1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/slab.h> 20 #include <linux/blkdev.h> 21 #include <linux/writeback.h> 22 #include <linux/pagevec.h> 23 #include "ctree.h" 24 #include "transaction.h" 25 #include "btrfs_inode.h" 26 #include "extent_io.h" 27 #include "disk-io.h" 28 29 static struct kmem_cache *btrfs_ordered_extent_cache; 30 31 static u64 entry_end(struct btrfs_ordered_extent *entry) 32 { 33 if (entry->file_offset + entry->len < entry->file_offset) 34 return (u64)-1; 35 return entry->file_offset + entry->len; 36 } 37 38 /* returns NULL if the insertion worked, or it returns the node it did find 39 * in the tree 40 */ 41 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset, 42 struct rb_node *node) 43 { 44 struct rb_node **p = &root->rb_node; 45 struct rb_node *parent = NULL; 46 struct btrfs_ordered_extent *entry; 47 48 while (*p) { 49 parent = *p; 50 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node); 51 52 if (file_offset < entry->file_offset) 53 p = &(*p)->rb_left; 54 else if (file_offset >= entry_end(entry)) 55 p = &(*p)->rb_right; 56 else 57 return parent; 58 } 59 60 rb_link_node(node, parent, p); 61 rb_insert_color(node, root); 62 return NULL; 63 } 64 65 static void ordered_data_tree_panic(struct inode *inode, int errno, 66 u64 offset) 67 { 68 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 69 btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset " 70 "%llu", offset); 71 } 72 73 /* 74 * look for a given offset in the tree, and if it can't be found return the 75 * first lesser offset 76 */ 77 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset, 78 struct rb_node **prev_ret) 79 { 80 struct rb_node *n = root->rb_node; 81 struct rb_node *prev = NULL; 82 struct rb_node *test; 83 struct btrfs_ordered_extent *entry; 84 struct btrfs_ordered_extent *prev_entry = NULL; 85 86 while (n) { 87 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node); 88 prev = n; 89 prev_entry = entry; 90 91 if (file_offset < entry->file_offset) 92 n = n->rb_left; 93 else if (file_offset >= entry_end(entry)) 94 n = n->rb_right; 95 else 96 return n; 97 } 98 if (!prev_ret) 99 return NULL; 100 101 while (prev && file_offset >= entry_end(prev_entry)) { 102 test = rb_next(prev); 103 if (!test) 104 break; 105 prev_entry = rb_entry(test, struct btrfs_ordered_extent, 106 rb_node); 107 if (file_offset < entry_end(prev_entry)) 108 break; 109 110 prev = test; 111 } 112 if (prev) 113 prev_entry = rb_entry(prev, struct btrfs_ordered_extent, 114 rb_node); 115 while (prev && file_offset < entry_end(prev_entry)) { 116 test = rb_prev(prev); 117 if (!test) 118 break; 119 prev_entry = rb_entry(test, struct btrfs_ordered_extent, 120 rb_node); 121 prev = test; 122 } 123 *prev_ret = prev; 124 return NULL; 125 } 126 127 /* 128 * helper to check if a given offset is inside a given entry 129 */ 130 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset) 131 { 132 if (file_offset < entry->file_offset || 133 entry->file_offset + entry->len <= file_offset) 134 return 0; 135 return 1; 136 } 137 138 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset, 139 u64 len) 140 { 141 if (file_offset + len <= entry->file_offset || 142 entry->file_offset + entry->len <= file_offset) 143 return 0; 144 return 1; 145 } 146 147 /* 148 * look find the first ordered struct that has this offset, otherwise 149 * the first one less than this offset 150 */ 151 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree, 152 u64 file_offset) 153 { 154 struct rb_root *root = &tree->tree; 155 struct rb_node *prev = NULL; 156 struct rb_node *ret; 157 struct btrfs_ordered_extent *entry; 158 159 if (tree->last) { 160 entry = rb_entry(tree->last, struct btrfs_ordered_extent, 161 rb_node); 162 if (offset_in_entry(entry, file_offset)) 163 return tree->last; 164 } 165 ret = __tree_search(root, file_offset, &prev); 166 if (!ret) 167 ret = prev; 168 if (ret) 169 tree->last = ret; 170 return ret; 171 } 172 173 /* allocate and add a new ordered_extent into the per-inode tree. 174 * file_offset is the logical offset in the file 175 * 176 * start is the disk block number of an extent already reserved in the 177 * extent allocation tree 178 * 179 * len is the length of the extent 180 * 181 * The tree is given a single reference on the ordered extent that was 182 * inserted. 