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