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/kernel.h> 20 #include <linux/bio.h> 21 #include <linux/buffer_head.h> 22 #include <linux/file.h> 23 #include <linux/fs.h> 24 #include <linux/fsnotify.h> 25 #include <linux/pagemap.h> 26 #include <linux/highmem.h> 27 #include <linux/time.h> 28 #include <linux/init.h> 29 #include <linux/string.h> 30 #include <linux/smp_lock.h> 31 #include <linux/backing-dev.h> 32 #include <linux/mount.h> 33 #include <linux/mpage.h> 34 #include <linux/namei.h> 35 #include <linux/swap.h> 36 #include <linux/writeback.h> 37 #include <linux/statfs.h> 38 #include <linux/compat.h> 39 #include <linux/bit_spinlock.h> 40 #include <linux/security.h> 41 #include <linux/xattr.h> 42 #include <linux/vmalloc.h> 43 #include "compat.h" 44 #include "ctree.h" 45 #include "disk-io.h" 46 #include "transaction.h" 47 #include "btrfs_inode.h" 48 #include "ioctl.h" 49 #include "print-tree.h" 50 #include "volumes.h" 51 #include "locking.h" 52 53 54 55 static noinline int create_subvol(struct btrfs_root *root, 56 struct dentry *dentry, 57 char *name, int namelen) 58 { 59 struct btrfs_trans_handle *trans; 60 struct btrfs_key key; 61 struct btrfs_root_item root_item; 62 struct btrfs_inode_item *inode_item; 63 struct extent_buffer *leaf; 64 struct btrfs_root *new_root = root; 65 struct inode *dir; 66 int ret; 67 int err; 68 u64 objectid; 69 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; 70 u64 index = 0; 71 unsigned long nr = 1; 72 73 ret = btrfs_check_metadata_free_space(root); 74 if (ret) 75 goto fail_commit; 76 77 trans = btrfs_start_transaction(root, 1); 78 BUG_ON(!trans); 79 80 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root, 81 0, &objectid); 82 if (ret) 83 goto fail; 84 85 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, 86 objectid, trans->transid, 0, 0, 0); 87 if (IS_ERR(leaf)) { 88 ret = PTR_ERR(leaf); 89 goto fail; 90 } 91 92 btrfs_set_header_nritems(leaf, 0); 93 btrfs_set_header_level(leaf, 0); 94 btrfs_set_header_bytenr(leaf, leaf->start); 95 btrfs_set_header_generation(leaf, trans->transid); 96 btrfs_set_header_owner(leaf, objectid); 97 98 write_extent_buffer(leaf, root->fs_info->fsid, 99 (unsigned long)btrfs_header_fsid(leaf), 100 BTRFS_FSID_SIZE); 101 btrfs_mark_buffer_dirty(leaf); 102 103 inode_item = &root_item.inode; 104 memset(inode_item, 0, sizeof(*inode_item)); 105 inode_item->generation = cpu_to_le64(1); 106 inode_item->size = cpu_to_le64(3); 107 inode_item->nlink = cpu_to_le32(1); 108 inode_item->nbytes = cpu_to_le64(root->leafsize); 109 inode_item->mode = cpu_to_le32(S_IFDIR | 0755); 110 111 btrfs_set_root_bytenr(&root_item, leaf->start); 112 btrfs_set_root_generation(&root_item, trans->transid); 113 btrfs_set_root_level(&root_item, 0); 114 btrfs_set_root_refs(&root_item, 1); 115 btrfs_set_root_used(&root_item, 0); 116 btrfs_set_root_last_snapshot(&root_item, 0); 117 118 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); 119 root_item.drop_level = 0; 120 121 btrfs_tree_unlock(leaf); 122 free_extent_buffer(leaf); 123 leaf = NULL; 124 125 btrfs_set_root_dirid(&root_item, new_dirid); 126 127 key.objectid = objectid; 128 key.offset = 1; 129 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); 130 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, 131 &root_item); 132 if (ret) 133 goto fail; 134 135 /* 136 * insert the directory item 137 */ 138 key.offset = (u64)-1; 139 dir = dentry->d_parent->d_inode; 140 ret = btrfs_set_inode_index(dir, &index); 141 BUG_ON(ret); 142 143 ret = btrfs_insert_dir_item(trans, root, 144 name, namelen, dir->i_ino, &key, 145 BTRFS_FT_DIR, index); 146 if (ret) 147 goto fail; 148 149 btrfs_i_size_write(dir, dir->i_size + namelen * 2); 150 ret = btrfs_update_inode(trans, root, dir); 151 BUG_ON(ret); 152 153 /* add the backref first */ 154 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 155 objectid, BTRFS_ROOT_BACKREF_KEY, 156 root->root_key.objectid, 157 dir->i_ino, index, name, namelen); 158 159 BUG_ON(ret); 160 161 /* now add the forward ref */ 162 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 163 root->root_key.objectid, BTRFS_ROOT_REF_KEY, 164 objectid, 165 dir->i_ino, index, name, namelen); 166 167 BUG_ON(ret); 168 169 ret = btrfs_commit_transaction(trans, root); 170 if (ret) 171 goto fail_commit; 172 173 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); 174 BUG_ON(!new_root); 175 176 trans = btrfs_start_transaction(new_root, 1); 177 BUG_ON(!trans); 178 179 ret = btrfs_create_subvol_root(trans, new_root, dentry, new_dirid, 180 BTRFS_I(dir)->block_group); 181 if (ret) 182 goto fail; 183 184 fail: 185 nr = trans->blocks_used; 186 err = btrfs_commit_transaction(trans, new_root); 187 if (err && !ret) 188 ret = err; 189 fail_commit: 190 btrfs_btree_balance_dirty(root, nr); 191 return ret; 192 } 193 194 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, 195 char *name, int namelen) 196 { 197 struct btrfs_pending_snapshot *pending_snapshot; 198 struct btrfs_trans_handle *trans; 199 int ret = 0; 200 int err; 201 unsigned long nr = 0; 202 203 if (!root->ref_cows) 204 return -EINVAL; 205 206 ret = btrfs_check_metadata_free_space(root); 207 if (ret) 208 goto fail_unlock; 209 210 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); 211 if (!pending_snapshot) { 212 ret = -ENOMEM; 213 goto fail_unlock; 214 } 215 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS); 216 if (!pending_snapshot->name) { 217 ret = -ENOMEM; 218 kfree(pending_snapshot); 219 goto fail_unlock; 220 } 221 memcpy(pending_snapshot->name, name, namelen); 222 pending_snapshot->name[namelen] = '\0'; 223 pending_snapshot->dentry = dentry; 224 trans = btrfs_start_transaction(root, 1); 225 BUG_ON(!trans); 226 pending_snapshot->root = root; 227 list_add(&pending_snapshot->list, 228 &trans->transaction->pending_snapshots); 229 err = btrfs_commit_transaction(trans, root); 230 231 fail_unlock: 232 btrfs_btree_balance_dirty(root, nr); 233 return ret; 234 } 235 236 /* copy of may_create in fs/namei.c() */ 237 static inline int btrfs_may_create(struct inode *dir, struct dentry *child) 238 { 239 if (child->d_inode) 240 return -EEXIST; 241 if (IS_DEADDIR(dir)) 242 return -ENOENT; 243 return inode_permission(dir, MAY_WRITE | MAY_EXEC); 244 } 245 246 /* 247 * Create a new subvolume below @parent. This is largely modeled after 248 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup 249 * inside this filesystem so it's quite a bit simpler. 250 */ 251 static noinline int btrfs_mksubvol(struct path *parent, char *name, 252 int mode, int namelen, 253 struct btrfs_root *snap_src) 254 { 255 struct dentry *dentry; 256 int error; 257 258 mutex_lock_nested(&parent->dentry->d_inode->i_mutex, I_MUTEX_PARENT); 259 260 dentry = lookup_one_len(name, parent->dentry, namelen); 261 error = PTR_ERR(dentry); 262 if (IS_ERR(dentry)) 263 goto out_unlock; 264 265 error = -EEXIST; 266 if (dentry->d_inode) 267 goto out_dput; 268 269 if (!IS_POSIXACL(parent->dentry->d_inode)) 270 mode &= ~current_umask(); 271 272 error = mnt_want_write(parent->mnt); 273 if (error) 274 goto out_dput; 275 276 error = btrfs_may_create(parent->dentry->d_inode, dentry); 277 if (error) 278 goto out_drop_write; 279 280 /* 281 * Actually perform the low-level subvolume creation after all 282 * this VFS fuzz. 283 * 284 * Eventually we want to pass in an inode under which we