xref: /openbmc/linux/fs/btrfs/ioctl.c (revision 113094f7)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/bio.h>
8 #include <linux/file.h>
9 #include <linux/fs.h>
10 #include <linux/fsnotify.h>
11 #include <linux/pagemap.h>
12 #include <linux/highmem.h>
13 #include <linux/time.h>
14 #include <linux/string.h>
15 #include <linux/backing-dev.h>
16 #include <linux/mount.h>
17 #include <linux/namei.h>
18 #include <linux/writeback.h>
19 #include <linux/compat.h>
20 #include <linux/security.h>
21 #include <linux/xattr.h>
22 #include <linux/mm.h>
23 #include <linux/slab.h>
24 #include <linux/blkdev.h>
25 #include <linux/uuid.h>
26 #include <linux/btrfs.h>
27 #include <linux/uaccess.h>
28 #include <linux/iversion.h>
29 #include "ctree.h"
30 #include "disk-io.h"
31 #include "transaction.h"
32 #include "btrfs_inode.h"
33 #include "print-tree.h"
34 #include "volumes.h"
35 #include "locking.h"
36 #include "inode-map.h"
37 #include "backref.h"
38 #include "rcu-string.h"
39 #include "send.h"
40 #include "dev-replace.h"
41 #include "props.h"
42 #include "sysfs.h"
43 #include "qgroup.h"
44 #include "tree-log.h"
45 #include "compression.h"
46 
47 #ifdef CONFIG_64BIT
48 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
49  * structures are incorrect, as the timespec structure from userspace
50  * is 4 bytes too small. We define these alternatives here to teach
51  * the kernel about the 32-bit struct packing.
52  */
53 struct btrfs_ioctl_timespec_32 {
54 	__u64 sec;
55 	__u32 nsec;
56 } __attribute__ ((__packed__));
57 
58 struct btrfs_ioctl_received_subvol_args_32 {
59 	char	uuid[BTRFS_UUID_SIZE];	/* in */
60 	__u64	stransid;		/* in */
61 	__u64	rtransid;		/* out */
62 	struct btrfs_ioctl_timespec_32 stime; /* in */
63 	struct btrfs_ioctl_timespec_32 rtime; /* out */
64 	__u64	flags;			/* in */
65 	__u64	reserved[16];		/* in */
66 } __attribute__ ((__packed__));
67 
68 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
69 				struct btrfs_ioctl_received_subvol_args_32)
70 #endif
71 
72 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
73 struct btrfs_ioctl_send_args_32 {
74 	__s64 send_fd;			/* in */
75 	__u64 clone_sources_count;	/* in */
76 	compat_uptr_t clone_sources;	/* in */
77 	__u64 parent_root;		/* in */
78 	__u64 flags;			/* in */
79 	__u64 reserved[4];		/* in */
80 } __attribute__ ((__packed__));
81 
82 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
83 			       struct btrfs_ioctl_send_args_32)
84 #endif
85 
86 static int btrfs_clone(struct inode *src, struct inode *inode,
87 		       u64 off, u64 olen, u64 olen_aligned, u64 destoff,
88 		       int no_time_update);
89 
90 /* Mask out flags that are inappropriate for the given type of inode. */
91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
92 		unsigned int flags)
93 {
94 	if (S_ISDIR(inode->i_mode))
95 		return flags;
96 	else if (S_ISREG(inode->i_mode))
97 		return flags & ~FS_DIRSYNC_FL;
98 	else
99 		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
100 }
101 
102 /*
103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
104  * ioctl.
105  */
106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
107 {
108 	unsigned int iflags = 0;
109 
110 	if (flags & BTRFS_INODE_SYNC)
111 		iflags |= FS_SYNC_FL;
112 	if (flags & BTRFS_INODE_IMMUTABLE)
113 		iflags |= FS_IMMUTABLE_FL;
114 	if (flags & BTRFS_INODE_APPEND)
115 		iflags |= FS_APPEND_FL;
116 	if (flags & BTRFS_INODE_NODUMP)
117 		iflags |= FS_NODUMP_FL;
118 	if (flags & BTRFS_INODE_NOATIME)
119 		iflags |= FS_NOATIME_FL;
120 	if (flags & BTRFS_INODE_DIRSYNC)
121 		iflags |= FS_DIRSYNC_FL;
122 	if (flags & BTRFS_INODE_NODATACOW)
123 		iflags |= FS_NOCOW_FL;
124 
125 	if (flags & BTRFS_INODE_NOCOMPRESS)
126 		iflags |= FS_NOCOMP_FL;
127 	else if (flags & BTRFS_INODE_COMPRESS)
128 		iflags |= FS_COMPR_FL;
129 
130 	return iflags;
131 }
132 
133 /*
134  * Update inode->i_flags based on the btrfs internal flags.
135  */
136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
137 {
138 	struct btrfs_inode *binode = BTRFS_I(inode);
139 	unsigned int new_fl = 0;
140 
141 	if (binode->flags & BTRFS_INODE_SYNC)
142 		new_fl |= S_SYNC;
143 	if (binode->flags & BTRFS_INODE_IMMUTABLE)
144 		new_fl |= S_IMMUTABLE;
145 	if (binode->flags & BTRFS_INODE_APPEND)
146 		new_fl |= S_APPEND;
147 	if (binode->flags & BTRFS_INODE_NOATIME)
148 		new_fl |= S_NOATIME;
149 	if (binode->flags & BTRFS_INODE_DIRSYNC)
150 		new_fl |= S_DIRSYNC;
151 
152 	set_mask_bits(&inode->i_flags,
153 		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
154 		      new_fl);
155 }
156 
157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
158 {
159 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
160 	unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
161 
162 	if (copy_to_user(arg, &flags, sizeof(flags)))
163 		return -EFAULT;
164 	return 0;
165 }
166 
167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
168 static int check_fsflags(unsigned int flags)
169 {
170 	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
171 		      FS_NOATIME_FL | FS_NODUMP_FL | \
172 		      FS_SYNC_FL | FS_DIRSYNC_FL | \
173 		      FS_NOCOMP_FL | FS_COMPR_FL |
174 		      FS_NOCOW_FL))
175 		return -EOPNOTSUPP;
176 
177 	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
178 		return -EINVAL;
179 
180 	return 0;
181 }
182 
183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
184 {
185 	struct inode *inode = file_inode(file);
186 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
187 	struct btrfs_inode *binode = BTRFS_I(inode);
188 	struct btrfs_root *root = binode->root;
189 	struct btrfs_trans_handle *trans;
190 	unsigned int fsflags, old_fsflags;
191 	int ret;
192 	const char *comp = NULL;
193 	u32 binode_flags = binode->flags;
194 
195 	if (!inode_owner_or_capable(inode))
196 		return -EPERM;
197 
198 	if (btrfs_root_readonly(root))
199 		return -EROFS;
200 
201 	if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
202 		return -EFAULT;
203 
204 	ret = check_fsflags(fsflags);
205 	if (ret)
206 		return ret;
207 
208 	ret = mnt_want_write_file(file);
209 	if (ret)
210 		return ret;
211 
212 	inode_lock(inode);
213 
214 	fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
215 	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
216 	ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags);
217 	if (ret)
218 		goto out_unlock;
219 
220 	if (fsflags & FS_SYNC_FL)
221 		binode_flags |= BTRFS_INODE_SYNC;
222 	else
223 		binode_flags &= ~BTRFS_INODE_SYNC;
224 	if (fsflags & FS_IMMUTABLE_FL)
225 		binode_flags |= BTRFS_INODE_IMMUTABLE;
226 	else
227 		binode_flags &= ~BTRFS_INODE_IMMUTABLE;
228 	if (fsflags & FS_APPEND_FL)
229 		binode_flags |= BTRFS_INODE_APPEND;
230 	else
231 		binode_flags &= ~BTRFS_INODE_APPEND;
232 	if (fsflags & FS_NODUMP_FL)
233 		binode_flags |= BTRFS_INODE_NODUMP;
234 	else
235 		binode_flags &= ~BTRFS_INODE_NODUMP;
236 	if (fsflags & FS_NOATIME_FL)
237 		binode_flags |= BTRFS_INODE_NOATIME;
238 	else
239 		binode_flags &= ~BTRFS_INODE_NOATIME;
240 	if (fsflags & FS_DIRSYNC_FL)
241 		binode_flags |= BTRFS_INODE_DIRSYNC;
242 	else
243 		binode_flags &= ~BTRFS_INODE_DIRSYNC;
244 	if (fsflags & FS_NOCOW_FL) {
245 		if (S_ISREG(inode->i_mode)) {
246 			/*
247 			 * It's safe to turn csums off here, no extents exist.
248 			 * Otherwise we want the flag to reflect the real COW
249 			 * status of the file and will not set it.
250 			 */
251 			if (inode->i_size == 0)
252 				binode_flags |= BTRFS_INODE_NODATACOW |
253 						BTRFS_INODE_NODATASUM;
254 		} else {
255 			binode_flags |= BTRFS_INODE_NODATACOW;
256 		}
257 	} else {
258 		/*
259 		 * Revert back under same assumptions as above
260 		 */
261 		if (S_ISREG(inode->i_mode)) {
262 			if (inode->i_size == 0)
263 				binode_flags &= ~(BTRFS_INODE_NODATACOW |
264 						  BTRFS_INODE_NODATASUM);
265 		} else {
266 			binode_flags &= ~BTRFS_INODE_NODATACOW;
267 		}
268 	}
269 
270 	/*
271 	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
272 	 * flag may be changed automatically if compression code won't make
273 	 * things smaller.
274 	 */
275 	if (fsflags & FS_NOCOMP_FL) {
276 		binode_flags &= ~BTRFS_INODE_COMPRESS;
277 		binode_flags |= BTRFS_INODE_NOCOMPRESS;
278 	} else if (fsflags & FS_COMPR_FL) {
279 
280 		if (IS_SWAPFILE(inode)) {
281 			ret = -ETXTBSY;
282 			goto out_unlock;
283 		}
284 
285 		binode_flags |= BTRFS_INODE_COMPRESS;
286 		binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
287 
288 		comp = btrfs_compress_type2str(fs_info->compress_type);
289 		if (!comp || comp[0] == 0)
290 			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
291 	} else {
292 		binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
293 	}
294 
295 	/*
296 	 * 1 for inode item
297 	 * 2 for properties
298 	 */
299 	trans = btrfs_start_transaction(root, 3);
300 	if (IS_ERR(trans)) {
301 		ret = PTR_ERR(trans);
302 		goto out_unlock;
303 	}
304 
305 	if (comp) {
306 		ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
307 				     strlen(comp), 0);
308 		if (ret) {
309 			btrfs_abort_transaction(trans, ret);
310 			goto out_end_trans;
311 		}
312 	} else {
313 		ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
314 				     0, 0);
315 		if (ret && ret != -ENODATA) {
316 			btrfs_abort_transaction(trans, ret);
317 			goto out_end_trans;
318 		}
319 	}
320 
321 	binode->flags = binode_flags;
322 	btrfs_sync_inode_flags_to_i_flags(inode);
323 	inode_inc_iversion(inode);
324 	inode->i_ctime = current_time(inode);
325 	ret = btrfs_update_inode(trans, root, inode);
326 
327  out_end_trans:
328 	btrfs_end_transaction(trans);
329  out_unlock:
330 	inode_unlock(inode);
331 	mnt_drop_write_file(file);
332 	return ret;
333 }
334 
335 /*
336  * Translate btrfs internal inode flags to xflags as expected by the
337  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
338  * silently dropped.
339  */
340 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
341 {
342 	unsigned int xflags = 0;
343 
344 	if (flags & BTRFS_INODE_APPEND)
345 		xflags |= FS_XFLAG_APPEND;
346 	if (flags & BTRFS_INODE_IMMUTABLE)
347 		xflags |= FS_XFLAG_IMMUTABLE;
348 	if (flags & BTRFS_INODE_NOATIME)
349 		xflags |= FS_XFLAG_NOATIME;
350 	if (flags & BTRFS_INODE_NODUMP)
351 		xflags |= FS_XFLAG_NODUMP;
352 	if (flags & BTRFS_INODE_SYNC)
353 		xflags |= FS_XFLAG_SYNC;
354 
355 	return xflags;
356 }
357 
358 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
359 static int check_xflags(unsigned int flags)
360 {
361 	if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
362 		      FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
363 		return -EOPNOTSUPP;
364 	return 0;
365 }
366 
367 /*
368  * Set the xflags from the internal inode flags. The remaining items of fsxattr
369  * are zeroed.
370  */
371 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
372 {
373 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
374 	struct fsxattr fa;
375 
376 	simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags));
377 	if (copy_to_user(arg, &fa, sizeof(fa)))
378 		return -EFAULT;
379 
380 	return 0;
381 }
382 
383 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
384 {
385 	struct inode *inode = file_inode(file);
386 	struct btrfs_inode *binode = BTRFS_I(inode);
387 	struct btrfs_root *root = binode->root;
388 	struct btrfs_trans_handle *trans;
389 	struct fsxattr fa, old_fa;
390 	unsigned old_flags;
391 	unsigned old_i_flags;
392 	int ret = 0;
393 
394 	if (!inode_owner_or_capable(inode))
395 		return -EPERM;
396 
397 	if (btrfs_root_readonly(root))
398 		return -EROFS;
399 
400 	if (copy_from_user(&fa, arg, sizeof(fa)))
401 		return -EFAULT;
402 
403 	ret = check_xflags(fa.fsx_xflags);
404 	if (ret)
405 		return ret;
406 
407 	if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
408 		return -EOPNOTSUPP;
409 
410 	ret = mnt_want_write_file(file);
411 	if (ret)
412 		return ret;
413 
414 	inode_lock(inode);
415 
416 	old_flags = binode->flags;
417 	old_i_flags = inode->i_flags;
418 
419 	simple_fill_fsxattr(&old_fa,
420 			    btrfs_inode_flags_to_xflags(binode->flags));
421 	ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
422 	if (ret)
423 		goto out_unlock;
424 
425 	if (fa.fsx_xflags & FS_XFLAG_SYNC)
426 		binode->flags |= BTRFS_INODE_SYNC;
427 	else
428 		binode->flags &= ~BTRFS_INODE_SYNC;
429 	if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
430 		binode->flags |= BTRFS_INODE_IMMUTABLE;
431 	else
432 		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
433 	if (fa.fsx_xflags & FS_XFLAG_APPEND)
434 		binode->flags |= BTRFS_INODE_APPEND;
435 	else
436 		binode->flags &= ~BTRFS_INODE_APPEND;
437 	if (fa.fsx_xflags & FS_XFLAG_NODUMP)
438 		binode->flags |= BTRFS_INODE_NODUMP;
439 	else
440 		binode->flags &= ~BTRFS_INODE_NODUMP;
441 	if (fa.fsx_xflags & FS_XFLAG_NOATIME)
442 		binode->flags |= BTRFS_INODE_NOATIME;
443 	else
444 		binode->flags &= ~BTRFS_INODE_NOATIME;
445 
446 	/* 1 item for the inode */
447 	trans = btrfs_start_transaction(root, 1);
448 	if (IS_ERR(trans)) {
449 		ret = PTR_ERR(trans);
450 		goto out_unlock;
451 	}
452 
453 	btrfs_sync_inode_flags_to_i_flags(inode);
454 	inode_inc_iversion(inode);
455 	inode->i_ctime = current_time(inode);
456 	ret = btrfs_update_inode(trans, root, inode);
457 
458 	btrfs_end_transaction(trans);
459 
460 out_unlock:
461 	if (ret) {
462 		binode->flags = old_flags;
463 		inode->i_flags = old_i_flags;
464 	}
465 
466 	inode_unlock(inode);
467 	mnt_drop_write_file(file);
468 
469 	return ret;
470 }
471 
472 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
473 {
474 	struct inode *inode = file_inode(file);
475 
476 	return put_user(inode->i_generation, arg);
477 }
478 
479 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
480 {
481 	struct inode *inode = file_inode(file);
482 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
483 	struct btrfs_device *device;
484 	struct request_queue *q;
485 	struct fstrim_range range;
486 	u64 minlen = ULLONG_MAX;
487 	u64 num_devices = 0;
488 	int ret;
489 
490 	if (!capable(CAP_SYS_ADMIN))
491 		return -EPERM;
492 
493 	/*
494 	 * If the fs is mounted with nologreplay, which requires it to be
495 	 * mounted in RO mode as well, we can not allow discard on free space
496 	 * inside block groups, because log trees refer to extents that are not
497 	 * pinned in a block group's free space cache (pinning the extents is
498 	 * precisely the first phase of replaying a log tree).
499 	 */
500 	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
501 		return -EROFS;
502 
503 	rcu_read_lock();
504 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
505 				dev_list) {
506 		if (!device->bdev)
507 			continue;
508 		q = bdev_get_queue(device->bdev);
509 		if (blk_queue_discard(q)) {
510 			num_devices++;
511 			minlen = min_t(u64, q->limits.discard_granularity,
512 				     minlen);
513 		}
514 	}
515 	rcu_read_unlock();
516 
517 	if (!num_devices)
518 		return -EOPNOTSUPP;
519 	if (copy_from_user(&range, arg, sizeof(range)))
520 		return -EFAULT;
521 
522 	/*
523 	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
524 	 * block group is in the logical address space, which can be any
525 	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
526 	 */
527 	if (range.len < fs_info->sb->s_blocksize)
528 		return -EINVAL;
529 
530 	range.minlen = max(range.minlen, minlen);
531 	ret = btrfs_trim_fs(fs_info, &range);
532 	if (ret < 0)
533 		return ret;
534 
535 	if (copy_to_user(arg, &range, sizeof(range)))
536 		return -EFAULT;
537 
538 	return 0;
539 }
540 
541 int btrfs_is_empty_uuid(u8 *uuid)
542 {
543 	int i;
544 
545 	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
546 		if (uuid[i])
547 			return 0;
548 	}
549 	return 1;
550 }
551 
552 static noinline int create_subvol(struct inode *dir,
553 				  struct dentry *dentry,
554 				  const char *name, int namelen,
555 				  u64 *async_transid,
556 				  struct btrfs_qgroup_inherit *inherit)
557 {
558 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
559 	struct btrfs_trans_handle *trans;
560 	struct btrfs_key key;
561 	struct btrfs_root_item *root_item;
562 	struct btrfs_inode_item *inode_item;
563 	struct extent_buffer *leaf;
564 	struct btrfs_root *root = BTRFS_I(dir)->root;
565 	struct btrfs_root *new_root;
566 	struct btrfs_block_rsv block_rsv;
567 	struct timespec64 cur_time = current_time(dir);
568 	struct inode *inode;
569 	int ret;
570 	int err;
571 	u64 objectid;
572 	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
573 	u64 index = 0;
574 	uuid_le new_uuid;
575 
576 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
577 	if (!root_item)
578 		return -ENOMEM;
579 
580 	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
581 	if (ret)
582 		goto fail_free;
583 
584 	/*
585 	 * Don't create subvolume whose level is not zero. Or qgroup will be
586 	 * screwed up since it assumes subvolume qgroup's level to be 0.
587 	 */
588 	if (btrfs_qgroup_level(objectid)) {
589 		ret = -ENOSPC;
590 		goto fail_free;
591 	}
592 
593 	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
594 	/*
595 	 * The same as the snapshot creation, please see the comment
596 	 * of create_snapshot().
597 	 */
598 	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
599 	if (ret)
600 		goto fail_free;
601 
602 	trans = btrfs_start_transaction(root, 0);
603 	if (IS_ERR(trans)) {
604 		ret = PTR_ERR(trans);
605 		btrfs_subvolume_release_metadata(fs_info, &block_rsv);
606 		goto fail_free;
607 	}
608 	trans->block_rsv = &block_rsv;
609 	trans->bytes_reserved = block_rsv.size;
610 
611 	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
612 	if (ret)
613 		goto fail;
614 
615 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
616 	if (IS_ERR(leaf)) {
617 		ret = PTR_ERR(leaf);
618 		goto fail;
619 	}
620 
621 	btrfs_mark_buffer_dirty(leaf);
622 
623 	inode_item = &root_item->inode;
624 	btrfs_set_stack_inode_generation(inode_item, 1);
625 	btrfs_set_stack_inode_size(inode_item, 3);
626 	btrfs_set_stack_inode_nlink(inode_item, 1);
627 	btrfs_set_stack_inode_nbytes(inode_item,
628 				     fs_info->nodesize);
629 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
630 
631 	btrfs_set_root_flags(root_item, 0);
632 	btrfs_set_root_limit(root_item, 0);
633 	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
634 
635 	btrfs_set_root_bytenr(root_item, leaf->start);
636 	btrfs_set_root_generation(root_item, trans->transid);
637 	btrfs_set_root_level(root_item, 0);
638 	btrfs_set_root_refs(root_item, 1);
639 	btrfs_set_root_used(root_item, leaf->len);
640 	btrfs_set_root_last_snapshot(root_item, 0);
641 
642 	btrfs_set_root_generation_v2(root_item,
643 			btrfs_root_generation(root_item));
644 	uuid_le_gen(&new_uuid);
645 	memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
646 	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
647 	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
648 	root_item->ctime = root_item->otime;
649 	btrfs_set_root_ctransid(root_item, trans->transid);
650 	btrfs_set_root_otransid(root_item, trans->transid);
651 
652 	btrfs_tree_unlock(leaf);
653 	free_extent_buffer(leaf);
654 	leaf = NULL;
655 
656 	btrfs_set_root_dirid(root_item, new_dirid);
657 
658 	key.objectid = objectid;
659 	key.offset = 0;
660 	key.type = BTRFS_ROOT_ITEM_KEY;
661 	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
662 				root_item);
663 	if (ret)
664 		goto fail;
665 
666 	key.offset = (u64)-1;
667 	new_root = btrfs_read_fs_root_no_name(fs_info, &key);
668 	if (IS_ERR(new_root)) {
669 		ret = PTR_ERR(new_root);
670 		btrfs_abort_transaction(trans, ret);
671 		goto fail;
672 	}
673 
674 	btrfs_record_root_in_trans(trans, new_root);
675 
676 	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
677 	if (ret) {
678 		/* We potentially lose an unused inode item here */
679 		btrfs_abort_transaction(trans, ret);
680 		goto fail;
681 	}
682 
683 	mutex_lock(&new_root->objectid_mutex);
684 	new_root->highest_objectid = new_dirid;
685 	mutex_unlock(&new_root->objectid_mutex);
686 
687 	/*
688 	 * insert the directory item
689 	 */
690 	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
691 	if (ret) {
692 		btrfs_abort_transaction(trans, ret);
693 		goto fail;
694 	}
695 
696 	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
697 				    BTRFS_FT_DIR, index);
698 	if (ret) {
699 		btrfs_abort_transaction(trans, ret);
700 		goto fail;
701 	}
702 
703 	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
704 	ret = btrfs_update_inode(trans, root, dir);
705 	BUG_ON(ret);
706 
707 	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
708 				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
709 	BUG_ON(ret);
710 
711 	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
712 				  BTRFS_UUID_KEY_SUBVOL, objectid);
713 	if (ret)
714 		btrfs_abort_transaction(trans, ret);
715 
716 fail:
717 	kfree(root_item);
718 	trans->block_rsv = NULL;
719 	trans->bytes_reserved = 0;
720 	btrfs_subvolume_release_metadata(fs_info, &block_rsv);
721 
722 	if (async_transid) {
723 		*async_transid = trans->transid;
724 		err = btrfs_commit_transaction_async(trans, 1);
725 		if (err)
726 			err = btrfs_commit_transaction(trans);
727 	} else {
728 		err = btrfs_commit_transaction(trans);
729 	}
730 	if (err && !ret)
731 		ret = err;
732 
733 	if (!ret) {
734 		inode = btrfs_lookup_dentry(dir, dentry);
735 		if (IS_ERR(inode))
736 			return PTR_ERR(inode);
737 		d_instantiate(dentry, inode);
738 	}
739 	return ret;
740 
741 fail_free:
742 	kfree(root_item);
743 	return ret;
744 }
745 
746 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
747 			   struct dentry *dentry,
748 			   u64 *async_transid, bool readonly,
749 			   struct btrfs_qgroup_inherit *inherit)
750 {
751 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
752 	struct inode *inode;
753 	struct btrfs_pending_snapshot *pending_snapshot;
754 	struct btrfs_trans_handle *trans;
755 	int ret;
756 	bool snapshot_force_cow = false;
757 
758 	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
759 		return -EINVAL;
760 
761 	if (atomic_read(&root->nr_swapfiles)) {
762 		btrfs_warn(fs_info,
763 			   "cannot snapshot subvolume with active swapfile");
764 		return -ETXTBSY;
765 	}
766 
767 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
768 	if (!pending_snapshot)
769 		return -ENOMEM;
770 
771 	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
772 			GFP_KERNEL);
773 	pending_snapshot->path = btrfs_alloc_path();
774 	if (!pending_snapshot->root_item || !pending_snapshot->path) {
775 		ret = -ENOMEM;
776 		goto free_pending;
777 	}
778 
779 	/*
780 	 * Force new buffered writes to reserve space even when NOCOW is
781 	 * possible. This is to avoid later writeback (running dealloc) to
782 	 * fallback to COW mode and unexpectedly fail with ENOSPC.
