;
-	int ret;
-
-	/* bch2_rechecksum_bio() can't encrypt or decrypt data: */
-
-	if (bch2_csum_type_is_encryption(op->crc.csum_type) !=
-	    bch2_csum_type_is_encryption(new_csum_type))
-		new_csum_type = op->crc.csum_type;
-
-	ret = bch2_rechecksum_bio(c, bio, op->version, op->crc,
-				  NULL, &new_crc,
-				  op->crc.offset, op->crc.live_size,
-				  new_csum_type);
-	if (ret)
-		return ret;
-
-	bio_advance(bio, op->crc.offset << 9);
-	bio->bi_iter.bi_size = op->crc.live_size << 9;
-	op->crc = new_crc;
-	return 0;
-}
-
-static int bch2_write_decrypt(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct nonce nonce = extent_nonce(op->version, op->crc);
-	struct bch_csum csum;
-	int ret;
-
-	if (!bch2_csum_type_is_encryption(op->crc.csum_type))
-		return 0;
-
-	/*
-	 * If we need to decrypt data in the write path, we'll no longer be able
-	 * to verify the existing checksum (poly1305 mac, in this case) after
-	 * it's decrypted - this is the last point we'll be able to reverify the
-	 * checksum:
-	 */
-	csum = bch2_checksum_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
-	if (bch2_crc_cmp(op->crc.csum, csum) && !c->opts.no_data_io)
-		return -EIO;
-
-	ret = bch2_encrypt_bio(c, op->crc.csum_type, nonce, &op->wbio.bio);
-	op->crc.csum_type = 0;
-	op->crc.csum = (struct bch_csum) { 0, 0 };
-	return ret;
-}
-
-static enum prep_encoded_ret {
-	PREP_ENCODED_OK,
-	PREP_ENCODED_ERR,
-	PREP_ENCODED_CHECKSUM_ERR,
-	PREP_ENCODED_DO_WRITE,
-} bch2_write_prep_encoded_data(struct bch_write_op *op, struct write_point *wp)
-{
-	struct bch_fs *c = op->c;
-	struct bio *bio = &op->wbio.bio;
-
-	if (!(op->flags & BCH_WRITE_DATA_ENCODED))
-		return PREP_ENCODED_OK;
-
-	BUG_ON(bio_sectors(bio) != op->crc.compressed_size);
-
-	/* Can we just write the entire extent as is? */
-	if (op->crc.uncompressed_size == op->crc.live_size &&
-	    op->crc.uncompressed_size <= c->opts.encoded_extent_max >> 9 &&
-	    op->crc.compressed_size <= wp->sectors_free &&
-	    (op->crc.compression_type == bch2_compression_opt_to_type(op->compression_opt) ||
-	     op->incompressible)) {
-		if (!crc_is_compressed(op->crc) &&
-		    op->csum_type != op->crc.csum_type &&
-		    bch2_write_rechecksum(c, op, op->csum_type) &&
-		    !c->opts.no_data_io)
-			return PREP_ENCODED_CHECKSUM_ERR;
-
-		return PREP_ENCODED_DO_WRITE;
-	}
-
-	/*
-	 * If the data is compressed and we couldn't write the entire extent as
-	 * is, we have to decompress it:
-	 */
-	if (crc_is_compressed(op->crc)) {
-		struct bch_csum csum;
-
-		if (bch2_write_decrypt(op))
-			return PREP_ENCODED_CHECKSUM_ERR;
-
-		/* Last point we can still verify checksum: */
-		csum = bch2_checksum_bio(c, op->crc.csum_type,
-					 extent_nonce(op->version, op->crc),
-					 bio);
-		if (bch2_crc_cmp(op->crc.csum, csum) && !c->opts.no_data_io)
-			return PREP_ENCODED_CHECKSUM_ERR;
-
-		if (bch2_bio_uncompress_inplace(c, bio, &op->crc))
-			return PREP_ENCODED_ERR;
-	}
-
-	/*
-	 * No longer have compressed data after this point - data might be
-	 * encrypted:
-	 */
-
-	/*
-	 * If the data is checksummed and we're only writing a subset,
-	 * rechecksum and adjust bio to point to currently live data:
-	 */
-	if ((op->crc.live_size != op->crc.uncompressed_size ||
-	     op->crc.csum_type != op->csum_type) &&
-	    bch2_write_rechecksum(c, op, op->csum_type) &&
-	    !c->opts.no_data_io)
-		return PREP_ENCODED_CHECKSUM_ERR;
-
-	/*
-	 * If we want to compress the data, it has to be decrypted:
-	 */