create this 285 * subvolume, but for now all are under the filesystem root. 286 * 287 * Also we should pass on the mode eventually to allow creating new 288 * subvolume with specific mode bits. 289 */ 290 if (snap_src) { 291 struct dentry *dir = dentry->d_parent; 292 struct dentry *test = dir->d_parent; 293 struct btrfs_path *path = btrfs_alloc_path(); 294 int ret; 295 u64 test_oid; 296 u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid; 297 298 test_oid = snap_src->root_key.objectid; 299 300 ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, 301 path, parent_oid, test_oid); 302 if (ret == 0) 303 goto create; 304 btrfs_release_path(snap_src->fs_info->tree_root, path); 305 306 /* we need to make sure we aren't creating a directory loop 307 * by taking a snapshot of something that has our current 308 * subvol in its directory tree. So, this loops through 309 * the dentries and checks the forward refs for each subvolume 310 * to see if is references the subvolume where we are 311 * placing this new snapshot. 312 */ 313 while (1) { 314 if (!test || 315 dir == snap_src->fs_info->sb->s_root || 316 test == snap_src->fs_info->sb->s_root || 317 test->d_inode->i_sb != snap_src->fs_info->sb) { 318 break; 319 } 320 if (S_ISLNK(test->d_inode->i_mode)) { 321 printk(KERN_INFO "Btrfs symlink in snapshot " 322 "path, failed\n"); 323 error = -EMLINK; 324 btrfs_free_path(path); 325 goto out_drop_write; 326 } 327 test_oid = 328 BTRFS_I(test->d_inode)->root->root_key.objectid; 329 ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, 330 path, test_oid, parent_oid); 331 if (ret == 0) { 332 printk(KERN_INFO "Btrfs snapshot creation " 333 "failed, looping\n"); 334 error = -EMLINK; 335 btrfs_free_path(path); 336 goto out_drop_write; 337 } 338 btrfs_release_path(snap_src->fs_info->tree_root, path); 339 test = test->d_parent; 340 } 341 create: 342 btrfs_free_path(path); 343 error = create_snapshot(snap_src, dentry, name, namelen); 344 } else { 345 error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root, 346 dentry, name, namelen); 347 } 348 if (error) 349 goto out_drop_write; 350 351 fsnotify_mkdir(parent->dentry->d_inode, dentry); 352 out_drop_write: 353 mnt_drop_write(parent->mnt); 354 out_dput: 355 dput(dentry); 356 out_unlock: 357 mutex_unlock(&parent->dentry->d_inode->i_mutex); 358 return error; 359 } 360 361 362 static int btrfs_defrag_file(struct file *file) 363 { 364 struct inode *inode = fdentry(file)->d_inode; 365 struct btrfs_root *root = BTRFS_I(inode)->root; 366 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 367 struct btrfs_ordered_extent *ordered; 368 struct page *page; 369 unsigned long last_index; 370 unsigned long ra_pages = root->fs_info->bdi.ra_pages; 371 unsigned long total_read = 0; 372 u64 page_start; 373 u64 page_end; 374 unsigned long i; 375 int ret; 376 377 ret = btrfs_check_data_free_space(root, inode, inode->i_size); 378 if (ret) 379 return -ENOSPC; 380 381 mutex_lock(&inode->i_mutex); 382 last_index = inode->i_size >> PAGE_CACHE_SHIFT; 383 for (i = 0; i <= last_index; i++) { 384 if (total_read % ra_pages == 0) { 385 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i, 386 min(last_index, i + ra_pages - 1)); 387 } 388 total_read++; 389 again: 390 page = grab_cache_page(inode->i_mapping, i); 391 if (!page) 392 goto out_unlock; 393 if (!PageUptodate(page)) { 394 btrfs_readpage(NULL, page); 395 lock_page(page); 396 if (!PageUptodate(page)) { 397 unlock_page(page); 398 page_cache_release(page); 399 goto out_unlock; 400 } 401 } 402 403 wait_on_page_writeback(page); 404 405 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 406 page_end = page_start + PAGE_CACHE_SIZE - 1; 