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cafe5635 KO |
1 | /* |
2 | * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com> | |
3 | * | |
4 | * Uses a block device as cache for other block devices; optimized for SSDs. | |
5 | * All allocation is done in buckets, which should match the erase block size | |
6 | * of the device. | |
7 | * | |
8 | * Buckets containing cached data are kept on a heap sorted by priority; | |
9 | * bucket priority is increased on cache hit, and periodically all the buckets | |
10 | * on the heap have their priority scaled down. This currently is just used as | |
11 | * an LRU but in the future should allow for more intelligent heuristics. | |
12 | * | |
13 | * Buckets have an 8 bit counter; freeing is accomplished by incrementing the | |
14 | * counter. Garbage collection is used to remove stale pointers. | |
15 | * | |
16 | * Indexing is done via a btree; nodes are not necessarily fully sorted, rather | |
17 | * as keys are inserted we only sort the pages that have not yet been written. | |
18 | * When garbage collection is run, we resort the entire node. | |
19 | * | |
20 | * All configuration is done via sysfs; see Documentation/bcache.txt. | |
21 | */ | |
22 | ||
23 | #include "bcache.h" | |
24 | #include "btree.h" | |
25 | #include "debug.h" | |
279afbad | 26 | #include "writeback.h" |
cafe5635 KO |
27 | |
28 | #include <linux/slab.h> | |
29 | #include <linux/bitops.h> | |
72a44517 | 30 | #include <linux/freezer.h> |
cafe5635 | 31 | #include <linux/hash.h> |
72a44517 | 32 | #include <linux/kthread.h> |
cd953ed0 | 33 | #include <linux/prefetch.h> |
cafe5635 KO |
34 | #include <linux/random.h> |
35 | #include <linux/rcupdate.h> | |
36 | #include <trace/events/bcache.h> | |
37 | ||
38 | /* | |
39 | * Todo: | |
40 | * register_bcache: Return errors out to userspace correctly | |
41 | * | |
42 | * Writeback: don't undirty key until after a cache flush | |
43 | * | |
44 | * Create an iterator for key pointers | |
45 | * | |
46 | * On btree write error, mark bucket such that it won't be freed from the cache | |
47 | * | |
48 | * Journalling: | |
49 | * Check for bad keys in replay | |
50 | * Propagate barriers | |
51 | * Refcount journal entries in journal_replay | |
52 | * | |
53 | * Garbage collection: | |
54 | * Finish incremental gc | |
55 | * Gc should free old UUIDs, data for invalid UUIDs | |
56 | * | |
57 | * Provide a way to list backing device UUIDs we have data cached for, and | |
58 | * probably how long it's been since we've seen them, and a way to invalidate | |
59 | * dirty data for devices that will never be attached again | |
60 | * | |
61 | * Keep 1 min/5 min/15 min statistics of how busy a block device has been, so | |
62 | * that based on that and how much dirty data we have we can keep writeback | |
63 | * from being starved | |
64 | * | |
65 | * Add a tracepoint or somesuch to watch for writeback starvation | |
66 | * | |
67 | * When btree depth > 1 and splitting an interior node, we have to make sure | |
68 | * alloc_bucket() cannot fail. This should be true but is not completely | |
69 | * obvious. | |
70 | * | |
71 | * Make sure all allocations get charged to the root cgroup | |
72 | * | |
73 | * Plugging? | |
74 | * | |
75 | * If data write is less than hard sector size of ssd, round up offset in open | |
76 | * bucket to the next whole sector | |
77 | * | |
78 | * Also lookup by cgroup in get_open_bucket() | |
79 | * | |
80 | * Superblock needs to be fleshed out for multiple cache devices | |
81 | * | |
82 | * Add a sysfs tunable for the number of writeback IOs in flight | |
83 | * | |
84 | * Add a sysfs tunable for the number of open data buckets | |
85 | * | |
86 | * IO tracking: Can we track when one process is doing io on behalf of another? | |
87 | * IO tracking: Don't use just an average, weigh more recent stuff higher | |
88 | * | |
89 | * Test module load/unload | |
90 | */ | |
91 | ||
df8e8970 KO |
92 | enum { |
93 | BTREE_INSERT_STATUS_INSERT, | |
94 | BTREE_INSERT_STATUS_BACK_MERGE, | |
95 | BTREE_INSERT_STATUS_OVERWROTE, | |
96 | BTREE_INSERT_STATUS_FRONT_MERGE, | |
97 | }; | |
98 | ||
cafe5635 KO |
99 | #define MAX_NEED_GC 64 |
100 | #define MAX_SAVE_PRIO 72 | |
101 | ||
102 | #define PTR_DIRTY_BIT (((uint64_t) 1 << 36)) | |
103 | ||
104 | #define PTR_HASH(c, k) \ | |
105 | (((k)->ptr[0] >> c->bucket_bits) | PTR_GEN(k, 0)) | |
106 | ||
cafe5635 KO |
107 | static struct workqueue_struct *btree_io_wq; |
108 | ||
df8e8970 KO |
109 | static inline bool should_split(struct btree *b) |
110 | { | |
111 | struct bset *i = write_block(b); | |
112 | return b->written >= btree_blocks(b) || | |
113 | (b->written + __set_blocks(i, i->keys + 15, b->c) | |
114 | > btree_blocks(b)); | |
115 | } | |
116 | ||
117 | #define insert_lock(s, b) ((b)->level <= (s)->lock) | |
118 | ||
119 | /* | |
120 | * These macros are for recursing down the btree - they handle the details of | |
121 | * locking and looking up nodes in the cache for you. They're best treated as | |
122 | * mere syntax when reading code that uses them. | |
123 | * | |
124 | * op->lock determines whether we take a read or a write lock at a given depth. | |
125 | * If you've got a read lock and find that you need a write lock (i.e. you're | |
126 | * going to have to split), set op->lock and return -EINTR; btree_root() will | |
127 | * call you again and you'll have the correct lock. | |
128 | */ | |
129 | ||
130 | /** | |
131 | * btree - recurse down the btree on a specified key | |
132 | * @fn: function to call, which will be passed the child node | |
133 | * @key: key to recurse on | |
134 | * @b: parent btree node | |
135 | * @op: pointer to struct btree_op | |
136 | */ | |
137 | #define btree(fn, key, b, op, ...) \ | |
138 | ({ \ | |
139 | int _r, l = (b)->level - 1; \ | |
140 | bool _w = l <= (op)->lock; \ | |
141 | struct btree *_child = bch_btree_node_get((b)->c, key, l, _w); \ | |
142 | if (!IS_ERR(_child)) { \ | |
143 | _child->parent = (b); \ | |
144 | _r = bch_btree_ ## fn(_child, op, ##__VA_ARGS__); \ | |
145 | rw_unlock(_w, _child); \ | |
146 | } else \ | |
147 | _r = PTR_ERR(_child); \ | |
148 | _r; \ | |
149 | }) | |
150 | ||
151 | /** | |
152 | * btree_root - call a function on the root of the btree | |
153 | * @fn: function to call, which will be passed the child node | |
154 | * @c: cache set | |
155 | * @op: pointer to struct btree_op | |
156 | */ | |
157 | #define btree_root(fn, c, op, ...) \ | |
158 | ({ \ | |
159 | int _r = -EINTR; \ | |
160 | do { \ | |
161 | struct btree *_b = (c)->root; \ | |
162 | bool _w = insert_lock(op, _b); \ | |
163 | rw_lock(_w, _b, _b->level); \ | |
164 | if (_b == (c)->root && \ | |
165 | _w == insert_lock(op, _b)) { \ | |
166 | _b->parent = NULL; \ | |
167 | _r = bch_btree_ ## fn(_b, op, ##__VA_ARGS__); \ | |
168 | } \ | |
169 | rw_unlock(_w, _b); \ | |
170 | bch_cannibalize_unlock(c); \ | |
171 | if (_r == -ENOSPC) { \ | |
172 | wait_event((c)->try_wait, \ | |
173 | !(c)->try_harder); \ | |
174 | _r = -EINTR; \ | |
175 | } \ | |
176 | } while (_r == -EINTR); \ | |
177 | \ | |
178 | _r; \ | |
179 | }) | |
180 | ||
cafe5635 KO |
181 | /* Btree key manipulation */ |
182 | ||
3a3b6a4e | 183 | void bkey_put(struct cache_set *c, struct bkey *k) |
e7c590eb KO |
184 | { |
185 | unsigned i; | |
186 | ||
187 | for (i = 0; i < KEY_PTRS(k); i++) | |
188 | if (ptr_available(c, k, i)) | |
189 | atomic_dec_bug(&PTR_BUCKET(c, k, i)->pin); | |
190 | } | |
191 | ||
cafe5635 KO |
192 | /* Btree IO */ |
193 | ||
194 | static uint64_t btree_csum_set(struct btree *b, struct bset *i) | |
195 | { | |
196 | uint64_t crc = b->key.ptr[0]; | |
197 | void *data = (void *) i + 8, *end = end(i); | |
198 | ||
169ef1cf | 199 | crc = bch_crc64_update(crc, data, end - data); |
c19ed23a | 200 | return crc ^ 0xffffffffffffffffULL; |
cafe5635 KO |
201 | } |
202 | ||
f3059a54 | 203 | static void bch_btree_node_read_done(struct btree *b) |
cafe5635 | 204 | { |
cafe5635 | 205 | const char *err = "bad btree header"; |
57943511 KO |
206 | struct bset *i = b->sets[0].data; |
207 | struct btree_iter *iter; | |
cafe5635 | 208 | |
57943511 KO |
209 | iter = mempool_alloc(b->c->fill_iter, GFP_NOWAIT); |
210 | iter->size = b->c->sb.bucket_size / b->c->sb.block_size; | |
cafe5635 KO |
211 | iter->used = 0; |
212 | ||
280481d0 KO |
213 | #ifdef CONFIG_BCACHE_DEBUG |
214 | iter->b = b; | |
215 | #endif | |
216 | ||
57943511 | 217 | if (!i->seq) |
cafe5635 KO |
218 | goto err; |
219 | ||
220 | for (; | |
221 | b->written < btree_blocks(b) && i->seq == b->sets[0].data->seq; | |
222 | i = write_block(b)) { | |
223 | err = "unsupported bset version"; | |
224 | if (i->version > BCACHE_BSET_VERSION) | |
225 | goto err; | |
226 | ||
227 | err = "bad btree header"; | |
228 | if (b->written + set_blocks(i, b->c) > btree_blocks(b)) | |
229 | goto err; | |
230 | ||
231 | err = "bad magic"; | |
81ab4190 | 232 | if (i->magic != bset_magic(&b->c->sb)) |
cafe5635 KO |
233 | goto err; |
234 | ||
235 | err = "bad checksum"; | |
236 | switch (i->version) { | |
237 | case 0: | |
238 | if (i->csum != csum_set(i)) | |
239 | goto err; | |
240 | break; | |
241 | case BCACHE_BSET_VERSION: | |
242 | if (i->csum != btree_csum_set(b, i)) | |
243 | goto err; | |
244 | break; | |
245 | } | |
246 | ||
247 | err = "empty set"; | |
248 | if (i != b->sets[0].data && !i->keys) | |
249 | goto err; | |
250 | ||
251 | bch_btree_iter_push(iter, i->start, end(i)); | |
252 | ||
253 | b->written += set_blocks(i, b->c); | |
254 | } | |
255 | ||
256 | err = "corrupted btree"; | |
257 | for (i = write_block(b); | |
258 | index(i, b) < btree_blocks(b); | |
259 | i = ((void *) i) + block_bytes(b->c)) | |
260 | if (i->seq == b->sets[0].data->seq) | |
261 | goto err; | |
262 | ||
263 | bch_btree_sort_and_fix_extents(b, iter); | |
264 | ||
265 | i = b->sets[0].data; | |
266 | err = "short btree key"; | |
267 | if (b->sets[0].size && | |
268 | bkey_cmp(&b->key, &b->sets[0].end) < 0) | |
269 | goto err; | |
270 | ||
271 | if (b->written < btree_blocks(b)) | |
272 | bch_bset_init_next(b); | |
273 | out: | |
57943511 KO |
274 | mempool_free(iter, b->c->fill_iter); |
275 | return; | |
cafe5635 KO |
276 | err: |
277 | set_btree_node_io_error(b); | |
07e86ccb | 278 | bch_cache_set_error(b->c, "%s at bucket %zu, block %zu, %u keys", |
cafe5635 KO |
279 | err, PTR_BUCKET_NR(b->c, &b->key, 0), |
280 | index(i, b), i->keys); | |
281 | goto out; | |
282 | } | |
283 | ||
57943511 | 284 | static void btree_node_read_endio(struct bio *bio, int error) |
cafe5635 | 285 | { |
57943511 KO |
286 | struct closure *cl = bio->bi_private; |
287 | closure_put(cl); | |
288 | } | |
cafe5635 | 289 | |
57943511 KO |
290 | void bch_btree_node_read(struct btree *b) |
291 | { | |
292 | uint64_t start_time = local_clock(); | |
293 | struct closure cl; | |
294 | struct bio *bio; | |
cafe5635 | 295 | |
c37511b8 KO |
296 | trace_bcache_btree_read(b); |
297 | ||
57943511 | 298 | closure_init_stack(&cl); |
cafe5635 | 299 | |
57943511 KO |
300 | bio = bch_bbio_alloc(b->c); |
