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 <linux/slab.h> 43 #include <linux/blkdev.h> 44 #include <linux/uuid.h> 45 #include <linux/btrfs.h> 46 #include <linux/uaccess.h> 47 #include "ctree.h" 48 #include "disk-io.h" 49 #include "transaction.h" 50 #include "btrfs_inode.h" 51 #include "print-tree.h" 52 #include "volumes.h" 53 #include "locking.h" 54 #include "inode-map.h" 55 #include "backref.h" 56 #include "rcu-string.h" 57 #include "send.h" 58 #include "dev-replace.h" 59 60 static int btrfs_clone(struct inode *src, struct inode *inode, 61 u64 off, u64 olen, u64 olen_aligned, u64 destoff); 62 63 /* Mask out flags that are inappropriate for the given type of inode. */ 64 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags) 65 { 66 if (S_ISDIR(mode)) 67 return flags; 68 else if (S_ISREG(mode)) 69 return flags & ~FS_DIRSYNC_FL; 70 else 71 return flags & (FS_NODUMP_FL | FS_NOATIME_FL); 72 } 73 74 /* 75 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl. 76 */ 77 static unsigned int btrfs_flags_to_ioctl(unsigned int flags) 78 { 79 unsigned int iflags = 0; 80 81 if (flags & BTRFS_INODE_SYNC) 82 iflags |= FS_SYNC_FL; 83 if (flags & BTRFS_INODE_IMMUTABLE) 84 iflags |= FS_IMMUTABLE_FL; 85 if (flags & BTRFS_INODE_APPEND) 86 iflags |= FS_APPEND_FL; 87 if (flags & BTRFS_INODE_NODUMP) 88 iflags |= FS_NODUMP_FL; 89 if (flags & BTRFS_INODE_NOATIME) 90 iflags |= FS_NOATIME_FL; 91 if (flags & BTRFS_INODE_DIRSYNC) 92 iflags |= FS_DIRSYNC_FL; 93 if (flags & BTRFS_INODE_NODATACOW) 94 iflags |= FS_NOCOW_FL; 95 96 if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS)) 97 iflags |= FS_COMPR_FL; 98 else if (flags & BTRFS_INODE_NOCOMPRESS) 99 iflags |= FS_NOCOMP_FL; 100 101 return iflags; 102 } 103 104 /* 105 * Update inode->i_flags based on the btrfs internal flags. 106 */ 107 void btrfs_update_iflags(struct inode *inode) 108 { 109 struct btrfs_inode *ip = BTRFS_I(inode); 110 111 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 112 113 if (ip->flags & BTRFS_INODE_SYNC) 114 inode->i_flags |= S_SYNC; 115 if (ip->flags & BTRFS_INODE_IMMUTABLE) 116 inode->i_flags |= S_IMMUTABLE; 117 if (ip->flags & BTRFS_INODE_APPEND) 118 inode->i_flags |= S_APPEND; 119 if (ip->flags & BTRFS_INODE_NOATIME) 120 inode->i_flags |= S_NOATIME; 121 if (ip->flags & BTRFS_INODE_DIRSYNC) 122 inode->i_flags |= S_DIRSYNC; 123 } 124 125 /* 126 * Inherit flags from the parent inode. 127 * 128 * Currently only the compression flags and the cow flags are inherited. 129 */ 130 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) 131 { 132 unsigned int flags; 133 134 if (!dir) 135 return; 136 137 flags = BTRFS_I(dir)->flags; 138 139 if (flags & BTRFS_INODE_NOCOMPRESS) { 140 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; 141 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 142 } else if (flags & BTRFS_INODE_COMPRESS) { 143 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; 144 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; 145 } 146 147 if (flags & BTRFS_INODE_NODATACOW) { 148 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; 149 if (S_ISREG(inode->i_mode)) 150 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; 151 } 152 153 btrfs_update_iflags(inode); 154 } 155 156 static int btrfs_ioctl_getflags(struct file *file, void __user *arg) 157 { 158 struct btrfs_inode *ip = BTRFS_I(file_inode(file)); 159 unsigned int flags = btrfs_flags_to_ioctl(ip->flags); 160 161 if (copy_to_user(arg, &flags, sizeof(flags))) 162 return -EFAULT; 163 return 0; 164 } 165 166 static int check_flags(unsigned int flags) 167 { 168 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ 169 FS_NOATIME_FL | FS_NODUMP_FL | \ 170 FS_SYNC_FL | FS_DIRSYNC_FL | \ 171 FS_NOCOMP_FL | FS_COMPR_FL | 172 FS_NOCOW_FL)) 173 return -EOPNOTSUPP; 174 175 if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL)) 176 return -EINVAL; 177 178 return 0; 179 } 180 181 static int btrfs_ioctl_setflags(struct file *file, void __user *arg) 182 { 183 struct inode *inode = file_inode(file); 184 struct btrfs_inode *ip = BTRFS_I(inode); 185 struct btrfs_root *root = ip->root; 186 struct btrfs_trans_handle *trans; 187 unsigned int flags, oldflags; 188 int ret; 189 u64 ip_oldflags; 190 unsigned int i_oldflags; 191 umode_t mode; 192 193 if (btrfs_root_readonly(root)) 194 return -EROFS; 195 196 if (copy_from_user(&flags, arg, sizeof(flags))) 197 return -EFAULT; 198 199 ret = check_flags(flags); 200 if (ret) 201 return ret; 202 203 if (!inode_owner_or_capable(inode)) 204 return -EACCES; 205 206 ret = mnt_want_write_file(file); 207 if (ret) 208 return ret; 209 210 mutex_lock(&inode->i_mutex); 211 212 ip_oldflags = ip->flags; 213 i_oldflags = inode->i_flags; 214 mode = inode->i_mode; 215 216 flags = btrfs_mask_flags(inode->i_mode, flags); 217 oldflags = btrfs_flags_to_ioctl(ip->flags); 218 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) { 219 if (!capable(CAP_LINUX_IMMUTABLE)) { 220 ret = -EPERM; 221 goto out_unlock; 222 } 223 } 224 225 if (flags & FS_SYNC_FL) 226 ip->flags |= BTRFS_INODE_SYNC; 227 else 228 ip->flags &= ~BTRFS_INODE_SYNC; 229 if (flags & FS_IMMUTABLE_FL) 230 ip->flags |= BTRFS_INODE_IMMUTABLE; 231 else 232 ip->flags &= ~BTRFS_INODE_IMMUTABLE; 233 if (flags & FS_APPEND_FL) 234 ip->flags |= BTRFS_INODE_APPEND; 235 else 236 ip->flags &= ~BTRFS_INODE_APPEND; 237 if (flags & FS_NODUMP_FL) 238 ip->flags |= BTRFS_INODE_NODUMP; 239 else 240 ip->flags &= ~BTRFS_INODE_NODUMP; 241 if (flags & FS_NOATIME_FL) 242 ip->flags |= BTRFS_INODE_NOATIME; 243 else 244 ip->flags &= ~BTRFS_INODE_NOATIME; 245 if (flags & FS_DIRSYNC_FL) 246 ip->flags |= BTRFS_INODE_DIRSYNC; 247 else 248 ip->flags &= ~BTRFS_INODE_DIRSYNC; 249 if (flags & FS_NOCOW_FL) { 250 if (S_ISREG(mode)) { 251 /* 252 * It's safe to turn csums off here, no extents exist. 253 * Otherwise we want the flag to reflect the real COW 254 * status of the file and will not set it. 255 */ 256 if (inode->i_size == 0) 257 ip->flags |= BTRFS_INODE_NODATACOW 258 | BTRFS_INODE_NODATASUM; 259 } else { 260 ip->flags |= BTRFS_INODE_NODATACOW; 261 } 262 } else { 263 /* 264 * Revert back under same assuptions as above 265 */ 266 if (S_ISREG(mode)) { 267 if (inode->i_size == 0) 268 ip->flags &= ~(BTRFS_INODE_NODATACOW 269 | BTRFS_INODE_NODATASUM); 270 } else { 271 ip->flags &= ~BTRFS_INODE_NODATACOW; 272 } 273 } 274 275 /* 276 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS 277 * flag may be changed automatically if compression code won't make 278 * things smaller. 279 */ 280 if (flags & FS_NOCOMP_FL) { 281 ip->flags &= ~BTRFS_INODE_COMPRESS; 282 ip->flags |= BTRFS_INODE_NOCOMPRESS; 283 } else if (flags & FS_COMPR_FL) { 284 ip->flags |= BTRFS_INODE_COMPRESS; 285 ip->flags &= ~BTRFS_INODE_NOCOMPRESS; 286 } else { 287 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS); 288 } 289 290 trans = btrfs_start_transaction(root, 1); 291 if (IS_ERR(trans)) { 292 ret = PTR_ERR(trans); 293 goto out_drop; 294 } 295 296 btrfs_update_iflags(inode); 297 inode_inc_iversion(inode); 298 inode->i_ctime = CURRENT_TIME; 299 ret = btrfs_update_inode(trans, root, inode); 300 301 btrfs_end_transaction(trans, root); 302 out_drop: 303 if (ret) { 304 ip->flags = ip_oldflags; 305 inode->i_flags = i_oldflags; 306 } 307 308 out_unlock: 309 mutex_unlock(&inode->i_mutex); 310 mnt_drop_write_file(file); 311 return ret; 312 } 313 314 static int btrfs_ioctl_getversion(struct file *file, int __user *arg) 315 { 316 struct inode *inode = file_inode(file); 317 318 return put_user(inode->i_generation, arg); 319 } 320 321 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) 322 { 323 struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb); 324 struct btrfs_device *device; 325 struct request_queue *q; 326 struct fstrim_range range; 327 u64 minlen = ULLONG_MAX; 328 u64 num_devices = 0; 329 u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy); 330 int ret; 331 332 if (!capable(CAP_SYS_ADMIN)) 333 return -EPERM; 334 335 rcu_read_lock(); 336 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices, 337 dev_list) { 338 if (!device->bdev) 339 continue; 340 q = bdev_get_queue(device->bdev); 341 if (blk_queue_discard(q)) { 342 num_devices++; 343 minlen = min((u64)q->limits.discard_granularity, 344 minlen); 345 } 346 } 347 rcu_read_unlock(); 348 349 if (!num_devices) 350 return -EOPNOTSUPP; 351 if (copy_from_user(&range, arg, sizeof(range))) 352 return -EFAULT; 353 if (range.start > total_bytes || 354 range.len < fs_info->sb->s_blocksize) 355 return -EINVAL; 356 357 range.len = min(range.len, total_bytes - range.start); 358 range.minlen = max(range.minlen, minlen); 359 ret = btrfs_trim_fs(fs_info->tree_root, &range); 360 if (ret < 0) 361 return ret; 362 363 if (copy_to_user(arg, &range, sizeof(range))) 364 return -EFAULT; 365 366 return 0; 367 } 368 369 int btrfs_is_empty_uuid(u8 *uuid) 370 { 371 int i; 372 373 for (i = 0; i < BTRFS_UUID_SIZE; i++) { 374 if (uuid[i]) 375 return 0; 376 } 377 return 1; 378 } 379 380 static noinline int create_subvol(struct inode *dir, 381 struct dentry *dentry, 382 char *name, int namelen, 383 u64 *async_transid, 384 struct btrfs_qgroup_inherit *inherit) 385 { 386 struct btrfs_trans_handle *trans; 387 struct btrfs_key key; 388 struct btrfs_root_item root_item; 389 struct btrfs_inode_item *inode_item; 390 struct extent_buffer *leaf; 391 struct btrfs_root *root = BTRFS_I(dir)->root; 392 struct btrfs_root *new_root; 393 struct btrfs_block_rsv block_rsv; 394 struct timespec cur_time = CURRENT_TIME; 395 int ret; 396 int err; 397 u64 objectid; 398 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; 399 u64 index = 0; 400 u64 qgroup_reserved; 401 uuid_le new_uuid; 402 403 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid); 404 if (ret) 405 return ret; 406 407 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP); 408 /* 409 * The same as the snapshot creation, please see the comment 410 * of create_snapshot(). 411 */ 412 ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 413 8, &qgroup_reserved, false); 414 if (ret) 415 return ret; 416 417 trans = btrfs_start_transaction(root, 0); 418 if (IS_ERR(trans)) { 419 ret = PTR_ERR(trans); 420 goto out; 421 } 422 trans->block_rsv = &block_rsv; 423 trans->bytes_reserved = block_rsv.size; 424 425 ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit); 426 if (ret) 427 goto fail; 428 429 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 430 0, objectid, NULL, 0, 0, 0); 431 if (IS_ERR(leaf)) { 432 ret = PTR_ERR(leaf); 433 goto fail; 434 } 435 436 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); 437 btrfs_set_header_bytenr(leaf, leaf->start); 438 btrfs_set_header_generation(leaf, trans->transid); 439 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); 440 btrfs_set_header_owner(leaf, objectid); 441 442 write_extent_buffer(leaf, root->fs_info->fsid, btrfs_header_fsid(), 443 BTRFS_FSID_SIZE); 444 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, 445 btrfs_header_chunk_tree_uuid(leaf), 446 BTRFS_UUID_SIZE); 447 btrfs_mark_buffer_dirty(leaf); 448 449 memset(&root_item, 0, sizeof(root_item)); 450 451 inode_item = &root_item.inode; 452 btrfs_set_stack_inode_generation(inode_item, 1); 453 btrfs_set_stack_inode_size(inode_item, 3); 454 btrfs_set_stack_inode_nlink(inode_item, 1); 455 btrfs_set_stack_inode_nbytes(inode_item, root->leafsize); 456 btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755); 457 458 btrfs_set_root_flags(&root_item, 0); 459 btrfs_set_root_limit(&root_item, 0); 460 btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT); 461 462 btrfs_set_root_bytenr(&root_item, leaf->start); 463 btrfs_set_root_generation(&root_item, trans->transid); 464 btrfs_set_root_level(&root_item, 0); 465 btrfs_set_root_refs(&root_item, 1); 466 btrfs_set_root_used(&root_item, leaf->len); 467 btrfs_set_root_last_snapshot(&root_item, 0); 468 469 btrfs_set_root_generation_v2(&root_item, 470 btrfs_root_generation(&root_item)); 471 uuid_le_gen(&new_uuid); 472 memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE); 473 btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec); 474 btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec); 475 root_item.ctime = root_item.otime; 476 btrfs_set_root_ctransid(&root_item, trans->transid); 477 btrfs_set_root_otransid(&root_item, trans->transid); 478 479 btrfs_tree_unlock(leaf); 480 free_extent_buffer(leaf); 481 leaf = NULL; 482 483 btrfs_set_root_dirid(&root_item, new_dirid); 484 485 key.objectid = objectid; 486 key.offset = 0; 487 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); 488 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, 489 &root_item); 490 if (ret) 491 goto fail; 492 493 key.offset = (u64)-1; 494 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); 495 if (IS_ERR(new_root)) { 496 btrfs_abort_transaction(trans, root, PTR_ERR(new_root)); 497 ret = PTR_ERR(new_root); 498 goto fail; 499 } 500 501 btrfs_record_root_in_trans(trans, new_root); 502 503 ret = btrfs_create_subvol_root(trans, new_root, new_dirid); 504 if (ret) { 505 /* We potentially lose an unused inode item here */ 506 btrfs_abort_transaction(trans, root, ret); 507 goto fail; 508 } 509 510 /* 511 * insert the directory item 512 */ 513 ret = btrfs_set_inode_index(dir, &index); 514 if (ret) { 515 btrfs_abort_transaction(trans, root, ret); 516 goto fail; 517 } 518 519 ret = btrfs_insert_dir_item(trans, root, 520 name, namelen, dir, &key, 521 BTRFS_FT_DIR, index); 522 if (ret) { 523 btrfs_abort_transaction(trans, root, ret); 524 goto fail; 525 } 526 527 btrfs_i_size_write(dir, dir->i_size + namelen * 2); 528 ret = btrfs_update_inode(trans, root, dir); 529 BUG_ON(ret); 530 531 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 532 objectid, root->root_key.objectid, 533 btrfs_ino(dir), index, name, namelen); 534 BUG_ON(ret); 535 536 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root, 537 root_item.uuid, BTRFS_UUID_KEY_SUBVOL, 538 objectid); 539 if (ret) 540 btrfs_abort_transaction(trans, root, ret); 541 542 fail: 543 trans->block_rsv = NULL; 544 trans->bytes_reserved = 0; 545 if (async_transid) { 546 *async_transid = trans->transid; 547 err = btrfs_commit_transaction_async(trans, root, 1); 548 if (err) 549 err = btrfs_commit_transaction(trans, root); 550 } else { 551 err = btrfs_commit_transaction(trans, root); 552 } 553 if (err && !ret) 554 ret = err; 555 556 if (!ret) 557 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); 558 out: 559 btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved); 560 return ret; 561 } 562 563 static int create_snapshot(struct btrfs_root *root, struct inode *dir, 564 struct dentry *dentry, char *name, int namelen, 565 u64 *async_transid, bool readonly, 566 struct btrfs_qgroup_inherit *inherit) 567 { 568 struct inode *inode; 569 struct btrfs_pending_snapshot *pending_snapshot; 570 struct btrfs_trans_handle *trans; 571 int ret; 572 573 if (!root->ref_cows) 574 return -EINVAL; 575 576 ret = btrfs_start_delalloc_inodes(root, 0); 577 if (ret) 578 return ret; 579 580 btrfs_wait_ordered_extents(root, -1); 581 582 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); 583 if (!pending_snapshot) 584 return -ENOMEM; 585 586 btrfs_init_block_rsv(&pending_snapshot->block_rsv, 587 BTRFS_BLOCK_RSV_TEMP); 588 /* 589 * 1 - parent dir inode 590 * 2 - dir entries 591 * 1 - root item 592 * 2 - root ref/backref 593 * 1 - root of snapshot 594 * 1 - UUID item 595 */ 596 ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root, 597 &pending_snapshot->block_rsv, 8, 598 &pending_snapshot->qgroup_reserved, 599 false); 600 if (ret) 601 goto out; 602 603 pending_snapshot->dentry = dentry; 604 pending_snapshot->root = root; 605 pending_snapshot->readonly = readonly; 606 pending_snapshot->dir = dir; 607 pending_snapshot->inherit = inherit; 608 609 trans = btrfs_start_transaction(root, 0); 610 if (IS_ERR(trans)) { 611 ret = PTR_ERR(trans); 612 goto fail; 613 } 614 615 spin_lock(&root->fs_info->trans_lock); 616 list_add(&pending_snapshot->list, 617 &trans->transaction->pending_snapshots); 618 spin_unlock(&root->fs_info->trans_lock); 619 if (async_transid) { 620 *async_transid = trans->transid; 621 ret = btrfs_commit_transaction_async(trans, 622 root->fs_info->extent_root, 1); 623 if (ret) 624 ret = btrfs_commit_transaction(trans, root); 625 } else { 626 ret = btrfs_commit_transaction(trans, 627 root->fs_info->extent_root); 628 } 629 if (ret) 630 goto fail; 631 632 ret = pending_snapshot->error; 633 if (ret) 634 goto fail; 635 636 ret = btrfs_orphan_cleanup(pending_snapshot->snap); 637 if (ret) 638 goto fail; 639 640 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry); 641 if (IS_ERR(inode)) { 642 ret = PTR_ERR(inode); 643 goto fail; 644 } 645 BUG_ON(!inode); 646 d_instantiate(dentry, inode); 647 ret = 0; 648 fail: 649 btrfs_subvolume_release_metadata(BTRFS_I(dir)->root, 650 &pending_snapshot->block_rsv, 651 pending_snapshot->qgroup_reserved); 652 out: 653 kfree(pending_snapshot); 654 return ret; 655 } 656 657 /* copy of check_sticky in fs/namei.c() 658 * It's inline, so penalty for filesystems that don't use sticky bit is 659 * minimal. 