407 lock_extent(io_tree, page_start, page_end, GFP_NOFS); 408 409 ordered = btrfs_lookup_ordered_extent(inode, page_start); 410 if (ordered) { 411 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 412 unlock_page(page); 413 page_cache_release(page); 414 btrfs_start_ordered_extent(inode, ordered, 1); 415 btrfs_put_ordered_extent(ordered); 416 goto again; 417 } 418 set_page_extent_mapped(page); 419 420 /* 421 * this makes sure page_mkwrite is called on the 422 * page if it is dirtied again later 423 */ 424 clear_page_dirty_for_io(page); 425 426 btrfs_set_extent_delalloc(inode, page_start, page_end); 427 428 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 429 set_page_dirty(page); 430 unlock_page(page); 431 page_cache_release(page); 432 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1); 433 } 434 435 out_unlock: 436 mutex_unlock(&inode->i_mutex); 437 return 0; 438 } 439 440 /* 441 * Called inside transaction, so use GFP_NOFS 442 */ 443 444 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) 445 { 446 u64 new_size; 447 u64 old_size; 448 u64 devid = 1; 449 struct btrfs_ioctl_vol_args *vol_args; 450 struct btrfs_trans_handle *trans; 451 struct btrfs_device *device = NULL; 452 char *sizestr; 453 char *devstr = NULL; 454 int ret = 0; 455 int namelen; 456 int mod = 0; 457 458 if (root->fs_info->sb->s_flags & MS_RDONLY) 459 return -EROFS; 460 461 if (!capable(CAP_SYS_ADMIN)) 462 return -EPERM; 463 464 vol_args = memdup_user(arg, sizeof(*vol_args)); 465 if (IS_ERR(vol_args)) 466 return PTR_ERR(vol_args); 467 468 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 469 namelen = strlen(vol_args->name); 470 471 mutex_lock(&root->fs_info->volume_mutex); 472 sizestr = vol_args->name; 473 devstr = strchr(sizestr, ':'); 474 if (devstr) { 475 char *end; 476 sizestr = devstr + 1; 477 *devstr = '\0'; 478 devstr = vol_args->name; 479 devid = simple_strtoull(devstr, &end, 10); 480 printk(KERN_INFO "resizing devid %llu\n", 481 (unsigned long long)devid); 482 } 483 device = btrfs_find_device(root, devid, NULL, NULL); 484 if (!device) { 485 printk(KERN_INFO "resizer unable to find device %llu\n", 486 (unsigned long long)devid); 487 ret = -EINVAL; 488 goto out_unlock; 489 } 490 if (!strcmp(sizestr, "max")) 491 new_size = device->bdev->bd_inode->i_size; 492 else { 493 if (sizestr[0] == '-') { 494 mod = -1; 495 sizestr++; 496 } else if (sizestr[0] == '+') { 497 mod = 1; 498 sizestr++; 499 } 500 new_size = btrfs_parse_size(sizestr); 501 if (new_size == 0) { 502 ret = -EINVAL; 503 goto out_unlock; 504 } 505 } 506 507 old_size = device->total_bytes; 508 509 if (mod < 0) { 510 if (new_size > old_size) { 511 ret = -EINVAL; 512 goto out_unlock; 513 } 514 new_size = old_size - new_size; 515 } else if (mod > 0) { 516 new_size = old_size + new_size; 517 } 518 519 if (new_size < 256 * 1024 * 1024) { 520 ret = -EINVAL; 521 goto out_unlock; 522 } 523 if (new_size > device->bdev->bd_inode->i_size) { 524 ret = -EFBIG; 525 goto out_unlock; 526 } 527 528 do_div(new_size, root->sectorsize); 529 new_size *= root->sectorsize; 530 531 printk(KERN_INFO "new size for %s is %llu\n", 532 device->name, (unsigned long long)new_size); 533 534 if (new_size > old_size) { 535 trans = btrfs_start_transaction(root, 1); 536 ret = btrfs_grow_device(trans, device, new_size); 537 btrfs_commit_transaction(trans, root); 538 } else { 539 ret = btrfs_shrink_device(device, new_size); 540 } 541 542 out_unlock: 543 mutex_unlock(&root->fs_info->volume_mutex); 544 kfree(vol_args); 545 return ret; 546 } 547 548 static noinline int btrfs_ioctl_snap_create(struct file *file, 549 void __user *arg, int subvol) 550 { 551 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 