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 "compat.h" 45 #include "ctree.h" 46 #include "disk-io.h" 47 #include "transaction.h" 48 #include "btrfs_inode.h" 49 #include "ioctl.h" 50 #include "print-tree.h" 51 #include "volumes.h" 52 #include "locking.h" 53 #include "inode-map.h" 54 #include "backref.h" 55 56 /* Mask out flags that are inappropriate for the given type of inode. */ 57 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags) 58 { 59 if (S_ISDIR(mode)) 60 return flags; 61 else if (S_ISREG(mode)) 62 return flags & ~FS_DIRSYNC_FL; 63 else 64 return flags & (FS_NODUMP_FL | FS_NOATIME_FL); 65 } 66 67 /* 68 * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl. 69 */ 70 static unsigned int btrfs_flags_to_ioctl(unsigned int flags) 71 { 72 unsigned int iflags = 0; 73 74 if (flags & BTRFS_INODE_SYNC) 75 iflags |= FS_SYNC_FL; 76 if (flags & BTRFS_INODE_IMMUTABLE) 77 iflags |= FS_IMMUTABLE_FL; 78 if (flags & BTRFS_INODE_APPEND) 79 iflags |= FS_APPEND_FL; 80 if (flags & BTRFS_INODE_NODUMP) 81 iflags |= FS_NODUMP_FL; 82 if (flags & BTRFS_INODE_NOATIME) 83 iflags |= FS_NOATIME_FL; 84 if (flags & BTRFS_INODE_DIRSYNC) 85 iflags |= FS_DIRSYNC_FL; 86 if (flags & BTRFS_INODE_NODATACOW) 87 iflags |= FS_NOCOW_FL; 88 89 if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS)) 90 iflags |= FS_COMPR_FL; 91 else if (flags & BTRFS_INODE_NOCOMPRESS) 92 iflags |= FS_NOCOMP_FL; 93 94 return iflags; 95 } 96 97 /* 98 * Update inode->i_flags based on the btrfs internal flags. 99 */ 100 void btrfs_update_iflags(struct inode *inode) 101 { 102 struct btrfs_inode *ip = BTRFS_I(inode); 103 104 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); 105 106 if (ip->flags & BTRFS_INODE_SYNC) 107 inode->i_flags |= S_SYNC; 108 if (ip->flags & BTRFS_INODE_IMMUTABLE) 109 inode->i_flags |= S_IMMUTABLE; 110 if (ip->flags & BTRFS_INODE_APPEND) 111 inode->i_flags |= S_APPEND; 112 if (ip->flags & BTRFS_INODE_NOATIME) 113 inode->i_flags |= S_NOATIME; 114 if (ip->flags & BTRFS_INODE_DIRSYNC) 115 inode->i_flags |= S_DIRSYNC; 116 } 117 118 /* 119 * Inherit flags from the parent inode. 120 * 121 * Currently only the compression flags and the cow flags are inherited. 122 */ 123 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) 124 { 125 unsigned int flags; 126 127 if (!dir) 128 return; 129 130 flags = BTRFS_I(dir)->flags; 131 132 if (flags & BTRFS_INODE_NOCOMPRESS) { 133 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; 134 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; 135 } else if (flags & BTRFS_INODE_COMPRESS) { 136 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; 137 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; 138 } 139 140 if (flags & BTRFS_INODE_NODATACOW) 141 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; 142 143 btrfs_update_iflags(inode); 144 } 145 146 static int btrfs_ioctl_getflags(struct file *file, void __user *arg) 147 { 148 struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode); 149 unsigned int flags = btrfs_flags_to_ioctl(ip->flags); 150 151 if (copy_to_user(arg, &flags, sizeof(flags))) 152 return -EFAULT; 153 return 0; 154 } 155 156 static int check_flags(unsigned int flags) 157 { 158 if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \ 159 FS_NOATIME_FL | FS_NODUMP_FL | \ 160 FS_SYNC_FL | FS_DIRSYNC_FL | \ 161 FS_NOCOMP_FL | FS_COMPR_FL | 162 FS_NOCOW_FL)) 163 return -EOPNOTSUPP; 164 165 if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL)) 166 return -EINVAL; 167 168 return 0; 169 } 170 171 static int btrfs_ioctl_setflags(struct file *file, void __user *arg) 172 { 173 struct inode *inode = file->f_path.dentry->d_inode; 174 struct btrfs_inode *ip = BTRFS_I(inode); 175 struct btrfs_root *root = ip->root; 176 struct btrfs_trans_handle *trans; 177 unsigned int flags, oldflags; 178 int ret; 179 180 if (btrfs_root_readonly(root)) 181 return -EROFS; 182 183 if (copy_from_user(&flags, arg, sizeof(flags))) 184 return -EFAULT; 185 186 ret = check_flags(flags); 187 if (ret) 188 return ret; 189 190 if (!inode_owner_or_capable(inode)) 191 return -EACCES; 192 193 mutex_lock(&inode->i_mutex); 194 195 flags = btrfs_mask_flags(inode->i_mode, flags); 196 oldflags = btrfs_flags_to_ioctl(ip->flags); 197 if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) { 198 if (!capable(CAP_LINUX_IMMUTABLE)) { 199 ret = -EPERM; 200 goto out_unlock; 201 } 202 } 203 204 ret = mnt_want_write_file(file); 205 if (ret) 206 goto out_unlock; 207 208 if (flags & FS_SYNC_FL) 209 ip->flags |= BTRFS_INODE_SYNC; 210 else 211 ip->flags &= ~BTRFS_INODE_SYNC; 212 if (flags & FS_IMMUTABLE_FL) 213 ip->flags |= BTRFS_INODE_IMMUTABLE; 214 else 215 ip->flags &= ~BTRFS_INODE_IMMUTABLE; 216 if (flags & FS_APPEND_FL) 217 ip->flags |= BTRFS_INODE_APPEND; 218 else 219 ip->flags &= ~BTRFS_INODE_APPEND; 220 if (flags & FS_NODUMP_FL) 221 ip->flags |= BTRFS_INODE_NODUMP; 222 else 223 ip->flags &= ~BTRFS_INODE_NODUMP; 224 if (flags & FS_NOATIME_FL) 225 ip->flags |= BTRFS_INODE_NOATIME; 226 else 227 ip->flags &= ~BTRFS_INODE_NOATIME; 228 if (flags & FS_DIRSYNC_FL) 229 ip->flags |= BTRFS_INODE_DIRSYNC; 230 else 231 ip->flags &= ~BTRFS_INODE_DIRSYNC; 232 if (flags & FS_NOCOW_FL) 233 ip->flags |= BTRFS_INODE_NODATACOW; 234 else 235 ip->flags &= ~BTRFS_INODE_NODATACOW; 236 237 /* 238 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS 239 * flag may be changed automatically if compression code won't make 240 * things smaller. 241 */ 242 if (flags & FS_NOCOMP_FL) { 243 ip->flags &= ~BTRFS_INODE_COMPRESS; 244 ip->flags |= BTRFS_INODE_NOCOMPRESS; 245 } else if (flags & FS_COMPR_FL) { 246 ip->flags |= BTRFS_INODE_COMPRESS; 247 ip->flags &= ~BTRFS_INODE_NOCOMPRESS; 248 } else { 249 ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS); 250 } 251 252 trans = btrfs_join_transaction(root); 253 BUG_ON(IS_ERR(trans)); 254 255 btrfs_update_iflags(inode); 256 inode->i_ctime = CURRENT_TIME; 257 ret = btrfs_update_inode(trans, root, inode); 258 BUG_ON(ret); 259 260 btrfs_end_transaction(trans, root); 261 262 mnt_drop_write_file(file); 263 264 ret = 0; 265 out_unlock: 266 mutex_unlock(&inode->i_mutex); 267 return ret; 268 } 269 270 static int btrfs_ioctl_getversion(struct file *file, int __user *arg) 271 { 272 struct inode *inode = file->f_path.dentry->d_inode; 273 274 return put_user(inode->i_generation, arg); 275 } 276 277 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) 278 { 279 struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info; 280 struct btrfs_fs_info *fs_info = root->fs_info; 281 struct btrfs_device *device; 282 struct request_queue *q; 283 struct fstrim_range range; 284 u64 minlen = ULLONG_MAX; 285 u64 num_devices = 0; 286 u64 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy); 287 int ret; 288 289 if (!capable(CAP_SYS_ADMIN)) 290 return -EPERM; 291 292 rcu_read_lock(); 293 list_for_each_entry_rcu(device, &fs_info->fs_devices->devices, 294 dev_list) { 295 if (!device->bdev) 296 continue; 297 q = bdev_get_queue(device->bdev); 298 if (blk_queue_discard(q)) { 299 num_devices++; 300 minlen = min((u64)q->limits.discard_granularity, 301 minlen); 302 } 303 } 304 rcu_read_unlock(); 305 306 if (!num_devices) 307 return -EOPNOTSUPP; 308 if (copy_from_user(&range, arg, sizeof(range))) 309 return -EFAULT; 310 if (range.start > total_bytes) 311 return -EINVAL; 312 313 range.len = min(range.len, total_bytes - range.start); 314 range.minlen = max(range.minlen, minlen); 315 ret = btrfs_trim_fs(root, &range); 316 if (ret < 0) 317 return ret; 318 319 if (copy_to_user(arg, &range, sizeof(range))) 320 return -EFAULT; 321 322 return 0; 323 } 324 325 static noinline int create_subvol(struct btrfs_root *root, 326 struct dentry *dentry, 327 char *name, int namelen, 328 u64 *async_transid) 329 { 330 struct btrfs_trans_handle *trans; 331 struct btrfs_key key; 332 struct btrfs_root_item root_item; 333 struct btrfs_inode_item *inode_item; 334 struct extent_buffer *leaf; 335 struct btrfs_root *new_root; 336 struct dentry *parent = dentry->d_parent; 337 struct inode *dir; 338 int ret; 339 int err; 340 u64 objectid; 341 u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID; 342 u64 index = 0; 343 344 ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid); 345 if (ret) 346 return ret; 347 348 dir = parent->d_inode; 349 350 /* 351 * 1 - inode item 352 * 2 - refs 353 * 1 - root item 354 * 2 - dir items 355 */ 356 trans = btrfs_start_transaction(root, 6); 357 if (IS_ERR(trans)) 358 return PTR_ERR(trans); 359 360 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 361 0, objectid, NULL, 0, 0, 0); 362 if (IS_ERR(leaf)) { 363 ret = PTR_ERR(leaf); 364 goto fail; 365 } 366 367 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header)); 368 btrfs_set_header_bytenr(leaf, leaf->start); 369 btrfs_set_header_generation(leaf, trans->transid); 370 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV); 371 btrfs_set_header_owner(leaf, objectid); 372 373 write_extent_buffer(leaf, root->fs_info->fsid, 374 (unsigned long)btrfs_header_fsid(leaf), 375 BTRFS_FSID_SIZE); 376 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid, 377 (unsigned long)btrfs_header_chunk_tree_uuid(leaf), 378 BTRFS_UUID_SIZE); 379 btrfs_mark_buffer_dirty(leaf); 380 381 inode_item = &root_item.inode; 382 memset(inode_item, 0, sizeof(*inode_item)); 383 inode_item->generation = cpu_to_le64(1); 384 inode_item->size = cpu_to_le64(3); 385 inode_item->nlink = cpu_to_le32(1); 386 inode_item->nbytes = cpu_to_le64(root->leafsize); 387 inode_item->mode = cpu_to_le32(S_IFDIR | 0755); 388 389 root_item.flags = 0; 390 root_item.byte_limit = 0; 391 inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT); 392 393 btrfs_set_root_bytenr(&root_item, leaf->start); 394 btrfs_set_root_generation(&root_item, trans->transid); 395 btrfs_set_root_level(&root_item, 0); 396 btrfs_set_root_refs(&root_item, 1); 397 btrfs_set_root_used(&root_item, leaf->len); 398 btrfs_set_root_last_snapshot(&root_item, 0); 399 400 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); 401 root_item.drop_level = 0; 402 403 btrfs_tree_unlock(leaf); 404 free_extent_buffer(leaf); 405 leaf = NULL; 406 407 btrfs_set_root_dirid(&root_item, new_dirid); 408 409 key.objectid = objectid; 410 key.offset = 0; 411 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); 412 ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, 413 &root_item); 414 if (ret) 415 goto fail; 416 417 key.offset = (u64)-1; 