1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _BCACHEFS_BTREE_UPDATE_INTERIOR_H
3#define _BCACHEFS_BTREE_UPDATE_INTERIOR_H
4
5#include "btree_cache.h"
6#include "btree_locking.h"
7#include "btree_update.h"
8
9#define BTREE_UPDATE_NODES_MAX ((BTREE_MAX_DEPTH - 2) * 2 + GC_MERGE_NODES)
10
11#define BTREE_UPDATE_JOURNAL_RES (BTREE_UPDATE_NODES_MAX * (BKEY_BTREE_PTR_U64s_MAX + 1))
12
13int bch2_btree_node_check_topology(struct btree_trans *, struct btree *);
14
15#define BTREE_UPDATE_MODES() \
16 x(none) \
17 x(node) \
18 x(root) \
19 x(update)
20
21enum btree_update_mode {
22#define x(n) BTREE_UPDATE_##n,
23 BTREE_UPDATE_MODES()
24#undef x
25};
26
27/*
28 * Tracks an in progress split/rewrite of a btree node and the update to the
29 * parent node:
30 *
31 * When we split/rewrite a node, we do all the updates in memory without
32 * waiting for any writes to complete - we allocate the new node(s) and update
33 * the parent node, possibly recursively up to the root.
34 *
35 * The end result is that we have one or more new nodes being written -
36 * possibly several, if there were multiple splits - and then a write (updating
37 * an interior node) which will make all these new nodes visible.
38 *
39 * Additionally, as we split/rewrite nodes we free the old nodes - but the old
40 * nodes can't be freed (their space on disk can't be reclaimed) until the
41 * update to the interior node that makes the new node visible completes -
42 * until then, the old nodes are still reachable on disk.
43 *
44 */
45struct btree_update {
46 struct closure cl;
47 struct bch_fs *c;
48 u64 start_time;
49 unsigned long ip_started;
50
51 struct list_head list;
52 struct list_head unwritten_list;
53
54 enum btree_update_mode mode;
55 enum bch_watermark watermark;
56 unsigned nodes_written:1;
57 unsigned took_gc_lock:1;
58
59 enum btree_id btree_id;
60 unsigned update_level_start;
61 unsigned update_level_end;
62
63 struct disk_reservation disk_res;
64
65 /*
66 * BTREE_UPDATE_node:
67 * The update that made the new nodes visible was a regular update to an
68 * existing interior node - @b. We can't write out the update to @b
69 * until the new nodes we created are finished writing, so we block @b
70 * from writing by putting this btree_interior update on the
71 * @b->write_blocked list with @write_blocked_list:
72 */
73 struct btree *b;
74 struct list_head write_blocked_list;
75
76 /*
77 * We may be freeing nodes that were dirty, and thus had journal entries
78 * pinned: we need to transfer the oldest of those pins to the
79 * btree_update operation, and release it when the new node(s)
80 * are all persistent and reachable:
81 */
82 struct journal_entry_pin journal;
83
84 /* Preallocated nodes we reserve when we start the update: */
85 struct prealloc_nodes {
86 struct btree *b[BTREE_UPDATE_NODES_MAX];
87 unsigned nr;
88 } prealloc_nodes[2];
89
90 /* Nodes being freed: */
91 struct keylist old_keys;
92 u64 _old_keys[BTREE_UPDATE_NODES_MAX *
93 BKEY_BTREE_PTR_U64s_MAX];
94
95 /* Nodes being added: */
96 struct keylist new_keys;
97 u64 _new_keys[BTREE_UPDATE_NODES_MAX *
98 BKEY_BTREE_PTR_U64s_MAX];
99
100 /* New nodes, that will be made reachable by this update: */
101 struct btree *new_nodes[BTREE_UPDATE_NODES_MAX];
102 unsigned nr_new_nodes;
103
104 struct btree *old_nodes[BTREE_UPDATE_NODES_MAX];
105 __le64 old_nodes_seq[BTREE_UPDATE_NODES_MAX];
106 unsigned nr_old_nodes;
107
108 open_bucket_idx_t open_buckets[BTREE_UPDATE_NODES_MAX *
109 BCH_REPLICAS_MAX];
