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/bio.h> 20 #include <linux/slab.h> 21 #include <linux/pagemap.h> 22 #include <linux/highmem.h> 23 #include "ctree.h" 24 #include "disk-io.h" 25 #include "transaction.h" 26 #include "volumes.h" 27 #include "print-tree.h" 28 #include "compression.h" 29 30 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \ 31 sizeof(struct btrfs_item) * 2) / \ 32 size) - 1)) 33 34 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \ 35 PAGE_SIZE)) 36 37 #define MAX_ORDERED_SUM_BYTES(fs_info) ((PAGE_SIZE - \ 38 sizeof(struct btrfs_ordered_sum)) / \ 39 sizeof(u32) * (fs_info)->sectorsize) 40 41 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans, 42 struct btrfs_root *root, 43 u64 objectid, u64 pos, 44 u64 disk_offset, u64 disk_num_bytes, 45 u64 num_bytes, u64 offset, u64 ram_bytes, 46 u8 compression, u8 encryption, u16 other_encoding) 47 { 48 int ret = 0; 49 struct btrfs_file_extent_item *item; 50 struct btrfs_key file_key; 51 struct btrfs_path *path; 52 struct extent_buffer *leaf; 53 54 path = btrfs_alloc_path(); 55 if (!path) 56 return -ENOMEM; 57 file_key.objectid = objectid; 58 file_key.offset = pos; 59 file_key.type = BTRFS_EXTENT_DATA_KEY; 60 61 path->leave_spinning = 1; 62 ret = btrfs_insert_empty_item(trans, root, path, &file_key, 63 sizeof(*item)); 64 if (ret < 0) 65 goto out; 66 BUG_ON(ret); /* Can't happen */ 67 leaf = path->nodes[0]; 68 item = btrfs_item_ptr(leaf, path->slots[0], 69 struct btrfs_file_extent_item); 70 btrfs_set_file_extent_disk_bytenr(leaf, item, disk_offset); 71 btrfs_set_file_extent_disk_num_bytes(leaf, item, disk_num_bytes); 72 btrfs_set_file_extent_offset(leaf, item, offset); 73 btrfs_set_file_extent_num_bytes(leaf, item, num_bytes); 74 btrfs_set_file_extent_ram_bytes(leaf, item, ram_bytes); 75 btrfs_set_file_extent_generation(leaf, item, trans->transid); 76 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG); 77 btrfs_set_file_extent_compression(leaf, item, compression); 78 btrfs_set_file_extent_encryption(leaf, item, encryption); 79 btrfs_set_file_extent_other_encoding(leaf, item, other_encoding); 80 81 btrfs_mark_buffer_dirty(leaf); 82 out: 83 btrfs_free_path(path); 84 return ret; 85 } 86 87 static struct btrfs_csum_item * 88 btrfs_lookup_csum(struct btrfs_trans_handle *trans, 89 struct btrfs_root *root, 90 struct btrfs_path *path, 91 u64 bytenr, int cow) 92 { 93 struct btrfs_fs_info *fs_info = root->fs_info; 94 int ret; 95 struct btrfs_key file_key; 96 struct btrfs_key found_key; 97 struct btrfs_csum_item *item; 98 struct extent_buffer *leaf; 99 u64 csum_offset = 0; 100 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); 101 int csums_in_item; 102 103 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 104 file_key.offset = bytenr; 105 file_key.type = BTRFS_EXTENT_CSUM_KEY; 106 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow); 107 if (ret < 0) 108 goto fail; 109 leaf = path->nodes[0]; 110 if (ret > 0) { 111 ret = 1; 112 if (path->slots[0] == 0) 113 goto fail; 114 path->slots[0]--; 115 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 116 if (found_key.type != BTRFS_EXTENT_CSUM_KEY) 117 goto fail; 118 119 csum_offset = (bytenr - found_key.offset) >> 120 fs_info->sb->s_blocksize_bits; 121 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]); 122 csums_in_item /= csum_size; 123 124 if (csum_offset == csums_in_item) { 125 ret = -EFBIG; 126 goto fail; 127 } else if (csum_offset > csums_in_item) { 128 goto fail; 129 } 130 } 131 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); 132 item = (struct