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; 240 241 /* 242 * 1 - inode item 243 * 2 - refs 244 * 1 - root item 245 * 2 - dir items 246 */ 247 ret = btrfs_reserve_metadata_space(root, 6); 248 if (ret) 249 return ret; 250 251 trans = btrfs_start_transaction(root, 1); 252 BUG_ON(!trans); 253 254 ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root, 255 0, &objectid); 256 if (ret) 257 goto fail; 258 259 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 260 0, objectid, NULL, 0, 0, 0); 261 if (IS_ERR(leaf)) { 262 ret = PTR_ERR(leaf); 263 goto fail; 264 } 265 266 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); 267 btrfs_set_header_bytenr(leaf, leaf->start); 268 btrfs_set_header_generation(leaf, trans->transid); 269 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); 270 btrfs_set_header_owner(leaf, objectid); 271 272 write_extent_buffer(leaf, root->fs_info->fsid, 273 (unsigned long)btrfs_header_fsid(leaf), 274 BTRFS_FSID_SIZE); 275 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, 276 (unsigned long)btrfs_header_chunk_tree_uuid(leaf), 277 BTRFS_UUID_SIZE); 278 btrfs_mark_buffer_dirty(leaf); 279 280 inode_item = &root_item.inode; 281 memset(inode_item, 0, sizeof(*inode_item)); 282 inode_item->generation = cpu_to_le64(1); 283 inode_item->size = cpu_to_le64(3); 284 inode_item->nlink = cpu_to_le32(1); 285 inode_item->nbytes = cpu_to_le64(root->leafsize); 286 inode_item->mode = cpu_to_le32(S_IFDIR | 0755); 287 288 btrfs_set_root_bytenr(&root_item, leaf->start); 289 btrfs_set_root_generation(&root_item, trans->transid); 290 btrfs_set_root_level(&root_item, 0); 291 btrfs_set_root_refs(&root_item, 1); 292 btrfs_set_root_used(&root_item, leaf->len); 293 btrfs_set_root_last_snapshot(&root_item, 0); 294 295 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); 296 root_item.drop_level = 0; 297 298 btrfs_tree_unlock(leaf); 299 free_extent_buffer(leaf); 300 leaf = NULL; 301 302 btrfs_set_root_dirid(&root_item, new_dirid); 303 304 key.objectid = objectid; 305 key.offset = 0; 306 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); 307 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, 308 &root_item); 309 if (ret) 310 goto fail; 311 312 key.offset = (u64)-1; 313 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); 314 BUG_ON(IS_ERR(new_root)); 315 316 btrfs_record_root_in_trans(trans, new_root); 317 318 ret = btrfs_create_subvol_root(trans, new_root, new_dirid, 319 BTRFS_I(dir)->block_group); 320 /* 321 * insert the directory item 322 */ 323 ret = btrfs_set_inode_index(dir, &index); 324 BUG_ON(ret); 325 326 ret = btrfs_insert_dir_item(trans, root, 327 name, namelen, dir->i_ino, &key, 328 BTRFS_FT_DIR, index); 329 if (ret) 330 goto fail; 331 332 btrfs_i_size_write(dir, dir->i_size + namelen * 2); 333 ret = btrfs_update_inode(trans, root, dir); 334 BUG_ON(ret); 335 336 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 337 objectid, root->root_key.objectid, 338 dir->i_ino, index, name, namelen); 339 340 BUG_ON(ret); 341 342 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); 343 fail: 344 err = btrfs_commit_transaction(trans, root); 345 if (err && !ret) 346 ret = err; 347 348 btrfs_unreserve_metadata_space(root, 6); 349 return ret; 350 } 351 352 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, 353 char *name, int namelen) 354 { 355 struct inode *inode; 356 struct btrfs_pending_snapshot *pending_snapshot; 357 struct btrfs_trans_handle *trans; 358 int ret; 359 360 if (!root->ref_cows) 361 return -EINVAL; 362 363 /* 364 * 1 - inode item 365 * 2 - refs 366 * 1 - root item 367 * 2 - dir items 368 */ 369 ret = btrfs_reserve_metadata_space(root, 6); 370 if (ret) 371 goto fail; 372 373 