183 */ 184 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, 185 u64 start, u64 len, u64 disk_len, 186 int type, int dio, int compress_type) 187 { 188 struct btrfs_root *root = BTRFS_I(inode)->root; 189 struct btrfs_ordered_inode_tree *tree; 190 struct rb_node *node; 191 struct btrfs_ordered_extent *entry; 192 193 tree = &BTRFS_I(inode)->ordered_tree; 194 entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS); 195 if (!entry) 196 return -ENOMEM; 197 198 entry->file_offset = file_offset; 199 entry->start = start; 200 entry->len = len; 201 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) && 202 !(type == BTRFS_ORDERED_NOCOW)) 203 entry->csum_bytes_left = disk_len; 204 entry->disk_len = disk_len; 205 entry->bytes_left = len; 206 entry->inode = igrab(inode); 207 entry->compress_type = compress_type; 208 entry->truncated_len = (u64)-1; 209 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE) 210 set_bit(type, &entry->flags); 211 212 if (dio) 213 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags); 214 215 /* one ref for the tree */ 216 atomic_set(&entry->refs, 1); 217 init_waitqueue_head(&entry->wait); 218 INIT_LIST_HEAD(&entry->list); 219 INIT_LIST_HEAD(&entry->root_extent_list); 220 INIT_LIST_HEAD(&entry->work_list); 221 init_completion(&entry->completion); 222 INIT_LIST_HEAD(&entry->log_list); 223 224 trace_btrfs_ordered_extent_add(inode, entry); 225 226 spin_lock_irq(&tree->lock); 227 node = tree_insert(&tree->tree, file_offset, 228 &entry->rb_node); 229 if (node) 230 ordered_data_tree_panic(inode, -EEXIST, file_offset); 231 spin_unlock_irq(&tree->lock); 232 233 spin_lock(&root->ordered_extent_lock); 234 list_add_tail(&entry->root_extent_list, 235 &root->ordered_extents); 236 root->nr_ordered_extents++; 237 if (root->nr_ordered_extents == 1) { 238 spin_lock(&root->fs_info->ordered_root_lock); 239 BUG_ON(!list_empty(&root->ordered_root)); 240 list_add_tail(&root->ordered_root, 241 &root->fs_info->ordered_roots); 242 spin_unlock(&root->fs_info->ordered_root_lock); 243 } 244 spin_unlock(&root->ordered_extent_lock); 245 246 return 0; 247 } 248 249 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, 250 u64 start, u64 len, u64 disk_len, int type) 251 { 252 return __btrfs_add_ordered_extent(inode, file_offset, start, len, 253 disk_len, type, 0, 254 BTRFS_COMPRESS_NONE); 255 } 256 257 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset, 258 u64 start, u64 len, u64 disk_len, int type) 259 { 260 return __btrfs_add_ordered_extent(inode, file_offset, start, len, 261 disk_len, type, 1, 262 BTRFS_COMPRESS_NONE); 263 } 264 265 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset, 266 u64 start, u64 len, u64 disk_len, 267 int type, int compress_type) 268 { 269 return __btrfs_add_ordered_extent(inode, file_offset, start, len, 270 disk_len, type, 0, 271 compress_type); 272 } 273 274 /* 275 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted 276 * when an ordered extent is finished. If the list covers more than one 277 * ordered extent, it is split across multiples. 