783 	 */
784 	atomic_inc(&root->will_be_snapshotted);
785 	smp_mb__after_atomic();
786 	/* wait for no snapshot writes */
787 	wait_event(root->subv_writers->wait,
788 		   percpu_counter_sum(&root->subv_writers->counter) == 0);
789 
790 	ret = btrfs_start_delalloc_snapshot(root);
791 	if (ret)
792 		goto dec_and_free;
793 
794 	/*
795 	 * All previous writes have started writeback in NOCOW mode, so now
796 	 * we force future writes to fallback to COW mode during snapshot
797 	 * creation.
798 	 */
799 	atomic_inc(&root->snapshot_force_cow);
800 	snapshot_force_cow = true;
801 
802 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
803 
804 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
805 			     BTRFS_BLOCK_RSV_TEMP);
806 	/*
807 	 * 1 - parent dir inode
808 	 * 2 - dir entries
809 	 * 1 - root item
810 	 * 2 - root ref/backref
811 	 * 1 - root of snapshot
812 	 * 1 - UUID item
813 	 */
814 	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
815 					&pending_snapshot->block_rsv, 8,
816 					false);
817 	if (ret)
818 		goto dec_and_free;
819 
820 	pending_snapshot->dentry = dentry;
821 	pending_snapshot->root = root;
822 	pending_snapshot->readonly = readonly;
823 	pending_snapshot->dir = dir;
824 	pending_snapshot->inherit = inherit;
825 
826 	trans = btrfs_start_transaction(root, 0);
827 	if (IS_ERR(trans)) {
828 		ret = PTR_ERR(trans);
829 		goto fail;
830 	}
831 
832 	spin_lock(&fs_info->trans_lock);
833 	list_add(&pending_snapshot->list,
834 		 &trans->transaction->pending_snapshots);
835 	spin_unlock(&fs_info->trans_lock);
836 	if (async_transid) {
837 		*async_transid = trans->transid;
838 		ret = btrfs_commit_transaction_async(trans, 1);
839 		if (ret)
840 			ret = btrfs_commit_transaction(trans);
841 	} else {
842 		ret = btrfs_commit_transaction(trans);
843 	}
844 	if (ret)
845 		goto fail;
846 
847 	ret = pending_snapshot->error;
848 	if (ret)
849 		goto fail;
850 
851 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
852 	if (ret)
853 		goto fail;
854 
855 	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
856 	if (IS_ERR(inode)) {
857 		ret = PTR_ERR(inode);
858 		goto fail;
859 	}
860 
861 	d_instantiate(dentry, inode);
862 	ret = 0;
863 fail:
864 	btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
865 dec_and_free:
866 	if (snapshot_force_cow)
867 		atomic_dec(&root->snapshot_force_cow);
868 	if (atomic_dec_and_test(&root->will_be_snapshotted))
869 		wake_up_var(&root->will_be_snapshotted);
870 free_pending:
871 	kfree(pending_snapshot->root_item);
872 	btrfs_free_path(pending_snapshot->path);
873 	kfree(pending_snapshot);
874 
875 	return ret;
876 }
877 
878 /*  copy of may_delete in fs/namei.c()
879  *	Check whether we can remove a link victim from directory dir, check
880  *  whether the type of victim is right.
881  *  1. We can't do it if dir is read-only (done in permission())
882  *  2. We should have write and exec permissions on dir
883  *  3. We can't remove anything from append-only dir
884  *  4. We can't do anything with immutable dir (done in permission())
885  *  5. If the sticky bit on dir is set we should either
886  *	a. be owner of dir, or
887  *	b. be owner of victim, or
888  *	c. have CAP_FOWNER capability
889  *  6. If the victim is append-only or immutable we can't do anything with
890  *     links pointing to it.
891  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
892  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
893  *  9. We can't remove a root or mountpoint.
894  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
895  *     nfs_async_unlink().
896  */
897 
898 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
899 {
900 	int error;
901 
902 	if (d_really_is_negative(victim))
903 		return -ENOENT;
904 
905 	BUG_ON(d_inode(victim->d_parent) != dir);
906 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
907 
908 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
909 	if (error)
910 		return error;
911 	if (IS_APPEND(dir))
912 		return -EPERM;
913 	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
914 	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
915 		return -EPERM;
916 	if (isdir) {
917 		if (!d_is_dir(victim))
918 			return -ENOTDIR;
919 		if (IS_ROOT(victim))
920 			return -EBUSY;
921 	} else if (d_is_dir(victim))
922 		return -EISDIR;
923 	if (IS_DEADDIR(dir))
924 		return -ENOENT;
925 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
926 		return -EBUSY;
927 	return 0;
928 }
929 
930 /* copy of may_create in fs/namei.c() */
931 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
932 {
933 	if (d_really_is_positive(child))
934 		return -EEXIST;
935 	if (IS_DEADDIR(dir))
936 		return -ENOENT;
937 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
938 }
939 
940 /*
941  * Create a new subvolume below @parent.  This is largely modeled after
942  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
943  * inside this filesystem so it's quite a bit simpler.
944  */
945 static noinline int btrfs_mksubvol(const struct path *parent,
946 				   const char *name, int namelen,
947 				   struct btrfs_root *snap_src,
948 				   u64 *async_transid, bool readonly,
949 				   struct btrfs_qgroup_inherit *inherit)
950 {
951 	struct inode *dir = d_inode(parent->dentry);
952 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
953 	struct dentry *dentry;
954 	int error;
955 
956 	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
957 	if (error == -EINTR)
958 		return error;
959 
960 	dentry = lookup_one_len(name, parent->dentry, namelen);
961 	error = PTR_ERR(dentry);
962 	if (IS_ERR(dentry))
963 		goto out_unlock;
964 
965 	error = btrfs_may_create(dir, dentry);
966 	if (error)
967 		goto out_dput;
968 
969 	/*
970 	 * even if this name doesn't exist, we may get hash collisions.
971 	 * check for them now when we can safely fail
972 	 */
973 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
974 					       dir->i_ino, name,
975 					       namelen);
976 	if (error)
977 		goto out_dput;
978 
979 	down_read(&fs_info->subvol_sem);
980 
981 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
982 		goto out_up_read;
983 
984 	if (snap_src) {
985 		error = create_snapshot(snap_src, dir, dentry,
986 					async_transid, readonly, inherit);
987 	} else {
988 		error = create_subvol(dir, dentry, name, namelen,
989 				      async_transid, inherit);
990 	}
991 	if (!error)
992 		fsnotify_mkdir(dir, dentry);
993 out_up_read:
994 	up_read(&fs_info->subvol_sem);
995 out_dput:
996 	dput(dentry);
997 out_unlock:
998 	inode_unlock(dir);
999 	return error;
1000 }
1001 
1002 /*
1003  * When we're defragging a range, we don't want to kick it off again
1004  * if it is really just waiting for delalloc to send it down.
1005  * If we find a nice big extent or delalloc range for the bytes in the
1006  * file you want to defrag, we return 0 to let you know to skip this
1007  * part of the file
1008  */
1009 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1010 {
1011 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1012 	struct extent_map *em = NULL;
1013 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1014 	u64 end;
1015 
1016 	read_lock(&em_tree->lock);
1017 	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1018 	read_unlock(&em_tree->lock);
1019 
1020 	if (em) {
1021 		end = extent_map_end(em);
1022 		free_extent_map(em);
1023 		if (end - offset > thresh)
1024 			return 0;
1025 	}
1026 	/* if we already have a nice delalloc here, just stop */
1027 	thresh /= 2;
1028 	end = count_range_bits(io_tree, &offset, offset + thresh,
1029 			       thresh, EXTENT_DELALLOC, 1);
1030 	if (end >= thresh)
1031 		return 0;
1032 	return 1;
1033 }
1034 
1035 /*
1036  * helper function to walk through a file and find extents
1037  * newer than a specific transid, and smaller than thresh.
1038  *
1039  * This is used by the defragging code to find new and small
1040  * extents
1041  */
1042 static int find_new_extents(struct btrfs_root *root,
1043 			    struct inode *inode, u64 newer_than,
1044 			    u64 *off, u32 thresh)
1045 {
1046 	struct btrfs_path *path;
1047 	struct btrfs_key min_key;
1048 	struct extent_buffer *leaf;
1049 	struct btrfs_file_extent_item *extent;
1050 	int type;
1051 	int ret;
1052 	u64 ino = btrfs_ino(BTRFS_I(inode));
1053 
1054 	path = btrfs_alloc_path();
1055 	if (!path)
1056 		return -ENOMEM;
1057 
1058 	min_key.objectid = ino;
1059 	min_key.type = BTRFS_EXTENT_DATA_KEY;
1060 	min_key.offset = *off;
1061 
1062 	while (1) {
1063 		ret = btrfs_search_forward(root, &min_key, path, newer_than);
1064 		if (ret != 0)
1065 			goto none;
1066 process_slot:
1067 		if (min_key.objectid != ino)
1068 			goto none;
1069 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1070 			goto none;
1071 
1072 		leaf = path->nodes[0];
1073 		extent = btrfs_item_ptr(leaf, path->slots[0],
1074 					struct btrfs_file_extent_item);
1075 
1076 		type = btrfs_file_extent_type(leaf, extent);
1077 		if (type == BTRFS_FILE_EXTENT_REG &&
1078 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1079 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
1080 			*off = min_key.offset;
1081 			btrfs_free_path(path);
1082 			return 0;
1083 		}
1084 
1085 		path->slots[0]++;
1086 		if (path->slots[0] < btrfs_header_nritems(leaf)) {
1087 			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1088 			goto process_slot;
1089 		}
1090 
1091 		if (min_key.offset == (u64)-1)
1092 			goto none;
1093 
1094 		min_key.offset++;
1095 		btrfs_release_path(path);
1096 	}
1097 none:
1098 	btrfs_free_path(path);
1099 	return -ENOENT;
1100 }
1101 
1102 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1103 {
1104 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1105 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1106 	struct extent_map *em;
1107 	u64 len = PAGE_SIZE;
1108 
1109 	/*
1110 	 * hopefully we have this extent in the tree already, try without
1111 	 * the full extent lock
1112 	 */
1113 	read_lock(&em_tree->lock);
1114 	em = lookup_extent_mapping(em_tree, start, len);
1115 	read_unlock(&em_tree->lock);
1116 
1117 	if (!em) {
1118 		struct extent_state *cached = NULL;
1119 		u64 end = start + len - 1;
1120 
1121 		/* get the big lock and read metadata off disk */
1122 		lock_extent_bits(io_tree, start, end, &cached);
1123 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1124 		unlock_extent_cached(io_tree, start, end, &cached);
1125 
1126 		if (IS_ERR(em))
1127 			return NULL;
1128 	}
1129 
1130 	return em;
1131 }
1132 
1133 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1134 {
1135 	struct extent_map *next;
1136 	bool ret = true;
1137 
1138 	/* this is the last extent */
1139 	if (em->start + em->len >= i_size_read(inode))
1140 		return false;
1141 
1142 	next = defrag_lookup_extent(inode, em->start + em->len);
1143 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1144 		ret = false;
1145 	else if ((em->block_start + em->block_len == next->block_start) &&
1146 		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1147 		ret = false;
1148 
1149 	free_extent_map(next);
1150 	return ret;
1151 }
1152 
1153 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1154 			       u64 *last_len, u64 *skip, u64 *defrag_end,
1155 			       int compress)
1156 {
1157 	struct extent_map *em;
1158 	int ret = 1;
1159 	bool next_mergeable = true;
1160 	bool prev_mergeable = true;
1161 
1162 	/*
1163 	 * make sure that once we start defragging an extent, we keep on
1164 	 * defragging it
1165 	 */
1166 	if (start < *defrag_end)
1167 		return 1;
1168 
1169 	*skip = 0;
1170 
1171 	em = defrag_lookup_extent(inode, start);
1172 	if (!em)
1173 		return 0;
1174 
1175 	/* this will cover holes, and inline extents */
1176 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1177 		ret = 0;
1178 		goto out;
1179 	}
1180 
1181 	if (!*defrag_end)
1182 		prev_mergeable = false;
1183 
1184 	next_mergeable = defrag_check_next_extent(inode, em);
1185 	/*
1186 	 * we hit a real extent, if it is big or the next extent is not a
1187 	 * real extent, don't bother defragging it
1188 	 */
1189 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1190 	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1191 		ret = 0;
1192 out:
1193 	/*
1194 	 * last_len ends up being a counter of how many bytes we've defragged.
1195 	 * every time we choose not to defrag an extent, we reset *last_len
1196 	 * so that the next tiny extent will force a defrag.
1197 	 *
1198 	 * The end result of this is that tiny extents before a single big
1199 	 * extent will force at least part of that big extent to be defragged.
1200 	 */
1201 	if (ret) {
1202 		*defrag_end = extent_map_end(em);
1203 	} else {
1204 		*last_len = 0;
1205 		*skip = extent_map_end(em);
1206 		*defrag_end = 0;
1207 	}
1208 
1209 	free_extent_map(em);
1210 	return ret;
1211 }
1212 
1213 /*
1214  * it doesn't do much good to defrag one or two pages
1215  * at a time.  This pulls in a nice chunk of pages
1216  * to COW and defrag.
1217  *
1218  * It also makes sure the delalloc code has enough
1219  * dirty data to avoid making new small extents as part
1220  * of the defrag
1221  *
1222  * It's a good idea to start RA on this range
1223  * before calling this.
1224  */
1225 static int cluster_pages_for_defrag(struct inode *inode,
1226 				    struct page **pages,
1227 				    unsigned long start_index,
1228 				    unsigned long num_pages)
1229 {
1230 	unsigned long file_end;
1231 	u64 isize = i_size_read(inode);
1232 	u64 page_start;
1233 	u64 page_end;
1234 	u64 page_cnt;
1235 	int ret;
1236 	int i;
1237 	int i_done;
1238 	struct btrfs_ordered_extent *ordered;
1239 	struct extent_state *cached_state = NULL;
1240 	struct extent_io_tree *tree;
1241 	struct extent_changeset *data_reserved = NULL;
1242 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1243 
1244 	file_end = (isize - 1) >> PAGE_SHIFT;
1245 	if (!isize || start_index > file_end)
1246 		return 0;
1247 
1248 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1249 
1250 	ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1251 			start_index << PAGE_SHIFT,
1252 			page_cnt << PAGE_SHIFT);
1253 	if (ret)
1254 		return ret;
1255 	i_done = 0;
1256 	tree = &BTRFS_I(inode)->io_tree;
1257 
1258 	/* step one, lock all the pages */
1259 	for (i = 0; i < page_cnt; i++) {
1260 		struct page *page;
1261 again:
1262 		page = find_or_create_page(inode->i_mapping,
1263 					   start_index + i, mask);
1264 		if (!page)
1265 			break;
1266 
1267 		page_start = page_offset(page);
1268 		page_end = page_start + PAGE_SIZE - 1;
1269 		while (1) {
1270 			lock_extent_bits(tree, page_start, page_end,
1271 					 &cached_state);
1272 			ordered = btrfs_lookup_ordered_extent(inode,
1273 							      page_start);
1274 			unlock_extent_cached(tree, page_start, page_end,
1275 					     &cached_state);
1276 			if (!ordered)
1277 				break;
1278 
1279 			unlock_page(page);
1280 			btrfs_start_ordered_extent(inode, ordered, 1);
1281 			btrfs_put_ordered_extent(ordered);
1282 			lock_page(page);
1283 			/*
1284 			 * we unlocked the page above, so we need check if
1285 			 * it was released or not.
1286 			 */
1287 			if (page->mapping != inode->i_mapping) {
1288 				unlock_page(page);
1289 				put_page(page);
1290 				goto again;
1291 			}
1292 		}
1293 
1294 		if (!PageUptodate(page)) {
1295 			btrfs_readpage(NULL, page);
1296 			lock_page(page);
1297 			if (!PageUptodate(page)) {
1298 				unlock_page(page);
1299 				put_page(page);
1300 				ret = -EIO;
1301 				break;
1302 			}
1303 		}
1304 
1305 		if (page->mapping != inode->i_mapping) {
1306 			unlock_page(page);
1307 			put_page(page);
1308 			goto again;
1309 		}
1310 
1311 		pages[i] = page;
1312 		i_done++;
1313 	}
1314 	if (!i_done || ret)
1315 		goto out;
1316 
1317 	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1318 		goto out;
1319 
1320 	/*
1321 	 * so now we have a nice long stream of locked
1322 	 * and up to date pages, lets wait on them
1323 	 */
1324 	for (i = 0; i < i_done; i++)
1325 		wait_on_page_writeback(pages[i]);
1326 
1327 	page_start = page_offset(pages[0]);
1328 	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1329 
1330 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1331 			 page_start, page_end - 1, &cached_state);
1332 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1333 			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1334 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1335 			  &cached_state);
1336 
1337 	if (i_done != page_cnt) {
1338 		spin_lock(&BTRFS_I(inode)->lock);
1339 		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1340 		spin_unlock(&BTRFS_I(inode)->lock);
1341 		btrfs_delalloc_release_space(inode, data_reserved,
1342 				start_index << PAGE_SHIFT,
1343 				(page_cnt - i_done) << PAGE_SHIFT, true);
1344 	}
1345 
1346 
1347 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1348 			  &cached_state);
1349 
1350 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1351 			     page_start, page_end - 1, &cached_state);
1352 
1353 	for (i = 0; i < i_done; i++) {
1354 		clear_page_dirty_for_io(pages[i]);
1355 		ClearPageChecked(pages[i]);
1356 		set_page_extent_mapped(pages[i]);
1357 		set_page_dirty(pages[i]);
1358 		unlock_page(pages[i]);
1359 		put_page(pages[i]);
1360 	}
1361 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1362 				       false);
1363 	extent_changeset_free(data_reserved);
1364 	return i_done;
1365 out:
1366 	for (i = 0; i < i_done; i++) {
1367 		unlock_page(pages[i]);
1368 		put_page(pages[i]);
1369 	}
1370 	btrfs_delalloc_release_space(inode, data_reserved,
1371 			start_index << PAGE_SHIFT,
1372 			page_cnt << PAGE_SHIFT, true);
1373 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1374 				       true);
1375 	extent_changeset_free(data_reserved);
1376 	return ret;
1377 
1378 }
1379 
1380 int btrfs_defrag_file(struct inode *inode, struct file *file,
1381 		      struct btrfs_ioctl_defrag_range_args *range,
1382 		      u64 newer_than, unsigned long max_to_defrag)
1383 {
1384 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1385 	struct btrfs_root *root = BTRFS_I(inode)->root;
1386 	struct file_ra_state *ra = NULL;
1387 	unsigned long last_index;
1388 	u64 isize = i_size_read(inode);
1389 	u64 last_len = 0;
1390 	u64 skip = 0;
1391 	u64 defrag_end = 0;
1392 	u64 newer_off = range->start;
1393 	unsigned long i;
1394 	unsigned long ra_index = 0;
1395 	int ret;
1396 	int defrag_count = 0;
1397 	int compress_type = BTRFS_COMPRESS_ZLIB;
1398 	u32 extent_thresh = range->extent_thresh;
1399 	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1400 	unsigned long cluster = max_cluster;
1401 	u64 new_align = ~((u64)SZ_128K - 1);
1402 	struct page **pages = NULL;
1403 	bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1404 
1405 	if (isize == 0)
1406 		return 0;
1407 
1408 	if (range->start >= isize)
1409 		return -EINVAL;
1410 
1411 	if (do_compress) {
1412 		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1413 			return -EINVAL;
1414 		if (range->compress_type)
1415 			compress_type = range->compress_type;
1416 	}
1417 
1418 	if (extent_thresh == 0)
1419 		extent_thresh = SZ_256K;
1420 
1421 	/*
1422 	 * If we were not given a file, allocate a readahead context. As
1423 	 * readahead is just an optimization, defrag will work without it so
1424 	 * we don't error out.