-	if ((op->compression_opt ||
-	     bch2_csum_type_is_encryption(op->crc.csum_type) !=
-	     bch2_csum_type_is_encryption(op->csum_type)) &&
-	    bch2_write_decrypt(op))
-		return PREP_ENCODED_CHECKSUM_ERR;
-
-	return PREP_ENCODED_OK;
-}
-
-static int bch2_write_extent(struct bch_write_op *op, struct write_point *wp,
-			     struct bio **_dst)
-{
-	struct bch_fs *c = op->c;
-	struct bio *src = &op->wbio.bio, *dst = src;
-	struct bvec_iter saved_iter;
-	void *ec_buf;
-	unsigned total_output = 0, total_input = 0;
-	bool bounce = false;
-	bool page_alloc_failed = false;
-	int ret, more = 0;
-
-	BUG_ON(!bio_sectors(src));
-
-	ec_buf = bch2_writepoint_ec_buf(c, wp);
-
-	switch (bch2_write_prep_encoded_data(op, wp)) {
-	case PREP_ENCODED_OK:
-		break;
-	case PREP_ENCODED_ERR:
-		ret = -EIO;
-		goto err;
-	case PREP_ENCODED_CHECKSUM_ERR:
-		goto csum_err;
-	case PREP_ENCODED_DO_WRITE:
-		/* XXX look for bug here */
-		if (ec_buf) {
-			dst = bch2_write_bio_alloc(c, wp, src,
-						   &page_alloc_failed,
-						   ec_buf);
-			bio_copy_data(dst, src);
-			bounce = true;
-		}
-		init_append_extent(op, wp, op->version, op->crc);
-		goto do_write;
-	}
-
-	if (ec_buf ||
-	    op->compression_opt ||
-	    (op->csum_type &&
-	     !(op->flags & BCH_WRITE_PAGES_STABLE)) ||
-	    (bch2_csum_type_is_encryption(op->csum_type) &&
-	     !(op->flags & BCH_WRITE_PAGES_OWNED))) {
-		dst = bch2_write_bio_alloc(c, wp, src,
-					   &page_alloc_failed,
-					   ec_buf);
-		bounce = true;
-	}
-
-	saved_iter = dst->bi_iter;
-
-	do {
-		struct bch_extent_crc_unpacked crc = { 0 };
-		struct bversion version = op->version;
-		size_t dst_len = 0, src_len = 0;
-
-		if (page_alloc_failed &&
-		    dst->bi_iter.bi_size  < (wp->sectors_free << 9) &&
-		    dst->bi_iter.bi_size < c->opts.encoded_extent_max)
-			break;
-
-		BUG_ON(op->compression_opt &&
-		       (op->flags & BCH_WRITE_DATA_ENCODED) &&
-		       bch2_csum_type_is_encryption(op->crc.csum_type));
-		BUG_ON(op->compression_opt && !bounce);
-
-		crc.compression_type = op->incompressible
-			? BCH_COMPRESSION_TYPE_incompressible
-			: op->compression_opt
-			? bch2_bio_compress(c, dst, &dst_len, src, &src_len,
-					    op->compression_opt)
-			: 0;
-		if (!crc_is_compressed(crc)) {
-			dst_len = min(dst->bi_iter.bi_size, src->bi_iter.bi_size);
-			dst_len = min_t(unsigned, dst_len, wp->sectors_free << 9);
-
-			if (op->csum_type)
-				dst_len = min_t(unsigned, dst_len,
-						c->opts.encoded_extent_max);
-
-			if (bounce) {
-				swap(dst->bi_iter.bi_size, dst_len);
-				bio_copy_data(dst, src);
-				swap(dst->bi_iter.bi_size, dst_len);
-			}
-
-			src_len = dst_len;
-		}
-
-		BUG_ON(!src_len || !dst_len);
-
-		if (bch2_csum_type_is_encryption(op->csum_type)) {
-			if (bversion_zero(version)) {
-				version.lo = atomic64_inc_return(&c->key_version);
-			} else {
-				crc.nonce = op->nonce;
-				op->nonce += src_len >> 9;
-			}
-		}
-
-		if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
-		    !crc_is_compressed(crc) &&
-		    bch2_csum_type_is_encryption(op->crc.csum_type) ==
-		    bch2_csum_type_is_encryption(op->csum_type)) {
-			u8 compression_type = crc.compression_type;
-			u16 nonce = crc.nonce;
-			/*
-			 * Note: when we're using rechecksum(), we need to be
-			 * checksumming @src because it has all the data our
-			 * existing checksum covers - if we bounced (because we
-			 * were trying to compress), @dst will only have the
-			 * part of the data the new checksum will cover.