btrfs_csum_item *)((unsigned char *)item + 133 csum_offset * csum_size); 134 return item; 135 fail: 136 if (ret > 0) 137 ret = -ENOENT; 138 return ERR_PTR(ret); 139 } 140 141 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, 142 struct btrfs_root *root, 143 struct btrfs_path *path, u64 objectid, 144 u64 offset, int mod) 145 { 146 int ret; 147 struct btrfs_key file_key; 148 int ins_len = mod < 0 ? -1 : 0; 149 int cow = mod != 0; 150 151 file_key.objectid = objectid; 152 file_key.offset = offset; 153 file_key.type = BTRFS_EXTENT_DATA_KEY; 154 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow); 155 return ret; 156 } 157 158 static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio *bio, int err) 159 { 160 kfree(bio->csum_allocated); 161 } 162 163 static int __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, 164 u64 logical_offset, u32 *dst, int dio) 165 { 166 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 167 struct bio_vec *bvec; 168 struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio); 169 struct btrfs_csum_item *item = NULL; 170 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 171 struct btrfs_path *path; 172 u8 *csum; 173 u64 offset = 0; 174 u64 item_start_offset = 0; 175 u64 item_last_offset = 0; 176 u64 disk_bytenr; 177 u64 page_bytes_left; 178 u32 diff; 179 int nblocks; 180 int count = 0, i; 181 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); 182 183 path = btrfs_alloc_path(); 184 if (!path) 185 return -ENOMEM; 186 187 nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; 188 if (!dst) { 189 if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) { 190 btrfs_bio->csum_allocated = kmalloc_array(nblocks, 191 csum_size, GFP_NOFS); 192 if (!btrfs_bio->csum_allocated) { 193 btrfs_free_path(path); 194 return -ENOMEM; 195 } 196 btrfs_bio->csum = btrfs_bio->csum_allocated; 197 btrfs_bio->end_io = btrfs_io_bio_endio_readpage; 198 } else { 199 btrfs_bio->csum = btrfs_bio->csum_inline; 200 } 201 csum = btrfs_bio->csum; 202 } else { 203 csum = (u8 *)dst; 204 } 205 206 if (bio->bi_iter.bi_size > PAGE_SIZE * 8) 207 path->reada = READA_FORWARD; 208 209 WARN_ON(bio->bi_vcnt <= 0); 210 211 /* 212 * the free space stuff is only read when it hasn't been 213 * updated in the current transaction. So, we can safely 214 * read from the commit root and sidestep a nasty deadlock 215 * between reading the free space cache and updating the csum tree. 216 */ 217 if (btrfs_is_free_space_inode(BTRFS_I(inode))) { 218 path->search_commit_root = 1; 219 path->skip_locking = 1; 220 } 221 222 disk_bytenr = (u64)bio->bi_iter.bi_sector << 9; 223 if (dio) 224 offset = logical_offset; 225 226 bio_for_each_segment_all(bvec, bio, i) { 227 page_bytes_left = bvec->bv_len; 228 if (count) 229 goto next; 230 231 if (!dio) 232 offset = page_offset(bvec->bv_page) + bvec->bv_offset; 233 count = btrfs_find_ordered_sum(inode, offset, disk_bytenr, 234 (u32 *)csum, nblocks); 235 if (count) 236 goto found; 237 238 if (!item || disk_bytenr < item_start_offset || 239 disk_bytenr >= item_last_offset) { 240 struct btrfs_key found_key; 241 u32 item_size; 242 243 if (item) 244 btrfs_release_path(path); 245 item = btrfs_lookup_csum(NULL, fs_info->csum_root, 246 path, disk_bytenr, 0); 247 if (IS_ERR(item)) { 248 count = 1; 249 memset(csum, 0, csum_size); 250 if (BTRFS_I(inode)->root->root_key.objectid == 251 BTRFS_DATA_RELOC_TREE_OBJECTID) { 252 set_extent_bits(io_tree, offset, 253 offset + fs_info->sectorsize - 1, 254 EXTENT_NODATASUM); 255 } else { 256 btrfs_info_rl(fs_info, 257 "no csum found for