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 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) 441 { 442 u64 new_size; 443 u64 old_size; 444 u64 devid = 1; 445 struct btrfs_ioctl_vol_args *vol_args; 446 struct btrfs_trans_handle *trans; 447 struct btrfs_device *device = NULL; 448 char *sizestr; 449 char *devstr = NULL; 450 int ret = 0; 451 int namelen; 452 int mod = 0; 453 454 if (root->fs_info->sb->s_flags & MS_RDONLY) 455 return -EROFS; 456 457 if (!capable(CAP_SYS_ADMIN)) 458 return -EPERM; 459 460 vol_args = memdup_user(arg, sizeof(*vol_args)); 461 if (IS_ERR(vol_args)) 462 return PTR_ERR(vol_args); 463 464 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 465 namelen = strlen(vol_args->name); 466 467 mutex_lock(&root->fs_info->volume_mutex); 468 sizestr = vol_args->name; 469 devstr = strchr(sizestr, ':'); 470 if (devstr) { 471 char *end; 472 sizestr = devstr + 1; 473 *devstr = '\0'; 474 devstr = vol_args->name; 475 devid = simple_strtoull(devstr, &end, 10); 476 printk(KERN_INFO "resizing devid %llu\n", 477 (unsigned long long)devid); 478 } 479 device = btrfs_find_device(root, devid, NULL, NULL); 480 if (!device) { 481 printk(KERN_INFO "resizer unable to find device %llu\n", 482 (unsigned long long)devid); 483 ret = -EINVAL; 484 goto out_unlock; 485 } 486 if (!strcmp(sizestr, "max")) 487 new_size = device->bdev->bd_inode->i_size; 488 else { 489 if (sizestr[0] == '-') { 490 mod = -1; 491 sizestr++; 492 } else if (sizestr[0] == '+') { 493 mod = 1; 494 sizestr++; 495 } 496 new_size = btrfs_parse_size(sizestr); 497 if (new_size == 0) { 498 ret = -EINVAL; 499 goto out_unlock; 500 } 501 } 502 503 old_size = device->total_bytes; 504 505 if (mod < 0) { 506 if (new_size > old_size) { 507 ret = -EINVAL; 508 goto out_unlock; 509 } 510 new_size = old_size - new_size; 511 } else if (mod > 0) { 512 new_size = old_size + new_size; 513 } 514 515 if (new_size < 256 * 1024 * 1024) { 516 ret = -EINVAL; 517 goto out_unlock; 518 } 519 if (new_size > device->bdev->bd_inode->i_size) { 520 ret = -EFBIG; 521 goto out_unlock; 522 } 523 524 do_div(new_size, root->sectorsize); 525 new_size *= root->sectorsize; 526 527 printk(KERN_INFO "new size for %s is %llu\n", 528 device->name, (unsigned long long)new_size); 529 530 if (new_size > old_size) { 531 trans = btrfs_start_transaction(root, 1); 532 ret = btrfs_grow_device(trans, device, new_size); 533 btrfs_commit_transaction(trans, root); 534 } else { 535 ret = btrfs_shrink_device(device, new_size); 536 } 537 538 out_unlock: 539 mutex_unlock(&root->fs_info->volume_mutex); 540 kfree(vol_args); 541 return ret; 542 } 543 544 static noinline int btrfs_ioctl_snap_create(struct file *file, 545 void __user *arg, int subvol) 546 { 547 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 548 struct btrfs_ioctl_vol_args *vol_args; 549 struct btrfs_dir_item *di; 550 struct btrfs_path *path; 551 struct file *src_file; 552 u64 root_dirid; 553 int namelen; 554 int ret = 0; 555 556 if (root->fs_info->sb->s_flags & MS_RDONLY) 557 return -EROFS; 558 559 vol_args = memdup_user(arg, sizeof(*vol_args)); 560 if (IS_ERR(vol_args)) 561 return PTR_ERR(vol_args); 562 563 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 564 namelen = strlen(vol_args->name); 565 if (strchr(vol_args->name, '/')) { 566 ret = -EINVAL; 567 goto out; 568 } 569 570 path = btrfs_alloc_path(); 571 if (!path) { 572 ret = -ENOMEM; 573 goto out; 574 } 575 576 root_dirid = root->fs_info->sb->s_root->d_inode->i_ino, 577 