Adding upstream version 6.7.7.upstream/6.7.7

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1154 insertions, 0 deletions

diff --git a/fs/bcachefs/move.c b/fs/bcachefs/move.c
new file mode 100644
index 0000000000..f3dac4511a
--- /dev/null
+++ b/fs/bcachefs/move.c
@@ -0,0 +1,1154 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "alloc_background.h"
+#include "alloc_foreground.h"
+#include "backpointers.h"
+#include "bkey_buf.h"
+#include "btree_gc.h"
+#include "btree_update.h"
+#include "btree_update_interior.h"
+#include "btree_write_buffer.h"
+#include "disk_groups.h"
+#include "ec.h"
+#include "errcode.h"
+#include "error.h"
+#include "inode.h"
+#include "io_read.h"
+#include "io_write.h"
+#include "journal_reclaim.h"
+#include "keylist.h"
+#include "move.h"
+#include "replicas.h"
+#include "snapshot.h"
+#include "super-io.h"
+#include "trace.h"
+
+#include <linux/ioprio.h>
+#include <linux/kthread.h>
+
+static void trace_move_extent2(struct bch_fs *c, struct bkey_s_c k)
+{
+	if (trace_move_extent_enabled()) {
+		struct printbuf buf = PRINTBUF;
+
+		bch2_bkey_val_to_text(&buf, c, k);
+		trace_move_extent(c, buf.buf);
+		printbuf_exit(&buf);
+	}
+}
+
+static void trace_move_extent_read2(struct bch_fs *c, struct bkey_s_c k)
+{
+	if (trace_move_extent_read_enabled()) {
+		struct printbuf buf = PRINTBUF;
+
+		bch2_bkey_val_to_text(&buf, c, k);
+		trace_move_extent_read(c, buf.buf);
+		printbuf_exit(&buf);
+	}
+}
+
+struct moving_io {
+	struct list_head		read_list;
+	struct list_head		io_list;
+	struct move_bucket_in_flight	*b;
+	struct closure			cl;
+	bool				read_completed;
+
+	unsigned			read_sectors;
+	unsigned			write_sectors;
+
+	struct bch_read_bio		rbio;
+
+	struct data_update		write;
+	/* Must be last since it is variable size */
+	struct bio_vec			bi_inline_vecs[0];
+};
+
+static void move_free(struct moving_io *io)
+{
+	struct moving_context *ctxt = io->write.ctxt;
+
+	if (io->b)
+		atomic_dec(&io->b->count);
+
+	bch2_data_update_exit(&io->write);
+
+	mutex_lock(&ctxt->lock);
+	list_del(&io->io_list);
+	wake_up(&ctxt->wait);
+	mutex_unlock(&ctxt->lock);
+
+	kfree(io);
+}
+
+static void move_write_done(struct bch_write_op *op)
+{
+	struct moving_io *io = container_of(op, struct moving_io, write.op);
+	struct moving_context *ctxt = io->write.ctxt;
+
+	if (io->write.op.error)
+		ctxt->write_error = true;
+
+	atomic_sub(io->write_sectors, &io->write.ctxt->write_sectors);
+	atomic_dec(&io->write.ctxt->write_ios);
+	move_free(io);
+	closure_put(&ctxt->cl);
+}
+
+static void move_write(struct moving_io *io)
+{
+	if (unlikely(io->rbio.bio.bi_status || io->rbio.hole)) {
+		move_free(io);
+		return;
+	}
+
+	closure_get(&io->write.ctxt->cl);
+	atomic_add(io->write_sectors, &io->write.ctxt->write_sectors);
+	atomic_inc(&io->write.ctxt->write_ios);
+
+	bch2_data_update_read_done(&io->write, io->rbio.pick.crc);
+}
+
+struct moving_io *bch2_moving_ctxt_next_pending_write(struct moving_context *ctxt)
+{
+	struct moving_io *io =
+		list_first_entry_or_null(&ctxt->reads, struct moving_io, read_list);
+
+	return io && io->read_completed ? io : NULL;
+}
+
+static void move_read_endio(struct bio *bio)
+{
+	struct moving_io *io = container_of(bio, struct moving_io, rbio.bio);
+	struct moving_context *ctxt = io->write.ctxt;
+
+	atomic_sub(io->read_sectors, &ctxt->read_sectors);
+	atomic_dec(&ctxt->read_ios);
+	io->read_completed = true;
+
+	wake_up(&ctxt->wait);
+	closure_put(&ctxt->cl);
+}
+
+void bch2_moving_ctxt_do_pending_writes(struct moving_context *ctxt)
+{
+	struct moving_io *io;
+
+	while ((io = bch2_moving_ctxt_next_pending_write(ctxt))) {
+		bch2_trans_unlock_long(ctxt->trans);
+		list_del(&io->read_list);
+		move_write(io);
+	}
+}
+
+void bch2_move_ctxt_wait_for_io(struct moving_context *ctxt)
+{
+	unsigned sectors_pending = atomic_read(&ctxt->write_sectors);
+
