xref: /linux/fs/btrfs/ioctl.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/fsnotify.h>
25 #include <linux/pagemap.h>
26 #include <linux/highmem.h>
27 #include <linux/time.h>
28 #include <linux/init.h>
29 #include <linux/string.h>
30 #include <linux/backing-dev.h>
31 #include <linux/mount.h>
32 #include <linux/mpage.h>
33 #include <linux/namei.h>
34 #include <linux/swap.h>
35 #include <linux/writeback.h>
36 #include <linux/statfs.h>
37 #include <linux/compat.h>
38 #include <linux/bit_spinlock.h>
39 #include <linux/security.h>
40 #include <linux/xattr.h>
41 #include <linux/vmalloc.h>
42 #include <linux/slab.h>
43 #include <linux/blkdev.h>
44 #include <linux/uuid.h>
45 #include "compat.h"
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "ioctl.h"
51 #include "print-tree.h"
52 #include "volumes.h"
53 #include "locking.h"
54 #include "inode-map.h"
55 #include "backref.h"
56 #include "rcu-string.h"
57 #include "send.h"
58 #include "dev-replace.h"
59 
60 /* Mask out flags that are inappropriate for the given type of inode. */
61 static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
62 {
63 	if (S_ISDIR(mode))
64 		return flags;
65 	else if (S_ISREG(mode))
66 		return flags & ~FS_DIRSYNC_FL;
67 	else
68 		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
69 }
70 
71 /*
72  * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
73  */
74 static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
75 {
76 	unsigned int iflags = 0;
77 
78 	if (flags & BTRFS_INODE_SYNC)
79 		iflags |= FS_SYNC_FL;
80 	if (flags & BTRFS_INODE_IMMUTABLE)
81 		iflags |= FS_IMMUTABLE_FL;
82 	if (flags & BTRFS_INODE_APPEND)
83 		iflags |= FS_APPEND_FL;
84 	if (flags & BTRFS_INODE_NODUMP)
85 		iflags |= FS_NODUMP_FL;
86 	if (flags & BTRFS_INODE_NOATIME)
87 		iflags |= FS_NOATIME_FL;
88 	if (flags & BTRFS_INODE_DIRSYNC)
89 		iflags |= FS_DIRSYNC_FL;
90 	if (flags & BTRFS_INODE_NODATACOW)
91 		iflags |= FS_NOCOW_FL;
92 
93 	if ((flags & BTRFS_INODE_COMPRESS) && !(flags & BTRFS_INODE_NOCOMPRESS))
94 		iflags |= FS_COMPR_FL;
95 	else if (flags & BTRFS_INODE_NOCOMPRESS)
96 		iflags |= FS_NOCOMP_FL;
97 
98 	return iflags;
99 }
100 
101 /*
102  * Update inode->i_flags based on the btrfs internal flags.
103  */
104 void btrfs_update_iflags(struct inode *inode)
105 {
106 	struct btrfs_inode *ip = BTRFS_I(inode);
107 
108 	inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
109 
110 	if (ip->flags & BTRFS_INODE_SYNC)
111 		inode->i_flags |= S_SYNC;
112 	if (ip->flags & BTRFS_INODE_IMMUTABLE)
113 		inode->i_flags |= S_IMMUTABLE;
114 	if (ip->flags & BTRFS_INODE_APPEND)
115 		inode->i_flags |= S_APPEND;
116 	if (ip->flags & BTRFS_INODE_NOATIME)
117 		inode->i_flags |= S_NOATIME;
118 	if (ip->flags & BTRFS_INODE_DIRSYNC)
119 		inode->i_flags |= S_DIRSYNC;
120 }
121 
122 /*
123  * Inherit flags from the parent inode.
124  *
125  * Currently only the compression flags and the cow flags are inherited.
126  */
127 void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
128 {
129 	unsigned int flags;
130 
131 	if (!dir)
132 		return;
133 
134 	flags = BTRFS_I(dir)->flags;
135 
136 	if (flags & BTRFS_INODE_NOCOMPRESS) {
137 		BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
138 		BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
139 	} else if (flags & BTRFS_INODE_COMPRESS) {
140 		BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
141 		BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
142 	}
143 
144 	if (flags & BTRFS_INODE_NODATACOW) {
145 		BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
146 		if (S_ISREG(inode->i_mode))
147 			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
148 	}
149 
150 	btrfs_update_iflags(inode);
151 }
152 
153 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
154 {
155 	struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
156 	unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
157 
158 	if (copy_to_user(arg, &flags, sizeof(flags)))
159 		return -EFAULT;
160 	return 0;
161 }
162 
163 static int check_flags(unsigned int flags)
164 {
165 	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
166 		      FS_NOATIME_FL | FS_NODUMP_FL | \
167 		      FS_SYNC_FL | FS_DIRSYNC_FL | \
168 		      FS_NOCOMP_FL | FS_COMPR_FL |
169 		      FS_NOCOW_FL))
170 		return -EOPNOTSUPP;
171 
172 	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
173 		return -EINVAL;
174 
175 	return 0;
176 }
177 
178 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
179 {
180 	struct inode *inode = file->f_path.dentry->d_inode;
181 	struct btrfs_inode *ip = BTRFS_I(inode);
182 	struct btrfs_root *root = ip->root;
183 	struct btrfs_trans_handle *trans;
184 	unsigned int flags, oldflags;
185 	int ret;
186 	u64 ip_oldflags;
187 	unsigned int i_oldflags;
188 	umode_t mode;
189 
190 	if (btrfs_root_readonly(root))
191 		return -EROFS;
192 
193 	if (copy_from_user(&flags, arg, sizeof(flags)))
194 		return -EFAULT;
195 
196 	ret = check_flags(flags);
197 	if (ret)
198 		return ret;
199 
200 	if (!inode_owner_or_capable(inode))
201 		return -EACCES;
202 
203 	ret = mnt_want_write_file(file);
204 	if (ret)
205 		return ret;
206 
207 	mutex_lock(&inode->i_mutex);
208 
209 	ip_oldflags = ip->flags;
210 	i_oldflags = inode->i_flags;
211 	mode = inode->i_mode;
212 
213 	flags = btrfs_mask_flags(inode->i_mode, flags);
214 	oldflags = btrfs_flags_to_ioctl(ip->flags);
215 	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
216 		if (!capable(CAP_LINUX_IMMUTABLE)) {
217 			ret = -EPERM;
218 			goto out_unlock;
219 		}
220 	}
221 
222 	if (flags & FS_SYNC_FL)
223 		ip->flags |= BTRFS_INODE_SYNC;
224 	else
225 		ip->flags &= ~BTRFS_INODE_SYNC;
226 	if (flags & FS_IMMUTABLE_FL)
227 		ip->flags |= BTRFS_INODE_IMMUTABLE;
228 	else
229 		ip->flags &= ~BTRFS_INODE_IMMUTABLE;
230 	if (flags & FS_APPEND_FL)
231 		ip->flags |= BTRFS_INODE_APPEND;
232 	else
233 		ip->flags &= ~BTRFS_INODE_APPEND;
234 	if (flags & FS_NODUMP_FL)
235 		ip->flags |= BTRFS_INODE_NODUMP;
236 	else
237 		ip->flags &= ~BTRFS_INODE_NODUMP;
238 	if (flags & FS_NOATIME_FL)
239 		ip->flags |= BTRFS_INODE_NOATIME;
240 	else
241 		ip->flags &= ~BTRFS_INODE_NOATIME;
242 	if (flags & FS_DIRSYNC_FL)
243 		ip->flags |= BTRFS_INODE_DIRSYNC;
244 	else
245 		ip->flags &= ~BTRFS_INODE_DIRSYNC;
246 	if (flags & FS_NOCOW_FL) {
247 		if (S_ISREG(mode)) {
248 			/*
249 			 * It's safe to turn csums off here, no extents exist.
250 			 * Otherwise we want the flag to reflect the real COW
251 			 * status of the file and will not set it.
252 			 */
253 			if (inode->i_size == 0)
254 				ip->flags |= BTRFS_INODE_NODATACOW
255 					   | BTRFS_INODE_NODATASUM;
256 		} else {
257 			ip->flags |= BTRFS_INODE_NODATACOW;
258 		}
259 	} else {
260 		/*
261 		 * Revert back under same assuptions as above
262 		 */
263 		if (S_ISREG(mode)) {
264 			if (inode->i_size == 0)
265 				ip->flags &= ~(BTRFS_INODE_NODATACOW
266 				             | BTRFS_INODE_NODATASUM);
267 		} else {
268 			ip->flags &= ~BTRFS_INODE_NODATACOW;
269 		}
270 	}
271 
272 	/*
273 	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
274 	 * flag may be changed automatically if compression code won't make
275 	 * things smaller.
276 	 */
277 	if (flags & FS_NOCOMP_FL) {
278 		ip->flags &= ~BTRFS_INODE_COMPRESS;
279 		ip->flags |= BTRFS_INODE_NOCOMPRESS;
280 	} else if (flags & FS_COMPR_FL) {
281 		ip->flags |= BTRFS_INODE_COMPRESS;
282 		ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
283 	} else {
284 		ip->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
285 	}
286 
287 	trans = btrfs_start_transaction(root, 1);
288 	if (IS_ERR(trans)) {
289 		ret = PTR_ERR(trans);
290 		goto out_drop;
291 	}
292 
293 	btrfs_update_iflags(inode);
294 	inode_inc_iversion(inode);
295 	inode->i_ctime = CURRENT_TIME;
296 	ret = btrfs_update_inode(trans, root, inode);
297 
298 	btrfs_end_transaction(trans, root);
299  out_drop:
300 	if (ret) {
301 		ip->flags = ip_oldflags;
302 		inode->i_flags = i_oldflags;
303 	}
304 
305  out_unlock:
306 	mutex_unlock(&inode->i_mutex);
307 	mnt_drop_write_file(file);
308 	return ret;
309 }
310 
311 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
312 {
313 	struct inode *inode = file->f_path.dentry->d_inode;
314 
315 	return put_user(inode->i_generation, arg);
316 }
317 
318 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
319 {
320 	struct btrfs_fs_info *fs_info = btrfs_sb(fdentry(file)->d_sb);
321 	struct btrfs_device *device;
322 	struct request_queue *q;
323 	struct fstrim_range range;
324 	u64 minlen = ULLONG_MAX;
325 	u64 num_devices = 0;
326 	u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
327 	int ret;
328 
329 	if (!capable(CAP_SYS_ADMIN))
330 		return -EPERM;
331 
332 	rcu_read_lock();
333 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
334 				dev_list) {
335 		if (!device->bdev)
336 			continue;
337 		q = bdev_get_queue(device->bdev);
338 		if (blk_queue_discard(q)) {
339 			num_devices++;
340 			minlen = min((u64)q->limits.discard_granularity,
341 				     minlen);
342 		}
343 	}
344 	rcu_read_unlock();
345 
346 	if (!num_devices)
347 		return -EOPNOTSUPP;
348 	if (copy_from_user(&range, arg, sizeof(range)))
349 		return -EFAULT;
350 	if (range.start > total_bytes ||
351 	    range.len < fs_info->sb->s_blocksize)
352 		return -EINVAL;
353 
354 	range.len = min(range.len, total_bytes - range.start);
355 	range.minlen = max(range.minlen, minlen);
356 	ret = btrfs_trim_fs(fs_info->tree_root, &range);
357 	if (ret < 0)
358 		return ret;
359 
360 	if (copy_to_user(arg, &range, sizeof(range)))
361 		return -EFAULT;
362 
363 	return 0;
364 }
365 
366 static noinline int create_subvol(struct btrfs_root *root,
367 				  struct dentry *dentry,
368 				  char *name, int namelen,
369 				  u64 *async_transid,
370 				  struct btrfs_qgroup_inherit **inherit)
371 {
372 	struct btrfs_trans_handle *trans;
373 	struct btrfs_key key;
374 	struct btrfs_root_item root_item;
375 	struct btrfs_inode_item *inode_item;
376 	struct extent_buffer *leaf;
377 	struct btrfs_root *new_root;
378 	struct dentry *parent = dentry->d_parent;
379 	struct inode *dir;
380 	struct timespec cur_time = CURRENT_TIME;
381 	int ret;
382 	int err;
383 	u64 objectid;
384 	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
385 	u64 index = 0;
386 	uuid_le new_uuid;
387 
388 	ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
389 	if (ret)
390 		return ret;
391 
392 	dir = parent->d_inode;
393 
394 	/*
395 	 * 1 - inode item
396 	 * 2 - refs
397 	 * 1 - root item
398 	 * 2 - dir items
399 	 */
400 	trans = btrfs_start_transaction(root, 6);
401 	if (IS_ERR(trans))
402 		return PTR_ERR(trans);
403 
404 	ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid,
405 				   inherit ? *inherit : NULL);
406 	if (ret)
407 		goto fail;
408 
409 	leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
410 				      0, objectid, NULL, 0, 0, 0);
411 	if (IS_ERR(leaf)) {
412 		ret = PTR_ERR(leaf);
413 		goto fail;
414 	}
415 
416 	memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
417 	btrfs_set_header_bytenr(leaf, leaf->start);
418 	btrfs_set_header_generation(leaf, trans->transid);
419 	btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
420 	btrfs_set_header_owner(leaf, objectid);
421 
422 	write_extent_buffer(leaf, root->fs_info->fsid,
423 			    (unsigned long)btrfs_header_fsid(leaf),
424 			    BTRFS_FSID_SIZE);
425 	write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
426 			    (unsigned long)btrfs_header_chunk_tree_uuid(leaf),
427 			    BTRFS_UUID_SIZE);
428 	btrfs_mark_buffer_dirty(leaf);
429 
430 	memset(&root_item, 0, sizeof(root_item));
431 
432 	inode_item = &root_item.inode;
433 	inode_item->generation = cpu_to_le64(1);
434 	inode_item->size = cpu_to_le64(3);
435 	inode_item->nlink = cpu_to_le32(1);
436 	inode_item->nbytes = cpu_to_le64(root->leafsize);
437 	inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
438 
439 	root_item.flags = 0;
440 	root_item.byte_limit = 0;
441 	inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT);
442 
443 	btrfs_set_root_bytenr(&root_item, leaf->start);
444 	btrfs_set_root_generation(&root_item, trans->transid);
445 	btrfs_set_root_level(&root_item, 0);
446 	btrfs_set_root_refs(&root_item, 1);
447 	btrfs_set_root_used(&root_item, leaf->len);
448 	btrfs_set_root_last_snapshot(&root_item, 0);
449 
450 	btrfs_set_root_generation_v2(&root_item,
451 			btrfs_root_generation(&root_item));
452 	uuid_le_gen(&new_uuid);
453 	memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
454 	root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
455 	root_item.otime.nsec = cpu_to_le32(cur_time.tv_nsec);
456 	root_item.ctime = root_item.otime;
457 	btrfs_set_root_ctransid(&root_item, trans->transid);
458 	btrfs_set_root_otransid(&root_item, trans->transid);
459 
460 	btrfs_tree_unlock(leaf);
461 	free_extent_buffer(leaf);
462 	leaf = NULL;
463 
464 	btrfs_set_root_dirid(&root_item, new_dirid);
465 
466 	key.objectid = objectid;
467 	key.offset = 0;
468 	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
469 	ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
470 				&root_item);
471 	if (ret)
472 		goto fail;
473 
474 	key.offset = (u64)-1;
475 	new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
476 	if (IS_ERR(new_root)) {
477 		btrfs_abort_transaction(trans, root, PTR_ERR(new_root));
478 		ret = PTR_ERR(new_root);
479 		goto fail;
480 	}
481 
482 	btrfs_record_root_in_trans(trans, new_root);
483 
484 	ret = btrfs_create_subvol_root(trans, new_root, new_dirid);
485 	if (ret) {
486 		/* We potentially lose an unused inode item here */
487 		btrfs_abort_transaction(trans, root, ret);
488 		goto fail;
489 	}
490 
491 	/*
492 	 * insert the directory item
493 	 */
494 	ret = btrfs_set_inode_index(dir, &index);
495 	if (ret) {
496 		btrfs_abort_transaction(trans, root, ret);
497 		goto fail;
498 	}
499 
500 	ret = btrfs_insert_dir_item(trans, root,
501 				    name, namelen, dir, &key,
502 				    BTRFS_FT_DIR, index);
503 	if (ret) {
504 		btrfs_abort_transaction(trans, root, ret);
505 		goto fail;
506 	}
507 
508 	btrfs_i_size_write(dir, dir->i_size + namelen * 2);
509 	ret = btrfs_update_inode(trans, root, dir);
510 	BUG_ON(ret);
511 
512 	ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
513 				 objectid, root->root_key.objectid,
514 				 btrfs_ino(dir), index, name, namelen);
515 
516 	BUG_ON(ret);
517 
518 	d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
519 fail:
520 	if (async_transid) {
521 		*async_transid = trans->transid;
522 		err = btrfs_commit_transaction_async(trans, root, 1);
523 	} else {
524 		err = btrfs_commit_transaction(trans, root);
525 	}
526 	if (err && !ret)
527 		ret = err;
528 	return ret;
529 }
530 
531 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
532 			   char *name, int namelen, u64 *async_transid,
533 			   bool readonly, struct btrfs_qgroup_inherit **inherit)
534 {
535 	struct inode *inode;
536 	struct btrfs_pending_snapshot *pending_snapshot;
537 	struct btrfs_trans_handle *trans;
538 	int ret;
539 
540 	if (!root->ref_cows)
541 		return -EINVAL;
542 
543 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
544 	if (!pending_snapshot)
545 		return -ENOMEM;
546 
547 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
548 			     BTRFS_BLOCK_RSV_TEMP);
549 	pending_snapshot->dentry = dentry;
550 	pending_snapshot->root = root;
551 	pending_snapshot->readonly = readonly;
552 	if (inherit) {
553 		pending_snapshot->inherit = *inherit;
554 		*inherit = NULL;	/* take responsibility to free it */
555 	}
556 
557 	trans = btrfs_start_transaction(root->fs_info->extent_root, 6);
558 	if (IS_ERR(trans)) {
559 		ret = PTR_ERR(trans);
560 		goto fail;
561 	}
562 
563 	ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
564 	BUG_ON(ret);
565 
566 	spin_lock(&root->fs_info->trans_lock);
567 	list_add(&pending_snapshot->list,
568 		 &trans->transaction->pending_snapshots);
569 	spin_unlock(&root->fs_info->trans_lock);
570 	if (async_transid) {
571 		*async_transid = trans->transid;
572 		ret = btrfs_commit_transaction_async(trans,
573 				     root->fs_info->extent_root, 1);
574 	} else {
575 		ret = btrfs_commit_transaction(trans,
576 					       root->fs_info->extent_root);
577 	}
578 	if (ret) {
579 		/* cleanup_transaction has freed this for us */
580 		if (trans->aborted)
581 			pending_snapshot = NULL;
582 		goto fail;
583 	}
584 
585 	ret = pending_snapshot->error;
586 	if (ret)
587 		goto fail;
588 
589 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
590 	if (ret)
591 		goto fail;
592 
593 	inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
594 	if (IS_ERR(inode)) {
595 		ret = PTR_ERR(inode);
596 		goto fail;
597 	}
598 	BUG_ON(!inode);
599 	d_instantiate(dentry, inode);
600 	ret = 0;
601 fail:
602 	kfree(pending_snapshot);
603 	return ret;
604 }
605 
606 /*  copy of check_sticky in fs/namei.c()
607 * It's inline, so penalty for filesystems that don't use sticky bit is
608 * minimal.