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); 374 if (!pending_snapshot) { 375 ret = -ENOMEM; 376 btrfs_unreserve_metadata_space(root, 6); 377 goto fail; 378 } 379 pending_snapshot->name = kmalloc(namelen + 1, GFP_NOFS); 380 if (!pending_snapshot->name) { 381 ret = -ENOMEM; 382 kfree(pending_snapshot); 383 btrfs_unreserve_metadata_space(root, 6); 384 goto fail; 385 } 386 memcpy(pending_snapshot->name, name, namelen); 387 pending_snapshot->name[namelen] = '\0'; 388 pending_snapshot->dentry = dentry; 389 trans = btrfs_start_transaction(root, 1); 390 BUG_ON(!trans); 391 pending_snapshot->root = root; 392 list_add(&pending_snapshot->list, 393 &trans->transaction->pending_snapshots); 394 ret = btrfs_commit_transaction(trans, root); 395 BUG_ON(ret); 396 btrfs_unreserve_metadata_space(root, 6); 397 398 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry); 399 if (IS_ERR(inode)) { 400 ret = PTR_ERR(inode); 401 goto fail; 402 } 403 BUG_ON(!inode); 404 d_instantiate(dentry, inode); 405 ret = 0; 406 fail: 407 return ret; 408 } 409 410 /* copy of may_create in fs/namei.c() */ 411 static inline int btrfs_may_create(struct inode *dir, struct dentry *child) 412 { 413 if (child->d_inode) 414 return -EEXIST; 415 if (IS_DEADDIR(dir)) 416 return -ENOENT; 417 return inode_permission(dir, MAY_WRITE | MAY_EXEC); 418 } 419 420 /* 421 * Create a new subvolume below @parent. This is largely modeled after 422 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup 423 * inside this filesystem so it's quite a bit simpler. 424 */ 425 static noinline int btrfs_mksubvol(struct path *parent, 426 char *name, int namelen, 427 struct btrfs_root *snap_src) 428 { 429 struct inode *dir = parent->dentry->d_inode; 430 struct dentry *dentry; 431 int error; 432 433 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 434 435 dentry = lookup_one_len(name, parent->dentry, namelen); 436 error = PTR_ERR(dentry); 437 if (IS_ERR(dentry)) 438 goto out_unlock; 439 440 error = -EEXIST; 441 if (dentry->d_inode) 442 goto out_dput; 443 444 error = mnt_want_write(parent->mnt); 445 if (error) 446 goto out_dput; 447 448 error = btrfs_may_create(dir, dentry); 449 if (error) 450 goto out_drop_write; 451 452 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 453 454 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) 455 goto out_up_read; 456 457 if (snap_src) { 458 error = create_snapshot(snap_src, dentry, 459 name, namelen); 460 } else { 461 error = create_subvol(BTRFS_I(dir)->root, dentry, 462 name, namelen); 463 } 464 if (!error) 465 fsnotify_mkdir(dir, dentry); 466 out_up_read: 467 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 468 out_drop_write: 469 mnt_drop_write(parent->mnt); 470 out_dput: 471 dput(dentry); 472 out_unlock: 473 mutex_unlock(&dir->i_mutex); 474 return error; 475 } 476 477 static int btrfs_defrag_file(struct file *file) 478 { 479 struct inode *inode = fdentry(file)->d_inode; 480 struct btrfs_root *root = BTRFS_I(inode)->root; 481 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 482 struct btrfs_ordered_extent *ordered; 483 struct page *page; 484 unsigned long last_index; 485 unsigned long ra_pages = root->fs_info->bdi.ra_pages; 486 unsigned long total_read = 0; 487 u64 page_start; 488 u64 page_end; 489 unsigned long i; 490 int ret; 491 492 ret = btrfs_check_data_free_space(root, inode, inode->i_size); 493 if (ret) 494 return -ENOSPC; 495 496 mutex_lock(&inode->i_mutex); 497 last_index = inode->i_size >> PAGE_CACHE_SHIFT; 498 for (i = 0; i <= last_index; i++) { 499 if (total_read % ra_pages == 0) { 500 btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i, 501 min(last_index, i + ra_pages - 1)); 502 } 503 total_read++; 504 again: 505 page = grab_cache_page(inode->i_mapping, i); 