1425 	 */
1426 	if (!file) {
1427 		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1428 		if (ra)
1429 			file_ra_state_init(ra, inode->i_mapping);
1430 	} else {
1431 		ra = &file->f_ra;
1432 	}
1433 
1434 	pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1435 	if (!pages) {
1436 		ret = -ENOMEM;
1437 		goto out_ra;
1438 	}
1439 
1440 	/* find the last page to defrag */
1441 	if (range->start + range->len > range->start) {
1442 		last_index = min_t(u64, isize - 1,
1443 			 range->start + range->len - 1) >> PAGE_SHIFT;
1444 	} else {
1445 		last_index = (isize - 1) >> PAGE_SHIFT;
1446 	}
1447 
1448 	if (newer_than) {
1449 		ret = find_new_extents(root, inode, newer_than,
1450 				       &newer_off, SZ_64K);
1451 		if (!ret) {
1452 			range->start = newer_off;
1453 			/*
1454 			 * we always align our defrag to help keep
1455 			 * the extents in the file evenly spaced
1456 			 */
1457 			i = (newer_off & new_align) >> PAGE_SHIFT;
1458 		} else
1459 			goto out_ra;
1460 	} else {
1461 		i = range->start >> PAGE_SHIFT;
1462 	}
1463 	if (!max_to_defrag)
1464 		max_to_defrag = last_index - i + 1;
1465 
1466 	/*
1467 	 * make writeback starts from i, so the defrag range can be
1468 	 * written sequentially.
1469 	 */
1470 	if (i < inode->i_mapping->writeback_index)
1471 		inode->i_mapping->writeback_index = i;
1472 
1473 	while (i <= last_index && defrag_count < max_to_defrag &&
1474 	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1475 		/*
1476 		 * make sure we stop running if someone unmounts
1477 		 * the FS
1478 		 */
1479 		if (!(inode->i_sb->s_flags & SB_ACTIVE))
1480 			break;
1481 
1482 		if (btrfs_defrag_cancelled(fs_info)) {
1483 			btrfs_debug(fs_info, "defrag_file cancelled");
1484 			ret = -EAGAIN;
1485 			break;
1486 		}
1487 
1488 		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1489 					 extent_thresh, &last_len, &skip,
1490 					 &defrag_end, do_compress)){
1491 			unsigned long next;
1492 			/*
1493 			 * the should_defrag function tells us how much to skip
1494 			 * bump our counter by the suggested amount
1495 			 */
1496 			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1497 			i = max(i + 1, next);
1498 			continue;
1499 		}
1500 
1501 		if (!newer_than) {
1502 			cluster = (PAGE_ALIGN(defrag_end) >>
1503 				   PAGE_SHIFT) - i;
1504 			cluster = min(cluster, max_cluster);
1505 		} else {
1506 			cluster = max_cluster;
1507 		}
1508 
1509 		if (i + cluster > ra_index) {
1510 			ra_index = max(i, ra_index);
1511 			if (ra)
1512 				page_cache_sync_readahead(inode->i_mapping, ra,
1513 						file, ra_index, cluster);
1514 			ra_index += cluster;
1515 		}
1516 
1517 		inode_lock(inode);
1518 		if (IS_SWAPFILE(inode)) {
1519 			ret = -ETXTBSY;
1520 		} else {
1521 			if (do_compress)
1522 				BTRFS_I(inode)->defrag_compress = compress_type;
1523 			ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1524 		}
1525 		if (ret < 0) {
1526 			inode_unlock(inode);
1527 			goto out_ra;
1528 		}
1529 
1530 		defrag_count += ret;
1531 		balance_dirty_pages_ratelimited(inode->i_mapping);
1532 		inode_unlock(inode);
1533 
1534 		if (newer_than) {
1535 			if (newer_off == (u64)-1)
1536 				break;
1537 
1538 			if (ret > 0)
1539 				i += ret;
1540 
1541 			newer_off = max(newer_off + 1,
1542 					(u64)i << PAGE_SHIFT);
1543 
1544 			ret = find_new_extents(root, inode, newer_than,
1545 					       &newer_off, SZ_64K);
1546 			if (!ret) {
1547 				range->start = newer_off;
1548 				i = (newer_off & new_align) >> PAGE_SHIFT;
1549 			} else {
1550 				break;
1551 			}
1552 		} else {
1553 			if (ret > 0) {
1554 				i += ret;
1555 				last_len += ret << PAGE_SHIFT;
1556 			} else {
1557 				i++;
1558 				last_len = 0;
1559 			}
1560 		}
1561 	}
1562 
1563 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1564 		filemap_flush(inode->i_mapping);
1565 		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1566 			     &BTRFS_I(inode)->runtime_flags))
1567 			filemap_flush(inode->i_mapping);
1568 	}
1569 
1570 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1571 		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1572 	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1573 		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1574 	}
1575 
1576 	ret = defrag_count;
1577 
1578 out_ra:
1579 	if (do_compress) {
1580 		inode_lock(inode);
1581 		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1582 		inode_unlock(inode);
1583 	}
1584 	if (!file)
1585 		kfree(ra);
1586 	kfree(pages);
1587 	return ret;
1588 }
1589 
1590 static noinline int btrfs_ioctl_resize(struct file *file,
1591 					void __user *arg)
1592 {
1593 	struct inode *inode = file_inode(file);
1594 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1595 	u64 new_size;
1596 	u64 old_size;
1597 	u64 devid = 1;
1598 	struct btrfs_root *root = BTRFS_I(inode)->root;
1599 	struct btrfs_ioctl_vol_args *vol_args;
1600 	struct btrfs_trans_handle *trans;
1601 	struct btrfs_device *device = NULL;
1602 	char *sizestr;
1603 	char *retptr;
1604 	char *devstr = NULL;
1605 	int ret = 0;
1606 	int mod = 0;
1607 
1608 	if (!capable(CAP_SYS_ADMIN))
1609 		return -EPERM;
1610 
1611 	ret = mnt_want_write_file(file);
1612 	if (ret)
1613 		return ret;
1614 
1615 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1616 		mnt_drop_write_file(file);
1617 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1618 	}
1619 
1620 	vol_args = memdup_user(arg, sizeof(*vol_args));
1621 	if (IS_ERR(vol_args)) {
1622 		ret = PTR_ERR(vol_args);
1623 		goto out;
1624 	}
1625 
1626 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1627 
1628 	sizestr = vol_args->name;
1629 	devstr = strchr(sizestr, ':');
1630 	if (devstr) {
1631 		sizestr = devstr + 1;
1632 		*devstr = '\0';
1633 		devstr = vol_args->name;
1634 		ret = kstrtoull(devstr, 10, &devid);
1635 		if (ret)
1636 			goto out_free;
1637 		if (!devid) {
1638 			ret = -EINVAL;
1639 			goto out_free;
1640 		}
1641 		btrfs_info(fs_info, "resizing devid %llu", devid);
1642 	}
1643 
1644 	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
1645 	if (!device) {
1646 		btrfs_info(fs_info, "resizer unable to find device %llu",
1647 			   devid);
1648 		ret = -ENODEV;
1649 		goto out_free;
1650 	}
1651 
1652 	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1653 		btrfs_info(fs_info,
1654 			   "resizer unable to apply on readonly device %llu",
1655 		       devid);
1656 		ret = -EPERM;
1657 		goto out_free;
1658 	}
1659 
1660 	if (!strcmp(sizestr, "max"))
1661 		new_size = device->bdev->bd_inode->i_size;
1662 	else {
1663 		if (sizestr[0] == '-') {
1664 			mod = -1;
1665 			sizestr++;
1666 		} else if (sizestr[0] == '+') {
1667 			mod = 1;
1668 			sizestr++;
1669 		}
1670 		new_size = memparse(sizestr, &retptr);
1671 		if (*retptr != '\0' || new_size == 0) {
1672 			ret = -EINVAL;
1673 			goto out_free;
1674 		}
1675 	}
1676 
1677 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1678 		ret = -EPERM;
1679 		goto out_free;
1680 	}
1681 
1682 	old_size = btrfs_device_get_total_bytes(device);
1683 
1684 	if (mod < 0) {
1685 		if (new_size > old_size) {
1686 			ret = -EINVAL;
1687 			goto out_free;
1688 		}
1689 		new_size = old_size - new_size;
1690 	} else if (mod > 0) {
1691 		if (new_size > ULLONG_MAX - old_size) {
1692 			ret = -ERANGE;
1693 			goto out_free;
1694 		}
1695 		new_size = old_size + new_size;
1696 	}
1697 
1698 	if (new_size < SZ_256M) {
1699 		ret = -EINVAL;
1700 		goto out_free;
1701 	}
1702 	if (new_size > device->bdev->bd_inode->i_size) {
1703 		ret = -EFBIG;
1704 		goto out_free;
1705 	}
1706 
1707 	new_size = round_down(new_size, fs_info->sectorsize);
1708 
1709 	btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1710 			  rcu_str_deref(device->name), new_size);
1711 
1712 	if (new_size > old_size) {
1713 		trans = btrfs_start_transaction(root, 0);
1714 		if (IS_ERR(trans)) {
1715 			ret = PTR_ERR(trans);
1716 			goto out_free;
1717 		}
1718 		ret = btrfs_grow_device(trans, device, new_size);
1719 		btrfs_commit_transaction(trans);
1720 	} else if (new_size < old_size) {
1721 		ret = btrfs_shrink_device(device, new_size);
1722 	} /* equal, nothing need to do */
1723 
1724 out_free:
1725 	kfree(vol_args);
1726 out:
1727 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1728 	mnt_drop_write_file(file);
1729 	return ret;
1730 }
1731 
1732 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1733 				const char *name, unsigned long fd, int subvol,
1734 				u64 *transid, bool readonly,
1735 				struct btrfs_qgroup_inherit *inherit)
1736 {
1737 	int namelen;
1738 	int ret = 0;
1739 
1740 	if (!S_ISDIR(file_inode(file)->i_mode))
1741 		return -ENOTDIR;
1742 
1743 	ret = mnt_want_write_file(file);
1744 	if (ret)
1745 		goto out;
1746 
1747 	namelen = strlen(name);
1748 	if (strchr(name, '/')) {
1749 		ret = -EINVAL;
1750 		goto out_drop_write;
1751 	}
1752 
1753 	if (name[0] == '.' &&
1754 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1755 		ret = -EEXIST;
1756 		goto out_drop_write;
1757 	}
1758 
1759 	if (subvol) {
1760 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1761 				     NULL, transid, readonly, inherit);
1762 	} else {
1763 		struct fd src = fdget(fd);
1764 		struct inode *src_inode;
1765 		if (!src.file) {
1766 			ret = -EINVAL;
1767 			goto out_drop_write;
1768 		}
1769 
1770 		src_inode = file_inode(src.file);
1771 		if (src_inode->i_sb != file_inode(file)->i_sb) {
1772 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1773 				   "Snapshot src from another FS");
1774 			ret = -EXDEV;
1775 		} else if (!inode_owner_or_capable(src_inode)) {
1776 			/*
1777 			 * Subvolume creation is not restricted, but snapshots
1778 			 * are limited to own subvolumes only
1779 			 */
1780 			ret = -EPERM;
1781 		} else {
1782 			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1783 					     BTRFS_I(src_inode)->root,
1784 					     transid, readonly, inherit);
1785 		}
1786 		fdput(src);
1787 	}
1788 out_drop_write:
1789 	mnt_drop_write_file(file);
1790 out:
1791 	return ret;
1792 }
1793 
1794 static noinline int btrfs_ioctl_snap_create(struct file *file,
1795 					    void __user *arg, int subvol)
1796 {
1797 	struct btrfs_ioctl_vol_args *vol_args;
1798 	int ret;
1799 
1800 	if (!S_ISDIR(file_inode(file)->i_mode))
1801 		return -ENOTDIR;
1802 
1803 	vol_args = memdup_user(arg, sizeof(*vol_args));
1804 	if (IS_ERR(vol_args))
1805 		return PTR_ERR(vol_args);
1806 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1807 
1808 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1809 					      vol_args->fd, subvol,
1810 					      NULL, false, NULL);
1811 
1812 	kfree(vol_args);
1813 	return ret;
1814 }
1815 
1816 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1817 					       void __user *arg, int subvol)
1818 {
1819 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1820 	int ret;
1821 	u64 transid = 0;
1822 	u64 *ptr = NULL;
1823 	bool readonly = false;
1824 	struct btrfs_qgroup_inherit *inherit = NULL;
1825 
1826 	if (!S_ISDIR(file_inode(file)->i_mode))
1827 		return -ENOTDIR;
1828 
1829 	vol_args = memdup_user(arg, sizeof(*vol_args));
1830 	if (IS_ERR(vol_args))
1831 		return PTR_ERR(vol_args);
1832 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1833 
1834 	if (vol_args->flags &
1835 	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1836 	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1837 		ret = -EOPNOTSUPP;
1838 		goto free_args;
1839 	}
1840 
1841 	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1842 		ptr = &transid;
1843 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1844 		readonly = true;
1845 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1846 		if (vol_args->size > PAGE_SIZE) {
1847 			ret = -EINVAL;
1848 			goto free_args;
1849 		}
1850 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1851 		if (IS_ERR(inherit)) {
1852 			ret = PTR_ERR(inherit);
1853 			goto free_args;
1854 		}
1855 	}
1856 
1857 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1858 					      vol_args->fd, subvol, ptr,
1859 					      readonly, inherit);
1860 	if (ret)
1861 		goto free_inherit;
1862 
1863 	if (ptr && copy_to_user(arg +
1864 				offsetof(struct btrfs_ioctl_vol_args_v2,
1865 					transid),
1866 				ptr, sizeof(*ptr)))
1867 		ret = -EFAULT;
1868 
1869 free_inherit:
1870 	kfree(inherit);
1871 free_args:
1872 	kfree(vol_args);
1873 	return ret;
1874 }
1875 
1876 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1877 						void __user *arg)
1878 {
1879 	struct inode *inode = file_inode(file);
1880 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1881 	struct btrfs_root *root = BTRFS_I(inode)->root;
1882 	int ret = 0;
1883 	u64 flags = 0;
1884 
1885 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1886 		return -EINVAL;
1887 
1888 	down_read(&fs_info->subvol_sem);
1889 	if (btrfs_root_readonly(root))
1890 		flags |= BTRFS_SUBVOL_RDONLY;
1891 	up_read(&fs_info->subvol_sem);
1892 
1893 	if (copy_to_user(arg, &flags, sizeof(flags)))
1894 		ret = -EFAULT;
1895 
1896 	return ret;
1897 }
1898 
1899 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1900 					      void __user *arg)
1901 {
1902 	struct inode *inode = file_inode(file);
1903 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1904 	struct btrfs_root *root = BTRFS_I(inode)->root;
1905 	struct btrfs_trans_handle *trans;
1906 	u64 root_flags;
1907 	u64 flags;
1908 	int ret = 0;
1909 
1910 	if (!inode_owner_or_capable(inode))
1911 		return -EPERM;
1912 
1913 	ret = mnt_want_write_file(file);
1914 	if (ret)
1915 		goto out;
1916 
1917 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1918 		ret = -EINVAL;
1919 		goto out_drop_write;
1920 	}
1921 
1922 	if (copy_from_user(&flags, arg, sizeof(flags))) {
1923 		ret = -EFAULT;
1924 		goto out_drop_write;
1925 	}
1926 
1927 	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1928 		ret = -EINVAL;
1929 		goto out_drop_write;
1930 	}
1931 
1932 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1933 		ret = -EOPNOTSUPP;
1934 		goto out_drop_write;
1935 	}
1936 
1937 	down_write(&fs_info->subvol_sem);
1938 
1939 	/* nothing to do */
1940 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1941 		goto out_drop_sem;
1942 
1943 	root_flags = btrfs_root_flags(&root->root_item);
1944 	if (flags & BTRFS_SUBVOL_RDONLY) {
1945 		btrfs_set_root_flags(&root->root_item,
1946 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1947 	} else {
1948 		/*
1949 		 * Block RO -> RW transition if this subvolume is involved in
1950 		 * send
1951 		 */
1952 		spin_lock(&root->root_item_lock);
1953 		if (root->send_in_progress == 0) {
1954 			btrfs_set_root_flags(&root->root_item,
1955 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1956 			spin_unlock(&root->root_item_lock);
1957 		} else {
1958 			spin_unlock(&root->root_item_lock);
1959 			btrfs_warn(fs_info,
1960 				   "Attempt to set subvolume %llu read-write during send",
1961 				   root->root_key.objectid);
1962 			ret = -EPERM;
1963 			goto out_drop_sem;
1964 		}
1965 	}
1966 
1967 	trans = btrfs_start_transaction(root, 1);
1968 	if (IS_ERR(trans)) {
1969 		ret = PTR_ERR(trans);
1970 		goto out_reset;
1971 	}
1972 
1973 	ret = btrfs_update_root(trans, fs_info->tree_root,
1974 				&root->root_key, &root->root_item);
1975 	if (ret < 0) {
1976 		btrfs_end_transaction(trans);
1977 		goto out_reset;
1978 	}
1979 
1980 	ret = btrfs_commit_transaction(trans);
1981 
1982 out_reset:
1983 	if (ret)
1984 		btrfs_set_root_flags(&root->root_item, root_flags);
1985 out_drop_sem:
1986 	up_write(&fs_info->subvol_sem);
1987 out_drop_write:
1988 	mnt_drop_write_file(file);
1989 out:
1990 	return ret;
1991 }
1992 
1993 static noinline int key_in_sk(struct btrfs_key *key,
1994 			      struct btrfs_ioctl_search_key *sk)
1995 {
1996 	struct btrfs_key test;
1997 	int ret;
1998 
1999 	test.objectid = sk->min_objectid;
2000 	test.type = sk->min_type;
2001 	test.offset = sk->min_offset;
2002 
2003 	ret = btrfs_comp_cpu_keys(key, &test);
2004 	if (ret < 0)
2005 		return 0;
2006 
2007 	test.objectid = sk->max_objectid;
2008 	test.type = sk->max_type;
2009 	test.offset = sk->max_offset;
2010 
2011 	ret = btrfs_comp_cpu_keys(key, &test);
2012 	if (ret > 0)
2013 		return 0;
2014 	return 1;
2015 }
2016 
2017 static noinline int copy_to_sk(struct btrfs_path *path,
2018 			       struct btrfs_key *key,
2019 			       struct btrfs_ioctl_search_key *sk,
2020 			       size_t *buf_size,
2021 			       char __user *ubuf,
2022 			       unsigned long *sk_offset,
2023 			       int *num_found)
2024 {
2025 	u64 found_transid;
2026 	struct extent_buffer *leaf;
2027 	struct btrfs_ioctl_search_header sh;
2028 	struct btrfs_key test;
2029 	unsigned long item_off;
2030 	unsigned long item_len;
2031 	int nritems;
2032 	int i;
2033 	int slot;
2034 	int ret = 0;
2035 
2036 	leaf = path->nodes[0];
2037 	slot = path->slots[0];
2038 	nritems = btrfs_header_nritems(leaf);
2039 
2040 	if (btrfs_header_generation(leaf) > sk->max_transid) {
2041 		i = nritems;
2042 		goto advance_key;
2043 	}
2044 	found_transid = btrfs_header_generation(leaf);
2045 
2046 	for (i = slot; i < nritems; i++) {
2047 		item_off = btrfs_item_ptr_offset(leaf, i);
2048 		item_len = btrfs_item_size_nr(leaf, i);
2049 
2050 		btrfs_item_key_to_cpu(leaf, key, i);
2051 		if (!key_in_sk(key, sk))
2052 			continue;
2053 
2054 		if (sizeof(sh) + item_len > *buf_size) {
2055 			if (*num_found) {
2056 				ret = 1;
2057 				goto out;
2058 			}
2059 
2060 			/*
2061 			 * return one empty item back for v1, which does not
2062 			 * handle -EOVERFLOW
2063 			 */
2064 
2065 			*buf_size = sizeof(sh) + item_len;
2066 			item_len = 0;
2067 			ret = -EOVERFLOW;
2068 		}
2069 
2070 		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2071 			ret = 1;
2072 			goto out;
2073 		}
2074 
2075 		sh.objectid = key->objectid;
2076 		sh.offset = key->offset;
2077 		sh.type = key->type;
2078 		sh.len = item_len;
2079 		sh.transid = found_transid;
2080 
2081 		/* copy search result header */
2082 		if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2083 			ret = -EFAULT;
2084 			goto out;
2085 		}
2086 
2087 		*sk_offset += sizeof(sh);
2088 
2089 		if (item_len) {
2090 			char __user *up = ubuf + *sk_offset;
2091 			/* copy the item */
2092 			if (read_extent_buffer_to_user(leaf, up,
2093 						       item_off, item_len)) {
2094 				ret = -EFAULT;
2095 				goto out;
2096 			}
2097 
2098 			*sk_offset += item_len;
2099 		}
2100 		(*num_found)++;
2101 
2102 		if (ret) /* -EOVERFLOW from above */
2103 			goto out;
2104 
2105 		if (*num_found >= sk->nr_items) {
2106 			ret = 1;
2107 			goto out;
2108 		}
2109 	}
2110 advance_key:
2111 	ret = 0;
2112 	test.objectid = sk->max_objectid;
2113 	test.type = sk->max_type;
2114 	test.offset = sk->max_offset;
2115 	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2116 		ret = 1;
2117 	else if (key->offset < (u64)-1)
2118 		key->offset++;
2119 	else if (key->type < (u8)-1) {
2120 		key->offset = 0;
2121 		key->type++;
2122 	} else if (key->objectid < (u64)-1) {
2123 		key->offset = 0;
2124 		key->type = 0;
2125 		key->objectid++;
2126 	} else
2127 		ret = 1;
2128 out:
2129 	/*
2130 	 *  0: all items from this leaf copied, continue with next
2131 	 *  1: * more items can be copied, but unused buffer is too small
2132 	 *     * all items were found
2133 	 *     Either way, it will stops the loop which iterates to the next
2134 	 *     leaf
2135 	 *  -EOVERFLOW: item was to large for buffer
2136 	 *  -EFAULT: could not copy extent buffer back to userspace
2137 	 */
2138 	return ret;
2139 }
2140 
2141 static noinline int search_ioctl(struct inode *inode,
2142 				 struct btrfs_ioctl_search_key *sk,
2143 				 size_t *buf_size,
2144 				 char __user *ubuf)
2145 {
2146 	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2147 	struct btrfs_root *root;
2148 	struct btrfs_key key;
2149 	struct btrfs_path *path;
2150 	int ret;
2151 	int num_found = 0;
2152 	unsigned long sk_offset = 0;
2153 
2154 	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2155 		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2156 		return -EOVERFLOW;
2157 	}
2158 
2159 	path = btrfs_alloc_path();
2160 	if (!path)
2161 		return -ENOMEM;
2162 
2163 	if (sk->tree_id == 0) {
2164 		/* search the root of the inode that was passed */
2165 		root = BTRFS_I(inode)->root;
2166 	} else {
2167 		key.objectid = sk->tree_id;
2168 		key.type = BTRFS_ROOT_ITEM_KEY;
2169 		key.offset = (u64)-1;
2170 		root = btrfs_read_fs_root_no_name(info, &key);
2171 		if (IS_ERR(root)) {
2172 			btrfs_free_path(path);
2173 			return PTR_ERR(root);
2174 		}
2175 	}
2176 
2177 	key.objectid = sk->min_objectid;
2178 	key.type = sk->min_type;
2179 	key.offset = sk->min_offset;
2180 
2181 	while (1) {
2182 		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2183 		if (ret != 0) {
2184 			if (ret > 0)
2185 				ret = 0;
2186 			goto err;
2187 		}
2188 		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2189 				 &sk_offset, &num_found);
2190 		btrfs_release_path(path);
2191 		if (ret)
2192 			break;
2193 
2194 	}
2195 	if (ret > 0)
2196 		ret = 0;
2197 err:
2198 	sk->nr_items = num_found;
2199 	btrfs_free_path(path);
2200 	return ret;
2201 }
2202 
2203 static noinline int btrfs_ioctl_tree_search(struct file *file,
2204 					   void __user *argp)
2205 {
2206 	struct btrfs_ioctl_search_args __user *uargs;
2207 	struct btrfs_ioctl_search_key sk;
2208 	struct inode *inode;
2209 	int ret;
2210 	size_t buf_size;
2211 
2212 	if (!capable(CAP_SYS_ADMIN))
2213 		return -EPERM;
2214 
2215 	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2216 
2217 	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2218 		return -EFAULT;
2219 
2220 	buf_size = sizeof(uargs->buf);
2221 
2222 	inode = file_inode(file);
2223 	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2224 
2225 	/*
2226 	 * In the origin implementation an overflow is handled by returning a
2227 	 * search header with a len of zero, so reset ret.