609 */
610 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
611 {
612 	kuid_t fsuid = current_fsuid();
613 
614 	if (!(dir->i_mode & S_ISVTX))
615 		return 0;
616 	if (uid_eq(inode->i_uid, fsuid))
617 		return 0;
618 	if (uid_eq(dir->i_uid, fsuid))
619 		return 0;
620 	return !capable(CAP_FOWNER);
621 }
622 
623 /*  copy of may_delete in fs/namei.c()
624  *	Check whether we can remove a link victim from directory dir, check
625  *  whether the type of victim is right.
626  *  1. We can't do it if dir is read-only (done in permission())
627  *  2. We should have write and exec permissions on dir
628  *  3. We can't remove anything from append-only dir
629  *  4. We can't do anything with immutable dir (done in permission())
630  *  5. If the sticky bit on dir is set we should either
631  *	a. be owner of dir, or
632  *	b. be owner of victim, or
633  *	c. have CAP_FOWNER capability
634  *  6. If the victim is append-only or immutable we can't do antyhing with
635  *     links pointing to it.
636  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
637  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
638  *  9. We can't remove a root or mountpoint.
639  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
640  *     nfs_async_unlink().
641  */
642 
643 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
644 {
645 	int error;
646 
647 	if (!victim->d_inode)
648 		return -ENOENT;
649 
650 	BUG_ON(victim->d_parent->d_inode != dir);
651 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
652 
653 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
654 	if (error)
655 		return error;
656 	if (IS_APPEND(dir))
657 		return -EPERM;
658 	if (btrfs_check_sticky(dir, victim->d_inode)||
659 		IS_APPEND(victim->d_inode)||
660 	    IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
661 		return -EPERM;
662 	if (isdir) {
663 		if (!S_ISDIR(victim->d_inode->i_mode))
664 			return -ENOTDIR;
665 		if (IS_ROOT(victim))
666 			return -EBUSY;
667 	} else if (S_ISDIR(victim->d_inode->i_mode))
668 		return -EISDIR;
669 	if (IS_DEADDIR(dir))
670 		return -ENOENT;
671 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
672 		return -EBUSY;
673 	return 0;
674 }
675 
676 /* copy of may_create in fs/namei.c() */
677 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
678 {
679 	if (child->d_inode)
680 		return -EEXIST;
681 	if (IS_DEADDIR(dir))
682 		return -ENOENT;
683 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
684 }
685 
686 /*
687  * Create a new subvolume below @parent.  This is largely modeled after
688  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
689  * inside this filesystem so it's quite a bit simpler.
690  */
691 static noinline int btrfs_mksubvol(struct path *parent,
692 				   char *name, int namelen,
693 				   struct btrfs_root *snap_src,
694 				   u64 *async_transid, bool readonly,
695 				   struct btrfs_qgroup_inherit **inherit)
696 {
697 	struct inode *dir  = parent->dentry->d_inode;
698 	struct dentry *dentry;
699 	int error;
700 
701 	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
702 
703 	dentry = lookup_one_len(name, parent->dentry, namelen);
704 	error = PTR_ERR(dentry);
705 	if (IS_ERR(dentry))
706 		goto out_unlock;
707 
708 	error = -EEXIST;
709 	if (dentry->d_inode)
710 		goto out_dput;
711 
712 	error = btrfs_may_create(dir, dentry);
713 	if (error)
714 		goto out_dput;
715 
716 	/*
717 	 * even if this name doesn't exist, we may get hash collisions.
718 	 * check for them now when we can safely fail
719 	 */
720 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
721 					       dir->i_ino, name,
722 					       namelen);
723 	if (error)
724 		goto out_dput;
725 
726 	down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
727 
728 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
729 		goto out_up_read;
730 
731 	if (snap_src) {
732 		error = create_snapshot(snap_src, dentry, name, namelen,
733 					async_transid, readonly, inherit);
734 	} else {
735 		error = create_subvol(BTRFS_I(dir)->root, dentry,
736 				      name, namelen, async_transid, inherit);
737 	}
738 	if (!error)
739 		fsnotify_mkdir(dir, dentry);
740 out_up_read:
741 	up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
742 out_dput:
743 	dput(dentry);
744 out_unlock:
745 	mutex_unlock(&dir->i_mutex);
746 	return error;
747 }
748 
749 /*
750  * When we're defragging a range, we don't want to kick it off again
751  * if it is really just waiting for delalloc to send it down.
752  * If we find a nice big extent or delalloc range for the bytes in the
753  * file you want to defrag, we return 0 to let you know to skip this
754  * part of the file
755  */
756 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
757 {
758 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
759 	struct extent_map *em = NULL;
760 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
761 	u64 end;
762 
763 	read_lock(&em_tree->lock);
764 	em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
765 	read_unlock(&em_tree->lock);
766 
767 	if (em) {
768 		end = extent_map_end(em);
769 		free_extent_map(em);
770 		if (end - offset > thresh)
771 			return 0;
772 	}
773 	/* if we already have a nice delalloc here, just stop */
774 	thresh /= 2;
775 	end = count_range_bits(io_tree, &offset, offset + thresh,
776 			       thresh, EXTENT_DELALLOC, 1);
777 	if (end >= thresh)
778 		return 0;
779 	return 1;
780 }
781 
782 /*
783  * helper function to walk through a file and find extents
784  * newer than a specific transid, and smaller than thresh.
785  *
786  * This is used by the defragging code to find new and small
787  * extents
788  */
789 static int find_new_extents(struct btrfs_root *root,
790 			    struct inode *inode, u64 newer_than,
791 			    u64 *off, int thresh)
792 {
793 	struct btrfs_path *path;
794 	struct btrfs_key min_key;
795 	struct btrfs_key max_key;
796 	struct extent_buffer *leaf;
797 	struct btrfs_file_extent_item *extent;
798 	int type;
799 	int ret;
800 	u64 ino = btrfs_ino(inode);
801 
802 	path = btrfs_alloc_path();
803 	if (!path)
804 		return -ENOMEM;
805 
806 	min_key.objectid = ino;
807 	min_key.type = BTRFS_EXTENT_DATA_KEY;
808 	min_key.offset = *off;
809 
810 	max_key.objectid = ino;
811 	max_key.type = (u8)-1;
812 	max_key.offset = (u64)-1;
813 
814 	path->keep_locks = 1;
815 
816 	while(1) {
817 		ret = btrfs_search_forward(root, &min_key, &max_key,
818 					   path, 0, newer_than);
819 		if (ret != 0)
820 			goto none;
821 		if (min_key.objectid != ino)
822 			goto none;
823 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
824 			goto none;
825 
826 		leaf = path->nodes[0];
827 		extent = btrfs_item_ptr(leaf, path->slots[0],
828 					struct btrfs_file_extent_item);
829 
830 		type = btrfs_file_extent_type(leaf, extent);
831 		if (type == BTRFS_FILE_EXTENT_REG &&
832 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
833 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
834 			*off = min_key.offset;
835 			btrfs_free_path(path);
836 			return 0;
837 		}
838 
839 		if (min_key.offset == (u64)-1)
840 			goto none;
841 
842 		min_key.offset++;
843 		btrfs_release_path(path);
844 	}
845 none:
846 	btrfs_free_path(path);
847 	return -ENOENT;
848 }
849 
850 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
851 {
852 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
853 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
854 	struct extent_map *em;
855 	u64 len = PAGE_CACHE_SIZE;
856 
857 	/*
858 	 * hopefully we have this extent in the tree already, try without
859 	 * the full extent lock
860 	 */
861 	read_lock(&em_tree->lock);
862 	em = lookup_extent_mapping(em_tree, start, len);
863 	read_unlock(&em_tree->lock);
864 
865 	if (!em) {
866 		/* get the big lock and read metadata off disk */
867 		lock_extent(io_tree, start, start + len - 1);
868 		em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
869 		unlock_extent(io_tree, start, start + len - 1);
870 
871 		if (IS_ERR(em))
872 			return NULL;
873 	}
874 
875 	return em;
876 }
877 
878 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
879 {
880 	struct extent_map *next;
881 	bool ret = true;
882 
883 	/* this is the last extent */
884 	if (em->start + em->len >= i_size_read(inode))
885 		return false;
886 
887 	next = defrag_lookup_extent(inode, em->start + em->len);
888 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
889 		ret = false;
890 
891 	free_extent_map(next);
892 	return ret;
893 }
894 
895 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
896 			       u64 *last_len, u64 *skip, u64 *defrag_end,
897 			       int compress)
898 {
899 	struct extent_map *em;
900 	int ret = 1;
901 	bool next_mergeable = true;
902 
903 	/*
904 	 * make sure that once we start defragging an extent, we keep on
905 	 * defragging it
906 	 */
907 	if (start < *defrag_end)
908 		return 1;
909 
910 	*skip = 0;
911 
912 	em = defrag_lookup_extent(inode, start);
913 	if (!em)
914 		return 0;
915 
916 	/* this will cover holes, and inline extents */
917 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
918 		ret = 0;
919 		goto out;
920 	}
921 
922 	next_mergeable = defrag_check_next_extent(inode, em);
923 
924 	/*
925 	 * we hit a real extent, if it is big or the next extent is not a
926 	 * real extent, don't bother defragging it
927 	 */
928 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
929 	    (em->len >= thresh || !next_mergeable))
930 		ret = 0;
931 out:
932 	/*
933 	 * last_len ends up being a counter of how many bytes we've defragged.
934 	 * every time we choose not to defrag an extent, we reset *last_len
935 	 * so that the next tiny extent will force a defrag.
936 	 *
937 	 * The end result of this is that tiny extents before a single big
938 	 * extent will force at least part of that big extent to be defragged.
939 	 */
940 	if (ret) {
941 		*defrag_end = extent_map_end(em);
942 	} else {
943 		*last_len = 0;
944 		*skip = extent_map_end(em);
945 		*defrag_end = 0;
946 	}
947 
948 	free_extent_map(em);
949 	return ret;
950 }
951 
952 /*
953  * it doesn't do much good to defrag one or two pages
954  * at a time.  This pulls in a nice chunk of pages
955  * to COW and defrag.
956  *
957  * It also makes sure the delalloc code has enough
958  * dirty data to avoid making new small extents as part
959  * of the defrag
960  *
961  * It's a good idea to start RA on this range
962  * before calling this.
963  */
964 static int cluster_pages_for_defrag(struct inode *inode,
965 				    struct page **pages,
966 				    unsigned long start_index,
967 				    int num_pages)
968 {
969 	unsigned long file_end;
970 	u64 isize = i_size_read(inode);
971 	u64 page_start;
972 	u64 page_end;
973 	u64 page_cnt;
974 	int ret;
975 	int i;
976 	int i_done;
977 	struct btrfs_ordered_extent *ordered;
978 	struct extent_state *cached_state = NULL;
979 	struct extent_io_tree *tree;
980 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
981 
982 	file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
983 	if (!isize || start_index > file_end)
984 		return 0;
985 
986 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
987 
988 	ret = btrfs_delalloc_reserve_space(inode,
989 					   page_cnt << PAGE_CACHE_SHIFT);
990 	if (ret)
991 		return ret;
992 	i_done = 0;
993 	tree = &BTRFS_I(inode)->io_tree;
994 
995 	/* step one, lock all the pages */
996 	for (i = 0; i < page_cnt; i++) {
997 		struct page *page;
998 again:
999 		page = find_or_create_page(inode->i_mapping,
1000 					   start_index + i, mask);
1001 		if (!page)
1002 			break;
1003 
1004 		page_start = page_offset(page);
1005 		page_end = page_start + PAGE_CACHE_SIZE - 1;
1006 		while (1) {
1007 			lock_extent(tree, page_start, page_end);
1008 			ordered = btrfs_lookup_ordered_extent(inode,
1009 							      page_start);
1010 			unlock_extent(tree, page_start, page_end);
1011 			if (!ordered)
1012 				break;
1013 
1014 			unlock_page(page);
1015 			btrfs_start_ordered_extent(inode, ordered, 1);
1016 			btrfs_put_ordered_extent(ordered);
1017 			lock_page(page);
1018 			/*
1019 			 * we unlocked the page above, so we need check if
1020 			 * it was released or not.