552 struct btrfs_ioctl_vol_args *vol_args; 553 struct btrfs_dir_item *di; 554 struct btrfs_path *path; 555 struct file *src_file; 556 u64 root_dirid; 557 int namelen; 558 int ret = 0; 559 560 if (root->fs_info->sb->s_flags & MS_RDONLY) 561 return -EROFS; 562 563 vol_args = memdup_user(arg, sizeof(*vol_args)); 564 if (IS_ERR(vol_args)) 565 return PTR_ERR(vol_args); 566 567 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 568 namelen = strlen(vol_args->name); 569 if (strchr(vol_args->name, '/')) { 570 ret = -EINVAL; 571 goto out; 572 } 573 574 path = btrfs_alloc_path(); 575 if (!path) { 576 ret = -ENOMEM; 577 goto out; 578 } 579 580 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino, 581 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, 582 path, root_dirid, 583 vol_args->name, namelen, 0); 584 btrfs_free_path(path); 585 586 if (di && !IS_ERR(di)) { 587 ret = -EEXIST; 588 goto out; 589 } 590 591 if (IS_ERR(di)) { 592 ret = PTR_ERR(di); 593 goto out; 594 } 595 596 if (subvol) { 597 ret = btrfs_mksubvol(&file->f_path, vol_args->name, 598 file->f_path.dentry->d_inode->i_mode, 599 namelen, NULL); 600 } else { 601 struct inode *src_inode; 602 src_file = fget(vol_args->fd); 603 if (!src_file) { 604 ret = -EINVAL; 605 goto out; 606 } 607 608 src_inode = src_file->f_path.dentry->d_inode; 609 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { 610 printk(KERN_INFO "btrfs: Snapshot src from " 611 "another FS\n"); 612 ret = -EINVAL; 613 fput(src_file); 614 goto out; 615 } 616 ret = btrfs_mksubvol(&file->f_path, vol_args->name, 617 file->f_path.dentry->d_inode->i_mode, 618 namelen, BTRFS_I(src_inode)->root); 619 fput(src_file); 620 } 621 622 out: 623 kfree(vol_args); 624 return ret; 625 } 626 627 static int btrfs_ioctl_defrag(struct file *file) 628 { 629 struct inode *inode = fdentry(file)->d_inode; 630 struct btrfs_root *root = BTRFS_I(inode)->root; 631 int ret; 632 633 ret = mnt_want_write(file->f_path.mnt); 634 if (ret) 635 return ret; 636 637 switch (inode->i_mode & S_IFMT) { 638 case S_IFDIR: 639 if (!capable(CAP_SYS_ADMIN)) { 640 ret = -EPERM; 641 goto out; 642 } 643 btrfs_defrag_root(root, 0); 644 btrfs_defrag_root(root->fs_info->extent_root, 0); 645 break; 646 case S_IFREG: 647 if (!(file->f_mode & FMODE_WRITE)) { 648 ret = -EINVAL; 649 goto out; 650 } 651 btrfs_defrag_file(file); 652 break; 653 } 654 out: 655 mnt_drop_write(file->f_path.mnt); 656 return ret; 657 } 658 659 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 660 { 661 struct btrfs_ioctl_vol_args *vol_args; 662 int ret; 663 664 if (!capable(CAP_SYS_ADMIN)) 665 return -EPERM; 666 667 vol_args = memdup_user(arg, sizeof(*vol_args)); 668 if (IS_ERR(vol_args)) 669 return PTR_ERR(vol_args); 670 671 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 672 ret = btrfs_init_new_device(root, vol_args->name); 673 674 kfree(vol_args); 675 return ret; 676 } 677 678 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 679 { 680 struct btrfs_ioctl_vol_args *vol_args; 681 int ret; 682 683 if (!capable(CAP_SYS_ADMIN)) 684 return -EPERM; 685 686 if (root->fs_info->sb->s_flags & MS_RDONLY) 687 return -EROFS; 688 689 vol_args = memdup_user(arg, sizeof(*vol_args)); 690 if (IS_ERR(vol_args)) 691 return PTR_ERR(vol_args); 692 693 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 694 ret = btrfs_rm_device(root, vol_args->name); 695 696 kfree(vol_args); 697 return ret; 698 } 699 700 static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 701 u64 off, u64 olen, u64 destoff) 702 { 703 struct inode *inode = fdentry(file)->d_inode; 704 struct btrfs_root *root = BTRFS_I(inode)->root; 705 struct file *src_file; 706 struct inode *src; 707 struct btrfs_trans_handle *trans; 708 struct btrfs_path *path; 709 struct extent_buffer *leaf; 710 char *buf; 711 struct btrfs_key key; 712 u32 nritems; 713 int slot; 714 int ret; 715 u64 len = olen; 716 u64 bs = root->fs_info->sb->s_blocksize; 717 u64 hint_byte; 718 719 /* 720 * TODO: 721 * - split compressed inline extents. annoying: we need to 722 * decompress into destination's address_space (the file offset 723 * may change, so source mapping won't do), then recompress (or 724 * otherwise reinsert) a subrange. 