inode %llu start %llu", 258 btrfs_ino(BTRFS_I(inode)), offset); 259 } 260 item = NULL; 261 btrfs_release_path(path); 262 goto found; 263 } 264 btrfs_item_key_to_cpu(path->nodes[0], &found_key, 265 path->slots[0]); 266 267 item_start_offset = found_key.offset; 268 item_size = btrfs_item_size_nr(path->nodes[0], 269 path->slots[0]); 270 item_last_offset = item_start_offset + 271 (item_size / csum_size) * 272 fs_info->sectorsize; 273 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 274 struct btrfs_csum_item); 275 } 276 /* 277 * this byte range must be able to fit inside 278 * a single leaf so it will also fit inside a u32 279 */ 280 diff = disk_bytenr - item_start_offset; 281 diff = diff / fs_info->sectorsize; 282 diff = diff * csum_size; 283 count = min_t(int, nblocks, (item_last_offset - disk_bytenr) >> 284 inode->i_sb->s_blocksize_bits); 285 read_extent_buffer(path->nodes[0], csum, 286 ((unsigned long)item) + diff, 287 csum_size * count); 288 found: 289 csum += count * csum_size; 290 nblocks -= count; 291 next: 292 while (count--) { 293 disk_bytenr += fs_info->sectorsize; 294 offset += fs_info->sectorsize; 295 page_bytes_left -= fs_info->sectorsize; 296 if (!page_bytes_left) 297 break; /* move to next bio */ 298 } 299 } 300 301 WARN_ON_ONCE(count); 302 btrfs_free_path(path); 303 return 0; 304 } 305 306 int btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u32 *dst) 307 { 308 return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0); 309 } 310 311 int btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio, u64 offset) 312 { 313 return __btrfs_lookup_bio_sums(inode, bio, offset, NULL, 1); 314 } 315 316 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end, 317 struct list_head *list, int search_commit) 318 { 319 struct btrfs_fs_info *fs_info = root->fs_info; 320 struct btrfs_key key; 321 struct btrfs_path *path; 322 struct extent_buffer *leaf; 323 struct btrfs_ordered_sum *sums; 324 struct btrfs_csum_item *item; 325 LIST_HEAD(tmplist); 326 unsigned long offset; 327 int ret; 328 size_t size; 329 u64 csum_end; 330 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); 331 332 ASSERT(IS_ALIGNED(start, fs_info->sectorsize) && 333 IS_ALIGNED(end + 1, fs_info->sectorsize)); 334 335 path = btrfs_alloc_path(); 336 if (!path) 337 return -ENOMEM; 338 339 if (search_commit) { 340 path->skip_locking = 1; 341 path->reada = READA_FORWARD; 342 path->search_commit_root = 1; 343 } 344 345 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 346 key.offset = start; 347 key.type = BTRFS_EXTENT_CSUM_KEY; 348 349 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 350 if (ret < 0) 351 goto fail; 352 if (ret > 0 && path->slots[0] > 0) { 353 leaf = path->nodes[0]; 354 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); 355 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID && 356 key.type == BTRFS_EXTENT_CSUM_KEY) { 357 offset = (start - key.offset) >> 358 fs_info->sb->s_blocksize_bits; 359 if (offset * csum_size < 360 btrfs_item_size_nr(leaf, path->slots[0] - 1)) 361 path->slots[0]--; 362 } 363 } 364 365 while (start <= end) { 366 leaf = path->nodes[0]; 367 if (path->slots[0] >= btrfs_header_nritems(leaf)) { 368 ret = btrfs_next_leaf(root, path); 369 if (ret < 0) 370 goto fail; 371 if (ret > 0) 372 break; 373 leaf = path->nodes[0]; 374 } 375 376 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 377 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || 378 key.type != BTRFS_EXTENT_CSUM_KEY || 379 key.offset > end) 380 break; 381 382 if (key.offset > start) 383 start = key.offset; 