1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2007 Oracle. All rights reserved. 4 */ 5 6 #include "ctree.h" 7 #include "fs.h" 8 #include "messages.h" 9 #include "inode-item.h" 10 #include "disk-io.h" 11 #include "transaction.h" 12 #include "space-info.h" 13 #include "accessors.h" 14 #include "extent-tree.h" 15 #include "file-item.h" 16 17 struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf, 18 int slot, 19 const struct fscrypt_str *name) 20 { 21 struct btrfs_inode_ref *ref; 22 unsigned long ptr; 23 unsigned long name_ptr; 24 u32 item_size; 25 u32 cur_offset = 0; 26 int len; 27 28 item_size = btrfs_item_size(leaf, slot); 29 ptr = btrfs_item_ptr_offset(leaf, slot); 30 while (cur_offset < item_size) { 31 ref = (struct btrfs_inode_ref *)(ptr + cur_offset); 32 len = btrfs_inode_ref_name_len(leaf, ref); 33 name_ptr = (unsigned long)(ref + 1); 34 cur_offset += len + sizeof(*ref); 35 if (len != name->len) 36 continue; 37 if (memcmp_extent_buffer(leaf, name->name, name_ptr, 38 name->len) == 0) 39 return ref; 40 } 41 return NULL; 42 } 43 44 struct btrfs_inode_extref *btrfs_find_name_in_ext_backref( 45 struct extent_buffer *leaf, int slot, u64 ref_objectid, 46 const struct fscrypt_str *name) 47 { 48 struct btrfs_inode_extref *extref; 49 unsigned long ptr; 50 unsigned long name_ptr; 51 u32 item_size; 52 u32 cur_offset = 0; 53 int ref_name_len; 54 55 item_size = btrfs_item_size(leaf, slot); 56 ptr = btrfs_item_ptr_offset(leaf, slot); 57 58 /* 59 * Search all extended backrefs in this item. We're only 60 * looking through any collisions so most of the time this is 61 * just going to compare against one buffer. If all is well, 62 * we'll return success and the inode ref object. 63 */ 64 while (cur_offset < item_size) { 65 extref = (struct btrfs_inode_extref *) (ptr + cur_offset); 66 name_ptr = (unsigned long)(&extref->name); 67 ref_name_len = btrfs_inode_extref_name_len(leaf, extref); 68 69 if (ref_name_len == name->len && 70 btrfs_inode_extref_parent(leaf, extref) == ref_objectid && 71 (memcmp_extent_buffer(leaf, name->name, name_ptr, 72 name->len) == 0)) 73 return extref; 74 75 cur_offset += ref_name_len + sizeof(*extref); 76 } 77 return NULL; 78 } 79 80 /* Returns NULL if no extref found */ 81 struct btrfs_inode_extref * 82 btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans, 83 struct btrfs_root *root, 84 struct btrfs_path *path, 85 const struct fscrypt_str *name, 86 u64 inode_objectid, u64 ref_objectid, int ins_len, 87 int cow) 88 { 89 int ret; 90 struct btrfs_key key; 91 92 key.objectid = inode_objectid; 93 key.type = BTRFS_INODE_EXTREF_KEY; 94 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len); 95 96 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); 97 if (ret < 0) 98 return ERR_PTR(ret); 99 if (ret > 0) 100 return NULL; 101 return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], 102 ref_objectid, name); 103 104 } 105 106 static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, 107 struct btrfs_root *root, 108 const struct fscrypt_str *name, 109 u64 inode_objectid, u64 ref_objectid, 110 u64 *index) 111 { 112 struct btrfs_path *path; 113 struct btrfs_key key; 114 struct btrfs_inode_extref *extref; 115 struct extent_buffer *leaf; 116 int ret; 117 int del_len = name->len + sizeof(*extref); 118 unsigned long ptr; 119 unsigned long item_start; 120 u32 item_size; 121 122 key.objectid = inode_objectid; 123 key.type = BTRFS_INODE_EXTREF_KEY; 124 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len); 125 126 path = btrfs_alloc_path(); 127 if (!path) 128 return -ENOMEM; 129 130 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 131 if (ret > 0) 132 ret = -ENOENT; 133 if (ret < 0) 134 goto out; 135 136 /* 137 * Sanity check - did we find the right item for this name? 138 * This should always succeed so error here will make the FS 139 * readonly. 