xref: /linux/fs/btrfs/ioctl.c (revision 861e10be08c69808065d755d3e3cab5d520a2d32)
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 fail:
519 	if (async_transid) {
520 		*async_transid = trans->transid;
521 		err = btrfs_commit_transaction_async(trans, root, 1);
522 	} else {
523 		err = btrfs_commit_transaction(trans, root);
524 	}
525 	if (err && !ret)
526 		ret = err;
527 
528 	if (!ret)
529 		d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
530 
531 	return ret;
532 }
533 
534 static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
535 			   char *name, int namelen, u64 *async_transid,
536 			   bool readonly, struct btrfs_qgroup_inherit **inherit)
537 {
538 	struct inode *inode;
539 	struct btrfs_pending_snapshot *pending_snapshot;
540 	struct btrfs_trans_handle *trans;
541 	int ret;
542 
543 	if (!root->ref_cows)
544 		return -EINVAL;
545 
546 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
547 	if (!pending_snapshot)
548 		return -ENOMEM;
549 
550 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
551 			     BTRFS_BLOCK_RSV_TEMP);
552 	pending_snapshot->dentry = dentry;
553 	pending_snapshot->root = root;
554 	pending_snapshot->readonly = readonly;
555 	if (inherit) {
556 		pending_snapshot->inherit = *inherit;
557 		*inherit = NULL;	/* take responsibility to free it */
558 	}
559 
560 	trans = btrfs_start_transaction(root->fs_info->extent_root, 6);
561 	if (IS_ERR(trans)) {
562 		ret = PTR_ERR(trans);
563 		goto fail;
564 	}
565 
566 	ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
567 	BUG_ON(ret);
568 
569 	spin_lock(&root->fs_info->trans_lock);
570 	list_add(&pending_snapshot->list,
571 		 &trans->transaction->pending_snapshots);
572 	spin_unlock(&root->fs_info->trans_lock);
573 	if (async_transid) {
574 		*async_transid = trans->transid;
575 		ret = btrfs_commit_transaction_async(trans,
576 				     root->fs_info->extent_root, 1);
577 	} else {
578 		ret = btrfs_commit_transaction(trans,
579 					       root->fs_info->extent_root);
580 	}
581 	if (ret) {
582 		/* cleanup_transaction has freed this for us */
583 		if (trans->aborted)
584 			pending_snapshot = NULL;
585 		goto fail;
586 	}
587 
588 	ret = pending_snapshot->error;
589 	if (ret)
590 		goto fail;
591 
592 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
593 	if (ret)
594 		goto fail;
595 
596 	inode = btrfs_lookup_dentry(dentry->d_parent->d_inode, dentry);
597 	if (IS_ERR(inode)) {
598 		ret = PTR_ERR(inode);
599 		goto fail;
600 	}
601 	BUG_ON(!inode);
602 	d_instantiate(dentry, inode);
603 	ret = 0;
604 fail:
605 	kfree(pending_snapshot);
606 	return ret;
607 }
608 
609 /*  copy of check_sticky in fs/namei.c()
610 * It's inline, so penalty for filesystems that don't use sticky bit is
611 * minimal.
612 */
613 static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
614 {
615 	kuid_t fsuid = current_fsuid();
616 
617 	if (!(dir->i_mode & S_ISVTX))
618 		return 0;
619 	if (uid_eq(inode->i_uid, fsuid))
620 		return 0;
621 	if (uid_eq(dir->i_uid, fsuid))
622 		return 0;
623 	return !capable(CAP_FOWNER);
624 }
625 
626 /*  copy of may_delete in fs/namei.c()
627  *	Check whether we can remove a link victim from directory dir, check
628  *  whether the type of victim is right.
629  *  1. We can't do it if dir is read-only (done in permission())
630  *  2. We should have write and exec permissions on dir
631  *  3. We can't remove anything from append-only dir
632  *  4. We can't do anything with immutable dir (done in permission())
633  *  5. If the sticky bit on dir is set we should either
634  *	a. be owner of dir, or
635  *	b. be owner of victim, or
636  *	c. have CAP_FOWNER capability
637  *  6. If the victim is append-only or immutable we can't do antyhing with
638  *     links pointing to it.
639  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
640  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
641  *  9. We can't remove a root or mountpoint.
642  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
643  *     nfs_async_unlink().
644  */
645 
646 static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
647 {
648 	int error;
649 
650 	if (!victim->d_inode)
651 		return -ENOENT;
652 
653 	BUG_ON(victim->d_parent->d_inode != dir);
654 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
655 
656 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
657 	if (error)
658 		return error;
659 	if (IS_APPEND(dir))
660 		return -EPERM;
661 	if (btrfs_check_sticky(dir, victim->d_inode)||
662 		IS_APPEND(victim->d_inode)||
663 	    IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
664 		return -EPERM;
665 	if (isdir) {
666 		if (!S_ISDIR(victim->d_inode->i_mode))
667 			return -ENOTDIR;
668 		if (IS_ROOT(victim))
669 			return -EBUSY;
670 	} else if (S_ISDIR(victim->d_inode->i_mode))
671 		return -EISDIR;
672 	if (IS_DEADDIR(dir))
673 		return -ENOENT;
674 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
675 		return -EBUSY;
676 	return 0;
677 }
678 
679 /* copy of may_create in fs/namei.c() */
680 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
681 {
682 	if (child->d_inode)
683 		return -EEXIST;
684 	if (IS_DEADDIR(dir))
685 		return -ENOENT;
686 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
687 }
688 
689 /*
690  * Create a new subvolume below @parent.  This is largely modeled after
691  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
692  * inside this filesystem so it's quite a bit simpler.
693  */
694 static noinline int btrfs_mksubvol(struct path *parent,
695 				   char *name, int namelen,
696 				   struct btrfs_root *snap_src,
697 				   u64 *async_transid, bool readonly,
698 				   struct btrfs_qgroup_inherit **inherit)
699 {
700 	struct inode *dir  = parent->dentry->d_inode;
701 	struct dentry *dentry;
702 	int error;
703 
704 	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
705 
706 	dentry = lookup_one_len(name, parent->dentry, namelen);
707 	error = PTR_ERR(dentry);
708 	if (IS_ERR(dentry))
709 		goto out_unlock;
710 
711 	error = -EEXIST;
712 	if (dentry->d_inode)
713 		goto out_dput;
714 
715 	error = btrfs_may_create(dir, dentry);
716 	if (error)
717 		goto out_dput;
718 
719 	/*
720 	 * even if this name doesn't exist, we may get hash collisions.
721 	 * check for them now when we can safely fail
722 	 */
723 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
724 					       dir->i_ino, name,
725 					       namelen);
726 	if (error)
727 		goto out_dput;
728 
729 	down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
730 
731 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
732 		goto out_up_read;
733 
734 	if (snap_src) {
735 		error = create_snapshot(snap_src, dentry, name, namelen,
736 					async_transid, readonly, inherit);
737 	} else {
738 		error = create_subvol(BTRFS_I(dir)->root, dentry,
739 				      name, namelen, async_transid, inherit);
740 	}
741 	if (!error)
742 		fsnotify_mkdir(dir, dentry);
743 out_up_read:
744 	up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
745 out_dput:
746 	dput(dentry);
747 out_unlock:
748 	mutex_unlock(&dir->i_mutex);
749 	return error;
750 }
751 
752 /*
753  * When we're defragging a range, we don't want to kick it off again
754  * if it is really just waiting for delalloc to send it down.
755  * If we find a nice big extent or delalloc range for the bytes in the
756  * file you want to defrag, we return 0 to let you know to skip this
757  * part of the file
758  */
759 static int check_defrag_in_cache(struct inode *inode, u64 offset, int thresh)
760 {
761 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
762 	struct extent_map *em = NULL;
763 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
764 	u64 end;
765 
766 	read_lock(&em_tree->lock);
767 	em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
768 	read_unlock(&em_tree->lock);
769 
770 	if (em) {
771 		end = extent_map_end(em);
772 		free_extent_map(em);
773 		if (end - offset > thresh)
774 			return 0;
775 	}
776 	/* if we already have a nice delalloc here, just stop */
777 	thresh /= 2;
778 	end = count_range_bits(io_tree, &offset, offset + thresh,
779 			       thresh, EXTENT_DELALLOC, 1);
780 	if (end >= thresh)
781 		return 0;
782 	return 1;
783 }
784 
785 /*
786  * helper function to walk through a file and find extents
787  * newer than a specific transid, and smaller than thresh.
788  *
789  * This is used by the defragging code to find new and small
790  * extents
791  */
792 static int find_new_extents(struct btrfs_root *root,
793 			    struct inode *inode, u64 newer_than,
794 			    u64 *off, int thresh)
795 {
796 	struct btrfs_path *path;
797 	struct btrfs_key min_key;
798 	struct btrfs_key max_key;
799 	struct extent_buffer *leaf;
800 	struct btrfs_file_extent_item *extent;
801 	int type;
802 	int ret;
803 	u64 ino = btrfs_ino(inode);
804 
805 	path = btrfs_alloc_path();
806 	if (!path)
807 		return -ENOMEM;
808 
809 	min_key.objectid = ino;
810 	min_key.type = BTRFS_EXTENT_DATA_KEY;
811 	min_key.offset = *off;
812 
813 	max_key.objectid = ino;
814 	max_key.type = (u8)-1;
815 	max_key.offset = (u64)-1;
816 
817 	path->keep_locks = 1;
818 
819 	while(1) {
820 		ret = btrfs_search_forward(root, &min_key, &max_key,
821 					   path, 0, newer_than);
822 		if (ret != 0)
823 			goto none;
824 		if (min_key.objectid != ino)
825 			goto none;
826 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
827 			goto none;
828 
829 		leaf = path->nodes[0];
830 		extent = btrfs_item_ptr(leaf, path->slots[0],
831 					struct btrfs_file_extent_item);
832 
833 		type = btrfs_file_extent_type(leaf, extent);
834 		if (type == BTRFS_FILE_EXTENT_REG &&
835 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
836 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
837 			*off = min_key.offset;
838 			btrfs_free_path(path);
839 			return 0;
840 		}
841 
842 		if (min_key.offset == (u64)-1)
843 			goto none;
844 
845 		min_key.offset++;
846 		btrfs_release_path(path);
847 	}
848 none:
849 	btrfs_free_path(path);
850 	return -ENOENT;
851 }
852 
853 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
854 {
855 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
856 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
857 	struct extent_map *em;
858 	u64 len = PAGE_CACHE_SIZE;
859 
860 	/*
861 	 * hopefully we have this extent in the tree already, try without
862 	 * the full extent lock
863 	 */
864 	read_lock(&em_tree->lock);
865 	em = lookup_extent_mapping(em_tree, start, len);
866 	read_unlock(&em_tree->lock);
867 
868 	if (!em) {
869 		/* get the big lock and read metadata off disk */
870 		lock_extent(io_tree, start, start + len - 1);
871 		em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
872 		unlock_extent(io_tree, start, start + len - 1);
873 
874 		if (IS_ERR(em))
875 			return NULL;
876 	}
877 
878 	return em;
879 }
880 
881 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
882 {
883 	struct extent_map *next;
884 	bool ret = true;
885 
886 	/* this is the last extent */
887 	if (em->start + em->len >= i_size_read(inode))
888 		return false;
889 
890 	next = defrag_lookup_extent(inode, em->start + em->len);
891 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
892 		ret = false;
893 
894 	free_extent_map(next);
895 	return ret;
896 }
897 
898 static int should_defrag_range(struct inode *inode, u64 start, int thresh,
899 			       u64 *last_len, u64 *skip, u64 *defrag_end,
900 			       int compress)
901 {
902 	struct extent_map *em;
903 	int ret = 1;
904 	bool next_mergeable = true;
905 
906 	/*
907 	 * make sure that once we start defragging an extent, we keep on
908 	 * defragging it
909 	 */
910 	if (start < *defrag_end)
911 		return 1;
912 
913 	*skip = 0;
914 
915 	em = defrag_lookup_extent(inode, start);
916 	if (!em)
917 		return 0;
918 
919 	/* this will cover holes, and inline extents */
920 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
921 		ret = 0;
922 		goto out;
923 	}
924 
925 	next_mergeable = defrag_check_next_extent(inode, em);
926 
927 	/*
928 	 * we hit a real extent, if it is big or the next extent is not a
929 	 * real extent, don't bother defragging it
930 	 */
931 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
932 	    (em->len >= thresh || !next_mergeable))
933 		ret = 0;
934 out:
935 	/*
936 	 * last_len ends up being a counter of how many bytes we've defragged.
937 	 * every time we choose not to defrag an extent, we reset *last_len
938 	 * so that the next tiny extent will force a defrag.
939 	 *
940 	 * The end result of this is that tiny extents before a single big
941 	 * extent will force at least part of that big extent to be defragged.
942 	 */
943 	if (ret) {
944 		*defrag_end = extent_map_end(em);
945 	} else {
946 		*last_len = 0;
947 		*skip = extent_map_end(em);
948 		*defrag_end = 0;
949 	}
950 
951 	free_extent_map(em);
952 	return ret;
953 }
954 
955 /*
956  * it doesn't do much good to defrag one or two pages
957  * at a time.  This pulls in a nice chunk of pages
958  * to COW and defrag.
959  *
960  * It also makes sure the delalloc code has enough
961  * dirty data to avoid making new small extents as part
962  * of the defrag
963  *
964  * It's a good idea to start RA on this range
965  * before calling this.