+	move_ctxt_wait_event(ctxt,
+		!atomic_read(&ctxt->write_sectors) ||
+		atomic_read(&ctxt->write_sectors) != sectors_pending);
+}
+
+void bch2_moving_ctxt_flush_all(struct moving_context *ctxt)
+{
+	move_ctxt_wait_event(ctxt, list_empty(&ctxt->reads));
+	bch2_trans_unlock_long(ctxt->trans);
+	closure_sync(&ctxt->cl);
+}
+
+void bch2_moving_ctxt_exit(struct moving_context *ctxt)
+{
+	struct bch_fs *c = ctxt->trans->c;
+
+	bch2_moving_ctxt_flush_all(ctxt);
+
+	EBUG_ON(atomic_read(&ctxt->write_sectors));
+	EBUG_ON(atomic_read(&ctxt->write_ios));
+	EBUG_ON(atomic_read(&ctxt->read_sectors));
+	EBUG_ON(atomic_read(&ctxt->read_ios));
+
+	mutex_lock(&c->moving_context_lock);
+	list_del(&ctxt->list);
+	mutex_unlock(&c->moving_context_lock);
+
+	bch2_trans_put(ctxt->trans);
+	memset(ctxt, 0, sizeof(*ctxt));
+}
+
+void bch2_moving_ctxt_init(struct moving_context *ctxt,
+			   struct bch_fs *c,
+			   struct bch_ratelimit *rate,
+			   struct bch_move_stats *stats,
+			   struct write_point_specifier wp,
+			   bool wait_on_copygc)
+{
+	memset(ctxt, 0, sizeof(*ctxt));
+
+	ctxt->trans	= bch2_trans_get(c);
+	ctxt->fn	= (void *) _RET_IP_;
+	ctxt->rate	= rate;
+	ctxt->stats	= stats;
+	ctxt->wp	= wp;
+	ctxt->wait_on_copygc = wait_on_copygc;
+
+	closure_init_stack(&ctxt->cl);
+
+	mutex_init(&ctxt->lock);
+	INIT_LIST_HEAD(&ctxt->reads);
+	INIT_LIST_HEAD(&ctxt->ios);
+	init_waitqueue_head(&ctxt->wait);
+
+	mutex_lock(&c->moving_context_lock);
+	list_add(&ctxt->list, &c->moving_context_list);
+	mutex_unlock(&c->moving_context_lock);
+}
+
+void bch2_move_stats_exit(struct bch_move_stats *stats, struct bch_fs *c)
+{
+	trace_move_data(c, stats);
+}
+
+void bch2_move_stats_init(struct bch_move_stats *stats, char *name)
+{
+	memset(stats, 0, sizeof(*stats));
+	stats->data_type = BCH_DATA_user;
+	scnprintf(stats->name, sizeof(stats->name), "%s", name);
+}
+
+int bch2_move_extent(struct moving_context *ctxt,
+		     struct move_bucket_in_flight *bucket_in_flight,
+		     struct btree_iter *iter,
+		     struct bkey_s_c k,
+		     struct bch_io_opts io_opts,
+		     struct data_update_opts data_opts)
+{
+	struct btree_trans *trans = ctxt->trans;
+	struct bch_fs *c = trans->c;
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+	struct moving_io *io;
+	const union bch_extent_entry *entry;
+	struct extent_ptr_decoded p;
+	unsigned sectors = k.k->size, pages;
+	int ret = -ENOMEM;
+
+	if (ctxt->stats)
+		ctxt->stats->pos = BBPOS(iter->btree_id, iter->pos);
+	trace_move_extent2(c, k);
+
+	bch2_data_update_opts_normalize(k, &data_opts);
+
+	if (!data_opts.rewrite_ptrs &&
+	    !data_opts.extra_replicas) {
+		if (data_opts.kill_ptrs)
+			return bch2_extent_drop_ptrs(trans, iter, k, data_opts);
+		return 0;
+	}
+
+	/*
+	 * Before memory allocations & taking nocow locks in
+	 * bch2_data_update_init():
+	 */
+	bch2_trans_unlock(trans);
+
+	/* write path might have to decompress data: */
+	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
+		sectors = max_t(unsigned, sectors, p.crc.uncompressed_size);
+
+	pages = DIV_ROUND_UP(sectors, PAGE_SECTORS);
+	io = kzalloc(sizeof(struct moving_io) +
+		     sizeof(struct bio_vec) * pages, GFP_KERNEL);
+	if (!io)
+		goto err;
+
+	INIT_LIST_HEAD(&io->io_list);
+	io->write.ctxt		= ctxt;
+	io->read_sectors	= k.k->size;
+	io->write_sectors	= k.k->size;
+
+	bio_init(&io->write.op.wbio.bio, NULL, io->bi_inline_vecs, pages, 0);
+	bio_set_prio(&io->write.op.wbio.bio,
+		     IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
+
+	if (bch2_bio_alloc_pages(&io->write.op.wbio.bio, sectors << 9,
+				 GFP_KERNEL))
+		goto err_free;
+
+	io->rbio.c		= c;
+	io->rbio.opts		= io_opts;
+	bio_init(&io->rbio.bio, NULL, io->bi_inline_vecs, pages, 0);
+	io->rbio.bio.bi_vcnt = pages;
+	bio_set_prio(&io->rbio.bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
