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->f_path.mnt); 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 ret = btrfs_update_inode(trans, root, inode); 256 BUG_ON(ret); 257 258 btrfs_update_iflags(inode); 259 inode->i_ctime = CURRENT_TIME; 260 btrfs_end_transaction(trans, root); 261 262 mnt_drop_write(file->f_path.mnt); 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 ret = btrfs_delalloc_reserve_space(inode, 862 num_pages << PAGE_CACHE_SHIFT); 863 if (ret) 864 return ret; 865 again: 866 ret = 0; 867 i_done = 0; 868 869 /* step one, lock all the pages */ 870 for (i = 0; i < num_pages; i++) { 871 struct page *page; 872 page = find_or_create_page(inode->i_mapping, 873 start_index + i, mask); 874 if (!page) 875 break; 876 877 if (!PageUptodate(page)) { 878 btrfs_readpage(NULL, page); 879 lock_page(page); 880 if (!PageUptodate(page)) { 881 unlock_page(page); 882 page_cache_release(page); 883 ret = -EIO; 884 break; 885 } 886 } 887 isize = i_size_read(inode); 888 file_end = (isize - 1) >> PAGE_CACHE_SHIFT; 889 if (!isize || page->index > file_end || 890 page->mapping != inode->i_mapping) { 891 /* whoops, we blew past eof, skip this page */ 892 unlock_page(page); 893 page_cache_release(page); 894 break; 895 } 896 pages[i] = page; 897 i_done++; 898 } 899 if (!i_done || ret) 900 goto out; 901 902 if (!(inode->i_sb->s_flags & MS_ACTIVE)) 903 goto out; 904 905 /* 906 * so now we have a nice long stream of locked 907 * and up to date pages, lets wait on them 908 */ 909 for (i = 0; i < i_done; i++) 910 wait_on_page_writeback(pages[i]); 911 912 page_start = page_offset(pages[0]); 913 page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE; 914 915 lock_extent_bits(&BTRFS_I(inode)->io_tree, 916 page_start, page_end - 1, 0, &cached_state, 917 GFP_NOFS); 918 ordered = btrfs_lookup_first_ordered_extent(inode, page_end - 1); 919 if (ordered && 920 ordered->file_offset + ordered->len > page_start && 921 ordered->file_offset < page_end) { 922 btrfs_put_ordered_extent(ordered); 923 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 924 page_start, page_end - 1, 925 &cached_state, GFP_NOFS); 926 for (i = 0; i < i_done; i++) { 927 unlock_page(pages[i]); 928 page_cache_release(pages[i]); 929 } 930 btrfs_wait_ordered_range(inode, page_start, 931 page_end - page_start); 932 goto again; 933 } 934 if (ordered) 935 btrfs_put_ordered_extent(ordered); 936 937 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, 938 page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC | 939 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state, 940 GFP_NOFS); 941 942 if (i_done != num_pages) { 943 spin_lock(&BTRFS_I(inode)->lock); 944 BTRFS_I(inode)->outstanding_extents++; 945 spin_unlock(&BTRFS_I(inode)->lock); 946 btrfs_delalloc_release_space(inode, 947 (num_pages - i_done) << PAGE_CACHE_SHIFT); 948 } 949 950 951 btrfs_set_extent_delalloc(inode, page_start, page_end - 1, 952 &cached_state); 953 954 unlock_extent_cached(&BTRFS_I(inode)->io_tree, 955 page_start, page_end - 1, &cached_state, 956 GFP_NOFS); 957 958 for (i = 0; i < i_done; i++) { 959 clear_page_dirty_for_io(pages[i]); 960 ClearPageChecked(pages[i]); 961 set_page_extent_mapped(pages[i]); 962 set_page_dirty(pages[i]); 963 unlock_page(pages[i]); 964 page_cache_release(pages[i]); 965 } 966 return i_done; 967 out: 968 for (i = 0; i < i_done; i++) { 969 unlock_page(pages[i]); 970 page_cache_release(pages[i]); 971 } 972 btrfs_delalloc_release_space(inode, num_pages << PAGE_CACHE_SHIFT); 973 return ret; 974 975 } 976 977 int btrfs_defrag_file(struct inode *inode, struct file *file, 978 struct btrfs_ioctl_defrag_range_args *range, 979 u64 newer_than, unsigned long max_to_defrag) 980 { 981 struct btrfs_root *root = BTRFS_I(inode)->root; 982 struct btrfs_super_block *disk_super; 983 struct file_ra_state *ra = NULL; 984 unsigned long last_index; 985 u64 isize = i_size_read(inode); 986 u64 features; 987 u64 last_len = 0; 988 u64 skip = 0; 989 u64 defrag_end = 0; 990 u64 newer_off = range->start; 991 unsigned long i; 992 unsigned long ra_index = 0; 993 int ret; 994 int defrag_count = 0; 995 int compress_type = BTRFS_COMPRESS_ZLIB; 996 int extent_thresh = range->extent_thresh; 997 int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT; 998 int cluster = max_cluster; 999 u64 new_align = ~((u64)128 * 1024 - 1); 1000 struct page **pages = NULL; 1001 1002 if (extent_thresh == 0) 1003 extent_thresh = 256 * 1024; 1004 1005 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) { 1006 if (range->compress_type > BTRFS_COMPRESS_TYPES) 1007 return -EINVAL; 1008 if (range->compress_type) 1009 compress_type = range->compress_type; 1010 } 1011 1012 if (isize == 0) 1013 return 0; 1014 1015 /* 1016 * if we were not given a file, allocate a readahead 1017 * context 1018 */ 1019 if (!file) { 1020 ra = kzalloc(sizeof(*ra), GFP_NOFS); 1021 if (!ra) 1022 return -ENOMEM; 1023 file_ra_state_init(ra, inode->i_mapping); 1024 } else { 1025 ra = &file->f_ra; 1026 } 1027 1028 pages = kmalloc(sizeof(struct page *) * max_cluster, 1029 GFP_NOFS); 1030 if (!pages) { 1031 ret = -ENOMEM; 1032 goto out_ra; 1033 } 1034 1035 /* find the last page to defrag */ 1036 if (range->start + range->len > range->start) { 1037 last_index = min_t(u64, isize - 1, 1038 range->start + range->len - 1) >> PAGE_CACHE_SHIFT; 1039 } else { 1040 last_index = (isize - 1) >> PAGE_CACHE_SHIFT; 1041 } 1042 1043 if (newer_than) { 1044 ret = find_new_extents(root, inode, newer_than, 1045 &newer_off, 64 * 1024); 1046 if (!ret) { 1047 range->start = newer_off; 1048 /* 1049 * we always align our defrag to help keep 1050 * the extents in the file evenly spaced 1051 */ 1052 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; 1053 } else 1054 goto out_ra; 1055 } else { 1056 i = range->start >> PAGE_CACHE_SHIFT; 1057 } 1058 if (!max_to_defrag) 1059 max_to_defrag = last_index; 1060 1061 /* 1062 * make writeback starts from i, so the defrag range can be 1063 * written sequentially. 1064 */ 1065 if (i < inode->i_mapping->writeback_index) 1066 inode->i_mapping->writeback_index = i; 1067 1068 while (i <= last_index && defrag_count < max_to_defrag && 1069 (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> 1070 PAGE_CACHE_SHIFT)) { 1071 /* 1072 * make sure we stop running if someone unmounts 1073 * the FS 1074 */ 1075 if (!(inode->i_sb->s_flags & MS_ACTIVE)) 1076 break; 1077 1078 if (!newer_than && 1079 !should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT, 1080 PAGE_CACHE_SIZE, 1081 extent_thresh, 1082 &last_len, &skip, 1083 &defrag_end)) { 1084 unsigned long next; 1085 /* 1086 * the should_defrag function tells us how much to skip 1087 * bump our counter by the suggested amount 1088 */ 1089 next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 1090 i = max(i + 1, next); 1091 continue; 1092 } 1093 1094 if (!newer_than) { 1095 cluster = (PAGE_CACHE_ALIGN(defrag_end) >> 1096 PAGE_CACHE_SHIFT) - i; 1097 cluster = min(cluster, max_cluster); 1098 } else { 1099 cluster = max_cluster; 1100 } 1101 1102 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) 1103 BTRFS_I(inode)->force_compress = compress_type; 1104 1105 if (i + cluster > ra_index) { 1106 ra_index = max(i, ra_index); 1107 btrfs_force_ra(inode->i_mapping, ra, file, ra_index, 1108 cluster); 1109 ra_index += max_cluster; 1110 } 1111 1112 ret = cluster_pages_for_defrag(inode, pages, i, cluster); 1113 if (ret < 0) 1114 goto out_ra; 1115 1116 defrag_count += ret; 1117 balance_dirty_pages_ratelimited_nr(inode->i_mapping, ret); 1118 1119 if (newer_than) { 1120 if (newer_off == (u64)-1) 1121 break; 1122 1123 newer_off = max(newer_off + 1, 1124 (u64)i << PAGE_CACHE_SHIFT); 1125 1126 ret = find_new_extents(root, inode, 1127 newer_than, &newer_off, 1128 64 * 1024); 1129 if (!ret) { 1130 range->start = newer_off; 1131 i = (newer_off & new_align) >> PAGE_CACHE_SHIFT; 1132 } else { 1133 break; 1134 } 1135 } else { 1136 if (ret > 0) { 1137 i += ret; 1138 last_len += ret << PAGE_CACHE_SHIFT; 1139 } else { 1140 i++; 1141 last_len = 0; 1142 } 1143 } 1144 } 1145 1146 if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) 1147 filemap_flush(inode->i_mapping); 1148 1149 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { 1150 /* the filemap_flush will queue IO into the worker threads, but 1151 * we have to make sure the IO is actually started and that 1152 * ordered extents get created before we return 1153 */ 1154 atomic_inc(&root->fs_info->async_submit_draining); 1155 while (atomic_read(&root->fs_info->nr_async_submits) || 1156 atomic_read(&root->fs_info->async_delalloc_pages)) { 1157 wait_event(root->fs_info->async_submit_wait, 1158 (atomic_read(&root->fs_info->nr_async_submits) == 0 && 1159 atomic_read(&root->fs_info->async_delalloc_pages) == 0)); 1160 } 1161 atomic_dec(&root->fs_info->async_submit_draining); 1162 1163 mutex_lock(&inode->i_mutex); 1164 BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE; 1165 mutex_unlock(&inode->i_mutex); 1166 } 1167 1168 disk_super = root->fs_info->super_copy; 1169 features = btrfs_super_incompat_flags(disk_super); 1170 if (range->compress_type == BTRFS_COMPRESS_LZO) { 1171 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO; 1172 btrfs_set_super_incompat_flags(disk_super, features); 1173 } 1174 1175 ret = defrag_count; 1176 1177 out_ra: 1178 if (!file) 1179 kfree(ra); 1180 kfree(pages); 1181 return ret; 1182 } 1183 1184 static noinline int btrfs_ioctl_resize(struct btrfs_root *root, 1185 void __user *arg) 1186 { 1187 u64 new_size; 1188 u64 old_size; 1189 u64 devid = 1; 1190 struct btrfs_ioctl_vol_args *vol_args; 1191 struct btrfs_trans_handle *trans; 1192 struct btrfs_device *device = NULL; 1193 char *sizestr; 1194 char *devstr = NULL; 1195 int ret = 0; 1196 int mod = 0; 1197 1198 if (root->fs_info->sb->s_flags & MS_RDONLY) 1199 return -EROFS; 1200 1201 if (!capable(CAP_SYS_ADMIN)) 1202 return -EPERM; 1203 1204 vol_args = memdup_user(arg, sizeof(*vol_args)); 1205 if (IS_ERR(vol_args)) 1206 return PTR_ERR(vol_args); 1207 1208 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1209 1210 mutex_lock(&root->fs_info->volume_mutex); 1211 sizestr = vol_args->name; 1212 devstr = strchr(sizestr, ':'); 1213 if (devstr) { 1214 char *end; 1215 sizestr = devstr + 1; 1216 *devstr = '\0'; 1217 devstr = vol_args->name; 1218 devid = simple_strtoull(devstr, &end, 10); 1219 printk(KERN_INFO "resizing devid %llu\n", 1220 (unsigned long long)devid); 1221 } 1222 device = btrfs_find_device(root, devid, NULL, NULL); 1223 if (!device) { 1224 printk(KERN_INFO "resizer unable to find device %llu\n", 1225 (unsigned long long)devid); 1226 ret = -EINVAL; 1227 goto out_unlock; 1228 } 1229 if (!strcmp(sizestr, "max")) 1230 new_size = device->bdev->bd_inode->i_size; 1231 else { 1232 if (sizestr[0] == '-') { 1233 mod = -1; 1234 sizestr++; 1235 } else if (sizestr[0] == '+') { 1236 mod = 1; 1237 sizestr++; 1238 } 1239 new_size = memparse(sizestr, NULL); 1240 if (new_size == 0) { 1241 ret = -EINVAL; 1242 goto out_unlock; 1243 } 1244 } 1245 1246 old_size = device->total_bytes; 1247 1248 if (mod < 0) { 1249 if (new_size > old_size) { 1250 ret = -EINVAL; 1251 goto out_unlock; 1252 } 1253 new_size = old_size - new_size; 1254 } else if (mod > 0) { 1255 new_size = old_size + new_size; 1256 } 1257 1258 if (new_size < 256 * 1024 * 1024) { 1259 ret = -EINVAL; 1260 goto out_unlock; 1261 } 1262 if (new_size > device->bdev->bd_inode->i_size) { 1263 ret = -EFBIG; 1264 goto out_unlock; 1265 } 1266 1267 do_div(new_size, root->sectorsize); 1268 new_size *= root->sectorsize; 1269 1270 printk(KERN_INFO "new size for %s is %llu\n", 1271 device->name, (unsigned long long)new_size); 1272 1273 if (new_size > old_size) { 1274 trans = btrfs_start_transaction(root, 0); 1275 if (IS_ERR(trans)) { 1276 ret = PTR_ERR(trans); 1277 goto out_unlock; 1278 } 1279 ret = btrfs_grow_device(trans, device, new_size); 1280 btrfs_commit_transaction(trans, root); 1281 } else { 1282 ret = btrfs_shrink_device(device, new_size); 1283 } 1284 1285 out_unlock: 1286 mutex_unlock(&root->fs_info->volume_mutex); 1287 kfree(vol_args); 1288 return ret; 1289 } 1290 1291 static noinline int btrfs_ioctl_snap_create_transid(struct file *file, 1292 char *name, 1293 unsigned long fd, 1294 int subvol, 1295 u64 *transid, 1296 bool readonly) 1297 { 1298 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 1299 struct file *src_file; 1300 int namelen; 1301 int ret = 0; 1302 1303 if (root->fs_info->sb->s_flags & MS_RDONLY) 1304 return -EROFS; 1305 1306 namelen = strlen(name); 1307 if (strchr(name, '/')) { 1308 ret = -EINVAL; 1309 goto out; 1310 } 1311 1312 if (subvol) { 1313 ret = btrfs_mksubvol(&file->f_path, name, namelen, 1314 NULL, transid, readonly); 1315 } else { 1316 struct inode *src_inode; 1317 src_file = fget(fd); 1318 if (!src_file) { 1319 ret = -EINVAL; 1320 goto out; 1321 } 1322 1323 src_inode = src_file->f_path.dentry->d_inode; 1324 if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) { 1325 printk(KERN_INFO "btrfs: Snapshot src from " 1326 "another FS\n"); 1327 ret = -EINVAL; 1328 fput(src_file); 1329 goto out; 1330 } 1331 ret = btrfs_mksubvol(&file->f_path, name, namelen, 1332 BTRFS_I(src_inode)->root, 1333 transid, readonly); 1334 fput(src_file); 1335 } 1336 out: 1337 return ret; 1338 } 1339 1340 static noinline int btrfs_ioctl_snap_create(struct file *file, 1341 void __user *arg, int subvol) 1342 { 1343 struct btrfs_ioctl_vol_args *vol_args; 1344 int ret; 1345 1346 vol_args = memdup_user(arg, sizeof(*vol_args)); 1347 if (IS_ERR(vol_args)) 1348 return PTR_ERR(vol_args); 1349 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1350 1351 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, 1352 vol_args->fd, subvol, 1353 NULL, false); 1354 1355 kfree(vol_args); 1356 return ret; 1357 } 1358 1359 static noinline int btrfs_ioctl_snap_create_v2(struct file *file, 1360 void __user *arg, int subvol) 1361 { 1362 struct btrfs_ioctl_vol_args_v2 *vol_args; 1363 int ret; 1364 u64 transid = 0; 1365 u64 *ptr = NULL; 1366 bool readonly = false; 1367 1368 vol_args = memdup_user(arg, sizeof(*vol_args)); 1369 if (IS_ERR(vol_args)) 1370 return PTR_ERR(vol_args); 1371 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0'; 1372 1373 if (vol_args->flags & 1374 ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) { 1375 ret = -EOPNOTSUPP; 1376 goto out; 1377 } 1378 1379 if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC) 1380 ptr = &transid; 1381 if (vol_args->flags & BTRFS_SUBVOL_RDONLY) 1382 readonly = true; 1383 1384 ret = btrfs_ioctl_snap_create_transid(file, vol_args->name, 1385 vol_args->fd, subvol, 1386 ptr, readonly); 1387 1388 if (ret == 0 && ptr && 1389 copy_to_user(arg + 1390 offsetof(struct btrfs_ioctl_vol_args_v2, 1391 transid), ptr, sizeof(*ptr))) 1392 ret = -EFAULT; 1393 out: 1394 kfree(vol_args); 1395 return ret; 1396 } 1397 1398 static noinline int btrfs_ioctl_subvol_getflags(struct file *file, 1399 void __user *arg) 1400 { 1401 struct inode *inode = fdentry(file)->d_inode; 1402 struct btrfs_root *root = BTRFS_I(inode)->root; 1403 int ret = 0; 1404 u64 flags = 0; 1405 1406 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) 1407 return -EINVAL; 1408 1409 down_read(&root->fs_info->subvol_sem); 1410 if (btrfs_root_readonly(root)) 1411 flags |= BTRFS_SUBVOL_RDONLY; 1412 up_read(&root->fs_info->subvol_sem); 1413 1414 if (copy_to_user(arg, &flags, sizeof(flags))) 1415 ret = -EFAULT; 1416 1417 return ret; 1418 } 1419 1420 static noinline int btrfs_ioctl_subvol_setflags(struct file *file, 1421 void __user *arg) 1422 { 1423 struct inode *inode = fdentry(file)->d_inode; 1424 struct btrfs_root *root = BTRFS_I(inode)->root; 1425 struct btrfs_trans_handle *trans; 1426 u64 root_flags; 1427 u64 flags; 1428 int ret = 0; 1429 1430 if (root->fs_info->sb->s_flags & MS_RDONLY) 1431 return -EROFS; 1432 1433 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) 1434 return -EINVAL; 1435 1436 if (copy_from_user(&flags, arg, sizeof(flags))) 1437 return -EFAULT; 1438 1439 if (flags & BTRFS_SUBVOL_CREATE_ASYNC) 1440 return -EINVAL; 1441 1442 if (flags & ~BTRFS_SUBVOL_RDONLY) 1443 return -EOPNOTSUPP; 1444 1445 if (!inode_owner_or_capable(inode)) 1446 return -EACCES; 1447 1448 down_write(&root->fs_info->subvol_sem); 1449 1450 /* nothing to do */ 1451 if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root)) 1452 goto out; 1453 1454 root_flags = btrfs_root_flags(&root->root_item); 1455 if (flags & BTRFS_SUBVOL_RDONLY) 1456 btrfs_set_root_flags(&root->root_item, 1457 root_flags | BTRFS_ROOT_SUBVOL_RDONLY); 1458 else 1459 btrfs_set_root_flags(&root->root_item, 1460 root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY); 1461 1462 trans = btrfs_start_transaction(root, 1); 1463 if (IS_ERR(trans)) { 1464 ret = PTR_ERR(trans); 1465 goto out_reset; 1466 } 1467 1468 ret = btrfs_update_root(trans, root->fs_info->tree_root, 1469 &root->root_key, &root->root_item); 1470 1471 btrfs_commit_transaction(trans, root); 1472 out_reset: 1473 if (ret) 1474 btrfs_set_root_flags(&root->root_item, root_flags); 1475 out: 1476 up_write(&root->fs_info->subvol_sem); 1477 return ret; 1478 } 1479 1480 /* 1481 * helper to check if the subvolume references other subvolumes 1482 */ 1483 static noinline int may_destroy_subvol(struct btrfs_root *root) 1484 { 1485 struct btrfs_path *path; 1486 struct btrfs_key key; 1487 int ret; 1488 1489 path = btrfs_alloc_path(); 1490 if (!path) 1491 return -ENOMEM; 1492 1493 key.objectid = root->root_key.objectid; 1494 key.type = BTRFS_ROOT_REF_KEY; 1495 key.offset = (u64)-1; 1496 1497 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, 1498 &key, path, 0, 0); 1499 if (ret < 0) 1500 goto out; 1501 BUG_ON(ret == 0); 1502 1503 ret = 0; 1504 if (path->slots[0] > 0) { 1505 path->slots[0]--; 1506 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1507 if (key.objectid == root->root_key.objectid && 1508 key.type == BTRFS_ROOT_REF_KEY) 1509 ret = -ENOTEMPTY; 1510 } 1511 out: 1512 btrfs_free_path(path); 1513 return ret; 1514 } 1515 1516 static noinline int key_in_sk(struct btrfs_key *key, 1517 struct btrfs_ioctl_search_key *sk) 1518 { 1519 struct btrfs_key test; 1520 int ret; 1521 1522 test.objectid = sk->min_objectid; 1523 test.type = sk->min_type; 1524 test.offset = sk->min_offset; 1525 1526 ret = btrfs_comp_cpu_keys(key, &test); 1527 if (ret < 0) 1528 return 0; 1529 1530 test.objectid = sk->max_objectid; 1531 test.type = sk->max_type; 1532 test.offset = sk->max_offset; 1533 1534 ret = btrfs_comp_cpu_keys(key, &test); 1535 if (ret > 0) 1536 return 0; 1537 return 1; 1538 } 1539 1540 static noinline int copy_to_sk(struct btrfs_root *root, 1541 struct btrfs_path *path, 1542 struct btrfs_key *key, 1543 struct btrfs_ioctl_search_key *sk, 1544 char *buf, 1545 unsigned long *sk_offset, 1546 int *num_found) 1547 { 1548 u64 found_transid; 1549 struct extent_buffer *leaf; 1550 struct btrfs_ioctl_search_header sh; 1551 unsigned long item_off; 1552 unsigned long item_len; 1553 int nritems; 1554 int i; 1555 int slot; 1556 int ret = 0; 1557 1558 leaf = path->nodes[0]; 1559 slot = path->slots[0]; 1560 nritems = btrfs_header_nritems(leaf); 1561 1562 if (btrfs_header_generation(leaf) > sk->max_transid) { 1563 i = nritems; 1564 goto advance_key; 1565 } 1566 found_transid = btrfs_header_generation(leaf); 1567 1568 for (i = slot; i < nritems; i++) { 1569 item_off = btrfs_item_ptr_offset(leaf, i); 1570 item_len = btrfs_item_size_nr(leaf, i); 1571 1572 if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE) 1573 item_len = 0; 1574 1575 if (sizeof(sh) + item_len + *sk_offset > 1576 BTRFS_SEARCH_ARGS_BUFSIZE) { 1577 ret = 1; 1578 goto overflow; 1579 } 1580 1581 btrfs_item_key_to_cpu(leaf, key, i); 1582 if (!key_in_sk(key, sk)) 1583 continue; 1584 1585 sh.objectid = key->objectid; 1586 sh.offset = key->offset; 1587 sh.type = key->type; 1588 sh.len = item_len; 1589 sh.transid = found_transid; 1590 1591 /* copy search result header */ 1592 memcpy(buf + *sk_offset, &sh, sizeof(sh)); 1593 *sk_offset += sizeof(sh); 1594 1595 if (item_len) { 1596 char *p = buf + *sk_offset; 1597 /* copy the item */ 1598 read_extent_buffer(leaf, p, 1599 item_off, item_len); 1600 *sk_offset += item_len; 1601 } 1602 (*num_found)++; 1603 1604 if (*num_found >= sk->nr_items) 1605 break; 1606 } 1607 advance_key: 1608 ret = 0; 1609 if (key->offset < (u64)-1 && key->offset < sk->max_offset) 1610 key->offset++; 1611 else if (key->type < (u8)-1 && key->type < sk->max_type) { 1612 key->offset = 0; 1613 key->type++; 1614 } else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) { 1615 key->offset = 0; 1616 key->type = 0; 1617 key->objectid++; 1618 } else 1619 ret = 1; 1620 overflow: 1621 return ret; 1622 } 1623 1624 static noinline int search_ioctl(struct inode *inode, 1625 struct btrfs_ioctl_search_args *args) 1626 { 1627 struct btrfs_root *root; 1628 struct btrfs_key key; 1629 struct btrfs_key max_key; 1630 struct btrfs_path *path; 1631 struct btrfs_ioctl_search_key *sk = &args->key; 1632 struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info; 1633 int ret; 1634 int num_found = 0; 1635 unsigned long sk_offset = 0; 1636 1637 path = btrfs_alloc_path(); 1638 if (!path) 1639 return -ENOMEM; 1640 1641 if (sk->tree_id == 0) { 1642 /* search the root of the inode that was passed */ 1643 root = BTRFS_I(inode)->root; 1644 } else { 1645 key.objectid = sk->tree_id; 1646 key.type = BTRFS_ROOT_ITEM_KEY; 1647 key.offset = (u64)-1; 1648 root = btrfs_read_fs_root_no_name(info, &key); 1649 if (IS_ERR(root)) { 1650 printk(KERN_ERR "could not find root %llu\n", 1651 sk->tree_id); 1652 btrfs_free_path(path); 1653 return -ENOENT; 1654 } 1655 } 1656 1657 key.objectid = sk->min_objectid; 1658 key.type = sk->min_type; 1659 key.offset = sk->min_offset; 1660 1661 max_key.objectid = sk->max_objectid; 1662 max_key.type = sk->max_type; 1663 max_key.offset = sk->max_offset; 1664 1665 path->keep_locks = 1; 1666 1667 while(1) { 1668 ret = btrfs_search_forward(root, &key, &max_key, path, 0, 1669 sk->min_transid); 1670 if (ret != 0) { 1671 if (ret > 0) 1672 ret = 0; 1673 goto err; 1674 } 1675 ret = copy_to_sk(root, path, &key, sk, args->buf, 1676 &sk_offset, &num_found); 1677 btrfs_release_path(path); 1678 if (ret || num_found >= sk->nr_items) 1679 break; 1680 1681 } 1682 ret = 0; 1683 err: 1684 sk->nr_items = num_found; 1685 btrfs_free_path(path); 1686 return ret; 1687 } 1688 1689 static noinline int btrfs_ioctl_tree_search(struct file *file, 1690 void __user *argp) 1691 { 1692 struct btrfs_ioctl_search_args *args; 1693 struct inode *inode; 1694 int ret; 1695 1696 if (!capable(CAP_SYS_ADMIN)) 1697 return -EPERM; 1698 1699 args = memdup_user(argp, sizeof(*args)); 1700 if (IS_ERR(args)) 1701 return PTR_ERR(args); 1702 1703 inode = fdentry(file)->d_inode; 1704 ret = search_ioctl(inode, args); 1705 if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) 1706 ret = -EFAULT; 1707 kfree(args); 1708 return ret; 1709 } 1710 1711 /* 1712 * Search INODE_REFs to identify path name of 'dirid' directory 1713 * in a 'tree_id' tree. and sets path name to 'name'. 