660 */ 661 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode) 662 { 663 kuid_t fsuid = current_fsuid(); 664 665 if (!(dir->i_mode & S_ISVTX)) 666 return 0; 667 if (uid_eq(inode->i_uid, fsuid)) 668 return 0; 669 if (uid_eq(dir->i_uid, fsuid)) 670 return 0; 671 return !capable(CAP_FOWNER); 672 } 673 674 /* copy of may_delete in fs/namei.c() 675 * Check whether we can remove a link victim from directory dir, check 676 * whether the type of victim is right. 677 * 1. We can't do it if dir is read-only (done in permission()) 678 * 2. We should have write and exec permissions on dir 679 * 3. We can't remove anything from append-only dir 680 * 4. We can't do anything with immutable dir (done in permission()) 681 * 5. If the sticky bit on dir is set we should either 682 * a. be owner of dir, or 683 * b. be owner of victim, or 684 * c. have CAP_FOWNER capability 685 * 6. If the victim is append-only or immutable we can't do antyhing with 686 * links pointing to it. 687 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR. 688 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR. 689 * 9. We can't remove a root or mountpoint. 690 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by 691 * nfs_async_unlink(). 692 */ 693 694 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir) 695 { 696 int error; 697 698 if (!victim->d_inode) 699 return -ENOENT; 700 701 BUG_ON(victim->d_parent->d_inode != dir); 702 audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); 703 704 error = inode_permission(dir, MAY_WRITE | MAY_EXEC); 705 if (error) 706 return error; 707 if (IS_APPEND(dir)) 708 return -EPERM; 709 if (btrfs_check_sticky(dir, victim->d_inode)|| 710 IS_APPEND(victim->d_inode)|| 711 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) 712 return -EPERM; 713 if (isdir) { 714 if (!S_ISDIR(victim->d_inode->i_mode)) 715 return -ENOTDIR; 716 if (IS_ROOT(victim)) 717 return -EBUSY; 718 } else if (S_ISDIR(victim->d_inode->i_mode)) 719 return -EISDIR; 720 if (IS_DEADDIR(dir)) 721 return -ENOENT; 722 if (victim->d_flags & DCACHE_NFSFS_RENAMED) 723 return -EBUSY; 724 return 0; 725 } 726 727 /* copy of may_create in fs/namei.c() */ 728 static inline int btrfs_may_create(struct inode *dir, struct dentry *child) 729 { 730 if (child->d_inode) 731 return -EEXIST; 732 if (IS_DEADDIR(dir)) 733 return -ENOENT; 734 return inode_permission(dir, MAY_WRITE | MAY_EXEC); 735 } 736 737 /* 738 * Create a new subvolume below @parent. This is largely modeled after 739 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup 740 * inside this filesystem so it's quite a bit simpler. 741 */ 742 static noinline int btrfs_mksubvol(struct path *parent, 743 char *name, int namelen, 744 struct btrfs_root *snap_src, 745 u64 *async_transid, bool readonly, 746 struct btrfs_qgroup_inherit *inherit) 747 { 748 struct inode *dir = parent->dentry->d_inode; 749 struct dentry *dentry; 750 int error; 751 752 error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT); 753 if (error == -EINTR) 754 return error; 755 756 dentry = lookup_one_len(name, parent->dentry, namelen); 757 error = PTR_ERR(dentry); 758 if (IS_ERR(dentry)) 759 goto out_unlock; 760 761 error = -EEXIST; 762 if (dentry->d_inode) 763 goto out_dput; 764 765 error = btrfs_may_create(dir, dentry); 766 if (error) 767 goto out_dput; 768 769 /* 770 * even if this name doesn't exist, we may get hash collisions. 771 * check for them now when we can safely fail 772 */ 773 error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root, 774 dir->i_ino, name, 775 namelen); 776 if (error) 777 goto out_dput; 778 779 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 780 781 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) 782 goto out_up_read; 783 784 if (snap_src) { 785 error = create_snapshot(snap_src, dir, dentry, name, namelen, 786 async_transid, readonly, inherit); 787 } else { 788 error = create_subvol(dir, dentry, name, namelen, 789 async_transid, inherit); 790 } 791 if (!error) 792 fsnotify_mkdir(dir, dentry); 793 out_up_read: 794 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 795 out_dput: 796 dput(dentry); 797 out_unlock: 798 mutex_unlock(&dir->i_mutex); 799 return error; 800 } 801 802 /* 803 * When we're defragging a range, we don't want to kick it off again 804 * if it is really just waiting for delalloc to send it down. 805 * If we find a nice big extent or delalloc range for the bytes in the 806 * file you want to defrag, we return 0 to let you know to skip this 807 * part of the file 808 */ 809 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh) 810 { 811 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 812 struct extent_map *em = NULL; 813 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 814 u64 end; 815 816 read_lock(&em_tree->lock); 817 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE); 818 read_unlock(&em_tree->lock); 819 820 if (em) { 821 end = extent_map_end(em); 822 free_extent_map(em); 823 if (end - offset > thresh) 824 return 0; 825 } 826 /* if we already have a nice delalloc here, just stop */ 827 thresh /= 2; 828 end = count_range_bits(io_tree, &offset, offset + thresh, 829 thresh, EXTENT_DELALLOC, 1); 830 if (end >= thresh) 831 return 0; 832 return 1; 833 } 834 835 /* 836 * helper function to walk through a file and find extents 837 * newer than a specific transid, and smaller than thresh. 838 * 839 * This is used by the defragging code to find new and small 840 * extents 841 */ 842 static int find_new_extents(struct btrfs_root *root, 843 struct inode *inode, u64 newer_than, 844 u64 *off, int thresh) 845 { 846 struct btrfs_path *path; 847 struct btrfs_key min_key; 848 struct extent_buffer *leaf; 849 struct btrfs_file_extent_item *extent; 850 int type; 851 int ret; 852 u64 ino = btrfs_ino(inode); 853 854 path = btrfs_alloc_path(); 855 if (!path) 856 return -ENOMEM; 857 858 min_key.objectid = ino; 859 min_key.type = BTRFS_EXTENT_DATA_KEY; 860 min_key.offset = *off; 861 862 path->keep_locks = 1; 863 864 while (1) { 865 ret = btrfs_search_forward(root, &min_key, path, newer_than); 866 if (ret != 0) 867 goto none; 868 if (min_key.objectid != ino) 869 goto none; 870 if (min_key.type != BTRFS_EXTENT_DATA_KEY) 871 goto none; 872 873 leaf = path->nodes[0]; 874 extent = btrfs_item_ptr(leaf, path->slots[0], 875 struct btrfs_file_extent_item); 876 877 type = btrfs_file_extent_type(leaf, extent); 878 if (type == BTRFS_FILE_EXTENT_REG && 879 btrfs_file_extent_num_bytes(leaf, extent) < thresh && 880 check_defrag_in_cache(inode, min_key.offset, thresh)) { 881 *off = min_key.offset; 882 btrfs_free_path(path); 883 return 0; 884 } 885 886 if (min_key.offset == (u64)-1) 887 goto none; 888 889 min_key.offset++; 890 btrfs_release_path(path); 891 } 892 none: 893 btrfs_free_path(path); 894 return -ENOENT; 895 } 896 897 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start) 898 { 899 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 900 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 901 struct extent_map *em; 902 u64 len = PAGE_CACHE_SIZE; 903 904 /* 905 * hopefully we have this extent in the tree already, try without 906 * the full extent lock 907 */ 908 read_lock(&em_tree->lock); 909 em = lookup_extent_mapping(em_tree, start, len); 910 read_unlock(&em_tree->lock); 911 912 if (!em) { 913 /* get the big lock and read metadata off disk */ 914 lock_extent(io_tree, start, start + len - 1); 915 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 916 unlock_extent(io_tree, start, start + len - 1); 917 918 if (IS_ERR(em)) 919 return NULL; 920 } 921 922 return em; 923 } 924 925 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em) 926 { 927 struct extent_map *next; 928 bool ret = true; 929 930 /* this is the last extent */ 931 if (em->start + em->len >= i_size_read(inode)) 932 return false; 933 934 next = defrag_lookup_extent(inode, em->start + em->len); 935 if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE) 936 ret = false; 937 938 free_extent_map(next); 939 return ret; 940 } 941 942 static int should_defrag_range(struct inode *inode, u64 start, int thresh, 943 u64 *last_len, u64 *skip, u64 *defrag_end, 944 int compress) 945 { 946 struct extent_map *em; 947 int ret = 1; 948 bool next_mergeable = true; 949 950 /* 951 * make sure that once we start defragging an extent, we keep on 952 * defragging it 953 */ 954 if (start < *defrag_end) 955 return 1; 956 957 *skip = 0; 958 959 em = defrag_lookup_extent(inode, start); 960 if (!em) 961 return 0; 962 963 /* this will cover holes, and inline extents */ 964 if (em->block_start >= EXTENT_MAP_LAST_BYTE) { 965 ret = 0; 966 goto out; 967 } 968 969 next_mergeable = defrag_check_next_extent(inode, em); 970 971 /* 972 * we hit a real extent, if it is big or the next extent is not a 973 * real extent, don't bother defragging it 974 */ 975 if (!compress && (*last_len == 0 || *last_len >= thresh) && 976 (em->len >= thresh || !next_mergeable)) 977 ret = 0; 978 out: 979 /* 980 * last_len ends up being a counter of how many bytes we've defragged. 981 * every time we choose not to defrag an extent, we reset *last_len 982 * so that the next tiny extent will force a defrag. 983 * 984 * The end result of this is that tiny extents before a single big 985 * extent will force at least part of that big extent to be defragged. 986 */ 987 if (ret) { 988 *defrag_end = extent_map_end(em); 989 } else { 990 *last_len = 0; 991 *skip = extent_map_end(em); 992 *defrag_end = 0; 993 } 994 995 free_extent_map(em); 996 return ret; 997 } 998 999 /* 1000 * it doesn't do much good to defrag one or two pages 1001 * at a time. This pulls in a nice chunk of pages 1002 * to COW and defrag. 1003 * 1004 * It also makes sure the delalloc code has enough 1005 * dirty data to avoid making new small extents as part 1006 * of the defrag 1007 * 1008 * It's a good idea to start RA on this range 1009 * before calling this. 1010 */ 1011 static int cluster_pages_for_defrag(struct inode *inode, 1012 struct page **pages, 1013 unsigned long start_index, 1014 int num_pages) 1015 { 1016 unsigned long file_end; 1017 u64 isize = i_size_read(inode); 1018 u64 page_start; 1019 u64 page_end; 1020 u64 page_cnt; 1021 int ret; 1022 int i; 1023 int i_done; 1024 struct btrfs_ordered_extent *ordered; 1025 struct extent_state *cached_state = NULL; 1026 struct extent_io_tree *tree; 1027 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); 1028 1029 file_end = (isize - 1) >> PAGE_CACHE_SHIFT; 1030 if (!isize || start_index > file_end) 1031 return 0; 1032 1033 page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1); 1034 1035 ret = btrfs_delalloc_reserve_space(inode, 1036 page_cnt << PAGE_CACHE_SHIFT); 1037 if (ret) 1038 return ret; 1039 i_done = 0; 1040 tree = &BTRFS_I(inode)->io_tree; 1041 1042 /* step one, lock all the pages */ 1043 for (i = 0; i < page_cnt; i++) { 1044 struct page *page; 1045 again: 1046 page = find_or_create_page(inode->i_mapping, 1047 start_index + i, mask); 1048 if (!page) 1049 break; 1050 1051 page_start = page_offset(page); 1052 page_end = page_start + PAGE_CACHE_SIZE - 1; 1053 while (1) { 1054 lock_extent(tree, page_start, page_end); 1055 ordered = btrfs_lookup_ordered_extent(inode, 1056 page_start); 1057 unlock_extent(tree, page_start, page_end); 1058 if (!ordered) 1059 break; 1060 1061 unlock_page(page); 1062 btrfs_start_ordered_extent(inode, ordered, 1); 1063 btrfs_put_ordered_extent(ordered); 1064 lock_page(page); 1065 /* 1066 * we unlocked the page above, so we need check if 1067 * it was released or not. 1068 */ 1069 if (page->mapping != inode->i_mapping) { 1070 unlock_page(page); 1071 page_cache_release(page); 1072 goto again; 1073 } 1074 } 1075 1076 if (!PageUptodate(page)) { 1077 btrfs_readpage(NULL, page); 1078 lock_page(page); 1079 if (!PageUptodate(page)) { 1080 unlock_page(page); 1081 page_cache_release(page); 1082 ret = -EIO; 1083 break; 1084 } 1085 } 1086 1087 if (page->mapping != inode->i_mapping) { 1088 unlock_page(page); 1089 page_cache_release(page); 1090 goto again; 1091 } 1092 1093 pages[i] = page; 1094 i_done++; 1095 } 1096 if (!i_done || ret) 1097 goto out; 1098 1099 if (!