fs/bcachefs/bkey_sort.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "bcachefs.h"
   3 #include "bkey_buf.h"
   4 #include "bkey_cmp.h"
   5 #include "bkey_sort.h"
   6 #include "bset.h"
   7 #include "extents.h"
   8
   9 typedef int (*sort_cmp_fn)(const struct btree *,
  10                            const struct bkey_packed *,
  11                            const struct bkey_packed *);
  12
  13 static inline bool sort_iter_end(struct sort_iter *iter)
  14 {
  15         return !iter->used;
  16 }
  17
  18 static inline void sort_iter_sift(struct sort_iter *iter, unsigned from,
  19                                   sort_cmp_fn cmp)
  20 {
  21         unsigned i;
  22
  23         for (i = from;
  24              i + 1 < iter->used &&
  25              cmp(iter->b, iter->data[i].k, iter->data[i + 1].k) > 0;
  26              i++)
  27                 swap(iter->data[i], iter->data[i + 1]);
  28 }
  29
  30 static inline void sort_iter_sort(struct sort_iter *iter, sort_cmp_fn cmp)
  31 {
  32         unsigned i = iter->used;
  33
  34         while (i--)
  35                 sort_iter_sift(iter, i, cmp);
  36 }
  37
  38 static inline struct bkey_packed *sort_iter_peek(struct sort_iter *iter)
  39 {
  40         return !sort_iter_end(iter) ? iter->data->k : NULL;
  41 }
  42
  43 static inline void sort_iter_advance(struct sort_iter *iter, sort_cmp_fn cmp)
  44 {
  45         struct sort_iter_set *i = iter->data;
  46
  47         BUG_ON(!iter->used);
  48
  49         i->k = bkey_p_next(i->k);
  50
  51         BUG_ON(i->k > i->end);
  52
  53         if (i->k == i->end)
  54                 array_remove_item(iter->data, iter->used, 0);
  55         else
  56                 sort_iter_sift(iter, 0, cmp);
  57 }
  58
  59 static inline struct bkey_packed *sort_iter_next(struct sort_iter *iter,
  60                                                  sort_cmp_fn cmp)
  61 {
  62         struct bkey_packed *ret = sort_iter_peek(iter);
  63
  64         if (ret)
  65                 sort_iter_advance(iter, cmp);
  66
  67         return ret;
  68 }
  69
  70 /*
  71  * If keys compare equal, compare by pointer order:
  72  */
  73 static inline int key_sort_fix_overlapping_cmp(const struct btree *b,
  74                                                const struct bkey_packed *l,
  75                                                const struct bkey_packed *r)
  76 {
  77         return bch2_bkey_cmp_packed(b, l, r) ?:
  78                 cmp_int((unsigned long) l, (unsigned long) r);
  79 }
  80
  81 static inline bool should_drop_next_key(struct sort_iter *iter)
  82 {
  83         /*
  84          * key_sort_cmp() ensures that when keys compare equal the older key
  85          * comes first; so if l->k compares equal to r->k then l->k is older
  86          * and should be dropped.