1021 			 */
1022 			if (page->mapping != inode->i_mapping) {
1023 				unlock_page(page);
1024 				page_cache_release(page);
1025 				goto again;
1026 			}
1027 		}
1028 
1029 		if (!PageUptodate(page)) {
1030 			btrfs_readpage(NULL, page);
1031 			lock_page(page);
1032 			if (!PageUptodate(page)) {
1033 				unlock_page(page);
1034 				page_cache_release(page);
1035 				ret = -EIO;
1036 				break;
1037 			}
1038 		}
1039 
1040 		if (page->mapping != inode->i_mapping) {
1041 			unlock_page(page);
1042 			page_cache_release(page);
1043 			goto again;
1044 		}
1045 
1046 		pages[i] = page;
1047 		i_done++;
1048 	}
1049 	if (!i_done || ret)
1050 		goto out;
1051 
1052 	if (!(inode->i_sb->s_flags & MS_ACTIVE))
1053 		goto out;
1054 
1055 	/*
1056 	 * so now we have a nice long stream of locked
1057 	 * and up to date pages, lets wait on them
1058 	 */
1059 	for (i = 0; i < i_done; i++)
1060 		wait_on_page_writeback(pages[i]);
1061 
1062 	page_start = page_offset(pages[0]);
1063 	page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1064 
1065 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1066 			 page_start, page_end - 1, 0, &cached_state);
1067 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1068 			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1069 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1070 			  &cached_state, GFP_NOFS);
1071 
1072 	if (i_done != page_cnt) {
1073 		spin_lock(&BTRFS_I(inode)->lock);
1074 		BTRFS_I(inode)->outstanding_extents++;
1075 		spin_unlock(&BTRFS_I(inode)->lock);
1076 		btrfs_delalloc_release_space(inode,
1077 				     (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1078 	}
1079 
1080 
1081 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1082 			  &cached_state, GFP_NOFS);
1083 
1084 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1085 			     page_start, page_end - 1, &cached_state,
1086 			     GFP_NOFS);
1087 
1088 	for (i = 0; i < i_done; i++) {
1089 		clear_page_dirty_for_io(pages[i]);
1090 		ClearPageChecked(pages[i]);
1091 		set_page_extent_mapped(pages[i]);
1092 		set_page_dirty(pages[i]);
1093 		unlock_page(pages[i]);
1094 		page_cache_release(pages[i]);
1095 	}
1096 	return i_done;
1097 out:
1098 	for (i = 0; i < i_done; i++) {
1099 		unlock_page(pages[i]);
1100 		page_cache_release(pages[i]);
1101 	}
1102 	btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1103 	return ret;
1104 
1105 }
1106 
1107 int btrfs_defrag_file(struct inode *inode, struct file *file,
1108 		      struct btrfs_ioctl_defrag_range_args *range,
1109 		      u64 newer_than, unsigned long max_to_defrag)
1110 {
1111 	struct btrfs_root *root = BTRFS_I(inode)->root;
1112 	struct file_ra_state *ra = NULL;
1113 	unsigned long last_index;
1114 	u64 isize = i_size_read(inode);
1115 	u64 last_len = 0;
1116 	u64 skip = 0;
1117 	u64 defrag_end = 0;
1118 	u64 newer_off = range->start;
1119 	unsigned long i;
1120 	unsigned long ra_index = 0;
1121 	int ret;
1122 	int defrag_count = 0;
1123 	int compress_type = BTRFS_COMPRESS_ZLIB;
1124 	int extent_thresh = range->extent_thresh;
1125 	int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1126 	int cluster = max_cluster;
1127 	u64 new_align = ~((u64)128 * 1024 - 1);
1128 	struct page **pages = NULL;
1129 
1130 	if (extent_thresh == 0)
1131 		extent_thresh = 256 * 1024;
1132 
1133 	if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1134 		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1135 			return -EINVAL;
1136 		if (range->compress_type)
1137 			compress_type = range->compress_type;
1138 	}
1139 
1140 	if (isize == 0)
1141 		return 0;
1142 
1143 	/*
1144 	 * if we were not given a file, allocate a readahead
1145 	 * context
1146 	 */
1147 	if (!file) {
1148 		ra = kzalloc(sizeof(*ra), GFP_NOFS);
1149 		if (!ra)
1150 			return -ENOMEM;
1151 		file_ra_state_init(ra, inode->i_mapping);
1152 	} else {
1153 		ra = &file->f_ra;
1154 	}
1155 
1156 	pages = kmalloc(sizeof(struct page *) * max_cluster,
1157 			GFP_NOFS);
1158 	if (!pages) {
1159 		ret = -ENOMEM;
1160 		goto out_ra;
1161 	}
1162 
1163 	/* find the last page to defrag */
1164 	if (range->start + range->len > range->start) {
1165 		last_index = min_t(u64, isize - 1,
1166 			 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1167 	} else {
1168 		last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1169 	}
1170 
1171 	if (newer_than) {
1172 		ret = find_new_extents(root, inode, newer_than,
1173 				       &newer_off, 64 * 1024);
1174 		if (!ret) {
1175 			range->start = newer_off;
1176 			/*
1177 			 * we always align our defrag to help keep
1178 			 * the extents in the file evenly spaced
1179 			 */
1180 			i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1181 		} else
1182 			goto out_ra;
1183 	} else {
1184 		i = range->start >> PAGE_CACHE_SHIFT;
1185 	}
1186 	if (!max_to_defrag)
1187 		max_to_defrag = last_index + 1;
1188 
1189 	/*
1190 	 * make writeback starts from i, so the defrag range can be
1191 	 * written sequentially.
1192 	 */
1193 	if (i < inode->i_mapping->writeback_index)
1194 		inode->i_mapping->writeback_index = i;
1195 
1196 	while (i <= last_index && defrag_count < max_to_defrag &&
1197 	       (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1198 		PAGE_CACHE_SHIFT)) {
1199 		/*
1200 		 * make sure we stop running if someone unmounts
1201 		 * the FS
1202 		 */
1203 		if (!(inode->i_sb->s_flags & MS_ACTIVE))
1204 			break;
1205 
1206 		if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1207 					 extent_thresh, &last_len, &skip,
1208 					 &defrag_end, range->flags &
1209 					 BTRFS_DEFRAG_RANGE_COMPRESS)) {
1210 			unsigned long next;
1211 			/*
1212 			 * the should_defrag function tells us how much to skip
1213 			 * bump our counter by the suggested amount
1214 			 */
1215 			next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1216 			i = max(i + 1, next);
1217 			continue;
1218 		}
1219 
1220 		if (!newer_than) {
1221 			cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1222 				   PAGE_CACHE_SHIFT) - i;
1223 			cluster = min(cluster, max_cluster);
1224 		} else {
1225 			cluster = max_cluster;
1226 		}
1227 
1228 		if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1229 			BTRFS_I(inode)->force_compress = compress_type;
1230 
1231 		if (i + cluster > ra_index) {
1232 			ra_index = max(i, ra_index);
1233 			btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1234 				       cluster);
1235 			ra_index += max_cluster;
1236 		}
1237 
1238 		mutex_lock(&inode->i_mutex);
1239 		ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1240 		if (ret < 0) {
1241 			mutex_unlock(&inode->i_mutex);
1242 			goto out_ra;
1243 		}
1244 
1245 		defrag_count += ret;
1246 		balance_dirty_pages_ratelimited(inode->i_mapping);
1247 		mutex_unlock(&inode->i_mutex);
1248 
1249 		if (newer_than) {
1250 			if (newer_off == (u64)-1)
1251 				break;
1252 
1253 			if (ret > 0)
1254 				i += ret;
1255 
1256 			newer_off = max(newer_off + 1,
1257 					(u64)i << PAGE_CACHE_SHIFT);
1258 
1259 			ret = find_new_extents(root, inode,
1260 					       newer_than, &newer_off,
1261 					       64 * 1024);
1262 			if (!ret) {
1263 				range->start = newer_off;
1264 				i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1265 			} else {
1266 				break;
1267 			}
1268 		} else {
1269 			if (ret > 0) {
1270 				i += ret;
1271 				last_len += ret << PAGE_CACHE_SHIFT;
1272 			} else {
1273 				i++;
1274 				last_len = 0;
1275 			}
1276 		}
1277 	}
1278 
1279 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1280 		filemap_flush(inode->i_mapping);
1281 
1282 	if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1283 		/* the filemap_flush will queue IO into the worker threads, but
1284 		 * we have to make sure the IO is actually started and that
1285 		 * ordered extents get created before we return
1286 		 */
1287 		atomic_inc(&root->fs_info->async_submit_draining);
1288 		while (atomic_read(&root->fs_info->nr_async_submits) ||
1289 		      atomic_read(&root->fs_info->async_delalloc_pages)) {
1290 			wait_event(root->fs_info->async_submit_wait,
1291 			   (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1292 			    atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1293 		}
1294 		atomic_dec(&root->fs_info->async_submit_draining);
1295 
1296 		mutex_lock(&inode->i_mutex);
1297 		BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1298 		mutex_unlock(&inode->i_mutex);
1299 	}
1300 
1301 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1302 		btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1303 	}
1304 
1305 	ret = defrag_count;
1306 
1307 out_ra:
1308 	if (!file)
1309 		kfree(ra);
1310 	kfree(pages);
1311 	return ret;
1312 }
1313 
1314 static noinline int btrfs_ioctl_resize(struct file *file,
1315 					void __user *arg)
1316 {
1317 	u64 new_size;
1318 	u64 old_size;
1319 	u64 devid = 1;
1320 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1321 	struct btrfs_ioctl_vol_args *vol_args;
1322 	struct btrfs_trans_handle *trans;
1323 	struct btrfs_device *device = NULL;
1324 	char *sizestr;
1325 	char *devstr = NULL;
1326 	int ret = 0;
1327 	int mod = 0;
1328 
1329 	if (root->fs_info->sb->s_flags & MS_RDONLY)
1330 		return -EROFS;
1331 
1332 	if (!capable(CAP_SYS_ADMIN))
1333 		return -EPERM;
1334 
1335 	ret = mnt_want_write_file(file);
1336 	if (ret)
1337 		return ret;
1338 
1339 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1340 			1)) {
1341 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
1342 		return -EINPROGRESS;
1343 	}
1344 
1345 	mutex_lock(&root->fs_info->volume_mutex);
1346 	vol_args = memdup_user(arg, sizeof(*vol_args));
1347 	if (IS_ERR(vol_args)) {
1348 		ret = PTR_ERR(vol_args);
1349 		goto out;
1350 	}
1351 
1352 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1353 
1354 	sizestr = vol_args->name;
1355 	devstr = strchr(sizestr, ':');
1356 	if (devstr) {
1357 		char *end;
1358 		sizestr = devstr + 1;
1359 		*devstr = '\0';
1360 		devstr = vol_args->name;
1361 		devid = simple_strtoull(devstr, &end, 10);
1362 		printk(KERN_INFO "btrfs: resizing devid %llu\n",
1363 		       (unsigned long long)devid);
1364 	}
1365 	device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1366 	if (!device) {
1367 		printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1368 		       (unsigned long long)devid);
1369 		ret = -EINVAL;
1370 		goto out_free;
1371 	}
1372 	if (device->fs_devices && device->fs_devices->seeding) {
1373 		printk(KERN_INFO "btrfs: resizer unable to apply on "
1374 		       "seeding device %llu\n",
1375 		       (unsigned long long)devid);
1376 		ret = -EINVAL;
1377 		goto out_free;
1378 	}
1379 
1380 	if (!strcmp(sizestr, "max"))
1381 		new_size = device->bdev->bd_inode->i_size;
1382 	else {
1383 		if (sizestr[0] == '-') {
1384 			mod = -1;
1385 			sizestr++;
1386 		} else if (sizestr[0] == '+') {
1387 			mod = 1;
1388 			sizestr++;
1389 		}
1390 		new_size = memparse(sizestr, NULL);
1391 		if (new_size == 0) {
1392 			ret = -EINVAL;
1393 			goto out_free;
1394 		}
1395 	}
1396 
1397 	if (device->is_tgtdev_for_dev_replace) {
1398 		ret = -EINVAL;
1399 		goto out_free;
1400 	}
1401 
1402 	old_size = device->total_bytes;
1403 
1404 	if (mod < 0) {
1405 		if (new_size > old_size) {
1406 			ret = -EINVAL;
1407 			goto out_free;
1408 		}
1409 		new_size = old_size - new_size;
1410 	} else if (mod > 0) {
1411 		new_size = old_size + new_size;
1412 	}
1413 
1414 	if (new_size < 256 * 1024 * 1024) {
1415 		ret = -EINVAL;
1416 		goto out_free;
1417 	}
1418 	if (new_size > device->bdev->bd_inode->i_size) {
1419 		ret = -EFBIG;
1420 		goto out_free;
1421 	}
1422 
1423 	do_div(new_size, root->sectorsize);
1424 	new_size *= root->sectorsize;
1425 
1426 	printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1427 		      rcu_str_deref(device->name),
1428 		      (unsigned long long)new_size);
1429 
1430 	if (new_size > old_size) {
1431 		trans = btrfs_start_transaction(root, 0);
1432 		if (IS_ERR(trans)) {
1433 			ret = PTR_ERR(trans);
1434 			goto out_free;
1435 		}
1436 		ret = btrfs_grow_device(trans, device, new_size);
1437 		btrfs_commit_transaction(trans, root);
1438 	} else if (new_size < old_size) {
1439 		ret = btrfs_shrink_device(device, new_size);
1440 	} /* equal, nothing need to do */
1441 
1442 out_free:
1443 	kfree(vol_args);
1444 out:
1445 	mutex_unlock(&root->fs_info->volume_mutex);
1446 	mnt_drop_write_file(file);
1447 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1448 	return ret;
1449 }
1450 
1451 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1452 				char *name, unsigned long fd, int subvol,
1453 				u64 *transid, bool readonly,
1454 				struct btrfs_qgroup_inherit **inherit)
1455 {
1456 	int namelen;
1457 	int ret = 0;
1458 
1459 	ret = mnt_want_write_file(file);
1460 	if (ret)
1461 		goto out;
1462 
1463 	namelen = strlen(name);
1464 	if (strchr(name, '/')) {
1465 		ret = -EINVAL;
1466 		goto out_drop_write;
1467 	}
1468 
1469 	if (name[0] == '.' &&
1470 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1471 		ret = -EEXIST;
1472 		goto out_drop_write;
1473 	}
1474 
1475 	if (subvol) {
1476 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1477 				     NULL, transid, readonly, inherit);
1478 	} else {
1479 		struct fd src = fdget(fd);
1480 		struct inode *src_inode;
1481 		if (!src.file) {
1482 			ret = -EINVAL;
1483 			goto out_drop_write;
1484 		}
1485 
1486 		src_inode = src.file->f_path.dentry->d_inode;
1487 		if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1488 			printk(KERN_INFO "btrfs: Snapshot src from "
1489 			       "another FS\n");
1490 			ret = -EINVAL;
1491 		} else {
1492 			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1493 					     BTRFS_I(src_inode)->root,
1494 					     transid, readonly, inherit);
1495 		}
1496 		fdput(src);
1497 	}
1498 out_drop_write:
1499 	mnt_drop_write_file(file);
1500 out:
1501 	return ret;
1502 }
1503 
1504 static noinline int btrfs_ioctl_snap_create(struct file *file,
1505 					    void __user *arg, int subvol)
1506 {
1507 	struct btrfs_ioctl_vol_args *vol_args;
1508 	int ret;
1509 
1510 	vol_args = memdup_user(arg, sizeof(*vol_args));
1511 	if (IS_ERR(vol_args))
1512 		return PTR_ERR(vol_args);
1513 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1514 
1515 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1516 					      vol_args->fd, subvol,
1517 					      NULL, false, NULL);
1518 
1519 	kfree(vol_args);
1520 	return ret;
1521 }
1522 
1523 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1524 					       void __user *arg, int subvol)
1525 {
1526 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1527 	int ret;
1528 	u64 transid = 0;
1529 	u64 *ptr = NULL;
1530 	bool readonly = false;
