]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/move.c
Disable pristine-tar option in gbp.conf, since there is no pristine-tar branch.
[bcachefs-tools-debian] / libbcachefs / move.c
index 1b15b010461ae19b7b52dfda1f7bcbcbad63bb93..bf68ea49447b95055a4f6a1e6e7c6a7e373aebc5 100644 (file)
@@ -6,9 +6,11 @@
 #include "backpointers.h"
 #include "bkey_buf.h"
 #include "btree_gc.h"
+#include "btree_io.h"
 #include "btree_update.h"
 #include "btree_update_interior.h"
 #include "btree_write_buffer.h"
+#include "compress.h"
 #include "disk_groups.h"
 #include "ec.h"
 #include "errcode.h"
 #include <linux/ioprio.h>
 #include <linux/kthread.h>
 
-static void trace_move_extent2(struct bch_fs *c, struct bkey_s_c k)
+const char * const bch2_data_ops_strs[] = {
+#define x(t, n, ...) [n] = #t,
+       BCH_DATA_OPS()
+#undef x
+       NULL
+};
+
+static void bch2_data_update_opts_to_text(struct printbuf *out, struct bch_fs *c,
+                                         struct bch_io_opts *io_opts,
+                                         struct data_update_opts *data_opts)
+{
+       printbuf_tabstop_push(out, 20);
+       prt_str(out, "rewrite ptrs:");
+       prt_tab(out);
+       bch2_prt_u64_base2(out, data_opts->rewrite_ptrs);
+       prt_newline(out);
+
+       prt_str(out, "kill ptrs: ");
+       prt_tab(out);
+       bch2_prt_u64_base2(out, data_opts->kill_ptrs);
+       prt_newline(out);
+
+       prt_str(out, "target: ");
+       prt_tab(out);
+       bch2_target_to_text(out, c, data_opts->target);
+       prt_newline(out);
+
+       prt_str(out, "compression: ");
+       prt_tab(out);
+       bch2_compression_opt_to_text(out, background_compression(*io_opts));
+       prt_newline(out);
+
+       prt_str(out, "extra replicas: ");
+       prt_tab(out);
+       prt_u64(out, data_opts->extra_replicas);
+}
+
+static void trace_move_extent2(struct bch_fs *c, struct bkey_s_c k,
+                              struct bch_io_opts *io_opts,
+                              struct data_update_opts *data_opts)
 {
        if (trace_move_extent_enabled()) {
                struct printbuf buf = PRINTBUF;
 
                bch2_bkey_val_to_text(&buf, c, k);
+               prt_newline(&buf);
+               bch2_data_update_opts_to_text(&buf, c, io_opts, data_opts);
                trace_move_extent(c, buf.buf);
                printbuf_exit(&buf);
        }
@@ -49,17 +92,6 @@ static void trace_move_extent_read2(struct bch_fs *c, struct bkey_s_c k)
        }
 }
 
-static void trace_move_extent_alloc_mem_fail2(struct bch_fs *c, struct bkey_s_c k)
-{
-       if (trace_move_extent_alloc_mem_fail_enabled()) {
-               struct printbuf buf = PRINTBUF;
-
-               bch2_bkey_val_to_text(&buf, c, k);
-               trace_move_extent_alloc_mem_fail(c, buf.buf);
-               printbuf_exit(&buf);
-       }
-}
-
 struct moving_io {
        struct list_head                read_list;
        struct list_head                io_list;
@@ -74,7 +106,7 @@ struct moving_io {
 
        struct data_update              write;
        /* Must be last since it is variable size */
-       struct bio_vec                  bi_inline_vecs[0];
+       struct bio_vec                  bi_inline_vecs[];
 };
 
 static void move_free(struct moving_io *io)
@@ -115,6 +147,15 @@ static void move_write(struct moving_io *io)
                return;
        }
 
+       if (trace_move_extent_write_enabled()) {
+               struct bch_fs *c = io->write.op.c;
+               struct printbuf buf = PRINTBUF;
+
+               bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(io->write.k.k));
+               trace_move_extent_write(c, buf.buf);
+               printbuf_exit(&buf);
+       }
+
        closure_get(&io->write.ctxt->cl);
        atomic_add(io->write_sectors, &io->write.ctxt->write_sectors);
        atomic_inc(&io->write.ctxt->write_ios);
@@ -147,9 +188,8 @@ void bch2_moving_ctxt_do_pending_writes(struct moving_context *ctxt)
 {
        struct moving_io *io;
 
