]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/move.c
Update bcachefs sources to 9abf628c70 bcachefs: Fix a spurious error in fsck
[bcachefs-tools-debian] / libbcachefs / move.c
index 8ce63d665e8ab53deecbfeb9699fddc8d89b1a13..3e52b7a26c7f51e5e3c37ec73da41885fa93fcb9 100644 (file)
@@ -5,7 +5,9 @@
 #include "buckets.h"
 #include "inode.h"
 #include "io.h"
+#include "journal_reclaim.h"
 #include "move.h"
+#include "replicas.h"
 #include "super-io.h"
 #include "keylist.h"
 
 
 #include <trace/events/bcachefs.h>
 
+#define SECTORS_IN_FLIGHT_PER_DEVICE   2048
+
 struct moving_io {
        struct list_head        list;
        struct closure          cl;
        bool                    read_completed;
-       unsigned                sectors;
+
+       unsigned                read_sectors;
+       unsigned                write_sectors;
 
        struct bch_read_bio     rbio;
 
@@ -31,14 +37,13 @@ struct moving_context {
        /* Closure for waiting on all reads and writes to complete */
        struct closure          cl;
 
-       /* Key and sector moves issued, updated from submission context */
-       u64                     keys_moved;
-       u64                     sectors_moved;
-       atomic64_t              sectors_raced;
+       struct bch_move_stats   *stats;
 
        struct list_head        reads;
 
-       atomic_t                sectors_in_flight;
+       /* in flight sectors: */
+       atomic_t                read_sectors;
+       atomic_t                write_sectors;
 
        wait_queue_head_t       wait;
 };
@@ -54,16 +59,17 @@ static int bch2_migrate_index_update(struct bch_write_op *op)
 
        bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS,
                             bkey_start_pos(&bch2_keylist_front(keys)->k),
-                            BTREE_ITER_INTENT);
+                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
 
        while (1) {
-               struct bkey_s_c k = bch2_btree_iter_peek_with_holes(&iter);
+               struct bkey_s_c k = bch2_btree_iter_peek_slot(&iter);
                struct bkey_i_extent *insert, *new =
                        bkey_i_to_extent(bch2_keylist_front(keys));
                BKEY_PADDED(k) _new, _insert;
                struct bch_extent_ptr *ptr;
                struct bch_extent_crc_unpacked crc;
                bool did_work = false;
+               int nr;
 
                if (btree_iter_err(k)) {
                        ret = bch2_btree_iter_unlock(&iter);
@@ -76,6 +82,11 @@ static int bch2_migrate_index_update(struct bch_write_op *op)
                                             m->ptr, m->offset))
                        goto nomatch;
 
+               if (m->data_cmd == DATA_REWRITE &&
+                   !bch2_extent_has_device(bkey_s_c_to_extent(k),
+                                           m->data_opts.rewrite_dev))
+                       goto nomatch;
+
                bkey_reassemble(&_insert.k, k);
                insert = bkey_i_to_extent(&_insert.k);
 
@@ -86,12 +97,12 @@ static int bch2_migrate_index_update(struct bch_write_op *op)
                bch2_cut_back(new->k.p, &insert->k);
                bch2_cut_back(insert->k.p, &new->k);
 
-               if (m->move_dev >= 0 &&
-                   (ptr = (struct bch_extent_ptr *)
-                    bch2_extent_has_device(extent_i_to_s_c(insert),
-                                           m->move_dev)))
+               if (m->data_cmd == DATA_REWRITE) {
+                       ptr = (struct bch_extent_ptr *)
+                               bch2_extent_has_device(extent_i_to_s_c(insert),
+                                                      m->data_opts.rewrite_dev);
                        bch2_extent_drop_ptr(extent_i_to_s(insert), ptr);
-
+               }
 
