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/fs.h> 20 #include <linux/pagemap.h> 21 #include <linux/highmem.h> 22 #include <linux/time.h> 23 #include <linux/init.h> 24 #include <linux/string.h> 25 #include <linux/smp_lock.h> 26 #include <linux/backing-dev.h> 27 #include <linux/mpage.h> 28 #include <linux/swap.h> 29 #include <linux/writeback.h> 30 #include <linux/statfs.h> 31 #include <linux/compat.h> 32 #include <linux/version.h> 33 #include "ctree.h" 34 #include "disk-io.h" 35 #include "transaction.h" 36 #include "btrfs_inode.h" 37 #include "ioctl.h" 38 #include "print-tree.h" 39 #include "tree-log.h" 40 #include "locking.h" 41 #include "compat.h" 42 43 44 static int noinline btrfs_copy_from_user(loff_t pos, int num_pages, 45 int write_bytes, 46 struct page **prepared_pages, 47 const char __user * buf) 48 { 49 long page_fault = 0; 50 int i; 51 int offset = pos & (PAGE_CACHE_SIZE - 1); 52 53 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { 54 size_t count = min_t(size_t, 55 PAGE_CACHE_SIZE - offset, write_bytes); 56 struct page *page = prepared_pages[i]; 57 fault_in_pages_readable(buf, count); 58 59 /* Copy data from userspace to the current page */ 60 kmap(page); 61 page_fault = __copy_from_user(page_address(page) + offset, 62 buf, count); 63 /* Flush processor's dcache for this page */ 64 flush_dcache_page(page); 65 kunmap(page); 66 buf += count; 67 write_bytes -= count; 68 69 if (page_fault) 70 break; 71 } 72 return page_fault ? -EFAULT : 0; 73 } 74 75 static void noinline btrfs_drop_pages(struct page **pages, size_t num_pages) 76 { 77 size_t i; 78 for (i = 0; i < num_pages; i++) { 79 if (!pages[i]) 80 break; 81 ClearPageChecked(pages[i]); 82 unlock_page(pages[i]); 83 mark_page_accessed(pages[i]); 84 page_cache_release(pages[i]); 85 } 86 } 87 88 static int noinline insert_inline_extent(struct btrfs_trans_handle *trans, 89 struct btrfs_root *root, struct inode *inode, 90 u64 offset, size_t size, 91 struct page **pages, size_t page_offset, 92 int num_pages) 93 { 94 struct btrfs_key key; 95 struct btrfs_path *path; 96 struct extent_buffer *leaf; 97 char *kaddr; 98 unsigned long ptr; 99 struct btrfs_file_extent_item *ei; 100 struct page *page; 101 u32 datasize; 102 int err = 0; 103 int ret; 104 int i; 105 ssize_t cur_size; 106 107 path = btrfs_alloc_path(); 108 if (!path) 109 return -ENOMEM; 110 111 btrfs_set_trans_block_group(trans, inode); 112 113 key.objectid = inode->i_ino; 114 key.offset = offset; 115 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); 116 117 ret = btrfs_search_slot(trans, root, &key, path, 0, 1); 118 if (ret < 0) { 119 err = ret; 120 goto fail; 121 } 122 if (ret == 1) { 123 struct btrfs_key found_key; 124 125 if (path->slots[0] == 0) 126 goto insert; 127 128 path->slots[0]--; 129 leaf = path->nodes[0]; 130 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 131 132 if (found_key.objectid != inode->i_ino) 133 goto insert; 134 135 if (found_key.type != BTRFS_EXTENT_DATA_KEY) 136 goto insert; 137 ei = btrfs_item_ptr(leaf, path->slots[0], 138 struct btrfs_file_extent_item); 139 140 if (btrfs_file_extent_type(leaf, ei) != 141 BTRFS_FILE_EXTENT_INLINE) { 142 goto insert; 143 } 144 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 145 ret = 0; 146 } 147 if (ret == 0) { 148 u32 found_size; 149 u64 found_end; 150 151 leaf = path->nodes[0]; 152 ei = btrfs_item_ptr(leaf, path->slots[0], 153 struct btrfs_file_extent_item); 154 155 if (btrfs_file_extent_type(leaf, ei) != 156 BTRFS_FILE_EXTENT_INLINE) { 157 err = ret; 158 btrfs_print_leaf(root, leaf); 159 printk("found wasn't inline offset %Lu inode %lu\n", 160 offset, inode->i_ino); 161 goto fail; 162 } 163 found_size = btrfs_file_extent_inline_len(leaf, 164 btrfs_item_nr(leaf, path->slots[0])); 165 found_end = key.offset + found_size; 166 167 if (found_end < offset + size) { 168 btrfs_release_path(root, path); 169 ret = btrfs_search_slot(trans, root, &key, path, 