xref: /openbmc/linux/fs/btrfs/ioctl.c (revision d003d772)
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 	u64 old_flags;
193 	unsigned int old_i_flags;
194 	umode_t mode;
195 
196 	if (!inode_owner_or_capable(inode))
197 		return -EPERM;
198 
199 	if (btrfs_root_readonly(root))
200 		return -EROFS;
201 
202 	if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
203 		return -EFAULT;
204 
205 	ret = check_fsflags(fsflags);
206 	if (ret)
207 		return ret;
208 
209 	ret = mnt_want_write_file(file);
210 	if (ret)
211 		return ret;
212 
213 	inode_lock(inode);
214 
215 	old_flags = binode->flags;
216 	old_i_flags = inode->i_flags;
217 	mode = inode->i_mode;
218 
219 	fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
220 	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
221 	if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
222 		if (!capable(CAP_LINUX_IMMUTABLE)) {
223 			ret = -EPERM;
224 			goto out_unlock;
225 		}
226 	}
227 
228 	if (fsflags & FS_SYNC_FL)
229 		binode->flags |= BTRFS_INODE_SYNC;
230 	else
231 		binode->flags &= ~BTRFS_INODE_SYNC;
232 	if (fsflags & FS_IMMUTABLE_FL)
233 		binode->flags |= BTRFS_INODE_IMMUTABLE;
234 	else
235 		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
236 	if (fsflags & FS_APPEND_FL)
237 		binode->flags |= BTRFS_INODE_APPEND;
238 	else
239 		binode->flags &= ~BTRFS_INODE_APPEND;
240 	if (fsflags & FS_NODUMP_FL)
241 		binode->flags |= BTRFS_INODE_NODUMP;
242 	else
243 		binode->flags &= ~BTRFS_INODE_NODUMP;
244 	if (fsflags & FS_NOATIME_FL)
245 		binode->flags |= BTRFS_INODE_NOATIME;
246 	else
247 		binode->flags &= ~BTRFS_INODE_NOATIME;
248 	if (fsflags & FS_DIRSYNC_FL)
249 		binode->flags |= BTRFS_INODE_DIRSYNC;
250 	else
251 		binode->flags &= ~BTRFS_INODE_DIRSYNC;
252 	if (fsflags & FS_NOCOW_FL) {
253 		if (S_ISREG(mode)) {
254 			/*
255 			 * It's safe to turn csums off here, no extents exist.
256 			 * Otherwise we want the flag to reflect the real COW
257 			 * status of the file and will not set it.
258 			 */
259 			if (inode->i_size == 0)
260 				binode->flags |= BTRFS_INODE_NODATACOW
261 					      | BTRFS_INODE_NODATASUM;
262 		} else {
263 			binode->flags |= BTRFS_INODE_NODATACOW;
264 		}
265 	} else {
266 		/*
267 		 * Revert back under same assumptions as above
268 		 */
269 		if (S_ISREG(mode)) {
270 			if (inode->i_size == 0)
271 				binode->flags &= ~(BTRFS_INODE_NODATACOW
272 				             | BTRFS_INODE_NODATASUM);
273 		} else {
274 			binode->flags &= ~BTRFS_INODE_NODATACOW;
275 		}
276 	}
277 
278 	/*
279 	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
280 	 * flag may be changed automatically if compression code won't make
281 	 * things smaller.
282 	 */
283 	if (fsflags & FS_NOCOMP_FL) {
284 		binode->flags &= ~BTRFS_INODE_COMPRESS;
285 		binode->flags |= BTRFS_INODE_NOCOMPRESS;
286 
287 		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
288 		if (ret && ret != -ENODATA)
289 			goto out_drop;
290 	} else if (fsflags & FS_COMPR_FL) {
291 		const char *comp;
292 
293 		if (IS_SWAPFILE(inode)) {
294 			ret = -ETXTBSY;
295 			goto out_unlock;
296 		}
297 
298 		binode->flags |= BTRFS_INODE_COMPRESS;
299 		binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
300 
301 		comp = btrfs_compress_type2str(fs_info->compress_type);
302 		if (!comp || comp[0] == 0)
303 			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
304 
305 		ret = btrfs_set_prop(inode, "btrfs.compression",
306 				     comp, strlen(comp), 0);
307 		if (ret)
308 			goto out_drop;
309 
310 	} else {
311 		ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
312 		if (ret && ret != -ENODATA)
313 			goto out_drop;
314 		binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
315 	}
316 
317 	trans = btrfs_start_transaction(root, 1);
318 	if (IS_ERR(trans)) {
319 		ret = PTR_ERR(trans);
320 		goto out_drop;
321 	}
322 
323 	btrfs_sync_inode_flags_to_i_flags(inode);
324 	inode_inc_iversion(inode);
325 	inode->i_ctime = current_time(inode);
326 	ret = btrfs_update_inode(trans, root, inode);
327 
328 	btrfs_end_transaction(trans);
329  out_drop:
330 	if (ret) {
331 		binode->flags = old_flags;
332 		inode->i_flags = old_i_flags;
333 	}
334 
335  out_unlock:
336 	inode_unlock(inode);
337 	mnt_drop_write_file(file);
338 	return ret;
339 }
340 
341 /*
342  * Translate btrfs internal inode flags to xflags as expected by the
343  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
344  * silently dropped.
345  */
346 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
347 {
348 	unsigned int xflags = 0;
349 
350 	if (flags & BTRFS_INODE_APPEND)
351 		xflags |= FS_XFLAG_APPEND;
352 	if (flags & BTRFS_INODE_IMMUTABLE)
353 		xflags |= FS_XFLAG_IMMUTABLE;
354 	if (flags & BTRFS_INODE_NOATIME)
355 		xflags |= FS_XFLAG_NOATIME;
356 	if (flags & BTRFS_INODE_NODUMP)
357 		xflags |= FS_XFLAG_NODUMP;
358 	if (flags & BTRFS_INODE_SYNC)
359 		xflags |= FS_XFLAG_SYNC;
360 
361 	return xflags;
362 }
363 
364 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
365 static int check_xflags(unsigned int flags)
366 {
367 	if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
368 		      FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
369 		return -EOPNOTSUPP;
370 	return 0;
371 }
372 
373 /*
374  * Set the xflags from the internal inode flags. The remaining items of fsxattr
375  * are zeroed.
376  */
377 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
378 {
379 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
380 	struct fsxattr fa;
381 
382 	memset(&fa, 0, sizeof(fa));
383 	fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
384 
385 	if (copy_to_user(arg, &fa, sizeof(fa)))
386 		return -EFAULT;
387 
388 	return 0;
389 }
390 
391 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
392 {
393 	struct inode *inode = file_inode(file);
394 	struct btrfs_inode *binode = BTRFS_I(inode);
395 	struct btrfs_root *root = binode->root;
396 	struct btrfs_trans_handle *trans;
397 	struct fsxattr fa;
398 	unsigned old_flags;
399 	unsigned old_i_flags;
400 	int ret = 0;
401 
402 	if (!inode_owner_or_capable(inode))
403 		return -EPERM;
404 
405 	if (btrfs_root_readonly(root))
406 		return -EROFS;
407 
408 	memset(&fa, 0, sizeof(fa));
409 	if (copy_from_user(&fa, arg, sizeof(fa)))
410 		return -EFAULT;
411 
412 	ret = check_xflags(fa.fsx_xflags);
413 	if (ret)
414 		return ret;
415 
416 	if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
417 		return -EOPNOTSUPP;
418 
419 	ret = mnt_want_write_file(file);
420 	if (ret)
421 		return ret;
422 
423 	inode_lock(inode);
424 
425 	old_flags = binode->flags;
426 	old_i_flags = inode->i_flags;
427 
428 	/* We need the capabilities to change append-only or immutable inode */
429 	if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
430 	     (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
431 	    !capable(CAP_LINUX_IMMUTABLE)) {
432 		ret = -EPERM;
433 		goto out_unlock;
434 	}
435 
436 	if (fa.fsx_xflags & FS_XFLAG_SYNC)
437 		binode->flags |= BTRFS_INODE_SYNC;
438 	else
439 		binode->flags &= ~BTRFS_INODE_SYNC;
440 	if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
441 		binode->flags |= BTRFS_INODE_IMMUTABLE;
442 	else
443 		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
444 	if (fa.fsx_xflags & FS_XFLAG_APPEND)
445 		binode->flags |= BTRFS_INODE_APPEND;
446 	else
447 		binode->flags &= ~BTRFS_INODE_APPEND;
448 	if (fa.fsx_xflags & FS_XFLAG_NODUMP)
449 		binode->flags |= BTRFS_INODE_NODUMP;
450 	else
451 		binode->flags &= ~BTRFS_INODE_NODUMP;
452 	if (fa.fsx_xflags & FS_XFLAG_NOATIME)
453 		binode->flags |= BTRFS_INODE_NOATIME;
454 	else
455 		binode->flags &= ~BTRFS_INODE_NOATIME;
456 
457 	/* 1 item for the inode */
458 	trans = btrfs_start_transaction(root, 1);
459 	if (IS_ERR(trans)) {
460 		ret = PTR_ERR(trans);
461 		goto out_unlock;
462 	}
463 
464 	btrfs_sync_inode_flags_to_i_flags(inode);
465 	inode_inc_iversion(inode);
466 	inode->i_ctime = current_time(inode);
467 	ret = btrfs_update_inode(trans, root, inode);
468 
469 	btrfs_end_transaction(trans);
470 
471 out_unlock:
472 	if (ret) {
473 		binode->flags = old_flags;
474 		inode->i_flags = old_i_flags;
475 	}
476 
477 	inode_unlock(inode);
478 	mnt_drop_write_file(file);
479 
480 	return ret;
481 }
482 
483 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
484 {
485 	struct inode *inode = file_inode(file);
486 
487 	return put_user(inode->i_generation, arg);
488 }
489 
490 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
491 {
492 	struct inode *inode = file_inode(file);
493 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
494 	struct btrfs_device *device;
495 	struct request_queue *q;
496 	struct fstrim_range range;
497 	u64 minlen = ULLONG_MAX;
498 	u64 num_devices = 0;
499 	int ret;
500 
501 	if (!capable(CAP_SYS_ADMIN))
502 		return -EPERM;
503 
504 	/*
505 	 * If the fs is mounted with nologreplay, which requires it to be
506 	 * mounted in RO mode as well, we can not allow discard on free space
507 	 * inside block groups, because log trees refer to extents that are not
508 	 * pinned in a block group's free space cache (pinning the extents is
509 	 * precisely the first phase of replaying a log tree).