278 */ 279 void btrfs_add_ordered_sum(struct inode *inode, 280 struct btrfs_ordered_extent *entry, 281 struct btrfs_ordered_sum *sum) 282 { 283 struct btrfs_ordered_inode_tree *tree; 284 285 tree = &BTRFS_I(inode)->ordered_tree; 286 spin_lock_irq(&tree->lock); 287 list_add_tail(&sum->list, &entry->list); 288 WARN_ON(entry->csum_bytes_left < sum->len); 289 entry->csum_bytes_left -= sum->len; 290 if (entry->csum_bytes_left == 0) 291 wake_up(&entry->wait); 292 spin_unlock_irq(&tree->lock); 293 } 294 295 /* 296 * this is used to account for finished IO across a given range 297 * of the file. The IO may span ordered extents. If 298 * a given ordered_extent is completely done, 1 is returned, otherwise 299 * 0. 300 * 301 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used 302 * to make sure this function only returns 1 once for a given ordered extent. 303 * 304 * file_offset is updated to one byte past the range that is recorded as 305 * complete. This allows you to walk forward in the file. 306 */ 307 int btrfs_dec_test_first_ordered_pending(struct inode *inode, 308 struct btrfs_ordered_extent **cached, 309 u64 *file_offset, u64 io_size, int uptodate) 310 { 311 struct btrfs_ordered_inode_tree *tree; 312 struct rb_node *node; 313 struct btrfs_ordered_extent *entry = NULL; 314 int ret; 315 unsigned long flags; 316 u64 dec_end; 317 u64 dec_start; 318 u64 to_dec; 319 320 tree = &BTRFS_I(inode)->ordered_tree; 321 spin_lock_irqsave(&tree->lock, flags); 322 node = tree_search(tree, *file_offset); 323 if (!node) { 324 ret = 1; 325 goto out; 326 } 327 328 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); 329 if (!offset_in_entry(entry, *file_offset)) { 330 ret = 1; 331 goto out; 332 } 333 334 dec_start = max(*file_offset, entry->file_offset); 335 dec_end = min(*file_offset + io_size, entry->file_offset + 336 entry->len); 337 *file_offset = dec_end; 338 if (dec_start > dec_end) { 339 btrfs_crit(BTRFS_I(inode)->root->fs_info, 340 "bad ordering dec_start %llu end %llu", dec_start, dec_end); 341 } 342 to_dec = dec_end - dec_start; 343 if (to_dec > entry->bytes_left) { 344 btrfs_crit(BTRFS_I(inode)->root->fs_info, 345 "bad ordered accounting left %llu size %llu", 346 entry->bytes_left, to_dec); 347 } 348 entry->bytes_left -= to_dec; 349 if (!uptodate) 350 set_bit(BTRFS_ORDERED_IOERR, &entry->flags); 351 352 if (entry->bytes_left == 0) { 353 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); 354 if (waitqueue_active(&entry->wait)) 355 wake_up(&entry->wait); 356 } else { 357 ret = 1; 358 } 359 out: 360 if (!ret && cached && entry) { 361 *cached = entry; 362 atomic_inc(&entry->refs); 363 } 364 spin_unlock_irqrestore(&tree->lock, flags); 365 return ret == 0; 366 } 367 368 /* 369 * this is used to account for finished IO across a given range 370 * of the file. The IO should not span ordered extents. If 371 * a given ordered_extent is completely done, 1 is returned, otherwise 372 * 0. 373 * 374 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used 375 * to make sure this function only returns 1 once for a given ordered extent. 376 */ 377 int btrfs_dec_test_ordered_pending(struct inode *inode, 378 struct btrfs_ordered_extent **cached, 379 u64 file_offset, u64 io_size, int uptodate) 380 { 381 struct btrfs_ordered_inode_tree *tree; 382 struct rb_node *node; 383 struct btrfs_ordered_extent *entry = NULL; 384 unsigned long flags; 385 int ret; 386 387 tree = &BTRFS_I(inode)->ordered_tree; 388 spin_lock_irqsave(&tree->lock, flags); 389 if (cached && *cached) { 390 entry = *cached; 391 goto have_entry; 392 } 393 394 node = tree_search(tree, file_offset); 395 if (!node) { 396 ret = 1; 397 goto out; 398 } 399 400 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); 401 have_entry: 402 if (!offset_in_entry(entry, file_offset)) { 403 ret = 1; 404 goto out; 405 } 406 407 if (io_size > entry->bytes_left) { 408 btrfs_crit(BTRFS_I(inode)->root->fs_info, 409 "bad ordered accounting left %llu size %llu", 410 entry->bytes_left, io_size); 411 } 412 entry->bytes_left -= io_size; 413 if (!uptodate) 414 set_bit(BTRFS_ORDERED_IOERR, &entry->flags); 415 416 if (entry->bytes_left == 0) { 417 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags); 