506 if (!page) 507 goto out_unlock; 508 if (!PageUptodate(page)) { 509 btrfs_readpage(NULL, page); 510 lock_page(page); 511 if (!PageUptodate(page)) { 512 unlock_page(page); 513 page_cache_release(page); 514 goto out_unlock; 515 } 516 } 517 518 wait_on_page_writeback(page); 519 520 page_start = (u64)page->index << PAGE_CACHE_SHIFT; 521 page_end = page_start + PAGE_CACHE_SIZE - 1; 522 lock_extent(io_tree, page_start, page_end, GFP_NOFS); 523 524 ordered = btrfs_lookup_ordered_extent(inode, page_start); 525 if (ordered) { 526 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 527 unlock_page(page); 528 page_cache_release(page); 529 btrfs_start_ordered_extent(inode, ordered, 1); 530 btrfs_put_ordered_extent(ordered); 531 goto again; 532 } 533 set_page_extent_mapped(page); 534 535 /* 536 * this makes sure page_mkwrite is called on the 537 * page if it is dirtied again later 538 */ 539 clear_page_dirty_for_io(page); 540 541 btrfs_set_extent_delalloc(inode, page_start, page_end); 542 set_page_dirty(page); 543 unlock_extent(io_tree, page_start, page_end, GFP_NOFS); 544 unlock_page(page); 545 page_cache_release(page); 546 balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1); 547 } 548 549 out_unlock: 550 mutex_unlock(&inode->i_mutex); 551 return 0; 552 } 553 554 static noinline int btrfs_ioctl_resize(struct btrfs_root *root, 555 void __user *arg) 556 { 557 u64 new_size; 558 u64 old_size; 559 u64 devid = 1; 560 struct btrfs_ioctl_vol_args *vol_args; 561 struct btrfs_trans_handle *trans; 562 struct btrfs_device *device = NULL; 563 char *sizestr; 564 char *devstr = NULL; 565 int ret = 0; 566 int namelen; 567 int mod = 0; 568 569 if (root->fs_info->sb->s_flags & MS_RDONLY) 570 return -EROFS; 571 572 if (!capable(CAP_SYS_ADMIN)) 573 return -EPERM; 574 575 vol_args = memdup_user(arg, sizeof(*vol_args)); 576 if (IS_ERR(vol_args)) 577 return PTR_ERR(vol_args); 578 579 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 580 namelen = strlen(vol_args->name); 581 582 mutex_lock(&root->fs_info->volume_mutex); 583 sizestr = vol_args->name; 584 devstr = strchr(sizestr, ':'); 585 if (devstr) { 586 char *end; 587 sizestr = devstr + 1; 588 *devstr = '\0'; 589 devstr = vol_args->name; 590 devid = simple_strtoull(devstr, &end, 10); 591 printk(KERN_INFO "resizing devid %llu\n", 592 (unsigned long long)devid); 593 } 594 device = btrfs_find_device(root, devid, NULL, NULL); 595 if (!device) { 596 printk(KERN_INFO "resizer unable to find device %llu\n", 597 (unsigned long long)devid); 598 ret = -EINVAL; 599 goto out_unlock; 600 } 601 if (!strcmp(sizestr, "max")) 602 new_size = device->bdev->bd_inode->i_size; 603 else { 604 if (sizestr[0] == '-') { 605 mod = -1; 606 sizestr++; 607 } else if (sizestr[0] == '+') { 608 mod = 1; 609 sizestr++; 610 } 611 new_size = btrfs_parse_size(sizestr); 612 if (new_size == 0) { 613 ret = -EINVAL; 614 goto out_unlock; 615 } 616 } 617 618 old_size = device->total_bytes; 619 620 if (mod < 0) { 621 if (new_size > old_size) { 622 ret = -EINVAL; 623 goto out_unlock; 624 } 625 new_size = old_size - new_size; 626 } else if (mod > 0) { 627 new_size = old_size + new_size; 628 } 629 630 if (new_size < 256 * 1024 * 1024) { 631 ret = -EINVAL; 632 goto out_unlock; 633 } 634 if (new_size > device->bdev->bd_inode->i_size) { 635 ret = -EFBIG; 636 goto out_unlock; 637 } 638 639 do_div(new_size, root->sectorsize); 640 new_size *= root->sectorsize; 641 642 printk(KERN_INFO "new size for %s is %llu\n", 643 device->name, (unsigned long long)new_size); 644 645 if (new_size > old_size) { 646 trans = btrfs_start_transaction(root, 1); 647 ret = btrfs_grow_device(trans, device, new_size); 648 btrfs_commit_transaction(trans, root); 649 } else { 650 ret = btrfs_shrink_device(device, new_size); 651 } 652 653 out_unlock: 654 mutex_unlock(&root->fs_info->volume_mutex); 655 kfree(vol_args); 656 return ret; 657 } 658 659 static noinline int btrfs_ioctl_snap_create(struct file *file, 660 void __user *arg, int subvol) 661 { 662 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 663 struct btrfs_ioctl_vol_args *vol_args; 664 struct file *src_file; 665 int namelen; 666 int ret = 0; 667 668 if (root->fs_info->sb->s_flags & MS_RDONLY) 669 return -EROFS; 670 671 vol_args = memdup_user(arg, sizeof(*vol_args)); 672 if (IS_ERR(vol_args)) 673 return PTR_ERR(vol_args); 674 675 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 676 namelen = strlen(vol_args->name); 677 if (strchr(vol_args->name, '/')) { 678 ret = -EINVAL; 679 goto out; 680 } 681 682 if (subvol) { 683 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen, 684 NULL); 685 } else { 686 struct inode *src_inode; 687 src_file = fget(vol_args->fd); 688 if (!src_file) { 689 ret = -EINVAL; 690 goto out; 691 } 692 693 src_inode = src_file->f_path.dentry->d_inode; 694 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { 695 printk(KERN_INFO "btrfs: Snapshot src from " 696 "another FS\n"); 697 ret = -EINVAL; 698 fput(src_file); 699 goto out; 700 } 701 ret = btrfs_mksubvol(&file->f_path, vol_args->name, namelen, 702 BTRFS_I(src_inode)->root); 703 fput(src_file); 704 } 705 out: 706 kfree(vol_args); 707 return ret; 708 } 709 710 /* 711 * helper to check if the subvolume references other subvolumes 712 */ 713 static noinline int may_destroy_subvol(struct btrfs_root *root) 714 { 715 struct btrfs_path *path; 716 struct btrfs_key key; 717 int ret; 718 719 path = btrfs_alloc_path(); 720 if (!path) 721 return -ENOMEM; 722 723 key.objectid = root->root_key.objectid; 724 key.type = BTRFS_ROOT_REF_KEY; 725 key.offset = (u64)-1; 726 727 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, 728 &key, path, 0, 0); 729 if (ret < 0) 730 goto out; 731 BUG_ON(ret == 0); 732 733 ret = 0; 734 if (path->slots[0] > 0) { 735 path->slots[0]--; 736 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 737 if (key.objectid == root->root_key.objectid && 738 key.type == BTRFS_ROOT_REF_KEY) 739 ret = -ENOTEMPTY; 740 } 741 out: 742 btrfs_free_path(path); 743 return ret; 744 } 745 746 static noinline int btrfs_ioctl_snap_destroy(struct file *file, 747 void __user *arg) 748 { 749 struct dentry *parent = fdentry(file); 750 struct dentry *dentry; 751 struct inode *dir = parent->d_inode; 752 struct inode *inode; 753 struct btrfs_root *root = BTRFS_I(dir)->root; 754 struct btrfs_root *dest = NULL; 755 struct btrfs_ioctl_vol_args *vol_args; 756 struct btrfs_trans_handle *trans; 757 int namelen; 758 int ret; 759 int err = 0; 760 761 if (!capable(CAP_SYS_ADMIN)) 762 return -EPERM; 763 764 vol_args = memdup_user(arg, sizeof(*vol_args)); 765 if (IS_ERR(vol_args)) 766 return PTR_ERR(vol_args); 767 768 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 769 namelen = strlen(vol_args->name); 770 if (strchr(vol_args->name, '/') || 771 strncmp(vol_args->name, "..", namelen) == 0) { 772 err = -EINVAL; 773 goto out; 774 } 775 776 err = mnt_want_write(file->f_path.mnt); 777 if (err) 778 goto out; 779 780 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 781 dentry = lookup_one_len(vol_args->name, parent, namelen); 782 if (IS_ERR(dentry)) { 783 err = PTR_ERR(dentry); 784 goto out_unlock_dir; 785 } 786 787 if (!dentry->d_inode) { 788 err = -ENOENT; 789 goto out_dput; 790 } 791 792 inode = dentry->d_inode; 793 if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) { 794 err = -EINVAL; 795 goto out_dput; 796 } 797 798 dest = BTRFS_I(inode)->root; 799 800 mutex_lock(&inode->i_mutex); 