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/backing-dev.h> 31 #include <linux/mount.h> 32 #include <linux/mpage.h> 33 #include <linux/namei.h> 34 #include <linux/swap.h> 35 #include <linux/writeback.h> 36 #include <linux/statfs.h> 37 #include <linux/compat.h> 38 #include <linux/bit_spinlock.h> 39 #include <linux/security.h> 40 #include <linux/xattr.h> 41 #include <linux/vmalloc.h> 42 #include "compat.h" 43 #include "ctree.h" 44 #include "disk-io.h" 45 #include "transaction.h" 46 #include "btrfs_inode.h" 47 #include "ioctl.h" 48 #include "print-tree.h" 49 #include "volumes.h" 50 #include "locking.h" 51 52 /* Mask out flags that are inappropriate for the given type of inode. */ 53 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags) 54 { 55 if (S_ISDIR(mode)) 56 return flags; 57 else if (S_ISREG(mode)) 58 return flags & ~FS_DIRSYNC_FL; 59 else 60 return flags & (FS_NODUMP_FL | FS_NOATIME_FL); 61 } 62 63 /* 64 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl. 65 */ 66 static unsigned int btrfs_flags_to_ioctl(unsigned int flags) 67 { 68 unsigned int iflags = 0; 69 70 if (flags & BTRFS_INODE_SYNC) 71 iflags |= FS_SYNC_FL; 72 if (flags & BTRFS_INODE_IMMUTABLE) 73 iflags |= FS_IMMUTABLE_FL; 74 if (flags & BTRFS_INODE_APPEND) 75 iflags |= FS_APPEND_FL; 76 if (flags & BTRFS_INODE_NODUMP) 77 iflags |= FS_NODUMP_FL; 78 if (flags & BTRFS_INODE_NOATIME) 79 iflags |= FS_NOATIME_FL; 80 if (flags & BTRFS_INODE_DIRSYNC) 81 iflags |= FS_DIRSYNC_FL; 82 83 return iflags; 84 } 85 86 /* 87 * Update inode->i_flags based on the btrfs internal flags. 88 */ 89 void btrfs_update_iflags(struct inode *inode) 90 { 91 struct btrfs_inode *ip = BTRFS_I(inode); 92 93 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 94 95 if (ip->flags & BTRFS_INODE_SYNC) 96 inode->i_flags |= S_SYNC; 97 if (ip->flags & BTRFS_INODE_IMMUTABLE) 98 inode->i_flags |= S_IMMUTABLE; 99 if (ip->flags & BTRFS_INODE_APPEND) 100 inode->i_flags |= S_APPEND; 101 if (ip->flags & BTRFS_INODE_NOATIME) 102 inode->i_flags |= S_NOATIME; 103 if (ip->flags & BTRFS_INODE_DIRSYNC) 104 inode->i_flags |= S_DIRSYNC; 105 } 106 107 /* 108 * Inherit flags from the parent inode. 109 * 110 * Unlike extN we don't have any flags we don't want to inherit currently. 111 */ 112 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) 113 { 114 unsigned int flags; 115 116 if (!dir) 117 return; 118 119 flags = BTRFS_I(dir)->flags; 120 121 if (S_ISREG(inode->i_mode)) 122 flags &= ~BTRFS_INODE_DIRSYNC; 123 else if (!S_ISDIR(inode->i_mode)) 124 flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME); 125 126 BTRFS_I(inode)->flags = flags; 127 btrfs_update_iflags(inode); 128 } 129 130 static int btrfs_ioctl_getflags(struct file *file, void __user *arg) 131 { 132 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode); 133 unsigned int flags = btrfs_flags_to_ioctl(ip->flags); 134 135 if (copy_to_user(arg, &flags, sizeof(flags))) 136 return -EFAULT; 137 return 0; 138 } 139 140 static int btrfs_ioctl_setflags(struct file *file, void __user *arg) 141 { 142 struct inode *inode = file->f_path.dentry->d_inode; 143 struct btrfs_inode *ip = BTRFS_I(inode); 144 struct btrfs_root *root = ip->root; 145 struct btrfs_trans_handle *trans; 146 unsigned int flags, oldflags; 147 int ret; 148 149 if (copy_from_user(&flags, arg, sizeof(flags))) 150 return -EFAULT; 151 152 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ 153 FS_NOATIME_FL | FS_NODUMP_FL | \ 154 FS_SYNC_FL | FS_DIRSYNC_FL)) 155 return -EOPNOTSUPP; 156 157 if (!is_owner_or_cap(inode)) 158 return -EACCES; 159 160 mutex_lock(&inode->i_mutex); 161 162 flags = btrfs_mask_flags(inode->i_mode, flags); 163 oldflags = btrfs_flags_to_ioctl(ip->flags); 164 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) { 165 if (!capable(CAP_LINUX_IMMUTABLE)) { 166 ret = -EPERM; 167 goto out_unlock; 168 } 169 } 170 171 ret = mnt_want_write(file->f_path.mnt); 172 if (ret) 173 goto out_unlock; 174 175 if (flags & FS_SYNC_FL) 176 ip->flags |= BTRFS_INODE_SYNC; 177 else 178 ip->flags &= ~BTRFS_INODE_SYNC; 179 if (flags & FS_IMMUTABLE_FL) 180 ip->flags |= BTRFS_INODE_IMMUTABLE; 181 else 182 ip->flags &= ~BTRFS_INODE_IMMUTABLE; 183 if (flags & FS_APPEND_FL) 184 ip->flags |= BTRFS_INODE_APPEND; 185 else 186 ip->flags &= ~BTRFS_INODE_APPEND; 187 if (flags & FS_NODUMP_FL) 188 ip->flags |= BTRFS_INODE_NODUMP; 189 else 190 ip->flags &= ~BTRFS_INODE_NODUMP; 191 if (flags & FS_NOATIME_FL) 192 ip->flags |= BTRFS_INODE_NOATIME; 193 else 194 ip->flags &= ~BTRFS_INODE_NOATIME; 195 if (flags & FS_DIRSYNC_FL) 196 ip->flags |= BTRFS_INODE_DIRSYNC; 197 else 198 ip->flags &= ~BTRFS_INODE_DIRSYNC; 199 200 201 trans = btrfs_join_transaction(root, 1); 202 BUG_ON(!trans); 203 204 ret = btrfs_update_inode(trans, root, inode); 205 BUG_ON(ret); 206 207 btrfs_update_iflags(inode); 208 inode->i_ctime = CURRENT_TIME; 209 btrfs_end_transaction(trans, root); 210 211 mnt_drop_write(file->f_path.mnt); 212 out_unlock: 213 mutex_unlock(&inode->i_mutex); 214 return 0; 215 } 216 217 static int btrfs_ioctl_getversion(struct file *file, int __user *arg) 218 { 219 struct inode *inode = file->f_path.dentry->d_inode; 220 221 return put_user(inode->i_generation, arg); 222 } 223 224 static noinline int create_subvol(struct btrfs_root *root, 225 struct dentry *dentry, 226 char *name, int namelen) 227 { 228 struct btrfs_trans_handle *trans; 229 struct btrfs_key key; 230 struct btrfs_root_item root_item; 231 struct btrfs_inode_item *inode_item; 232 struct extent_buffer *leaf; 233 struct btrfs_root *new_root; 234 struct inode *dir = dentry->d_parent->d_inode; 235 int ret; 236 int err; 237 u64 objectid; 238 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; 239 u64 index = 0; 240 unsigned long nr = 1; 241 242 /* 243 * 1 - inode item 244 * 2 - refs 245 * 1 - root item 246 * 2 - dir items 247 */ 248 ret = btrfs_reserve_metadata_space(root, 6); 249 if (ret) 250 return ret; 251 252 trans = btrfs_start_transaction(root, 1); 253 BUG_ON(!trans); 254 255 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root, 256 0, &objectid); 257 if (ret) 258 goto fail; 259 260 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 261 0, objectid, NULL, 0, 0, 0); 262 if (IS_ERR(leaf)) { 263 ret = PTR_ERR(leaf); 264 goto fail; 265 } 266 267 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); 268 btrfs_set_header_bytenr(leaf, leaf->start); 269 btrfs_set_header_generation(leaf, trans->transid); 270 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); 271 btrfs_set_header_owner(leaf, objectid); 272 273 write_extent_buffer(leaf, root->fs_info->fsid, 274 (unsigned long)btrfs_header_fsid(leaf), 275 BTRFS_FSID_SIZE); 276 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, 277 (unsigned long)btrfs_header_chunk_tree_uuid(leaf), 278 BTRFS_UUID_SIZE); 279 btrfs_mark_buffer_dirty(leaf); 280 281 inode_item = &root_item.inode; 282 memset(inode_item, 0, sizeof(*inode_item)); 283 inode_item->generation = cpu_to_le64(1); 284 inode_item->size = cpu_to_le64(3); 285 inode_item->nlink = cpu_to_le32(1); 286 inode_item->nbytes = cpu_to_le64(root->leafsize); 287 inode_item->mode = cpu_to_le32(S_IFDIR | 0755); 288 289 btrfs_set_root_bytenr(&root_item, leaf->start); 290 btrfs_set_root_generation(&root_item, trans->transid); 291 btrfs_set_root_level(&root_item, 0); 292 btrfs_set_root_refs(&root_item, 1); 293 btrfs_set_root_used(&root_item, 0); 294 btrfs_set_root_last_snapshot(&root_item, 0); 295 296 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); 297 root_item.drop_level = 0; 298 299 btrfs_tree_unlock(leaf); 300 free_extent_buffer(leaf); 301 leaf = NULL; 302 303 btrfs_set_root_dirid(&root_item, new_dirid); 304 305 key.objectid = objectid; 306 key.offset = 0; 307 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); 308 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, 309 &root_item); 310 if (ret) 311 goto fail; 312 313 key.offset = (u64)-1; 314 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); 315 BUG_ON(IS_ERR(new_root)); 316 317 btrfs_record_root_in_trans(trans, new_root); 318 319 ret = btrfs_create_subvol_root(trans, new_root, new_dirid, 320 BTRFS_I(dir)->block_group); 321 /* 322 * insert the directory item 323 */ 324 ret = btrfs_set_inode_index(dir, &index); 325 BUG_ON(ret); 326 327 ret = btrfs_insert_dir_item(trans, root, 328 name, namelen, dir->i_ino, &key, 329 BTRFS_FT_DIR, index); 330 if (ret) 331 goto fail; 332 333 btrfs_i_size_write(dir, dir->i_size + namelen * 2); 334 ret = btrfs_update_inode(trans, root, dir); 335 BUG_ON(ret); 336 337 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 338 objectid, root->root_key.objectid, 339 dir->i_ino, index, name, namelen); 340 341 BUG_ON(ret); 342 343 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); 344 fail: 345 nr = trans->blocks_used; 346 err = btrfs_commit_transaction(trans, root); 