966  */
967 static int cluster_pages_for_defrag(struct inode *inode,
968 				    struct page **pages,
969 				    unsigned long start_index,
970 				    int num_pages)
971 {
972 	unsigned long file_end;
973 	u64 isize = i_size_read(inode);
974 	u64 page_start;
975 	u64 page_end;
976 	u64 page_cnt;
977 	int ret;
978 	int i;
979 	int i_done;
980 	struct btrfs_ordered_extent *ordered;
981 	struct extent_state *cached_state = NULL;
982 	struct extent_io_tree *tree;
983 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
984 
985 	file_end = (isize - 1) >> PAGE_CACHE_SHIFT;
986 	if (!isize || start_index > file_end)
987 		return 0;
988 
989 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
990 
991 	ret = btrfs_delalloc_reserve_space(inode,
992 					   page_cnt << PAGE_CACHE_SHIFT);
993 	if (ret)
994 		return ret;
995 	i_done = 0;
996 	tree = &BTRFS_I(inode)->io_tree;
997 
998 	/* step one, lock all the pages */
999 	for (i = 0; i < page_cnt; i++) {
1000 		struct page *page;
1001 again:
1002 		page = find_or_create_page(inode->i_mapping,
1003 					   start_index + i, mask);
1004 		if (!page)
1005 			break;
1006 
1007 		page_start = page_offset(page);
1008 		page_end = page_start + PAGE_CACHE_SIZE - 1;
1009 		while (1) {
1010 			lock_extent(tree, page_start, page_end);
1011 			ordered = btrfs_lookup_ordered_extent(inode,
1012 							      page_start);
1013 			unlock_extent(tree, page_start, page_end);
1014 			if (!ordered)
1015 				break;
1016 
1017 			unlock_page(page);
1018 			btrfs_start_ordered_extent(inode, ordered, 1);
1019 			btrfs_put_ordered_extent(ordered);
1020 			lock_page(page);
1021 			/*
1022 			 * we unlocked the page above, so we need check if
1023 			 * it was released or not.
1024 			 */
1025 			if (page->mapping != inode->i_mapping) {
1026 				unlock_page(page);
1027 				page_cache_release(page);
1028 				goto again;
1029 			}
1030 		}
1031 
1032 		if (!PageUptodate(page)) {
1033 			btrfs_readpage(NULL, page);
1034 			lock_page(page);
1035 			if (!PageUptodate(page)) {
1036 				unlock_page(page);
1037 				page_cache_release(page);
1038 				ret = -EIO;
1039 				break;
1040 			}
1041 		}
1042 
1043 		if (page->mapping != inode->i_mapping) {
1044 			unlock_page(page);
1045 			page_cache_release(page);
1046 			goto again;
1047 		}
1048 
1049 		pages[i] = page;
1050 		i_done++;
1051 	}
1052 	if (!i_done || ret)
1053 		goto out;
1054 
1055 	if (!(inode->i_sb->s_flags & MS_ACTIVE))
1056 		goto out;
1057 
1058 	/*
1059 	 * so now we have a nice long stream of locked
1060 	 * and up to date pages, lets wait on them
1061 	 */
1062 	for (i = 0; i < i_done; i++)
1063 		wait_on_page_writeback(pages[i]);
1064 
1065 	page_start = page_offset(pages[0]);
1066 	page_end = page_offset(pages[i_done - 1]) + PAGE_CACHE_SIZE;
1067 
1068 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1069 			 page_start, page_end - 1, 0, &cached_state);
1070 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1071 			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1072 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1073 			  &cached_state, GFP_NOFS);
1074 
1075 	if (i_done != page_cnt) {
1076 		spin_lock(&BTRFS_I(inode)->lock);
1077 		BTRFS_I(inode)->outstanding_extents++;
1078 		spin_unlock(&BTRFS_I(inode)->lock);
1079 		btrfs_delalloc_release_space(inode,
1080 				     (page_cnt - i_done) << PAGE_CACHE_SHIFT);
1081 	}
1082 
1083 
1084 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1085 			  &cached_state, GFP_NOFS);
1086 
1087 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1088 			     page_start, page_end - 1, &cached_state,
1089 			     GFP_NOFS);
1090 
1091 	for (i = 0; i < i_done; i++) {
1092 		clear_page_dirty_for_io(pages[i]);
1093 		ClearPageChecked(pages[i]);
1094 		set_page_extent_mapped(pages[i]);
1095 		set_page_dirty(pages[i]);
1096 		unlock_page(pages[i]);
1097 		page_cache_release(pages[i]);
1098 	}
1099 	return i_done;
1100 out:
1101 	for (i = 0; i < i_done; i++) {
1102 		unlock_page(pages[i]);
1103 		page_cache_release(pages[i]);
1104 	}
1105 	btrfs_delalloc_release_space(inode, page_cnt << PAGE_CACHE_SHIFT);
1106 	return ret;
1107 
1108 }
1109 
1110 int btrfs_defrag_file(struct inode *inode, struct file *file,
1111 		      struct btrfs_ioctl_defrag_range_args *range,
1112 		      u64 newer_than, unsigned long max_to_defrag)
1113 {
1114 	struct btrfs_root *root = BTRFS_I(inode)->root;
1115 	struct file_ra_state *ra = NULL;
1116 	unsigned long last_index;
1117 	u64 isize = i_size_read(inode);
1118 	u64 last_len = 0;
1119 	u64 skip = 0;
1120 	u64 defrag_end = 0;
1121 	u64 newer_off = range->start;
1122 	unsigned long i;
1123 	unsigned long ra_index = 0;
1124 	int ret;
1125 	int defrag_count = 0;
1126 	int compress_type = BTRFS_COMPRESS_ZLIB;
1127 	int extent_thresh = range->extent_thresh;
1128 	int max_cluster = (256 * 1024) >> PAGE_CACHE_SHIFT;
1129 	int cluster = max_cluster;
1130 	u64 new_align = ~((u64)128 * 1024 - 1);
1131 	struct page **pages = NULL;
1132 
1133 	if (extent_thresh == 0)
1134 		extent_thresh = 256 * 1024;
1135 
1136 	if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
1137 		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1138 			return -EINVAL;
1139 		if (range->compress_type)
1140 			compress_type = range->compress_type;
1141 	}
1142 
1143 	if (isize == 0)
1144 		return 0;
1145 
1146 	/*
1147 	 * if we were not given a file, allocate a readahead
1148 	 * context
1149 	 */
1150 	if (!file) {
1151 		ra = kzalloc(sizeof(*ra), GFP_NOFS);
1152 		if (!ra)
1153 			return -ENOMEM;
1154 		file_ra_state_init(ra, inode->i_mapping);
1155 	} else {
1156 		ra = &file->f_ra;
1157 	}
1158 
1159 	pages = kmalloc(sizeof(struct page *) * max_cluster,
1160 			GFP_NOFS);
1161 	if (!pages) {
1162 		ret = -ENOMEM;
1163 		goto out_ra;
1164 	}
1165 
1166 	/* find the last page to defrag */
1167 	if (range->start + range->len > range->start) {
1168 		last_index = min_t(u64, isize - 1,
1169 			 range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
1170 	} else {
1171 		last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
1172 	}
1173 
1174 	if (newer_than) {
1175 		ret = find_new_extents(root, inode, newer_than,
1176 				       &newer_off, 64 * 1024);
1177 		if (!ret) {
1178 			range->start = newer_off;
1179 			/*
1180 			 * we always align our defrag to help keep
1181 			 * the extents in the file evenly spaced
1182 			 */
1183 			i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1184 		} else
1185 			goto out_ra;
1186 	} else {
1187 		i = range->start >> PAGE_CACHE_SHIFT;
1188 	}
1189 	if (!max_to_defrag)
1190 		max_to_defrag = last_index + 1;
1191 
1192 	/*
1193 	 * make writeback starts from i, so the defrag range can be
1194 	 * written sequentially.
1195 	 */
1196 	if (i < inode->i_mapping->writeback_index)
1197 		inode->i_mapping->writeback_index = i;
1198 
1199 	while (i <= last_index && defrag_count < max_to_defrag &&
1200 	       (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
1201 		PAGE_CACHE_SHIFT)) {
1202 		/*
1203 		 * make sure we stop running if someone unmounts
1204 		 * the FS
1205 		 */
1206 		if (!(inode->i_sb->s_flags & MS_ACTIVE))
1207 			break;
1208 
1209 		if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
1210 					 extent_thresh, &last_len, &skip,
1211 					 &defrag_end, range->flags &
1212 					 BTRFS_DEFRAG_RANGE_COMPRESS)) {
1213 			unsigned long next;
1214 			/*
1215 			 * the should_defrag function tells us how much to skip
1216 			 * bump our counter by the suggested amount
1217 			 */
1218 			next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1219 			i = max(i + 1, next);
1220 			continue;
1221 		}
1222 
1223 		if (!newer_than) {
1224 			cluster = (PAGE_CACHE_ALIGN(defrag_end) >>
1225 				   PAGE_CACHE_SHIFT) - i;
1226 			cluster = min(cluster, max_cluster);
1227 		} else {
1228 			cluster = max_cluster;
1229 		}
1230 
1231 		if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
1232 			BTRFS_I(inode)->force_compress = compress_type;
1233 
1234 		if (i + cluster > ra_index) {
1235 			ra_index = max(i, ra_index);
1236 			btrfs_force_ra(inode->i_mapping, ra, file, ra_index,
1237 				       cluster);
1238 			ra_index += max_cluster;
1239 		}
1240 
1241 		mutex_lock(&inode->i_mutex);
1242 		ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1243 		if (ret < 0) {
1244 			mutex_unlock(&inode->i_mutex);
1245 			goto out_ra;
1246 		}
1247 
1248 		defrag_count += ret;
1249 		balance_dirty_pages_ratelimited(inode->i_mapping);
1250 		mutex_unlock(&inode->i_mutex);
1251 
1252 		if (newer_than) {
1253 			if (newer_off == (u64)-1)
1254 				break;
1255 
1256 			if (ret > 0)
1257 				i += ret;
1258 
1259 			newer_off = max(newer_off + 1,
1260 					(u64)i << PAGE_CACHE_SHIFT);
1261 
1262 			ret = find_new_extents(root, inode,
1263 					       newer_than, &newer_off,
1264 					       64 * 1024);
1265 			if (!ret) {
1266 				range->start = newer_off;
1267 				i = (newer_off & new_align) >> PAGE_CACHE_SHIFT;
1268 			} else {
1269 				break;
1270 			}
1271 		} else {
1272 			if (ret > 0) {
1273 				i += ret;
1274 				last_len += ret << PAGE_CACHE_SHIFT;
1275 			} else {
1276 				i++;
1277 				last_len = 0;
1278 			}
1279 		}
1280 	}
1281 
1282 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
1283 		filemap_flush(inode->i_mapping);
1284 
1285 	if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
1286 		/* the filemap_flush will queue IO into the worker threads, but
1287 		 * we have to make sure the IO is actually started and that
1288 		 * ordered extents get created before we return
1289 		 */
1290 		atomic_inc(&root->fs_info->async_submit_draining);
1291 		while (atomic_read(&root->fs_info->nr_async_submits) ||
1292 		      atomic_read(&root->fs_info->async_delalloc_pages)) {
1293 			wait_event(root->fs_info->async_submit_wait,
1294 			   (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
1295 			    atomic_read(&root->fs_info->async_delalloc_pages) == 0));
1296 		}
1297 		atomic_dec(&root->fs_info->async_submit_draining);
1298 
1299 		mutex_lock(&inode->i_mutex);
1300 		BTRFS_I(inode)->force_compress = BTRFS_COMPRESS_NONE;
1301 		mutex_unlock(&inode->i_mutex);
1302 	}
1303 
1304 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1305 		btrfs_set_fs_incompat(root->fs_info, COMPRESS_LZO);
1306 	}
1307 
1308 	ret = defrag_count;
1309 
1310 out_ra:
1311 	if (!file)
1312 		kfree(ra);
1313 	kfree(pages);
1314 	return ret;
1315 }
1316 
1317 static noinline int btrfs_ioctl_resize(struct file *file,
1318 					void __user *arg)
1319 {
1320 	u64 new_size;
1321 	u64 old_size;
1322 	u64 devid = 1;
1323 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
1324 	struct btrfs_ioctl_vol_args *vol_args;
1325 	struct btrfs_trans_handle *trans;
1326 	struct btrfs_device *device = NULL;
1327 	char *sizestr;
1328 	char *devstr = NULL;
1329 	int ret = 0;
1330 	int mod = 0;
1331 
1332 	if (root->fs_info->sb->s_flags & MS_RDONLY)
1333 		return -EROFS;
1334 
1335 	if (!capable(CAP_SYS_ADMIN))
1336 		return -EPERM;
1337 
1338 	ret = mnt_want_write_file(file);
1339 	if (ret)
1340 		return ret;
1341 
1342 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1343 			1)) {
1344 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
1345 		mnt_drop_write_file(file);
1346 		return -EINVAL;
1347 	}
1348 
1349 	mutex_lock(&root->fs_info->volume_mutex);
1350 	vol_args = memdup_user(arg, sizeof(*vol_args));
1351 	if (IS_ERR(vol_args)) {
1352 		ret = PTR_ERR(vol_args);
1353 		goto out;
1354 	}
1355 
1356 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1357 
1358 	sizestr = vol_args->name;
1359 	devstr = strchr(sizestr, ':');
1360 	if (devstr) {
1361 		char *end;
1362 		sizestr = devstr + 1;
1363 		*devstr = '\0';
1364 		devstr = vol_args->name;
1365 		devid = simple_strtoull(devstr, &end, 10);
1366 		printk(KERN_INFO "btrfs: resizing devid %llu\n",
1367 		       (unsigned long long)devid);
1368 	}
1369 
1370 	device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
1371 	if (!device) {
1372 		printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
1373 		       (unsigned long long)devid);
1374 		ret = -EINVAL;
1375 		goto out_free;
1376 	}
1377 
1378 	if (!device->writeable) {
1379 		printk(KERN_INFO "btrfs: resizer unable to apply on "
1380 		       "readonly device %llu\n",
1381 		       (unsigned long long)devid);
1382 		ret = -EINVAL;
1383 		goto out_free;
1384 	}
1385 
1386 	if (!strcmp(sizestr, "max"))
1387 		new_size = device->bdev->bd_inode->i_size;
1388 	else {
1389 		if (sizestr[0] == '-') {
1390 			mod = -1;
1391 			sizestr++;
1392 		} else if (sizestr[0] == '+') {
1393 			mod = 1;
1394 			sizestr++;
1395 		}
1396 		new_size = memparse(sizestr, NULL);
1397 		if (new_size == 0) {
1398 			ret = -EINVAL;
1399 			goto out_free;
1400 		}
1401 	}
1402 
1403 	if (device->is_tgtdev_for_dev_replace) {
1404 		ret = -EINVAL;
1405 		goto out_free;
1406 	}
1407 
1408 	old_size = device->total_bytes;
1409 
1410 	if (mod < 0) {
1411 		if (new_size > old_size) {
1412 			ret = -EINVAL;
1413 			goto out_free;
1414 		}
1415 		new_size = old_size - new_size;
1416 	} else if (mod > 0) {
1417 		new_size = old_size + new_size;
1418 	}
1419 
1420 	if (new_size < 256 * 1024 * 1024) {
1421 		ret = -EINVAL;
1422 		goto out_free;
1423 	}
1424 	if (new_size > device->bdev->bd_inode->i_size) {
1425 		ret = -EFBIG;
1426 		goto out_free;
1427 	}
1428 