+	io->rbio.bio.bi_iter.bi_size = sectors << 9;
+
+	io->rbio.bio.bi_opf		= REQ_OP_READ;
+	io->rbio.bio.bi_iter.bi_sector	= bkey_start_offset(k.k);
+	io->rbio.bio.bi_end_io		= move_read_endio;
+
+	ret = bch2_data_update_init(trans, iter, ctxt, &io->write, ctxt->wp,
+				    io_opts, data_opts, iter->btree_id, k);
+	if (ret)
+		goto err_free_pages;
+
+	io->write.op.end_io = move_write_done;
+
+	if (ctxt->rate)
+		bch2_ratelimit_increment(ctxt->rate, k.k->size);
+
+	if (ctxt->stats) {
+		atomic64_inc(&ctxt->stats->keys_moved);
+		atomic64_add(k.k->size, &ctxt->stats->sectors_moved);
+	}
+
+	if (bucket_in_flight) {
+		io->b = bucket_in_flight;
+		atomic_inc(&io->b->count);
+	}
+
+	this_cpu_add(c->counters[BCH_COUNTER_io_move], k.k->size);
+	this_cpu_add(c->counters[BCH_COUNTER_move_extent_read], k.k->size);
+	trace_move_extent_read2(c, k);
+
+	mutex_lock(&ctxt->lock);
+	atomic_add(io->read_sectors, &ctxt->read_sectors);
+	atomic_inc(&ctxt->read_ios);
+
+	list_add_tail(&io->read_list, &ctxt->reads);
+	list_add_tail(&io->io_list, &ctxt->ios);
+	mutex_unlock(&ctxt->lock);
+
+	/*
+	 * dropped by move_read_endio() - guards against use after free of
+	 * ctxt when doing wakeup
+	 */
+	closure_get(&ctxt->cl);
+	bch2_read_extent(trans, &io->rbio,
+			 bkey_start_pos(k.k),
+			 iter->btree_id, k, 0,
+			 BCH_READ_NODECODE|
+			 BCH_READ_LAST_FRAGMENT);
+	return 0;
+err_free_pages:
+	bio_free_pages(&io->write.op.wbio.bio);
+err_free:
+	kfree(io);
+err:
+	if (ret == -BCH_ERR_data_update_done)
+		return 0;
+
+	if (bch2_err_matches(ret, EROFS) ||
+	    bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		return ret;
+
+	this_cpu_inc(c->counters[BCH_COUNTER_move_extent_start_fail]);
+	if (trace_move_extent_start_fail_enabled()) {
+		struct printbuf buf = PRINTBUF;
+
+		bch2_bkey_val_to_text(&buf, c, k);
+		prt_str(&buf, ": ");
+		prt_str(&buf, bch2_err_str(ret));
+		trace_move_extent_start_fail(c, buf.buf);
+		printbuf_exit(&buf);
+	}
+	return ret;
+}
+
+struct bch_io_opts *bch2_move_get_io_opts(struct btree_trans *trans,
+			  struct per_snapshot_io_opts *io_opts,
+			  struct bkey_s_c extent_k)
+{
+	struct bch_fs *c = trans->c;
+	u32 restart_count = trans->restart_count;
+	int ret = 0;
+
+	if (io_opts->cur_inum != extent_k.k->p.inode) {
+		struct btree_iter iter;
+		struct bkey_s_c k;
+
+		io_opts->d.nr = 0;
+
+		for_each_btree_key(trans, iter, BTREE_ID_inodes, POS(0, extent_k.k->p.inode),
+				   BTREE_ITER_ALL_SNAPSHOTS, k, ret) {
+			if (k.k->p.offset != extent_k.k->p.inode)
+				break;
+
+			if (!bkey_is_inode(k.k))
+				continue;
+
+			struct bch_inode_unpacked inode;
+			BUG_ON(bch2_inode_unpack(k, &inode));
+
+			struct snapshot_io_opts_entry e = { .snapshot = k.k->p.snapshot };
+			bch2_inode_opts_get(&e.io_opts, trans->c, &inode);
+
+			ret = darray_push(&io_opts->d, e);
+			if (ret)
+				break;
+		}
+		bch2_trans_iter_exit(trans, &iter);
+		io_opts->cur_inum = extent_k.k->p.inode;
+	}
+
+	ret = ret ?: trans_was_restarted(trans, restart_count);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (extent_k.k->p.snapshot) {
+		struct snapshot_io_opts_entry *i;
+		darray_for_each(io_opts->d, i)
+			if (bch2_snapshot_is_ancestor(c, extent_k.k->p.snapshot, i->snapshot))
+				return &i->io_opts;
+	}
+
+	return &io_opts->fs_io_opts;
+}
+
+int bch2_move_get_io_opts_one(struct btree_trans *trans,
+			      struct bch_io_opts *io_opts,
+			      struct bkey_s_c extent_k)
+{
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	int ret;
+
+	/* reflink btree? */
+	if (!extent_k.k->p.inode) {
+		*io_opts = bch2_opts_to_inode_opts(trans->c->opts);
+		return 0;
+	}
+
+	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
+			       SPOS(0, extent_k.k->p.inode, extent_k.k->p.snapshot),
+			       BTREE_ITER_CACHED);
+	ret = bkey_err(k);
+	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		return ret;
+