347 if (err && !ret) 348 ret = err; 349 350 btrfs_unreserve_metadata_space(root, 6); 351 btrfs_btree_balance_dirty(root, nr); 352 return ret; 353 } 354 355 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, 356 char *name, int namelen) 357 { 358 struct btrfs_pending_snapshot *pending_snapshot; 359 struct btrfs_trans_handle *trans; 360 int ret = 0; 361 int err; 362 unsigned long nr = 0; 363 364 if (!root->ref_cows) 365 return -EINVAL; 366 367 /* 368 * 1 - inode item 369 * 2 - refs 370 * 1 - root item 371 * 2 - dir items 372 */ 373 ret = btrfs_reserve_metadata_space(root, 6); 374 if (ret) 375 goto fail_unlock; 376 377 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); 378 if (!pending_snapshot) { 379 ret = -ENOMEM; 380 btrfs_unreserve_metadata_space(root, 6); 381 goto fail_unlock; 382 } 383 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS); 384 if (!pending_snapshot->name) { 385 ret = -ENOMEM; 386 kfree(pending_snapshot); 387 btrfs_unreserve_metadata_space(root, 6); 388 goto fail_unlock; 389 } 390 memcpy(pending_snapshot->name, name, namelen); 391 pending_snapshot->name[namelen] = '\0'; 392 pending_snapshot->dentry = dentry; 393 trans = btrfs_start_transaction(root, 1); 394 BUG_ON(!trans); 395 pending_snapshot->root = root; 396 list_add(&pending_snapshot->list, 397 &trans->transaction->pending_snapshots); 398 err = btrfs_commit_transaction(trans, root); 399 400 fail_unlock: 401 btrfs_btree_balance_dirty(root, nr); 402 return ret; 403 } 404 405 /* copy of may_create in fs/namei.c() */ 406 static inline int btrfs_may_create(struct inode *dir, struct dentry *child) 407 { 408 if (child->d_inode) 409 return -EEXIST; 410 if (IS_DEADDIR(dir)) 411 return -ENOENT; 412 return inode_permission(dir, MAY_WRITE | MAY_EXEC); 413 } 414 415 /* 416 * Create a new subvolume below @parent. This is largely modeled after 417 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup 418 * inside this filesystem so it's quite a bit simpler. 419 */ 420 static noinline int btrfs_mksubvol(struct path *parent, 421 char *name, int namelen, 422 struct btrfs_root *snap_src) 423 { 424 struct inode *dir = parent->dentry->d_inode; 425 struct dentry *dentry; 426 int error; 427 428 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 429 430 dentry = lookup_one_len(name, parent->dentry, namelen); 431 error = PTR_ERR(dentry); 432 if (IS_ERR(dentry)) 433 goto out_unlock; 434 435 error = -EEXIST; 436 if (dentry->d_inode) 437 goto out_dput; 438 439 error = mnt_want_write(parent->mnt); 440 if (error) 441 goto out_dput; 442 443 error = btrfs_may_create(dir, dentry); 444 if (error) 445 goto out_drop_write; 446 447 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 448 449 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) 450 goto out_up_read; 451 452 if (snap_src) { 453 error = create_snapshot(snap_src, dentry, 454 name, namelen); 455 } else { 456 error = create_subvol(BTRFS_I(dir)->root, dentry, 457 name, namelen); 458 } 459 if (!error) 460 fsnotify_mkdir(dir, dentry); 461 out_up_read: 462 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 463 out_drop_write: 464 mnt_drop_write(parent->mnt); 465 out_dput: 466 dput(dentry); 467 out_unlock: 468 mutex_unlock(&dir->i_mutex); 469 return error; 470 } 471 472 static int btrfs_defrag_file(struct file *file) 473 { 474 struct inode *inode = fdentry(file)->d_inode; 475 struct btrfs_root *root = BTRFS_I(inode)->root; 476 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 477 struct btrfs_ordered_extent *ordered; 478 struct page *page; 479 unsigned long last_index; 480 unsigned long ra_pages = root->fs_info->bdi.ra_pages; 481 unsigned long total_read = 0; 482 u64 page_start; 483 u64 page_end; 484 unsigned long i; 485 int ret; 486 487 ret = btrfs_check_data_free_space(root, inode, inode->i_size); 488 if (ret) 489 return -ENOSPC; 490 491 mutex_lock(&inode->i_mutex); 492 last_index = inode->i_size >> PAGE_CACHE_SHIFT; 493 for (i = 0; i <= last_index; i++) { 494 if (total_read % ra_pages == 0) { 495 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i, 496 min(last_index, i + ra_pages - 1)); 497 } 498 total_read++; 499 again: 500 page = grab_cache_page(inode->i_mapping, i); 501 if (!page) 502 goto out_unlock; 503 if (!PageUptodate(page)) { 504 btrfs_readpage(NULL, page); 505 lock_page(page); 506 if (!PageUptodate(page)) { 507 unlock_page(page); 508 page_cache_release(page); 509 