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         if (*nr_iters >= max_iters) {
  48                 *end = bpos_min(*end, k.k->p);
  49                 ret = 1;
  50         }
  51
  52         switch (k.k->type) {
  53         case KEY_TYPE_extent:
  54         case KEY_TYPE_reflink_v:
  55                 *nr_iters += bch2_bkey_nr_alloc_ptrs(k);
  56
  57                 if (*nr_iters >= max_iters) {
  58                         *end = bpos_min(*end, k.k->p);
  59                         ret = 1;
  60                 }
  61
  62                 break;
  63         case KEY_TYPE_reflink_p: {
  64                 struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
  65                 u64 idx = le64_to_cpu(p.v->idx);
  66                 unsigned sectors = bpos_min(*end, p.k->p).offset -
  67                         bkey_start_offset(p.k);
  68                 struct btree_iter *iter;
  69                 struct bkey_s_c r_k;
  70
  71                 for_each_btree_key(trans, iter,
  72                                    BTREE_ID_REFLINK, POS(0, idx + offset),
  73                                    BTREE_ITER_SLOTS, r_k, ret) {
  74                         if (bkey_cmp(bkey_start_pos(r_k.k),
  75                                      POS(0, idx + sectors)) >= 0)
  76                                 break;
  77
  78                         *nr_iters += 1 + bch2_bkey_nr_alloc_ptrs(r_k);
  79
  80                         if (*nr_iters >= max_iters) {
  81                                 struct bpos pos = bkey_start_pos(k.k);
  82                                 pos.offset += r_k.k->p.offset - idx;
  83
  84                                 *end = bpos_min(*end, pos);
  85                                 ret = 1;
  86                                 break;
  87                         }
  88                 }
  89
  90                 bch2_trans_iter_put(trans, iter);
  91                 break;
  92         }
  93         }
  94
  95         return ret;
  96 }
  97
  98 #define EXTENT_ITERS_MAX        (BTREE_ITER_MAX / 3)
  99
 100 int bch2_extent_atomic_end(struct btree_iter *iter,
 101                            struct bkey_i *insert,
 102                            struct bpos *end)
 103 {
 104         struct btree_trans *trans = iter->trans;
 105         struct btree *b;
 106         struct btree_node_iter  node_iter;
 107         struct bkey_packed      *_k;
 108         unsigned                nr_iters = 0;
 109         int ret;
 110
 111         ret = bch2_btree_iter_traverse(iter);
 112         if (ret)
 113                 return ret;
 114
 115         b = iter->l[0].b;
 116         node_iter = iter->l[0].iter;
 117
 118         BUG_ON(bkey_cmp(bkey_start_pos(&insert->k), b->data->min_key) < 0);
 119
 120         *end = bpos_min(insert->k.p, b->key.k.p);
 121
 122         ret = count_iters_for_insert(trans, bkey_i_to_s_c(insert), 0, end,
 123                                      &nr_iters, EXTENT_ITERS_MAX / 2, false);
 124         if (ret < 0)
 125                 return ret;
 126
 127         while ((_k = bch2_btree_node_iter_peek(&node_iter, b))) {
 128                 struct bkey     unpacked;
 129                 struct bkey_s_c k = bkey_disassemble(b, _k, &unpacked);
 130                 unsigned offset = 0;
 131
 132                 if (bkey_cmp(bkey_start_pos(k.k), *end) >= 0)
 133                         break;
 134
 135                 if (bkey_cmp(bkey_start_pos(&insert->k),
 136                              bkey_start_pos(k.k)) > 0)
 137                         offset = bkey_start_offset(&insert->k) -
 138                                 bkey_start_offset(k.k);
 139
 140                 ret = count_iters_for_insert(trans, k, offset, end,
 141                                         &nr_iters, EXTENT_ITERS_MAX, true);
 142                 if (ret)
 143                         break;
 144
 145                 bch2_btree_node_iter_advance(&node_iter, b);
 146         }
 147
 148         return ret < 0 ? ret : 0;
 149 }
 150
 151 int bch2_extent_trim_atomic(struct bkey_i *k, struct btree_iter *iter)
 152 {
 153         struct bpos end;
 154         int ret;
 155
 156         ret = bch2_extent_atomic_end(iter, k, &end);
 157         if (ret)
 158                 return ret;
 159
 160         bch2_cut_back(end, k);
 161         return 0;
 162 }
 163
 164 int bch2_extent_is_atomic(struct bkey_i *k, struct btree_iter *iter)
 165 {
 166         struct bpos end;
 167         int ret;
 168
 169         ret = bch2_extent_atomic_end(iter, k, &end);
 170         if (ret)
 171                 return ret;
 172
 173         return !bkey_cmp(end, k->k.p);
 174 }
 175
 176 enum btree_insert_ret
 177 bch2_extent_can_insert(struct btree_trans *trans,
 178                        struct btree_iter *iter,
 179                        struct bkey_i *insert)
 180 {
 181         struct btree_iter_level *l = &iter->l[0];
 182         struct btree_node_iter node_iter = l->iter;
 183         struct bkey_packed *_k;
 184         struct bkey_s_c k;
 185         struct bkey unpacked;
 186         int sectors;
 187
 188         _k = bch2_btree_node_iter_peek(&node_iter, l->b);
 189         if (!_k)
 190                 return BTREE_INSERT_OK;
 191
 192         k = bkey_disassemble(l->b, _k, &unpacked);
 193
 194         /* Check if we're splitting a compressed extent: */
 195
 196         if (bkey_cmp(bkey_start_pos(&insert->k), bkey_start_pos(k.k)) > 0 &&
 197             bkey_cmp(insert->k.p, k.k->p) < 0 &&
 198             (sectors = bch2_bkey_sectors_compressed(k))) {
 199                 int flags = trans->flags & BTREE_INSERT_NOFAIL
 200                         ? BCH_DISK_RESERVATION_NOFAIL : 0;
 201
 202                 switch (bch2_disk_reservation_add(trans->c, trans->disk_res,
 203                                                   sectors, flags)) {
 204                 case 0:
 205                         break;
 206                 case -ENOSPC:
 207                         return BTREE_INSERT_ENOSPC;
 208                 default:
 209                         BUG();
 210                 }
 211         }
 212
 213         return BTREE_INSERT_OK;
 214 }