301 | bio->bi_rw = REQ_META|READ_SYNC; | |
4f024f37 | 302 | bio->bi_iter.bi_size = KEY_SIZE(&b->key) << 9; |
57943511 KO |
303 | bio->bi_end_io = btree_node_read_endio; |
304 | bio->bi_private = &cl; | |
cafe5635 | 305 | |
57943511 | 306 | bch_bio_map(bio, b->sets[0].data); |
cafe5635 | 307 | |
57943511 KO |
308 | bch_submit_bbio(bio, b->c, &b->key, 0); |
309 | closure_sync(&cl); | |
cafe5635 | 310 | |
57943511 KO |
311 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
312 | set_btree_node_io_error(b); | |
313 | ||
314 | bch_bbio_free(bio, b->c); | |
315 | ||
316 | if (btree_node_io_error(b)) | |
317 | goto err; | |
318 | ||
319 | bch_btree_node_read_done(b); | |
57943511 | 320 | bch_time_stats_update(&b->c->btree_read_time, start_time); |
57943511 KO |
321 | |
322 | return; | |
323 | err: | |
61cbd250 | 324 | bch_cache_set_error(b->c, "io error reading bucket %zu", |
57943511 | 325 | PTR_BUCKET_NR(b->c, &b->key, 0)); |
cafe5635 KO |
326 | } |
327 | ||
328 | static void btree_complete_write(struct btree *b, struct btree_write *w) | |
329 | { | |
330 | if (w->prio_blocked && | |
331 | !atomic_sub_return(w->prio_blocked, &b->c->prio_blocked)) | |
119ba0f8 | 332 | wake_up_allocators(b->c); |
cafe5635 KO |
333 | |
334 | if (w->journal) { | |
335 | atomic_dec_bug(w->journal); | |
336 | __closure_wake_up(&b->c->journal.wait); | |
337 | } | |
338 | ||
cafe5635 KO |
339 | w->prio_blocked = 0; |
340 | w->journal = NULL; | |
cafe5635 KO |
341 | } |
342 | ||
57943511 | 343 | static void __btree_node_write_done(struct closure *cl) |
cafe5635 KO |
344 | { |
345 | struct btree *b = container_of(cl, struct btree, io.cl); | |
346 | struct btree_write *w = btree_prev_write(b); | |
347 | ||
348 | bch_bbio_free(b->bio, b->c); | |
349 | b->bio = NULL; | |
350 | btree_complete_write(b, w); | |
351 | ||
352 | if (btree_node_dirty(b)) | |
353 | queue_delayed_work(btree_io_wq, &b->work, | |
354 | msecs_to_jiffies(30000)); | |
355 | ||
356 | closure_return(cl); | |
357 | } | |
358 | ||
57943511 | 359 | static void btree_node_write_done(struct closure *cl) |
cafe5635 KO |
360 | { |
361 | struct btree *b = container_of(cl, struct btree, io.cl); | |
362 | struct bio_vec *bv; | |
363 | int n; | |
364 | ||
365 | __bio_for_each_segment(bv, b->bio, n, 0) | |
366 | __free_page(bv->bv_page); | |
367 | ||
57943511 | 368 | __btree_node_write_done(cl); |
cafe5635 KO |
369 | } |
370 | ||
57943511 KO |
371 | static void btree_node_write_endio(struct bio *bio, int error) |
372 | { | |
373 | struct closure *cl = bio->bi_private; | |
374 | struct btree *b = container_of(cl, struct btree, io.cl); | |
375 | ||
376 | if (error) | |
377 | set_btree_node_io_error(b); | |
378 | ||
379 | bch_bbio_count_io_errors(b->c, bio, error, "writing btree"); | |
380 | closure_put(cl); | |
381 | } | |
382 | ||
383 | static void do_btree_node_write(struct btree *b) | |
cafe5635 KO |
384 | { |
385 | struct closure *cl = &b->io.cl; | |
386 | struct bset *i = b->sets[b->nsets].data; | |
387 | BKEY_PADDED(key) k; | |
388 | ||
389 | i->version = BCACHE_BSET_VERSION; | |
390 | i->csum = btree_csum_set(b, i); | |
391 | ||
57943511 KO |
392 | BUG_ON(b->bio); |
393 | b->bio = bch_bbio_alloc(b->c); | |
394 | ||
395 | b->bio->bi_end_io = btree_node_write_endio; | |
faadf0c9 | 396 | b->bio->bi_private = cl; |
e49c7c37 | 397 | b->bio->bi_rw = REQ_META|WRITE_SYNC|REQ_FUA; |
4f024f37 | 398 | b->bio->bi_iter.bi_size = set_blocks(i, b->c) * block_bytes(b->c); |
169ef1cf | 399 | bch_bio_map(b->bio, i); |
cafe5635 | 400 | |
e49c7c37 KO |
401 | /* |
402 | * If we're appending to a leaf node, we don't technically need FUA - | |
403 | * this write just needs to be persisted before the next journal write, | |
404 | * which will be marked FLUSH|FUA. | |
405 | * | |
406 | * Similarly if we're writing a new btree root - the pointer is going to | |
407 | * be in the next journal entry. | |
408 | * | |
409 | * But if we're writing a new btree node (that isn't a root) or | |
410 | * appending to a non leaf btree node, we need either FUA or a flush | |
411 | * when we write the parent with the new pointer. FUA is cheaper than a | |
412 | * flush, and writes appending to leaf nodes aren't blocking anything so | |
413 | * just make all btree node writes FUA to keep things sane. | |
414 | */ | |
415 | ||
cafe5635 KO |
416 | bkey_copy(&k.key, &b->key); |
417 | SET_PTR_OFFSET(&k.key, 0, PTR_OFFSET(&k.key, 0) + bset_offset(b, i)); | |
418 | ||
8e51e414 | 419 | if (!bio_alloc_pages(b->bio, GFP_NOIO)) { |
cafe5635 KO |
420 | int j; |
421 | struct bio_vec *bv; | |
422 | void *base = (void *) ((unsigned long) i & ~(PAGE_SIZE - 1)); | |
423 | ||
424 | bio_for_each_segment(bv, b->bio, j) | |
425 | memcpy(page_address(bv->bv_page), | |
426 | base + j * PAGE_SIZE, PAGE_SIZE); | |
427 | ||
cafe5635 KO |
428 | bch_submit_bbio(b->bio, b->c, &k.key, 0); |
429 | ||
57943511 | 430 | continue_at(cl, btree_node_write_done, NULL); |
cafe5635 KO |
431 | } else { |
432 | b->bio->bi_vcnt = 0; | |
169ef1cf | 433 | bch_bio_map(b->bio, i); |
cafe5635 | 434 | |
cafe5635 KO |
435 | bch_submit_bbio(b->bio, b->c, &k.key, 0); |
436 | ||
437 | closure_sync(cl); | |
57943511 | 438 | __btree_node_write_done(cl); |
cafe5635 KO |
439 | } |
440 | } | |
441 | ||
57943511 | 442 | void bch_btree_node_write(struct btree *b, struct closure *parent) |
cafe5635 KO |
443 | { |
444 | struct bset *i = b->sets[b->nsets].data; | |
445 | ||
c37511b8 KO |
446 | trace_bcache_btree_write(b); |
447 | ||
cafe5635 | 448 | BUG_ON(current->bio_list); |
57943511 KO |
449 | BUG_ON(b->written >= btree_blocks(b)); |
450 | BUG_ON(b->written && !i->keys); | |
451 | BUG_ON(b->sets->data->seq != i->seq); | |
280481d0 | 452 | bch_check_keys(b, "writing"); |
cafe5635 | 453 | |
cafe5635 KO |
454 | cancel_delayed_work(&b->work); |
455 | ||
57943511 KO |
456 | /* If caller isn't waiting for write, parent refcount is cache set */ |
457 | closure_lock(&b->io, parent ?: &b->c->cl); | |
458 | ||
cafe5635 KO |
459 | clear_bit(BTREE_NODE_dirty, &b->flags); |
460 | change_bit(BTREE_NODE_write_idx, &b->flags); | |
461 | ||
57943511 | 462 | do_btree_node_write(b); |
cafe5635 | 463 | |
cafe5635 KO |
464 | b->written += set_blocks(i, b->c); |
465 | atomic_long_add(set_blocks(i, b->c) * b->c->sb.block_size, | |
466 | &PTR_CACHE(b->c, &b->key, 0)->btree_sectors_written); | |
467 | ||
468 | bch_btree_sort_lazy(b); | |
469 | ||
470 | if (b->written < btree_blocks(b)) | |
471 | bch_bset_init_next(b); | |
472 | } | |
473 | ||
f269af5a KO |
474 | static void bch_btree_node_write_sync(struct btree *b) |
475 | { | |
476 | struct closure cl; | |
477 | ||
478 | closure_init_stack(&cl); | |
479 | bch_btree_node_write(b, &cl); | |
480 | closure_sync(&cl); | |
481 | } | |
482 | ||
57943511 | 483 | static void btree_node_write_work(struct work_struct *w) |
cafe5635 KO |
484 | { |
485 | struct btree *b = container_of(to_delayed_work(w), struct btree, work); | |
486 | ||
57943511 | 487 | rw_lock(true, b, b->level); |
cafe5635 KO |
488 | |
489 | if (btree_node_dirty(b)) | |
57943511 KO |
490 | bch_btree_node_write(b, NULL); |
491 | rw_unlock(true, b); | |
cafe5635 KO |
492 | } |
493 | ||
c18536a7 | 494 | static void bch_btree_leaf_dirty(struct btree *b, atomic_t *journal_ref) |
cafe5635 KO |
495 | { |
496 | struct bset *i = b->sets[b->nsets].data; | |
497 | struct btree_write *w = btree_current_write(b); | |
498 | ||
57943511 KO |
499 | BUG_ON(!b->written); |
500 | BUG_ON(!i->keys); | |
cafe5635 | 501 | |
57943511 KO |
502 | if (!btree_node_dirty(b)) |
503 | queue_delayed_work(btree_io_wq, &b->work, 30 * HZ); | |
cafe5635 | 504 | |
57943511 | 505 | set_btree_node_dirty(b); |
cafe5635 | 506 | |
c18536a7 | 507 | if (journal_ref) { |
cafe5635 | 508 | if (w->journal && |
c18536a7 | 509 | journal_pin_cmp(b->c, w->journal, journal_ref)) { |
cafe5635 KO |
510 | atomic_dec_bug(w->journal); |
511 | w->journal = NULL; | |
512 | } | |
513 | ||
514 | if (!w->journal) { | |
c18536a7 | 515 | w->journal = journal_ref; |
cafe5635 KO |
516 | atomic_inc(w->journal); |
517 | } | |
518 | } | |
519 | ||
cafe5635 | 520 | /* Force write if set is too big */ |
57943511 KO |
521 | if (set_bytes(i) > PAGE_SIZE - 48 && |
522 | !current->bio_list) | |
523 | bch_btree_node_write(b, NULL); | |
cafe5635 KO |
524 | } |
525 | ||
526 | /* | |
527 | * Btree in memory cache - allocation/freeing | |
528 | * mca -> memory cache | |
529 | */ | |
530 | ||
531 | static void mca_reinit(struct btree *b) | |
532 | { | |
533 | unsigned i; | |
534 | ||
535 | b->flags = 0; | |
536 | b->written = 0; | |
537 | b->nsets = 0; | |
538 | ||
539 | for (i = 0; i < MAX_BSETS; i++) | |
540 | b->sets[i].size = 0; | |
541 | /* | |
542 | * Second loop starts at 1 because b->sets[0]->data is the memory we | |
543 | * allocated | |
544 | */ | |
545 | for (i = 1; i < MAX_BSETS; i++) | |
546 | b->sets[i].data = NULL; | |
547 | } | |
548 | ||
549 | #define mca_reserve(c) (((c->root && c->root->level) \ | |
550 | ? c->root->level : 1) * 8 + 16) | |
551 | #define mca_can_free(c) \ | |
552 | max_t(int, 0, c->bucket_cache_used - mca_reserve(c)) | |
553 | ||
554 | static void mca_data_free(struct btree *b) | |
555 | { | |
556 | struct bset_tree *t = b->sets; | |
557 | BUG_ON(!closure_is_unlocked(&b->io.cl)); | |
558 | ||
559 | if (bset_prev_bytes(b) < PAGE_SIZE) | |
560 | kfree(t->prev); | |
561 | else | |
562 | free_pages((unsigned long) t->prev, | |
563 | get_order(bset_prev_bytes(b))); | |
564 | ||
565 | if (bset_tree_bytes(b) < PAGE_SIZE) | |
566 | kfree(t->tree); | |
567 | else | |
568 | free_pages((unsigned long) t->tree, | |
569 | get_order(bset_tree_bytes(b))); | |
570 | ||
571 | free_pages((unsigned long) t->data, b->page_order); | |
572 | ||
573 | t->prev = NULL; | |
574 | t->tree = NULL; | |
575 | t->data = NULL; | |
576 | list_move(&b->list, &b->c->btree_cache_freed); | |
577 | b->c->bucket_cache_used--; | |
578 | } | |
579 | ||
580 | static void mca_bucket_free(struct btree *b) | |
581 | { | |
582 | BUG_ON(btree_node_dirty(b)); | |
583 | ||
584 | b->key.ptr[0] = 0; | |
585 | hlist_del_init_rcu(&b->hash); | |
586 | list_move(&b->list, &b->c->btree_cache_freeable); | |
587 | } | |
588 | ||
589 | static unsigned btree_order(struct bkey *k) | |
590 | { | |
591 | return ilog2(KEY_SIZE(k) / PAGE_SECTORS ?: 1); | |
592 | } | |
593 | ||
594 | static void mca_data_alloc(struct btree *b, struct bkey *k, gfp_t gfp) | |
595 | { | |
596 | struct bset_tree *t = b->sets; | |
597 | BUG_ON(t->data); | |
598 | ||
599 | b->page_order = max_t(unsigned, | |
600 | ilog2(b->c->btree_pages), | |
601 | btree_order(k)); | |
602 | ||
603 | t->data = (void *) __get_free_pages(gfp, b->page_order); | |
604 | if (!t->data) | |
605 | goto err; | |
606 | ||
607 | t->tree = bset_tree_bytes(b) < PAGE_SIZE | |
608 | ? kmalloc(bset_tree_bytes(b), gfp) | |
609 | : (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b))); | |
610 | if (!t->tree) | |
611 | goto err; | |
612 | ||
613 | t->prev = bset_prev_bytes(b) < PAGE_SIZE | |
614 | ? kmalloc(bset_prev_bytes(b), gfp) | |
