| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Main bcache entry point - handle a read or a write request and decide what to |
| 4 | * do with it; the make_request functions are called by the block layer. |
| 5 | * |
| 6 | * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> |
| 7 | * Copyright 2012 Google, Inc. |
| 8 | */ |
| 9 | |
| 10 | #include "bcache.h" |
| 11 | #include "btree.h" |
| 12 | #include "debug.h" |
| 13 | #include "request.h" |
| 14 | #include "writeback.h" |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/hash.h> |
| 18 | #include <linux/random.h> |
| 19 | #include <linux/backing-dev.h> |
| 20 | |
| 21 | #include <trace/events/bcache.h> |
| 22 | |
| 23 | #define CUTOFF_CACHE_ADD 95 |
| 24 | #define CUTOFF_CACHE_READA 90 |
| 25 | |
| 26 | struct kmem_cache *bch_search_cache; |
| 27 | |
| 28 | static void bch_data_insert_start(struct closure *); |
| 29 | |
| 30 | static unsigned cache_mode(struct cached_dev *dc, struct bio *bio) |
| 31 | { |
| 32 | return BDEV_CACHE_MODE(&dc->sb); |
| 33 | } |
| 34 | |
| 35 | static bool verify(struct cached_dev *dc, struct bio *bio) |
| 36 | { |
| 37 | return dc->verify; |
| 38 | } |
| 39 | |
| 40 | static void bio_csum(struct bio *bio, struct bkey *k) |
| 41 | { |
| 42 | struct bio_vec bv; |
| 43 | struct bvec_iter iter; |
| 44 | uint64_t csum = 0; |
| 45 | |
| 46 | bio_for_each_segment(bv, bio, iter) { |
| 47 | void *d = kmap(bv.bv_page) + bv.bv_offset; |
| 48 | csum = bch_crc64_update(csum, d, bv.bv_len); |
| 49 | kunmap(bv.bv_page); |
| 50 | } |
| 51 | |
| 52 | k->ptr[KEY_PTRS(k)] = csum & (~0ULL >> 1); |
| 53 | } |
| 54 | |
| 55 | /* Insert data into cache */ |
| 56 | |
| 57 | static void bch_data_insert_keys(struct closure *cl) |
| 58 | { |
| 59 | struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); |
| 60 | atomic_t *journal_ref = NULL; |
| 61 | struct bkey *replace_key = op->replace ? &op->replace_key : NULL; |
| 62 | int ret; |
| 63 | |
| 64 | /* |
| 65 | * If we're looping, might already be waiting on |
| 66 | * another journal write - can't wait on more than one journal write at |
| 67 | * a time |
| 68 | * |
| 69 | * XXX: this looks wrong |
| 70 | */ |
| 71 | #if 0 |
| 72 | while (atomic_read(&s->cl.remaining) & CLOSURE_WAITING) |
| 73 | closure_sync(&s->cl); |
| 74 | #endif |
| 75 | |
| 76 | if (!op->replace) |
| 77 | journal_ref = bch_journal(op->c, &op->insert_keys, |
| 78 | op->flush_journal ? cl : NULL); |
| 79 | |
| 80 | ret = bch_btree_insert(op->c, &op->insert_keys, |
| 81 | journal_ref, replace_key); |
| 82 | if (ret == -ESRCH) { |
| 83 | op->replace_collision = true; |
| 84 | } else if (ret) { |
| 85 | op->status = BLK_STS_RESOURCE; |
| 86 | op->insert_data_done = true; |
| 87 | } |
| 88 | |
| 89 | if (journal_ref) |
| 90 | atomic_dec_bug(journal_ref); |
| 91 | |
| 92 | if (!op->insert_data_done) { |
| 93 | continue_at(cl, bch_data_insert_start, op->wq); |
| 94 | return; |
| 95 | } |
| 96 | |
| 97 | bch_keylist_free(&op->insert_keys); |
| 98 | closure_return(cl); |
| 99 | } |
| 100 | |
| 101 | static int bch_keylist_realloc(struct keylist *l, unsigned u64s, |
| 102 | struct cache_set *c) |
| 103 | { |
| 104 | size_t oldsize = bch_keylist_nkeys(l); |
| 105 | size_t newsize = oldsize + u64s; |
| 106 | |
| 107 | /* |
| 108 | * The journalling code doesn't handle the case where the keys to insert |
| 109 | * is bigger than an empty write: If we just return -ENOMEM here, |
| 110 | * bio_insert() and bio_invalidate() will insert the keys created so far |
| 111 | * and finish the rest when the keylist is empty. |
| 112 | */ |
| 113 | if (newsize * sizeof(uint64_t) > block_bytes(c) - sizeof(struct jset)) |
| 114 | return -ENOMEM; |
| 115 | |
| 116 | return __bch_keylist_realloc(l, u64s); |
| 117 | } |
| 118 | |
| 119 | static void bch_data_invalidate(struct closure *cl) |
| 120 | { |
| 121 | struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); |
| 122 | struct bio *bio = op->bio; |
| 123 | |
| 124 | pr_debug("invalidating %i sectors from %llu", |
| 125 | bio_sectors(bio), (uint64_t) bio->bi_iter.bi_sector); |
| 126 | |
| 127 | while (bio_sectors(bio)) { |
| 128 | unsigned sectors = min(bio_sectors(bio), |
| 129 | 1U << (KEY_SIZE_BITS - 1)); |
| 130 | |
| 131 | if (bch_keylist_realloc(&op->insert_keys, 2, op->c)) |
| 132 | goto out; |
| 133 | |
| 134 | bio->bi_iter.bi_sector += sectors; |
| 135 | bio->bi_iter.bi_size -= sectors << 9; |
| 136 | |
| 137 | bch_keylist_add(&op->insert_keys, |
| 138 | &KEY(op->inode, bio->bi_iter.bi_sector, sectors)); |
| 139 | } |
| 140 | |
| 141 | op->insert_data_done = true; |
| 142 | bio_put(bio); |
| 143 | out: |
| 144 | continue_at(cl, bch_data_insert_keys, op->wq); |
| 145 | } |
| 146 | |
| 147 | static void bch_data_insert_error(struct closure *cl) |
| 148 | { |
| 149 | struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); |