2228 	 */
2229 	if (ret == -EOVERFLOW)
2230 		ret = 0;
2231 
2232 	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2233 		ret = -EFAULT;
2234 	return ret;
2235 }
2236 
2237 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2238 					       void __user *argp)
2239 {
2240 	struct btrfs_ioctl_search_args_v2 __user *uarg;
2241 	struct btrfs_ioctl_search_args_v2 args;
2242 	struct inode *inode;
2243 	int ret;
2244 	size_t buf_size;
2245 	const size_t buf_limit = SZ_16M;
2246 
2247 	if (!capable(CAP_SYS_ADMIN))
2248 		return -EPERM;
2249 
2250 	/* copy search header and buffer size */
2251 	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2252 	if (copy_from_user(&args, uarg, sizeof(args)))
2253 		return -EFAULT;
2254 
2255 	buf_size = args.buf_size;
2256 
2257 	/* limit result size to 16MB */
2258 	if (buf_size > buf_limit)
2259 		buf_size = buf_limit;
2260 
2261 	inode = file_inode(file);
2262 	ret = search_ioctl(inode, &args.key, &buf_size,
2263 			   (char __user *)(&uarg->buf[0]));
2264 	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2265 		ret = -EFAULT;
2266 	else if (ret == -EOVERFLOW &&
2267 		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2268 		ret = -EFAULT;
2269 
2270 	return ret;
2271 }
2272 
2273 /*
2274  * Search INODE_REFs to identify path name of 'dirid' directory
2275  * in a 'tree_id' tree. and sets path name to 'name'.
2276  */
2277 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2278 				u64 tree_id, u64 dirid, char *name)
2279 {
2280 	struct btrfs_root *root;
2281 	struct btrfs_key key;
2282 	char *ptr;
2283 	int ret = -1;
2284 	int slot;
2285 	int len;
2286 	int total_len = 0;
2287 	struct btrfs_inode_ref *iref;
2288 	struct extent_buffer *l;
2289 	struct btrfs_path *path;
2290 
2291 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2292 		name[0]='\0';
2293 		return 0;
2294 	}
2295 
2296 	path = btrfs_alloc_path();
2297 	if (!path)
2298 		return -ENOMEM;
2299 
2300 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2301 
2302 	key.objectid = tree_id;
2303 	key.type = BTRFS_ROOT_ITEM_KEY;
2304 	key.offset = (u64)-1;
2305 	root = btrfs_read_fs_root_no_name(info, &key);
2306 	if (IS_ERR(root)) {
2307 		ret = PTR_ERR(root);
2308 		goto out;
2309 	}
2310 
2311 	key.objectid = dirid;
2312 	key.type = BTRFS_INODE_REF_KEY;
2313 	key.offset = (u64)-1;
2314 
2315 	while (1) {
2316 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2317 		if (ret < 0)
2318 			goto out;
2319 		else if (ret > 0) {
2320 			ret = btrfs_previous_item(root, path, dirid,
2321 						  BTRFS_INODE_REF_KEY);
2322 			if (ret < 0)
2323 				goto out;
2324 			else if (ret > 0) {
2325 				ret = -ENOENT;
2326 				goto out;
2327 			}
2328 		}
2329 
2330 		l = path->nodes[0];
2331 		slot = path->slots[0];
2332 		btrfs_item_key_to_cpu(l, &key, slot);
2333 
2334 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2335 		len = btrfs_inode_ref_name_len(l, iref);
2336 		ptr -= len + 1;
2337 		total_len += len + 1;
2338 		if (ptr < name) {
2339 			ret = -ENAMETOOLONG;
2340 			goto out;
2341 		}
2342 
2343 		*(ptr + len) = '/';
2344 		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2345 
2346 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2347 			break;
2348 
2349 		btrfs_release_path(path);
2350 		key.objectid = key.offset;
2351 		key.offset = (u64)-1;
2352 		dirid = key.objectid;
2353 	}
2354 	memmove(name, ptr, total_len);
2355 	name[total_len] = '\0';
2356 	ret = 0;
2357 out:
2358 	btrfs_free_path(path);
2359 	return ret;
2360 }
2361 
2362 static int btrfs_search_path_in_tree_user(struct inode *inode,
2363 				struct btrfs_ioctl_ino_lookup_user_args *args)
2364 {
2365 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2366 	struct super_block *sb = inode->i_sb;
2367 	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2368 	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2369 	u64 dirid = args->dirid;
2370 	unsigned long item_off;
2371 	unsigned long item_len;
2372 	struct btrfs_inode_ref *iref;
2373 	struct btrfs_root_ref *rref;
2374 	struct btrfs_root *root;
2375 	struct btrfs_path *path;
2376 	struct btrfs_key key, key2;
2377 	struct extent_buffer *leaf;
2378 	struct inode *temp_inode;
2379 	char *ptr;
2380 	int slot;
2381 	int len;
2382 	int total_len = 0;
2383 	int ret;
2384 
2385 	path = btrfs_alloc_path();
2386 	if (!path)
2387 		return -ENOMEM;
2388 
2389 	/*
2390 	 * If the bottom subvolume does not exist directly under upper_limit,
2391 	 * construct the path in from the bottom up.
2392 	 */
2393 	if (dirid != upper_limit.objectid) {
2394 		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2395 
2396 		key.objectid = treeid;
2397 		key.type = BTRFS_ROOT_ITEM_KEY;
2398 		key.offset = (u64)-1;
2399 		root = btrfs_read_fs_root_no_name(fs_info, &key);
2400 		if (IS_ERR(root)) {
2401 			ret = PTR_ERR(root);
2402 			goto out;
2403 		}
2404 
2405 		key.objectid = dirid;
2406 		key.type = BTRFS_INODE_REF_KEY;
2407 		key.offset = (u64)-1;
2408 		while (1) {
2409 			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2410 			if (ret < 0) {
2411 				goto out;
2412 			} else if (ret > 0) {
2413 				ret = btrfs_previous_item(root, path, dirid,
2414 							  BTRFS_INODE_REF_KEY);
2415 				if (ret < 0) {
2416 					goto out;
2417 				} else if (ret > 0) {
2418 					ret = -ENOENT;
2419 					goto out;
2420 				}
2421 			}
2422 
2423 			leaf = path->nodes[0];
2424 			slot = path->slots[0];
2425 			btrfs_item_key_to_cpu(leaf, &key, slot);
2426 
2427 			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2428 			len = btrfs_inode_ref_name_len(leaf, iref);
2429 			ptr -= len + 1;
2430 			total_len += len + 1;
2431 			if (ptr < args->path) {
2432 				ret = -ENAMETOOLONG;
2433 				goto out;
2434 			}
2435 
2436 			*(ptr + len) = '/';
2437 			read_extent_buffer(leaf, ptr,
2438 					(unsigned long)(iref + 1), len);
2439 
2440 			/* Check the read+exec permission of this directory */
2441 			ret = btrfs_previous_item(root, path, dirid,
2442 						  BTRFS_INODE_ITEM_KEY);
2443 			if (ret < 0) {
2444 				goto out;
2445 			} else if (ret > 0) {
2446 				ret = -ENOENT;
2447 				goto out;
2448 			}
2449 
2450 			leaf = path->nodes[0];
2451 			slot = path->slots[0];
2452 			btrfs_item_key_to_cpu(leaf, &key2, slot);
2453 			if (key2.objectid != dirid) {
2454 				ret = -ENOENT;
2455 				goto out;
2456 			}
2457 
2458 			temp_inode = btrfs_iget(sb, &key2, root, NULL);
2459 			if (IS_ERR(temp_inode)) {
2460 				ret = PTR_ERR(temp_inode);
2461 				goto out;
2462 			}
2463 			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2464 			iput(temp_inode);
2465 			if (ret) {
2466 				ret = -EACCES;
2467 				goto out;
2468 			}
2469 
2470 			if (key.offset == upper_limit.objectid)
2471 				break;
2472 			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2473 				ret = -EACCES;
2474 				goto out;
2475 			}
2476 
2477 			btrfs_release_path(path);
2478 			key.objectid = key.offset;
2479 			key.offset = (u64)-1;
2480 			dirid = key.objectid;
2481 		}
2482 
2483 		memmove(args->path, ptr, total_len);
2484 		args->path[total_len] = '\0';
2485 		btrfs_release_path(path);
2486 	}
2487 
2488 	/* Get the bottom subvolume's name from ROOT_REF */
2489 	root = fs_info->tree_root;
2490 	key.objectid = treeid;
2491 	key.type = BTRFS_ROOT_REF_KEY;
2492 	key.offset = args->treeid;
2493 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2494 	if (ret < 0) {
2495 		goto out;
2496 	} else if (ret > 0) {
2497 		ret = -ENOENT;
2498 		goto out;
2499 	}
2500 
2501 	leaf = path->nodes[0];
2502 	slot = path->slots[0];
2503 	btrfs_item_key_to_cpu(leaf, &key, slot);
2504 
2505 	item_off = btrfs_item_ptr_offset(leaf, slot);
2506 	item_len = btrfs_item_size_nr(leaf, slot);
2507 	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2508 	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2509 	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2510 		ret = -EINVAL;
2511 		goto out;
2512 	}
2513 
2514 	/* Copy subvolume's name */
2515 	item_off += sizeof(struct btrfs_root_ref);
2516 	item_len -= sizeof(struct btrfs_root_ref);
2517 	read_extent_buffer(leaf, args->name, item_off, item_len);
2518 	args->name[item_len] = 0;
2519 
2520 out:
2521 	btrfs_free_path(path);
2522 	return ret;
2523 }
2524 
2525 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2526 					   void __user *argp)
2527 {
2528 	struct btrfs_ioctl_ino_lookup_args *args;
2529 	struct inode *inode;
2530 	int ret = 0;
2531 
2532 	args = memdup_user(argp, sizeof(*args));
2533 	if (IS_ERR(args))
2534 		return PTR_ERR(args);
2535 
2536 	inode = file_inode(file);
2537 
2538 	/*
2539 	 * Unprivileged query to obtain the containing subvolume root id. The
2540 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2541 	 */
2542 	if (args->treeid == 0)
2543 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2544 
2545 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2546 		args->name[0] = 0;
2547 		goto out;
2548 	}
2549 
2550 	if (!capable(CAP_SYS_ADMIN)) {
2551 		ret = -EPERM;
2552 		goto out;
2553 	}
2554 
2555 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2556 					args->treeid, args->objectid,
2557 					args->name);
2558 
2559 out:
2560 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2561 		ret = -EFAULT;
2562 
2563 	kfree(args);
2564 	return ret;
2565 }
2566 
2567 /*
2568  * Version of ino_lookup ioctl (unprivileged)
2569  *
2570  * The main differences from ino_lookup ioctl are:
2571  *
2572  *   1. Read + Exec permission will be checked using inode_permission() during
2573  *      path construction. -EACCES will be returned in case of failure.
2574  *   2. Path construction will be stopped at the inode number which corresponds
2575  *      to the fd with which this ioctl is called. If constructed path does not
2576  *      exist under fd's inode, -EACCES will be returned.
2577  *   3. The name of bottom subvolume is also searched and filled.
2578  */
2579 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2580 {
2581 	struct btrfs_ioctl_ino_lookup_user_args *args;
2582 	struct inode *inode;
2583 	int ret;
2584 
2585 	args = memdup_user(argp, sizeof(*args));
2586 	if (IS_ERR(args))
2587 		return PTR_ERR(args);
2588 
2589 	inode = file_inode(file);
2590 
2591 	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2592 	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2593 		/*
2594 		 * The subvolume does not exist under fd with which this is
2595 		 * called
2596 		 */
2597 		kfree(args);
2598 		return -EACCES;
2599 	}
2600 
2601 	ret = btrfs_search_path_in_tree_user(inode, args);
2602 
2603 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2604 		ret = -EFAULT;
2605 
2606 	kfree(args);
2607 	return ret;
2608 }
2609 
2610 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2611 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2612 {
2613 	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2614 	struct btrfs_fs_info *fs_info;
2615 	struct btrfs_root *root;
2616 	struct btrfs_path *path;
2617 	struct btrfs_key key;
2618 	struct btrfs_root_item *root_item;
2619 	struct btrfs_root_ref *rref;
2620 	struct extent_buffer *leaf;
2621 	unsigned long item_off;
2622 	unsigned long item_len;
2623 	struct inode *inode;
2624 	int slot;
2625 	int ret = 0;
2626 
2627 	path = btrfs_alloc_path();
2628 	if (!path)
2629 		return -ENOMEM;
2630 
2631 	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2632 	if (!subvol_info) {
2633 		btrfs_free_path(path);
2634 		return -ENOMEM;
2635 	}
2636 
2637 	inode = file_inode(file);
2638 	fs_info = BTRFS_I(inode)->root->fs_info;
2639 
2640 	/* Get root_item of inode's subvolume */
2641 	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2642 	key.type = BTRFS_ROOT_ITEM_KEY;
2643 	key.offset = (u64)-1;
2644 	root = btrfs_read_fs_root_no_name(fs_info, &key);
2645 	if (IS_ERR(root)) {
2646 		ret = PTR_ERR(root);
2647 		goto out;
2648 	}
2649 	root_item = &root->root_item;
2650 
2651 	subvol_info->treeid = key.objectid;
2652 
2653 	subvol_info->generation = btrfs_root_generation(root_item);
2654 	subvol_info->flags = btrfs_root_flags(root_item);
2655 
2656 	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2657 	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2658 						    BTRFS_UUID_SIZE);
2659 	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2660 						    BTRFS_UUID_SIZE);
2661 
2662 	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2663 	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2664 	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2665 
2666 	subvol_info->otransid = btrfs_root_otransid(root_item);
2667 	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2668 	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2669 
2670 	subvol_info->stransid = btrfs_root_stransid(root_item);
2671 	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2672 	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2673 
2674 	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2675 	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2676 	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2677 
2678 	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2679 		/* Search root tree for ROOT_BACKREF of this subvolume */
2680 		root = fs_info->tree_root;
2681 
2682 		key.type = BTRFS_ROOT_BACKREF_KEY;
2683 		key.offset = 0;
2684 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2685 		if (ret < 0) {
2686 			goto out;
2687 		} else if (path->slots[0] >=
2688 			   btrfs_header_nritems(path->nodes[0])) {
2689 			ret = btrfs_next_leaf(root, path);
2690 			if (ret < 0) {
2691 				goto out;
2692 			} else if (ret > 0) {
2693 				ret = -EUCLEAN;
2694 				goto out;
2695 			}
2696 		}
2697 
2698 		leaf = path->nodes[0];
2699 		slot = path->slots[0];
2700 		btrfs_item_key_to_cpu(leaf, &key, slot);
2701 		if (key.objectid == subvol_info->treeid &&
2702 		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2703 			subvol_info->parent_id = key.offset;
2704 
2705 			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2706 			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2707 
2708 			item_off = btrfs_item_ptr_offset(leaf, slot)
2709 					+ sizeof(struct btrfs_root_ref);
2710 			item_len = btrfs_item_size_nr(leaf, slot)
2711 					- sizeof(struct btrfs_root_ref);
2712 			read_extent_buffer(leaf, subvol_info->name,
2713 					   item_off, item_len);
2714 		} else {
2715 			ret = -ENOENT;
2716 			goto out;
2717 		}
2718 	}
2719 
2720 	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2721 		ret = -EFAULT;
2722 
2723 out:
2724 	btrfs_free_path(path);
2725 	kzfree(subvol_info);
2726 	return ret;
2727 }
2728 
2729 /*
2730  * Return ROOT_REF information of the subvolume containing this inode
2731  * except the subvolume name.
2732  */
2733 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2734 {
2735 	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2736 	struct btrfs_root_ref *rref;
2737 	struct btrfs_root *root;
2738 	struct btrfs_path *path;
2739 	struct btrfs_key key;
2740 	struct extent_buffer *leaf;
2741 	struct inode *inode;
2742 	u64 objectid;
2743 	int slot;
2744 	int ret;
2745 	u8 found;
2746 
2747 	path = btrfs_alloc_path();
2748 	if (!path)
2749 		return -ENOMEM;
2750 
2751 	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2752 	if (IS_ERR(rootrefs)) {
2753 		btrfs_free_path(path);
2754 		return PTR_ERR(rootrefs);
2755 	}
2756 
2757 	inode = file_inode(file);
2758 	root = BTRFS_I(inode)->root->fs_info->tree_root;
2759 	objectid = BTRFS_I(inode)->root->root_key.objectid;
2760 
2761 	key.objectid = objectid;
2762 	key.type = BTRFS_ROOT_REF_KEY;
2763 	key.offset = rootrefs->min_treeid;
2764 	found = 0;
2765 
2766 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2767 	if (ret < 0) {
2768 		goto out;
2769 	} else if (path->slots[0] >=
2770 		   btrfs_header_nritems(path->nodes[0])) {
2771 		ret = btrfs_next_leaf(root, path);
2772 		if (ret < 0) {
2773 			goto out;
2774 		} else if (ret > 0) {
2775 			ret = -EUCLEAN;
2776 			goto out;
2777 		}
2778 	}
2779 	while (1) {
2780 		leaf = path->nodes[0];
2781 		slot = path->slots[0];
2782 
2783 		btrfs_item_key_to_cpu(leaf, &key, slot);
2784 		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2785 			ret = 0;
2786 			goto out;
2787 		}
2788 
2789 		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2790 			ret = -EOVERFLOW;
2791 			goto out;
2792 		}
2793 
2794 		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2795 		rootrefs->rootref[found].treeid = key.offset;
2796 		rootrefs->rootref[found].dirid =
2797 				  btrfs_root_ref_dirid(leaf, rref);
2798 		found++;
2799 
2800 		ret = btrfs_next_item(root, path);
2801 		if (ret < 0) {
2802 			goto out;
2803 		} else if (ret > 0) {
2804 			ret = -EUCLEAN;
2805 			goto out;
2806 		}
2807 	}
2808 
2809 out:
2810 	if (!ret || ret == -EOVERFLOW) {
2811 		rootrefs->num_items = found;
2812 		/* update min_treeid for next search */
2813 		if (found)
2814 			rootrefs->min_treeid =
2815 				rootrefs->rootref[found - 1].treeid + 1;
2816 		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2817 			ret = -EFAULT;
2818 	}
2819 
2820 	kfree(rootrefs);
2821 	btrfs_free_path(path);
2822 
2823 	return ret;
2824 }
2825 
2826 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2827 					     void __user *arg)
2828 {
2829 	struct dentry *parent = file->f_path.dentry;
2830 	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2831 	struct dentry *dentry;
2832 	struct inode *dir = d_inode(parent);
2833 	struct inode *inode;
2834 	struct btrfs_root *root = BTRFS_I(dir)->root;
2835 	struct btrfs_root *dest = NULL;
2836 	struct btrfs_ioctl_vol_args *vol_args;
2837 	int namelen;
2838 	int err = 0;
2839 
2840 	if (!S_ISDIR(dir->i_mode))
2841 		return -ENOTDIR;
2842 
2843 	vol_args = memdup_user(arg, sizeof(*vol_args));
2844 	if (IS_ERR(vol_args))
2845 		return PTR_ERR(vol_args);
2846 
2847 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2848 	namelen = strlen(vol_args->name);
2849 	if (strchr(vol_args->name, '/') ||
2850 	    strncmp(vol_args->name, "..", namelen) == 0) {
2851 		err = -EINVAL;
2852 		goto out;
2853 	}
2854 
2855 	err = mnt_want_write_file(file);
2856 	if (err)
2857 		goto out;
2858 
2859 
2860 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2861 	if (err == -EINTR)
2862 		goto out_drop_write;
2863 	dentry = lookup_one_len(vol_args->name, parent, namelen);
2864 	if (IS_ERR(dentry)) {
2865 		err = PTR_ERR(dentry);
2866 		goto out_unlock_dir;
2867 	}
2868 
2869 	if (d_really_is_negative(dentry)) {
2870 		err = -ENOENT;
2871 		goto out_dput;
2872 	}
2873 
2874 	inode = d_inode(dentry);
2875 	dest = BTRFS_I(inode)->root;
2876 	if (!capable(CAP_SYS_ADMIN)) {
2877 		/*
2878 		 * Regular user.  Only allow this with a special mount
2879 		 * option, when the user has write+exec access to the
2880 		 * subvol root, and when rmdir(2) would have been
2881 		 * allowed.
2882 		 *
2883 		 * Note that this is _not_ check that the subvol is
2884 		 * empty or doesn't contain data that we wouldn't
2885 		 * otherwise be able to delete.
2886 		 *
2887 		 * Users who want to delete empty subvols should try
2888 		 * rmdir(2).
2889 		 */
2890 		err = -EPERM;
2891 		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2892 			goto out_dput;
2893 
2894 		/*
2895 		 * Do not allow deletion if the parent dir is the same
2896 		 * as the dir to be deleted.  That means the ioctl
2897 		 * must be called on the dentry referencing the root
2898 		 * of the subvol, not a random directory contained
2899 		 * within it.