725 * - allow ranges within the same file to be cloned (provided 726 * they don't overlap)? 727 */ 728 729 /* the destination must be opened for writing */ 730 if (!(file->f_mode & FMODE_WRITE)) 731 return -EINVAL; 732 733 ret = mnt_want_write(file->f_path.mnt); 734 if (ret) 735 return ret; 736 737 src_file = fget(srcfd); 738 if (!src_file) { 739 ret = -EBADF; 740 goto out_drop_write; 741 } 742 src = src_file->f_dentry->d_inode; 743 744 ret = -EINVAL; 745 if (src == inode) 746 goto out_fput; 747 748 ret = -EISDIR; 749 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 750 goto out_fput; 751 752 ret = -EXDEV; 753 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) 754 goto out_fput; 755 756 ret = -ENOMEM; 757 buf = vmalloc(btrfs_level_size(root, 0)); 758 if (!buf) 759 goto out_fput; 760 761 path = btrfs_alloc_path(); 762 if (!path) { 763 vfree(buf); 764 goto out_fput; 765 } 766 path->reada = 2; 767 768 if (inode < src) { 769 mutex_lock(&inode->i_mutex); 770 mutex_lock(&src->i_mutex); 771 } else { 772 mutex_lock(&src->i_mutex); 773 mutex_lock(&inode->i_mutex); 774 } 775 776 /* determine range to clone */ 777 ret = -EINVAL; 778 if (off >= src->i_size || off + len > src->i_size) 779 goto out_unlock; 780 if (len == 0) 781 olen = len = src->i_size - off; 782 /* if we extend to eof, continue to block boundary */ 783 if (off + len == src->i_size) 784 len = ((src->i_size + bs-1) & ~(bs-1)) 785 - off; 786 787 /* verify the end result is block aligned */ 788 if ((off & (bs-1)) || 789 ((off + len) & (bs-1))) 790 goto out_unlock; 791 792 /* do any pending delalloc/csum calc on src, one way or 793 another, and lock file content */ 794 while (1) { 795 struct btrfs_ordered_extent *ordered; 796 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 797 ordered = btrfs_lookup_first_ordered_extent(inode, off+len); 798 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered) 799 break; 800 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 801 if (ordered) 802 btrfs_put_ordered_extent(ordered); 803 btrfs_wait_ordered_range(src, off, off+len); 804 } 805 806 trans = btrfs_start_transaction(root, 1); 807 BUG_ON(!trans); 808 809 /* punch hole in destination first */ 810 btrfs_drop_extents(trans, root, inode, off, off + len, 811 off + len, 0, &hint_byte); 812 813 /* clone data */ 814 key.objectid = src->i_ino; 815 key.type = BTRFS_EXTENT_DATA_KEY; 816 key.offset = 0; 817 818 while (1) { 819 /* 820 * note the key will change type as we walk through the 821 * tree. 822 */ 823 ret = btrfs_search_slot(trans, root, &key, path, 0, 0); 824 if (ret < 0) 825 goto out; 826 827 nritems = btrfs_header_nritems(path->nodes[0]); 828 if (path->slots[0] >= nritems) { 829 ret = btrfs_next_leaf(root, path); 830 if (ret < 0) 831 goto out; 832 if (ret > 0) 833 break; 834 nritems = btrfs_header_nritems(path->nodes[0]); 835 } 836 leaf = path->nodes[0]; 837 slot = path->slots[0]; 838 839 btrfs_item_key_to_cpu(leaf, &key, slot); 840 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 841 key.objectid != src->i_ino) 842 break; 843 844 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 845 struct