                extent_for_each_ptr_crc(extent_i_to_s(new), ptr, crc) {
                        if (bch2_extent_has_device(extent_i_to_s_c(insert), ptr->dev)) {
@@ -114,13 +125,44 @@ static int bch2_migrate_index_update(struct bch_write_op *op)
                bch2_extent_narrow_crcs(insert,
                                (struct bch_extent_crc_unpacked) { 0 });
                bch2_extent_normalize(c, extent_i_to_s(insert).s);
-               bch2_extent_mark_replicas_cached(c, extent_i_to_s(insert));
+               bch2_extent_mark_replicas_cached(c, extent_i_to_s(insert),
+                                                op->opts.background_target,
+                                                op->opts.data_replicas);
+
+               /*
+                * It's possible we race, and for whatever reason the extent now
+                * has fewer replicas than when we last looked at it - meaning
+                * we need to get a disk reservation here:
+                */
+               nr = bch2_extent_nr_dirty_ptrs(bkey_i_to_s_c(&insert->k_i)) -
+                       (bch2_extent_nr_dirty_ptrs(k) + m->nr_ptrs_reserved);
+               if (nr > 0) {
+                       /*
+                        * can't call bch2_disk_reservation_add() with btree
+                        * locks held, at least not without a song and dance
+                        */
+                       bch2_btree_iter_unlock(&iter);
+
+                       ret = bch2_disk_reservation_add(c, &op->res,
+                                       keylist_sectors(keys) * nr, 0);
+                       if (ret)
+                               goto out;
+
+                       m->nr_ptrs_reserved += nr;
+                       goto next;
+               }
+
+               ret = bch2_mark_bkey_replicas(c, BCH_DATA_USER,
+                                             extent_i_to_s_c(insert).s_c);
+               if (ret)
+                       break;
 
                ret = bch2_btree_insert_at(c, &op->res,
                                NULL, op_journal_seq(op),
                                BTREE_INSERT_ATOMIC|
                                BTREE_INSERT_NOFAIL|
-                               m->btree_insert_flags,
+                               BTREE_INSERT_USE_RESERVE|
+                               m->data_opts.btree_insert_flags,
                                BTREE_INSERT_ENTRY(&iter, &insert->k_i));
                if (!ret)
                        atomic_long_inc(&c->extent_migrate_done);
@@ -140,10 +182,10 @@ next:
 nomatch:
                if (m->ctxt)
                        atomic64_add(k.k->p.offset - iter.pos.offset,
-                                    &m->ctxt->sectors_raced);
+                                    &m->ctxt->stats->sectors_raced);
                atomic_long_inc(&c->extent_migrate_raced);
                trace_move_race(&new->k);
-               bch2_btree_iter_advance_pos(&iter);
+               bch2_btree_iter_next_slot(&iter);
                goto next;
        }
 out:
@@ -151,8 +193,7 @@ out:
        return ret;
 }
 
-void bch2_migrate_write_init(struct migrate_write *m,
-                            struct bch_read_bio *rbio)
+void bch2_migrate_read_done(struct migrate_write *m, struct bch_read_bio *rbio)
 {
        /* write bio must own pages: */
        BUG_ON(!m->op.wbio.bio.bi_vcnt);
@@ -163,27 +204,76 @@ void bch2_migrate_write_init(struct migrate_write *m,
        m->op.pos       = rbio->pos;
        m->op.version   = rbio->version;
        m->op.crc       = rbio->pick.crc;
+       m->op.wbio.bio.bi_iter.bi_size = m->op.crc.compressed_size << 9;
 
        if (bch2_csum_type_is_encryption(m->op.crc.csum_type)) {
                m->op.nonce     = m->op.crc.nonce + m->op.crc.offset;
                m->op.csum_type = m->op.crc.csum_type;
        }
 
-       if (m->move_dev >= 0)
-               bch2_dev_list_drop_dev(&m->op.devs_have, m->move_dev);
+       if (m->data_cmd == DATA_REWRITE)
+               bch2_dev_list_drop_dev(&m->op.devs_have, m->data_opts.rewrite_dev);
+}
+
+int bch2_migrate_write_init(struct bch_fs *c, struct migrate_write *m,
+                           struct write_point_specifier wp,
+                           struct bch_io_opts io_opts,
+                           enum data_cmd data_cmd,
+                           struct data_opts data_opts,
+                           struct bkey_s_c k)
+{
+       int ret;
+
+       m->data_cmd     = data_cmd;
+       m->data_opts    = data_opts;
+       m->nr_ptrs_reserved = 0;
+
+       bch2_write_op_init(&m->op, c, io_opts);
+       m->op.compression_type =
+               bch2_compression_opt_to_type[io_opts.background_compression ?:
+                                            io_opts.compression];
+       m->op.target    = data_opts.target,
+       m->op.write_point = wp;
 