615 | : (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b))); | |
616 | if (!t->prev) | |
617 | goto err; | |
618 | ||
619 | list_move(&b->list, &b->c->btree_cache); | |
620 | b->c->bucket_cache_used++; | |
621 | return; | |
622 | err: | |
623 | mca_data_free(b); | |
624 | } | |
625 | ||
626 | static struct btree *mca_bucket_alloc(struct cache_set *c, | |
627 | struct bkey *k, gfp_t gfp) | |
628 | { | |
629 | struct btree *b = kzalloc(sizeof(struct btree), gfp); | |
630 | if (!b) | |
631 | return NULL; | |
632 | ||
633 | init_rwsem(&b->lock); | |
634 | lockdep_set_novalidate_class(&b->lock); | |
635 | INIT_LIST_HEAD(&b->list); | |
57943511 | 636 | INIT_DELAYED_WORK(&b->work, btree_node_write_work); |
cafe5635 KO |
637 | b->c = c; |
638 | closure_init_unlocked(&b->io); | |
639 | ||
640 | mca_data_alloc(b, k, gfp); | |
641 | return b; | |
642 | } | |
643 | ||
e8e1d468 | 644 | static int mca_reap(struct btree *b, unsigned min_order, bool flush) |
cafe5635 | 645 | { |
e8e1d468 KO |
646 | struct closure cl; |
647 | ||
648 | closure_init_stack(&cl); | |
cafe5635 KO |
649 | lockdep_assert_held(&b->c->bucket_lock); |
650 | ||
651 | if (!down_write_trylock(&b->lock)) | |
652 | return -ENOMEM; | |
653 | ||
e8e1d468 KO |
654 | BUG_ON(btree_node_dirty(b) && !b->sets[0].data); |
655 | ||
656 | if (b->page_order < min_order || | |
657 | (!flush && | |
658 | (btree_node_dirty(b) || | |
659 | atomic_read(&b->io.cl.remaining) != -1))) { | |
cafe5635 KO |
660 | rw_unlock(true, b); |
661 | return -ENOMEM; | |
662 | } | |
663 | ||
f269af5a KO |
664 | if (btree_node_dirty(b)) |
665 | bch_btree_node_write_sync(b); | |
cafe5635 | 666 | |
e8e1d468 | 667 | /* wait for any in flight btree write */ |
faadf0c9 KO |
668 | closure_wait_event(&b->io.wait, &cl, |
669 | atomic_read(&b->io.cl.remaining) == -1); | |
e8e1d468 | 670 | |
cafe5635 KO |
671 | return 0; |
672 | } | |
673 | ||
7dc19d5a DC |
674 | static unsigned long bch_mca_scan(struct shrinker *shrink, |
675 | struct shrink_control *sc) | |
cafe5635 KO |
676 | { |
677 | struct cache_set *c = container_of(shrink, struct cache_set, shrink); | |
678 | struct btree *b, *t; | |
679 | unsigned long i, nr = sc->nr_to_scan; | |
7dc19d5a | 680 | unsigned long freed = 0; |
cafe5635 KO |
681 | |
682 | if (c->shrinker_disabled) | |
7dc19d5a | 683 | return SHRINK_STOP; |
cafe5635 KO |
684 | |
685 | if (c->try_harder) | |
7dc19d5a | 686 | return SHRINK_STOP; |
cafe5635 KO |
687 | |
688 | /* Return -1 if we can't do anything right now */ | |
a698e08c | 689 | if (sc->gfp_mask & __GFP_IO) |
cafe5635 KO |
690 | mutex_lock(&c->bucket_lock); |
691 | else if (!mutex_trylock(&c->bucket_lock)) | |
692 | return -1; | |
693 | ||
36c9ea98 KO |
694 | /* |
695 | * It's _really_ critical that we don't free too many btree nodes - we | |
696 | * have to always leave ourselves a reserve. The reserve is how we | |
697 | * guarantee that allocating memory for a new btree node can always | |
698 | * succeed, so that inserting keys into the btree can always succeed and | |
699 | * IO can always make forward progress: | |
700 | */ | |
cafe5635 KO |
701 | nr /= c->btree_pages; |
702 | nr = min_t(unsigned long, nr, mca_can_free(c)); | |
703 | ||
704 | i = 0; | |
705 | list_for_each_entry_safe(b, t, &c->btree_cache_freeable, list) { | |
7dc19d5a | 706 | if (freed >= nr) |
cafe5635 KO |
707 | break; |
708 | ||
709 | if (++i > 3 && | |
e8e1d468 | 710 | !mca_reap(b, 0, false)) { |
cafe5635 KO |
711 | mca_data_free(b); |
712 | rw_unlock(true, b); | |
7dc19d5a | 713 | freed++; |
cafe5635 KO |
714 | } |
715 | } | |
716 | ||
717 | /* | |
718 | * Can happen right when we first start up, before we've read in any | |
719 | * btree nodes | |
720 | */ | |
721 | if (list_empty(&c->btree_cache)) | |
722 | goto out; | |
723 | ||
7dc19d5a | 724 | for (i = 0; (nr--) && i < c->bucket_cache_used; i++) { |
cafe5635 KO |
725 | b = list_first_entry(&c->btree_cache, struct btree, list); |
726 | list_rotate_left(&c->btree_cache); | |
727 | ||
728 | if (!b->accessed && | |
e8e1d468 | 729 | !mca_reap(b, 0, false)) { |
cafe5635 KO |
730 | mca_bucket_free(b); |
731 | mca_data_free(b); | |
732 | rw_unlock(true, b); | |
7dc19d5a | 733 | freed++; |
cafe5635 KO |
734 | } else |
735 | b->accessed = 0; | |
736 | } | |
737 | out: | |
cafe5635 | 738 | mutex_unlock(&c->bucket_lock); |
7dc19d5a DC |
739 | return freed; |
740 | } | |
741 | ||
742 | static unsigned long bch_mca_count(struct shrinker *shrink, | |
743 | struct shrink_control *sc) | |
744 | { | |
745 | struct cache_set *c = container_of(shrink, struct cache_set, shrink); | |
746 | ||
747 | if (c->shrinker_disabled) | |
748 | return 0; | |
749 | ||
750 | if (c->try_harder) | |
751 | return 0; | |
752 | ||
753 | return mca_can_free(c) * c->btree_pages; | |
cafe5635 KO |
754 | } |
755 | ||
756 | void bch_btree_cache_free(struct cache_set *c) | |
757 | { | |
758 | struct btree *b; | |
759 | struct closure cl; | |
760 | closure_init_stack(&cl); | |
761 | ||
762 | if (c->shrink.list.next) | |
763 | unregister_shrinker(&c->shrink); | |
764 | ||
765 | mutex_lock(&c->bucket_lock); | |
766 | ||
767 | #ifdef CONFIG_BCACHE_DEBUG | |
768 | if (c->verify_data) | |
769 | list_move(&c->verify_data->list, &c->btree_cache); | |
770 | #endif | |
771 | ||
772 | list_splice(&c->btree_cache_freeable, | |
773 | &c->btree_cache); | |
774 | ||
775 | while (!list_empty(&c->btree_cache)) { | |
776 | b = list_first_entry(&c->btree_cache, struct btree, list); | |
777 | ||
778 | if (btree_node_dirty(b)) | |
779 | btree_complete_write(b, btree_current_write(b)); | |
780 | clear_bit(BTREE_NODE_dirty, &b->flags); | |
781 | ||
782 | mca_data_free(b); | |
783 | } | |
784 | ||
785 | while (!list_empty(&c->btree_cache_freed)) { | |
786 | b = list_first_entry(&c->btree_cache_freed, | |
787 | struct btree, list); | |
788 | list_del(&b->list); | |
789 | cancel_delayed_work_sync(&b->work); | |
790 | kfree(b); | |
791 | } | |
792 | ||
793 | mutex_unlock(&c->bucket_lock); | |
794 | } | |
795 | ||
796 | int bch_btree_cache_alloc(struct cache_set *c) | |
797 | { | |
798 | unsigned i; | |
799 | ||
cafe5635 | 800 | for (i = 0; i < mca_reserve(c); i++) |
72a44517 KO |
801 | if (!mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL)) |
802 | return -ENOMEM; | |
cafe5635 KO |
803 | |
804 | list_splice_init(&c->btree_cache, | |
805 | &c->btree_cache_freeable); | |
806 | ||
807 | #ifdef CONFIG_BCACHE_DEBUG | |
808 | mutex_init(&c->verify_lock); | |
809 | ||
810 | c->verify_data = mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL); | |
811 | ||
812 | if (c->verify_data && | |
813 | c->verify_data->sets[0].data) | |
814 | list_del_init(&c->verify_data->list); | |
815 | else | |
816 | c->verify_data = NULL; | |
817 | #endif | |
818 | ||
7dc19d5a DC |
819 | c->shrink.count_objects = bch_mca_count; |
820 | c->shrink.scan_objects = bch_mca_scan; | |
cafe5635 KO |
821 | c->shrink.seeks = 4; |
822 | c->shrink.batch = c->btree_pages * 2; | |
823 | register_shrinker(&c->shrink); | |
824 | ||
825 | return 0; | |
826 | } | |
827 | ||
828 | /* Btree in memory cache - hash table */ | |
829 | ||
830 | static struct hlist_head *mca_hash(struct cache_set *c, struct bkey *k) | |
831 | { | |
832 | return &c->bucket_hash[hash_32(PTR_HASH(c, k), BUCKET_HASH_BITS)]; | |
833 | } | |
834 | ||
835 | static struct btree *mca_find(struct cache_set *c, struct bkey *k) | |
836 | { | |
837 | struct btree *b; | |
838 | ||
839 | rcu_read_lock(); | |
840 | hlist_for_each_entry_rcu(b, mca_hash(c, k), hash) | |
841 | if (PTR_HASH(c, &b->key) == PTR_HASH(c, k)) | |
842 | goto out; | |
843 | b = NULL; | |
844 | out: | |
845 | rcu_read_unlock(); | |
846 | return b; | |
847 | } | |
848 | ||
e8e1d468 | 849 | static struct btree *mca_cannibalize(struct cache_set *c, struct bkey *k) |
cafe5635 | 850 | { |
e8e1d468 | 851 | struct btree *b; |
cafe5635 | 852 | |
c37511b8 KO |
853 | trace_bcache_btree_cache_cannibalize(c); |
854 | ||
e8e1d468 KO |
855 | if (!c->try_harder) { |
856 | c->try_harder = current; | |
857 | c->try_harder_start = local_clock(); | |
858 | } else if (c->try_harder != current) | |
859 | return ERR_PTR(-ENOSPC); | |
cafe5635 | 860 | |
e8e1d468 KO |
861 | list_for_each_entry_reverse(b, &c->btree_cache, list) |
862 | if (!mca_reap(b, btree_order(k), false)) | |
863 | return b; | |
cafe5635 | 864 | |
e8e1d468 KO |
865 | list_for_each_entry_reverse(b, &c->btree_cache, list) |
866 | if (!mca_reap(b, btree_order(k), true)) | |
867 | return b; | |
cafe5635 | 868 | |
e8e1d468 | 869 | return ERR_PTR(-ENOMEM); |
cafe5635 KO |
870 | } |
871 | ||
872 | /* | |
873 | * We can only have one thread cannibalizing other cached btree nodes at a time, | |
874 | * or we'll deadlock. We use an open coded mutex to ensure that, which a | |
875 | * cannibalize_bucket() will take. This means every time we unlock the root of | |
876 | * the btree, we need to release this lock if we have it held. | |
877 | */ | |
df8e8970 | 878 | static void bch_cannibalize_unlock(struct cache_set *c) |
cafe5635 | 879 | { |
e8e1d468 | 880 | if (c->try_harder == current) { |
169ef1cf | 881 | bch_time_stats_update(&c->try_harder_time, c->try_harder_start); |
cafe5635 | 882 | c->try_harder = NULL; |
e8e1d468 | 883 | wake_up(&c->try_wait); |
cafe5635 KO |
884 | } |
885 | } | |
886 | ||
e8e1d468 | 887 | static struct btree *mca_alloc(struct cache_set *c, struct bkey *k, int level) |
cafe5635 KO |
888 | { |
889 | struct btree *b; | |
890 | ||
e8e1d468 KO |
891 | BUG_ON(current->bio_list); |
892 | ||
cafe5635 KO |
893 | lockdep_assert_held(&c->bucket_lock); |
894 | ||
895 | if (mca_find(c, k)) | |
896 | return NULL; | |
897 | ||
898 | /* btree_free() doesn't free memory; it sticks the node on the end of | |
899 | * the list. Check if there's any freed nodes there: | |
900 | */ | |
901 | list_for_each_entry(b, &c->btree_cache_freeable, list) | |
e8e1d468 | 902 | if (!mca_reap(b, btree_order(k), false)) |
cafe5635 KO |
903 | goto out; |
904 | ||
905 | /* We never free struct btree itself, just the memory that holds the on | |
906 | * disk node. Check the freed list before allocating a new one: | |
907 | */ | |
908 | list_for_each_entry(b, &c->btree_cache_freed, list) | |
e8e1d468 | 909 | if (!mca_reap(b, 0, false)) { |
cafe5635 KO |
910 | mca_data_alloc(b, k, __GFP_NOWARN|GFP_NOIO); |
911 | if (!b->sets[0].data) | |
912 | goto err; | |
913 | else | |
914 | goto out; | |
915 | } | |
916 | ||
917 | b = mca_bucket_alloc(c, k, __GFP_NOWARN|GFP_NOIO); | |
918 | if (!b) | |
919 | goto err; | |
920 | ||
921 | BUG_ON(!down_write_trylock(&b->lock)); | |
922 | if (!b->sets->data) | |
923 | goto err; | |
924 | out: | |
925 | BUG_ON(!closure_is_unlocked(&b->io.cl)); | |
926 | ||
927 | bkey_copy(&b->key, k); | |
928 | list_move(&b->list, &c->btree_cache); | |
929 | hlist_del_init_rcu(&b->hash); | |
930 | hlist_add_head_rcu(&b->hash, mca_hash(c, k)); | |
931 | ||
932 | lock_set_subclass(&b->lock.dep_map, level + 1, _THIS_IP_); | |
933 | b->level = level; | |
d6fd3b11 | 934 | b->parent = (void *) ~0UL; |
cafe5635 KO |
935 | |
936 | mca_reinit(b); | |
937 | ||
