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_on_stack.h"
   8 #include "btree_update.h"
   9 #include "btree_update_interior.h"
  10 #include "buckets.h"
  11 #include "extents.h"
  12 #include "io.h"
  13 #include "journal.h"
  14 #include "keylist.h"
  15 #include "migrate.h"
  16 #include "move.h"
  17 #include "replicas.h"
  18 #include "super-io.h"
  19
  20 static int drop_dev_ptrs(struct bch_fs *c, struct bkey_s k,
  21                          unsigned dev_idx, int flags, bool metadata)
  22 {
  23         unsigned replicas = metadata ? c->opts.metadata_replicas : c->opts.data_replicas;
  24         unsigned lost = metadata ? BCH_FORCE_IF_METADATA_LOST : BCH_FORCE_IF_DATA_LOST;
  25         unsigned degraded = metadata ? BCH_FORCE_IF_METADATA_DEGRADED : BCH_FORCE_IF_DATA_DEGRADED;
  26         unsigned nr_good;
  27
  28         bch2_bkey_drop_device(k, dev_idx);
  29
  30         nr_good = bch2_bkey_durability(c, k.s_c);
  31         if ((!nr_good && !(flags & lost)) ||
  32             (nr_good < replicas && !(flags & degraded)))
  33                 return -EINVAL;
  34
  35         return 0;
  36 }
  37
  38 static int __bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags,
  39                                    enum btree_id btree_id)
  40 {
  41         struct btree_trans trans;
  42         struct btree_iter *iter;
  43         struct bkey_s_c k;
  44         struct bkey_on_stack sk;
  45         int ret = 0;
  46
  47         bkey_on_stack_init(&sk);
  48         bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
  49
  50         iter = bch2_trans_get_iter(&trans, btree_id, POS_MIN,
  51                                    BTREE_ITER_PREFETCH);
  52
  53         while ((k = bch2_btree_iter_peek(iter)).k &&
  54                !(ret = bkey_err(k))) {
  55                 if (!bch2_bkey_has_device(k, dev_idx)) {
  56                         bch2_btree_iter_next(iter);
  57                         continue;
  58                 }
  59
  60                 bkey_on_stack_reassemble(&sk, c, k);
  61
  62                 ret = drop_dev_ptrs(c, bkey_i_to_s(sk.k),
  63                                     dev_idx, flags, false);
  64                 if (ret)
  65                         break;
  66
  67                 /*
  68                  * If the new extent no longer has any pointers, bch2_extent_normalize()
  69                  * will do the appropriate thing with it (turning it into a
  70                  * KEY_TYPE_error key, or just a discard if it was a cached extent)
  71                  */
  72                 bch2_extent_normalize(c, bkey_i_to_s(sk.k));
  73
  74                 bch2_btree_iter_set_pos(iter, bkey_start_pos(&sk.k->k));
  75
  76                 bch2_trans_update(&trans, iter, sk.k, 0);
  77
  78                 ret = bch2_trans_commit(&trans, NULL, NULL,
  79                                         BTREE_INSERT_NOFAIL);
  80
  81                 /*
  82                  * don't want to leave ret == -EINTR, since if we raced and
  83                  * something else overwrote the key we could spuriously return
  84                  * -EINTR below:
  85                  */
  86                 if (ret == -EINTR)
  87                         ret = 0;
  88                 if (ret)
  89                         break;
  90         }
  91
  92         ret = bch2_trans_exit(&trans) ?: ret;
  93         bkey_on_stack_exit(&sk, c);
  94
  95         BUG_ON(ret == -EINTR);
  96
  97         return ret;
  98 }
  99
 100 static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 101 {
 102         return  __bch2_dev_usrdata_drop(c, dev_idx, flags, BTREE_ID_EXTENTS) ?:
 103                 __bch2_dev_usrdata_drop(c, dev_idx, flags, BTREE_ID_REFLINK);
 104 }
 105
 106 static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 107 {
 108         struct btree_trans trans;
 109         struct btree_iter *iter;
 110         struct closure cl;
 111         struct btree *b;
 112         unsigned id;
 113         int ret;
 114
 115         /* don't handle this yet: */
 116         if (flags & BCH_FORCE_IF_METADATA_LOST)
 117                 return -EINVAL;
 118
 119         bch2_trans_init(&trans, c, 0, 0);
 120         closure_init_stack(&cl);
 121
 122         for (id = 0; id < BTREE_ID_NR; id++) {
 123                 for_each_btree_node(&trans, iter, id, POS_MIN,
 124                                     BTREE_ITER_PREFETCH, b) {
 125                         __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX) tmp;
 126 retry:
 127                         if (!bch2_bkey_has_device(bkey_i_to_s_c(&b->key),
 128                                                   dev_idx))
 129                                 continue;
 130
 131                         bkey_copy(&tmp.k, &b->key);
 132
 133                         ret = drop_dev_ptrs(c, bkey_i_to_s(&tmp.k),
 134                                             dev_idx, flags, true);
 135                         if (ret) {
 136                                 bch_err(c, "Cannot drop device without losing data");
 137                                 goto err;
 138                         }
 139
 140                         ret = bch2_btree_node_update_key(c, iter, b, &tmp.k);
 141                         if (ret == -EINTR) {
 142                                 b = bch2_btree_iter_peek_node(iter);
 143                                 goto retry;
 144                         }
 145                         if (ret) {
 146                                 bch_err(c, "Error updating btree node key: %i", ret);
 147                                 goto err;
 148                         }
 149                 }
 150                 bch2_trans_iter_free(&trans, iter);
 151         }
 152
 153         /* flush relevant btree updates */
 154         closure_wait_event(&c->btree_interior_update_wait,
 155                            !bch2_btree_interior_updates_nr_pending(c));
 156
 157         ret = 0;
 158 err:
 159         ret = bch2_trans_exit(&trans) ?: ret;
 160
 161         BUG_ON(ret == -EINTR);
 162
 163         return ret;
 164 }
 165
 166 int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 167 {
 168         return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
 169                 bch2_dev_metadata_drop(c, dev_idx, flags);
 170 }