384 385 size = btrfs_item_size_nr(leaf, path->slots[0]); 386 csum_end = key.offset + (size / csum_size) * fs_info->sectorsize; 387 if (csum_end <= start) { 388 path->slots[0]++; 389 continue; 390 } 391 392 csum_end = min(csum_end, end + 1); 393 item = btrfs_item_ptr(path->nodes[0], path->slots[0], 394 struct btrfs_csum_item); 395 while (start < csum_end) { 396 size = min_t(size_t, csum_end - start, 397 MAX_ORDERED_SUM_BYTES(fs_info)); 398 sums = kzalloc(btrfs_ordered_sum_size(fs_info, size), 399 GFP_NOFS); 400 if (!sums) { 401 ret = -ENOMEM; 402 goto fail; 403 } 404 405 sums->bytenr = start; 406 sums->len = (int)size; 407 408 offset = (start - key.offset) >> 409 fs_info->sb->s_blocksize_bits; 410 offset *= csum_size; 411 size >>= fs_info->sb->s_blocksize_bits; 412 413 read_extent_buffer(path->nodes[0], 414 sums->sums, 415 ((unsigned long)item) + offset, 416 csum_size * size); 417 418 start += fs_info->sectorsize * size; 419 list_add_tail(&sums->list, &tmplist); 420 } 421 path->slots[0]++; 422 } 423 ret = 0; 424 fail: 425 while (ret < 0 && !list_empty(&tmplist)) { 426 sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list); 427 list_del(&sums->list); 428 kfree(sums); 429 } 430 list_splice_tail(&tmplist, list); 431 432 btrfs_free_path(path); 433 return ret; 434 } 435 436 int btrfs_csum_one_bio(struct inode *inode, struct bio *bio, 437 u64 file_start, int contig) 438 { 439 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); 440 struct btrfs_ordered_sum *sums; 441 struct btrfs_ordered_extent *ordered = NULL; 442 char *data; 443 struct bio_vec *bvec; 444 int index; 445 int nr_sectors; 446 int i, j; 447 unsigned long total_bytes = 0; 448 unsigned long this_sum_bytes = 0; 449 u64 offset; 450 451 WARN_ON(bio->bi_vcnt <= 0); 452 sums = kzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size), 453 GFP_NOFS); 454 if (!sums) 455 return -ENOMEM; 456 457 sums->len = bio->bi_iter.bi_size; 458 INIT_LIST_HEAD(&sums->list); 459 460 if (contig) 461 offset = file_start; 462 else 463 offset = 0; /* shut up gcc */ 464 465 sums->bytenr = (u64)bio->bi_iter.bi_sector << 9; 466 index = 0; 467 468 bio_for_each_segment_all(bvec, bio, j) { 469 if (!contig) 470 offset = page_offset(bvec->bv_page) + bvec->bv_offset; 471 472 if (!ordered) { 473 ordered = btrfs_lookup_ordered_extent(inode, offset); 474 BUG_ON(!ordered); /* Logic error */ 475 } 476 477 data = kmap_atomic(bvec->bv_page); 478 479 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, 480 bvec->bv_len + fs_info->sectorsize 481 - 1); 482 483 for (i = 0; i < nr_sectors; i++) { 484 if (offset >= ordered->file_offset + ordered->len || 485 offset < ordered->file_offset) { 486 unsigned long bytes_left; 487 488 kunmap_atomic(data); 489 sums->len = this_sum_bytes; 490 this_sum_bytes = 0; 491 btrfs_add_ordered_sum(inode, ordered, sums); 492 btrfs_put_ordered_extent(ordered); 493 494 bytes_left = bio->bi_iter.bi_size - total_bytes; 495 496 sums = kzalloc(btrfs_ordered_sum_size(fs_info, bytes_left), 497 GFP_NOFS); 498 BUG_ON(!sums); /* -ENOMEM */ 499 sums->len = bytes_left; 500 ordered = btrfs_lookup_ordered_extent(inode, 501 offset); 502 ASSERT(ordered); /* Logic error */ 503 sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9) 504 + total_bytes; 505 index = 0; 506 507 data = kmap_atomic(bvec->bv_page); 508 } 509 510 sums->sums[index] = ~(u32)0; 511 sums->sums[index] 512 = btrfs_csum_data(data + bvec->bv_offset 513 + (i * fs_info->sectorsize), 514 sums->sums[index], 515 fs_info->sectorsize); 516 btrfs_csum_final(sums->sums[index], 517 (char *)(sums->sums + index)); 518 index++; 519 offset += fs_info->sectorsize; 520 this_sum_bytes += fs_info->sectorsize; 521 total_bytes += fs_info->sectorsize; 522 } 523 524 kunmap_atomic(data); 525 } 526 this_sum_bytes = 0; 527 btrfs_add_ordered_sum(inode, ordered, sums); 528 btrfs_put_ordered_extent(ordered); 529 return 0; 530 } 531 532 /* 533 * helper function for csum removal, this expects the 534 * key to describe the csum pointed to by the path, and it expects 535 * the csum to overlap the range [bytenr, len] 536 * 537 * The csum should not be entirely contained in the range and the 538 * range should not be entirely contained in the csum. 539 * 540 * This calls btrfs_truncate_item with the correct args based on the 541 * overlap, and fixes up the key as required. 542 */ 543 static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info, 544 struct btrfs_path *path, 545 struct btrfs_key *key, 546 u64 bytenr, u64 len) 547 { 548 struct extent_buffer *leaf; 549 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); 550 u64 csum_end; 551 u64 end_byte = bytenr + len; 552 u32 blocksize_bits = fs_info->sb->s_blocksize_bits; 553 554 leaf = path->nodes[0]; 555 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; 556 csum_end <<= fs_info->sb->s_blocksize_bits; 557 csum_end += key->offset; 558 559 if (key->offset < bytenr && csum_end <= end_byte) { 560 /* 561 * [ bytenr - len ] 562 * [ ] 563 * [csum ] 564 * A simple truncate off the end of the item 565 */ 566 u32 new_size = (bytenr - key->offset) >> blocksize_bits; 567 new_size *= csum_size; 568 btrfs_truncate_item(fs_info, path, new_size, 1); 569 } else if (key->offset >= bytenr && csum_end > end_byte && 570 end_byte > key->offset) { 571 /* 572 * [ bytenr - len ] 573 * [ ] 574 * [csum ] 575 * we need to truncate from the beginning of the csum 576 */ 577 u32 new_size = (csum_end - end_byte) >> blocksize_bits; 578 new_size *= csum_size; 579 580 btrfs_truncate_item(fs_info, path, new_size, 0); 581 582 key->offset = end_byte; 583 btrfs_set_item_key_safe(fs_info, path, key); 584 } else { 585 BUG(); 586 } 587 } 588 589 /* 590 * deletes the csum items from the csum tree for a given 591 * range of bytes. 592 */ 593 int btrfs_del_csums(struct btrfs_trans_handle *trans, 594 struct btrfs_fs_info *fs_info, u64 bytenr, u64 len) 595 { 596 struct btrfs_root *root = fs_info->csum_root; 597 struct btrfs_path *path; 598 struct btrfs_key key; 599 u64 end_byte = bytenr + len; 600 u64 csum_end; 601 struct extent_buffer *leaf; 602 int ret; 603 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); 604 int blocksize_bits = fs_info->sb->s_blocksize_bits; 605 606 path = btrfs_alloc_path(); 607 if (!path) 608 return -ENOMEM; 609 610 while (1) { 611 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 612 key.offset = end_byte - 1; 613 key.type = BTRFS_EXTENT_CSUM_KEY; 614 615 path->leave_spinning = 1; 616 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 617 if (ret > 0) { 618 if (path->slots[0] == 0) 619 break; 620 path->slots[0]--; 621 } else if (ret < 0) { 622 break; 623 } 624 625 leaf = path->nodes[0]; 626 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 627 628 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || 629 key.type != BTRFS_EXTENT_CSUM_KEY) { 630 break; 631 } 632 633 if (key.offset >= end_byte) 634 break; 635 636 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size; 637 csum_end <<= blocksize_bits; 638 csum_end += key.offset; 639 640 /* this csum ends before we start, we're done */ 641 if (csum_end <= bytenr) 642 break; 643 644 /* delete the entire item, it