418 new_root = btrfs_read_fs_root_no_name(root->fs_info, &key); 419 BUG_ON(IS_ERR(new_root)); 420 421 btrfs_record_root_in_trans(trans, new_root); 422 423 ret = btrfs_create_subvol_root(trans, new_root, new_dirid); 424 /* 425 * insert the directory item 426 */ 427 ret = btrfs_set_inode_index(dir, &index); 428 BUG_ON(ret); 429 430 ret = btrfs_insert_dir_item(trans, root, 431 name, namelen, dir, &key, 432 BTRFS_FT_DIR, index); 433 if (ret) 434 goto fail; 435 436 btrfs_i_size_write(dir, dir->i_size + namelen * 2); 437 ret = btrfs_update_inode(trans, root, dir); 438 BUG_ON(ret); 439 440 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, 441 objectid, root->root_key.objectid, 442 btrfs_ino(dir), index, name, namelen); 443 444 BUG_ON(ret); 445 446 d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry)); 447 fail: 448 if (async_transid) { 449 *async_transid = trans->transid; 450 err = btrfs_commit_transaction_async(trans, root, 1); 451 } else { 452 err = btrfs_commit_transaction(trans, root); 453 } 454 if (err && !ret) 455 ret = err; 456 return ret; 457 } 458 459 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry, 460 char *name, int namelen, u64 *async_transid, 461 bool readonly) 462 { 463 struct inode *inode; 464 struct btrfs_pending_snapshot *pending_snapshot; 465 struct btrfs_trans_handle *trans; 466 int ret; 467 468 if (!root->ref_cows) 469 return -EINVAL; 470 471 pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS); 472 if (!pending_snapshot) 473 return -ENOMEM; 474 475 btrfs_init_block_rsv(&pending_snapshot->block_rsv); 476 pending_snapshot->dentry = dentry; 477 pending_snapshot->root = root; 478 pending_snapshot->readonly = readonly; 479 480 trans = btrfs_start_transaction(root->fs_info->extent_root, 5); 481 if (IS_ERR(trans)) { 482 ret = PTR_ERR(trans); 483 goto fail; 484 } 485 486 ret = btrfs_snap_reserve_metadata(trans, pending_snapshot); 487 BUG_ON(ret); 488 489 spin_lock(&root->fs_info->trans_lock); 490 list_add(&pending_snapshot->list, 491 &trans->transaction->pending_snapshots); 492 spin_unlock(&root->fs_info->trans_lock); 493 if (async_transid) { 494 *async_transid = trans->transid; 495 ret = btrfs_commit_transaction_async(trans, 496 root->fs_info->extent_root, 1); 497 } else { 498 ret = btrfs_commit_transaction(trans, 499 root->fs_info->extent_root); 500 } 501 BUG_ON(ret); 502 503 ret = pending_snapshot->error; 504 if (ret) 505 goto fail; 506 507 ret = btrfs_orphan_cleanup(pending_snapshot->snap); 508 if (ret) 509 goto fail; 510 511 inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry); 512 if (IS_ERR(inode)) { 513 ret = PTR_ERR(inode); 514 goto fail; 515 } 516 BUG_ON(!inode); 517 d_instantiate(dentry, inode); 518 ret = 0; 519 fail: 520 kfree(pending_snapshot); 521 return ret; 522 } 523 524 /* copy of check_sticky in fs/namei.c() 525 * It's inline, so penalty for filesystems that don't use sticky bit is 526 * minimal. 527 */ 528 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode) 529 { 530 uid_t fsuid = current_fsuid(); 531 532 if (!(dir->i_mode & S_ISVTX)) 533 return 0; 534 if (inode->i_uid == fsuid) 535 return 0; 536 if (dir->i_uid == fsuid) 537 return 0; 538 return !capable(CAP_FOWNER); 539 } 540 541 /* copy of may_delete in fs/namei.c() 542 * Check whether we can remove a link victim from directory dir, check 543 * whether the type of victim is right. 544 * 1. We can't do it if dir is read-only (done in permission()) 545 * 2. We should have write and exec permissions on dir 546 * 3. We can't remove anything from append-only dir 547 * 4. We can't do anything with immutable dir (done in permission()) 548 * 5. If the sticky bit on dir is set we should either 549 * a. be owner of dir, or 550 * b. be owner of victim, or 551 * c. have CAP_FOWNER capability 552 * 6. If the victim is append-only or immutable we can't do antyhing with 553 * links pointing to it. 554 * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR. 555 * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR. 556 * 9. We can't remove a root or mountpoint. 557 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by 558 * nfs_async_unlink(). 559 */ 560 561 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir) 562 { 563 int error; 564 565 if (!victim->d_inode) 566 return -ENOENT; 567 568 BUG_ON(victim->d_parent->d_inode != dir); 569 audit_inode_child(victim, dir); 570 571 error = inode_permission(dir, MAY_WRITE | MAY_EXEC); 572 if (error) 573 return error; 574 if (IS_APPEND(dir)) 575 return -EPERM; 576 if (btrfs_check_sticky(dir, victim->d_inode)|| 577 IS_APPEND(victim->d_inode)|| 578 IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) 579 return -EPERM; 580 if (isdir) { 581 if (!S_ISDIR(victim->d_inode->i_mode)) 582 return -ENOTDIR; 583 if (IS_ROOT(victim)) 584 return -EBUSY; 585 } else if (S_ISDIR(victim->d_inode->i_mode)) 586 return -EISDIR; 587 if (IS_DEADDIR(dir)) 588 return -ENOENT; 589 if (victim->d_flags & DCACHE_NFSFS_RENAMED) 590 return -EBUSY; 591 return 0; 592 } 593 594 /* copy of may_create in fs/namei.c() */ 595 static inline int btrfs_may_create(struct inode *dir, struct dentry *child) 596 { 597 if (child->d_inode) 598 return -EEXIST; 599 if (IS_DEADDIR(dir)) 600 return -ENOENT; 601 return inode_permission(dir, MAY_WRITE | MAY_EXEC); 602 } 603 604 /* 605 * Create a new subvolume below @parent. This is largely modeled after 606 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup 607 * inside this filesystem so it's quite a bit simpler. 608 */ 609 static noinline int btrfs_mksubvol(struct path *parent, 610 char *name, int namelen, 611 struct btrfs_root *snap_src, 612 u64 *async_transid, bool readonly) 613 { 614 struct inode *dir = parent->dentry->d_inode; 615 struct dentry *dentry; 616 int error; 617 618 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 619 620 dentry = lookup_one_len(name, parent->dentry, namelen); 621 error = PTR_ERR(dentry); 622 if (IS_ERR(dentry)) 623 goto out_unlock; 624 625 error = -EEXIST; 626 if (dentry->d_inode) 627 goto out_dput; 628 629 error = mnt_want_write(parent->mnt); 630 if (error) 631 goto out_dput; 632 633 error = btrfs_may_create(dir, dentry); 634 if (error) 635 goto out_drop_write; 636 637 down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 638 639 if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0) 640 goto out_up_read; 641 642 if (snap_src) { 643 error = create_snapshot(snap_src, dentry, 644 name, namelen, async_transid, readonly); 645 } else { 646 error = create_subvol(BTRFS_I(dir)->root, dentry, 647 name, namelen, async_transid); 648 } 649 if (!error) 650 fsnotify_mkdir(dir, dentry); 651 out_up_read: 652 up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); 653 out_drop_write: 654 mnt_drop_write(parent->mnt); 655 out_dput: 656 dput(dentry); 657 out_unlock: 658 mutex_unlock(&dir->i_mutex); 659 return error; 660 } 661 662 /* 663 * When we're defragging a range, we don't want to kick it off again 664 * if it is really just waiting for delalloc to send it down. 665 * If we find a nice big extent or delalloc range for the bytes in the 666 * file you want to defrag, we return 0 to let you know to skip this 667 * part of the file 668 */ 669 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh) 670 { 671 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 672 struct extent_map *em = NULL; 673 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 674 u64 end; 675 676 read_lock(&em_tree->lock); 677 em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE); 678 read_unlock(&em_tree->lock); 679 680 if (em) { 681 end = extent_map_end(em); 682 free_extent_map(em); 683 if (end - offset > thresh) 684 return 0; 685 } 686 /* if we already have a nice delalloc here, just stop */ 687 thresh /= 2; 688 end = count_range_bits(io_tree, &offset, offset + thresh, 689 thresh, EXTENT_DELALLOC, 1); 690 if (end >= thresh) 691 return 0; 692 return 1; 693 } 694 695 /* 696 * helper function to walk through a file and find extents 697 * newer than a specific transid, and smaller than thresh. 698 * 699 * This is used by the defragging code to find new and small 700 * extents 701 */ 702 static int find_new_extents(struct btrfs_root *root, 703 struct inode *inode, u64 newer_than, 704 u64 *off, int thresh) 705 { 706 struct btrfs_path *path; 707 struct btrfs_key min_key; 708 struct btrfs_key max_key; 709 struct extent_buffer *leaf; 710 struct btrfs_file_extent_item *extent; 711 int type; 712 int ret; 713 u64 ino = btrfs_ino(inode); 714 715 path = btrfs_alloc_path(); 716 if (!path) 717 return -ENOMEM; 718 719 min_key.objectid = ino; 720 min_key.type = BTRFS_EXTENT_DATA_KEY; 721 min_key.offset = *off; 722 723 max_key.objectid = ino; 724 max_key.type = (u8)-1; 725 max_key.offset = (u64)-1; 726 727 path->keep_locks = 1; 728 729 while(1) { 730 ret = btrfs_search_forward(root, &min_key, &max_key, 731 path, 0, newer_than); 732 if (ret != 0) 733 goto none; 734 if (min_key.objectid != ino) 735 goto none; 736 if (min_key.type != BTRFS_EXTENT_DATA_KEY) 737 goto none; 738 739 leaf = path->nodes[0]; 740 extent = btrfs_item_ptr(leaf, path->slots[0], 741 struct btrfs_file_extent_item); 742 743 type = btrfs_file_extent_type(leaf, extent); 744 if (type == BTRFS_FILE_EXTENT_REG && 745 btrfs_file_extent_num_bytes(leaf, extent) < thresh && 746 check_defrag_in_cache(inode, min_key.offset, thresh)) { 747 *off = min_key.offset; 748 btrfs_free_path(path); 749 return 0; 750 } 751 752 if (min_key.offset == (u64)-1) 753 goto none; 754 755 min_key.offset++; 756 btrfs_release_path(path); 757 } 758 none: 759 btrfs_free_path(path); 760 return -ENOENT; 761 } 762 763 static int should_defrag_range(struct inode *inode, u64 start, u64 len, 764 int thresh, u64 *last_len, u64 *skip, 765 u64 *defrag_end) 766 { 767 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; 768 struct extent_map *em = NULL; 769 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 770 int ret = 1; 771 772 /* 773 * make sure that once we start defragging an extent, we keep on 774 * defragging it 775 */ 776 if (start < *defrag_end) 777 return 1; 778 779 *skip = 0; 780 781 /* 782 * hopefully we have this extent in the tree already, try without 783 * the full extent lock 784 */ 785 read_lock(&em_tree->lock); 786 em = lookup_extent_mapping(em_tree, start, len); 787 read_unlock(&em_tree->lock); 788 789 if (!em) { 790 /* get the big lock and read metadata off disk */ 791 lock_extent(io_tree, start, start + len - 1, GFP_NOFS); 792 em = btrfs_get_extent(inode, NULL, 0, start, len, 0); 793 unlock_extent(io_tree, start, start + len - 1, GFP_NOFS); 794 795 if (IS_ERR(em)) 796 return 0; 797 } 798 799 /* this will cover holes, and inline extents */ 800 if (em->block_start >= EXTENT_MAP_LAST_BYTE) 801 ret = 0; 802 803 /* 804 * we hit a real extent, if it is big don't bother defragging it again 805 */ 806 if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh) 807 ret = 0; 808 809 /* 810 * last_len ends up being a counter of how many bytes we've defragged. 