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, 578 path, root_dirid, 579 vol_args->name, namelen, 0); 580 btrfs_free_path(path); 581 582 if (di && !IS_ERR(di)) { 583 ret = -EEXIST; 584 goto out; 585 } 586 587 if (IS_ERR(di)) { 588 ret = PTR_ERR(di); 589 goto out; 590 } 591 592 if (subvol) { 593 ret = btrfs_mksubvol(&file->f_path, vol_args->name, 594 file->f_path.dentry->d_inode->i_mode, 595 namelen, NULL); 596 } else { 597 struct inode *src_inode; 598 src_file = fget(vol_args->fd); 599 if (!src_file) { 600 ret = -EINVAL; 601 goto out; 602 } 603 604 src_inode = src_file->f_path.dentry->d_inode; 605 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { 606 printk(KERN_INFO "btrfs: Snapshot src from " 607 "another FS\n"); 608 ret = -EINVAL; 609 fput(src_file); 610 goto out; 611 } 612 ret = btrfs_mksubvol(&file->f_path, vol_args->name, 613 file->f_path.dentry->d_inode->i_mode, 614 namelen, BTRFS_I(src_inode)->root); 615 fput(src_file); 616 } 617 618 out: 619 kfree(vol_args); 620 return ret; 621 } 622 623 static int btrfs_ioctl_defrag(struct file *file) 624 { 625 struct inode *inode = fdentry(file)->d_inode; 626 struct btrfs_root *root = BTRFS_I(inode)->root; 627 int ret; 628 629 ret = mnt_want_write(file->f_path.mnt); 630 if (ret) 631 return ret; 632 633 switch (inode->i_mode & S_IFMT) { 634 case S_IFDIR: 635 if (!capable(CAP_SYS_ADMIN)) { 636 ret = -EPERM; 637 goto out; 638 } 639 btrfs_defrag_root(root, 0); 640 btrfs_defrag_root(root->fs_info->extent_root, 0); 641 break; 642 case S_IFREG: 643 if (!(file->f_mode & FMODE_WRITE)) { 644 ret = -EINVAL; 645 goto out; 646 } 647 btrfs_defrag_file(file); 648 break; 649 } 650 out: 651 mnt_drop_write(file->f_path.mnt); 652 return ret; 653 } 654 655 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 656 { 657 struct btrfs_ioctl_vol_args *vol_args; 658 int ret; 659 660 if (!capable(CAP_SYS_ADMIN)) 661 return -EPERM; 662 663 vol_args = memdup_user(arg, sizeof(*vol_args)); 664 if (IS_ERR(vol_args)) 665 return PTR_ERR(vol_args); 666 667 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 668 ret = btrfs_init_new_device(root, vol_args->name); 669 670 kfree(vol_args); 671 return ret; 672 } 673 674 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 675 { 676 struct btrfs_ioctl_vol_args *vol_args; 677 int ret; 678 679 if (!capable(CAP_SYS_ADMIN)) 680 return -EPERM; 681 682 if (root->fs_info->sb->s_flags & MS_RDONLY) 683 return -EROFS; 684 685 vol_args = memdup_user(arg, sizeof(*vol_args)); 686 if (IS_ERR(vol_args)) 687 return PTR_ERR(vol_args); 688 689 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 690 ret = btrfs_rm_device(root, vol_args->name); 691 692 kfree(vol_args); 693 return ret; 694 } 695 696 static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 697 u64 off, u64 olen, u64 destoff) 698 { 699 struct inode *inode = fdentry(file)->d_inode; 700 struct btrfs_root *root = BTRFS_I(inode)->root; 701 struct file *src_file; 702 struct inode *src; 703 struct btrfs_trans_handle *trans; 704 struct btrfs_path *path; 705 struct extent_buffer *leaf; 706 char *buf; 707 struct btrfs_key key; 708 u32 nritems; 709 int slot; 710 int ret; 711 u64 len = olen; 712 u64 bs = root->fs_info->sb->s_blocksize; 713 u64 hint_byte; 714 715 /* 716 * TODO: 717 * - split compressed inline extents. annoying: we need to 718 * decompress into destination's address_space (the file offset 719 * may change, so source mapping won't do), then recompress (or 720 * otherwise reinsert) a subrange. 