1429 	do_div(new_size, root->sectorsize);
1430 	new_size *= root->sectorsize;
1431 
1432 	printk_in_rcu(KERN_INFO "btrfs: new size for %s is %llu\n",
1433 		      rcu_str_deref(device->name),
1434 		      (unsigned long long)new_size);
1435 
1436 	if (new_size > old_size) {
1437 		trans = btrfs_start_transaction(root, 0);
1438 		if (IS_ERR(trans)) {
1439 			ret = PTR_ERR(trans);
1440 			goto out_free;
1441 		}
1442 		ret = btrfs_grow_device(trans, device, new_size);
1443 		btrfs_commit_transaction(trans, root);
1444 	} else if (new_size < old_size) {
1445 		ret = btrfs_shrink_device(device, new_size);
1446 	} /* equal, nothing need to do */
1447 
1448 out_free:
1449 	kfree(vol_args);
1450 out:
1451 	mutex_unlock(&root->fs_info->volume_mutex);
1452 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
1453 	mnt_drop_write_file(file);
1454 	return ret;
1455 }
1456 
1457 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1458 				char *name, unsigned long fd, int subvol,
1459 				u64 *transid, bool readonly,
1460 				struct btrfs_qgroup_inherit **inherit)
1461 {
1462 	int namelen;
1463 	int ret = 0;
1464 
1465 	ret = mnt_want_write_file(file);
1466 	if (ret)
1467 		goto out;
1468 
1469 	namelen = strlen(name);
1470 	if (strchr(name, '/')) {
1471 		ret = -EINVAL;
1472 		goto out_drop_write;
1473 	}
1474 
1475 	if (name[0] == '.' &&
1476 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1477 		ret = -EEXIST;
1478 		goto out_drop_write;
1479 	}
1480 
1481 	if (subvol) {
1482 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1483 				     NULL, transid, readonly, inherit);
1484 	} else {
1485 		struct fd src = fdget(fd);
1486 		struct inode *src_inode;
1487 		if (!src.file) {
1488 			ret = -EINVAL;
1489 			goto out_drop_write;
1490 		}
1491 
1492 		src_inode = src.file->f_path.dentry->d_inode;
1493 		if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
1494 			printk(KERN_INFO "btrfs: Snapshot src from "
1495 			       "another FS\n");
1496 			ret = -EINVAL;
1497 		} else {
1498 			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1499 					     BTRFS_I(src_inode)->root,
1500 					     transid, readonly, inherit);
1501 		}
1502 		fdput(src);
1503 	}
1504 out_drop_write:
1505 	mnt_drop_write_file(file);
1506 out:
1507 	return ret;
1508 }
1509 
1510 static noinline int btrfs_ioctl_snap_create(struct file *file,
1511 					    void __user *arg, int subvol)
1512 {
1513 	struct btrfs_ioctl_vol_args *vol_args;
1514 	int ret;
1515 
1516 	vol_args = memdup_user(arg, sizeof(*vol_args));
1517 	if (IS_ERR(vol_args))
1518 		return PTR_ERR(vol_args);
1519 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1520 
1521 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1522 					      vol_args->fd, subvol,
1523 					      NULL, false, NULL);
1524 
1525 	kfree(vol_args);
1526 	return ret;
1527 }
1528 
1529 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1530 					       void __user *arg, int subvol)
1531 {
1532 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1533 	int ret;
1534 	u64 transid = 0;
1535 	u64 *ptr = NULL;
1536 	bool readonly = false;
1537 	struct btrfs_qgroup_inherit *inherit = NULL;
1538 
1539 	vol_args = memdup_user(arg, sizeof(*vol_args));
1540 	if (IS_ERR(vol_args))
1541 		return PTR_ERR(vol_args);
1542 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1543 
1544 	if (vol_args->flags &
1545 	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1546 	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1547 		ret = -EOPNOTSUPP;
1548 		goto out;
1549 	}
1550 
1551 	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1552 		ptr = &transid;
1553 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1554 		readonly = true;
1555 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1556 		if (vol_args->size > PAGE_CACHE_SIZE) {
1557 			ret = -EINVAL;
1558 			goto out;
1559 		}
1560 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1561 		if (IS_ERR(inherit)) {
1562 			ret = PTR_ERR(inherit);
1563 			goto out;
1564 		}
1565 	}
1566 
1567 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1568 					      vol_args->fd, subvol, ptr,
1569 					      readonly, &inherit);
1570 
1571 	if (ret == 0 && ptr &&
1572 	    copy_to_user(arg +
1573 			 offsetof(struct btrfs_ioctl_vol_args_v2,
1574 				  transid), ptr, sizeof(*ptr)))
1575 		ret = -EFAULT;
1576 out:
1577 	kfree(vol_args);
1578 	kfree(inherit);
1579 	return ret;
1580 }
1581 
1582 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1583 						void __user *arg)
1584 {
1585 	struct inode *inode = fdentry(file)->d_inode;
1586 	struct btrfs_root *root = BTRFS_I(inode)->root;
1587 	int ret = 0;
1588 	u64 flags = 0;
1589 
1590 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID)
1591 		return -EINVAL;
1592 
1593 	down_read(&root->fs_info->subvol_sem);
1594 	if (btrfs_root_readonly(root))
1595 		flags |= BTRFS_SUBVOL_RDONLY;
1596 	up_read(&root->fs_info->subvol_sem);
1597 
1598 	if (copy_to_user(arg, &flags, sizeof(flags)))
1599 		ret = -EFAULT;
1600 
1601 	return ret;
1602 }
1603 
1604 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1605 					      void __user *arg)
1606 {
1607 	struct inode *inode = fdentry(file)->d_inode;
1608 	struct btrfs_root *root = BTRFS_I(inode)->root;
1609 	struct btrfs_trans_handle *trans;
1610 	u64 root_flags;
1611 	u64 flags;
1612 	int ret = 0;
1613 
1614 	ret = mnt_want_write_file(file);
1615 	if (ret)
1616 		goto out;
1617 
1618 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
1619 		ret = -EINVAL;
1620 		goto out_drop_write;
1621 	}
1622 
1623 	if (copy_from_user(&flags, arg, sizeof(flags))) {
1624 		ret = -EFAULT;
1625 		goto out_drop_write;
1626 	}
1627 
1628 	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1629 		ret = -EINVAL;
1630 		goto out_drop_write;
1631 	}
1632 
1633 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1634 		ret = -EOPNOTSUPP;
1635 		goto out_drop_write;
1636 	}
1637 
1638 	if (!inode_owner_or_capable(inode)) {
1639 		ret = -EACCES;
1640 		goto out_drop_write;
1641 	}
1642 
1643 	down_write(&root->fs_info->subvol_sem);
1644 
1645 	/* nothing to do */
1646 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1647 		goto out_drop_sem;
1648 
1649 	root_flags = btrfs_root_flags(&root->root_item);
1650 	if (flags & BTRFS_SUBVOL_RDONLY)
1651 		btrfs_set_root_flags(&root->root_item,
1652 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1653 	else
1654 		btrfs_set_root_flags(&root->root_item,
1655 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1656 
1657 	trans = btrfs_start_transaction(root, 1);
1658 	if (IS_ERR(trans)) {
1659 		ret = PTR_ERR(trans);
1660 		goto out_reset;
1661 	}
1662 
1663 	ret = btrfs_update_root(trans, root->fs_info->tree_root,
1664 				&root->root_key, &root->root_item);
1665 
1666 	btrfs_commit_transaction(trans, root);
1667 out_reset:
1668 	if (ret)
1669 		btrfs_set_root_flags(&root->root_item, root_flags);
1670 out_drop_sem:
1671 	up_write(&root->fs_info->subvol_sem);
1672 out_drop_write:
1673 	mnt_drop_write_file(file);
1674 out:
1675 	return ret;
1676 }
1677 
1678 /*
1679  * helper to check if the subvolume references other subvolumes
1680  */
1681 static noinline int may_destroy_subvol(struct btrfs_root *root)
1682 {
1683 	struct btrfs_path *path;
1684 	struct btrfs_key key;
1685 	int ret;
1686 
1687 	path = btrfs_alloc_path();
1688 	if (!path)
1689 		return -ENOMEM;
1690 
1691 	key.objectid = root->root_key.objectid;
1692 	key.type = BTRFS_ROOT_REF_KEY;
1693 	key.offset = (u64)-1;
1694 
1695 	ret = btrfs_search_slot(NULL, root->fs_info->tree_root,
1696 				&key, path, 0, 0);
1697 	if (ret < 0)
1698 		goto out;
1699 	BUG_ON(ret == 0);
1700 
1701 	ret = 0;
1702 	if (path->slots[0] > 0) {
1703 		path->slots[0]--;
1704 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1705 		if (key.objectid == root->root_key.objectid &&
1706 		    key.type == BTRFS_ROOT_REF_KEY)
1707 			ret = -ENOTEMPTY;
1708 	}
1709 out:
1710 	btrfs_free_path(path);
1711 	return ret;
1712 }
1713 
1714 static noinline int key_in_sk(struct btrfs_key *key,
1715 			      struct btrfs_ioctl_search_key *sk)
1716 {
1717 	struct btrfs_key test;
1718 	int ret;
1719 
1720 	test.objectid = sk->min_objectid;
1721 	test.type = sk->min_type;
1722 	test.offset = sk->min_offset;
1723 
1724 	ret = btrfs_comp_cpu_keys(key, &test);
1725 	if (ret < 0)
1726 		return 0;
1727 
1728 	test.objectid = sk->max_objectid;
1729 	test.type = sk->max_type;
1730 	test.offset = sk->max_offset;
1731 
1732 	ret = btrfs_comp_cpu_keys(key, &test);
1733 	if (ret > 0)
1734 		return 0;
1735 	return 1;
1736 }
1737 
1738 static noinline int copy_to_sk(struct btrfs_root *root,
1739 			       struct btrfs_path *path,
1740 			       struct btrfs_key *key,
1741 			       struct btrfs_ioctl_search_key *sk,
1742 			       char *buf,
1743 			       unsigned long *sk_offset,
1744 			       int *num_found)
1745 {
1746 	u64 found_transid;
1747 	struct extent_buffer *leaf;
1748 	struct btrfs_ioctl_search_header sh;
1749 	unsigned long item_off;
1750 	unsigned long item_len;
1751 	int nritems;
1752 	int i;
1753 	int slot;
1754 	int ret = 0;
1755 
1756 	leaf = path->nodes[0];
1757 	slot = path->slots[0];
1758 	nritems = btrfs_header_nritems(leaf);
1759 
1760 	if (btrfs_header_generation(leaf) > sk->max_transid) {
1761 		i = nritems;
1762 		goto advance_key;
1763 	}
1764 	found_transid = btrfs_header_generation(leaf);
1765 
1766 	for (i = slot; i < nritems; i++) {
1767 		item_off = btrfs_item_ptr_offset(leaf, i);
1768 		item_len = btrfs_item_size_nr(leaf, i);
1769 
1770 		if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
1771 			item_len = 0;
1772 
1773 		if (sizeof(sh) + item_len + *sk_offset >
1774 		    BTRFS_SEARCH_ARGS_BUFSIZE) {
1775 			ret = 1;
1776 			goto overflow;
1777 		}
1778 
1779 		btrfs_item_key_to_cpu(leaf, key, i);
1780 		if (!key_in_sk(key, sk))
1781 			continue;
1782 
1783 		sh.objectid = key->objectid;
1784 		sh.offset = key->offset;
1785 		sh.type = key->type;
1786 		sh.len = item_len;
1787 		sh.transid = found_transid;
1788 
1789 		/* copy search result header */
1790 		memcpy(buf + *sk_offset, &sh, sizeof(sh));
1791 		*sk_offset += sizeof(sh);
1792 
1793 		if (item_len) {
1794 			char *p = buf + *sk_offset;
1795 			/* copy the item */
1796 			read_extent_buffer(leaf, p,
1797 					   item_off, item_len);
1798 			*sk_offset += item_len;
1799 		}
1800 		(*num_found)++;
1801 
1802 		if (*num_found >= sk->nr_items)
1803 			break;
1804 	}
1805 advance_key:
1806 	ret = 0;
1807 	if (key->offset < (u64)-1 && key->offset < sk->max_offset)
1808 		key->offset++;
1809 	else if (key->type < (u8)-1 && key->type < sk->max_type) {
1810 		key->offset = 0;
1811 		key->type++;
1812 	} else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
1813 		key->offset = 0;
1814 		key->type = 0;
1815 		key->objectid++;
1816 	} else
1817 		ret = 1;
1818 overflow:
1819 	return ret;
1820 }
1821 
1822 static noinline int search_ioctl(struct inode *inode,
1823 				 struct btrfs_ioctl_search_args *args)
1824 {
1825 	struct btrfs_root *root;
1826 	struct btrfs_key key;
1827 	struct btrfs_key max_key;
1828 	struct btrfs_path *path;
1829 	struct btrfs_ioctl_search_key *sk = &args->key;
1830 	struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
1831 	int ret;
1832 	int num_found = 0;
1833 	unsigned long sk_offset = 0;
1834 
1835 	path = btrfs_alloc_path();
1836 	if (!path)
1837 		return -ENOMEM;
1838 
1839 	if (sk->tree_id == 0) {
1840 		/* search the root of the inode that was passed */
1841 		root = BTRFS_I(inode)->root;
1842 	} else {
1843 		key.objectid = sk->tree_id;
1844 		key.type = BTRFS_ROOT_ITEM_KEY;
1845 		key.offset = (u64)-1;
1846 		root = btrfs_read_fs_root_no_name(info, &key);
1847 		if (IS_ERR(root)) {
1848 			printk(KERN_ERR "could not find root %llu\n",
1849 			       sk->tree_id);
1850 			btrfs_free_path(path);
1851 			return -ENOENT;
1852 		}
1853 	}
1854 
1855 	key.objectid = sk->min_objectid;
1856 	key.type = sk->min_type;
1857 	key.offset = sk->min_offset;
1858 
1859 	max_key.objectid = sk->max_objectid;
1860 	max_key.type = sk->max_type;
1861 	max_key.offset = sk->max_offset;
1862 
1863 	path->keep_locks = 1;
1864 
1865 	while(1) {
1866 		ret = btrfs_search_forward(root, &key, &max_key, path, 0,
1867 					   sk->min_transid);
1868 		if (ret != 0) {
1869 			if (ret > 0)
1870 				ret = 0;
1871 			goto err;
1872 		}
1873 		ret = copy_to_sk(root, path, &key, sk, args->buf,
1874 				 &sk_offset, &num_found);
1875 		btrfs_release_path(path);
1876 		if (ret || num_found >= sk->nr_items)
1877 			break;
1878 
1879 	}
1880 	ret = 0;
1881 err:
1882 	sk->nr_items = num_found;
1883 	btrfs_free_path(path);
1884 	return ret;
1885 }
1886 
1887 static noinline int btrfs_ioctl_tree_search(struct file *file,
1888 					   void __user *argp)
1889 {
1890 	 struct btrfs_ioctl_search_args *args;
1891 	 struct inode *inode;
1892 	 int ret;
1893 
1894 	if (!capable(CAP_SYS_ADMIN))
1895 		return -EPERM;
1896 
1897 	args = memdup_user(argp, sizeof(*args));
1898 	if (IS_ERR(args))
1899 		return PTR_ERR(args);
1900 
1901 	inode = fdentry(file)->d_inode;
1902 	ret = search_ioctl(inode, args);
1903 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
1904 		ret = -EFAULT;
1905 	kfree(args);
1906 	return ret;
1907 }
1908 
1909 /*
1910  * Search INODE_REFs to identify path name of 'dirid' directory
1911  * in a 'tree_id' tree. and sets path name to 'name'.