811 * every time we choose not to defrag an extent, we reset *last_len 812 * so that the next tiny extent will force a defrag. 813 * 814 * The end result of this is that tiny extents before a single big 815 * extent will force at least part of that big extent to be defragged. 816 */ 817 if (ret) { 818 *defrag_end = extent_map_end(em); 819 } else { 820 *last_len = 0; 821 *skip = extent_map_end(em); 822 *defrag_end = 0; 823 } 824 825 free_extent_map(em); 826 return ret; 827 } 828 829 /* 830 * it doesn't do much good to defrag one or two pages 831 * at a time. This pulls in a nice chunk of pages 832 * to COW and defrag. 833 * 834 * It also makes sure the delalloc code has enough 835 * dirty data to avoid making new small extents as part 836 * of the defrag 837 * 838 * It's a good idea to start RA on this range 839 * before calling this. 840 */ 841 static int cluster_pages_for_defrag(struct inode *inode, 842 struct page **pages, 843 unsigned long start_index, 844 int num_pages) 845 { 846 unsigned long file_end; 847 u64 isize = i_size_read(inode); 848 u64 page_start; 849 u64 page_end; 850 int ret; 851 int i; 852 int i_done; 853 struct btrfs_ordered_extent *ordered; 854 struct extent_state *cached_state = NULL; 855 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); 856 857 if (isize == 0) 858 return 0; 859 file_end = (isize - 1) >> PAGE_CACHE_SHIFT; 860 861 mutex_lock(&inode->i_mutex); 862 ret = btrfs_delalloc_reserve_space(inode, 863 num_pages << PAGE_CACHE_SHIFT); 864 mutex_unlock(&inode->i_mutex); 865 if (ret) 866 return ret; 867 again: 868 ret = 0; 869 i_done = 0; 870 871 /* step one, lock all the pages */ 872 for (i = 0; i < num_pages; i++) { 873 struct page *page; 874 page = find_or_create_page(inode->i_mapping, 875 start_index + i, mask); 876 if (!page) 877 break; 878 879 if (!PageUptodate(page)) { 880 btrfs_readpage(NULL, page); 881 lock_page(page); 882 if (!PageUptodate(page)) { 883 unlock_page(page); 884 page_cache_release(page); 885 ret = -EIO; 886 break; 887 } 888 } 889 isize = i_size_read(inode); 890 file_end = (isize - 1) >> PAGE_CACHE_SHIFT; 891 if (!isize || page->index > file_end || 892 page->mapping != inode->i_mapping) { 893 /* whoops, we blew past eof, skip this page */ 894 unlock_page(page); 895 page_cache_release(page); 896 break; 897 } 898 pages[i] = page; 899 i_done++; 900 } 901 if (!i_done || ret) 902 goto out; 903 904 if (!(inode->i_sb->s_flags & MS_ACTIVE)) 905 goto out; 906 907 /* 908 * so now we have a nice long stream of locked 909 * and up to date pages, lets wait on them 910 */ 911 for (i = 0; i < i_done; i++) 912 wait_on_page_writeback(pages[i]); 913 914 page_start = page_offset(pages[0]); 915 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE; 916 917 lock_extent_bits(&BTRFS_I(inode)->io_tree, 918 page_start, page_end - 1, 0, &cached_state, 919 GFP_NOFS); 920 ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1); 921 if (ordered && 922 ordered->file_offset + ordered->len > page_start && 923 ordered->file_offset < page_end) { 924 btrfs_put_ordered_extent(ordered); 925 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 926 page_start, page_end - 1, 927 &cached_state, GFP_NOFS); 928 for (i = 0; i < i_done; i++) { 929 unlock_page(pages[i]); 930 page_cache_release(pages[i]); 931 } 932 btrfs_wait_ordered_range(inode, page_start, 933 page_end - page_start); 934 goto again; 935 } 936 if (ordered) 937 btrfs_put_ordered_extent(ordered); 938 939 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, 940 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC | 941 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, 942 GFP_NOFS); 943 944 if (i_done != num_pages) { 945 spin_lock(&BTRFS_I(inode)->lock); 946 BTRFS_I(inode)->outstanding_extents++; 947 spin_unlock(&BTRFS_I(inode)->lock); 948 btrfs_delalloc_release_space(inode, 949 (num_pages - i_done) << PAGE_CACHE_SHIFT); 950 } 951 952 953 btrfs_set_extent_delalloc(inode, page_start, page_end - 1, 954 &cached_state); 955 956 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 957 page_start, page_end - 1, &cached_state, 958 GFP_NOFS); 959 960 for (i = 0; i < i_done; i++) { 961 clear_page_dirty_for_io(pages[i]); 962 ClearPageChecked(pages[i]); 963 set_page_extent_mapped(pages[i]); 964 set_page_dirty(pages[i]); 965 unlock_page(pages[i]); 966 page_cache_release(pages[i]); 967 } 968 return i_done; 969 out: 970 for (i = 0; i < i_done; i++) { 971 unlock_page(pages[i]); 972 page_cache_release(pages[i]); 973 } 974 btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT); 975 return ret; 976 977 } 978 979 int btrfs_defrag_file(struct inode *inode, struct file *file, 980 struct btrfs_ioctl_defrag_range_args *range, 981 u64 newer_than, unsigned long max_to_defrag) 982 { 983 struct btrfs_root *root = BTRFS_I(inode)->root; 984 struct btrfs_super_block *disk_super; 985 struct file_ra_state *ra = NULL; 986 unsigned long last_index; 987 u64 isize = i_size_read(inode); 988 u64 features; 989 u64 last_len = 0; 990 u64 skip = 0; 991 u64 defrag_end = 0; 992 u64 newer_off = range->start; 993 unsigned long i; 994 unsigned long ra_index = 0; 995 int ret; 996 int defrag_count = 0; 997 int compress_type = BTRFS_COMPRESS_ZLIB; 998 int extent_thresh = range->extent_thresh; 999 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; 1000 int cluster = max_cluster; 1001 u64 new_align = ~((u64)128 * 1024 - 1); 1002 struct page **pages = NULL; 1003 1004 if (extent_thresh == 0) 1005 extent_thresh = 256 * 1024; 1006 1007 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) { 1008 if (range->compress_type > BTRFS_COMPRESS_TYPES) 1009 return -EINVAL; 1010 if (range->compress_type) 1011 compress_type = range->compress_type; 1012 } 1013 1014 if (isize == 0) 1015 return 0; 1016 1017 /* 1018 * if we were not given a file, allocate a readahead 1019 * context 1020 */ 1021 if (!file) { 1022 ra = kzalloc(sizeof(*ra), GFP_NOFS); 1023 if (!ra) 1024 return -ENOMEM; 1025 file_ra_state_init(ra, inode->i_mapping); 1026 } else { 1027 ra = &file->f_ra; 1028 } 1029 1030 pages = kmalloc(sizeof(struct page *) * max_cluster, 1031 GFP_NOFS); 1032 if (!pages) { 1033 ret = -ENOMEM; 1034 goto out_ra; 1035 } 1036 1037 /* find the last page to defrag */ 1038 if (range->start + range->len > range->start) { 1039 last_index = min_t(u64, isize - 1, 1040 range->start + range->len - 1) >> PAGE_CACHE_SHIFT; 1041 } else { 1042 last_index = (isize - 1) >> PAGE_CACHE_SHIFT; 1043 } 1044 1045 if (newer_than) { 1046 ret = find_new_extents(root, inode, newer_than, 1047 &newer_off, 64 * 1024); 1048 if (!ret) { 1049 range->start = newer_off; 1050 /* 1051 * we always align our defrag to help keep 1052 * the extents in the file evenly spaced 1053 */ 1054 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; 1055 } else 1056 goto out_ra; 1057 } else { 1058 i = range->start >> PAGE_CACHE_SHIFT; 1059 } 1060 if (!max_to_defrag) 1061 max_to_defrag = last_index; 1062 1063 /* 1064 * make writeback starts from i, so the defrag range can be 1065 * written sequentially. 1066 */ 1067 if (i < inode->i_mapping->writeback_index) 1068 inode->i_mapping->writeback_index = i; 1069 1070 while (i <= last_index && defrag_count < max_to_defrag && 1071 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> 1072 PAGE_CACHE_SHIFT)) { 1073 /* 1074 * make sure we stop running if someone unmounts 1075 * the FS 1076 */ 1077 if (!(inode->i_sb->s_flags & MS_ACTIVE)) 1078 break; 1079 1080 if (!newer_than && 1081 !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT, 1082 PAGE_CACHE_SIZE, 1083 extent_thresh, 1084 &last_len, &skip, 1085 &defrag_end)) { 1086 unsigned long next; 1087 /* 1088 * the should_defrag function tells us how much to skip 1089 * bump our counter by the suggested amount 1090 */ 1091 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 1092 i = max(i + 1, next); 1093 continue; 1094 } 1095 1096 if (!newer_than) { 1097 cluster = (PAGE_CACHE_ALIGN(defrag_end) >> 1098 PAGE_CACHE_SHIFT) - i; 1099 cluster = min(cluster, max_cluster); 1100 } else { 1101 cluster = max_cluster; 1102 } 1103 1104 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) 1105 BTRFS_I(inode)->force_compress = compress_type; 1106 1107 if (i + cluster > ra_index) { 1108 ra_index = max(i, ra_index); 1109 btrfs_force_ra(inode->i_mapping, ra, file, ra_index, 1110 cluster); 1111 ra_index += max_cluster; 1112 } 1113 1114 ret = cluster_pages_for_defrag(inode, pages, i, cluster); 1115 if (ret < 0) 1116 goto out_ra; 1117 1118 defrag_count += ret; 1119 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret); 1120 1121 if (newer_than) { 1122 if (newer_off == (u64)-1) 1123 break; 1124 1125 newer_off = max(newer_off + 1, 1126 (u64)i << PAGE_CACHE_SHIFT); 1127 1128 ret = find_new_extents(root, inode, 1129 newer_than, &newer_off, 1130 64 * 1024); 1131 if (!ret) { 1132 range->start = newer_off; 1133 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; 1134 } else { 1135 break; 1136 } 1137 } else { 1138 if (ret > 0) { 1139 i += ret; 1140 last_len += ret << PAGE_CACHE_SHIFT; 1141 } else { 1142 i++; 1143 last_len = 0; 1144 } 1145 } 1146 } 1147 1148 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) 1149 filemap_flush(inode->i_mapping); 1150 1151 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { 1152 /* the filemap_flush will queue IO into the worker threads, but 1153 * we have to make sure the IO is actually started and that 1154 * ordered extents get created before we return 1155 */ 1156 atomic_inc(&root->fs_info->async_submit_draining); 1157 while (atomic_read(&root->fs_info->nr_async_submits) || 1158 atomic_read(&root->fs_info->async_delalloc_pages)) { 1159 wait_event(root->fs_info->async_submit_wait, 1160 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 1161 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 1162 } 1163 atomic_dec(&root->fs_info->async_submit_draining); 1164 1165 