170 offset + size - found_end, 1); 171 BUG_ON(ret != 0); 172 173 ret = btrfs_extend_item(trans, root, path, 174 offset + size - found_end); 175 if (ret) { 176 err = ret; 177 goto fail; 178 } 179 leaf = path->nodes[0]; 180 ei = btrfs_item_ptr(leaf, path->slots[0], 181 struct btrfs_file_extent_item); 182 inode->i_blocks += (offset + size - found_end) >> 9; 183 } 184 if (found_end < offset) { 185 ptr = btrfs_file_extent_inline_start(ei) + found_size; 186 memset_extent_buffer(leaf, 0, ptr, offset - found_end); 187 } 188 } else { 189 insert: 190 btrfs_release_path(root, path); 191 datasize = offset + size - key.offset; 192 inode->i_blocks += datasize >> 9; 193 datasize = btrfs_file_extent_calc_inline_size(datasize); 194 ret = btrfs_insert_empty_item(trans, root, path, &key, 195 datasize); 196 if (ret) { 197 err = ret; 198 printk("got bad ret %d\n", ret); 199 goto fail; 200 } 201 leaf = path->nodes[0]; 202 ei = btrfs_item_ptr(leaf, path->slots[0], 203 struct btrfs_file_extent_item); 204 btrfs_set_file_extent_generation(leaf, ei, trans->transid); 205 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); 206 } 207 ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset; 208 209 cur_size = size; 210 i = 0; 211 while (size > 0) { 212 page = pages[i]; 213 kaddr = kmap_atomic(page, KM_USER0); 214 cur_size = min_t(size_t, PAGE_CACHE_SIZE - page_offset, size); 215 write_extent_buffer(leaf, kaddr + page_offset, ptr, cur_size); 216 kunmap_atomic(kaddr, KM_USER0); 217 page_offset = 0; 218 ptr += cur_size; 219 size -= cur_size; 220 if (i >= num_pages) { 221 printk("i %d num_pages %d\n", i, num_pages); 222 } 223 i++; 224 } 225 btrfs_mark_buffer_dirty(leaf); 226 fail: 227 btrfs_free_path(path); 228 return err; 229 } 230 231 static int noinline dirty_and_release_pages(struct btrfs_trans_handle *trans, 232 struct btrfs_root *root, 233 struct file *file, 234 struct page **pages, 235 size_t num_pages, 236 loff_t pos, 237 size_t write_bytes) 238 { 239 int err = 0; 240 int i; 241 struct inode *inode = fdentry(file)->d_inode; 242 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 243 u64 hint_byte; 244 u64 num_bytes; 245 u64 start_pos; 246 u64 end_of_last_block; 247 u64 end_pos = pos + write_bytes; 248 u64 inline_size; 249 int did_inline = 0; 250 loff_t isize = i_size_read(inode); 251 252 start_pos = pos & ~((u64)root->sectorsize - 1); 253 num_bytes = (write_bytes + pos - start_pos + 254 root->sectorsize - 1) & ~((u64)root->sectorsize - 1); 255 256 end_of_last_block = start_pos + num_bytes - 1; 257 258 lock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS); 259 trans = btrfs_join_transaction(root, 1); 260 if (!trans) { 261 err = -ENOMEM; 262 goto out_unlock; 263 } 264 btrfs_set_trans_block_group(trans, inode); 265 hint_byte = 0; 266 267 if ((end_of_last_block & 4095) == 0) { 268 printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block); 269 } 270 set_extent_uptodate(io_tree, start_pos, end_of_last_block, GFP_NOFS); 271 272 /* FIXME...EIEIO, ENOSPC and more */ 273 /* insert any holes we need to create */ 274 if (isize < start_pos) { 275 u64 last_pos_in_file; 276 u64 hole_size; 277 u64 mask = root->sectorsize - 1; 278 last_pos_in_file = (isize + mask) & ~mask; 279 hole_size = (start_pos - last_pos_in_file + mask) & ~mask; 280 if (hole_size > 0) { 281 btrfs_wait_ordered_range(inode, last_pos_in_file, 282 last_pos_in_file + hole_size); 283 mutex_lock(&BTRFS_I(inode)->extent_mutex); 284 err = btrfs_drop_extents(trans, root, inode, 285 last_pos_in_file, 286 last_pos_in_file + hole_size, 287 last_pos_in_file, 288 &hint_byte); 289 if (err) 290 goto failed; 291 292 err = btrfs_insert_file_extent(trans, root, 293 inode->i_ino, 294 last_pos_in_file, 295 0, 0, hole_size, 0); 296 btrfs_drop_extent_cache(inode, last_pos_in_file, 297 last_pos_in_file + hole_size -1); 298 mutex_unlock(&BTRFS_I(inode)->extent_mutex); 299 btrfs_check_file(root, inode); 300 } 301 if (err) 302 goto failed; 303 } 304 305 /* 306 * either allocate an extent for the new bytes or setup the key 307 * to show we are doing inline data in the extent 308 */ 309 inline_size = end_pos; 310 if (isize >= BTRFS_MAX_INLINE_DATA_SIZE(root) || 311 inline_size > root->fs_info->max_inline || 312 (inline_size & (root->sectorsize -1)) == 0 || 313 inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root)) { 314 /* check for reserved extents on each page, we don't want 315 * to reset the delalloc bit on things that already have 316 * extents reserved. 