-       bch2_trans_unlock(ctxt->trans);
-
        while ((io = bch2_moving_ctxt_next_pending_write(ctxt))) {
+               bch2_trans_unlock_long(ctxt->trans);
                list_del(&io->read_list);
                move_write(io);
        }
@@ -164,12 +204,18 @@ void bch2_move_ctxt_wait_for_io(struct moving_context *ctxt)
                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;
 
-       move_ctxt_wait_event(ctxt, list_empty(&ctxt->reads));
-       closure_sync(&ctxt->cl);
+       bch2_moving_ctxt_flush_all(ctxt);
 
        EBUG_ON(atomic_read(&ctxt->write_sectors));
        EBUG_ON(atomic_read(&ctxt->write_ios));
@@ -217,56 +263,13 @@ 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)
+void bch2_move_stats_init(struct bch_move_stats *stats, const char *name)
 {
        memset(stats, 0, sizeof(*stats));
        stats->data_type = BCH_DATA_user;
        scnprintf(stats->name, sizeof(stats->name), "%s", name);
 }
 
-static int bch2_extent_drop_ptrs(struct btree_trans *trans,
-                                struct btree_iter *iter,
-                                struct bkey_s_c k,
-                                struct data_update_opts data_opts)
-{
-       struct bch_fs *c = trans->c;
-       struct bkey_i *n;
-       int ret;
-
-       n = bch2_bkey_make_mut_noupdate(trans, k);
-       ret = PTR_ERR_OR_ZERO(n);
-       if (ret)
-               return ret;
-
-       while (data_opts.kill_ptrs) {
-               unsigned i = 0, drop = __fls(data_opts.kill_ptrs);
-               struct bch_extent_ptr *ptr;
-
-               bch2_bkey_drop_ptrs(bkey_i_to_s(n), ptr, i++ == drop);
-               data_opts.kill_ptrs ^= 1U << drop;
-       }
-
-       /*
-        * If the new extent no longer has any pointers, bch2_extent_normalize()
-        * will do the appropriate thing with it (turning it into a
-        * KEY_TYPE_error key, or just a discard if it was a cached extent)
-        */
-       bch2_extent_normalize(c, bkey_i_to_s(n));
-
-       /*
-        * Since we're not inserting through an extent iterator
-        * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
-        * we aren't using the extent overwrite path to delete, we're
-        * just using the normal key deletion path:
-        */
-       if (bkey_deleted(&n->k))
-               n->k.size = 0;
-
-       return bch2_trans_relock(trans) ?:
-               bch2_trans_update(trans, iter, n, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
-               bch2_trans_commit(trans, NULL, NULL, BTREE_INSERT_NOFAIL);
-}
-
 int bch2_move_extent(struct moving_context *ctxt,
                     struct move_bucket_in_flight *bucket_in_flight,
                     struct btree_iter *iter,
@@ -283,9 +286,10 @@ int bch2_move_extent(struct moving_context *ctxt,
        unsigned sectors = k.k->size, pages;
        int ret = -ENOMEM;
 
+       trace_move_extent2(c, k, &io_opts, &data_opts);
+
        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);
 
@@ -336,19 +340,11 @@ int bch2_move_extent(struct moving_context *ctxt,
        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, ctxt, &io->write, ctxt->wp,
+       ret = bch2_data_update_init(trans, iter, ctxt, &io->write, ctxt->wp,
                                    io_opts, data_opts, iter->btree_id, k);
-       if (ret && ret != -BCH_ERR_unwritten_extent_update)
+       if (ret)
                goto err_free_pages;
 
-       if (ret == -BCH_ERR_unwritten_extent_update) {
-               bch2_update_unwritten_extent(trans, &io->write);
-               move_free(io);
-               return 0;
-       }
-
-       BUG_ON(ret);
-
        io->write.op.end_io = move_write_done;
 
        if (ctxt->rate)
@@ -392,8 +388,24 @@ err_free_pages:
 err_free:
        kfree(io);
 err:
-       this_cpu_inc(c->counters[BCH_COUNTER_move_extent_alloc_mem_fail]);
-       trace_move_extent_alloc_mem_fail2(c, k);
+       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;
+
+       count_event(c, 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;
 }
 
@@ -406,13 +418,10 @@ struct bch_io_opts *bch2_move_get_io_opts(struct btree_trans *trans,
        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) {
+               ret = for_each_btree_key(trans, iter, BTREE_ID_inodes, POS(0, extent_k.k->p.inode),
+                                        BTREE_ITER_ALL_SNAPSHOTS, k, ({
                        if (k.k->p.offset != extent_k.k->p.inode)
                                break;
 
@@ -425,11 +434,8 @@ struct bch_io_opts *bch2_move_get_io_opts(struct btree_trans *trans,
                        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);
+                       darray_push(&io_opts->d, e);
+               }));
                io_opts->cur_inum = extent_k.k->p.inode;
        }
 