1714 */ 1715 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info, 1716 u64 tree_id, u64 dirid, char *name) 1717 { 1718 struct btrfs_root *root; 1719 struct btrfs_key key; 1720 char *ptr; 1721 int ret = -1; 1722 int slot; 1723 int len; 1724 int total_len = 0; 1725 struct btrfs_inode_ref *iref; 1726 struct extent_buffer *l; 1727 struct btrfs_path *path; 1728 1729 if (dirid == BTRFS_FIRST_FREE_OBJECTID) { 1730 name[0]='\0'; 1731 return 0; 1732 } 1733 1734 path = btrfs_alloc_path(); 1735 if (!path) 1736 return -ENOMEM; 1737 1738 ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX]; 1739 1740 key.objectid = tree_id; 1741 key.type = BTRFS_ROOT_ITEM_KEY; 1742 key.offset = (u64)-1; 1743 root = btrfs_read_fs_root_no_name(info, &key); 1744 if (IS_ERR(root)) { 1745 printk(KERN_ERR "could not find root %llu\n", tree_id); 1746 ret = -ENOENT; 1747 goto out; 1748 } 1749 1750 key.objectid = dirid; 1751 key.type = BTRFS_INODE_REF_KEY; 1752 key.offset = (u64)-1; 1753 1754 while(1) { 1755 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1756 if (ret < 0) 1757 goto out; 1758 1759 l = path->nodes[0]; 1760 slot = path->slots[0]; 1761 if (ret > 0 && slot > 0) 1762 slot--; 1763 btrfs_item_key_to_cpu(l, &key, slot); 1764 1765 if (ret > 0 && (key.objectid != dirid || 1766 key.type != BTRFS_INODE_REF_KEY)) { 1767 ret = -ENOENT; 1768 goto out; 1769 } 1770 1771 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref); 1772 len = btrfs_inode_ref_name_len(l, iref); 1773 ptr -= len + 1; 1774 total_len += len + 1; 1775 if (ptr < name) 1776 goto out; 1777 1778 *(ptr + len) = '/'; 1779 read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len); 1780 1781 if (key.offset == BTRFS_FIRST_FREE_OBJECTID) 1782 break; 1783 1784 btrfs_release_path(path); 1785 key.objectid = key.offset; 1786 key.offset = (u64)-1; 1787 dirid = key.objectid; 1788 } 1789 if (ptr < name) 1790 goto out; 1791 memmove(name, ptr, total_len); 1792 name[total_len]='\0'; 1793 ret = 0; 1794 out: 1795 btrfs_free_path(path); 1796 return ret; 1797 } 1798 1799 static noinline int btrfs_ioctl_ino_lookup(struct file *file, 1800 void __user *argp) 1801 { 1802 struct btrfs_ioctl_ino_lookup_args *args; 1803 struct inode *inode; 1804 int ret; 1805 1806 if (!capable(CAP_SYS_ADMIN)) 1807 return -EPERM; 1808 1809 args = memdup_user(argp, sizeof(*args)); 1810 if (IS_ERR(args)) 1811 return PTR_ERR(args); 1812 1813 inode = fdentry(file)->d_inode; 1814 1815 if (args->treeid == 0) 1816 args->treeid = BTRFS_I(inode)->root->root_key.objectid; 1817 1818 ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info, 1819 args->treeid, args->objectid, 1820 args->name); 1821 1822 if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) 1823 ret = -EFAULT; 1824 1825 kfree(args); 1826 return ret; 1827 } 1828 1829 static noinline int btrfs_ioctl_snap_destroy(struct file *file, 1830 void __user *arg) 1831 { 1832 struct dentry *parent = fdentry(file); 1833 struct dentry *dentry; 1834 struct inode *dir = parent->d_inode; 1835 struct inode *inode; 1836 struct btrfs_root *root = BTRFS_I(dir)->root; 1837 struct btrfs_root *dest = NULL; 1838 struct btrfs_ioctl_vol_args *vol_args; 1839 struct btrfs_trans_handle *trans; 1840 int namelen; 1841 int ret; 1842 int err = 0; 1843 1844 vol_args = memdup_user(arg, sizeof(*vol_args)); 1845 if (IS_ERR(vol_args)) 1846 return PTR_ERR(vol_args); 1847 1848 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 1849 namelen = strlen(vol_args->name); 1850 if (strchr(vol_args->name, '/') || 1851 strncmp(vol_args->name, "..", namelen) == 0) { 1852 err = -EINVAL; 1853 goto out; 1854 } 1855 1856 err = mnt_want_write(file->f_path.mnt); 1857 if (err) 1858 goto out; 1859 1860 mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); 1861 dentry = lookup_one_len(vol_args->name, parent, namelen); 1862 if (IS_ERR(dentry)) { 1863 err = PTR_ERR(dentry); 1864 goto out_unlock_dir; 1865 } 1866 1867 if (!dentry->d_inode) { 1868 err = -ENOENT; 1869 goto out_dput; 1870 } 1871 1872 inode = dentry->d_inode; 1873 dest = BTRFS_I(inode)->root; 1874 if (!capable(CAP_SYS_ADMIN)){ 1875 /* 1876 * Regular user. Only allow this with a special mount 1877 * option, when the user has write+exec access to the 1878 * subvol root, and when rmdir(2) would have been 1879 * allowed. 1880 * 1881 * Note that this is _not_ check that the subvol is 1882 * empty or doesn't contain data that we wouldn't 1883 * otherwise be able to delete. 1884 * 1885 * Users who want to delete empty subvols should try 1886 * rmdir(2). 1887 */ 1888 err = -EPERM; 1889 if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 1890 goto out_dput; 1891 1892 /* 1893 * Do not allow deletion if the parent dir is the same 1894 * as the dir to be deleted. That means the ioctl 1895 * must be called on the dentry referencing the root 1896 * of the subvol, not a random directory contained 1897 * within it. 1898 */ 1899 err = -EINVAL; 1900 if (root == dest) 1901 goto out_dput; 1902 1903 err = inode_permission(inode, MAY_WRITE | MAY_EXEC); 1904 if (err) 1905 goto out_dput; 1906 1907 /* check if subvolume may be deleted by a non-root user */ 1908 err = btrfs_may_delete(dir, dentry, 1); 1909 if (err) 1910 goto out_dput; 1911 } 1912 1913 if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) { 1914 err = -EINVAL; 1915 goto out_dput; 1916 } 1917 1918 mutex_lock(&inode->i_mutex); 1919 err = d_invalidate(dentry); 1920 if (err) 1921 goto out_unlock; 1922 1923 down_write(&root->fs_info->subvol_sem); 1924 1925 err = may_destroy_subvol(dest); 1926 if (err) 1927 goto out_up_write; 1928 1929 trans = btrfs_start_transaction(root, 0); 1930 if (IS_ERR(trans)) { 1931 err = PTR_ERR(trans); 1932 goto out_up_write; 1933 } 1934 trans->block_rsv = &root->fs_info->global_block_rsv; 1935 1936 ret = btrfs_unlink_subvol(trans, root, dir, 1937 dest->root_key.objectid, 1938 dentry->d_name.name, 1939 dentry->d_name.len); 1940 BUG_ON(ret); 1941 1942 btrfs_record_root_in_trans(trans, dest); 1943 1944 memset(&dest->root_item.drop_progress, 0, 1945 sizeof(dest->root_item.drop_progress)); 1946 dest->root_item.drop_level = 0; 1947 btrfs_set_root_refs(&dest->root_item, 0); 1948 1949 if (!xchg(&dest->orphan_item_inserted, 1)) { 1950 ret = btrfs_insert_orphan_item(trans, 1951 root->fs_info->tree_root, 1952 dest->root_key.objectid); 1953 BUG_ON(ret); 1954 } 1955 1956 ret = btrfs_end_transaction(trans, root); 1957 BUG_ON(ret); 1958 inode->i_flags |= S_DEAD; 1959 out_up_write: 1960 up_write(&root->fs_info->subvol_sem); 1961 out_unlock: 1962 mutex_unlock(&inode->i_mutex); 1963 if (!err) { 1964 shrink_dcache_sb(root->fs_info->sb); 1965 btrfs_invalidate_inodes(dest); 1966 d_delete(dentry); 1967 } 1968 out_dput: 1969 dput(dentry); 1970 out_unlock_dir: 1971 mutex_unlock(&dir->i_mutex); 1972 mnt_drop_write(file->f_path.mnt); 1973 out: 1974 kfree(vol_args); 1975 return err; 1976 } 1977 1978 static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 1979 { 1980 struct inode *inode = fdentry(file)->d_inode; 1981 struct btrfs_root *root = BTRFS_I(inode)->root; 1982 struct btrfs_ioctl_defrag_range_args *range; 1983 int ret; 1984 1985 if (btrfs_root_readonly(root)) 1986 return -EROFS; 1987 1988 ret = mnt_want_write(file->f_path.mnt); 1989 if (ret) 1990 return ret; 1991 1992 switch (inode->i_mode & S_IFMT) { 1993 case S_IFDIR: 1994 if (!capable(CAP_SYS_ADMIN)) { 1995 ret = -EPERM; 1996 goto out; 1997 } 1998 ret = btrfs_defrag_root(root, 0); 1999 if (ret) 2000 goto out; 2001 ret = btrfs_defrag_root(root->fs_info->extent_root, 0); 2002 break; 2003 case S_IFREG: 2004 if (!