1531 	struct btrfs_qgroup_inherit *inherit = NULL;
1532 
1533 	vol_args = memdup_user(arg, sizeof(*vol_args));
1534 	if (IS_ERR(vol_args))
1535 		return PTR_ERR(vol_args);
1536 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1537 
1538 	if (vol_args->flags &
1539 	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1540 	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1541 		ret = -EOPNOTSUPP;
1542 		goto out;
1543 	}
1544 
1545 	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1546 		ptr = &transid;
1547 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1548 		readonly = true;
1549 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1550 		if (vol_args->size > PAGE_CACHE_SIZE) {
1551 			ret = -EINVAL;
1552 			goto out;
1553 		}
1554 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1555 		if (IS_ERR(inherit)) {
1556 			ret = PTR_ERR(inherit);
1557 			goto out;
1558 		}
1559 	}
1560 
1561 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1562 					      vol_args->fd, subvol, ptr,
1563 					      readonly, &inherit);
1564 
1565 	if (ret == 0 && ptr &&
1566 	    copy_to_user(arg +
1567 			 offsetof(struct btrfs_ioctl_vol_args_v2,
1568 				  transid), ptr, sizeof(*ptr)))
1569 		ret = -EFAULT;
1570 out:
1571 	kfree(vol_args);
1572 	kfree(inherit);
1573 	return ret;
1574 }
1575 
1576 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1577 						void __user *arg)
1578 {
1579 	struct inode *inode = fdentry(file)->d_inode;
1580 	struct btrfs_root *root = BTRFS_I(inode)->root;
1581 	int ret = 0;
1582 	u64 flags = 0;
1583 
1584 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1585 		return -EINVAL;
1586 
1587 	down_read(&root->fs_info->subvol_sem);
1588 	if (btrfs_root_readonly(root))
1589 		flags |= BTRFS_SUBVOL_RDONLY;
1590 	up_read(&root->fs_info->subvol_sem);
1591 
1592 	if (copy_to_user(arg, &flags, sizeof(flags)))
1593 		ret = -EFAULT;
1594 
1595 	return ret;
1596 }
1597 
1598 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1599 					      void __user *arg)
1600 {
1601 	struct inode *inode = fdentry(file)->d_inode;
1602 	struct btrfs_root *root = BTRFS_I(inode)->root;
1603 	struct btrfs_trans_handle *trans;
1604 	u64 root_flags;
1605 	u64 flags;
1606 	int ret = 0;
1607 
1608 	ret = mnt_want_write_file(file);
1609 	if (ret)
1610 		goto out;
1611 
1612 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1613 		ret = -EINVAL;
1614 		goto out_drop_write;
1615 	}
1616 
1617 	if (copy_from_user(&flags, arg, sizeof(flags))) {
1618 		ret = -EFAULT;
1619 		goto out_drop_write;
1620 	}
1621 
1622 	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1623 		ret = -EINVAL;
1624 		goto out_drop_write;
1625 	}
1626 
1627 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1628 		ret = -EOPNOTSUPP;
1629 		goto out_drop_write;
1630 	}
1631 
1632 	if (!inode_owner_or_capable(inode)) {
1633 		ret = -EACCES;
1634 		goto out_drop_write;
1635 	}
1636 
1637 	down_write(&root->fs_info->subvol_sem);
1638 
1639 	/* nothing to do */
1640 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1641 		goto out_drop_sem;
1642 
1643 	root_flags = btrfs_root_flags(&root->root_item);
1644 	if (flags & BTRFS_SUBVOL_RDONLY)
1645 		btrfs_set_root_flags(&root->root_item,
1646 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1647 	else
1648 		btrfs_set_root_flags(&root->root_item,
1649 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1650 
1651 	trans = btrfs_start_transaction(root, 1);
1652 	if (IS_ERR(trans)) {
1653 		ret = PTR_ERR(trans);
1654 		goto out_reset;
1655 	}
1656 
1657 	ret = btrfs_update_root(trans, root->fs_info->tree_root,
1658 				&root->root_key, &root->root_item);
1659 
1660 	btrfs_commit_transaction(trans, root);
1661 out_reset:
1662 	if (ret)
1663 		btrfs_set_root_flags(&root->root_item, root_flags);
1664 out_drop_sem:
1665 	up_write(&root->fs_info->subvol_sem);
1666 out_drop_write:
1667 	mnt_drop_write_file(file);
1668 out:
1669 	return ret;
1670 }
1671 
1672 /*
1673  * helper to check if the subvolume references other subvolumes
1674  */
1675 static noinline int may_destroy_subvol(struct btrfs_root *root)
1676 {
1677 	struct btrfs_path *path;
1678 	struct btrfs_key key;
1679 	int ret;
1680 
1681 	path = btrfs_alloc_path();
1682 	if (!path)
1683 		return -ENOMEM;
1684 
1685 	key.objectid = root->root_key.objectid;
1686 	key.type = BTRFS_ROOT_REF_KEY;
1687 	key.offset = (u64)-1;
1688 
1689 	ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1690 				&key, path, 0, 0);
1691 	if (ret < 0)
1692 		goto out;
1693 	BUG_ON(ret == 0);
1694 
1695 	ret = 0;
1696 	if (path->slots[0] > 0) {
1697 		path->slots[0]--;
1698 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1699 		if (key.objectid == root->root_key.objectid &&
1700 		    key.type == BTRFS_ROOT_REF_KEY)
1701 			ret = -ENOTEMPTY;
1702 	}
1703 out:
1704 	btrfs_free_path(path);
1705 	return ret;
1706 }
1707 
1708 static noinline int key_in_sk(struct btrfs_key *key,
1709 			      struct btrfs_ioctl_search_key *sk)
1710 {
1711 	struct btrfs_key test;
1712 	int ret;
1713 
1714 	test.objectid = sk->min_objectid;
1715 	test.type = sk->min_type;
1716 	test.offset = sk->min_offset;
1717 
1718 	ret = btrfs_comp_cpu_keys(key, &test);
1719 	if (ret < 0)
1720 		return 0;
1721 
1722 	test.objectid = sk->max_objectid;
1723 	test.type = sk->max_type;
1724 	test.offset = sk->max_offset;
1725 
1726 	ret = btrfs_comp_cpu_keys(key, &test);
1727 	if (ret > 0)
1728 		return 0;
1729 	return 1;
1730 }
1731 
1732 static noinline int copy_to_sk(struct btrfs_root *root,
1733 			       struct btrfs_path *path,
1734 			       struct btrfs_key *key,
1735 			       struct btrfs_ioctl_search_key *sk,
1736 			       char *buf,
1737 			       unsigned long *sk_offset,
1738 			       int *num_found)
1739 {
1740 	u64 found_transid;
1741 	struct extent_buffer *leaf;
1742 	struct btrfs_ioctl_search_header sh;
1743 	unsigned long item_off;
1744 	unsigned long item_len;
1745 	int nritems;
1746 	int i;
1747 	int slot;
1748 	int ret = 0;
1749 
1750 	leaf = path->nodes[0];
1751 	slot = path->slots[0];
1752 	nritems = btrfs_header_nritems(leaf);
1753 
1754 	if (btrfs_header_generation(leaf) > sk->max_transid) {
1755 		i = nritems;
1756 		goto advance_key;
1757 	}
1758 	found_transid = btrfs_header_generation(leaf);
1759 
1760 	for (i = slot; i < nritems; i++) {
1761 		item_off = btrfs_item_ptr_offset(leaf, i);
1762 		item_len = btrfs_item_size_nr(leaf, i);
1763 
1764 		if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1765 			item_len = 0;
1766 
1767 		if (sizeof(sh) + item_len + *sk_offset >
1768 		    BTRFS_SEARCH_ARGS_BUFSIZE) {
1769 			ret = 1;
1770 			goto overflow;
1771 		}
1772 
1773 		btrfs_item_key_to_cpu(leaf, key, i);
1774 		if (!key_in_sk(key, sk))
1775 			continue;
1776 
1777 		sh.objectid = key->objectid;
1778 		sh.offset = key->offset;
1779 		sh.type = key->type;
1780 		sh.len = item_len;
1781 		sh.transid = found_transid;
1782 
1783 		/* copy search result header */
1784 		memcpy(buf + *sk_offset, &sh, sizeof(sh));
1785 		*sk_offset += sizeof(sh);
1786 
1787 		if (item_len) {
1788 			char *p = buf + *sk_offset;
1789 			/* copy the item */
1790 			read_extent_buffer(leaf, p,
1791 					   item_off, item_len);
1792 			*sk_offset += item_len;
1793 		}
1794 		(*num_found)++;
1795 
1796 		if (*num_found >= sk->nr_items)
1797 			break;
1798 	}
1799 advance_key:
1800 	ret = 0;
1801 	if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1802 		key->offset++;
1803 	else if (key->type < (u8)-1 && key->type < sk->max_type) {
1804 		key->offset = 0;
1805 		key->type++;
1806 	} else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1807 		key->offset = 0;
1808 		key->type = 0;
1809 		key->objectid++;
1810 	} else
1811 		ret = 1;
1812 overflow:
1813 	return ret;
1814 }
1815 
1816 static noinline int search_ioctl(struct inode *inode,
1817 				 struct btrfs_ioctl_search_args *args)
1818 {
1819 	struct btrfs_root *root;
1820 	struct btrfs_key key;
1821 	struct btrfs_key max_key;
1822 	struct btrfs_path *path;
1823 	struct btrfs_ioctl_search_key *sk = &args->key;
1824 	struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1825 	int ret;
1826 	int num_found = 0;
1827 	unsigned long sk_offset = 0;
1828 
1829 	path = btrfs_alloc_path();
1830 	if (!path)
1831 		return -ENOMEM;
1832 
1833 	if (sk->tree_id == 0) {
1834 		/* search the root of the inode that was passed */
1835 		root = BTRFS_I(inode)->root;
1836 	} else {
1837 		key.objectid = sk->tree_id;
1838 		key.type = BTRFS_ROOT_ITEM_KEY;
1839 		key.offset = (u64)-1;
1840 		root = btrfs_read_fs_root_no_name(info, &key);
1841 		if (IS_ERR(root)) {
1842 			printk(KERN_ERR "could not find root %llu\n",
1843 			       sk->tree_id);
1844 			btrfs_free_path(path);
1845 			return -ENOENT;
1846 		}
1847 	}
1848 
1849 	key.objectid = sk->min_objectid;
1850 	key.type = sk->min_type;
1851 	key.offset = sk->min_offset;
1852 
1853 	max_key.objectid = sk->max_objectid;
1854 	max_key.type = sk->max_type;
1855 	max_key.offset = sk->max_offset;
1856 
1857 	path->keep_locks = 1;
1858 
1859 	while(1) {
1860 		ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1861 					   sk->min_transid);
1862 		if (ret != 0) {
1863 			if (ret > 0)
1864 				ret = 0;
1865 			goto err;
1866 		}
1867 		ret = copy_to_sk(root, path, &key, sk, args->buf,
1868 				 &sk_offset, &num_found);
1869 		btrfs_release_path(path);
1870 		if (ret || num_found >= sk->nr_items)
1871 			break;
1872 
1873 	}
1874 	ret = 0;
1875 err:
1876 	sk->nr_items = num_found;
1877 	btrfs_free_path(path);
1878 	return ret;
1879 }
1880 
1881 static noinline int btrfs_ioctl_tree_search(struct file *file,
1882 					   void __user *argp)
1883 {
1884 	 struct btrfs_ioctl_search_args *args;
1885 	 struct inode *inode;
1886 	 int ret;
1887 
1888 	if (!capable(CAP_SYS_ADMIN))
1889 		return -EPERM;
1890 
1891 	args = memdup_user(argp, sizeof(*args));
1892 	if (IS_ERR(args))
1893 		return PTR_ERR(args);
1894 
1895 	inode = fdentry(file)->d_inode;
1896 	ret = search_ioctl(inode, args);
1897 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1898 		ret = -EFAULT;
1899 	kfree(args);
1900 	return ret;
1901 }
1902 
1903 /*
1904  * Search INODE_REFs to identify path name of 'dirid' directory
1905  * in a 'tree_id' tree. and sets path name to 'name'.
1906  */
1907 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1908 				u64 tree_id, u64 dirid, char *name)
1909 {
1910 	struct btrfs_root *root;
1911 	struct btrfs_key key;
1912 	char *ptr;
1913 	int ret = -1;
1914 	int slot;
1915 	int len;
1916 	int total_len = 0;
1917 	struct btrfs_inode_ref *iref;
1918 	struct extent_buffer *l;
1919 	struct btrfs_path *path;
1920 
1921 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1922 		name[0]='\0';
1923 		return 0;
1924 	}
1925 
1926 	path = btrfs_alloc_path();
1927 	if (!path)
1928 		return -ENOMEM;
1929 
1930 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1931 
1932 	key.objectid = tree_id;
1933 	key.type = BTRFS_ROOT_ITEM_KEY;
1934 	key.offset = (u64)-1;
1935 	root = btrfs_read_fs_root_no_name(info, &key);
1936 	if (IS_ERR(root)) {
1937 		printk(KERN_ERR "could not find root %llu\n", tree_id);
1938 		ret = -ENOENT;
1939 		goto out;
1940 	}
1941 
1942 	key.objectid = dirid;
1943 	key.type = BTRFS_INODE_REF_KEY;
1944 	key.offset = (u64)-1;
1945 
1946 	while(1) {
1947 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1948 		if (ret < 0)
1949 			goto out;
1950 
1951 		l = path->nodes[0];
1952 		slot = path->slots[0];
1953 		if (ret > 0 && slot > 0)
1954 			slot--;
1955 		btrfs_item_key_to_cpu(l, &key, slot);
1956 
1957 		if (ret > 0 && (key.objectid != dirid ||
1958 				key.type != BTRFS_INODE_REF_KEY)) {
1959 			ret = -ENOENT;
1960 			goto out;
1961 		}
1962 
1963 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1964 		len = btrfs_inode_ref_name_len(l, iref);
1965 		ptr -= len + 1;
1966 		total_len += len + 1;
1967 		if (ptr < name)
1968 			goto out;
1969 
1970 		*(ptr + len) = '/';
1971 		read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1972 
1973 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1974 			break;
1975 
1976 		btrfs_release_path(path);
1977 		key.objectid = key.offset;
1978 		key.offset = (u64)-1;
1979 		dirid = key.objectid;
1980 	}
1981 	if (ptr < name)
1982 		goto out;
1983 	memmove(name, ptr, total_len);
1984 	name[total_len]='\0';
1985 	ret = 0;
1986 out:
1987 	btrfs_free_path(path);
1988 	return ret;
1989 }
1990 
1991 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1992 					   void __user *argp)
1993 {
1994 	 struct btrfs_ioctl_ino_lookup_args *args;
1995 	 struct inode *inode;
1996 	 int ret;
1997 
1998 	if (!capable(CAP_SYS_ADMIN))
1999 		return -EPERM;
2000 
2001 	args = memdup_user(argp, sizeof(*args));
2002 	if (IS_ERR(args))
2003 		return PTR_ERR(args);
2004 
2005 	inode = fdentry(file)->d_inode;
2006 
2007 	if (args->treeid == 0)
2008 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2009 
2010 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2011 					args->treeid, args->objectid,
2012 					args->name);
2013 
2014 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2015 		ret = -EFAULT;
2016 
2017 	kfree(args);
2018 	return ret;
2019 }
2020 
2021 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2022 					     void __user *arg)
2023 {
2024 	struct dentry *parent = fdentry(file);
2025 	struct dentry *dentry;
2026 	struct inode *dir = parent->d_inode;
2027 	struct inode *inode;
2028 	struct btrfs_root *root = BTRFS_I(dir)->root;
2029 	struct btrfs_root *dest = NULL;
2030 	struct btrfs_ioctl_vol_args *vol_args;
2031 	struct btrfs_trans_handle *trans;
2032 	int namelen;
2033 	int ret;
2034 	int err = 0;
2035 
2036 	vol_args = memdup_user(arg, sizeof(*vol_args));
2037 	if (IS_ERR(vol_args))
2038 		return PTR_ERR(vol_args);
2039 
2040 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2041 	namelen = strlen(vol_args->name);
2042 	if (strchr(vol_args->name, '/') ||
2043 	    strncmp(vol_args->name, "..", namelen) == 0) {
2044 		err = -EINVAL;
2045 		goto out;
2046 	}
2047 
2048 	err = mnt_want_write_file(file);
2049 	if (err)
2050 		goto out;
2051 
2052 	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
2053 	dentry = lookup_one_len(vol_args->name, parent, namelen);
2054 	if (IS_ERR(dentry)) {
2055 		err = PTR_ERR(dentry);
2056 		goto out_unlock_dir;
2057 	}
2058 
2059 	if (!dentry->d_inode) {
2060 		err = -ENOENT;
2061 		goto out_dput;
2062 	}
2063 
2064 	inode = dentry->d_inode;
2065 	dest = BTRFS_I(inode)->root;
2066 	if (!capable(CAP_SYS_ADMIN)){
2067 		/*
2068 		 * Regular user.  Only allow this with a special mount
2069 		 * option, when the user has write+exec access to the
2070 		 * subvol root, and when rmdir(2) would have been
2071 		 * allowed.
