1 // SPDX-License-Identifier: GPL-2.0 2 #ifndef NO_BCACHEFS_FS 3 4 #include "bcachefs.h" 5 #include "alloc_foreground.h" 6 #include "fs.h" 7 #include "fs-io.h" 8 #include "fs-io-direct.h" 9 #include "fs-io-pagecache.h" 10 #include "io_read.h" 11 #include "io_write.h" 12 13 #include <linux/kthread.h> 14 #include <linux/pagemap.h> 15 #include <linux/prefetch.h> 16 #include <linux/task_io_accounting_ops.h> 17 18 /* O_DIRECT reads */ 19 20 struct dio_read { 21 struct closure cl; 22 struct kiocb *req; 23 long ret; 24 bool should_dirty; 25 struct bch_read_bio rbio; 26 }; 27 28 static void bio_check_or_release(struct bio *bio, bool check_dirty) 29 { 30 if (check_dirty) { 31 bio_check_pages_dirty(bio); 32 } else { 33 bio_release_pages(bio, false); 34 bio_put(bio); 35 } 36 } 37 38 static CLOSURE_CALLBACK(bch2_dio_read_complete) 39 { 40 closure_type(dio, struct dio_read, cl); 41 42 dio->req->ki_complete(dio->req, dio->ret); 43 bio_check_or_release(&dio->rbio.bio, dio->should_dirty); 44 } 45 46 static void bch2_direct_IO_read_endio(struct bio *bio) 47 { 48 struct dio_read *dio = bio->bi_private; 49 50 if (bio->bi_status) 51 dio->ret = blk_status_to_errno(bio->bi_status); 52 53 closure_put(&dio->cl); 54 } 55 56 static void bch2_direct_IO_read_split_endio(struct bio *bio) 57 { 58 struct dio_read *dio = bio->bi_private; 59 bool should_dirty = dio->should_dirty; 60 61 bch2_direct_IO_read_endio(bio); 62 bio_check_or_release(bio, should_dirty); 63 } 64 65 static int bch2_direct_IO_read(struct kiocb *req, struct iov_iter *iter) 66 { 67 struct file *file = req->ki_filp; 68 struct bch_inode_info *inode = file_bch_inode(file); 69 struct bch_fs *c = inode->v.i_sb->s_fs_info; 70 struct bch_io_opts opts; 71 struct dio_read *dio; 72 struct bio *bio; 73 loff_t offset = req->ki_pos; 74 bool sync = is_sync_kiocb(req); 75 size_t shorten; 76 ssize_t ret; 77 78 bch2_inode_opts_get(&opts, c, &inode->ei_inode); 79 80 /* bios must be 512 byte aligned: */ 81 if ((offset|iter->count) & (SECTOR_SIZE - 1)) 82 return -EINVAL; 83 84 ret = min_t(loff_t, iter->count, 85 max_t(loff_t, 0, i_size_read(&inode->v) - offset)); 86 87 if (!ret) 88 return ret; 89 90 shorten = iov_iter_count(iter) - round_up(ret, block_bytes(c)); 91 if (shorten >= iter->count) 92 shorten = 0; 93 iter->count -= shorten; 94 95 bio = bio_alloc_bioset(NULL, 96 bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS), 97 REQ_OP_READ, 98 GFP_KERNEL, 99 &c->dio_read_bioset); 100 101 bio->bi_end_io = bch2_direct_IO_read_endio; 102 103 dio = container_of(bio, struct dio_read, rbio.bio); 104 closure_init(&dio->cl, NULL); 105 106 /* 107 * this is a _really_ horrible hack just to avoid an atomic sub at the 108 * end: 109 */ 110 if (!sync) { 111 set_closure_fn(&dio->cl, bch2_dio_read_complete, NULL); 112 atomic_set(&dio->cl.remaining, 113 CLOSURE_REMAINING_INITIALIZER - 114 CLOSURE_RUNNING + 115 CLOSURE_DESTRUCTOR); 116 } else { 117 atomic_set(&dio->cl.remaining, 118 CLOSURE_REMAINING_INITIALIZER + 1); 119 dio->cl.closure_get_happened = true; 120 } 121 122 dio->req = req; 123 dio->ret = ret; 124 /* 125 * This is one of the sketchier things I've encountered: we have to skip 126 * the dirtying of requests that are internal from the kernel (i.e. from 127 * loopback), because we'll deadlock on page_lock. 128 */ 129 dio->should_dirty = iter_is_iovec(iter); 130 131 goto start; 132 while (iter->count) { 133 bio = bio_alloc_bioset(NULL, 134 bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS), 135 REQ_OP_READ, 136 GFP_KERNEL, 137 &c->bio_read); 138 bio->bi_end_io = bch2_direct_IO_read_split_endio; 139 start: 140 bio->bi_opf = REQ_OP_READ|REQ_SYNC; 141 bio->bi_iter.bi_sector = offset >> 9; 142 bio->bi_private = dio; 143 144 ret = bio_iov_iter_get_pages(bio, iter); 145 if (ret < 0) { 146 /* XXX: fault inject this path */ 147 bio->bi_status = BLK_STS_RESOURCE; 148 bio_endio(bio); 149 break; 150 } 151 152 offset += bio->bi_iter.bi_size; 153 154 if (dio->should_dirty) 155 bio_set_pages_dirty(bio); 156 157 if (iter->count) 158 closure_get(&dio->cl); 159 160 bch2_read(c, rbio_init(bio, opts), inode_inum(inode)); 161 } 162 163 iter->count += shorten; 164 165 if (sync) { 166 closure_sync(&dio->cl); 167 closure_debug_destroy(&dio->cl); 168 ret = dio->ret; 169 bio_check_or_release(&dio->rbio.bio, dio->should_dirty); 170 return ret; 171 } else { 172 return -EIOCBQUEUED; 173 } 174 } 175 176 ssize_t bch2_read_iter(struct kiocb *iocb, struct iov_iter *iter) 177 { 178 struct file *file = iocb->ki_filp; 179 struct bch_inode_info *inode = file_bch_inode(file); 180 struct address_space *mapping = file->f_mapping; 181 size_t count = iov_iter_count(iter); 182 ssize_t ret = 0; 183 184 if (!count) 185 return 0; /* skip atime */ 186 187 if (iocb->ki_flags & IOCB_DIRECT) { 188 struct blk_plug plug; 189 190 if (unlikely(mapping->nrpages)) { 191 ret = filemap_write_and_wait_range(mapping, 192 iocb->ki_pos, 193 iocb->ki_pos + count - 1); 194 if (ret < 0) 195 goto out; 196 } 197 198 file_accessed(file); 199 200 blk_start_plug(&plug); 201 ret = bch2_direct_IO_read(iocb, iter); 202 blk_finish_plug(&plug); 203 204 if (ret >= 0) 205 iocb->ki_pos += ret; 206 } else { 207 bch2_pagecache_add_get(inode); 208 ret = filemap_read(iocb, iter, ret); 209 bch2_pagecache_add_put(inode); 210 } 211 out: 212 return bch2_err_class(ret); 213 } 214 215 /* O_DIRECT writes */ 216 217 struct dio_write { 218 struct kiocb *req; 219 struct address_space *mapping; 220 struct bch_inode_info *inode; 221 struct mm_struct *mm; 222 const struct iovec *iov; 223 unsigned loop:1, 224 extending:1, 225 sync:1, 226 flush:1; 227 struct quota_res quota_res; 228 u64 written; 229 230 struct iov_iter iter; 231 struct iovec inline_vecs[2]; 232 233 /* must be last: */ 234 struct bch_write_op op; 235 }; 236 237 static bool bch2_check_range_allocated(struct bch_fs *c, subvol_inum inum, 238 u64 offset, u64 size, 239 unsigned nr_replicas, bool compressed) 240 { 241 struct btree_trans *trans = bch2_trans_get(c); 242 struct btree_iter iter; 243 