  87          */
  88         return iter->used >= 2 &&
  89                 !bch2_bkey_cmp_packed(iter->b,
  90                                  iter->data[0].k,
  91                                  iter->data[1].k);
  92 }
  93
  94 struct btree_nr_keys
  95 bch2_key_sort_fix_overlapping(struct bch_fs *c, struct bset *dst,
  96                               struct sort_iter *iter)
  97 {
  98         struct bkey_packed *out = dst->start;
  99         struct bkey_packed *k;
 100         struct btree_nr_keys nr;
 101
 102         memset(&nr, 0, sizeof(nr));
 103
 104         sort_iter_sort(iter, key_sort_fix_overlapping_cmp);
 105
 106         while ((k = sort_iter_peek(iter))) {
 107                 if (!bkey_deleted(k) &&
 108                     !should_drop_next_key(iter)) {
 109                         bkey_p_copy(out, k);
 110                         btree_keys_account_key_add(&nr, 0, out);
 111                         out = bkey_p_next(out);
 112                 }
 113
 114                 sort_iter_advance(iter, key_sort_fix_overlapping_cmp);
 115         }
 116
 117         dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
 118         return nr;
 119 }
 120
 121 /* Sort + repack in a new format: */
 122 struct btree_nr_keys
 123 bch2_sort_repack(struct bset *dst, struct btree *src,
 124                  struct btree_node_iter *src_iter,
 125                  struct bkey_format *out_f,
 126                  bool filter_whiteouts)
 127 {
 128         struct bkey_format *in_f = &src->format;
 129         struct bkey_packed *in, *out = vstruct_last(dst);
 130         struct btree_nr_keys nr;
 131         bool transform = memcmp(out_f, &src->format, sizeof(*out_f));
 132
 133         memset(&nr, 0, sizeof(nr));
 134
 135         while ((in = bch2_btree_node_iter_next_all(src_iter, src))) {
 136                 if (filter_whiteouts && bkey_deleted(in))
 137                         continue;
 138
 139                 if (!transform)
 140                         bkey_p_copy(out, in);
 141                 else if (bch2_bkey_transform(out_f, out, bkey_packed(in)
 142                                              ? in_f : &bch2_bkey_format_current, in))
 143                         out->format = KEY_FORMAT_LOCAL_BTREE;
 144                 else
 145                         bch2_bkey_unpack(src, (void *) out, in);
 146
 147                 out->needs_whiteout = false;
 148
 149                 btree_keys_account_key_add(&nr, 0, out);
 150                 out = bkey_p_next(out);
 151         }
 152
 153         dst->u64s = cpu_to_le16((u64 *) out - dst->_data);
 154         return nr;
 155 }
 156
 157 static inline int keep_unwritten_whiteouts_cmp(const struct btree *b,
 158                                 const struct bkey_packed *l,
 159                                 const struct bkey_packed *r)
 160 {
 161         return bch2_bkey_cmp_packed_inlined(b, l, r) ?:
 162                 (int) bkey_deleted(r) - (int) bkey_deleted(l) ?:
 163                 (long) l - (long) r;
 164 }
 165
 166 #include "btree_update_interior.h"
 167
 168 /*
 169  * For sorting in the btree node write path: whiteouts not in the unwritten
 170  * whiteouts area are dropped, whiteouts in the unwritten whiteouts area are
 171  * dropped if overwritten by real keys:
 172  */
 173 unsigned bch2_sort_keys_keep_unwritten_whiteouts(struct bkey_packed *dst, struct sort_iter *iter)
 174 {
 175         struct bkey_packed *in, *next, *out = dst;
 176
 177         sort_iter_sort(iter, keep_unwritten_whiteouts_cmp);
 178
 179         while ((in = sort_iter_next(iter, keep_unwritten_whiteouts_cmp))) {
 180                 if (bkey_deleted(in) && in < unwritten_whiteouts_start(iter->b))
 181                         continue;
 182
 183                 if ((next = sort_iter_peek(iter)) &&
 184                     !bch2_bkey_cmp_packed_inlined(iter->b, in, next))
 185                         continue;
 186
 187                 bkey_p_copy(out, in);
 188                 out = bkey_p_next(out);
 189         }
 190
 191         return (u64 *) out - (u64 *) dst;
 192 }
 193
 194 /*
 195  * Main sort routine for compacting a btree node in memory: we always drop
 196  * whiteouts because any whiteouts that need to be written are in the unwritten
 197  * whiteouts area:
 198  */
 199 unsigned bch2_sort_keys(struct bkey_packed *dst, struct sort_iter *iter)
 200 {
 201         struct bkey_packed *in, *out = dst;
 202
 203         sort_iter_sort(iter, bch2_bkey_cmp_packed_inlined);
 204
 205         while ((in = sort_iter_next(iter, bch2_bkey_cmp_packed_inlined))) {
 206                 if (bkey_deleted(in))
 207                         continue;
 208
 209                 bkey_p_copy(out, in);
 210                 out = bkey_p_next(out);
 211         }
 212
 213         return (u64 *) out - (u64 *) dst;
 214 }