(file->f_mode & FMODE_WRITE)) { 2005 ret = -EINVAL; 2006 goto out; 2007 } 2008 2009 range = kzalloc(sizeof(*range), GFP_KERNEL); 2010 if (!range) { 2011 ret = -ENOMEM; 2012 goto out; 2013 } 2014 2015 if (argp) { 2016 if (copy_from_user(range, argp, 2017 sizeof(*range))) { 2018 ret = -EFAULT; 2019 kfree(range); 2020 goto out; 2021 } 2022 /* compression requires us to start the IO */ 2023 if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) { 2024 range->flags |= BTRFS_DEFRAG_RANGE_START_IO; 2025 range->extent_thresh = (u32)-1; 2026 } 2027 } else { 2028 /* the rest are all set to zero by kzalloc */ 2029 range->len = (u64)-1; 2030 } 2031 ret = btrfs_defrag_file(fdentry(file)->d_inode, file, 2032 range, 0, 0); 2033 if (ret > 0) 2034 ret = 0; 2035 kfree(range); 2036 break; 2037 default: 2038 ret = -EINVAL; 2039 } 2040 out: 2041 mnt_drop_write(file->f_path.mnt); 2042 return ret; 2043 } 2044 2045 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) 2046 { 2047 struct btrfs_ioctl_vol_args *vol_args; 2048 int ret; 2049 2050 if (!capable(CAP_SYS_ADMIN)) 2051 return -EPERM; 2052 2053 vol_args = memdup_user(arg, sizeof(*vol_args)); 2054 if (IS_ERR(vol_args)) 2055 return PTR_ERR(vol_args); 2056 2057 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2058 ret = btrfs_init_new_device(root, vol_args->name); 2059 2060 kfree(vol_args); 2061 return ret; 2062 } 2063 2064 static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) 2065 { 2066 struct btrfs_ioctl_vol_args *vol_args; 2067 int ret; 2068 2069 if (!capable(CAP_SYS_ADMIN)) 2070 return -EPERM; 2071 2072 if (root->fs_info->sb->s_flags & MS_RDONLY) 2073 return -EROFS; 2074 2075 vol_args = memdup_user(arg, sizeof(*vol_args)); 2076 if (IS_ERR(vol_args)) 2077 return PTR_ERR(vol_args); 2078 2079 vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; 2080 ret = btrfs_rm_device(root, vol_args->name); 2081 2082 kfree(vol_args); 2083 return ret; 2084 } 2085 2086 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg) 2087 { 2088 struct btrfs_ioctl_fs_info_args *fi_args; 2089 struct btrfs_device *device; 2090 struct btrfs_device *next; 2091 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 2092 int ret = 0; 2093 2094 if (!capable(CAP_SYS_ADMIN)) 2095 return -EPERM; 2096 2097 fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL); 2098 if (!fi_args) 2099 return -ENOMEM; 2100 2101 fi_args->num_devices = fs_devices->num_devices; 2102 memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid)); 2103 2104 mutex_lock(&fs_devices->device_list_mutex); 2105 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { 2106 if (device->devid > fi_args->max_id) 2107 fi_args->max_id = device->devid; 2108 } 2109 mutex_unlock(&fs_devices->device_list_mutex); 2110 2111 if (copy_to_user(arg, fi_args, sizeof(*fi_args))) 2112 ret = -EFAULT; 2113 2114 kfree(fi_args); 2115 return ret; 2116 } 2117 2118 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg) 2119 { 2120 struct btrfs_ioctl_dev_info_args *di_args; 2121 struct btrfs_device *dev; 2122 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; 2123 int ret = 0; 2124 char *s_uuid = NULL; 2125 char empty_uuid[BTRFS_UUID_SIZE] = {0}; 2126 2127 if (!capable(CAP_SYS_ADMIN)) 2128 return -EPERM; 2129 2130 di_args = memdup_user(arg, sizeof(*di_args)); 2131 if (IS_ERR(di_args)) 2132 return PTR_ERR(di_args); 2133 2134 if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0) 2135 s_uuid = di_args->uuid; 2136 2137 mutex_lock(&fs_devices->device_list_mutex); 2138 dev = btrfs_find_device(root, di_args->devid, s_uuid, NULL); 2139 mutex_unlock(&fs_devices->device_list_mutex); 2140 2141 if (!dev) { 2142 ret = -ENODEV; 2143 goto out; 2144 } 2145 2146 di_args->devid = dev->devid; 2147 di_args->bytes_used = dev->bytes_used; 2148 di_args->total_bytes = dev->total_bytes; 2149 memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid)); 2150 strncpy(di_args->path, dev->name, sizeof(di_args->path)); 2151 2152 out: 2153 if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args))) 2154 ret = -EFAULT; 2155 2156 kfree(di_args); 2157 return ret; 2158 } 2159 2160 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, 2161 u64 off, u64 olen, u64 destoff) 2162 { 2163 struct inode *inode = fdentry(file)->d_inode; 2164 struct btrfs_root *root = BTRFS_I(inode)->root; 2165 struct file *src_file; 2166 struct inode *src; 2167 struct btrfs_trans_handle *trans; 2168 struct btrfs_path *path; 2169 struct extent_buffer *leaf; 2170 char *buf; 2171 struct btrfs_key key; 2172 u32 nritems; 2173 int slot; 2174 int ret; 2175 u64 len = olen; 2176 u64 bs = root->fs_info->sb->s_blocksize; 2177 u64 hint_byte; 2178 2179 /* 2180 * TODO: 2181 * - split compressed inline extents. annoying: we need to 2182 * decompress into destination's address_space (the file offset 2183 * may change, so source mapping won't do), then recompress (or 2184 * otherwise reinsert) a subrange. 2185 * - allow ranges within the same file to be cloned (provided 2186 * they don't overlap)? 2187 */ 2188 2189 /* the destination must be opened for writing */ 2190 if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND)) 2191 return -EINVAL; 2192 2193 if (btrfs_root_readonly(root)) 2194 return -EROFS; 2195 2196 ret = mnt_want_write(file->f_path.mnt); 2197 if (ret) 2198 return ret; 2199 2200 src_file = fget(srcfd); 2201 if (!src_file) { 2202 ret = -EBADF; 2203 goto out_drop_write; 2204 } 2205 2206 src = src_file->f_dentry->d_inode; 2207 2208 ret = -EINVAL; 2209 if (src == inode) 2210 goto out_fput; 2211 2212 /* the src must be open for reading */ 2213 if (!(src_file->f_mode & FMODE_READ)) 2214 goto out_fput; 2215 2216 /* don't make the dst file partly checksummed */ 2217 if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) != 2218 (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) 2219 goto out_fput; 2220 2221 ret = -EISDIR; 2222 if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode)) 2223 goto out_fput; 2224 2225 ret = -EXDEV; 2226 if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root) 2227 goto out_fput; 2228 2229 ret = -ENOMEM; 2230 buf = vmalloc(btrfs_level_size(root, 0)); 2231 if (!buf) 2232 goto out_fput; 2233 2234 path = btrfs_alloc_path(); 2235 if (!path) { 2236 vfree(buf); 2237 goto out_fput; 2238 } 2239 path->reada = 2; 2240 2241 if (inode < src) { 2242 mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); 2243 mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD); 2244 } else { 2245 mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT); 2246 mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); 2247 } 2248 2249 /* determine range to clone */ 2250 ret = -EINVAL; 2251 if (off + len > src->i_size || off + len < off) 2252 goto out_unlock; 2253 if (len == 0) 2254 olen = len = src->i_size - off; 2255 /* if we extend to eof, continue to block boundary */ 2256 if (off + len == src->i_size) 2257 len = ALIGN(src->i_size, bs) - off; 2258 2259 /* verify the end result is block aligned */ 2260 if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) || 2261 !IS_ALIGNED(destoff, bs)) 2262 goto out_unlock; 2263 2264 if (destoff > inode->i_size) { 2265 ret = btrfs_cont_expand(inode, inode->i_size, destoff); 2266 if (ret) 2267 goto out_unlock; 2268 } 2269 2270 /* truncate page cache pages from target inode range */ 2271 truncate_inode_pages_range(&inode->i_data, destoff, 2272 PAGE_CACHE_ALIGN(destoff + len) - 1); 2273 2274 /* do any pending delalloc/csum calc on src, one way or 2275 another, and lock file content */ 2276 while (1) { 