-       if (m->btree_insert_flags & BTREE_INSERT_USE_RESERVE)
+       if (m->data_opts.btree_insert_flags & BTREE_INSERT_USE_RESERVE)
                m->op.alloc_reserve = RESERVE_MOVINGGC;
 
        m->op.flags |= BCH_WRITE_ONLY_SPECIFIED_DEVS|
                BCH_WRITE_PAGES_STABLE|
                BCH_WRITE_PAGES_OWNED|
-               BCH_WRITE_DATA_ENCODED;
+               BCH_WRITE_DATA_ENCODED|
+               BCH_WRITE_NOMARK_REPLICAS;
 
-       m->op.wbio.bio.bi_iter.bi_size = m->op.crc.compressed_size << 9;
        m->op.nr_replicas       = 1;
        m->op.nr_replicas_required = 1;
        m->op.index_update_fn   = bch2_migrate_index_update;
+
+       switch (data_cmd) {
+       case DATA_ADD_REPLICAS: {
+               int nr = (int) io_opts.data_replicas -
+                       bch2_extent_nr_dirty_ptrs(k);
+
+               if (nr > 0) {
+                       m->op.nr_replicas = m->nr_ptrs_reserved = nr;
+
+                       ret = bch2_disk_reservation_get(c, &m->op.res,
+                                       k.k->size, m->op.nr_replicas, 0);
+                       if (ret)
+                               return ret;
+               }
+               break;
+       }
+       case DATA_REWRITE:
+               break;
+       case DATA_PROMOTE:
+               m->op.flags     |= BCH_WRITE_ALLOC_NOWAIT;
+               m->op.flags     |= BCH_WRITE_CACHED;
+               break;
+       default:
+               BUG();
+       }
+
+       return 0;
 }
 
 static void move_free(struct closure *cl)
@@ -193,26 +283,39 @@ static void move_free(struct closure *cl)
        struct bio_vec *bv;
        int i;
 
+       bch2_disk_reservation_put(io->write.op.c, &io->write.op.res);
+
        bio_for_each_segment_all(bv, &io->write.op.wbio.bio, i)
                if (bv->bv_page)
                        __free_page(bv->bv_page);
 
-       atomic_sub(io->sectors, &ctxt->sectors_in_flight);
        wake_up(&ctxt->wait);
 
        kfree(io);
 }
 
+static void move_write_done(struct closure *cl)
+{
+       struct moving_io *io = container_of(cl, struct moving_io, cl);
+
+       atomic_sub(io->write_sectors, &io->write.ctxt->write_sectors);
+       closure_return_with_destructor(cl, move_free);
+}
+
 static void move_write(struct closure *cl)
 {
        struct moving_io *io = container_of(cl, struct moving_io, cl);
 
-       if (likely(!io->rbio.bio.bi_status)) {
-               bch2_migrate_write_init(&io->write, &io->rbio);
-               closure_call(&io->write.op.cl, bch2_write, NULL, cl);
+       if (unlikely(io->rbio.bio.bi_status || io->rbio.hole)) {
+               closure_return_with_destructor(cl, move_free);
+               return;
        }
 