140 */ 141 extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], 142 ref_objectid, name); 143 if (!extref) { 144 btrfs_abort_transaction(trans, -ENOENT); 145 ret = -ENOENT; 146 goto out; 147 } 148 149 leaf = path->nodes[0]; 150 item_size = btrfs_item_size(leaf, path->slots[0]); 151 if (index) 152 *index = btrfs_inode_extref_index(leaf, extref); 153 154 if (del_len == item_size) { 155 /* 156 * Common case only one ref in the item, remove the 157 * whole item. 158 */ 159 ret = btrfs_del_item(trans, root, path); 160 goto out; 161 } 162 163 ptr = (unsigned long)extref; 164 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); 165 166 memmove_extent_buffer(leaf, ptr, ptr + del_len, 167 item_size - (ptr + del_len - item_start)); 168 169 btrfs_truncate_item(trans, path, item_size - del_len, 1); 170 171 out: 172 btrfs_free_path(path); 173 174 return ret; 175 } 176 177 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans, 178 struct btrfs_root *root, const struct fscrypt_str *name, 179 u64 inode_objectid, u64 ref_objectid, u64 *index) 180 { 181 struct btrfs_path *path; 182 struct btrfs_key key; 183 struct btrfs_inode_ref *ref; 184 struct extent_buffer *leaf; 185 unsigned long ptr; 186 unsigned long item_start; 187 u32 item_size; 188 u32 sub_item_len; 189 int ret; 190 int search_ext_refs = 0; 191 int del_len = name->len + sizeof(*ref); 192 193 key.objectid = inode_objectid; 194 key.offset = ref_objectid; 195 key.type = BTRFS_INODE_REF_KEY; 196 197 path = btrfs_alloc_path(); 198 if (!path) 199 return -ENOMEM; 200 201 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 202 if (ret > 0) { 203 ret = -ENOENT; 204 search_ext_refs = 1; 205 goto out; 206 } else if (ret < 0) { 207 goto out; 208 } 209 210 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name); 211 if (!ref) { 212 ret = -ENOENT; 213 search_ext_refs = 1; 214 goto out; 215 } 216 leaf = path->nodes[0]; 217 item_size = btrfs_item_size(leaf, path->slots[0]); 218 219 if (index) 220 *index = btrfs_inode_ref_index(leaf, ref); 221 222 if (del_len == item_size) { 223 ret = btrfs_del_item(trans, root, path); 224 goto out; 225 } 226 ptr = (unsigned long)ref; 227 sub_item_len = name->len + sizeof(*ref); 228 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); 229 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len, 230 item_size - (ptr + sub_item_len - item_start)); 231 btrfs_truncate_item(trans, path, item_size - sub_item_len, 1); 232 out: 233 btrfs_free_path(path); 234 235 if (search_ext_refs) { 236 /* 237 * No refs were found, or we could not find the 238 * name in our ref array. Find and remove the extended 239 * inode ref then. 240 */ 241 return btrfs_del_inode_extref(trans, root, name, 242 inode_objectid, ref_objectid, index); 243 } 244 245 return ret; 246 } 247 248 /* 249 * Insert an extended inode ref into a tree. 250 * 251 * The caller must have checked against BTRFS_LINK_MAX already. 