1912  */
1913 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
1914 				u64 tree_id, u64 dirid, char *name)
1915 {
1916 	struct btrfs_root *root;
1917 	struct btrfs_key key;
1918 	char *ptr;
1919 	int ret = -1;
1920 	int slot;
1921 	int len;
1922 	int total_len = 0;
1923 	struct btrfs_inode_ref *iref;
1924 	struct extent_buffer *l;
1925 	struct btrfs_path *path;
1926 
1927 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
1928 		name[0]='\0';
1929 		return 0;
1930 	}
1931 
1932 	path = btrfs_alloc_path();
1933 	if (!path)
1934 		return -ENOMEM;
1935 
1936 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
1937 
1938 	key.objectid = tree_id;
1939 	key.type = BTRFS_ROOT_ITEM_KEY;
1940 	key.offset = (u64)-1;
1941 	root = btrfs_read_fs_root_no_name(info, &key);
1942 	if (IS_ERR(root)) {
1943 		printk(KERN_ERR "could not find root %llu\n", tree_id);
1944 		ret = -ENOENT;
1945 		goto out;
1946 	}
1947 
1948 	key.objectid = dirid;
1949 	key.type = BTRFS_INODE_REF_KEY;
1950 	key.offset = (u64)-1;
1951 
1952 	while(1) {
1953 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1954 		if (ret < 0)
1955 			goto out;
1956 
1957 		l = path->nodes[0];
1958 		slot = path->slots[0];
1959 		if (ret > 0 && slot > 0)
1960 			slot--;
1961 		btrfs_item_key_to_cpu(l, &key, slot);
1962 
1963 		if (ret > 0 && (key.objectid != dirid ||
1964 				key.type != BTRFS_INODE_REF_KEY)) {
1965 			ret = -ENOENT;
1966 			goto out;
1967 		}
1968 
1969 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
1970 		len = btrfs_inode_ref_name_len(l, iref);
1971 		ptr -= len + 1;
1972 		total_len += len + 1;
1973 		if (ptr < name)
1974 			goto out;
1975 
1976 		*(ptr + len) = '/';
1977 		read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
1978 
1979 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
1980 			break;
1981 
1982 		btrfs_release_path(path);
1983 		key.objectid = key.offset;
1984 		key.offset = (u64)-1;
1985 		dirid = key.objectid;
1986 	}
1987 	if (ptr < name)
1988 		goto out;
1989 	memmove(name, ptr, total_len);
1990 	name[total_len]='\0';
1991 	ret = 0;
1992 out:
1993 	btrfs_free_path(path);
1994 	return ret;
1995 }
1996 
1997 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
1998 					   void __user *argp)
1999 {
2000 	 struct btrfs_ioctl_ino_lookup_args *args;
2001 	 struct inode *inode;
2002 	 int ret;
2003 
2004 	if (!capable(CAP_SYS_ADMIN))
2005 		return -EPERM;
2006 
2007 	args = memdup_user(argp, sizeof(*args));
2008 	if (IS_ERR(args))
2009 		return PTR_ERR(args);
2010 
2011 	inode = fdentry(file)->d_inode;
2012 
2013 	if (args->treeid == 0)
2014 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2015 
2016 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2017 					args->treeid, args->objectid,
2018 					args->name);
2019 
2020 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2021 		ret = -EFAULT;
2022 
2023 	kfree(args);
2024 	return ret;
2025 }
2026 
2027 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2028 					     void __user *arg)
2029 {
2030 	struct dentry *parent = fdentry(file);
2031 	struct dentry *dentry;
2032 	struct inode *dir = parent->d_inode;
2033 	struct inode *inode;
2034 	struct btrfs_root *root = BTRFS_I(dir)->root;
2035 	struct btrfs_root *dest = NULL;
2036 	struct btrfs_ioctl_vol_args *vol_args;
2037 	struct btrfs_trans_handle *trans;
2038 	int namelen;
2039 	int ret;
2040 	int err = 0;
2041 
2042 	vol_args = memdup_user(arg, sizeof(*vol_args));
2043 	if (IS_ERR(vol_args))
2044 		return PTR_ERR(vol_args);
2045 
2046 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2047 	namelen = strlen(vol_args->name);
2048 	if (strchr(vol_args->name, '/') ||
2049 	    strncmp(vol_args->name, "..", namelen) == 0) {
2050 		err = -EINVAL;
2051 		goto out;
2052 	}
2053 
2054 	err = mnt_want_write_file(file);
2055 	if (err)
2056 		goto out;
2057 
2058 	mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
2059 	dentry = lookup_one_len(vol_args->name, parent, namelen);
2060 	if (IS_ERR(dentry)) {
2061 		err = PTR_ERR(dentry);
2062 		goto out_unlock_dir;
2063 	}
2064 
2065 	if (!dentry->d_inode) {
2066 		err = -ENOENT;
2067 		goto out_dput;
2068 	}
2069 
2070 	inode = dentry->d_inode;
2071 	dest = BTRFS_I(inode)->root;
2072 	if (!capable(CAP_SYS_ADMIN)){
2073 		/*
2074 		 * Regular user.  Only allow this with a special mount
2075 		 * option, when the user has write+exec access to the
2076 		 * subvol root, and when rmdir(2) would have been
2077 		 * allowed.
2078 		 *
2079 		 * Note that this is _not_ check that the subvol is
2080 		 * empty or doesn't contain data that we wouldn't
2081 		 * otherwise be able to delete.
2082 		 *
2083 		 * Users who want to delete empty subvols should try
2084 		 * rmdir(2).
2085 		 */
2086 		err = -EPERM;
2087 		if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
2088 			goto out_dput;
2089 
2090 		/*
2091 		 * Do not allow deletion if the parent dir is the same
2092 		 * as the dir to be deleted.  That means the ioctl
2093 		 * must be called on the dentry referencing the root
2094 		 * of the subvol, not a random directory contained
2095 		 * within it.
2096 		 */
2097 		err = -EINVAL;
2098 		if (root == dest)
2099 			goto out_dput;
2100 
2101 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2102 		if (err)
2103 			goto out_dput;
2104 	}
2105 
2106 	/* check if subvolume may be deleted by a user */
2107 	err = btrfs_may_delete(dir, dentry, 1);
2108 	if (err)
2109 		goto out_dput;
2110 
2111 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
2112 		err = -EINVAL;
2113 		goto out_dput;
2114 	}
2115 
2116 	mutex_lock(&inode->i_mutex);
2117 	err = d_invalidate(dentry);
2118 	if (err)
2119 		goto out_unlock;
2120 
2121 	down_write(&root->fs_info->subvol_sem);
2122 
2123 	err = may_destroy_subvol(dest);
2124 	if (err)
2125 		goto out_up_write;
2126 
2127 	trans = btrfs_start_transaction(root, 0);
2128 	if (IS_ERR(trans)) {
2129 		err = PTR_ERR(trans);
2130 		goto out_up_write;
2131 	}
2132 	trans->block_rsv = &root->fs_info->global_block_rsv;
2133 
2134 	ret = btrfs_unlink_subvol(trans, root, dir,
2135 				dest->root_key.objectid,
2136 				dentry->d_name.name,
2137 				dentry->d_name.len);
2138 	if (ret) {
2139 		err = ret;
2140 		btrfs_abort_transaction(trans, root, ret);
2141 		goto out_end_trans;
2142 	}
2143 
2144 	btrfs_record_root_in_trans(trans, dest);
2145 
2146 	memset(&dest->root_item.drop_progress, 0,
2147 		sizeof(dest->root_item.drop_progress));
2148 	dest->root_item.drop_level = 0;
2149 	btrfs_set_root_refs(&dest->root_item, 0);
2150 
2151 	if (!xchg(&dest->orphan_item_inserted, 1)) {
2152 		ret = btrfs_insert_orphan_item(trans,
2153 					root->fs_info->tree_root,
2154 					dest->root_key.objectid);
2155 		if (ret) {
2156 			btrfs_abort_transaction(trans, root, ret);
2157 			err = ret;
2158 			goto out_end_trans;
2159 		}
2160 	}
2161 out_end_trans:
2162 	ret = btrfs_end_transaction(trans, root);
2163 	if (ret && !err)
2164 		err = ret;
2165 	inode->i_flags |= S_DEAD;
2166 out_up_write:
2167 	up_write(&root->fs_info->subvol_sem);
2168 out_unlock:
2169 	mutex_unlock(&inode->i_mutex);
2170 	if (!err) {
2171 		shrink_dcache_sb(root->fs_info->sb);
2172 		btrfs_invalidate_inodes(dest);
2173 		d_delete(dentry);
2174 	}
2175 out_dput:
2176 	dput(dentry);
2177 out_unlock_dir:
2178 	mutex_unlock(&dir->i_mutex);
2179 	mnt_drop_write_file(file);
2180 out:
2181 	kfree(vol_args);
2182 	return err;
2183 }
2184 
2185 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2186 {
2187 	struct inode *inode = fdentry(file)->d_inode;
2188 	struct btrfs_root *root = BTRFS_I(inode)->root;
2189 	struct btrfs_ioctl_defrag_range_args *range;
2190 	int ret;
2191 
2192 	ret = mnt_want_write_file(file);
2193 	if (ret)
2194 		return ret;
2195 
2196 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2197 			1)) {
2198 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2199 		mnt_drop_write_file(file);
2200 		return -EINVAL;
2201 	}
2202 
2203 	if (btrfs_root_readonly(root)) {
2204 		ret = -EROFS;
2205 		goto out;
2206 	}
2207 
2208 	switch (inode->i_mode & S_IFMT) {
2209 	case S_IFDIR:
2210 		if (!capable(CAP_SYS_ADMIN)) {
2211 			ret = -EPERM;
2212 			goto out;
2213 		}
2214 		ret = btrfs_defrag_root(root, 0);
2215 		if (ret)
2216 			goto out;
2217 		ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
2218 		break;
2219 	case S_IFREG:
2220 		if (!(file->f_mode & FMODE_WRITE)) {
2221 			ret = -EINVAL;
2222 			goto out;
2223 		}
2224 
2225 		range = kzalloc(sizeof(*range), GFP_KERNEL);
2226 		if (!range) {
2227 			ret = -ENOMEM;
2228 			goto out;
2229 		}
2230 
2231 		if (argp) {
2232 			if (copy_from_user(range, argp,
2233 					   sizeof(*range))) {
2234 				ret = -EFAULT;
2235 				kfree(range);
2236 				goto out;
2237 			}
2238 			/* compression requires us to start the IO */
2239 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2240 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2241 				range->extent_thresh = (u32)-1;
2242 			}
2243 		} else {
2244 			/* the rest are all set to zero by kzalloc */
2245 			range->len = (u64)-1;
2246 		}
2247 		ret = btrfs_defrag_file(fdentry(file)->d_inode, file,
2248 					range, 0, 0);
2249 		if (ret > 0)
2250 			ret = 0;
2251 		kfree(range);
2252 		break;
2253 	default:
2254 		ret = -EINVAL;
2255 	}
2256 out:
2257 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2258 	mnt_drop_write_file(file);
2259 	return ret;
2260 }
2261 
2262 static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
2263 {
2264 	struct btrfs_ioctl_vol_args *vol_args;
2265 	int ret;
2266 
2267 	if (!capable(CAP_SYS_ADMIN))
2268 		return -EPERM;
2269 
2270 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2271 			1)) {
2272 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2273 		return -EINVAL;
2274 	}
2275 
2276 	mutex_lock(&root->fs_info->volume_mutex);
2277 	vol_args = memdup_user(arg, sizeof(*vol_args));
2278 	if (IS_ERR(vol_args)) {
2279 		ret = PTR_ERR(vol_args);
2280 		goto out;
2281 	}
2282 
2283 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2284 	ret = btrfs_init_new_device(root, vol_args->name);
2285 
2286 	kfree(vol_args);
2287 out:
2288 	mutex_unlock(&root->fs_info->volume_mutex);
2289 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2290 	return ret;
2291 }
2292 
2293 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
2294 {
2295 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
2296 	struct btrfs_ioctl_vol_args *vol_args;
2297 	int ret;
2298 
2299 	if (!capable(CAP_SYS_ADMIN))
2300 		return -EPERM;
2301 
2302 	ret = mnt_want_write_file(file);
2303 	if (ret)
2304 		return ret;
2305 
2306 	if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
2307 			1)) {
2308 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
2309 		mnt_drop_write_file(file);
2310 		return -EINVAL;
2311 	}
2312 
2313 	mutex_lock(&root->fs_info->volume_mutex);
2314 	vol_args = memdup_user(arg, sizeof(*vol_args));
2315 	if (IS_ERR(vol_args)) {
2316 		ret = PTR_ERR(vol_args);
2317 		goto out;
2318 	}
2319 
2320 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2321 	ret = btrfs_rm_device(root, vol_args->name);
2322 
2323 	kfree(vol_args);
2324 out:
2325 	mutex_unlock(&root->fs_info->volume_mutex);
2326 	atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
2327 	mnt_drop_write_file(file);
2328 	return ret;
2329 }
2330 
2331 static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
2332 {
2333 	struct btrfs_ioctl_fs_info_args *fi_args;
2334 	struct btrfs_device *device;
2335 	struct btrfs_device *next;
2336 	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2337 	int ret = 0;
2338 
2339 	if (!capable(CAP_SYS_ADMIN))
2340 		return -EPERM;
2341 
2342 	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
2343 	if (!fi_args)
2344 		return -ENOMEM;
2345 
2346 	fi_args->num_devices = fs_devices->num_devices;
2347 	memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
2348 
2349 	mutex_lock(&fs_devices->device_list_mutex);
2350 	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2351 		if (device->devid > fi_args->max_id)
2352 			fi_args->max_id = device->devid;
2353 	}
2354 	mutex_unlock(&fs_devices->device_list_mutex);
2355 
2356 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
2357 		ret = -EFAULT;
2358 
2359 	kfree(fi_args);
2360 	return ret;
2361 }
2362 
2363 static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
2364 {
2365 	struct btrfs_ioctl_dev_info_args *di_args;
2366 	struct btrfs_device *dev;
2367 	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2368 	int ret = 0;
2369 	char *s_uuid = NULL;
2370 	char empty_uuid[BTRFS_UUID_SIZE] = {0};
2371 
2372 	if (!capable(CAP_SYS_ADMIN))
2373 		return -EPERM;
2374 
2375 	di_args = memdup_user(arg, sizeof(*di_args));
2376 	if (IS_ERR(di_args))
2377 		return PTR_ERR(di_args);
2378 
2379 	if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0)
2380 		s_uuid = di_args->uuid;
2381 
2382 	mutex_lock(&fs_devices->device_list_mutex);
2383 	dev = btrfs_find_device(root->fs_info, di_args->devid, s_uuid, NULL);
2384 	mutex_unlock(&fs_devices->device_list_mutex);
2385 
2386 	if (!dev) {
2387 		ret = -ENODEV;
2388 		goto out;
2389 	}
2390 
2391 	di_args->devid = dev->devid;
2392 	di_args->bytes_used = dev->bytes_used;
2393 	di_args->total_bytes = dev->total_bytes;
2394 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
2395 	if (dev->name) {
2396 		struct rcu_string *name;
2397 
2398 		rcu_read_lock();
2399 		name = rcu_dereference(dev->name);
2400 		strncpy(di_args->path, name->str, sizeof(di_args->path));
2401 		rcu_read_unlock();
2402 		di_args->path[sizeof(di_args->path) - 1] = 0;
2403 	} else {
2404 		di_args->path[0] = '\0';
2405 	}
2406 
2407 out:
2408 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
2409 		ret = -EFAULT;
2410 
2411 	kfree(di_args);
2412 	return ret;
2413 }
2414 
2415 static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
2416 				       u64 off, u64 olen, u64 destoff)
2417 {
2418 	struct inode *inode = fdentry(file)->d_inode;
2419 	struct btrfs_root *root = BTRFS_I(inode)->root;
2420 	struct fd src_file;
2421 	struct inode *src;
2422 	struct btrfs_trans_handle *trans;
2423 	struct btrfs_path *path;
2424 	struct extent_buffer *leaf;
2425 	char *buf;
2426 	struct btrfs_key key;
2427 	u32 nritems;
2428 	int slot;
2429 	int ret;
2430 	u64 len = olen;
2431 	u64 bs = root->fs_info->sb->s_blocksize;
2432 
2433 	/*
2434 	 * TODO:
2435 	 * - split compressed inline extents.  annoying: we need to
2436 	 *   decompress into destination's address_space (the file offset
2437 	 *   may change, so source mapping won't do), then recompress (or
2438 	 *   otherwise reinsert) a subrange.