-			 *
-			 * But normally we want to be checksumming post bounce,
-			 * because part of the reason for bouncing is so the
-			 * data can't be modified (by userspace) while it's in
-			 * flight.
-			 */
-			if (bch2_rechecksum_bio(c, src, version, op->crc,
-					&crc, &op->crc,
-					src_len >> 9,
-					bio_sectors(src) - (src_len >> 9),
-					op->csum_type))
-				goto csum_err;
-			/*
-			 * rchecksum_bio sets compression_type on crc from op->crc,
-			 * this isn't always correct as sometimes we're changing
-			 * an extent from uncompressed to incompressible.
-			 */
-			crc.compression_type = compression_type;
-			crc.nonce = nonce;
-		} else {
-			if ((op->flags & BCH_WRITE_DATA_ENCODED) &&
-			    bch2_rechecksum_bio(c, src, version, op->crc,
-					NULL, &op->crc,
-					src_len >> 9,
-					bio_sectors(src) - (src_len >> 9),
-					op->crc.csum_type))
-				goto csum_err;
-
-			crc.compressed_size	= dst_len >> 9;
-			crc.uncompressed_size	= src_len >> 9;
-			crc.live_size		= src_len >> 9;
-
-			swap(dst->bi_iter.bi_size, dst_len);
-			ret = bch2_encrypt_bio(c, op->csum_type,
-					       extent_nonce(version, crc), dst);
-			if (ret)
-				goto err;
-
-			crc.csum = bch2_checksum_bio(c, op->csum_type,
-					 extent_nonce(version, crc), dst);
-			crc.csum_type = op->csum_type;
-			swap(dst->bi_iter.bi_size, dst_len);
-		}
-
-		init_append_extent(op, wp, version, crc);
-
-		if (dst != src)
-			bio_advance(dst, dst_len);
-		bio_advance(src, src_len);
-		total_output	+= dst_len;
-		total_input	+= src_len;
-	} while (dst->bi_iter.bi_size &&
-		 src->bi_iter.bi_size &&
-		 wp->sectors_free &&
-		 !bch2_keylist_realloc(&op->insert_keys,
-				      op->inline_keys,
-				      ARRAY_SIZE(op->inline_keys),
-				      BKEY_EXTENT_U64s_MAX));
-
-	more = src->bi_iter.bi_size != 0;
-
-	dst->bi_iter = saved_iter;
-
-	if (dst == src && more) {
-		BUG_ON(total_output != total_input);
-
-		dst = bio_split(src, total_input >> 9,
-				GFP_NOFS, &c->bio_write);
-		wbio_init(dst)->put_bio	= true;
-		/* copy WRITE_SYNC flag */
-		dst->bi_opf		= src->bi_opf;
-	}
-
-	dst->bi_iter.bi_size = total_output;
-do_write:
-	*_dst = dst;
-	return more;
-csum_err:
-	bch_err(c, "error verifying existing checksum while rewriting existing data (memory corruption?)");
-	ret = -EIO;
-err:
-	if (to_wbio(dst)->bounce)
-		bch2_bio_free_pages_pool(c, dst);
-	if (to_wbio(dst)->put_bio)
-		bio_put(dst);
-
-	return ret;
-}
-
-static bool bch2_extent_is_writeable(struct bch_write_op *op,
-				     struct bkey_s_c k)
-{
-	struct bch_fs *c = op->c;
-	struct bkey_s_c_extent e;
-	struct extent_ptr_decoded p;
-	const union bch_extent_entry *entry;
-	unsigned replicas = 0;
-
-	if (k.k->type != KEY_TYPE_extent)
-		return false;
-
-	e = bkey_s_c_to_extent(k);
-	extent_for_each_ptr_decode(e, p, entry) {
-		if (crc_is_encoded(p.crc) || p.has_ec)
-			return false;
-
-		replicas += bch2_extent_ptr_durability(c, &p);
-	}
-
-	return replicas >= op->opts.data_replicas;