btrfs_file_extent_item *extent; 846 int type; 847 u32 size; 848 struct btrfs_key new_key; 849 u64 disko = 0, diskl = 0; 850 u64 datao = 0, datal = 0; 851 u8 comp; 852 853 size = btrfs_item_size_nr(leaf, slot); 854 read_extent_buffer(leaf, buf, 855 btrfs_item_ptr_offset(leaf, slot), 856 size); 857 858 extent = btrfs_item_ptr(leaf, slot, 859 struct btrfs_file_extent_item); 860 comp = btrfs_file_extent_compression(leaf, extent); 861 type = btrfs_file_extent_type(leaf, extent); 862 if (type == BTRFS_FILE_EXTENT_REG) { 863 disko = btrfs_file_extent_disk_bytenr(leaf, 864 extent); 865 diskl = btrfs_file_extent_disk_num_bytes(leaf, 866 extent); 867 datao = btrfs_file_extent_offset(leaf, extent); 868 datal = btrfs_file_extent_num_bytes(leaf, 869 extent); 870 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 871 /* take upper bound, may be compressed */ 872 datal = btrfs_file_extent_ram_bytes(leaf, 873 extent); 874 } 875 btrfs_release_path(root, path); 876 877 if (key.offset + datal < off || 878 key.offset >= off+len) 879 goto next; 880 881 memcpy(&new_key, &key, sizeof(new_key)); 882 new_key.objectid = inode->i_ino; 883 new_key.offset = key.offset + destoff - off; 884 885 if (type == BTRFS_FILE_EXTENT_REG) { 886 ret = btrfs_insert_empty_item(trans, root, path, 887 &new_key, size); 888 if (ret) 889 goto out; 890 891 leaf = path->nodes[0]; 892 slot = path->slots[0]; 893 write_extent_buffer(leaf, buf, 894 btrfs_item_ptr_offset(leaf, slot), 895 size); 896 897 extent = btrfs_item_ptr(leaf, slot, 898 struct btrfs_file_extent_item); 899 900 if (off > key.offset) { 901 datao += off - key.offset; 902 datal -= off - key.offset; 903 } 904 if (key.offset + datao + datal + key.offset > 905 off + len) 906 datal = off + len - key.offset - datao; 907 /* disko == 0 means it's a hole */ 908 if (!disko) 909 datao = 0; 910 911 btrfs_set_file_extent_offset(leaf, extent, 912 datao); 913 btrfs_set_file_extent_num_bytes(leaf, extent, 914 datal); 915 if (disko) { 916 inode_add_bytes(inode, datal); 917 ret = btrfs_inc_extent_ref(trans, root, 918 disko, diskl, leaf->start, 919 root->root_key.objectid, 920 trans->transid, 921 inode->i_ino); 922 BUG_ON(ret); 923 } 924 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 925 u64 skip = 0; 926 u64 trim = 0; 927 if (off > key.offset) { 928 skip = off - key.offset; 929 new_key.offset += skip; 930 } 931 932 if (key.offset + datal > off+len) 933 trim = key.offset + datal - (off+len); 934 935 if (comp && (skip || trim)) { 936 ret = -EINVAL; 937 goto out; 938 } 939 size -= skip + trim; 940 datal -= skip + trim; 941 ret = btrfs_insert_empty_item(trans, root, path, 942 &new_key, size); 943 if (ret) 944 goto out; 945 946 if (skip) { 947 u32 start = 948 btrfs_file_extent_calc_inline_size(0); 949 memmove(buf+start, buf+start+skip, 950 datal); 951 } 952 953 leaf = path->nodes[0]; 954 slot = path->slots[0]; 955 write_extent_buffer(leaf, buf, 956 btrfs_item_ptr_offset(leaf, slot), 957 size); 958 inode_add_bytes(inode, datal); 959 } 960 961 btrfs_mark_buffer_dirty(leaf); 962 } 963 964 next: 965 btrfs_release_path(root, path); 966 key.offset++; 967 } 968 ret = 0; 969 out: 970 btrfs_release_path(root, path); 971 if (ret == 0) { 972 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 973 if (destoff + olen > inode->i_size) 974 btrfs_i_size_write(inode, destoff + olen); 975 BTRFS_I(inode)->flags = BTRFS_I(src)->flags; 976 ret = btrfs_update_inode(trans, root, inode); 977 } 978 btrfs_end_transaction(trans, root); 979 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 980 if (ret) 981 vmtruncate(inode, 0); 982 out_unlock: 983 mutex_unlock(&src->i_mutex); 984 mutex_unlock(&inode->i_mutex); 985 vfree(buf); 