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