-       closure_return_with_destructor(cl, move_free);
+       bch2_migrate_read_done(&io->write, &io->rbio);
+
+       atomic_add(io->write_sectors, &io->write.ctxt->write_sectors);
+       closure_call(&io->write.op.cl, bch2_write, NULL, cl);
+       continue_at(cl, move_write_done, NULL);
 }
 
 static inline struct moving_io *next_pending_write(struct moving_context *ctxt)
@@ -228,34 +331,68 @@ 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);
        io->read_completed = true;
+
        if (next_pending_write(ctxt))
                wake_up(&ctxt->wait);
 
        closure_put(&ctxt->cl);
 }
 
+static void do_pending_writes(struct moving_context *ctxt)
+{
+       struct moving_io *io;
+
+       while ((io = next_pending_write(ctxt))) {
+               list_del(&io->list);
+               closure_call(&io->cl, move_write, NULL, &ctxt->cl);
+       }
+}
+
+#define move_ctxt_wait_event(_ctxt, _cond)                     \
+do {                                                           \
+       do_pending_writes(_ctxt);                               \
+                                                               \
+       if (_cond)                                              \
+               break;                                          \
+       __wait_event((_ctxt)->wait,                             \
+                    next_pending_write(_ctxt) || (_cond));     \
+} while (1)
+
+static 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);
+}
+
 static int bch2_move_extent(struct bch_fs *c,
-                         struct moving_context *ctxt,
-                         struct bch_devs_mask *devs,
-                         struct write_point_specifier wp,
-                         int btree_insert_flags,
-                         int move_device,
-                         struct bch_io_opts opts,
-                         struct bkey_s_c k)
+                           struct moving_context *ctxt,
+                           struct write_point_specifier wp,
+                           struct bch_io_opts io_opts,
+                           struct bkey_s_c_extent e,
+                           enum data_cmd data_cmd,
+                           struct data_opts data_opts)
 {
-       struct extent_pick_ptr pick;
        struct moving_io *io;
        const struct bch_extent_ptr *ptr;
        struct bch_extent_crc_unpacked crc;
-       unsigned sectors = k.k->size, pages;
+       unsigned sectors = e.k->size, pages;
+       int ret = -ENOMEM;
+
+       move_ctxt_wait_event(ctxt,
+               atomic_read(&ctxt->write_sectors) <
+               SECTORS_IN_FLIGHT_PER_DEVICE);
 
-       bch2_extent_pick_ptr(c, k, NULL, &pick);
-       if (IS_ERR_OR_NULL(pick.ca))
-               return pick.ca ? PTR_ERR(pick.ca) : 0;
+       move_ctxt_wait_event(ctxt,
+               atomic_read(&ctxt->read_sectors) <
+               SECTORS_IN_FLIGHT_PER_DEVICE);
 
        /* write path might have to decompress data: */
-       extent_for_each_ptr_crc(bkey_s_c_to_extent(k), ptr, crc)
+       extent_for_each_ptr_crc(e, ptr, crc)
                sectors = max_t(unsigned, sectors, crc.uncompressed_size);
 
        pages = DIV_ROUND_UP(sectors, PAGE_SECTORS);
@@ -264,8 +401,9 @@ static int bch2_move_extent(struct bch_fs *c,
        if (!io)
                goto err;
 
-       io->write.ctxt  = ctxt;
-       io->sectors     = k.k->size;
+       io->write.ctxt          = ctxt;
+       io->read_sectors        = e.k->size;
+       io->write_sectors       = e.k->size;
 
        bio_init(&io->write.op.wbio.bio, io->bi_inline_vecs, pages);
        bio_set_prio(&io->write.op.wbio.bio,
@@ -273,36 +411,30 @@ static int bch2_move_extent(struct bch_fs *c,
        io->write.op.wbio.bio.bi_iter.bi_size = sectors << 9;
 
        bch2_bio_map(&io->write.op.wbio.bio, NULL);
-       if (bio_alloc_pages(&io->write.op.wbio.bio, GFP_KERNEL)) {
-               kfree(io);
-               goto err;
-       }
+       if (bch2_bio_alloc_pages(&io->write.op.wbio.bio, GFP_KERNEL))
+               goto err_free;
 
-       io->rbio.opts = opts;
+       io->rbio.opts = io_opts;
        bio_init(&io->rbio.bio, io->bi_inline_vecs, pages);
+       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;
 
        bio_set_op_attrs(&io->rbio.bio, REQ_OP_READ, 0);
-       io->rbio.bio.bi_iter.bi_sector  = bkey_start_offset(k.k);
+       io->rbio.bio.bi_iter.bi_sector  = bkey_start_offset(e.k);
        io->rbio.bio.bi_end_io          = move_read_endio;
 