goto out_unlock; 510 } 511 } 512 513 wait_on_page_writeback(page); 514 515 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 516 page_end = page_start + PAGE_CACHE_SIZE - 1; 517 lock_extent(io_tree, page_start, page_end, GFP_NOFS); 518 519 ordered = btrfs_lookup_ordered_extent(inode, page_start); 520 if (ordered) { 521 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 522 unlock_page(page); 523 page_cache_release(page); 524 btrfs_start_ordered_extent(inode, ordered, 1); 525 btrfs_put_ordered_extent(ordered); 526 goto again; 527 } 528 set_page_extent_mapped(page); 529 530 /* 531 * this makes sure page_mkwrite is called on the 532 * page if it is dirtied again later 533 */ 534 clear_page_dirty_for_io(page); 535 536 btrfs_set_extent_delalloc(inode, page_start, page_end); 537 set_page_dirty(page); 538 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 539 unlock_page(page); 540 page_cache_release(page); 541 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1); 542 } 543 544 out_unlock: 545 mutex_unlock(&inode->i_mutex); 546 return 0; 547 } 548 549 static noinline int btrfs_ioctl_resize(struct btrfs_root *root, 550 void __user *arg) 551 { 552 u64 new_size; 553 u64 old_size; 554 u64 devid = 1; 555 struct btrfs_ioctl_vol_args *vol_args; 556 struct btrfs_trans_handle *trans; 557 struct btrfs_device *device = NULL; 558 char *sizestr; 559 char *devstr = NULL; 560 int ret = 0; 561 int namelen; 562 int mod = 0; 563 564 if (root->fs_info->sb->s_flags & MS_RDONLY) 565 return -EROFS; 566 567 if (!capable(CAP_SYS_ADMIN)) 568 return -EPERM; 569 570 vol_args = memdup_user(arg, sizeof(*vol_args)); 571 if (IS_ERR(vol_args)) 572 return PTR_ERR(vol_args); 573 574 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 575 namelen = strlen(vol_args->name); 576 577 mutex_lock(&root->fs_info->volume_mutex); 578 sizestr = vol_args->name; 579 devstr = strchr(sizestr, ':'); 580 if (devstr) { 581 char *end; 582 sizestr = devstr + 1; 583 *devstr = '\0'; 584 devstr = vol_args->name; 585 devid = simple_strtoull(devstr, &end, 10); 586 printk(KERN_INFO "resizing devid %llu\n", 587 (unsigned long long)devid); 588 } 589 device = btrfs_find_device(root, devid, NULL, NULL); 590 if (!device) { 591 printk(KERN_INFO "resizer unable to find device %llu\n", 592 (unsigned long long)devid); 593 ret = -EINVAL; 594 goto out_unlock; 595 } 596 if (!strcmp(sizestr, "max")) 597 new_size = device->bdev->bd_inode->i_size; 598 else { 599 if (sizestr[0] == '-') { 600 mod = -1; 601 sizestr++; 602 } else if (sizestr[0] == '+') { 603 mod = 1; 604 sizestr++; 605 } 606 new_size = btrfs_parse_size(sizestr); 607 if (new_size == 0) { 608 ret = -EINVAL; 609 goto out_unlock; 610 } 611 } 612 613 old_size = device->total_bytes; 614 615 if (mod < 0) { 616 if (new_size > old_size) { 617 ret = -EINVAL; 618 goto out_unlock; 619 } 620 new_size = old_size - new_size; 621 } else if (mod > 0) { 622 new_size = old_size + new_size; 623 } 624 625 if (new_size < 256 * 1024 * 1024) { 626 ret = -EINVAL; 627 goto out_unlock; 628 } 629 if (new_size > device->bdev->bd_inode->i_size) { 630 ret = -EFBIG; 631 goto out_unlock; 632 } 633 634 do_div(new_size, root->sectorsize); 635 new_size *= root->sectorsize; 636 637 printk(KERN_INFO "new size for %s is %llu\n", 638 device->name, (unsigned long long)new_size); 639 640 if (new_size > old_size) { 641 trans = btrfs_start_transaction(root, 1); 642 ret = btrfs_grow_device(trans, device, new_size); 643 btrfs_commit_transaction(trans, root); 644 } else { 645 ret = btrfs_shrink_device(device, new_size); 646 } 647 648 out_unlock: 649 mutex_unlock(&root->fs_info->volume_mutex); 650 kfree(vol_args); 651 return ret; 652 } 653 654 static noinline int btrfs_ioctl_snap_create(struct file *file, 655 void __user *arg, int subvol) 656 { 657 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 658 struct btrfs_ioctl_vol_args *vol_args; 659 struct file *src_file; 660 int namelen; 661 int ret = 0; 662 663 if (root->fs_info->sb->s_flags & MS_RDONLY) 664 return -EROFS; 665 666 vol_args = memdup_user(arg, sizeof(*vol_args)); 667 if (IS_ERR(vol_args)) 668 return PTR_ERR(vol_args); 669 670 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 671 namelen = strlen(vol_args->name); 672 if (strchr(vol_args->name, '/')) { 673 ret = -EINVAL; 674 goto out; 675 } 676 677 if (subvol) { 678 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen, 679 NULL); 680 } else { 681 