2439 	 * - allow ranges within the same file to be cloned (provided
2440 	 *   they don't overlap)?
2441 	 */
2442 
2443 	/* the destination must be opened for writing */
2444 	if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
2445 		return -EINVAL;
2446 
2447 	if (btrfs_root_readonly(root))
2448 		return -EROFS;
2449 
2450 	ret = mnt_want_write_file(file);
2451 	if (ret)
2452 		return ret;
2453 
2454 	src_file = fdget(srcfd);
2455 	if (!src_file.file) {
2456 		ret = -EBADF;
2457 		goto out_drop_write;
2458 	}
2459 
2460 	ret = -EXDEV;
2461 	if (src_file.file->f_path.mnt != file->f_path.mnt)
2462 		goto out_fput;
2463 
2464 	src = src_file.file->f_dentry->d_inode;
2465 
2466 	ret = -EINVAL;
2467 	if (src == inode)
2468 		goto out_fput;
2469 
2470 	/* the src must be open for reading */
2471 	if (!(src_file.file->f_mode & FMODE_READ))
2472 		goto out_fput;
2473 
2474 	/* don't make the dst file partly checksummed */
2475 	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
2476 	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
2477 		goto out_fput;
2478 
2479 	ret = -EISDIR;
2480 	if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
2481 		goto out_fput;
2482 
2483 	ret = -EXDEV;
2484 	if (src->i_sb != inode->i_sb)
2485 		goto out_fput;
2486 
2487 	ret = -ENOMEM;
2488 	buf = vmalloc(btrfs_level_size(root, 0));
2489 	if (!buf)
2490 		goto out_fput;
2491 
2492 	path = btrfs_alloc_path();
2493 	if (!path) {
2494 		vfree(buf);
2495 		goto out_fput;
2496 	}
2497 	path->reada = 2;
2498 
2499 	if (inode < src) {
2500 		mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
2501 		mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
2502 	} else {
2503 		mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
2504 		mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
2505 	}
2506 
2507 	/* determine range to clone */
2508 	ret = -EINVAL;
2509 	if (off + len > src->i_size || off + len < off)
2510 		goto out_unlock;
2511 	if (len == 0)
2512 		olen = len = src->i_size - off;
2513 	/* if we extend to eof, continue to block boundary */
2514 	if (off + len == src->i_size)
2515 		len = ALIGN(src->i_size, bs) - off;
2516 
2517 	/* verify the end result is block aligned */
2518 	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
2519 	    !IS_ALIGNED(destoff, bs))
2520 		goto out_unlock;
2521 
2522 	if (destoff > inode->i_size) {
2523 		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
2524 		if (ret)
2525 			goto out_unlock;
2526 	}
2527 
2528 	/* truncate page cache pages from target inode range */
2529 	truncate_inode_pages_range(&inode->i_data, destoff,
2530 				   PAGE_CACHE_ALIGN(destoff + len) - 1);
2531 
2532 	/* do any pending delalloc/csum calc on src, one way or
2533 	   another, and lock file content */
2534 	while (1) {
2535 		struct btrfs_ordered_extent *ordered;
2536 		lock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2537 		ordered = btrfs_lookup_first_ordered_extent(src, off + len - 1);
2538 		if (!ordered &&
2539 		    !test_range_bit(&BTRFS_I(src)->io_tree, off, off + len - 1,
2540 				    EXTENT_DELALLOC, 0, NULL))
2541 			break;
2542 		unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2543 		if (ordered)
2544 			btrfs_put_ordered_extent(ordered);
2545 		btrfs_wait_ordered_range(src, off, len);
2546 	}
2547 
2548 	/* clone data */
2549 	key.objectid = btrfs_ino(src);
2550 	key.type = BTRFS_EXTENT_DATA_KEY;
2551 	key.offset = 0;
2552 
2553 	while (1) {
2554 		/*
2555 		 * note the key will change type as we walk through the
2556 		 * tree.
2557 		 */
2558 		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
2559 				0, 0);
2560 		if (ret < 0)
2561 			goto out;
2562 
2563 		nritems = btrfs_header_nritems(path->nodes[0]);
2564 		if (path->slots[0] >= nritems) {
2565 			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
2566 			if (ret < 0)
2567 				goto out;
2568 			if (ret > 0)
2569 				break;
2570 			nritems = btrfs_header_nritems(path->nodes[0]);
2571 		}
2572 		leaf = path->nodes[0];
2573 		slot = path->slots[0];
2574 
2575 		btrfs_item_key_to_cpu(leaf, &key, slot);
2576 		if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
2577 		    key.objectid != btrfs_ino(src))
2578 			break;
2579 
2580 		if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
2581 			struct btrfs_file_extent_item *extent;
2582 			int type;
2583 			u32 size;
2584 			struct btrfs_key new_key;
2585 			u64 disko = 0, diskl = 0;
2586 			u64 datao = 0, datal = 0;
2587 			u8 comp;
2588 			u64 endoff;
2589 
2590 			size = btrfs_item_size_nr(leaf, slot);
2591 			read_extent_buffer(leaf, buf,
2592 					   btrfs_item_ptr_offset(leaf, slot),
2593 					   size);
2594 
2595 			extent = btrfs_item_ptr(leaf, slot,
2596 						struct btrfs_file_extent_item);
2597 			comp = btrfs_file_extent_compression(leaf, extent);
2598 			type = btrfs_file_extent_type(leaf, extent);
2599 			if (type == BTRFS_FILE_EXTENT_REG ||
2600 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
2601 				disko = btrfs_file_extent_disk_bytenr(leaf,
2602 								      extent);
2603 				diskl = btrfs_file_extent_disk_num_bytes(leaf,
2604 								 extent);
2605 				datao = btrfs_file_extent_offset(leaf, extent);
2606 				datal = btrfs_file_extent_num_bytes(leaf,
2607 								    extent);
2608 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
2609 				/* take upper bound, may be compressed */
2610 				datal = btrfs_file_extent_ram_bytes(leaf,
2611 								    extent);
2612 			}
2613 			btrfs_release_path(path);
2614 
2615 			if (key.offset + datal <= off ||
2616 			    key.offset >= off + len - 1)
2617 				goto next;
2618 
2619 			memcpy(&new_key, &key, sizeof(new_key));
2620 			new_key.objectid = btrfs_ino(inode);
2621 			if (off <= key.offset)
2622 				new_key.offset = key.offset + destoff - off;
2623 			else
2624 				new_key.offset = destoff;
2625 
2626 			/*
2627 			 * 1 - adjusting old extent (we may have to split it)
2628 			 * 1 - add new extent
2629 			 * 1 - inode update
2630 			 */
2631 			trans = btrfs_start_transaction(root, 3);
2632 			if (IS_ERR(trans)) {
2633 				ret = PTR_ERR(trans);
2634 				goto out;
2635 			}
2636 
2637 			if (type == BTRFS_FILE_EXTENT_REG ||
2638 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
2639 				/*
2640 				 *    a  | --- range to clone ---|  b
2641 				 * | ------------- extent ------------- |
2642 				 */
2643 
2644 				/* substract range b */
2645 				if (key.offset + datal > off + len)
2646 					datal = off + len - key.offset;
2647 
2648 				/* substract range a */
2649 				if (off > key.offset) {
2650 					datao += off - key.offset;
2651 					datal -= off - key.offset;
2652 				}
2653 
2654 				ret = btrfs_drop_extents(trans, root, inode,
2655 							 new_key.offset,
2656 							 new_key.offset + datal,
2657 							 1);
2658 				if (ret) {
2659 					btrfs_abort_transaction(trans, root,
2660 								ret);
2661 					btrfs_end_transaction(trans, root);
2662 					goto out;
2663 				}
2664 
2665 				ret = btrfs_insert_empty_item(trans, root, path,
2666 							      &new_key, size);
2667 				if (ret) {
2668 					btrfs_abort_transaction(trans, root,
2669 								ret);
2670 					btrfs_end_transaction(trans, root);
2671 					goto out;
2672 				}
2673 
2674 				leaf = path->nodes[0];
2675 				slot = path->slots[0];
2676 				write_extent_buffer(leaf, buf,
2677 					    btrfs_item_ptr_offset(leaf, slot),
2678 					    size);
2679 
2680 				extent = btrfs_item_ptr(leaf, slot,
2681 						struct btrfs_file_extent_item);
2682 
2683 				/* disko == 0 means it's a hole */
2684 				if (!disko)
2685 					datao = 0;
2686 
2687 				btrfs_set_file_extent_offset(leaf, extent,
2688 							     datao);
2689 				btrfs_set_file_extent_num_bytes(leaf, extent,
2690 								datal);
2691 				if (disko) {
2692 					inode_add_bytes(inode, datal);
2693 					ret = btrfs_inc_extent_ref(trans, root,
2694 							disko, diskl, 0,
2695 							root->root_key.objectid,
2696 							btrfs_ino(inode),
2697 							new_key.offset - datao,
2698 							0);
2699 					if (ret) {
2700 						btrfs_abort_transaction(trans,
2701 									root,
2702 									ret);
2703 						btrfs_end_transaction(trans,
2704 								      root);
2705 						goto out;
2706 
2707 					}
2708 				}
2709 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
2710 				u64 skip = 0;
2711 				u64 trim = 0;
2712 				if (off > key.offset) {
2713 					skip = off - key.offset;
2714 					new_key.offset += skip;
2715 				}
2716 
2717 				if (key.offset + datal > off + len)
2718 					trim = key.offset + datal - (off + len);
2719 
2720 				if (comp && (skip || trim)) {
2721 					ret = -EINVAL;
2722 					btrfs_end_transaction(trans, root);
2723 					goto out;
2724 				}
2725 				size -= skip + trim;
2726 				datal -= skip + trim;
2727 
2728 				ret = btrfs_drop_extents(trans, root, inode,
2729 							 new_key.offset,
2730 							 new_key.offset + datal,
2731 							 1);
2732 				if (ret) {
2733 					btrfs_abort_transaction(trans, root,
2734 								ret);
2735 					btrfs_end_transaction(trans, root);
2736 					goto out;
2737 				}
2738 
2739 				ret = btrfs_insert_empty_item(trans, root, path,
2740 							      &new_key, size);
2741 				if (ret) {
2742 					btrfs_abort_transaction(trans, root,
2743 								ret);
2744 					btrfs_end_transaction(trans, root);
2745 					goto out;
2746 				}
2747 
2748 				if (skip) {
2749 					u32 start =
2750 					  btrfs_file_extent_calc_inline_size(0);
2751 					memmove(buf+start, buf+start+skip,
2752 						datal);
2753 				}
2754 
2755 				leaf = path->nodes[0];
2756 				slot = path->slots[0];
2757 				write_extent_buffer(leaf, buf,
2758 					    btrfs_item_ptr_offset(leaf, slot),
2759 					    size);
2760 				inode_add_bytes(inode, datal);
2761 			}
2762 
2763 			btrfs_mark_buffer_dirty(leaf);
2764 			btrfs_release_path(path);
2765 
2766 			inode_inc_iversion(inode);
2767 			inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2768 
2769 			/*
2770 			 * we round up to the block size at eof when
2771 			 * determining which extents to clone above,
2772 			 * but shouldn't round up the file size
2773 			 */
2774 			endoff = new_key.offset + datal;
2775 			if (endoff > destoff+olen)
2776 				endoff = destoff+olen;
2777 			if (endoff > inode->i_size)
2778 				btrfs_i_size_write(inode, endoff);
2779 
2780 			ret = btrfs_update_inode(trans, root, inode);
2781 			if (ret) {
2782 				btrfs_abort_transaction(trans, root, ret);
2783 				btrfs_end_transaction(trans, root);
2784 				goto out;
2785 			}
2786 			ret = btrfs_end_transaction(trans, root);
2787 		}
2788 next:
2789 		btrfs_release_path(path);
2790 		key.offset++;
2791 	}
2792 	ret = 0;
2793 out:
2794 	btrfs_release_path(path);
2795 	unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1);
2796 out_unlock:
2797 	mutex_unlock(&src->i_mutex);
2798 	mutex_unlock(&inode->i_mutex);
2799 	vfree(buf);
2800 	btrfs_free_path(path);
2801 out_fput:
2802 	fdput(src_file);
2803 out_drop_write:
2804 	mnt_drop_write_file(file);
2805 	return ret;
2806 }
2807 
2808 static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
2809 {
2810 	struct btrfs_ioctl_clone_range_args args;
2811 
2812 	if (copy_from_user(&args, argp, sizeof(args)))
2813 		return -EFAULT;
2814 	return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
2815 				 args.src_length, args.dest_offset);
2816 }
2817 
2818 /*
2819  * there are many ways the trans_start and trans_end ioctls can lead
2820  * to deadlocks.  They should only be used by applications that
2821  * basically own the machine, and have a very in depth understanding
2822  * of all the possible deadlocks and enospc problems.