986 btrfs_free_path(path); 987 out_fput: 988 fput(src_file); 989 out_drop_write: 990 mnt_drop_write(file->f_path.mnt); 991 return ret; 992 } 993 994 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 995 { 996 struct btrfs_ioctl_clone_range_args args; 997 998 if (copy_from_user(&args, argp, sizeof(args))) 999 return -EFAULT; 1000 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 1001 args.src_length, args.dest_offset); 1002 } 1003 1004 /* 1005 * there are many ways the trans_start and trans_end ioctls can lead 1006 * to deadlocks. They should only be used by applications that 1007 * basically own the machine, and have a very in depth understanding 1008 * of all the possible deadlocks and enospc problems. 1009 */ 1010 static long btrfs_ioctl_trans_start(struct file *file) 1011 { 1012 struct inode *inode = fdentry(file)->d_inode; 1013 struct btrfs_root *root = BTRFS_I(inode)->root; 1014 struct btrfs_trans_handle *trans; 1015 int ret = 0; 1016 1017 if (!capable(CAP_SYS_ADMIN)) 1018 return -EPERM; 1019 1020 if (file->private_data) { 1021 ret = -EINPROGRESS; 1022 goto out; 1023 } 1024 1025 ret = mnt_want_write(file->f_path.mnt); 1026 if (ret) 1027 goto out; 1028 1029 mutex_lock(&root->fs_info->trans_mutex); 1030 root->fs_info->open_ioctl_trans++; 1031 mutex_unlock(&root->fs_info->trans_mutex); 1032 1033 trans = btrfs_start_ioctl_transaction(root, 0); 1034 if (trans) 1035 file->private_data = trans; 1036 else 1037 ret = -ENOMEM; 1038 /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/ 1039 out: 1040 return ret; 1041 } 1042 1043 /* 1044 * there are many ways the trans_start and trans_end ioctls can lead 1045 * to deadlocks. They should only be used by applications that 1046 * basically own the machine, and have a very in depth understanding 1047 * of all the possible deadlocks and enospc problems. 1048 */ 1049 long btrfs_ioctl_trans_end(struct file *file) 1050 { 1051 struct inode *inode = fdentry(file)->d_inode; 1052 struct btrfs_root *root = BTRFS_I(inode)->root; 1053 struct btrfs_trans_handle *trans; 1054 int ret = 0; 1055 1056 trans = file->private_data; 1057 if (!trans) { 1058 ret = -EINVAL; 1059 goto out; 1060 } 1061 btrfs_end_transaction(trans, root); 1062 file->private_data = NULL; 1063 1064 mutex_lock(&root->fs_info->trans_mutex); 1065 root->fs_info->open_ioctl_trans--; 1066 mutex_unlock(&root->fs_info->trans_mutex); 1067 1068 mnt_drop_write(file->f_path.mnt); 1069 1070 out: 1071 return ret; 1072 } 1073 1074 long btrfs_ioctl(struct file *file, unsigned int 1075 cmd, unsigned long arg) 1076 { 1077 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 1078 void __user *argp = (void __user *)arg; 1079 1080 switch (cmd) { 1081 case BTRFS_IOC_SNAP_CREATE: 1082 return btrfs_ioctl_snap_create(file, argp, 0); 1083 case BTRFS_IOC_SUBVOL_CREATE: 1084 return btrfs_ioctl_snap_create(file, argp, 1); 1085 case BTRFS_IOC_DEFRAG: 1086 return btrfs_ioctl_defrag(file); 1087 case BTRFS_IOC_RESIZE: 1088 return btrfs_ioctl_resize(root, argp); 1089 case BTRFS_IOC_ADD_DEV: 1090 return btrfs_ioctl_add_dev(root, argp); 1091 case BTRFS_IOC_RM_DEV: 1092 return btrfs_ioctl_rm_dev(root, argp); 1093 case BTRFS_IOC_BALANCE: 1094 return btrfs_balance(root->fs_info->dev_root); 1095 case BTRFS_IOC_CLONE: 1096 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 1097 case BTRFS_IOC_CLONE_RANGE: 1098 return btrfs_ioctl_clone_range(file, argp); 1099 case BTRFS_IOC_TRANS_START: 1100 return btrfs_ioctl_trans_start(file); 1101 case BTRFS_IOC_TRANS_END: 1102 return btrfs_ioctl_trans_end(file); 1103 case BTRFS_IOC_SYNC: 1104 btrfs_sync_fs(file->f_dentry->d_sb, 1); 1105 return 0; 1106 } 1107 1108 return -ENOTTY; 1109 } 1110