-}
-
-static inline void bch2_nocow_write_unlock(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-
-	for_each_keylist_key(&op->insert_keys, k) {
-		struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
-
-		bkey_for_each_ptr(ptrs, ptr)
-			bch2_bucket_nocow_unlock(&c->nocow_locks,
-						 PTR_BUCKET_POS(c, ptr),
-						 BUCKET_NOCOW_LOCK_UPDATE);
-	}
-}
-
-static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
-						  struct btree_iter *iter,
-						  struct bkey_i *orig,
-						  struct bkey_s_c k,
-						  u64 new_i_size)
-{
-	if (!bch2_extents_match(bkey_i_to_s_c(orig), k)) {
-		/* trace this */
-		return 0;
-	}
-
-	struct bkey_i *new = bch2_bkey_make_mut_noupdate(trans, k);
-	int ret = PTR_ERR_OR_ZERO(new);
-	if (ret)
-		return ret;
-
-	bch2_cut_front(bkey_start_pos(&orig->k), new);
-	bch2_cut_back(orig->k.p, new);
-
-	struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
-	bkey_for_each_ptr(ptrs, ptr)
-		ptr->unwritten = 0;
-
-	/*
-	 * Note that we're not calling bch2_subvol_get_snapshot() in this path -
-	 * that was done when we kicked off the write, and here it's important
-	 * that we update the extent that we wrote to - even if a snapshot has
-	 * since been created. The write is still outstanding, so we're ok
-	 * w.r.t. snapshot atomicity:
-	 */
-	return  bch2_extent_update_i_size_sectors(trans, iter,
-					min(new->k.p.offset << 9, new_i_size), 0) ?:
-		bch2_trans_update(trans, iter, new,
-				  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
-}
-
-static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct btree_trans *trans = bch2_trans_get(c);
-
-	for_each_keylist_key(&op->insert_keys, orig) {
-		int ret = for_each_btree_key_upto_commit(trans, iter, BTREE_ID_extents,
-				     bkey_start_pos(&orig->k), orig->k.p,
-				     BTREE_ITER_INTENT, k,
-				     NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
-			bch2_nocow_write_convert_one_unwritten(trans, &iter, orig, k, op->new_i_size);
-		}));
-
-		if (ret && !bch2_err_matches(ret, EROFS)) {
-			struct bkey_i *insert = bch2_keylist_front(&op->insert_keys);
-
-			bch_err_inum_offset_ratelimited(c,
-				insert->k.p.inode, insert->k.p.offset << 9,
-				"write error while doing btree update: %s",
-				bch2_err_str(ret));
-		}
-
-		if (ret) {
-			op->error = ret;
-			break;
-		}
-	}
-
-	bch2_trans_put(trans);
-}
-
-static void __bch2_nocow_write_done(struct bch_write_op *op)
-{
-	bch2_nocow_write_unlock(op);
-
-	if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
-		op->error = -EIO;
-	} else if (unlikely(op->flags & BCH_WRITE_CONVERT_UNWRITTEN))
-		bch2_nocow_write_convert_unwritten(op);
-}
-
-static CLOSURE_CALLBACK(bch2_nocow_write_done)
-{
-	closure_type(op, struct bch_write_op, cl);
-
-	__bch2_nocow_write_done(op);
-	bch2_write_done(cl);
-}
-
-struct bucket_to_lock {
-	struct bpos		b;
-	unsigned		gen;
-	struct nocow_lock_bucket *l;
-};
-