938 | return b; | |
939 | err: | |
940 | if (b) | |
941 | rw_unlock(true, b); | |
942 | ||
e8e1d468 | 943 | b = mca_cannibalize(c, k); |
cafe5635 KO |
944 | if (!IS_ERR(b)) |
945 | goto out; | |
946 | ||
947 | return b; | |
948 | } | |
949 | ||
950 | /** | |
951 | * bch_btree_node_get - find a btree node in the cache and lock it, reading it | |
952 | * in from disk if necessary. | |
953 | * | |
b54d6934 | 954 | * If IO is necessary and running under generic_make_request, returns -EAGAIN. |
cafe5635 KO |
955 | * |
956 | * The btree node will have either a read or a write lock held, depending on | |
957 | * level and op->lock. | |
958 | */ | |
959 | struct btree *bch_btree_node_get(struct cache_set *c, struct bkey *k, | |
e8e1d468 | 960 | int level, bool write) |
cafe5635 KO |
961 | { |
962 | int i = 0; | |
cafe5635 KO |
963 | struct btree *b; |
964 | ||
965 | BUG_ON(level < 0); | |
966 | retry: | |
967 | b = mca_find(c, k); | |
968 | ||
969 | if (!b) { | |
57943511 KO |
970 | if (current->bio_list) |
971 | return ERR_PTR(-EAGAIN); | |
972 | ||
cafe5635 | 973 | mutex_lock(&c->bucket_lock); |
e8e1d468 | 974 | b = mca_alloc(c, k, level); |
cafe5635 KO |
975 | mutex_unlock(&c->bucket_lock); |
976 | ||
977 | if (!b) | |
978 | goto retry; | |
979 | if (IS_ERR(b)) | |
980 | return b; | |
981 | ||
57943511 | 982 | bch_btree_node_read(b); |
cafe5635 KO |
983 | |
984 | if (!write) | |
985 | downgrade_write(&b->lock); | |
986 | } else { | |
987 | rw_lock(write, b, level); | |
988 | if (PTR_HASH(c, &b->key) != PTR_HASH(c, k)) { | |
989 | rw_unlock(write, b); | |
990 | goto retry; | |
991 | } | |
992 | BUG_ON(b->level != level); | |
993 | } | |
994 | ||
995 | b->accessed = 1; | |
996 | ||
997 | for (; i <= b->nsets && b->sets[i].size; i++) { | |
998 | prefetch(b->sets[i].tree); | |
999 | prefetch(b->sets[i].data); | |
1000 | } | |
1001 | ||
1002 | for (; i <= b->nsets; i++) | |
1003 | prefetch(b->sets[i].data); | |
1004 | ||
57943511 | 1005 | if (btree_node_io_error(b)) { |
cafe5635 | 1006 | rw_unlock(write, b); |
57943511 KO |
1007 | return ERR_PTR(-EIO); |
1008 | } | |
1009 | ||
1010 | BUG_ON(!b->written); | |
cafe5635 KO |
1011 | |
1012 | return b; | |
1013 | } | |
1014 | ||
1015 | static void btree_node_prefetch(struct cache_set *c, struct bkey *k, int level) | |
1016 | { | |
1017 | struct btree *b; | |
1018 | ||
1019 | mutex_lock(&c->bucket_lock); | |
e8e1d468 | 1020 | b = mca_alloc(c, k, level); |
cafe5635 KO |
1021 | mutex_unlock(&c->bucket_lock); |
1022 | ||
1023 | if (!IS_ERR_OR_NULL(b)) { | |
57943511 | 1024 | bch_btree_node_read(b); |
cafe5635 KO |
1025 | rw_unlock(true, b); |
1026 | } | |
1027 | } | |
1028 | ||
1029 | /* Btree alloc */ | |
1030 | ||
e8e1d468 | 1031 | static void btree_node_free(struct btree *b) |
cafe5635 KO |
1032 | { |
1033 | unsigned i; | |
1034 | ||
c37511b8 KO |
1035 | trace_bcache_btree_node_free(b); |
1036 | ||
cafe5635 | 1037 | BUG_ON(b == b->c->root); |
cafe5635 KO |
1038 | |
1039 | if (btree_node_dirty(b)) | |
1040 | btree_complete_write(b, btree_current_write(b)); | |
1041 | clear_bit(BTREE_NODE_dirty, &b->flags); | |
1042 | ||
cafe5635 KO |
1043 | cancel_delayed_work(&b->work); |
1044 | ||
1045 | mutex_lock(&b->c->bucket_lock); | |
1046 | ||
1047 | for (i = 0; i < KEY_PTRS(&b->key); i++) { | |
1048 | BUG_ON(atomic_read(&PTR_BUCKET(b->c, &b->key, i)->pin)); | |
1049 | ||
1050 | bch_inc_gen(PTR_CACHE(b->c, &b->key, i), | |
1051 | PTR_BUCKET(b->c, &b->key, i)); | |
1052 | } | |
1053 | ||
1054 | bch_bucket_free(b->c, &b->key); | |
1055 | mca_bucket_free(b); | |
1056 | mutex_unlock(&b->c->bucket_lock); | |
1057 | } | |
1058 | ||
bc9389ee | 1059 | struct btree *bch_btree_node_alloc(struct cache_set *c, int level, bool wait) |
cafe5635 KO |
1060 | { |
1061 | BKEY_PADDED(key) k; | |
1062 | struct btree *b = ERR_PTR(-EAGAIN); | |
1063 | ||
1064 | mutex_lock(&c->bucket_lock); | |
1065 | retry: | |
bc9389ee | 1066 | if (__bch_bucket_alloc_set(c, WATERMARK_METADATA, &k.key, 1, wait)) |
cafe5635 KO |
1067 | goto err; |
1068 | ||
3a3b6a4e | 1069 | bkey_put(c, &k.key); |
cafe5635 KO |
1070 | SET_KEY_SIZE(&k.key, c->btree_pages * PAGE_SECTORS); |
1071 | ||
e8e1d468 | 1072 | b = mca_alloc(c, &k.key, level); |
cafe5635 KO |
1073 | if (IS_ERR(b)) |
1074 | goto err_free; | |
1075 | ||
1076 | if (!b) { | |
b1a67b0f KO |
1077 | cache_bug(c, |
1078 | "Tried to allocate bucket that was in btree cache"); | |
cafe5635 KO |
1079 | goto retry; |
1080 | } | |
1081 | ||
cafe5635 KO |
1082 | b->accessed = 1; |
1083 | bch_bset_init_next(b); | |
1084 | ||
1085 | mutex_unlock(&c->bucket_lock); | |
c37511b8 KO |
1086 | |
1087 | trace_bcache_btree_node_alloc(b); | |
cafe5635 KO |
1088 | return b; |
1089 | err_free: | |
1090 | bch_bucket_free(c, &k.key); | |
cafe5635 KO |
1091 | err: |
1092 | mutex_unlock(&c->bucket_lock); | |
c37511b8 KO |
1093 | |
1094 | trace_bcache_btree_node_alloc_fail(b); | |
cafe5635 KO |
1095 | return b; |
1096 | } | |
1097 | ||
bc9389ee | 1098 | static struct btree *btree_node_alloc_replacement(struct btree *b, bool wait) |
cafe5635 | 1099 | { |
bc9389ee | 1100 | struct btree *n = bch_btree_node_alloc(b->c, b->level, wait); |
cafe5635 KO |
1101 | if (!IS_ERR_OR_NULL(n)) |
1102 | bch_btree_sort_into(b, n); | |
1103 | ||
1104 | return n; | |
1105 | } | |
1106 | ||
8835c123 KO |
1107 | static void make_btree_freeing_key(struct btree *b, struct bkey *k) |
1108 | { | |
1109 | unsigned i; | |
1110 | ||
1111 | bkey_copy(k, &b->key); | |
1112 | bkey_copy_key(k, &ZERO_KEY); | |
1113 | ||
1114 | for (i = 0; i < KEY_PTRS(k); i++) { | |
1115 | uint8_t g = PTR_BUCKET(b->c, k, i)->gen + 1; | |
1116 | ||
1117 | SET_PTR_GEN(k, i, g); | |
1118 | } | |
1119 | ||
1120 | atomic_inc(&b->c->prio_blocked); | |
1121 | } | |
1122 | ||
cafe5635 KO |
1123 | /* Garbage collection */ |
1124 | ||
1125 | uint8_t __bch_btree_mark_key(struct cache_set *c, int level, struct bkey *k) | |
1126 | { | |
1127 | uint8_t stale = 0; | |
1128 | unsigned i; | |
1129 | struct bucket *g; | |
1130 | ||
1131 | /* | |
1132 | * ptr_invalid() can't return true for the keys that mark btree nodes as | |
1133 | * freed, but since ptr_bad() returns true we'll never actually use them | |
1134 | * for anything and thus we don't want mark their pointers here | |
1135 | */ | |
1136 | if (!bkey_cmp(k, &ZERO_KEY)) | |
1137 | return stale; | |
1138 | ||
1139 | for (i = 0; i < KEY_PTRS(k); i++) { | |
1140 | if (!ptr_available(c, k, i)) | |
1141 | continue; | |
1142 | ||
1143 | g = PTR_BUCKET(c, k, i); | |
1144 | ||
1145 | if (gen_after(g->gc_gen, PTR_GEN(k, i))) | |
1146 | g->gc_gen = PTR_GEN(k, i); | |
1147 | ||
1148 | if (ptr_stale(c, k, i)) { | |
1149 | stale = max(stale, ptr_stale(c, k, i)); | |
1150 | continue; | |
1151 | } | |
1152 | ||
1153 | cache_bug_on(GC_MARK(g) && | |
1154 | (GC_MARK(g) == GC_MARK_METADATA) != (level != 0), | |
1155 | c, "inconsistent ptrs: mark = %llu, level = %i", | |
1156 | GC_MARK(g), level); | |
1157 | ||
1158 | if (level) | |
1159 | SET_GC_MARK(g, GC_MARK_METADATA); | |
1160 | else if (KEY_DIRTY(k)) | |
1161 | SET_GC_MARK(g, GC_MARK_DIRTY); | |
1162 | ||
1163 | /* guard against overflow */ | |
1164 | SET_GC_SECTORS_USED(g, min_t(unsigned, | |
1165 | GC_SECTORS_USED(g) + KEY_SIZE(k), | |
1166 | (1 << 14) - 1)); | |
1167 | ||
1168 | BUG_ON(!GC_SECTORS_USED(g)); | |
1169 | } | |
1170 | ||
1171 | return stale; | |
1172 | } | |
1173 | ||
1174 | #define btree_mark_key(b, k) __bch_btree_mark_key(b->c, b->level, k) | |
1175 | ||
a1f0358b | 1176 | static bool btree_gc_mark_node(struct btree *b, struct gc_stat *gc) |
cafe5635 KO |
1177 | { |
1178 | uint8_t stale = 0; | |
a1f0358b | 1179 | unsigned keys = 0, good_keys = 0; |
cafe5635 KO |
1180 | struct bkey *k; |
1181 | struct btree_iter iter; | |
1182 | struct bset_tree *t; | |
1183 | ||
1184 | gc->nodes++; | |
1185 | ||
1186 | for_each_key_filter(b, k, &iter, bch_ptr_invalid) { | |
cafe5635 | 1187 | stale = max(stale, btree_mark_key(b, k)); |
a1f0358b | 1188 | keys++; |
cafe5635 KO |
1189 | |
1190 | if (bch_ptr_bad(b, k)) | |
1191 | continue; | |
1192 | ||
cafe5635 KO |
1193 | gc->key_bytes += bkey_u64s(k); |
1194 | gc->nkeys++; | |
a1f0358b | 1195 | good_keys++; |
cafe5635 KO |
1196 | |
1197 | gc->data += KEY_SIZE(k); | |
cafe5635 KO |
1198 | } |
1199 | ||
1200 | for (t = b->sets; t <= &b->sets[b->nsets]; t++) | |
1201 | btree_bug_on(t->size && | |
1202 | bset_written(b, t) && | |
1203 | bkey_cmp(&b->key, &t->end) < 0, | |
1204 | b, "found short btree key in gc"); | |
1205 | ||
a1f0358b KO |
1206 | if (b->c->gc_always_rewrite) |
1207 | return true; | |
cafe5635 | 1208 | |
a1f0358b KO |
1209 | if (stale > 10) |
1210 | return true; | |
cafe5635 | 1211 | |
a1f0358b KO |
1212 | if ((keys - good_keys) * 2 > keys) |
1213 | return true; | |
cafe5635 | 1214 | |
a1f0358b | 1215 | return false; |
cafe5635 KO |
1216 | } |
1217 | ||
a1f0358b | 1218 | #define GC_MERGE_NODES 4U |
cafe5635 KO |
1219 | |
1220 | struct gc_merge_info { | |
1221 | struct btree *b; | |
cafe5635 KO |
1222 | unsigned keys; |
1223 | }; | |
1224 | ||
a1f0358b KO |
1225 | static int bch_btree_insert_node(struct btree *, struct btree_op *, |
1226 | struct keylist *, atomic_t *, struct bkey *); | |
1227 | ||
1228 | static int btree_gc_coalesce(struct btree *b, struct btree_op *op, | |
1229 | struct keylist *keylist, struct gc_stat *gc, | |
1230 | struct gc_merge_info *r) | |
cafe5635 | 1231 | { |
a1f0358b KO |
1232 | unsigned i, nodes = 0, keys = 0, blocks; |
1233 | struct btree *new_nodes[GC_MERGE_NODES]; | |
b54d6934 | 1234 | struct closure cl; |
a1f0358b | 1235 | struct bkey *k; |
b54d6934 | 1236 | |
a1f0358b | 1237 | memset(new_nodes, 0, sizeof(new_nodes)); |
b54d6934 | 1238 | closure_init_stack(&cl); |
cafe5635 | 1239 | |
a1f0358b | 1240 | while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b)) |
cafe5635 KO |
1241 | keys += r[nodes++].keys; |
1242 | ||
1243 | blocks = btree_default_blocks(b->c) * 2 / 3; | |
1244 | ||
1245 | if (nodes < 2 || | |
1246 | __set_blocks(b->sets[0].data, keys, b->c) > blocks * (nodes - 1)) | |
a1f0358b | 1247 | return 0; |
cafe5635 | 1248 | |
a1f0358b | 1249 | for (i = 0; i < nodes; i++) { |
bc9389ee | 1250 | new_nodes[i] = btree_node_alloc_replacement(r[i].b, false); |
a1f0358b KO |
1251 | if (IS_ERR_OR_NULL(new_nodes[i])) |
1252 | goto out_nocoalesce; | |
cafe5635 KO |
1253 | } |
1254 | ||
1255 | for (i = nodes - 1; i > 0; --i) { | |
a1f0358b KO |
1256 | struct bset *n1 = new_nodes[i]->sets->data; |
1257 | struct bset *n2 = new_nodes[i - 1]->sets->data; | |
cafe5635 KO |
1258 | struct bkey *k, *last = NULL; |
1259 | ||
1260 | keys = 0; | |
1261 | ||
a1f0358b KO |
1262 | if (i > 1) { |
1263 | for (k = n2->start; | |
1264 | k < end(n2); | |
1265 | k = bkey_next(k)) { | |
1266 | if (__set_blocks(n1, n1->keys + keys + | |
1267 | bkey_u64s(k), b->c) > blocks) | |
1268 | break; | |
1269 | ||
1270 | last = k; | |
1271 | keys += bkey_u64s(k); | |
1272 | } | |
1273 | } else { | |
cafe5635 KO |
1274 | /* |
1275 | * Last node we're not getting rid of - we're getting | |
1276 | * rid of the node at r[0]. Have to try and fit all of | |