| 150 | |
| 151 | /* |
| 152 | * Our data write just errored, which means we've got a bunch of keys to |
| 153 | * insert that point to data that wasn't succesfully written. |
| 154 | * |
| 155 | * We don't have to insert those keys but we still have to invalidate |
| 156 | * that region of the cache - so, if we just strip off all the pointers |
| 157 | * from the keys we'll accomplish just that. |
| 158 | */ |
| 159 | |
| 160 | struct bkey *src = op->insert_keys.keys, *dst = op->insert_keys.keys; |
| 161 | |
| 162 | while (src != op->insert_keys.top) { |
| 163 | struct bkey *n = bkey_next(src); |
| 164 | |
| 165 | SET_KEY_PTRS(src, 0); |
| 166 | memmove(dst, src, bkey_bytes(src)); |
| 167 | |
| 168 | dst = bkey_next(dst); |
| 169 | src = n; |
| 170 | } |
| 171 | |
| 172 | op->insert_keys.top = dst; |
| 173 | |
| 174 | bch_data_insert_keys(cl); |
| 175 | } |
| 176 | |
| 177 | static void bch_data_insert_endio(struct bio *bio) |
| 178 | { |
| 179 | struct closure *cl = bio->bi_private; |
| 180 | struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); |
| 181 | |
| 182 | if (bio->bi_status) { |
| 183 | /* TODO: We could try to recover from this. */ |
| 184 | if (op->writeback) |
| 185 | op->status = bio->bi_status; |
| 186 | else if (!op->replace) |
| 187 | set_closure_fn(cl, bch_data_insert_error, op->wq); |
| 188 | else |
| 189 | set_closure_fn(cl, NULL, NULL); |
| 190 | } |
| 191 | |
| 192 | bch_bbio_endio(op->c, bio, bio->bi_status, "writing data to cache"); |
| 193 | } |
| 194 | |
| 195 | static void bch_data_insert_start(struct closure *cl) |
| 196 | { |
| 197 | struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); |
| 198 | struct bio *bio = op->bio, *n; |
| 199 | |
| 200 | if (op->bypass) |
| 201 | return bch_data_invalidate(cl); |
| 202 | |
| 203 | if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0) |
| 204 | wake_up_gc(op->c); |
| 205 | |
| 206 | /* |
| 207 | * Journal writes are marked REQ_PREFLUSH; if the original write was a |
| 208 | * flush, it'll wait on the journal write. |
| 209 | */ |
| 210 | bio->bi_opf &= ~(REQ_PREFLUSH|REQ_FUA); |
| 211 | |
| 212 | do { |
| 213 | unsigned i; |
| 214 | struct bkey *k; |
| 215 | struct bio_set *split = op->c->bio_split; |
| 216 | |
| 217 | /* 1 for the device pointer and 1 for the chksum */ |
| 218 | if (bch_keylist_realloc(&op->insert_keys, |
| 219 | 3 + (op->csum ? 1 : 0), |
| 220 | op->c)) { |
| 221 | continue_at(cl, bch_data_insert_keys, op->wq); |
| 222 | return; |
| 223 | } |
| 224 | |
| 225 | k = op->insert_keys.top; |
| 226 | bkey_init(k); |
| 227 | SET_KEY_INODE(k, op->inode); |
| 228 | SET_KEY_OFFSET(k, bio->bi_iter.bi_sector); |
| 229 | |
| 230 | if (!bch_alloc_sectors(op->c, k, bio_sectors(bio), |
| 231 | op->write_point, op->write_prio, |
| 232 | op->writeback)) |
| 233 | goto err; |
| 234 | |
| 235 | n = bio_next_split(bio, KEY_SIZE(k), GFP_NOIO, split); |
| 236 | |
| 237 | n->bi_end_io = bch_data_insert_endio; |
| 238 | n->bi_private = cl; |
| 239 | |
| 240 | if (op->writeback) { |
| 241 | SET_KEY_DIRTY(k, true); |
| 242 | |
| 243 | for (i = 0; i < KEY_PTRS(k); i++) |
| 244 | SET_GC_MARK(PTR_BUCKET(op->c, k, i), |
| 245 | GC_MARK_DIRTY); |
| 246 | } |
| 247 | |
| 248 | SET_KEY_CSUM(k, op->csum); |
| 249 | if (KEY_CSUM(k)) |
| 250 | bio_csum(n, k); |
| 251 | |
| 252 | trace_bcache_cache_insert(k); |
| 253 | bch_keylist_push(&op->insert_keys); |
| 254 | |
| 255 | bio_set_op_attrs(n, REQ_OP_WRITE, 0); |
| 256 | bch_submit_bbio(n, op->c, k, 0); |
| 257 | } while (n != bio); |
| 258 | |
| 259 | op->insert_data_done = true; |
| 260 | continue_at(cl, bch_data_insert_keys, op->wq); |
| 261 | return; |
| 262 | err: |
| 263 | /* bch_alloc_sectors() blocks if s->writeback = true */ |
| 264 | BUG_ON(op->writeback); |
| 265 | |
| 266 | /* |
| 267 | * But if it's not a writeback write we'd rather just bail out if |
| 268 | * there aren't any buckets ready to write to - it might take awhile and |
| 269 | * we might be starving btree writes for gc or something. |
| 270 | */ |
| 271 | |
| 272 | if (!op->replace) { |
| 273 | /* |
| 274 | * Writethrough write: We can't complete the write until we've |
| 275 | * updated the index. But we don't want to delay the write while |
| 276 | * we wait for buckets to be freed up, so just invalidate the |
| 277 | * rest of the write. |
| 278 | */ |
| 279 | op->bypass = true; |
| 280 | return bch_data_invalidate(cl); |
| 281 | } else { |
| 282 | /* |
| 283 | * From a cache miss, we can just insert the keys for the data |
| 284 | * we have written or bail out if we didn't do anything. |
| 285 | */ |
| 286 | op->insert_data_done = true; |
| 287 | bio_put(bio); |
| 288 | |
| 289 | if (!bch_keylist_empty(&op->insert_keys)) |
| 290 | continue_at(cl, bch_data_insert_keys, op->wq); |
| 291 | else |