(inode->i_sb->s_flags & MS_ACTIVE)) 1100 goto out; 1101 1102 /* 1103 * so now we have a nice long stream of locked 1104 * and up to date pages, lets wait on them 1105 */ 1106 for (i = 0; i < i_done; i++) 1107 wait_on_page_writeback(pages[i]); 1108 1109 page_start = page_offset(pages[0]); 1110 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE; 1111 1112 lock_extent_bits(&BTRFS_I(inode)->io_tree, 1113 page_start, page_end - 1, 0, &cached_state); 1114 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, 1115 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC | 1116 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, 1117 &cached_state, GFP_NOFS); 1118 1119 if (i_done != page_cnt) { 1120 spin_lock(&BTRFS_I(inode)->lock); 1121 BTRFS_I(inode)->outstanding_extents++; 1122 spin_unlock(&BTRFS_I(inode)->lock); 1123 btrfs_delalloc_release_space(inode, 1124 (page_cnt - i_done) << PAGE_CACHE_SHIFT); 1125 } 1126 1127 1128 set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1, 1129 &cached_state, GFP_NOFS); 1130 1131 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 1132 page_start, page_end - 1, &cached_state, 1133 GFP_NOFS); 1134 1135 for (i = 0; i < i_done; i++) { 1136 clear_page_dirty_for_io(pages[i]); 1137 ClearPageChecked(pages[i]); 1138 set_page_extent_mapped(pages[i]); 1139 set_page_dirty(pages[i]); 1140 unlock_page(pages[i]); 1141 page_cache_release(pages[i]); 1142 } 1143 return i_done; 1144 out: 1145 for (i = 0; i < i_done; i++) { 1146 unlock_page(pages[i]); 1147 page_cache_release(pages[i]); 1148 } 1149 btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT); 1150 return ret; 1151 1152 } 1153 1154 int btrfs_defrag_file(struct inode *inode, struct file *file, 1155 struct btrfs_ioctl_defrag_range_args *range, 1156 u64 newer_than, unsigned long max_to_defrag) 1157 { 1158 struct btrfs_root *root = BTRFS_I(inode)->root; 1159 struct file_ra_state *ra = NULL; 1160 unsigned long last_index; 1161 u64 isize = i_size_read(inode); 1162 u64 last_len = 0; 1163 u64 skip = 0; 1164 u64 defrag_end = 0; 1165 u64 newer_off = range->start; 1166 unsigned long i; 1167 unsigned long ra_index = 0; 1168 int ret; 1169 int defrag_count = 0; 1170 int compress_type = BTRFS_COMPRESS_ZLIB; 1171 int extent_thresh = range->extent_thresh; 1172 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; 1173 int cluster = max_cluster; 1174 u64 new_align = ~((u64)128 * 1024 - 1); 1175 struct page **pages = NULL; 1176 1177 if (isize == 0) 1178 return 0; 1179 1180 if (range->start >= isize) 1181 return -EINVAL; 1182 1183 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) { 1184 if (range->compress_type > BTRFS_COMPRESS_TYPES) 1185 return -EINVAL; 1186 if (range->compress_type) 1187 compress_type = range->compress_type; 1188 } 1189 1190 if (extent_thresh == 0) 1191 extent_thresh = 256 * 1024; 1192 1193 /* 1194 * if we were not given a file, allocate a readahead 1195 * context 1196 */ 1197 if (!file) { 1198 ra = kzalloc(sizeof(*ra), GFP_NOFS); 1199 if (!ra) 1200 return -ENOMEM; 1201 file_ra_state_init(ra, inode->i_mapping); 1202 } else { 1203 ra = &file->f_ra; 1204 } 1205 1206 pages = kmalloc_array(max_cluster, sizeof(struct page *), 1207 GFP_NOFS); 1208 if (!pages) { 1209 ret = -ENOMEM; 1210 goto out_ra; 1211 } 1212 1213 /* find the last page to defrag */ 1214 if (range->start + range->len > range->start) { 1215 last_index = min_t(u64, isize - 1, 1216 range->start + range->len - 1) >> PAGE_CACHE_SHIFT; 1217 } else { 1218 last_index = (isize - 1) >> PAGE_CACHE_SHIFT; 1219 } 1220 1221 if (newer_than) { 1222 ret = find_new_extents(root, inode, newer_than, 1223 &newer_off, 64 * 1024); 1224 if (!ret) { 1225 range->start = newer_off; 1226 /* 1227 * we always align our defrag to help keep 1228 * the extents in the file evenly spaced 1229 */ 1230 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; 1231 } else 1232 goto out_ra; 1233 } else { 1234 i = range->start >> PAGE_CACHE_SHIFT; 1235 } 1236 if (!max_to_defrag) 1237 max_to_defrag = last_index + 1; 1238 1239 /* 1240 * make writeback starts from i, so the defrag range can be 1241 * written sequentially. 1242 */ 1243 if (i < inode->i_mapping->writeback_index) 1244 inode->i_mapping->writeback_index = i; 1245 1246 while (i <= last_index && defrag_count < max_to_defrag && 1247 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> 1248 PAGE_CACHE_SHIFT)) { 1249 /* 1250 * make sure we stop running if someone unmounts 1251 * the FS 1252 */ 1253 if (!(inode->i_sb->s_flags & MS_ACTIVE)) 1254 break; 1255 1256 if (btrfs_defrag_cancelled(root->fs_info)) { 1257 printk(KERN_DEBUG "btrfs: defrag_file cancelled\n"); 1258 ret = -EAGAIN; 1259 break; 1260 } 1261 1262 if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT, 1263 extent_thresh, &last_len, &skip, 1264 &defrag_end, range->flags & 1265 BTRFS_DEFRAG_RANGE_COMPRESS)) { 1266 unsigned long next; 1267 /* 1268 * the should_defrag function tells us how much to skip 1269 * bump our counter by the suggested amount 1270 */ 1271 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 1272 i = max(i + 1, next); 1273 continue; 1274 } 1275 1276 if (!newer_than) { 1277 cluster = (PAGE_CACHE_ALIGN(defrag_end) >> 1278 PAGE_CACHE_SHIFT) - i; 1279 cluster = min(cluster, max_cluster); 1280 } else { 1281 cluster = max_cluster; 1282 } 1283 1284 if (i + cluster > ra_index) { 1285 ra_index = max(i, ra_index); 1286 btrfs_force_ra(inode->i_mapping, ra, file, ra_index, 1287 cluster); 1288 ra_index += max_cluster; 1289 } 1290 1291 mutex_lock(&inode->i_mutex); 1292 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) 1293 BTRFS_I(inode)->force_compress = compress_type; 1294 ret = cluster_pages_for_defrag(inode, pages, i, cluster); 1295 if (ret < 0) { 1296 mutex_unlock(&inode->i_mutex); 1297 goto out_ra; 1298 } 1299 1300 defrag_count += ret; 1301 balance_dirty_pages_ratelimited(inode->i_mapping); 1302 mutex_unlock(&inode->i_mutex); 1303 1304 if (newer_than) { 1305 if (newer_off == (u64)-1) 1306 break; 1307 1308 if (ret > 0) 1309 i += ret; 1310 1311 newer_off = max(newer_off + 1, 1312 (u64)i << PAGE_CACHE_SHIFT); 1313 1314 ret = find_new_extents(root, inode, 1315 newer_than, &newer_off, 1316 64 * 1024); 1317 if (!ret) { 1318 range->start = newer_off; 1319 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; 1320 } else { 1321 break; 1322 } 1323 } else { 1324 if (ret > 0) { 1325 i += ret; 1326 last_len += ret << PAGE_CACHE_SHIFT; 1327 } else { 1328 i++; 1329 last_len = 0; 1330 } 1331 } 1332 } 1333 1334 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) 1335 filemap_flush(inode->i_mapping); 1336 1337 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { 1338 /* the filemap_flush will queue IO into the worker threads, but 1339 * we have to make sure the IO is actually started and that 1340 * ordered extents get created before we return 1341 */ 1342 atomic_inc(&root->fs_info->async_submit_draining); 1343 while (atomic_read(&root->fs_info->nr_async_submits) || 1344 atomic_read(&root->fs_info->async_delalloc_pages)) { 1345 wait_event(root->fs_info->async_submit_wait, 1346 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 1347 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 1348 } 1349 atomic_dec(&root->fs_info->async_submit_draining); 1350 } 1351 1352 if (range->compress_type == BTRFS_COMPRESS_LZO) { 1353 btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO); 1354 } 1355 1356 ret = defrag_count; 1357 1358 out_ra: 1359 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) { 1360 mutex_lock(&inode->i_mutex); 1361 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; 1362 mutex_unlock(&inode->i_mutex); 1363 } 1364 if (!file) 1365 kfree(ra); 1366 kfree(pages); 1367 return ret; 1368 } 1369 1370 static noinline int btrfs_ioctl_resize(struct file *file, 1371 void __user *arg) 1372 { 1373 u64 new_size; 1374 u64 old_size; 1375 u64 devid = 1; 1376 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 1377 struct btrfs_ioctl_vol_args *vol_args; 1378 struct btrfs_trans_handle *trans; 1379 struct btrfs_device *device = NULL; 1380 char *sizestr; 1381 char *devstr = NULL; 1382 int ret = 0; 1383 int mod = 0; 1384 1385 if (!capable(CAP_SYS_ADMIN)) 1386 return -EPERM; 1387 1388 ret = mnt_want_write_file(file); 1389 if (ret) 1390 return ret; 1391 1392 if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running, 1393 1)) { 1394 mnt_drop_write_file(file); 1395 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; 1396 } 1397 1398 mutex_lock(&root->fs_info->volume_mutex); 1399 vol_args = memdup_user(arg, sizeof(*vol_args)); 1400 if (IS_ERR(vol_args)) { 1401 ret = PTR_ERR(vol_args); 1402 goto out; 1403 } 1404 1405 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1406 1407 sizestr = vol_args->name; 1408 devstr = strchr(sizestr, ':'); 1409 if (devstr) { 1410 char *end; 1411 sizestr = devstr + 1; 1412 *devstr = '\0'; 1413 devstr = vol_args->name; 1414 devid = simple_strtoull(devstr, &end, 10); 1415 if (!devid) { 1416 ret = -EINVAL; 1417 goto out_free; 1418 } 1419 printk(KERN_INFO "btrfs: resizing devid %llu\n", devid); 1420 } 1421 1422 device = btrfs_find_device(root->fs_info, devid, NULL, NULL); 1423 if (!device) { 1424 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n", 1425 devid); 1426 ret = -ENODEV; 1427 goto out_free; 1428 } 1429 1430 if (!device->writeable) { 1431 printk(KERN_INFO "btrfs: resizer unable to apply on " 1432 "readonly device %llu\n", 1433 devid); 1434 ret = -EPERM; 1435 goto out_free; 1436 } 1437 1438 if (!strcmp(sizestr, "max")) 1439 new_size = device->bdev->bd_inode->i_size; 1440 else { 1441 if (sizestr[0] == '-') { 1442 mod = -1; 1443 sizestr++; 1444 } else if (sizestr[0] == '+') { 1445 mod = 1; 1446 sizestr++; 1447 } 1448 new_size = memparse(sizestr, NULL); 1449 if (new_size == 0) { 1450 ret = -EINVAL; 1451 goto out_free; 1452 } 1453 } 1454 1455 if (device->is_tgtdev_for_dev_replace) { 1456 ret = -EPERM; 1457 goto out_free; 1458 } 1459 1460 old_size = device->total_bytes; 1461 1462 if (mod < 0) { 1463 if (new_size > old_size) { 1464 ret = -EINVAL; 1465 goto out_free; 1466 } 1467 new_size = old_size - new_size; 1468 } else if (mod > 0) { 1469 new_size = old_size + new_size; 1470 } 1471 1472 if (new_size < 256 * 1024 * 1024) { 1473 ret = -EINVAL; 1474 goto out_free; 1475 } 1476 if (new_size > device->bdev->bd_inode->i_size) { 1477 ret = -EFBIG; 1478 goto out_free; 1479 } 1480 1481 do_div(new_size, root->sectorsize); 1482 new_size *= root->sectorsize; 1483 1484 printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n", 1485 rcu_str_deref(device->name), new_size); 1486 1487 if (new_size > old_size) { 1488 trans = btrfs_start_transaction(root, 0); 1489 if (IS_ERR(trans)) { 1490 ret = PTR_ERR(trans); 1491 goto out_free; 1492 } 1493 ret = btrfs_grow_device(trans, device, new_size); 1494 btrfs_commit_transaction(trans, root); 1495 } else if (new_size < old_size) { 1496 ret = btrfs_shrink_device(device, new_size); 1497 } /* equal, nothing need to do */ 1498 1499 out_free: 1500 kfree(vol_args); 1501 out: 1502 mutex_unlock(&root->fs_info->volume_mutex); 1503 atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0); 1504 mnt_drop_write_file(file); 1505 return ret; 1506 } 1507 1508 static noinline int btrfs_ioctl_snap_create_transid(struct file *file, 1509 char *name, unsigned long fd, int subvol, 1510 u64 *transid, bool readonly, 1511 struct btrfs_qgroup_inherit *inherit) 1512 { 1513 int namelen; 1514 int ret = 0; 1515 1516 ret = mnt_want_write_file(file); 1517 if (ret) 1518 goto out; 1519 1520 namelen = strlen(name); 1521 if (strchr(name, '/')) { 1522 ret = -EINVAL; 1523 goto out_drop_write; 1524 } 1525 1526 if (name[0] == '.' && 1527 (namelen == 1 || (name[1] == '.' && namelen == 2))) { 1528 ret = -EEXIST; 1529 goto out_drop_write; 1530 } 1531 1532 if (subvol) { 1533 ret = btrfs_mksubvol(&file->f_path, name, namelen, 1534 NULL, transid, readonly, inherit); 1535 } else { 1536 struct fd src = fdget(fd); 1537 struct inode *src_inode; 1538 if (!src.file) { 1539 ret = -EINVAL; 1540 goto out_drop_write; 1541 } 1542 1543 src_inode = file_inode(src.file); 1544 if (src_inode->i_sb != file_inode(file)->i_sb) { 1545 printk(KERN_INFO "btrfs: Snapshot src from " 1546 "another FS\n"); 1547 ret = -EINVAL; 1548 } else { 1549 ret = btrfs_mksubvol(&file->f_path, name, namelen, 1550 BTRFS_I(src_inode)->root, 1551 transid, readonly, inherit); 1552 } 1553 fdput(src); 1554 } 1555 out_drop_write: 1556 mnt_drop_write_file(file); 1557 out: 1558 return ret; 1559 } 1560 1561 static noinline int btrfs_ioctl_snap_create(struct file *file, 1562 void __user *arg, int subvol) 1563 { 1564 struct btrfs_ioctl_vol_args *vol_args; 1565 int ret; 1566 1567 vol_args = memdup_user(arg, sizeof(*vol_args)); 1568 if (IS_ERR(vol_args)) 1569 return PTR_ERR(vol_args); 1570 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1571 1572 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, 1573 vol_args->fd, subvol, 1574 NULL, false, NULL); 1575 1576 kfree(vol_args); 1577 return ret; 1578 } 1579 1580 static noinline int btrfs_ioctl_snap_create_v2(struct file *file, 1581 void __user *arg, int subvol) 1582 { 1583 struct btrfs_ioctl_vol_args_v2 *vol_args; 1584 int ret; 1585 u64 transid = 0; 1586 u64 *ptr = NULL; 1587 bool readonly = false; 1588 struct btrfs_qgroup_inherit *inherit = NULL; 1589 1590 vol_args = memdup_user(arg, sizeof(*vol_args)); 1591 if (IS_ERR(vol_args)) 1592 return PTR_ERR(vol_args); 1593 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0'; 1594 1595 if (vol_args->flags & 1596 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY | 1597 BTRFS_SUBVOL_QGROUP_INHERIT)) { 1598 ret = -EOPNOTSUPP; 1599 goto out; 1600 } 1601 1602 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC) 1603 ptr = &transid; 1604 if (vol_args->flags & BTRFS_SUBVOL_RDONLY) 1605 readonly = true; 1606 if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) { 1607 if (vol_args->size > PAGE_CACHE_SIZE) { 1608 ret = -EINVAL; 1609 goto out; 1610 } 1611 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size); 1612 if (IS_ERR(inherit)) { 1613 ret = PTR_ERR(inherit); 1614 goto out; 1615 } 1616 } 1617 1618 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, 1619 vol_args->fd, subvol, ptr, 1620 readonly, inherit); 1621 1622 if (ret == 0 && ptr && 1623 copy_to_user(arg + 1624 offsetof(struct btrfs_ioctl_vol_args_v2, 1625 transid), ptr, sizeof(*ptr))) 1626 ret = -EFAULT; 1627 out: 1628 kfree(vol_args); 1629 kfree(inherit); 1630 return ret; 1631 } 1632 1633 static noinline int btrfs_ioctl_subvol_getflags(struct file *file, 1634 void __user *arg) 1635 { 1636 struct inode *inode = file_inode(file); 1637 struct btrfs_root *root = BTRFS_I(inode)->root; 1638 int ret = 0; 1639 u64 flags = 0; 1640 1641 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) 1642 return -EINVAL; 1643 1644 down_read(&root->fs_info->subvol_sem); 1645 if (btrfs_root_readonly(root)) 1646 flags |= BTRFS_SUBVOL_RDONLY; 1647 up_read(&root->fs_info->subvol_sem); 1648 1649 if (copy_to_user(arg, &flags, sizeof(flags))) 1650 ret = -EFAULT; 1651 1652 return ret; 1653 } 1654 1655 static noinline int btrfs_ioctl_subvol_setflags(struct file *file, 1656 void __user *arg) 1657 { 1658 struct inode *inode = file_inode(file); 1659 struct btrfs_root *root = BTRFS_I(inode)->root; 1660 struct btrfs_trans_handle *trans; 1661 u64 root_flags; 1662 u64 flags; 1663 int ret = 0; 1664 1665 ret = mnt_want_write_file(file); 1666 if (ret) 1667 goto out; 1668 1669 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) { 1670 ret = -EINVAL; 1671 goto out_drop_write; 1672 } 1673 1674 if (copy_from_user(&flags, arg, sizeof(flags))) { 1675 ret = -EFAULT; 1676 goto out_drop_write; 1677 } 1678 1679 if (flags & BTRFS_SUBVOL_CREATE_ASYNC) { 1680 ret = -EINVAL; 1681 goto out_drop_write; 1682 } 1683 1684 if (flags & ~BTRFS_SUBVOL_RDONLY) { 1685 ret = -EOPNOTSUPP; 1686 goto out_drop_write; 1687 } 1688 1689 if (!inode_owner_or_capable(inode)) { 1690 ret = -EACCES; 1691 goto out_drop_write; 1692 } 1693 1694 down_write(&root->fs_info->subvol_sem); 1695 1696 /* nothing to do */ 1697 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root)) 1698 goto out_drop_sem; 1699 1700 root_flags = btrfs_root_flags(&root->root_item); 1701 if (flags & BTRFS_SUBVOL_RDONLY) 1702 btrfs_set_root_flags(&root->root_item, 1703 root_flags | BTRFS_ROOT_SUBVOL_RDONLY); 1704 else 1705 btrfs_set_root_flags(&root->root_item, 1706 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY); 1707 1708 trans = btrfs_start_transaction(root, 1); 1709 if (IS_ERR(trans)) { 1710 ret = PTR_ERR(trans); 1711 goto out_reset; 1712 } 1713 1714 ret = btrfs_update_root(trans, root->fs_info->tree_root, 