801 err = d_invalidate(dentry); 802 if (err) 803 goto out_unlock; 804 805 down_write(&root->fs_info->subvol_sem); 806 807 err = may_destroy_subvol(dest); 808 if (err) 809 goto out_up_write; 810 811 trans = btrfs_start_transaction(root, 1); 812 ret = btrfs_unlink_subvol(trans, root, dir, 813 dest->root_key.objectid, 814 dentry->d_name.name, 815 dentry->d_name.len); 816 BUG_ON(ret); 817 818 btrfs_record_root_in_trans(trans, dest); 819 820 memset(&dest->root_item.drop_progress, 0, 821 sizeof(dest->root_item.drop_progress)); 822 dest->root_item.drop_level = 0; 823 btrfs_set_root_refs(&dest->root_item, 0); 824 825 ret = btrfs_insert_orphan_item(trans, 826 root->fs_info->tree_root, 827 dest->root_key.objectid); 828 BUG_ON(ret); 829 830 ret = btrfs_commit_transaction(trans, root); 831 BUG_ON(ret); 832 inode->i_flags |= S_DEAD; 833 out_up_write: 834 up_write(&root->fs_info->subvol_sem); 835 out_unlock: 836 mutex_unlock(&inode->i_mutex); 837 if (!err) { 838 shrink_dcache_sb(root->fs_info->sb); 839 btrfs_invalidate_inodes(dest); 840 d_delete(dentry); 841 } 842 out_dput: 843 dput(dentry); 844 out_unlock_dir: 845 mutex_unlock(&dir->i_mutex); 846 mnt_drop_write(file->f_path.mnt); 847 out: 848 kfree(vol_args); 849 return err; 850 } 851 852 static int btrfs_ioctl_defrag(struct file *file) 853 { 854 struct inode *inode = fdentry(file)->d_inode; 855 struct btrfs_root *root = BTRFS_I(inode)->root; 856 int ret; 857 858 ret = mnt_want_write(file->f_path.mnt); 859 if (ret) 860 return ret; 861 862 switch (inode->i_mode & S_IFMT) { 863 case S_IFDIR: 864 if (!capable(CAP_SYS_ADMIN)) { 865 ret = -EPERM; 866 goto out; 867 } 868 btrfs_defrag_root(root, 0); 869 btrfs_defrag_root(root->fs_info->extent_root, 0); 870 break; 871 case S_IFREG: 872 if (!(file->f_mode & FMODE_WRITE)) { 873 ret = -EINVAL; 874 goto out; 875 } 876 btrfs_defrag_file(file); 877 break; 878 } 879 out: 880 mnt_drop_write(file->f_path.mnt); 881 return ret; 882 } 883 884 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 885 { 886 struct btrfs_ioctl_vol_args *vol_args; 887 int ret; 888 889 if (!capable(CAP_SYS_ADMIN)) 890 return -EPERM; 891 892 vol_args = memdup_user(arg, sizeof(*vol_args)); 893 if (IS_ERR(vol_args)) 894 return PTR_ERR(vol_args); 895 896 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 897 ret = btrfs_init_new_device(root, vol_args->name); 898 899 kfree(vol_args); 900 return ret; 901 } 902 903 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 904 { 905 struct btrfs_ioctl_vol_args *vol_args; 906 int ret; 907 908 if (!capable(CAP_SYS_ADMIN)) 909 return -EPERM; 910 911 if (root->fs_info->sb->s_flags & MS_RDONLY) 912 return -EROFS; 913 914 vol_args = memdup_user(arg, sizeof(*vol_args)); 915 if (IS_ERR(vol_args)) 916 return PTR_ERR(vol_args); 917 918 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 919 ret = btrfs_rm_device(root, vol_args->name); 920 921 kfree(vol_args); 922 return ret; 923 } 924 925 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 926 u64 off, u64 olen, u64 destoff) 927 { 928 struct inode *inode = fdentry(file)->d_inode; 929 struct btrfs_root *root = BTRFS_I(inode)->root; 930 struct file *src_file; 931 struct inode *src; 932 struct btrfs_trans_handle *trans; 933 struct btrfs_path *path; 934 struct extent_buffer *leaf; 935 char *buf; 936 struct btrfs_key key; 937 u32 nritems; 938 int slot; 939 int ret; 940 u64 len = olen; 941 u64 bs = root->fs_info->sb->s_blocksize; 942 u64 hint_byte; 943 944 /* 945 * TODO: 946 * - split compressed inline extents. annoying: we need to 947 * decompress into destination's address_space (the file offset 948 * may change, so source mapping won't do), then recompress (or 949 * otherwise reinsert) a subrange. 