| 292 | closure_return(cl); |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | /** |
| 297 | * bch_data_insert - stick some data in the cache |
| 298 | * |
| 299 | * This is the starting point for any data to end up in a cache device; it could |
| 300 | * be from a normal write, or a writeback write, or a write to a flash only |
| 301 | * volume - it's also used by the moving garbage collector to compact data in |
| 302 | * mostly empty buckets. |
| 303 | * |
| 304 | * It first writes the data to the cache, creating a list of keys to be inserted |
| 305 | * (if the data had to be fragmented there will be multiple keys); after the |
| 306 | * data is written it calls bch_journal, and after the keys have been added to |
| 307 | * the next journal write they're inserted into the btree. |
| 308 | * |
| 309 | * It inserts the data in s->cache_bio; bi_sector is used for the key offset, |
| 310 | * and op->inode is used for the key inode. |
| 311 | * |
| 312 | * If s->bypass is true, instead of inserting the data it invalidates the |
| 313 | * region of the cache represented by s->cache_bio and op->inode. |
| 314 | */ |
| 315 | void bch_data_insert(struct closure *cl) |
| 316 | { |
| 317 | struct data_insert_op *op = container_of(cl, struct data_insert_op, cl); |
| 318 | |
| 319 | trace_bcache_write(op->c, op->inode, op->bio, |
| 320 | op->writeback, op->bypass); |
| 321 | |
| 322 | bch_keylist_init(&op->insert_keys); |
| 323 | bio_get(op->bio); |
| 324 | bch_data_insert_start(cl); |
| 325 | } |
| 326 | |
| 327 | /* Congested? */ |
| 328 | |
| 329 | unsigned bch_get_congested(struct cache_set *c) |
| 330 | { |
| 331 | int i; |
| 332 | long rand; |
| 333 | |
| 334 | if (!c->congested_read_threshold_us && |
| 335 | !c->congested_write_threshold_us) |
| 336 | return 0; |
| 337 | |
| 338 | i = (local_clock_us() - c->congested_last_us) / 1024; |
| 339 | if (i < 0) |
| 340 | return 0; |
| 341 | |
| 342 | i += atomic_read(&c->congested); |
| 343 | if (i >= 0) |
| 344 | return 0; |
| 345 | |
| 346 | i += CONGESTED_MAX; |
| 347 | |
| 348 | if (i > 0) |
| 349 | i = fract_exp_two(i, 6); |
| 350 | |
| 351 | rand = get_random_int(); |
| 352 | i -= bitmap_weight(&rand, BITS_PER_LONG); |
| 353 | |
| 354 | return i > 0 ? i : 1; |
| 355 | } |
| 356 | |
| 357 | static void add_sequential(struct task_struct *t) |
| 358 | { |
| 359 | ewma_add(t->sequential_io_avg, |
| 360 | t->sequential_io, 8, 0); |
| 361 | |
| 362 | t->sequential_io = 0; |
| 363 | } |
| 364 | |
| 365 | static struct hlist_head *iohash(struct cached_dev *dc, uint64_t k) |
| 366 | { |
| 367 | return &dc->io_hash[hash_64(k, RECENT_IO_BITS)]; |
| 368 | } |
| 369 | |
| 370 | static bool check_should_bypass(struct cached_dev *dc, struct bio *bio) |
| 371 | { |
| 372 | struct cache_set *c = dc->disk.c; |
| 373 | unsigned mode = cache_mode(dc, bio); |
| 374 | unsigned sectors, congested = bch_get_congested(c); |
| 375 | struct task_struct *task = current; |
| 376 | struct io *i; |
| 377 | |
| 378 | if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) || |
| 379 | c->gc_stats.in_use > CUTOFF_CACHE_ADD || |
| 380 | (bio_op(bio) == REQ_OP_DISCARD)) |
| 381 | goto skip; |
| 382 | |
| 383 | if (mode == CACHE_MODE_NONE || |
| 384 | (mode == CACHE_MODE_WRITEAROUND && |
| 385 | op_is_write(bio_op(bio)))) |
| 386 | goto skip; |
| 387 | |
| 388 | if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) || |
| 389 | bio_sectors(bio) & (c->sb.block_size - 1)) { |
| 390 | pr_debug("skipping unaligned io"); |
| 391 | goto skip; |
| 392 | } |
| 393 | |
| 394 | if (bypass_torture_test(dc)) { |
| 395 | if ((get_random_int() & 3) == 3) |
| 396 | goto skip; |
| 397 | else |
| 398 | goto rescale; |
| 399 | } |
| 400 | |
| 401 | if (!congested && !dc->sequential_cutoff) |
| 402 | goto rescale; |
| 403 | |
| 404 | spin_lock(&dc->io_lock); |
| 405 | |
| 406 | hlist_for_each_entry(i, iohash(dc, bio->bi_iter.bi_sector), hash) |
| 407 | if (i->last == bio->bi_iter.bi_sector && |
| 408 | time_before(jiffies, i->jiffies)) |
| 409 | goto found; |
| 410 | |
| 411 | i = list_first_entry(&dc->io_lru, struct io, lru); |
| 412 | |
| 413 | add_sequential(task); |
| 414 | i->sequential = 0; |
| 415 | found: |
| 416 | if (i->sequential + bio->bi_iter.bi_size > i->sequential) |
| 417 | i->sequential += bio->bi_iter.bi_size; |
| 418 | |
| 419 | i->last = bio_end_sector(bio); |
| 420 | i->jiffies = jiffies + msecs_to_jiffies(5000); |
| 421 | task->sequential_io = i->sequential; |
| 422 | |
| 423 | hlist_del(&i->hash); |
| 424 | hlist_add_head(&i->hash, iohash(dc, i->last)); |
| 425 | list_move_tail(&i->lru, &dc->io_lru); |
| 426 | |
| 427 | spin_unlock(&dc->io_lock); |
| 428 | |
| 429 | sectors = max(task->sequential_io, |
| 430 | task->sequential_io_avg) >> 9; |
| 431 | |
| 432 | if (dc->sequential_cutoff && |
| 433 | sectors >= dc->sequential_cutoff >> 9) { |