252 */ 253 static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans, 254 struct btrfs_root *root, 255 const struct fscrypt_str *name, 256 u64 inode_objectid, u64 ref_objectid, 257 u64 index) 258 { 259 struct btrfs_inode_extref *extref; 260 int ret; 261 int ins_len = name->len + sizeof(*extref); 262 unsigned long ptr; 263 struct btrfs_path *path; 264 struct btrfs_key key; 265 struct extent_buffer *leaf; 266 267 key.objectid = inode_objectid; 268 key.type = BTRFS_INODE_EXTREF_KEY; 269 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len); 270 271 path = btrfs_alloc_path(); 272 if (!path) 273 return -ENOMEM; 274 275 ret = btrfs_insert_empty_item(trans, root, path, &key, 276 ins_len); 277 if (ret == -EEXIST) { 278 if (btrfs_find_name_in_ext_backref(path->nodes[0], 279 path->slots[0], 280 ref_objectid, 281 name)) 282 goto out; 283 284 btrfs_extend_item(trans, path, ins_len); 285 ret = 0; 286 } 287 if (ret < 0) 288 goto out; 289 290 leaf = path->nodes[0]; 291 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char); 292 ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len; 293 extref = (struct btrfs_inode_extref *)ptr; 294 295 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len); 296 btrfs_set_inode_extref_index(path->nodes[0], extref, index); 297 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid); 298 299 ptr = (unsigned long)&extref->name; 300 write_extent_buffer(path->nodes[0], name->name, ptr, name->len); 301 btrfs_mark_buffer_dirty(trans, path->nodes[0]); 302 303 out: 304 btrfs_free_path(path); 305 return ret; 306 } 307 308 /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */ 309 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans, 310 struct btrfs_root *root, const struct fscrypt_str *name, 311 u64 inode_objectid, u64 ref_objectid, u64 index) 312 { 313 struct btrfs_fs_info *fs_info = root->fs_info; 314 struct btrfs_path *path; 315 struct btrfs_key key; 316 struct btrfs_inode_ref *ref; 317 unsigned long ptr; 318 int ret; 319 int ins_len = name->len + sizeof(*ref); 320 321 key.objectid = inode_objectid; 322 key.offset = ref_objectid; 323 key.type = BTRFS_INODE_REF_KEY; 324 325 path = btrfs_alloc_path(); 326 if (!path) 327 return -ENOMEM; 328 329 path->skip_release_on_error = 1; 330 ret = btrfs_insert_empty_item(trans, root, path, &key, 331 ins_len); 332 if (ret == -EEXIST) { 333 u32 old_size; 334 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], 335 name); 336 if (ref) 337 goto out; 338 339 old_size = btrfs_item_size(path->nodes[0], path->slots[0]); 340 btrfs_extend_item(trans, path, ins_len); 341 ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 342 struct btrfs_inode_ref); 343 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size); 344 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len); 345 btrfs_set_inode_ref_index(path->nodes[0], ref, index); 346 ptr = (unsigned long)(ref + 1); 347 ret = 0; 348 } else if (ret < 0) { 349 if (ret == -EOVERFLOW) { 350 if (btrfs_find_name_in_backref(path->nodes[0], 351 path->slots[0], 352 name)) 353 ret = -EEXIST; 354 else 355 ret = -EMLINK; 356 } 357 goto out; 358 } else { 359 ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 360 struct btrfs_inode_ref); 361 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len); 362 btrfs_set_inode_ref_index(path->nodes[0], ref, index); 363 ptr = (unsigned long)(ref + 1); 364 } 365 write_extent_buffer(path->nodes[0], name->name, ptr, name->len); 366 btrfs_mark_buffer_dirty(trans, path->nodes[0]); 367 368 out: 369 btrfs_free_path(path); 370 371 if (ret == -EMLINK) { 372 struct btrfs_super_block *disk_super = fs_info->super_copy; 373 /* We ran out of space in the ref array. Need to 374 * add an extended ref. */ 375 if (btrfs_super_incompat_flags(disk_super) 376 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF) 377 ret = btrfs_insert_inode_extref(trans, root, name, 378 inode_objectid, 379 ref_objectid, index); 380 } 381 382 return ret; 