+	if (!ret && bkey_is_inode(k.k)) {
+		struct bch_inode_unpacked inode;
+		bch2_inode_unpack(k, &inode);
+		bch2_inode_opts_get(io_opts, trans->c, &inode);
+	} else {
+		*io_opts = bch2_opts_to_inode_opts(trans->c->opts);
+	}
+
+	bch2_trans_iter_exit(trans, &iter);
+	return 0;
+}
+
+int bch2_move_ratelimit(struct moving_context *ctxt)
+{
+	struct bch_fs *c = ctxt->trans->c;
+	bool is_kthread = current->flags & PF_KTHREAD;
+	u64 delay;
+
+	if (ctxt->wait_on_copygc && c->copygc_running) {
+		bch2_moving_ctxt_flush_all(ctxt);
+		wait_event_killable(c->copygc_running_wq,
+				    !c->copygc_running ||
+				    (is_kthread && kthread_should_stop()));
+	}
+
+	do {
+		delay = ctxt->rate ? bch2_ratelimit_delay(ctxt->rate) : 0;
+
+		if (is_kthread && kthread_should_stop())
+			return 1;
+
+		if (delay)
+			move_ctxt_wait_event_timeout(ctxt,
+					freezing(current) ||
+					(is_kthread && kthread_should_stop()),
+					delay);
+
+		if (unlikely(freezing(current))) {
+			bch2_moving_ctxt_flush_all(ctxt);
+			try_to_freeze();
+		}
+	} while (delay);
+
+	/*
+	 * XXX: these limits really ought to be per device, SSDs and hard drives
+	 * will want different limits
+	 */
+	move_ctxt_wait_event(ctxt,
+		atomic_read(&ctxt->write_sectors) < c->opts.move_bytes_in_flight >> 9 &&
+		atomic_read(&ctxt->read_sectors) < c->opts.move_bytes_in_flight >> 9 &&
+		atomic_read(&ctxt->write_ios) < c->opts.move_ios_in_flight &&
+		atomic_read(&ctxt->read_ios) < c->opts.move_ios_in_flight);
+
+	return 0;
+}
+
+static int bch2_move_data_btree(struct moving_context *ctxt,
+				struct bpos start,
+				struct bpos end,
+				move_pred_fn pred, void *arg,
+				enum btree_id btree_id)
+{
+	struct btree_trans *trans = ctxt->trans;
+	struct bch_fs *c = trans->c;
+	struct per_snapshot_io_opts snapshot_io_opts;
+	struct bch_io_opts *io_opts;
+	struct bkey_buf sk;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	struct data_update_opts data_opts;
+	int ret = 0, ret2;
+
+	per_snapshot_io_opts_init(&snapshot_io_opts, c);
+	bch2_bkey_buf_init(&sk);
+
+	if (ctxt->stats) {
+		ctxt->stats->data_type	= BCH_DATA_user;
+		ctxt->stats->pos	= BBPOS(btree_id, start);
+	}
+
+	bch2_trans_iter_init(trans, &iter, btree_id, start,
+			     BTREE_ITER_PREFETCH|
+			     BTREE_ITER_ALL_SNAPSHOTS);
+
+	if (ctxt->rate)
+		bch2_ratelimit_reset(ctxt->rate);
+
+	while (!bch2_move_ratelimit(ctxt)) {
+		bch2_trans_begin(trans);
+
+		k = bch2_btree_iter_peek(&iter);
+		if (!k.k)
+			break;
+
+		ret = bkey_err(k);
+		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+			continue;
+		if (ret)
+			break;
+
+		if (bkey_ge(bkey_start_pos(k.k), end))
+			break;
+
+		if (ctxt->stats)
+			ctxt->stats->pos = BBPOS(iter.btree_id, iter.pos);
+
+		if (!bkey_extent_is_direct_data(k.k))
+			goto next_nondata;
+
+		io_opts = bch2_move_get_io_opts(trans, &snapshot_io_opts, k);
+		ret = PTR_ERR_OR_ZERO(io_opts);
+		if (ret)
+			continue;
+
+		memset(&data_opts, 0, sizeof(data_opts));
+		if (!pred(c, arg, k, io_opts, &data_opts))
+			goto next;
+
+		/*
+		 * The iterator gets unlocked by __bch2_read_extent - need to
+		 * save a copy of @k elsewhere:
+		 */
+		bch2_bkey_buf_reassemble(&sk, c, k);
+		k = bkey_i_to_s_c(sk.k);
+
+		ret2 = bch2_move_extent(ctxt, NULL, &iter, k, *io_opts, data_opts);
+		if (ret2) {
+			if (bch2_err_matches(ret2, BCH_ERR_transaction_restart))
+				continue;
+
+			if (ret2 == -ENOMEM) {
+				/* memory allocation failure, wait for some IO to finish */
+				bch2_move_ctxt_wait_for_io(ctxt);
+				continue;
+			}
+
+			/* XXX signal failure */
+			goto next;
+		}
+next:
+		if (ctxt->stats)
+			atomic64_add(k.k->size, &ctxt->stats->sectors_seen);
+next_nondata:
+		bch2_btree_iter_advance(&iter);
+	}
+
+	bch2_trans_iter_exit(trans, &iter);
+	bch2_bkey_buf_exit(&sk, c);
+	per_snapshot_io_opts_exit(&snapshot_io_opts);
+
+	return ret;
+}
+