| 434 | trace_bcache_bypass_sequential(bio); |
| 435 | goto skip; |
| 436 | } |
| 437 | |
| 438 | if (congested && sectors >= congested) { |
| 439 | trace_bcache_bypass_congested(bio); |
| 440 | goto skip; |
| 441 | } |
| 442 | |
| 443 | rescale: |
| 444 | bch_rescale_priorities(c, bio_sectors(bio)); |
| 445 | return false; |
| 446 | skip: |
| 447 | bch_mark_sectors_bypassed(c, dc, bio_sectors(bio)); |
| 448 | return true; |
| 449 | } |
| 450 | |
| 451 | /* Cache lookup */ |
| 452 | |
| 453 | struct search { |
| 454 | /* Stack frame for bio_complete */ |
| 455 | struct closure cl; |
| 456 | |
| 457 | struct bbio bio; |
| 458 | struct bio *orig_bio; |
| 459 | struct bio *cache_miss; |
| 460 | struct bcache_device *d; |
| 461 | |
| 462 | unsigned insert_bio_sectors; |
| 463 | unsigned recoverable:1; |
| 464 | unsigned write:1; |
| 465 | unsigned read_dirty_data:1; |
| 466 | |
| 467 | unsigned long start_time; |
| 468 | |
| 469 | struct btree_op op; |
| 470 | struct data_insert_op iop; |
| 471 | }; |
| 472 | |
| 473 | static void bch_cache_read_endio(struct bio *bio) |
| 474 | { |
| 475 | struct bbio *b = container_of(bio, struct bbio, bio); |
| 476 | struct closure *cl = bio->bi_private; |
| 477 | struct search *s = container_of(cl, struct search, cl); |
| 478 | |
| 479 | /* |
| 480 | * If the bucket was reused while our bio was in flight, we might have |
| 481 | * read the wrong data. Set s->error but not error so it doesn't get |
| 482 | * counted against the cache device, but we'll still reread the data |
| 483 | * from the backing device. |
| 484 | */ |
| 485 | |
| 486 | if (bio->bi_status) |
| 487 | s->iop.status = bio->bi_status; |
| 488 | else if (!KEY_DIRTY(&b->key) && |
| 489 | ptr_stale(s->iop.c, &b->key, 0)) { |
| 490 | atomic_long_inc(&s->iop.c->cache_read_races); |
| 491 | s->iop.status = BLK_STS_IOERR; |
| 492 | } |
| 493 | |
| 494 | bch_bbio_endio(s->iop.c, bio, bio->bi_status, "reading from cache"); |
| 495 | } |
| 496 | |
| 497 | /* |
| 498 | * Read from a single key, handling the initial cache miss if the key starts in |
| 499 | * the middle of the bio |
| 500 | */ |
| 501 | static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k) |
| 502 | { |
| 503 | struct search *s = container_of(op, struct search, op); |
| 504 | struct bio *n, *bio = &s->bio.bio; |
| 505 | struct bkey *bio_key; |
| 506 | unsigned ptr; |
| 507 | |
| 508 | if (bkey_cmp(k, &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0)) <= 0) |
| 509 | return MAP_CONTINUE; |
| 510 | |
| 511 | if (KEY_INODE(k) != s->iop.inode || |
| 512 | KEY_START(k) > bio->bi_iter.bi_sector) { |
| 513 | unsigned bio_sectors = bio_sectors(bio); |
| 514 | unsigned sectors = KEY_INODE(k) == s->iop.inode |
| 515 | ? min_t(uint64_t, INT_MAX, |
| 516 | KEY_START(k) - bio->bi_iter.bi_sector) |
| 517 | : INT_MAX; |
| 518 | |
| 519 | int ret = s->d->cache_miss(b, s, bio, sectors); |
| 520 | if (ret != MAP_CONTINUE) |
| 521 | return ret; |
| 522 | |
| 523 | /* if this was a complete miss we shouldn't get here */ |
| 524 | BUG_ON(bio_sectors <= sectors); |
| 525 | } |
| 526 | |
| 527 | if (!KEY_SIZE(k)) |
| 528 | return MAP_CONTINUE; |
| 529 | |
| 530 | /* XXX: figure out best pointer - for multiple cache devices */ |
| 531 | ptr = 0; |
| 532 | |
| 533 | PTR_BUCKET(b->c, k, ptr)->prio = INITIAL_PRIO; |
| 534 | |
| 535 | if (KEY_DIRTY(k)) |
| 536 | s->read_dirty_data = true; |
| 537 | |
| 538 | n = bio_next_split(bio, min_t(uint64_t, INT_MAX, |
| 539 | KEY_OFFSET(k) - bio->bi_iter.bi_sector), |
| 540 | GFP_NOIO, s->d->bio_split); |
| 541 | |
| 542 | bio_key = &container_of(n, struct bbio, bio)->key; |
| 543 | bch_bkey_copy_single_ptr(bio_key, k, ptr); |
| 544 | |
| 545 | bch_cut_front(&KEY(s->iop.inode, n->bi_iter.bi_sector, 0), bio_key); |
| 546 | bch_cut_back(&KEY(s->iop.inode, bio_end_sector(n), 0), bio_key); |
| 547 | |
| 548 | n->bi_end_io = bch_cache_read_endio; |
| 549 | n->bi_private = &s->cl; |
| 550 | |
| 551 | /* |
| 552 | * The bucket we're reading from might be reused while our bio |
| 553 | * is in flight, and we could then end up reading the wrong |
| 554 | * data. |
| 555 | * |
| 556 | * We guard against this by checking (in cache_read_endio()) if |
| 557 | * the pointer is stale again; if so, we treat it as an error |
| 558 | * and reread from the backing device (but we don't pass that |
| 559 | * error up anywhere). |
| 560 | */ |
| 561 | |
| 562 | __bch_submit_bbio(n, b->c); |
| 563 | return n == bio ? MAP_DONE : MAP_CONTINUE; |
| 564 | } |
| 565 | |
| 566 | static void cache_lookup(struct closure *cl) |
| 567 | { |
| 568 | struct search *s = container_of(cl, struct search, iop.cl); |
| 569 | struct bio *bio = &s->bio.bio; |
| 570 | int ret; |
| 571 | |
| 572 | bch_btree_op_init(&s->op, -1); |
| 573 | |
| 574 | ret = bch_btree_map_keys(&s->op, s->iop.c, |