418 if (waitqueue_active(&entry->wait)) 419 wake_up(&entry->wait); 420 } else { 421 ret = 1; 422 } 423 out: 424 if (!ret && cached && entry) { 425 *cached = entry; 426 atomic_inc(&entry->refs); 427 } 428 spin_unlock_irqrestore(&tree->lock, flags); 429 return ret == 0; 430 } 431 432 /* Needs to either be called under a log transaction or the log_mutex */ 433 void btrfs_get_logged_extents(struct inode *inode, 434 struct list_head *logged_list) 435 { 436 struct btrfs_ordered_inode_tree *tree; 437 struct btrfs_ordered_extent *ordered; 438 struct rb_node *n; 439 440 tree = &BTRFS_I(inode)->ordered_tree; 441 spin_lock_irq(&tree->lock); 442 for (n = rb_first(&tree->tree); n; n = rb_next(n)) { 443 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node); 444 if (!list_empty(&ordered->log_list)) 445 continue; 446 list_add_tail(&ordered->log_list, logged_list); 447 atomic_inc(&ordered->refs); 448 } 449 spin_unlock_irq(&tree->lock); 450 } 451 452 void btrfs_put_logged_extents(struct list_head *logged_list) 453 { 454 struct btrfs_ordered_extent *ordered; 455 456 while (!list_empty(logged_list)) { 457 ordered = list_first_entry(logged_list, 458 struct btrfs_ordered_extent, 459 log_list); 460 list_del_init(&ordered->log_list); 461 btrfs_put_ordered_extent(ordered); 462 } 463 } 464 465 void btrfs_submit_logged_extents(struct list_head *logged_list, 466 struct btrfs_root *log) 467 { 468 int index = log->log_transid % 2; 469 470 spin_lock_irq(&log->log_extents_lock[index]); 471 list_splice_tail(logged_list, &log->logged_list[index]); 472 spin_unlock_irq(&log->log_extents_lock[index]); 473 } 474 475 void btrfs_wait_logged_extents(struct btrfs_root *log, u64 transid) 476 { 477 struct btrfs_ordered_extent *ordered; 478 int index = transid % 2; 479 480 spin_lock_irq(&log->log_extents_lock[index]); 481 while (!list_empty(&log->logged_list[index])) { 482 ordered = list_first_entry(&log->logged_list[index], 483 struct btrfs_ordered_extent, 484 log_list); 485 list_del_init(&ordered->log_list); 486 spin_unlock_irq(&log->log_extents_lock[index]); 487 488 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) && 489 !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) { 490 struct inode *inode = ordered->inode; 491 u64 start = ordered->file_offset; 492 u64 end = ordered->file_offset + ordered->len - 1; 493 494 WARN_ON(!inode); 495 filemap_fdatawrite_range(inode->i_mapping, start, end); 496 } 497 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE, 498 &ordered->flags)); 499 500 btrfs_put_ordered_extent(ordered); 501 spin_lock_irq(&log->log_extents_lock[index]); 502 } 503 spin_unlock_irq(&log->log_extents_lock[index]); 504 } 505 506 void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid) 507 { 508 struct btrfs_ordered_extent *ordered; 509 int index = transid % 2; 510 511 spin_lock_irq(&log->log_extents_lock[index]); 512 while (!list_empty(&log->logged_list[index])) { 513 ordered = list_first_entry(&log->logged_list[index], 514 struct btrfs_ordered_extent, 515 log_list); 516 list_del_init(&ordered->log_list); 517 spin_unlock_irq(&log->log_extents_lock[index]); 518 btrfs_put_ordered_extent(ordered); 519 spin_lock_irq(&log->log_extents_lock[index]); 520 } 521 spin_unlock_irq(&log->log_extents_lock[index]); 522 } 523 524 /* 525 * used to drop a reference on an ordered extent. This will free 526 * the extent if the last reference is dropped 527 */ 528 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) 529 { 530 struct list_head *cur; 531 struct btrfs_ordered_sum *sum; 532 533 trace_btrfs_ordered_extent_put(entry->inode, entry); 534 535 if (atomic_dec_and_test(&entry->refs)) { 536 if (entry->inode) 537 btrfs_add_delayed_iput(entry->inode); 538 while (!list_empty(&entry->list)) { 539 cur = entry->list.next; 540 sum = list_entry(cur, struct btrfs_ordered_sum, list); 541 list_del(&sum->list); 542 