721 * - allow ranges within the same file to be cloned (provided 722 * they don't overlap)? 723 */ 724 725 /* the destination must be opened for writing */ 726 if (!(file->f_mode & FMODE_WRITE)) 727 return -EINVAL; 728 729 ret = mnt_want_write(file->f_path.mnt); 730 if (ret) 731 return ret; 732 733 src_file = fget(srcfd); 734 if (!src_file) { 735 ret = -EBADF; 736 goto out_drop_write; 737 } 738 src = src_file->f_dentry->d_inode; 739 740 ret = -EINVAL; 741 if (src == inode) 742 goto out_fput; 743 744 ret = -EISDIR; 745 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 746 goto out_fput; 747 748 ret = -EXDEV; 749 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) 750 goto out_fput; 751 752 ret = -ENOMEM; 753 buf = vmalloc(btrfs_level_size(root, 0)); 754 if (!buf) 755 goto out_fput; 756 757 path = btrfs_alloc_path(); 758 if (!path) { 759 vfree(buf); 760 goto out_fput; 761 } 762 path->reada = 2; 763 764 if (inode < src) { 765 mutex_lock(&inode->i_mutex); 766 mutex_lock(&src->i_mutex); 767 } else { 768 mutex_lock(&src->i_mutex); 769 mutex_lock(&inode->i_mutex); 770 } 771 772 /* determine range to clone */ 773 ret = -EINVAL; 774 if (off >= src->i_size || off + len > src->i_size) 775 goto out_unlock; 776 if (len == 0) 777 olen = len = src->i_size - off; 778 /* if we extend to eof, continue to block boundary */ 779 if (off + len == src->i_size) 780 len = ((src->i_size + bs-1) & ~(bs-1)) 781 - off; 782 783 /* verify the end result is block aligned */ 784 if ((off & (bs-1)) || 785 ((off + len) & (bs-1))) 786 goto out_unlock; 787 788 /* do any pending delalloc/csum calc on src, one way or 789 another, and lock file content */ 790 while (1) { 791 struct btrfs_ordered_extent *ordered; 792 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 793 ordered = btrfs_lookup_first_ordered_extent(inode, off+len); 794 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered) 795 break; 796 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 797 if (ordered) 798 btrfs_put_ordered_extent(ordered); 799 btrfs_wait_ordered_range(src, off, off+len); 800 } 801 802 trans = btrfs_start_transaction(root, 1); 803 BUG_ON(!trans); 804 805 /* punch hole in destination first */ 806 btrfs_drop_extents(trans, root, inode, off, off + len, 807 off + len, 0, &hint_byte); 808 809 /* clone data */ 810 key.objectid = src->i_ino; 811 key.type = BTRFS_EXTENT_DATA_KEY; 812 key.offset = 0; 813 814 while (1) { 815 /* 816 * note the key will change type as we walk through the 817 * tree. 818 */ 819 ret = btrfs_search_slot(trans, root, &key, path, 0, 0); 820 if (ret < 0) 821 goto out; 822 823 nritems = btrfs_header_nritems(path->nodes[0]); 824 if (path->slots[0] >= nritems) { 825 ret = btrfs_next_leaf(root, path); 826 if (ret < 0) 827 goto out; 828 if (ret > 0) 829 break; 830 nritems = btrfs_header_nritems(path->nodes[0]); 831 } 832 leaf = path->nodes[0]; 833 slot = path->slots[0]; 834 835 btrfs_item_key_to_cpu(leaf, &key, slot); 836 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 837 key.objectid != src->i_ino) 838 break; 839 840 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 841 struct btrfs_file_extent_item *extent; 842 int type; 843 u32 size; 844 struct btrfs_key new_key; 845 u64 disko = 0, diskl = 0; 846 u64 datao = 0, datal = 0; 847 u8 comp; 848 849 size = btrfs_item_size_nr(leaf, slot); 850 read_extent_buffer(leaf, buf, 851 btrfs_item_ptr_offset(leaf, slot), 852 size); 853 854 extent = btrfs_item_ptr(leaf, slot, 855 struct btrfs_file_extent_item); 