| 575 | &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0), |
| 576 | cache_lookup_fn, MAP_END_KEY); |
| 577 | if (ret == -EAGAIN) { |
| 578 | continue_at(cl, cache_lookup, bcache_wq); |
| 579 | return; |
| 580 | } |
| 581 | |
| 582 | closure_return(cl); |
| 583 | } |
| 584 | |
| 585 | /* Common code for the make_request functions */ |
| 586 | |
| 587 | static void request_endio(struct bio *bio) |
| 588 | { |
| 589 | struct closure *cl = bio->bi_private; |
| 590 | |
| 591 | if (bio->bi_status) { |
| 592 | struct search *s = container_of(cl, struct search, cl); |
| 593 | s->iop.status = bio->bi_status; |
| 594 | /* Only cache read errors are recoverable */ |
| 595 | s->recoverable = false; |
| 596 | } |
| 597 | |
| 598 | bio_put(bio); |
| 599 | closure_put(cl); |
| 600 | } |
| 601 | |
| 602 | static void bio_complete(struct search *s) |
| 603 | { |
| 604 | if (s->orig_bio) { |
| 605 | struct request_queue *q = s->orig_bio->bi_disk->queue; |
| 606 | generic_end_io_acct(q, bio_data_dir(s->orig_bio), |
| 607 | &s->d->disk->part0, s->start_time); |
| 608 | |
| 609 | trace_bcache_request_end(s->d, s->orig_bio); |
| 610 | s->orig_bio->bi_status = s->iop.status; |
| 611 | bio_endio(s->orig_bio); |
| 612 | s->orig_bio = NULL; |
| 613 | } |
| 614 | } |
| 615 | |
| 616 | static void do_bio_hook(struct search *s, struct bio *orig_bio) |
| 617 | { |
| 618 | struct bio *bio = &s->bio.bio; |
| 619 | |
| 620 | bio_init(bio, NULL, 0); |
| 621 | __bio_clone_fast(bio, orig_bio); |
| 622 | bio->bi_end_io = request_endio; |
| 623 | bio->bi_private = &s->cl; |
| 624 | |
| 625 | bio_cnt_set(bio, 3); |
| 626 | } |
| 627 | |
| 628 | static void search_free(struct closure *cl) |
| 629 | { |
| 630 | struct search *s = container_of(cl, struct search, cl); |
| 631 | bio_complete(s); |
| 632 | |
| 633 | if (s->iop.bio) |
| 634 | bio_put(s->iop.bio); |
| 635 | |
| 636 | closure_debug_destroy(cl); |
| 637 | mempool_free(s, s->d->c->search); |
| 638 | } |
| 639 | |
| 640 | static inline struct search *search_alloc(struct bio *bio, |
| 641 | struct bcache_device *d) |
| 642 | { |
| 643 | struct search *s; |
| 644 | |
| 645 | s = mempool_alloc(d->c->search, GFP_NOIO); |
| 646 | |
| 647 | closure_init(&s->cl, NULL); |
| 648 | do_bio_hook(s, bio); |
| 649 | |
| 650 | s->orig_bio = bio; |
| 651 | s->cache_miss = NULL; |
| 652 | s->d = d; |
| 653 | s->recoverable = 1; |
| 654 | s->write = op_is_write(bio_op(bio)); |
| 655 | s->read_dirty_data = 0; |
| 656 | s->start_time = jiffies; |
| 657 | |
| 658 | s->iop.c = d->c; |
| 659 | s->iop.bio = NULL; |
| 660 | s->iop.inode = d->id; |
| 661 | s->iop.write_point = hash_long((unsigned long) current, 16); |
| 662 | s->iop.write_prio = 0; |
| 663 | s->iop.status = 0; |
| 664 | s->iop.flags = 0; |
| 665 | s->iop.flush_journal = op_is_flush(bio->bi_opf); |
| 666 | s->iop.wq = bcache_wq; |
| 667 | |
| 668 | return s; |
| 669 | } |
| 670 | |
| 671 | /* Cached devices */ |
| 672 | |
| 673 | static void cached_dev_bio_complete(struct closure *cl) |
| 674 | { |
| 675 | struct search *s = container_of(cl, struct search, cl); |
| 676 | struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); |
| 677 | |
| 678 | search_free(cl); |
| 679 | cached_dev_put(dc); |
| 680 | } |
| 681 | |
| 682 | /* Process reads */ |
| 683 | |
| 684 | static void cached_dev_cache_miss_done(struct closure *cl) |
| 685 | { |
| 686 | struct search *s = container_of(cl, struct search, cl); |
| 687 | |
| 688 | if (s->iop.replace_collision) |
| 689 | bch_mark_cache_miss_collision(s->iop.c, s->d); |
| 690 | |
| 691 | if (s->iop.bio) |
| 692 | bio_free_pages(s->iop.bio); |
| 693 | |
| 694 | cached_dev_bio_complete(cl); |
| 695 | } |
| 696 | |
| 697 | static void cached_dev_read_error(struct closure *cl) |
| 698 | { |
| 699 | struct search *s = container_of(cl, struct search, cl); |
| 700 | struct bio *bio = &s->bio.bio; |
| 701 | |
| 702 | if (s->recoverable) { |
| 703 | /* Retry from the backing device: */ |
| 704 | trace_bcache_read_retry(s->orig_bio); |
| 705 | |
| 706 | s->iop.status = 0; |
| 707 | do_bio_hook(s, s->orig_bio); |
| 708 | |
| 709 | /* XXX: invalidate cache */ |
| 710 | |
| 711 | closure_bio_submit(bio, cl); |
| 712 | } |
| 713 | |
| 714 | continue_at(cl, cached_dev_cache_miss_done, NULL); |
| 715 | } |
| 716 | |
| 717 | static void cached_dev_read_done(struct closure *cl) |
| 718 | { |
| 719 | struct search *s = container_of(cl, struct search, cl); |
| 720 | struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); |
| 721 | |
| 722 | /* |
| 723 | * We had a cache miss; cache_bio now contains data ready to be inserted |
| 724 | * into the cache. |
| 725 | * |
| 726 | * First, we copy the data we just read from cache_bio's bounce buffers |
| 727 | * to the buffers the original bio pointed to: |
| 728 | */ |
| 729 | |