mutex_lock(&inode->i_mutex); 1166 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; 1167 mutex_unlock(&inode->i_mutex); 1168 } 1169 1170 disk_super = root->fs_info->super_copy; 1171 features = btrfs_super_incompat_flags(disk_super); 1172 if (range->compress_type == BTRFS_COMPRESS_LZO) { 1173 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO; 1174 btrfs_set_super_incompat_flags(disk_super, features); 1175 } 1176 1177 ret = defrag_count; 1178 1179 out_ra: 1180 if (!file) 1181 kfree(ra); 1182 kfree(pages); 1183 return ret; 1184 } 1185 1186 static noinline int btrfs_ioctl_resize(struct btrfs_root *root, 1187 void __user *arg) 1188 { 1189 u64 new_size; 1190 u64 old_size; 1191 u64 devid = 1; 1192 struct btrfs_ioctl_vol_args *vol_args; 1193 struct btrfs_trans_handle *trans; 1194 struct btrfs_device *device = NULL; 1195 char *sizestr; 1196 char *devstr = NULL; 1197 int ret = 0; 1198 int mod = 0; 1199 1200 if (root->fs_info->sb->s_flags & MS_RDONLY) 1201 return -EROFS; 1202 1203 if (!capable(CAP_SYS_ADMIN)) 1204 return -EPERM; 1205 1206 vol_args = memdup_user(arg, sizeof(*vol_args)); 1207 if (IS_ERR(vol_args)) 1208 return PTR_ERR(vol_args); 1209 1210 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1211 1212 mutex_lock(&root->fs_info->volume_mutex); 1213 sizestr = vol_args->name; 1214 devstr = strchr(sizestr, ':'); 1215 if (devstr) { 1216 char *end; 1217 sizestr = devstr + 1; 1218 *devstr = '\0'; 1219 devstr = vol_args->name; 1220 devid = simple_strtoull(devstr, &end, 10); 1221 printk(KERN_INFO "btrfs: resizing devid %llu\n", 1222 (unsigned long long)devid); 1223 } 1224 device = btrfs_find_device(root, devid, NULL, NULL); 1225 if (!device) { 1226 printk(KERN_INFO "btrfs: resizer unable to find device %llu\n", 1227 (unsigned long long)devid); 1228 ret = -EINVAL; 1229 goto out_unlock; 1230 } 1231 if (!strcmp(sizestr, "max")) 1232 new_size = device->bdev->bd_inode->i_size; 1233 else { 1234 if (sizestr[0] == '-') { 1235 mod = -1; 1236 sizestr++; 1237 } else if (sizestr[0] == '+') { 1238 mod = 1; 1239 sizestr++; 1240 } 1241 new_size = memparse(sizestr, NULL); 1242 if (new_size == 0) { 1243 ret = -EINVAL; 1244 goto out_unlock; 1245 } 1246 } 1247 1248 old_size = device->total_bytes; 1249 1250 if (mod < 0) { 1251 if (new_size > old_size) { 1252 ret = -EINVAL; 1253 goto out_unlock; 1254 } 1255 new_size = old_size - new_size; 1256 } else if (mod > 0) { 1257 new_size = old_size + new_size; 1258 } 1259 1260 if (new_size < 256 * 1024 * 1024) { 1261 ret = -EINVAL; 1262 goto out_unlock; 1263 } 1264 if (new_size > device->bdev->bd_inode->i_size) { 1265 ret = -EFBIG; 1266 goto out_unlock; 1267 } 1268 1269 do_div(new_size, root->sectorsize); 1270 new_size *= root->sectorsize; 1271 1272 printk(KERN_INFO "btrfs: new size for %s is %llu\n", 1273 device->name, (unsigned long long)new_size); 1274 1275 if (new_size > old_size) { 1276 trans = btrfs_start_transaction(root, 0); 1277 if (IS_ERR(trans)) { 1278 ret = PTR_ERR(trans); 1279 goto out_unlock; 1280 } 1281 ret = btrfs_grow_device(trans, device, new_size); 1282 btrfs_commit_transaction(trans, root); 1283 } else if (new_size < old_size) { 1284 ret = btrfs_shrink_device(device, new_size); 1285 } 1286 1287 out_unlock: 1288 mutex_unlock(&root->fs_info->volume_mutex); 1289 kfree(vol_args); 1290 return ret; 1291 } 1292 1293 static noinline int btrfs_ioctl_snap_create_transid(struct file *file, 1294 char *name, 1295 unsigned long fd, 1296 int subvol, 1297 u64 *transid, 1298 bool readonly) 1299 { 1300 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 1301 struct file *src_file; 1302 int namelen; 1303 int ret = 0; 1304 1305 if (root->fs_info->sb->s_flags & MS_RDONLY) 1306 return -EROFS; 1307 1308 namelen = strlen(name); 1309 if (strchr(name, '/')) { 1310 ret = -EINVAL; 1311 goto out; 1312 } 1313 1314 if (subvol) { 1315 ret = btrfs_mksubvol(&file->f_path, name, namelen, 1316 NULL, transid, readonly); 1317 } else { 1318 struct inode *src_inode; 1319 src_file = fget(fd); 1320 if (!src_file) { 1321 ret = -EINVAL; 1322 goto out; 1323 } 1324 1325 src_inode = src_file->f_path.dentry->d_inode; 1326 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { 1327 printk(KERN_INFO "btrfs: Snapshot src from " 1328 "another FS\n"); 1329 ret = -EINVAL; 1330 fput(src_file); 1331 goto out; 1332 } 1333 ret = btrfs_mksubvol(&file->f_path, name, namelen, 1334 BTRFS_I(src_inode)->root, 1335 transid, readonly); 1336 fput(src_file); 1337 } 1338 out: 1339 return ret; 1340 } 1341 1342 static noinline int btrfs_ioctl_snap_create(struct file *file, 1343 void __user *arg, int subvol) 1344 { 1345 struct btrfs_ioctl_vol_args *vol_args; 1346 int ret; 1347 1348 vol_args = memdup_user(arg, sizeof(*vol_args)); 1349 if (IS_ERR(vol_args)) 1350 return PTR_ERR(vol_args); 1351 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1352 1353 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, 1354 vol_args->fd, subvol, 1355 NULL, false); 1356 1357 kfree(vol_args); 1358 return ret; 1359 } 1360 1361 static noinline int btrfs_ioctl_snap_create_v2(struct file *file, 1362 void __user *arg, int subvol) 1363 { 1364 struct btrfs_ioctl_vol_args_v2 *vol_args; 1365 int ret; 1366 u64 transid = 0; 1367 u64 *ptr = NULL; 1368 bool readonly = false; 1369 1370 vol_args = memdup_user(arg, sizeof(*vol_args)); 1371 if (IS_ERR(vol_args)) 1372 return PTR_ERR(vol_args); 1373 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0'; 1374 1375 if (vol_args->flags & 1376 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) { 1377 ret = -EOPNOTSUPP; 1378 goto out; 1379 } 1380 1381 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC) 1382 ptr = &transid; 1383 if (vol_args->flags & BTRFS_SUBVOL_RDONLY) 1384 readonly = true; 1385 1386 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, 1387 vol_args->fd, subvol, 1388 ptr, readonly); 1389 1390 if (ret == 0 && ptr && 1391 copy_to_user(arg + 1392 offsetof(struct btrfs_ioctl_vol_args_v2, 1393 transid), ptr, sizeof(*ptr))) 1394 ret = -EFAULT; 1395 out: 1396 kfree(vol_args); 1397 return ret; 1398 } 1399 1400 static noinline int btrfs_ioctl_subvol_getflags(struct file *file, 1401 void __user *arg) 1402 { 1403 struct inode *inode = fdentry(file)->d_inode; 1404 struct btrfs_root *root = BTRFS_I(inode)->root; 1405 int ret = 0; 1406 u64 flags = 0; 1407 1408 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) 1409 return -EINVAL; 1410 1411 down_read(&root->fs_info->subvol_sem); 1412 if (btrfs_root_readonly(root)) 1413 flags |= BTRFS_SUBVOL_RDONLY; 1414 up_read(&root->fs_info->subvol_sem); 1415 1416 if (copy_to_user(arg, &flags, sizeof(flags))) 1417 ret = -EFAULT; 1418 1419 return ret; 1420 } 1421 1422 static noinline int btrfs_ioctl_subvol_setflags(struct file *file, 1423 void __user *arg) 1424 { 1425 struct inode *inode = fdentry(file)->d_inode; 1426 struct btrfs_root *root = BTRFS_I(inode)->root; 1427 struct btrfs_trans_handle *trans; 1428 u64 root_flags; 1429 u64 flags; 1430 int ret = 0; 1431 1432 if (root->fs_info->sb->s_flags & MS_RDONLY) 1433 return -EROFS; 1434 1435 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) 1436 return -EINVAL; 1437 1438 if (copy_from_user(&flags, arg, sizeof(flags))) 1439 return -EFAULT; 1440 1441 if (flags & BTRFS_SUBVOL_CREATE_ASYNC) 1442 return -EINVAL; 1443 1444 if (flags & ~BTRFS_SUBVOL_RDONLY) 1445 return -EOPNOTSUPP; 1446 1447 if (!inode_owner_or_capable(inode)) 1448 return -EACCES; 1449 1450 down_write(&root->fs_info->subvol_sem); 1451 1452 /* nothing to do */ 1453 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root)) 1454 goto out; 1455 1456 root_flags = btrfs_root_flags(&root->root_item); 1457 if (flags & BTRFS_SUBVOL_RDONLY) 1458 btrfs_set_root_flags(&root->root_item, 1459 root_flags | BTRFS_ROOT_SUBVOL_RDONLY); 1460 else 1461 btrfs_set_root_flags(&root->root_item, 1462 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY); 1463 1464 trans = btrfs_start_transaction(root, 1); 1465 if (IS_ERR(trans)) { 1466 ret = PTR_ERR(trans); 1467 goto out_reset; 1468 } 1469 1470 ret = btrfs_update_root(trans, root->fs_info->tree_root, 1471 &root->root_key, &root->root_item); 1472 1473 btrfs_commit_transaction(trans, root); 1474 out_reset: 1475 if (ret) 1476 btrfs_set_root_flags(&root->root_item, root_flags); 1477 out: 1478 up_write(&root->fs_info->subvol_sem); 1479 return ret; 1480 } 1481 1482 /* 1483 * helper to check if the subvolume references other subvolumes 1484 */ 1485 static noinline int may_destroy_subvol(struct btrfs_root *root) 1486 { 1487 struct btrfs_path *path; 1488 struct btrfs_key key; 1489 int ret; 1490 1491 path = btrfs_alloc_path(); 1492 if (!path) 1493 return -ENOMEM; 1494 1495 key.objectid = root->root_key.objectid; 1496 key.type = BTRFS_ROOT_REF_KEY; 1497 key.offset = (u64)-1; 1498 1499 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, 1500 &key, path, 0, 0); 1501 if (ret < 0) 1502 goto out; 1503 BUG_ON(ret == 0); 1504 1505 ret = 0; 1506 if (path->slots[0] > 0) { 1507 path->slots[0]--; 1508 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1509 if (key.objectid == root->root_key.objectid && 1510 key.type == BTRFS_ROOT_REF_KEY) 1511 ret = -ENOTEMPTY; 1512 } 1513 out: 1514 btrfs_free_path(path); 1515 return ret; 1516 } 1517 1518 static noinline int key_in_sk(struct btrfs_key *key, 1519 struct btrfs_ioctl_search_key *sk) 1520 { 1521 struct btrfs_key test; 1522 int ret; 1523 1524 test.objectid = sk->min_objectid; 1525 test.type = sk->min_type; 1526 test.offset = sk->min_offset; 1527 1528 ret = btrfs_comp_cpu_keys(key, &test); 1529 if (ret < 0) 1530 return 0; 1531 1532 test.objectid = sk->max_objectid; 1533 test.type = sk->max_type; 1534 test.offset = sk->max_offset; 1535 1536 ret = btrfs_comp_cpu_keys(key, &test); 1537 if (ret > 0) 1538 return 0; 1539 return 1; 1540 } 1541 1542 static noinline int copy_to_sk(struct btrfs_root *root, 1543 struct btrfs_path *path, 1544 struct btrfs_key *key, 1545 struct btrfs_ioctl_search_key *sk, 1546 char *buf, 1547 unsigned long *sk_offset, 1548 int *num_found) 1549 { 1550 u64 found_transid; 1551 struct extent_buffer *leaf; 1552 struct btrfs_ioctl_search_header sh; 1553 unsigned long item_off; 1554 unsigned long item_len; 1555 int nritems; 1556 int i; 1557 int slot; 1558 int ret = 0; 1559 1560 leaf = path->nodes[0]; 1561 slot = path->slots[0]; 1562 nritems = btrfs_header_nritems(leaf); 1563 1564 if (btrfs_header_generation(leaf) > sk->max_transid) { 1565 i = nritems; 1566 goto