510 	 */
511 	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
512 		return -EROFS;
513 
514 	rcu_read_lock();
515 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
516 				dev_list) {
517 		if (!device->bdev)
518 			continue;
519 		q = bdev_get_queue(device->bdev);
520 		if (blk_queue_discard(q)) {
521 			num_devices++;
522 			minlen = min_t(u64, q->limits.discard_granularity,
523 				     minlen);
524 		}
525 	}
526 	rcu_read_unlock();
527 
528 	if (!num_devices)
529 		return -EOPNOTSUPP;
530 	if (copy_from_user(&range, arg, sizeof(range)))
531 		return -EFAULT;
532 
533 	/*
534 	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
535 	 * block group is in the logical address space, which can be any
536 	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
537 	 */
538 	if (range.len < fs_info->sb->s_blocksize)
539 		return -EINVAL;
540 
541 	range.minlen = max(range.minlen, minlen);
542 	ret = btrfs_trim_fs(fs_info, &range);
543 	if (ret < 0)
544 		return ret;
545 
546 	if (copy_to_user(arg, &range, sizeof(range)))
547 		return -EFAULT;
548 
549 	return 0;
550 }
551 
552 int btrfs_is_empty_uuid(u8 *uuid)
553 {
554 	int i;
555 
556 	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
557 		if (uuid[i])
558 			return 0;
559 	}
560 	return 1;
561 }
562 
563 static noinline int create_subvol(struct inode *dir,
564 				  struct dentry *dentry,
565 				  const char *name, int namelen,
566 				  u64 *async_transid,
567 				  struct btrfs_qgroup_inherit *inherit)
568 {
569 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
570 	struct btrfs_trans_handle *trans;
571 	struct btrfs_key key;
572 	struct btrfs_root_item *root_item;
573 	struct btrfs_inode_item *inode_item;
574 	struct extent_buffer *leaf;
575 	struct btrfs_root *root = BTRFS_I(dir)->root;
576 	struct btrfs_root *new_root;
577 	struct btrfs_block_rsv block_rsv;
578 	struct timespec64 cur_time = current_time(dir);
579 	struct inode *inode;
580 	int ret;
581 	int err;
582 	u64 objectid;
583 	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
584 	u64 index = 0;
585 	uuid_le new_uuid;
586 
587 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
588 	if (!root_item)
589 		return -ENOMEM;
590 
591 	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
592 	if (ret)
593 		goto fail_free;
594 
595 	/*
596 	 * Don't create subvolume whose level is not zero. Or qgroup will be
597 	 * screwed up since it assumes subvolume qgroup's level to be 0.
598 	 */
599 	if (btrfs_qgroup_level(objectid)) {
600 		ret = -ENOSPC;
601 		goto fail_free;
602 	}
603 
604 	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
605 	/*
606 	 * The same as the snapshot creation, please see the comment
607 	 * of create_snapshot().
608 	 */
609 	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
610 	if (ret)
611 		goto fail_free;
612 
613 	trans = btrfs_start_transaction(root, 0);
614 	if (IS_ERR(trans)) {
615 		ret = PTR_ERR(trans);
616 		btrfs_subvolume_release_metadata(fs_info, &block_rsv);
617 		goto fail_free;
618 	}
619 	trans->block_rsv = &block_rsv;
620 	trans->bytes_reserved = block_rsv.size;
621 
622 	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
623 	if (ret)
624 		goto fail;
625 
626 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
627 	if (IS_ERR(leaf)) {
628 		ret = PTR_ERR(leaf);
629 		goto fail;
630 	}
631 
632 	btrfs_mark_buffer_dirty(leaf);
633 
634 	inode_item = &root_item->inode;
635 	btrfs_set_stack_inode_generation(inode_item, 1);
636 	btrfs_set_stack_inode_size(inode_item, 3);
637 	btrfs_set_stack_inode_nlink(inode_item, 1);
638 	btrfs_set_stack_inode_nbytes(inode_item,
639 				     fs_info->nodesize);
640 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
641 
642 	btrfs_set_root_flags(root_item, 0);
643 	btrfs_set_root_limit(root_item, 0);
644 	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
645 
646 	btrfs_set_root_bytenr(root_item, leaf->start);
647 	btrfs_set_root_generation(root_item, trans->transid);
648 	btrfs_set_root_level(root_item, 0);
649 	btrfs_set_root_refs(root_item, 1);
650 	btrfs_set_root_used(root_item, leaf->len);
651 	btrfs_set_root_last_snapshot(root_item, 0);
652 
653 	btrfs_set_root_generation_v2(root_item,
654 			btrfs_root_generation(root_item));
655 	uuid_le_gen(&new_uuid);
656 	memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
657 	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
658 	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
659 	root_item->ctime = root_item->otime;
660 	btrfs_set_root_ctransid(root_item, trans->transid);
661 	btrfs_set_root_otransid(root_item, trans->transid);
662 
663 	btrfs_tree_unlock(leaf);
664 	free_extent_buffer(leaf);
665 	leaf = NULL;
666 
667 	btrfs_set_root_dirid(root_item, new_dirid);
668 
669 	key.objectid = objectid;
670 	key.offset = 0;
671 	key.type = BTRFS_ROOT_ITEM_KEY;
672 	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
673 				root_item);
674 	if (ret)
675 		goto fail;
676 
677 	key.offset = (u64)-1;
678 	new_root = btrfs_read_fs_root_no_name(fs_info, &key);
679 	if (IS_ERR(new_root)) {
680 		ret = PTR_ERR(new_root);
681 		btrfs_abort_transaction(trans, ret);
682 		goto fail;
683 	}
684 
685 	btrfs_record_root_in_trans(trans, new_root);
686 
687 	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
688 	if (ret) {
689 		/* We potentially lose an unused inode item here */
690 		btrfs_abort_transaction(trans, ret);
691 		goto fail;
692 	}
693 
694 	mutex_lock(&new_root->objectid_mutex);
695 	new_root->highest_objectid = new_dirid;
696 	mutex_unlock(&new_root->objectid_mutex);
697 
698 	/*
699 	 * insert the directory item
700 	 */
701 	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
702 	if (ret) {
703 		btrfs_abort_transaction(trans, ret);
704 		goto fail;
705 	}
706 
707 	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
708 				    BTRFS_FT_DIR, index);
709 	if (ret) {
710 		btrfs_abort_transaction(trans, ret);
711 		goto fail;
712 	}
713 
714 	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
715 	ret = btrfs_update_inode(trans, root, dir);
716 	BUG_ON(ret);
717 
718 	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
719 				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
720 	BUG_ON(ret);
721 
722 	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
723 				  BTRFS_UUID_KEY_SUBVOL, objectid);
724 	if (ret)
725 		btrfs_abort_transaction(trans, ret);
726 
727 fail:
728 	kfree(root_item);
729 	trans->block_rsv = NULL;
730 	trans->bytes_reserved = 0;
731 	btrfs_subvolume_release_metadata(fs_info, &block_rsv);
732 
733 	if (async_transid) {
734 		*async_transid = trans->transid;
735 		err = btrfs_commit_transaction_async(trans, 1);
736 		if (err)
737 			err = btrfs_commit_transaction(trans);
738 	} else {
739 		err = btrfs_commit_transaction(trans);
740 	}
741 	if (err && !ret)
742 		ret = err;
743 
744 	if (!ret) {
745 		inode = btrfs_lookup_dentry(dir, dentry);
746 		if (IS_ERR(inode))
747 			return PTR_ERR(inode);
748 		d_instantiate(dentry, inode);
749 	}
750 	return ret;
751 
752 fail_free:
753 	kfree(root_item);
754 	return ret;
755 }
756 
757 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
758 			   struct dentry *dentry,
759 			   u64 *async_transid, bool readonly,
760 			   struct btrfs_qgroup_inherit *inherit)
761 {
762 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
763 	struct inode *inode;
764 	struct btrfs_pending_snapshot *pending_snapshot;
765 	struct btrfs_trans_handle *trans;
766 	int ret;
767 	bool snapshot_force_cow = false;
768 
769 	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
770 		return -EINVAL;
771 
772 	if (atomic_read(&root->nr_swapfiles)) {
773 		btrfs_warn(fs_info,
774 			   "cannot snapshot subvolume with active swapfile");
775 		return -ETXTBSY;
776 	}
777 
778 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
779 	if (!pending_snapshot)
780 		return -ENOMEM;
781 
782 	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
783 			GFP_KERNEL);
784 	pending_snapshot->path = btrfs_alloc_path();
785 	if (!pending_snapshot->root_item || !pending_snapshot->path) {
786 		ret = -ENOMEM;
787 		goto free_pending;
788 	}
789 
790 	/*
791 	 * Force new buffered writes to reserve space even when NOCOW is
792 	 * possible. This is to avoid later writeback (running dealloc) to
793 	 * fallback to COW mode and unexpectedly fail with ENOSPC.