is inside our range */ 645 if (key.offset >= bytenr && csum_end <= end_byte) { 646 int del_nr = 1; 647 648 /* 649 * Check how many csum items preceding this one in this 650 * leaf correspond to our range and then delete them all 651 * at once. 652 */ 653 if (key.offset > bytenr && path->slots[0] > 0) { 654 int slot = path->slots[0] - 1; 655 656 while (slot >= 0) { 657 struct btrfs_key pk; 658 659 btrfs_item_key_to_cpu(leaf, &pk, slot); 660 if (pk.offset < bytenr || 661 pk.type != BTRFS_EXTENT_CSUM_KEY || 662 pk.objectid != 663 BTRFS_EXTENT_CSUM_OBJECTID) 664 break; 665 path->slots[0] = slot; 666 del_nr++; 667 key.offset = pk.offset; 668 slot--; 669 } 670 } 671 ret = btrfs_del_items(trans, root, path, 672 path->slots[0], del_nr); 673 if (ret) 674 goto out; 675 if (key.offset == bytenr) 676 break; 677 } else if (key.offset < bytenr && csum_end > end_byte) { 678 unsigned long offset; 679 unsigned long shift_len; 680 unsigned long item_offset; 681 /* 682 * [ bytenr - len ] 683 * [csum ] 684 * 685 * Our bytes are in the middle of the csum, 686 * we need to split this item and insert a new one. 687 * 688 * But we can't drop the path because the 689 * csum could change, get removed, extended etc. 690 * 691 * The trick here is the max size of a csum item leaves 692 * enough room in the tree block for a single 693 * item header. So, we split the item in place, 694 * adding a new header pointing to the existing 695 * bytes. Then we loop around again and we have 696 * a nicely formed csum item that we can neatly 697 * truncate. 698 */ 699 offset = (bytenr - key.offset) >> blocksize_bits; 700 offset *= csum_size; 701 702 shift_len = (len >> blocksize_bits) * csum_size; 703 704 item_offset = btrfs_item_ptr_offset(leaf, 705 path->slots[0]); 706 707 memzero_extent_buffer(leaf, item_offset + offset, 708 shift_len); 709 key.offset = bytenr; 710 711 /* 712 * btrfs_split_item returns -EAGAIN when the 713 * item changed size or key 714 */ 715 ret = btrfs_split_item(trans, root, path, &key, offset); 716 if (ret && ret != -EAGAIN) { 717 btrfs_abort_transaction(trans, ret); 718 goto out; 719 } 720 721 key.offset = end_byte - 1; 722 } else { 723 truncate_one_csum(fs_info, path, &key, bytenr, len); 724 if (key.offset < bytenr) 725 break; 726 } 727 btrfs_release_path(path); 728 } 729 ret = 0; 730 out: 731 btrfs_free_path(path); 732 return ret; 733 } 734 735 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, 736 struct btrfs_root *root, 737 struct btrfs_ordered_sum *sums) 738 { 739 struct btrfs_fs_info *fs_info = root->fs_info; 740 struct btrfs_key file_key; 741 struct btrfs_key found_key; 742 struct btrfs_path *path; 743 struct btrfs_csum_item *item; 744 struct btrfs_csum_item *item_end; 745 struct extent_buffer *leaf = NULL; 746 u64 next_offset; 747 u64 total_bytes = 0; 748 u64 csum_offset; 749 u64 bytenr; 750 u32 nritems; 751 u32 ins_size; 752 int index = 0; 753 int found_next; 754 int ret; 755 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); 756 757 path = btrfs_alloc_path(); 758 if (!path) 759 return -ENOMEM; 760 again: 761 next_offset = (u64)-1; 762 found_next = 0; 763 bytenr = sums->bytenr + total_bytes; 764 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID; 765 file_key.offset = bytenr; 766 file_key.type = BTRFS_EXTENT_CSUM_KEY; 767 768 item = btrfs_lookup_csum(trans, root, path, bytenr, 1); 769 if (!IS_ERR(item)) { 770 ret = 0; 771 leaf = path->nodes[0]; 772 item_end = btrfs_item_ptr(leaf, path->slots[0], 773 struct btrfs_csum_item); 774 item_end = (struct btrfs_csum_item *)((char *)item_end + 