2072 		 *
2073 		 * Note that this is _not_ check that the subvol is
2074 		 * empty or doesn't contain data that we wouldn't
2075 		 * otherwise be able to delete.
2076 		 *
2077 		 * Users who want to delete empty subvols should try
2078 		 * rmdir(2).
2079 		 */
2080 		err = -EPERM;
2081 		if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2082 			goto out_dput;
2083 
2084 		/*
2085 		 * Do not allow deletion if the parent dir is the same
2086 		 * as the dir to be deleted.  That means the ioctl
2087 		 * must be called on the dentry referencing the root
2088 		 * of the subvol, not a random directory contained
2089 		 * within it.
2090 		 */
2091 		err = -EINVAL;
2092 		if (root == dest)
2093 			goto out_dput;
2094 
2095 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2096 		if (err)
2097 			goto out_dput;
2098 
2099 		/* check if subvolume may be deleted by a non-root user */
2100 		err = btrfs_may_delete(dir, dentry, 1);
2101 		if (err)
2102 			goto out_dput;
2103 	}
2104 
2105 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2106 		err = -EINVAL;
2107 		goto out_dput;
2108 	}
2109 
2110 	mutex_lock(&inode->i_mutex);
2111 	err = d_invalidate(dentry);
2112 	if (err)
2113 		goto out_unlock;
2114 
2115 	down_write(&root->fs_info->subvol_sem);
2116 
2117 	err = may_destroy_subvol(dest);
2118 	if (err)
2119 		goto out_up_write;
2120 
2121 	trans = btrfs_start_transaction(root, 0);
2122 	if (IS_ERR(trans)) {
2123 		err = PTR_ERR(trans);
2124 		goto out_up_write;
2125 	}
2126 	trans->block_rsv = &root->fs_info->global_block_rsv;
2127 
2128 	ret = btrfs_unlink_subvol(trans, root, dir,
2129 				dest->root_key.objectid,
2130 				dentry->d_name.name,
2131 				dentry->d_name.len);
2132 	if (ret) {
2133 		err = ret;
2134 		btrfs_abort_transaction(trans, root, ret);
2135 		goto out_end_trans;
2136 	}
2137 
2138 	btrfs_record_root_in_trans(trans, dest);
2139 
2140 	memset(&dest->root_item.drop_progress, 0,
2141 		sizeof(dest->root_item.drop_progress));
2142 	dest->root_item.drop_level = 0;
2143 	btrfs_set_root_refs(&dest->root_item, 0);
2144 
2145 	if (!xchg(&dest->orphan_item_inserted, 1)) {
2146 		ret = btrfs_insert_orphan_item(trans,
2147 					root->fs_info->tree_root,
2148 					dest->root_key.objectid);
2149 		if (ret) {
2150 			btrfs_abort_transaction(trans, root, ret);
2151 			err = ret;
2152 			goto out_end_trans;
2153 		}
2154 	}
2155 out_end_trans:
2156 	ret = btrfs_end_transaction(trans, root);
2157 	if (ret && !err)
2158 		err = ret;
2159 	inode->i_flags |= S_DEAD;
2160 out_up_write:
2161 	up_write(&root->fs_info->subvol_sem);
2162 out_unlock:
2163 	mutex_unlock(&inode->i_mutex);
2164 	if (!err) {
2165 		shrink_dcache_sb(root->fs_info->sb);
2166 		btrfs_invalidate_inodes(dest);
2167 		d_delete(dentry);
2168 	}
2169 out_dput:
2170 	dput(dentry);
2171 out_unlock_dir:
2172 	mutex_unlock(&dir->i_mutex);
2173 	mnt_drop_write_file(file);
2174 out:
2175 	kfree(vol_args);
2176 	return err;
2177 }
2178 
2179 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2180 {
2181 	struct inode *inode = fdentry(file)->d_inode;
2182 	struct btrfs_root *root = BTRFS_I(inode)->root;
2183 	struct btrfs_ioctl_defrag_range_args *range;
2184 	int ret;
2185 
2186 	if (btrfs_root_readonly(root))
2187 		return -EROFS;
2188 
2189 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2190 			1)) {
2191 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2192 		return -EINPROGRESS;
2193 	}
2194 	ret = mnt_want_write_file(file);
2195 	if (ret) {
2196 		atomic_set(&root->fs_info->mutually_exclusive_operation_running,
2197 			   0);
2198 		return ret;
2199 	}
2200 
2201 	switch (inode->i_mode & S_IFMT) {
2202 	case S_IFDIR:
2203 		if (!capable(CAP_SYS_ADMIN)) {
2204 			ret = -EPERM;
2205 			goto out;
2206 		}
2207 		ret = btrfs_defrag_root(root, 0);
2208 		if (ret)
2209 			goto out;
2210 		ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2211 		break;
2212 	case S_IFREG:
2213 		if (!(file->f_mode & FMODE_WRITE)) {
2214 			ret = -EINVAL;
2215 			goto out;
2216 		}
2217 
2218 		range = kzalloc(sizeof(*range), GFP_KERNEL);
2219 		if (!range) {
2220 			ret = -ENOMEM;
2221 			goto out;
2222 		}
2223 
2224 		if (argp) {
2225 			if (copy_from_user(range, argp,
2226 					   sizeof(*range))) {
2227 				ret = -EFAULT;
2228 				kfree(range);
2229 				goto out;
2230 			}
2231 			/* compression requires us to start the IO */
2232 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2233 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2234 				range->extent_thresh = (u32)-1;
2235 			}
2236 		} else {
2237 			/* the rest are all set to zero by kzalloc */
2238 			range->len = (u64)-1;
2239 		}
2240 		ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2241 					range, 0, 0);
2242 		if (ret > 0)
2243 			ret = 0;
2244 		kfree(range);
2245 		break;
2246 	default:
2247 		ret = -EINVAL;
2248 	}
2249 out:
2250 	mnt_drop_write_file(file);
2251 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2252 	return ret;
2253 }
2254 
2255 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2256 {
2257 	struct btrfs_ioctl_vol_args *vol_args;
2258 	int ret;
2259 
2260 	if (!capable(CAP_SYS_ADMIN))
2261 		return -EPERM;
2262 
2263 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2264 			1)) {
2265 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2266 		return -EINPROGRESS;
2267 	}
2268 
2269 	mutex_lock(&root->fs_info->volume_mutex);
2270 	vol_args = memdup_user(arg, sizeof(*vol_args));
2271 	if (IS_ERR(vol_args)) {
2272 		ret = PTR_ERR(vol_args);
2273 		goto out;
2274 	}
2275 
2276 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2277 	ret = btrfs_init_new_device(root, vol_args->name);
2278 
2279 	kfree(vol_args);
2280 out:
2281 	mutex_unlock(&root->fs_info->volume_mutex);
2282 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2283 	return ret;
2284 }
2285 
2286 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2287 {
2288 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2289 	struct btrfs_ioctl_vol_args *vol_args;
2290 	int ret;
2291 
2292 	if (!capable(CAP_SYS_ADMIN))
2293 		return -EPERM;
2294 
2295 	ret = mnt_want_write_file(file);
2296 	if (ret)
2297 		return ret;
2298 
2299 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2300 			1)) {
2301 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2302 		mnt_drop_write_file(file);
2303 		return -EINPROGRESS;
2304 	}
2305 
2306 	mutex_lock(&root->fs_info->volume_mutex);
2307 	vol_args = memdup_user(arg, sizeof(*vol_args));
2308 	if (IS_ERR(vol_args)) {
2309 		ret = PTR_ERR(vol_args);
2310 		goto out;
2311 	}
2312 
2313 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2314 	ret = btrfs_rm_device(root, vol_args->name);
2315 
2316 	kfree(vol_args);
2317 out:
2318 	mutex_unlock(&root->fs_info->volume_mutex);
2319 	mnt_drop_write_file(file);
2320 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2321 	return ret;
2322 }
2323 
2324 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2325 {
2326 	struct btrfs_ioctl_fs_info_args *fi_args;
2327 	struct btrfs_device *device;
2328 	struct btrfs_device *next;
2329 	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2330 	int ret = 0;
2331 
2332 	if (!capable(CAP_SYS_ADMIN))
2333 		return -EPERM;
2334 
2335 	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2336 	if (!fi_args)
2337 		return -ENOMEM;
2338 
2339 	fi_args->num_devices = fs_devices->num_devices;
2340 	memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2341 
2342 	mutex_lock(&fs_devices->device_list_mutex);
2343 	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2344 		if (device->devid > fi_args->max_id)
2345 			fi_args->max_id = device->devid;
2346 	}
2347 	mutex_unlock(&fs_devices->device_list_mutex);
2348 
2349 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2350 		ret = -EFAULT;
2351 
2352 	kfree(fi_args);
2353 	return ret;
2354 }
2355 
2356 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2357 {
2358 	struct btrfs_ioctl_dev_info_args *di_args;
2359 	struct btrfs_device *dev;
2360 	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2361 	int ret = 0;
2362 	char *s_uuid = NULL;
2363 	char empty_uuid[BTRFS_UUID_SIZE] = {0};
2364 
2365 	if (!capable(CAP_SYS_ADMIN))
2366 		return -EPERM;
2367 
2368 	di_args = memdup_user(arg, sizeof(*di_args));
2369 	if (IS_ERR(di_args))
2370 		return PTR_ERR(di_args);
2371 
2372 	if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2373 		s_uuid = di_args->uuid;
2374 
2375 	mutex_lock(&fs_devices->device_list_mutex);
2376 	dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2377 	mutex_unlock(&fs_devices->device_list_mutex);
2378 
2379 	if (!dev) {
2380 		ret = -ENODEV;
2381 		goto out;
2382 	}
2383 
2384 	di_args->devid = dev->devid;
2385 	di_args->bytes_used = dev->bytes_used;
2386 	di_args->total_bytes = dev->total_bytes;
2387 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2388 	if (dev->name) {
2389 		struct rcu_string *name;
2390 
2391 		rcu_read_lock();
2392 		name = rcu_dereference(dev->name);
2393 		strncpy(di_args->path, name->str, sizeof(di_args->path));
2394 		rcu_read_unlock();
2395 		di_args->path[sizeof(di_args->path) - 1] = 0;
2396 	} else {
2397 		di_args->path[0] = '\0';
2398 	}
2399 
2400 out:
2401 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2402 		ret = -EFAULT;
2403 
2404 	kfree(di_args);
2405 	return ret;
2406 }
2407 
2408 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2409 				       u64 off, u64 olen, u64 destoff)
2410 {
2411 	struct inode *inode = fdentry(file)->d_inode;
2412 	struct btrfs_root *root = BTRFS_I(inode)->root;
2413 	struct fd src_file;
2414 	struct inode *src;
2415 	struct btrfs_trans_handle *trans;
2416 	struct btrfs_path *path;
2417 	struct extent_buffer *leaf;
2418 	char *buf;
2419 	struct btrfs_key key;
2420 	u32 nritems;
2421 	int slot;
2422 	int ret;
2423 	u64 len = olen;
2424 	u64 bs = root->fs_info->sb->s_blocksize;
2425 
2426 	/*
2427 	 * TODO:
2428 	 * - split compressed inline extents.  annoying: we need to
2429 	 *   decompress into destination's address_space (the file offset
2430 	 *   may change, so source mapping won't do), then recompress (or
2431 	 *   otherwise reinsert) a subrange.
2432 	 * - allow ranges within the same file to be cloned (provided
2433 	 *   they don't overlap)?
2434 	 */
2435 
2436 	/* the destination must be opened for writing */
2437 	if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2438 		return -EINVAL;
2439 
2440 	if (btrfs_root_readonly(root))
2441 		return -EROFS;
2442 
2443 	ret = mnt_want_write_file(file);
2444 	if (ret)
2445 		return ret;
2446 
2447 	src_file = fdget(srcfd);
2448 	if (!src_file.file) {
2449 		ret = -EBADF;
2450 		goto out_drop_write;
2451 	}
2452 
2453 	ret = -EXDEV;
2454 	if (src_file.file->f_path.mnt != file->f_path.mnt)
2455 		goto out_fput;
2456 
2457 	src = src_file.file->f_dentry->d_inode;
2458 
2459 	ret = -EINVAL;
2460 	if (src == inode)
2461 		goto out_fput;
2462 
2463 	/* the src must be open for reading */
2464 	if (!(src_file.file->f_mode & FMODE_READ))
2465 		goto out_fput;
2466 
2467 	/* don't make the dst file partly checksummed */
2468 	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2469 	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2470 		goto out_fput;
2471 
2472 	ret = -EISDIR;
2473 	if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2474 		goto out_fput;
2475 
2476 	ret = -EXDEV;
2477 	if (src->i_sb != inode->i_sb)
2478 		goto out_fput;
2479 
2480 	ret = -ENOMEM;
2481 	buf = vmalloc(btrfs_level_size(root, 0));
2482 	if (!buf)
2483 		goto out_fput;
2484 
2485 	path = btrfs_alloc_path();
2486 	if (!path) {
2487 		vfree(buf);
2488 		goto out_fput;
2489 	}
2490 	path->reada = 2;
2491 
2492 	if (inode < src) {
2493 		mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2494 		mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2495 	} else {
2496 		mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2497 		mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2498 	}
2499 
2500 	/* determine range to clone */
2501 	ret = -EINVAL;
2502 	if (off + len > src->i_size || off + len < off)
2503 		goto out_unlock;
2504 	if (len == 0)
2505 		olen = len = src->i_size - off;
2506 	/* if we extend to eof, continue to block boundary */
2507 	if (off + len == src->i_size)
2508 		len = ALIGN(src->i_size, bs) - off;
2509 
2510 	/* verify the end result is block aligned */
2511 	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2512 	    !IS_ALIGNED(destoff, bs))
2513 		goto out_unlock;
2514 
2515 	if (destoff > inode->i_size) {
2516 		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2517 		if (ret)
2518 			goto out_unlock;
2519 	}
2520 
2521 	/* truncate page cache pages from target inode range */
2522 	truncate_inode_pages_range(&inode->i_data, destoff,
2523 				   PAGE_CACHE_ALIGN(destoff + len) - 1);
2524 
2525 	/* do any pending delalloc/csum calc on src, one way or
2526 	   another, and lock file content */
2527 	while (1) {
2528 		struct btrfs_ordered_extent *ordered;
2529 		lock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2530 		ordered = btrfs_lookup_first_ordered_extent(src, off + len - 1);
2531 		if (!ordered &&
2532 		    !test_range_bit(&BTRFS_I(src)->io_tree, off, off + len - 1,
2533 				    EXTENT_DELALLOC, 0, NULL))
2534 			break;
2535 		unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2536 		if (ordered)
2537 			btrfs_put_ordered_extent(ordered);
2538 		btrfs_wait_ordered_range(src, off, len);
2539 	}
2540 
2541 	/* clone data */
2542 	key.objectid = btrfs_ino(src);
2543 	key.type = BTRFS_EXTENT_DATA_KEY;
2544 	key.offset = 0;
2545 
2546 	while (1) {
2547 		/*
2548 		 * note the key will change type as we walk through the
2549 		 * tree.
