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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "bcachefs.h"
   3 #include "bkey_buf.h"
   4 #include "bkey_sort.h"
   5 #include "bset.h"
   6 #include "extents.h"
   7
   8 typedef int (*sort_cmp_fn)(struct btree *,
   9                            struct bkey_packed *,
  10                            struct bkey_packed *);
  11
  12 static inline bool sort_iter_end(struct sort_iter *iter)
  13 {
  14         return !iter->used;
  15 }
  16
  17 static inline void sort_iter_sift(struct sort_iter *iter, unsigned from,
  18                                   sort_cmp_fn cmp)
  19 {
  20         unsigned i;
  21
  22         for (i = from;
  23              i + 1 < iter->used &&
  24              cmp(iter->b, iter->data[i].k, iter->data[i + 1].k) > 0;
  25              i++)
  26                 swap(iter->data[i], iter->data[i + 1]);
  27 }
  28
  29 static inline void sort_iter_sort(struct sort_iter *iter, sort_cmp_fn cmp)
  30 {
  31         unsigned i = iter->used;
  32
  33         while (i--)
  34                 sort_iter_sift(iter, i, cmp);
  35 }
  36
  37 static inline struct bkey_packed *sort_iter_peek(struct sort_iter *iter)
  38 {
  39         return !sort_iter_end(iter) ? iter->data->k : NULL;
  40 }
  41
  42 static inline void sort_iter_advance(struct sort_iter *iter, sort_cmp_fn cmp)
  43 {
  44         struct sort_iter_set *i = iter->data;
  45
  46         BUG_ON(!iter->used);
  47
  48         i->k = bkey_next(i->k);
  49
  50         BUG_ON(i->k > i->end);
  51
  52         if (i->k == i->end)
  53                 array_remove_item(iter->data, iter->used, 0);
  54         else
  55                 sort_iter_sift(iter, 0, cmp);
  56 }
  57
  58 static inline struct bkey_packed *sort_iter_next(struct sort_iter *iter,
  59                                                  sort_cmp_fn cmp)
  60 {
  61         struct bkey_packed *ret = sort_iter_peek(iter);
  62
  63         if (ret)
  64                 sort_iter_advance(iter, cmp);
  65
  66         return ret;
  67 }
  68
  69 /*
  70  * If keys compare equal, compare by pointer order:
  71  */
  72 static inline int key_sort_fix_overlapping_cmp(struct btree *b,
  73                                                struct bkey_packed *l,
  74                                                struct bkey_packed *r)
  75 {
  76         return bch2_bkey_cmp_packed(b, l, r) ?:
  77                 cmp_int((unsigned long) l, (unsigned long) r);
  78 }
  79
  80 static inline bool should_drop_next_key(struct sort_iter *iter)
  81 {
  82         /*
  83          * key_sort_cmp() ensures that when keys compare equal the older key
  84          * comes first; so if l->k compares equal to r->k then l->k is older
  85          * and should be dropped.
  86          */
  87         return iter->used >= 2 &&
  88                 !bch2_bkey_cmp_packed(iter->b,
  89                                  iter->data[0].k,
  90                                  iter->data[1].k);
  91 }
  92
  93 struct btree_nr_keys
  94 bch2_key_sort_fix_overlapping(struct bch_fs *c, struct bset *dst,
  95                               struct sort_iter *iter)
  96 {
  97         struct bkey_packed *out = dst->start;
  98         struct bkey_packed *k;
  99         struct btree_nr_keys nr;
 100
 101         memset(&nr, 0, sizeof(nr));
 102
 103         sort_iter_sort(iter, key_sort_fix_overlapping_cmp);
 104
 105         while ((k = sort_iter_peek(iter))) {
 106                 if (!bkey_deleted(k) &&
 107                     !should_drop_next_key(iter)) {
 108                         bkey_copy(out, k);
 109                         btree_keys_account_key_add(&nr, 0, out);
 110                         out = bkey_next(out);
 111                 }
 112
 113                 sort_iter_advance(iter, key_sort_fix_overlapping_cmp);
 114         }
 115
 116         dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
 117         return nr;
 118 }
 119
 120 /* Sort + repack in a new format: */
 121 struct btree_nr_keys
 122 bch2_sort_repack(struct bset *dst, struct btree *src,
 123                  struct btree_node_iter *src_iter,
 124                  struct bkey_format *out_f,
 125                  bool filter_whiteouts)
 126 {
 127         struct bkey_format *in_f = &src->format;
 128         struct bkey_packed *in, *out = vstruct_last(dst);
 129         struct btree_nr_keys nr;
 130         bool transform = memcmp(out_f, &src->format, sizeof(*out_f));
 131
 132         memset(&nr, 0, sizeof(nr));
 133
 134         while ((in = bch2_btree_node_iter_next_all(src_iter, src))) {
 135                 if (filter_whiteouts && bkey_deleted(in))
 136                         continue;
 137
 138                 if (!transform)
 139                         bkey_copy(out, in);
 140                 else if (bch2_bkey_transform(out_f, out, bkey_packed(in)
 141                                              ? in_f : &bch2_bkey_format_current, in))
 142                         out->format = KEY_FORMAT_LOCAL_BTREE;
 143                 else
 144                         bch2_bkey_unpack(src, (void *) out, in);
 145
 146                 btree_keys_account_key_add(&nr, 0, out);
 147                 out = bkey_next(out);
 148         }
 149
 150         dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
 151         return nr;
 152 }
 153
 154 static inline int sort_keys_cmp(struct btree *b,
 155                                 struct bkey_packed *l,
 156                                 struct bkey_packed *r)
 157 {
 158         return bch2_bkey_cmp_packed(b, l, r) ?:
 159                 (int) bkey_deleted(r) - (int) bkey_deleted(l) ?:
 160                 (int) l->needs_whiteout - (int) r->needs_whiteout;
 161 }
 162
 163 unsigned bch2_sort_keys(struct bkey_packed *dst,
 164                         struct sort_iter *iter,
 165                         bool filter_whiteouts)
 166 {
 167         const struct bkey_format *f = &iter->b->format;
 168         struct bkey_packed *in, *next, *out = dst;
 169
 170         sort_iter_sort(iter, sort_keys_cmp);
 171
 172         while ((in = sort_iter_next(iter, sort_keys_cmp))) {
 173                 bool needs_whiteout = false;
 174
 175                 if (bkey_deleted(in) &&
 176                     (filter_whiteouts || !in->needs_whiteout))
 177                         continue;
 178
 179                 while ((next = sort_iter_peek(iter)) &&
 180                        !bch2_bkey_cmp_packed(iter->b, in, next)) {
 181                         BUG_ON(in->needs_whiteout &&
 182                                next->needs_whiteout);
 183                         needs_whiteout |= in->needs_whiteout;
 184                         in = sort_iter_next(iter, sort_keys_cmp);
 185                 }
 186
 187                 if (bkey_deleted(in)) {
 188                         memcpy_u64s(out, in, bkeyp_key_u64s(f, in));
 189                         set_bkeyp_val_u64s(f, out, 0);
 190                 } else {
 191                         bkey_copy(out, in);
 192                 }
 193                 out->needs_whiteout |= needs_whiteout;
 194                 out = bkey_next(out);
 195         }
 196
 197         return (u64 *) out - (u64 *) dst;
 198 }