| 730 | if (s->iop.bio) { |
| 731 | bio_reset(s->iop.bio); |
| 732 | s->iop.bio->bi_iter.bi_sector = s->cache_miss->bi_iter.bi_sector; |
| 733 | bio_copy_dev(s->iop.bio, s->cache_miss); |
| 734 | s->iop.bio->bi_iter.bi_size = s->insert_bio_sectors << 9; |
| 735 | bch_bio_map(s->iop.bio, NULL); |
| 736 | |
| 737 | bio_copy_data(s->cache_miss, s->iop.bio); |
| 738 | |
| 739 | bio_put(s->cache_miss); |
| 740 | s->cache_miss = NULL; |
| 741 | } |
| 742 | |
| 743 | if (verify(dc, &s->bio.bio) && s->recoverable && !s->read_dirty_data) |
| 744 | bch_data_verify(dc, s->orig_bio); |
| 745 | |
| 746 | bio_complete(s); |
| 747 | |
| 748 | if (s->iop.bio && |
| 749 | !test_bit(CACHE_SET_STOPPING, &s->iop.c->flags)) { |
| 750 | BUG_ON(!s->iop.replace); |
| 751 | closure_call(&s->iop.cl, bch_data_insert, NULL, cl); |
| 752 | } |
| 753 | |
| 754 | continue_at(cl, cached_dev_cache_miss_done, NULL); |
| 755 | } |
| 756 | |
| 757 | static void cached_dev_read_done_bh(struct closure *cl) |
| 758 | { |
| 759 | struct search *s = container_of(cl, struct search, cl); |
| 760 | struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); |
| 761 | |
| 762 | bch_mark_cache_accounting(s->iop.c, s->d, |
| 763 | !s->cache_miss, s->iop.bypass); |
| 764 | trace_bcache_read(s->orig_bio, !s->cache_miss, s->iop.bypass); |
| 765 | |
| 766 | if (s->iop.status) |
| 767 | continue_at_nobarrier(cl, cached_dev_read_error, bcache_wq); |
| 768 | else if (s->iop.bio || verify(dc, &s->bio.bio)) |
| 769 | continue_at_nobarrier(cl, cached_dev_read_done, bcache_wq); |
| 770 | else |
| 771 | continue_at_nobarrier(cl, cached_dev_bio_complete, NULL); |
| 772 | } |
| 773 | |
| 774 | static int cached_dev_cache_miss(struct btree *b, struct search *s, |
| 775 | struct bio *bio, unsigned sectors) |
| 776 | { |
| 777 | int ret = MAP_CONTINUE; |
| 778 | unsigned reada = 0; |
| 779 | struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); |
| 780 | struct bio *miss, *cache_bio; |
| 781 | |
| 782 | if (s->cache_miss || s->iop.bypass) { |
| 783 | miss = bio_next_split(bio, sectors, GFP_NOIO, s->d->bio_split); |
| 784 | ret = miss == bio ? MAP_DONE : MAP_CONTINUE; |
| 785 | goto out_submit; |
| 786 | } |
| 787 | |
| 788 | if (!(bio->bi_opf & REQ_RAHEAD) && |
| 789 | !(bio->bi_opf & REQ_META) && |
| 790 | s->iop.c->gc_stats.in_use < CUTOFF_CACHE_READA) |
| 791 | reada = min_t(sector_t, dc->readahead >> 9, |
| 792 | get_capacity(bio->bi_disk) - bio_end_sector(bio)); |
| 793 | |
| 794 | s->insert_bio_sectors = min(sectors, bio_sectors(bio) + reada); |
| 795 | |
| 796 | s->iop.replace_key = KEY(s->iop.inode, |
| 797 | bio->bi_iter.bi_sector + s->insert_bio_sectors, |
| 798 | s->insert_bio_sectors); |
| 799 | |
| 800 | ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key); |
| 801 | if (ret) |
| 802 | return ret; |
| 803 | |
| 804 | s->iop.replace = true; |
| 805 | |
| 806 | miss = bio_next_split(bio, sectors, GFP_NOIO, s->d->bio_split); |
| 807 | |
| 808 | /* btree_search_recurse()'s btree iterator is no good anymore */ |
| 809 | ret = miss == bio ? MAP_DONE : -EINTR; |
| 810 | |
| 811 | cache_bio = bio_alloc_bioset(GFP_NOWAIT, |
| 812 | DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS), |
| 813 | dc->disk.bio_split); |
| 814 | if (!cache_bio) |
| 815 | goto out_submit; |
| 816 | |
| 817 | cache_bio->bi_iter.bi_sector = miss->bi_iter.bi_sector; |
| 818 | bio_copy_dev(cache_bio, miss); |
| 819 | cache_bio->bi_iter.bi_size = s->insert_bio_sectors << 9; |
| 820 | |
| 821 | cache_bio->bi_end_io = request_endio; |
| 822 | cache_bio->bi_private = &s->cl; |
| 823 | |
| 824 | bch_bio_map(cache_bio, NULL); |
| 825 | if (bio_alloc_pages(cache_bio, __GFP_NOWARN|GFP_NOIO)) |
| 826 | goto out_put; |
| 827 | |
| 828 | if (reada) |
| 829 | bch_mark_cache_readahead(s->iop.c, s->d); |
| 830 | |
| 831 | s->cache_miss = miss; |
| 832 | s->iop.bio = cache_bio; |
| 833 | bio_get(cache_bio); |
| 834 | closure_bio_submit(cache_bio, &s->cl); |
| 835 | |
| 836 | return ret; |
| 837 | out_put: |
| 838 | bio_put(cache_bio); |
| 839 | out_submit: |
| 840 | miss->bi_end_io = request_endio; |
| 841 | miss->bi_private = &s->cl; |
| 842 | closure_bio_submit(miss, &s->cl); |
| 843 | return ret; |
| 844 | } |
| 845 | |
| 846 | static void cached_dev_read(struct cached_dev *dc, struct search *s) |
| 847 | { |
| 848 | struct closure *cl = &s->cl; |
| 849 | |
| 850 | closure_call(&s->iop.cl, cache_lookup, NULL, cl); |
| 851 | continue_at(cl, cached_dev_read_done_bh, NULL); |
| 852 | } |
| 853 | |
| 854 | /* Process writes */ |
| 855 | |
| 856 | static void cached_dev_write_complete(struct closure *cl) |
| 857 | { |
| 858 | struct search *s = container_of(cl, struct search, cl); |
| 859 | struct cached_dev *dc = container_of(s->d, struct cached_dev, disk); |
| 860 | |
| 861 | up_read_non_owner(&dc->writeback_lock); |