2550 		 */
2551 		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2552 				0, 0);
2553 		if (ret < 0)
2554 			goto out;
2555 
2556 		nritems = btrfs_header_nritems(path->nodes[0]);
2557 		if (path->slots[0] >= nritems) {
2558 			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2559 			if (ret < 0)
2560 				goto out;
2561 			if (ret > 0)
2562 				break;
2563 			nritems = btrfs_header_nritems(path->nodes[0]);
2564 		}
2565 		leaf = path->nodes[0];
2566 		slot = path->slots[0];
2567 
2568 		btrfs_item_key_to_cpu(leaf, &key, slot);
2569 		if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2570 		    key.objectid != btrfs_ino(src))
2571 			break;
2572 
2573 		if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2574 			struct btrfs_file_extent_item *extent;
2575 			int type;
2576 			u32 size;
2577 			struct btrfs_key new_key;
2578 			u64 disko = 0, diskl = 0;
2579 			u64 datao = 0, datal = 0;
2580 			u8 comp;
2581 			u64 endoff;
2582 
2583 			size = btrfs_item_size_nr(leaf, slot);
2584 			read_extent_buffer(leaf, buf,
2585 					   btrfs_item_ptr_offset(leaf, slot),
2586 					   size);
2587 
2588 			extent = btrfs_item_ptr(leaf, slot,
2589 						struct btrfs_file_extent_item);
2590 			comp = btrfs_file_extent_compression(leaf, extent);
2591 			type = btrfs_file_extent_type(leaf, extent);
2592 			if (type == BTRFS_FILE_EXTENT_REG ||
2593 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
2594 				disko = btrfs_file_extent_disk_bytenr(leaf,
2595 								      extent);
2596 				diskl = btrfs_file_extent_disk_num_bytes(leaf,
2597 								 extent);
2598 				datao = btrfs_file_extent_offset(leaf, extent);
2599 				datal = btrfs_file_extent_num_bytes(leaf,
2600 								    extent);
2601 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
2602 				/* take upper bound, may be compressed */
2603 				datal = btrfs_file_extent_ram_bytes(leaf,
2604 								    extent);
2605 			}
2606 			btrfs_release_path(path);
2607 
2608 			if (key.offset + datal <= off ||
2609 			    key.offset >= off + len - 1)
2610 				goto next;
2611 
2612 			memcpy(&new_key, &key, sizeof(new_key));
2613 			new_key.objectid = btrfs_ino(inode);
2614 			if (off <= key.offset)
2615 				new_key.offset = key.offset + destoff - off;
2616 			else
2617 				new_key.offset = destoff;
2618 
2619 			/*
2620 			 * 1 - adjusting old extent (we may have to split it)
2621 			 * 1 - add new extent
2622 			 * 1 - inode update
2623 			 */
2624 			trans = btrfs_start_transaction(root, 3);
2625 			if (IS_ERR(trans)) {
2626 				ret = PTR_ERR(trans);
2627 				goto out;
2628 			}
2629 
2630 			if (type == BTRFS_FILE_EXTENT_REG ||
2631 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
2632 				/*
2633 				 *    a  | --- range to clone ---|  b
2634 				 * | ------------- extent ------------- |
2635 				 */
2636 
2637 				/* substract range b */
2638 				if (key.offset + datal > off + len)
2639 					datal = off + len - key.offset;
2640 
2641 				/* substract range a */
2642 				if (off > key.offset) {
2643 					datao += off - key.offset;
2644 					datal -= off - key.offset;
2645 				}
2646 
2647 				ret = btrfs_drop_extents(trans, root, inode,
2648 							 new_key.offset,
2649 							 new_key.offset + datal,
2650 							 1);
2651 				if (ret) {
2652 					btrfs_abort_transaction(trans, root,
2653 								ret);
2654 					btrfs_end_transaction(trans, root);
2655 					goto out;
2656 				}
2657 
2658 				ret = btrfs_insert_empty_item(trans, root, path,
2659 							      &new_key, size);
2660 				if (ret) {
2661 					btrfs_abort_transaction(trans, root,
2662 								ret);
2663 					btrfs_end_transaction(trans, root);
2664 					goto out;
2665 				}
2666 
2667 				leaf = path->nodes[0];
2668 				slot = path->slots[0];
2669 				write_extent_buffer(leaf, buf,
2670 					    btrfs_item_ptr_offset(leaf, slot),
2671 					    size);
2672 
2673 				extent = btrfs_item_ptr(leaf, slot,
2674 						struct btrfs_file_extent_item);
2675 
2676 				/* disko == 0 means it's a hole */
2677 				if (!disko)
2678 					datao = 0;
2679 
2680 				btrfs_set_file_extent_offset(leaf, extent,
2681 							     datao);
2682 				btrfs_set_file_extent_num_bytes(leaf, extent,
2683 								datal);
2684 				if (disko) {
2685 					inode_add_bytes(inode, datal);
2686 					ret = btrfs_inc_extent_ref(trans, root,
2687 							disko, diskl, 0,
2688 							root->root_key.objectid,
2689 							btrfs_ino(inode),
2690 							new_key.offset - datao,
2691 							0);
2692 					if (ret) {
2693 						btrfs_abort_transaction(trans,
2694 									root,
2695 									ret);
2696 						btrfs_end_transaction(trans,
2697 								      root);
2698 						goto out;
2699 
2700 					}
2701 				}
2702 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
2703 				u64 skip = 0;
2704 				u64 trim = 0;
2705 				if (off > key.offset) {
2706 					skip = off - key.offset;
2707 					new_key.offset += skip;
2708 				}
2709 
2710 				if (key.offset + datal > off + len)
2711 					trim = key.offset + datal - (off + len);
2712 
2713 				if (comp && (skip || trim)) {
2714 					ret = -EINVAL;
2715 					btrfs_end_transaction(trans, root);
2716 					goto out;
2717 				}
2718 				size -= skip + trim;
2719 				datal -= skip + trim;
2720 
2721 				ret = btrfs_drop_extents(trans, root, inode,
2722 							 new_key.offset,
2723 							 new_key.offset + datal,
2724 							 1);
2725 				if (ret) {
2726 					btrfs_abort_transaction(trans, root,
2727 								ret);
2728 					btrfs_end_transaction(trans, root);
2729 					goto out;
2730 				}
2731 
2732 				ret = btrfs_insert_empty_item(trans, root, path,
2733 							      &new_key, size);
2734 				if (ret) {
2735 					btrfs_abort_transaction(trans, root,
2736 								ret);
2737 					btrfs_end_transaction(trans, root);
2738 					goto out;
2739 				}
2740 
2741 				if (skip) {
2742 					u32 start =
2743 					  btrfs_file_extent_calc_inline_size(0);
2744 					memmove(buf+start, buf+start+skip,
2745 						datal);
2746 				}
2747 
2748 				leaf = path->nodes[0];
2749 				slot = path->slots[0];
2750 				write_extent_buffer(leaf, buf,
2751 					    btrfs_item_ptr_offset(leaf, slot),
2752 					    size);
2753 				inode_add_bytes(inode, datal);
2754 			}
2755 
2756 			btrfs_mark_buffer_dirty(leaf);
2757 			btrfs_release_path(path);
2758 
2759 			inode_inc_iversion(inode);
2760 			inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2761 
2762 			/*
2763 			 * we round up to the block size at eof when
2764 			 * determining which extents to clone above,
2765 			 * but shouldn't round up the file size
2766 			 */
2767 			endoff = new_key.offset + datal;
2768 			if (endoff > destoff+olen)
2769 				endoff = destoff+olen;
2770 			if (endoff > inode->i_size)
2771 				btrfs_i_size_write(inode, endoff);
2772 
2773 			ret = btrfs_update_inode(trans, root, inode);
2774 			if (ret) {
2775 				btrfs_abort_transaction(trans, root, ret);
2776 				btrfs_end_transaction(trans, root);
2777 				goto out;
2778 			}
2779 			ret = btrfs_end_transaction(trans, root);
2780 		}
2781 next:
2782 		btrfs_release_path(path);
2783 		key.offset++;
2784 	}
2785 	ret = 0;
2786 out:
2787 	btrfs_release_path(path);
2788 	unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2789 out_unlock:
2790 	mutex_unlock(&src->i_mutex);
2791 	mutex_unlock(&inode->i_mutex);
2792 	vfree(buf);
2793 	btrfs_free_path(path);
2794 out_fput:
2795 	fdput(src_file);
2796 out_drop_write:
2797 	mnt_drop_write_file(file);
2798 	return ret;
2799 }
2800 
2801 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2802 {
2803 	struct btrfs_ioctl_clone_range_args args;
2804 
2805 	if (copy_from_user(&args, argp, sizeof(args)))
2806 		return -EFAULT;
2807 	return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2808 				 args.src_length, args.dest_offset);
2809 }
2810 
2811 /*
2812  * there are many ways the trans_start and trans_end ioctls can lead
2813  * to deadlocks.  They should only be used by applications that
2814  * basically own the machine, and have a very in depth understanding
2815  * of all the possible deadlocks and enospc problems.
2816  */
2817 static long btrfs_ioctl_trans_start(struct file *file)
2818 {
2819 	struct inode *inode = fdentry(file)->d_inode;
2820 	struct btrfs_root *root = BTRFS_I(inode)->root;
2821 	struct btrfs_trans_handle *trans;
2822 	int ret;
2823 
2824 	ret = -EPERM;
2825 	if (!capable(CAP_SYS_ADMIN))
2826 		goto out;
2827 
2828 	ret = -EINPROGRESS;
2829 	if (file->private_data)
2830 		goto out;
2831 
2832 	ret = -EROFS;
2833 	if (btrfs_root_readonly(root))
2834 		goto out;
2835 
2836 	ret = mnt_want_write_file(file);
2837 	if (ret)
2838 		goto out;
2839 
2840 	atomic_inc(&root->fs_info->open_ioctl_trans);
2841 
2842 	ret = -ENOMEM;
2843 	trans = btrfs_start_ioctl_transaction(root);
2844 	if (IS_ERR(trans))
2845 		goto out_drop;
2846 
2847 	file->private_data = trans;
2848 	return 0;
2849 
2850 out_drop:
2851 	atomic_dec(&root->fs_info->open_ioctl_trans);
2852 	mnt_drop_write_file(file);
2853 out:
2854 	return ret;
2855 }
2856 
2857 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2858 {
2859 	struct inode *inode = fdentry(file)->d_inode;
2860 	struct btrfs_root *root = BTRFS_I(inode)->root;
2861 	struct btrfs_root *new_root;
2862 	struct btrfs_dir_item *di;
2863 	struct btrfs_trans_handle *trans;
2864 	struct btrfs_path *path;
2865 	struct btrfs_key location;
2866 	struct btrfs_disk_key disk_key;
2867 	u64 objectid = 0;
2868 	u64 dir_id;
2869 	int ret;
2870 
2871 	if (!capable(CAP_SYS_ADMIN))
2872 		return -EPERM;
2873 
2874 	ret = mnt_want_write_file(file);
2875 	if (ret)
2876 		return ret;
2877 
2878 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2879 		ret = -EFAULT;
2880 		goto out;
2881 	}
2882 
2883 	if (!objectid)
2884 		objectid = root->root_key.objectid;
2885 
2886 	location.objectid = objectid;
2887 	location.type = BTRFS_ROOT_ITEM_KEY;
2888 	location.offset = (u64)-1;
2889 
2890 	new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2891 	if (IS_ERR(new_root)) {
2892 		ret = PTR_ERR(new_root);
2893 		goto out;
2894 	}
2895 
2896 	if (btrfs_root_refs(&new_root->root_item) == 0) {
2897 		ret = -ENOENT;
2898 		goto out;
2899 	}
2900 
2901 	path = btrfs_alloc_path();
2902 	if (!path) {
2903 		ret = -ENOMEM;
2904 		goto out;
2905 	}
2906 	path->leave_spinning = 1;
2907 
2908 	trans = btrfs_start_transaction(root, 1);
2909 	if (IS_ERR(trans)) {
2910 		btrfs_free_path(path);
2911 		ret = PTR_ERR(trans);
2912 		goto out;
2913 	}
2914 
2915 	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2916 	di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2917 				   dir_id, "default", 7, 1);
2918 	if (IS_ERR_OR_NULL(di)) {
2919 		btrfs_free_path(path);
2920 		btrfs_end_transaction(trans, root);
2921 		printk(KERN_ERR "Umm, you don't have the default dir item, "
2922 		       "this isn't going to work\n");
2923 		ret = -ENOENT;
2924 		goto out;
2925 	}
2926 
2927 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2928 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2929 	btrfs_mark_buffer_dirty(path->nodes[0]);
2930 	btrfs_free_path(path);
2931 
2932 	btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2933 	btrfs_end_transaction(trans, root);
2934 out:
2935 	mnt_drop_write_file(file);
2936 	return ret;
2937 }
2938 
2939 void btrfs_get_block_group_info(struct list_head *groups_list,
2940 				struct btrfs_ioctl_space_info *space)
2941 {
2942 	struct btrfs_block_group_cache *block_group;
2943 
2944 	space->total_bytes = 0;
2945 	space->used_bytes = 0;
2946 	space->flags = 0;
2947 	list_for_each_entry(block_group, groups_list, list) {
2948 		space->flags = block_group->flags;
2949 		space->total_bytes += block_group->key.offset;
2950 		space->used_bytes +=
2951 			btrfs_block_group_used(&block_group->item);
2952 	}
2953 }
2954 
2955 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2956 {
2957 	struct btrfs_ioctl_space_args space_args;
2958 	struct btrfs_ioctl_space_info space;
2959 	struct btrfs_ioctl_space_info *dest;
2960 	struct btrfs_ioctl_space_info *dest_orig;
2961 	struct btrfs_ioctl_space_info __user *user_dest;
2962 	struct btrfs_space_info *info;
2963 	u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2964 		       BTRFS_BLOCK_GROUP_SYSTEM,
2965 		       BTRFS_BLOCK_GROUP_METADATA,
2966 		       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2967 	int num_types = 4;
2968 	int alloc_size;
2969 	int ret = 0;
2970 	u64 slot_count = 0;
2971 	int i, c;
2972 
2973 	if (copy_from_user(&space_args,
2974 			   (struct btrfs_ioctl_space_args __user *)arg,
2975 			   sizeof(space_args)))
2976 		return -EFAULT;
2977 
2978 	for (i = 0; i < num_types; i++) {
2979 		struct btrfs_space_info *tmp;
2980 
2981 		info = NULL;
2982 		rcu_read_lock();
2983 		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2984 					list) {
2985 			if (tmp->flags == types[i]) {
2986 				info = tmp;
2987 				break;
2988 			}
2989 		}
2990 		rcu_read_unlock();
2991 
2992 		if (!info)
2993 			continue;
2994 
2995 		down_read(&info->groups_sem);
2996 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
2997 			if (!list_empty(&info->block_groups[c]))
2998 				slot_count++;
2999 		}
3000 		up_read(&info->groups_sem);
3001 	}
3002 
3003 	/* space_slots == 0 means they are asking for a count */
3004 	if (space_args.space_slots == 0) {
3005 		space_args.total_spaces = slot_count;
3006 		goto out;
3007 	}
3008 
3009 	slot_count = min_t(u64, space_args.space_slots, slot_count);
3010 
3011 	alloc_size = sizeof(*dest) * slot_count;
3012 
3013 	/* we generally have at most 6 or so space infos, one for each raid
3014 	 * level.  So, a whole page should be more than enough for everyone
3015 	 */
3016 	if (alloc_size > PAGE_CACHE_SIZE)
3017 		return -ENOMEM;
3018 
3019 	space_args.total_spaces = 0;
3020 	dest = kmalloc(alloc_size, GFP_NOFS);
3021 	if (!dest)
3022 		return -ENOMEM;
3023 	dest_orig = dest;
3024 
3025 	/* now we have a buffer to copy into */
3026 	for (i = 0; i < num_types; i++) {
3027 		struct btrfs_space_info *tmp;
3028 
3029 		if (!slot_count)
3030 			break;
3031 
3032 		info = NULL;
3033 		rcu_read_lock();
3034 		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3035 					list) {
3036 			if (tmp->flags == types[i]) {
3037 				info = tmp;
3038 				break;
3039 			}
3040 		}
3041 		rcu_read_unlock();
3042 
3043 		if (!info)
3044 			continue;
3045 		down_read(&info->groups_sem);
3046 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3047 			if (!list_empty(&info->block_groups[c])) {
3048 				btrfs_get_block_group_info(
3049 					&info->block_groups[c], &space);
3050 				memcpy(dest, &space, sizeof(space));
3051 				dest++;
3052 				space_args.total_spaces++;
3053 				slot_count--;
3054 			}
3055 			if (!slot_count)
3056 				break;
3057 		}
3058 		up_read(&info->groups_sem);
3059 	}
3060 
3061 	user_dest = (struct btrfs_ioctl_space_info __user *)
3062 		(arg + sizeof(struct btrfs_ioctl_space_args));
3063 
3064 	if (copy_to_user(user_dest, dest_orig, alloc_size))
3065 		ret = -EFAULT;
3066 
3067 	kfree(dest_orig);
3068 out:
3069 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3070 		ret = -EFAULT;
3071 
3072 	return ret;
3073 }
3074 
3075 /*
3076  * there are many ways the trans_start and trans_end ioctls can lead
3077  * to deadlocks.  They should only be used by applications that
3078  * basically own the machine, and have a very in depth understanding
3079  * of all the possible deadlocks and enospc problems.