-static void bch2_nocow_write(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct btree_trans *trans;
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	DARRAY_PREALLOCATED(struct bucket_to_lock, 3) buckets;
-	u32 snapshot;
-	struct bucket_to_lock *stale_at;
-	int ret;
-
-	if (op->flags & BCH_WRITE_MOVE)
-		return;
-
-	darray_init(&buckets);
-	trans = bch2_trans_get(c);
-retry:
-	bch2_trans_begin(trans);
-
-	ret = bch2_subvolume_get_snapshot(trans, op->subvol, &snapshot);
-	if (unlikely(ret))
-		goto err;
-
-	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
-			     SPOS(op->pos.inode, op->pos.offset, snapshot),
-			     BTREE_ITER_SLOTS);
-	while (1) {
-		struct bio *bio = &op->wbio.bio;
-
-		buckets.nr = 0;
-
-		k = bch2_btree_iter_peek_slot(&iter);
-		ret = bkey_err(k);
-		if (ret)
-			break;
-
-		/* fall back to normal cow write path? */
-		if (unlikely(k.k->p.snapshot != snapshot ||
-			     !bch2_extent_is_writeable(op, k)))
-			break;
-
-		if (bch2_keylist_realloc(&op->insert_keys,
-					 op->inline_keys,
-					 ARRAY_SIZE(op->inline_keys),
-					 k.k->u64s))
-			break;
-
-		/* Get iorefs before dropping btree locks: */
-		struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
-		bkey_for_each_ptr(ptrs, ptr) {
-			struct bpos b = PTR_BUCKET_POS(c, ptr);
-			struct nocow_lock_bucket *l =
-				bucket_nocow_lock(&c->nocow_locks, bucket_to_u64(b));
-			prefetch(l);
-
-			if (unlikely(!bch2_dev_get_ioref(bch_dev_bkey_exists(c, ptr->dev), WRITE)))
-				goto err_get_ioref;
-
-			/* XXX allocating memory with btree locks held - rare */
-			darray_push_gfp(&buckets, ((struct bucket_to_lock) {
-						   .b = b, .gen = ptr->gen, .l = l,
-						   }), GFP_KERNEL|__GFP_NOFAIL);
-
-			if (ptr->unwritten)
-				op->flags |= BCH_WRITE_CONVERT_UNWRITTEN;
-		}
-
-		/* Unlock before taking nocow locks, doing IO: */
-		bkey_reassemble(op->insert_keys.top, k);
-		bch2_trans_unlock(trans);
-
-		bch2_cut_front(op->pos, op->insert_keys.top);
-		if (op->flags & BCH_WRITE_CONVERT_UNWRITTEN)
-			bch2_cut_back(POS(op->pos.inode, op->pos.offset + bio_sectors(bio)), op->insert_keys.top);
-
-		darray_for_each(buckets, i) {
-			struct bch_dev *ca = bch_dev_bkey_exists(c, i->b.inode);
-
-			__bch2_bucket_nocow_lock(&c->nocow_locks, i->l,
-						 bucket_to_u64(i->b),
-						 BUCKET_NOCOW_LOCK_UPDATE);
-
-			rcu_read_lock();
-			bool stale = gen_after(*bucket_gen(ca, i->b.offset), i->gen);
-			rcu_read_unlock();
-
-			if (unlikely(stale)) {
-				stale_at = i;
-				goto err_bucket_stale;
-			}
-		}
-
-		bio = &op->wbio.bio;
-		if (k.k->p.offset < op->pos.offset + bio_sectors(bio)) {
-			bio = bio_split(bio, k.k->p.offset - op->pos.offset,
-					GFP_KERNEL, &c->bio_write);
-			wbio_init(bio)->put_bio = true;
-			bio->bi_opf = op->wbio.bio.bi_opf;
-		} else {
-			op->flags |= BCH_WRITE_DONE;
-		}
-
-		op->pos.offset += bio_sectors(bio);
-		op->written += bio_sectors(bio);
-
-		bio->bi_end_io	= bch2_write_endio;
-		bio->bi_private	= &op->cl;
-		bio->bi_opf |= REQ_OP_WRITE;