1715 &root->root_key, &root->root_item); 1716 1717 btrfs_commit_transaction(trans, root); 1718 out_reset: 1719 if (ret) 1720 btrfs_set_root_flags(&root->root_item, root_flags); 1721 out_drop_sem: 1722 up_write(&root->fs_info->subvol_sem); 1723 out_drop_write: 1724 mnt_drop_write_file(file); 1725 out: 1726 return ret; 1727 } 1728 1729 /* 1730 * helper to check if the subvolume references other subvolumes 1731 */ 1732 static noinline int may_destroy_subvol(struct btrfs_root *root) 1733 { 1734 struct btrfs_path *path; 1735 struct btrfs_dir_item *di; 1736 struct btrfs_key key; 1737 u64 dir_id; 1738 int ret; 1739 1740 path = btrfs_alloc_path(); 1741 if (!path) 1742 return -ENOMEM; 1743 1744 /* Make sure this root isn't set as the default subvol */ 1745 dir_id = btrfs_super_root_dir(root->fs_info->super_copy); 1746 di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path, 1747 dir_id, "default", 7, 0); 1748 if (di && !IS_ERR(di)) { 1749 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key); 1750 if (key.objectid == root->root_key.objectid) { 1751 ret = -ENOTEMPTY; 1752 goto out; 1753 } 1754 btrfs_release_path(path); 1755 } 1756 1757 key.objectid = root->root_key.objectid; 1758 key.type = BTRFS_ROOT_REF_KEY; 1759 key.offset = (u64)-1; 1760 1761 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, 1762 &key, path, 0, 0); 1763 if (ret < 0) 1764 goto out; 1765 BUG_ON(ret == 0); 1766 1767 ret = 0; 1768 if (path->slots[0] > 0) { 1769 path->slots[0]--; 1770 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1771 if (key.objectid == root->root_key.objectid && 1772 key.type == BTRFS_ROOT_REF_KEY) 1773 ret = -ENOTEMPTY; 1774 } 1775 out: 1776 btrfs_free_path(path); 1777 return ret; 1778 } 1779 1780 static noinline int key_in_sk(struct btrfs_key *key, 1781 struct btrfs_ioctl_search_key *sk) 1782 { 1783 struct btrfs_key test; 1784 int ret; 1785 1786 test.objectid = sk->min_objectid; 1787 test.type = sk->min_type; 1788 test.offset = sk->min_offset; 1789 1790 ret = btrfs_comp_cpu_keys(key, &test); 1791 if (ret < 0) 1792 return 0; 1793 1794 test.objectid = sk->max_objectid; 1795 test.type = sk->max_type; 1796 test.offset = sk->max_offset; 1797 1798 ret = btrfs_comp_cpu_keys(key, &test); 1799 if (ret > 0) 1800 return 0; 1801 return 1; 1802 } 1803 1804 static noinline int copy_to_sk(struct btrfs_root *root, 1805 struct btrfs_path *path, 1806 struct btrfs_key *key, 1807 struct btrfs_ioctl_search_key *sk, 1808 char *buf, 1809 unsigned long *sk_offset, 1810 int *num_found) 1811 { 1812 u64 found_transid; 1813 struct extent_buffer *leaf; 1814 struct btrfs_ioctl_search_header sh; 1815 unsigned long item_off; 1816 unsigned long item_len; 1817 int nritems; 1818 int i; 1819 int slot; 1820 int ret = 0; 1821 1822 leaf = path->nodes[0]; 1823 slot = path->slots[0]; 1824 nritems = btrfs_header_nritems(leaf); 1825 1826 if (btrfs_header_generation(leaf) > sk->max_transid) { 1827 i = nritems; 1828 goto advance_key; 1829 } 1830 found_transid = btrfs_header_generation(leaf); 1831 1832 for (i = slot; i < nritems; i++) { 1833 item_off = btrfs_item_ptr_offset(leaf, i); 1834 item_len = btrfs_item_size_nr(leaf, i); 1835 1836 btrfs_item_key_to_cpu(leaf, key, i); 1837 if (!key_in_sk(key, sk)) 1838 continue; 1839 1840 if (sizeof(sh) + item_len > BTRFS_SEARCH_ARGS_BUFSIZE) 1841 item_len = 0; 1842 1843 if (sizeof(sh) + item_len + *sk_offset > 1844 BTRFS_SEARCH_ARGS_BUFSIZE) { 1845 ret = 1; 1846 goto overflow; 1847 } 1848 1849 sh.objectid = key->objectid; 1850 sh.offset = key->offset; 1851 sh.type = key->type; 1852 sh.len = item_len; 1853 sh.transid = found_transid; 1854 1855 /* copy search result header */ 1856 memcpy(buf + *sk_offset, &sh, sizeof(sh)); 1857 *sk_offset += sizeof(sh); 1858 1859 if (item_len) { 1860 char *p = buf + *sk_offset; 1861 /* copy the item */ 1862 read_extent_buffer(leaf, p, 1863 item_off, item_len); 1864 *sk_offset += item_len; 1865 } 1866 (*num_found)++; 1867 1868 if (*num_found >= sk->nr_items) 1869 break; 1870 } 1871 advance_key: 1872 ret = 0; 1873 if (key->offset < (u64)-1 && key->offset < sk->max_offset) 1874 key->offset++; 1875 else if (key->type < (u8)-1 && key->type < sk->max_type) { 1876 key->offset = 0; 1877 key->type++; 1878 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) { 1879 key->offset = 0; 1880 key->type = 0; 1881 key->objectid++; 1882 } else 1883 ret = 1; 1884 overflow: 1885 return ret; 1886 } 1887 1888 static noinline int search_ioctl(struct inode *inode, 1889 struct btrfs_ioctl_search_args *args) 1890 { 1891 struct btrfs_root *root; 1892 struct btrfs_key key; 1893 struct btrfs_path *path; 1894 struct btrfs_ioctl_search_key *sk = &args->key; 1895 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info; 1896 int ret; 1897 int num_found = 0; 1898 unsigned long sk_offset = 0; 1899 1900 path = btrfs_alloc_path(); 1901 if (!path) 1902 return -ENOMEM; 1903 1904 if (sk->tree_id == 0) { 1905 /* search the root of the inode that was passed */ 1906 root = BTRFS_I(inode)->root; 1907 } else { 1908 key.objectid = sk->tree_id; 1909 key.type = BTRFS_ROOT_ITEM_KEY; 1910 key.offset = (u64)-1; 1911 root = btrfs_read_fs_root_no_name(info, &key); 1912 if (IS_ERR(root)) { 1913 printk(KERN_ERR "could not find root %llu\n", 1914 sk->tree_id); 1915 btrfs_free_path(path); 1916 return -ENOENT; 1917 } 1918 } 1919 1920 key.objectid = sk->min_objectid; 1921 key.type = sk->min_type; 1922 key.offset = sk->min_offset; 1923 1924 path->keep_locks = 1; 1925 1926 while (1) { 1927 ret = btrfs_search_forward(root, &key, path, sk->min_transid); 1928 if (ret != 0) { 1929 if (ret > 0) 1930 ret = 0; 1931 goto err; 1932 } 1933 ret = copy_to_sk(root, path, &key, sk, args->buf, 1934 &sk_offset, &num_found); 1935 btrfs_release_path(path); 1936 if (ret || num_found >= sk->nr_items) 1937 break; 1938 1939 } 1940 ret = 0; 1941 err: 1942 sk->nr_items = num_found; 1943 btrfs_free_path(path); 1944 return ret; 1945 } 1946 1947 static noinline int btrfs_ioctl_tree_search(struct file *file, 1948 void __user *argp) 1949 { 1950 struct btrfs_ioctl_search_args *args; 1951 struct inode *inode; 1952 int ret; 1953 1954 if (!capable(CAP_SYS_ADMIN)) 1955 return -EPERM; 1956 1957 args = memdup_user(argp, sizeof(*args)); 1958 if (IS_ERR(args)) 1959 return PTR_ERR(args); 1960 1961 inode = file_inode(file); 1962 ret = search_ioctl(inode, args); 1963 if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) 1964 ret = -EFAULT; 1965 kfree(args); 1966 return ret; 1967 } 1968 1969 /* 1970 * Search INODE_REFs to identify path name of 'dirid' directory 1971 * in a 'tree_id' tree. and sets path name to 'name'. 1972 */ 1973 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info, 1974 u64 tree_id, u64 dirid, char *name) 1975 { 1976 struct btrfs_root *root; 1977 struct btrfs_key key; 1978 char *ptr; 1979 int ret = -1; 1980 int slot; 1981 int len; 1982 int total_len = 0; 1983 struct btrfs_inode_ref *iref; 1984 struct extent_buffer *l; 1985 struct btrfs_path *path; 1986 1987 if (dirid == BTRFS_FIRST_FREE_OBJECTID) { 1988 name[0]='\0'; 1989 return 0; 1990 } 1991 1992 path = btrfs_alloc_path(); 1993 if (!path) 1994 return -ENOMEM; 1995 1996 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX]; 1997 1998 key.objectid = tree_id; 1999 key.type = BTRFS_ROOT_ITEM_KEY; 2000 key.offset = (u64)-1; 2001 root = btrfs_read_fs_root_no_name(info, &key); 2002 if (IS_ERR(root)) { 2003 printk(KERN_ERR "could not find root %llu\n", tree_id); 2004 ret = -ENOENT; 2005 goto out; 2006 } 2007 2008 key.objectid = dirid; 2009 key.type = BTRFS_INODE_REF_KEY; 2010 key.offset = (u64)-1; 2011 2012 while (1) { 2013 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2014 if (ret < 0) 2015 goto out; 2016 else if (ret > 0) { 2017 ret = btrfs_previous_item(root, path, dirid, 2018 BTRFS_INODE_REF_KEY); 2019 if (ret < 0) 2020 goto out; 2021 else if (ret > 0) { 2022 ret = -ENOENT; 2023 goto out; 2024 } 2025 } 2026 2027 l = path->nodes[0]; 2028 slot = path->slots[0]; 2029 btrfs_item_key_to_cpu(l, &key, slot); 2030 2031 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref); 2032 len = btrfs_inode_ref_name_len(l, iref); 2033 ptr -= len + 1; 2034 total_len += len + 1; 2035 if (ptr < name) { 2036 ret = -ENAMETOOLONG; 2037 goto out; 2038 } 2039 2040 *(ptr + len) = '/'; 2041 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len); 2042 2043 if (key.offset == BTRFS_FIRST_FREE_OBJECTID) 2044 break; 2045 2046 btrfs_release_path(path); 2047 key.objectid = key.offset; 2048 key.offset = (u64)-1; 2049 dirid = key.objectid; 2050 } 2051 memmove(name, ptr, total_len); 2052 name[total_len] = '\0'; 2053 ret = 0; 2054 out: 2055 btrfs_free_path(path); 2056 return ret; 2057 } 2058 2059 static noinline int btrfs_ioctl_ino_lookup(struct file *file, 2060 void __user *argp) 2061 { 2062 struct btrfs_ioctl_ino_lookup_args *args; 2063 struct inode *inode; 2064 int ret; 2065 2066 if (!capable(CAP_SYS_ADMIN)) 2067 return -EPERM; 2068 2069 args = memdup_user(argp, sizeof(*args)); 2070 if (IS_ERR(args)) 2071 return PTR_ERR(args); 2072 2073 inode = file_inode(file); 2074 2075 if (args->treeid == 0) 2076 args->treeid = BTRFS_I(inode)->root->root_key.objectid; 2077 2078 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info, 2079 args->treeid, args->objectid, 2080 args->name); 2081 2082 if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) 2083 ret = -EFAULT; 2084 2085 kfree(args); 2086 return ret; 2087 } 2088 2089 static noinline int btrfs_ioctl_snap_destroy(struct file *file, 2090 void __user *arg) 2091 { 2092 struct dentry *parent = file->f_path.dentry; 2093 struct dentry *dentry; 2094 struct inode *dir = parent->d_inode; 2095 struct inode *inode; 2096 struct btrfs_root *root = BTRFS_I(dir)->root; 2097 struct btrfs_root *dest = NULL; 2098 struct btrfs_ioctl_vol_args *vol_args; 2099 struct btrfs_trans_handle *trans; 2100 struct btrfs_block_rsv block_rsv; 2101 u64 qgroup_reserved; 2102 int namelen; 2103 int ret; 2104 int err = 0; 2105 2106 vol_args = memdup_user(arg, sizeof(*vol_args)); 2107 if (IS_ERR(vol_args)) 2108 return PTR_ERR(vol_args); 2109 2110 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2111 namelen = strlen(vol_args->name); 2112 if (strchr(vol_args->name, '/') || 2113 strncmp(vol_args->name, "..", namelen) == 0) { 2114 err = -EINVAL; 2115 goto out; 2116 } 2117 2118 err = mnt_want_write_file(file); 2119 if (err) 2120 goto out; 2121 2122 err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT); 2123 if (err == -EINTR) 2124 goto out_drop_write; 2125 dentry = lookup_one_len(vol_args->name, parent, namelen); 2126 if (IS_ERR(dentry)) { 2127 err = PTR_ERR(dentry); 2128 goto out_unlock_dir; 2129 } 2130 2131 if (!dentry->d_inode) { 2132 err = -ENOENT; 2133 goto out_dput; 2134 } 2135 2136 inode = dentry->d_inode; 2137 dest = BTRFS_I(inode)->root; 2138 if (!capable(CAP_SYS_ADMIN)) { 2139 /* 2140 * Regular user. Only allow this with a special mount 2141 * option, when the user has write+exec access to the 2142 * subvol root, and when rmdir(2) would have been 2143 * allowed. 2144 * 2145 * Note that this is _not_ check that the subvol is 2146 * empty or doesn't contain data that we wouldn't 2147 * otherwise be able to delete. 2148 * 2149 * Users who want to delete empty subvols should try 2150 * rmdir(2). 2151 */ 2152 err = -EPERM; 2153 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 2154 goto out_dput; 2155 2156 /* 2157 * Do not allow deletion if the parent dir is the same 2158 * as the dir to be deleted. That means the ioctl 2159 * must be called on the dentry referencing the root 2160 * of the subvol, not a random directory contained 2161 * within it. 2162 */ 2163 err = -EINVAL; 2164 if (root == dest) 2165 goto out_dput; 2166 2167 err = inode_permission(inode, MAY_WRITE | MAY_EXEC); 2168 if (err) 2169 goto out_dput; 2170 } 2171 2172 /* check if subvolume may be deleted by a user */ 2173 err = btrfs_may_delete(dir, dentry, 1); 2174 if (err) 2175 goto out_dput; 2176 2177 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) { 2178 err = -EINVAL; 2179 goto out_dput; 2180 } 2181 2182 mutex_lock(&inode->i_mutex); 2183 err = d_invalidate(dentry); 2184 if (err) 2185 goto out_unlock; 2186 2187 down_write(&root->fs_info->subvol_sem); 2188 2189 err = may_destroy_subvol(dest); 2190 if (err) 2191 goto out_up_write; 2192 2193 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP); 2194 /* 2195 * One for dir inode, two for dir entries, two for root 2196 * ref/backref. 2197 */ 2198 err = btrfs_subvolume_reserve_metadata(root, &block_rsv, 2199 5, &qgroup_reserved, true); 2200 if (err) 2201 goto out_up_write; 2202 2203 trans = btrfs_start_transaction(root, 0); 2204 if (IS_ERR(trans)) { 2205 err = PTR_ERR(trans); 2206 goto out_release; 2207 } 2208 trans->block_rsv = &block_rsv; 2209 trans->bytes_reserved = block_rsv.size; 2210 2211 ret = btrfs_unlink_subvol(trans, root, dir, 2212 dest->root_key.objectid, 2213 dentry->d_name.name, 2214 dentry->d_name.len); 2215 if (ret) { 2216 err = ret; 2217 btrfs_abort_transaction(trans, root, ret); 2218 goto out_end_trans; 2219 } 2220 2221 btrfs_record_root_in_trans(trans, dest); 2222 2223 memset(&dest->root_item.drop_progress, 0, 2224 sizeof(dest->root_item.drop_progress)); 2225 dest->root_item.drop_level = 0; 2226 btrfs_set_root_refs(&dest->root_item, 0); 2227 2228 if (!xchg(&dest->orphan_item_inserted, 1)) { 2229 ret = btrfs_insert_orphan_item(trans, 2230 root->fs_info->tree_root, 2231 dest->root_key.objectid); 2232 if (ret) { 2233 btrfs_abort_transaction(trans, root, ret); 2234 err = ret; 2235 goto out_end_trans; 2236 } 2237 } 2238 2239 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root, 2240 dest->root_item.uuid, BTRFS_UUID_KEY_SUBVOL, 2241 dest->root_key.objectid); 2242 if (ret && ret != -ENOENT) { 2243 btrfs_abort_transaction(trans, root, ret); 2244 err = ret; 2245 goto out_end_trans; 2246 } 2247 if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) { 2248 ret = btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root, 2249 dest->root_item.received_uuid, 2250 BTRFS_UUID_KEY_RECEIVED_SUBVOL, 2251 dest->root_key.objectid); 2252 if (ret && ret != -ENOENT) { 2253 btrfs_abort_transaction(trans, root, ret); 2254 err = ret; 2255 goto out_end_trans; 2256 } 2257 } 2258 2259 out_end_trans: 2260 trans->block_rsv = NULL; 2261 trans->bytes_reserved = 0; 2262 ret = btrfs_end_transaction(trans, root); 2263 if (ret && !err) 2264 err = ret; 2265 inode->i_flags |= S_DEAD; 2266 out_release: 2267 btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved); 2268 out_up_write: 2269 up_write(&root->fs_info->subvol_sem); 2270 out_unlock: 2271 mutex_unlock(&inode->i_mutex); 2272 if (!err) { 2273 shrink_dcache_sb(root->fs_info->sb); 2274 btrfs_invalidate_inodes(dest); 2275 d_delete(dentry); 2276 2277 /* the last ref */ 2278 if (dest->cache_inode) { 2279 iput(dest->cache_inode); 2280 dest->cache_inode = NULL; 2281 } 2282 } 2283 out_dput: 2284 dput(dentry); 2285 out_unlock_dir: 2286 mutex_unlock(&dir->i_mutex); 2287 out_drop_write: 2288 mnt_drop_write_file(file); 2289 out: 2290 kfree(vol_args); 2291 return err; 2292 } 2293 2294 static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 2295 { 2296 struct inode *inode = file_inode(file); 2297 struct btrfs_root *root = BTRFS_I(inode)->root; 2298 struct btrfs_ioctl_defrag_range_args *range; 2299 int ret; 2300 2301 ret = mnt_want_write_file(file); 2302 if (ret) 2303 return ret; 2304 2305 if (btrfs_root_readonly(root)) { 2306 ret = -EROFS; 2307 goto out; 2308 } 2309 2310 switch (inode->i_mode & S_IFMT) { 2311 case S_IFDIR: 2312 if (!capable(CAP_SYS_ADMIN)) { 2313 ret = -EPERM; 2314 goto out; 2315 } 2316 ret = btrfs_defrag_root(root); 2317 if (ret) 2318 goto out; 2319 ret = btrfs_defrag_root(root->fs_info->extent_root); 2320 break; 2321 case S_IFREG: 2322 if (!