317 */ 318 btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block); 319 for (i = 0; i < num_pages; i++) { 320 struct page *p = pages[i]; 321 SetPageUptodate(p); 322 ClearPageChecked(p); 323 set_page_dirty(p); 324 } 325 } else { 326 u64 aligned_end; 327 /* step one, delete the existing extents in this range */ 328 aligned_end = (pos + write_bytes + root->sectorsize - 1) & 329 ~((u64)root->sectorsize - 1); 330 mutex_lock(&BTRFS_I(inode)->extent_mutex); 331 err = btrfs_drop_extents(trans, root, inode, start_pos, 332 aligned_end, aligned_end, &hint_byte); 333 if (err) 334 goto failed; 335 if (isize > inline_size) 336 inline_size = min_t(u64, isize, aligned_end); 337 inline_size -= start_pos; 338 err = insert_inline_extent(trans, root, inode, start_pos, 339 inline_size, pages, 0, num_pages); 340 btrfs_drop_extent_cache(inode, start_pos, aligned_end - 1); 341 BUG_ON(err); 342 mutex_unlock(&BTRFS_I(inode)->extent_mutex); 343 344 /* 345 * an ugly way to do all the prop accounting around 346 * the page bits and mapping tags 347 */ 348 set_page_writeback(pages[0]); 349 end_page_writeback(pages[0]); 350 did_inline = 1; 351 } 352 if (end_pos > isize) { 353 i_size_write(inode, end_pos); 354 if (did_inline) 355 BTRFS_I(inode)->disk_i_size = end_pos; 356 btrfs_update_inode(trans, root, inode); 357 } 358 failed: 359 err = btrfs_end_transaction(trans, root); 360 out_unlock: 361 unlock_extent(io_tree, start_pos, end_of_last_block, GFP_NOFS); 362 return err; 363 } 364 365 int noinline btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) 366 { 367 struct extent_map *em; 368 struct extent_map *split = NULL; 369 struct extent_map *split2 = NULL; 370 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 371 u64 len = end - start + 1; 372 int ret; 373 int testend = 1; 374 375 WARN_ON(end < start); 376 if (end == (u64)-1) { 377 len = (u64)-1; 378 testend = 0; 379 } 380 while(1) { 381 if (!split) 382 split = alloc_extent_map(GFP_NOFS); 383 if (!split2) 384 split2 = alloc_extent_map(GFP_NOFS); 385 386 spin_lock(&em_tree->lock); 387 em = lookup_extent_mapping(em_tree, start, len); 388 if (!em) { 389 spin_unlock(&em_tree->lock); 390 break; 391 } 392 clear_bit(EXTENT_FLAG_PINNED, &em->flags); 393 remove_extent_mapping(em_tree, em); 394 395 if (em->block_start < EXTENT_MAP_LAST_BYTE && 396 em->start < start) { 397 split->start = em->start; 398 split->len = start - em->start; 399 split->block_start = em->block_start; 400 split->bdev = em->bdev; 401 split->flags = em->flags; 402 ret = add_extent_mapping(em_tree, split); 403 BUG_ON(ret); 404 free_extent_map(split); 405 split = split2; 406 split2 = NULL; 407 } 408 if (em->block_start < EXTENT_MAP_LAST_BYTE && 409 testend && em->start + em->len > start + len) { 410 u64 diff = start + len - em->start; 411 412 split->start = start + len; 413 split->len = em->start + em->len - (start + len); 414 split->bdev = em->bdev; 415 split->flags = em->flags; 416 417 split->block_start = em->block_start + diff; 418 419 ret = add_extent_mapping(em_tree, split); 420 BUG_ON(ret); 421 free_extent_map(split); 422 split = NULL; 423 } 424 spin_unlock(&em_tree->lock); 425 426 /* once for us */ 427 free_extent_map(em); 428 /* once for the tree*/ 429 free_extent_map(em); 430 } 431 if (split) 432 free_extent_map(split); 433 if (split2) 434 free_extent_map(split2); 