-		closure_get(&op->cl);
-		bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
-					  op->insert_keys.top, true);
-
-		bch2_keylist_push(&op->insert_keys);
-		if (op->flags & BCH_WRITE_DONE)
-			break;
-		bch2_btree_iter_advance(&iter);
-	}
-out:
-	bch2_trans_iter_exit(trans, &iter);
-err:
-	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
-		goto retry;
-
-	if (ret) {
-		bch_err_inum_offset_ratelimited(c,
-			op->pos.inode, op->pos.offset << 9,
-			"%s: btree lookup error %s", __func__, bch2_err_str(ret));
-		op->error = ret;
-		op->flags |= BCH_WRITE_DONE;
-	}
-
-	bch2_trans_put(trans);
-	darray_exit(&buckets);
-
-	/* fallback to cow write path? */
-	if (!(op->flags & BCH_WRITE_DONE)) {
-		closure_sync(&op->cl);
-		__bch2_nocow_write_done(op);
-		op->insert_keys.top = op->insert_keys.keys;
-	} else if (op->flags & BCH_WRITE_SYNC) {
-		closure_sync(&op->cl);
-		bch2_nocow_write_done(&op->cl.work);
-	} else {
-		/*
-		 * XXX
-		 * needs to run out of process context because ei_quota_lock is
-		 * a mutex
-		 */
-		continue_at(&op->cl, bch2_nocow_write_done, index_update_wq(op));
-	}
-	return;
-err_get_ioref:
-	darray_for_each(buckets, i)
-		percpu_ref_put(&bch_dev_bkey_exists(c, i->b.inode)->io_ref);
-
-	/* Fall back to COW path: */
-	goto out;
-err_bucket_stale:
-	darray_for_each(buckets, i) {
-		bch2_bucket_nocow_unlock(&c->nocow_locks, i->b, BUCKET_NOCOW_LOCK_UPDATE);
-		if (i == stale_at)
-			break;
-	}
-
-	/* We can retry this: */
-	ret = -BCH_ERR_transaction_restart;
-	goto err_get_ioref;
-}
-
-static void __bch2_write(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct write_point *wp = NULL;
-	struct bio *bio = NULL;
-	unsigned nofs_flags;
-	int ret;
-
-	nofs_flags = memalloc_nofs_save();
-
-	if (unlikely(op->opts.nocow && c->opts.nocow_enabled)) {
-		bch2_nocow_write(op);
-		if (op->flags & BCH_WRITE_DONE)
-			goto out_nofs_restore;
-	}
-again:
-	memset(&op->failed, 0, sizeof(op->failed));
-
-	do {
-		struct bkey_i *key_to_write;
-		unsigned key_to_write_offset = op->insert_keys.top_p -
-			op->insert_keys.keys_p;
-
-		/* +1 for possible cache device: */
-		if (op->open_buckets.nr + op->nr_replicas + 1 >
-		    ARRAY_SIZE(op->open_buckets.v))
-			break;
-
-		if (bch2_keylist_realloc(&op->insert_keys,
-					op->inline_keys,
-					ARRAY_SIZE(op->inline_keys),
-					BKEY_EXTENT_U64s_MAX))
-			break;
-
-		/*
-		 * The copygc thread is now global, which means it's no longer
-		 * freeing up space on specific disks, which means that
-		 * allocations for specific disks may hang arbitrarily long:
-		 */
-		ret = bch2_trans_do(c, NULL, NULL, 0,
-			bch2_alloc_sectors_start_trans(trans,
-				op->target,
-				op->opts.erasure_code && !(op->flags & BCH_WRITE_CACHED),
-				op->write_point,
-				&op->devs_have,
-				op->nr_replicas,
-				op->nr_replicas_required,
-				op->watermark,
-				op->flags,
-				(op->flags & (BCH_WRITE_ALLOC_NOWAIT|
-					      BCH_WRITE_ONLY_SPECIFIED_DEVS))