2900 		 */
2901 		err = -EINVAL;
2902 		if (root == dest)
2903 			goto out_dput;
2904 
2905 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2906 		if (err)
2907 			goto out_dput;
2908 	}
2909 
2910 	/* check if subvolume may be deleted by a user */
2911 	err = btrfs_may_delete(dir, dentry, 1);
2912 	if (err)
2913 		goto out_dput;
2914 
2915 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2916 		err = -EINVAL;
2917 		goto out_dput;
2918 	}
2919 
2920 	inode_lock(inode);
2921 	err = btrfs_delete_subvolume(dir, dentry);
2922 	inode_unlock(inode);
2923 	if (!err) {
2924 		fsnotify_rmdir(dir, dentry);
2925 		d_delete(dentry);
2926 	}
2927 
2928 out_dput:
2929 	dput(dentry);
2930 out_unlock_dir:
2931 	inode_unlock(dir);
2932 out_drop_write:
2933 	mnt_drop_write_file(file);
2934 out:
2935 	kfree(vol_args);
2936 	return err;
2937 }
2938 
2939 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2940 {
2941 	struct inode *inode = file_inode(file);
2942 	struct btrfs_root *root = BTRFS_I(inode)->root;
2943 	struct btrfs_ioctl_defrag_range_args *range;
2944 	int ret;
2945 
2946 	ret = mnt_want_write_file(file);
2947 	if (ret)
2948 		return ret;
2949 
2950 	if (btrfs_root_readonly(root)) {
2951 		ret = -EROFS;
2952 		goto out;
2953 	}
2954 
2955 	switch (inode->i_mode & S_IFMT) {
2956 	case S_IFDIR:
2957 		if (!capable(CAP_SYS_ADMIN)) {
2958 			ret = -EPERM;
2959 			goto out;
2960 		}
2961 		ret = btrfs_defrag_root(root);
2962 		break;
2963 	case S_IFREG:
2964 		/*
2965 		 * Note that this does not check the file descriptor for write
2966 		 * access. This prevents defragmenting executables that are
2967 		 * running and allows defrag on files open in read-only mode.
2968 		 */
2969 		if (!capable(CAP_SYS_ADMIN) &&
2970 		    inode_permission(inode, MAY_WRITE)) {
2971 			ret = -EPERM;
2972 			goto out;
2973 		}
2974 
2975 		range = kzalloc(sizeof(*range), GFP_KERNEL);
2976 		if (!range) {
2977 			ret = -ENOMEM;
2978 			goto out;
2979 		}
2980 
2981 		if (argp) {
2982 			if (copy_from_user(range, argp,
2983 					   sizeof(*range))) {
2984 				ret = -EFAULT;
2985 				kfree(range);
2986 				goto out;
2987 			}
2988 			/* compression requires us to start the IO */
2989 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2990 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2991 				range->extent_thresh = (u32)-1;
2992 			}
2993 		} else {
2994 			/* the rest are all set to zero by kzalloc */
2995 			range->len = (u64)-1;
2996 		}
2997 		ret = btrfs_defrag_file(file_inode(file), file,
2998 					range, BTRFS_OLDEST_GENERATION, 0);
2999 		if (ret > 0)
3000 			ret = 0;
3001 		kfree(range);
3002 		break;
3003 	default:
3004 		ret = -EINVAL;
3005 	}
3006 out:
3007 	mnt_drop_write_file(file);
3008 	return ret;
3009 }
3010 
3011 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3012 {
3013 	struct btrfs_ioctl_vol_args *vol_args;
3014 	int ret;
3015 
3016 	if (!capable(CAP_SYS_ADMIN))
3017 		return -EPERM;
3018 
3019 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3020 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3021 
3022 	vol_args = memdup_user(arg, sizeof(*vol_args));
3023 	if (IS_ERR(vol_args)) {
3024 		ret = PTR_ERR(vol_args);
3025 		goto out;
3026 	}
3027 
3028 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3029 	ret = btrfs_init_new_device(fs_info, vol_args->name);
3030 
3031 	if (!ret)
3032 		btrfs_info(fs_info, "disk added %s", vol_args->name);
3033 
3034 	kfree(vol_args);
3035 out:
3036 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3037 	return ret;
3038 }
3039 
3040 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3041 {
3042 	struct inode *inode = file_inode(file);
3043 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3044 	struct btrfs_ioctl_vol_args_v2 *vol_args;
3045 	int ret;
3046 
3047 	if (!capable(CAP_SYS_ADMIN))
3048 		return -EPERM;
3049 
3050 	ret = mnt_want_write_file(file);
3051 	if (ret)
3052 		return ret;
3053 
3054 	vol_args = memdup_user(arg, sizeof(*vol_args));
3055 	if (IS_ERR(vol_args)) {
3056 		ret = PTR_ERR(vol_args);
3057 		goto err_drop;
3058 	}
3059 
3060 	/* Check for compatibility reject unknown flags */
3061 	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3062 		ret = -EOPNOTSUPP;
3063 		goto out;
3064 	}
3065 
3066 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3067 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3068 		goto out;
3069 	}
3070 
3071 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3072 		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3073 	} else {
3074 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3075 		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3076 	}
3077 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3078 
3079 	if (!ret) {
3080 		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3081 			btrfs_info(fs_info, "device deleted: id %llu",
3082 					vol_args->devid);
3083 		else
3084 			btrfs_info(fs_info, "device deleted: %s",
3085 					vol_args->name);
3086 	}
3087 out:
3088 	kfree(vol_args);
3089 err_drop:
3090 	mnt_drop_write_file(file);
3091 	return ret;
3092 }
3093 
3094 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3095 {
3096 	struct inode *inode = file_inode(file);
3097 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3098 	struct btrfs_ioctl_vol_args *vol_args;
3099 	int ret;
3100 
3101 	if (!capable(CAP_SYS_ADMIN))
3102 		return -EPERM;
3103 
3104 	ret = mnt_want_write_file(file);
3105 	if (ret)
3106 		return ret;
3107 
3108 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3109 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3110 		goto out_drop_write;
3111 	}
3112 
3113 	vol_args = memdup_user(arg, sizeof(*vol_args));
3114 	if (IS_ERR(vol_args)) {
3115 		ret = PTR_ERR(vol_args);
3116 		goto out;
3117 	}
3118 
3119 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3120 	ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3121 
3122 	if (!ret)
3123 		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3124 	kfree(vol_args);
3125 out:
3126 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3127 out_drop_write:
3128 	mnt_drop_write_file(file);
3129 
3130 	return ret;
3131 }
3132 
3133 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3134 				void __user *arg)
3135 {
3136 	struct btrfs_ioctl_fs_info_args *fi_args;
3137 	struct btrfs_device *device;
3138 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3139 	int ret = 0;
3140 
3141 	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3142 	if (!fi_args)
3143 		return -ENOMEM;
3144 
3145 	rcu_read_lock();
3146 	fi_args->num_devices = fs_devices->num_devices;
3147 
3148 	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3149 		if (device->devid > fi_args->max_id)
3150 			fi_args->max_id = device->devid;
3151 	}
3152 	rcu_read_unlock();
3153 
3154 	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3155 	fi_args->nodesize = fs_info->nodesize;
3156 	fi_args->sectorsize = fs_info->sectorsize;
3157 	fi_args->clone_alignment = fs_info->sectorsize;
3158 
3159 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3160 		ret = -EFAULT;
3161 
3162 	kfree(fi_args);
3163 	return ret;
3164 }
3165 
3166 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3167 				 void __user *arg)
3168 {
3169 	struct btrfs_ioctl_dev_info_args *di_args;
3170 	struct btrfs_device *dev;
3171 	int ret = 0;
3172 	char *s_uuid = NULL;
3173 
3174 	di_args = memdup_user(arg, sizeof(*di_args));
3175 	if (IS_ERR(di_args))
3176 		return PTR_ERR(di_args);
3177 
3178 	if (!btrfs_is_empty_uuid(di_args->uuid))
3179 		s_uuid = di_args->uuid;
3180 
3181 	rcu_read_lock();
3182 	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3183 				NULL, true);
3184 
3185 	if (!dev) {
3186 		ret = -ENODEV;
3187 		goto out;
3188 	}
3189 
3190 	di_args->devid = dev->devid;
3191 	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3192 	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3193 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3194 	if (dev->name) {
3195 		strncpy(di_args->path, rcu_str_deref(dev->name),
3196 				sizeof(di_args->path) - 1);
3197 		di_args->path[sizeof(di_args->path) - 1] = 0;
3198 	} else {
3199 		di_args->path[0] = '\0';
3200 	}
3201 
3202 out:
3203 	rcu_read_unlock();
3204 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3205 		ret = -EFAULT;
3206 
3207 	kfree(di_args);
3208 	return ret;
3209 }
3210 
3211 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3212 				       struct inode *inode2, u64 loff2, u64 len)
3213 {
3214 	unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3215 	unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3216 }
3217 
3218 static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3219 				     struct inode *inode2, u64 loff2, u64 len)
3220 {
3221 	if (inode1 < inode2) {
3222 		swap(inode1, inode2);
3223 		swap(loff1, loff2);
3224 	} else if (inode1 == inode2 && loff2 < loff1) {
3225 		swap(loff1, loff2);
3226 	}
3227 	lock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3228 	lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3229 }
3230 
3231 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
3232 				   struct inode *dst, u64 dst_loff)
3233 {
3234 	int ret;
3235 
3236 	/*
3237 	 * Lock destination range to serialize with concurrent readpages() and
3238 	 * source range to serialize with relocation.
3239 	 */
3240 	btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
3241 	ret = btrfs_clone(src, dst, loff, len, len, dst_loff, 1);
3242 	btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3243 
3244 	return ret;
3245 }
3246 
3247 #define BTRFS_MAX_DEDUPE_LEN	SZ_16M
3248 
3249 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3250 			     struct inode *dst, u64 dst_loff)
3251 {
3252 	int ret;
3253 	u64 i, tail_len, chunk_count;
3254 	struct btrfs_root *root_dst = BTRFS_I(dst)->root;
3255 
3256 	spin_lock(&root_dst->root_item_lock);
3257 	if (root_dst->send_in_progress) {
3258 		btrfs_warn_rl(root_dst->fs_info,
3259 "cannot deduplicate to root %llu while send operations are using it (%d in progress)",
3260 			      root_dst->root_key.objectid,
3261 			      root_dst->send_in_progress);
3262 		spin_unlock(&root_dst->root_item_lock);
3263 		return -EAGAIN;
3264 	}
3265 	root_dst->dedupe_in_progress++;
3266 	spin_unlock(&root_dst->root_item_lock);
3267 
3268 	tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3269 	chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3270 
3271 	for (i = 0; i < chunk_count; i++) {
3272 		ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3273 					      dst, dst_loff);
3274 		if (ret)
3275 			goto out;
3276 
3277 		loff += BTRFS_MAX_DEDUPE_LEN;
3278 		dst_loff += BTRFS_MAX_DEDUPE_LEN;
3279 	}
3280 
3281 	if (tail_len > 0)
3282 		ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3283 					      dst_loff);
3284 out:
3285 	spin_lock(&root_dst->root_item_lock);
3286 	root_dst->dedupe_in_progress--;
3287 	spin_unlock(&root_dst->root_item_lock);
3288 
3289 	return ret;
3290 }
3291 
3292 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3293 				     struct inode *inode,
3294 				     u64 endoff,
3295 				     const u64 destoff,
3296 				     const u64 olen,
3297 				     int no_time_update)
3298 {
3299 	struct btrfs_root *root = BTRFS_I(inode)->root;
3300 	int ret;
3301 
3302 	inode_inc_iversion(inode);
3303 	if (!no_time_update)
3304 		inode->i_mtime = inode->i_ctime = current_time(inode);
3305 	/*
3306 	 * We round up to the block size at eof when determining which
3307 	 * extents to clone above, but shouldn't round up the file size.
3308 	 */
3309 	if (endoff > destoff + olen)
3310 		endoff = destoff + olen;
3311 	if (endoff > inode->i_size)
3312 		btrfs_i_size_write(BTRFS_I(inode), endoff);
3313 
3314 	ret = btrfs_update_inode(trans, root, inode);
3315 	if (ret) {
3316 		btrfs_abort_transaction(trans, ret);
3317 		btrfs_end_transaction(trans);
3318 		goto out;
3319 	}
3320 	ret = btrfs_end_transaction(trans);
3321 out:
3322 	return ret;
3323 }
3324 
3325 static void clone_update_extent_map(struct btrfs_inode *inode,
3326 				    const struct btrfs_trans_handle *trans,
3327 				    const struct btrfs_path *path,
3328 				    const u64 hole_offset,
3329 				    const u64 hole_len)
3330 {
3331 	struct extent_map_tree *em_tree = &inode->extent_tree;
3332 	struct extent_map *em;
3333 	int ret;
3334 
3335 	em = alloc_extent_map();
3336 	if (!em) {
3337 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3338 		return;
3339 	}
3340 
3341 	if (path) {
3342 		struct btrfs_file_extent_item *fi;
3343 
3344 		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3345 				    struct btrfs_file_extent_item);
3346 		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3347 		em->generation = -1;
3348 		if (btrfs_file_extent_type(path->nodes[0], fi) ==
3349 		    BTRFS_FILE_EXTENT_INLINE)
3350 			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3351 					&inode->runtime_flags);
3352 	} else {
3353 		em->start = hole_offset;
3354 		em->len = hole_len;
3355 		em->ram_bytes = em->len;
3356 		em->orig_start = hole_offset;
3357 		em->block_start = EXTENT_MAP_HOLE;
3358 		em->block_len = 0;
3359 		em->orig_block_len = 0;
3360 		em->compress_type = BTRFS_COMPRESS_NONE;
3361 		em->generation = trans->transid;
3362 	}
3363 
3364 	while (1) {
3365 		write_lock(&em_tree->lock);
3366 		ret = add_extent_mapping(em_tree, em, 1);
3367 		write_unlock(&em_tree->lock);
3368 		if (ret != -EEXIST) {
3369 			free_extent_map(em);
3370 			break;
3371 		}
3372 		btrfs_drop_extent_cache(inode, em->start,
3373 					em->start + em->len - 1, 0);
3374 	}
3375 
3376 	if (ret)
3377 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3378 }
3379 
3380 /*
3381  * Make sure we do not end up inserting an inline extent into a file that has
3382  * already other (non-inline) extents. If a file has an inline extent it can
3383  * not have any other extents and the (single) inline extent must start at the
3384  * file offset 0. Failing to respect these rules will lead to file corruption,
3385  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3386  *
3387  * We can have extents that have been already written to disk or we can have
3388  * dirty ranges still in delalloc, in which case the extent maps and items are
3389  * created only when we run delalloc, and the delalloc ranges might fall outside
3390  * the range we are currently locking in the inode's io tree. So we check the
3391  * inode's i_size because of that (i_size updates are done while holding the
3392  * i_mutex, which we are holding here).
3393  * We also check to see if the inode has a size not greater than "datal" but has
3394  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3395  * protected against such concurrent fallocate calls by the i_mutex).
3396  *
3397  * If the file has no extents but a size greater than datal, do not allow the
3398  * copy because we would need turn the inline extent into a non-inline one (even
3399  * with NO_HOLES enabled). If we find our destination inode only has one inline
3400  * extent, just overwrite it with the source inline extent if its size is less
3401  * than the source extent's size, or we could copy the source inline extent's
3402  * data into the destination inode's inline extent if the later is greater then
3403  * the former.
3404  */
3405 static int clone_copy_inline_extent(struct inode *dst,
3406 				    struct btrfs_trans_handle *trans,
3407 				    struct btrfs_path *path,
3408 				    struct btrfs_key *new_key,
3409 				    const u64 drop_start,
3410 				    const u64 datal,
3411 				    const u64 skip,
3412 				    const u64 size,
3413 				    char *inline_data)
3414 {
3415 	struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3416 	struct btrfs_root *root = BTRFS_I(dst)->root;
3417 	const u64 aligned_end = ALIGN(new_key->offset + datal,
3418 				      fs_info->sectorsize);
3419 	int ret;
3420 	struct btrfs_key key;
3421 
3422 	if (new_key->offset > 0)
3423 		return -EOPNOTSUPP;
3424 
3425 	key.objectid = btrfs_ino(BTRFS_I(dst));
3426 	key.type = BTRFS_EXTENT_DATA_KEY;
3427 	key.offset = 0;
3428 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3429 	if (ret < 0) {
3430 		return ret;
3431 	} else if (ret > 0) {
3432 		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3433 			ret = btrfs_next_leaf(root, path);
3434 			if (ret < 0)
3435 				return ret;
3436 			else if (ret > 0)
3437 				goto copy_inline_extent;
3438 		}
3439 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3440 		if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3441 		    key.type == BTRFS_EXTENT_DATA_KEY) {
3442 			ASSERT(key.offset > 0);
3443 			return -EOPNOTSUPP;
3444 		}
3445 	} else if (i_size_read(dst) <= datal) {
3446 		struct btrfs_file_extent_item *ei;
3447 		u64 ext_len;
3448 
3449 		/*
3450 		 * If the file size is <= datal, make sure there are no other
3451 		 * extents following (can happen do to an fallocate call with
3452 		 * the flag FALLOC_FL_KEEP_SIZE).
3453 		 */
3454 		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3455 				    struct btrfs_file_extent_item);
3456 		/*
3457 		 * If it's an inline extent, it can not have other extents
3458 		 * following it.
3459 		 */
3460 		if (btrfs_file_extent_type(path->nodes[0], ei) ==
3461 		    BTRFS_FILE_EXTENT_INLINE)
3462 			goto copy_inline_extent;
3463 
3464 		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3465 		if (ext_len > aligned_end)
3466 			return -EOPNOTSUPP;
3467 
3468 		ret = btrfs_next_item(root, path);
3469 		if (ret < 0) {
3470 			return ret;
3471 		} else if (ret == 0) {
3472 			btrfs_item_key_to_cpu(path->nodes[0], &key,
3473 					      path->slots[0]);
3474 			if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3475 			    key.type == BTRFS_EXTENT_DATA_KEY)
3476 				return -EOPNOTSUPP;
3477 		}
3478 	}
3479 
3480 copy_inline_extent:
3481 	/*
3482 	 * We have no extent items, or we have an extent at offset 0 which may
3483 	 * or may not be inlined. All these cases are dealt the same way.
3484 	 */
3485 	if (i_size_read(dst) > datal) {
3486 		/*
3487 		 * If the destination inode has an inline extent...
3488 		 * This would require copying the data from the source inline
3489 		 * extent into the beginning of the destination's inline extent.
3490 		 * But this is really complex, both extents can be compressed
3491 		 * or just one of them, which would require decompressing and
3492 		 * re-compressing data (which could increase the new compressed
3493 		 * size, not allowing the compressed data to fit anymore in an
3494 		 * inline extent).
3495 		 * So just don't support this case for now (it should be rare,
3496 		 * we are not really saving space when cloning inline extents).
3497 		 */
3498 		return -EOPNOTSUPP;
3499 	}
3500 
3501 	btrfs_release_path(path);
3502 	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3503 	if (ret)
3504 		return ret;
3505 	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3506 	if (ret)
3507 		return ret;
3508 
3509 	if (skip) {
3510 		const u32 start = btrfs_file_extent_calc_inline_size(0);
3511 
3512 		memmove(inline_data + start, inline_data + start + skip, datal);
3513 	}
3514 
3515 	write_extent_buffer(path->nodes[0], inline_data,
3516 			    btrfs_item_ptr_offset(path->nodes[0],
3517 						  path->slots[0]),
3518 			    size);
3519 	inode_add_bytes(dst, datal);
3520 
3521 	return 0;
3522 }
3523 
3524 /**
3525  * btrfs_clone() - clone a range from inode file to another
3526  *
3527  * @src: Inode to clone from
3528  * @inode: Inode to clone to
3529  * @off: Offset within source to start clone from
3530  * @olen: Original length, passed by user, of range to clone
3531  * @olen_aligned: Block-aligned value of olen
3532  * @destoff: Offset within @inode to start clone
3533  * @no_time_update: Whether to update mtime/ctime on the target inode
3534  */
3535 static int btrfs_clone(struct inode *src, struct inode *inode,
3536 		       const u64 off, const u64 olen, const u64 olen_aligned,
3537 		       const u64 destoff, int no_time_update)
3538 {
3539 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3540 	struct btrfs_root *root = BTRFS_I(inode)->root;
3541 	struct btrfs_path *path = NULL;
3542 	struct extent_buffer *leaf;
3543 	struct btrfs_trans_handle *trans;
3544 	char *buf = NULL;
3545 	struct btrfs_key key;
3546 	u32 nritems;
3547 	int slot;
3548 	int ret;
3549 	const u64 len = olen_aligned;
3550 	u64 last_dest_end = destoff;
3551 
3552 	ret = -ENOMEM;
3553 	buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3554 	if (!buf)
3555 		return ret;
3556 
3557 	path = btrfs_alloc_path();
3558 	if (!path) {
3559 		kvfree(buf);
3560 		return ret;
3561 	}
3562 
3563 	path->reada = READA_FORWARD;
3564 	/* clone data */
3565 	key.objectid = btrfs_ino(BTRFS_I(src));
3566 	key.type = BTRFS_EXTENT_DATA_KEY;
3567 	key.offset = off;
3568 
3569 	while (1) {
3570 		u64 next_key_min_offset = key.offset + 1;
3571 
3572 		/*
3573 		 * note the key will change type as we walk through the
3574 		 * tree.
3575 		 */
3576 		path->leave_spinning = 1;
3577 		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3578 				0, 0);
3579 		if (ret < 0)
3580 			goto out;
3581 		/*
3582 		 * First search, if no extent item that starts at offset off was
3583 		 * found but the previous item is an extent item, it's possible
3584 		 * it might overlap our target range, therefore process it.
3585 		 */
3586 		if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3587 			btrfs_item_key_to_cpu(path->nodes[0], &key,
3588 					      path->slots[0] - 1);
3589 			if (key.type == BTRFS_EXTENT_DATA_KEY)
3590 				path->slots[0]--;
3591 		}
3592 
3593 		nritems = btrfs_header_nritems(path->nodes[0]);
3594 process_slot:
3595 		if (path->slots[0] >= nritems) {
3596 			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3597 			if (ret < 0)
3598 				goto out;
3599 			if (ret > 0)
3600 				break;
3601 			nritems = btrfs_header_nritems(path->nodes[0]);
3602 		}
3603 		leaf = path->nodes[0];
3604 		slot = path->slots[0];
3605 
3606 		btrfs_item_key_to_cpu(leaf, &key, slot);
3607 		if (key.type > BTRFS_EXTENT_DATA_KEY ||
3608 		    key.objectid != btrfs_ino(BTRFS_I(src)))
3609 			break;
3610 
3611 		if (key.type == BTRFS_EXTENT_DATA_KEY) {
3612 			struct btrfs_file_extent_item *extent;
3613 			int type;
3614 			u32 size;
3615 			struct btrfs_key new_key;
3616 			u64 disko = 0, diskl = 0;
3617 			u64 datao = 0, datal = 0;
3618 			u8 comp;
3619 			u64 drop_start;
3620 
3621 			extent = btrfs_item_ptr(leaf, slot,
3622 						struct btrfs_file_extent_item);
3623 			comp = btrfs_file_extent_compression(leaf, extent);
3624 			type = btrfs_file_extent_type(leaf, extent);
3625 			if (type == BTRFS_FILE_EXTENT_REG ||
3626 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3627 				disko = btrfs_file_extent_disk_bytenr(leaf,
3628 								      extent);
3629 				diskl = btrfs_file_extent_disk_num_bytes(leaf,
3630 								 extent);
3631 				datao = btrfs_file_extent_offset(leaf, extent);
3632 				datal = btrfs_file_extent_num_bytes(leaf,
3633 								    extent);
3634 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3635 				/* take upper bound, may be compressed */
3636 				datal = btrfs_file_extent_ram_bytes(leaf,
3637 								    extent);
3638 			}
3639 
3640 			/*
3641 			 * The first search might have left us at an extent
3642 			 * item that ends before our target range's start, can
3643 			 * happen if we have holes and NO_HOLES feature enabled.