435 return 0; 436 } 437 438 int btrfs_check_file(struct btrfs_root *root, struct inode *inode) 439 { 440 return 0; 441 #if 0 442 struct btrfs_path *path; 443 struct btrfs_key found_key; 444 struct extent_buffer *leaf; 445 struct btrfs_file_extent_item *extent; 446 u64 last_offset = 0; 447 int nritems; 448 int slot; 449 int found_type; 450 int ret; 451 int err = 0; 452 u64 extent_end = 0; 453 454 path = btrfs_alloc_path(); 455 ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino, 456 last_offset, 0); 457 while(1) { 458 nritems = btrfs_header_nritems(path->nodes[0]); 459 if (path->slots[0] >= nritems) { 460 ret = btrfs_next_leaf(root, path); 461 if (ret) 462 goto out; 463 nritems = btrfs_header_nritems(path->nodes[0]); 464 } 465 slot = path->slots[0]; 466 leaf = path->nodes[0]; 467 btrfs_item_key_to_cpu(leaf, &found_key, slot); 468 if (found_key.objectid != inode->i_ino) 469 break; 470 if (found_key.type != BTRFS_EXTENT_DATA_KEY) 471 goto out; 472 473 if (found_key.offset < last_offset) { 474 WARN_ON(1); 475 btrfs_print_leaf(root, leaf); 476 printk("inode %lu found offset %Lu expected %Lu\n", 477 inode->i_ino, found_key.offset, last_offset); 478 err = 1; 479 goto out; 480 } 481 extent = btrfs_item_ptr(leaf, slot, 482 struct btrfs_file_extent_item); 483 found_type = btrfs_file_extent_type(leaf, extent); 484 if (found_type == BTRFS_FILE_EXTENT_REG) { 485 extent_end = found_key.offset + 486 btrfs_file_extent_num_bytes(leaf, extent); 487 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 488 struct btrfs_item *item; 489 item = btrfs_item_nr(leaf, slot); 490 extent_end = found_key.offset + 491 btrfs_file_extent_inline_len(leaf, item); 492 extent_end = (extent_end + root->sectorsize - 1) & 493 ~((u64)root->sectorsize -1 ); 494 } 495 last_offset = extent_end; 496 path->slots[0]++; 497 } 498 if (0 && last_offset < inode->i_size) { 499 WARN_ON(1); 500 btrfs_print_leaf(root, leaf); 501 printk("inode %lu found offset %Lu size %Lu\n", inode->i_ino, 502 last_offset, inode->i_size); 503 err = 1; 504 505 } 506 out: 507 btrfs_free_path(path); 508 return err; 509 #endif 510 } 511 512 /* 513 * this is very complex, but the basic idea is to drop all extents 514 * in the range start - end. hint_block is filled in with a block number 515 * that would be a good hint to the block allocator for this file. 516 * 517 * If an extent intersects the range but is not entirely inside the range 518 * it is either truncated or split. Anything entirely inside the range 519 * is deleted from the tree. 520 */ 521 int noinline btrfs_drop_extents(struct btrfs_trans_handle *trans, 522 struct btrfs_root *root, struct inode *inode, 523 u64 start, u64 end, u64 inline_limit, u64 *hint_byte) 524 { 525 u64 extent_end = 0; 526 u64 search_start = start; 527 struct extent_buffer *leaf; 528 struct btrfs_file_extent_item *extent; 529 struct btrfs_path *path; 530 struct btrfs_key key; 531 struct btrfs_file_extent_item old; 532 int keep; 533 int slot; 534 int bookend; 535 int found_type; 536 int found_extent; 537 int found_inline; 538 int recow; 539 int ret; 540 541 btrfs_drop_extent_cache(inode, start, end - 1); 542 543 path = btrfs_alloc_path(); 544 if (!path) 545 return -ENOMEM; 546 while(1) { 547 recow = 0; 548 btrfs_release_path(root, path); 549 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, 550 search_start, -1); 551 if (ret < 0) 552 goto out; 553 if (ret > 0) { 554 if (path->slots[0] == 0) { 555 ret = 0; 556 goto out; 557 } 558 path->slots[0]--; 559 } 560 next_slot: 561 keep = 0; 562 bookend = 0; 563 found_extent = 0; 564 found_inline = 0; 565 extent = NULL; 566 leaf = path->nodes[0]; 567 slot = path->slots[0]; 568 ret = 0; 569 btrfs_item_key_to_cpu(leaf, &key, slot); 570 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY && 571 key.offset >= end) { 572 goto out; 573 } 574 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 575 key.objectid != inode->i_ino) { 