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