-       io->write.btree_insert_flags = btree_insert_flags;
-       io->write.move_dev      = move_device;
+       ret = bch2_migrate_write_init(c, &io->write, wp, io_opts,
+                                     data_cmd, data_opts, e.s_c);
+       if (ret)
+               goto err_free_pages;
 
-       bch2_write_op_init(&io->write.op, c);
-       io->write.op.csum_type = bch2_data_checksum_type(c, opts.data_checksum);
-       io->write.op.compression_type =
-               bch2_compression_opt_to_type(opts.compression);
-       io->write.op.devs       = devs;
-       io->write.op.write_point = wp;
+       atomic64_inc(&ctxt->stats->keys_moved);
+       atomic64_add(e.k->size, &ctxt->stats->sectors_moved);
 
-       ctxt->keys_moved++;
-       ctxt->sectors_moved += k.k->size;
+       trace_move_extent(e.k);
 
-       trace_move_extent(k.k);
-
-       atomic_add(io->sectors, &ctxt->sectors_in_flight);
+       atomic_add(io->read_sectors, &ctxt->read_sectors);
        list_add_tail(&io->list, &ctxt->reads);
 
        /*
@@ -310,155 +442,321 @@ static int bch2_move_extent(struct bch_fs *c,
         * ctxt when doing wakeup
         */
        closure_get(&ctxt->cl);
-       bch2_read_extent(c, &io->rbio, bkey_s_c_to_extent(k),
-                        &pick, BCH_READ_NODECODE);
+       bch2_read_extent(c, &io->rbio, e.s_c,
+                        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:
-       trace_move_alloc_fail(k.k);
-       return -ENOMEM;
-}
-
-static void do_pending_writes(struct moving_context *ctxt)
-{
-       struct moving_io *io;
-
-       while ((io = next_pending_write(ctxt))) {
-               list_del(&io->list);
-               closure_call(&io->cl, move_write, NULL, &ctxt->cl);
-       }
-}
-
-#define move_ctxt_wait_event(_ctxt, _cond)                     \
-do {                                                           \
-       do_pending_writes(_ctxt);                               \
-                                                               \
-       if (_cond)                                              \
-               break;                                          \
-       __wait_event((_ctxt)->wait,                             \
-                    next_pending_write(_ctxt) || (_cond));     \
-} while (1)
-
-static void bch2_move_ctxt_wait_for_io(struct moving_context *ctxt)
-{
-       unsigned sectors_pending = atomic_read(&ctxt->sectors_in_flight);
-
-       move_ctxt_wait_event(ctxt,
-               !atomic_read(&ctxt->sectors_in_flight) ||
-               atomic_read(&ctxt->sectors_in_flight) != sectors_pending);
-}
-
-static void bch2_move_ctxt_exit(struct moving_context *ctxt)
-{
-       move_ctxt_wait_event(ctxt, !atomic_read(&ctxt->sectors_in_flight));
-       closure_sync(&ctxt->cl);
-
-       EBUG_ON(!list_empty(&ctxt->reads));
-       EBUG_ON(atomic_read(&ctxt->sectors_in_flight));
-}
-
-static void bch2_move_ctxt_init(struct moving_context *ctxt)
-{
-       memset(ctxt, 0, sizeof(*ctxt));
-       closure_init_stack(&ctxt->cl);
-
-       INIT_LIST_HEAD(&ctxt->reads);
-       init_waitqueue_head(&ctxt->wait);
+       trace_move_alloc_fail(e.k);
+       return ret;
 }
 