576 goto out; 577 } 578 if (recow) { 579 search_start = key.offset; 580 continue; 581 } 582 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 583 extent = btrfs_item_ptr(leaf, slot, 584 struct btrfs_file_extent_item); 585 found_type = btrfs_file_extent_type(leaf, extent); 586 if (found_type == BTRFS_FILE_EXTENT_REG) { 587 extent_end = 588 btrfs_file_extent_disk_bytenr(leaf, 589 extent); 590 if (extent_end) 591 *hint_byte = extent_end; 592 593 extent_end = key.offset + 594 btrfs_file_extent_num_bytes(leaf, extent); 595 found_extent = 1; 596 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { 597 struct btrfs_item *item; 598 item = btrfs_item_nr(leaf, slot); 599 found_inline = 1; 600 extent_end = key.offset + 601 btrfs_file_extent_inline_len(leaf, item); 602 } 603 } else { 604 extent_end = search_start; 605 } 606 607 /* we found nothing we can drop */ 608 if ((!found_extent && !found_inline) || 609 search_start >= extent_end) { 610 int nextret; 611 u32 nritems; 612 nritems = btrfs_header_nritems(leaf); 613 if (slot >= nritems - 1) { 614 nextret = btrfs_next_leaf(root, path); 615 if (nextret) 616 goto out; 617 recow = 1; 618 } else { 619 path->slots[0]++; 620 } 621 goto next_slot; 622 } 623 624 if (found_inline) { 625 u64 mask = root->sectorsize - 1; 626 search_start = (extent_end + mask) & ~mask; 627 } else 628 search_start = extent_end; 629 if (end <= extent_end && start >= key.offset && found_inline) { 630 *hint_byte = EXTENT_MAP_INLINE; 631 continue; 632 } 633 if (end < extent_end && end >= key.offset) { 634 if (found_extent) { 635 u64 disk_bytenr = 636 btrfs_file_extent_disk_bytenr(leaf, extent); 637 u64 disk_num_bytes = 638 btrfs_file_extent_disk_num_bytes(leaf, 639 extent); 640 read_extent_buffer(leaf, &old, 641 (unsigned long)extent, 642 sizeof(old)); 643 if (disk_bytenr != 0) { 644 ret = btrfs_inc_extent_ref(trans, root, 645 disk_bytenr, disk_num_bytes, 646 root->root_key.objectid, 647 trans->transid, 648 key.objectid, end); 649 BUG_ON(ret); 650 } 651 } 652 bookend = 1; 653 if (found_inline && start <= key.offset) 654 keep = 1; 655 } 656 /* truncate existing extent */ 657 if (start > key.offset) { 658 u64 new_num; 659 u64 old_num; 660 keep = 1; 661 WARN_ON(start & (root->sectorsize - 1)); 662 if (found_extent) { 663 new_num = start - key.offset; 664 old_num = btrfs_file_extent_num_bytes(leaf, 665 extent); 666 *hint_byte = 667 btrfs_file_extent_disk_bytenr(leaf, 668 extent); 669 if (btrfs_file_extent_disk_bytenr(leaf, 670 extent)) { 671 dec_i_blocks(inode, old_num - new_num); 672 } 673 btrfs_set_file_extent_num_bytes(leaf, extent, 674 new_num); 675 btrfs_mark_buffer_dirty(leaf); 676 } else if (key.offset < inline_limit && 677 (end > extent_end) && 678 (inline_limit < extent_end)) { 679 u32 new_size; 680 new_size = btrfs_file_extent_calc_inline_size( 681 inline_limit - key.offset); 682 dec_i_blocks(inode, (extent_end - key.offset) - 683 (inline_limit - key.offset)); 684 btrfs_truncate_item(trans, root, path, 685 new_size, 1); 686 } 687 } 688 /* delete the entire extent */ 689 if (!keep) { 690 u64 disk_bytenr = 0; 691 u64 disk_num_bytes = 0; 692 u64 extent_num_bytes = 0; 693 u64 root_gen; 694 u64 root_owner; 695 696 root_gen = btrfs_header_generation(leaf); 697 root_owner = btrfs_header_owner(leaf); 698 if (found_extent) { 699 disk_bytenr = 700 btrfs_file_extent_disk_bytenr(leaf, 701 extent); 702 disk_num_bytes = 703 btrfs_file_extent_disk_num_bytes(leaf, 704 extent); 705 extent_num_bytes = 706 btrfs_file_extent_num_bytes(leaf, extent); 707 *hint_byte = 708 btrfs_file_extent_disk_bytenr(leaf, 709 extent); 710 } 711 ret = btrfs_del_item(trans, root, path); 712 /* TODO update progress marker and return */ 713 BUG_ON(ret); 714 btrfs_release_path(root, path); 715 extent = NULL; 716 if (found_extent && disk_bytenr != 0) { 717 dec_i_blocks(inode, extent_num_bytes); 718 ret = btrfs_free_extent(trans, root, 719 disk_bytenr, 720 