advance_key; 1567 } 1568 found_transid = btrfs_header_generation(leaf); 1569 1570 for (i = slot; i < nritems; i++) { 1571 item_off = btrfs_item_ptr_offset(leaf, i); 1572 item_len = btrfs_item_size_nr(leaf, i); 1573 1574 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE) 1575 item_len = 0; 1576 1577 if (sizeof(sh) + item_len + *sk_offset > 1578 BTRFS_SEARCH_ARGS_BUFSIZE) { 1579 ret = 1; 1580 goto overflow; 1581 } 1582 1583 btrfs_item_key_to_cpu(leaf, key, i); 1584 if (!key_in_sk(key, sk)) 1585 continue; 1586 1587 sh.objectid = key->objectid; 1588 sh.offset = key->offset; 1589 sh.type = key->type; 1590 sh.len = item_len; 1591 sh.transid = found_transid; 1592 1593 /* copy search result header */ 1594 memcpy(buf + *sk_offset, &sh, sizeof(sh)); 1595 *sk_offset += sizeof(sh); 1596 1597 if (item_len) { 1598 char *p = buf + *sk_offset; 1599 /* copy the item */ 1600 read_extent_buffer(leaf, p, 1601 item_off, item_len); 1602 *sk_offset += item_len; 1603 } 1604 (*num_found)++; 1605 1606 if (*num_found >= sk->nr_items) 1607 break; 1608 } 1609 advance_key: 1610 ret = 0; 1611 if (key->offset < (u64)-1 && key->offset < sk->max_offset) 1612 key->offset++; 1613 else if (key->type < (u8)-1 && key->type < sk->max_type) { 1614 key->offset = 0; 1615 key->type++; 1616 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) { 1617 key->offset = 0; 1618 key->type = 0; 1619 key->objectid++; 1620 } else 1621 ret = 1; 1622 overflow: 1623 return ret; 1624 } 1625 1626 static noinline int search_ioctl(struct inode *inode, 1627 struct btrfs_ioctl_search_args *args) 1628 { 1629 struct btrfs_root *root; 1630 struct btrfs_key key; 1631 struct btrfs_key max_key; 1632 struct btrfs_path *path; 1633 struct btrfs_ioctl_search_key *sk = &args->key; 1634 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info; 1635 int ret; 1636 int num_found = 0; 1637 unsigned long sk_offset = 0; 1638 1639 path = btrfs_alloc_path(); 1640 if (!path) 1641 return -ENOMEM; 1642 1643 if (sk->tree_id == 0) { 1644 /* search the root of the inode that was passed */ 1645 root = BTRFS_I(inode)->root; 1646 } else { 1647 key.objectid = sk->tree_id; 1648 key.type = BTRFS_ROOT_ITEM_KEY; 1649 key.offset = (u64)-1; 1650 root = btrfs_read_fs_root_no_name(info, &key); 1651 if (IS_ERR(root)) { 1652 printk(KERN_ERR "could not find root %llu\n", 1653 sk->tree_id); 1654 btrfs_free_path(path); 1655 return -ENOENT; 1656 } 1657 } 1658 1659 key.objectid = sk->min_objectid; 1660 key.type = sk->min_type; 1661 key.offset = sk->min_offset; 1662 1663 max_key.objectid = sk->max_objectid; 1664 max_key.type = sk->max_type; 1665 max_key.offset = sk->max_offset; 1666 1667 path->keep_locks = 1; 1668 1669 while(1) { 1670 ret = btrfs_search_forward(root, &key, &max_key, path, 0, 1671 sk->min_transid); 1672 if (ret != 0) { 1673 if (ret > 0) 1674 ret = 0; 1675 goto err; 1676 } 1677 ret = copy_to_sk(root, path, &key, sk, args->buf, 1678 &sk_offset, &num_found); 1679 btrfs_release_path(path); 1680 if (ret || num_found >= sk->nr_items) 1681 break; 1682 1683 } 1684 ret = 0; 1685 err: 1686 sk->nr_items = num_found; 1687 btrfs_free_path(path); 1688 return ret; 1689 } 1690 1691 static noinline int btrfs_ioctl_tree_search(struct file *file, 1692 void __user *argp) 1693 { 1694 struct btrfs_ioctl_search_args *args; 1695 struct inode *inode; 1696 int ret; 1697 1698 if (!capable(CAP_SYS_ADMIN)) 1699 return -EPERM; 1700 1701 args = memdup_user(argp, sizeof(*args)); 1702 if (IS_ERR(args)) 1703 return PTR_ERR(args); 1704 1705 inode = fdentry(file)->d_inode; 1706 ret = search_ioctl(inode, args); 1707 if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) 1708 ret = -EFAULT; 1709 kfree(args); 1710 return ret; 1711 } 1712 1713 /* 1714 * Search INODE_REFs to identify path name of 'dirid' directory 1715 * in a 'tree_id' tree. and sets path name to 'name'. 1716 */ 1717 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info, 1718 u64 tree_id, u64 dirid, char *name) 1719 { 1720 struct btrfs_root *root; 1721 struct btrfs_key key; 1722 char *ptr; 1723 int ret = -1; 1724 int slot; 1725 int len; 1726 int total_len = 0; 1727 struct btrfs_inode_ref *iref; 1728 struct extent_buffer *l; 1729 struct btrfs_path *path; 1730 1731 if (dirid == BTRFS_FIRST_FREE_OBJECTID) { 1732 name[0]='\0'; 1733 return 0; 1734 } 1735 1736 path = btrfs_alloc_path(); 1737 if (!path) 1738 return -ENOMEM; 1739 1740 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX]; 1741 1742 key.objectid = tree_id; 1743 key.type = BTRFS_ROOT_ITEM_KEY; 1744 key.offset = (u64)-1; 1745 root = btrfs_read_fs_root_no_name(info, &key); 1746 if (IS_ERR(root)) { 1747 printk(KERN_ERR "could not find root %llu\n", tree_id); 1748 ret = -ENOENT; 1749 goto out; 1750 } 1751 1752 key.objectid = dirid; 1753 key.type = BTRFS_INODE_REF_KEY; 1754 key.offset = (u64)-1; 1755 1756 while(1) { 1757 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1758 if (ret < 0) 1759 goto out; 1760 1761 l = path->nodes[0]; 1762 slot = path->slots[0]; 1763 if (ret > 0 && slot > 0) 1764 slot--; 1765 btrfs_item_key_to_cpu(l, &key, slot); 1766 1767 if (ret > 0 && (key.objectid != dirid || 1768 key.type != BTRFS_INODE_REF_KEY)) { 1769 ret = -ENOENT; 1770 goto out; 1771 } 1772 1773 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref); 1774 len = btrfs_inode_ref_name_len(l, iref); 1775 ptr -= len + 1; 1776 total_len += len + 1; 1777 if (ptr < name) 1778 goto out; 1779 1780 *(ptr + len) = '/'; 1781 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len); 1782 1783 if (key.offset == BTRFS_FIRST_FREE_OBJECTID) 1784 break; 1785 1786 btrfs_release_path(path); 1787 key.objectid = key.offset; 1788 key.offset = (u64)-1; 1789 dirid = key.objectid; 1790 } 1791 if (ptr < name) 1792 goto out; 1793 memmove(name, ptr, total_len); 1794 name[total_len]='\0'; 1795 ret = 0; 1796 out: 1797 btrfs_free_path(path); 1798 return ret; 1799 } 1800 1801 static noinline int btrfs_ioctl_ino_lookup(struct file *file, 1802 void __user *argp) 1803 { 1804 struct btrfs_ioctl_ino_lookup_args *args; 1805 struct inode *inode; 1806 int ret; 1807 1808 if (!capable(CAP_SYS_ADMIN)) 1809 return -EPERM; 1810 1811 args = memdup_user(argp, sizeof(*args)); 1812 if (IS_ERR(args)) 1813 return PTR_ERR(args); 1814 1815 inode = fdentry(file)->d_inode; 1816 1817 if (args->treeid == 0) 1818 args->treeid = BTRFS_I(inode)->root->root_key.objectid; 1819 1820 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info, 1821 args->treeid, args->objectid, 1822 args->name); 1823 1824 if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) 1825 ret = -EFAULT; 1826 1827 kfree(args); 1828 return ret; 1829 } 1830 1831 static noinline int btrfs_ioctl_snap_destroy(struct file *file, 1832 void __user *arg) 1833 { 1834 struct dentry *parent = fdentry(file); 1835 struct dentry *dentry; 1836 struct inode *dir = parent->d_inode; 1837 struct inode *inode; 1838 struct btrfs_root *root = BTRFS_I(dir)->root; 1839 struct btrfs_root *dest = NULL; 1840 struct btrfs_ioctl_vol_args *vol_args; 1841 struct btrfs_trans_handle *trans; 1842 int namelen; 1843 int ret; 1844 int err = 0; 1845 1846 vol_args = memdup_user(arg, sizeof(*vol_args)); 1847 if (IS_ERR(vol_args)) 1848 return PTR_ERR(vol_args); 1849 1850 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1851 namelen = strlen(vol_args->name); 1852 if (strchr(vol_args->name, '/') || 1853 strncmp(vol_args->name, "..", namelen) == 0) { 1854 err = -EINVAL; 1855 goto out; 1856 } 1857 1858 err = mnt_want_write_file(file); 1859 if (err) 1860 goto out; 1861 1862 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 1863 dentry = lookup_one_len(vol_args->name, parent, namelen); 1864 if (IS_ERR(dentry)) { 1865 err = PTR_ERR(dentry); 1866 goto out_unlock_dir; 1867 } 1868 1869 if (!dentry->d_inode) { 1870 err = -ENOENT; 1871 goto out_dput; 1872 } 1873 1874 inode = dentry->d_inode; 1875 dest = BTRFS_I(inode)->root; 1876 if (!capable(CAP_SYS_ADMIN)){ 1877 /* 1878 * Regular user. Only allow this with a special mount 1879 * option, when the user has write+exec access to the 1880 * subvol root, and when rmdir(2) would have been 1881 * allowed. 1882 * 1883 * Note that this is _not_ check that the subvol is 1884 * empty or doesn't contain data that we wouldn't 1885 * otherwise be able to delete. 1886 * 1887 * Users who want to delete empty subvols should try 1888 * rmdir(2). 1889 */ 1890 err = -EPERM; 1891 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 1892 goto out_dput; 1893 1894 /* 1895 * Do not allow deletion if the parent dir is the same 1896 * as the dir to be deleted. That means the ioctl 1897 * must be called on the dentry referencing the root 1898 * of the subvol, not a random directory contained 1899 * within it. 1900 */ 1901 err = -EINVAL; 1902 if (root == dest) 1903 goto out_dput; 1904 1905 err = inode_permission(inode, MAY_WRITE | MAY_EXEC); 1906 if (err) 1907 goto out_dput; 1908 1909 /* check if subvolume may be deleted by a non-root user */ 1910 err = btrfs_may_delete(dir, dentry, 1); 1911 if (err) 1912 goto out_dput; 1913 } 1914 1915 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) { 1916 err = -EINVAL; 1917 goto out_dput; 1918 } 1919 1920 mutex_lock(&inode->i_mutex); 1921 err = d_invalidate(dentry); 1922 if (err) 1923 goto out_unlock; 1924 1925 down_write(&root->fs_info->subvol_sem); 1926 1927 err = may_destroy_subvol(dest); 1928 if (err) 1929 goto out_up_write; 1930 1931 trans = btrfs_start_transaction(root, 0); 1932 if (IS_ERR(trans)) { 1933 err = PTR_ERR(trans); 1934 goto out_up_write; 1935 } 1936 trans->block_rsv = &root->fs_info->global_block_rsv; 1937 1938 ret = btrfs_unlink_subvol(trans, root, dir, 1939 dest->root_key.objectid, 1940 dentry->d_name.name, 1941 dentry->d_name.len); 1942 BUG_ON(ret); 1943 1944 btrfs_record_root_in_trans(trans, dest); 1945 1946 memset(&dest->root_item.drop_progress, 0, 1947 sizeof(dest->root_item.drop_progress)); 1948 dest->root_item.drop_level = 0; 1949 btrfs_set_root_refs(&dest->root_item, 0); 1950 1951 if (!xchg(&dest->orphan_item_inserted, 1)) { 1952 ret = btrfs_insert_orphan_item(trans, 1953 root->fs_info->tree_root, 1954 dest->root_key.objectid); 1955 BUG_ON(ret); 1956 } 1957 1958 ret = btrfs_end_transaction(trans, root); 1959 BUG_ON(ret); 1960 inode->i_flags |= S_DEAD; 1961 out_up_write: 1962 up_write(&root->fs_info->subvol_sem); 1963 out_unlock: 1964 mutex_unlock(&inode->i_mutex); 1965 if (!err) { 1966 shrink_dcache_sb(root->fs_info->sb); 1967 btrfs_invalidate_inodes(dest); 1968 d_delete(dentry); 1969 } 1970 out_dput: 1971 dput(dentry); 1972 out_unlock_dir: 1973 mutex_unlock(&dir->i_mutex); 1974 mnt_drop_write_file(file); 1975 out: 1976 kfree(vol_args); 1977 return err; 1978 } 1979 1980 static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 1981 { 1982 struct inode *inode = fdentry(file)->d_inode; 1983 struct btrfs_root *root = BTRFS_I(inode)->root; 1984 struct btrfs_ioctl_defrag_range_args *range; 1985 int ret; 1986 1987 if (btrfs_root_readonly(root)) 1988 return -EROFS; 1989 1990 ret = mnt_want_write_file(file); 1991 if (ret) 1992 return ret; 1993 1994 switch (inode->i_mode & S_IFMT) { 1995 case S_IFDIR: 1996 if (!capable(CAP_SYS_ADMIN)) { 1997 ret = -EPERM; 1998 goto out; 1999 } 2000 ret = btrfs_defrag_root(root, 0); 2001 if (ret) 2002 goto out; 2003 ret = btrfs_defrag_root(root->fs_info->extent_root, 0); 2004 break; 2005 case S_IFREG: 2006 if (!