794 	 */
795 	atomic_inc(&root->will_be_snapshotted);
796 	smp_mb__after_atomic();
797 	/* wait for no snapshot writes */
798 	wait_event(root->subv_writers->wait,
799 		   percpu_counter_sum(&root->subv_writers->counter) == 0);
800 
801 	ret = btrfs_start_delalloc_snapshot(root);
802 	if (ret)
803 		goto dec_and_free;
804 
805 	/*
806 	 * All previous writes have started writeback in NOCOW mode, so now
807 	 * we force future writes to fallback to COW mode during snapshot
808 	 * creation.
809 	 */
810 	atomic_inc(&root->snapshot_force_cow);
811 	snapshot_force_cow = true;
812 
813 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
814 
815 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
816 			     BTRFS_BLOCK_RSV_TEMP);
817 	/*
818 	 * 1 - parent dir inode
819 	 * 2 - dir entries
820 	 * 1 - root item
821 	 * 2 - root ref/backref
822 	 * 1 - root of snapshot
823 	 * 1 - UUID item
824 	 */
825 	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
826 					&pending_snapshot->block_rsv, 8,
827 					false);
828 	if (ret)
829 		goto dec_and_free;
830 
831 	pending_snapshot->dentry = dentry;
832 	pending_snapshot->root = root;
833 	pending_snapshot->readonly = readonly;
834 	pending_snapshot->dir = dir;
835 	pending_snapshot->inherit = inherit;
836 
837 	trans = btrfs_start_transaction(root, 0);
838 	if (IS_ERR(trans)) {
839 		ret = PTR_ERR(trans);
840 		goto fail;
841 	}
842 
843 	spin_lock(&fs_info->trans_lock);
844 	list_add(&pending_snapshot->list,
845 		 &trans->transaction->pending_snapshots);
846 	spin_unlock(&fs_info->trans_lock);
847 	if (async_transid) {
848 		*async_transid = trans->transid;
849 		ret = btrfs_commit_transaction_async(trans, 1);
850 		if (ret)
851 			ret = btrfs_commit_transaction(trans);
852 	} else {
853 		ret = btrfs_commit_transaction(trans);
854 	}
855 	if (ret)
856 		goto fail;
857 
858 	ret = pending_snapshot->error;
859 	if (ret)
860 		goto fail;
861 
862 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
863 	if (ret)
864 		goto fail;
865 
866 	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
867 	if (IS_ERR(inode)) {
868 		ret = PTR_ERR(inode);
869 		goto fail;
870 	}
871 
872 	d_instantiate(dentry, inode);
873 	ret = 0;
874 fail:
875 	btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
876 dec_and_free:
877 	if (snapshot_force_cow)
878 		atomic_dec(&root->snapshot_force_cow);
879 	if (atomic_dec_and_test(&root->will_be_snapshotted))
880 		wake_up_var(&root->will_be_snapshotted);
881 free_pending:
882 	kfree(pending_snapshot->root_item);
883 	btrfs_free_path(pending_snapshot->path);
884 	kfree(pending_snapshot);
885 
886 	return ret;
887 }
888 
889 /*  copy of may_delete in fs/namei.c()
890  *	Check whether we can remove a link victim from directory dir, check
891  *  whether the type of victim is right.
892  *  1. We can't do it if dir is read-only (done in permission())
893  *  2. We should have write and exec permissions on dir
894  *  3. We can't remove anything from append-only dir
895  *  4. We can't do anything with immutable dir (done in permission())
896  *  5. If the sticky bit on dir is set we should either
897  *	a. be owner of dir, or
898  *	b. be owner of victim, or
899  *	c. have CAP_FOWNER capability
900  *  6. If the victim is append-only or immutable we can't do anything with
901  *     links pointing to it.
902  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
903  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
904  *  9. We can't remove a root or mountpoint.
905  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
906  *     nfs_async_unlink().
907  */
908 
909 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
910 {
911 	int error;
912 
913 	if (d_really_is_negative(victim))
914 		return -ENOENT;
915 
916 	BUG_ON(d_inode(victim->d_parent) != dir);
917 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
918 
919 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
920 	if (error)
921 		return error;
922 	if (IS_APPEND(dir))
923 		return -EPERM;
924 	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
925 	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
926 		return -EPERM;
927 	if (isdir) {
928 		if (!d_is_dir(victim))
929 			return -ENOTDIR;
930 		if (IS_ROOT(victim))
931 			return -EBUSY;
932 	} else if (d_is_dir(victim))
933 		return -EISDIR;
934 	if (IS_DEADDIR(dir))
935 		return -ENOENT;
936 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
937 		return -EBUSY;
938 	return 0;
939 }
940 
941 /* copy of may_create in fs/namei.c() */
942 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
943 {
944 	if (d_really_is_positive(child))
945 		return -EEXIST;
946 	if (IS_DEADDIR(dir))
947 		return -ENOENT;
948 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
949 }
950 
951 /*
952  * Create a new subvolume below @parent.  This is largely modeled after
953  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
954  * inside this filesystem so it's quite a bit simpler.
955  */
956 static noinline int btrfs_mksubvol(const struct path *parent,
957 				   const char *name, int namelen,
958 				   struct btrfs_root *snap_src,
959 				   u64 *async_transid, bool readonly,
960 				   struct btrfs_qgroup_inherit *inherit)
961 {
962 	struct inode *dir = d_inode(parent->dentry);
963 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
964 	struct dentry *dentry;
965 	int error;
966 
967 	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
968 	if (error == -EINTR)
969 		return error;
970 
971 	dentry = lookup_one_len(name, parent->dentry, namelen);
972 	error = PTR_ERR(dentry);
973 	if (IS_ERR(dentry))
974 		goto out_unlock;
975 
976 	error = btrfs_may_create(dir, dentry);
977 	if (error)
978 		goto out_dput;
979 
980 	/*
981 	 * even if this name doesn't exist, we may get hash collisions.
982 	 * check for them now when we can safely fail
983 	 */
984 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
985 					       dir->i_ino, name,
986 					       namelen);
987 	if (error)
988 		goto out_dput;
989 
990 	down_read(&fs_info->subvol_sem);
991 
992 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
993 		goto out_up_read;
994 
995 	if (snap_src) {
996 		error = create_snapshot(snap_src, dir, dentry,
997 					async_transid, readonly, inherit);
998 	} else {
999 		error = create_subvol(dir, dentry, name, namelen,
1000 				      async_transid, inherit);
1001 	}
1002 	if (!error)
1003 		fsnotify_mkdir(dir, dentry);
1004 out_up_read:
1005 	up_read(&fs_info->subvol_sem);
1006 out_dput:
1007 	dput(dentry);
1008 out_unlock:
1009 	inode_unlock(dir);
1010 	return error;
1011 }
1012 
1013 /*
1014  * When we're defragging a range, we don't want to kick it off again
1015  * if it is really just waiting for delalloc to send it down.
1016  * If we find a nice big extent or delalloc range for the bytes in the
1017  * file you want to defrag, we return 0 to let you know to skip this
1018  * part of the file
1019  */
1020 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1021 {
1022 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1023 	struct extent_map *em = NULL;
1024 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1025 	u64 end;
1026 
1027 	read_lock(&em_tree->lock);
1028 	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1029 	read_unlock(&em_tree->lock);
1030 
1031 	if (em) {
1032 		end = extent_map_end(em);
1033 		free_extent_map(em);
1034 		if (end - offset > thresh)
1035 			return 0;
1036 	}
1037 	/* if we already have a nice delalloc here, just stop */
1038 	thresh /= 2;
1039 	end = count_range_bits(io_tree, &offset, offset + thresh,
1040 			       thresh, EXTENT_DELALLOC, 1);
1041 	if (end >= thresh)
1042 		return 0;
1043 	return 1;
1044 }
1045 
1046 /*
1047  * helper function to walk through a file and find extents
1048  * newer than a specific transid, and smaller than thresh.