383 } 384 385 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans, 386 struct btrfs_root *root, 387 struct btrfs_path *path, u64 objectid) 388 { 389 struct btrfs_key key; 390 int ret; 391 key.objectid = objectid; 392 key.type = BTRFS_INODE_ITEM_KEY; 393 key.offset = 0; 394 395 ret = btrfs_insert_empty_item(trans, root, path, &key, 396 sizeof(struct btrfs_inode_item)); 397 return ret; 398 } 399 400 int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root 401 *root, struct btrfs_path *path, 402 struct btrfs_key *location, int mod) 403 { 404 int ins_len = mod < 0 ? -1 : 0; 405 int cow = mod != 0; 406 int ret; 407 int slot; 408 struct extent_buffer *leaf; 409 struct btrfs_key found_key; 410 411 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow); 412 if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY && 413 location->offset == (u64)-1 && path->slots[0] != 0) { 414 slot = path->slots[0] - 1; 415 leaf = path->nodes[0]; 416 btrfs_item_key_to_cpu(leaf, &found_key, slot); 417 if (found_key.objectid == location->objectid && 418 found_key.type == location->type) { 419 path->slots[0]--; 420 return 0; 421 } 422 } 423 return ret; 424 } 425 426 static inline void btrfs_trace_truncate(struct btrfs_inode *inode, 427 struct extent_buffer *leaf, 428 struct btrfs_file_extent_item *fi, 429 u64 offset, int extent_type, int slot) 430 { 431 if (!inode) 432 return; 433 if (extent_type == BTRFS_FILE_EXTENT_INLINE) 434 trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot, 435 offset); 436 else 437 trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset); 438 } 439 440 /* 441 * Remove inode items from a given root. 442 * 443 * @trans: A transaction handle. 444 * @root: The root from which to remove items. 445 * @inode: The inode whose items we want to remove. 446 * @control: The btrfs_truncate_control to control how and what we 447 * are truncating. 448 * 449 * Remove all keys associated with the inode from the given root that have a key 450 * with a type greater than or equals to @min_type. When @min_type has a value of 451 * BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value 452 * greater than or equals to @new_size. If a file extent item that starts before 453 * @new_size and ends after it is found, its length is adjusted. 454 * 455 * Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is 456 * BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block. 457 */ 458 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 459 struct btrfs_root *root, 460 struct btrfs_truncate_control *control) 461 { 462 struct btrfs_fs_info *fs_info = root->fs_info; 463 struct btrfs_path *path; 464 struct extent_buffer *leaf; 465 struct btrfs_file_extent_item *fi; 466 struct btrfs_key key; 467 struct btrfs_key found_key; 468 u64 new_size = control->new_size; 469 u64 extent_num_bytes = 0; 470 u64 extent_offset = 0; 471 u64 item_end = 0; 472 u32 found_type = (u8)-1; 473 int del_item; 474 int pending_del_nr = 0; 475 int pending_del_slot = 0; 476 int extent_type = -1; 477 int ret; 478 u64 bytes_deleted = 0; 479 bool be_nice = false; 480 481 ASSERT(control->inode || !control->clear_extent_range); 482 ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY); 483 484 control->last_size = new_size; 485 control->sub_bytes = 0; 486 487 /* 488 * For shareable roots we want to back off from time to time, this turns 489 * out to be subvolume roots, reloc roots, and data reloc roots. 