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_trans_kmalloc(trans, bkey_bytes(k.k));
  53         ret = PTR_ERR_OR_ZERO(n);
  54         if (ret)
  55                 return ret;
  56
  57         bkey_reassemble(n, k);
  58
  59         ret = drop_dev_ptrs(c, bkey_i_to_s(n), dev_idx, flags, false);
  60         if (ret)
  61                 return ret;
  62
  63         /*
  64          * If the new extent no longer has any pointers, bch2_extent_normalize()
  65          * will do the appropriate thing with it (turning it into a
  66          * KEY_TYPE_error key, or just a discard if it was a cached extent)
  67          */
  68         bch2_extent_normalize(c, bkey_i_to_s(n));
  69
  70         /*
  71          * Since we're not inserting through an extent iterator
  72          * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
  73          * we aren't using the extent overwrite path to delete, we're
  74          * just using the normal key deletion path:
  75          */
  76         if (bkey_deleted(&n->k))
  77                 n->k.size = 0;
  78
  79         return bch2_trans_update(trans, iter, n, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
  80 }
  81
  82 static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
  83 {
  84         struct btree_trans trans;
  85         struct btree_iter iter;
  86         struct bkey_s_c k;
  87         enum btree_id id;
  88         int ret = 0;
  89
  90         bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
  91
  92         for (id = 0; id < BTREE_ID_NR; id++) {
  93                 if (!btree_type_has_ptrs(id))
  94                         continue;
  95
  96                 ret = for_each_btree_key_commit(&trans, iter, id, POS_MIN,
  97                                 BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
  98                                 NULL, NULL, BTREE_INSERT_NOFAIL,
  99                         bch2_dev_usrdata_drop_key(&trans, &iter, k, dev_idx, flags));
 100                 if (ret)
 101                         break;
 102         }
 103
 104         bch2_trans_exit(&trans);
 105
 106         return ret;
 107 }
 108
 109 static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 110 {
 111         struct btree_trans trans;
 112         struct btree_iter iter;
 113         struct closure cl;
 114         struct btree *b;
 115         struct bkey_buf k;
 116         unsigned id;
 117         int ret;
 118
 119         /* don't handle this yet: */
 120         if (flags & BCH_FORCE_IF_METADATA_LOST)
 121                 return -EINVAL;
 122
 123         bch2_bkey_buf_init(&k);
 124         bch2_trans_init(&trans, c, 0, 0);
 125         closure_init_stack(&cl);
 126
 127         for (id = 0; id < BTREE_ID_NR; id++) {
 128                 bch2_trans_node_iter_init(&trans, &iter, id, POS_MIN, 0, 0,
 129                                           BTREE_ITER_PREFETCH);
 130 retry:
 131                 ret = 0;
 132                 while (bch2_trans_begin(&trans),
 133                        (b = bch2_btree_iter_peek_node(&iter)) &&
 134                        !(ret = PTR_ERR_OR_ZERO(b))) {
 135                         if (!bch2_bkey_has_device(bkey_i_to_s_c(&b->key),
 136                                                   dev_idx))
 137                                 goto next;
 138
 139                         bch2_bkey_buf_copy(&k, c, &b->key);
 140
 141                         ret = drop_dev_ptrs(c, bkey_i_to_s(k.k),
 142                                             dev_idx, flags, true);
 143                         if (ret) {
 144                                 bch_err(c, "Cannot drop device without losing data");
 145                                 break;
 146                         }
 147
 148                         ret = bch2_btree_node_update_key(&trans, &iter, b, k.k, false);
 149                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
 150                                 ret = 0;
 151                                 continue;
 152                         }
 153
 154                         if (ret) {
 155                                 bch_err(c, "Error updating btree node key: %s",
 156                                         bch2_err_str(ret));
 157                                 break;
 158                         }
 159 next:
 160                         bch2_btree_iter_next_node(&iter);
 161                 }
 162                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 163                         goto retry;
 164
 165                 bch2_trans_iter_exit(&trans, &iter);
 166
 167                 if (ret)
 168                         goto err;
 169         }
 170
 171         bch2_btree_interior_updates_flush(c);
 172         ret = 0;
 173 err:
 174         bch2_trans_exit(&trans);
 175         bch2_bkey_buf_exit(&k, c);
 176
 177         BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
 178
 179         return ret;
 180 }
 181
 182 int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 183 {
 184         return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
 185                 bch2_dev_metadata_drop(c, dev_idx, flags);
 186 }