1049  *
1050  * This is used by the defragging code to find new and small
1051  * extents
1052  */
1053 static int find_new_extents(struct btrfs_root *root,
1054 			    struct inode *inode, u64 newer_than,
1055 			    u64 *off, u32 thresh)
1056 {
1057 	struct btrfs_path *path;
1058 	struct btrfs_key min_key;
1059 	struct extent_buffer *leaf;
1060 	struct btrfs_file_extent_item *extent;
1061 	int type;
1062 	int ret;
1063 	u64 ino = btrfs_ino(BTRFS_I(inode));
1064 
1065 	path = btrfs_alloc_path();
1066 	if (!path)
1067 		return -ENOMEM;
1068 
1069 	min_key.objectid = ino;
1070 	min_key.type = BTRFS_EXTENT_DATA_KEY;
1071 	min_key.offset = *off;
1072 
1073 	while (1) {
1074 		ret = btrfs_search_forward(root, &min_key, path, newer_than);
1075 		if (ret != 0)
1076 			goto none;
1077 process_slot:
1078 		if (min_key.objectid != ino)
1079 			goto none;
1080 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1081 			goto none;
1082 
1083 		leaf = path->nodes[0];
1084 		extent = btrfs_item_ptr(leaf, path->slots[0],
1085 					struct btrfs_file_extent_item);
1086 
1087 		type = btrfs_file_extent_type(leaf, extent);
1088 		if (type == BTRFS_FILE_EXTENT_REG &&
1089 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1090 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
1091 			*off = min_key.offset;
1092 			btrfs_free_path(path);
1093 			return 0;
1094 		}
1095 
1096 		path->slots[0]++;
1097 		if (path->slots[0] < btrfs_header_nritems(leaf)) {
1098 			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1099 			goto process_slot;
1100 		}
1101 
1102 		if (min_key.offset == (u64)-1)
1103 			goto none;
1104 
1105 		min_key.offset++;
1106 		btrfs_release_path(path);
1107 	}
1108 none:
1109 	btrfs_free_path(path);
1110 	return -ENOENT;
1111 }
1112 
1113 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1114 {
1115 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1116 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1117 	struct extent_map *em;
1118 	u64 len = PAGE_SIZE;
1119 
1120 	/*
1121 	 * hopefully we have this extent in the tree already, try without
1122 	 * the full extent lock
1123 	 */
1124 	read_lock(&em_tree->lock);
1125 	em = lookup_extent_mapping(em_tree, start, len);
1126 	read_unlock(&em_tree->lock);
1127 
1128 	if (!em) {
1129 		struct extent_state *cached = NULL;
1130 		u64 end = start + len - 1;
1131 
1132 		/* get the big lock and read metadata off disk */
1133 		lock_extent_bits(io_tree, start, end, &cached);
1134 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1135 		unlock_extent_cached(io_tree, start, end, &cached);
1136 
1137 		if (IS_ERR(em))
1138 			return NULL;
1139 	}
1140 
1141 	return em;
1142 }
1143 
1144 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1145 {
1146 	struct extent_map *next;
1147 	bool ret = true;
1148 
1149 	/* this is the last extent */
1150 	if (em->start + em->len >= i_size_read(inode))
1151 		return false;
1152 
1153 	next = defrag_lookup_extent(inode, em->start + em->len);
1154 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1155 		ret = false;
1156 	else if ((em->block_start + em->block_len == next->block_start) &&
1157 		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1158 		ret = false;
1159 
1160 	free_extent_map(next);
1161 	return ret;
1162 }
1163 
1164 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1165 			       u64 *last_len, u64 *skip, u64 *defrag_end,
1166 			       int compress)
1167 {
1168 	struct extent_map *em;
1169 	int ret = 1;
1170 	bool next_mergeable = true;
1171 	bool prev_mergeable = true;
1172 
1173 	/*
1174 	 * make sure that once we start defragging an extent, we keep on
1175 	 * defragging it
1176 	 */
1177 	if (start < *defrag_end)
1178 		return 1;
1179 
1180 	*skip = 0;
1181 
1182 	em = defrag_lookup_extent(inode, start);
1183 	if (!em)
1184 		return 0;
1185 
1186 	/* this will cover holes, and inline extents */
1187 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1188 		ret = 0;
1189 		goto out;
1190 	}
1191 
1192 	if (!*defrag_end)
1193 		prev_mergeable = false;
1194 
1195 	next_mergeable = defrag_check_next_extent(inode, em);
1196 	/*
1197 	 * we hit a real extent, if it is big or the next extent is not a
1198 	 * real extent, don't bother defragging it
1199 	 */
1200 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1201 	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1202 		ret = 0;
1203 out:
1204 	/*
1205 	 * last_len ends up being a counter of how many bytes we've defragged.
1206 	 * every time we choose not to defrag an extent, we reset *last_len
1207 	 * so that the next tiny extent will force a defrag.
1208 	 *
1209 	 * The end result of this is that tiny extents before a single big
1210 	 * extent will force at least part of that big extent to be defragged.
1211 	 */
1212 	if (ret) {
1213 		*defrag_end = extent_map_end(em);
1214 	} else {
1215 		*last_len = 0;
1216 		*skip = extent_map_end(em);
1217 		*defrag_end = 0;
1218 	}
1219 
1220 	free_extent_map(em);
1221 	return ret;
1222 }
1223 
1224 /*
1225  * it doesn't do much good to defrag one or two pages
1226  * at a time.  This pulls in a nice chunk of pages
1227  * to COW and defrag.
1228  *
1229  * It also makes sure the delalloc code has enough
1230  * dirty data to avoid making new small extents as part
1231  * of the defrag
1232  *
1233  * It's a good idea to start RA on this range
1234  * before calling this.
1235  */
1236 static int cluster_pages_for_defrag(struct inode *inode,
1237 				    struct page **pages,
1238 				    unsigned long start_index,
1239 				    unsigned long num_pages)
1240 {
1241 	unsigned long file_end;
1242 	u64 isize = i_size_read(inode);
1243 	u64 page_start;
1244 	u64 page_end;
1245 	u64 page_cnt;
1246 	int ret;
1247 	int i;
1248 	int i_done;
1249 	struct btrfs_ordered_extent *ordered;
1250 	struct extent_state *cached_state = NULL;
1251 	struct extent_io_tree *tree;
1252 	struct extent_changeset *data_reserved = NULL;
1253 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1254 
1255 	file_end = (isize - 1) >> PAGE_SHIFT;
1256 	if (!isize || start_index > file_end)
1257 		return 0;
1258 
1259 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1260 
1261 	ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1262 			start_index << PAGE_SHIFT,
1263 			page_cnt << PAGE_SHIFT);
1264 	if (ret)
1265 		return ret;
1266 	i_done = 0;
1267 	tree = &BTRFS_I(inode)->io_tree;
1268 
1269 	/* step one, lock all the pages */
1270 	for (i = 0; i < page_cnt; i++) {
1271 		struct page *page;
1272 again:
1273 		page = find_or_create_page(inode->i_mapping,
1274 					   start_index + i, mask);
1275 		if (!page)
1276 			break;
1277 
1278 		page_start = page_offset(page);
1279 		page_end = page_start + PAGE_SIZE - 1;
1280 		while (1) {
1281 			lock_extent_bits(tree, page_start, page_end,
1282 					 &cached_state);
1283 			ordered = btrfs_lookup_ordered_extent(inode,
1284 							      page_start);
1285 			unlock_extent_cached(tree, page_start, page_end,
1286 					     &cached_state);
1287 			if (!ordered)
1288 				break;
1289 
1290 			unlock_page(page);
1291 			btrfs_start_ordered_extent(inode, ordered, 1);
1292 			btrfs_put_ordered_extent(ordered);
1293 			lock_page(page);
1294 			/*
1295 			 * we unlocked the page above, so we need check if
1296 			 * it was released or not.
1297 			 */
1298 			if (page->mapping != inode->i_mapping) {
1299 				unlock_page(page);
1300 				put_page(page);
1301 				goto again;
1302 			}
1303 		}
1304 
1305 		if (!PageUptodate(page)) {
1306 			btrfs_readpage(NULL, page);
1307 			lock_page(page);
1308 			if (!PageUptodate(page)) {
1309 				unlock_page(page);
1310 				put_page(page);
1311 				ret = -EIO;
1312 				break;
1313 			}
1314 		}
1315 
1316 		if (page->mapping != inode->i_mapping) {
1317 			unlock_page(page);
1318 			put_page(page);
1319 			goto again;
1320 		}
1321 
1322 		pages[i] = page;
1323 		i_done++;
1324 	}
1325 	if (!i_done || ret)
1326 		goto out;
1327 
1328 	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1329 		goto out;
1330 
1331 	/*
1332 	 * so now we have a nice long stream of locked
1333 	 * and up to date pages, lets wait on them
1334 	 */
1335 	for (i = 0; i < i_done; i++)
1336 		wait_on_page_writeback(pages[i]);
1337 
1338 	page_start = page_offset(pages[0]);
1339 	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1340 
1341 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1342 			 page_start, page_end - 1, &cached_state);
1343 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1344 			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1345 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1346 			  &cached_state);
1347 
1348 	if (i_done != page_cnt) {
1349 		spin_lock(&BTRFS_I(inode)->lock);
1350 		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1351 		spin_unlock(&BTRFS_I(inode)->lock);
1352 		btrfs_delalloc_release_space(inode, data_reserved,
1353 				start_index << PAGE_SHIFT,
1354 				(page_cnt - i_done) << PAGE_SHIFT, true);
1355 	}
1356 
1357 
1358 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1359 			  &cached_state);
1360 
1361 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1362 			     page_start, page_end - 1, &cached_state);
1363 
1364 	for (i = 0; i < i_done; i++) {
1365 		clear_page_dirty_for_io(pages[i]);
1366 		ClearPageChecked(pages[i]);
1367 		set_page_extent_mapped(pages[i]);
1368 		set_page_dirty(pages[i]);
1369 		unlock_page(pages[i]);
1370 		put_page(pages[i]);
1371 	}
1372 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1373 				       false);
1374 	extent_changeset_free(data_reserved);
1375 	return i_done;
1376 out:
1377 	for (i = 0; i < i_done; i++) {
1378 		unlock_page(pages[i]);
1379 		put_page(pages[i]);
1380 	}
1381 	btrfs_delalloc_release_space(inode, data_reserved,
1382 			start_index << PAGE_SHIFT,
1383 			page_cnt << PAGE_SHIFT, true);
1384 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1385 				       true);
1386 	extent_changeset_free(data_reserved);
1387 	return ret;
1388 
1389 }
1390 
1391 int btrfs_defrag_file(struct inode *inode, struct file *file,
1392 		      struct btrfs_ioctl_defrag_range_args *range,
1393 		      u64 newer_than, unsigned long max_to_defrag)
1394 {
1395 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1396 	struct btrfs_root *root = BTRFS_I(inode)->root;
1397 	struct file_ra_state *ra = NULL;
1398 	unsigned long last_index;
1399 	u64 isize = i_size_read(inode);
1400 	u64 last_len = 0;
1401 	u64 skip = 0;
1402 	u64 defrag_end = 0;
1403 	u64 newer_off = range->start;
1404 	unsigned long i;
1405 	unsigned long ra_index = 0;
1406 	int ret;
1407 	int defrag_count = 0;
1408 	int compress_type = BTRFS_COMPRESS_ZLIB;
1409 	u32 extent_thresh = range->extent_thresh;
1410 	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1411 	unsigned long cluster = max_cluster;
1412 	u64 new_align = ~((u64)SZ_128K - 1);
1413 	struct page **pages = NULL;
1414 	bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1415 
1416 	if (isize == 0)
1417 		return 0;
1418 
1419 	if (range->start >= isize)
1420 		return -EINVAL;
1421 
1422 	if (do_compress) {
1423 		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1424 			return -EINVAL;
1425 		if (range->compress_type)
1426 			compress_type = range->compress_type;
1427 	}
1428 
1429 	if (extent_thresh == 0)
1430 		extent_thresh = SZ_256K;
1431 
1432 	/*
1433 	 * If we were not given a file, allocate a readahead context. As
1434 	 * readahead is just an optimization, defrag will work without it so
1435 	 * we don't error out.
