fs/bcachefs/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_write.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 -BCH_ERR_remove_would_lose_data;
  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_c(k, dev_idx))
  50                 return 0;
  51
  52         n = bch2_bkey_make_mut(trans, iter, &k, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
  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         return 0;
  77 }
  78
  79 static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
  80 {
  81         struct btree_trans *trans = bch2_trans_get(c);
  82         enum btree_id id;
  83         int ret = 0;
  84
  85         for (id = 0; id < BTREE_ID_NR; id++) {
  86                 if (!btree_type_has_ptrs(id))
  87                         continue;
  88
  89                 ret = for_each_btree_key_commit(trans, iter, id, POS_MIN,
  90                                 BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
  91                                 NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
  92                         bch2_dev_usrdata_drop_key(trans, &iter, k, dev_idx, flags));
  93                 if (ret)
  94                         break;
  95         }
  96
  97         bch2_trans_put(trans);
  98
  99         return ret;
 100 }
 101
 102 static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 103 {
 104         struct btree_trans *trans;
 105         struct btree_iter iter;
 106         struct closure cl;
 107         struct btree *b;
 108         struct bkey_buf k;
 109         unsigned id;
 110         int ret;
 111
 112         /* don't handle this yet: */
 113         if (flags & BCH_FORCE_IF_METADATA_LOST)
 114                 return -BCH_ERR_remove_with_metadata_missing_unimplemented;
 115
 116         trans = bch2_trans_get(c);
 117         bch2_bkey_buf_init(&k);
 118         closure_init_stack(&cl);
 119
 120         for (id = 0; id < BTREE_ID_NR; id++) {
 121                 bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
 122                                           BTREE_ITER_PREFETCH);
 123 retry:
 124                 ret = 0;
 125                 while (bch2_trans_begin(trans),
 126                        (b = bch2_btree_iter_peek_node(&iter)) &&
 127                        !(ret = PTR_ERR_OR_ZERO(b))) {
 128                         if (!bch2_bkey_has_device_c(bkey_i_to_s_c(&b->key), dev_idx))
 129                                 goto next;
 130
 131                         bch2_bkey_buf_copy(&k, c, &b->key);
 132
 133                         ret = drop_dev_ptrs(c, bkey_i_to_s(k.k),
 134                                             dev_idx, flags, true);
 135                         if (ret)
 136                                 break;
 137
 138                         ret = bch2_btree_node_update_key(trans, &iter, b, k.k, 0, false);
 139                         if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
 140                                 ret = 0;
 141                                 continue;
 142                         }
 143
 144                         bch_err_msg(c, ret, "updating btree node key");
 145                         if (ret)
 146                                 break;
 147 next:
 148                         bch2_btree_iter_next_node(&iter);
 149                 }
 150                 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 151                         goto retry;
 152
 153                 bch2_trans_iter_exit(trans, &iter);
 154
 155                 if (ret)
 156                         goto err;
 157         }
 158
 159         bch2_btree_interior_updates_flush(c);
 160         ret = 0;
 161 err:
 162         bch2_bkey_buf_exit(&k, c);
 163         bch2_trans_put(trans);
 164
 165         BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
 166
 167         return ret;
 168 }
 169
 170 int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 171 {
 172         return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
 173                 bch2_dev_metadata_drop(c, dev_idx, flags);
 174 }