1277 | * the remaining keys into this node; we can't ensure | |
1278 | * they will always fit due to rounding and variable | |
1279 | * length keys (shouldn't be possible in practice, | |
1280 | * though) | |
1281 | */ | |
a1f0358b KO |
1282 | if (__set_blocks(n1, n1->keys + n2->keys, |
1283 | b->c) > btree_blocks(new_nodes[i])) | |
1284 | goto out_nocoalesce; | |
cafe5635 KO |
1285 | |
1286 | keys = n2->keys; | |
a1f0358b | 1287 | /* Take the key of the node we're getting rid of */ |
cafe5635 | 1288 | last = &r->b->key; |
a1f0358b | 1289 | } |
cafe5635 KO |
1290 | |
1291 | BUG_ON(__set_blocks(n1, n1->keys + keys, | |
a1f0358b | 1292 | b->c) > btree_blocks(new_nodes[i])); |
cafe5635 | 1293 | |
a1f0358b KO |
1294 | if (last) |
1295 | bkey_copy_key(&new_nodes[i]->key, last); | |
cafe5635 KO |
1296 | |
1297 | memcpy(end(n1), | |
1298 | n2->start, | |
1299 | (void *) node(n2, keys) - (void *) n2->start); | |
1300 | ||
1301 | n1->keys += keys; | |
a1f0358b | 1302 | r[i].keys = n1->keys; |
cafe5635 KO |
1303 | |
1304 | memmove(n2->start, | |
1305 | node(n2, keys), | |
1306 | (void *) end(n2) - (void *) node(n2, keys)); | |
1307 | ||
1308 | n2->keys -= keys; | |
1309 | ||
a1f0358b KO |
1310 | if (bch_keylist_realloc(keylist, |
1311 | KEY_PTRS(&new_nodes[i]->key), b->c)) | |
1312 | goto out_nocoalesce; | |
1313 | ||
1314 | bch_btree_node_write(new_nodes[i], &cl); | |
1315 | bch_keylist_add(keylist, &new_nodes[i]->key); | |
cafe5635 KO |
1316 | } |
1317 | ||
a1f0358b KO |
1318 | for (i = 0; i < nodes; i++) { |
1319 | if (bch_keylist_realloc(keylist, KEY_PTRS(&r[i].b->key), b->c)) | |
1320 | goto out_nocoalesce; | |
cafe5635 | 1321 | |
a1f0358b KO |
1322 | make_btree_freeing_key(r[i].b, keylist->top); |
1323 | bch_keylist_push(keylist); | |
1324 | } | |
cafe5635 | 1325 | |
a1f0358b KO |
1326 | /* We emptied out this node */ |
1327 | BUG_ON(new_nodes[0]->sets->data->keys); | |
1328 | btree_node_free(new_nodes[0]); | |
1329 | rw_unlock(true, new_nodes[0]); | |
1330 | ||
1331 | closure_sync(&cl); | |
1332 | ||
1333 | for (i = 0; i < nodes; i++) { | |
1334 | btree_node_free(r[i].b); | |
1335 | rw_unlock(true, r[i].b); | |
1336 | ||
1337 | r[i].b = new_nodes[i]; | |
1338 | } | |
1339 | ||
1340 | bch_btree_insert_node(b, op, keylist, NULL, NULL); | |
1341 | BUG_ON(!bch_keylist_empty(keylist)); | |
1342 | ||
1343 | memmove(r, r + 1, sizeof(r[0]) * (nodes - 1)); | |
1344 | r[nodes - 1].b = ERR_PTR(-EINTR); | |
1345 | ||
1346 | trace_bcache_btree_gc_coalesce(nodes); | |
cafe5635 | 1347 | gc->nodes--; |
cafe5635 | 1348 | |
a1f0358b KO |
1349 | /* Invalidated our iterator */ |
1350 | return -EINTR; | |
1351 | ||
1352 | out_nocoalesce: | |
1353 | closure_sync(&cl); | |
1354 | ||
1355 | while ((k = bch_keylist_pop(keylist))) | |
1356 | if (!bkey_cmp(k, &ZERO_KEY)) | |
1357 | atomic_dec(&b->c->prio_blocked); | |
1358 | ||
1359 | for (i = 0; i < nodes; i++) | |
1360 | if (!IS_ERR_OR_NULL(new_nodes[i])) { | |
1361 | btree_node_free(new_nodes[i]); | |
1362 | rw_unlock(true, new_nodes[i]); | |
1363 | } | |
1364 | return 0; | |
cafe5635 KO |
1365 | } |
1366 | ||
a1f0358b | 1367 | static unsigned btree_gc_count_keys(struct btree *b) |
cafe5635 | 1368 | { |
a1f0358b KO |
1369 | struct bkey *k; |
1370 | struct btree_iter iter; | |
1371 | unsigned ret = 0; | |
cafe5635 | 1372 | |
a1f0358b KO |
1373 | for_each_key_filter(b, k, &iter, bch_ptr_bad) |
1374 | ret += bkey_u64s(k); | |
1375 | ||
1376 | return ret; | |
1377 | } | |
cafe5635 | 1378 | |
a1f0358b KO |
1379 | static int btree_gc_recurse(struct btree *b, struct btree_op *op, |
1380 | struct closure *writes, struct gc_stat *gc) | |
1381 | { | |
cafe5635 | 1382 | unsigned i; |
a1f0358b KO |
1383 | int ret = 0; |
1384 | bool should_rewrite; | |
1385 | struct btree *n; | |
1386 | struct bkey *k; | |
1387 | struct keylist keys; | |
1388 | struct btree_iter iter; | |
cafe5635 | 1389 | struct gc_merge_info r[GC_MERGE_NODES]; |
a1f0358b | 1390 | struct gc_merge_info *last = r + GC_MERGE_NODES - 1; |
cafe5635 | 1391 | |
a1f0358b KO |
1392 | bch_keylist_init(&keys); |
1393 | bch_btree_iter_init(b, &iter, &b->c->gc_done); | |
cafe5635 | 1394 | |
a1f0358b KO |
1395 | for (i = 0; i < GC_MERGE_NODES; i++) |
1396 | r[i].b = ERR_PTR(-EINTR); | |
cafe5635 | 1397 | |
a1f0358b KO |
1398 | while (1) { |
1399 | k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad); | |
1400 | if (k) { | |
1401 | r->b = bch_btree_node_get(b->c, k, b->level - 1, true); | |
1402 | if (IS_ERR(r->b)) { | |
1403 | ret = PTR_ERR(r->b); | |
1404 | break; | |
1405 | } | |
1406 | ||
1407 | r->keys = btree_gc_count_keys(r->b); | |
1408 | ||
1409 | ret = btree_gc_coalesce(b, op, &keys, gc, r); | |
1410 | if (ret) | |
1411 | break; | |
cafe5635 KO |
1412 | } |
1413 | ||
a1f0358b KO |
1414 | if (!last->b) |
1415 | break; | |
cafe5635 | 1416 | |
a1f0358b KO |
1417 | if (!IS_ERR(last->b)) { |
1418 | should_rewrite = btree_gc_mark_node(last->b, gc); | |
1419 | if (should_rewrite) { | |
bc9389ee KO |
1420 | n = btree_node_alloc_replacement(last->b, |
1421 | false); | |
cafe5635 | 1422 | |
a1f0358b KO |
1423 | if (!IS_ERR_OR_NULL(n)) { |
1424 | bch_btree_node_write_sync(n); | |
1425 | bch_keylist_add(&keys, &n->key); | |
cafe5635 | 1426 | |
a1f0358b KO |
1427 | make_btree_freeing_key(last->b, |
1428 | keys.top); | |
1429 | bch_keylist_push(&keys); | |
1430 | ||
1431 | btree_node_free(last->b); | |
cafe5635 | 1432 | |
a1f0358b KO |
1433 | bch_btree_insert_node(b, op, &keys, |
1434 | NULL, NULL); | |
1435 | BUG_ON(!bch_keylist_empty(&keys)); | |
cafe5635 | 1436 | |
a1f0358b KO |
1437 | rw_unlock(true, last->b); |
1438 | last->b = n; | |
cafe5635 | 1439 | |
a1f0358b KO |
1440 | /* Invalidated our iterator */ |
1441 | ret = -EINTR; | |
1442 | break; | |
1443 | } | |
1444 | } | |
1445 | ||
1446 | if (last->b->level) { | |
1447 | ret = btree_gc_recurse(last->b, op, writes, gc); | |
1448 | if (ret) | |
1449 | break; | |
1450 | } | |
cafe5635 | 1451 | |
a1f0358b KO |
1452 | bkey_copy_key(&b->c->gc_done, &last->b->key); |
1453 | ||
1454 | /* | |
1455 | * Must flush leaf nodes before gc ends, since replace | |
1456 | * operations aren't journalled | |
1457 | */ | |
1458 | if (btree_node_dirty(last->b)) | |
1459 | bch_btree_node_write(last->b, writes); | |
1460 | rw_unlock(true, last->b); | |
1461 | } | |
1462 | ||
1463 | memmove(r + 1, r, sizeof(r[0]) * (GC_MERGE_NODES - 1)); | |
1464 | r->b = NULL; | |
cafe5635 | 1465 | |
cafe5635 KO |
1466 | if (need_resched()) { |
1467 | ret = -EAGAIN; | |
1468 | break; | |
1469 | } | |
cafe5635 KO |
1470 | } |
1471 | ||
a1f0358b KO |
1472 | for (i = 0; i < GC_MERGE_NODES; i++) |
1473 | if (!IS_ERR_OR_NULL(r[i].b)) { | |
1474 | if (btree_node_dirty(r[i].b)) | |
1475 | bch_btree_node_write(r[i].b, writes); | |
1476 | rw_unlock(true, r[i].b); | |
1477 | } | |
cafe5635 | 1478 | |
a1f0358b | 1479 | bch_keylist_free(&keys); |
cafe5635 KO |
1480 | |
1481 | return ret; | |
1482 | } | |
1483 | ||
1484 | static int bch_btree_gc_root(struct btree *b, struct btree_op *op, | |
1485 | struct closure *writes, struct gc_stat *gc) | |
1486 | { | |
1487 | struct btree *n = NULL; | |
a1f0358b KO |
1488 | int ret = 0; |
1489 | bool should_rewrite; | |
cafe5635 | 1490 | |
a1f0358b KO |
1491 | should_rewrite = btree_gc_mark_node(b, gc); |
1492 | if (should_rewrite) { | |
bc9389ee | 1493 | n = btree_node_alloc_replacement(b, false); |
cafe5635 | 1494 | |
a1f0358b KO |
1495 | if (!IS_ERR_OR_NULL(n)) { |
1496 | bch_btree_node_write_sync(n); | |
1497 | bch_btree_set_root(n); | |
1498 | btree_node_free(b); | |
1499 | rw_unlock(true, n); | |
cafe5635 | 1500 | |
a1f0358b KO |
1501 | return -EINTR; |
1502 | } | |
1503 | } | |
cafe5635 | 1504 | |
a1f0358b KO |
1505 | if (b->level) { |
1506 | ret = btree_gc_recurse(b, op, writes, gc); | |
1507 | if (ret) | |
1508 | return ret; | |
cafe5635 KO |
1509 | } |
1510 | ||
a1f0358b KO |
1511 | bkey_copy_key(&b->c->gc_done, &b->key); |
1512 | ||
cafe5635 KO |
1513 | return ret; |
1514 | } | |
1515 | ||
1516 | static void btree_gc_start(struct cache_set *c) | |
1517 | { | |
1518 | struct cache *ca; | |
1519 | struct bucket *b; | |
cafe5635 KO |
1520 | unsigned i; |
1521 | ||
1522 | if (!c->gc_mark_valid) | |
1523 | return; | |
1524 | ||
1525 | mutex_lock(&c->bucket_lock); | |
1526 | ||
1527 | c->gc_mark_valid = 0; | |
1528 | c->gc_done = ZERO_KEY; | |
1529 | ||
1530 | for_each_cache(ca, c, i) | |
1531 | for_each_bucket(b, ca) { | |
1532 | b->gc_gen = b->gen; | |
29ebf465 | 1533 | if (!atomic_read(&b->pin)) { |
cafe5635 | 1534 | SET_GC_MARK(b, GC_MARK_RECLAIMABLE); |
29ebf465 KO |
1535 | SET_GC_SECTORS_USED(b, 0); |
1536 | } | |
cafe5635 KO |
1537 | } |
1538 | ||
cafe5635 KO |
1539 | mutex_unlock(&c->bucket_lock); |
1540 | } | |
1541 | ||
1542 | size_t bch_btree_gc_finish(struct cache_set *c) | |
1543 | { | |
1544 | size_t available = 0; | |
1545 | struct bucket *b; | |
1546 | struct cache *ca; | |
cafe5635 KO |
1547 | unsigned i; |
1548 | ||
1549 | mutex_lock(&c->bucket_lock); | |
1550 | ||
1551 | set_gc_sectors(c); | |
1552 | c->gc_mark_valid = 1; | |
1553 | c->need_gc = 0; | |
1554 | ||
1555 | if (c->root) | |
1556 | for (i = 0; i < KEY_PTRS(&c->root->key); i++) | |
1557 | SET_GC_MARK(PTR_BUCKET(c, &c->root->key, i), | |
1558 | GC_MARK_METADATA); | |
1559 | ||
1560 | for (i = 0; i < KEY_PTRS(&c->uuid_bucket); i++) | |
1561 | SET_GC_MARK(PTR_BUCKET(c, &c->uuid_bucket, i), | |
1562 | GC_MARK_METADATA); | |
1563 | ||
1564 | for_each_cache(ca, c, i) { | |
1565 | uint64_t *i; | |
1566 | ||
1567 | ca->invalidate_needs_gc = 0; | |
1568 | ||
1569 | for (i = ca->sb.d; i < ca->sb.d + ca->sb.keys; i++) | |
1570 | SET_GC_MARK(ca->buckets + *i, GC_MARK_METADATA); | |
1571 | ||
1572 | for (i = ca->prio_buckets; | |
1573 | i < ca->prio_buckets + prio_buckets(ca) * 2; i++) | |
1574 | SET_GC_MARK(ca->buckets + *i, GC_MARK_METADATA); | |
1575 | ||
1576 | for_each_bucket(b, ca) { | |
1577 | b->last_gc = b->gc_gen; | |
1578 | c->need_gc = max(c->need_gc, bucket_gc_gen(b)); | |
1579 | ||
1580 | if (!atomic_read(&b->pin) && | |
1581 | GC_MARK(b) == GC_MARK_RECLAIMABLE) { | |
1582 | available++; | |
1583 | if (!GC_SECTORS_USED(b)) | |
1584 | bch_bucket_add_unused(ca, b); | |
1585 | } | |
1586 | } | |
1587 | } | |
1588 | ||
cafe5635 KO |
1589 | mutex_unlock(&c->bucket_lock); |
1590 | return available; | |
1591 | } | |
1592 | ||
72a44517 | 1593 | static void bch_btree_gc(struct cache_set *c) |
cafe5635 | 1594 | { |
cafe5635 KO |
1595 | int ret; |
1596 | unsigned long available; | |
1597 | struct gc_stat stats; | |
1598 | struct closure writes; | |
1599 | struct btree_op op; | |
cafe5635 | 1600 | uint64_t start_time = local_clock(); |
57943511 | 1601 | |
c37511b8 | 1602 | trace_bcache_gc_start(c); |
cafe5635 KO |
1603 | |
1604 | memset(&stats, 0, sizeof(struct gc_stat)); | |
1605 | closure_init_stack(&writes); | |
b54d6934 | 1606 | bch_btree_op_init(&op, SHRT_MAX); |
cafe5635 KO |
1607 | |
1608 | btree_gc_start(c); | |
1609 | ||
a1f0358b KO |
1610 | do { |
1611 | ret = btree_root(gc_root, c, &op, &writes, &stats); | |