disk_num_bytes, 721 root_owner, 722 root_gen, inode->i_ino, 723 key.offset, 0); 724 } 725 726 BUG_ON(ret); 727 if (!bookend && search_start >= end) { 728 ret = 0; 729 goto out; 730 } 731 if (!bookend) 732 continue; 733 } 734 if (bookend && found_inline && start <= key.offset) { 735 u32 new_size; 736 new_size = btrfs_file_extent_calc_inline_size( 737 extent_end - end); 738 dec_i_blocks(inode, (extent_end - key.offset) - 739 (extent_end - end)); 740 btrfs_truncate_item(trans, root, path, new_size, 0); 741 } 742 /* create bookend, splitting the extent in two */ 743 if (bookend && found_extent) { 744 struct btrfs_key ins; 745 ins.objectid = inode->i_ino; 746 ins.offset = end; 747 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY); 748 btrfs_release_path(root, path); 749 ret = btrfs_insert_empty_item(trans, root, path, &ins, 750 sizeof(*extent)); 751 752 leaf = path->nodes[0]; 753 if (ret) { 754 btrfs_print_leaf(root, leaf); 755 printk("got %d on inserting %Lu %u %Lu start %Lu end %Lu found %Lu %Lu keep was %d\n", ret , ins.objectid, ins.type, ins.offset, start, end, key.offset, extent_end, keep); 756 } 757 BUG_ON(ret); 758 extent = btrfs_item_ptr(leaf, path->slots[0], 759 struct btrfs_file_extent_item); 760 write_extent_buffer(leaf, &old, 761 (unsigned long)extent, sizeof(old)); 762 763 btrfs_set_file_extent_offset(leaf, extent, 764 le64_to_cpu(old.offset) + end - key.offset); 765 WARN_ON(le64_to_cpu(old.num_bytes) < 766 (extent_end - end)); 767 btrfs_set_file_extent_num_bytes(leaf, extent, 768 extent_end - end); 769 btrfs_set_file_extent_type(leaf, extent, 770 BTRFS_FILE_EXTENT_REG); 771 772 btrfs_mark_buffer_dirty(path->nodes[0]); 773 if (le64_to_cpu(old.disk_bytenr) != 0) { 774 inode->i_blocks += 775 btrfs_file_extent_num_bytes(leaf, 776 extent) >> 9; 777 } 778 ret = 0; 779 goto out; 780 } 781 } 782 out: 783 btrfs_free_path(path); 784 btrfs_check_file(root, inode); 785 return ret; 786 } 787 788 /* 789 * this gets pages into the page cache and locks them down 790 */ 791 static int noinline prepare_pages(struct btrfs_root *root, struct file *file, 792 struct page **pages, size_t num_pages, 793 loff_t pos, unsigned long first_index, 794 unsigned long last_index, size_t write_bytes) 795 { 796 int i; 797 unsigned long index = pos >> PAGE_CACHE_SHIFT; 798 struct inode *inode = fdentry(file)->d_inode; 799 int err = 0; 800 u64 start_pos; 801 u64 last_pos; 802 803 start_pos = pos & ~((u64)root->sectorsize - 1); 804 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT; 805 806 memset(pages, 0, num_pages * sizeof(struct page *)); 807 again: 808 for (i = 0; i < num_pages; i++) { 809 pages[i] = grab_cache_page(inode->i_mapping, index + i); 810 if (!pages[i]) { 811 err = -ENOMEM; 812 BUG_ON(1); 813 } 814 wait_on_page_writeback(pages[i]); 815 } 816 if (start_pos < inode->i_size) { 817 struct btrfs_ordered_extent *ordered; 818 lock_extent(&BTRFS_I(inode)->io_tree, 819 start_pos, last_pos - 1, GFP_NOFS); 820 ordered = btrfs_lookup_first_ordered_extent(inode, last_pos -1); 821 if (ordered && 822 ordered->file_offset + ordered->len > start_pos && 823 ordered->file_offset < last_pos) { 824 btrfs_put_ordered_extent(ordered); 825 unlock_extent(&BTRFS_I(inode)->io_tree, 826 start_pos, last_pos - 1, GFP_NOFS); 827 for (i = 0; i < num_pages; i++) { 828 unlock_page(pages[i]); 829 page_cache_release(pages[i]); 830 } 831 btrfs_wait_ordered_range(inode, start_pos, 832 last_pos - start_pos); 833 goto again; 834 } 835 if (ordered) 836 btrfs_put_ordered_extent(ordered); 837 838 clear_extent_bits(&BTRFS_I(inode)->io_tree, start_pos, 839 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC, 840 GFP_NOFS); 841 unlock_extent(&BTRFS_I(inode)->io_tree, 842 start_pos, last_pos - 1, GFP_NOFS); 843 } 844 for (i = 0; i < num_pages; i++) { 845 clear_page_dirty_for_io(pages[i]); 846 set_page_extent_mapped(pages[i]); 847 WARN_ON(!PageLocked(pages[i])); 848 } 849 return 