856 comp = btrfs_file_extent_compression(leaf, extent); 857 type = btrfs_file_extent_type(leaf, extent); 858 if (type == BTRFS_FILE_EXTENT_REG) { 859 disko = btrfs_file_extent_disk_bytenr(leaf, 860 extent); 861 diskl = btrfs_file_extent_disk_num_bytes(leaf, 862 extent); 863 datao = btrfs_file_extent_offset(leaf, extent); 864 datal = btrfs_file_extent_num_bytes(leaf, 865 extent); 866 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 867 /* take upper bound, may be compressed */ 868 datal = btrfs_file_extent_ram_bytes(leaf, 869 extent); 870 } 871 btrfs_release_path(root, path); 872 873 if (key.offset + datal < off || 874 key.offset >= off+len) 875 goto next; 876 877 memcpy(&new_key, &key, sizeof(new_key)); 878 new_key.objectid = inode->i_ino; 879 new_key.offset = key.offset + destoff - off; 880 881 if (type == BTRFS_FILE_EXTENT_REG) { 882 ret = btrfs_insert_empty_item(trans, root, path, 883 &new_key, size); 884 if (ret) 885 goto out; 886 887 leaf = path->nodes[0]; 888 slot = path->slots[0]; 889 write_extent_buffer(leaf, buf, 890 btrfs_item_ptr_offset(leaf, slot), 891 size); 892 893 extent = btrfs_item_ptr(leaf, slot, 894 struct btrfs_file_extent_item); 895 896 if (off > key.offset) { 897 datao += off - key.offset; 898 datal -= off - key.offset; 899 } 900 if (key.offset + datao + datal + key.offset > 901 off + len) 902 datal = off + len - key.offset - datao; 903 /* disko == 0 means it's a hole */ 904 if (!disko) 905 datao = 0; 906 907 btrfs_set_file_extent_offset(leaf, extent, 908 datao); 909 btrfs_set_file_extent_num_bytes(leaf, extent, 910 datal); 911 if (disko) { 912 inode_add_bytes(inode, datal); 913 ret = btrfs_inc_extent_ref(trans, root, 914 disko, diskl, leaf->start, 915 root->root_key.objectid, 916 trans->transid, 917 inode->i_ino); 918 BUG_ON(ret); 919 } 920 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 921 u64 skip = 0; 922 u64 trim = 0; 923 if (off > key.offset) { 924 skip = off - key.offset; 925 new_key.offset += skip; 926 } 927 928 if (key.offset + datal > off+len) 929 trim = key.offset + datal - (off+len); 930 931 if (comp && (skip || trim)) { 932 ret = -EINVAL; 933 goto out; 934 } 935 size -= skip + trim; 936 datal -= skip + trim; 937 ret = btrfs_insert_empty_item(trans, root, path, 938 &new_key, size); 939 if (ret) 940 goto out; 941 942 if (skip) { 943 u32 start = 944 btrfs_file_extent_calc_inline_size(0); 945 memmove(buf+start, buf+start+skip, 946 datal); 947 } 948 949 leaf = path->nodes[0]; 950 slot = path->slots[0]; 951 write_extent_buffer(leaf, buf, 952 btrfs_item_ptr_offset(leaf, slot), 953 size); 954 inode_add_bytes(inode, datal); 955 } 956 957 btrfs_mark_buffer_dirty(leaf); 958 } 959 960 next: 961 btrfs_release_path(root, path); 962 key.offset++; 963 } 964 ret = 0; 965 out: 966 btrfs_release_path(root, path); 967 if (ret == 0) { 968 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 969 if (destoff + olen > inode->i_size) 970 btrfs_i_size_write(inode, destoff + olen); 971 BTRFS_I(inode)->flags = BTRFS_I(src)->flags; 972 ret = btrfs_update_inode(trans, root, inode); 973 } 974 btrfs_end_transaction(trans, root); 975 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 976 if (ret) 977 vmtruncate(inode, 0); 978 out_unlock: 979 mutex_unlock(&src->i_mutex); 980 mutex_unlock(&inode->i_mutex); 981 vfree(buf); 982 btrfs_free_path(path); 983 out_fput: 984 fput(src_file); 985 out_drop_write: 986 mnt_drop_write(file->f_path.mnt); 987 return ret; 988 } 989 990 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 