(file->f_mode & FMODE_WRITE)) { 2007 ret = -EINVAL; 2008 goto out; 2009 } 2010 2011 range = kzalloc(sizeof(*range), GFP_KERNEL); 2012 if (!range) { 2013 ret = -ENOMEM; 2014 goto out; 2015 } 2016 2017 if (argp) { 2018 if (copy_from_user(range, argp, 2019 sizeof(*range))) { 2020 ret = -EFAULT; 2021 kfree(range); 2022 goto out; 2023 } 2024 /* compression requires us to start the IO */ 2025 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { 2026 range->flags |= BTRFS_DEFRAG_RANGE_START_IO; 2027 range->extent_thresh = (u32)-1; 2028 } 2029 } else { 2030 /* the rest are all set to zero by kzalloc */ 2031 range->len = (u64)-1; 2032 } 2033 ret = btrfs_defrag_file(fdentry(file)->d_inode, file, 2034 range, 0, 0); 2035 if (ret > 0) 2036 ret = 0; 2037 kfree(range); 2038 break; 2039 default: 2040 ret = -EINVAL; 2041 } 2042 out: 2043 mnt_drop_write_file(file); 2044 return ret; 2045 } 2046 2047 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 2048 { 2049 struct btrfs_ioctl_vol_args *vol_args; 2050 int ret; 2051 2052 if (!capable(CAP_SYS_ADMIN)) 2053 return -EPERM; 2054 2055 vol_args = memdup_user(arg, sizeof(*vol_args)); 2056 if (IS_ERR(vol_args)) 2057 return PTR_ERR(vol_args); 2058 2059 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2060 ret = btrfs_init_new_device(root, vol_args->name); 2061 2062 kfree(vol_args); 2063 return ret; 2064 } 2065 2066 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 2067 { 2068 struct btrfs_ioctl_vol_args *vol_args; 2069 int ret; 2070 2071 if (!capable(CAP_SYS_ADMIN)) 2072 return -EPERM; 2073 2074 if (root->fs_info->sb->s_flags & MS_RDONLY) 2075 return -EROFS; 2076 2077 vol_args = memdup_user(arg, sizeof(*vol_args)); 2078 if (IS_ERR(vol_args)) 2079 return PTR_ERR(vol_args); 2080 2081 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2082 ret = btrfs_rm_device(root, vol_args->name); 2083 2084 kfree(vol_args); 2085 return ret; 2086 } 2087 2088 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) 2089 { 2090 struct btrfs_ioctl_fs_info_args *fi_args; 2091 struct btrfs_device *device; 2092 struct btrfs_device *next; 2093 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 2094 int ret = 0; 2095 2096 if (!capable(CAP_SYS_ADMIN)) 2097 return -EPERM; 2098 2099 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL); 2100 if (!fi_args) 2101 return -ENOMEM; 2102 2103 fi_args->num_devices = fs_devices->num_devices; 2104 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); 2105 2106 mutex_lock(&fs_devices->device_list_mutex); 2107 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { 2108 if (device->devid > fi_args->max_id) 2109 fi_args->max_id = device->devid; 2110 } 2111 mutex_unlock(&fs_devices->device_list_mutex); 2112 2113 if (copy_to_user(arg, fi_args, sizeof(*fi_args))) 2114 ret = -EFAULT; 2115 2116 kfree(fi_args); 2117 return ret; 2118 } 2119 2120 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg) 2121 { 2122 struct btrfs_ioctl_dev_info_args *di_args; 2123 struct btrfs_device *dev; 2124 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 2125 int ret = 0; 2126 char *s_uuid = NULL; 2127 char empty_uuid[BTRFS_UUID_SIZE] = {0}; 2128 2129 if (!capable(CAP_SYS_ADMIN)) 2130 return -EPERM; 2131 2132 di_args = memdup_user(arg, sizeof(*di_args)); 2133 if (IS_ERR(di_args)) 2134 return PTR_ERR(di_args); 2135 2136 if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0) 2137 s_uuid = di_args->uuid; 2138 2139 mutex_lock(&fs_devices->device_list_mutex); 2140 dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL); 2141 mutex_unlock(&fs_devices->device_list_mutex); 2142 2143 if (!dev) { 2144 ret = -ENODEV; 2145 goto out; 2146 } 2147 2148 di_args->devid = dev->devid; 2149 di_args->bytes_used = dev->bytes_used; 2150 di_args->total_bytes = dev->total_bytes; 2151 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid)); 2152 strncpy(di_args->path, dev->name, sizeof(di_args->path)); 2153 2154 out: 2155 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args))) 2156 ret = -EFAULT; 2157 2158 kfree(di_args); 2159 return ret; 2160 } 2161 2162 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 2163 u64 off, u64 olen, u64 destoff) 2164 { 2165 struct inode *inode = fdentry(file)->d_inode; 2166 struct btrfs_root *root = BTRFS_I(inode)->root; 2167 struct file *src_file; 2168 struct inode *src; 2169 struct btrfs_trans_handle *trans; 2170 struct btrfs_path *path; 2171 struct extent_buffer *leaf; 2172 char *buf; 2173 struct btrfs_key key; 2174 u32 nritems; 2175 int slot; 2176 int ret; 2177 u64 len = olen; 2178 u64 bs = root->fs_info->sb->s_blocksize; 2179 u64 hint_byte; 2180 2181 /* 2182 * TODO: 2183 * - split compressed inline extents. annoying: we need to 2184 * decompress into destination's address_space (the file offset 2185 * may change, so source mapping won't do), then recompress (or 2186 * otherwise reinsert) a subrange. 2187 * - allow ranges within the same file to be cloned (provided 2188 * they don't overlap)? 2189 */ 2190 2191 /* the destination must be opened for writing */ 2192 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND)) 2193 return -EINVAL; 2194 2195 if (btrfs_root_readonly(root)) 2196 return -EROFS; 2197 2198 ret = mnt_want_write_file(file); 2199 if (ret) 2200 return ret; 2201 2202 src_file = fget(srcfd); 2203 if (!src_file) { 2204 ret = -EBADF; 2205 goto out_drop_write; 2206 } 2207 2208 src = src_file->f_dentry->d_inode; 2209 2210 ret = -EINVAL; 2211 if (src == inode) 2212 goto out_fput; 2213 2214 /* the src must be open for reading */ 2215 if (!(src_file->f_mode & FMODE_READ)) 2216 goto out_fput; 2217 2218 /* don't make the dst file partly checksummed */ 2219 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) != 2220 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) 2221 goto out_fput; 2222 2223 ret = -EISDIR; 2224 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 2225 goto out_fput; 2226 2227 ret = -EXDEV; 2228 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) 2229 goto out_fput; 2230 2231 ret = -ENOMEM; 2232 buf = vmalloc(btrfs_level_size(root, 0)); 2233 if (!buf) 2234 goto out_fput; 2235 2236 path = btrfs_alloc_path(); 2237 if (!path) { 2238 vfree(buf); 2239 goto out_fput; 2240 } 2241 path->reada = 2; 2242 2243 if (inode < src) { 2244 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); 2245 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD); 2246 } else { 2247 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT); 2248 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); 2249 } 2250 2251 /* determine range to clone */ 2252 ret = -EINVAL; 2253 if (off + len > src->i_size || off + len < off) 2254 goto out_unlock; 2255 if (len == 0) 2256 olen = len = src->i_size - off; 2257 /* if we extend to eof, continue to block boundary */ 2258 if (off + len == src->i_size) 2259 len = ALIGN(src->i_size, bs) - off; 2260 2261 /* verify the end result is block aligned */ 2262 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) || 2263 !IS_ALIGNED(destoff, bs)) 2264 goto out_unlock; 2265 2266 if (destoff > inode->i_size) { 2267 ret = btrfs_cont_expand(inode, inode->i_size, destoff); 2268 if (ret) 2269 goto out_unlock; 2270 } 2271 2272 /* truncate page cache pages from target inode range */ 2273 truncate_inode_pages_range(&inode->i_data, destoff, 2274 PAGE_CACHE_ALIGN(destoff + len) - 1); 2275 2276 /* do any pending delalloc/csum calc on src, one way or 2277 another, and lock file content */ 2278 while (1) { 2279 struct btrfs_ordered_extent *ordered; 2280 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 2281 ordered = btrfs_lookup_first_ordered_extent(src, off+len); 2282 if (!ordered && 2283 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len, 2284 EXTENT_DELALLOC, 0, NULL)) 2285 break; 2286 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 2287 if (ordered) 2288 btrfs_put_ordered_extent(ordered); 2289 btrfs_wait_ordered_range(src, off, len); 2290 } 2291 2292 /* clone data */ 2293 key.objectid = btrfs_ino(src); 2294 key.type = BTRFS_EXTENT_DATA_KEY; 2295 key.offset = 0; 2296 2297 while (1) { 2298 /* 2299 * note the key will change type as we walk through the 2300 * tree. 2301 */ 2302 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2303 if (ret < 0) 2304 goto out; 2305 2306 nritems = btrfs_header_nritems(path->nodes[0]); 2307 if (path->slots[0] >= nritems) { 2308 ret = btrfs_next_leaf(root, path); 2309 if (ret < 0) 2310 goto out; 2311 if (ret > 0) 2312 break; 2313 nritems = btrfs_header_nritems(path->nodes[0]); 2314 } 2315 leaf = path->nodes[0]; 2316 slot = path->slots[0]; 2317 2318 btrfs_item_key_to_cpu(leaf, &key, slot); 2319 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 2320 key.objectid != btrfs_ino(src)) 2321 break; 2322 2323 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 2324 struct btrfs_file_extent_item *extent; 2325 int type; 2326 u32 size; 2327 struct btrfs_key new_key; 2328 u64 disko = 0, diskl = 0; 2329 u64 datao = 0, datal = 0; 2330 u8 comp; 2331 u64 endoff; 2332 2333 size = btrfs_item_size_nr(leaf, slot); 2334 read_extent_buffer(leaf, buf, 2335 btrfs_item_ptr_offset(leaf, slot), 2336 size); 2337 2338 extent = btrfs_item_ptr(leaf, slot, 2339 struct btrfs_file_extent_item); 2340 comp = btrfs_file_extent_compression(leaf, extent); 2341 type = btrfs_file_extent_type(leaf, extent); 2342 if (type == BTRFS_FILE_EXTENT_REG || 2343 type == BTRFS_FILE_EXTENT_PREALLOC) { 2344 disko = btrfs_file_extent_disk_bytenr(leaf, 2345 extent); 2346 diskl = btrfs_file_extent_disk_num_bytes(leaf, 