1612 | closure_sync(&writes); | |
cafe5635 | 1613 | |
a1f0358b KO |
1614 | if (ret && ret != -EAGAIN) |
1615 | pr_warn("gc failed!"); | |
1616 | } while (ret); | |
cafe5635 KO |
1617 | |
1618 | available = bch_btree_gc_finish(c); | |
57943511 KO |
1619 | wake_up_allocators(c); |
1620 | ||
169ef1cf | 1621 | bch_time_stats_update(&c->btree_gc_time, start_time); |
cafe5635 KO |
1622 | |
1623 | stats.key_bytes *= sizeof(uint64_t); | |
cafe5635 KO |
1624 | stats.data <<= 9; |
1625 | stats.in_use = (c->nbuckets - available) * 100 / c->nbuckets; | |
1626 | memcpy(&c->gc_stats, &stats, sizeof(struct gc_stat)); | |
cafe5635 | 1627 | |
c37511b8 | 1628 | trace_bcache_gc_end(c); |
cafe5635 | 1629 | |
72a44517 KO |
1630 | bch_moving_gc(c); |
1631 | } | |
1632 | ||
1633 | static int bch_gc_thread(void *arg) | |
1634 | { | |
1635 | struct cache_set *c = arg; | |
a1f0358b KO |
1636 | struct cache *ca; |
1637 | unsigned i; | |
72a44517 KO |
1638 | |
1639 | while (1) { | |
a1f0358b | 1640 | again: |
72a44517 KO |
1641 | bch_btree_gc(c); |
1642 | ||
1643 | set_current_state(TASK_INTERRUPTIBLE); | |
1644 | if (kthread_should_stop()) | |
1645 | break; | |
1646 | ||
a1f0358b KO |
1647 | mutex_lock(&c->bucket_lock); |
1648 | ||
1649 | for_each_cache(ca, c, i) | |
1650 | if (ca->invalidate_needs_gc) { | |
1651 | mutex_unlock(&c->bucket_lock); | |
1652 | set_current_state(TASK_RUNNING); | |
1653 | goto again; | |
1654 | } | |
1655 | ||
1656 | mutex_unlock(&c->bucket_lock); | |
1657 | ||
72a44517 KO |
1658 | try_to_freeze(); |
1659 | schedule(); | |
1660 | } | |
1661 | ||
1662 | return 0; | |
cafe5635 KO |
1663 | } |
1664 | ||
72a44517 | 1665 | int bch_gc_thread_start(struct cache_set *c) |
cafe5635 | 1666 | { |
72a44517 KO |
1667 | c->gc_thread = kthread_create(bch_gc_thread, c, "bcache_gc"); |
1668 | if (IS_ERR(c->gc_thread)) | |
1669 | return PTR_ERR(c->gc_thread); | |
1670 | ||
1671 | set_task_state(c->gc_thread, TASK_INTERRUPTIBLE); | |
1672 | return 0; | |
cafe5635 KO |
1673 | } |
1674 | ||
1675 | /* Initial partial gc */ | |
1676 | ||
1677 | static int bch_btree_check_recurse(struct btree *b, struct btree_op *op, | |
1678 | unsigned long **seen) | |
1679 | { | |
50310164 | 1680 | int ret = 0; |
cafe5635 | 1681 | unsigned i; |
50310164 | 1682 | struct bkey *k, *p = NULL; |
cafe5635 KO |
1683 | struct bucket *g; |
1684 | struct btree_iter iter; | |
1685 | ||
1686 | for_each_key_filter(b, k, &iter, bch_ptr_invalid) { | |
1687 | for (i = 0; i < KEY_PTRS(k); i++) { | |
1688 | if (!ptr_available(b->c, k, i)) | |
1689 | continue; | |
1690 | ||
1691 | g = PTR_BUCKET(b->c, k, i); | |
1692 | ||
1693 | if (!__test_and_set_bit(PTR_BUCKET_NR(b->c, k, i), | |
1694 | seen[PTR_DEV(k, i)]) || | |
1695 | !ptr_stale(b->c, k, i)) { | |
1696 | g->gen = PTR_GEN(k, i); | |
1697 | ||
1698 | if (b->level) | |
1699 | g->prio = BTREE_PRIO; | |
1700 | else if (g->prio == BTREE_PRIO) | |
1701 | g->prio = INITIAL_PRIO; | |
1702 | } | |
1703 | } | |
1704 | ||
1705 | btree_mark_key(b, k); | |
1706 | } | |
1707 | ||
1708 | if (b->level) { | |
50310164 | 1709 | bch_btree_iter_init(b, &iter, NULL); |
cafe5635 | 1710 | |
50310164 KO |
1711 | do { |
1712 | k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad); | |
1713 | if (k) | |
1714 | btree_node_prefetch(b->c, k, b->level - 1); | |
cafe5635 | 1715 | |
50310164 KO |
1716 | if (p) |
1717 | ret = btree(check_recurse, p, b, op, seen); | |
cafe5635 | 1718 | |
50310164 KO |
1719 | p = k; |
1720 | } while (p && !ret); | |
cafe5635 KO |
1721 | } |
1722 | ||
1723 | return 0; | |
1724 | } | |
1725 | ||
c18536a7 | 1726 | int bch_btree_check(struct cache_set *c) |
cafe5635 KO |
1727 | { |
1728 | int ret = -ENOMEM; | |
1729 | unsigned i; | |
1730 | unsigned long *seen[MAX_CACHES_PER_SET]; | |
c18536a7 | 1731 | struct btree_op op; |
cafe5635 KO |
1732 | |
1733 | memset(seen, 0, sizeof(seen)); | |
b54d6934 | 1734 | bch_btree_op_init(&op, SHRT_MAX); |
cafe5635 KO |
1735 | |
1736 | for (i = 0; c->cache[i]; i++) { | |
1737 | size_t n = DIV_ROUND_UP(c->cache[i]->sb.nbuckets, 8); | |
1738 | seen[i] = kmalloc(n, GFP_KERNEL); | |
1739 | if (!seen[i]) | |
1740 | goto err; | |
1741 | ||
1742 | /* Disables the seen array until prio_read() uses it too */ | |
1743 | memset(seen[i], 0xFF, n); | |
1744 | } | |
1745 | ||
c18536a7 | 1746 | ret = btree_root(check_recurse, c, &op, seen); |
cafe5635 KO |
1747 | err: |
1748 | for (i = 0; i < MAX_CACHES_PER_SET; i++) | |
1749 | kfree(seen[i]); | |
1750 | return ret; | |
1751 | } | |
1752 | ||
1753 | /* Btree insertion */ | |
1754 | ||
1755 | static void shift_keys(struct btree *b, struct bkey *where, struct bkey *insert) | |
1756 | { | |
1757 | struct bset *i = b->sets[b->nsets].data; | |
1758 | ||
1759 | memmove((uint64_t *) where + bkey_u64s(insert), | |
1760 | where, | |
1761 | (void *) end(i) - (void *) where); | |
1762 | ||
1763 | i->keys += bkey_u64s(insert); | |
1764 | bkey_copy(where, insert); | |
1765 | bch_bset_fix_lookup_table(b, where); | |
1766 | } | |
1767 | ||
1b207d80 | 1768 | static bool fix_overlapping_extents(struct btree *b, struct bkey *insert, |
cafe5635 | 1769 | struct btree_iter *iter, |
1b207d80 | 1770 | struct bkey *replace_key) |
cafe5635 | 1771 | { |
279afbad | 1772 | void subtract_dirty(struct bkey *k, uint64_t offset, int sectors) |
cafe5635 | 1773 | { |
279afbad KO |
1774 | if (KEY_DIRTY(k)) |
1775 | bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k), | |
1776 | offset, -sectors); | |
cafe5635 KO |
1777 | } |
1778 | ||
279afbad | 1779 | uint64_t old_offset; |
cafe5635 KO |
1780 | unsigned old_size, sectors_found = 0; |
1781 | ||
1782 | while (1) { | |
1783 | struct bkey *k = bch_btree_iter_next(iter); | |
1784 | if (!k || | |
1785 | bkey_cmp(&START_KEY(k), insert) >= 0) | |
1786 | break; | |
1787 | ||
1788 | if (bkey_cmp(k, &START_KEY(insert)) <= 0) | |
1789 | continue; | |
1790 | ||
279afbad | 1791 | old_offset = KEY_START(k); |
cafe5635 KO |
1792 | old_size = KEY_SIZE(k); |
1793 | ||
1794 | /* | |
1795 | * We might overlap with 0 size extents; we can't skip these | |
1796 | * because if they're in the set we're inserting to we have to | |
1797 | * adjust them so they don't overlap with the key we're | |
1b207d80 | 1798 | * inserting. But we don't want to check them for replace |
cafe5635 KO |
1799 | * operations. |
1800 | */ | |
1801 | ||
1b207d80 | 1802 | if (replace_key && KEY_SIZE(k)) { |
cafe5635 KO |
1803 | /* |
1804 | * k might have been split since we inserted/found the | |
1805 | * key we're replacing | |
1806 | */ | |
1807 | unsigned i; | |
1808 | uint64_t offset = KEY_START(k) - | |
1b207d80 | 1809 | KEY_START(replace_key); |
cafe5635 KO |
1810 | |
1811 | /* But it must be a subset of the replace key */ | |
1b207d80 KO |
1812 | if (KEY_START(k) < KEY_START(replace_key) || |
1813 | KEY_OFFSET(k) > KEY_OFFSET(replace_key)) | |
cafe5635 KO |
1814 | goto check_failed; |
1815 | ||
1816 | /* We didn't find a key that we were supposed to */ | |
1817 | if (KEY_START(k) > KEY_START(insert) + sectors_found) | |
1818 | goto check_failed; | |
1819 | ||
1b207d80 | 1820 | if (KEY_PTRS(replace_key) != KEY_PTRS(k)) |
cafe5635 KO |
1821 | goto check_failed; |
1822 | ||
1823 | /* skip past gen */ | |
1824 | offset <<= 8; | |
1825 | ||
1b207d80 | 1826 | BUG_ON(!KEY_PTRS(replace_key)); |
cafe5635 | 1827 | |
1b207d80 KO |
1828 | for (i = 0; i < KEY_PTRS(replace_key); i++) |
1829 | if (k->ptr[i] != replace_key->ptr[i] + offset) | |
cafe5635 KO |
1830 | goto check_failed; |
1831 | ||
1832 | sectors_found = KEY_OFFSET(k) - KEY_START(insert); | |
1833 | } | |
1834 | ||
1835 | if (bkey_cmp(insert, k) < 0 && | |
1836 | bkey_cmp(&START_KEY(insert), &START_KEY(k)) > 0) { | |
1837 | /* | |
1838 | * We overlapped in the middle of an existing key: that | |
1839 | * means we have to split the old key. But we have to do | |
1840 | * slightly different things depending on whether the | |
1841 | * old key has been written out yet. | |
1842 | */ | |
1843 | ||
1844 | struct bkey *top; | |
1845 | ||
279afbad | 1846 | subtract_dirty(k, KEY_START(insert), KEY_SIZE(insert)); |
cafe5635 KO |
1847 | |
1848 | if (bkey_written(b, k)) { | |
1849 | /* | |
1850 | * We insert a new key to cover the top of the | |
1851 | * old key, and the old key is modified in place | |
1852 | * to represent the bottom split. | |
1853 | * | |
1854 | * It's completely arbitrary whether the new key | |
1855 | * is the top or the bottom, but it has to match | |
1856 | * up with what btree_sort_fixup() does - it | |
1857 | * doesn't check for this kind of overlap, it | |
1858 | * depends on us inserting a new key for the top | |
1859 | * here. | |
1860 | */ | |
1861 | top = bch_bset_search(b, &b->sets[b->nsets], | |
1862 | insert); | |
1863 | shift_keys(b, top, k); | |
1864 | } else { | |
1865 | BKEY_PADDED(key) temp; | |
1866 | bkey_copy(&temp.key, k); | |
1867 | shift_keys(b, k, &temp.key); | |
1868 | top = bkey_next(k); | |
1869 | } | |
1870 | ||
1871 | bch_cut_front(insert, top); | |
1872 | bch_cut_back(&START_KEY(insert), k); | |
1873 | bch_bset_fix_invalidated_key(b, k); | |
1874 | return false; | |
1875 | } | |
1876 | ||
1877 | if (bkey_cmp(insert, k) < 0) { | |
1878 | bch_cut_front(insert, k); | |
1879 | } else { | |
1fa8455d KO |
1880 | if (bkey_cmp(&START_KEY(insert), &START_KEY(k)) > 0) |
1881 | old_offset = KEY_START(insert); | |
1882 | ||
cafe5635 KO |
1883 | if (bkey_written(b, k) && |
1884 | bkey_cmp(&START_KEY(insert), &START_KEY(k)) <= 0) { | |
1885 | /* | |
1886 | * Completely overwrote, so we don't have to | |
1887 | * invalidate the binary search tree | |
1888 | */ | |
1889 | bch_cut_front(k, k); | |
1890 | } else { | |
1891 | __bch_cut_back(&START_KEY(insert), k); | |
1892 | bch_bset_fix_invalidated_key(b, k); | |
1893 | } | |
1894 | } | |
1895 | ||
279afbad | 1896 | subtract_dirty(k, old_offset, old_size - KEY_SIZE(k)); |
cafe5635 KO |
1897 | } |
1898 | ||
1899 | check_failed: | |
1b207d80 | 1900 | if (replace_key) { |
cafe5635 | 1901 | if (!sectors_found) { |
cafe5635 KO |
1902 | return true; |
1903 | } else if (sectors_found < KEY_SIZE(insert)) { | |
1904 | SET_KEY_OFFSET(insert, KEY_OFFSET(insert) - | |
1905 | (KEY_SIZE(insert) - sectors_found)); | |
1906 | SET_KEY_SIZE(insert, sectors_found); | |
1907 | } | |
1908 | } | |
1909 | ||
1910 | return false; | |
1911 | } | |
1912 | ||
1913 | static bool btree_insert_key(struct btree *b, struct btree_op *op, | |
1b207d80 | 1914 | struct bkey *k, struct bkey *replace_key) |
cafe5635 KO |
1915 | { |
1916 | struct bset *i = b->sets[b->nsets].data; | |
1917 | struct bkey *m, *prev; | |
85b1492e | 1918 | unsigned status = BTREE_INSERT_STATUS_INSERT; |
cafe5635 KO |
1919 | |
1920 | BUG_ON(bkey_cmp(k, &b->key) > 0); | |
1921 | BUG_ON(b->level && !KEY_PTRS(k)); | |
1922 | BUG_ON(!b->level && !KEY_OFFSET(k)); | |
1923 | ||
1924 | if (!b->level) { | |
1925 | struct btree_iter iter; | |
cafe5635 KO |
1926 | |
1927 | /* | |
1928 | * bset_search() returns the first key that is strictly greater | |
1929 | * than the search key - but for back merging, we want to find | |