+int __bch2_move_data(struct moving_context *ctxt,
+		     struct bbpos start,
+		     struct bbpos end,
+		     move_pred_fn pred, void *arg)
+{
+	struct bch_fs *c = ctxt->trans->c;
+	enum btree_id id;
+	int ret = 0;
+
+	for (id = start.btree;
+	     id <= min_t(unsigned, end.btree, btree_id_nr_alive(c) - 1);
+	     id++) {
+		ctxt->stats->pos = BBPOS(id, POS_MIN);
+
+		if (!btree_type_has_ptrs(id) ||
+		    !bch2_btree_id_root(c, id)->b)
+			continue;
+
+		ret = bch2_move_data_btree(ctxt,
+				       id == start.btree ? start.pos : POS_MIN,
+				       id == end.btree   ? end.pos   : POS_MAX,
+				       pred, arg, id);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+int bch2_move_data(struct bch_fs *c,
+		   struct bbpos start,
+		   struct bbpos end,
+		   struct bch_ratelimit *rate,
+		   struct bch_move_stats *stats,
+		   struct write_point_specifier wp,
+		   bool wait_on_copygc,
+		   move_pred_fn pred, void *arg)
+{
+
+	struct moving_context ctxt;
+	int ret;
+
+	bch2_moving_ctxt_init(&ctxt, c, rate, stats, wp, wait_on_copygc);
+	ret = __bch2_move_data(&ctxt, start, end, pred, arg);
+	bch2_moving_ctxt_exit(&ctxt);
+
+	return ret;
+}
+
+int __bch2_evacuate_bucket(struct moving_context *ctxt,
+			   struct move_bucket_in_flight *bucket_in_flight,
+			   struct bpos bucket, int gen,
+			   struct data_update_opts _data_opts)
+{
+	struct btree_trans *trans = ctxt->trans;
+	struct bch_fs *c = trans->c;
+	bool is_kthread = current->flags & PF_KTHREAD;
+	struct bch_io_opts io_opts = bch2_opts_to_inode_opts(c->opts);
+	struct btree_iter iter;
+	struct bkey_buf sk;
+	struct bch_backpointer bp;
+	struct bch_alloc_v4 a_convert;
+	const struct bch_alloc_v4 *a;
+	struct bkey_s_c k;
+	struct data_update_opts data_opts;
+	unsigned dirty_sectors, bucket_size;
+	u64 fragmentation;
+	struct bpos bp_pos = POS_MIN;
+	int ret = 0;
+
+	trace_bucket_evacuate(c, &bucket);
+
+	bch2_bkey_buf_init(&sk);
+
+	/*
+	 * We're not run in a context that handles transaction restarts:
+	 */
+	bch2_trans_begin(trans);
+
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
+			     bucket, BTREE_ITER_CACHED);
+	ret = lockrestart_do(trans,
+			bkey_err(k = bch2_btree_iter_peek_slot(&iter)));
+	bch2_trans_iter_exit(trans, &iter);
+
+	if (ret) {
+		bch_err_msg(c, ret, "looking up alloc key");
+		goto err;
+	}
+
+	a = bch2_alloc_to_v4(k, &a_convert);
+	dirty_sectors = a->dirty_sectors;
+	bucket_size = bch_dev_bkey_exists(c, bucket.inode)->mi.bucket_size;
+	fragmentation = a->fragmentation_lru;
+
+	ret = bch2_btree_write_buffer_flush(trans);
+	if (ret) {
+		bch_err_msg(c, ret, "flushing btree write buffer");
+		goto err;
+	}
+
+	while (!(ret = bch2_move_ratelimit(ctxt))) {
+		if (is_kthread && kthread_should_stop())
+			break;
+
+		bch2_trans_begin(trans);
+
+		ret = bch2_get_next_backpointer(trans, bucket, gen,
+						&bp_pos, &bp,
+						BTREE_ITER_CACHED);
+		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+			continue;
+		if (ret)
+			goto err;
+		if (bkey_eq(bp_pos, POS_MAX))
+			break;
+
+		if (!bp.level) {
+			const struct bch_extent_ptr *ptr;
+			unsigned i = 0;
+
+			k = bch2_backpointer_get_key(trans, &iter, bp_pos, bp, 0);
+			ret = bkey_err(k);
+			if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+				continue;
+			if (ret)
+				goto err;
+			if (!k.k)
+				goto next;
+
+			bch2_bkey_buf_reassemble(&sk, c, k);
+			k = bkey_i_to_s_c(sk.k);
+
+			ret = bch2_move_get_io_opts_one(trans, &io_opts, k);
+			if (ret) {
+				bch2_trans_iter_exit(trans, &iter);
+				continue;
+			}
+
+			data_opts = _data_opts;
+			data_opts.target	= io_opts.background_target;
+			data_opts.rewrite_ptrs = 0;
+
+			bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr) {
+				if (ptr->dev == bucket.inode) {
+					data_opts.rewrite_ptrs |= 1U << i;
+					if (ptr->cached) {
+						bch2_trans_iter_exit(trans, &iter);