struct bkey_s_c k; 244 u64 end = offset + size; 245 u32 snapshot; 246 bool ret = true; 247 int err; 248 retry: 249 bch2_trans_begin(trans); 250 251 err = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); 252 if (err) 253 goto err; 254 255 for_each_btree_key_norestart(trans, iter, BTREE_ID_extents, 256 SPOS(inum.inum, offset, snapshot), 257 BTREE_ITER_slots, k, err) { 258 if (bkey_ge(bkey_start_pos(k.k), POS(inum.inum, end))) 259 break; 260 261 if (k.k->p.snapshot != snapshot || 262 nr_replicas > bch2_bkey_replicas(c, k) || 263 (!compressed && bch2_bkey_sectors_compressed(k))) { 264 ret = false; 265 break; 266 } 267 } 268 269 offset = iter.pos.offset; 270 bch2_trans_iter_exit(trans, &iter); 271 err: 272 if (bch2_err_matches(err, BCH_ERR_transaction_restart)) 273 goto retry; 274 bch2_trans_put(trans); 275 276 return err ? false : ret; 277 } 278 279 static noinline bool bch2_dio_write_check_allocated(struct dio_write *dio) 280 { 281 struct bch_fs *c = dio->op.c; 282 struct bch_inode_info *inode = dio->inode; 283 struct bio *bio = &dio->op.wbio.bio; 284 285 return bch2_check_range_allocated(c, inode_inum(inode), 286 dio->op.pos.offset, bio_sectors(bio), 287 dio->op.opts.data_replicas, 288 dio->op.opts.compression != 0); 289 } 290 291 static void bch2_dio_write_loop_async(struct bch_write_op *); 292 static __always_inline long bch2_dio_write_done(struct dio_write *dio); 293 294 /* 295 * We're going to return -EIOCBQUEUED, but we haven't finished consuming the 296 * iov_iter yet, so we need to stash a copy of the iovec: it might be on the 297 * caller's stack, we're not guaranteed that it will live for the duration of 298 * the IO: 299 */ 300 static noinline int bch2_dio_write_copy_iov(struct dio_write *dio) 301 { 302 struct iovec *iov = dio->inline_vecs; 303 304 /* 305 * iov_iter has a single embedded iovec - nothing to do: 306 */ 307 if (iter_is_ubuf(&dio->iter)) 308 return 0; 309 310 /* 311 * We don't currently handle non-iovec iov_iters here - return an error, 312 * and we'll fall back to doing the IO synchronously: 313 */ 314 if (!iter_is_iovec(&dio->iter)) 315 return -1; 316 317 if (dio->iter.nr_segs > ARRAY_SIZE(dio->inline_vecs)) { 318 dio->iov = iov = kmalloc_array(dio->iter.nr_segs, sizeof(*iov), 319 GFP_KERNEL); 320 if (unlikely(!iov)) 321 return -ENOMEM; 322 } 323 324 memcpy(iov, dio->iter.__iov, dio->iter.nr_segs * sizeof(*iov)); 325 dio->iter.__iov = iov; 326 return 0; 327 } 328 329 static CLOSURE_CALLBACK(bch2_dio_write_flush_done) 330 { 331 closure_type(dio, struct dio_write, op.cl); 332 struct bch_fs *c = dio->op.c; 333 334 closure_debug_destroy(cl); 335 336 dio->op.error = bch2_journal_error(&c->journal); 337 338 bch2_dio_write_done(dio); 339 } 340 341 static noinline void bch2_dio_write_flush(struct dio_write *dio) 342 { 343 struct bch_fs *c = dio->op.c; 344 struct bch_inode_unpacked inode; 345 int ret; 346 347 dio->flush = 0; 348 349 closure_init(&dio->op.cl, NULL); 350 351 if (!dio->op.error) { 352 ret = bch2_inode_find_by_inum(c, inode_inum(dio->inode), &inode); 353 if (ret) { 354 dio->op.error = ret; 355 } else { 356 bch2_journal_flush_seq_async(&c->journal, inode.bi_journal_seq, 357 &dio->op.cl); 358 bch2_inode_flush_nocow_writes_async(c, dio->inode, &dio->op.cl); 359 } 360 } 361 362 if (dio->sync) { 363 closure_sync(&dio->op.cl); 364 closure_debug_destroy(&dio->op.cl); 365 } else { 366 continue_at(&dio->op.cl, bch2_dio_write_flush_done, NULL); 367 } 368 } 369 370 static __always_inline long bch2_dio_write_done(struct dio_write *dio) 371 { 372 struct kiocb *req = dio->req; 373 struct bch_inode_info *inode = dio->inode; 374 bool sync = dio->sync; 375 long ret; 376 377 if (unlikely(dio->flush)) { 378 bch2_dio_write_flush(dio); 379 if (!sync) 380 return -EIOCBQUEUED; 381 } 382 383 bch2_pagecache_block_put(inode); 384 385 kfree(dio->iov); 386 387 ret = dio->op.error ?: ((long) dio->written << 9); 388 bio_put(&dio->op.wbio.bio); 389 390 bch2_write_ref_put(dio->op.c, BCH_WRITE_REF_dio_write); 391 392 /* inode->i_dio_count is our ref on inode and thus bch_fs */ 393 inode_dio_end(&inode->v); 394 395 if (ret < 0) 396 ret = bch2_err_class(ret); 397 398 if (!sync) { 399 req->ki_complete(req, ret); 400 ret = -EIOCBQUEUED; 401 } 402 return ret; 403 } 404 405 static __always_inline void bch2_dio_write_end(struct dio_write *dio) 406 { 407 struct bch_fs *c = dio->op.c; 408 struct kiocb *req = dio->req; 409 struct bch_inode_info *inode = dio->inode; 410 struct bio *bio = &dio->op.wbio.bio; 411 412 req->ki_pos += (u64) dio->op.written << 9; 413 dio->written += dio->op.written; 414 415 if (dio->extending) { 416 spin_lock(&inode->v.i_lock); 417 if (req->ki_pos > inode->v.i_size) 418 i_size_write(&inode->v, req->ki_pos); 419 spin_unlock(&inode->v.i_lock); 420 } 421 422 if (dio->op.i_sectors_delta || dio->quota_res.sectors) { 423 mutex_lock(&inode->ei_quota_lock); 424 __bch2_i_sectors_acct(c, inode, &dio->quota_res, dio->op.i_sectors_delta); 425 __bch2_quota_reservation_put(c, inode, &dio->quota_res); 426 mutex_unlock(&inode->ei_quota_lock); 427 } 428 429 bio_release_pages(bio, false); 430 431 if (unlikely(dio->op.error)) 432 set_bit(EI_INODE_ERROR, &inode->ei_flags); 433 } 434 435 static __always_inline long bch2_dio_write_loop(struct dio_write *dio) 436 { 437 struct bch_fs *c = dio->op.c; 438 struct kiocb *req = dio->req; 439 struct address_space *mapping = dio->mapping; 440 struct bch_inode_info *inode = dio->inode; 441 struct bch_io_opts opts; 442 struct bio *bio = &dio->op.wbio.bio; 443 unsigned unaligned, iter_count; 444 bool sync = dio->sync, dropped_locks; 445 long ret; 446 447 bch2_inode_opts_get(&opts, c, &inode->ei_inode); 448 449 while (1) { 450 iter_count = dio->iter.count; 451 452 EBUG_ON(current->faults_disabled_mapping); 453 current->faults_disabled_mapping = mapping; 454 455 ret = bio_iov_iter_get_pages(bio, &dio->iter); 456 457 dropped_locks = fdm_dropped_locks(); 458 459 current->faults_disabled_mapping = NULL; 460 461 /* 462 * If the fault handler returned an