| 862 | cached_dev_bio_complete(cl); |
| 863 | } |
| 864 | |
| 865 | static void cached_dev_write(struct cached_dev *dc, struct search *s) |
| 866 | { |
| 867 | struct closure *cl = &s->cl; |
| 868 | struct bio *bio = &s->bio.bio; |
| 869 | struct bkey start = KEY(dc->disk.id, bio->bi_iter.bi_sector, 0); |
| 870 | struct bkey end = KEY(dc->disk.id, bio_end_sector(bio), 0); |
| 871 | |
| 872 | bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys, &start, &end); |
| 873 | |
| 874 | down_read_non_owner(&dc->writeback_lock); |
| 875 | if (bch_keybuf_check_overlapping(&dc->writeback_keys, &start, &end)) { |
| 876 | /* |
| 877 | * We overlap with some dirty data undergoing background |
| 878 | * writeback, force this write to writeback |
| 879 | */ |
| 880 | s->iop.bypass = false; |
| 881 | s->iop.writeback = true; |
| 882 | } |
| 883 | |
| 884 | /* |
| 885 | * Discards aren't _required_ to do anything, so skipping if |
| 886 | * check_overlapping returned true is ok |
| 887 | * |
| 888 | * But check_overlapping drops dirty keys for which io hasn't started, |
| 889 | * so we still want to call it. |
| 890 | */ |
| 891 | if (bio_op(bio) == REQ_OP_DISCARD) |
| 892 | s->iop.bypass = true; |
| 893 | |
| 894 | if (should_writeback(dc, s->orig_bio, |
| 895 | cache_mode(dc, bio), |
| 896 | s->iop.bypass)) { |
| 897 | s->iop.bypass = false; |
| 898 | s->iop.writeback = true; |
| 899 | } |
| 900 | |
| 901 | if (s->iop.bypass) { |
| 902 | s->iop.bio = s->orig_bio; |
| 903 | bio_get(s->iop.bio); |
| 904 | |
| 905 | if ((bio_op(bio) != REQ_OP_DISCARD) || |
| 906 | blk_queue_discard(bdev_get_queue(dc->bdev))) |
| 907 | closure_bio_submit(bio, cl); |
| 908 | } else if (s->iop.writeback) { |
| 909 | bch_writeback_add(dc); |
| 910 | s->iop.bio = bio; |
| 911 | |
| 912 | if (bio->bi_opf & REQ_PREFLUSH) { |
| 913 | /* Also need to send a flush to the backing device */ |
| 914 | struct bio *flush = bio_alloc_bioset(GFP_NOIO, 0, |
| 915 | dc->disk.bio_split); |
| 916 | |
| 917 | bio_copy_dev(flush, bio); |
| 918 | flush->bi_end_io = request_endio; |
| 919 | flush->bi_private = cl; |
| 920 | flush->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; |
| 921 | |
| 922 | closure_bio_submit(flush, cl); |
| 923 | } |
| 924 | } else { |
| 925 | s->iop.bio = bio_clone_fast(bio, GFP_NOIO, dc->disk.bio_split); |
| 926 | |
| 927 | closure_bio_submit(bio, cl); |
| 928 | } |
| 929 | |
| 930 | closure_call(&s->iop.cl, bch_data_insert, NULL, cl); |
| 931 | continue_at(cl, cached_dev_write_complete, NULL); |
| 932 | } |
| 933 | |
| 934 | static void cached_dev_nodata(struct closure *cl) |
| 935 | { |
| 936 | struct search *s = container_of(cl, struct search, cl); |
| 937 | struct bio *bio = &s->bio.bio; |
| 938 | |
| 939 | if (s->iop.flush_journal) |
| 940 | bch_journal_meta(s->iop.c, cl); |
| 941 | |
| 942 | /* If it's a flush, we send the flush to the backing device too */ |
| 943 | closure_bio_submit(bio, cl); |
| 944 | |
| 945 | continue_at(cl, cached_dev_bio_complete, NULL); |
| 946 | } |
| 947 | |
| 948 | /* Cached devices - read & write stuff */ |
| 949 | |
| 950 | static blk_qc_t cached_dev_make_request(struct request_queue *q, |
| 951 | struct bio *bio) |
| 952 | { |
| 953 | struct search *s; |
| 954 | struct bcache_device *d = bio->bi_disk->private_data; |
| 955 | struct cached_dev *dc = container_of(d, struct cached_dev, disk); |
| 956 | int rw = bio_data_dir(bio); |
| 957 | |
| 958 | generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0); |
| 959 | |
| 960 | bio_set_dev(bio, dc->bdev); |
| 961 | bio->bi_iter.bi_sector += dc->sb.data_offset; |
| 962 | |
| 963 | if (cached_dev_get(dc)) { |
| 964 | s = search_alloc(bio, d); |
| 965 | trace_bcache_request_start(s->d, bio); |
| 966 | |
| 967 | if (!bio->bi_iter.bi_size) { |
| 968 | /* |
| 969 | * can't call bch_journal_meta from under |
| 970 | * generic_make_request |
| 971 | */ |
| 972 | continue_at_nobarrier(&s->cl, |
| 973 | cached_dev_nodata, |
| 974 | bcache_wq); |
| 975 | } else { |
| 976 | s->iop.bypass = check_should_bypass(dc, bio); |
| 977 | |
| 978 | if (rw) |
| 979 | cached_dev_write(dc, s); |
| 980 | else |
| 981 | cached_dev_read(dc, s); |
| 982 | } |
| 983 | } else { |
| 984 | if ((bio_op(bio) == REQ_OP_DISCARD) && |
| 985 | !blk_queue_discard(bdev_get_queue(dc->bdev))) |
| 986 | bio_endio(bio); |
| 987 | else |
| 988 | generic_make_request(bio); |
| 989 | } |
| 990 | |
| 991 | return BLK_QC_T_NONE; |
| 992 | } |
| 993 | |
| 994 | static int cached_dev_ioctl(struct bcache_device *d, fmode_t mode, |
| 995 | unsigned int cmd, unsigned long arg) |
| 996 | { |
| 997 | struct cached_dev *dc = container_of(d, struct cached_dev, disk); |
| 998 | return __blkdev_driver_ioctl(dc->bdev, mode, cmd, arg); |
| 999 | } |
| 1000 | |
| 1001 | static int cached_dev_congested(void *data, int bits) |