 int bch2_move_data(struct bch_fs *c,
                   struct bch_ratelimit *rate,
-                  unsigned sectors_in_flight,
-                  struct bch_devs_mask *devs,
                   struct write_point_specifier wp,
-                  int btree_insert_flags,
-                  int move_device,
+                  struct bpos start,
+                  struct bpos end,
                   move_pred_fn pred, void *arg,
-                  u64 *keys_moved,
-                  u64 *sectors_moved)
+                  struct bch_move_stats *stats)
 {
        bool kthread = (current->flags & PF_KTHREAD) != 0;
-       struct moving_context ctxt;
-       struct bch_io_opts opts = bch2_opts_to_inode_opts(c->opts);
-       struct btree_iter iter;
+       struct moving_context ctxt = { .stats = stats };
+       struct bch_io_opts io_opts = bch2_opts_to_inode_opts(c->opts);
        BKEY_PADDED(k) tmp;
        struct bkey_s_c k;
+       struct bkey_s_c_extent e;
+       struct data_opts data_opts;
+       enum data_cmd data_cmd;
        u64 cur_inum = U64_MAX;
-       int ret = 0;
+       int ret = 0, ret2;
+
+       closure_init_stack(&ctxt.cl);
+       INIT_LIST_HEAD(&ctxt.reads);
+       init_waitqueue_head(&ctxt.wait);
 
-       bch2_move_ctxt_init(&ctxt);
-       bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN,
+       stats->data_type = BCH_DATA_USER;
+       bch2_btree_iter_init(&stats->iter, c, BTREE_ID_EXTENTS, start,
                             BTREE_ITER_PREFETCH);
 
        if (rate)
                bch2_ratelimit_reset(rate);
 
        while (!kthread || !(ret = kthread_should_stop())) {
-               if (atomic_read(&ctxt.sectors_in_flight) >= sectors_in_flight) {
-                       bch2_btree_iter_unlock(&iter);
-                       move_ctxt_wait_event(&ctxt,
-                                            atomic_read(&ctxt.sectors_in_flight) <
-                                            sectors_in_flight);
-               }
-
                if (rate &&
                    bch2_ratelimit_delay(rate) &&
-                   (bch2_btree_iter_unlock(&iter),
+                   (bch2_btree_iter_unlock(&stats->iter),
                     (ret = bch2_ratelimit_wait_freezable_stoppable(rate))))
                        break;
 peek:
-               k = bch2_btree_iter_peek(&iter);
+               k = bch2_btree_iter_peek(&stats->iter);
                if (!k.k)
                        break;
                ret = btree_iter_err(k);
                if (ret)
                        break;
+               if (bkey_cmp(bkey_start_pos(k.k), end) >= 0)
+                       break;
 
                if (!bkey_extent_is_data(k.k))
-                       goto next;
+                       goto next_nondata;
+
+               e = bkey_s_c_to_extent(k);
 
                if (cur_inum != k.k->p.inode) {
                        struct bch_inode_unpacked inode;
 
                        /* don't hold btree locks while looking up inode: */
-                       bch2_btree_iter_unlock(&iter);
+                       bch2_btree_iter_unlock(&stats->iter);
 
-                       opts = bch2_opts_to_inode_opts(c->opts);
+                       io_opts = bch2_opts_to_inode_opts(c->opts);
                        if (!bch2_inode_find_by_inum(c, k.k->p.inode, &inode))
-                               bch2_io_opts_apply(&opts, bch2_inode_opts_get(&inode));
+                               bch2_io_opts_apply(&io_opts, bch2_inode_opts_get(&inode));
                        cur_inum = k.k->p.inode;
                        goto peek;
                }
 
-               if (!pred(arg, bkey_s_c_to_extent(k)))
+               switch ((data_cmd = pred(c, arg, BKEY_TYPE_EXTENTS, e,
+                                        &io_opts, &data_opts))) {
+               case DATA_SKIP:
                        goto next;
+               case DATA_SCRUB:
+                       BUG();
+               case DATA_ADD_REPLICAS:
+               case DATA_REWRITE:
+               case DATA_PROMOTE:
+                       break;
+               default:
+                       BUG();
+               }
 