-				? NULL : &op->cl, &wp));
-		if (unlikely(ret)) {
-			if (bch2_err_matches(ret, BCH_ERR_operation_blocked))
-				break;
-
-			goto err;
-		}
-
-		EBUG_ON(!wp);
-
-		bch2_open_bucket_get(c, wp, &op->open_buckets);
-		ret = bch2_write_extent(op, wp, &bio);
-
-		bch2_alloc_sectors_done_inlined(c, wp);
-err:
-		if (ret <= 0) {
-			op->flags |= BCH_WRITE_DONE;
-
-			if (ret < 0) {
-				bch_err_inum_offset_ratelimited(c,
-					op->pos.inode,
-					op->pos.offset << 9,
-					"%s(): error: %s", __func__, bch2_err_str(ret));
-				op->error = ret;
-				break;
-			}
-		}
-
-		bio->bi_end_io	= bch2_write_endio;
-		bio->bi_private	= &op->cl;
-		bio->bi_opf |= REQ_OP_WRITE;
-
-		closure_get(bio->bi_private);
-
-		key_to_write = (void *) (op->insert_keys.keys_p +
-					 key_to_write_offset);
-
-		bch2_submit_wbio_replicas(to_wbio(bio), c, BCH_DATA_user,
-					  key_to_write, false);
-	} while (ret);
-
-	/*
-	 * Sync or no?
-	 *
-	 * If we're running asynchronously, wne may still want to block
-	 * synchronously here if we weren't able to submit all of the IO at
-	 * once, as that signals backpressure to the caller.
-	 */
-	if ((op->flags & BCH_WRITE_SYNC) ||
-	    (!(op->flags & BCH_WRITE_DONE) &&
-	     !(op->flags & BCH_WRITE_IN_WORKER))) {
-		closure_sync(&op->cl);
-		__bch2_write_index(op);
-
-		if (!(op->flags & BCH_WRITE_DONE))
-			goto again;
-		bch2_write_done(&op->cl);
-	} else {
-		bch2_write_queue(op, wp);
-		continue_at(&op->cl, bch2_write_index, NULL);
-	}
-out_nofs_restore:
-	memalloc_nofs_restore(nofs_flags);
-}
-
-static void bch2_write_data_inline(struct bch_write_op *op, unsigned data_len)
-{
-	struct bio *bio = &op->wbio.bio;
-	struct bvec_iter iter;
-	struct bkey_i_inline_data *id;
-	unsigned sectors;
-	int ret;
-
-	op->flags |= BCH_WRITE_WROTE_DATA_INLINE;
-	op->flags |= BCH_WRITE_DONE;
-
-	bch2_check_set_feature(op->c, BCH_FEATURE_inline_data);
-
-	ret = bch2_keylist_realloc(&op->insert_keys, op->inline_keys,
-				   ARRAY_SIZE(op->inline_keys),
-				   BKEY_U64s + DIV_ROUND_UP(data_len, 8));
-	if (ret) {
-		op->error = ret;
-		goto err;
-	}
-
-	sectors = bio_sectors(bio);
-	op->pos.offset += sectors;
-
-	id = bkey_inline_data_init(op->insert_keys.top);
-	id->k.p		= op->pos;
-	id->k.version	= op->version;
-	id->k.size	= sectors;
-
-	iter = bio->bi_iter;
-	iter.bi_size = data_len;
-	memcpy_from_bio(id->v.data, bio, iter);
-
-	while (data_len & 7)
-		id->v.data[data_len++] = '\0';
-	set_bkey_val_bytes(&id->k, data_len);
-	bch2_keylist_push(&op->insert_keys);
-
-	__bch2_write_index(op);
-err:
-	bch2_write_done(&op->cl);
-}
-
-/**
- * bch2_write() - handle a write to a cache device or flash only volume
- * @cl:		&bch_write_op->cl
- *
- * This is the starting point for any data to end up in a cache device; it could
- * be from a normal write, or a writeback write, or a write to a flash only
- * volume - it's also used by the moving garbage collector to compact data in
- * mostly empty buckets.