(file->f_mode & FMODE_WRITE)) { 2323 ret = -EINVAL; 2324 goto out; 2325 } 2326 2327 range = kzalloc(sizeof(*range), GFP_KERNEL); 2328 if (!range) { 2329 ret = -ENOMEM; 2330 goto out; 2331 } 2332 2333 if (argp) { 2334 if (copy_from_user(range, argp, 2335 sizeof(*range))) { 2336 ret = -EFAULT; 2337 kfree(range); 2338 goto out; 2339 } 2340 /* compression requires us to start the IO */ 2341 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { 2342 range->flags |= BTRFS_DEFRAG_RANGE_START_IO; 2343 range->extent_thresh = (u32)-1; 2344 } 2345 } else { 2346 /* the rest are all set to zero by kzalloc */ 2347 range->len = (u64)-1; 2348 } 2349 ret = btrfs_defrag_file(file_inode(file), file, 2350 range, 0, 0); 2351 if (ret > 0) 2352 ret = 0; 2353 kfree(range); 2354 break; 2355 default: 2356 ret = -EINVAL; 2357 } 2358 out: 2359 mnt_drop_write_file(file); 2360 return ret; 2361 } 2362 2363 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 2364 { 2365 struct btrfs_ioctl_vol_args *vol_args; 2366 int ret; 2367 2368 if (!capable(CAP_SYS_ADMIN)) 2369 return -EPERM; 2370 2371 if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running, 2372 1)) { 2373 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; 2374 } 2375 2376 mutex_lock(&root->fs_info->volume_mutex); 2377 vol_args = memdup_user(arg, sizeof(*vol_args)); 2378 if (IS_ERR(vol_args)) { 2379 ret = PTR_ERR(vol_args); 2380 goto out; 2381 } 2382 2383 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2384 ret = btrfs_init_new_device(root, vol_args->name); 2385 2386 kfree(vol_args); 2387 out: 2388 mutex_unlock(&root->fs_info->volume_mutex); 2389 atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0); 2390 return ret; 2391 } 2392 2393 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg) 2394 { 2395 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 2396 struct btrfs_ioctl_vol_args *vol_args; 2397 int ret; 2398 2399 if (!capable(CAP_SYS_ADMIN)) 2400 return -EPERM; 2401 2402 ret = mnt_want_write_file(file); 2403 if (ret) 2404 return ret; 2405 2406 vol_args = memdup_user(arg, sizeof(*vol_args)); 2407 if (IS_ERR(vol_args)) { 2408 ret = PTR_ERR(vol_args); 2409 goto out; 2410 } 2411 2412 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2413 2414 if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running, 2415 1)) { 2416 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; 2417 goto out; 2418 } 2419 2420 mutex_lock(&root->fs_info->volume_mutex); 2421 ret = btrfs_rm_device(root, vol_args->name); 2422 mutex_unlock(&root->fs_info->volume_mutex); 2423 atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0); 2424 2425 out: 2426 kfree(vol_args); 2427 mnt_drop_write_file(file); 2428 return ret; 2429 } 2430 2431 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) 2432 { 2433 struct btrfs_ioctl_fs_info_args *fi_args; 2434 struct btrfs_device *device; 2435 struct btrfs_device *next; 2436 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 2437 int ret = 0; 2438 2439 if (!capable(CAP_SYS_ADMIN)) 2440 return -EPERM; 2441 2442 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL); 2443 if (!fi_args) 2444 return -ENOMEM; 2445 2446 mutex_lock(&fs_devices->device_list_mutex); 2447 fi_args->num_devices = fs_devices->num_devices; 2448 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); 2449 2450 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { 2451 if (device->devid > fi_args->max_id) 2452 fi_args->max_id = device->devid; 2453 } 2454 mutex_unlock(&fs_devices->device_list_mutex); 2455 2456 if (copy_to_user(arg, fi_args, sizeof(*fi_args))) 2457 ret = -EFAULT; 2458 2459 kfree(fi_args); 2460 return ret; 2461 } 2462 2463 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg) 2464 { 2465 struct btrfs_ioctl_dev_info_args *di_args; 2466 struct btrfs_device *dev; 2467 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 2468 int ret = 0; 2469 char *s_uuid = NULL; 2470 2471 if (!capable(CAP_SYS_ADMIN)) 2472 return -EPERM; 2473 2474 di_args = memdup_user(arg, sizeof(*di_args)); 2475 if (IS_ERR(di_args)) 2476 return PTR_ERR(di_args); 2477 2478 if (!btrfs_is_empty_uuid(di_args->uuid)) 2479 s_uuid = di_args->uuid; 2480 2481 mutex_lock(&fs_devices->device_list_mutex); 2482 dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL); 2483 2484 if (!dev) { 2485 ret = -ENODEV; 2486 goto out; 2487 } 2488 2489 di_args->devid = dev->devid; 2490 di_args->bytes_used = dev->bytes_used; 2491 di_args->total_bytes = dev->total_bytes; 2492 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid)); 2493 if (dev->name) { 2494 struct rcu_string *name; 2495 2496 rcu_read_lock(); 2497 name = rcu_dereference(dev->name); 2498 strncpy(di_args->path, name->str, sizeof(di_args->path)); 2499 rcu_read_unlock(); 2500 di_args->path[sizeof(di_args->path) - 1] = 0; 2501 } else { 2502 di_args->path[0] = '\0'; 2503 } 2504 2505 out: 2506 mutex_unlock(&fs_devices->device_list_mutex); 2507 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args))) 2508 ret = -EFAULT; 2509 2510 kfree(di_args); 2511 return ret; 2512 } 2513 2514 static struct page *extent_same_get_page(struct inode *inode, u64 off) 2515 { 2516 struct page *page; 2517 pgoff_t index; 2518 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; 2519 2520 index = off >> PAGE_CACHE_SHIFT; 2521 2522 page = grab_cache_page(inode->i_mapping, index); 2523 if (!page) 2524 return NULL; 2525 2526 if (!PageUptodate(page)) { 2527 if (extent_read_full_page_nolock(tree, page, btrfs_get_extent, 2528 0)) 2529 return NULL; 2530 lock_page(page); 2531 if (!PageUptodate(page)) { 2532 unlock_page(page); 2533 page_cache_release(page); 2534 return NULL; 2535 } 2536 } 2537 unlock_page(page); 2538 2539 return page; 2540 } 2541 2542 static inline void lock_extent_range(struct inode *inode, u64 off, u64 len) 2543 { 2544 /* do any pending delalloc/csum calc on src, one way or 2545 another, and lock file content */ 2546 while (1) { 2547 struct btrfs_ordered_extent *ordered; 2548 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1); 2549 ordered = btrfs_lookup_first_ordered_extent(inode, 2550 off + len - 1); 2551 if (!ordered && 2552 !test_range_bit(&BTRFS_I(inode)->io_tree, off, 2553 off + len - 1, EXTENT_DELALLOC, 0, NULL)) 2554 break; 2555 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1); 2556 if (ordered) 2557 btrfs_put_ordered_extent(ordered); 2558 btrfs_wait_ordered_range(inode, off, len); 2559 } 2560 } 2561 2562 static void btrfs_double_unlock(struct inode *inode1, u64 loff1, 2563 struct inode *inode2, u64 loff2, u64 len) 2564 { 2565 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1); 2566 unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1); 2567 2568 mutex_unlock(&inode1->i_mutex); 2569 mutex_unlock(&inode2->i_mutex); 2570 } 2571 2572 static void btrfs_double_lock(struct inode *inode1, u64 loff1, 2573 struct inode *inode2, u64 loff2, u64 len) 2574 { 2575 if (inode1 < inode2) { 2576 swap(inode1, inode2); 2577 swap(loff1, loff2); 2578 } 2579 2580 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); 2581 lock_extent_range(inode1, loff1, len); 2582 if (inode1 != inode2) { 2583 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); 2584 lock_extent_range(inode2, loff2, len); 2585 } 2586 } 2587 2588 static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst, 2589 u64 dst_loff, u64 len) 2590 { 2591 int ret = 0; 2592 struct page *src_page, *dst_page; 2593 unsigned int cmp_len = PAGE_CACHE_SIZE; 2594 void *addr, *dst_addr; 2595 2596 while (len) { 2597 if (len < PAGE_CACHE_SIZE) 2598 cmp_len = len; 2599 2600 src_page = extent_same_get_page(src, loff); 2601 if (!src_page) 2602 return -EINVAL; 2603 dst_page = extent_same_get_page(dst, dst_loff); 2604 if (!dst_page) { 2605 page_cache_release(src_page); 2606 return -EINVAL; 2607 } 2608 addr = kmap_atomic(src_page); 2609 dst_addr = kmap_atomic(dst_page); 2610 2611 flush_dcache_page(src_page); 2612 flush_dcache_page(dst_page); 2613 2614 if (memcmp(addr, dst_addr, cmp_len)) 2615 ret = BTRFS_SAME_DATA_DIFFERS; 2616 2617 kunmap_atomic(addr); 2618 kunmap_atomic(dst_addr); 2619 page_cache_release(src_page); 2620 page_cache_release(dst_page); 2621 2622 if (ret) 2623 break; 2624 2625 loff += cmp_len; 2626 dst_loff += cmp_len; 2627 len -= cmp_len; 2628 } 2629 2630 return ret; 2631 } 2632 2633 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 len) 2634 { 2635 u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize; 2636 2637 if (off + len > inode->i_size || off + len < off) 2638 return -EINVAL; 2639 /* Check that we are block aligned - btrfs_clone() requires this */ 2640 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs)) 2641 return -EINVAL; 2642 2643 return 0; 2644 } 2645 2646 static int btrfs_extent_same(struct inode *src, u64 loff, u64 len, 2647 struct inode *dst, u64 dst_loff) 2648 { 2649 int ret; 2650 2651 /* 2652 * btrfs_clone() can't handle extents in the same file 2653 * yet. Once that works, we can drop this check and replace it 2654 * with a check for the same inode, but overlapping extents. 2655 */ 2656 if (src == dst) 2657 return -EINVAL; 2658 2659 btrfs_double_lock(src, loff, dst, dst_loff, len); 2660 2661 ret = extent_same_check_offsets(src, loff, len); 2662 if (ret) 2663 goto out_unlock; 2664 2665 ret = extent_same_check_offsets(dst, dst_loff, len); 2666 if (ret) 2667 goto out_unlock; 2668 2669 /* don't make the dst file partly checksummed */ 2670 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) != 2671 (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) { 2672 ret = -EINVAL; 2673 goto out_unlock; 2674 } 2675 2676 ret = btrfs_cmp_data(src, loff, dst, dst_loff, len); 2677 if (ret == 0) 2678 ret = btrfs_clone(src, dst, loff, len, len, dst_loff); 2679 2680 out_unlock: 2681 btrfs_double_unlock(src, loff, dst, dst_loff, len); 2682 2683 return ret; 2684 } 2685 2686 #define BTRFS_MAX_DEDUPE_LEN (16 * 1024 * 1024) 2687 2688 static long btrfs_ioctl_file_extent_same(struct file *file, 2689 void __user *argp) 2690 { 2691 struct btrfs_ioctl_same_args tmp; 2692 struct btrfs_ioctl_same_args *same; 2693 struct btrfs_ioctl_same_extent_info *info; 2694 struct inode *src = file->f_dentry->d_inode; 2695 struct file *dst_file = NULL; 2696 struct inode *dst; 2697 u64 off; 2698 u64 len; 2699 int i; 2700 int ret; 2701 unsigned long size; 2702 u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize; 2703 bool is_admin = capable(CAP_SYS_ADMIN); 2704 2705 if (!(file->f_mode & FMODE_READ)) 2706 return -EINVAL; 2707 2708 ret = mnt_want_write_file(file); 2709 if (ret) 2710 return ret; 2711 2712 if (copy_from_user(&tmp, 2713 (struct btrfs_ioctl_same_args __user *)argp, 2714 sizeof(tmp))) { 2715 ret = -EFAULT; 2716 goto out; 2717 } 2718 2719 size = sizeof(tmp) + 2720 tmp.dest_count * sizeof(struct btrfs_ioctl_same_extent_info); 2721 2722 same = memdup_user((struct btrfs_ioctl_same_args __user *)argp, size); 2723 2724 if (IS_ERR(same)) { 2725 ret = PTR_ERR(same); 2726 goto out; 2727 } 2728 2729 off = same->logical_offset; 2730 len = same->length; 2731 2732 /* 2733 * Limit the total length we will dedupe for each operation. 2734 * This is intended to bound the total time spent in this 2735 * ioctl to something sane. 2736 */ 2737 if (len > BTRFS_MAX_DEDUPE_LEN) 2738 len = BTRFS_MAX_DEDUPE_LEN; 2739 2740 if (WARN_ON_ONCE(bs < PAGE_CACHE_SIZE)) { 2741 /* 2742 * Btrfs does not support blocksize < page_size. As a 2743 * result, btrfs_cmp_data() won't correctly handle 2744 * this situation without an update. 2745 */ 2746 ret = -EINVAL; 2747 goto out; 2748 } 2749 2750 ret = -EISDIR; 2751 if (S_ISDIR(src->i_mode)) 2752 goto out; 2753 2754 ret = -EACCES; 2755 if (!S_ISREG(src->i_mode)) 2756 goto out; 2757 2758 /* pre-format output fields to sane values */ 2759 for (i = 0; i < same->dest_count; i++) { 2760 same->info[i].bytes_deduped = 0ULL; 2761 same->info[i].status = 0; 2762 } 2763 2764 ret = 0; 2765 for (i = 0; i < same->dest_count; i++) { 2766 info = &same->info[i]; 2767 2768 dst_file = fget(info->fd); 2769 if (!dst_file) { 2770 info->status = -EBADF; 2771 goto next; 2772 } 2773 2774 if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) { 2775 info->status = -EINVAL; 2776 goto next; 2777 } 2778 2779 info->status = -EXDEV; 2780 if (file->f_path.mnt != dst_file->f_path.mnt) 2781 goto next; 2782 2783 dst = dst_file->f_dentry->d_inode; 2784 if (src->i_sb != dst->i_sb) 2785 goto next; 2786 2787 if (S_ISDIR(dst->i_mode)) { 2788 info->status = -EISDIR; 2789 goto next; 2790 } 2791 2792 if (!S_ISREG(dst->i_mode)) { 2793 info->status = -EACCES; 2794 goto next; 2795 } 2796 2797 info->status = btrfs_extent_same(src, off, len, dst, 2798 info->logical_offset); 2799 if (info->status == 0) 2800 info->bytes_deduped += len; 2801 2802 next: 2803 if (dst_file) 2804 fput(dst_file); 2805 } 2806 2807 ret = copy_to_user(argp, same, size); 2808 if (ret) 2809 ret = -EFAULT; 2810 2811 out: 2812 mnt_drop_write_file(file); 2813 return ret; 2814 } 2815 2816 /** 2817 * btrfs_clone() - clone a range from inode file to another 2818 * 2819 * @src: Inode to clone from 2820 * @inode: Inode to clone to 2821 * @off: Offset within source to start clone from 2822 * @olen: Original length, passed by user, of range to clone 2823 * @olen_aligned: Block-aligned value of olen, extent_same uses 2824 * identical values here 2825 * @destoff: Offset within @inode to start clone 2826 */ 2827 static int btrfs_clone(struct inode *src, struct inode *inode, 2828 u64 off, u64 olen, u64 olen_aligned, u64 destoff) 2829 { 2830 struct btrfs_root *root = BTRFS_I(inode)->root; 2831 struct btrfs_path *path = NULL; 2832 struct extent_buffer *leaf; 2833 struct btrfs_trans_handle *trans; 2834 char *buf = NULL; 2835 struct btrfs_key key; 2836 u32 nritems; 2837 int slot; 2838 int ret; 2839 u64 len = olen_aligned; 2840 2841 ret = -ENOMEM; 2842 buf = vmalloc(btrfs_level_size(root, 0)); 2843 if (!buf) 2844 return ret; 2845 2846 path = btrfs_alloc_path(); 2847 if (!path) { 2848 vfree(buf); 2849 return ret; 2850 } 2851 2852 path->reada = 2; 2853 /* clone data */ 2854 key.objectid = btrfs_ino(src); 2855 key.type = BTRFS_EXTENT_DATA_KEY; 2856 key.offset = 0; 2857 2858 while (1) { 2859 /* 2860 * note the key will change type as we walk through the 2861 * tree. 2862 */ 2863 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path, 2864 0, 0); 2865 if (ret < 0) 2866 goto out; 2867 2868 nritems = btrfs_header_nritems(path->nodes[0]); 2869 if (path->slots[0] >= nritems) { 2870 ret = btrfs_next_leaf(BTRFS_I(src)->root, path); 2871 if (ret < 0) 2872 goto out; 2873 if (ret > 0) 2874 break; 2875 nritems = btrfs_header_nritems(path->nodes[0]); 2876 } 2877 leaf = path->nodes[0]; 2878 slot = path->slots[0]; 2879 2880 btrfs_item_key_to_cpu(leaf, &key, slot); 2881 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 2882 key.objectid != btrfs_ino(src)) 2883 break; 2884 2885 