kfree(sum); 543 } 544 kmem_cache_free(btrfs_ordered_extent_cache, entry); 545 } 546 } 547 548 /* 549 * remove an ordered extent from the tree. No references are dropped 550 * and waiters are woken up. 551 */ 552 void btrfs_remove_ordered_extent(struct inode *inode, 553 struct btrfs_ordered_extent *entry) 554 { 555 struct btrfs_ordered_inode_tree *tree; 556 struct btrfs_root *root = BTRFS_I(inode)->root; 557 struct rb_node *node; 558 559 tree = &BTRFS_I(inode)->ordered_tree; 560 spin_lock_irq(&tree->lock); 561 node = &entry->rb_node; 562 rb_erase(node, &tree->tree); 563 if (tree->last == node) 564 tree->last = NULL; 565 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags); 566 spin_unlock_irq(&tree->lock); 567 568 spin_lock(&root->ordered_extent_lock); 569 list_del_init(&entry->root_extent_list); 570 root->nr_ordered_extents--; 571 572 trace_btrfs_ordered_extent_remove(inode, entry); 573 574 if (!root->nr_ordered_extents) { 575 spin_lock(&root->fs_info->ordered_root_lock); 576 BUG_ON(list_empty(&root->ordered_root)); 577 list_del_init(&root->ordered_root); 578 spin_unlock(&root->fs_info->ordered_root_lock); 579 } 580 spin_unlock(&root->ordered_extent_lock); 581 wake_up(&entry->wait); 582 } 583 584 static void btrfs_run_ordered_extent_work(struct btrfs_work *work) 585 { 586 struct btrfs_ordered_extent *ordered; 587 588 ordered = container_of(work, struct btrfs_ordered_extent, flush_work); 589 btrfs_start_ordered_extent(ordered->inode, ordered, 1); 590 complete(&ordered->completion); 591 } 592 593 /* 594 * wait for all the ordered extents in a root. This is done when balancing 595 * space between drives. 596 */ 597 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr) 598 { 599 struct list_head splice, works; 600 struct btrfs_ordered_extent *ordered, *next; 601 int count = 0; 602 603 INIT_LIST_HEAD(&splice); 604 INIT_LIST_HEAD(&works); 605 606 mutex_lock(&root->ordered_extent_mutex); 607 spin_lock(&root->ordered_extent_lock); 608 list_splice_init(&root->ordered_extents, &splice); 609 while (!list_empty(&splice) && nr) { 610 ordered = list_first_entry(&splice, struct btrfs_ordered_extent, 611 root_extent_list); 612 list_move_tail(&ordered->root_extent_list, 613 &root->ordered_extents); 614 atomic_inc(&ordered->refs); 615 spin_unlock(&root->ordered_extent_lock); 616 617 btrfs_init_work(&ordered->flush_work, 618 btrfs_flush_delalloc_helper, 619 btrfs_run_ordered_extent_work, NULL, NULL); 620 list_add_tail(&ordered->work_list, &works); 621 btrfs_queue_work(root->fs_info->flush_workers, 622 &ordered->flush_work); 623 624 cond_resched(); 625 spin_lock(&root->ordered_extent_lock); 626 if (nr != -1) 627 nr--; 628 count++; 629 } 630 list_splice_tail(&splice, &root->ordered_extents); 631 spin_unlock(&root->ordered_extent_lock); 632 633 list_for_each_entry_safe(ordered, next, &works, work_list) { 634 list_del_init(&ordered->work_list); 635 wait_for_completion(&ordered->completion); 636 btrfs_put_ordered_extent(ordered); 637 cond_resched(); 638 } 639 mutex_unlock(&root->ordered_extent_mutex); 640 641 return count; 642 } 643 644 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr) 645 { 646 struct btrfs_root *root; 647 struct list_head splice; 648 int done; 649 650 INIT_LIST_HEAD(&splice); 651 652 mutex_lock(&fs_info->ordered_operations_mutex); 653 spin_lock(&fs_info->ordered_root_lock); 654 list_splice_init(&fs_info->ordered_roots, &splice); 655 while (!list_empty(&splice) && nr) { 656 root = list_first_entry(&splice, struct btrfs_root, 657 ordered_root); 658 root = btrfs_grab_fs_root(root); 659 BUG_ON(!root); 660 list_move_tail(&root->ordered_root, 661 &fs_info->ordered_roots); 662 spin_unlock(&fs_info->ordered_root_lock); 663 664 done = btrfs_wait_ordered_extents(root, nr); 665 btrfs_put_fs_root(root); 666 667 spin_lock(&fs_info->ordered_root_lock); 668 if (nr != -1) { 669 nr -= done; 670 WARN_ON(nr < 0); 671 } 672 } 673 list_splice_tail(&splice, &fs_info->ordered_roots); 674 spin_unlock(&fs_info->ordered_root_lock); 675 mutex_unlock(&fs_info->ordered_operations_mutex); 676 } 677 678 /* 679 * Used to start IO or wait for a given ordered extent to finish. 