490 */ 491 if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) 492 be_nice = true; 493 494 path = btrfs_alloc_path(); 495 if (!path) 496 return -ENOMEM; 497 path->reada = READA_BACK; 498 499 key.objectid = control->ino; 500 key.offset = (u64)-1; 501 key.type = (u8)-1; 502 503 search_again: 504 /* 505 * With a 16K leaf size and 128MiB extents, you can actually queue up a 506 * huge file in a single leaf. Most of the time that bytes_deleted is 507 * > 0, it will be huge by the time we get here 508 */ 509 if (be_nice && bytes_deleted > SZ_32M && 510 btrfs_should_end_transaction(trans)) { 511 ret = -EAGAIN; 512 goto out; 513 } 514 515 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 516 if (ret < 0) 517 goto out; 518 519 if (ret > 0) { 520 ret = 0; 521 /* There are no items in the tree for us to truncate, we're done */ 522 if (path->slots[0] == 0) 523 goto out; 524 path->slots[0]--; 525 } 526 527 while (1) { 528 u64 clear_start = 0, clear_len = 0, extent_start = 0; 529 bool refill_delayed_refs_rsv = false; 530 531 fi = NULL; 532 leaf = path->nodes[0]; 533 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 534 found_type = found_key.type; 535 536 if (found_key.objectid != control->ino) 537 break; 538 539 if (found_type < control->min_type) 540 break; 541 542 item_end = found_key.offset; 543 if (found_type == BTRFS_EXTENT_DATA_KEY) { 544 fi = btrfs_item_ptr(leaf, path->slots[0], 545 struct btrfs_file_extent_item); 546 extent_type = btrfs_file_extent_type(leaf, fi); 547 if (extent_type != BTRFS_FILE_EXTENT_INLINE) 548 item_end += 549 btrfs_file_extent_num_bytes(leaf, fi); 550 else if (extent_type == BTRFS_FILE_EXTENT_INLINE) 551 item_end += btrfs_file_extent_ram_bytes(leaf, fi); 552 553 btrfs_trace_truncate(control->inode, leaf, fi, 554 found_key.offset, extent_type, 555 path->slots[0]); 556 item_end--; 557 } 558 if (found_type > control->min_type) { 559 del_item = 1; 560 } else { 561 if (item_end < new_size) 562 break; 563 if (found_key.offset >= new_size) 564 del_item = 1; 565 else 566 del_item = 0; 567 } 568 569 /* FIXME, shrink the extent if the ref count is only 1 */ 570 if (found_type != BTRFS_EXTENT_DATA_KEY) 571 goto delete; 572 573 control->extents_found++; 574 575 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 576 u64 num_dec; 577 578 clear_start = found_key.offset; 579 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 580 if (!del_item) { 581 u64 orig_num_bytes = 582 btrfs_file_extent_num_bytes(leaf, fi); 583 extent_num_bytes = ALIGN(new_size - 584 found_key.offset, 585 fs_info->sectorsize); 586 clear_start = ALIGN(new_size, fs_info->sectorsize); 587 588 btrfs_set_file_extent_num_bytes(leaf, fi, 589 extent_num_bytes); 590 num_dec = (orig_num_bytes - extent_num_bytes); 591 if (extent_start != 0) 592 control->sub_bytes += num_dec; 593 btrfs_mark_buffer_dirty(trans, leaf); 594 } else { 595 extent_num_bytes = 596 btrfs_file_extent_disk_num_bytes(leaf, fi); 597 extent_offset = found_key.offset - 598 btrfs_file_extent_offset(leaf, fi); 599 600 /* FIXME blocksize != 4096 */ 601 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 602 if (extent_start != 0) 603 control->sub_bytes += num_dec; 604 } 605 clear_len = num_dec; 606 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 607 /* 608 * We can't truncate inline items that have had 609 * special encodings 610 */ 611 if (!del_item && 612 btrfs_file_extent_encryption(leaf, fi) == 0 && 613 btrfs_file_extent_other_encoding(leaf, fi) == 0 && 614 btrfs_file_extent_compression(leaf, fi) == 0) { 615 u32 size = (u32)(new_size - found_key.offset); 616 617 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 618 size = btrfs_file_extent_calc_inline_size(size); 619 btrfs_truncate_item(trans, path, size, 1); 620 } else if (!del_item) { 621 /* 622 * We have to bail so the last_size is set to 623 * just before this extent. 