2277 struct btrfs_ordered_extent *ordered; 2278 lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 2279 ordered = btrfs_lookup_first_ordered_extent(src, off+len); 2280 if (!ordered && 2281 !test_range_bit(&BTRFS_I(src)->io_tree, off, off+len, 2282 EXTENT_DELALLOC, 0, NULL)) 2283 break; 2284 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 2285 if (ordered) 2286 btrfs_put_ordered_extent(ordered); 2287 btrfs_wait_ordered_range(src, off, len); 2288 } 2289 2290 /* clone data */ 2291 key.objectid = btrfs_ino(src); 2292 key.type = BTRFS_EXTENT_DATA_KEY; 2293 key.offset = 0; 2294 2295 while (1) { 2296 /* 2297 * note the key will change type as we walk through the 2298 * tree. 2299 */ 2300 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 2301 if (ret < 0) 2302 goto out; 2303 2304 nritems = btrfs_header_nritems(path->nodes[0]); 2305 if (path->slots[0] >= nritems) { 2306 ret = btrfs_next_leaf(root, path); 2307 if (ret < 0) 2308 goto out; 2309 if (ret > 0) 2310 break; 2311 nritems = btrfs_header_nritems(path->nodes[0]); 2312 } 2313 leaf = path->nodes[0]; 2314 slot = path->slots[0]; 2315 2316 btrfs_item_key_to_cpu(leaf, &key, slot); 2317 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY || 2318 key.objectid != btrfs_ino(src)) 2319 break; 2320 2321 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { 2322 struct btrfs_file_extent_item *extent; 2323 int type; 2324 u32 size; 2325 struct btrfs_key new_key; 2326 u64 disko = 0, diskl = 0; 2327 u64 datao = 0, datal = 0; 2328 u8 comp; 2329 u64 endoff; 2330 2331 size = btrfs_item_size_nr(leaf, slot); 2332 read_extent_buffer(leaf, buf, 2333 btrfs_item_ptr_offset(leaf, slot), 2334 size); 2335 2336 extent = btrfs_item_ptr(leaf, slot, 2337 struct btrfs_file_extent_item); 2338 comp = btrfs_file_extent_compression(leaf, extent); 2339 type = btrfs_file_extent_type(leaf, extent); 2340 if (type == BTRFS_FILE_EXTENT_REG || 2341 type == BTRFS_FILE_EXTENT_PREALLOC) { 2342 disko = btrfs_file_extent_disk_bytenr(leaf, 2343 extent); 2344 diskl = btrfs_file_extent_disk_num_bytes(leaf, 2345 extent); 2346 datao = btrfs_file_extent_offset(leaf, extent); 2347 datal = btrfs_file_extent_num_bytes(leaf, 2348 extent); 2349 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 2350 /* take upper bound, may be compressed */ 2351 datal = btrfs_file_extent_ram_bytes(leaf, 2352 extent); 2353 } 2354 btrfs_release_path(path); 2355 2356 if (key.offset + datal <= off || 2357 key.offset >= off+len) 2358 goto next; 2359 2360 memcpy(&new_key, &key, sizeof(new_key)); 2361 new_key.objectid = btrfs_ino(inode); 2362 if (off <= key.offset) 2363 new_key.offset = key.offset + destoff - off; 2364 else 2365 new_key.offset = destoff; 2366 2367 /* 2368 * 1 - adjusting old extent (we may have to split it) 2369 * 1 - add new extent 2370 * 1 - inode update 2371 */ 2372 trans = btrfs_start_transaction(root, 3); 2373 if (IS_ERR(trans)) { 2374 ret = PTR_ERR(trans); 2375 goto out; 2376 } 2377 2378 if (type == BTRFS_FILE_EXTENT_REG || 2379 type == BTRFS_FILE_EXTENT_PREALLOC) { 2380 /* 2381 * a | --- range to clone ---| b 2382 * | ------------- extent ------------- | 2383 */ 2384 2385 /* substract range b */ 2386 if (key.offset + datal > off + len) 2387 datal = off + len - key.offset; 2388 2389 /* substract range a */ 2390 if (off > key.offset) { 2391 datao += off - key.offset; 2392 datal -= off - key.offset; 2393 } 2394 2395 ret = btrfs_drop_extents(trans, inode, 2396 new_key.offset, 2397 new_key.offset + datal, 2398 &hint_byte, 1); 2399 BUG_ON(ret); 2400 2401 ret = btrfs_insert_empty_item(trans, root, path, 2402 &new_key, size); 2403 BUG_ON(ret); 2404 2405 leaf = path->nodes[0]; 2406 slot = path->slots[0]; 2407 write_extent_buffer(leaf, buf, 2408 btrfs_item_ptr_offset(leaf, slot), 2409 size); 2410 2411 extent = btrfs_item_ptr(leaf, slot, 2412 struct btrfs_file_extent_item); 2413 2414 /* disko == 0 means it's a hole */ 2415 if (!disko) 2416 datao = 0; 2417 2418 btrfs_set_file_extent_offset(leaf, extent, 2419 datao); 2420 btrfs_set_file_extent_num_bytes(leaf, extent, 2421 datal); 2422 if (disko) { 2423 inode_add_bytes(inode, datal); 2424 ret = btrfs_inc_extent_ref(trans, root, 2425 disko, diskl, 0, 2426 root->root_key.objectid, 2427 btrfs_ino(inode), 2428 new_key.offset - datao); 2429 BUG_ON(ret); 2430 } 2431 } else if (type == BTRFS_FILE_EXTENT_INLINE) { 2432 u64 skip = 0; 2433 u64 trim = 0; 2434 if (off > key.offset) { 2435 skip = off - key.offset; 2436 new_key.offset += skip; 2437 } 2438 2439 if (key.offset + datal > off+len) 2440 trim = key.offset + datal - (off+len); 2441 2442 if (comp && (skip || trim)) { 2443 ret = -EINVAL; 2444 btrfs_end_transaction(trans, root); 2445 goto out; 2446 } 2447 size -= skip + trim; 2448 datal -= skip + trim; 2449 2450 ret = btrfs_drop_extents(trans, inode, 2451 new_key.offset, 2452 new_key.offset + datal, 2453 &hint_byte, 1); 2454 BUG_ON(ret); 2455 2456 ret = btrfs_insert_empty_item(trans, root, path, 2457 &new_key, size); 2458 BUG_ON(ret); 2459 2460 if (skip) { 2461 u32 start = 2462 btrfs_file_extent_calc_inline_size(0); 2463 memmove(buf+start, buf+start+skip, 2464 datal); 2465 } 2466 2467 leaf = path->nodes[0]; 2468 slot = path->slots[0]; 2469 write_extent_buffer(leaf, buf, 2470 btrfs_item_ptr_offset(leaf, slot), 2471 size); 2472 inode_add_bytes(inode, datal); 2473 } 2474 2475 btrfs_mark_buffer_dirty(leaf); 2476 btrfs_release_path(path); 2477 2478 inode->i_mtime = inode->i_ctime = CURRENT_TIME; 2479 2480 /* 2481 * we round up to the block size at eof when 2482 * determining which extents to clone above, 2483 * but shouldn't round up the file size 2484 */ 2485 endoff = new_key.offset + datal; 2486 if (endoff > destoff+olen) 2487 endoff = destoff+olen; 2488 if (endoff > inode->i_size) 2489 btrfs_i_size_write(inode, endoff); 2490 2491 ret = btrfs_update_inode(trans, root, inode); 2492 BUG_ON(ret); 2493 btrfs_end_transaction(trans, root); 2494 } 2495 next: 2496 btrfs_release_path(path); 2497 key.offset++; 2498 } 2499 ret = 0; 2500 out: 2501 btrfs_release_path(path); 2502 unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS); 2503 out_unlock: 2504 mutex_unlock(&src->i_mutex); 2505 mutex_unlock(&inode->i_mutex); 2506 vfree(buf); 2507 btrfs_free_path(path); 2508 out_fput: 2509 fput(src_file); 2510 out_drop_write: 2511 mnt_drop_write(file->f_path.mnt); 2512 return ret; 2513 } 2514 2515 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp) 2516 { 2517 struct btrfs_ioctl_clone_range_args args; 2518 2519 if (copy_from_user(&args, argp, sizeof(args))) 2520 return -EFAULT; 2521 return btrfs_ioctl_clone(file, args.src_fd, args.src_offset, 2522 args.src_length, args.dest_offset); 2523 } 2524 2525 /* 2526 * there are many ways the trans_start and trans_end ioctls can lead 2527 * to deadlocks. They should only be used by applications that 2528 * basically own the machine, and have a very in depth understanding 2529 * of all the possible deadlocks and enospc problems. 