3644 			 */
3645 			if (key.offset + datal <= off) {
3646 				path->slots[0]++;
3647 				goto process_slot;
3648 			} else if (key.offset >= off + len) {
3649 				break;
3650 			}
3651 			next_key_min_offset = key.offset + datal;
3652 			size = btrfs_item_size_nr(leaf, slot);
3653 			read_extent_buffer(leaf, buf,
3654 					   btrfs_item_ptr_offset(leaf, slot),
3655 					   size);
3656 
3657 			btrfs_release_path(path);
3658 			path->leave_spinning = 0;
3659 
3660 			memcpy(&new_key, &key, sizeof(new_key));
3661 			new_key.objectid = btrfs_ino(BTRFS_I(inode));
3662 			if (off <= key.offset)
3663 				new_key.offset = key.offset + destoff - off;
3664 			else
3665 				new_key.offset = destoff;
3666 
3667 			/*
3668 			 * Deal with a hole that doesn't have an extent item
3669 			 * that represents it (NO_HOLES feature enabled).
3670 			 * This hole is either in the middle of the cloning
3671 			 * range or at the beginning (fully overlaps it or
3672 			 * partially overlaps it).
3673 			 */
3674 			if (new_key.offset != last_dest_end)
3675 				drop_start = last_dest_end;
3676 			else
3677 				drop_start = new_key.offset;
3678 
3679 			/*
3680 			 * 1 - adjusting old extent (we may have to split it)
3681 			 * 1 - add new extent
3682 			 * 1 - inode update
3683 			 */
3684 			trans = btrfs_start_transaction(root, 3);
3685 			if (IS_ERR(trans)) {
3686 				ret = PTR_ERR(trans);
3687 				goto out;
3688 			}
3689 
3690 			if (type == BTRFS_FILE_EXTENT_REG ||
3691 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3692 				/*
3693 				 *    a  | --- range to clone ---|  b
3694 				 * | ------------- extent ------------- |
3695 				 */
3696 
3697 				/* subtract range b */
3698 				if (key.offset + datal > off + len)
3699 					datal = off + len - key.offset;
3700 
3701 				/* subtract range a */
3702 				if (off > key.offset) {
3703 					datao += off - key.offset;
3704 					datal -= off - key.offset;
3705 				}
3706 
3707 				ret = btrfs_drop_extents(trans, root, inode,
3708 							 drop_start,
3709 							 new_key.offset + datal,
3710 							 1);
3711 				if (ret) {
3712 					if (ret != -EOPNOTSUPP)
3713 						btrfs_abort_transaction(trans,
3714 									ret);
3715 					btrfs_end_transaction(trans);
3716 					goto out;
3717 				}
3718 
3719 				ret = btrfs_insert_empty_item(trans, root, path,
3720 							      &new_key, size);
3721 				if (ret) {
3722 					btrfs_abort_transaction(trans, ret);
3723 					btrfs_end_transaction(trans);
3724 					goto out;
3725 				}
3726 
3727 				leaf = path->nodes[0];
3728 				slot = path->slots[0];
3729 				write_extent_buffer(leaf, buf,
3730 					    btrfs_item_ptr_offset(leaf, slot),
3731 					    size);
3732 
3733 				extent = btrfs_item_ptr(leaf, slot,
3734 						struct btrfs_file_extent_item);
3735 
3736 				/* disko == 0 means it's a hole */
3737 				if (!disko)
3738 					datao = 0;
3739 
3740 				btrfs_set_file_extent_offset(leaf, extent,
3741 							     datao);
3742 				btrfs_set_file_extent_num_bytes(leaf, extent,
3743 								datal);
3744 
3745 				if (disko) {
3746 					struct btrfs_ref ref = { 0 };
3747 					inode_add_bytes(inode, datal);
3748 					btrfs_init_generic_ref(&ref,
3749 						BTRFS_ADD_DELAYED_REF, disko,
3750 						diskl, 0);
3751 					btrfs_init_data_ref(&ref,
3752 						root->root_key.objectid,
3753 						btrfs_ino(BTRFS_I(inode)),
3754 						new_key.offset - datao);
3755 					ret = btrfs_inc_extent_ref(trans, &ref);
3756 					if (ret) {
3757 						btrfs_abort_transaction(trans,
3758 									ret);
3759 						btrfs_end_transaction(trans);
3760 						goto out;
3761 
3762 					}
3763 				}
3764 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3765 				u64 skip = 0;
3766 				u64 trim = 0;
3767 
3768 				if (off > key.offset) {
3769 					skip = off - key.offset;
3770 					new_key.offset += skip;
3771 				}
3772 
3773 				if (key.offset + datal > off + len)
3774 					trim = key.offset + datal - (off + len);
3775 
3776 				if (comp && (skip || trim)) {
3777 					ret = -EINVAL;
3778 					btrfs_end_transaction(trans);
3779 					goto out;
3780 				}
3781 				size -= skip + trim;
3782 				datal -= skip + trim;
3783 
3784 				ret = clone_copy_inline_extent(inode,
3785 							       trans, path,
3786 							       &new_key,
3787 							       drop_start,
3788 							       datal,
3789 							       skip, size, buf);
3790 				if (ret) {
3791 					if (ret != -EOPNOTSUPP)
3792 						btrfs_abort_transaction(trans,
3793 									ret);
3794 					btrfs_end_transaction(trans);
3795 					goto out;
3796 				}
3797 				leaf = path->nodes[0];
3798 				slot = path->slots[0];
3799 			}
3800 
3801 			/* If we have an implicit hole (NO_HOLES feature). */
3802 			if (drop_start < new_key.offset)
3803 				clone_update_extent_map(BTRFS_I(inode), trans,
3804 						NULL, drop_start,
3805 						new_key.offset - drop_start);
3806 
3807 			clone_update_extent_map(BTRFS_I(inode), trans,
3808 					path, 0, 0);
3809 
3810 			btrfs_mark_buffer_dirty(leaf);
3811 			btrfs_release_path(path);
3812 
3813 			last_dest_end = ALIGN(new_key.offset + datal,
3814 					      fs_info->sectorsize);
3815 			ret = clone_finish_inode_update(trans, inode,
3816 							last_dest_end,
3817 							destoff, olen,
3818 							no_time_update);
3819 			if (ret)
3820 				goto out;
3821 			if (new_key.offset + datal >= destoff + len)
3822 				break;
3823 		}
3824 		btrfs_release_path(path);
3825 		key.offset = next_key_min_offset;
3826 
3827 		if (fatal_signal_pending(current)) {
3828 			ret = -EINTR;
3829 			goto out;
3830 		}
3831 	}
3832 	ret = 0;
3833 
3834 	if (last_dest_end < destoff + len) {
3835 		/*
3836 		 * We have an implicit hole (NO_HOLES feature is enabled) that
3837 		 * fully or partially overlaps our cloning range at its end.
3838 		 */
3839 		btrfs_release_path(path);
3840 
3841 		/*
3842 		 * 1 - remove extent(s)
3843 		 * 1 - inode update
3844 		 */
3845 		trans = btrfs_start_transaction(root, 2);
3846 		if (IS_ERR(trans)) {
3847 			ret = PTR_ERR(trans);
3848 			goto out;
3849 		}
3850 		ret = btrfs_drop_extents(trans, root, inode,
3851 					 last_dest_end, destoff + len, 1);
3852 		if (ret) {
3853 			if (ret != -EOPNOTSUPP)
3854 				btrfs_abort_transaction(trans, ret);
3855 			btrfs_end_transaction(trans);
3856 			goto out;
3857 		}
3858 		clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3859 				last_dest_end,
3860 				destoff + len - last_dest_end);
3861 		ret = clone_finish_inode_update(trans, inode, destoff + len,
3862 						destoff, olen, no_time_update);
3863 	}
3864 
3865 out:
3866 	btrfs_free_path(path);
3867 	kvfree(buf);
3868 	return ret;
3869 }
3870 
3871 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3872 					u64 off, u64 olen, u64 destoff)
3873 {
3874 	struct inode *inode = file_inode(file);
3875 	struct inode *src = file_inode(file_src);
3876 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3877 	int ret;
3878 	u64 len = olen;
3879 	u64 bs = fs_info->sb->s_blocksize;
3880 
3881 	/*
3882 	 * TODO:
3883 	 * - split compressed inline extents.  annoying: we need to
3884 	 *   decompress into destination's address_space (the file offset
3885 	 *   may change, so source mapping won't do), then recompress (or
3886 	 *   otherwise reinsert) a subrange.
3887 	 *
3888 	 * - split destination inode's inline extents.  The inline extents can
3889 	 *   be either compressed or non-compressed.
3890 	 */
3891 
3892 	/*
3893 	 * VFS's generic_remap_file_range_prep() protects us from cloning the
3894 	 * eof block into the middle of a file, which would result in corruption
3895 	 * if the file size is not blocksize aligned. So we don't need to check
3896 	 * for that case here.
3897 	 */
3898 	if (off + len == src->i_size)
3899 		len = ALIGN(src->i_size, bs) - off;
3900 
3901 	if (destoff > inode->i_size) {
3902 		const u64 wb_start = ALIGN_DOWN(inode->i_size, bs);
3903 
3904 		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3905 		if (ret)
3906 			return ret;
3907 		/*
3908 		 * We may have truncated the last block if the inode's size is
3909 		 * not sector size aligned, so we need to wait for writeback to
3910 		 * complete before proceeding further, otherwise we can race
3911 		 * with cloning and attempt to increment a reference to an
3912 		 * extent that no longer exists (writeback completed right after
3913 		 * we found the previous extent covering eof and before we
3914 		 * attempted to increment its reference count).
3915 		 */
3916 		ret = btrfs_wait_ordered_range(inode, wb_start,
3917 					       destoff - wb_start);
3918 		if (ret)
3919 			return ret;
3920 	}
3921 
3922 	/*
3923 	 * Lock destination range to serialize with concurrent readpages() and
3924 	 * source range to serialize with relocation.
3925 	 */
3926 	btrfs_double_extent_lock(src, off, inode, destoff, len);
3927 	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3928 	btrfs_double_extent_unlock(src, off, inode, destoff, len);
3929 	/*
3930 	 * Truncate page cache pages so that future reads will see the cloned
3931 	 * data immediately and not the previous data.
3932 	 */
3933 	truncate_inode_pages_range(&inode->i_data,
3934 				round_down(destoff, PAGE_SIZE),
3935 				round_up(destoff + len, PAGE_SIZE) - 1);
3936 
3937 	return ret;
3938 }
3939 
3940 static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
3941 				       struct file *file_out, loff_t pos_out,
3942 				       loff_t *len, unsigned int remap_flags)
3943 {
3944 	struct inode *inode_in = file_inode(file_in);
3945 	struct inode *inode_out = file_inode(file_out);
3946 	u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
3947 	bool same_inode = inode_out == inode_in;
3948 	u64 wb_len;
3949 	int ret;
3950 
3951 	if (!(remap_flags & REMAP_FILE_DEDUP)) {
3952 		struct btrfs_root *root_out = BTRFS_I(inode_out)->root;
3953 
3954 		if (btrfs_root_readonly(root_out))
3955 			return -EROFS;
3956 
3957 		if (file_in->f_path.mnt != file_out->f_path.mnt ||
3958 		    inode_in->i_sb != inode_out->i_sb)
3959 			return -EXDEV;
3960 	}
3961 
3962 	/* don't make the dst file partly checksummed */
3963 	if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) !=
3964 	    (BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) {
3965 		return -EINVAL;
3966 	}
3967 
3968 	/*
3969 	 * Now that the inodes are locked, we need to start writeback ourselves
3970 	 * and can not rely on the writeback from the VFS's generic helper
3971 	 * generic_remap_file_range_prep() because:
3972 	 *
3973 	 * 1) For compression we must call filemap_fdatawrite_range() range
3974 	 *    twice (btrfs_fdatawrite_range() does it for us), and the generic
3975 	 *    helper only calls it once;
3976 	 *
3977 	 * 2) filemap_fdatawrite_range(), called by the generic helper only
3978 	 *    waits for the writeback to complete, i.e. for IO to be done, and
3979 	 *    not for the ordered extents to complete. We need to wait for them
3980 	 *    to complete so that new file extent items are in the fs tree.
3981 	 */
3982 	if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP))
3983 		wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs);
3984 	else
3985 		wb_len = ALIGN(*len, bs);
3986 
3987 	/*
3988 	 * Since we don't lock ranges, wait for ongoing lockless dio writes (as
3989 	 * any in progress could create its ordered extents after we wait for
3990 	 * existing ordered extents below).
3991 	 */
3992 	inode_dio_wait(inode_in);
3993 	if (!same_inode)
3994 		inode_dio_wait(inode_out);
3995 
3996 	ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
3997 				       wb_len);
3998 	if (ret < 0)
3999 		return ret;
4000 	ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs),
4001 				       wb_len);
4002 	if (ret < 0)
4003 		return ret;
4004 
4005 	return generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
4006 					    len, remap_flags);
4007 }
4008 
4009 loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
4010 		struct file *dst_file, loff_t destoff, loff_t len,
4011 		unsigned int remap_flags)
4012 {
4013 	struct inode *src_inode = file_inode(src_file);
4014 	struct inode *dst_inode = file_inode(dst_file);
4015 	bool same_inode = dst_inode == src_inode;
4016 	int ret;
4017 
4018 	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
4019 		return -EINVAL;
4020 
4021 	if (same_inode)
4022 		inode_lock(src_inode);
4023 	else
4024 		lock_two_nondirectories(src_inode, dst_inode);
4025 
4026 	ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
4027 					  &len, remap_flags);
4028 	if (ret < 0 || len == 0)
4029 		goto out_unlock;
4030 
4031 	if (remap_flags & REMAP_FILE_DEDUP)
4032 		ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
4033 	else
4034 		ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
4035 
4036 out_unlock:
4037 	if (same_inode)
4038 		inode_unlock(src_inode);
4039 	else
4040 		unlock_two_nondirectories(src_inode, dst_inode);
4041 
4042 	return ret < 0 ? ret : len;
4043 }
4044 
4045 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4046 {
4047 	struct inode *inode = file_inode(file);
4048 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4049 	struct btrfs_root *root = BTRFS_I(inode)->root;
4050 	struct btrfs_root *new_root;
4051 	struct btrfs_dir_item *di;
4052 	struct btrfs_trans_handle *trans;
4053 	struct btrfs_path *path;
4054 	struct btrfs_key location;
4055 	struct btrfs_disk_key disk_key;
4056 	u64 objectid = 0;
4057 	u64 dir_id;
4058 	int ret;
4059 
4060 	if (!capable(CAP_SYS_ADMIN))
4061 		return -EPERM;
4062 
4063 	ret = mnt_want_write_file(file);
4064 	if (ret)
4065 		return ret;
4066 
4067 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4068 		ret = -EFAULT;
4069 		goto out;
4070 	}
4071 
4072 	if (!objectid)
4073 		objectid = BTRFS_FS_TREE_OBJECTID;
4074 
4075 	location.objectid = objectid;
4076 	location.type = BTRFS_ROOT_ITEM_KEY;
4077 	location.offset = (u64)-1;
4078 
4079 	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4080 	if (IS_ERR(new_root)) {
4081 		ret = PTR_ERR(new_root);
4082 		goto out;
4083 	}
4084 	if (!is_fstree(new_root->root_key.objectid)) {
4085 		ret = -ENOENT;
4086 		goto out;
4087 	}
4088 
4089 	path = btrfs_alloc_path();
4090 	if (!path) {
4091 		ret = -ENOMEM;
4092 		goto out;
4093 	}
4094 	path->leave_spinning = 1;
4095 
4096 	trans = btrfs_start_transaction(root, 1);
4097 	if (IS_ERR(trans)) {
4098 		btrfs_free_path(path);
4099 		ret = PTR_ERR(trans);
4100 		goto out;
4101 	}
4102 
4103 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
4104 	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4105 				   dir_id, "default", 7, 1);
4106 	if (IS_ERR_OR_NULL(di)) {
4107 		btrfs_free_path(path);
4108 		btrfs_end_transaction(trans);
4109 		btrfs_err(fs_info,
4110 			  "Umm, you don't have the default diritem, this isn't going to work");
4111 		ret = -ENOENT;
4112 		goto out;
4113 	}
4114 
4115 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4116 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4117 	btrfs_mark_buffer_dirty(path->nodes[0]);
4118 	btrfs_free_path(path);
4119 
4120 	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4121 	btrfs_end_transaction(trans);
4122 out:
4123 	mnt_drop_write_file(file);
4124 	return ret;
4125 }
4126 
4127 static void get_block_group_info(struct list_head *groups_list,
4128 				 struct btrfs_ioctl_space_info *space)
4129 {
4130 	struct btrfs_block_group_cache *block_group;
4131 
4132 	space->total_bytes = 0;
4133 	space->used_bytes = 0;
4134 	space->flags = 0;
4135 	list_for_each_entry(block_group, groups_list, list) {
4136 		space->flags = block_group->flags;
4137 		space->total_bytes += block_group->key.offset;
4138 		space->used_bytes +=
4139 			btrfs_block_group_used(&block_group->item);
4140 	}
4141 }
4142 
4143 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4144 				   void __user *arg)
4145 {
4146 	struct btrfs_ioctl_space_args space_args;
4147 	struct btrfs_ioctl_space_info space;
4148 	struct btrfs_ioctl_space_info *dest;
4149 	struct btrfs_ioctl_space_info *dest_orig;
4150 	struct btrfs_ioctl_space_info __user *user_dest;
4151 	struct btrfs_space_info *info;
4152 	static const u64 types[] = {
4153 		BTRFS_BLOCK_GROUP_DATA,
4154 		BTRFS_BLOCK_GROUP_SYSTEM,
4155 		BTRFS_BLOCK_GROUP_METADATA,
4156 		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4157 	};
4158 	int num_types = 4;
4159 	int alloc_size;
4160 	int ret = 0;
4161 	u64 slot_count = 0;
4162 	int i, c;
4163 
4164 	if (copy_from_user(&space_args,
4165 			   (struct btrfs_ioctl_space_args __user *)arg,
4166 			   sizeof(space_args)))
4167 		return -EFAULT;
4168 
4169 	for (i = 0; i < num_types; i++) {
4170 		struct btrfs_space_info *tmp;
4171 
4172 		info = NULL;
4173 		rcu_read_lock();
4174 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4175 					list) {
4176 			if (tmp->flags == types[i]) {
4177 				info = tmp;
4178 				break;
4179 			}
4180 		}
4181 		rcu_read_unlock();
4182 
4183 		if (!info)
4184 			continue;
4185 
4186 		down_read(&info->groups_sem);
4187 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4188 			if (!list_empty(&info->block_groups[c]))
4189 				slot_count++;
4190 		}
4191 		up_read(&info->groups_sem);
4192 	}
4193 
4194 	/*
4195 	 * Global block reserve, exported as a space_info
4196 	 */
4197 	slot_count++;
4198 
4199 	/* space_slots == 0 means they are asking for a count */
4200 	if (space_args.space_slots == 0) {
4201 		space_args.total_spaces = slot_count;
4202 		goto out;
4203 	}
4204 
4205 	slot_count = min_t(u64, space_args.space_slots, slot_count);
4206 
4207 	alloc_size = sizeof(*dest) * slot_count;
4208 
4209 	/* we generally have at most 6 or so space infos, one for each raid
4210 	 * level.  So, a whole page should be more than enough for everyone
4211 	 */
4212 	if (alloc_size > PAGE_SIZE)
4213 		return -ENOMEM;
4214 
4215 	space_args.total_spaces = 0;
4216 	dest = kmalloc(alloc_size, GFP_KERNEL);
4217 	if (!dest)
4218 		return -ENOMEM;
4219 	dest_orig = dest;
4220 
4221 	/* now we have a buffer to copy into */
4222 	for (i = 0; i < num_types; i++) {
4223 		struct btrfs_space_info *tmp;
4224 
4225 		if (!slot_count)
4226 			break;
4227 
4228 		info = NULL;
4229 		rcu_read_lock();
4230 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4231 					list) {
4232 			if (tmp->flags == types[i]) {
4233 				info = tmp;
4234 				break;
4235 			}
4236 		}
4237 		rcu_read_unlock();
4238 
4239 		if (!info)
4240 			continue;
4241 		down_read(&info->groups_sem);
4242 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4243 			if (!list_empty(&info->block_groups[c])) {
4244 				get_block_group_info(&info->block_groups[c],
4245 						     &space);
4246 				memcpy(dest, &space, sizeof(space));
4247 				dest++;
4248 				space_args.total_spaces++;
4249 				slot_count--;
4250 			}
4251 			if (!slot_count)
4252 				break;
4253 		}
4254 		up_read(&info->groups_sem);
4255 	}
4256 
4257 	/*
4258 	 * Add global block reserve
4259 	 */
4260 	if (slot_count) {
4261 		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4262 
4263 		spin_lock(&block_rsv->lock);
4264 		space.total_bytes = block_rsv->size;
4265 		space.used_bytes = block_rsv->size - block_rsv->reserved;
4266 		spin_unlock(&block_rsv->lock);
4267 		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4268 		memcpy(dest, &space, sizeof(space));
4269 		space_args.total_spaces++;
4270 	}
4271 
4272 	user_dest = (struct btrfs_ioctl_space_info __user *)
4273 		(arg + sizeof(struct btrfs_ioctl_space_args));
4274 
4275 	if (copy_to_user(user_dest, dest_orig, alloc_size))
4276 		ret = -EFAULT;
4277 
4278 	kfree(dest_orig);
4279 out:
4280 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4281 		ret = -EFAULT;
4282 
4283 	return ret;
4284 }
4285 
4286 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4287 					    void __user *argp)
4288 {
4289 	struct btrfs_trans_handle *trans;
4290 	u64 transid;
4291 	int ret;
4292 
4293 	trans = btrfs_attach_transaction_barrier(root);
4294 	if (IS_ERR(trans)) {
4295 		if (PTR_ERR(trans) != -ENOENT)
4296 			return PTR_ERR(trans);
4297 
4298 		/* No running transaction, don't bother */
4299 		transid = root->fs_info->last_trans_committed;
4300 		goto out;
4301 	}
4302 	transid = trans->transid;
4303 	ret = btrfs_commit_transaction_async(trans, 0);