2823  */
2824 static long btrfs_ioctl_trans_start(struct file *file)
2825 {
2826 	struct inode *inode = fdentry(file)->d_inode;
2827 	struct btrfs_root *root = BTRFS_I(inode)->root;
2828 	struct btrfs_trans_handle *trans;
2829 	int ret;
2830 
2831 	ret = -EPERM;
2832 	if (!capable(CAP_SYS_ADMIN))
2833 		goto out;
2834 
2835 	ret = -EINPROGRESS;
2836 	if (file->private_data)
2837 		goto out;
2838 
2839 	ret = -EROFS;
2840 	if (btrfs_root_readonly(root))
2841 		goto out;
2842 
2843 	ret = mnt_want_write_file(file);
2844 	if (ret)
2845 		goto out;
2846 
2847 	atomic_inc(&root->fs_info->open_ioctl_trans);
2848 
2849 	ret = -ENOMEM;
2850 	trans = btrfs_start_ioctl_transaction(root);
2851 	if (IS_ERR(trans))
2852 		goto out_drop;
2853 
2854 	file->private_data = trans;
2855 	return 0;
2856 
2857 out_drop:
2858 	atomic_dec(&root->fs_info->open_ioctl_trans);
2859 	mnt_drop_write_file(file);
2860 out:
2861 	return ret;
2862 }
2863 
2864 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
2865 {
2866 	struct inode *inode = fdentry(file)->d_inode;
2867 	struct btrfs_root *root = BTRFS_I(inode)->root;
2868 	struct btrfs_root *new_root;
2869 	struct btrfs_dir_item *di;
2870 	struct btrfs_trans_handle *trans;
2871 	struct btrfs_path *path;
2872 	struct btrfs_key location;
2873 	struct btrfs_disk_key disk_key;
2874 	u64 objectid = 0;
2875 	u64 dir_id;
2876 	int ret;
2877 
2878 	if (!capable(CAP_SYS_ADMIN))
2879 		return -EPERM;
2880 
2881 	ret = mnt_want_write_file(file);
2882 	if (ret)
2883 		return ret;
2884 
2885 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
2886 		ret = -EFAULT;
2887 		goto out;
2888 	}
2889 
2890 	if (!objectid)
2891 		objectid = root->root_key.objectid;
2892 
2893 	location.objectid = objectid;
2894 	location.type = BTRFS_ROOT_ITEM_KEY;
2895 	location.offset = (u64)-1;
2896 
2897 	new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
2898 	if (IS_ERR(new_root)) {
2899 		ret = PTR_ERR(new_root);
2900 		goto out;
2901 	}
2902 
2903 	if (btrfs_root_refs(&new_root->root_item) == 0) {
2904 		ret = -ENOENT;
2905 		goto out;
2906 	}
2907 
2908 	path = btrfs_alloc_path();
2909 	if (!path) {
2910 		ret = -ENOMEM;
2911 		goto out;
2912 	}
2913 	path->leave_spinning = 1;
2914 
2915 	trans = btrfs_start_transaction(root, 1);
2916 	if (IS_ERR(trans)) {
2917 		btrfs_free_path(path);
2918 		ret = PTR_ERR(trans);
2919 		goto out;
2920 	}
2921 
2922 	dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
2923 	di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
2924 				   dir_id, "default", 7, 1);
2925 	if (IS_ERR_OR_NULL(di)) {
2926 		btrfs_free_path(path);
2927 		btrfs_end_transaction(trans, root);
2928 		printk(KERN_ERR "Umm, you don't have the default dir item, "
2929 		       "this isn't going to work\n");
2930 		ret = -ENOENT;
2931 		goto out;
2932 	}
2933 
2934 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
2935 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
2936 	btrfs_mark_buffer_dirty(path->nodes[0]);
2937 	btrfs_free_path(path);
2938 
2939 	btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL);
2940 	btrfs_end_transaction(trans, root);
2941 out:
2942 	mnt_drop_write_file(file);
2943 	return ret;
2944 }
2945 
2946 void btrfs_get_block_group_info(struct list_head *groups_list,
2947 				struct btrfs_ioctl_space_info *space)
2948 {
2949 	struct btrfs_block_group_cache *block_group;
2950 
2951 	space->total_bytes = 0;
2952 	space->used_bytes = 0;
2953 	space->flags = 0;
2954 	list_for_each_entry(block_group, groups_list, list) {
2955 		space->flags = block_group->flags;
2956 		space->total_bytes += block_group->key.offset;
2957 		space->used_bytes +=
2958 			btrfs_block_group_used(&block_group->item);
2959 	}
2960 }
2961 
2962 long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
2963 {
2964 	struct btrfs_ioctl_space_args space_args;
2965 	struct btrfs_ioctl_space_info space;
2966 	struct btrfs_ioctl_space_info *dest;
2967 	struct btrfs_ioctl_space_info *dest_orig;
2968 	struct btrfs_ioctl_space_info __user *user_dest;
2969 	struct btrfs_space_info *info;
2970 	u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
2971 		       BTRFS_BLOCK_GROUP_SYSTEM,
2972 		       BTRFS_BLOCK_GROUP_METADATA,
2973 		       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
2974 	int num_types = 4;
2975 	int alloc_size;
2976 	int ret = 0;
2977 	u64 slot_count = 0;
2978 	int i, c;
2979 
2980 	if (copy_from_user(&space_args,
2981 			   (struct btrfs_ioctl_space_args __user *)arg,
2982 			   sizeof(space_args)))
2983 		return -EFAULT;
2984 
2985 	for (i = 0; i < num_types; i++) {
2986 		struct btrfs_space_info *tmp;
2987 
2988 		info = NULL;
2989 		rcu_read_lock();
2990 		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
2991 					list) {
2992 			if (tmp->flags == types[i]) {
2993 				info = tmp;
2994 				break;
2995 			}
2996 		}
2997 		rcu_read_unlock();
2998 
2999 		if (!info)
3000 			continue;
3001 
3002 		down_read(&info->groups_sem);
3003 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3004 			if (!list_empty(&info->block_groups[c]))
3005 				slot_count++;
3006 		}
3007 		up_read(&info->groups_sem);
3008 	}
3009 
3010 	/* space_slots == 0 means they are asking for a count */
3011 	if (space_args.space_slots == 0) {
3012 		space_args.total_spaces = slot_count;
3013 		goto out;
3014 	}
3015 
3016 	slot_count = min_t(u64, space_args.space_slots, slot_count);
3017 
3018 	alloc_size = sizeof(*dest) * slot_count;
3019 
3020 	/* we generally have at most 6 or so space infos, one for each raid
3021 	 * level.  So, a whole page should be more than enough for everyone
3022 	 */
3023 	if (alloc_size > PAGE_CACHE_SIZE)
3024 		return -ENOMEM;
3025 
3026 	space_args.total_spaces = 0;
3027 	dest = kmalloc(alloc_size, GFP_NOFS);
3028 	if (!dest)
3029 		return -ENOMEM;
3030 	dest_orig = dest;
3031 
3032 	/* now we have a buffer to copy into */
3033 	for (i = 0; i < num_types; i++) {
3034 		struct btrfs_space_info *tmp;
3035 
3036 		if (!slot_count)
3037 			break;
3038 
3039 		info = NULL;
3040 		rcu_read_lock();
3041 		list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
3042 					list) {
3043 			if (tmp->flags == types[i]) {
3044 				info = tmp;
3045 				break;
3046 			}
3047 		}
3048 		rcu_read_unlock();
3049 
3050 		if (!info)
3051 			continue;
3052 		down_read(&info->groups_sem);
3053 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3054 			if (!list_empty(&info->block_groups[c])) {
3055 				btrfs_get_block_group_info(
3056 					&info->block_groups[c], &space);
3057 				memcpy(dest, &space, sizeof(space));
3058 				dest++;
3059 				space_args.total_spaces++;
3060 				slot_count--;
3061 			}
3062 			if (!slot_count)
3063 				break;
3064 		}
3065 		up_read(&info->groups_sem);
3066 	}
3067 
3068 	user_dest = (struct btrfs_ioctl_space_info __user *)
3069 		(arg + sizeof(struct btrfs_ioctl_space_args));
3070 
3071 	if (copy_to_user(user_dest, dest_orig, alloc_size))
3072 		ret = -EFAULT;
3073 
3074 	kfree(dest_orig);
3075 out:
3076 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3077 		ret = -EFAULT;
3078 
3079 	return ret;
3080 }
3081 
3082 /*
3083  * there are many ways the trans_start and trans_end ioctls can lead
3084  * to deadlocks.  They should only be used by applications that
3085  * basically own the machine, and have a very in depth understanding
3086  * of all the possible deadlocks and enospc problems.