| 1002 | { |
| 1003 | struct bcache_device *d = data; |
| 1004 | struct cached_dev *dc = container_of(d, struct cached_dev, disk); |
| 1005 | struct request_queue *q = bdev_get_queue(dc->bdev); |
| 1006 | int ret = 0; |
| 1007 | |
| 1008 | if (bdi_congested(q->backing_dev_info, bits)) |
| 1009 | return 1; |
| 1010 | |
| 1011 | if (cached_dev_get(dc)) { |
| 1012 | unsigned i; |
| 1013 | struct cache *ca; |
| 1014 | |
| 1015 | for_each_cache(ca, d->c, i) { |
| 1016 | q = bdev_get_queue(ca->bdev); |
| 1017 | ret |= bdi_congested(q->backing_dev_info, bits); |
| 1018 | } |
| 1019 | |
| 1020 | cached_dev_put(dc); |
| 1021 | } |
| 1022 | |
| 1023 | return ret; |
| 1024 | } |
| 1025 | |
| 1026 | void bch_cached_dev_request_init(struct cached_dev *dc) |
| 1027 | { |
| 1028 | struct gendisk *g = dc->disk.disk; |
| 1029 | |
| 1030 | g->queue->make_request_fn = cached_dev_make_request; |
| 1031 | g->queue->backing_dev_info->congested_fn = cached_dev_congested; |
| 1032 | dc->disk.cache_miss = cached_dev_cache_miss; |
| 1033 | dc->disk.ioctl = cached_dev_ioctl; |
| 1034 | } |
| 1035 | |
| 1036 | /* Flash backed devices */ |
| 1037 | |
| 1038 | static int flash_dev_cache_miss(struct btree *b, struct search *s, |
| 1039 | struct bio *bio, unsigned sectors) |
| 1040 | { |
| 1041 | unsigned bytes = min(sectors, bio_sectors(bio)) << 9; |
| 1042 | |
| 1043 | swap(bio->bi_iter.bi_size, bytes); |
| 1044 | zero_fill_bio(bio); |
| 1045 | swap(bio->bi_iter.bi_size, bytes); |
| 1046 | |
| 1047 | bio_advance(bio, bytes); |
| 1048 | |
| 1049 | if (!bio->bi_iter.bi_size) |
| 1050 | return MAP_DONE; |
| 1051 | |
| 1052 | return MAP_CONTINUE; |
| 1053 | } |
| 1054 | |
| 1055 | static void flash_dev_nodata(struct closure *cl) |
| 1056 | { |
| 1057 | struct search *s = container_of(cl, struct search, cl); |
| 1058 | |
| 1059 | if (s->iop.flush_journal) |
| 1060 | bch_journal_meta(s->iop.c, cl); |
| 1061 | |
| 1062 | continue_at(cl, search_free, NULL); |
| 1063 | } |
| 1064 | |
| 1065 | static blk_qc_t flash_dev_make_request(struct request_queue *q, |
| 1066 | struct bio *bio) |
| 1067 | { |
| 1068 | struct search *s; |
| 1069 | struct closure *cl; |
| 1070 | struct bcache_device *d = bio->bi_disk->private_data; |
| 1071 | int rw = bio_data_dir(bio); |
| 1072 | |
| 1073 | generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0); |
| 1074 | |
| 1075 | s = search_alloc(bio, d); |
| 1076 | cl = &s->cl; |
| 1077 | bio = &s->bio.bio; |
| 1078 | |
| 1079 | trace_bcache_request_start(s->d, bio); |
| 1080 | |
| 1081 | if (!bio->bi_iter.bi_size) { |
| 1082 | /* |
| 1083 | * can't call bch_journal_meta from under |
| 1084 | * generic_make_request |
| 1085 | */ |
| 1086 | continue_at_nobarrier(&s->cl, |
| 1087 | flash_dev_nodata, |
| 1088 | bcache_wq); |
| 1089 | return BLK_QC_T_NONE; |
| 1090 | } else if (rw) { |
| 1091 | bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys, |
| 1092 | &KEY(d->id, bio->bi_iter.bi_sector, 0), |
| 1093 | &KEY(d->id, bio_end_sector(bio), 0)); |
| 1094 | |
| 1095 | s->iop.bypass = (bio_op(bio) == REQ_OP_DISCARD) != 0; |
| 1096 | s->iop.writeback = true; |
| 1097 | s->iop.bio = bio; |
| 1098 | |
| 1099 | closure_call(&s->iop.cl, bch_data_insert, NULL, cl); |
| 1100 | } else { |
| 1101 | closure_call(&s->iop.cl, cache_lookup, NULL, cl); |
| 1102 | } |
| 1103 | |
| 1104 | continue_at(cl, search_free, NULL); |
| 1105 | return BLK_QC_T_NONE; |
| 1106 | } |
| 1107 | |
| 1108 | static int flash_dev_ioctl(struct bcache_device *d, fmode_t mode, |
| 1109 | unsigned int cmd, unsigned long arg) |
| 1110 | { |
| 1111 | return -ENOTTY; |
| 1112 | } |
| 1113 | |
| 1114 | static int flash_dev_congested(void *data, int bits) |
| 1115 | { |
| 1116 | struct bcache_device *d = data; |
| 1117 | struct request_queue *q; |
| 1118 | struct cache *ca; |
| 1119 | unsigned i; |
| 1120 | int ret = 0; |
| 1121 | |
| 1122 | for_each_cache(ca, d->c, i) { |
| 1123 | q = bdev_get_queue(ca->bdev); |
| 1124 | ret |= bdi_congested(q->backing_dev_info, bits); |
| 1125 | } |
| 1126 | |
| 1127 | return ret; |
| 1128 | } |
| 1129 | |
| 1130 | void bch_flash_dev_request_init(struct bcache_device *d) |
| 1131 | { |
| 1132 | struct gendisk *g = d->disk; |
| 1133 | |
| 1134 | g->queue->make_request_fn = flash_dev_make_request; |
| 1135 | g->queue->backing_dev_info->congested_fn = flash_dev_congested; |
| 1136 | d->cache_miss = flash_dev_cache_miss; |
| 1137 | d->ioctl = flash_dev_ioctl; |
| 1138 | } |
| 1139 | |
| 1140 | void bch_request_exit(void) |
| 1141 | { |
| 1142 | if (bch_search_cache) |
| 1143 | kmem_cache_destroy(bch_search_cache); |
| 1144 | } |
| 1145 | |
| 1146 | int __init bch_request_init(void) |
| 1147 | { |
| 1148 | bch_search_cache = KMEM_CACHE(search, 0); |
| 1149 | if (!bch_search_cache) |
| 1150 | return -ENOMEM; |
| 1151 | |
| 1152 | return 0; |
| 1153 | } |