624 */ 625 ret = BTRFS_NEED_TRUNCATE_BLOCK; 626 break; 627 } else { 628 /* 629 * Inline extents are special, we just treat 630 * them as a full sector worth in the file 631 * extent tree just for simplicity sake. 632 */ 633 clear_len = fs_info->sectorsize; 634 } 635 636 control->sub_bytes += item_end + 1 - new_size; 637 } 638 delete: 639 /* 640 * We only want to clear the file extent range if we're 641 * modifying the actual inode's mapping, which is just the 642 * normal truncate path. 643 */ 644 if (control->clear_extent_range) { 645 ret = btrfs_inode_clear_file_extent_range(control->inode, 646 clear_start, clear_len); 647 if (ret) { 648 btrfs_abort_transaction(trans, ret); 649 break; 650 } 651 } 652 653 if (del_item) { 654 ASSERT(!pending_del_nr || 655 ((path->slots[0] + 1) == pending_del_slot)); 656 657 control->last_size = found_key.offset; 658 if (!pending_del_nr) { 659 /* No pending yet, add ourselves */ 660 pending_del_slot = path->slots[0]; 661 pending_del_nr = 1; 662 } else if (path->slots[0] + 1 == pending_del_slot) { 663 /* Hop on the pending chunk */ 664 pending_del_nr++; 665 pending_del_slot = path->slots[0]; 666 } 667 } else { 668 control->last_size = new_size; 669 break; 670 } 671 672 if (del_item && extent_start != 0 && !control->skip_ref_updates) { 673 struct btrfs_ref ref = { 674 .action = BTRFS_DROP_DELAYED_REF, 675 .bytenr = extent_start, 676 .num_bytes = extent_num_bytes, 677 .owning_root = btrfs_root_id(root), 678 .ref_root = btrfs_header_owner(leaf), 679 }; 680 681 bytes_deleted += extent_num_bytes; 682 683 btrfs_init_data_ref(&ref, control->ino, extent_offset, 684 btrfs_root_id(root), false); 685 ret = btrfs_free_extent(trans, &ref); 686 if (ret) { 687 btrfs_abort_transaction(trans, ret); 688 break; 689 } 690 if (be_nice && btrfs_check_space_for_delayed_refs(fs_info)) 691 refill_delayed_refs_rsv = true; 692 } 693 694 if (found_type == BTRFS_INODE_ITEM_KEY) 695 break; 696 697 if (path->slots[0] == 0 || 698 path->slots[0] != pending_del_slot || 699 refill_delayed_refs_rsv) { 700 if (pending_del_nr) { 701 ret = btrfs_del_items(trans, root, path, 702 pending_del_slot, 703 pending_del_nr); 704 if (ret) { 705 btrfs_abort_transaction(trans, ret); 706 break; 707 } 708 pending_del_nr = 0; 709 } 710 btrfs_release_path(path); 711 712 /* 713 * We can generate a lot of delayed refs, so we need to 714 * throttle every once and a while and make sure we're 715 * adding enough space to keep up with the work we are 716 * generating. Since we hold a transaction here we 717 * can't flush, and we don't want to FLUSH_LIMIT because 718 * we could have generated too many delayed refs to 719 * actually allocate, so just bail if we're short and 720 * let the normal reservation dance happen higher up. 721 */ 722 if (refill_delayed_refs_rsv) { 723 ret = btrfs_delayed_refs_rsv_refill(fs_info, 724 BTRFS_RESERVE_NO_FLUSH); 725 if (ret) { 726 ret = -EAGAIN; 727 break; 728 } 729 } 730 goto search_again; 731 } else { 732 path->slots[0]--; 733 } 734 } 735 out: 736 if (ret >= 0 && pending_del_nr) { 737 int err; 738 739 err = btrfs_del_items(trans, root, path, pending_del_slot, 740 pending_del_nr); 741 if (err) { 742 btrfs_abort_transaction(trans, err); 743 ret = err; 744 } 745 } 746 747 ASSERT(control->last_size >= new_size); 748 if (!ret && control->last_size > new_size) 749 control->last_size = new_size; 750 751 btrfs_free_path(path); 752 return ret; 753 } 754