                /* unlock before doing IO: */
                bkey_reassemble(&tmp.k, k);
                k = bkey_i_to_s_c(&tmp.k);
-               bch2_btree_iter_unlock(&iter);
-
-               if (bch2_move_extent(c, &ctxt, devs, wp,
-                                    btree_insert_flags,
-                                    move_device, opts, k)) {
-                       /* memory allocation failure, wait for some IO to finish */
-                       bch2_move_ctxt_wait_for_io(&ctxt);
-                       continue;
+               bch2_btree_iter_unlock(&stats->iter);
+
+               ret2 = bch2_move_extent(c, &ctxt, wp, io_opts,
+                                       bkey_s_c_to_extent(k),
+                                       data_cmd, data_opts);
+               if (ret2) {
+                       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;
                }
 
                if (rate)
                        bch2_ratelimit_increment(rate, k.k->size);
 next:
-               bch2_btree_iter_advance_pos(&iter);
-               bch2_btree_iter_cond_resched(&iter);
+               atomic64_add(k.k->size * bch2_extent_nr_dirty_ptrs(k),
+                            &stats->sectors_seen);
+next_nondata:
+               bch2_btree_iter_next(&stats->iter);
+               bch2_btree_iter_cond_resched(&stats->iter);
        }
 
-       bch2_btree_iter_unlock(&iter);
-       bch2_move_ctxt_exit(&ctxt);
+       bch2_btree_iter_unlock(&stats->iter);
+
+       move_ctxt_wait_event(&ctxt, list_empty(&ctxt.reads));
+       closure_sync(&ctxt.cl);
+
+       EBUG_ON(atomic_read(&ctxt.write_sectors));
 
-       trace_move_data(c, ctxt.sectors_moved, ctxt.keys_moved);
+       trace_move_data(c,
+                       atomic64_read(&stats->sectors_moved),
+                       atomic64_read(&stats->keys_moved));
+
+       return ret;
+}
 