775 btrfs_item_size_nr(leaf, path->slots[0])); 776 goto found; 777 } 778 ret = PTR_ERR(item); 779 if (ret != -EFBIG && ret != -ENOENT) 780 goto fail_unlock; 781 782 if (ret == -EFBIG) { 783 u32 item_size; 784 /* we found one, but it isn't big enough yet */ 785 leaf = path->nodes[0]; 786 item_size = btrfs_item_size_nr(leaf, path->slots[0]); 787 if ((item_size / csum_size) >= 788 MAX_CSUM_ITEMS(fs_info, csum_size)) { 789 /* already at max size, make a new one */ 790 goto insert; 791 } 792 } else { 793 int slot = path->slots[0] + 1; 794 /* we didn't find a csum item, insert one */ 795 nritems = btrfs_header_nritems(path->nodes[0]); 796 if (!nritems || (path->slots[0] >= nritems - 1)) { 797 ret = btrfs_next_leaf(root, path); 798 if (ret == 1) 799 found_next = 1; 800 if (ret != 0) 801 goto insert; 802 slot = path->slots[0]; 803 } 804 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot); 805 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || 806 found_key.type != BTRFS_EXTENT_CSUM_KEY) { 807 found_next = 1; 808 goto insert; 809 } 810 next_offset = found_key.offset; 811 found_next = 1; 812 goto insert; 813 } 814 815 /* 816 * at this point, we know the tree has an item, but it isn't big 817 * enough yet to put our csum in. Grow it 818 */ 819 btrfs_release_path(path); 820 ret = btrfs_search_slot(trans, root, &file_key, path, 821 csum_size, 1); 822 if (ret < 0) 823 goto fail_unlock; 824 825 if (ret > 0) { 826 if (path->slots[0] == 0) 827 goto insert; 828 path->slots[0]--; 829 } 830 831 leaf = path->nodes[0]; 832 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 833 csum_offset = (bytenr - found_key.offset) >> 834 fs_info->sb->s_blocksize_bits; 835 836 if (found_key.type != BTRFS_EXTENT_CSUM_KEY || 837 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID || 838 csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) { 839 goto insert; 840 } 841 842 if (csum_offset == btrfs_item_size_nr(leaf, path->slots[0]) / 843 csum_size) { 844 int extend_nr; 845 u64 tmp; 846 u32 diff; 847 u32 free_space; 848 849 if (btrfs_leaf_free_space(fs_info, leaf) < 850 sizeof(struct btrfs_item) + csum_size * 2) 851 goto insert; 852 853 free_space = btrfs_leaf_free_space(fs_info, leaf) - 854 sizeof(struct btrfs_item) - csum_size; 855 tmp = sums->len - total_bytes; 856 tmp >>= fs_info->sb->s_blocksize_bits; 857 WARN_ON(tmp < 1); 858 859 extend_nr = max_t(int, 1, (int)tmp); 860 diff = (csum_offset + extend_nr) * csum_size; 861 diff = min(diff, 862 MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size); 863 864 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]); 865 diff = min(free_space, diff); 866 diff /= csum_size; 867 diff *= csum_size; 868 869 btrfs_extend_item(fs_info, path, diff); 870 ret = 0; 871 goto csum; 872 } 873 874 insert: 875 btrfs_release_path(path); 876 csum_offset = 0; 877 if (found_next) { 878 u64 tmp; 879 880 tmp = sums->len - total_bytes; 881 tmp >>= fs_info->sb->s_blocksize_bits; 882 tmp = min(tmp, (next_offset - file_key.offset) >> 883 fs_info->sb->s_blocksize_bits); 884 885 tmp = max_t(u64, 1, tmp); 886 tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size)); 887 ins_size = csum_size * tmp; 888 } else { 889 ins_size = csum_size; 890 } 891 path->leave_spinning = 1; 892 ret = btrfs_insert_empty_item(trans, root, path, &file_key, 893 ins_size); 894 path->leave_spinning = 0; 895 if (ret < 0) 896 goto fail_unlock; 897 if (WARN_ON(ret != 0)) 898 goto fail_unlock; 899 leaf = path->nodes[0]; 900 csum: 901 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); 902 item_end = (struct