struct inode *src_inode; 682 src_file = fget(vol_args->fd); 683 if (!src_file) { 684 ret = -EINVAL; 685 goto out; 686 } 687 688 src_inode = src_file->f_path.dentry->d_inode; 689 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { 690 printk(KERN_INFO "btrfs: Snapshot src from " 691 "another FS\n"); 692 ret = -EINVAL; 693 fput(src_file); 694 goto out; 695 } 696 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen, 697 BTRFS_I(src_inode)->root); 698 fput(src_file); 699 } 700 out: 701 kfree(vol_args); 702 return ret; 703 } 704 705 /* 706 * helper to check if the subvolume references other subvolumes 707 */ 708 static noinline int may_destroy_subvol(struct btrfs_root *root) 709 { 710 struct btrfs_path *path; 711 struct btrfs_key key; 712 int ret; 713 714 path = btrfs_alloc_path(); 715 if (!path) 716 return -ENOMEM; 717 718 key.objectid = root->root_key.objectid; 719 key.type = BTRFS_ROOT_REF_KEY; 720 key.offset = (u64)-1; 721 722 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, 723 &key, path, 0, 0); 724 if (ret < 0) 725 goto out; 726 BUG_ON(ret == 0); 727 728 ret = 0; 729 if (path->slots[0] > 0) { 730 path->slots[0]--; 731 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 732 if (key.objectid == root->root_key.objectid && 733 key.type == BTRFS_ROOT_REF_KEY) 734 ret = -ENOTEMPTY; 735 } 736 out: 737 btrfs_free_path(path); 738 return ret; 739 } 740 741 static noinline int btrfs_ioctl_snap_destroy(struct file *file, 742 void __user *arg) 743 { 744 struct dentry *parent = fdentry(file); 745 struct dentry *dentry; 746 struct inode *dir = parent->d_inode; 747 struct inode *inode; 748 struct btrfs_root *root = BTRFS_I(dir)->root; 749 struct btrfs_root *dest = NULL; 750 struct btrfs_ioctl_vol_args *vol_args; 751 struct btrfs_trans_handle *trans; 752 int namelen; 753 int ret; 754 int err = 0; 755 756 if (!capable(CAP_SYS_ADMIN)) 757 return -EPERM; 758 759 vol_args = memdup_user(arg, sizeof(*vol_args)); 760 if (IS_ERR(vol_args)) 761 return PTR_ERR(vol_args); 762 763 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 764 namelen = strlen(vol_args->name); 765 if (strchr(vol_args->name, '/') || 766 strncmp(vol_args->name, "..", namelen) == 0) { 767 err = -EINVAL; 768 goto out; 769 } 770 771 err = mnt_want_write(file->f_path.mnt); 772 if (err) 773 goto out; 774 775 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 776 dentry = lookup_one_len(vol_args->name, parent, namelen); 777 if (IS_ERR(dentry)) { 778 err = PTR_ERR(dentry); 779 goto out_unlock_dir; 780 } 781 782 if (!dentry->d_inode) { 783 err = -ENOENT; 784 goto out_dput; 785 } 786 787 inode = dentry->d_inode; 788 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { 789 err = -EINVAL; 790 goto out_dput; 791 } 792 793 dest = BTRFS_I(inode)->root; 794 795 mutex_lock(&inode->i_mutex); 796 err = d_invalidate(dentry); 797 if (err) 798 goto out_unlock; 799 800 down_write(&root->fs_info->subvol_sem); 801 802 err = may_destroy_subvol(dest); 803 if (err) 804 goto out_up_write; 805 806 trans = btrfs_start_transaction(root, 1); 807 ret = btrfs_unlink_subvol(trans, root, dir, 808 dest->root_key.objectid, 809 dentry->d_name.name, 810 dentry->d_name.len); 811 BUG_ON(ret); 812 813 btrfs_record_root_in_trans(trans, dest); 814 815 memset(&dest->root_item.drop_progress, 0, 816 sizeof(dest->root_item.drop_progress)); 817 dest->root_item.drop_level = 0; 818 btrfs_set_root_refs(&dest->root_item, 0); 819 820 ret = btrfs_insert_orphan_item(trans, 821 root->fs_info->tree_root, 822 dest->root_key.objectid); 823 BUG_ON(ret); 824 825 ret = btrfs_commit_transaction(trans, root); 826 BUG_ON(ret); 827 inode->i_flags |= S_DEAD; 828 out_up_write: 829 up_write(&root->fs_info->subvol_sem); 830 out_unlock: 831 mutex_unlock(&inode->i_mutex); 832 if (!err) { 833 btrfs_invalidate_inodes(dest); 834 d_delete(dentry); 835 } 836 out_dput: 837 dput(dentry); 838 out_unlock_dir: 839 mutex_unlock(&dir->i_mutex); 840 mnt_drop_write(file->f_path.mnt); 841 out: 842 kfree(vol_args); 843 return err; 844 } 845 846 static int btrfs_ioctl_defrag(struct file *file) 847 { 848 struct inode *inode = fdentry(file)->d_inode; 849 struct btrfs_root *root = BTRFS_I(inode)->root; 850 int ret; 851 852 ret = mnt_want_write(file->f_path.mnt); 853 if (ret) 854 return ret; 855 856 switch (inode->i_mode & S_IFMT) { 857 case S_IFDIR: 858 if (!capable(CAP_SYS_ADMIN)) { 859 ret = -EPERM; 860 goto out; 861 } 862 btrfs_defrag_root(root, 0); 863 btrfs_defrag_root(root->fs_info->extent_root, 0); 864 break; 865 case S_IFREG: 866 if (!