3087  */
3088 long btrfs_ioctl_trans_end(struct file *file)
3089 {
3090 	struct inode *inode = fdentry(file)->d_inode;
3091 	struct btrfs_root *root = BTRFS_I(inode)->root;
3092 	struct btrfs_trans_handle *trans;
3093 
3094 	trans = file->private_data;
3095 	if (!trans)
3096 		return -EINVAL;
3097 	file->private_data = NULL;
3098 
3099 	btrfs_end_transaction(trans, root);
3100 
3101 	atomic_dec(&root->fs_info->open_ioctl_trans);
3102 
3103 	mnt_drop_write_file(file);
3104 	return 0;
3105 }
3106 
3107 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3108 					    void __user *argp)
3109 {
3110 	struct btrfs_trans_handle *trans;
3111 	u64 transid;
3112 	int ret;
3113 
3114 	trans = btrfs_attach_transaction(root);
3115 	if (IS_ERR(trans)) {
3116 		if (PTR_ERR(trans) != -ENOENT)
3117 			return PTR_ERR(trans);
3118 
3119 		/* No running transaction, don't bother */
3120 		transid = root->fs_info->last_trans_committed;
3121 		goto out;
3122 	}
3123 	transid = trans->transid;
3124 	ret = btrfs_commit_transaction_async(trans, root, 0);
3125 	if (ret) {
3126 		btrfs_end_transaction(trans, root);
3127 		return ret;
3128 	}
3129 out:
3130 	if (argp)
3131 		if (copy_to_user(argp, &transid, sizeof(transid)))
3132 			return -EFAULT;
3133 	return 0;
3134 }
3135 
3136 static noinline long btrfs_ioctl_wait_sync(struct btrfs_root *root,
3137 					   void __user *argp)
3138 {
3139 	u64 transid;
3140 
3141 	if (argp) {
3142 		if (copy_from_user(&transid, argp, sizeof(transid)))
3143 			return -EFAULT;
3144 	} else {
3145 		transid = 0;  /* current trans */
3146 	}
3147 	return btrfs_wait_for_commit(root, transid);
3148 }
3149 
3150 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3151 {
3152 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3153 	struct btrfs_ioctl_scrub_args *sa;
3154 	int ret;
3155 
3156 	if (!capable(CAP_SYS_ADMIN))
3157 		return -EPERM;
3158 
3159 	sa = memdup_user(arg, sizeof(*sa));
3160 	if (IS_ERR(sa))
3161 		return PTR_ERR(sa);
3162 
3163 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3164 		ret = mnt_want_write_file(file);
3165 		if (ret)
3166 			goto out;
3167 	}
3168 
3169 	ret = btrfs_scrub_dev(root->fs_info, sa->devid, sa->start, sa->end,
3170 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3171 			      0);
3172 
3173 	if (copy_to_user(arg, sa, sizeof(*sa)))
3174 		ret = -EFAULT;
3175 
3176 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
3177 		mnt_drop_write_file(file);
3178 out:
3179 	kfree(sa);
3180 	return ret;
3181 }
3182 
3183 static long btrfs_ioctl_scrub_cancel(struct btrfs_root *root, void __user *arg)
3184 {
3185 	if (!capable(CAP_SYS_ADMIN))
3186 		return -EPERM;
3187 
3188 	return btrfs_scrub_cancel(root->fs_info);
3189 }
3190 
3191 static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
3192 				       void __user *arg)
3193 {
3194 	struct btrfs_ioctl_scrub_args *sa;
3195 	int ret;
3196 
3197 	if (!capable(CAP_SYS_ADMIN))
3198 		return -EPERM;
3199 
3200 	sa = memdup_user(arg, sizeof(*sa));
3201 	if (IS_ERR(sa))
3202 		return PTR_ERR(sa);
3203 
3204 	ret = btrfs_scrub_progress(root, sa->devid, &sa->progress);
3205 
3206 	if (copy_to_user(arg, sa, sizeof(*sa)))
3207 		ret = -EFAULT;
3208 
3209 	kfree(sa);
3210 	return ret;
3211 }
3212 
3213 static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
3214 				      void __user *arg)
3215 {
3216 	struct btrfs_ioctl_get_dev_stats *sa;
3217 	int ret;
3218 
3219 	sa = memdup_user(arg, sizeof(*sa));
3220 	if (IS_ERR(sa))
3221 		return PTR_ERR(sa);
3222 
3223 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3224 		kfree(sa);
3225 		return -EPERM;
3226 	}
3227 
3228 	ret = btrfs_get_dev_stats(root, sa);
3229 
3230 	if (copy_to_user(arg, sa, sizeof(*sa)))
3231 		ret = -EFAULT;
3232 
3233 	kfree(sa);
3234 	return ret;
3235 }
3236 
3237 static long btrfs_ioctl_dev_replace(struct btrfs_root *root, void __user *arg)
3238 {
3239 	struct btrfs_ioctl_dev_replace_args *p;
3240 	int ret;
3241 
3242 	if (!capable(CAP_SYS_ADMIN))
3243 		return -EPERM;
3244 
3245 	p = memdup_user(arg, sizeof(*p));
3246 	if (IS_ERR(p))
3247 		return PTR_ERR(p);
3248 
3249 	switch (p->cmd) {
3250 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3251 		if (atomic_xchg(
3252 			&root->fs_info->mutually_exclusive_operation_running,
3253 			1)) {
3254 			pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3255 			ret = -EINPROGRESS;
3256 		} else {
3257 			ret = btrfs_dev_replace_start(root, p);
3258 			atomic_set(
3259 			 &root->fs_info->mutually_exclusive_operation_running,
3260 			 0);
3261 		}
3262 		break;
3263 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3264 		btrfs_dev_replace_status(root->fs_info, p);
3265 		ret = 0;
3266 		break;
3267 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3268 		ret = btrfs_dev_replace_cancel(root->fs_info, p);
3269 		break;
3270 	default:
3271 		ret = -EINVAL;
3272 		break;
3273 	}
3274 
3275 	if (copy_to_user(arg, p, sizeof(*p)))
3276 		ret = -EFAULT;
3277 
3278 	kfree(p);
3279 	return ret;
3280 }
3281 
3282 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3283 {
3284 	int ret = 0;
3285 	int i;
3286 	u64 rel_ptr;
3287 	int size;
3288 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
3289 	struct inode_fs_paths *ipath = NULL;
3290 	struct btrfs_path *path;
3291 
3292 	if (!capable(CAP_SYS_ADMIN))
3293 		return -EPERM;
3294 
3295 	path = btrfs_alloc_path();
3296 	if (!path) {
3297 		ret = -ENOMEM;
3298 		goto out;
3299 	}
3300 
3301 	ipa = memdup_user(arg, sizeof(*ipa));
3302 	if (IS_ERR(ipa)) {
3303 		ret = PTR_ERR(ipa);
3304 		ipa = NULL;
3305 		goto out;
3306 	}
3307 
3308 	size = min_t(u32, ipa->size, 4096);
3309 	ipath = init_ipath(size, root, path);
3310 	if (IS_ERR(ipath)) {
3311 		ret = PTR_ERR(ipath);
3312 		ipath = NULL;
3313 		goto out;
3314 	}
3315 
3316 	ret = paths_from_inode(ipa->inum, ipath);
3317 	if (ret < 0)
3318 		goto out;
3319 
3320 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3321 		rel_ptr = ipath->fspath->val[i] -
3322 			  (u64)(unsigned long)ipath->fspath->val;
3323 		ipath->fspath->val[i] = rel_ptr;
3324 	}
3325 
3326 	ret = copy_to_user((void *)(unsigned long)ipa->fspath,
3327 			   (void *)(unsigned long)ipath->fspath, size);
3328 	if (ret) {
3329 		ret = -EFAULT;
3330 		goto out;
3331 	}
3332 
3333 out:
3334 	btrfs_free_path(path);
3335 	free_ipath(ipath);
3336 	kfree(ipa);
3337 
3338 	return ret;
3339 }
3340 
3341 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3342 {
3343 	struct btrfs_data_container *inodes = ctx;
3344 	const size_t c = 3 * sizeof(u64);
3345 
3346 	if (inodes->bytes_left >= c) {
3347 		inodes->bytes_left -= c;
3348 		inodes->val[inodes->elem_cnt] = inum;
3349 		inodes->val[inodes->elem_cnt + 1] = offset;
3350 		inodes->val[inodes->elem_cnt + 2] = root;
3351 		inodes->elem_cnt += 3;
3352 	} else {
3353 		inodes->bytes_missing += c - inodes->bytes_left;
3354 		inodes->bytes_left = 0;
3355 		inodes->elem_missed += 3;
3356 	}
3357 
3358 	return 0;
3359 }
3360 
3361 static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
3362 					void __user *arg)
3363 {
3364 	int ret = 0;
3365 	int size;
3366 	struct btrfs_ioctl_logical_ino_args *loi;
3367 	struct btrfs_data_container *inodes = NULL;
3368 	struct btrfs_path *path = NULL;
3369 
3370 	if (!capable(CAP_SYS_ADMIN))
3371 		return -EPERM;
3372 
3373 	loi = memdup_user(arg, sizeof(*loi));
3374 	if (IS_ERR(loi)) {
3375 		ret = PTR_ERR(loi);
3376 		loi = NULL;
3377 		goto out;
3378 	}
3379 
3380 	path = btrfs_alloc_path();
3381 	if (!path) {
3382 		ret = -ENOMEM;
3383 		goto out;
3384 	}
3385 
3386 	size = min_t(u32, loi->size, 64 * 1024);
3387 	inodes = init_data_container(size);
3388 	if (IS_ERR(inodes)) {
3389 		ret = PTR_ERR(inodes);
3390 		inodes = NULL;
3391 		goto out;
3392 	}
3393 
3394 	ret = iterate_inodes_from_logical(loi->logical, root->fs_info, path,
3395 					  build_ino_list, inodes);
3396 	if (ret == -EINVAL)
3397 		ret = -ENOENT;
3398 	if (ret < 0)
3399 		goto out;
3400 
3401 	ret = copy_to_user((void *)(unsigned long)loi->inodes,
3402 			   (void *)(unsigned long)inodes, size);
3403 	if (ret)
3404 		ret = -EFAULT;
3405 
3406 out:
3407 	btrfs_free_path(path);
3408 	vfree(inodes);
3409 	kfree(loi);
3410 
3411 	return ret;
3412 }
3413 
3414 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3415 			       struct btrfs_ioctl_balance_args *bargs)
3416 {
3417 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3418 
3419 	bargs->flags = bctl->flags;
3420 
3421 	if (atomic_read(&fs_info->balance_running))
3422 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3423 	if (atomic_read(&fs_info->balance_pause_req))
3424 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3425 	if (atomic_read(&fs_info->balance_cancel_req))
3426 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3427 
3428 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3429 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3430 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3431 
3432 	if (lock) {
3433 		spin_lock(&fs_info->balance_lock);
3434 		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3435 		spin_unlock(&fs_info->balance_lock);
3436 	} else {
3437 		memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3438 	}
3439 }
3440 
3441 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3442 {
3443 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3444 	struct btrfs_fs_info *fs_info = root->fs_info;
3445 	struct btrfs_ioctl_balance_args *bargs;
3446 	struct btrfs_balance_control *bctl;
3447 	bool need_unlock; /* for mut. excl. ops lock */
3448 	int ret;
3449 
3450 	if (!capable(CAP_SYS_ADMIN))
3451 		return -EPERM;
3452 
3453 	ret = mnt_want_write_file(file);
3454 	if (ret)
3455 		return ret;
3456 
3457 again:
3458 	if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
3459 		mutex_lock(&fs_info->volume_mutex);
3460 		mutex_lock(&fs_info->balance_mutex);
3461 		need_unlock = true;
3462 		goto locked;
3463 	}
3464 
3465 	/*
3466 	 * mut. excl. ops lock is locked.  Three possibilites:
3467 	 *   (1) some other op is running
3468 	 *   (2) balance is running
3469 	 *   (3) balance is paused -- special case (think resume)
3470 	 */
3471 	mutex_lock(&fs_info->balance_mutex);
3472 	if (fs_info->balance_ctl) {
3473 		/* this is either (2) or (3) */
3474 		if (!atomic_read(&fs_info->balance_running)) {
3475 			mutex_unlock(&fs_info->balance_mutex);
3476 			if (!mutex_trylock(&fs_info->volume_mutex))
3477 				goto again;
3478 			mutex_lock(&fs_info->balance_mutex);
3479 
3480 			if (fs_info->balance_ctl &&
3481 			    !atomic_read(&fs_info->balance_running)) {
3482 				/* this is (3) */
3483 				need_unlock = false;
3484 				goto locked;
3485 			}
3486 
3487 			mutex_unlock(&fs_info->balance_mutex);
3488 			mutex_unlock(&fs_info->volume_mutex);
3489 			goto again;
3490 		} else {
3491 			/* this is (2) */
3492 			mutex_unlock(&fs_info->balance_mutex);
3493 			ret = -EINPROGRESS;
3494 			goto out;
3495 		}
3496 	} else {
3497 		/* this is (1) */
3498 		mutex_unlock(&fs_info->balance_mutex);
3499 		pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
3500 		ret = -EINVAL;
3501 		goto out;
3502 	}
3503 
3504 locked:
3505 	BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
3506 
3507 	if (arg) {
3508 		bargs = memdup_user(arg, sizeof(*bargs));
3509 		if (IS_ERR(bargs)) {
3510 			ret = PTR_ERR(bargs);
3511 			goto out_unlock;
3512 		}
3513 
3514 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
3515 			if (!fs_info->balance_ctl) {
3516 				ret = -ENOTCONN;
3517 				goto out_bargs;
3518 			}
3519 
3520 			bctl = fs_info->balance_ctl;
3521 			spin_lock(&fs_info->balance_lock);
3522 			bctl->flags |= BTRFS_BALANCE_RESUME;
3523 			spin_unlock(&fs_info->balance_lock);
3524 
3525 			goto do_balance;
3526 		}
3527 	} else {
3528 		bargs = NULL;
3529 	}
3530 
3531 	if (fs_info->balance_ctl) {
3532 		ret = -EINPROGRESS;
3533 		goto out_bargs;
3534 	}
3535 
3536 	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3537 	if (!bctl) {
3538 		ret = -ENOMEM;
3539 		goto out_bargs;
3540 	}
3541 
3542 	bctl->fs_info = fs_info;
3543 	if (arg) {
3544 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
3545 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
3546 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
3547 
3548 		bctl->flags = bargs->flags;
3549 	} else {
3550 		/* balance everything - no filters */
3551 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
3552 	}
3553 
3554 do_balance:
3555 	/*
3556 	 * Ownership of bctl and mutually_exclusive_operation_running
3557 	 * goes to to btrfs_balance.  bctl is freed in __cancel_balance,
3558 	 * or, if restriper was paused all the way until unmount, in
3559 	 * free_fs_info.  mutually_exclusive_operation_running is
3560 	 * cleared in __cancel_balance.