950 * - allow ranges within the same file to be cloned (provided 951 * they don't overlap)? 952 */ 953 954 /* the destination must be opened for writing */ 955 if (!(file->f_mode & FMODE_WRITE)) 956 return -EINVAL; 957 958 ret = mnt_want_write(file->f_path.mnt); 959 if (ret) 960 return ret; 961 962 src_file = fget(srcfd); 963 if (!src_file) { 964 ret = -EBADF; 965 goto out_drop_write; 966 } 967 src = src_file->f_dentry->d_inode; 968 969 ret = -EINVAL; 970 if (src == inode) 971 goto out_fput; 972 973 ret = -EISDIR; 974 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 975 goto out_fput; 976 977 ret = -EXDEV; 978 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) 979 goto out_fput; 980 981 ret = -ENOMEM; 982 buf = vmalloc(btrfs_level_size(root, 0)); 983 if (!buf) 984 goto out_fput; 985 986 path = btrfs_alloc_path(); 987 if (!path) { 988 vfree(buf); 989 goto out_fput; 990 } 991 path->reada = 2; 992 993 if (inode < src) { 994 mutex_lock(&inode->i_mutex); 995 mutex_lock(&src->i_mutex); 996 } else { 997 mutex_lock(&src->i_mutex); 998 mutex_lock(&inode->i_mutex); 999 } 1000 1001 /* determine range to clone */ 1002 ret = -EINVAL; 1003 if (off >= src->i_size || off + len > src->i_size) 1004 goto out_unlock; 1005 if (len == 0) 1006 olen = len = src->i_size - off; 1007 /* if we extend to eof, continue to block boundary */ 1008 if (off + len == src->i_size) 1009 len = ((src->i_size + bs-1) & ~(bs-1)) 1010 - off; 1011 1012 /* verify the end result is block aligned */ 1013 if ((off & (bs-1)) || 1014 ((off + len) & (bs-1))) 1015 goto out_unlock; 1016 1017 /* do any pending delalloc/csum calc on src, one way or 1018 another, and lock file content */ 1019 while (1) { 1020 struct btrfs_ordered_extent *ordered; 1021 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 1022 ordered = btrfs_lookup_first_ordered_extent(inode, off+len); 1023 if (BTRFS_I(src)->delalloc_bytes == 0 && !ordered) 1024 break; 1025 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 1026 if (ordered) 1027 btrfs_put_ordered_extent(ordered); 1028 btrfs_wait_ordered_range(src, off, off+len); 1029 } 1030 1031 trans = btrfs_start_transaction(root, 1); 1032 BUG_ON(!trans); 1033 1034 /* punch hole in destination first */ 1035 btrfs_drop_extents(trans, inode, off, off + len, &hint_byte, 1); 1036 1037 /* clone data */ 1038 key.objectid = src->i_ino; 1039 key.type = BTRFS_EXTENT_DATA_KEY; 1040 key.offset = 0; 1041 1042 while (1) { 1043 /* 1044 * note the key will change type as we walk through the 1045 * tree. 1046 */ 1047 ret = btrfs_search_slot(trans, root, &key, path, 0, 0); 1048 if (ret < 0) 1049 goto out; 1050 1051 nritems = btrfs_header_nritems(path->nodes[0]); 1052 if (path->slots[0] >= nritems) { 1053 ret = btrfs_next_leaf(root, path); 1054 if (ret < 0) 1055 goto out; 1056 if (ret > 0) 1057 break; 1058 nritems = btrfs_header_nritems(path->nodes[0]); 1059 } 1060 leaf = path->nodes[0]; 1061 slot = path->slots[0]; 1062 1063 btrfs_item_key_to_cpu(leaf, &key, slot); 1064 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 1065 key.objectid != src->i_ino) 1066 break; 1067 1068 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 1069 struct btrfs_file_extent_item *extent; 1070 int type; 1071 u32 size; 1072 struct btrfs_key new_key; 1073 u64 disko = 0, diskl = 0; 1074 u64 datao = 0, datal = 0; 1075 u8 comp; 1076 1077 size = btrfs_item_size_nr(leaf, slot); 1078 read_extent_buffer(leaf, buf, 1079 btrfs_item_ptr_offset(leaf, slot), 1080 size); 1081 1082 extent = btrfs_item_ptr(leaf, slot, 1083 struct btrfs_file_extent_item); 1084 comp = btrfs_file_extent_compression(leaf, extent); 1085 type = btrfs_file_extent_type(leaf, extent); 1086 if (type == BTRFS_FILE_EXTENT_REG || 1087 type == BTRFS_FILE_EXTENT_PREALLOC) { 1088 disko = btrfs_file_extent_disk_bytenr(leaf, 1089 extent); 1090 diskl = btrfs_file_extent_disk_num_bytes(leaf, 1091 extent); 1092 datao = btrfs_file_extent_offset(leaf, extent); 1093 datal = btrfs_file_extent_num_bytes(leaf, 1094 extent); 1095 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 1096 /* take upper bound, may be compressed */ 1097 datal = btrfs_file_extent_ram_bytes(leaf, 1098 extent); 1099 } 1100 btrfs_release_path(root, path); 1101 1102 if (key.offset + datal < off || 1103 key.offset >= off+len) 1104 goto next; 1105 1106 memcpy(&new_key, &key, sizeof(new_key)); 1107 new_key.objectid = inode->i_ino; 1108 new_key.offset = key.offset + destoff - off; 1109 1110 if (type == BTRFS_FILE_EXTENT_REG || 1111 type == BTRFS_FILE_EXTENT_PREALLOC) { 1112 ret = btrfs_insert_empty_item(trans, root, path, 1113 &new_key, size); 1114 if (ret) 1115 goto out; 1116 1117 leaf = path->nodes[0]; 1118 slot = path->slots[0]; 1119 write_extent_buffer(leaf, buf, 1120 btrfs_item_ptr_offset(leaf, slot), 1121 size); 1122 1123 extent = btrfs_item_ptr(leaf, slot, 1124 struct btrfs_file_extent_item); 1125 1126 if (off > key.offset) { 1127 datao += off - key.offset; 1128 datal -= off - key.offset; 1129 } 1130 1131 if (key.offset + datal > off + len) 1132 datal = off + len - key.offset; 1133 1134 /* disko == 0 means it's a hole */ 1135 if (!disko) 1136 datao = 0; 1137 1138 btrfs_set_file_extent_offset(leaf, extent, 1139 datao); 1140 btrfs_set_file_extent_num_bytes(leaf, extent, 1141 datal); 1142 if (disko) { 1143 inode_add_bytes(inode, datal); 1144 ret = btrfs_inc_extent_ref(trans, root, 1145 disko, diskl, 0, 1146 root->root_key.objectid, 1147 inode->i_ino, 1148 new_key.offset - datao); 1149 BUG_ON(ret); 1150 } 1151 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 1152 u64 skip = 0; 1153 u64 trim = 0; 1154 if (off > key.offset) { 1155 skip = off - key.offset; 1156 new_key.offset += skip; 1157 } 1158 1159 if (key.offset + datal > off+len) 1160 trim = key.offset + datal - (off+len); 1161 1162 if (comp && (skip || trim)) { 1163 ret = -EINVAL; 1164 goto out; 1165 } 1166 size -= skip + trim; 1167 datal -= skip + trim; 1168 ret = btrfs_insert_empty_item(trans, root, path, 1169 &new_key, size); 1170 if (ret) 1171 goto out; 1172 1173 if (skip) { 1174 u32 start = 1175 btrfs_file_extent_calc_inline_size(0); 1176 memmove(buf+start, buf+start+skip, 1177 datal); 1178 } 1179 1180 leaf = path->nodes[0]; 1181 slot = path->slots[0]; 1182 write_extent_buffer(leaf, buf, 1183 btrfs_item_ptr_offset(leaf, slot), 1184 size); 1185 inode_add_bytes(inode, datal); 1186 } 1187 1188 btrfs_mark_buffer_dirty(leaf); 1189 } 1190 1191 next: 1192 btrfs_release_path(root, path); 1193 key.offset++; 1194 } 1195 ret = 0; 1196 out: 1197 btrfs_release_path(root, path); 1198 if (ret == 0) { 1199 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 1200 if (destoff + olen > inode->i_size) 1201 btrfs_i_size_write(inode, destoff + olen); 1202 BTRFS_I(inode)->flags = BTRFS_I(src)->flags; 1203 ret = btrfs_update_inode(trans, root, inode); 1204 } 1205 btrfs_end_transaction(trans, root); 1206 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 1207 if (ret) 1208 vmtruncate(inode, 0); 1209 out_unlock: 1210 mutex_unlock(&src->i_mutex); 1211 mutex_unlock(&inode->i_mutex); 1212 vfree(buf); 1213 btrfs_free_path(path); 1214 out_fput: 1215 fput(src_file); 1216 out_drop_write: 1217 mnt_drop_write(file->f_path.mnt); 1218 return ret; 1219 } 1220 1221 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 1222 { 1223 struct btrfs_ioctl_clone_range_args args; 1224 1225 if (copy_from_user(&args, argp, sizeof(args))) 1226 return -EFAULT; 1227 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 1228 args.src_length, args.dest_offset); 1229 } 1230 1231 /* 1232 * there are many ways the trans_start and trans_end ioctls can lead 1233 * to deadlocks. They should only be used by applications that 1234 * basically own the machine, and have a very in depth understanding 1235 * of all the possible deadlocks and enospc problems. 