git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/migrate.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Code for moving data off a device.
   4  */
   5
   6 #include "bcachefs.h"
   7 #include "bkey_buf.h"
   8 #include "btree_update.h"
   9 #include "btree_update_interior.h"
  10 #include "buckets.h"
  11 #include "errcode.h"
  12 #include "extents.h"
  13 #include "io.h"
  14 #include "journal.h"
  15 #include "keylist.h"
  16 #include "migrate.h"
  17 #include "move.h"
  18 #include "replicas.h"
  19 #include "super-io.h"
  20
  21 static int drop_dev_ptrs(struct bch_fs *c, struct bkey_s k,
  22                          unsigned dev_idx, int flags, bool metadata)
  23 {
  24         unsigned replicas = metadata ? c->opts.metadata_replicas : c->opts.data_replicas;
  25         unsigned lost = metadata ? BCH_FORCE_IF_METADATA_LOST : BCH_FORCE_IF_DATA_LOST;
  26         unsigned degraded = metadata ? BCH_FORCE_IF_METADATA_DEGRADED : BCH_FORCE_IF_DATA_DEGRADED;
  27         unsigned nr_good;
  28
  29         bch2_bkey_drop_device(k, dev_idx);
  30
  31         nr_good = bch2_bkey_durability(c, k.s_c);
  32         if ((!nr_good && !(flags & lost)) ||
  33             (nr_good < replicas && !(flags & degraded)))
  34                 return -EINVAL;
  35
  36         return 0;
  37 }
  38
  39 static int bch2_dev_usrdata_drop_key(struct btree_trans *trans,
  40                                      struct btree_iter *iter,
  41                                      struct bkey_s_c k,
  42                                      unsigned dev_idx,
  43                                      int flags)
  44 {
  45         struct bch_fs *c = trans->c;
  46         struct bkey_i *n;
  47         int ret;
  48
  49         if (!bch2_bkey_has_device(k, dev_idx))
  50                 return 0;
  51
  52         n = bch2_bkey_make_mut(trans, k);
  53         ret = PTR_ERR_OR_ZERO(n);
  54         if (ret)
  55                 return ret;
  56
  57         ret = drop_dev_ptrs(c, bkey_i_to_s(n), dev_idx, flags, false);
  58         if (ret)
  59                 return ret;
  60
  61         /*
  62          * If the new extent no longer has any pointers, bch2_extent_normalize()
  63          * will do the appropriate thing with it (turning it into a
  64          * KEY_TYPE_error key, or just a discard if it was a cached extent)
  65          */
  66         bch2_extent_normalize(c, bkey_i_to_s(n));
  67
  68         /*
  69          * Since we're not inserting through an extent iterator
  70          * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
  71          * we aren't using the extent overwrite path to delete, we're
  72          * just using the normal key deletion path:
  73          */
  74         if (bkey_deleted(&n->k))
  75                 n->k.size = 0;
  76
  77         return bch2_trans_update(trans, iter, n, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
  78 }
  79
  80 static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
  81 {
  82         struct btree_trans trans;
  83         struct btree_iter iter;
  84         struct bkey_s_c k;
  85         enum btree_id id;
  86         int ret = 0;
  87
  88         bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
  89
  90         for (id = 0; id < BTREE_ID_NR; id++) {
  91                 if (!btree_type_has_ptrs(id))
  92                         continue;
  93
  94                 ret = for_each_btree_key_commit(&trans, iter, id, POS_MIN,
  95                                 BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
  96                                 NULL, NULL, BTREE_INSERT_NOFAIL,
  97                         bch2_dev_usrdata_drop_key(&trans, &iter, k, dev_idx, flags));
  98                 if (ret)
  99                         break;
 100         }
 101
 102         bch2_trans_exit(&trans);
 103
 104         return ret;
 105 }
 106
 107 static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 108 {
 109         struct btree_trans trans;
 110         struct btree_iter iter;
 111         struct closure cl;
 112         struct btree *b;
 113         struct bkey_buf k;
 114         unsigned id;
 115         int ret;
 116
 117         /* don't handle this yet: */
 118         if (flags & BCH_FORCE_IF_METADATA_LOST)
 119                 return -EINVAL;
 120
 121         bch2_bkey_buf_init(&k);
 122         bch2_trans_init(&trans, c, 0, 0);
 123         closure_init_stack(&cl);
 124
 125         for (id = 0; id < BTREE_ID_NR; id++) {
 126                 bch2_trans_node_iter_init(&trans, &iter, id, POS_MIN, 0, 0,
 127                                           BTREE_ITER_PREFETCH);
 128 retry:
 129                 ret = 0;
 130                 while (bch2_trans_begin(&trans),
 131                        (b = bch2_btree_iter_peek_node(&iter)) &&
 132                        !(ret = PTR_ERR_OR_ZERO(b))) {
 133                         if (!bch2_bkey_has_device(bkey_i_to_s_c(&b->key),
 134                                                   dev_idx))
 135                                 goto next;
 136
 137                         bch2_bkey_buf_copy(&k, c, &b->key);
 138
 139                         ret = drop_dev_ptrs(c, bkey_i_to_s(k.k),
 140                                             dev_idx, flags, true);
 141                         if (ret) {
 142                                 bch_err(c, "Cannot drop device without losing data");
 143                                 break;
 144                         }
 145
 146                         ret = bch2_btree_node_update_key(&trans, &iter, b, k.k, false);
 147                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
 148                                 ret = 0;
 149                                 continue;
 150                         }
 151
 152                         if (ret) {
 153                                 bch_err(c, "Error updating btree node key: %s",
 154                                         bch2_err_str(ret));
 155                                 break;
 156                         }
 157 next:
 158                         bch2_btree_iter_next_node(&iter);
 159                 }
 160                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 161                         goto retry;
 162
 163                 bch2_trans_iter_exit(&trans, &iter);
 164
 165                 if (ret)
 166                         goto err;
 167         }
 168
 169         bch2_btree_interior_updates_flush(c);
 170         ret = 0;
 171 err:
 172         bch2_trans_exit(&trans);
 173         bch2_bkey_buf_exit(&k, c);
 174
 175         BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
 176
 177         return ret;
 178 }
 179
 180 int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 181 {
 182         return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
 183                 bch2_dev_metadata_drop(c, dev_idx, flags);
 184 }