3080  */
3081 long btrfs_ioctl_trans_end(struct file *file)
3082 {
3083 	struct inode *inode = fdentry(file)->d_inode;
3084 	struct btrfs_root *root = BTRFS_I(inode)->root;
3085 	struct btrfs_trans_handle *trans;
3086 
3087 	trans = file->private_data;
3088 	if (!trans)
3089 		return -EINVAL;
3090 	file->private_data = NULL;
3091 
3092 	btrfs_end_transaction(trans, root);
3093 
3094 	atomic_dec(&root->fs_info->open_ioctl_trans);
3095 
3096 	mnt_drop_write_file(file);
3097 	return 0;
3098 }
3099 
3100 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3101 					    void __user *argp)
3102 {
3103 	struct btrfs_trans_handle *trans;
3104 	u64 transid;
3105 	int ret;
3106 
3107 	trans = btrfs_attach_transaction(root);
3108 	if (IS_ERR(trans)) {
3109 		if (PTR_ERR(trans) != -ENOENT)
3110 			return PTR_ERR(trans);
3111 
3112 		/* No running transaction, don't bother */
3113 		transid = root->fs_info->last_trans_committed;
3114 		goto out;
3115 	}
3116 	transid = trans->transid;
3117 	ret = btrfs_commit_transaction_async(trans, root, 0);
3118 	if (ret) {
3119 		btrfs_end_transaction(trans, root);
3120 		return ret;
3121 	}
3122 out:
3123 	if (argp)
3124 		if (copy_to_user(argp, &transid, sizeof(transid)))
3125 			return -EFAULT;
3126 	return 0;
3127 }
3128 
3129 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
3130 					   void __user *argp)
3131 {
3132 	u64 transid;
3133 
3134 	if (argp) {
3135 		if (copy_from_user(&transid, argp, sizeof(transid)))
3136 			return -EFAULT;
3137 	} else {
3138 		transid = 0;  /* current trans */
3139 	}
3140 	return btrfs_wait_for_commit(root, transid);
3141 }
3142 
3143 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3144 {
3145 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3146 	struct btrfs_ioctl_scrub_args *sa;
3147 	int ret;
3148 
3149 	if (!capable(CAP_SYS_ADMIN))
3150 		return -EPERM;
3151 
3152 	sa = memdup_user(arg, sizeof(*sa));
3153 	if (IS_ERR(sa))
3154 		return PTR_ERR(sa);
3155 
3156 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3157 		ret = mnt_want_write_file(file);
3158 		if (ret)
3159 			goto out;
3160 	}
3161 
3162 	ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
3163 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3164 			      0);
3165 
3166 	if (copy_to_user(arg, sa, sizeof(*sa)))
3167 		ret = -EFAULT;
3168 
3169 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
3170 		mnt_drop_write_file(file);
3171 out:
3172 	kfree(sa);
3173 	return ret;
3174 }
3175 
3176 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3177 {
3178 	if (!capable(CAP_SYS_ADMIN))
3179 		return -EPERM;
3180 
3181 	return btrfs_scrub_cancel(root->fs_info);
3182 }
3183 
3184 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3185 				       void __user *arg)
3186 {
3187 	struct btrfs_ioctl_scrub_args *sa;
3188 	int ret;
3189 
3190 	if (!capable(CAP_SYS_ADMIN))
3191 		return -EPERM;
3192 
3193 	sa = memdup_user(arg, sizeof(*sa));
3194 	if (IS_ERR(sa))
3195 		return PTR_ERR(sa);
3196 
3197 	ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3198 
3199 	if (copy_to_user(arg, sa, sizeof(*sa)))
3200 		ret = -EFAULT;
3201 
3202 	kfree(sa);
3203 	return ret;
3204 }
3205 
3206 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3207 				      void __user *arg)
3208 {
3209 	struct btrfs_ioctl_get_dev_stats *sa;
3210 	int ret;
3211 
3212 	sa = memdup_user(arg, sizeof(*sa));
3213 	if (IS_ERR(sa))
3214 		return PTR_ERR(sa);
3215 
3216 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3217 		kfree(sa);
3218 		return -EPERM;
3219 	}
3220 
3221 	ret = btrfs_get_dev_stats(root, sa);
3222 
3223 	if (copy_to_user(arg, sa, sizeof(*sa)))
3224 		ret = -EFAULT;
3225 
3226 	kfree(sa);
3227 	return ret;
3228 }
3229 
3230 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
3231 {
3232 	struct btrfs_ioctl_dev_replace_args *p;
3233 	int ret;
3234 
3235 	if (!capable(CAP_SYS_ADMIN))
3236 		return -EPERM;
3237 
3238 	p = memdup_user(arg, sizeof(*p));
3239 	if (IS_ERR(p))
3240 		return PTR_ERR(p);
3241 
3242 	switch (p->cmd) {
3243 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3244 		if (atomic_xchg(
3245 			&root->fs_info->mutually_exclusive_operation_running,
3246 			1)) {
3247 			pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3248 			ret = -EINPROGRESS;
3249 		} else {
3250 			ret = btrfs_dev_replace_start(root, p);
3251 			atomic_set(
3252 			 &root->fs_info->mutually_exclusive_operation_running,
3253 			 0);
3254 		}
3255 		break;
3256 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3257 		btrfs_dev_replace_status(root->fs_info, p);
3258 		ret = 0;
3259 		break;
3260 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3261 		ret = btrfs_dev_replace_cancel(root->fs_info, p);
3262 		break;
3263 	default:
3264 		ret = -EINVAL;
3265 		break;
3266 	}
3267 
3268 	if (copy_to_user(arg, p, sizeof(*p)))
3269 		ret = -EFAULT;
3270 
3271 	kfree(p);
3272 	return ret;
3273 }
3274 
3275 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3276 {
3277 	int ret = 0;
3278 	int i;
3279 	u64 rel_ptr;
3280 	int size;
3281 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
3282 	struct inode_fs_paths *ipath = NULL;
3283 	struct btrfs_path *path;
3284 
3285 	if (!capable(CAP_SYS_ADMIN))
3286 		return -EPERM;
3287 
3288 	path = btrfs_alloc_path();
3289 	if (!path) {
3290 		ret = -ENOMEM;
3291 		goto out;
3292 	}
3293 
3294 	ipa = memdup_user(arg, sizeof(*ipa));
3295 	if (IS_ERR(ipa)) {
3296 		ret = PTR_ERR(ipa);
3297 		ipa = NULL;
3298 		goto out;
3299 	}
3300 
3301 	size = min_t(u32, ipa->size, 4096);
3302 	ipath = init_ipath(size, root, path);
3303 	if (IS_ERR(ipath)) {
3304 		ret = PTR_ERR(ipath);
3305 		ipath = NULL;
3306 		goto out;
3307 	}
3308 
3309 	ret = paths_from_inode(ipa->inum, ipath);
3310 	if (ret < 0)
3311 		goto out;
3312 
3313 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3314 		rel_ptr = ipath->fspath->val[i] -
3315 			  (u64)(unsigned long)ipath->fspath->val;
3316 		ipath->fspath->val[i] = rel_ptr;
3317 	}
3318 
3319 	ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3320 			   (void *)(unsigned long)ipath->fspath, size);
3321 	if (ret) {
3322 		ret = -EFAULT;
3323 		goto out;
3324 	}
3325 
3326 out:
3327 	btrfs_free_path(path);
3328 	free_ipath(ipath);
3329 	kfree(ipa);
3330 
3331 	return ret;
3332 }
3333 
3334 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3335 {
3336 	struct btrfs_data_container *inodes = ctx;
3337 	const size_t c = 3 * sizeof(u64);
3338 
3339 	if (inodes->bytes_left >= c) {
3340 		inodes->bytes_left -= c;
3341 		inodes->val[inodes->elem_cnt] = inum;
3342 		inodes->val[inodes->elem_cnt + 1] = offset;
3343 		inodes->val[inodes->elem_cnt + 2] = root;
3344 		inodes->elem_cnt += 3;
3345 	} else {
3346 		inodes->bytes_missing += c - inodes->bytes_left;
3347 		inodes->bytes_left = 0;
3348 		inodes->elem_missed += 3;
3349 	}
3350 
3351 	return 0;
3352 }
3353 
3354 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3355 					void __user *arg)
3356 {
3357 	int ret = 0;
3358 	int size;
3359 	struct btrfs_ioctl_logical_ino_args *loi;
3360 	struct btrfs_data_container *inodes = NULL;
3361 	struct btrfs_path *path = NULL;
3362 
3363 	if (!capable(CAP_SYS_ADMIN))
3364 		return -EPERM;
3365 
3366 	loi = memdup_user(arg, sizeof(*loi));
3367 	if (IS_ERR(loi)) {
3368 		ret = PTR_ERR(loi);
3369 		loi = NULL;
3370 		goto out;
3371 	}
3372 
3373 	path = btrfs_alloc_path();
3374 	if (!path) {
3375 		ret = -ENOMEM;
3376 		goto out;
3377 	}
3378 
3379 	size = min_t(u32, loi->size, 64 * 1024);
3380 	inodes = init_data_container(size);
3381 	if (IS_ERR(inodes)) {
3382 		ret = PTR_ERR(inodes);
3383 		inodes = NULL;
3384 		goto out;
3385 	}
3386 
3387 	ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
3388 					  build_ino_list, inodes);
3389 	if (ret == -EINVAL)
3390 		ret = -ENOENT;
3391 	if (ret < 0)
3392 		goto out;
3393 
3394 	ret = copy_to_user((void *)(unsigned long)loi->inodes,
3395 			   (void *)(unsigned long)inodes, size);
3396 	if (ret)
3397 		ret = -EFAULT;
3398 
3399 out:
3400 	btrfs_free_path(path);
3401 	vfree(inodes);
3402 	kfree(loi);
3403 
3404 	return ret;
3405 }
3406 
3407 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3408 			       struct btrfs_ioctl_balance_args *bargs)
3409 {
3410 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3411 
3412 	bargs->flags = bctl->flags;
3413 
3414 	if (atomic_read(&fs_info->balance_running))
3415 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3416 	if (atomic_read(&fs_info->balance_pause_req))
3417 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3418 	if (atomic_read(&fs_info->balance_cancel_req))
3419 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3420 
3421 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3422 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3423 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3424 
3425 	if (lock) {
3426 		spin_lock(&fs_info->balance_lock);
3427 		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3428 		spin_unlock(&fs_info->balance_lock);
3429 	} else {
3430 		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3431 	}
3432 }
3433 
3434 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3435 {
3436 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3437 	struct btrfs_fs_info *fs_info = root->fs_info;
3438 	struct btrfs_ioctl_balance_args *bargs;
3439 	struct btrfs_balance_control *bctl;
3440 	int ret;
3441 	int need_to_clear_lock = 0;
3442 
3443 	if (!capable(CAP_SYS_ADMIN))
3444 		return -EPERM;
3445 
3446 	ret = mnt_want_write_file(file);
3447 	if (ret)
3448 		return ret;
3449 
3450 	mutex_lock(&fs_info->volume_mutex);
3451 	mutex_lock(&fs_info->balance_mutex);
3452 
3453 	if (arg) {
3454 		bargs = memdup_user(arg, sizeof(*bargs));
3455 		if (IS_ERR(bargs)) {
3456 			ret = PTR_ERR(bargs);
3457 			goto out;
3458 		}
3459 
3460 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
3461 			if (!fs_info->balance_ctl) {
3462 				ret = -ENOTCONN;
3463 				goto out_bargs;
3464 			}
3465 
3466 			bctl = fs_info->balance_ctl;
3467 			spin_lock(&fs_info->balance_lock);
3468 			bctl->flags |= BTRFS_BALANCE_RESUME;
3469 			spin_unlock(&fs_info->balance_lock);
3470 
3471 			goto do_balance;
3472 		}
3473 	} else {
3474 		bargs = NULL;
3475 	}
3476 
3477 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
3478 			1)) {
3479 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3480 		ret = -EINPROGRESS;
3481 		goto out_bargs;
3482 	}
3483 	need_to_clear_lock = 1;
3484 
3485 	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3486 	if (!bctl) {
3487 		ret = -ENOMEM;
3488 		goto out_bargs;
3489 	}
3490 
3491 	bctl->fs_info = fs_info;
3492 	if (arg) {
3493 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3494 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3495 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3496 
3497 		bctl->flags = bargs->flags;
3498 	} else {
3499 		/* balance everything - no filters */
3500 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3501 	}
3502 
3503 do_balance:
3504 	ret = btrfs_balance(bctl, bargs);
3505 	/*
3506 	 * bctl is freed in __cancel_balance or in free_fs_info if
3507 	 * restriper was paused all the way until unmount
3508 	 */
3509 	if (arg) {
3510 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
3511 			ret = -EFAULT;
3512 	}
3513 
3514 out_bargs:
3515 	kfree(bargs);
3516 out:
3517 	if (need_to_clear_lock)
3518 		atomic_set(&root->fs_info->mutually_exclusive_operation_running,
3519 			   0);
3520 	mutex_unlock(&fs_info->balance_mutex);
3521 	mutex_unlock(&fs_info->volume_mutex);
3522 	mnt_drop_write_file(file);
3523 	return ret;
3524 }
3525 
3526 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3527 {
3528 	if (!capable(CAP_SYS_ADMIN))
3529 		return -EPERM;
3530 
3531 	switch (cmd) {
3532 	case BTRFS_BALANCE_CTL_PAUSE:
3533 		return btrfs_pause_balance(root->fs_info);
3534 	case BTRFS_BALANCE_CTL_CANCEL:
3535 		return btrfs_cancel_balance(root->fs_info);
3536 	}
3537 
3538 	return -EINVAL;
3539 }
3540 
