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