@@ -437,12 +443,10 @@ struct bch_io_opts *bch2_move_get_io_opts(struct btree_trans *trans,
        if (ret)
                return ERR_PTR(ret);
 
-       if (extent_k.k->p.snapshot) {
-               struct snapshot_io_opts_entry *i;
+       if (extent_k.k->p.snapshot)
                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;
 }
@@ -483,33 +487,30 @@ int bch2_move_get_io_opts_one(struct btree_trans *trans,
 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) {
-               bch2_trans_unlock(ctxt->trans);
+       if (ctxt->wait_on_copygc && c->copygc_running) {
+               bch2_moving_ctxt_flush_all(ctxt);
                wait_event_killable(c->copygc_running_wq,
                                    !c->copygc_running ||
-                                   kthread_should_stop());
+                                   (is_kthread && kthread_should_stop()));
        }
 
        do {
                delay = ctxt->rate ? bch2_ratelimit_delay(ctxt->rate) : 0;
 
-               if (delay) {
-                       bch2_trans_unlock(ctxt->trans);
-                       set_current_state(TASK_INTERRUPTIBLE);
-               }
-
-               if ((current->flags & PF_KTHREAD) && kthread_should_stop()) {
-                       __set_current_state(TASK_RUNNING);
+               if (is_kthread && kthread_should_stop())
                        return 1;
-               }
 
                if (delay)
-                       schedule_timeout(delay);
+                       move_ctxt_wait_event_timeout(ctxt,
+                                       freezing(current) ||
+                                       (is_kthread && kthread_should_stop()),
+                                       delay);
 
                if (unlikely(freezing(current))) {
-                       move_ctxt_wait_event(ctxt, list_empty(&ctxt->reads));
+                       bch2_moving_ctxt_flush_all(ctxt);
                        try_to_freeze();
                }
        } while (delay);
@@ -673,13 +674,14 @@ int bch2_move_data(struct bch_fs *c,
        return ret;
 }
 
-int __bch2_evacuate_bucket(struct moving_context *ctxt,
+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;
@@ -708,23 +710,24 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
                        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");
+       bch_err_msg(c, ret, "looking up alloc key");
+       if (ret)
                goto err;
-       }
 
        a = bch2_alloc_to_v4(k, &a_convert);
-       dirty_sectors = a->dirty_sectors;
+       dirty_sectors = bch2_bucket_sectors_dirty(*a);
        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");
+       ret = bch2_btree_write_buffer_tryflush(trans);
+       bch_err_msg(c, ret, "flushing btree write buffer");
+       if (ret)
                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,
@@ -738,9 +741,6 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
                        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))
@@ -763,6 +763,7 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
                        data_opts.target        = io_opts.background_target;
                        data_opts.rewrite_ptrs = 0;
 
+                       unsigned i = 0;
                        bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr) {
                                if (ptr->dev == bucket.inode) {
                                        data_opts.rewrite_ptrs |= 1U << i;
@@ -804,6 +805,8 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
                        if (!b)
                                goto next;
 
+                       unsigned sectors = btree_ptr_sectors_written(&b->key);
+
                        ret = bch2_btree_node_rewrite(trans, &iter, b, 0);
                        bch2_trans_iter_exit(trans, &iter);
 
@@ -813,11 +816,10 @@ int __bch2_evacuate_bucket(struct moving_context *ctxt,
                                goto err;
 
                        if (ctxt->rate)
-                               bch2_ratelimit_increment(ctxt->rate,
-                                                        c->opts.btree_node_size >> 9);
+                               bch2_ratelimit_increment(ctxt->rate, sectors);
                        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);
+                               atomic64_add(sectors, &ctxt->stats->sectors_seen);
+                               atomic64_add(sectors, &ctxt->stats->sectors_moved);
                        }
                }
 next:
@@ -830,31 +832,13 @@ err:
        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,
+                          struct bbpos start,
+                          struct bbpos end,
                           move_btree_pred pred, void *arg,
                           struct bch_move_stats *stats)
 {
@@ -864,7 +848,7 @@ static int bch2_move_btree(struct bch_fs *c,
        struct btree_trans *trans;
        struct btree_iter iter;
        struct btree *b;
-       enum btree_id id;
+       enum btree_id btree;
        struct data_update_opts data_opts;
        int ret = 0;
 
@@ -875,15 +859,15 @@ static int bch2_move_btree(struct bch_fs *c,
 
        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);
+       for (btree = start.btree;
+            btree <= min_t(unsigned, end.btree, btree_id_nr_alive(c) - 1);
+            btree ++) {
+               stats->pos = BBPOS(btree, POS_MIN);
 