1236 */ 1237 static long btrfs_ioctl_trans_start(struct file *file) 1238 { 1239 struct inode *inode = fdentry(file)->d_inode; 1240 struct btrfs_root *root = BTRFS_I(inode)->root; 1241 struct btrfs_trans_handle *trans; 1242 int ret; 1243 1244 ret = -EPERM; 1245 if (!capable(CAP_SYS_ADMIN)) 1246 goto out; 1247 1248 ret = -EINPROGRESS; 1249 if (file->private_data) 1250 goto out; 1251 1252 ret = mnt_want_write(file->f_path.mnt); 1253 if (ret) 1254 goto out; 1255 1256 mutex_lock(&root->fs_info->trans_mutex); 1257 root->fs_info->open_ioctl_trans++; 1258 mutex_unlock(&root->fs_info->trans_mutex); 1259 1260 ret = -ENOMEM; 1261 trans = btrfs_start_ioctl_transaction(root, 0); 1262 if (!trans) 1263 goto out_drop; 1264 1265 file->private_data = trans; 1266 return 0; 1267 1268 out_drop: 1269 mutex_lock(&root->fs_info->trans_mutex); 1270 root->fs_info->open_ioctl_trans--; 1271 mutex_unlock(&root->fs_info->trans_mutex); 1272 mnt_drop_write(file->f_path.mnt); 1273 out: 1274 return ret; 1275 } 1276 1277 /* 1278 * there are many ways the trans_start and trans_end ioctls can lead 1279 * to deadlocks. They should only be used by applications that 1280 * basically own the machine, and have a very in depth understanding 1281 * of all the possible deadlocks and enospc problems. 1282 */ 1283 long btrfs_ioctl_trans_end(struct file *file) 1284 { 1285 struct inode *inode = fdentry(file)->d_inode; 1286 struct btrfs_root *root = BTRFS_I(inode)->root; 1287 struct btrfs_trans_handle *trans; 1288 1289 trans = file->private_data; 1290 if (!trans) 1291 return -EINVAL; 1292 file->private_data = NULL; 1293 1294 btrfs_end_transaction(trans, root); 1295 1296 mutex_lock(&root->fs_info->trans_mutex); 1297 root->fs_info->open_ioctl_trans--; 1298 mutex_unlock(&root->fs_info->trans_mutex); 1299 1300 mnt_drop_write(file->f_path.mnt); 1301 return 0; 1302 } 1303 1304 long btrfs_ioctl(struct file *file, unsigned int 1305 cmd, unsigned long arg) 1306 { 1307 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 1308 void __user *argp = (void __user *)arg; 1309 1310 switch (cmd) { 1311 case FS_IOC_GETFLAGS: 1312 return btrfs_ioctl_getflags(file, argp); 1313 case FS_IOC_SETFLAGS: 1314 return btrfs_ioctl_setflags(file, argp); 1315 case FS_IOC_GETVERSION: 1316 return btrfs_ioctl_getversion(file, argp); 1317 case BTRFS_IOC_SNAP_CREATE: 1318 return btrfs_ioctl_snap_create(file, argp, 0); 1319 case BTRFS_IOC_SUBVOL_CREATE: 1320 return btrfs_ioctl_snap_create(file, argp, 1); 1321 case BTRFS_IOC_SNAP_DESTROY: 1322 return btrfs_ioctl_snap_destroy(file, argp); 1323 case BTRFS_IOC_DEFRAG: 1324 return btrfs_ioctl_defrag(file); 1325 case BTRFS_IOC_RESIZE: 1326 return btrfs_ioctl_resize(root, argp); 1327 case BTRFS_IOC_ADD_DEV: 1328 return btrfs_ioctl_add_dev(root, argp); 1329 case BTRFS_IOC_RM_DEV: 1330 return btrfs_ioctl_rm_dev(root, argp); 1331 case BTRFS_IOC_BALANCE: 1332 return btrfs_balance(root->fs_info->dev_root); 1333 case BTRFS_IOC_CLONE: 1334 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 1335 case BTRFS_IOC_CLONE_RANGE: 1336 return btrfs_ioctl_clone_range(file, argp); 1337 case BTRFS_IOC_TRANS_START: 1338 return btrfs_ioctl_trans_start(file); 1339 case BTRFS_IOC_TRANS_END: 1340 return btrfs_ioctl_trans_end(file); 1341 case BTRFS_IOC_SYNC: 1342 btrfs_sync_fs(file->f_dentry->d_sb, 1); 1343 return 0; 1344 } 1345 1346 return -ENOTTY; 1347 } 1348