0; 850 } 851 852 static ssize_t btrfs_file_write(struct file *file, const char __user *buf, 853 size_t count, loff_t *ppos) 854 { 855 loff_t pos; 856 loff_t start_pos; 857 ssize_t num_written = 0; 858 ssize_t err = 0; 859 int ret = 0; 860 struct inode *inode = fdentry(file)->d_inode; 861 struct btrfs_root *root = BTRFS_I(inode)->root; 862 struct page **pages = NULL; 863 int nrptrs; 864 struct page *pinned[2]; 865 unsigned long first_index; 866 unsigned long last_index; 867 868 nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, 869 PAGE_CACHE_SIZE / (sizeof(struct page *))); 870 pinned[0] = NULL; 871 pinned[1] = NULL; 872 873 pos = *ppos; 874 start_pos = pos; 875 876 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); 877 current->backing_dev_info = inode->i_mapping->backing_dev_info; 878 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); 879 if (err) 880 goto out_nolock; 881 if (count == 0) 882 goto out_nolock; 883 #ifdef REMOVE_SUID_PATH 884 err = remove_suid(&file->f_path); 885 #else 886 # if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26) 887 err = file_remove_suid(file); 888 # else 889 err = remove_suid(fdentry(file)); 890 # endif 891 #endif 892 if (err) 893 goto out_nolock; 894 file_update_time(file); 895 896 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); 897 898 mutex_lock(&inode->i_mutex); 899 first_index = pos >> PAGE_CACHE_SHIFT; 900 last_index = (pos + count) >> PAGE_CACHE_SHIFT; 901 902 /* 903 * if this is a nodatasum mount, force summing off for the inode 904 * all the time. That way a later mount with summing on won't 905 * get confused 906 */ 907 if (btrfs_test_opt(root, NODATASUM)) 908 btrfs_set_flag(inode, NODATASUM); 909 910 /* 911 * there are lots of better ways to do this, but this code 912 * makes sure the first and last page in the file range are 913 * up to date and ready for cow 914 */ 915 if ((pos & (PAGE_CACHE_SIZE - 1))) { 916 pinned[0] = grab_cache_page(inode->i_mapping, first_index); 917 if (!PageUptodate(pinned[0])) { 918 ret = btrfs_readpage(NULL, pinned[0]); 919 BUG_ON(ret); 920 wait_on_page_locked(pinned[0]); 921 } else { 922 unlock_page(pinned[0]); 923 } 924 } 925 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) { 926 pinned[1] = grab_cache_page(inode->i_mapping, last_index); 927 if (!PageUptodate(pinned[1])) { 928 ret = btrfs_readpage(NULL, pinned[1]); 929 BUG_ON(ret); 930 wait_on_page_locked(pinned[1]); 931 } else { 932 unlock_page(pinned[1]); 933 } 934 } 935 936 while(count > 0) { 937 size_t offset = pos & (PAGE_CACHE_SIZE - 1); 938 size_t write_bytes = min(count, nrptrs * 939 (size_t)PAGE_CACHE_SIZE - 940 offset); 941 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> 942 PAGE_CACHE_SHIFT; 943 944 WARN_ON(num_pages > nrptrs); 945 memset(pages, 0, sizeof(pages)); 946 947 ret = btrfs_check_free_space(root, write_bytes, 0); 948 if (ret) 949 goto out; 950 951 ret = prepare_pages(root, file, pages, num_pages, 952 pos, first_index, last_index, 953 write_bytes); 954 if (ret) 955 goto out; 956 957 ret = btrfs_copy_from_user(pos, num_pages, 958 write_bytes, pages, buf); 959 if (ret) { 960 btrfs_drop_pages(pages, num_pages); 961 goto out; 962 } 963 964 ret = dirty_and_release_pages(NULL, root, file, pages, 965 num_pages, pos, write_bytes); 966 btrfs_drop_pages(pages, num_pages); 967 if (ret) 968 goto out; 969 970 buf += write_bytes; 971 count -= write_bytes; 972 pos += write_bytes; 973 num_written += write_bytes; 974 975 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages); 976 if (num_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1) 977 btrfs_btree_balance_dirty(root, 1); 978 btrfs_throttle(root); 979 cond_resched(); 980 } 981 out: 982 mutex_unlock(&inode->i_mutex); 983 984 out_nolock: 985 kfree(pages); 986 if (pinned[0]) 987 page_cache_release(pinned[0]); 988 if (pinned[1]) 989 page_cache_release(pinned[1]); 990 *ppos = pos; 991 992 