-       *keys_moved     = ctxt.keys_moved;
-       *sectors_moved  = ctxt.sectors_moved;
+static int bch2_gc_data_replicas(struct bch_fs *c)
+{
+       struct btree_iter iter;
+       struct bkey_s_c k;
+       int ret;
+
+       mutex_lock(&c->replicas_gc_lock);
+       bch2_replicas_gc_start(c, (1 << BCH_DATA_USER)|(1 << BCH_DATA_CACHED));
+
+       for_each_btree_key(&iter, c, BTREE_ID_EXTENTS, POS_MIN,
+                          BTREE_ITER_PREFETCH, k) {
+               ret = bch2_mark_bkey_replicas(c, BCH_DATA_USER, k);
+               if (ret)
+                       break;
+       }
+       ret = bch2_btree_iter_unlock(&iter) ?: ret;
+
+       bch2_replicas_gc_end(c, ret);
+       mutex_unlock(&c->replicas_gc_lock);
+
+       return ret;
+}
+
+static int bch2_gc_btree_replicas(struct bch_fs *c)
+{
+       struct btree_iter iter;
+       struct btree *b;
+       unsigned id;
+       int ret = 0;
+
+       mutex_lock(&c->replicas_gc_lock);
+       bch2_replicas_gc_start(c, 1 << BCH_DATA_BTREE);
+
+       for (id = 0; id < BTREE_ID_NR; id++) {
+               for_each_btree_node(&iter, c, id, POS_MIN, BTREE_ITER_PREFETCH, b) {
+                       ret = bch2_mark_bkey_replicas(c, BCH_DATA_BTREE,
+                                                     bkey_i_to_s_c(&b->key));
+
+                       bch2_btree_iter_cond_resched(&iter);
+               }
+
+               ret = bch2_btree_iter_unlock(&iter) ?: ret;
+       }
+
+       bch2_replicas_gc_end(c, ret);
+       mutex_unlock(&c->replicas_gc_lock);
+
+       return ret;
+}
+
+static int bch2_move_btree(struct bch_fs *c,
+                          move_pred_fn pred,
+                          void *arg,
+                          struct bch_move_stats *stats)
+{
+       struct bch_io_opts io_opts = bch2_opts_to_inode_opts(c->opts);
+       struct btree *b;
+       unsigned id;
+       struct data_opts data_opts;
+       enum data_cmd cmd;
+       int ret = 0;
+
+       stats->data_type = BCH_DATA_BTREE;
+
+       for (id = 0; id < BTREE_ID_NR; id++) {
+               for_each_btree_node(&stats->iter, c, id, POS_MIN, BTREE_ITER_PREFETCH, b) {
+                       switch ((cmd = pred(c, arg, BKEY_TYPE_BTREE,
+                                           bkey_i_to_s_c_extent(&b->key),
+                                           &io_opts,
+                                           &data_opts))) {
+                       case DATA_SKIP:
+                               goto next;
+                       case DATA_SCRUB:
+                               BUG();
+                       case DATA_ADD_REPLICAS:
+                       case DATA_REWRITE:
+                               break;
+                       default:
+                               BUG();
+                       }
+
+                       ret = bch2_btree_node_rewrite(c, &stats->iter,
+                                       b->data->keys.seq, 0) ?: ret;
+next:
+                       bch2_btree_iter_cond_resched(&stats->iter);
+               }
+
+               ret = bch2_btree_iter_unlock(&stats->iter) ?: ret;
+       }
+
+       return ret;
+}
+
+#if 0
+static enum data_cmd scrub_pred(struct bch_fs *c, void *arg,
+                               enum bkey_type type,
+                               struct bkey_s_c_extent e,
+                               struct bch_io_opts *io_opts,
+                               struct data_opts *data_opts)
+{
+       return DATA_SCRUB;
+}
+#endif
+
+static enum data_cmd rereplicate_pred(struct bch_fs *c, void *arg,
+                                     enum bkey_type type,
+                                     struct bkey_s_c_extent e,
+                                     struct bch_io_opts *io_opts,
+                                     struct data_opts *data_opts)
+{
+       unsigned nr_good = bch2_extent_durability(c, e);
+       unsigned replicas = type == BKEY_TYPE_BTREE
+               ? c->opts.metadata_replicas
+               : io_opts->data_replicas;
+
+       if (!nr_good || nr_good >= replicas)
+               return DATA_SKIP;
+
+       data_opts->target               = 0;
+       data_opts->btree_insert_flags = 0;
+       return DATA_ADD_REPLICAS;
+}
+
+static enum data_cmd migrate_pred(struct bch_fs *c, void *arg,
+                                 enum bkey_type type,
+                                 struct bkey_s_c_extent e,
+                                 struct bch_io_opts *io_opts,
+                                 struct data_opts *data_opts)
+{
+       struct bch_ioctl_data *op = arg;
+
+       if (!bch2_extent_has_device(e, op->migrate.dev))
+               return DATA_SKIP;
+
+       data_opts->target               = 0;
+       data_opts->btree_insert_flags   = 0;
+       data_opts->rewrite_dev          = op->migrate.dev;
+       return DATA_REWRITE;
+}
+
+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:
+               stats->data_type = BCH_DATA_JOURNAL;
+               ret = bch2_journal_flush_device_pins(&c->journal, -1);
+
+               ret = bch2_move_btree(c, rereplicate_pred, c, stats) ?: ret;
+               ret = bch2_gc_btree_replicas(c) ?: ret;
+
+               ret = bch2_move_data(c, NULL,
+                                    writepoint_hashed((unsigned long) current),
+                                    op.start,
+                                    op.end,
+                                    rereplicate_pred, c, stats) ?: ret;
+               ret = bch2_gc_data_replicas(c) ?: ret;
+               break;
+       case BCH_DATA_OP_MIGRATE:
+               if (op.migrate.dev >= c->sb.nr_devices)
+                       return -EINVAL;
+
+               stats->data_type = BCH_DATA_JOURNAL;
+               ret = bch2_journal_flush_device_pins(&c->journal, op.migrate.dev);
+
+               ret = bch2_move_btree(c, migrate_pred, &op, stats) ?: ret;
+               ret = bch2_gc_btree_replicas(c) ?: ret;
+
+               ret = bch2_move_data(c, NULL,
+                                    writepoint_hashed((unsigned long) current),
+                                    op.start,
+                                    op.end,
+                                    migrate_pred, &op, stats) ?: ret;
+               ret = bch2_gc_data_replicas(c) ?: ret;
+               break;
+       default:
+               ret = -EINVAL;
+       }
 
        return ret;
 }