-               if (!bch2_btree_id_root(c, id)->b)
+               if (!bch2_btree_id_root(c, btree)->b)
                        continue;
 
-               bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
+               bch2_trans_node_iter_init(trans, &iter, btree, POS_MIN, 0, 0,
                                          BTREE_ITER_PREFETCH);
 retry:
                ret = 0;
@@ -893,8 +877,8 @@ retry:
                        if (kthread && kthread_should_stop())
                                break;
 
-                       if ((cmp_int(id, end_btree_id) ?:
-                            bpos_cmp(b->key.k.p, end_pos)) > 0)
+                       if ((cmp_int(btree, end.btree) ?:
+                            bpos_cmp(b->key.k.p, end.pos)) > 0)
                                break;
 
                        stats->pos = BBPOS(iter.btree_id, iter.pos);
@@ -951,7 +935,6 @@ static bool migrate_pred(struct bch_fs *c, void *arg,
                         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;
 
@@ -1031,8 +1014,8 @@ 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,
+                             BBPOS_MIN,
+                             BBPOS_MAX,
                              rewrite_old_nodes_pred, c, stats);
        if (!ret) {
                mutex_lock(&c->sb_lock);
@@ -1047,79 +1030,109 @@ int bch2_scan_old_btree_nodes(struct bch_fs *c, struct bch_move_stats *stats)
        return ret;
 }
 
+static bool drop_extra_replicas_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 durability = bch2_bkey_durability(c, k);
+       unsigned replicas = bkey_is_btree_ptr(k.k)
+               ? c->opts.metadata_replicas
+               : io_opts->data_replicas;
+       const union bch_extent_entry *entry;
+       struct extent_ptr_decoded p;
+       unsigned i = 0;
+
+       bkey_for_each_ptr_decode(k.k, bch2_bkey_ptrs_c(k), p, entry) {
+               unsigned d = bch2_extent_ptr_durability(c, &p);
+
+               if (d && durability - d >= replicas) {
+                       data_opts->kill_ptrs |= BIT(i);
+                       durability -= d;
+               }
+
+               i++;
+       }
+
+       return data_opts->kill_ptrs != 0;
+}
+
+static bool drop_extra_replicas_btree_pred(struct bch_fs *c, void *arg,
+                                  struct btree *b,
+                                  struct bch_io_opts *io_opts,
+                                  struct data_update_opts *data_opts)
+{
+       return drop_extra_replicas_pred(c, arg, bkey_i_to_s_c(&b->key), io_opts, data_opts);
+}
+
 int bch2_data_job(struct bch_fs *c,
                  struct bch_move_stats *stats,
                  struct bch_ioctl_data op)
 {
+       struct bbpos start      = BBPOS(op.start_btree, op.start_pos);
+       struct bbpos end        = BBPOS(op.end_btree, op.end_pos);
        int ret = 0;
 
+       if (op.op >= BCH_DATA_OP_NR)
+               return -EINVAL;
+
+       bch2_move_stats_init(stats, bch2_data_ops_strs[op.op]);
+
        switch (op.op) {
-       case BCH_DATA_OP_REREPLICATE:
-               bch2_move_stats_init(stats, "rereplicate");
+       case BCH_DATA_OP_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,
+               ret = bch2_move_btree(c, start, end,
                                      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 },
+               ret = bch2_move_data(c, start, end,
                                     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:
+       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,
+               ret = bch2_move_btree(c, start, end,
                                      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 },
+               ret = bch2_move_data(c, start, end,
                                     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");
+       case BCH_DATA_OP_rewrite_old_nodes:
                ret = bch2_scan_old_btree_nodes(c, stats);
-               bch2_move_stats_exit(stats, c);
+               break;
+       case BCH_DATA_OP_drop_extra_replicas:
+               ret = bch2_move_btree(c, start, end,
+                               drop_extra_replicas_btree_pred, c, stats) ?: ret;
+               ret = bch2_move_data(c, start, end, NULL, stats,
+                               writepoint_hashed((unsigned long) current),
+                               true,
+                               drop_extra_replicas_pred, c) ?: ret;
+               ret = bch2_replicas_gc2(c) ?: ret;
                break;
        default:
                ret = -EINVAL;
        }
 
+       bch2_move_stats_exit(stats, c);
        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]);
+       prt_printf(out, "%s: data type==", stats->name);
+       bch2_prt_data_type(out, stats->data_type);
+       prt_str(out, " pos=");
        bch2_bbpos_to_text(out, stats->pos);
        prt_newline(out);
        printbuf_indent_add(out, 2);