4304 	if (ret) {
4305 		btrfs_end_transaction(trans);
4306 		return ret;
4307 	}
4308 out:
4309 	if (argp)
4310 		if (copy_to_user(argp, &transid, sizeof(transid)))
4311 			return -EFAULT;
4312 	return 0;
4313 }
4314 
4315 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4316 					   void __user *argp)
4317 {
4318 	u64 transid;
4319 
4320 	if (argp) {
4321 		if (copy_from_user(&transid, argp, sizeof(transid)))
4322 			return -EFAULT;
4323 	} else {
4324 		transid = 0;  /* current trans */
4325 	}
4326 	return btrfs_wait_for_commit(fs_info, transid);
4327 }
4328 
4329 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4330 {
4331 	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4332 	struct btrfs_ioctl_scrub_args *sa;
4333 	int ret;
4334 
4335 	if (!capable(CAP_SYS_ADMIN))
4336 		return -EPERM;
4337 
4338 	sa = memdup_user(arg, sizeof(*sa));
4339 	if (IS_ERR(sa))
4340 		return PTR_ERR(sa);
4341 
4342 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4343 		ret = mnt_want_write_file(file);
4344 		if (ret)
4345 			goto out;
4346 	}
4347 
4348 	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4349 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4350 			      0);
4351 
4352 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4353 		ret = -EFAULT;
4354 
4355 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
4356 		mnt_drop_write_file(file);
4357 out:
4358 	kfree(sa);
4359 	return ret;
4360 }
4361 
4362 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4363 {
4364 	if (!capable(CAP_SYS_ADMIN))
4365 		return -EPERM;
4366 
4367 	return btrfs_scrub_cancel(fs_info);
4368 }
4369 
4370 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4371 				       void __user *arg)
4372 {
4373 	struct btrfs_ioctl_scrub_args *sa;
4374 	int ret;
4375 
4376 	if (!capable(CAP_SYS_ADMIN))
4377 		return -EPERM;
4378 
4379 	sa = memdup_user(arg, sizeof(*sa));
4380 	if (IS_ERR(sa))
4381 		return PTR_ERR(sa);
4382 
4383 	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4384 
4385 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4386 		ret = -EFAULT;
4387 
4388 	kfree(sa);
4389 	return ret;
4390 }
4391 
4392 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4393 				      void __user *arg)
4394 {
4395 	struct btrfs_ioctl_get_dev_stats *sa;
4396 	int ret;
4397 
4398 	sa = memdup_user(arg, sizeof(*sa));
4399 	if (IS_ERR(sa))
4400 		return PTR_ERR(sa);
4401 
4402 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4403 		kfree(sa);
4404 		return -EPERM;
4405 	}
4406 
4407 	ret = btrfs_get_dev_stats(fs_info, sa);
4408 
4409 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4410 		ret = -EFAULT;
4411 
4412 	kfree(sa);
4413 	return ret;
4414 }
4415 
4416 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4417 				    void __user *arg)
4418 {
4419 	struct btrfs_ioctl_dev_replace_args *p;
4420 	int ret;
4421 
4422 	if (!capable(CAP_SYS_ADMIN))
4423 		return -EPERM;
4424 
4425 	p = memdup_user(arg, sizeof(*p));
4426 	if (IS_ERR(p))
4427 		return PTR_ERR(p);
4428 
4429 	switch (p->cmd) {
4430 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4431 		if (sb_rdonly(fs_info->sb)) {
4432 			ret = -EROFS;
4433 			goto out;
4434 		}
4435 		if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4436 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4437 		} else {
4438 			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4439 			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4440 		}
4441 		break;
4442 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4443 		btrfs_dev_replace_status(fs_info, p);
4444 		ret = 0;
4445 		break;
4446 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4447 		p->result = btrfs_dev_replace_cancel(fs_info);
4448 		ret = 0;
4449 		break;
4450 	default:
4451 		ret = -EINVAL;
4452 		break;
4453 	}
4454 
4455 	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
4456 		ret = -EFAULT;
4457 out:
4458 	kfree(p);
4459 	return ret;
4460 }
4461 
4462 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4463 {
4464 	int ret = 0;
4465 	int i;
4466 	u64 rel_ptr;
4467 	int size;
4468 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
4469 	struct inode_fs_paths *ipath = NULL;
4470 	struct btrfs_path *path;
4471 
4472 	if (!capable(CAP_DAC_READ_SEARCH))
4473 		return -EPERM;
4474 
4475 	path = btrfs_alloc_path();
4476 	if (!path) {
4477 		ret = -ENOMEM;
4478 		goto out;
4479 	}
4480 
4481 	ipa = memdup_user(arg, sizeof(*ipa));
4482 	if (IS_ERR(ipa)) {
4483 		ret = PTR_ERR(ipa);
4484 		ipa = NULL;
4485 		goto out;
4486 	}
4487 
4488 	size = min_t(u32, ipa->size, 4096);
4489 	ipath = init_ipath(size, root, path);
4490 	if (IS_ERR(ipath)) {
4491 		ret = PTR_ERR(ipath);
4492 		ipath = NULL;
4493 		goto out;
4494 	}
4495 
4496 	ret = paths_from_inode(ipa->inum, ipath);
4497 	if (ret < 0)
4498 		goto out;
4499 
4500 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4501 		rel_ptr = ipath->fspath->val[i] -
4502 			  (u64)(unsigned long)ipath->fspath->val;
4503 		ipath->fspath->val[i] = rel_ptr;
4504 	}
4505 
4506 	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4507 			   ipath->fspath, size);
4508 	if (ret) {
4509 		ret = -EFAULT;
4510 		goto out;
4511 	}
4512 
4513 out:
4514 	btrfs_free_path(path);
4515 	free_ipath(ipath);
4516 	kfree(ipa);
4517 
4518 	return ret;
4519 }
4520 
4521 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4522 {
4523 	struct btrfs_data_container *inodes = ctx;
4524 	const size_t c = 3 * sizeof(u64);
4525 
4526 	if (inodes->bytes_left >= c) {
4527 		inodes->bytes_left -= c;
4528 		inodes->val[inodes->elem_cnt] = inum;
4529 		inodes->val[inodes->elem_cnt + 1] = offset;
4530 		inodes->val[inodes->elem_cnt + 2] = root;
4531 		inodes->elem_cnt += 3;
4532 	} else {
4533 		inodes->bytes_missing += c - inodes->bytes_left;
4534 		inodes->bytes_left = 0;
4535 		inodes->elem_missed += 3;
4536 	}
4537 
4538 	return 0;
4539 }
4540 
4541 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4542 					void __user *arg, int version)
4543 {
4544 	int ret = 0;
4545 	int size;
4546 	struct btrfs_ioctl_logical_ino_args *loi;
4547 	struct btrfs_data_container *inodes = NULL;
4548 	struct btrfs_path *path = NULL;
4549 	bool ignore_offset;
4550 
4551 	if (!capable(CAP_SYS_ADMIN))
4552 		return -EPERM;
4553 
4554 	loi = memdup_user(arg, sizeof(*loi));
4555 	if (IS_ERR(loi))
4556 		return PTR_ERR(loi);
4557 
4558 	if (version == 1) {
4559 		ignore_offset = false;
4560 		size = min_t(u32, loi->size, SZ_64K);
4561 	} else {
4562 		/* All reserved bits must be 0 for now */
4563 		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4564 			ret = -EINVAL;
4565 			goto out_loi;
4566 		}
4567 		/* Only accept flags we have defined so far */
4568 		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4569 			ret = -EINVAL;
4570 			goto out_loi;
4571 		}
4572 		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4573 		size = min_t(u32, loi->size, SZ_16M);
4574 	}
4575 
4576 	path = btrfs_alloc_path();
4577 	if (!path) {
4578 		ret = -ENOMEM;
4579 		goto out;
4580 	}
4581 
4582 	inodes = init_data_container(size);
4583 	if (IS_ERR(inodes)) {
4584 		ret = PTR_ERR(inodes);
4585 		inodes = NULL;
4586 		goto out;
4587 	}
4588 
4589 	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4590 					  build_ino_list, inodes, ignore_offset);
4591 	if (ret == -EINVAL)
4592 		ret = -ENOENT;
4593 	if (ret < 0)
4594 		goto out;
4595 
4596 	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4597 			   size);
4598 	if (ret)
4599 		ret = -EFAULT;
4600 
4601 out:
4602 	btrfs_free_path(path);
4603 	kvfree(inodes);
4604 out_loi:
4605 	kfree(loi);
4606 
4607 	return ret;
4608 }
4609 
4610 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4611 			       struct btrfs_ioctl_balance_args *bargs)
4612 {
4613 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4614 
4615 	bargs->flags = bctl->flags;
4616 
4617 	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4618 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4619 	if (atomic_read(&fs_info->balance_pause_req))
4620 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4621 	if (atomic_read(&fs_info->balance_cancel_req))
4622 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4623 
4624 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4625 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4626 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4627 
4628 	spin_lock(&fs_info->balance_lock);
4629 	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4630 	spin_unlock(&fs_info->balance_lock);
4631 }
4632 
4633 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4634 {
4635 	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4636 	struct btrfs_fs_info *fs_info = root->fs_info;
4637 	struct btrfs_ioctl_balance_args *bargs;
4638 	struct btrfs_balance_control *bctl;
4639 	bool need_unlock; /* for mut. excl. ops lock */
4640 	int ret;
4641 
4642 	if (!capable(CAP_SYS_ADMIN))
4643 		return -EPERM;
4644 
4645 	ret = mnt_want_write_file(file);
4646 	if (ret)
4647 		return ret;
4648 
4649 again:
4650 	if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4651 		mutex_lock(&fs_info->balance_mutex);
4652 		need_unlock = true;
4653 		goto locked;
4654 	}
4655 
4656 	/*
4657 	 * mut. excl. ops lock is locked.  Three possibilities:
4658 	 *   (1) some other op is running
4659 	 *   (2) balance is running
4660 	 *   (3) balance is paused -- special case (think resume)
4661 	 */
4662 	mutex_lock(&fs_info->balance_mutex);
4663 	if (fs_info->balance_ctl) {
4664 		/* this is either (2) or (3) */
4665 		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4666 			mutex_unlock(&fs_info->balance_mutex);
4667 			/*
4668 			 * Lock released to allow other waiters to continue,
4669 			 * we'll reexamine the status again.
4670 			 */
4671 			mutex_lock(&fs_info->balance_mutex);
4672 
4673 			if (fs_info->balance_ctl &&
4674 			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4675 				/* this is (3) */
4676 				need_unlock = false;
4677 				goto locked;
4678 			}
4679 
4680 			mutex_unlock(&fs_info->balance_mutex);
4681 			goto again;
4682 		} else {
4683 			/* this is (2) */
4684 			mutex_unlock(&fs_info->balance_mutex);
4685 			ret = -EINPROGRESS;
4686 			goto out;
4687 		}
4688 	} else {
4689 		/* this is (1) */
4690 		mutex_unlock(&fs_info->balance_mutex);
4691 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4692 		goto out;
4693 	}
4694 
4695 locked:
4696 	BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4697 
4698 	if (arg) {
4699 		bargs = memdup_user(arg, sizeof(*bargs));
4700 		if (IS_ERR(bargs)) {
4701 			ret = PTR_ERR(bargs);
4702 			goto out_unlock;
4703 		}
4704 
4705 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4706 			if (!fs_info->balance_ctl) {
4707 				ret = -ENOTCONN;
4708 				goto out_bargs;
4709 			}
4710 
4711 			bctl = fs_info->balance_ctl;
4712 			spin_lock(&fs_info->balance_lock);
4713 			bctl->flags |= BTRFS_BALANCE_RESUME;
4714 			spin_unlock(&fs_info->balance_lock);
4715 
4716 			goto do_balance;
4717 		}
4718 	} else {
4719 		bargs = NULL;
4720 	}
4721 
4722 	if (fs_info->balance_ctl) {
4723 		ret = -EINPROGRESS;
4724 		goto out_bargs;
4725 	}
4726 
4727 	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4728 	if (!bctl) {
4729 		ret = -ENOMEM;
4730 		goto out_bargs;
4731 	}
4732 
4733 	if (arg) {
4734 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4735 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4736 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4737 
4738 		bctl->flags = bargs->flags;
4739 	} else {
4740 		/* balance everything - no filters */
4741 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4742 	}
4743 
4744 	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4745 		ret = -EINVAL;
4746 		goto out_bctl;
4747 	}
4748 
4749 do_balance:
4750 	/*
4751 	 * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
4752 	 * btrfs_balance.  bctl is freed in reset_balance_state, or, if
4753 	 * restriper was paused all the way until unmount, in free_fs_info.
4754 	 * The flag should be cleared after reset_balance_state.
4755 	 */
4756 	need_unlock = false;
4757 
4758 	ret = btrfs_balance(fs_info, bctl, bargs);
4759 	bctl = NULL;
4760 
4761 	if ((ret == 0 || ret == -ECANCELED) && arg) {
4762 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4763 			ret = -EFAULT;
4764 	}
4765 
4766 out_bctl:
4767 	kfree(bctl);
4768 out_bargs:
4769 	kfree(bargs);
4770 out_unlock:
4771 	mutex_unlock(&fs_info->balance_mutex);
4772 	if (need_unlock)
4773 		clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4774 out:
4775 	mnt_drop_write_file(file);
4776 	return ret;
4777 }
4778 
4779 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4780 {
4781 	if (!capable(CAP_SYS_ADMIN))
4782 		return -EPERM;
4783 
4784 	switch (cmd) {
4785 	case BTRFS_BALANCE_CTL_PAUSE:
4786 		return btrfs_pause_balance(fs_info);
4787 	case BTRFS_BALANCE_CTL_CANCEL:
4788 		return btrfs_cancel_balance(fs_info);
4789 	}
4790 
4791 	return -EINVAL;
4792 }
4793 
4794 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4795 					 void __user *arg)
4796 {
4797 	struct btrfs_ioctl_balance_args *bargs;
4798 	int ret = 0;
4799 
4800 	if (!capable(CAP_SYS_ADMIN))
4801 		return -EPERM;
4802 
4803 	mutex_lock(&fs_info->balance_mutex);
4804 	if (!fs_info->balance_ctl) {
4805 		ret = -ENOTCONN;
4806 		goto out;
4807 	}
4808 
4809 	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4810 	if (!bargs) {
4811 		ret = -ENOMEM;
4812 		goto out;
4813 	}
4814 
4815 	btrfs_update_ioctl_balance_args(fs_info, bargs);
4816 
4817 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4818 		ret = -EFAULT;
4819 
4820 	kfree(bargs);
4821 out:
4822 	mutex_unlock(&fs_info->balance_mutex);
4823 	return ret;
4824 }
4825 
4826 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4827 {
4828 	struct inode *inode = file_inode(file);
4829 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4830 	struct btrfs_ioctl_quota_ctl_args *sa;
4831 	int ret;
4832 
4833 	if (!capable(CAP_SYS_ADMIN))
4834 		return -EPERM;
4835 
4836 	ret = mnt_want_write_file(file);
4837 	if (ret)
4838 		return ret;
4839 
4840 	sa = memdup_user(arg, sizeof(*sa));
4841 	if (IS_ERR(sa)) {
4842 		ret = PTR_ERR(sa);
4843 		goto drop_write;
4844 	}
4845 
4846 	down_write(&fs_info->subvol_sem);
4847 
4848 	switch (sa->cmd) {
4849 	case BTRFS_QUOTA_CTL_ENABLE:
4850 		ret = btrfs_quota_enable(fs_info);
4851 		break;
4852 	case BTRFS_QUOTA_CTL_DISABLE:
4853 		ret = btrfs_quota_disable(fs_info);
4854 		break;
4855 	default:
4856 		ret = -EINVAL;
4857 		break;
4858 	}
4859 
4860 	kfree(sa);
4861 	up_write(&fs_info->subvol_sem);
4862 drop_write:
4863 	mnt_drop_write_file(file);
4864 	return ret;
4865 }
4866 
4867 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4868 {
4869 	struct inode *inode = file_inode(file);
4870 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4871 	struct btrfs_root *root = BTRFS_I(inode)->root;
4872 	struct btrfs_ioctl_qgroup_assign_args *sa;
4873 	struct btrfs_trans_handle *trans;
4874 	int ret;
4875 	int err;
4876 
4877 	if (!capable(CAP_SYS_ADMIN))
4878 		return -EPERM;
4879 
4880 	ret = mnt_want_write_file(file);
4881 	if (ret)
4882 		return ret;
4883 
4884 	sa = memdup_user(arg, sizeof(*sa));
4885 	if (IS_ERR(sa)) {
4886 		ret = PTR_ERR(sa);
4887 		goto drop_write;
4888 	}
4889 
4890 	trans = btrfs_join_transaction(root);
4891 	if (IS_ERR(trans)) {
4892 		ret = PTR_ERR(trans);
4893 		goto out;
4894 	}
4895 
4896 	if (sa->assign) {
4897 		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4898 	} else {
4899 		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4900 	}
4901 
4902 	/* update qgroup status and info */
4903 	err = btrfs_run_qgroups(trans);
4904 	if (err < 0)
4905 		btrfs_handle_fs_error(fs_info, err,
4906 				      "failed to update qgroup status and info");
4907 	err = btrfs_end_transaction(trans);
4908 	if (err && !ret)
4909 		ret = err;
4910 
4911 out:
4912 	kfree(sa);
4913 drop_write:
4914 	mnt_drop_write_file(file);
4915 	return ret;
4916 }
4917 
4918 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4919 {
4920 	struct inode *inode = file_inode(file);
4921 	struct btrfs_root *root = BTRFS_I(inode)->root;
4922 	struct btrfs_ioctl_qgroup_create_args *sa;
4923 	struct btrfs_trans_handle *trans;
4924 	int ret;
4925 	int err;
4926 
4927 	if (!capable(CAP_SYS_ADMIN))
4928 		return -EPERM;
4929 
4930 	ret = mnt_want_write_file(file);
4931 	if (ret)
4932 		return ret;
4933 
4934 	sa = memdup_user(arg, sizeof(*sa));
4935 	if (IS_ERR(sa)) {
4936 		ret = PTR_ERR(sa);
4937 		goto drop_write;
4938 	}
4939 
4940 	if (!sa->qgroupid) {
4941 		ret = -EINVAL;
4942 		goto out;
4943 	}
4944 
4945 	trans = btrfs_join_transaction(root);
4946 	if (IS_ERR(trans)) {
4947 		ret = PTR_ERR(trans);
4948 		goto out;
4949 	}
4950 
4951 	if (sa->create) {
4952 		ret = btrfs_create_qgroup(trans, sa->qgroupid);
4953 	} else {
4954 		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4955 	}
4956 
4957 	err = btrfs_end_transaction(trans);
4958 	if (err && !ret)
4959 		ret = err;
4960 
4961 out:
4962 	kfree(sa);
4963 drop_write:
4964 	mnt_drop_write_file(file);
4965 	return ret;
4966 }
4967 
4968 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4969 {
4970 	struct inode *inode = file_inode(file);
4971 	struct btrfs_root *root = BTRFS_I(inode)->root;
4972 	struct btrfs_ioctl_qgroup_limit_args *sa;
4973 	struct btrfs_trans_handle *trans;
4974 	int ret;
4975 	int err;
4976 	u64 qgroupid;
4977 
4978 	if (!capable(CAP_SYS_ADMIN))
4979 		return -EPERM;
4980 
4981 	ret = mnt_want_write_file(file);
4982 	if (ret)
4983 		return ret;
4984 
4985 	sa = memdup_user(arg, sizeof(*sa));
4986 	if (IS_ERR(sa)) {
4987 		ret = PTR_ERR(sa);
4988 		goto drop_write;
4989 	}
4990 
4991 	trans = btrfs_join_transaction(root);
4992 	if (IS_ERR(trans)) {
4993 		ret = PTR_ERR(trans);
4994 		goto out;
4995 	}
4996 
4997 	qgroupid = sa->qgroupid;
4998 	if (!qgroupid) {
4999 		/* take the current subvol as qgroup */
5000 		qgroupid = root->root_key.objectid;
5001 	}
5002 
5003 	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
5004 
5005 	err = btrfs_end_transaction(trans);
5006 	if (err && !ret)
5007 		ret = err;
5008 
5009 out:
5010 	kfree(sa);
5011 drop_write:
5012 	mnt_drop_write_file(file);
5013 	return ret;
5014 }
5015 
5016 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5017 {
5018 	struct inode *inode = file_inode(file);
5019 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5020 	struct btrfs_ioctl_quota_rescan_args *qsa;
5021 	int ret;
5022 
5023 	if (!capable(CAP_SYS_ADMIN))
5024 		return -EPERM;
5025 
5026 	ret = mnt_want_write_file(file);
5027 	if (ret)
5028 		return ret;
5029 
5030 	qsa = memdup_user(arg, sizeof(*qsa));
5031 	if (IS_ERR(qsa)) {
5032 		ret = PTR_ERR(qsa);
5033 		goto drop_write;
5034 	}
5035 
5036 	if (qsa->flags) {
5037 		ret = -EINVAL;
5038 		goto out;
5039 	}
5040 
5041 	ret = btrfs_qgroup_rescan(fs_info);
5042 
5043 out:
5044 	kfree(qsa);
5045 drop_write:
5046 	mnt_drop_write_file(file);
5047 	return ret;
5048 }
5049 
5050 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5051 {
5052 	struct inode *inode = file_inode(file);
5053 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5054 	struct btrfs_ioctl_quota_rescan_args *qsa;
5055 	int ret = 0;
5056 
5057 	if (!capable(CAP_SYS_ADMIN))
5058 		return -EPERM;
5059 
5060 	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5061 	if (!qsa)
5062 		return -ENOMEM;
5063 
5064 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5065 		qsa->flags = 1;
5066 		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5067 	}
5068 
5069 	if (copy_to_user(arg, qsa, sizeof(*qsa)))
5070 		ret = -EFAULT;
5071 
5072 	kfree(qsa);
5073 	return ret;
5074 }
5075 
5076 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5077 {
5078 	struct inode *inode = file_inode(file);
5079 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5080 
5081 	if (!capable(CAP_SYS_ADMIN))
5082 		return -EPERM;
5083 
5084 	return btrfs_qgroup_wait_for_completion(fs_info, true);
5085 }
5086 
5087 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5088 					    struct btrfs_ioctl_received_subvol_args *sa)
5089 {
