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
9typedef int (*sort_cmp_fn)(struct btree *,
10 struct bkey_packed *,
11 struct bkey_packed *);
12
13static inline bool sort_iter_end(struct sort_iter *iter)
14{
15 return !iter->used;
16}
17
18static 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
30static 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, from: i, cmp);
36}
37
38static inline struct bkey_packed *sort_iter_peek(struct sort_iter *iter)
39{
40 return !sort_iter_end(iter) ? iter->data->k : NULL;
41}
42
43static 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, from: 0, cmp);
57}
58
59static 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 */
73static inline int key_sort_fix_overlapping_cmp(struct btree *b,
74 struct bkey_packed *l,
75 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
81static 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
94struct btree_nr_keys
95bch2_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, cmp: 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(dst: out, src: k);
110 btree_keys_account_key_add(&nr, 0, out);
111 out = bkey_p_next(out);
112 }
113
114 sort_iter_advance(iter, cmp: 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: */
122struct btree_nr_keys
123bch2_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(p: out_f, q: &src->format, size: sizeof(*out_f));
132
133 memset(&nr, 0, sizeof(nr));
134
135 while ((in = bch2_btree_node_iter_next_all(iter: src_iter, b: src))) {
136 if (filter_whiteouts && bkey_deleted(in))
137 continue;
138
139 if (!transform)
140 bkey_p_copy(dst: out, src: 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
157static inline int sort_keys_cmp(struct btree *b,
158 struct bkey_packed *l,
159 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 (int) l->needs_whiteout - (int) r->needs_whiteout;
164}
165
166unsigned bch2_sort_keys(struct bkey_packed *dst,
167 struct sort_iter *iter,
168 bool filter_whiteouts)
169{
170 const struct bkey_format *f = &iter->b->format;
171 struct bkey_packed *in, *next, *out = dst;
172
173 sort_iter_sort(iter, cmp: sort_keys_cmp);
174
175 while ((in = sort_iter_next(iter, cmp: sort_keys_cmp))) {
176 bool needs_whiteout = false;
177
178 if (bkey_deleted(in) &&
179 (filter_whiteouts || !in->needs_whiteout))
180 continue;
181
182 while ((next = sort_iter_peek(iter)) &&
183 !bch2_bkey_cmp_packed_inlined(b: iter->b, l: in, r: next)) {
184 BUG_ON(in->needs_whiteout &&
185 next->needs_whiteout);
186 needs_whiteout |= in->needs_whiteout;
187 in = sort_iter_next(iter, cmp: sort_keys_cmp);
188 }
189
190 if (bkey_deleted(in)) {
191 memcpy_u64s_small(dst: out, src: in, u64s: bkeyp_key_u64s(format: f, k: in));
192 set_bkeyp_val_u64s(format: f, k: out, val_u64s: 0);
193 } else {
194 bkey_p_copy(dst: out, src: in);
195 }
196 out->needs_whiteout |= needs_whiteout;
197 out = bkey_p_next(out);
198 }
199
200 return (u64 *) out - (u64 *) dst;
201}
202

source code of linux/fs/bcachefs/bkey_sort.c