error but also signalled 463 * that it dropped & retook ei_pagecache_lock, we just need to 464 * re-shoot down the page cache and retry: 465 */ 466 if (dropped_locks && ret) 467 ret = 0; 468 469 if (unlikely(ret < 0)) 470 goto err; 471 472 if (unlikely(dropped_locks)) { 473 ret = bch2_write_invalidate_inode_pages_range(mapping, 474 req->ki_pos, 475 req->ki_pos + iter_count - 1); 476 if (unlikely(ret)) 477 goto err; 478 479 if (!bio->bi_iter.bi_size) 480 continue; 481 } 482 483 unaligned = bio->bi_iter.bi_size & (block_bytes(c) - 1); 484 bio->bi_iter.bi_size -= unaligned; 485 iov_iter_revert(&dio->iter, unaligned); 486 487 if (!bio->bi_iter.bi_size) { 488 /* 489 * bio_iov_iter_get_pages was only able to get < 490 * blocksize worth of pages: 491 */ 492 ret = -EFAULT; 493 goto err; 494 } 495 496 bch2_write_op_init(&dio->op, c, opts); 497 dio->op.end_io = sync 498 ? NULL 499 : bch2_dio_write_loop_async; 500 dio->op.target = dio->op.opts.foreground_target; 501 dio->op.write_point = writepoint_hashed((unsigned long) current); 502 dio->op.nr_replicas = dio->op.opts.data_replicas; 503 dio->op.subvol = inode->ei_subvol; 504 dio->op.pos = POS(inode->v.i_ino, (u64) req->ki_pos >> 9); 505 dio->op.devs_need_flush = &inode->ei_devs_need_flush; 506 507 if (sync) 508 dio->op.flags |= BCH_WRITE_SYNC; 509 dio->op.flags |= BCH_WRITE_CHECK_ENOSPC; 510 511 ret = bch2_quota_reservation_add(c, inode, &dio->quota_res, 512 bio_sectors(bio), true); 513 if (unlikely(ret)) 514 goto err; 515 516 ret = bch2_disk_reservation_get(c, &dio->op.res, bio_sectors(bio), 517 dio->op.opts.data_replicas, 0); 518 if (unlikely(ret) && 519 !bch2_dio_write_check_allocated(dio)) 520 goto err; 521 522 task_io_account_write(bio->bi_iter.bi_size); 523 524 if (unlikely(dio->iter.count) && 525 !dio->sync && 526 !dio->loop && 527 bch2_dio_write_copy_iov(dio)) 528 dio->sync = sync = true; 529 530 dio->loop = true; 531 closure_call(&dio->op.cl, bch2_write, NULL, NULL); 532 533 if (!sync) 534 return -EIOCBQUEUED; 535 536 bch2_dio_write_end(dio); 537 538 if (likely(!dio->iter.count) || dio->op.error) 539 break; 540 541 bio_reset(bio, NULL, REQ_OP_WRITE | REQ_SYNC | REQ_IDLE); 542 } 543 out: 544 return bch2_dio_write_done(dio); 545 err: 546 dio->op.error = ret; 547 548 bio_release_pages(bio, false); 549 550 bch2_quota_reservation_put(c, inode, &dio->quota_res); 551 goto out; 552 } 553 554 static noinline __cold void bch2_dio_write_continue(struct dio_write *dio) 555 { 556 struct mm_struct *mm = dio->mm; 557 558 bio_reset(&dio->op.wbio.bio, NULL, REQ_OP_WRITE); 559 560 if (mm) 561 kthread_use_mm(mm); 562 bch2_dio_write_loop(dio); 563 if (mm) 564 kthread_unuse_mm(mm); 565 } 566 567 static void bch2_dio_write_loop_async(struct bch_write_op *op) 568 { 569 struct dio_write *dio = container_of(op, struct dio_write, op); 570 571 bch2_dio_write_end(dio); 572 573 if (likely(!dio->iter.count) || dio->op.error) 574 bch2_dio_write_done(dio); 575 else 576 bch2_dio_write_continue(dio); 577 } 578 579 ssize_t