+						goto next;
+					}
+				}
+				i++;
+			}
+
+			ret = bch2_move_extent(ctxt, bucket_in_flight,
+					       &iter, k, io_opts, data_opts);
+			bch2_trans_iter_exit(trans, &iter);
+
+			if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+				continue;
+			if (ret == -ENOMEM) {
+				/* memory allocation failure, wait for some IO to finish */
+				bch2_move_ctxt_wait_for_io(ctxt);
+				continue;
+			}
+			if (ret)
+				goto err;
+
+			if (ctxt->stats)
+				atomic64_add(k.k->size, &ctxt->stats->sectors_seen);
+		} else {
+			struct btree *b;
+
+			b = bch2_backpointer_get_node(trans, &iter, bp_pos, bp);
+			ret = PTR_ERR_OR_ZERO(b);
+			if (ret == -BCH_ERR_backpointer_to_overwritten_btree_node)
+				continue;
+			if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+				continue;
+			if (ret)
+				goto err;
+			if (!b)
+				goto next;
+
+			ret = bch2_btree_node_rewrite(trans, &iter, b, 0);
+			bch2_trans_iter_exit(trans, &iter);
+
+			if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+				continue;
+			if (ret)
+				goto err;
+
+			if (ctxt->rate)
+				bch2_ratelimit_increment(ctxt->rate,
+							 c->opts.btree_node_size >> 9);
+			if (ctxt->stats) {
+				atomic64_add(c->opts.btree_node_size >> 9, &ctxt->stats->sectors_seen);
+				atomic64_add(c->opts.btree_node_size >> 9, &ctxt->stats->sectors_moved);
+			}
+		}
+next:
+		bp_pos = bpos_nosnap_successor(bp_pos);
+	}
+
+	trace_evacuate_bucket(c, &bucket, dirty_sectors, bucket_size, fragmentation, ret);
+err:
+	bch2_bkey_buf_exit(&sk, c);
+	return ret;
+}
+
+int bch2_evacuate_bucket(struct bch_fs *c,
+			 struct bpos bucket, int gen,
+			 struct data_update_opts data_opts,
+			 struct bch_ratelimit *rate,
+			 struct bch_move_stats *stats,
+			 struct write_point_specifier wp,
+			 bool wait_on_copygc)
+{
+	struct moving_context ctxt;
+	int ret;
+
+	bch2_moving_ctxt_init(&ctxt, c, rate, stats, wp, wait_on_copygc);
+	ret = __bch2_evacuate_bucket(&ctxt, NULL, bucket, gen, data_opts);
+	bch2_moving_ctxt_exit(&ctxt);
+
+	return ret;
+}
+
+typedef bool (*move_btree_pred)(struct bch_fs *, void *,
+				struct btree *, struct bch_io_opts *,
+				struct data_update_opts *);
+
+static int bch2_move_btree(struct bch_fs *c,
+			   enum btree_id start_btree_id, struct bpos start_pos,
+			   enum btree_id end_btree_id,   struct bpos end_pos,
+			   move_btree_pred pred, void *arg,
+			   struct bch_move_stats *stats)
+{
+	bool kthread = (current->flags & PF_KTHREAD) != 0;
+	struct bch_io_opts io_opts = bch2_opts_to_inode_opts(c->opts);
+	struct moving_context ctxt;
+	struct btree_trans *trans;
+	struct btree_iter iter;
+	struct btree *b;
+	enum btree_id id;
+	struct data_update_opts data_opts;
+	int ret = 0;
+
+	bch2_moving_ctxt_init(&ctxt, c, NULL, stats,
+			      writepoint_ptr(&c->btree_write_point),
+			      true);
+	trans = ctxt.trans;
+
+	stats->data_type = BCH_DATA_btree;
+
+	for (id = start_btree_id;
+	     id <= min_t(unsigned, end_btree_id, btree_id_nr_alive(c) - 1);
+	     id++) {
+		stats->pos = BBPOS(id, POS_MIN);
+
+		if (!bch2_btree_id_root(c, id)->b)
+			continue;
+
+		bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
+					  BTREE_ITER_PREFETCH);
+retry:
+		ret = 0;
+		while (bch2_trans_begin(trans),
+		       (b = bch2_btree_iter_peek_node(&iter)) &&
+		       !(ret = PTR_ERR_OR_ZERO(b))) {
+			if (kthread && kthread_should_stop())
+				break;
+
+			if ((cmp_int(id, end_btree_id) ?:
+			     bpos_cmp(b->key.k.p, end_pos)) > 0)
+				break;
+
+			stats->pos = BBPOS(iter.btree_id, iter.pos);
+
+			if (!pred(c, arg, b, &io_opts, &data_opts))
+				goto next;
+
+			ret = bch2_btree_node_rewrite(trans, &iter, b, 0) ?: ret;
+			if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+				continue;
+			if (ret)
+				break;
+next:
+			bch2_btree_iter_next_node(&iter);
+		}