0eacac22 | 1930 | * the previous key. |
cafe5635 | 1931 | */ |
cafe5635 | 1932 | prev = NULL; |
0eacac22 | 1933 | m = bch_btree_iter_init(b, &iter, PRECEDING_KEY(&START_KEY(k))); |
cafe5635 | 1934 | |
1b207d80 KO |
1935 | if (fix_overlapping_extents(b, k, &iter, replace_key)) { |
1936 | op->insert_collision = true; | |
cafe5635 | 1937 | return false; |
1b207d80 | 1938 | } |
cafe5635 | 1939 | |
1fa8455d KO |
1940 | if (KEY_DIRTY(k)) |
1941 | bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k), | |
1942 | KEY_START(k), KEY_SIZE(k)); | |
1943 | ||
cafe5635 KO |
1944 | while (m != end(i) && |
1945 | bkey_cmp(k, &START_KEY(m)) > 0) | |
1946 | prev = m, m = bkey_next(m); | |
1947 | ||
1948 | if (key_merging_disabled(b->c)) | |
1949 | goto insert; | |
1950 | ||
1951 | /* prev is in the tree, if we merge we're done */ | |
85b1492e | 1952 | status = BTREE_INSERT_STATUS_BACK_MERGE; |
cafe5635 KO |
1953 | if (prev && |
1954 | bch_bkey_try_merge(b, prev, k)) | |
1955 | goto merged; | |
1956 | ||
85b1492e | 1957 | status = BTREE_INSERT_STATUS_OVERWROTE; |
cafe5635 KO |
1958 | if (m != end(i) && |
1959 | KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m)) | |
1960 | goto copy; | |
1961 | ||
85b1492e | 1962 | status = BTREE_INSERT_STATUS_FRONT_MERGE; |
cafe5635 KO |
1963 | if (m != end(i) && |
1964 | bch_bkey_try_merge(b, k, m)) | |
1965 | goto copy; | |
1b207d80 KO |
1966 | } else { |
1967 | BUG_ON(replace_key); | |
cafe5635 | 1968 | m = bch_bset_search(b, &b->sets[b->nsets], k); |
1b207d80 | 1969 | } |
cafe5635 KO |
1970 | |
1971 | insert: shift_keys(b, m, k); | |
1972 | copy: bkey_copy(m, k); | |
1973 | merged: | |
1b207d80 KO |
1974 | bch_check_keys(b, "%u for %s", status, |
1975 | replace_key ? "replace" : "insert"); | |
cafe5635 KO |
1976 | |
1977 | if (b->level && !KEY_OFFSET(k)) | |
57943511 | 1978 | btree_current_write(b)->prio_blocked++; |
cafe5635 | 1979 | |
1b207d80 | 1980 | trace_bcache_btree_insert_key(b, k, replace_key != NULL, status); |
cafe5635 KO |
1981 | |
1982 | return true; | |
1983 | } | |
1984 | ||
26c949f8 | 1985 | static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op, |
1b207d80 KO |
1986 | struct keylist *insert_keys, |
1987 | struct bkey *replace_key) | |
cafe5635 KO |
1988 | { |
1989 | bool ret = false; | |
280481d0 | 1990 | int oldsize = bch_count_data(b); |
cafe5635 | 1991 | |
26c949f8 | 1992 | while (!bch_keylist_empty(insert_keys)) { |
403b6cde | 1993 | struct bset *i = write_block(b); |
c2f95ae2 | 1994 | struct bkey *k = insert_keys->keys; |
26c949f8 | 1995 | |
403b6cde KO |
1996 | if (b->written + __set_blocks(i, i->keys + bkey_u64s(k), b->c) |
1997 | > btree_blocks(b)) | |
1998 | break; | |
1999 | ||
2000 | if (bkey_cmp(k, &b->key) <= 0) { | |
3a3b6a4e KO |
2001 | if (!b->level) |
2002 | bkey_put(b->c, k); | |
26c949f8 | 2003 | |
1b207d80 | 2004 | ret |= btree_insert_key(b, op, k, replace_key); |
26c949f8 KO |
2005 | bch_keylist_pop_front(insert_keys); |
2006 | } else if (bkey_cmp(&START_KEY(k), &b->key) < 0) { | |
26c949f8 | 2007 | BKEY_PADDED(key) temp; |
c2f95ae2 | 2008 | bkey_copy(&temp.key, insert_keys->keys); |
26c949f8 KO |
2009 | |
2010 | bch_cut_back(&b->key, &temp.key); | |
c2f95ae2 | 2011 | bch_cut_front(&b->key, insert_keys->keys); |
26c949f8 | 2012 | |
1b207d80 | 2013 | ret |= btree_insert_key(b, op, &temp.key, replace_key); |
26c949f8 KO |
2014 | break; |
2015 | } else { | |
2016 | break; | |
2017 | } | |
cafe5635 KO |
2018 | } |
2019 | ||
403b6cde KO |
2020 | BUG_ON(!bch_keylist_empty(insert_keys) && b->level); |
2021 | ||
cafe5635 KO |
2022 | BUG_ON(bch_count_data(b) < oldsize); |
2023 | return ret; | |
2024 | } | |
2025 | ||
26c949f8 KO |
2026 | static int btree_split(struct btree *b, struct btree_op *op, |
2027 | struct keylist *insert_keys, | |
1b207d80 | 2028 | struct bkey *replace_key) |
cafe5635 | 2029 | { |
d6fd3b11 | 2030 | bool split; |
cafe5635 KO |
2031 | struct btree *n1, *n2 = NULL, *n3 = NULL; |
2032 | uint64_t start_time = local_clock(); | |
b54d6934 | 2033 | struct closure cl; |
17e21a9f | 2034 | struct keylist parent_keys; |
b54d6934 KO |
2035 | |
2036 | closure_init_stack(&cl); | |
17e21a9f | 2037 | bch_keylist_init(&parent_keys); |
cafe5635 | 2038 | |
bc9389ee | 2039 | n1 = btree_node_alloc_replacement(b, true); |
cafe5635 KO |
2040 | if (IS_ERR(n1)) |
2041 | goto err; | |
2042 | ||
2043 | split = set_blocks(n1->sets[0].data, n1->c) > (btree_blocks(b) * 4) / 5; | |
2044 | ||
cafe5635 KO |
2045 | if (split) { |
2046 | unsigned keys = 0; | |
2047 | ||
c37511b8 KO |
2048 | trace_bcache_btree_node_split(b, n1->sets[0].data->keys); |
2049 | ||
bc9389ee | 2050 | n2 = bch_btree_node_alloc(b->c, b->level, true); |
cafe5635 KO |
2051 | if (IS_ERR(n2)) |
2052 | goto err_free1; | |
2053 | ||
d6fd3b11 | 2054 | if (!b->parent) { |
bc9389ee | 2055 | n3 = bch_btree_node_alloc(b->c, b->level + 1, true); |
cafe5635 KO |
2056 | if (IS_ERR(n3)) |
2057 | goto err_free2; | |
2058 | } | |
2059 | ||
1b207d80 | 2060 | bch_btree_insert_keys(n1, op, insert_keys, replace_key); |
cafe5635 | 2061 | |
d6fd3b11 KO |
2062 | /* |
2063 | * Has to be a linear search because we don't have an auxiliary | |
cafe5635 KO |
2064 | * search tree yet |
2065 | */ | |
2066 | ||
2067 | while (keys < (n1->sets[0].data->keys * 3) / 5) | |
2068 | keys += bkey_u64s(node(n1->sets[0].data, keys)); | |
2069 | ||
2070 | bkey_copy_key(&n1->key, node(n1->sets[0].data, keys)); | |
2071 | keys += bkey_u64s(node(n1->sets[0].data, keys)); | |
2072 | ||
2073 | n2->sets[0].data->keys = n1->sets[0].data->keys - keys; | |
2074 | n1->sets[0].data->keys = keys; | |
2075 | ||
2076 | memcpy(n2->sets[0].data->start, | |
2077 | end(n1->sets[0].data), | |
2078 | n2->sets[0].data->keys * sizeof(uint64_t)); | |
2079 | ||
2080 | bkey_copy_key(&n2->key, &b->key); | |
2081 | ||
17e21a9f | 2082 | bch_keylist_add(&parent_keys, &n2->key); |
b54d6934 | 2083 | bch_btree_node_write(n2, &cl); |
cafe5635 | 2084 | rw_unlock(true, n2); |
c37511b8 KO |
2085 | } else { |
2086 | trace_bcache_btree_node_compact(b, n1->sets[0].data->keys); | |
2087 | ||
1b207d80 | 2088 | bch_btree_insert_keys(n1, op, insert_keys, replace_key); |
c37511b8 | 2089 | } |
cafe5635 | 2090 | |
17e21a9f | 2091 | bch_keylist_add(&parent_keys, &n1->key); |
b54d6934 | 2092 | bch_btree_node_write(n1, &cl); |
cafe5635 KO |
2093 | |
2094 | if (n3) { | |
d6fd3b11 | 2095 | /* Depth increases, make a new root */ |
cafe5635 | 2096 | bkey_copy_key(&n3->key, &MAX_KEY); |
17e21a9f | 2097 | bch_btree_insert_keys(n3, op, &parent_keys, NULL); |
b54d6934 | 2098 | bch_btree_node_write(n3, &cl); |
cafe5635 | 2099 | |
b54d6934 | 2100 | closure_sync(&cl); |
cafe5635 KO |
2101 | bch_btree_set_root(n3); |
2102 | rw_unlock(true, n3); | |
17e21a9f KO |
2103 | |
2104 | btree_node_free(b); | |
d6fd3b11 KO |
2105 | } else if (!b->parent) { |
2106 | /* Root filled up but didn't need to be split */ | |
b54d6934 | 2107 | closure_sync(&cl); |
cafe5635 | 2108 | bch_btree_set_root(n1); |
17e21a9f KO |
2109 | |
2110 | btree_node_free(b); | |
cafe5635 | 2111 | } else { |
17e21a9f | 2112 | /* Split a non root node */ |
b54d6934 | 2113 | closure_sync(&cl); |
17e21a9f KO |
2114 | make_btree_freeing_key(b, parent_keys.top); |
2115 | bch_keylist_push(&parent_keys); | |
2116 | ||
2117 | btree_node_free(b); | |
2118 | ||
2119 | bch_btree_insert_node(b->parent, op, &parent_keys, NULL, NULL); | |
2120 | BUG_ON(!bch_keylist_empty(&parent_keys)); | |
cafe5635 KO |
2121 | } |
2122 | ||
2123 | rw_unlock(true, n1); | |
cafe5635 | 2124 | |
169ef1cf | 2125 | bch_time_stats_update(&b->c->btree_split_time, start_time); |
cafe5635 KO |
2126 | |
2127 | return 0; | |
2128 | err_free2: | |
e8e1d468 | 2129 | btree_node_free(n2); |
cafe5635 KO |
2130 | rw_unlock(true, n2); |
2131 | err_free1: | |
e8e1d468 | 2132 | btree_node_free(n1); |
cafe5635 KO |
2133 | rw_unlock(true, n1); |
2134 | err: | |
2135 | if (n3 == ERR_PTR(-EAGAIN) || | |
2136 | n2 == ERR_PTR(-EAGAIN) || | |
2137 | n1 == ERR_PTR(-EAGAIN)) | |
2138 | return -EAGAIN; | |
2139 | ||
2140 | pr_warn("couldn't split"); | |
2141 | return -ENOMEM; | |
2142 | } | |
2143 | ||
26c949f8 | 2144 | static int bch_btree_insert_node(struct btree *b, struct btree_op *op, |
c18536a7 | 2145 | struct keylist *insert_keys, |
1b207d80 KO |
2146 | atomic_t *journal_ref, |
2147 | struct bkey *replace_key) | |
cafe5635 | 2148 | { |
17e21a9f KO |
2149 | BUG_ON(b->level && replace_key); |
2150 | ||
2151 | if (should_split(b)) { | |
2152 | if (current->bio_list) { | |
2153 | op->lock = b->c->root->level + 1; | |
2154 | return -EAGAIN; | |
2155 | } else if (op->lock <= b->c->root->level) { | |
2156 | op->lock = b->c->root->level + 1; | |
2157 | return -EINTR; | |
26c949f8 | 2158 | } else { |
17e21a9f KO |
2159 | /* Invalidated all iterators */ |
2160 | return btree_split(b, op, insert_keys, replace_key) ?: | |
2161 | -EINTR; | |
cafe5635 | 2162 | } |
17e21a9f KO |
2163 | } else { |
2164 | BUG_ON(write_block(b) != b->sets[b->nsets].data); | |
cafe5635 | 2165 | |
17e21a9f KO |
2166 | if (bch_btree_insert_keys(b, op, insert_keys, replace_key)) { |
2167 | if (!b->level) | |
2168 | bch_btree_leaf_dirty(b, journal_ref); | |
2169 | else | |
2170 | bch_btree_node_write_sync(b); | |
2171 | } | |
2172 | ||
2173 | return 0; | |
2174 | } | |
26c949f8 | 2175 | } |
cafe5635 | 2176 | |
e7c590eb KO |
2177 | int bch_btree_insert_check_key(struct btree *b, struct btree_op *op, |
2178 | struct bkey *check_key) | |
2179 | { | |
2180 | int ret = -EINTR; | |
2181 | uint64_t btree_ptr = b->key.ptr[0]; | |
2182 | unsigned long seq = b->seq; | |
2183 | struct keylist insert; | |
2184 | bool upgrade = op->lock == -1; | |
2185 | ||
2186 | bch_keylist_init(&insert); | |
2187 | ||
2188 | if (upgrade) { | |
2189 | rw_unlock(false, b); | |
2190 | rw_lock(true, b, b->level); | |
2191 | ||
2192 | if (b->key.ptr[0] != btree_ptr || | |
2193 | b->seq != seq + 1) | |
2194 | goto out; | |
2195 | } | |
2196 | ||
2197 | SET_KEY_PTRS(check_key, 1); | |
2198 | get_random_bytes(&check_key->ptr[0], sizeof(uint64_t)); | |
2199 | ||
2200 | SET_PTR_DEV(check_key, 0, PTR_CHECK_DEV); | |
2201 | ||
2202 | bch_keylist_add(&insert, check_key); | |
2203 | ||
1b207d80 | 2204 | ret = bch_btree_insert_node(b, op, &insert, NULL, NULL); |
e7c590eb KO |
2205 | |
2206 | BUG_ON(!ret && !bch_keylist_empty(&insert)); | |
2207 | out: | |
2208 | if (upgrade) | |
2209 | downgrade_write(&b->lock); | |
2210 | return ret; | |
2211 | } | |
2212 | ||
cc7b8819 KO |
2213 | struct btree_insert_op { |
2214 | struct btree_op op; | |
2215 | struct keylist *keys; | |
2216 | atomic_t *journal_ref; | |
2217 | struct bkey *replace_key; | |
2218 | }; | |
cafe5635 | 2219 | |
cc7b8819 KO |
2220 | int btree_insert_fn(struct btree_op *b_op, struct btree *b) |
2221 | { | |
2222 | struct btree_insert_op *op = container_of(b_op, | |
2223 | struct btree_insert_op, op); | |
cafe5635 | 2224 | |
cc7b8819 KO |
2225 | int ret = bch_btree_insert_node(b, &op->op, op->keys, |
2226 | op->journal_ref, op->replace_key); | |
2227 | if (ret && !bch_keylist_empty(op->keys)) | |