(file->f_mode & FMODE_WRITE)) { 867 ret = -EINVAL; 868 goto out; 869 } 870 btrfs_defrag_file(file); 871 break; 872 } 873 out: 874 mnt_drop_write(file->f_path.mnt); 875 return ret; 876 } 877 878 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 879 { 880 struct btrfs_ioctl_vol_args *vol_args; 881 int ret; 882 883 if (!capable(CAP_SYS_ADMIN)) 884 return -EPERM; 885 886 vol_args = memdup_user(arg, sizeof(*vol_args)); 887 if (IS_ERR(vol_args)) 888 return PTR_ERR(vol_args); 889 890 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 891 ret = btrfs_init_new_device(root, vol_args->name); 892 893 kfree(vol_args); 894 return ret; 895 } 896 897 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 898 { 899 struct btrfs_ioctl_vol_args *vol_args; 900 int ret; 901 902 if (!capable(CAP_SYS_ADMIN)) 903 return -EPERM; 904 905 if (root->fs_info->sb->s_flags & MS_RDONLY) 906 return -EROFS; 907 908 vol_args = memdup_user(arg, sizeof(*vol_args)); 909 if (IS_ERR(vol_args)) 910 return PTR_ERR(vol_args); 911 912 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 913 ret = btrfs_rm_device(root, vol_args->name); 914 915 kfree(vol_args); 916 return ret; 917 } 918 919 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 920 u64 off, u64 olen, u64 destoff) 921 { 922 struct inode *inode = fdentry(file)->d_inode; 923 struct btrfs_root *root = BTRFS_I(inode)->root; 924 struct file *src_file; 925 struct inode *src; 926 struct btrfs_trans_handle *trans; 927 struct btrfs_path *path; 928 struct extent_buffer *leaf; 929 char *buf; 930 struct btrfs_key key; 931 u32 nritems; 932 int slot; 933 int ret; 934 u64 len = olen; 935 u64 bs = root->fs_info->sb->s_blocksize; 936 u64 hint_byte; 937 938 /* 939 * TODO: 940 * - split compressed inline extents. annoying: we need to 941 * decompress into destination's address_space (the file offset 942 * may change, so source mapping won't do), then recompress (or 943 * otherwise reinsert) a subrange. 944 * - allow ranges within the same file to be cloned (provided 945 * they don't overlap)? 946 */ 947 948 /* the destination must be opened for writing */ 949 if (!(file->f_mode & FMODE_WRITE)) 950 return -EINVAL; 951 952 ret = mnt_want_write(file->f_path.mnt); 953 if (ret) 954 return ret; 955 956 src_file = fget(srcfd); 957 if (!src_file) { 958 ret = -EBADF; 959 goto out_drop_write; 960 } 961 src = src_file->f_dentry->d_inode; 962 963 ret = -EINVAL; 964 if (src == inode) 965 goto out_fput; 966 967 ret = -EISDIR; 968 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 969 goto out_fput; 970 971 ret = -EXDEV; 972 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) 973 goto out_fput; 974 975 ret = -ENOMEM; 976 buf = vmalloc(btrfs_level_size(root, 0)); 977 if (!buf) 978 goto out_fput; 979 980 path = btrfs_alloc_path(); 981 if (!path) { 982 vfree(buf); 983 goto out_fput; 984 } 985 path->reada = 2; 986 987 if (inode < src) { 988 mutex_lock(&inode->i_mutex); 989 mutex_lock(&src->i_mutex); 990 } else { 991 mutex_lock(&src->i_mutex); 992 mutex_lock(&inode->i_mutex); 993 } 994 995 /* determine range to clone */ 996 ret = -EINVAL; 997 if (off >= src->i_size || off + len > src->i_size) 998 goto out_unlock; 999 if (len == 0) 1000 olen = len = src->i_size - off; 1001 /* if we extend to eof, continue to block boundary */ 1002 if (off + len == src->i_size) 1003 len = ((src->i_size + bs-1) & ~(bs-1)) 1004 - off; 1005 1006 /* verify the end result is block aligned */ 1007 if ((off & (bs-1)) || 1008 ((off + len) & (bs-1))) 1009 goto out_unlock; 1010 1011 /* do any pending delalloc/csum calc on src, one way or 1012 another, and lock file content */ 1013 while (1) { 1014 struct btrfs_ordered_extent *ordered; 1015 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 1016 ordered = btrfs_lookup_first_ordered_extent(inode, off+len); 1017 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered) 1018 break; 1019 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 1020 if (ordered) 1021 btrfs_put_ordered_extent(ordered); 1022 btrfs_wait_ordered_range(src, off, off+len); 1023 } 1024 1025 trans = btrfs_start_transaction(root, 1); 1026 BUG_ON(!trans); 1027 1028 /* punch hole in destination first */ 1029 btrfs_drop_extents(trans, root, inode, off, off + len, 1030 off + len, 0, &hint_byte, 1); 1031 1032 /* clone data */ 1033 key.objectid = src->i_ino; 1034 key.type = BTRFS_EXTENT_DATA_KEY; 1035 key.offset = 0; 1036 1037 while (1) { 1038 /* 1039 * note the key will change type as we walk through the 1040 * tree. 1041 */ 1042 ret = btrfs_search_slot(trans, root, &key, path, 0, 0); 1043 if (ret < 0) 1044 goto out; 1045 1046 nritems = btrfs_header_nritems(path->nodes[0]); 1047 if (path->slots[0] >= nritems) { 1048 ret = btrfs_next_leaf(root, path); 1049 if (ret < 0) 1050 goto out; 1051 if (ret > 0) 1052 break; 1053 nritems = btrfs_header_nritems(path->nodes[0]); 1054 } 1055 leaf = path->nodes[0]; 1056 slot = path->slots[0]; 1057 1058 btrfs_item_key_to_cpu(leaf, &key, slot); 1059 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 1060 key.objectid != src->i_ino) 1061 break; 1062 1063 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 1064 struct btrfs_file_extent_item *extent; 1065 int type; 1066 u32 size; 1067 struct btrfs_key new_key; 1068 u64 disko = 0, diskl = 0; 1069 u64 datao = 0, datal = 0; 1070 u8 comp; 1071 1072 size = btrfs_item_size_nr(leaf, slot); 1073 read_extent_buffer(leaf, buf, 1074 btrfs_item_ptr_offset(leaf, slot), 1075 size); 1076 1077 extent = btrfs_item_ptr(leaf, slot, 1078 struct btrfs_file_extent_item); 1079 comp = btrfs_file_extent_compression(leaf, extent); 1080 type = btrfs_file_extent_type(leaf, extent); 1081 if (type == BTRFS_FILE_EXTENT_REG || 1082 type == BTRFS_FILE_EXTENT_PREALLOC) { 1083 disko = btrfs_file_extent_disk_bytenr(leaf, 1084 extent); 1085 diskl = btrfs_file_extent_disk_num_bytes(leaf, 1086 extent); 1087 datao = btrfs_file_extent_offset(leaf, extent); 1088 datal = btrfs_file_extent_num_bytes(leaf, 1089 extent); 1090 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 1091 /* take upper bound, may be compressed */ 1092 datal = btrfs_file_extent_ram_bytes(leaf, 1093 extent); 1094 } 1095 btrfs_release_path(root, path); 1096 1097 if (key.offset + datal < off || 1098 key.offset >= off+len) 1099 goto next; 1100 1101 memcpy(&new_key, &key, sizeof(new_key)); 1102 new_key.objectid = inode->i_ino; 1103 new_key.offset = key.offset + destoff - off; 1104 1105 if (type == BTRFS_FILE_EXTENT_REG || 1106 type == BTRFS_FILE_EXTENT_PREALLOC) { 1107 ret = btrfs_insert_empty_item(trans, root, path, 1108 &new_key, size); 1109 if (ret) 1110 goto out; 1111 1112 leaf = path->nodes[0]; 1113 slot = path->slots[0]; 1114 write_extent_buffer(leaf, buf, 1115 btrfs_item_ptr_offset(leaf, slot), 1116 size); 1117 1118 extent = btrfs_item_ptr(leaf, slot, 1119 struct btrfs_file_extent_item); 1120 1121 if (off > key.offset) { 1122 datao += off - key.offset; 1123 datal -= off - key.offset; 1124 } 1125 if (key.offset + datao + datal > off + len) 1126 datal = off + len - key.offset - datao; 1127 /* disko == 0 means it's a hole */ 1128 if (!disko) 1129 datao = 0; 1130 1131 btrfs_set_file_extent_offset(leaf, extent, 1132 datao); 1133 btrfs_set_file_extent_num_bytes(leaf, extent, 1134 datal); 1135 if (disko) { 1136 inode_add_bytes(inode, datal); 1137 ret = btrfs_inc_extent_ref(trans, root, 1138 disko, diskl, 0, 1139 root->root_key.objectid, 1140 inode->i_ino, 1141 new_key.offset - datao); 1142 BUG_ON(ret); 1143 } 1144 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 1145 u64 skip = 0; 1146 u64 trim = 0; 1147 if (off > key.offset) { 1148 skip = off - key.offset; 1149 new_key.offset += skip; 1150 } 1151 1152 if (key.offset + datal > off+len) 1153 trim = key.offset + datal - (off+len); 1154 1155 if (comp && (skip || trim)) { 1156 ret = -EINVAL; 1157 goto out; 1158 } 1159 size -= skip + trim; 1160 datal -= skip + trim; 1161 ret = btrfs_insert_empty_item(trans, root, path, 1162 &new_key, size); 1163 if (ret) 1164 goto out; 1165 1166 if (skip) { 1167 u32 start = 1168 btrfs_file_extent_calc_inline_size(0); 1169 memmove(buf+start, buf+start+skip, 1170 datal); 1171 } 1172 1173 leaf = path->nodes[0]; 1174 slot = path->slots[0]; 1175 write_extent_buffer(leaf, buf, 1176 btrfs_item_ptr_offset(leaf, slot), 1177 size); 1178 inode_add_bytes(inode, datal); 1179 } 1180 1181 btrfs_mark_buffer_dirty(leaf); 1182 } 1183 1184 next: 1185 btrfs_release_path(root, path); 1186 key.offset++; 1187 } 1188 ret = 0; 1189 out: 1190 btrfs_release_path(root, path); 1191 if (ret == 0) { 1192 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1193 if (destoff + olen > inode->i_size) 1194 btrfs_i_size_write(inode, destoff + olen); 1195 BTRFS_I(inode)->flags = BTRFS_I(src)->flags; 