3561 	 */
3562 	need_unlock = false;
3563 
3564 	ret = btrfs_balance(bctl, bargs);
3565 
3566 	if (arg) {
3567 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
3568 			ret = -EFAULT;
3569 	}
3570 
3571 out_bargs:
3572 	kfree(bargs);
3573 out_unlock:
3574 	mutex_unlock(&fs_info->balance_mutex);
3575 	mutex_unlock(&fs_info->volume_mutex);
3576 	if (need_unlock)
3577 		atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3578 out:
3579 	mnt_drop_write_file(file);
3580 	return ret;
3581 }
3582 
3583 static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
3584 {
3585 	if (!capable(CAP_SYS_ADMIN))
3586 		return -EPERM;
3587 
3588 	switch (cmd) {
3589 	case BTRFS_BALANCE_CTL_PAUSE:
3590 		return btrfs_pause_balance(root->fs_info);
3591 	case BTRFS_BALANCE_CTL_CANCEL:
3592 		return btrfs_cancel_balance(root->fs_info);
3593 	}
3594 
3595 	return -EINVAL;
3596 }
3597 
3598 static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
3599 					 void __user *arg)
3600 {
3601 	struct btrfs_fs_info *fs_info = root->fs_info;
3602 	struct btrfs_ioctl_balance_args *bargs;
3603 	int ret = 0;
3604 
3605 	if (!capable(CAP_SYS_ADMIN))
3606 		return -EPERM;
3607 
3608 	mutex_lock(&fs_info->balance_mutex);
3609 	if (!fs_info->balance_ctl) {
3610 		ret = -ENOTCONN;
3611 		goto out;
3612 	}
3613 
3614 	bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
3615 	if (!bargs) {
3616 		ret = -ENOMEM;
3617 		goto out;
3618 	}
3619 
3620 	update_ioctl_balance_args(fs_info, 1, bargs);
3621 
3622 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
3623 		ret = -EFAULT;
3624 
3625 	kfree(bargs);
3626 out:
3627 	mutex_unlock(&fs_info->balance_mutex);
3628 	return ret;
3629 }
3630 
3631 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
3632 {
3633 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3634 	struct btrfs_ioctl_quota_ctl_args *sa;
3635 	struct btrfs_trans_handle *trans = NULL;
3636 	int ret;
3637 	int err;
3638 
3639 	if (!capable(CAP_SYS_ADMIN))
3640 		return -EPERM;
3641 
3642 	ret = mnt_want_write_file(file);
3643 	if (ret)
3644 		return ret;
3645 
3646 	sa = memdup_user(arg, sizeof(*sa));
3647 	if (IS_ERR(sa)) {
3648 		ret = PTR_ERR(sa);
3649 		goto drop_write;
3650 	}
3651 
3652 	if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
3653 		trans = btrfs_start_transaction(root, 2);
3654 		if (IS_ERR(trans)) {
3655 			ret = PTR_ERR(trans);
3656 			goto out;
3657 		}
3658 	}
3659 
3660 	switch (sa->cmd) {
3661 	case BTRFS_QUOTA_CTL_ENABLE:
3662 		ret = btrfs_quota_enable(trans, root->fs_info);
3663 		break;
3664 	case BTRFS_QUOTA_CTL_DISABLE:
3665 		ret = btrfs_quota_disable(trans, root->fs_info);
3666 		break;
3667 	case BTRFS_QUOTA_CTL_RESCAN:
3668 		ret = btrfs_quota_rescan(root->fs_info);
3669 		break;
3670 	default:
3671 		ret = -EINVAL;
3672 		break;
3673 	}
3674 
3675 	if (copy_to_user(arg, sa, sizeof(*sa)))
3676 		ret = -EFAULT;
3677 
3678 	if (trans) {
3679 		err = btrfs_commit_transaction(trans, root);
3680 		if (err && !ret)
3681 			ret = err;
3682 	}
3683 out:
3684 	kfree(sa);
3685 drop_write:
3686 	mnt_drop_write_file(file);
3687 	return ret;
3688 }
3689 
3690 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
3691 {
3692 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3693 	struct btrfs_ioctl_qgroup_assign_args *sa;
3694 	struct btrfs_trans_handle *trans;
3695 	int ret;
3696 	int err;
3697 
3698 	if (!capable(CAP_SYS_ADMIN))
3699 		return -EPERM;
3700 
3701 	ret = mnt_want_write_file(file);
3702 	if (ret)
3703 		return ret;
3704 
3705 	sa = memdup_user(arg, sizeof(*sa));
3706 	if (IS_ERR(sa)) {
3707 		ret = PTR_ERR(sa);
3708 		goto drop_write;
3709 	}
3710 
3711 	trans = btrfs_join_transaction(root);
3712 	if (IS_ERR(trans)) {
3713 		ret = PTR_ERR(trans);
3714 		goto out;
3715 	}
3716 
3717 	/* FIXME: check if the IDs really exist */
3718 	if (sa->assign) {
3719 		ret = btrfs_add_qgroup_relation(trans, root->fs_info,
3720 						sa->src, sa->dst);
3721 	} else {
3722 		ret = btrfs_del_qgroup_relation(trans, root->fs_info,
3723 						sa->src, sa->dst);
3724 	}
3725 
3726 	err = btrfs_end_transaction(trans, root);
3727 	if (err && !ret)
3728 		ret = err;
3729 
3730 out:
3731 	kfree(sa);
3732 drop_write:
3733 	mnt_drop_write_file(file);
3734 	return ret;
3735 }
3736 
3737 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
3738 {
3739 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3740 	struct btrfs_ioctl_qgroup_create_args *sa;
3741 	struct btrfs_trans_handle *trans;
3742 	int ret;
3743 	int err;
3744 
3745 	if (!capable(CAP_SYS_ADMIN))
3746 		return -EPERM;
3747 
3748 	ret = mnt_want_write_file(file);
3749 	if (ret)
3750 		return ret;
3751 
3752 	sa = memdup_user(arg, sizeof(*sa));
3753 	if (IS_ERR(sa)) {
3754 		ret = PTR_ERR(sa);
3755 		goto drop_write;
3756 	}
3757 
3758 	if (!sa->qgroupid) {
3759 		ret = -EINVAL;
3760 		goto out;
3761 	}
3762 
3763 	trans = btrfs_join_transaction(root);
3764 	if (IS_ERR(trans)) {
3765 		ret = PTR_ERR(trans);
3766 		goto out;
3767 	}
3768 
3769 	/* FIXME: check if the IDs really exist */
3770 	if (sa->create) {
3771 		ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
3772 					  NULL);
3773 	} else {
3774 		ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
3775 	}
3776 
3777 	err = btrfs_end_transaction(trans, root);
3778 	if (err && !ret)
3779 		ret = err;
3780 
3781 out:
3782 	kfree(sa);
3783 drop_write:
3784 	mnt_drop_write_file(file);
3785 	return ret;
3786 }
3787 
3788 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
3789 {
3790 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3791 	struct btrfs_ioctl_qgroup_limit_args *sa;
3792 	struct btrfs_trans_handle *trans;
3793 	int ret;
3794 	int err;
3795 	u64 qgroupid;
3796 
3797 	if (!capable(CAP_SYS_ADMIN))
3798 		return -EPERM;
3799 
3800 	ret = mnt_want_write_file(file);
3801 	if (ret)
3802 		return ret;
3803 
3804 	sa = memdup_user(arg, sizeof(*sa));
3805 	if (IS_ERR(sa)) {
3806 		ret = PTR_ERR(sa);
3807 		goto drop_write;
3808 	}
3809 
3810 	trans = btrfs_join_transaction(root);
3811 	if (IS_ERR(trans)) {
3812 		ret = PTR_ERR(trans);
3813 		goto out;
3814 	}
3815 
3816 	qgroupid = sa->qgroupid;
3817 	if (!qgroupid) {
3818 		/* take the current subvol as qgroup */
3819 		qgroupid = root->root_key.objectid;
3820 	}
3821 
3822 	/* FIXME: check if the IDs really exist */
3823 	ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
3824 
3825 	err = btrfs_end_transaction(trans, root);
3826 	if (err && !ret)
3827 		ret = err;
3828 
3829 out:
3830 	kfree(sa);
3831 drop_write:
3832 	mnt_drop_write_file(file);
3833 	return ret;
3834 }
3835 
3836 static long btrfs_ioctl_set_received_subvol(struct file *file,
3837 					    void __user *arg)
3838 {
3839 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
3840 	struct inode *inode = fdentry(file)->d_inode;
3841 	struct btrfs_root *root = BTRFS_I(inode)->root;
3842 	struct btrfs_root_item *root_item = &root->root_item;
3843 	struct btrfs_trans_handle *trans;
3844 	struct timespec ct = CURRENT_TIME;
3845 	int ret = 0;
3846 
3847 	ret = mnt_want_write_file(file);
3848 	if (ret < 0)
3849 		return ret;
3850 
3851 	down_write(&root->fs_info->subvol_sem);
3852 
3853 	if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) {
3854 		ret = -EINVAL;
3855 		goto out;
3856 	}
3857 
3858 	if (btrfs_root_readonly(root)) {
3859 		ret = -EROFS;
3860 		goto out;
3861 	}
3862 
3863 	if (!inode_owner_or_capable(inode)) {
3864 		ret = -EACCES;
3865 		goto out;
3866 	}
3867 
3868 	sa = memdup_user(arg, sizeof(*sa));
3869 	if (IS_ERR(sa)) {
3870 		ret = PTR_ERR(sa);
3871 		sa = NULL;
3872 		goto out;
3873 	}
3874 
3875 	trans = btrfs_start_transaction(root, 1);
3876 	if (IS_ERR(trans)) {
3877 		ret = PTR_ERR(trans);
3878 		trans = NULL;
3879 		goto out;
3880 	}
3881 
3882 	sa->rtransid = trans->transid;
3883 	sa->rtime.sec = ct.tv_sec;
3884 	sa->rtime.nsec = ct.tv_nsec;
3885 
3886 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
3887 	btrfs_set_root_stransid(root_item, sa->stransid);
3888 	btrfs_set_root_rtransid(root_item, sa->rtransid);
3889 	root_item->stime.sec = cpu_to_le64(sa->stime.sec);
3890 	root_item->stime.nsec = cpu_to_le32(sa->stime.nsec);
3891 	root_item->rtime.sec = cpu_to_le64(sa->rtime.sec);
3892 	root_item->rtime.nsec = cpu_to_le32(sa->rtime.nsec);
3893 
3894 	ret = btrfs_update_root(trans, root->fs_info->tree_root,
3895 				&root->root_key, &root->root_item);
3896 	if (ret < 0) {
3897 		btrfs_end_transaction(trans, root);
3898 		trans = NULL;
3899 		goto out;
3900 	} else {
3901 		ret = btrfs_commit_transaction(trans, root);
3902 		if (ret < 0)
3903 			goto out;
3904 	}
3905 
3906 	ret = copy_to_user(arg, sa, sizeof(*sa));
3907 	if (ret)
3908 		ret = -EFAULT;
3909 
3910 out:
3911 	kfree(sa);
3912 	up_write(&root->fs_info->subvol_sem);
3913 	mnt_drop_write_file(file);
3914 	return ret;
3915 }
3916 
3917 long btrfs_ioctl(struct file *file, unsigned int
3918 		cmd, unsigned long arg)
3919 {
3920 	struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
3921 	void __user *argp = (void __user *)arg;
3922 
3923 	switch (cmd) {
3924 	case FS_IOC_GETFLAGS:
3925 		return btrfs_ioctl_getflags(file, argp);
3926 	case FS_IOC_SETFLAGS:
3927 		return btrfs_ioctl_setflags(file, argp);
3928 	case FS_IOC_GETVERSION:
3929 		return btrfs_ioctl_getversion(file, argp);
3930 	case FITRIM:
3931 		return btrfs_ioctl_fitrim(file, argp);
3932 	case BTRFS_IOC_SNAP_CREATE:
3933 		return btrfs_ioctl_snap_create(file, argp, 0);
3934 	case BTRFS_IOC_SNAP_CREATE_V2:
3935 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
3936 	case BTRFS_IOC_SUBVOL_CREATE:
3937 		return btrfs_ioctl_snap_create(file, argp, 1);
3938 	case BTRFS_IOC_SUBVOL_CREATE_V2:
3939 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
3940 	case BTRFS_IOC_SNAP_DESTROY:
3941 		return btrfs_ioctl_snap_destroy(file, argp);
3942 	case BTRFS_IOC_SUBVOL_GETFLAGS:
3943 		return btrfs_ioctl_subvol_getflags(file, argp);
3944 	case BTRFS_IOC_SUBVOL_SETFLAGS:
3945 		return btrfs_ioctl_subvol_setflags(file, argp);
3946 	case BTRFS_IOC_DEFAULT_SUBVOL:
3947 		return btrfs_ioctl_default_subvol(file, argp);
3948 	case BTRFS_IOC_DEFRAG:
3949 		return btrfs_ioctl_defrag(file, NULL);
3950 	case BTRFS_IOC_DEFRAG_RANGE:
3951 		return btrfs_ioctl_defrag(file, argp);
3952 	case BTRFS_IOC_RESIZE:
3953 		return btrfs_ioctl_resize(file, argp);
3954 	case BTRFS_IOC_ADD_DEV:
3955 		return btrfs_ioctl_add_dev(root, argp);
3956 	case BTRFS_IOC_RM_DEV:
3957 		return btrfs_ioctl_rm_dev(file, argp);
3958 	case BTRFS_IOC_FS_INFO:
3959 		return btrfs_ioctl_fs_info(root, argp);
3960 	case BTRFS_IOC_DEV_INFO:
3961 		return btrfs_ioctl_dev_info(root, argp);
3962 	case BTRFS_IOC_BALANCE:
3963 		return btrfs_ioctl_balance(file, NULL);
3964 	case BTRFS_IOC_CLONE:
3965 		return btrfs_ioctl_clone(file, arg, 0, 0, 0);
3966 	case BTRFS_IOC_CLONE_RANGE:
3967 		return btrfs_ioctl_clone_range(file, argp);
3968 	case BTRFS_IOC_TRANS_START:
3969 		return btrfs_ioctl_trans_start(file);
3970 	case BTRFS_IOC_TRANS_END:
3971 		return btrfs_ioctl_trans_end(file);
3972 	case BTRFS_IOC_TREE_SEARCH:
3973 		return btrfs_ioctl_tree_search(file, argp);
3974 	case BTRFS_IOC_INO_LOOKUP:
3975 		return btrfs_ioctl_ino_lookup(file, argp);
3976 	case BTRFS_IOC_INO_PATHS:
3977 		return btrfs_ioctl_ino_to_path(root, argp);
3978 	case BTRFS_IOC_LOGICAL_INO:
3979 		return btrfs_ioctl_logical_to_ino(root, argp);
3980 	case BTRFS_IOC_SPACE_INFO:
3981 		return btrfs_ioctl_space_info(root, argp);
3982 	case BTRFS_IOC_SYNC:
3983 		btrfs_sync_fs(file->f_dentry->d_sb, 1);
3984 		return 0;
3985 	case BTRFS_IOC_START_SYNC:
3986 		return btrfs_ioctl_start_sync(root, argp);
3987 	case BTRFS_IOC_WAIT_SYNC:
3988 		return btrfs_ioctl_wait_sync(root, argp);
3989 	case BTRFS_IOC_SCRUB:
3990 		return btrfs_ioctl_scrub(file, argp);
3991 	case BTRFS_IOC_SCRUB_CANCEL:
3992 		return btrfs_ioctl_scrub_cancel(root, argp);
3993 	case BTRFS_IOC_SCRUB_PROGRESS:
3994 		return btrfs_ioctl_scrub_progress(root, argp);
3995 	case BTRFS_IOC_BALANCE_V2:
3996 		return btrfs_ioctl_balance(file, argp);
3997 	case BTRFS_IOC_BALANCE_CTL:
3998 		return btrfs_ioctl_balance_ctl(root, arg);
3999 	case BTRFS_IOC_BALANCE_PROGRESS:
4000 		return btrfs_ioctl_balance_progress(root, argp);
4001 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4002 		return btrfs_ioctl_set_received_subvol(file, argp);
4003 	case BTRFS_IOC_SEND:
4004 		return btrfs_ioctl_send(file, argp);
4005 	case BTRFS_IOC_GET_DEV_STATS:
4006 		return btrfs_ioctl_get_dev_stats(root, argp);
4007 	case BTRFS_IOC_QUOTA_CTL:
4008 		return btrfs_ioctl_quota_ctl(file, argp);
4009 	case BTRFS_IOC_QGROUP_ASSIGN:
4010 		return btrfs_ioctl_qgroup_assign(file, argp);
4011 	case BTRFS_IOC_QGROUP_CREATE:
4012 		return btrfs_ioctl_qgroup_create(file, argp);
4013 	case BTRFS_IOC_QGROUP_LIMIT:
4014 		return btrfs_ioctl_qgroup_limit(file, argp);
4015 	case BTRFS_IOC_DEV_REPLACE:
4016 		return btrfs_ioctl_dev_replace(root, argp);
4017 	}
4018 
4019 	return -ENOTTY;
4020 }
4021