2347 extent); 2348 datao = btrfs_file_extent_offset(leaf, extent); 2349 datal = btrfs_file_extent_num_bytes(leaf, 2350 extent); 2351 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 2352 /* take upper bound, may be compressed */ 2353 datal = btrfs_file_extent_ram_bytes(leaf, 2354 extent); 2355 } 2356 btrfs_release_path(path); 2357 2358 if (key.offset + datal <= off || 2359 key.offset >= off+len) 2360 goto next; 2361 2362 memcpy(&new_key, &key, sizeof(new_key)); 2363 new_key.objectid = btrfs_ino(inode); 2364 if (off <= key.offset) 2365 new_key.offset = key.offset + destoff - off; 2366 else 2367 new_key.offset = destoff; 2368 2369 /* 2370 * 1 - adjusting old extent (we may have to split it) 2371 * 1 - add new extent 2372 * 1 - inode update 2373 */ 2374 trans = btrfs_start_transaction(root, 3); 2375 if (IS_ERR(trans)) { 2376 ret = PTR_ERR(trans); 2377 goto out; 2378 } 2379 2380 if (type == BTRFS_FILE_EXTENT_REG || 2381 type == BTRFS_FILE_EXTENT_PREALLOC) { 2382 /* 2383 * a | --- range to clone ---| b 2384 * | ------------- extent ------------- | 2385 */ 2386 2387 /* substract range b */ 2388 if (key.offset + datal > off + len) 2389 datal = off + len - key.offset; 2390 2391 /* substract range a */ 2392 if (off > key.offset) { 2393 datao += off - key.offset; 2394 datal -= off - key.offset; 2395 } 2396 2397 ret = btrfs_drop_extents(trans, inode, 2398 new_key.offset, 2399 new_key.offset + datal, 2400 &hint_byte, 1); 2401 BUG_ON(ret); 2402 2403 ret = btrfs_insert_empty_item(trans, root, path, 2404 &new_key, size); 2405 BUG_ON(ret); 2406 2407 leaf = path->nodes[0]; 2408 slot = path->slots[0]; 2409 write_extent_buffer(leaf, buf, 2410 btrfs_item_ptr_offset(leaf, slot), 2411 size); 2412 2413 extent = btrfs_item_ptr(leaf, slot, 2414 struct btrfs_file_extent_item); 2415 2416 /* disko == 0 means it's a hole */ 2417 if (!disko) 2418 datao = 0; 2419 2420 btrfs_set_file_extent_offset(leaf, extent, 2421 datao); 2422 btrfs_set_file_extent_num_bytes(leaf, extent, 2423 datal); 2424 if (disko) { 2425 inode_add_bytes(inode, datal); 2426 ret = btrfs_inc_extent_ref(trans, root, 2427 disko, diskl, 0, 2428 root->root_key.objectid, 2429 btrfs_ino(inode), 2430 new_key.offset - datao); 2431 BUG_ON(ret); 2432 } 2433 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 2434 u64 skip = 0; 2435 u64 trim = 0; 2436 if (off > key.offset) { 2437 skip = off - key.offset; 2438 new_key.offset += skip; 2439 } 2440 2441 if (key.offset + datal > off+len) 2442 trim = key.offset + datal - (off+len); 2443 2444 if (comp && (skip || trim)) { 2445 ret = -EINVAL; 2446 btrfs_end_transaction(trans, root); 2447 goto out; 2448 } 2449 size -= skip + trim; 2450 datal -= skip + trim; 2451 2452 ret = btrfs_drop_extents(trans, inode, 2453 new_key.offset, 2454 new_key.offset + datal, 2455 &hint_byte, 1); 2456 BUG_ON(ret); 2457 2458 ret = btrfs_insert_empty_item(trans, root, path, 2459 &new_key, size); 2460 BUG_ON(ret); 2461 2462 if (skip) { 2463 u32 start = 2464 btrfs_file_extent_calc_inline_size(0); 2465 memmove(buf+start, buf+start+skip, 2466 datal); 2467 } 2468 2469 leaf = path->nodes[0]; 2470 slot = path->slots[0]; 2471 write_extent_buffer(leaf, buf, 2472 btrfs_item_ptr_offset(leaf, slot), 2473 size); 2474 inode_add_bytes(inode, datal); 2475 } 2476 2477 btrfs_mark_buffer_dirty(leaf); 2478 btrfs_release_path(path); 2479 2480 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 2481 2482 /* 2483 * we round up to the block size at eof when 2484 * determining which extents to clone above, 2485 * but shouldn't round up the file size 2486 */ 2487 endoff = new_key.offset + datal; 2488 if (endoff > destoff+olen) 2489 endoff = destoff+olen; 2490 if (endoff > inode->i_size) 2491 btrfs_i_size_write(inode, endoff); 2492 2493 ret = btrfs_update_inode(trans, root, inode); 2494 BUG_ON(ret); 2495 btrfs_end_transaction(trans, root); 2496 } 2497 next: 2498 btrfs_release_path(path); 2499 key.offset++; 2500 } 2501 ret = 0; 2502 out: 2503 btrfs_release_path(path); 2504 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 2505 out_unlock: 2506 mutex_unlock(&src->i_mutex); 2507 mutex_unlock(&inode->i_mutex); 2508 vfree(buf); 2509 btrfs_free_path(path); 2510 out_fput: 2511 fput(src_file); 2512 out_drop_write: 2513 mnt_drop_write_file(file); 2514 return ret; 2515 } 2516 2517 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 2518 { 2519 struct btrfs_ioctl_clone_range_args args; 2520 2521 if (copy_from_user(&args, argp, sizeof(args))) 2522 return -EFAULT; 2523 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 2524 args.src_length, args.dest_offset); 2525 } 2526 2527 /* 2528 * there are many ways the trans_start and trans_end ioctls can lead 2529 * to deadlocks. They should only be used by applications that 2530 * basically own the machine, and have a very in depth understanding 2531 * of all the possible deadlocks and enospc problems. 2532 */ 2533 static long btrfs_ioctl_trans_start(struct file *file) 2534 { 2535 struct inode *inode = fdentry(file)->d_inode; 2536 struct btrfs_root *root = BTRFS_I(inode)->root; 2537 struct btrfs_trans_handle *trans; 2538 int ret; 2539 2540 ret = -EPERM; 2541 if (!capable(CAP_SYS_ADMIN)) 2542 goto out; 2543 2544 ret = -EINPROGRESS; 2545 if (file->private_data) 2546 goto out; 2547 2548 ret = -EROFS; 2549 if (btrfs_root_readonly(root)) 2550 goto out; 2551 2552 ret = mnt_want_write_file(file); 2553 if (ret) 2554 goto out; 2555 2556 atomic_inc(&root->fs_info->open_ioctl_trans); 2557 2558 ret = -ENOMEM; 2559 trans = btrfs_start_ioctl_transaction(root); 2560 if (IS_ERR(trans)) 2561 goto out_drop; 2562 2563 file->private_data = trans; 2564 return 0; 2565 2566 out_drop: 2567 atomic_dec(&root->fs_info->open_ioctl_trans); 2568 mnt_drop_write_file(file); 2569 out: 2570 return ret; 2571 } 2572 2573 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) 2574 { 2575 struct inode *inode = fdentry(file)->d_inode; 2576 struct btrfs_root *root = BTRFS_I(inode)->root; 2577 struct btrfs_root *new_root; 2578 struct btrfs_dir_item *di; 2579 struct btrfs_trans_handle *trans; 2580 struct btrfs_path *path; 2581 struct btrfs_key location; 2582 struct btrfs_disk_key disk_key; 2583 struct btrfs_super_block *disk_super; 2584 u64 features; 2585 u64 objectid = 0; 2586 u64 dir_id; 2587 2588 if (!capable(CAP_SYS_ADMIN)) 2589 return -EPERM; 2590 2591 if (copy_from_user(&objectid, argp, sizeof(objectid))) 2592 return -EFAULT; 2593 2594 if (!objectid) 2595 objectid = root->root_key.objectid; 2596 2597 location.objectid = objectid; 2598 location.type = BTRFS_ROOT_ITEM_KEY; 2599 location.offset = (u64)-1; 2600 2601 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 2602 if (IS_ERR(new_root)) 2603 return PTR_ERR(new_root); 2604 2605 if (btrfs_root_refs(&new_root->root_item) == 0) 2606 return -ENOENT; 2607 2608 path = btrfs_alloc_path(); 2609 if (!path) 2610 return -ENOMEM; 2611 path->leave_spinning = 1; 2612 2613 trans = btrfs_start_transaction(root, 1); 2614 if (IS_ERR(trans)) { 2615 btrfs_free_path(path); 2616 return PTR_ERR(trans); 2617 } 2618 2619 dir_id = btrfs_super_root_dir(root->fs_info->super_copy); 2620 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path, 2621 dir_id, "default", 7, 1); 2622 if (IS_ERR_OR_NULL(di)) { 2623 btrfs_free_path(path); 2624 btrfs_end_transaction(trans, root); 2625 printk(KERN_ERR "Umm, you don't have the default dir item, " 2626 "this isn't going to work\n"); 2627 return -ENOENT; 2628 } 2629 2630 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); 2631 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key); 2632 btrfs_mark_buffer_dirty(path->nodes[0]); 2633 btrfs_free_path(path); 2634 2635 disk_super = root->fs_info->super_copy; 2636 features = btrfs_super_incompat_flags(disk_super); 2637 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) { 2638 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL; 2639 btrfs_set_super_incompat_flags(disk_super, features); 2640 } 2641 btrfs_end_transaction(trans, root); 2642 2643 return 0; 2644 } 2645 2646 static void get_block_group_info(struct list_head *groups_list, 2647 struct btrfs_ioctl_space_info *space) 2648 { 2649 struct btrfs_block_group_cache *block_group; 2650 2651 space->total_bytes = 0; 2652 space->used_bytes = 0; 2653 space->flags = 0; 2654 list_for_each_entry(block_group, groups_list, list) { 2655 space->flags = block_group->flags; 2656 space->total_bytes += block_group->key.offset; 2657 space->used_bytes += 2658 btrfs_block_group_used(&block_group->item); 2659 } 2660 } 2661 2662 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg) 2663 { 2664 struct btrfs_ioctl_space_args space_args; 2665 struct btrfs_ioctl_space_info space; 2666 struct btrfs_ioctl_space_info *dest; 2667 struct btrfs_ioctl_space_info *dest_orig; 2668 struct btrfs_ioctl_space_info __user *user_dest; 2669 struct btrfs_space_info *info; 2670 u64 types[] = {BTRFS_BLOCK_GROUP_DATA, 2671 BTRFS_BLOCK_GROUP_SYSTEM, 2672 BTRFS_BLOCK_GROUP_METADATA, 2673 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA}; 2674 int num_types = 4; 2675 int alloc_size; 2676 int ret = 0; 2677 u64 slot_count = 0; 2678 int i, c; 2679 2680 if (copy_from_user(&space_args, 2681 (struct btrfs_ioctl_space_args __user *)arg, 2682 sizeof(space_args))) 2683 return -EFAULT; 2684 2685 for (i = 0; i < num_types; i++) { 2686 struct btrfs_space_info *tmp; 2687 2688 info = NULL; 2689 rcu_read_lock(); 2690 list_for_each_entry_rcu(tmp, &root->fs_info->space_info, 2691 list) { 2692 if (tmp->flags == types[i]) { 2693 info = tmp; 2694 break; 2695 } 2696 } 2697 rcu_read_unlock(); 2698 2699 if (!info) 2700 continue; 2701 2702 down_read(&info->groups_sem); 2703 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { 2704 if (!list_empty(&info->block_groups[c])) 2705 slot_count++; 2706 } 2707 up_read(&info->groups_sem); 2708 } 2709 2710 /* space_slots == 0 means they are asking for a count */ 2711 if (space_args.space_slots == 0) { 2712 space_args.total_spaces = slot_count; 2713 goto out; 2714 } 2715 2716 slot_count = min_t(u64, space_args.space_slots, slot_count); 2717 2718 alloc_size = sizeof(*dest) * slot_count; 2719 2720 /* we generally have at most 6 or so space infos, one for each raid 2721 * level. So, a whole page should be more than enough for everyone 2722 */ 2723 if (alloc_size > PAGE_CACHE_SIZE) 2724 return -ENOMEM; 2725 2726 space_args.total_spaces = 0; 2727 dest = kmalloc(alloc_size, GFP_NOFS); 2728 if (!dest) 2729 return -ENOMEM; 2730 dest_orig = dest; 2731 2732 /* now we have a buffer to copy into */ 2733 for (i = 0; i < num_types; i++) { 2734 struct btrfs_space_info *tmp; 2735 2736 if (!slot_count) 2737 break; 2738 2739 info = NULL; 2740 rcu_read_lock(); 2741 list_for_each_entry_rcu(tmp, &root->fs_info->space_info, 2742 list) { 2743 if (tmp->flags == types[i]) { 2744 info = tmp; 2745 break; 2746 } 2747 } 2748 rcu_read_unlock(); 2749 2750 if (!info) 2751 continue; 2752 down_read(&info->groups_sem); 2753 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { 2754 if (!list_empty(&info->block_groups[c])) { 2755 get_block_group_info(&info->block_groups[c], 2756 &space); 2757 memcpy(dest, &space, sizeof(space)); 2758 dest++; 2759 space_args.total_spaces++; 2760 slot_count--; 2761 } 2762 if (!slot_count) 2763 break; 2764 } 2765 up_read(&info->groups_sem); 2766 } 2767 2768 user_dest = (struct btrfs_ioctl_space_info *) 2769 (arg + sizeof(struct btrfs_ioctl_space_args)); 2770 2771 if (copy_to_user(user_dest, dest_orig, alloc_size)) 2772 ret = -EFAULT; 2773 2774 kfree(dest_orig); 2775 out: 2776 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args))) 2777 ret = -EFAULT; 2778 2779 return ret; 2780 } 2781 2782 /* 2783 * there are many ways the trans_start and trans_end ioctls can lead 2784 * to deadlocks. They should only be used by applications that 2785 * basically own the machine, and have a very in depth understanding 2786 * of all the possible deadlocks and enospc problems. 