+		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+			goto retry;
+
+		bch2_trans_iter_exit(trans, &iter);
+
+		if (kthread && kthread_should_stop())
+			break;
+	}
+
+	bch_err_fn(c, ret);
+	bch2_moving_ctxt_exit(&ctxt);
+	bch2_btree_interior_updates_flush(c);
+
+	return ret;
+}
+
+static bool rereplicate_pred(struct bch_fs *c, void *arg,
+			     struct bkey_s_c k,
+			     struct bch_io_opts *io_opts,
+			     struct data_update_opts *data_opts)
+{
+	unsigned nr_good = bch2_bkey_durability(c, k);
+	unsigned replicas = bkey_is_btree_ptr(k.k)
+		? c->opts.metadata_replicas
+		: io_opts->data_replicas;
+
+	if (!nr_good || nr_good >= replicas)
+		return false;
+
+	data_opts->target		= 0;
+	data_opts->extra_replicas	= replicas - nr_good;
+	data_opts->btree_insert_flags	= 0;
+	return true;
+}
+
+static bool migrate_pred(struct bch_fs *c, void *arg,
+			 struct bkey_s_c k,
+			 struct bch_io_opts *io_opts,
+			 struct data_update_opts *data_opts)
+{
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+	const struct bch_extent_ptr *ptr;
+	struct bch_ioctl_data *op = arg;
+	unsigned i = 0;
+
+	data_opts->rewrite_ptrs		= 0;
+	data_opts->target		= 0;
+	data_opts->extra_replicas	= 0;
+	data_opts->btree_insert_flags	= 0;
+
+	bkey_for_each_ptr(ptrs, ptr) {
+		if (ptr->dev == op->migrate.dev)
+			data_opts->rewrite_ptrs |= 1U << i;
+		i++;
+	}
+
+	return data_opts->rewrite_ptrs != 0;
+}
+
+static bool rereplicate_btree_pred(struct bch_fs *c, void *arg,
+				   struct btree *b,
+				   struct bch_io_opts *io_opts,
+				   struct data_update_opts *data_opts)
+{
+	return rereplicate_pred(c, arg, bkey_i_to_s_c(&b->key), io_opts, data_opts);
+}
+
+static bool migrate_btree_pred(struct bch_fs *c, void *arg,
+			       struct btree *b,
+			       struct bch_io_opts *io_opts,
+			       struct data_update_opts *data_opts)
+{
+	return migrate_pred(c, arg, bkey_i_to_s_c(&b->key), io_opts, data_opts);
+}
+
+static bool bformat_needs_redo(struct bkey_format *f)
+{
+	unsigned i;
+
+	for (i = 0; i < f->nr_fields; i++) {
+		unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
+		u64 unpacked_mask = ~((~0ULL << 1) << (unpacked_bits - 1));
+		u64 field_offset = le64_to_cpu(f->field_offset[i]);
+
+		if (f->bits_per_field[i] > unpacked_bits)
+			return true;
+
+		if ((f->bits_per_field[i] == unpacked_bits) && field_offset)
+			return true;
+
+		if (((field_offset + ((1ULL << f->bits_per_field[i]) - 1)) &
+		     unpacked_mask) <
+		    field_offset)
+			return true;
+	}
+
+	return false;
+}
+
+static bool rewrite_old_nodes_pred(struct bch_fs *c, void *arg,
+				   struct btree *b,
+				   struct bch_io_opts *io_opts,
+				   struct data_update_opts *data_opts)
+{
+	if (b->version_ondisk != c->sb.version ||
+	    btree_node_need_rewrite(b) ||
+	    bformat_needs_redo(&b->format)) {
+		data_opts->target		= 0;
+		data_opts->extra_replicas	= 0;
+		data_opts->btree_insert_flags	= 0;
+		return true;
+	}
+
+	return false;
+}
+
+int bch2_scan_old_btree_nodes(struct bch_fs *c, struct bch_move_stats *stats)
+{
+	int ret;
+
+	ret = bch2_move_btree(c,
+			      0,		POS_MIN,
+			      BTREE_ID_NR,	SPOS_MAX,
+			      rewrite_old_nodes_pred, c, stats);
+	if (!ret) {
+		mutex_lock(&c->sb_lock);
+		c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_extents_above_btree_updates_done);
+		c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_bformat_overflow_done);
+		c->disk_sb.sb->version_min = c->disk_sb.sb->version;
+		bch2_write_super(c);
+		mutex_unlock(&c->sb_lock);
+	}
+
+	bch_err_fn(c, ret);
+	return ret;
+}
+
+int bch2_data_job(struct bch_fs *c,
+		  struct bch_move_stats *stats,
+		  struct bch_ioctl_data op)
+{
+	int ret = 0;
+
+	switch (op.op) {
+	case BCH_DATA_OP_REREPLICATE:
+		bch2_move_stats_init(stats, "rereplicate");
+		stats->data_type = BCH_DATA_journal;
+		ret = bch2_journal_flush_device_pins(&c->journal, -1);