1196 ret = btrfs_update_inode(trans, root, inode); 1197 } 1198 btrfs_end_transaction(trans, root); 1199 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 1200 if (ret) 1201 vmtruncate(inode, 0); 1202 out_unlock: 1203 mutex_unlock(&src->i_mutex); 1204 mutex_unlock(&inode->i_mutex); 1205 vfree(buf); 1206 btrfs_free_path(path); 1207 out_fput: 1208 fput(src_file); 1209 out_drop_write: 1210 mnt_drop_write(file->f_path.mnt); 1211 return ret; 1212 } 1213 1214 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 1215 { 1216 struct btrfs_ioctl_clone_range_args args; 1217 1218 if (copy_from_user(&args, argp, sizeof(args))) 1219 return -EFAULT; 1220 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 1221 args.src_length, args.dest_offset); 1222 } 1223 1224 /* 1225 * there are many ways the trans_start and trans_end ioctls can lead 1226 * to deadlocks. They should only be used by applications that 1227 * basically own the machine, and have a very in depth understanding 1228 * of all the possible deadlocks and enospc problems. 1229 */ 1230 static long btrfs_ioctl_trans_start(struct file *file) 1231 { 1232 struct inode *inode = fdentry(file)->d_inode; 1233 struct btrfs_root *root = BTRFS_I(inode)->root; 1234 struct btrfs_trans_handle *trans; 1235 int ret; 1236 1237 ret = -EPERM; 1238 if (!capable(CAP_SYS_ADMIN)) 1239 goto out; 1240 1241 ret = -EINPROGRESS; 1242 if (file->private_data) 1243 goto out; 1244 1245 ret = mnt_want_write(file->f_path.mnt); 1246 if (ret) 1247 goto out; 1248 1249 mutex_lock(&root->fs_info->trans_mutex); 1250 root->fs_info->open_ioctl_trans++; 1251 mutex_unlock(&root->fs_info->trans_mutex); 1252 1253 ret = -ENOMEM; 1254 trans = btrfs_start_ioctl_transaction(root, 0); 1255 if (!trans) 1256 goto out_drop; 1257 1258 file->private_data = trans; 1259 return 0; 1260 1261 out_drop: 1262 mutex_lock(&root->fs_info->trans_mutex); 1263 root->fs_info->open_ioctl_trans--; 1264 mutex_unlock(&root->fs_info->trans_mutex); 1265 mnt_drop_write(file->f_path.mnt); 1266 out: 1267 return ret; 1268 } 1269 1270 /* 1271 * there are many ways the trans_start and trans_end ioctls can lead 1272 * to deadlocks. They should only be used by applications that 1273 * basically own the machine, and have a very in depth understanding 1274 * of all the possible deadlocks and enospc problems. 1275 */ 1276 long btrfs_ioctl_trans_end(struct file *file) 1277 { 1278 struct inode *inode = fdentry(file)->d_inode; 1279 struct btrfs_root *root = BTRFS_I(inode)->root; 1280 struct btrfs_trans_handle *trans; 1281 1282 trans = file->private_data; 1283 if (!trans) 1284 return -EINVAL; 1285 file->private_data = NULL; 1286 1287 btrfs_end_transaction(trans, root); 1288 1289 mutex_lock(&root->fs_info->trans_mutex); 1290 root->fs_info->open_ioctl_trans--; 1291 mutex_unlock(&root->fs_info->trans_mutex); 1292 1293 mnt_drop_write(file->f_path.mnt); 1294 return 0; 1295 } 1296 1297 long btrfs_ioctl(struct file *file, unsigned int 1298 cmd, unsigned long arg) 1299 { 1300 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 1301 void __user *argp = (void __user *)arg; 1302 1303 switch (cmd) { 1304 case FS_IOC_GETFLAGS: 1305 return btrfs_ioctl_getflags(file, argp); 1306 case FS_IOC_SETFLAGS: 1307 return btrfs_ioctl_setflags(file, argp); 1308 case FS_IOC_GETVERSION: 1309 return btrfs_ioctl_getversion(file, argp); 1310 case BTRFS_IOC_SNAP_CREATE: 1311 return btrfs_ioctl_snap_create(file, argp, 0); 1312 case BTRFS_IOC_SUBVOL_CREATE: 1313 return btrfs_ioctl_snap_create(file, argp, 1); 1314 case BTRFS_IOC_SNAP_DESTROY: 1315 return btrfs_ioctl_snap_destroy(file, argp); 1316 case BTRFS_IOC_DEFRAG: 1317 return btrfs_ioctl_defrag(file); 1318 case BTRFS_IOC_RESIZE: 1319 return btrfs_ioctl_resize(root, argp); 1320 case BTRFS_IOC_ADD_DEV: 1321 return btrfs_ioctl_add_dev(root, argp); 1322 case BTRFS_IOC_RM_DEV: 1323 return btrfs_ioctl_rm_dev(root, argp); 1324 case BTRFS_IOC_BALANCE: 1325 return btrfs_balance(root->fs_info->dev_root); 1326 case BTRFS_IOC_CLONE: 1327 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 1328 case BTRFS_IOC_CLONE_RANGE: 1329 return btrfs_ioctl_clone_range(file, argp); 1330 case BTRFS_IOC_TRANS_START: 1331 return btrfs_ioctl_trans_start(file); 1332 case BTRFS_IOC_TRANS_END: 1333 return btrfs_ioctl_trans_end(file); 1334 case BTRFS_IOC_SYNC: 1335 btrfs_sync_fs(file->f_dentry->d_sb, 1); 1336 return 0; 1337 } 1338 1339 return -ENOTTY; 1340 } 1341