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 2886 struct btrfs_file_extent_item *extent; 2887 int type; 2888 u32 size; 2889 struct btrfs_key new_key; 2890 u64 disko = 0, diskl = 0; 2891 u64 datao = 0, datal = 0; 2892 u8 comp; 2893 u64 endoff; 2894 2895 size = btrfs_item_size_nr(leaf, slot); 2896 read_extent_buffer(leaf, buf, 2897 btrfs_item_ptr_offset(leaf, slot), 2898 size); 2899 2900 extent = btrfs_item_ptr(leaf, slot, 2901 struct btrfs_file_extent_item); 2902 comp = btrfs_file_extent_compression(leaf, extent); 2903 type = btrfs_file_extent_type(leaf, extent); 2904 if (type == BTRFS_FILE_EXTENT_REG || 2905 type == BTRFS_FILE_EXTENT_PREALLOC) { 2906 disko = btrfs_file_extent_disk_bytenr(leaf, 2907 extent); 2908 diskl = btrfs_file_extent_disk_num_bytes(leaf, 2909 extent); 2910 datao = btrfs_file_extent_offset(leaf, extent); 2911 datal = btrfs_file_extent_num_bytes(leaf, 2912 extent); 2913 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 2914 /* take upper bound, may be compressed */ 2915 datal = btrfs_file_extent_ram_bytes(leaf, 2916 extent); 2917 } 2918 btrfs_release_path(path); 2919 2920 if (key.offset + datal <= off || 2921 key.offset >= off + len - 1) 2922 goto next; 2923 2924 memcpy(&new_key, &key, sizeof(new_key)); 2925 new_key.objectid = btrfs_ino(inode); 2926 if (off <= key.offset) 2927 new_key.offset = key.offset + destoff - off; 2928 else 2929 new_key.offset = destoff; 2930 2931 /* 2932 * 1 - adjusting old extent (we may have to split it) 2933 * 1 - add new extent 2934 * 1 - inode update 2935 */ 2936 trans = btrfs_start_transaction(root, 3); 2937 if (IS_ERR(trans)) { 2938 ret = PTR_ERR(trans); 2939 goto out; 2940 } 2941 2942 if (type == BTRFS_FILE_EXTENT_REG || 2943 type == BTRFS_FILE_EXTENT_PREALLOC) { 2944 /* 2945 * a | --- range to clone ---| b 2946 * | ------------- extent ------------- | 2947 */ 2948 2949 /* substract range b */ 2950 if (key.offset + datal > off + len) 2951 datal = off + len - key.offset; 2952 2953 /* substract range a */ 2954 if (off > key.offset) { 2955 datao += off - key.offset; 2956 datal -= off - key.offset; 2957 } 2958 2959 ret = btrfs_drop_extents(trans, root, inode, 2960 new_key.offset, 2961 new_key.offset + datal, 2962 1); 2963 if (ret) { 2964 btrfs_abort_transaction(trans, root, 2965 ret); 2966 btrfs_end_transaction(trans, root); 2967 goto out; 2968 } 2969 2970 ret = btrfs_insert_empty_item(trans, root, path, 2971 &new_key, size); 2972 if (ret) { 2973 btrfs_abort_transaction(trans, root, 2974 ret); 2975 btrfs_end_transaction(trans, root); 2976 goto out; 2977 } 2978 2979 leaf = path->nodes[0]; 2980 slot = path->slots[0]; 2981 write_extent_buffer(leaf, buf, 2982 btrfs_item_ptr_offset(leaf, slot), 2983 size); 2984 2985 extent = btrfs_item_ptr(leaf, slot, 2986 struct btrfs_file_extent_item); 2987 2988 /* disko == 0 means it's a hole */ 2989 if (!disko) 2990 datao = 0; 2991 2992 btrfs_set_file_extent_offset(leaf, extent, 2993 datao); 2994 btrfs_set_file_extent_num_bytes(leaf, extent, 2995 datal); 2996 if (disko) { 2997 inode_add_bytes(inode, datal); 2998 ret = btrfs_inc_extent_ref(trans, root, 2999 disko, diskl, 0, 3000 root->root_key.objectid, 3001 btrfs_ino(inode), 3002 new_key.offset - datao, 3003 0); 3004 if (ret) { 3005 btrfs_abort_transaction(trans, 3006 root, 3007 ret); 3008 btrfs_end_transaction(trans, 3009 root); 3010 goto out; 3011 3012 } 3013 } 3014 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 3015 u64 skip = 0; 3016 u64 trim = 0; 3017 if (off > key.offset) { 3018 skip = off - key.offset; 3019 new_key.offset += skip; 3020 } 3021 3022 if (key.offset + datal > off + len) 3023 trim = key.offset + datal - (off + len); 3024 3025 if (comp && (skip || trim)) { 3026 ret = -EINVAL; 3027 btrfs_end_transaction(trans, root); 3028 goto out; 3029 } 3030 size -= skip + trim; 3031 datal -= skip + trim; 3032 3033 ret = btrfs_drop_extents(trans, root, inode, 3034 new_key.offset, 3035 new_key.offset + datal, 3036 1); 3037 if (ret) { 3038 btrfs_abort_transaction(trans, root, 3039 ret); 3040 btrfs_end_transaction(trans, root); 3041 goto out; 3042 } 3043 3044 ret = btrfs_insert_empty_item(trans, root, path, 3045 &new_key, size); 3046 if (ret) { 3047 btrfs_abort_transaction(trans, root, 3048 ret); 3049 btrfs_end_transaction(trans, root); 3050 goto out; 3051 } 3052 3053 if (skip) { 3054 u32 start = 3055 btrfs_file_extent_calc_inline_size(0); 3056 memmove(buf+start, buf+start+skip, 3057 datal); 3058 } 3059 3060 leaf = path->nodes[0]; 3061 slot = path->slots[0]; 3062 write_extent_buffer(leaf, buf, 3063 btrfs_item_ptr_offset(leaf, slot), 3064 size); 3065 inode_add_bytes(inode, datal); 3066 } 3067 3068 btrfs_mark_buffer_dirty(leaf); 3069 btrfs_release_path(path); 3070 3071 inode_inc_iversion(inode); 3072 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 3073 3074 /* 3075 * we round up to the block size at eof when 3076 * determining which extents to clone above, 3077 * but shouldn't round up the file size 3078 */ 3079 endoff = new_key.offset + datal; 3080 if (endoff > destoff+olen) 3081 endoff = destoff+olen; 3082 if (endoff > inode->i_size) 3083 btrfs_i_size_write(inode, endoff); 3084 3085 ret = btrfs_update_inode(trans, root, inode); 3086 if (ret) { 3087 btrfs_abort_transaction(trans, root, ret); 3088 btrfs_end_transaction(trans, root); 3089 goto out; 3090 } 3091 ret = btrfs_end_transaction(trans, root); 3092 } 3093 next: 3094 btrfs_release_path(path); 3095 key.offset++; 3096 } 3097 ret = 0; 3098 3099 out: 3100 btrfs_release_path(path); 3101 btrfs_free_path(path); 3102 vfree(buf); 3103 return ret; 3104 } 3105 3106 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 3107 u64 off, u64 olen, u64 destoff) 3108 { 3109 struct inode *inode = file_inode(file); 3110 struct btrfs_root *root = BTRFS_I(inode)->root; 3111 struct fd src_file; 3112 struct inode *src; 3113 int ret; 3114 u64 len = olen; 3115 u64 bs = root->fs_info->sb->s_blocksize; 3116 int same_inode = 0; 3117 3118 /* 3119 * TODO: 3120 * - split compressed inline extents. annoying: we need to 3121 * decompress into destination's address_space (the file offset 3122 * may change, so source mapping won't do), then recompress (or 3123 * otherwise reinsert) a subrange. 3124 * - allow ranges within the same file to be cloned (provided 3125 * they don't overlap)? 3126 */ 3127 3128 /* the destination must be opened for writing */ 3129 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND)) 3130 return -EINVAL; 3131 3132 if (btrfs_root_readonly(root)) 3133 return -EROFS; 3134 3135 ret = mnt_want_write_file(file); 3136 if (ret) 3137 return ret; 3138 3139 src_file = fdget(srcfd); 3140 if (!src_file.file) { 3141 ret = -EBADF; 3142 goto out_drop_write; 3143 } 3144 3145 ret = -EXDEV; 3146 if (src_file.file->f_path.mnt != file->f_path.mnt) 3147 goto out_fput; 3148 3149 src = file_inode(src_file.file); 3150 3151 ret = -EINVAL; 3152 if (src == inode) 3153 same_inode = 1; 3154 3155 /* the src must be open for reading */ 3156 if (!(src_file.file->f_mode & FMODE_READ)) 3157 goto out_fput; 3158 3159 /* don't make the dst file partly checksummed */ 3160 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) != 3161 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) 3162 goto out_fput; 3163 3164 ret = -EISDIR; 3165 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 3166 goto out_fput; 3167 3168 ret = -EXDEV; 3169 if (src->i_sb != inode->i_sb) 3170 goto out_fput; 3171 3172 if (!same_inode) { 3173 if (inode < src) { 3174 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); 3175 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD); 3176 } else { 3177 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT); 3178 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); 3179 } 3180 } else { 3181 mutex_lock(&src->i_mutex); 3182 } 3183 3184 /* determine range to clone */ 3185 ret = -EINVAL; 3186 if (off + len > src->i_size || off + len < off) 3187 goto out_unlock; 3188 if (len == 0) 3189 olen = len = src->i_size - off; 3190 /* if we extend to eof, continue to block boundary */ 3191 if (off + len == src->i_size) 3192 len = ALIGN(src->i_size, bs) - off; 3193 3194 /* verify the end result is block aligned */ 3195 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) || 3196 !IS_ALIGNED(destoff, bs)) 3197 goto out_unlock; 3198 3199 /* verify if ranges are overlapped within the same file */ 3200 if (same_inode) { 3201 if (destoff + len > off && destoff < off + len) 3202 goto out_unlock; 3203 } 3204 3205 if (destoff > inode->i_size) { 3206 ret = btrfs_cont_expand(inode, inode->i_size, destoff); 3207 if (ret) 3208 goto out_unlock; 3209 } 3210 3211 /* truncate page cache pages from target inode range */ 3212 truncate_inode_pages_range(&inode->i_data, destoff, 3213 PAGE_CACHE_ALIGN(destoff + len) - 1); 3214 3215 lock_extent_range(src, off, len); 3216 3217 ret = btrfs_clone(src, inode, off, olen, len, destoff); 3218 3219 unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1); 3220 out_unlock: 3221 mutex_unlock(&src->i_mutex); 3222 if (!same_inode) 3223 mutex_unlock(&inode->i_mutex); 3224 out_fput: 3225 fdput(src_file); 3226 out_drop_write: 3227 mnt_drop_write_file(file); 3228 return ret; 3229 } 3230 3231 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 3232 { 3233 struct btrfs_ioctl_clone_range_args args; 3234 3235 if (copy_from_user(&args, argp, sizeof(args))) 3236 return -EFAULT; 3237 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 3238 args.src_length, args.dest_offset); 3239 } 3240 3241 /* 3242 * there are many ways the trans_start and trans_end ioctls can lead 3243 * to deadlocks. They should only be used by applications that 3244 * basically own the machine, and have a very in depth understanding 3245 * of all the possible deadlocks and enospc problems. 3246 */ 3247 static long btrfs_ioctl_trans_start(struct file *file) 3248 { 3249 struct inode *inode = file_inode(file); 3250 struct btrfs_root *root = BTRFS_I(inode)->root; 3251 struct btrfs_trans_handle *trans; 3252 int ret; 3253 3254 ret = -EPERM; 3255 if (!capable(CAP_SYS_ADMIN)) 3256 goto out; 3257 3258 ret = -EINPROGRESS; 3259 if (file->private_data) 3260 goto out; 3261 3262 ret = -EROFS; 3263 if (btrfs_root_readonly(root)) 3264 goto out; 3265 3266 ret = mnt_want_write_file(file); 3267 if (ret) 3268 goto out; 3269 3270 atomic_inc(&root->fs_info->open_ioctl_trans); 3271 3272 ret = -ENOMEM; 3273 trans = btrfs_start_ioctl_transaction(root); 3274 if (IS_ERR(trans)) 3275 goto out_drop; 3276 3277 file->private_data = trans; 3278 return 0; 3279 3280 out_drop: 3281 atomic_dec(&root->fs_info->open_ioctl_trans); 3282 mnt_drop_write_file(file); 3283 out: 3284 return ret; 3285 } 3286 3287 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) 3288 { 3289 struct inode *inode = file_inode(file); 3290 struct btrfs_root *root = BTRFS_I(inode)->root; 3291 struct btrfs_root *new_root; 3292 struct btrfs_dir_item *di; 3293 struct btrfs_trans_handle *trans; 3294 struct btrfs_path *path; 3295 struct btrfs_key location; 3296 struct btrfs_disk_key disk_key; 3297 u64 objectid = 0; 3298 u64 dir_id; 3299 int ret; 3300 3301 if (!capable(CAP_SYS_ADMIN)) 3302 return -EPERM; 3303 3304 ret = mnt_want_write_file(file); 3305 if (ret) 3306 return ret; 3307 3308 if (copy_from_user(&objectid, argp, sizeof(objectid))) { 3309 ret = -EFAULT; 3310 goto out; 3311 } 3312 3313 if (!objectid) 3314 objectid = BTRFS_FS_TREE_OBJECTID; 3315 3316 location.objectid = objectid; 3317 location.type = BTRFS_ROOT_ITEM_KEY; 3318 location.offset = (u64)-1; 3319 3320 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 3321 if (IS_ERR(new_root)) { 3322 ret = PTR_ERR(new_root); 3323 goto out; 3324 } 3325 3326 path = btrfs_alloc_path(); 3327 if (!path) { 3328 ret = -ENOMEM; 3329 goto out; 3330 } 3331 path->leave_spinning = 1; 3332 3333 trans = btrfs_start_transaction(root, 1); 3334 if (IS_ERR(trans)) { 3335 btrfs_free_path(path); 3336 ret = PTR_ERR(trans); 3337 goto out; 3338 } 3339 3340 dir_id = btrfs_super_root_dir(root->fs_info->super_copy); 3341 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path, 3342 dir_id, "default", 7, 1); 3343 if (IS_ERR_OR_NULL(di)) { 3344 btrfs_free_path(path); 3345 btrfs_end_transaction(trans, root); 3346 printk(KERN_ERR "Umm, you don't have the default dir item, " 3347 "this isn't going to work\n"); 3348 ret = -ENOENT; 3349 goto out; 3350 } 3351 3352 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); 3353 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key); 3354 btrfs_mark_buffer_dirty(path->nodes[0]); 3355 btrfs_free_path(path); 3356 3357 btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL); 3358 btrfs_end_transaction(trans, root); 3359 out: 3360 mnt_drop_write_file(file); 3361 return ret; 3362 } 3363 3364 void btrfs_get_block_group_info(struct list_head *groups_list, 3365 struct btrfs_ioctl_space_info *space) 3366 { 3367 struct btrfs_block_group_cache *block_group; 3368 3369 space->total_bytes = 0; 3370 space->used_bytes = 0; 3371 space->flags = 0; 3372 list_for_each_entry(block_group, groups_list, list) { 3373 space->flags = block_group->flags; 3374 space->total_bytes += block_group->key.offset; 3375 space->used_bytes += 3376 btrfs_block_group_used(&block_group->item); 3377 } 3378 } 3379 3380 static long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg) 3381 { 3382 struct btrfs_ioctl_space_args space_args; 3383 struct btrfs_ioctl_space_info space; 3384 struct btrfs_ioctl_space_info *dest; 3385 struct btrfs_ioctl_space_info *dest_orig; 3386 struct btrfs_ioctl_space_info __user *user_dest; 3387 struct btrfs_space_info *info; 3388 u64 types[] = {BTRFS_BLOCK_GROUP_DATA, 3389 BTRFS_BLOCK_GROUP_SYSTEM, 3390 BTRFS_BLOCK_GROUP_METADATA, 3391 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA}; 3392 int num_types = 4; 3393 int alloc_size; 3394 int ret = 0; 3395 u64 slot_count = 0; 3396 int i, c; 3397 3398 if (copy_from_user(&space_args, 3399 (struct btrfs_ioctl_space_args __user *)arg, 3400 sizeof(space_args))) 3401 return -EFAULT; 3402 3403 for (i = 0; i < num_types; i++) { 3404 struct btrfs_space_info *tmp; 3405 3406 info = NULL; 3407 rcu_read_lock(); 3408 list_for_each_entry_rcu(tmp, &root->fs_info->space_info, 3409 list) { 3410 if (tmp->flags == types[i]) { 3411 info = tmp; 3412 break; 3413 } 3414 } 3415 rcu_read_unlock(); 3416 3417 if (!info) 3418 continue; 3419 3420 down_read(&info->groups_sem); 3421 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { 3422 if (!list_empty(&info->block_groups[c])) 3423 slot_count++; 3424 } 3425 up_read(&info->groups_sem); 3426 } 3427 3428 /* space_slots == 0 means they are asking for a count */ 3429 if (space_args.space_slots == 0) { 3430 space_args.total_spaces = slot_count; 3431 goto out; 3432 } 3433 3434 slot_count = min_t(u64, space_args.space_slots, slot_count); 3435 3436 alloc_size = sizeof(*dest) * slot_count; 3437 3438 /* we generally have at most 6 or so space infos, one for each raid 3439 * level. So, a whole page should be more than enough for everyone 3440 */ 3441 if (alloc_size > PAGE_CACHE_SIZE) 3442 return -ENOMEM; 3443 3444 space_args.total_spaces = 0; 3445 dest = kmalloc(alloc_size, GFP_NOFS); 3446 if (!dest) 3447 return -ENOMEM; 3448 dest_orig = dest; 3449 3450 /* now we have a buffer to copy into */ 3451 for (i = 0; i < num_types; i++) { 3452 struct btrfs_space_info *tmp; 3453 3454 if (!slot_count) 3455 break; 3456 3457 info = NULL; 3458 rcu_read_lock(); 3459 list_for_each_entry_rcu(tmp, &root->fs_info->space_info, 3460 list) { 3461 if (tmp->flags == types[i]) { 3462 info = tmp; 3463 break; 3464 } 3465 } 3466 rcu_read_unlock(); 3467 3468 if (!info) 3469 continue; 3470 down_read(&info->groups_sem); 3471 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { 3472 if (!list_empty(&info->block_groups[c])) { 3473 btrfs_get_block_group_info( 3474 &info->block_groups[c], &space); 3475 memcpy(dest, &space, sizeof(space)); 3476 dest++; 3477 space_args.total_spaces++; 3478 slot_count--; 3479 } 3480 if (!slot_count) 3481 break; 3482 } 3483 up_read(&info->groups_sem); 3484 } 3485 3486 user_dest = (struct btrfs_ioctl_space_info __user *) 3487 (arg + sizeof(struct btrfs_ioctl_space_args)); 3488 3489 if (copy_to_user(user_dest, dest_orig, alloc_size)) 3490 ret = -EFAULT; 3491 3492 kfree(dest_orig); 3493 out: 3494 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args))) 3495 ret = -EFAULT; 3496 3497 return ret; 3498 } 3499 3500 /* 3501 * there are many ways the trans_start and trans_end ioctls can lead 3502 * to deadlocks. They should only be used by applications that 3503 * basically own the machine, and have a very in depth understanding 3504 * of all the possible deadlocks and enospc problems. 