680 * 681 * If wait is one, this effectively waits on page writeback for all the pages 682 * in the extent, and it waits on the io completion code to insert 683 * metadata into the btree corresponding to the extent 684 */ 685 void btrfs_start_ordered_extent(struct inode *inode, 686 struct btrfs_ordered_extent *entry, 687 int wait) 688 { 689 u64 start = entry->file_offset; 690 u64 end = start + entry->len - 1; 691 692 trace_btrfs_ordered_extent_start(inode, entry); 693 694 /* 695 * pages in the range can be dirty, clean or writeback. We 696 * start IO on any dirty ones so the wait doesn't stall waiting 697 * for the flusher thread to find them 698 */ 699 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags)) 700 filemap_fdatawrite_range(inode->i_mapping, start, end); 701 if (wait) { 702 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, 703 &entry->flags)); 704 } 705 } 706 707 /* 708 * Used to wait on ordered extents across a large range of bytes. 709 */ 710 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len) 711 { 712 int ret = 0; 713 u64 end; 714 u64 orig_end; 715 struct btrfs_ordered_extent *ordered; 716 717 if (start + len < start) { 718 orig_end = INT_LIMIT(loff_t); 719 } else { 720 orig_end = start + len - 1; 721 if (orig_end > INT_LIMIT(loff_t)) 722 orig_end = INT_LIMIT(loff_t); 723 } 724 725 /* start IO across the range first to instantiate any delalloc 726 * extents 727 */ 728 ret = filemap_fdatawrite_range(inode->i_mapping, start, orig_end); 729 if (ret) 730 return ret; 731 /* 732 * So with compression we will find and lock a dirty page and clear the 733 * first one as dirty, setup an async extent, and immediately return 734 * with the entire range locked but with nobody actually marked with 735 * writeback. So we can't just filemap_write_and_wait_range() and 736 * expect it to work since it will just kick off a thread to do the 737 * actual work. So we need to call filemap_fdatawrite_range _again_ 738 * since it will wait on the page lock, which won't be unlocked until 739 * after the pages have been marked as writeback and so we're good to go 740 * from there. We have to do this otherwise we'll miss the ordered 741 * extents and that results in badness. Please Josef, do not think you 742 * know better and pull this out at some point in the future, it is 743 * right and you are wrong. 744 */ 745 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, 746 &BTRFS_I(inode)->runtime_flags)) { 747 ret = filemap_fdatawrite_range(inode->i_mapping, start, 748 orig_end); 749 if (ret) 750 return ret; 751 } 752 ret = filemap_fdatawait_range(inode->i_mapping, start, orig_end); 753 if (ret) 754 return ret; 755 756 end = orig_end; 757 while (1) { 758 ordered = btrfs_lookup_first_ordered_extent(inode, end); 759 if (!ordered) 760 break; 761 if (ordered->file_offset > orig_end) { 762 btrfs_put_ordered_extent(ordered); 763 break; 764 } 765 if (ordered->file_offset + ordered->len <= start) { 766 btrfs_put_ordered_extent(ordered); 767 break; 768 } 769 btrfs_start_ordered_extent(inode, ordered, 1); 770 end = ordered->file_offset; 771 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) 772 ret = -EIO; 773 btrfs_put_ordered_extent(ordered); 774 if (ret || end == 0 || end == start) 775 break; 776 end--; 777 } 778 return ret; 779 } 780 781 /* 782 * find an ordered extent corresponding to file_offset. return NULL if 783 * nothing is found, otherwise take a reference on the extent and return it 784 */ 785 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode, 786 u64 file_offset) 787 { 788 struct btrfs_ordered_inode_tree *tree; 789 struct rb_node *node; 790 struct btrfs_ordered_extent *entry = NULL; 791 792 tree = &BTRFS_I(inode)->ordered_tree; 793 spin_lock_irq(&tree->lock); 794 node = tree_search(tree, file_offset); 795 if (!node) 796 goto out; 797 798 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); 799 if (!offset_in_entry(entry, file_offset)) 800 entry = NULL; 801 if (entry) 802 atomic_inc(&entry->refs); 803 out: 804 spin_unlock_irq(&tree->lock); 805 return entry; 806 } 807 808 /* Since the DIO code tries to lock a wide area we need to look for any ordered 809 * extents that exist in the range, rather than just the start of the range. 810 */ 811 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode, 812 u64 file_offset, 813 u64 len) 814 { 815 struct btrfs_ordered_inode_tree *tree; 816 struct rb_node *node; 817 struct btrfs_ordered_extent *entry = NULL; 818 819 tree = &BTRFS_I(inode)->ordered_tree; 820 spin_lock_irq(&tree->lock); 821 node = tree_search(tree, file_offset); 822 if (!node) { 823 node = tree_search(tree, file_offset + len); 824 if (!node) 825 goto out; 826 } 827 828 while (1) { 829 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); 830 if (range_overlaps(entry, file_offset, len)) 831 break; 832 833 if (entry->file_offset >= file_offset + len) { 834 entry = NULL; 835 break; 836 } 837 entry = NULL; 838 node = rb_next(node); 839 if (!node) 840 break; 841 } 842 out: 843 if (entry) 844 atomic_inc(&entry->refs); 845 spin_unlock_irq(&tree->lock); 846 return entry; 847 } 848 849 /* 850 * lookup and return any extent before 'file_offset'. NULL is returned 851 * if none is found 852 */ 853 struct btrfs_ordered_extent * 854 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset) 855 { 856 struct btrfs_ordered_inode_tree *tree; 857 struct rb_node *node; 858 struct btrfs_ordered_extent *entry = NULL; 859 860 tree = &BTRFS_I(inode)->ordered_tree; 861 spin_lock_irq(&tree->lock); 862 node = tree_search(tree, file_offset); 863 if (!node) 864 goto out; 865 866 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); 867 atomic_inc(&entry->refs); 868 out: 869 spin_unlock_irq(&tree->lock); 870 return entry; 871 } 872 873 /* 874 * After an extent is done, call this to conditionally update the on disk 875 * i_size. i_size is updated to cover any fully written part of the file. 876 */ 877 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, 878 struct btrfs_ordered_extent *ordered) 879 { 880 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; 881 u64 disk_i_size; 882 u64 new_i_size; 883 u64 i_size = i_size_read(inode); 884 struct rb_node *node; 885 struct rb_node *prev = NULL; 886 struct btrfs_ordered_extent *test; 887 int ret = 1; 888 889 spin_lock_irq(&tree->lock); 890 if (ordered) { 891 offset = entry_end(ordered); 892 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) 893 offset = min(offset, 894 ordered->file_offset + 895 ordered->truncated_len); 896 } else { 897 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize); 898 } 899 disk_i_size = BTRFS_I(inode)->disk_i_size; 900 901 /* truncate file */ 902 if (disk_i_size > i_size) { 903 BTRFS_I(inode)->disk_i_size = i_size; 904 ret = 0; 905 goto out; 906 } 907 908 /* 909 * if the disk i_size is already at the inode->i_size, or 910 * this ordered extent is inside the disk i_size, we're done 911 */ 912 if (disk_i_size == i_size) 913 goto out; 914 915 /* 916 * We still need to update disk_i_size if outstanding_isize is greater 917 * than disk_i_size. 918 */ 919 if (offset <= disk_i_size && 920 (!ordered || ordered->outstanding_isize <= disk_i_size)) 921 goto out; 922 923 /* 924 * walk backward from this ordered extent to disk_i_size. 925 * if we find an ordered extent then we can't update disk i_size 926 * yet 927 */ 928 if (ordered) { 929 node = rb_prev(&ordered->rb_node); 930 } else { 931 prev = tree_search(tree, offset); 