bch2_direct_write(struct kiocb *req, struct iov_iter *iter) 580 { 581 struct file *file = req->ki_filp; 582 struct address_space *mapping = file->f_mapping; 583 struct bch_inode_info *inode = file_bch_inode(file); 584 struct bch_fs *c = inode->v.i_sb->s_fs_info; 585 struct dio_write *dio; 586 struct bio *bio; 587 bool locked = true, extending; 588 ssize_t ret; 589 590 prefetch(&c->opts); 591 prefetch((void *) &c->opts + 64); 592 prefetch(&inode->ei_inode); 593 prefetch((void *) &inode->ei_inode + 64); 594 595 if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_dio_write)) 596 return -EROFS; 597 598 inode_lock(&inode->v); 599 600 ret = generic_write_checks(req, iter); 601 if (unlikely(ret <= 0)) 602 goto err_put_write_ref; 603 604 ret = file_remove_privs(file); 605 if (unlikely(ret)) 606 goto err_put_write_ref; 607 608 ret = file_update_time(file); 609 if (unlikely(ret)) 610 goto err_put_write_ref; 611 612 if (unlikely((req->ki_pos|iter->count) & (block_bytes(c) - 1))) { 613 ret = -EINVAL; 614 goto err_put_write_ref; 615 } 616 617 inode_dio_begin(&inode->v); 618 bch2_pagecache_block_get(inode); 619 620 extending = req->ki_pos + iter->count > inode->v.i_size; 621 if (!extending) { 622 inode_unlock(&inode->v); 623 locked = false; 624 } 625 626 bio = bio_alloc_bioset(NULL, 627 bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS), 628 REQ_OP_WRITE | REQ_SYNC | REQ_IDLE, 629 GFP_KERNEL, 630 &c->dio_write_bioset); 631 dio = container_of(bio, struct dio_write, op.wbio.bio); 632 dio->req = req; 633 dio->mapping = mapping; 634 dio->inode = inode; 635 dio->mm = current->mm; 636 dio->iov = NULL; 637 dio->loop = false; 638 dio->extending = extending; 639 dio->sync = is_sync_kiocb(req) || extending; 640 dio->flush = iocb_is_dsync(req) && !c->opts.journal_flush_disabled; 641 dio->quota_res.sectors = 0; 642 dio->written = 0; 643 dio->iter = *iter; 644 dio->op.c = c; 645 646 if (unlikely(mapping->nrpages)) { 647 ret = bch2_write_invalidate_inode_pages_range(mapping, 648 req->ki_pos, 649 req->ki_pos + iter->count - 1); 650 if (unlikely(ret)) 651 goto err_put_bio; 652 } 653 654 ret = bch2_dio_write_loop(dio); 655 out: 656 if (locked) 657 inode_unlock(&inode->v); 658 return ret; 659 err_put_bio: 660 bch2_pagecache_block_put(inode); 661 bio_put(bio); 662 inode_dio_end(&inode->v); 663 err_put_write_ref: 664 bch2_write_ref_put(c, BCH_WRITE_REF_dio_write); 665 goto out; 666 } 667 668 void bch2_fs_fs_io_direct_exit(struct bch_fs *c) 669 { 670 bioset_exit(&c->dio_write_bioset); 671 bioset_exit(&c->dio_read_bioset); 672 } 673 674 int bch2_fs_fs_io_direct_init(struct bch_fs *c) 675 { 676 if (bioset_init(&c->dio_read_bioset, 677 4, offsetof(struct dio_read, rbio.bio), 678 BIOSET_NEED_BVECS)) 679 return -BCH_ERR_ENOMEM_dio_read_bioset_init; 680 681 if (bioset_init(&c->dio_write_bioset, 682 4, offsetof(struct dio_write, op.wbio.bio), 683 BIOSET_NEED_BVECS)) 684 return -BCH_ERR_ENOMEM_dio_write_bioset_init; 685 686 return 0; 687 } 688 689 #endif /* NO_BCACHEFS_FS */ 690