3541 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3542 					 void __user *arg)
3543 {
3544 	struct btrfs_fs_info *fs_info = root->fs_info;
3545 	struct btrfs_ioctl_balance_args *bargs;
3546 	int ret = 0;
3547 
3548 	if (!capable(CAP_SYS_ADMIN))
3549 		return -EPERM;
3550 
3551 	mutex_lock(&fs_info->balance_mutex);
3552 	if (!fs_info->balance_ctl) {
3553 		ret = -ENOTCONN;
3554 		goto out;
3555 	}
3556 
3557 	bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3558 	if (!bargs) {
3559 		ret = -ENOMEM;
3560 		goto out;
3561 	}
3562 
3563 	update_ioctl_balance_args(fs_info, 1, bargs);
3564 
3565 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
3566 		ret = -EFAULT;
3567 
3568 	kfree(bargs);
3569 out:
3570 	mutex_unlock(&fs_info->balance_mutex);
3571 	return ret;
3572 }
3573 
3574 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3575 {
3576 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3577 	struct btrfs_ioctl_quota_ctl_args *sa;
3578 	struct btrfs_trans_handle *trans = NULL;
3579 	int ret;
3580 	int err;
3581 
3582 	if (!capable(CAP_SYS_ADMIN))
3583 		return -EPERM;
3584 
3585 	ret = mnt_want_write_file(file);
3586 	if (ret)
3587 		return ret;
3588 
3589 	sa = memdup_user(arg, sizeof(*sa));
3590 	if (IS_ERR(sa)) {
3591 		ret = PTR_ERR(sa);
3592 		goto drop_write;
3593 	}
3594 
3595 	if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
3596 		trans = btrfs_start_transaction(root, 2);
3597 		if (IS_ERR(trans)) {
3598 			ret = PTR_ERR(trans);
3599 			goto out;
3600 		}
3601 	}
3602 
3603 	switch (sa->cmd) {
3604 	case BTRFS_QUOTA_CTL_ENABLE:
3605 		ret = btrfs_quota_enable(trans, root->fs_info);
3606 		break;
3607 	case BTRFS_QUOTA_CTL_DISABLE:
3608 		ret = btrfs_quota_disable(trans, root->fs_info);
3609 		break;
3610 	case BTRFS_QUOTA_CTL_RESCAN:
3611 		ret = btrfs_quota_rescan(root->fs_info);
3612 		break;
3613 	default:
3614 		ret = -EINVAL;
3615 		break;
3616 	}
3617 
3618 	if (copy_to_user(arg, sa, sizeof(*sa)))
3619 		ret = -EFAULT;
3620 
3621 	if (trans) {
3622 		err = btrfs_commit_transaction(trans, root);
3623 		if (err && !ret)
3624 			ret = err;
3625 	}
3626 out:
3627 	kfree(sa);
3628 drop_write:
3629 	mnt_drop_write_file(file);
3630 	return ret;
3631 }
3632 
3633 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3634 {
3635 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3636 	struct btrfs_ioctl_qgroup_assign_args *sa;
3637 	struct btrfs_trans_handle *trans;
3638 	int ret;
3639 	int err;
3640 
3641 	if (!capable(CAP_SYS_ADMIN))
3642 		return -EPERM;
3643 
3644 	ret = mnt_want_write_file(file);
3645 	if (ret)
3646 		return ret;
3647 
3648 	sa = memdup_user(arg, sizeof(*sa));
3649 	if (IS_ERR(sa)) {
3650 		ret = PTR_ERR(sa);
3651 		goto drop_write;
3652 	}
3653 
3654 	trans = btrfs_join_transaction(root);
3655 	if (IS_ERR(trans)) {
3656 		ret = PTR_ERR(trans);
3657 		goto out;
3658 	}
3659 
3660 	/* FIXME: check if the IDs really exist */
3661 	if (sa->assign) {
3662 		ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3663 						sa->src, sa->dst);
3664 	} else {
3665 		ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3666 						sa->src, sa->dst);
3667 	}
3668 
3669 	err = btrfs_end_transaction(trans, root);
3670 	if (err && !ret)
3671 		ret = err;
3672 
3673 out:
3674 	kfree(sa);
3675 drop_write:
3676 	mnt_drop_write_file(file);
3677 	return ret;
3678 }
3679 
3680 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3681 {
3682 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3683 	struct btrfs_ioctl_qgroup_create_args *sa;
3684 	struct btrfs_trans_handle *trans;
3685 	int ret;
3686 	int err;
3687 
3688 	if (!capable(CAP_SYS_ADMIN))
3689 		return -EPERM;
3690 
3691 	ret = mnt_want_write_file(file);
3692 	if (ret)
3693 		return ret;
3694 
3695 	sa = memdup_user(arg, sizeof(*sa));
3696 	if (IS_ERR(sa)) {
3697 		ret = PTR_ERR(sa);
3698 		goto drop_write;
3699 	}
3700 
3701 	trans = btrfs_join_transaction(root);
3702 	if (IS_ERR(trans)) {
3703 		ret = PTR_ERR(trans);
3704 		goto out;
3705 	}
3706 
3707 	/* FIXME: check if the IDs really exist */
3708 	if (sa->create) {
3709 		ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3710 					  NULL);
3711 	} else {
3712 		ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3713 	}
3714 
3715 	err = btrfs_end_transaction(trans, root);
3716 	if (err && !ret)
3717 		ret = err;
3718 
3719 out:
3720 	kfree(sa);
3721 drop_write:
3722 	mnt_drop_write_file(file);
3723 	return ret;
3724 }
3725 
3726 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3727 {
3728 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3729 	struct btrfs_ioctl_qgroup_limit_args *sa;
3730 	struct btrfs_trans_handle *trans;
3731 	int ret;
3732 	int err;
3733 	u64 qgroupid;
3734 
3735 	if (!capable(CAP_SYS_ADMIN))
3736 		return -EPERM;
3737 
3738 	ret = mnt_want_write_file(file);
3739 	if (ret)
3740 		return ret;
3741 
3742 	sa = memdup_user(arg, sizeof(*sa));
3743 	if (IS_ERR(sa)) {
3744 		ret = PTR_ERR(sa);
3745 		goto drop_write;
3746 	}
3747 
3748 	trans = btrfs_join_transaction(root);
3749 	if (IS_ERR(trans)) {
3750 		ret = PTR_ERR(trans);
3751 		goto out;
3752 	}
3753 
3754 	qgroupid = sa->qgroupid;
3755 	if (!qgroupid) {
3756 		/* take the current subvol as qgroup */
3757 		qgroupid = root->root_key.objectid;
3758 	}
3759 
3760 	/* FIXME: check if the IDs really exist */
3761 	ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3762 
3763 	err = btrfs_end_transaction(trans, root);
3764 	if (err && !ret)
3765 		ret = err;
3766 
3767 out:
3768 	kfree(sa);
3769 drop_write:
3770 	mnt_drop_write_file(file);
3771 	return ret;
3772 }
3773 
3774 static long btrfs_ioctl_set_received_subvol(struct file *file,
3775 					    void __user *arg)
3776 {
3777 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
3778 	struct inode *inode = fdentry(file)->d_inode;
3779 	struct btrfs_root *root = BTRFS_I(inode)->root;
3780 	struct btrfs_root_item *root_item = &root->root_item;
3781 	struct btrfs_trans_handle *trans;
3782 	struct timespec ct = CURRENT_TIME;
3783 	int ret = 0;
3784 
3785 	ret = mnt_want_write_file(file);
3786 	if (ret < 0)
3787 		return ret;
3788 
3789 	down_write(&root->fs_info->subvol_sem);
3790 
3791 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3792 		ret = -EINVAL;
3793 		goto out;
3794 	}
3795 
3796 	if (btrfs_root_readonly(root)) {
3797 		ret = -EROFS;
3798 		goto out;
3799 	}
3800 
3801 	if (!inode_owner_or_capable(inode)) {
3802 		ret = -EACCES;
3803 		goto out;
3804 	}
3805 
3806 	sa = memdup_user(arg, sizeof(*sa));
3807 	if (IS_ERR(sa)) {
3808 		ret = PTR_ERR(sa);
3809 		sa = NULL;
3810 		goto out;
3811 	}
3812 
3813 	trans = btrfs_start_transaction(root, 1);
3814 	if (IS_ERR(trans)) {
3815 		ret = PTR_ERR(trans);
3816 		trans = NULL;
3817 		goto out;
3818 	}
3819 
3820 	sa->rtransid = trans->transid;
3821 	sa->rtime.sec = ct.tv_sec;
3822 	sa->rtime.nsec = ct.tv_nsec;
3823 
3824 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3825 	btrfs_set_root_stransid(root_item, sa->stransid);
3826 	btrfs_set_root_rtransid(root_item, sa->rtransid);
3827 	root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3828 	root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3829 	root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3830 	root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
3831 
3832 	ret = btrfs_update_root(trans, root->fs_info->tree_root,
3833 				&root->root_key, &root->root_item);
3834 	if (ret < 0) {
3835 		btrfs_end_transaction(trans, root);
3836 		trans = NULL;
3837 		goto out;
3838 	} else {
3839 		ret = btrfs_commit_transaction(trans, root);
3840 		if (ret < 0)
3841 			goto out;
3842 	}
3843 
3844 	ret = copy_to_user(arg, sa, sizeof(*sa));
3845 	if (ret)
3846 		ret = -EFAULT;
3847 
3848 out:
3849 	kfree(sa);
3850 	up_write(&root->fs_info->subvol_sem);
3851 	mnt_drop_write_file(file);
3852 	return ret;
3853 }
3854 
3855 long btrfs_ioctl(struct file *file, unsigned int
3856 		cmd, unsigned long arg)
3857 {
3858 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3859 	void __user *argp = (void __user *)arg;
3860 
3861 	switch (cmd) {
3862 	case FS_IOC_GETFLAGS:
3863 		return btrfs_ioctl_getflags(file, argp);
3864 	case FS_IOC_SETFLAGS:
3865 		return btrfs_ioctl_setflags(file, argp);
3866 	case FS_IOC_GETVERSION:
3867 		return btrfs_ioctl_getversion(file, argp);
3868 	case FITRIM:
3869 		return btrfs_ioctl_fitrim(file, argp);
3870 	case BTRFS_IOC_SNAP_CREATE:
3871 		return btrfs_ioctl_snap_create(file, argp, 0);
3872 	case BTRFS_IOC_SNAP_CREATE_V2:
3873 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
3874 	case BTRFS_IOC_SUBVOL_CREATE:
3875 		return btrfs_ioctl_snap_create(file, argp, 1);
3876 	case BTRFS_IOC_SUBVOL_CREATE_V2:
3877 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
3878 	case BTRFS_IOC_SNAP_DESTROY:
3879 		return btrfs_ioctl_snap_destroy(file, argp);
3880 	case BTRFS_IOC_SUBVOL_GETFLAGS:
3881 		return btrfs_ioctl_subvol_getflags(file, argp);
3882 	case BTRFS_IOC_SUBVOL_SETFLAGS:
3883 		return btrfs_ioctl_subvol_setflags(file, argp);
3884 	case BTRFS_IOC_DEFAULT_SUBVOL:
3885 		return btrfs_ioctl_default_subvol(file, argp);
3886 	case BTRFS_IOC_DEFRAG:
3887 		return btrfs_ioctl_defrag(file, NULL);
3888 	case BTRFS_IOC_DEFRAG_RANGE:
3889 		return btrfs_ioctl_defrag(file, argp);
3890 	case BTRFS_IOC_RESIZE:
3891 		return btrfs_ioctl_resize(file, argp);
3892 	case BTRFS_IOC_ADD_DEV:
3893 		return btrfs_ioctl_add_dev(root, argp);
3894 	case BTRFS_IOC_RM_DEV:
3895 		return btrfs_ioctl_rm_dev(file, argp);
3896 	case BTRFS_IOC_FS_INFO:
3897 		return btrfs_ioctl_fs_info(root, argp);
3898 	case BTRFS_IOC_DEV_INFO:
3899 		return btrfs_ioctl_dev_info(root, argp);
3900 	case BTRFS_IOC_BALANCE:
3901 		return btrfs_ioctl_balance(file, NULL);
3902 	case BTRFS_IOC_CLONE:
3903 		return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3904 	case BTRFS_IOC_CLONE_RANGE:
3905 		return btrfs_ioctl_clone_range(file, argp);
3906 	case BTRFS_IOC_TRANS_START:
3907 		return btrfs_ioctl_trans_start(file);
3908 	case BTRFS_IOC_TRANS_END:
3909 		return btrfs_ioctl_trans_end(file);
3910 	case BTRFS_IOC_TREE_SEARCH:
3911 		return btrfs_ioctl_tree_search(file, argp);
3912 	case BTRFS_IOC_INO_LOOKUP:
3913 		return btrfs_ioctl_ino_lookup(file, argp);
3914 	case BTRFS_IOC_INO_PATHS:
3915 		return btrfs_ioctl_ino_to_path(root, argp);
3916 	case BTRFS_IOC_LOGICAL_INO:
3917 		return btrfs_ioctl_logical_to_ino(root, argp);
3918 	case BTRFS_IOC_SPACE_INFO:
3919 		return btrfs_ioctl_space_info(root, argp);
3920 	case BTRFS_IOC_SYNC:
3921 		btrfs_sync_fs(file->f_dentry->d_sb, 1);
3922 		return 0;
3923 	case BTRFS_IOC_START_SYNC:
3924 		return btrfs_ioctl_start_sync(root, argp);
3925 	case BTRFS_IOC_WAIT_SYNC:
3926 		return btrfs_ioctl_wait_sync(root, argp);
3927 	case BTRFS_IOC_SCRUB:
3928 		return btrfs_ioctl_scrub(file, argp);
3929 	case BTRFS_IOC_SCRUB_CANCEL:
3930 		return btrfs_ioctl_scrub_cancel(root, argp);
3931 	case BTRFS_IOC_SCRUB_PROGRESS:
3932 		return btrfs_ioctl_scrub_progress(root, argp);
3933 	case BTRFS_IOC_BALANCE_V2:
3934 		return btrfs_ioctl_balance(file, argp);
3935 	case BTRFS_IOC_BALANCE_CTL:
3936 		return btrfs_ioctl_balance_ctl(root, arg);
3937 	case BTRFS_IOC_BALANCE_PROGRESS:
3938 		return btrfs_ioctl_balance_progress(root, argp);
3939 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
3940 		return btrfs_ioctl_set_received_subvol(file, argp);
3941 	case BTRFS_IOC_SEND:
3942 		return btrfs_ioctl_send(file, argp);
3943 	case BTRFS_IOC_GET_DEV_STATS:
3944 		return btrfs_ioctl_get_dev_stats(root, argp);
3945 	case BTRFS_IOC_QUOTA_CTL:
3946 		return btrfs_ioctl_quota_ctl(file, argp);
3947 	case BTRFS_IOC_QGROUP_ASSIGN:
3948 		return btrfs_ioctl_qgroup_assign(file, argp);
3949 	case BTRFS_IOC_QGROUP_CREATE:
3950 		return btrfs_ioctl_qgroup_create(file, argp);
3951 	case BTRFS_IOC_QGROUP_LIMIT:
3952 		return btrfs_ioctl_qgroup_limit(file, argp);
3953 	case BTRFS_IOC_DEV_REPLACE:
3954 		return btrfs_ioctl_dev_replace(root, argp);
3955 	}
3956 
3957 	return -ENOTTY;
3958 }
3959