991 { 992 struct btrfs_ioctl_clone_range_args args; 993 994 if (copy_from_user(&args, argp, sizeof(args))) 995 return -EFAULT; 996 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 997 args.src_length, args.dest_offset); 998 } 999 1000 /* 1001 * there are many ways the trans_start and trans_end ioctls can lead 1002 * to deadlocks. They should only be used by applications that 1003 * basically own the machine, and have a very in depth understanding 1004 * of all the possible deadlocks and enospc problems. 1005 */ 1006 static long btrfs_ioctl_trans_start(struct file *file) 1007 { 1008 struct inode *inode = fdentry(file)->d_inode; 1009 struct btrfs_root *root = BTRFS_I(inode)->root; 1010 struct btrfs_trans_handle *trans; 1011 int ret = 0; 1012 1013 if (!capable(CAP_SYS_ADMIN)) 1014 return -EPERM; 1015 1016 if (file->private_data) { 1017 ret = -EINPROGRESS; 1018 goto out; 1019 } 1020 1021 ret = mnt_want_write(file->f_path.mnt); 1022 if (ret) 1023 goto out; 1024 1025 mutex_lock(&root->fs_info->trans_mutex); 1026 root->fs_info->open_ioctl_trans++; 1027 mutex_unlock(&root->fs_info->trans_mutex); 1028 1029 trans = btrfs_start_ioctl_transaction(root, 0); 1030 if (trans) 1031 file->private_data = trans; 1032 else 1033 ret = -ENOMEM; 1034 /*printk(KERN_INFO "btrfs_ioctl_trans_start on %p\n", file);*/ 1035 out: 1036 return ret; 1037 } 1038 1039 /* 1040 * there are many ways the trans_start and trans_end ioctls can lead 1041 * to deadlocks. They should only be used by applications that 1042 * basically own the machine, and have a very in depth understanding 1043 * of all the possible deadlocks and enospc problems. 1044 */ 1045 long btrfs_ioctl_trans_end(struct file *file) 1046 { 1047 struct inode *inode = fdentry(file)->d_inode; 1048 struct btrfs_root *root = BTRFS_I(inode)->root; 1049 struct btrfs_trans_handle *trans; 1050 int ret = 0; 1051 1052 trans = file->private_data; 1053 if (!trans) { 1054 ret = -EINVAL; 1055 goto out; 1056 } 1057 btrfs_end_transaction(trans, root); 1058 file->private_data = NULL; 1059 1060 mutex_lock(&root->fs_info->trans_mutex); 1061 root->fs_info->open_ioctl_trans--; 1062 mutex_unlock(&root->fs_info->trans_mutex); 1063 1064 mnt_drop_write(file->f_path.mnt); 1065 1066 out: 1067 return ret; 1068 } 1069 1070 long btrfs_ioctl(struct file *file, unsigned int 1071 cmd, unsigned long arg) 1072 { 1073 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 1074 void __user *argp = (void __user *)arg; 1075 1076 switch (cmd) { 1077 case BTRFS_IOC_SNAP_CREATE: 1078 return btrfs_ioctl_snap_create(file, argp, 0); 1079 case BTRFS_IOC_SUBVOL_CREATE: 1080 return btrfs_ioctl_snap_create(file, argp, 1); 1081 case BTRFS_IOC_DEFRAG: 1082 return btrfs_ioctl_defrag(file); 1083 case BTRFS_IOC_RESIZE: 1084 return btrfs_ioctl_resize(root, argp); 1085 case BTRFS_IOC_ADD_DEV: 1086 return btrfs_ioctl_add_dev(root, argp); 1087 case BTRFS_IOC_RM_DEV: 1088 return btrfs_ioctl_rm_dev(root, argp); 1089 case BTRFS_IOC_BALANCE: 1090 return btrfs_balance(root->fs_info->dev_root); 1091 case BTRFS_IOC_CLONE: 1092 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 1093 case BTRFS_IOC_CLONE_RANGE: 1094 return btrfs_ioctl_clone_range(file, argp); 1095 case BTRFS_IOC_TRANS_START: 1096 return btrfs_ioctl_trans_start(file); 1097 case BTRFS_IOC_TRANS_END: 1098 return btrfs_ioctl_trans_end(file); 1099 case BTRFS_IOC_SYNC: 1100 btrfs_sync_fs(file->f_dentry->d_sb, 1); 1101 return 0; 1102 } 1103 1104 return -ENOTTY; 1105 } 1106