1436 	 */
1437 	if (!file) {
1438 		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1439 		if (ra)
1440 			file_ra_state_init(ra, inode->i_mapping);
1441 	} else {
1442 		ra = &file->f_ra;
1443 	}
1444 
1445 	pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1446 	if (!pages) {
1447 		ret = -ENOMEM;
1448 		goto out_ra;
1449 	}
1450 
1451 	/* find the last page to defrag */
1452 	if (range->start + range->len > range->start) {
1453 		last_index = min_t(u64, isize - 1,
1454 			 range->start + range->len - 1) >> PAGE_SHIFT;
1455 	} else {
1456 		last_index = (isize - 1) >> PAGE_SHIFT;
1457 	}
1458 
1459 	if (newer_than) {
1460 		ret = find_new_extents(root, inode, newer_than,
1461 				       &newer_off, SZ_64K);
1462 		if (!ret) {
1463 			range->start = newer_off;
1464 			/*
1465 			 * we always align our defrag to help keep
1466 			 * the extents in the file evenly spaced
1467 			 */
1468 			i = (newer_off & new_align) >> PAGE_SHIFT;
1469 		} else
1470 			goto out_ra;
1471 	} else {
1472 		i = range->start >> PAGE_SHIFT;
1473 	}
1474 	if (!max_to_defrag)
1475 		max_to_defrag = last_index - i + 1;
1476 
1477 	/*
1478 	 * make writeback starts from i, so the defrag range can be
1479 	 * written sequentially.
1480 	 */
1481 	if (i < inode->i_mapping->writeback_index)
1482 		inode->i_mapping->writeback_index = i;
1483 
1484 	while (i <= last_index && defrag_count < max_to_defrag &&
1485 	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1486 		/*
1487 		 * make sure we stop running if someone unmounts
1488 		 * the FS
1489 		 */
1490 		if (!(inode->i_sb->s_flags & SB_ACTIVE))
1491 			break;
1492 
1493 		if (btrfs_defrag_cancelled(fs_info)) {
1494 			btrfs_debug(fs_info, "defrag_file cancelled");
1495 			ret = -EAGAIN;
1496 			break;
1497 		}
1498 
1499 		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1500 					 extent_thresh, &last_len, &skip,
1501 					 &defrag_end, do_compress)){
1502 			unsigned long next;
1503 			/*
1504 			 * the should_defrag function tells us how much to skip
1505 			 * bump our counter by the suggested amount
1506 			 */
1507 			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1508 			i = max(i + 1, next);
1509 			continue;
1510 		}
1511 
1512 		if (!newer_than) {
1513 			cluster = (PAGE_ALIGN(defrag_end) >>
1514 				   PAGE_SHIFT) - i;
1515 			cluster = min(cluster, max_cluster);
1516 		} else {
1517 			cluster = max_cluster;
1518 		}
1519 
1520 		if (i + cluster > ra_index) {
1521 			ra_index = max(i, ra_index);
1522 			if (ra)
1523 				page_cache_sync_readahead(inode->i_mapping, ra,
1524 						file, ra_index, cluster);
1525 			ra_index += cluster;
1526 		}
1527 
1528 		inode_lock(inode);
1529 		if (IS_SWAPFILE(inode)) {
1530 			ret = -ETXTBSY;
1531 		} else {
1532 			if (do_compress)
1533 				BTRFS_I(inode)->defrag_compress = compress_type;
1534 			ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1535 		}
1536 		if (ret < 0) {
1537 			inode_unlock(inode);
1538 			goto out_ra;
1539 		}
1540 
1541 		defrag_count += ret;
1542 		balance_dirty_pages_ratelimited(inode->i_mapping);
1543 		inode_unlock(inode);
1544 
1545 		if (newer_than) {
1546 			if (newer_off == (u64)-1)
1547 				break;
1548 
1549 			if (ret > 0)
1550 				i += ret;
1551 
1552 			newer_off = max(newer_off + 1,
1553 					(u64)i << PAGE_SHIFT);
1554 
1555 			ret = find_new_extents(root, inode, newer_than,
1556 					       &newer_off, SZ_64K);
1557 			if (!ret) {
1558 				range->start = newer_off;
1559 				i = (newer_off & new_align) >> PAGE_SHIFT;
1560 			} else {
1561 				break;
1562 			}
1563 		} else {
1564 			if (ret > 0) {
1565 				i += ret;
1566 				last_len += ret << PAGE_SHIFT;
1567 			} else {
1568 				i++;
1569 				last_len = 0;
1570 			}
1571 		}
1572 	}
1573 
1574 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1575 		filemap_flush(inode->i_mapping);
1576 		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1577 			     &BTRFS_I(inode)->runtime_flags))
1578 			filemap_flush(inode->i_mapping);
1579 	}
1580 
1581 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1582 		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1583 	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1584 		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1585 	}
1586 
1587 	ret = defrag_count;
1588 
1589 out_ra:
1590 	if (do_compress) {
1591 		inode_lock(inode);
1592 		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1593 		inode_unlock(inode);
1594 	}
1595 	if (!file)
1596 		kfree(ra);
1597 	kfree(pages);
1598 	return ret;
1599 }
1600 
1601 static noinline int btrfs_ioctl_resize(struct file *file,
1602 					void __user *arg)
1603 {
1604 	struct inode *inode = file_inode(file);
1605 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1606 	u64 new_size;
1607 	u64 old_size;
1608 	u64 devid = 1;
1609 	struct btrfs_root *root = BTRFS_I(inode)->root;
1610 	struct btrfs_ioctl_vol_args *vol_args;
1611 	struct btrfs_trans_handle *trans;
1612 	struct btrfs_device *device = NULL;
1613 	char *sizestr;
1614 	char *retptr;
1615 	char *devstr = NULL;
1616 	int ret = 0;
1617 	int mod = 0;
1618 
1619 	if (!capable(CAP_SYS_ADMIN))
1620 		return -EPERM;
1621 
1622 	ret = mnt_want_write_file(file);
1623 	if (ret)
1624 		return ret;
1625 
1626 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1627 		mnt_drop_write_file(file);
1628 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1629 	}
1630 
1631 	vol_args = memdup_user(arg, sizeof(*vol_args));
1632 	if (IS_ERR(vol_args)) {
1633 		ret = PTR_ERR(vol_args);
1634 		goto out;
1635 	}
1636 
1637 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1638 
1639 	sizestr = vol_args->name;
1640 	devstr = strchr(sizestr, ':');
1641 	if (devstr) {
1642 		sizestr = devstr + 1;
1643 		*devstr = '\0';
1644 		devstr = vol_args->name;
1645 		ret = kstrtoull(devstr, 10, &devid);
1646 		if (ret)
1647 			goto out_free;
1648 		if (!devid) {
1649 			ret = -EINVAL;
1650 			goto out_free;
1651 		}
1652 		btrfs_info(fs_info, "resizing devid %llu", devid);
1653 	}
1654 
1655 	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
1656 	if (!device) {
1657 		btrfs_info(fs_info, "resizer unable to find device %llu",
1658 			   devid);
1659 		ret = -ENODEV;
1660 		goto out_free;
1661 	}
1662 
1663 	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1664 		btrfs_info(fs_info,
1665 			   "resizer unable to apply on readonly device %llu",
1666 		       devid);
1667 		ret = -EPERM;
1668 		goto out_free;
1669 	}
1670 
1671 	if (!strcmp(sizestr, "max"))
1672 		new_size = device->bdev->bd_inode->i_size;
1673 	else {
1674 		if (sizestr[0] == '-') {
1675 			mod = -1;
1676 			sizestr++;
1677 		} else if (sizestr[0] == '+') {
1678 			mod = 1;
1679 			sizestr++;
1680 		}
1681 		new_size = memparse(sizestr, &retptr);
1682 		if (*retptr != '\0' || new_size == 0) {
1683 			ret = -EINVAL;
1684 			goto out_free;
1685 		}
1686 	}
1687 
1688 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1689 		ret = -EPERM;
1690 		goto out_free;
1691 	}
1692 
1693 	old_size = btrfs_device_get_total_bytes(device);
1694 
1695 	if (mod < 0) {
1696 		if (new_size > old_size) {
1697 			ret = -EINVAL;
1698 			goto out_free;
1699 		}
1700 		new_size = old_size - new_size;
1701 	} else if (mod > 0) {
1702 		if (new_size > ULLONG_MAX - old_size) {
1703 			ret = -ERANGE;
1704 			goto out_free;
1705 		}
1706 		new_size = old_size + new_size;
1707 	}
1708 
1709 	if (new_size < SZ_256M) {
1710 		ret = -EINVAL;
1711 		goto out_free;
1712 	}
1713 	if (new_size > device->bdev->bd_inode->i_size) {
1714 		ret = -EFBIG;
1715 		goto out_free;
1716 	}
1717 
1718 	new_size = round_down(new_size, fs_info->sectorsize);
1719 
1720 	btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1721 			  rcu_str_deref(device->name), new_size);
1722 
1723 	if (new_size > old_size) {