932 /* 933 * we insert file extents without involving ordered struct, 934 * so there should be no ordered struct cover this offset 935 */ 936 if (prev) { 937 test = rb_entry(prev, struct btrfs_ordered_extent, 938 rb_node); 939 BUG_ON(offset_in_entry(test, offset)); 940 } 941 node = prev; 942 } 943 for (; node; node = rb_prev(node)) { 944 test = rb_entry(node, struct btrfs_ordered_extent, rb_node); 945 946 /* We treat this entry as if it doesnt exist */ 947 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags)) 948 continue; 949 if (test->file_offset + test->len <= disk_i_size) 950 break; 951 if (test->file_offset >= i_size) 952 break; 953 if (entry_end(test) > disk_i_size) { 954 /* 955 * we don't update disk_i_size now, so record this 956 * undealt i_size. Or we will not know the real 957 * i_size. 958 */ 959 if (test->outstanding_isize < offset) 960 test->outstanding_isize = offset; 961 if (ordered && 962 ordered->outstanding_isize > 963 test->outstanding_isize) 964 test->outstanding_isize = 965 ordered->outstanding_isize; 966 goto out; 967 } 968 } 969 new_i_size = min_t(u64, offset, i_size); 970 971 /* 972 * Some ordered extents may completed before the current one, and 973 * we hold the real i_size in ->outstanding_isize. 974 */ 975 if (ordered && ordered->outstanding_isize > new_i_size) 976 new_i_size = min_t(u64, ordered->outstanding_isize, i_size); 977 BTRFS_I(inode)->disk_i_size = new_i_size; 978 ret = 0; 979 out: 980 /* 981 * We need to do this because we can't remove ordered extents until 982 * after the i_disk_size has been updated and then the inode has been 983 * updated to reflect the change, so we need to tell anybody who finds 984 * this ordered extent that we've already done all the real work, we 985 * just haven't completed all the other work. 986 */ 987 if (ordered) 988 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags); 989 spin_unlock_irq(&tree->lock); 990 return ret; 991 } 992 993 /* 994 * search the ordered extents for one corresponding to 'offset' and 995 * try to find a checksum. This is used because we allow pages to 996 * be reclaimed before their checksum is actually put into the btree 997 */ 998 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, 999 u32 *sum, int len) 1000 { 1001 struct btrfs_ordered_sum *ordered_sum; 1002 struct btrfs_ordered_extent *ordered; 1003 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree; 1004 unsigned long num_sectors; 1005 unsigned long i; 1006 u32 sectorsize = BTRFS_I(inode)->root->sectorsize; 1007 int index = 0; 1008 1009 ordered = btrfs_lookup_ordered_extent(inode, offset); 1010 if (!ordered) 1011 return 0; 1012 1013 spin_lock_irq(&tree->lock); 1014 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) { 1015 if (disk_bytenr >= ordered_sum->bytenr && 1016 disk_bytenr < ordered_sum->bytenr + ordered_sum->len) { 1017 i = (disk_bytenr - ordered_sum->bytenr) >> 1018 inode->i_sb->s_blocksize_bits; 1019 num_sectors = ordered_sum->len >> 1020 inode->i_sb->s_blocksize_bits; 1021 num_sectors = min_t(int, len - index, num_sectors - i); 1022 memcpy(sum + index, ordered_sum->sums + i, 1023 num_sectors); 1024 1025 index += (int)num_sectors; 1026 if (index == len) 1027 goto out; 1028 disk_bytenr += num_sectors * sectorsize; 1029 } 1030 } 1031 out: 1032 spin_unlock_irq(&tree->lock); 1033 btrfs_put_ordered_extent(ordered); 1034 return index; 1035 } 1036 1037 int __init ordered_data_init(void) 1038 { 1039 btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent", 1040 sizeof(struct btrfs_ordered_extent), 0, 1041 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, 1042 NULL); 1043 if (!btrfs_ordered_extent_cache) 1044 return -ENOMEM; 1045 1046 return 0; 1047 } 1048 1049 void ordered_data_exit(void) 1050 { 1051 if (btrfs_ordered_extent_cache) 1052 kmem_cache_destroy(btrfs_ordered_extent_cache); 1053 } 1054