3505 */ 3506 long btrfs_ioctl_trans_end(struct file *file) 3507 { 3508 struct inode *inode = file_inode(file); 3509 struct btrfs_root *root = BTRFS_I(inode)->root; 3510 struct btrfs_trans_handle *trans; 3511 3512 trans = file->private_data; 3513 if (!trans) 3514 return -EINVAL; 3515 file->private_data = NULL; 3516 3517 btrfs_end_transaction(trans, root); 3518 3519 atomic_dec(&root->fs_info->open_ioctl_trans); 3520 3521 mnt_drop_write_file(file); 3522 return 0; 3523 } 3524 3525 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root, 3526 void __user *argp) 3527 { 3528 struct btrfs_trans_handle *trans; 3529 u64 transid; 3530 int ret; 3531 3532 trans = btrfs_attach_transaction_barrier(root); 3533 if (IS_ERR(trans)) { 3534 if (PTR_ERR(trans) != -ENOENT) 3535 return PTR_ERR(trans); 3536 3537 /* No running transaction, don't bother */ 3538 transid = root->fs_info->last_trans_committed; 3539 goto out; 3540 } 3541 transid = trans->transid; 3542 ret = btrfs_commit_transaction_async(trans, root, 0); 3543 if (ret) { 3544 btrfs_end_transaction(trans, root); 3545 return ret; 3546 } 3547 out: 3548 if (argp) 3549 if (copy_to_user(argp, &transid, sizeof(transid))) 3550 return -EFAULT; 3551 return 0; 3552 } 3553 3554 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root, 3555 void __user *argp) 3556 { 3557 u64 transid; 3558 3559 if (argp) { 3560 if (copy_from_user(&transid, argp, sizeof(transid))) 3561 return -EFAULT; 3562 } else { 3563 transid = 0; /* current trans */ 3564 } 3565 return btrfs_wait_for_commit(root, transid); 3566 } 3567 3568 static long btrfs_ioctl_scrub(struct file *file, void __user *arg) 3569 { 3570 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 3571 struct btrfs_ioctl_scrub_args *sa; 3572 int ret; 3573 3574 if (!capable(CAP_SYS_ADMIN)) 3575 return -EPERM; 3576 3577 sa = memdup_user(arg, sizeof(*sa)); 3578 if (IS_ERR(sa)) 3579 return PTR_ERR(sa); 3580 3581 if (!(sa->flags & BTRFS_SCRUB_READONLY)) { 3582 ret = mnt_want_write_file(file); 3583 if (ret) 3584 goto out; 3585 } 3586 3587 ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end, 3588 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY, 3589 0); 3590 3591 if (copy_to_user(arg, sa, sizeof(*sa))) 3592 ret = -EFAULT; 3593 3594 if (!(sa->flags & BTRFS_SCRUB_READONLY)) 3595 mnt_drop_write_file(file); 3596 out: 3597 kfree(sa); 3598 return ret; 3599 } 3600 3601 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg) 3602 { 3603 if (!capable(CAP_SYS_ADMIN)) 3604 return -EPERM; 3605 3606 return btrfs_scrub_cancel(root->fs_info); 3607 } 3608 3609 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root, 3610 void __user *arg) 3611 { 3612 struct btrfs_ioctl_scrub_args *sa; 3613 int ret; 3614 3615 if (!capable(CAP_SYS_ADMIN)) 3616 return -EPERM; 3617 3618 sa = memdup_user(arg, sizeof(*sa)); 3619 if (IS_ERR(sa)) 3620 return PTR_ERR(sa); 3621 3622 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress); 3623 3624 if (copy_to_user(arg, sa, sizeof(*sa))) 3625 ret = -EFAULT; 3626 3627 kfree(sa); 3628 return ret; 3629 } 3630 3631 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root, 3632 void __user *arg) 3633 { 3634 struct btrfs_ioctl_get_dev_stats *sa; 3635 int ret; 3636 3637 sa = memdup_user(arg, sizeof(*sa)); 3638 if (IS_ERR(sa)) 3639 return PTR_ERR(sa); 3640 3641 if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) { 3642 kfree(sa); 3643 return -EPERM; 3644 } 3645 3646 ret = btrfs_get_dev_stats(root, sa); 3647 3648 if (copy_to_user(arg, sa, sizeof(*sa))) 3649 ret = -EFAULT; 3650 3651 kfree(sa); 3652 return ret; 3653 } 3654 3655 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg) 3656 { 3657 struct btrfs_ioctl_dev_replace_args *p; 3658 int ret; 3659 3660 if (!capable(CAP_SYS_ADMIN)) 3661 return -EPERM; 3662 3663 p = memdup_user(arg, sizeof(*p)); 3664 if (IS_ERR(p)) 3665 return PTR_ERR(p); 3666 3667 switch (p->cmd) { 3668 case BTRFS_IOCTL_DEV_REPLACE_CMD_START: 3669 if (root->fs_info->sb->s_flags & MS_RDONLY) { 3670 ret = -EROFS; 3671 goto out; 3672 } 3673 if (atomic_xchg( 3674 &root->fs_info->mutually_exclusive_operation_running, 3675 1)) { 3676 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; 3677 } else { 3678 ret = btrfs_dev_replace_start(root, p); 3679 atomic_set( 3680 &root->fs_info->mutually_exclusive_operation_running, 3681 0); 3682 } 3683 break; 3684 case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS: 3685 btrfs_dev_replace_status(root->fs_info, p); 3686 ret = 0; 3687 break; 3688 case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL: 3689 ret = btrfs_dev_replace_cancel(root->fs_info, p); 3690 break; 3691 default: 3692 ret = -EINVAL; 3693 break; 3694 } 3695 3696 if (copy_to_user(arg, p, sizeof(*p))) 3697 ret = -EFAULT; 3698 out: 3699 kfree(p); 3700 return ret; 3701 } 3702 3703 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg) 3704 { 3705 int ret = 0; 3706 int i; 3707 u64 rel_ptr; 3708 int size; 3709 struct btrfs_ioctl_ino_path_args *ipa = NULL; 3710 struct inode_fs_paths *ipath = NULL; 3711 struct btrfs_path *path; 3712 3713 if (!capable(CAP_DAC_READ_SEARCH)) 3714 return -EPERM; 3715 3716 path = btrfs_alloc_path(); 3717 if (!path) { 3718 ret = -ENOMEM; 3719 goto out; 3720 } 3721 3722 ipa = memdup_user(arg, sizeof(*ipa)); 3723 if (IS_ERR(ipa)) { 3724 ret = PTR_ERR(ipa); 3725 ipa = NULL; 3726 goto out; 3727 } 3728 3729 size = min_t(u32, ipa->size, 4096); 3730 ipath = init_ipath(size, root, path); 3731 if (IS_ERR(ipath)) { 3732 ret = PTR_ERR(ipath); 3733 ipath = NULL; 3734 goto out; 3735 } 3736 3737 ret = paths_from_inode(ipa->inum, ipath); 3738 if (ret < 0) 3739 goto out; 3740 3741 for (i = 0; i < ipath->fspath->elem_cnt; ++i) { 3742 rel_ptr = ipath->fspath->val[i] - 3743 (u64)(unsigned long)ipath->fspath->val; 3744 ipath->fspath->val[i] = rel_ptr; 3745 } 3746 3747 ret = copy_to_user((void *)(unsigned long)ipa->fspath, 3748 (void *)(unsigned long)ipath->fspath, size); 3749 if (ret) { 3750 ret = -EFAULT; 3751 goto out; 3752 } 3753 3754 out: 3755 btrfs_free_path(path); 3756 free_ipath(ipath); 3757 kfree(ipa); 3758 3759 return ret; 3760 } 3761 3762 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx) 3763 { 3764 struct btrfs_data_container *inodes = ctx; 3765 const size_t c = 3 * sizeof(u64); 3766 3767 if (inodes->bytes_left >= c) { 3768 inodes->bytes_left -= c; 3769 inodes->val[inodes->elem_cnt] = inum; 3770 inodes->val[inodes->elem_cnt + 1] = offset; 3771 inodes->val[inodes->elem_cnt + 2] = root; 3772 inodes->elem_cnt += 3; 3773 } else { 3774 inodes->bytes_missing += c - inodes->bytes_left; 3775 inodes->bytes_left = 0; 3776 inodes->elem_missed += 3; 3777 } 3778 3779 return 0; 3780 } 3781 3782 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root, 3783 void __user *arg) 3784 { 3785 int ret = 0; 3786 int size; 3787 struct btrfs_ioctl_logical_ino_args *loi; 3788 struct btrfs_data_container *inodes = NULL; 3789 struct btrfs_path *path = NULL; 3790 3791 if (!capable(CAP_SYS_ADMIN)) 3792 return -EPERM; 3793 3794 loi = memdup_user(arg, sizeof(*loi)); 3795 if (IS_ERR(loi)) { 3796 ret = PTR_ERR(loi); 3797 loi = NULL; 3798 goto out; 3799 } 3800 3801 path = btrfs_alloc_path(); 3802 if (!path) { 3803 ret = -ENOMEM; 3804 goto out; 3805 } 3806 3807 size = min_t(u32, loi->size, 64 * 1024); 3808 inodes = init_data_container(size); 3809 if (IS_ERR(inodes)) { 3810 ret = PTR_ERR(inodes); 3811 inodes = NULL; 3812 goto out; 3813 } 3814 3815 ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path, 3816 build_ino_list, inodes); 3817 if (ret == -EINVAL) 3818 ret = -ENOENT; 3819 if (ret < 0) 3820 goto out; 3821 3822 ret = copy_to_user((void *)(unsigned long)loi->inodes, 3823 (void *)(unsigned long)inodes, size); 3824 if (ret) 3825 ret = -EFAULT; 3826 3827 out: 3828 btrfs_free_path(path); 3829 vfree(inodes); 3830 kfree(loi); 3831 3832 return ret; 3833 } 3834 3835 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock, 3836 struct btrfs_ioctl_balance_args *bargs) 3837 { 3838 struct btrfs_balance_control *bctl = fs_info->balance_ctl; 3839 3840 bargs->flags = bctl->flags; 3841 3842 if (atomic_read(&fs_info->balance_running)) 3843 bargs->state |= BTRFS_BALANCE_STATE_RUNNING; 3844 if (atomic_read(&fs_info->balance_pause_req)) 3845 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ; 3846 if (atomic_read(&fs_info->balance_cancel_req)) 3847 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ; 3848 3849 memcpy(&bargs->data, &bctl->data, sizeof(bargs->data)); 3850 memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta)); 3851 memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys)); 3852 3853 if (lock) { 3854 spin_lock(&fs_info->balance_lock); 3855 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat)); 3856 spin_unlock(&fs_info->balance_lock); 3857 } else { 3858 memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat)); 3859 } 3860 } 3861 3862 static long btrfs_ioctl_balance(struct file *file, void __user *arg) 3863 { 3864 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 3865 struct btrfs_fs_info *fs_info = root->fs_info; 3866 struct btrfs_ioctl_balance_args *bargs; 3867 struct btrfs_balance_control *bctl; 3868 bool need_unlock; /* for mut. excl. ops lock */ 3869 int ret; 3870 3871 if (!capable(CAP_SYS_ADMIN)) 3872 return -EPERM; 3873 3874 ret = mnt_want_write_file(file); 3875 if (ret) 3876 return ret; 3877 3878 again: 3879 if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) { 3880 mutex_lock(&fs_info->volume_mutex); 3881 mutex_lock(&fs_info->balance_mutex); 3882 need_unlock = true; 3883 goto locked; 3884 } 3885 3886 /* 3887 * mut. excl. ops lock is locked. Three possibilites: 3888 * (1) some other op is running 3889 * (2) balance is running 3890 * (3) balance is paused -- special case (think resume) 3891 */ 3892 mutex_lock(&fs_info->balance_mutex); 3893 if (fs_info->balance_ctl) { 3894 /* this is either (2) or (3) */ 3895 if (!atomic_read(&fs_info->balance_running)) { 3896 mutex_unlock(&fs_info->balance_mutex); 3897 if (!mutex_trylock(&fs_info->volume_mutex)) 3898 goto again; 3899 mutex_lock(&fs_info->balance_mutex); 3900 3901 if (fs_info->balance_ctl && 3902 !atomic_read(&fs_info->balance_running)) { 3903 /* this is (3) */ 3904 need_unlock = false; 3905 goto locked; 3906 } 3907 3908 mutex_unlock(&fs_info->balance_mutex); 3909 mutex_unlock(&fs_info->volume_mutex); 3910 goto again; 3911 } else { 3912 /* this is (2) */ 3913 mutex_unlock(&fs_info->balance_mutex); 3914 ret = -EINPROGRESS; 3915 goto out; 3916 } 3917 } else { 3918 /* this is (1) */ 3919 mutex_unlock(&fs_info->balance_mutex); 3920 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS; 3921 goto out; 3922 } 3923 3924 locked: 3925 BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running)); 3926 3927 if (arg) { 3928 bargs = memdup_user(arg, sizeof(*bargs)); 3929 if (IS_ERR(bargs)) { 3930 ret = PTR_ERR(bargs); 3931 goto out_unlock; 3932 } 3933 3934 if (bargs->flags & BTRFS_BALANCE_RESUME) { 3935 if (!fs_info->balance_ctl) { 3936 ret = -ENOTCONN; 3937 goto out_bargs; 3938 } 3939 3940 bctl = fs_info->balance_ctl; 3941 spin_lock(&fs_info->balance_lock); 3942 bctl->flags |= BTRFS_BALANCE_RESUME; 3943 spin_unlock(&fs_info->balance_lock); 3944 3945 goto do_balance; 3946 } 3947 } else { 3948 bargs = NULL; 3949 } 3950 3951 if (fs_info->balance_ctl) { 3952 ret = -EINPROGRESS; 3953 goto out_bargs; 3954 } 3955 3956 bctl = kzalloc(sizeof(*bctl), GFP_NOFS); 3957 if (!bctl) { 3958 ret = -ENOMEM; 3959 goto out_bargs; 3960 } 3961 3962 bctl->fs_info = fs_info; 3963 if (arg) { 3964 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data)); 3965 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta)); 3966 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys)); 3967 3968 bctl->flags = bargs->flags; 3969 } else { 3970 /* balance everything - no filters */ 3971 bctl->flags |= BTRFS_BALANCE_TYPE_MASK; 3972 } 3973 3974 do_balance: 3975 /* 3976 * Ownership of bctl and mutually_exclusive_operation_running 3977 * goes to to btrfs_balance. bctl is freed in __cancel_balance, 3978 * or, if restriper was paused all the way until unmount, in 3979 * free_fs_info. mutually_exclusive_operation_running is 3980 * cleared in __cancel_balance. 