1724 		trans = btrfs_start_transaction(root, 0);
1725 		if (IS_ERR(trans)) {
1726 			ret = PTR_ERR(trans);
1727 			goto out_free;
1728 		}
1729 		ret = btrfs_grow_device(trans, device, new_size);
1730 		btrfs_commit_transaction(trans);
1731 	} else if (new_size < old_size) {
1732 		ret = btrfs_shrink_device(device, new_size);
1733 	} /* equal, nothing need to do */
1734 
1735 out_free:
1736 	kfree(vol_args);
1737 out:
1738 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1739 	mnt_drop_write_file(file);
1740 	return ret;
1741 }
1742 
1743 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1744 				const char *name, unsigned long fd, int subvol,
1745 				u64 *transid, bool readonly,
1746 				struct btrfs_qgroup_inherit *inherit)
1747 {
1748 	int namelen;
1749 	int ret = 0;
1750 
1751 	if (!S_ISDIR(file_inode(file)->i_mode))
1752 		return -ENOTDIR;
1753 
1754 	ret = mnt_want_write_file(file);
1755 	if (ret)
1756 		goto out;
1757 
1758 	namelen = strlen(name);
1759 	if (strchr(name, '/')) {
1760 		ret = -EINVAL;
1761 		goto out_drop_write;
1762 	}
1763 
1764 	if (name[0] == '.' &&
1765 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1766 		ret = -EEXIST;
1767 		goto out_drop_write;
1768 	}
1769 
1770 	if (subvol) {
1771 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1772 				     NULL, transid, readonly, inherit);
1773 	} else {
1774 		struct fd src = fdget(fd);
1775 		struct inode *src_inode;
1776 		if (!src.file) {
1777 			ret = -EINVAL;
1778 			goto out_drop_write;
1779 		}
1780 
1781 		src_inode = file_inode(src.file);
1782 		if (src_inode->i_sb != file_inode(file)->i_sb) {
1783 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1784 				   "Snapshot src from another FS");
1785 			ret = -EXDEV;
1786 		} else if (!inode_owner_or_capable(src_inode)) {
1787 			/*
1788 			 * Subvolume creation is not restricted, but snapshots
1789 			 * are limited to own subvolumes only
1790 			 */
1791 			ret = -EPERM;
1792 		} else {
1793 			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1794 					     BTRFS_I(src_inode)->root,
1795 					     transid, readonly, inherit);
1796 		}
1797 		fdput(src);
1798 	}
1799 out_drop_write:
1800 	mnt_drop_write_file(file);
1801 out:
1802 	return ret;
1803 }
1804 
1805 static noinline int btrfs_ioctl_snap_create(struct file *file,
1806 					    void __user *arg, int subvol)
1807 {
1808 	struct btrfs_ioctl_vol_args *vol_args;
1809 	int ret;
1810 
1811 	if (!S_ISDIR(file_inode(file)->i_mode))
1812 		return -ENOTDIR;
1813 
1814 	vol_args = memdup_user(arg, sizeof(*vol_args));
1815 	if (IS_ERR(vol_args))
1816 		return PTR_ERR(vol_args);
1817 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1818 
1819 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1820 					      vol_args->fd, subvol,
1821 					      NULL, false, NULL);
1822 
1823 	kfree(vol_args);
1824 	return ret;
1825 }
1826 
1827 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1828 					       void __user *arg, int subvol)
1829 {
1830 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1831 	int ret;
1832 	u64 transid = 0;
1833 	u64 *ptr = NULL;
1834 	bool readonly = false;
1835 	struct btrfs_qgroup_inherit *inherit = NULL;
1836 
1837 	if (!S_ISDIR(file_inode(file)->i_mode))
1838 		return -ENOTDIR;
1839 
1840 	vol_args = memdup_user(arg, sizeof(*vol_args));
1841 	if (IS_ERR(vol_args))
1842 		return PTR_ERR(vol_args);
1843 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1844 
1845 	if (vol_args->flags &
1846 	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1847 	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1848 		ret = -EOPNOTSUPP;
1849 		goto free_args;
1850 	}
1851 
1852 	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1853 		ptr = &transid;
1854 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1855 		readonly = true;
1856 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1857 		if (vol_args->size > PAGE_SIZE) {
1858 			ret = -EINVAL;
1859 			goto free_args;
1860 		}
1861 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1862 		if (IS_ERR(inherit)) {
1863 			ret = PTR_ERR(inherit);
1864 			goto free_args;
1865 		}
1866 	}
1867 
1868 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1869 					      vol_args->fd, subvol, ptr,
1870 					      readonly, inherit);
1871 	if (ret)
1872 		goto free_inherit;
1873 
1874 	if (ptr && copy_to_user(arg +
1875 				offsetof(struct btrfs_ioctl_vol_args_v2,
1876 					transid),
1877 				ptr, sizeof(*ptr)))
1878 		ret = -EFAULT;
1879 
1880 free_inherit:
1881 	kfree(inherit);
1882 free_args:
1883 	kfree(vol_args);
1884 	return ret;
1885 }
1886 
1887 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1888 						void __user *arg)
1889 {
1890 	struct inode *inode = file_inode(file);
1891 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1892 	struct btrfs_root *root = BTRFS_I(inode)->root;
1893 	int ret = 0;
1894 	u64 flags = 0;
1895 
1896 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1897 		return -EINVAL;
1898 
1899 	down_read(&fs_info->subvol_sem);
1900 	if (btrfs_root_readonly(root))
1901 		flags |= BTRFS_SUBVOL_RDONLY;
1902 	up_read(&fs_info->subvol_sem);
1903 
1904 	if (copy_to_user(arg, &flags, sizeof(flags)))
1905 		ret = -EFAULT;
1906 
1907 	return ret;
1908 }
1909 
1910 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1911 					      void __user *arg)
1912 {
1913 	struct inode *inode = file_inode(file);
1914 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1915 	struct btrfs_root *root = BTRFS_I(inode)->root;
1916 	struct btrfs_trans_handle *trans;
1917 	u64 root_flags;
1918 	u64 flags;
1919 	int ret = 0;
1920 
1921 	if (!inode_owner_or_capable(inode))
1922 		return -EPERM;
1923 
1924 	ret = mnt_want_write_file(file);
1925 	if (ret)
1926 		goto out;
1927 
1928 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1929 		ret = -EINVAL;
1930 		goto out_drop_write;
1931 	}
1932 
1933 	if (copy_from_user(&flags, arg, sizeof(flags))) {
1934 		ret = -EFAULT;
1935 		goto out_drop_write;
1936 	}
1937 
1938 	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1939 		ret = -EINVAL;
1940 		goto out_drop_write;
1941 	}
1942 
1943 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1944 		ret = -EOPNOTSUPP;
1945 		goto out_drop_write;
1946 	}
1947 
1948 	down_write(&fs_info->subvol_sem);
1949 
1950 	/* nothing to do */
1951 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1952 		goto out_drop_sem;
1953 
1954 	root_flags = btrfs_root_flags(&root->root_item);
1955 	if (flags & BTRFS_SUBVOL_RDONLY) {
1956 		btrfs_set_root_flags(&root->root_item,
1957 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1958 	} else {
1959 		/*
1960 		 * Block RO -> RW transition if this subvolume is involved in
1961 		 * send
1962 		 */
1963 		spin_lock(&root->root_item_lock);
1964 		if (root->send_in_progress == 0) {
1965 			btrfs_set_root_flags(&root->root_item,
1966 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1967 			spin_unlock(&root->root_item_lock);
1968 		} else {
1969 			spin_unlock(&root->root_item_lock);
1970 			btrfs_warn(fs_info,
1971 				   "Attempt to set subvolume %llu read-write during send",
1972 				   root->root_key.objectid);
1973 			ret = -EPERM;
1974 			goto out_drop_sem;
1975 		}
1976 	}
1977 
1978 	trans = btrfs_start_transaction(root, 1);
1979 	if (IS_ERR(trans)) {
1980 		ret = PTR_ERR(trans);
1981 		goto out_reset;
1982 	}
1983 
1984 	ret = btrfs_update_root(trans, fs_info->tree_root,
1985 				&root->root_key, &root->root_item);
1986 	if (ret < 0) {
1987 		btrfs_end_transaction(trans);
1988 		goto out_reset;
1989 	}
1990 
1991 	ret = btrfs_commit_transaction(trans);
1992 
1993 out_reset:
1994 	if (ret)
1995 		btrfs_set_root_flags(&root->root_item, root_flags);
1996 out_drop_sem:
1997 	up_write(&fs_info->subvol_sem);