- *
- * It first writes the data to the cache, creating a list of keys to be inserted
- * (if the data won't fit in a single open bucket, there will be multiple keys);
- * after the data is written it calls bch_journal, and after the keys have been
- * added to the next journal write they're inserted into the btree.
- *
- * If op->discard is true, instead of inserting the data it invalidates the
- * region of the cache represented by op->bio and op->inode.
- */
-CLOSURE_CALLBACK(bch2_write)
-{
-	closure_type(op, struct bch_write_op, cl);
-	struct bio *bio = &op->wbio.bio;
-	struct bch_fs *c = op->c;
-	unsigned data_len;
-
-	EBUG_ON(op->cl.parent);
-	BUG_ON(!op->nr_replicas);
-	BUG_ON(!op->write_point.v);
-	BUG_ON(bkey_eq(op->pos, POS_MAX));
-
-	op->start_time = local_clock();
-	bch2_keylist_init(&op->insert_keys, op->inline_keys);
-	wbio_init(bio)->put_bio = false;
-
-	if (bio->bi_iter.bi_size & (c->opts.block_size - 1)) {
-		bch_err_inum_offset_ratelimited(c,
-			op->pos.inode,
-			op->pos.offset << 9,
-			"misaligned write");
-		op->error = -EIO;
-		goto err;
-	}
-
-	if (c->opts.nochanges) {
-		op->error = -BCH_ERR_erofs_no_writes;
-		goto err;
-	}
-
-	if (!(op->flags & BCH_WRITE_MOVE) &&
-	    !bch2_write_ref_tryget(c, BCH_WRITE_REF_write)) {
-		op->error = -BCH_ERR_erofs_no_writes;
-		goto err;
-	}
-
-	this_cpu_add(c->counters[BCH_COUNTER_io_write], bio_sectors(bio));
-	bch2_increment_clock(c, bio_sectors(bio), WRITE);
-
-	data_len = min_t(u64, bio->bi_iter.bi_size,
-			 op->new_i_size - (op->pos.offset << 9));
-
-	if (c->opts.inline_data &&
-	    data_len <= min(block_bytes(c) / 2, 1024U)) {
-		bch2_write_data_inline(op, data_len);
-		return;
-	}
-
-	__bch2_write(op);
-	return;
-err:
-	bch2_disk_reservation_put(c, &op->res);
-
-	closure_debug_destroy(&op->cl);
-	if (op->end_io)
-		op->end_io(op);
-}
-
-static const char * const bch2_write_flags[] = {
-#define x(f)	#f,
-	BCH_WRITE_FLAGS()
-#undef x
-	NULL
-};
-
-void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
-{
-	prt_str(out, "pos: ");
-	bch2_bpos_to_text(out, op->pos);
-	prt_newline(out);
-	printbuf_indent_add(out, 2);
-
-	prt_str(out, "started: ");
-	bch2_pr_time_units(out, local_clock() - op->start_time);
-	prt_newline(out);
-
-	prt_str(out, "flags: ");
-	prt_bitflags(out, bch2_write_flags, op->flags);
-	prt_newline(out);
-
-	prt_printf(out, "ref: %u", closure_nr_remaining(&op->cl));
-	prt_newline(out);
-
-	printbuf_indent_sub(out, 2);
-}
-
-void bch2_fs_io_write_exit(struct bch_fs *c)
-{
-	mempool_exit(&c->bio_bounce_pages);
-	bioset_exit(&c->bio_write);
-}
-
-int bch2_fs_io_write_init(struct bch_fs *c)
-{
-	if (bioset_init(&c->bio_write, 1, offsetof(struct bch_write_bio, bio),
-			BIOSET_NEED_BVECS))
-		return -BCH_ERR_ENOMEM_bio_write_init;
-
-	if (mempool_init_page_pool(&c->bio_bounce_pages,
-				   max_t(unsigned,
-					 c->opts.btree_node_size,
-					 c->opts.encoded_extent_max) /
-				   PAGE_SIZE, 0))
-		return -BCH_ERR_ENOMEM_bio_bounce_pages_init;
-
-	return 0;
-}