3981 */ 3982 need_unlock = false; 3983 3984 ret = btrfs_balance(bctl, bargs); 3985 3986 if (arg) { 3987 if (copy_to_user(arg, bargs, sizeof(*bargs))) 3988 ret = -EFAULT; 3989 } 3990 3991 out_bargs: 3992 kfree(bargs); 3993 out_unlock: 3994 mutex_unlock(&fs_info->balance_mutex); 3995 mutex_unlock(&fs_info->volume_mutex); 3996 if (need_unlock) 3997 atomic_set(&fs_info->mutually_exclusive_operation_running, 0); 3998 out: 3999 mnt_drop_write_file(file); 4000 return ret; 4001 } 4002 4003 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd) 4004 { 4005 if (!capable(CAP_SYS_ADMIN)) 4006 return -EPERM; 4007 4008 switch (cmd) { 4009 case BTRFS_BALANCE_CTL_PAUSE: 4010 return btrfs_pause_balance(root->fs_info); 4011 case BTRFS_BALANCE_CTL_CANCEL: 4012 return btrfs_cancel_balance(root->fs_info); 4013 } 4014 4015 return -EINVAL; 4016 } 4017 4018 static long btrfs_ioctl_balance_progress(struct btrfs_root *root, 4019 void __user *arg) 4020 { 4021 struct btrfs_fs_info *fs_info = root->fs_info; 4022 struct btrfs_ioctl_balance_args *bargs; 4023 int ret = 0; 4024 4025 if (!capable(CAP_SYS_ADMIN)) 4026 return -EPERM; 4027 4028 mutex_lock(&fs_info->balance_mutex); 4029 if (!fs_info->balance_ctl) { 4030 ret = -ENOTCONN; 4031 goto out; 4032 } 4033 4034 bargs = kzalloc(sizeof(*bargs), GFP_NOFS); 4035 if (!bargs) { 4036 ret = -ENOMEM; 4037 goto out; 4038 } 4039 4040 update_ioctl_balance_args(fs_info, 1, bargs); 4041 4042 if (copy_to_user(arg, bargs, sizeof(*bargs))) 4043 ret = -EFAULT; 4044 4045 kfree(bargs); 4046 out: 4047 mutex_unlock(&fs_info->balance_mutex); 4048 return ret; 4049 } 4050 4051 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg) 4052 { 4053 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4054 struct btrfs_ioctl_quota_ctl_args *sa; 4055 struct btrfs_trans_handle *trans = NULL; 4056 int ret; 4057 int err; 4058 4059 if (!capable(CAP_SYS_ADMIN)) 4060 return -EPERM; 4061 4062 ret = mnt_want_write_file(file); 4063 if (ret) 4064 return ret; 4065 4066 sa = memdup_user(arg, sizeof(*sa)); 4067 if (IS_ERR(sa)) { 4068 ret = PTR_ERR(sa); 4069 goto drop_write; 4070 } 4071 4072 down_write(&root->fs_info->subvol_sem); 4073 trans = btrfs_start_transaction(root->fs_info->tree_root, 2); 4074 if (IS_ERR(trans)) { 4075 ret = PTR_ERR(trans); 4076 goto out; 4077 } 4078 4079 switch (sa->cmd) { 4080 case BTRFS_QUOTA_CTL_ENABLE: 4081 ret = btrfs_quota_enable(trans, root->fs_info); 4082 break; 4083 case BTRFS_QUOTA_CTL_DISABLE: 4084 ret = btrfs_quota_disable(trans, root->fs_info); 4085 break; 4086 default: 4087 ret = -EINVAL; 4088 break; 4089 } 4090 4091 err = btrfs_commit_transaction(trans, root->fs_info->tree_root); 4092 if (err && !ret) 4093 ret = err; 4094 out: 4095 kfree(sa); 4096 up_write(&root->fs_info->subvol_sem); 4097 drop_write: 4098 mnt_drop_write_file(file); 4099 return ret; 4100 } 4101 4102 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg) 4103 { 4104 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4105 struct btrfs_ioctl_qgroup_assign_args *sa; 4106 struct btrfs_trans_handle *trans; 4107 int ret; 4108 int err; 4109 4110 if (!capable(CAP_SYS_ADMIN)) 4111 return -EPERM; 4112 4113 ret = mnt_want_write_file(file); 4114 if (ret) 4115 return ret; 4116 4117 sa = memdup_user(arg, sizeof(*sa)); 4118 if (IS_ERR(sa)) { 4119 ret = PTR_ERR(sa); 4120 goto drop_write; 4121 } 4122 4123 trans = btrfs_join_transaction(root); 4124 if (IS_ERR(trans)) { 4125 ret = PTR_ERR(trans); 4126 goto out; 4127 } 4128 4129 /* FIXME: check if the IDs really exist */ 4130 if (sa->assign) { 4131 ret = btrfs_add_qgroup_relation(trans, root->fs_info, 4132 sa->src, sa->dst); 4133 } else { 4134 ret = btrfs_del_qgroup_relation(trans, root->fs_info, 4135 sa->src, sa->dst); 4136 } 4137 4138 err = btrfs_end_transaction(trans, root); 4139 if (err && !ret) 4140 ret = err; 4141 4142 out: 4143 kfree(sa); 4144 drop_write: 4145 mnt_drop_write_file(file); 4146 return ret; 4147 } 4148 4149 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg) 4150 { 4151 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4152 struct btrfs_ioctl_qgroup_create_args *sa; 4153 struct btrfs_trans_handle *trans; 4154 int ret; 4155 int err; 4156 4157 if (!capable(CAP_SYS_ADMIN)) 4158 return -EPERM; 4159 4160 ret = mnt_want_write_file(file); 4161 if (ret) 4162 return ret; 4163 4164 sa = memdup_user(arg, sizeof(*sa)); 4165 if (IS_ERR(sa)) { 4166 ret = PTR_ERR(sa); 4167 goto drop_write; 4168 } 4169 4170 if (!sa->qgroupid) { 4171 ret = -EINVAL; 4172 goto out; 4173 } 4174 4175 trans = btrfs_join_transaction(root); 4176 if (IS_ERR(trans)) { 4177 ret = PTR_ERR(trans); 4178 goto out; 4179 } 4180 4181 /* FIXME: check if the IDs really exist */ 4182 if (sa->create) { 4183 ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid, 4184 NULL); 4185 } else { 4186 ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid); 4187 } 4188 4189 err = btrfs_end_transaction(trans, root); 4190 if (err && !ret) 4191 ret = err; 4192 4193 out: 4194 kfree(sa); 4195 drop_write: 4196 mnt_drop_write_file(file); 4197 return ret; 4198 } 4199 4200 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg) 4201 { 4202 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4203 struct btrfs_ioctl_qgroup_limit_args *sa; 4204 struct btrfs_trans_handle *trans; 4205 int ret; 4206 int err; 4207 u64 qgroupid; 4208 4209 if (!capable(CAP_SYS_ADMIN)) 4210 return -EPERM; 4211 4212 ret = mnt_want_write_file(file); 4213 if (ret) 4214 return ret; 4215 4216 sa = memdup_user(arg, sizeof(*sa)); 4217 if (IS_ERR(sa)) { 4218 ret = PTR_ERR(sa); 4219 goto drop_write; 4220 } 4221 4222 trans = btrfs_join_transaction(root); 4223 if (IS_ERR(trans)) { 4224 ret = PTR_ERR(trans); 4225 goto out; 4226 } 4227 4228 qgroupid = sa->qgroupid; 4229 if (!qgroupid) { 4230 /* take the current subvol as qgroup */ 4231 qgroupid = root->root_key.objectid; 4232 } 4233 4234 /* FIXME: check if the IDs really exist */ 4235 ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim); 4236 4237 err = btrfs_end_transaction(trans, root); 4238 if (err && !ret) 4239 ret = err; 4240 4241 out: 4242 kfree(sa); 4243 drop_write: 4244 mnt_drop_write_file(file); 4245 return ret; 4246 } 4247 4248 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg) 4249 { 4250 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4251 struct btrfs_ioctl_quota_rescan_args *qsa; 4252 int ret; 4253 4254 if (!capable(CAP_SYS_ADMIN)) 4255 return -EPERM; 4256 4257 ret = mnt_want_write_file(file); 4258 if (ret) 4259 return ret; 4260 4261 qsa = memdup_user(arg, sizeof(*qsa)); 4262 if (IS_ERR(qsa)) { 4263 ret = PTR_ERR(qsa); 4264 goto drop_write; 4265 } 4266 4267 if (qsa->flags) { 4268 ret = -EINVAL; 4269 goto out; 4270 } 4271 4272 ret = btrfs_qgroup_rescan(root->fs_info); 4273 4274 out: 4275 kfree(qsa); 4276 drop_write: 4277 mnt_drop_write_file(file); 4278 return ret; 4279 } 4280 4281 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg) 4282 { 4283 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4284 struct btrfs_ioctl_quota_rescan_args *qsa; 4285 int ret = 0; 4286 4287 if (!capable(CAP_SYS_ADMIN)) 4288 return -EPERM; 4289 4290 qsa = kzalloc(sizeof(*qsa), GFP_NOFS); 4291 if (!qsa) 4292 return -ENOMEM; 4293 4294 if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { 4295 qsa->flags = 1; 4296 qsa->progress = root->fs_info->qgroup_rescan_progress.objectid; 4297 } 4298 4299 if (copy_to_user(arg, qsa, sizeof(*qsa))) 4300 ret = -EFAULT; 4301 4302 kfree(qsa); 4303 return ret; 4304 } 4305 4306 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg) 4307 { 4308 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4309 4310 if (!capable(CAP_SYS_ADMIN)) 4311 return -EPERM; 4312 4313 return btrfs_qgroup_wait_for_completion(root->fs_info); 4314 } 4315 4316 static long btrfs_ioctl_set_received_subvol(struct file *file, 4317 void __user *arg) 4318 { 4319 struct btrfs_ioctl_received_subvol_args *sa = NULL; 4320 struct inode *inode = file_inode(file); 4321 struct btrfs_root *root = BTRFS_I(inode)->root; 4322 struct btrfs_root_item *root_item = &root->root_item; 4323 struct btrfs_trans_handle *trans; 4324 struct timespec ct = CURRENT_TIME; 4325 int ret = 0; 4326 int received_uuid_changed; 4327 4328 ret = mnt_want_write_file(file); 4329 if (ret < 0) 4330 return ret; 4331 4332 down_write(&root->fs_info->subvol_sem); 4333 4334 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) { 4335 ret = -EINVAL; 4336 goto out; 4337 } 4338 4339 if (btrfs_root_readonly(root)) { 4340 ret = -EROFS; 4341 goto out; 4342 } 4343 4344 if (!inode_owner_or_capable(inode)) { 4345 ret = -EACCES; 4346 goto out; 4347 } 4348 4349 sa = memdup_user(arg, sizeof(*sa)); 4350 if (IS_ERR(sa)) { 4351 ret = PTR_ERR(sa); 4352 sa = NULL; 4353 goto out; 4354 } 4355 4356 /* 4357 * 1 - root item 4358 * 2 - uuid items (received uuid + subvol uuid) 4359 */ 4360 trans = btrfs_start_transaction(root, 3); 4361 if (IS_ERR(trans)) { 4362 ret = PTR_ERR(trans); 4363 trans = NULL; 4364 goto out; 4365 } 4366 4367 sa->rtransid = trans->transid; 4368 sa->rtime.sec = ct.tv_sec; 4369 sa->rtime.nsec = ct.tv_nsec; 4370 4371 received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid, 4372 BTRFS_UUID_SIZE); 4373 if (received_uuid_changed && 4374 !btrfs_is_empty_uuid(root_item->received_uuid)) 4375 btrfs_uuid_tree_rem(trans, root->fs_info->uuid_root, 4376 root_item->received_uuid, 4377 BTRFS_UUID_KEY_RECEIVED_SUBVOL, 4378 root->root_key.objectid); 4379 memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE); 4380 btrfs_set_root_stransid(root_item, sa->stransid); 4381 btrfs_set_root_rtransid(root_item, sa->rtransid); 4382 btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec); 4383 btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec); 4384 btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec); 4385 btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec); 4386 4387 ret = btrfs_update_root(trans, root->fs_info->tree_root, 4388 &root->root_key, &root->root_item); 4389 if (ret < 0) { 4390 btrfs_end_transaction(trans, root); 4391 goto out; 4392 } 4393 if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) { 4394 ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root, 4395 sa->uuid, 4396 BTRFS_UUID_KEY_RECEIVED_SUBVOL, 4397 root->root_key.objectid); 4398 if (ret < 0 && ret != -EEXIST) { 4399 btrfs_abort_transaction(trans, root, ret); 4400 goto out; 4401 } 4402 } 4403 ret = btrfs_commit_transaction(trans, root); 4404 if (ret < 0) { 4405 btrfs_abort_transaction(trans, root, ret); 4406 goto out; 4407 } 4408 4409 ret = copy_to_user(arg, sa, sizeof(*sa)); 4410 if (ret) 4411 ret = -EFAULT; 4412 4413 out: 4414 kfree(sa); 4415 up_write(&root->fs_info->subvol_sem); 4416 mnt_drop_write_file(file); 4417 return ret; 4418 } 4419 4420 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) 4421 { 4422 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4423 size_t len; 4424 int ret; 4425 char label[BTRFS_LABEL_SIZE]; 4426 4427 spin_lock(&root->fs_info->super_lock); 4428 memcpy(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE); 4429 spin_unlock(&root->fs_info->super_lock); 4430 4431 len = strnlen(label, BTRFS_LABEL_SIZE); 4432 4433 if (len == BTRFS_LABEL_SIZE) { 4434 pr_warn("btrfs: label is too long, return the first %zu bytes\n", 4435 --len); 4436 } 4437 4438 ret = copy_to_user(arg, label, len); 4439 4440 return ret ? -EFAULT : 0; 4441 } 4442 4443 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg) 4444 { 4445 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4446 struct btrfs_super_block *super_block = root->fs_info->super_copy; 4447 struct btrfs_trans_handle *trans; 4448 char label[BTRFS_LABEL_SIZE]; 4449 int ret; 4450 4451 if (!capable(CAP_SYS_ADMIN)) 4452 return -EPERM; 4453 4454 if (copy_from_user(label, arg, sizeof(label))) 4455 return -EFAULT; 4456 4457 if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) { 4458 pr_err("btrfs: unable to set label with more than %d bytes\n", 4459 BTRFS_LABEL_SIZE - 1); 4460 return -EINVAL; 4461 } 4462 4463 ret = mnt_want_write_file(file); 4464 if (ret) 4465 return ret; 4466 4467 trans = btrfs_start_transaction(root, 0); 4468 if (IS_ERR(trans)) { 4469 ret = PTR_ERR(trans); 4470 goto out_unlock; 4471 } 4472 4473 spin_lock(&root->fs_info->super_lock); 4474 strcpy(super_block->label, label); 4475 spin_unlock(&root->fs_info->super_lock); 4476 ret = btrfs_end_transaction(trans, root); 4477 4478 out_unlock: 4479 mnt_drop_write_file(file); 4480 return ret; 4481 } 4482 4483 long btrfs_ioctl(struct file *file, unsigned int 4484 cmd, unsigned long arg) 4485 { 4486 struct btrfs_root *root = BTRFS_I(file_inode(file))->root; 4487 void __user *argp = (void __user *)arg; 4488 4489 switch (cmd) { 4490 case FS_IOC_GETFLAGS: 4491 return btrfs_ioctl_getflags(file, argp); 4492 case FS_IOC_SETFLAGS: 4493 return btrfs_ioctl_setflags(file, argp); 4494 case FS_IOC_GETVERSION: 4495 return btrfs_ioctl_getversion(file, argp); 4496 case FITRIM: 4497 return btrfs_ioctl_fitrim(file, argp); 4498 case BTRFS_IOC_SNAP_CREATE: 4499 return btrfs_ioctl_snap_create(file, argp, 0); 4500 case BTRFS_IOC_SNAP_CREATE_V2: 4501 return btrfs_ioctl_snap_create_v2(file, argp, 0); 4502 case BTRFS_IOC_SUBVOL_CREATE: 4503 return btrfs_ioctl_snap_create(file, argp, 1); 4504 case BTRFS_IOC_SUBVOL_CREATE_V2: 4505 return btrfs_ioctl_snap_create_v2(file, argp, 1); 4506 case BTRFS_IOC_SNAP_DESTROY: 4507 return btrfs_ioctl_snap_destroy(file, argp); 4508 case BTRFS_IOC_SUBVOL_GETFLAGS: 4509 return btrfs_ioctl_subvol_getflags(file, argp); 4510 case BTRFS_IOC_SUBVOL_SETFLAGS: 4511 return btrfs_ioctl_subvol_setflags(file, argp); 4512 case BTRFS_IOC_DEFAULT_SUBVOL: 4513 return btrfs_ioctl_default_subvol(file, argp); 4514 case BTRFS_IOC_DEFRAG: 4515 return btrfs_ioctl_defrag(file, NULL); 4516 case BTRFS_IOC_DEFRAG_RANGE: 4517 return btrfs_ioctl_defrag(file, argp); 4518 case BTRFS_IOC_RESIZE: 4519 return btrfs_ioctl_resize(file, argp); 4520 case BTRFS_IOC_ADD_DEV: 4521 return btrfs_ioctl_add_dev(root, argp); 4522 case BTRFS_IOC_RM_DEV: 4523 return btrfs_ioctl_rm_dev(file, argp); 4524 case BTRFS_IOC_FS_INFO: 4525 return btrfs_ioctl_fs_info(root, argp); 4526 case BTRFS_IOC_DEV_INFO: 4527 return btrfs_ioctl_dev_info(root, argp); 4528 case BTRFS_IOC_BALANCE: 4529 return btrfs_ioctl_balance(file, NULL); 4530 case BTRFS_IOC_CLONE: 4531 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 4532 case BTRFS_IOC_CLONE_RANGE: 4533 return btrfs_ioctl_clone_range(file, argp); 4534 case BTRFS_IOC_TRANS_START: 4535 return btrfs_ioctl_trans_start(file); 4536 case BTRFS_IOC_TRANS_END: 4537 return btrfs_ioctl_trans_end(file); 4538 case BTRFS_IOC_TREE_SEARCH: 4539 return btrfs_ioctl_tree_search(file, argp); 4540 case BTRFS_IOC_INO_LOOKUP: 4541 return btrfs_ioctl_ino_lookup(file, argp); 4542 case BTRFS_IOC_INO_PATHS: 4543 return btrfs_ioctl_ino_to_path(root, argp); 4544 case BTRFS_IOC_LOGICAL_INO: 4545 return btrfs_ioctl_logical_to_ino(root, argp); 4546 case BTRFS_IOC_SPACE_INFO: 4547 return btrfs_ioctl_space_info(root, argp); 4548 case BTRFS_IOC_SYNC: { 4549 int ret; 4550 4551 ret = btrfs_start_delalloc_roots(root->fs_info, 0); 4552 if (ret) 4553 return ret; 4554 ret = btrfs_sync_fs(file->f_dentry->d_sb, 1); 4555 return ret; 4556 } 4557 case BTRFS_IOC_START_SYNC: 4558 return btrfs_ioctl_start_sync(root, argp); 4559 case BTRFS_IOC_WAIT_SYNC: 4560 return btrfs_ioctl_wait_sync(root, argp); 4561 case BTRFS_IOC_SCRUB: 4562 return btrfs_ioctl_scrub(file, argp); 4563 case BTRFS_IOC_SCRUB_CANCEL: 4564 return btrfs_ioctl_scrub_cancel(root, argp); 4565 case BTRFS_IOC_SCRUB_PROGRESS: 4566 return btrfs_ioctl_scrub_progress(root, argp); 4567 case BTRFS_IOC_BALANCE_V2: 4568 return btrfs_ioctl_balance(file, argp); 4569 case BTRFS_IOC_BALANCE_CTL: 4570 return btrfs_ioctl_balance_ctl(root, arg); 4571 case BTRFS_IOC_BALANCE_PROGRESS: 4572 return btrfs_ioctl_balance_progress(root, argp); 4573 case BTRFS_IOC_SET_RECEIVED_SUBVOL: 4574 return btrfs_ioctl_set_received_subvol(file, argp); 4575 case BTRFS_IOC_SEND: 4576 return btrfs_ioctl_send(file, argp); 4577 case BTRFS_IOC_GET_DEV_STATS: 4578 return btrfs_ioctl_get_dev_stats(root, argp); 4579 case BTRFS_IOC_QUOTA_CTL: 4580 return btrfs_ioctl_quota_ctl(file, argp); 4581 case BTRFS_IOC_QGROUP_ASSIGN: 4582 return btrfs_ioctl_qgroup_assign(file, argp); 4583 case BTRFS_IOC_QGROUP_CREATE: 4584 return btrfs_ioctl_qgroup_create(file, argp); 4585 case BTRFS_IOC_QGROUP_LIMIT: 4586 return btrfs_ioctl_qgroup_limit(file, argp); 4587 case BTRFS_IOC_QUOTA_RESCAN: 4588 return btrfs_ioctl_quota_rescan(file, argp); 4589 case BTRFS_IOC_QUOTA_RESCAN_STATUS: 4590 return btrfs_ioctl_quota_rescan_status(file, argp); 4591 case BTRFS_IOC_QUOTA_RESCAN_WAIT: 4592 return btrfs_ioctl_quota_rescan_wait(file, argp); 4593 case BTRFS_IOC_DEV_REPLACE: 4594 return btrfs_ioctl_dev_replace(root, argp); 4595 case BTRFS_IOC_GET_FSLABEL: 4596 return btrfs_ioctl_get_fslabel(file, argp); 4597 case BTRFS_IOC_SET_FSLABEL: 4598 return btrfs_ioctl_set_fslabel(file, argp); 4599 case BTRFS_IOC_FILE_EXTENT_SAME: 4600 return btrfs_ioctl_file_extent_same(file, argp); 4601 } 4602 4603 return -ENOTTY; 4604 } 4605