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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "bcachefs.h"
   3 #include "bkey_on_stack.h"
   4 #include "btree_update.h"
   5 #include "btree_update_interior.h"
   6 #include "buckets.h"
   7 #include "debug.h"
   8 #include "extents.h"
   9 #include "extent_update.h"
  10
  11 /*
  12  * This counts the number of iterators to the alloc & ec btrees we'll need
  13  * inserting/removing this extent:
  14  */
  15 static unsigned bch2_bkey_nr_alloc_ptrs(struct bkey_s_c k)
  16 {
  17         struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
  18         const union bch_extent_entry *entry;
  19         unsigned ret = 0;
  20
  21         bkey_extent_entry_for_each(ptrs, entry) {
  22                 switch (__extent_entry_type(entry)) {
  23                 case BCH_EXTENT_ENTRY_ptr:
  24                 case BCH_EXTENT_ENTRY_stripe_ptr:
  25                         ret++;
  26                 }
  27         }
  28
  29         return ret;
  30 }
  31
  32 static int count_iters_for_insert(struct btree_trans *trans,
  33                                   struct bkey_s_c k,
  34                                   unsigned offset,
  35                                   struct bpos *end,
  36                                   unsigned *nr_iters,
  37                                   unsigned max_iters,
  38                                   bool overwrite)
  39 {
  40         int ret = 0;
  41
  42         /*
  43          * The extent update path requires an _additional_ iterator for each
  44          * extent we're inserting and overwriting:
  45          */
  46         *nr_iters += 1;
  47
  48         switch (k.k->type) {
  49         case KEY_TYPE_extent:
  50         case KEY_TYPE_reflink_v:
  51                 *nr_iters += bch2_bkey_nr_alloc_ptrs(k);
  52
  53                 if (*nr_iters >= max_iters) {
  54                         *end = bpos_min(*end, k.k->p);
  55                         ret = 1;
  56                 }
  57
  58                 break;
  59         case KEY_TYPE_reflink_p: {
  60                 struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
  61                 u64 idx = le64_to_cpu(p.v->idx);
  62                 unsigned sectors = bpos_min(*end, p.k->p).offset -
  63                         bkey_start_offset(p.k);
  64                 struct btree_iter *iter;
  65                 struct bkey_s_c r_k;
  66
  67                 for_each_btree_key(trans, iter,
  68                                    BTREE_ID_REFLINK, POS(0, idx + offset),
  69                                    BTREE_ITER_SLOTS, r_k, ret) {
  70                         if (bkey_cmp(bkey_start_pos(r_k.k),
  71                                      POS(0, idx + sectors)) >= 0)
  72                                 break;
  73
  74                         *nr_iters += 1 + bch2_bkey_nr_alloc_ptrs(r_k);
  75
  76                         if (*nr_iters >= max_iters) {
  77                                 struct bpos pos = bkey_start_pos(k.k);
  78                                 pos.offset += r_k.k->p.offset - idx;
  79
  80                                 *end = bpos_min(*end, pos);
  81                                 ret = 1;
  82                                 break;
  83                         }
  84                 }
  85
  86                 bch2_trans_iter_put(trans, iter);
  87                 break;
  88         }
  89         }
  90
  91         return ret;
  92 }
  93
  94 #define EXTENT_ITERS_MAX        (BTREE_ITER_MAX / 3)
  95
  96 int bch2_extent_atomic_end(struct btree_iter *iter,
  97                            struct bkey_i *insert,
  98                            struct bpos *end)
  99 {
 100         struct btree_trans *trans = iter->trans;
 101         struct btree *b;
 102         struct btree_node_iter  node_iter;
 103         struct bkey_packed      *_k;
 104         unsigned                nr_iters = 0;
 105         int ret;
 106
 107         ret = bch2_btree_iter_traverse(iter);
 108         if (ret)
 109                 return ret;
 110
 111         b = iter->l[0].b;
 112         node_iter = iter->l[0].iter;
 113
 114         BUG_ON(bkey_cmp(bkey_start_pos(&insert->k), b->data->min_key) < 0);
 115
 116         *end = bpos_min(insert->k.p, b->key.k.p);
 117
 118         ret = count_iters_for_insert(trans, bkey_i_to_s_c(insert), 0, end,
 119                                      &nr_iters, EXTENT_ITERS_MAX / 2, false);
 120         if (ret < 0)
 121                 return ret;
 122
 123         while ((_k = bch2_btree_node_iter_peek(&node_iter, b))) {
 124                 struct bkey     unpacked;
 125                 struct bkey_s_c k = bkey_disassemble(b, _k, &unpacked);
 126                 unsigned offset = 0;
 127
 128                 if (bkey_cmp(bkey_start_pos(k.k), *end) >= 0)
 129                         break;
 130
 131                 if (bkey_cmp(bkey_start_pos(&insert->k),
 132                              bkey_start_pos(k.k)) > 0)
 133                         offset = bkey_start_offset(&insert->k) -
 134                                 bkey_start_offset(k.k);
 135
 136                 ret = count_iters_for_insert(trans, k, offset, end,
 137                                         &nr_iters, EXTENT_ITERS_MAX, true);
 138                 if (ret)
 139                         break;
 140
 141                 bch2_btree_node_iter_advance(&node_iter, b);
 142         }
 143
 144         return ret < 0 ? ret : 0;
 145 }
 146
 147 int bch2_extent_trim_atomic(struct bkey_i *k, struct btree_iter *iter)
 148 {
 149         struct bpos end;
 150         int ret;
 151
 152         ret = bch2_extent_atomic_end(iter, k, &end);
 153         if (ret)
 154                 return ret;
 155
 156         bch2_cut_back(end, k);
 157         return 0;
 158 }
 159
 160 int bch2_extent_is_atomic(struct bkey_i *k, struct btree_iter *iter)
 161 {
 162         struct bpos end;
 163         int ret;
 164
 165         ret = bch2_extent_atomic_end(iter, k, &end);
 166         if (ret)
 167                 return ret;
 168
 169         return !bkey_cmp(end, k->k.p);
 170 }
 171
 172 enum btree_insert_ret
 173 bch2_extent_can_insert(struct btree_trans *trans,
 174                        struct btree_iter *iter,
 175                        struct bkey_i *insert)
 176 {
 177         struct btree_iter_level *l = &iter->l[0];
 178         struct btree_node_iter node_iter = l->iter;
 179         struct bkey_packed *_k;
 180         struct bkey_s_c k;
 181         struct bkey unpacked;
 182         int sectors;
 183
 184         _k = bch2_btree_node_iter_peek(&node_iter, l->b);
 185         if (!_k)
 186                 return BTREE_INSERT_OK;
 187
 188         k = bkey_disassemble(l->b, _k, &unpacked);
 189
 190         /* Check if we're splitting a compressed extent: */
 191
 192         if (bkey_cmp(bkey_start_pos(&insert->k), bkey_start_pos(k.k)) > 0 &&
 193             bkey_cmp(insert->k.p, k.k->p) < 0 &&
 194             (sectors = bch2_bkey_sectors_compressed(k))) {
 195                 int flags = trans->flags & BTREE_INSERT_NOFAIL
 196                         ? BCH_DISK_RESERVATION_NOFAIL : 0;
 197
 198                 switch (bch2_disk_reservation_add(trans->c, trans->disk_res,
 199                                                   sectors, flags)) {
 200                 case 0:
 201                         break;
 202                 case -ENOSPC:
 203                         return BTREE_INSERT_ENOSPC;
 204                 default:
 205                         BUG();
 206                 }
 207         }
 208
 209         return BTREE_INSERT_OK;
 210 }