1998 out_drop_write:
1999 	mnt_drop_write_file(file);
2000 out:
2001 	return ret;
2002 }
2003 
2004 static noinline int key_in_sk(struct btrfs_key *key,
2005 			      struct btrfs_ioctl_search_key *sk)
2006 {
2007 	struct btrfs_key test;
2008 	int ret;
2009 
2010 	test.objectid = sk->min_objectid;
2011 	test.type = sk->min_type;
2012 	test.offset = sk->min_offset;
2013 
2014 	ret = btrfs_comp_cpu_keys(key, &test);
2015 	if (ret < 0)
2016 		return 0;
2017 
2018 	test.objectid = sk->max_objectid;
2019 	test.type = sk->max_type;
2020 	test.offset = sk->max_offset;
2021 
2022 	ret = btrfs_comp_cpu_keys(key, &test);
2023 	if (ret > 0)
2024 		return 0;
2025 	return 1;
2026 }
2027 
2028 static noinline int copy_to_sk(struct btrfs_path *path,
2029 			       struct btrfs_key *key,
2030 			       struct btrfs_ioctl_search_key *sk,
2031 			       size_t *buf_size,
2032 			       char __user *ubuf,
2033 			       unsigned long *sk_offset,
2034 			       int *num_found)
2035 {
2036 	u64 found_transid;
2037 	struct extent_buffer *leaf;
2038 	struct btrfs_ioctl_search_header sh;
2039 	struct btrfs_key test;
2040 	unsigned long item_off;
2041 	unsigned long item_len;
2042 	int nritems;
2043 	int i;
2044 	int slot;
2045 	int ret = 0;
2046 
2047 	leaf = path->nodes[0];
2048 	slot = path->slots[0];
2049 	nritems = btrfs_header_nritems(leaf);
2050 
2051 	if (btrfs_header_generation(leaf) > sk->max_transid) {
2052 		i = nritems;
2053 		goto advance_key;
2054 	}
2055 	found_transid = btrfs_header_generation(leaf);
2056 
2057 	for (i = slot; i < nritems; i++) {
2058 		item_off = btrfs_item_ptr_offset(leaf, i);
2059 		item_len = btrfs_item_size_nr(leaf, i);
2060 
2061 		btrfs_item_key_to_cpu(leaf, key, i);
2062 		if (!key_in_sk(key, sk))
2063 			continue;
2064 
2065 		if (sizeof(sh) + item_len > *buf_size) {
2066 			if (*num_found) {
2067 				ret = 1;
2068 				goto out;
2069 			}
2070 
2071 			/*
2072 			 * return one empty item back for v1, which does not
2073 			 * handle -EOVERFLOW
2074 			 */
2075 
2076 			*buf_size = sizeof(sh) + item_len;
2077 			item_len = 0;
2078 			ret = -EOVERFLOW;
2079 		}
2080 
2081 		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2082 			ret = 1;
2083 			goto out;
2084 		}
2085 
2086 		sh.objectid = key->objectid;
2087 		sh.offset = key->offset;
2088 		sh.type = key->type;
2089 		sh.len = item_len;
2090 		sh.transid = found_transid;
2091 
2092 		/* copy search result header */
2093 		if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2094 			ret = -EFAULT;
2095 			goto out;
2096 		}
2097 
2098 		*sk_offset += sizeof(sh);
2099 
2100 		if (item_len) {
2101 			char __user *up = ubuf + *sk_offset;
2102 			/* copy the item */
2103 			if (read_extent_buffer_to_user(leaf, up,
2104 						       item_off, item_len)) {
2105 				ret = -EFAULT;
2106 				goto out;
2107 			}
2108 
2109 			*sk_offset += item_len;
2110 		}
2111 		(*num_found)++;
2112 
2113 		if (ret) /* -EOVERFLOW from above */
2114 			goto out;
2115 
2116 		if (*num_found >= sk->nr_items) {
2117 			ret = 1;
2118 			goto out;
2119 		}
2120 	}
2121 advance_key:
2122 	ret = 0;
2123 	test.objectid = sk->max_objectid;
2124 	test.type = sk->max_type;
2125 	test.offset = sk->max_offset;
2126 	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2127 		ret = 1;
2128 	else if (key->offset < (u64)-1)
2129 		key->offset++;
2130 	else if (key->type < (u8)-1) {
2131 		key->offset = 0;
2132 		key->type++;
2133 	} else if (key->objectid < (u64)-1) {
2134 		key->offset = 0;
2135 		key->type = 0;
2136 		key->objectid++;
2137 	} else
2138 		ret = 1;
2139 out:
2140 	/*
2141 	 *  0: all items from this leaf copied, continue with next
2142 	 *  1: * more items can be copied, but unused buffer is too small
2143 	 *     * all items were found
2144 	 *     Either way, it will stops the loop which iterates to the next
2145 	 *     leaf
2146 	 *  -EOVERFLOW: item was to large for buffer
2147 	 *  -EFAULT: could not copy extent buffer back to userspace
2148 	 */
2149 	return ret;
2150 }
2151 
2152 static noinline int search_ioctl(struct inode *inode,
2153 				 struct btrfs_ioctl_search_key *sk,
2154 				 size_t *buf_size,
2155 				 char __user *ubuf)
2156 {
2157 	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2158 	struct btrfs_root *root;
2159 	struct btrfs_key key;
2160 	struct btrfs_path *path;
2161 	int ret;
2162 	int num_found = 0;
2163 	unsigned long sk_offset = 0;
2164 
2165 	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2166 		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2167 		return -EOVERFLOW;
2168 	}
2169 
2170 	path = btrfs_alloc_path();
2171 	if (!path)
2172 		return -ENOMEM;
2173 
2174 	if (sk->tree_id == 0) {
2175 		/* search the root of the inode that was passed */
2176 		root = BTRFS_I(inode)->root;
2177 	} else {
2178 		key.objectid = sk->tree_id;
2179 		key.type = BTRFS_ROOT_ITEM_KEY;
2180 		key.offset = (u64)-1;
2181 		root = btrfs_read_fs_root_no_name(info, &key);
2182 		if (IS_ERR(root)) {
2183 			btrfs_free_path(path);
2184 			return PTR_ERR(root);
2185 		}
2186 	}
2187 
2188 	key.objectid = sk->min_objectid;
2189 	key.type = sk->min_type;
2190 	key.offset = sk->min_offset;
2191 
2192 	while (1) {
2193 		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2194 		if (ret != 0) {
2195 			if (ret > 0)
2196 				ret = 0;
2197 			goto err;
2198 		}
2199 		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2200 				 &sk_offset, &num_found);
2201 		btrfs_release_path(path);
2202 		if (ret)
2203 			break;
2204 
2205 	}
2206 	if (ret > 0)
2207 		ret = 0;
2208 err:
2209 	sk->nr_items = num_found;
2210 	btrfs_free_path(path);
2211 	return ret;
2212 }
2213 
2214 static noinline int btrfs_ioctl_tree_search(struct file *file,
2215 					   void __user *argp)
2216 {
2217 	struct btrfs_ioctl_search_args __user *uargs;
2218 	struct btrfs_ioctl_search_key sk;
2219 	struct inode *inode;
2220 	int ret;
2221 	size_t buf_size;
2222 
2223 	if (!capable(CAP_SYS_ADMIN))
2224 		return -EPERM;
2225 
2226 	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2227 
2228 	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2229 		return -EFAULT;
2230 
2231 	buf_size = sizeof(uargs->buf);
2232 
2233 	inode = file_inode(file);
2234 	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2235 
2236 	/*
2237 	 * In the origin implementation an overflow is handled by returning a
2238 	 * search header with a len of zero, so reset ret.
2239 	 */
2240 	if (ret == -EOVERFLOW)
2241 		ret = 0;
2242 
2243 	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2244 		ret = -EFAULT;
2245 	return ret;
2246 }
2247 
2248 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2249 					       void __user *argp)
2250 {
2251 	struct btrfs_ioctl_search_args_v2 __user *uarg;
2252 	struct btrfs_ioctl_search_args_v2 args;
2253 	struct inode *inode;
2254 	int ret;
2255 	size_t buf_size;
2256 	const size_t buf_limit = SZ_16M;
2257 
2258 	if (!capable(CAP_SYS_ADMIN))
2259 		return -EPERM;
2260 
2261 	/* copy search header and buffer size */
2262 	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2263 	if (copy_from_user(&args, uarg, sizeof(args)))
2264 		return -EFAULT;
2265 
2266 	buf_size = args.buf_size;
2267 
2268 	/* limit result size to 16MB */
2269 	if (buf_size > buf_limit)
2270 		buf_size = buf_limit;
2271 
2272 	inode = file_inode(file);
2273 	ret = search_ioctl(inode, &args.key, &buf_size,
2274 			   (char __user *)(&uarg->buf[0]));
2275 	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2276 		ret = -EFAULT;
2277 	else if (ret == -EOVERFLOW &&
2278 		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2279 		ret = -EFAULT;
2280 
2281 	return ret;
2282 }
2283 
2284 /*
2285  * Search INODE_REFs to identify path name of 'dirid' directory
2286  * in a 'tree_id' tree. and sets path name to 'name'.