2530 */ 2531 static long btrfs_ioctl_trans_start(struct file *file) 2532 { 2533 struct inode *inode = fdentry(file)->d_inode; 2534 struct btrfs_root *root = BTRFS_I(inode)->root; 2535 struct btrfs_trans_handle *trans; 2536 int ret; 2537 2538 ret = -EPERM; 2539 if (!capable(CAP_SYS_ADMIN)) 2540 goto out; 2541 2542 ret = -EINPROGRESS; 2543 if (file->private_data) 2544 goto out; 2545 2546 ret = -EROFS; 2547 if (btrfs_root_readonly(root)) 2548 goto out; 2549 2550 ret = mnt_want_write(file->f_path.mnt); 2551 if (ret) 2552 goto out; 2553 2554 atomic_inc(&root->fs_info->open_ioctl_trans); 2555 2556 ret = -ENOMEM; 2557 trans = btrfs_start_ioctl_transaction(root); 2558 if (IS_ERR(trans)) 2559 goto out_drop; 2560 2561 file->private_data = trans; 2562 return 0; 2563 2564 out_drop: 2565 atomic_dec(&root->fs_info->open_ioctl_trans); 2566 mnt_drop_write(file->f_path.mnt); 2567 out: 2568 return ret; 2569 } 2570 2571 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) 2572 { 2573 struct inode *inode = fdentry(file)->d_inode; 2574 struct btrfs_root *root = BTRFS_I(inode)->root; 2575 struct btrfs_root *new_root; 2576 struct btrfs_dir_item *di; 2577 struct btrfs_trans_handle *trans; 2578 struct btrfs_path *path; 2579 struct btrfs_key location; 2580 struct btrfs_disk_key disk_key; 2581 struct btrfs_super_block *disk_super; 2582 u64 features; 2583 u64 objectid = 0; 2584 u64 dir_id; 2585 2586 if (!capable(CAP_SYS_ADMIN)) 2587 return -EPERM; 2588 2589 if (copy_from_user(&objectid, argp, sizeof(objectid))) 2590 return -EFAULT; 2591 2592 if (!objectid) 2593 objectid = root->root_key.objectid; 2594 2595 location.objectid = objectid; 2596 location.type = BTRFS_ROOT_ITEM_KEY; 2597 location.offset = (u64)-1; 2598 2599 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 2600 if (IS_ERR(new_root)) 2601 return PTR_ERR(new_root); 2602 2603 if (btrfs_root_refs(&new_root->root_item) == 0) 2604 return -ENOENT; 2605 2606 path = btrfs_alloc_path(); 2607 if (!path) 2608 return -ENOMEM; 2609 path->leave_spinning = 1; 2610 2611 trans = btrfs_start_transaction(root, 1); 2612 if (IS_ERR(trans)) { 2613 btrfs_free_path(path); 2614 return PTR_ERR(trans); 2615 } 2616 2617 dir_id = btrfs_super_root_dir(root->fs_info->super_copy); 2618 di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path, 2619 dir_id, "default", 7, 1); 2620 if (IS_ERR_OR_NULL(di)) { 2621 btrfs_free_path(path); 2622 btrfs_end_transaction(trans, root); 2623 printk(KERN_ERR "Umm, you don't have the default dir item, " 2624 "this isn't going to work\n"); 2625 return -ENOENT; 2626 } 2627 2628 btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); 2629 btrfs_set_dir_item_key(path->nodes[0], di, &disk_key); 2630 btrfs_mark_buffer_dirty(path->nodes[0]); 2631 btrfs_free_path(path); 2632 2633 disk_super = root->fs_info->super_copy; 2634 features = btrfs_super_incompat_flags(disk_super); 2635 if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) { 2636 features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL; 2637 btrfs_set_super_incompat_flags(disk_super, features); 2638 } 2639 btrfs_end_transaction(trans, root); 2640 2641 return 0; 2642 } 2643 2644 static void get_block_group_info(struct list_head *groups_list, 2645 struct btrfs_ioctl_space_info *space) 2646 { 2647 struct btrfs_block_group_cache *block_group; 2648 2649 space->total_bytes = 0; 2650 space->used_bytes = 0; 2651 space->flags = 0; 2652 list_for_each_entry(block_group, groups_list, list) { 2653 space->flags = block_group->flags; 2654 space->total_bytes += block_group->key.offset; 2655 space->used_bytes += 2656 btrfs_block_group_used(&block_group->item); 2657 } 2658 } 2659 2660 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg) 2661 { 2662 struct btrfs_ioctl_space_args space_args; 2663 struct btrfs_ioctl_space_info space; 2664 struct btrfs_ioctl_space_info *dest; 2665 struct btrfs_ioctl_space_info *dest_orig; 2666 struct btrfs_ioctl_space_info __user *user_dest; 2667 struct btrfs_space_info *info; 2668 u64 types[] = {BTRFS_BLOCK_GROUP_DATA, 2669 BTRFS_BLOCK_GROUP_SYSTEM, 2670 BTRFS_BLOCK_GROUP_METADATA, 2671 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA}; 2672 int num_types = 4; 2673 int alloc_size; 2674 int ret = 0; 2675 u64 slot_count = 0; 2676 int i, c; 2677 2678 if (copy_from_user(&space_args, 2679 (struct btrfs_ioctl_space_args __user *)arg, 2680 sizeof(space_args))) 2681 return -EFAULT; 2682 2683 for (i = 0; i < num_types; i++) { 2684 struct btrfs_space_info *tmp; 2685 2686 info = NULL; 2687 rcu_read_lock(); 2688 list_for_each_entry_rcu(tmp, &root->fs_info->space_info, 2689 list) { 2690 if (tmp->flags == types[i]) { 2691 info = tmp; 2692 break; 2693 } 2694 } 2695 rcu_read_unlock(); 2696 2697 if (!info) 2698 continue; 2699 2700 down_read(&info->groups_sem); 2701 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { 2702 if (!list_empty(&info->block_groups[c])) 2703 slot_count++; 2704 } 2705 up_read(&info->groups_sem); 2706 } 2707 2708 /* space_slots == 0 means they are asking for a count */ 2709 if (space_args.space_slots == 0) { 2710 space_args.total_spaces = slot_count; 2711 goto out; 2712 } 2713 2714 slot_count = min_t(u64, space_args.space_slots, slot_count); 2715 2716 alloc_size = sizeof(*dest) * slot_count; 2717 2718 /* we generally have at most 6 or so space infos, one for each raid 2719 * level. So, a whole page should be more than enough for everyone 2720 */ 2721 if (alloc_size > PAGE_CACHE_SIZE) 2722 return -ENOMEM; 2723 2724 space_args.total_spaces = 0; 2725 dest = kmalloc(alloc_size, GFP_NOFS); 2726 if (!dest) 2727 return -ENOMEM; 2728 dest_orig = dest; 2729 2730 /* now we have a buffer to copy into */ 2731 for (i = 0; i < num_types; i++) { 2732 struct btrfs_space_info *tmp; 2733 2734 if (!slot_count) 2735 break; 2736 2737 info = NULL; 2738 rcu_read_lock(); 2739 list_for_each_entry_rcu(tmp, &root->fs_info->space_info, 2740 list) { 2741 if (tmp->flags == types[i]) { 2742 info = tmp; 2743 break; 2744 } 2745 } 2746 rcu_read_unlock(); 2747 2748 if (!info) 2749 continue; 2750 down_read(&info->groups_sem); 2751 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) { 2752 if (!list_empty(&info->block_groups[c])) { 2753 get_block_group_info(&info->block_groups[c], 2754 &space); 2755 memcpy(dest, &space, sizeof(space)); 2756 dest++; 2757 space_args.total_spaces++; 2758 slot_count--; 2759 } 2760 if (!slot_count) 2761 break; 2762 } 2763 up_read(&info->groups_sem); 2764 } 2765 2766 user_dest = (struct btrfs_ioctl_space_info *) 2767 (arg + sizeof(struct btrfs_ioctl_space_args)); 2768 2769 if (copy_to_user(user_dest, dest_orig, alloc_size)) 2770 ret = -EFAULT; 2771 2772 kfree(dest_orig); 2773 out: 2774 if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args))) 2775 ret = -EFAULT; 2776 2777 return ret; 2778 } 2779 2780 /* 2781 * there are many ways the trans_start and trans_end ioctls can lead 2782 * to deadlocks. They should only be used by applications that 2783 * basically own the machine, and have a very in depth understanding 2784 * of all the possible deadlocks and enospc problems. 2785 */ 2786 long btrfs_ioctl_trans_end(struct file *file) 2787 { 2788 struct inode *inode = fdentry(file)->d_inode; 2789 struct btrfs_root *root = BTRFS_I(inode)->root; 2790 struct btrfs_trans_handle *trans; 2791 2792 trans = file->private_data; 2793 if (!trans) 2794 return -EINVAL; 2795 file->private_data = NULL; 2796 2797 btrfs_end_transaction(trans, root); 2798 2799 atomic_dec(&root->fs_info->open_ioctl_trans); 2800 2801 mnt_drop_write(file->f_path.mnt); 2802 return 0; 2803 } 2804 2805 static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp) 2806 { 2807 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root; 2808 struct btrfs_trans_handle *trans; 2809 u64 transid; 2810 int ret; 2811 2812 trans = btrfs_start_transaction(root, 0); 2813 if (IS_ERR(trans)) 2814 return PTR_ERR(trans); 2815 transid = trans->transid; 2816 ret = btrfs_commit_transaction_async(trans, root, 0); 2817 if (ret) { 2818 btrfs_end_transaction(trans, root); 2819 return ret; 2820 } 2821 2822 if (argp) 2823 if (copy_to_user(argp, &transid, sizeof(transid))) 2824 return -EFAULT; 2825 return 0; 2826 } 2827 2828 static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp) 2829 { 2830 struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root; 2831 u64 