110 open_bucket_idx_t nr_open_buckets;
111
112 unsigned journal_u64s;
113 u64 journal_entries[BTREE_UPDATE_JOURNAL_RES];
114
115 /* Only here to reduce stack usage on recursive splits: */
116 struct keylist parent_keys;
117 /*
118 * Enough room for btree_split's keys without realloc - btree node
119 * pointers never have crc/compression info, so we only need to acount
120 * for the pointers for three keys
121 */
122 u64 inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3];
123};
124
125struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *,
126 struct btree_trans *,
127 struct btree *,
128 struct bkey_format);
129
130int bch2_btree_split_leaf(struct btree_trans *, btree_path_idx_t, unsigned);
131
132int bch2_btree_increase_depth(struct btree_trans *, btree_path_idx_t, unsigned);
133
134int __bch2_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t,
135 unsigned, unsigned, enum btree_node_sibling);
136
137static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans,
138 btree_path_idx_t path_idx,
139 unsigned level, unsigned flags,
140 enum btree_node_sibling sib)
141{
142 struct btree_path *path = trans->paths + path_idx;
143 struct btree *b;
144
145 EBUG_ON(!btree_node_locked(path, level));
146
147 b = path->l[level].b;
148 if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold)
149 return 0;
150
151 return __bch2_foreground_maybe_merge(trans, path_idx, level, flags, sib);
152}
153
154static inline int bch2_foreground_maybe_merge(struct btree_trans *trans,
155 btree_path_idx_t path,
156 unsigned level,
157 unsigned flags)
158{
159 return bch2_foreground_maybe_merge_sibling(trans, path_idx: path, level, flags,
160 sib: btree_prev_sib) ?:
161 bch2_foreground_maybe_merge_sibling(trans, path_idx: path, level, flags,
162 sib: btree_next_sib);
163}
164
165int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *,
166 struct btree *, unsigned);
167void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *);
168int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *,
169 struct btree *, struct bkey_i *,
170 unsigned, bool);
171int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *,
172 struct bkey_i *, unsigned, bool);
173
174void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *);
175void bch2_btree_root_alloc_fake(struct bch_fs *, enum btree_id, unsigned);
176
177static inline unsigned btree_update_reserve_required(struct bch_fs *c,
178 struct btree *b)
179{
180 unsigned depth = btree_node_root(c, b)->c.level + 1;
181
182 /*
183 * Number of nodes we might have to allocate in a worst case btree
184 * split operation - we split all the way up to the root, then allocate
185 * a new root, unless we're already at max depth:
186 */
187 if (depth < BTREE_MAX_DEPTH)
188 return (depth - b->c.level) * 2 + 1;
189 else
190 return (depth - b->c.level) * 2 - 1;
191}
192
193static inline void btree_node_reset_sib_u64s(struct btree *b)
194{
195 b->sib_u64s[0] = b->nr.live_u64s;
196 b->sib_u64s[1] = b->nr.live_u64s;
197}
198
199static inline void *btree_data_end(struct btree *b)
200{
201 return (void *) b->data + btree_buf_bytes(b);
202}
203
204static inline struct bkey_packed *unwritten_whiteouts_start(struct btree *b)
205{
206 return (void *) ((u64 *) btree_data_end(b) - b->whiteout_u64s);
207}
208
209static inline struct bkey_packed *unwritten_whiteouts_end(struct btree *b)
210{
211 return btree_data_end(b);
212}
213
214static inline void *write_block(struct btree *b)
215{
216 return (void *) b->data + (b->written << 9);
217}
218