5090 	struct inode *inode = file_inode(file);
5091 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5092 	struct btrfs_root *root = BTRFS_I(inode)->root;
5093 	struct btrfs_root_item *root_item = &root->root_item;
5094 	struct btrfs_trans_handle *trans;
5095 	struct timespec64 ct = current_time(inode);
5096 	int ret = 0;
5097 	int received_uuid_changed;
5098 
5099 	if (!inode_owner_or_capable(inode))
5100 		return -EPERM;
5101 
5102 	ret = mnt_want_write_file(file);
5103 	if (ret < 0)
5104 		return ret;
5105 
5106 	down_write(&fs_info->subvol_sem);
5107 
5108 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5109 		ret = -EINVAL;
5110 		goto out;
5111 	}
5112 
5113 	if (btrfs_root_readonly(root)) {
5114 		ret = -EROFS;
5115 		goto out;
5116 	}
5117 
5118 	/*
5119 	 * 1 - root item
5120 	 * 2 - uuid items (received uuid + subvol uuid)
5121 	 */
5122 	trans = btrfs_start_transaction(root, 3);
5123 	if (IS_ERR(trans)) {
5124 		ret = PTR_ERR(trans);
5125 		trans = NULL;
5126 		goto out;
5127 	}
5128 
5129 	sa->rtransid = trans->transid;
5130 	sa->rtime.sec = ct.tv_sec;
5131 	sa->rtime.nsec = ct.tv_nsec;
5132 
5133 	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5134 				       BTRFS_UUID_SIZE);
5135 	if (received_uuid_changed &&
5136 	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
5137 		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5138 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5139 					  root->root_key.objectid);
5140 		if (ret && ret != -ENOENT) {
5141 		        btrfs_abort_transaction(trans, ret);
5142 		        btrfs_end_transaction(trans);
5143 		        goto out;
5144 		}
5145 	}
5146 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5147 	btrfs_set_root_stransid(root_item, sa->stransid);
5148 	btrfs_set_root_rtransid(root_item, sa->rtransid);
5149 	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5150 	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5151 	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5152 	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5153 
5154 	ret = btrfs_update_root(trans, fs_info->tree_root,
5155 				&root->root_key, &root->root_item);
5156 	if (ret < 0) {
5157 		btrfs_end_transaction(trans);
5158 		goto out;
5159 	}
5160 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5161 		ret = btrfs_uuid_tree_add(trans, sa->uuid,
5162 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5163 					  root->root_key.objectid);
5164 		if (ret < 0 && ret != -EEXIST) {
5165 			btrfs_abort_transaction(trans, ret);
5166 			btrfs_end_transaction(trans);
5167 			goto out;
5168 		}
5169 	}
5170 	ret = btrfs_commit_transaction(trans);
5171 out:
5172 	up_write(&fs_info->subvol_sem);
5173 	mnt_drop_write_file(file);
5174 	return ret;
5175 }
5176 
5177 #ifdef CONFIG_64BIT
5178 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5179 						void __user *arg)
5180 {
5181 	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5182 	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5183 	int ret = 0;
5184 
5185 	args32 = memdup_user(arg, sizeof(*args32));
5186 	if (IS_ERR(args32))
5187 		return PTR_ERR(args32);
5188 
5189 	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5190 	if (!args64) {
5191 		ret = -ENOMEM;
5192 		goto out;
5193 	}
5194 
5195 	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5196 	args64->stransid = args32->stransid;
5197 	args64->rtransid = args32->rtransid;
5198 	args64->stime.sec = args32->stime.sec;
5199 	args64->stime.nsec = args32->stime.nsec;
5200 	args64->rtime.sec = args32->rtime.sec;
5201 	args64->rtime.nsec = args32->rtime.nsec;
5202 	args64->flags = args32->flags;
5203 
5204 	ret = _btrfs_ioctl_set_received_subvol(file, args64);
5205 	if (ret)
5206 		goto out;
5207 
5208 	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5209 	args32->stransid = args64->stransid;
5210 	args32->rtransid = args64->rtransid;
5211 	args32->stime.sec = args64->stime.sec;
5212 	args32->stime.nsec = args64->stime.nsec;
5213 	args32->rtime.sec = args64->rtime.sec;
5214 	args32->rtime.nsec = args64->rtime.nsec;
5215 	args32->flags = args64->flags;
5216 
5217 	ret = copy_to_user(arg, args32, sizeof(*args32));
5218 	if (ret)
5219 		ret = -EFAULT;
5220 
5221 out:
5222 	kfree(args32);
5223 	kfree(args64);
5224 	return ret;
5225 }
5226 #endif
5227 
5228 static long btrfs_ioctl_set_received_subvol(struct file *file,
5229 					    void __user *arg)
5230 {
5231 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
5232 	int ret = 0;
5233 
5234 	sa = memdup_user(arg, sizeof(*sa));
5235 	if (IS_ERR(sa))
5236 		return PTR_ERR(sa);
5237 
5238 	ret = _btrfs_ioctl_set_received_subvol(file, sa);
5239 
5240 	if (ret)
5241 		goto out;
5242 
5243 	ret = copy_to_user(arg, sa, sizeof(*sa));
5244 	if (ret)
5245 		ret = -EFAULT;
5246 
5247 out:
5248 	kfree(sa);
5249 	return ret;
5250 }
5251 
5252 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5253 {
5254 	struct inode *inode = file_inode(file);
5255 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5256 	size_t len;
5257 	int ret;
5258 	char label[BTRFS_LABEL_SIZE];
5259 
5260 	spin_lock(&fs_info->super_lock);
5261 	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5262 	spin_unlock(&fs_info->super_lock);
5263 
5264 	len = strnlen(label, BTRFS_LABEL_SIZE);
5265 
5266 	if (len == BTRFS_LABEL_SIZE) {
5267 		btrfs_warn(fs_info,
5268 			   "label is too long, return the first %zu bytes",
5269 			   --len);
5270 	}
5271 
5272 	ret = copy_to_user(arg, label, len);
5273 
5274 	return ret ? -EFAULT : 0;
5275 }
5276 
5277 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5278 {
5279 	struct inode *inode = file_inode(file);
5280 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5281 	struct btrfs_root *root = BTRFS_I(inode)->root;
5282 	struct btrfs_super_block *super_block = fs_info->super_copy;
5283 	struct btrfs_trans_handle *trans;
5284 	char label[BTRFS_LABEL_SIZE];
5285 	int ret;
5286 
5287 	if (!capable(CAP_SYS_ADMIN))
5288 		return -EPERM;
5289 
5290 	if (copy_from_user(label, arg, sizeof(label)))
5291 		return -EFAULT;
5292 
5293 	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5294 		btrfs_err(fs_info,
5295 			  "unable to set label with more than %d bytes",
5296 			  BTRFS_LABEL_SIZE - 1);
5297 		return -EINVAL;
5298 	}
5299 
5300 	ret = mnt_want_write_file(file);
5301 	if (ret)
5302 		return ret;
5303 
5304 	trans = btrfs_start_transaction(root, 0);
5305 	if (IS_ERR(trans)) {
5306 		ret = PTR_ERR(trans);
5307 		goto out_unlock;
5308 	}
5309 
5310 	spin_lock(&fs_info->super_lock);
5311 	strcpy(super_block->label, label);
5312 	spin_unlock(&fs_info->super_lock);
5313 	ret = btrfs_commit_transaction(trans);
5314 
5315 out_unlock:
5316 	mnt_drop_write_file(file);
5317 	return ret;
5318 }
5319 
5320 #define INIT_FEATURE_FLAGS(suffix) \
5321 	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5322 	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5323 	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5324 
5325 int btrfs_ioctl_get_supported_features(void __user *arg)
5326 {
5327 	static const struct btrfs_ioctl_feature_flags features[3] = {
5328 		INIT_FEATURE_FLAGS(SUPP),
5329 		INIT_FEATURE_FLAGS(SAFE_SET),
5330 		INIT_FEATURE_FLAGS(SAFE_CLEAR)
5331 	};
5332 
5333 	if (copy_to_user(arg, &features, sizeof(features)))
5334 		return -EFAULT;
5335 
5336 	return 0;
5337 }
5338 
5339 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5340 {
5341 	struct inode *inode = file_inode(file);
5342 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5343 	struct btrfs_super_block *super_block = fs_info->super_copy;
5344 	struct btrfs_ioctl_feature_flags features;
5345 
5346 	features.compat_flags = btrfs_super_compat_flags(super_block);
5347 	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5348 	features.incompat_flags = btrfs_super_incompat_flags(super_block);
5349 
5350 	if (copy_to_user(arg, &features, sizeof(features)))
5351 		return -EFAULT;
5352 
5353 	return 0;
5354 }
5355 
5356 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5357 			      enum btrfs_feature_set set,
5358 			      u64 change_mask, u64 flags, u64 supported_flags,
5359 			      u64 safe_set, u64 safe_clear)
5360 {
5361 	const char *type = btrfs_feature_set_names[set];
5362 	char *names;
5363 	u64 disallowed, unsupported;
5364 	u64 set_mask = flags & change_mask;
5365 	u64 clear_mask = ~flags & change_mask;
5366 
5367 	unsupported = set_mask & ~supported_flags;
5368 	if (unsupported) {
5369 		names = btrfs_printable_features(set, unsupported);
5370 		if (names) {
5371 			btrfs_warn(fs_info,
5372 				   "this kernel does not support the %s feature bit%s",
5373 				   names, strchr(names, ',') ? "s" : "");
5374 			kfree(names);
5375 		} else
5376 			btrfs_warn(fs_info,
5377 				   "this kernel does not support %s bits 0x%llx",
5378 				   type, unsupported);
5379 		return -EOPNOTSUPP;
5380 	}
5381 
5382 	disallowed = set_mask & ~safe_set;
5383 	if (disallowed) {
5384 		names = btrfs_printable_features(set, disallowed);
5385 		if (names) {
5386 			btrfs_warn(fs_info,
5387 				   "can't set the %s feature bit%s while mounted",
5388 				   names, strchr(names, ',') ? "s" : "");
5389 			kfree(names);
5390 		} else
5391 			btrfs_warn(fs_info,
5392 				   "can't set %s bits 0x%llx while mounted",
5393 				   type, disallowed);
5394 		return -EPERM;
5395 	}
5396 
5397 	disallowed = clear_mask & ~safe_clear;
5398 	if (disallowed) {
5399 		names = btrfs_printable_features(set, disallowed);
5400 		if (names) {
5401 			btrfs_warn(fs_info,
5402 				   "can't clear the %s feature bit%s while mounted",
5403 				   names, strchr(names, ',') ? "s" : "");
5404 			kfree(names);
5405 		} else
5406 			btrfs_warn(fs_info,
5407 				   "can't clear %s bits 0x%llx while mounted",
5408 				   type, disallowed);
5409 		return -EPERM;
5410 	}
5411 
5412 	return 0;
5413 }
5414 
5415 #define check_feature(fs_info, change_mask, flags, mask_base)	\
5416 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
5417 		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
5418 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
5419 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5420 
5421 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5422 {
5423 	struct inode *inode = file_inode(file);
5424 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5425 	struct btrfs_root *root = BTRFS_I(inode)->root;
5426 	struct btrfs_super_block *super_block = fs_info->super_copy;
5427 	struct btrfs_ioctl_feature_flags flags[2];
5428 	struct btrfs_trans_handle *trans;
5429 	u64 newflags;
5430 	int ret;
5431 
5432 	if (!capable(CAP_SYS_ADMIN))
5433 		return -EPERM;
5434 
5435 	if (copy_from_user(flags, arg, sizeof(flags)))
5436 		return -EFAULT;
5437 
5438 	/* Nothing to do */
5439 	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5440 	    !flags[0].incompat_flags)
5441 		return 0;
5442 
5443 	ret = check_feature(fs_info, flags[0].compat_flags,
5444 			    flags[1].compat_flags, COMPAT);
5445 	if (ret)
5446 		return ret;
5447 
5448 	ret = check_feature(fs_info, flags[0].compat_ro_flags,
5449 			    flags[1].compat_ro_flags, COMPAT_RO);
5450 	if (ret)
5451 		return ret;
5452 
5453 	ret = check_feature(fs_info, flags[0].incompat_flags,
5454 			    flags[1].incompat_flags, INCOMPAT);
5455 	if (ret)
5456 		return ret;
5457 
5458 	ret = mnt_want_write_file(file);
5459 	if (ret)
5460 		return ret;
5461 
5462 	trans = btrfs_start_transaction(root, 0);
5463 	if (IS_ERR(trans)) {
5464 		ret = PTR_ERR(trans);
5465 		goto out_drop_write;
5466 	}
5467 
5468 	spin_lock(&fs_info->super_lock);
5469 	newflags = btrfs_super_compat_flags(super_block);
5470 	newflags |= flags[0].compat_flags & flags[1].compat_flags;
5471 	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5472 	btrfs_set_super_compat_flags(super_block, newflags);
5473 
5474 	newflags = btrfs_super_compat_ro_flags(super_block);
5475 	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5476 	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5477 	btrfs_set_super_compat_ro_flags(super_block, newflags);
5478 
5479 	newflags = btrfs_super_incompat_flags(super_block);
5480 	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5481 	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5482 	btrfs_set_super_incompat_flags(super_block, newflags);
5483 	spin_unlock(&fs_info->super_lock);
5484 
5485 	ret = btrfs_commit_transaction(trans);
5486 out_drop_write:
5487 	mnt_drop_write_file(file);
5488 
5489 	return ret;
5490 }
5491 
5492 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5493 {
5494 	struct btrfs_ioctl_send_args *arg;
5495 	int ret;
5496 
5497 	if (compat) {
5498 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5499 		struct btrfs_ioctl_send_args_32 args32;
5500 
5501 		ret = copy_from_user(&args32, argp, sizeof(args32));
5502 		if (ret)
5503 			return -EFAULT;
5504 		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5505 		if (!arg)
5506 			return -ENOMEM;
5507 		arg->send_fd = args32.send_fd;
5508 		arg->clone_sources_count = args32.clone_sources_count;
5509 		arg->clone_sources = compat_ptr(args32.clone_sources);
5510 		arg->parent_root = args32.parent_root;
5511 		arg->flags = args32.flags;
5512 		memcpy(arg->reserved, args32.reserved,
5513 		       sizeof(args32.reserved));
5514 #else
5515 		return -ENOTTY;
5516 #endif
5517 	} else {
5518 		arg = memdup_user(argp, sizeof(*arg));
5519 		if (IS_ERR(arg))
5520 			return PTR_ERR(arg);
5521 	}
5522 	ret = btrfs_ioctl_send(file, arg);
5523 	kfree(arg);
5524 	return ret;
5525 }
5526 
5527 long btrfs_ioctl(struct file *file, unsigned int
5528 		cmd, unsigned long arg)
5529 {
5530 	struct inode *inode = file_inode(file);
5531 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5532 	struct btrfs_root *root = BTRFS_I(inode)->root;
5533 	void __user *argp = (void __user *)arg;
5534 
5535 	switch (cmd) {
5536 	case FS_IOC_GETFLAGS:
5537 		return btrfs_ioctl_getflags(file, argp);
5538 	case FS_IOC_SETFLAGS:
5539 		return btrfs_ioctl_setflags(file, argp);
5540 	case FS_IOC_GETVERSION:
5541 		return btrfs_ioctl_getversion(file, argp);
5542 	case FITRIM:
5543 		return btrfs_ioctl_fitrim(file, argp);
5544 	case BTRFS_IOC_SNAP_CREATE:
5545 		return btrfs_ioctl_snap_create(file, argp, 0);
5546 	case BTRFS_IOC_SNAP_CREATE_V2:
5547 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
5548 	case BTRFS_IOC_SUBVOL_CREATE:
5549 		return btrfs_ioctl_snap_create(file, argp, 1);
5550 	case BTRFS_IOC_SUBVOL_CREATE_V2:
5551 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
5552 	case BTRFS_IOC_SNAP_DESTROY:
5553 		return btrfs_ioctl_snap_destroy(file, argp);
5554 	case BTRFS_IOC_SUBVOL_GETFLAGS:
5555 		return btrfs_ioctl_subvol_getflags(file, argp);
5556 	case BTRFS_IOC_SUBVOL_SETFLAGS:
5557 		return btrfs_ioctl_subvol_setflags(file, argp);
5558 	case BTRFS_IOC_DEFAULT_SUBVOL:
5559 		return btrfs_ioctl_default_subvol(file, argp);
5560 	case BTRFS_IOC_DEFRAG:
5561 		return btrfs_ioctl_defrag(file, NULL);
5562 	case BTRFS_IOC_DEFRAG_RANGE:
5563 		return btrfs_ioctl_defrag(file, argp);
5564 	case BTRFS_IOC_RESIZE:
5565 		return btrfs_ioctl_resize(file, argp);
5566 	case BTRFS_IOC_ADD_DEV:
5567 		return btrfs_ioctl_add_dev(fs_info, argp);
5568 	case BTRFS_IOC_RM_DEV:
5569 		return btrfs_ioctl_rm_dev(file, argp);
5570 	case BTRFS_IOC_RM_DEV_V2:
5571 		return btrfs_ioctl_rm_dev_v2(file, argp);
5572 	case BTRFS_IOC_FS_INFO:
5573 		return btrfs_ioctl_fs_info(fs_info, argp);
5574 	case BTRFS_IOC_DEV_INFO:
5575 		return btrfs_ioctl_dev_info(fs_info, argp);
5576 	case BTRFS_IOC_BALANCE:
5577 		return btrfs_ioctl_balance(file, NULL);
5578 	case BTRFS_IOC_TREE_SEARCH:
5579 		return btrfs_ioctl_tree_search(file, argp);
5580 	case BTRFS_IOC_TREE_SEARCH_V2:
5581 		return btrfs_ioctl_tree_search_v2(file, argp);
5582 	case BTRFS_IOC_INO_LOOKUP:
5583 		return btrfs_ioctl_ino_lookup(file, argp);
5584 	case BTRFS_IOC_INO_PATHS:
5585 		return btrfs_ioctl_ino_to_path(root, argp);
5586 	case BTRFS_IOC_LOGICAL_INO:
5587 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5588 	case BTRFS_IOC_LOGICAL_INO_V2:
5589 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5590 	case BTRFS_IOC_SPACE_INFO:
5591 		return btrfs_ioctl_space_info(fs_info, argp);
5592 	case BTRFS_IOC_SYNC: {
5593 		int ret;
5594 
5595 		ret = btrfs_start_delalloc_roots(fs_info, -1);
5596 		if (ret)
5597 			return ret;
5598 		ret = btrfs_sync_fs(inode->i_sb, 1);
5599 		/*
5600 		 * The transaction thread may want to do more work,
5601 		 * namely it pokes the cleaner kthread that will start
5602 		 * processing uncleaned subvols.
5603 		 */
5604 		wake_up_process(fs_info->transaction_kthread);
5605 		return ret;
5606 	}
5607 	case BTRFS_IOC_START_SYNC:
5608 		return btrfs_ioctl_start_sync(root, argp);
5609 	case BTRFS_IOC_WAIT_SYNC:
5610 		return btrfs_ioctl_wait_sync(fs_info, argp);
5611 	case BTRFS_IOC_SCRUB:
5612 		return btrfs_ioctl_scrub(file, argp);
5613 	case BTRFS_IOC_SCRUB_CANCEL:
5614 		return btrfs_ioctl_scrub_cancel(fs_info);
5615 	case BTRFS_IOC_SCRUB_PROGRESS:
5616 		return btrfs_ioctl_scrub_progress(fs_info, argp);
5617 	case BTRFS_IOC_BALANCE_V2:
5618 		return btrfs_ioctl_balance(file, argp);
5619 	case BTRFS_IOC_BALANCE_CTL:
5620 		return btrfs_ioctl_balance_ctl(fs_info, arg);
5621 	case BTRFS_IOC_BALANCE_PROGRESS:
5622 		return btrfs_ioctl_balance_progress(fs_info, argp);
5623 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5624 		return btrfs_ioctl_set_received_subvol(file, argp);
5625 #ifdef CONFIG_64BIT
5626 	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5627 		return btrfs_ioctl_set_received_subvol_32(file, argp);
5628 #endif
5629 	case BTRFS_IOC_SEND:
5630 		return _btrfs_ioctl_send(file, argp, false);
5631 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5632 	case BTRFS_IOC_SEND_32:
5633 		return _btrfs_ioctl_send(file, argp, true);
5634 #endif
5635 	case BTRFS_IOC_GET_DEV_STATS:
5636 		return btrfs_ioctl_get_dev_stats(fs_info, argp);
5637 	case BTRFS_IOC_QUOTA_CTL:
5638 		return btrfs_ioctl_quota_ctl(file, argp);
5639 	case BTRFS_IOC_QGROUP_ASSIGN:
5640 		return btrfs_ioctl_qgroup_assign(file, argp);
5641 	case BTRFS_IOC_QGROUP_CREATE:
5642 		return btrfs_ioctl_qgroup_create(file, argp);
5643 	case BTRFS_IOC_QGROUP_LIMIT:
5644 		return btrfs_ioctl_qgroup_limit(file, argp);
5645 	case BTRFS_IOC_QUOTA_RESCAN:
5646 		return btrfs_ioctl_quota_rescan(file, argp);
5647 	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5648 		return btrfs_ioctl_quota_rescan_status(file, argp);
5649 	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5650 		return btrfs_ioctl_quota_rescan_wait(file, argp);
5651 	case BTRFS_IOC_DEV_REPLACE:
5652 		return btrfs_ioctl_dev_replace(fs_info, argp);
5653 	case BTRFS_IOC_GET_FSLABEL:
5654 		return btrfs_ioctl_get_fslabel(file, argp);
5655 	case BTRFS_IOC_SET_FSLABEL:
5656 		return btrfs_ioctl_set_fslabel(file, argp);
5657 	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5658 		return btrfs_ioctl_get_supported_features(argp);
5659 	case BTRFS_IOC_GET_FEATURES:
5660 		return btrfs_ioctl_get_features(file, argp);
5661 	case BTRFS_IOC_SET_FEATURES:
5662 		return btrfs_ioctl_set_features(file, argp);
5663 	case FS_IOC_FSGETXATTR:
5664 		return btrfs_ioctl_fsgetxattr(file, argp);
5665 	case FS_IOC_FSSETXATTR:
5666 		return btrfs_ioctl_fssetxattr(file, argp);
5667 	case BTRFS_IOC_GET_SUBVOL_INFO:
5668 		return btrfs_ioctl_get_subvol_info(file, argp);
5669 	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5670 		return btrfs_ioctl_get_subvol_rootref(file, argp);
5671 	case BTRFS_IOC_INO_LOOKUP_USER:
5672 		return btrfs_ioctl_ino_lookup_user(file, argp);
5673 	}
5674 
5675 	return -ENOTTY;
5676 }
5677 
5678 #ifdef CONFIG_COMPAT
5679 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5680 {
5681 	/*
5682 	 * These all access 32-bit values anyway so no further
5683 	 * handling is necessary.
5684 	 */
5685 	switch (cmd) {
5686 	case FS_IOC32_GETFLAGS:
5687 		cmd = FS_IOC_GETFLAGS;
5688 		break;
5689 	case FS_IOC32_SETFLAGS:
5690 		cmd = FS_IOC_SETFLAGS;
5691 		break;
5692 	case FS_IOC32_GETVERSION:
5693 		cmd = FS_IOC_GETVERSION;
5694 		break;
5695 	}
5696 
5697 	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5698 }
5699 #endif
5700