2787 */ 2788 long btrfs_ioctl_trans_end(struct file *file) 2789 { 2790 struct inode *inode = fdentry(file)->d_inode; 2791 struct btrfs_root *root = BTRFS_I(inode)->root; 2792 struct btrfs_trans_handle *trans; 2793 2794 trans = file->private_data; 2795 if (!trans) 2796 return -EINVAL; 2797 file->private_data = NULL; 2798 2799 btrfs_end_transaction(trans, root); 2800 2801 atomic_dec(&root->fs_info->open_ioctl_trans); 2802 2803 mnt_drop_write_file(file); 2804 return 0; 2805 } 2806 2807 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp) 2808 { 2809 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root; 2810 struct btrfs_trans_handle *trans; 2811 u64 transid; 2812 int ret; 2813 2814 trans = btrfs_start_transaction(root, 0); 2815 if (IS_ERR(trans)) 2816 return PTR_ERR(trans); 2817 transid = trans->transid; 2818 ret = btrfs_commit_transaction_async(trans, root, 0); 2819 if (ret) { 2820 btrfs_end_transaction(trans, root); 2821 return ret; 2822 } 2823 2824 if (argp) 2825 if (copy_to_user(argp, &transid, sizeof(transid))) 2826 return -EFAULT; 2827 return 0; 2828 } 2829 2830 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp) 2831 { 2832 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root; 2833 u64 transid; 2834 2835 if (argp) { 2836 if (copy_from_user(&transid, argp, sizeof(transid))) 2837 return -EFAULT; 2838 } else { 2839 transid = 0; /* current trans */ 2840 } 2841 return btrfs_wait_for_commit(root, transid); 2842 } 2843 2844 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg) 2845 { 2846 int ret; 2847 struct btrfs_ioctl_scrub_args *sa; 2848 2849 if (!capable(CAP_SYS_ADMIN)) 2850 return -EPERM; 2851 2852 sa = memdup_user(arg, sizeof(*sa)); 2853 if (IS_ERR(sa)) 2854 return PTR_ERR(sa); 2855 2856 ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end, 2857 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY); 2858 2859 if (copy_to_user(arg, sa, sizeof(*sa))) 2860 ret = -EFAULT; 2861 2862 kfree(sa); 2863 return ret; 2864 } 2865 2866 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg) 2867 { 2868 if (!capable(CAP_SYS_ADMIN)) 2869 return -EPERM; 2870 2871 return btrfs_scrub_cancel(root); 2872 } 2873 2874 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root, 2875 void __user *arg) 2876 { 2877 struct btrfs_ioctl_scrub_args *sa; 2878 int ret; 2879 2880 if (!capable(CAP_SYS_ADMIN)) 2881 return -EPERM; 2882 2883 sa = memdup_user(arg, sizeof(*sa)); 2884 if (IS_ERR(sa)) 2885 return PTR_ERR(sa); 2886 2887 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress); 2888 2889 if (copy_to_user(arg, sa, sizeof(*sa))) 2890 ret = -EFAULT; 2891 2892 kfree(sa); 2893 return ret; 2894 } 2895 2896 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg) 2897 { 2898 int ret = 0; 2899 int i; 2900 u64 rel_ptr; 2901 int size; 2902 struct btrfs_ioctl_ino_path_args *ipa = NULL; 2903 struct inode_fs_paths *ipath = NULL; 2904 struct btrfs_path *path; 2905 2906 if (!capable(CAP_SYS_ADMIN)) 2907 return -EPERM; 2908 2909 path = btrfs_alloc_path(); 2910 if (!path) { 2911 ret = -ENOMEM; 2912 goto out; 2913 } 2914 2915 ipa = memdup_user(arg, sizeof(*ipa)); 2916 if (IS_ERR(ipa)) { 2917 ret = PTR_ERR(ipa); 2918 ipa = NULL; 2919 goto out; 2920 } 2921 2922 size = min_t(u32, ipa->size, 4096); 2923 ipath = init_ipath(size, root, path); 2924 if (IS_ERR(ipath)) { 2925 ret = PTR_ERR(ipath); 2926 ipath = NULL; 2927 goto out; 2928 } 2929 2930 ret = paths_from_inode(ipa->inum, ipath); 2931 if (ret < 0) 2932 goto out; 2933 2934 for (i = 0; i < ipath->fspath->elem_cnt; ++i) { 2935 rel_ptr = ipath->fspath->val[i] - 2936 (u64)(unsigned long)ipath->fspath->val; 2937 ipath->fspath->val[i] = rel_ptr; 2938 } 2939 2940 ret = copy_to_user((void *)(unsigned long)ipa->fspath, 2941 (void *)(unsigned long)ipath->fspath, size); 2942 if (ret) { 2943 ret = -EFAULT; 2944 goto out; 2945 } 2946 2947 out: 2948 btrfs_free_path(path); 2949 free_ipath(ipath); 2950 kfree(ipa); 2951 2952 return ret; 2953 } 2954 2955 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx) 2956 { 2957 struct btrfs_data_container *inodes = ctx; 2958 const size_t c = 3 * sizeof(u64); 2959 2960 if (inodes->bytes_left >= c) { 2961 inodes->bytes_left -= c; 2962 inodes->val[inodes->elem_cnt] = inum; 2963 inodes->val[inodes->elem_cnt + 1] = offset; 2964 inodes->val[inodes->elem_cnt + 2] = root; 2965 inodes->elem_cnt += 3; 2966 } else { 2967 inodes->bytes_missing += c - inodes->bytes_left; 2968 inodes->bytes_left = 0; 2969 inodes->elem_missed += 3; 2970 } 2971 2972 return 0; 2973 } 2974 2975 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root, 2976 void __user *arg) 2977 { 2978 int ret = 0; 2979 int size; 2980 u64 extent_offset; 2981 struct btrfs_ioctl_logical_ino_args *loi; 2982 struct btrfs_data_container *inodes = NULL; 2983 struct btrfs_path *path = NULL; 2984 struct btrfs_key key; 2985 2986 if (!capable(CAP_SYS_ADMIN)) 2987 return -EPERM; 2988 2989 loi = memdup_user(arg, sizeof(*loi)); 2990 if (IS_ERR(loi)) { 2991 ret = PTR_ERR(loi); 2992 loi = NULL; 2993 goto out; 2994 } 2995 2996 path = btrfs_alloc_path(); 2997 if (!path) { 2998 ret = -ENOMEM; 2999 goto out; 3000 } 3001 3002 size = min_t(u32, loi->size, 4096); 3003 inodes = init_data_container(size); 3004 if (IS_ERR(inodes)) { 3005 ret = PTR_ERR(inodes); 3006 inodes = NULL; 3007 goto out; 3008 } 3009 3010 ret = extent_from_logical(root->fs_info, loi->logical, path, &key); 3011 3012 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) 3013 ret = -ENOENT; 3014 if (ret < 0) 3015 goto out; 3016 3017 extent_offset = loi->logical - key.objectid; 3018 ret = iterate_extent_inodes(root->fs_info, path, key.objectid, 3019 extent_offset, build_ino_list, inodes); 3020 3021 if (ret < 0) 3022 goto out; 3023 3024 ret = copy_to_user((void *)(unsigned long)loi->inodes, 3025 (void *)(unsigned long)inodes, size); 3026 if (ret) 3027 ret = -EFAULT; 3028 3029 out: 3030 btrfs_free_path(path); 3031 kfree(inodes); 3032 kfree(loi); 3033 3034 return ret; 3035 } 3036 3037 long btrfs_ioctl(struct file *file, unsigned int 3038 cmd, unsigned long arg) 3039 { 3040 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 3041 void __user *argp = (void __user *)arg; 3042 3043 switch (cmd) { 3044 case FS_IOC_GETFLAGS: 3045 return btrfs_ioctl_getflags(file, argp); 3046 case FS_IOC_SETFLAGS: 3047 return btrfs_ioctl_setflags(file, argp); 3048 case FS_IOC_GETVERSION: 3049 return btrfs_ioctl_getversion(file, argp); 3050 case FITRIM: 3051 return btrfs_ioctl_fitrim(file, argp); 3052 case BTRFS_IOC_SNAP_CREATE: 3053 return btrfs_ioctl_snap_create(file, argp, 0); 3054 case BTRFS_IOC_SNAP_CREATE_V2: 3055 return btrfs_ioctl_snap_create_v2(file, argp, 0); 3056 case BTRFS_IOC_SUBVOL_CREATE: 3057 return btrfs_ioctl_snap_create(file, argp, 1); 3058 case BTRFS_IOC_SNAP_DESTROY: 3059 return btrfs_ioctl_snap_destroy(file, argp); 3060 case BTRFS_IOC_SUBVOL_GETFLAGS: 3061 return btrfs_ioctl_subvol_getflags(file, argp); 3062 case BTRFS_IOC_SUBVOL_SETFLAGS: 3063 return btrfs_ioctl_subvol_setflags(file, argp); 3064 case BTRFS_IOC_DEFAULT_SUBVOL: 3065 return btrfs_ioctl_default_subvol(file, argp); 3066 case BTRFS_IOC_DEFRAG: 3067 return btrfs_ioctl_defrag(file, NULL); 3068 case BTRFS_IOC_DEFRAG_RANGE: 3069 return btrfs_ioctl_defrag(file, argp); 3070 case BTRFS_IOC_RESIZE: 3071 return btrfs_ioctl_resize(root, argp); 3072 case BTRFS_IOC_ADD_DEV: 3073 return btrfs_ioctl_add_dev(root, argp); 3074 case BTRFS_IOC_RM_DEV: 3075 return btrfs_ioctl_rm_dev(root, argp); 3076 case BTRFS_IOC_FS_INFO: 3077 return btrfs_ioctl_fs_info(root, argp); 3078 case BTRFS_IOC_DEV_INFO: 3079 return btrfs_ioctl_dev_info(root, argp); 3080 case BTRFS_IOC_BALANCE: 3081 return btrfs_balance(root->fs_info->dev_root); 3082 case BTRFS_IOC_CLONE: 3083 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 3084 case BTRFS_IOC_CLONE_RANGE: 3085 return btrfs_ioctl_clone_range(file, argp); 3086 case BTRFS_IOC_TRANS_START: 3087 return btrfs_ioctl_trans_start(file); 3088 case BTRFS_IOC_TRANS_END: 3089 return btrfs_ioctl_trans_end(file); 3090 case BTRFS_IOC_TREE_SEARCH: 3091 return btrfs_ioctl_tree_search(file, argp); 3092 case BTRFS_IOC_INO_LOOKUP: 3093 return btrfs_ioctl_ino_lookup(file, argp); 3094 case BTRFS_IOC_INO_PATHS: 3095 return btrfs_ioctl_ino_to_path(root, argp); 3096 case BTRFS_IOC_LOGICAL_INO: 3097 return btrfs_ioctl_logical_to_ino(root, argp); 3098 case BTRFS_IOC_SPACE_INFO: 3099 return btrfs_ioctl_space_info(root, argp); 3100 case BTRFS_IOC_SYNC: 3101 btrfs_sync_fs(file->f_dentry->d_sb, 1); 3102 return 0; 3103 case BTRFS_IOC_START_SYNC: 3104 return btrfs_ioctl_start_sync(file, argp); 3105 case BTRFS_IOC_WAIT_SYNC: 3106 return btrfs_ioctl_wait_sync(file, argp); 3107 case BTRFS_IOC_SCRUB: 3108 return btrfs_ioctl_scrub(root, argp); 3109 case BTRFS_IOC_SCRUB_CANCEL: 3110 return btrfs_ioctl_scrub_cancel(root, argp); 3111 case BTRFS_IOC_SCRUB_PROGRESS: 3112 return btrfs_ioctl_scrub_progress(root, argp); 3113 } 3114 3115 return -ENOTTY; 3116 } 3117