btrfs_csum_item *)((unsigned char *)item + 903 btrfs_item_size_nr(leaf, path->slots[0])); 904 item = (struct btrfs_csum_item *)((unsigned char *)item + 905 csum_offset * csum_size); 906 found: 907 ins_size = (u32)(sums->len - total_bytes) >> 908 fs_info->sb->s_blocksize_bits; 909 ins_size *= csum_size; 910 ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item, 911 ins_size); 912 write_extent_buffer(leaf, sums->sums + index, (unsigned long)item, 913 ins_size); 914 915 ins_size /= csum_size; 916 total_bytes += ins_size * fs_info->sectorsize; 917 index += ins_size; 918 919 btrfs_mark_buffer_dirty(path->nodes[0]); 920 if (total_bytes < sums->len) { 921 btrfs_release_path(path); 922 cond_resched(); 923 goto again; 924 } 925 out: 926 btrfs_free_path(path); 927 return ret; 928 929 fail_unlock: 930 goto out; 931 } 932 933 void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode, 934 const struct btrfs_path *path, 935 struct btrfs_file_extent_item *fi, 936 const bool new_inline, 937 struct extent_map *em) 938 { 939 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb); 940 struct btrfs_root *root = inode->root; 941 struct extent_buffer *leaf = path->nodes[0]; 942 const int slot = path->slots[0]; 943 struct btrfs_key key; 944 u64 extent_start, extent_end; 945 u64 bytenr; 946 u8 type = btrfs_file_extent_type(leaf, fi); 947 int compress_type = btrfs_file_extent_compression(leaf, fi); 948 949 em->bdev = fs_info->fs_devices->latest_bdev; 950 btrfs_item_key_to_cpu(leaf, &key, slot); 951 extent_start = key.offset; 952 953 if (type == BTRFS_FILE_EXTENT_REG || 954 type == BTRFS_FILE_EXTENT_PREALLOC) { 955 extent_end = extent_start + 956 btrfs_file_extent_num_bytes(leaf, fi); 957 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 958 size_t size; 959 size = btrfs_file_extent_inline_len(leaf, slot, fi); 960 extent_end = ALIGN(extent_start + size, 961 fs_info->sectorsize); 962 } 963 964 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); 965 if (type == BTRFS_FILE_EXTENT_REG || 966 type == BTRFS_FILE_EXTENT_PREALLOC) { 967 em->start = extent_start; 968 em->len = extent_end - extent_start; 969 em->orig_start = extent_start - 970 btrfs_file_extent_offset(leaf, fi); 971 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); 972 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 973 if (bytenr == 0) { 974 em->block_start = EXTENT_MAP_HOLE; 975 return; 976 } 977 if (compress_type != BTRFS_COMPRESS_NONE) { 978 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 979 em->compress_type = compress_type; 980 em->block_start = bytenr; 981 em->block_len = em->orig_block_len; 982 } else { 983 bytenr += btrfs_file_extent_offset(leaf, fi); 984 em->block_start = bytenr; 985 em->block_len = em->len; 986 if (type == BTRFS_FILE_EXTENT_PREALLOC) 987 set_bit(EXTENT_FLAG_PREALLOC, &em->flags); 988 } 989 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 990 em->block_start = EXTENT_MAP_INLINE; 991 em->start = extent_start; 992 em->len = extent_end - extent_start; 993 /* 994 * Initialize orig_start and block_len with the same values 995 * as in inode.c:btrfs_get_extent(). 996 */ 997 em->orig_start = EXTENT_MAP_HOLE; 998 em->block_len = (u64)-1; 999 if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) { 1000 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); 1001 em->compress_type = compress_type; 1002 } 1003 } else { 1004 btrfs_err(fs_info, 1005 "unknown file extent item type %d, inode %llu, offset %llu, " 1006 "root %llu", type, btrfs_ino(inode), extent_start, 1007 root->root_key.objectid); 1008 } 1009 } 1010