2228 | return ret; | |
2229 | else | |
2230 | return MAP_DONE; | |
cafe5635 KO |
2231 | } |
2232 | ||
cc7b8819 KO |
2233 | int bch_btree_insert(struct cache_set *c, struct keylist *keys, |
2234 | atomic_t *journal_ref, struct bkey *replace_key) | |
cafe5635 | 2235 | { |
cc7b8819 | 2236 | struct btree_insert_op op; |
cafe5635 | 2237 | int ret = 0; |
cafe5635 | 2238 | |
cc7b8819 | 2239 | BUG_ON(current->bio_list); |
4f3d4014 | 2240 | BUG_ON(bch_keylist_empty(keys)); |
cafe5635 | 2241 | |
cc7b8819 KO |
2242 | bch_btree_op_init(&op.op, 0); |
2243 | op.keys = keys; | |
2244 | op.journal_ref = journal_ref; | |
2245 | op.replace_key = replace_key; | |
cafe5635 | 2246 | |
cc7b8819 KO |
2247 | while (!ret && !bch_keylist_empty(keys)) { |
2248 | op.op.lock = 0; | |
2249 | ret = bch_btree_map_leaf_nodes(&op.op, c, | |
2250 | &START_KEY(keys->keys), | |
2251 | btree_insert_fn); | |
2252 | } | |
cafe5635 | 2253 | |
cc7b8819 KO |
2254 | if (ret) { |
2255 | struct bkey *k; | |
cafe5635 | 2256 | |
cc7b8819 | 2257 | pr_err("error %i", ret); |
cafe5635 | 2258 | |
cc7b8819 | 2259 | while ((k = bch_keylist_pop(keys))) |
3a3b6a4e | 2260 | bkey_put(c, k); |
cc7b8819 KO |
2261 | } else if (op.op.insert_collision) |
2262 | ret = -ESRCH; | |
6054c6d4 | 2263 | |
cafe5635 KO |
2264 | return ret; |
2265 | } | |
2266 | ||
2267 | void bch_btree_set_root(struct btree *b) | |
2268 | { | |
2269 | unsigned i; | |
e49c7c37 KO |
2270 | struct closure cl; |
2271 | ||
2272 | closure_init_stack(&cl); | |
cafe5635 | 2273 | |
c37511b8 KO |
2274 | trace_bcache_btree_set_root(b); |
2275 | ||
cafe5635 KO |
2276 | BUG_ON(!b->written); |
2277 | ||
2278 | for (i = 0; i < KEY_PTRS(&b->key); i++) | |
2279 | BUG_ON(PTR_BUCKET(b->c, &b->key, i)->prio != BTREE_PRIO); | |
2280 | ||
2281 | mutex_lock(&b->c->bucket_lock); | |
2282 | list_del_init(&b->list); | |
2283 | mutex_unlock(&b->c->bucket_lock); | |
2284 | ||
2285 | b->c->root = b; | |
cafe5635 | 2286 | |
e49c7c37 KO |
2287 | bch_journal_meta(b->c, &cl); |
2288 | closure_sync(&cl); | |
cafe5635 KO |
2289 | } |
2290 | ||
48dad8ba KO |
2291 | /* Map across nodes or keys */ |
2292 | ||
2293 | static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op, | |
2294 | struct bkey *from, | |
2295 | btree_map_nodes_fn *fn, int flags) | |
2296 | { | |
2297 | int ret = MAP_CONTINUE; | |
2298 | ||
2299 | if (b->level) { | |
2300 | struct bkey *k; | |
2301 | struct btree_iter iter; | |
2302 | ||
2303 | bch_btree_iter_init(b, &iter, from); | |
2304 | ||
2305 | while ((k = bch_btree_iter_next_filter(&iter, b, | |
2306 | bch_ptr_bad))) { | |
2307 | ret = btree(map_nodes_recurse, k, b, | |
2308 | op, from, fn, flags); | |
2309 | from = NULL; | |
2310 | ||
2311 | if (ret != MAP_CONTINUE) | |
2312 | return ret; | |
2313 | } | |
2314 | } | |
2315 | ||
2316 | if (!b->level || flags == MAP_ALL_NODES) | |
2317 | ret = fn(op, b); | |
2318 | ||
2319 | return ret; | |
2320 | } | |
2321 | ||
2322 | int __bch_btree_map_nodes(struct btree_op *op, struct cache_set *c, | |
2323 | struct bkey *from, btree_map_nodes_fn *fn, int flags) | |
2324 | { | |
b54d6934 | 2325 | return btree_root(map_nodes_recurse, c, op, from, fn, flags); |
48dad8ba KO |
2326 | } |
2327 | ||
2328 | static int bch_btree_map_keys_recurse(struct btree *b, struct btree_op *op, | |
2329 | struct bkey *from, btree_map_keys_fn *fn, | |
2330 | int flags) | |
2331 | { | |
2332 | int ret = MAP_CONTINUE; | |
2333 | struct bkey *k; | |
2334 | struct btree_iter iter; | |
2335 | ||
2336 | bch_btree_iter_init(b, &iter, from); | |
2337 | ||
2338 | while ((k = bch_btree_iter_next_filter(&iter, b, bch_ptr_bad))) { | |
2339 | ret = !b->level | |
2340 | ? fn(op, b, k) | |
2341 | : btree(map_keys_recurse, k, b, op, from, fn, flags); | |
2342 | from = NULL; | |
2343 | ||
2344 | if (ret != MAP_CONTINUE) | |
2345 | return ret; | |
2346 | } | |
2347 | ||
2348 | if (!b->level && (flags & MAP_END_KEY)) | |
2349 | ret = fn(op, b, &KEY(KEY_INODE(&b->key), | |
2350 | KEY_OFFSET(&b->key), 0)); | |
2351 | ||
2352 | return ret; | |
2353 | } | |
2354 | ||
2355 | int bch_btree_map_keys(struct btree_op *op, struct cache_set *c, | |
2356 | struct bkey *from, btree_map_keys_fn *fn, int flags) | |
2357 | { | |
b54d6934 | 2358 | return btree_root(map_keys_recurse, c, op, from, fn, flags); |
48dad8ba KO |
2359 | } |
2360 | ||
cafe5635 KO |
2361 | /* Keybuf code */ |
2362 | ||
2363 | static inline int keybuf_cmp(struct keybuf_key *l, struct keybuf_key *r) | |
2364 | { | |
2365 | /* Overlapping keys compare equal */ | |
2366 | if (bkey_cmp(&l->key, &START_KEY(&r->key)) <= 0) | |
2367 | return -1; | |
2368 | if (bkey_cmp(&START_KEY(&l->key), &r->key) >= 0) | |
2369 | return 1; | |
2370 | return 0; | |
2371 | } | |
2372 | ||
2373 | static inline int keybuf_nonoverlapping_cmp(struct keybuf_key *l, | |
2374 | struct keybuf_key *r) | |
2375 | { | |
2376 | return clamp_t(int64_t, bkey_cmp(&l->key, &r->key), -1, 1); | |
2377 | } | |
2378 | ||
48dad8ba KO |
2379 | struct refill { |
2380 | struct btree_op op; | |
48a915a8 | 2381 | unsigned nr_found; |
48dad8ba KO |
2382 | struct keybuf *buf; |
2383 | struct bkey *end; | |
2384 | keybuf_pred_fn *pred; | |
2385 | }; | |
cafe5635 | 2386 | |
48dad8ba KO |
2387 | static int refill_keybuf_fn(struct btree_op *op, struct btree *b, |
2388 | struct bkey *k) | |
2389 | { | |
2390 | struct refill *refill = container_of(op, struct refill, op); | |
2391 | struct keybuf *buf = refill->buf; | |
2392 | int ret = MAP_CONTINUE; | |
cafe5635 | 2393 | |
48dad8ba KO |
2394 | if (bkey_cmp(k, refill->end) >= 0) { |
2395 | ret = MAP_DONE; | |
2396 | goto out; | |
2397 | } | |
cafe5635 | 2398 | |
48dad8ba KO |
2399 | if (!KEY_SIZE(k)) /* end key */ |
2400 | goto out; | |
cafe5635 | 2401 | |
48dad8ba KO |
2402 | if (refill->pred(buf, k)) { |
2403 | struct keybuf_key *w; | |
cafe5635 | 2404 | |
48dad8ba | 2405 | spin_lock(&buf->lock); |
cafe5635 | 2406 | |
48dad8ba KO |
2407 | w = array_alloc(&buf->freelist); |
2408 | if (!w) { | |
2409 | spin_unlock(&buf->lock); | |
2410 | return MAP_DONE; | |
2411 | } | |
cafe5635 | 2412 | |
48dad8ba KO |
2413 | w->private = NULL; |
2414 | bkey_copy(&w->key, k); | |
cafe5635 | 2415 | |
48dad8ba KO |
2416 | if (RB_INSERT(&buf->keys, w, node, keybuf_cmp)) |
2417 | array_free(&buf->freelist, w); | |
48a915a8 KO |
2418 | else |
2419 | refill->nr_found++; | |
cafe5635 | 2420 | |
48dad8ba KO |
2421 | if (array_freelist_empty(&buf->freelist)) |
2422 | ret = MAP_DONE; | |
cafe5635 | 2423 | |
48dad8ba | 2424 | spin_unlock(&buf->lock); |
cafe5635 | 2425 | } |
48dad8ba KO |
2426 | out: |
2427 | buf->last_scanned = *k; | |
2428 | return ret; | |
cafe5635 KO |
2429 | } |
2430 | ||
2431 | void bch_refill_keybuf(struct cache_set *c, struct keybuf *buf, | |
72c27061 | 2432 | struct bkey *end, keybuf_pred_fn *pred) |
cafe5635 KO |
2433 | { |
2434 | struct bkey start = buf->last_scanned; | |
48dad8ba | 2435 | struct refill refill; |
cafe5635 KO |
2436 | |
2437 | cond_resched(); | |
2438 | ||
b54d6934 | 2439 | bch_btree_op_init(&refill.op, -1); |
48a915a8 KO |
2440 | refill.nr_found = 0; |
2441 | refill.buf = buf; | |
2442 | refill.end = end; | |
2443 | refill.pred = pred; | |
48dad8ba KO |
2444 | |
2445 | bch_btree_map_keys(&refill.op, c, &buf->last_scanned, | |
2446 | refill_keybuf_fn, MAP_END_KEY); | |
cafe5635 | 2447 | |
48a915a8 KO |
2448 | trace_bcache_keyscan(refill.nr_found, |
2449 | KEY_INODE(&start), KEY_OFFSET(&start), | |
2450 | KEY_INODE(&buf->last_scanned), | |
2451 | KEY_OFFSET(&buf->last_scanned)); | |
cafe5635 KO |
2452 | |
2453 | spin_lock(&buf->lock); | |
2454 | ||
2455 | if (!RB_EMPTY_ROOT(&buf->keys)) { | |
2456 | struct keybuf_key *w; | |
2457 | w = RB_FIRST(&buf->keys, struct keybuf_key, node); | |
2458 | buf->start = START_KEY(&w->key); | |
2459 | ||
2460 | w = RB_LAST(&buf->keys, struct keybuf_key, node); | |
2461 | buf->end = w->key; | |
2462 | } else { | |
2463 | buf->start = MAX_KEY; | |
2464 | buf->end = MAX_KEY; | |
2465 | } | |
2466 | ||
2467 | spin_unlock(&buf->lock); | |
2468 | } | |
2469 | ||
2470 | static void __bch_keybuf_del(struct keybuf *buf, struct keybuf_key *w) | |
2471 | { | |
2472 | rb_erase(&w->node, &buf->keys); | |
2473 | array_free(&buf->freelist, w); | |
2474 | } | |
2475 | ||
2476 | void bch_keybuf_del(struct keybuf *buf, struct keybuf_key *w) | |
2477 | { | |
2478 | spin_lock(&buf->lock); | |
2479 | __bch_keybuf_del(buf, w); | |
2480 | spin_unlock(&buf->lock); | |
2481 | } | |
2482 | ||
2483 | bool bch_keybuf_check_overlapping(struct keybuf *buf, struct bkey *start, | |
2484 | struct bkey *end) | |
2485 | { | |
2486 | bool ret = false; | |
2487 | struct keybuf_key *p, *w, s; | |
2488 | s.key = *start; | |
2489 | ||
2490 | if (bkey_cmp(end, &buf->start) <= 0 || | |
2491 | bkey_cmp(start, &buf->end) >= 0) | |
2492 | return false; | |
2493 | ||
2494 | spin_lock(&buf->lock); | |
2495 | w = RB_GREATER(&buf->keys, s, node, keybuf_nonoverlapping_cmp); | |
2496 | ||
2497 | while (w && bkey_cmp(&START_KEY(&w->key), end) < 0) { | |
2498 | p = w; | |
2499 | w = RB_NEXT(w, node); | |
2500 | ||
2501 | if (p->private) | |
2502 | ret = true; | |
2503 | else | |
2504 | __bch_keybuf_del(buf, p); | |
2505 | } | |
2506 | ||
2507 | spin_unlock(&buf->lock); | |
2508 | return ret; | |
2509 | } | |
2510 | ||
2511 | struct keybuf_key *bch_keybuf_next(struct keybuf *buf) | |
2512 | { | |
2513 | struct keybuf_key *w; | |
2514 | spin_lock(&buf->lock); | |
2515 | ||
2516 | w = RB_FIRST(&buf->keys, struct keybuf_key, node); | |
2517 | ||
2518 | while (w && w->private) | |
2519 | w = RB_NEXT(w, node); | |
2520 | ||
2521 | if (w) | |
2522 | w->private = ERR_PTR(-EINTR); | |
2523 | ||
2524 | spin_unlock(&buf->lock); | |
2525 | return w; | |
2526 | } | |
2527 | ||
2528 | struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *c, | |
48dad8ba KO |
2529 | struct keybuf *buf, |
2530 | struct bkey *end, | |
2531 | keybuf_pred_fn *pred) | |
cafe5635 KO |
2532 | { |
2533 | struct keybuf_key *ret; | |
2534 | ||
2535 | while (1) { | |
2536 | ret = bch_keybuf_next(buf); | |
2537 | if (ret) | |
2538 | break; | |
2539 | ||
2540 | if (bkey_cmp(&buf->last_scanned, end) >= 0) { | |
2541 | pr_debug("scan finished"); | |
2542 | break; | |
2543 | } | |
2544 | ||
72c27061 | 2545 | bch_refill_keybuf(c, buf, end, pred); |
cafe5635 KO |
2546 | } |
2547 | ||
2548 | return ret; | |
2549 | } | |
2550 | ||
72c27061 | 2551 | void bch_keybuf_init(struct keybuf *buf) |
cafe5635 | 2552 | { |
cafe5635 KO |
2553 | buf->last_scanned = MAX_KEY; |
2554 | buf->keys = RB_ROOT; | |
2555 | ||
2556 | spin_lock_init(&buf->lock); | |
2557 | array_allocator_init(&buf->freelist); | |
2558 | } | |
2559 | ||
2560 | void bch_btree_exit(void) | |
2561 | { | |
2562 | if (btree_io_wq) | |
2563 | destroy_workqueue(btree_io_wq); | |
cafe5635 KO |
2564 | } |
2565 | ||
2566 | int __init bch_btree_init(void) | |
2567 | { | |
72a44517 KO |
2568 | btree_io_wq = create_singlethread_workqueue("bch_btree_io"); |
2569 | if (!btree_io_wq) | |
cafe5635 KO |
2570 | return -ENOMEM; |
2571 | ||
2572 | return 0; | |
2573 | } |