219static inline bool __btree_addr_written(struct btree *b, void *p)
220{
221 return p < write_block(b);
222}
223
224static inline bool bset_written(struct btree *b, struct bset *i)
225{
226 return __btree_addr_written(b, p: i);
227}
228
229static inline bool bkey_written(struct btree *b, struct bkey_packed *k)
230{
231 return __btree_addr_written(b, p: k);
232}
233
234static inline ssize_t __bch2_btree_u64s_remaining(struct btree *b, void *end)
235{
236 ssize_t used = bset_byte_offset(b, i: end) / sizeof(u64) +
237 b->whiteout_u64s;
238 ssize_t total = btree_buf_bytes(b) >> 3;
239
240 /* Always leave one extra u64 for bch2_varint_decode: */
241 used++;
242
243 return total - used;
244}
245
246static inline size_t bch2_btree_keys_u64s_remaining(struct btree *b)
247{
248 ssize_t remaining = __bch2_btree_u64s_remaining(b,
249 btree_bkey_last(b, bset_tree_last(b)));
250
251 BUG_ON(remaining < 0);
252
253 if (bset_written(b, i: btree_bset_last(b)))
254 return 0;
255
256 return remaining;
257}
258
259#define BTREE_WRITE_SET_U64s_BITS 9
260
261static inline unsigned btree_write_set_buffer(struct btree *b)
262{
263 /*
264 * Could buffer up larger amounts of keys for btrees with larger keys,
265 * pending benchmarking:
266 */
267 return 8 << BTREE_WRITE_SET_U64s_BITS;
268}
269
270static inline struct btree_node_entry *want_new_bset(struct bch_fs *c, struct btree *b)
271{
272 struct bset_tree *t = bset_tree_last(b);
273 struct btree_node_entry *bne = max(write_block(b),
274 (void *) btree_bkey_last(b, bset_tree_last(b)));
275 ssize_t remaining_space =
276 __bch2_btree_u64s_remaining(b, end: bne->keys.start);
277
278 if (unlikely(bset_written(b, bset(b, t)))) {
279 if (remaining_space > (ssize_t) (block_bytes(c) >> 3))
280 return bne;
281 } else {
282 if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) &&
283 remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3))
284 return bne;
285 }
286
287 return NULL;
288}
289
290static inline void push_whiteout(struct btree *b, struct bpos pos)
291{
292 struct bkey_packed k;
293
294 BUG_ON(bch2_btree_keys_u64s_remaining(b) < BKEY_U64s);
295 EBUG_ON(btree_node_just_written(b));
296
297 if (!bkey_pack_pos(out: &k, in: pos, b)) {
298 struct bkey *u = (void *) &k;
299
300 bkey_init(k: u);
301 u->p = pos;
302 }
303
304 k.needs_whiteout = true;
305
306 b->whiteout_u64s += k.u64s;
307 bkey_p_copy(dst: unwritten_whiteouts_start(b), src: &k);
308}
309
310/*
311 * write lock must be held on @b (else the dirty bset that we were going to
312 * insert into could be written out from under us)
313 */
314static inline bool bch2_btree_node_insert_fits(struct btree *b, unsigned u64s)
315{
316 if (unlikely(btree_node_need_rewrite(b)))
317 return false;
318
319 return u64s <= bch2_btree_keys_u64s_remaining(b);
320}
321
322void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *);
323
324bool bch2_btree_interior_updates_flush(struct bch_fs *);
325
326void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *);
327struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *,
328 struct jset_entry *, unsigned long);
329
330void bch2_do_pending_node_rewrites(struct bch_fs *);
331void bch2_free_pending_node_rewrites(struct bch_fs *);
332
333void bch2_fs_btree_interior_update_exit(struct bch_fs *);
334void bch2_fs_btree_interior_update_init_early(struct bch_fs *);
335int bch2_fs_btree_interior_update_init(struct bch_fs *);
336
337#endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */
338

source code of linux/fs/bcachefs/btree_update_interior.h