+
+		ret = bch2_move_btree(c,
+				      op.start_btree,	op.start_pos,
+				      op.end_btree,	op.end_pos,
+				      rereplicate_btree_pred, c, stats) ?: ret;
+		ret = bch2_replicas_gc2(c) ?: ret;
+
+		ret = bch2_move_data(c,
+				     (struct bbpos) { op.start_btree,	op.start_pos },
+				     (struct bbpos) { op.end_btree,	op.end_pos },
+				     NULL,
+				     stats,
+				     writepoint_hashed((unsigned long) current),
+				     true,
+				     rereplicate_pred, c) ?: ret;
+		ret = bch2_replicas_gc2(c) ?: ret;
+
+		bch2_move_stats_exit(stats, c);
+		break;
+	case BCH_DATA_OP_MIGRATE:
+		if (op.migrate.dev >= c->sb.nr_devices)
+			return -EINVAL;
+
+		bch2_move_stats_init(stats, "migrate");
+		stats->data_type = BCH_DATA_journal;
+		ret = bch2_journal_flush_device_pins(&c->journal, op.migrate.dev);
+
+		ret = bch2_move_btree(c,
+				      op.start_btree,	op.start_pos,
+				      op.end_btree,	op.end_pos,
+				      migrate_btree_pred, &op, stats) ?: ret;
+		ret = bch2_replicas_gc2(c) ?: ret;
+
+		ret = bch2_move_data(c,
+				     (struct bbpos) { op.start_btree,	op.start_pos },
+				     (struct bbpos) { op.end_btree,	op.end_pos },
+				     NULL,
+				     stats,
+				     writepoint_hashed((unsigned long) current),
+				     true,
+				     migrate_pred, &op) ?: ret;
+		ret = bch2_replicas_gc2(c) ?: ret;
+
+		bch2_move_stats_exit(stats, c);
+		break;
+	case BCH_DATA_OP_REWRITE_OLD_NODES:
+		bch2_move_stats_init(stats, "rewrite_old_nodes");
+		ret = bch2_scan_old_btree_nodes(c, stats);
+		bch2_move_stats_exit(stats, c);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+void bch2_move_stats_to_text(struct printbuf *out, struct bch_move_stats *stats)
+{
+	prt_printf(out, "%s: data type=%s pos=",
+		   stats->name,
+		   bch2_data_types[stats->data_type]);
+	bch2_bbpos_to_text(out, stats->pos);
+	prt_newline(out);
+	printbuf_indent_add(out, 2);
+
+	prt_str(out, "keys moved:  ");
+	prt_u64(out, atomic64_read(&stats->keys_moved));
+	prt_newline(out);
+
+	prt_str(out, "keys raced:  ");
+	prt_u64(out, atomic64_read(&stats->keys_raced));
+	prt_newline(out);
+
+	prt_str(out, "bytes seen:  ");
+	prt_human_readable_u64(out, atomic64_read(&stats->sectors_seen) << 9);
+	prt_newline(out);
+
+	prt_str(out, "bytes moved: ");
+	prt_human_readable_u64(out, atomic64_read(&stats->sectors_moved) << 9);
+	prt_newline(out);
+
+	prt_str(out, "bytes raced: ");
+	prt_human_readable_u64(out, atomic64_read(&stats->sectors_raced) << 9);
+	prt_newline(out);
+
+	printbuf_indent_sub(out, 2);
+}
+
+static void bch2_moving_ctxt_to_text(struct printbuf *out, struct bch_fs *c, struct moving_context *ctxt)
+{
+	struct moving_io *io;
+
+	bch2_move_stats_to_text(out, ctxt->stats);
+	printbuf_indent_add(out, 2);
+
+	prt_printf(out, "reads: ios %u/%u sectors %u/%u",
+		   atomic_read(&ctxt->read_ios),
+		   c->opts.move_ios_in_flight,
+		   atomic_read(&ctxt->read_sectors),
+		   c->opts.move_bytes_in_flight >> 9);
+	prt_newline(out);
+
+	prt_printf(out, "writes: ios %u/%u sectors %u/%u",
+		   atomic_read(&ctxt->write_ios),
+		   c->opts.move_ios_in_flight,
+		   atomic_read(&ctxt->write_sectors),
+		   c->opts.move_bytes_in_flight >> 9);
+	prt_newline(out);
+
+	printbuf_indent_add(out, 2);
+
+	mutex_lock(&ctxt->lock);
+	list_for_each_entry(io, &ctxt->ios, io_list)
+		bch2_write_op_to_text(out, &io->write.op);
+	mutex_unlock(&ctxt->lock);
+
+	printbuf_indent_sub(out, 4);
+}
+
+void bch2_fs_moving_ctxts_to_text(struct printbuf *out, struct bch_fs *c)
+{
+	struct moving_context *ctxt;
+
+	mutex_lock(&c->moving_context_lock);
+	list_for_each_entry(ctxt, &c->moving_context_list, list)
+		bch2_moving_ctxt_to_text(out, c, ctxt);
+	mutex_unlock(&c->moving_context_lock);
+}
+
+void bch2_fs_move_init(struct bch_fs *c)
+{
+	INIT_LIST_HEAD(&c->moving_context_list);
+	mutex_init(&c->moving_context_lock);
+}