transid; 2832 2833 if (argp) { 2834 if (copy_from_user(&transid, argp, sizeof(transid))) 2835 return -EFAULT; 2836 } else { 2837 transid = 0; /* current trans */ 2838 } 2839 return btrfs_wait_for_commit(root, transid); 2840 } 2841 2842 static long btrfs_ioctl_scrub(struct btrfs_root *root, void __user *arg) 2843 { 2844 int ret; 2845 struct btrfs_ioctl_scrub_args *sa; 2846 2847 if (!capable(CAP_SYS_ADMIN)) 2848 return -EPERM; 2849 2850 sa = memdup_user(arg, sizeof(*sa)); 2851 if (IS_ERR(sa)) 2852 return PTR_ERR(sa); 2853 2854 ret = btrfs_scrub_dev(root, sa->devid, sa->start, sa->end, 2855 &sa->progress, sa->flags & BTRFS_SCRUB_READONLY); 2856 2857 if (copy_to_user(arg, sa, sizeof(*sa))) 2858 ret = -EFAULT; 2859 2860 kfree(sa); 2861 return ret; 2862 } 2863 2864 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg) 2865 { 2866 if (!capable(CAP_SYS_ADMIN)) 2867 return -EPERM; 2868 2869 return btrfs_scrub_cancel(root); 2870 } 2871 2872 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root, 2873 void __user *arg) 2874 { 2875 struct btrfs_ioctl_scrub_args *sa; 2876 int ret; 2877 2878 if (!capable(CAP_SYS_ADMIN)) 2879 return -EPERM; 2880 2881 sa = memdup_user(arg, sizeof(*sa)); 2882 if (IS_ERR(sa)) 2883 return PTR_ERR(sa); 2884 2885 ret = btrfs_scrub_progress(root, sa->devid, &sa->progress); 2886 2887 if (copy_to_user(arg, sa, sizeof(*sa))) 2888 ret = -EFAULT; 2889 2890 kfree(sa); 2891 return ret; 2892 } 2893 2894 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg) 2895 { 2896 int ret = 0; 2897 int i; 2898 u64 rel_ptr; 2899 int size; 2900 struct btrfs_ioctl_ino_path_args *ipa = NULL; 2901 struct inode_fs_paths *ipath = NULL; 2902 struct btrfs_path *path; 2903 2904 if (!capable(CAP_SYS_ADMIN)) 2905 return -EPERM; 2906 2907 path = btrfs_alloc_path(); 2908 if (!path) { 2909 ret = -ENOMEM; 2910 goto out; 2911 } 2912 2913 ipa = memdup_user(arg, sizeof(*ipa)); 2914 if (IS_ERR(ipa)) { 2915 ret = PTR_ERR(ipa); 2916 ipa = NULL; 2917 goto out; 2918 } 2919 2920 size = min_t(u32, ipa->size, 4096); 2921 ipath = init_ipath(size, root, path); 2922 if (IS_ERR(ipath)) { 2923 ret = PTR_ERR(ipath); 2924 ipath = NULL; 2925 goto out; 2926 } 2927 2928 ret = paths_from_inode(ipa->inum, ipath); 2929 if (ret < 0) 2930 goto out; 2931 2932 for (i = 0; i < ipath->fspath->elem_cnt; ++i) { 2933 rel_ptr = ipath->fspath->val[i] - (u64)ipath->fspath->val; 2934 ipath->fspath->val[i] = rel_ptr; 2935 } 2936 2937 ret = copy_to_user((void *)ipa->fspath, (void *)ipath->fspath, size); 2938 if (ret) { 2939 ret = -EFAULT; 2940 goto out; 2941 } 2942 2943 out: 2944 btrfs_free_path(path); 2945 free_ipath(ipath); 2946 kfree(ipa); 2947 2948 return ret; 2949 } 2950 2951 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx) 2952 { 2953 struct btrfs_data_container *inodes = ctx; 2954 const size_t c = 3 * sizeof(u64); 2955 2956 if (inodes->bytes_left >= c) { 2957 inodes->bytes_left -= c; 2958 inodes->val[inodes->elem_cnt] = inum; 2959 inodes->val[inodes->elem_cnt + 1] = offset; 2960 inodes->val[inodes->elem_cnt + 2] = root; 2961 inodes->elem_cnt += 3; 2962 } else { 2963 inodes->bytes_missing += c - inodes->bytes_left; 2964 inodes->bytes_left = 0; 2965 inodes->elem_missed += 3; 2966 } 2967 2968 return 0; 2969 } 2970 2971 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root, 2972 void __user *arg) 2973 { 2974 int ret = 0; 2975 int size; 2976 u64 extent_offset; 2977 struct btrfs_ioctl_logical_ino_args *loi; 2978 struct btrfs_data_container *inodes = NULL; 2979 struct btrfs_path *path = NULL; 2980 struct btrfs_key key; 2981 2982 if (!capable(CAP_SYS_ADMIN)) 2983 return -EPERM; 2984 2985 loi = memdup_user(arg, sizeof(*loi)); 2986 if (IS_ERR(loi)) { 2987 ret = PTR_ERR(loi); 2988 loi = NULL; 2989 goto out; 2990 } 2991 2992 path = btrfs_alloc_path(); 2993 if (!path) { 2994 ret = -ENOMEM; 2995 goto out; 2996 } 2997 2998 size = min_t(u32, loi->size, 4096); 2999 inodes = init_data_container(size); 3000 if (IS_ERR(inodes)) { 3001 ret = PTR_ERR(inodes); 3002 inodes = NULL; 3003 goto out; 3004 } 3005 3006 ret = extent_from_logical(root->fs_info, loi->logical, path, &key); 3007 3008 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) 3009 ret = -ENOENT; 3010 if (ret < 0) 3011 goto out; 3012 3013 extent_offset = loi->logical - key.objectid; 3014 ret = iterate_extent_inodes(root->fs_info, path, key.objectid, 3015 extent_offset, build_ino_list, inodes); 3016 3017 if (ret < 0) 3018 goto out; 3019 3020 ret = copy_to_user((void *)loi->inodes, (void *)inodes, size); 3021 if (ret) 3022 ret = -EFAULT; 3023 3024 out: 3025 btrfs_free_path(path); 3026 kfree(inodes); 3027 kfree(loi); 3028 3029 return ret; 3030 } 3031 3032 long btrfs_ioctl(struct file *file, unsigned int 3033 cmd, unsigned long arg) 3034 { 3035 struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; 3036 void __user *argp = (void __user *)arg; 3037 3038 switch (cmd) { 3039 case FS_IOC_GETFLAGS: 3040 return btrfs_ioctl_getflags(file, argp); 3041 case FS_IOC_SETFLAGS: 3042 return btrfs_ioctl_setflags(file, argp); 3043 case FS_IOC_GETVERSION: 3044 return btrfs_ioctl_getversion(file, argp); 3045 case FITRIM: 3046 return btrfs_ioctl_fitrim(file, argp); 3047 case BTRFS_IOC_SNAP_CREATE: 3048 return btrfs_ioctl_snap_create(file, argp, 0); 3049 case BTRFS_IOC_SNAP_CREATE_V2: 3050 return btrfs_ioctl_snap_create_v2(file, argp, 0); 3051 case BTRFS_IOC_SUBVOL_CREATE: 3052 return btrfs_ioctl_snap_create(file, argp, 1); 3053 case BTRFS_IOC_SNAP_DESTROY: 3054 return btrfs_ioctl_snap_destroy(file, argp); 3055 case BTRFS_IOC_SUBVOL_GETFLAGS: 3056 return btrfs_ioctl_subvol_getflags(file, argp); 3057 case BTRFS_IOC_SUBVOL_SETFLAGS: 3058 return btrfs_ioctl_subvol_setflags(file, argp); 3059 case BTRFS_IOC_DEFAULT_SUBVOL: 3060 return btrfs_ioctl_default_subvol(file, argp); 3061 case BTRFS_IOC_DEFRAG: 3062 return btrfs_ioctl_defrag(file, NULL); 3063 case BTRFS_IOC_DEFRAG_RANGE: 3064 return btrfs_ioctl_defrag(file, argp); 3065 case BTRFS_IOC_RESIZE: 3066 return btrfs_ioctl_resize(root, argp); 3067 case BTRFS_IOC_ADD_DEV: 3068 return btrfs_ioctl_add_dev(root, argp); 3069 case BTRFS_IOC_RM_DEV: 3070 return btrfs_ioctl_rm_dev(root, argp); 3071 case BTRFS_IOC_FS_INFO: 3072 return btrfs_ioctl_fs_info(root, argp); 3073 case BTRFS_IOC_DEV_INFO: 3074 return btrfs_ioctl_dev_info(root, argp); 3075 case BTRFS_IOC_BALANCE: 3076 return btrfs_balance(root->fs_info->dev_root); 3077 case BTRFS_IOC_CLONE: 3078 return btrfs_ioctl_clone(file, arg, 0, 0, 0); 3079 case BTRFS_IOC_CLONE_RANGE: 3080 return btrfs_ioctl_clone_range(file, argp); 3081 case BTRFS_IOC_TRANS_START: 3082 return btrfs_ioctl_trans_start(file); 3083 case BTRFS_IOC_TRANS_END: 3084 return btrfs_ioctl_trans_end(file); 3085 case BTRFS_IOC_TREE_SEARCH: 3086 return btrfs_ioctl_tree_search(file, argp); 3087 case BTRFS_IOC_INO_LOOKUP: 3088 return btrfs_ioctl_ino_lookup(file, argp); 3089 case BTRFS_IOC_INO_PATHS: 3090 return btrfs_ioctl_ino_to_path(root, argp); 3091 case BTRFS_IOC_LOGICAL_INO: 3092 return btrfs_ioctl_logical_to_ino(root, argp); 3093 case BTRFS_IOC_SPACE_INFO: 3094 return btrfs_ioctl_space_info(root, argp); 3095 case BTRFS_IOC_SYNC: 3096 btrfs_sync_fs(file->f_dentry->d_sb, 1); 3097 return 0; 3098 case BTRFS_IOC_START_SYNC: 3099 return btrfs_ioctl_start_sync(file, argp); 3100 case BTRFS_IOC_WAIT_SYNC: 3101 return btrfs_ioctl_wait_sync(file, argp); 3102 case BTRFS_IOC_SCRUB: 3103 return btrfs_ioctl_scrub(root, argp); 3104 case BTRFS_IOC_SCRUB_CANCEL: 3105 return btrfs_ioctl_scrub_cancel(root, argp); 3106 case BTRFS_IOC_SCRUB_PROGRESS: 3107 return btrfs_ioctl_scrub_progress(root, argp); 3108 } 3109 3110 return -ENOTTY; 3111 } 3112