if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) { 993 struct btrfs_trans_handle *trans; 994 995 err = btrfs_fdatawrite_range(inode->i_mapping, start_pos, 996 start_pos + num_written -1, 997 WB_SYNC_NONE); 998 if (err < 0) 999 num_written = err; 1000 1001 err = btrfs_wait_on_page_writeback_range(inode->i_mapping, 1002 start_pos, start_pos + num_written - 1); 1003 if (err < 0) 1004 num_written = err; 1005 1006 trans = btrfs_start_transaction(root, 1); 1007 ret = btrfs_log_dentry_safe(trans, root, file->f_dentry); 1008 if (ret == 0) { 1009 btrfs_sync_log(trans, root); 1010 btrfs_end_transaction(trans, root); 1011 } else { 1012 btrfs_commit_transaction(trans, root); 1013 } 1014 } else if (num_written > 0 && (file->f_flags & O_DIRECT)) { 1015 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22) 1016 do_sync_file_range(file, start_pos, 1017 start_pos + num_written - 1, 1018 SYNC_FILE_RANGE_WRITE | 1019 SYNC_FILE_RANGE_WAIT_AFTER); 1020 #else 1021 do_sync_mapping_range(inode->i_mapping, start_pos, 1022 start_pos + num_written - 1, 1023 SYNC_FILE_RANGE_WRITE | 1024 SYNC_FILE_RANGE_WAIT_AFTER); 1025 #endif 1026 invalidate_mapping_pages(inode->i_mapping, 1027 start_pos >> PAGE_CACHE_SHIFT, 1028 (start_pos + num_written - 1) >> PAGE_CACHE_SHIFT); 1029 } 1030 current->backing_dev_info = NULL; 1031 return num_written ? num_written : err; 1032 } 1033 1034 int btrfs_release_file(struct inode * inode, struct file * filp) 1035 { 1036 if (filp->private_data) 1037 btrfs_ioctl_trans_end(filp); 1038 return 0; 1039 } 1040 1041 int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) 1042 { 1043 struct inode *inode = dentry->d_inode; 1044 struct btrfs_root *root = BTRFS_I(inode)->root; 1045 int ret = 0; 1046 struct btrfs_trans_handle *trans; 1047 1048 /* 1049 * check the transaction that last modified this inode 1050 * and see if its already been committed 1051 */ 1052 if (!BTRFS_I(inode)->last_trans) 1053 goto out; 1054 1055 mutex_lock(&root->fs_info->trans_mutex); 1056 if (BTRFS_I(inode)->last_trans <= 1057 root->fs_info->last_trans_committed) { 1058 BTRFS_I(inode)->last_trans = 0; 1059 mutex_unlock(&root->fs_info->trans_mutex); 1060 goto out; 1061 } 1062 mutex_unlock(&root->fs_info->trans_mutex); 1063 1064 filemap_fdatawait(inode->i_mapping); 1065 1066 /* 1067 * ok we haven't committed the transaction yet, lets do a commit 1068 */ 1069 if (file->private_data) 1070 btrfs_ioctl_trans_end(file); 1071 1072 trans = btrfs_start_transaction(root, 1); 1073 if (!trans) { 1074 ret = -ENOMEM; 1075 goto out; 1076 } 1077 1078 ret = btrfs_log_dentry_safe(trans, root, file->f_dentry); 1079 if (ret < 0) 1080 goto out; 1081 if (ret > 0) { 1082 ret = btrfs_commit_transaction(trans, root); 1083 } else { 1084 btrfs_sync_log(trans, root); 1085 ret = btrfs_end_transaction(trans, root); 1086 } 1087 out: 1088 return ret > 0 ? EIO : ret; 1089 } 1090 1091 static struct vm_operations_struct btrfs_file_vm_ops = { 1092 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23) 1093 .nopage = filemap_nopage, 1094 .populate = filemap_populate, 1095 #else 1096 .fault = filemap_fault, 1097 #endif 1098 .page_mkwrite = btrfs_page_mkwrite, 1099 }; 1100 1101 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) 1102 { 1103 vma->vm_ops = &btrfs_file_vm_ops; 1104 file_accessed(filp); 1105 return 0; 1106 } 1107 1108 struct file_operations btrfs_file_operations = { 1109 .llseek = generic_file_llseek, 1110 .read = do_sync_read, 1111 .aio_read = generic_file_aio_read, 1112 .splice_read = generic_file_splice_read, 1113 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) 1114 .sendfile = generic_file_sendfile, 1115 #endif 1116 .write = btrfs_file_write, 1117 .mmap = btrfs_file_mmap, 1118 .open = generic_file_open, 1119 .release = btrfs_release_file, 1120 .fsync = btrfs_sync_file, 1121 .unlocked_ioctl = btrfs_ioctl, 1122 #ifdef CONFIG_COMPAT 1123 .compat_ioctl = btrfs_ioctl, 1124 #endif 1125 }; 1126