2287  */
2288 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2289 				u64 tree_id, u64 dirid, char *name)
2290 {
2291 	struct btrfs_root *root;
2292 	struct btrfs_key key;
2293 	char *ptr;
2294 	int ret = -1;
2295 	int slot;
2296 	int len;
2297 	int total_len = 0;
2298 	struct btrfs_inode_ref *iref;
2299 	struct extent_buffer *l;
2300 	struct btrfs_path *path;
2301 
2302 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2303 		name[0]='\0';
2304 		return 0;
2305 	}
2306 
2307 	path = btrfs_alloc_path();
2308 	if (!path)
2309 		return -ENOMEM;
2310 
2311 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2312 
2313 	key.objectid = tree_id;
2314 	key.type = BTRFS_ROOT_ITEM_KEY;
2315 	key.offset = (u64)-1;
2316 	root = btrfs_read_fs_root_no_name(info, &key);
2317 	if (IS_ERR(root)) {
2318 		ret = PTR_ERR(root);
2319 		goto out;
2320 	}
2321 
2322 	key.objectid = dirid;
2323 	key.type = BTRFS_INODE_REF_KEY;
2324 	key.offset = (u64)-1;
2325 
2326 	while (1) {
2327 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2328 		if (ret < 0)
2329 			goto out;
2330 		else if (ret > 0) {
2331 			ret = btrfs_previous_item(root, path, dirid,
2332 						  BTRFS_INODE_REF_KEY);
2333 			if (ret < 0)
2334 				goto out;
2335 			else if (ret > 0) {
2336 				ret = -ENOENT;
2337 				goto out;
2338 			}
2339 		}
2340 
2341 		l = path->nodes[0];
2342 		slot = path->slots[0];
2343 		btrfs_item_key_to_cpu(l, &key, slot);
2344 
2345 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2346 		len = btrfs_inode_ref_name_len(l, iref);
2347 		ptr -= len + 1;
2348 		total_len += len + 1;
2349 		if (ptr < name) {
2350 			ret = -ENAMETOOLONG;
2351 			goto out;
2352 		}
2353 
2354 		*(ptr + len) = '/';
2355 		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2356 
2357 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2358 			break;
2359 
2360 		btrfs_release_path(path);
2361 		key.objectid = key.offset;
2362 		key.offset = (u64)-1;
2363 		dirid = key.objectid;
2364 	}
2365 	memmove(name, ptr, total_len);
2366 	name[total_len] = '\0';
2367 	ret = 0;
2368 out:
2369 	btrfs_free_path(path);
2370 	return ret;
2371 }
2372 
2373 static int btrfs_search_path_in_tree_user(struct inode *inode,
2374 				struct btrfs_ioctl_ino_lookup_user_args *args)
2375 {
2376 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2377 	struct super_block *sb = inode->i_sb;
2378 	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2379 	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2380 	u64 dirid = args->dirid;
2381 	unsigned long item_off;
2382 	unsigned long item_len;
2383 	struct btrfs_inode_ref *iref;
2384 	struct btrfs_root_ref *rref;
2385 	struct btrfs_root *root;
2386 	struct btrfs_path *path;
2387 	struct btrfs_key key, key2;
2388 	struct extent_buffer *leaf;
2389 	struct inode *temp_inode;
2390 	char *ptr;
2391 	int slot;
2392 	int len;
2393 	int total_len = 0;
2394 	int ret;
2395 
2396 	path = btrfs_alloc_path();
2397 	if (!path)
2398 		return -ENOMEM;
2399 
2400 	/*
2401 	 * If the bottom subvolume does not exist directly under upper_limit,
2402 	 * construct the path in from the bottom up.
2403 	 */
2404 	if (dirid != upper_limit.objectid) {
2405 		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2406 
2407 		key.objectid = treeid;
2408 		key.type = BTRFS_ROOT_ITEM_KEY;
2409 		key.offset = (u64)-1;
2410 		root = btrfs_read_fs_root_no_name(fs_info, &key);
2411 		if (IS_ERR(root)) {
2412 			ret = PTR_ERR(root);
2413 			goto out;
2414 		}
2415 
2416 		key.objectid = dirid;
2417 		key.type = BTRFS_INODE_REF_KEY;
2418 		key.offset = (u64)-1;
2419 		while (1) {
2420 			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2421 			if (ret < 0) {
2422 				goto out;
2423 			} else if (ret > 0) {
2424 				ret = btrfs_previous_item(root, path, dirid,
2425 							  BTRFS_INODE_REF_KEY);
2426 				if (ret < 0) {
2427 					goto out;
2428 				} else if (ret > 0) {
2429 					ret = -ENOENT;
2430 					goto out;
2431 				}
2432 			}
2433 
2434 			leaf = path->nodes[0];
2435 			slot = path->slots[0];
2436 			btrfs_item_key_to_cpu(leaf, &key, slot);
2437 
2438 			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2439 			len = btrfs_inode_ref_name_len(leaf, iref);
2440 			ptr -= len + 1;
2441 			total_len += len + 1;
2442 			if (ptr < args->path) {
2443 				ret = -ENAMETOOLONG;
2444 				goto out;
2445 			}
2446 
2447 			*(ptr + len) = '/';
2448 			read_extent_buffer(leaf, ptr,
2449 					(unsigned long)(iref + 1), len);
2450 
2451 			/* Check the read+exec permission of this directory */
2452 			ret = btrfs_previous_item(root, path, dirid,
2453 						  BTRFS_INODE_ITEM_KEY);
2454 			if (ret < 0) {
2455 				goto out;
2456 			} else if (ret > 0) {
2457 				ret = -ENOENT;
2458 				goto out;
2459 			}
2460 
2461 			leaf = path->nodes[0];
2462 			slot = path->slots[0];
2463 			btrfs_item_key_to_cpu(leaf, &key2, slot);
2464 			if (key2.objectid != dirid) {
2465 				ret = -ENOENT;
2466 				goto out;
2467 			}
2468 
2469 			temp_inode = btrfs_iget(sb, &key2, root, NULL);
2470 			if (IS_ERR(temp_inode)) {
2471 				ret = PTR_ERR(temp_inode);
2472 				goto out;
2473 			}
2474 			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2475 			iput(temp_inode);
2476 			if (ret) {
2477 				ret = -EACCES;
2478 				goto out;
2479 			}
2480 
2481 			if (key.offset == upper_limit.objectid)
2482 				break;
2483 			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2484 				ret = -EACCES;
2485 				goto out;
2486 			}
2487 
2488 			btrfs_release_path(path);
2489 			key.objectid = key.offset;
2490 			key.offset = (u64)-1;
2491 			dirid = key.objectid;
2492 		}
2493 
2494 		memmove(args->path, ptr, total_len);
2495 		args->path[total_len] = '\0';
2496 		btrfs_release_path(path);
2497 	}
2498 
2499 	/* Get the bottom subvolume's name from ROOT_REF */
2500 	root = fs_info->tree_root;
2501 	key.objectid = treeid;
2502 	key.type = BTRFS_ROOT_REF_KEY;
2503 	key.offset = args->treeid;
2504 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2505 	if (ret < 0) {
2506 		goto out;
2507 	} else if (ret > 0) {
2508 		ret = -ENOENT;
2509 		goto out;
2510 	}
2511 
2512 	leaf = path->nodes[0];
2513 	slot = path->slots[0];
2514 	btrfs_item_key_to_cpu(leaf, &key, slot);
2515 
2516 	item_off = btrfs_item_ptr_offset(leaf, slot);
2517 	item_len = btrfs_item_size_nr(leaf, slot);
2518 	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2519 	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2520 	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2521 		ret = -EINVAL;
2522 		goto out;
2523 	}
2524 
2525 	/* Copy subvolume's name */
2526 	item_off += sizeof(struct btrfs_root_ref);
2527 	item_len -= sizeof(struct btrfs_root_ref);
2528 	read_extent_buffer(leaf, args->name, item_off, item_len);
2529 	args->name[item_len] = 0;
2530 
2531 out:
2532 	btrfs_free_path(path);
2533 	return ret;
2534 }
2535 
2536 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2537 					   void __user *argp)
2538 {
2539 	struct btrfs_ioctl_ino_lookup_args *args;
2540 	struct inode *inode;
2541 	int ret = 0;
2542 
2543 	args = memdup_user(argp, sizeof(*args));
2544 	if (IS_ERR(args))
2545 		return PTR_ERR(args);
2546 
2547 	inode = file_inode(file);
2548 
2549 	/*
2550 	 * Unprivileged query to obtain the containing subvolume root id. The
2551 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2552 	 */
2553 	if (args->treeid == 0)
2554 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2555 
2556 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2557 		args->name[0] = 0;
2558 		goto out;
2559 	}
2560 
2561 	if (!capable(CAP_SYS_ADMIN)) {
2562 		ret = -EPERM;
2563 		goto out;
2564 	}
2565 
2566 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2567 					args->treeid, args->objectid,
2568 					args->name);
2569 
2570 out:
2571 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2572 		ret = -EFAULT;
2573 
2574 	kfree(args);
2575 	return ret;
2576 }
2577 
2578 /*
2579  * Version of ino_lookup ioctl (unprivileged)
2580  *
2581  * The main differences from ino_lookup ioctl are:
2582  *
2583  *   1. Read + Exec permission will be checked using inode_permission() during
2584  *      path construction. -EACCES will be returned in case of failure.
2585  *   2. Path construction will be stopped at the inode number which corresponds
2586  *      to the fd with which this ioctl is called. If constructed path does not
2587  *      exist under fd's inode, -EACCES will be returned.
2588  *   3. The name of bottom subvolume is also searched and filled.
2589  */
2590 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2591 {
2592 	struct btrfs_ioctl_ino_lookup_user_args *args;
2593 	struct inode *inode;
2594 	int ret;
2595 
2596 	args = memdup_user(argp, sizeof(*args));
2597 	if (IS_ERR(args))
2598 		return PTR_ERR(args);
2599 
2600 	inode = file_inode(file);
2601 
2602 	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2603 	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2604 		/*
2605 		 * The subvolume does not exist under fd with which this is
2606 		 * called
2607 		 */
2608 		kfree(args);
2609 		return -EACCES;
2610 	}
2611 
2612 	ret = btrfs_search_path_in_tree_user(inode, args);
2613 
2614 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2615 		ret = -EFAULT;
2616 
2617 	kfree(args);
2618 	return ret;
2619 }
2620 
2621 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2622 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2623 {
2624 	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2625 	struct btrfs_fs_info *fs_info;
2626 	struct btrfs_root *root;
2627 	struct btrfs_path *path;
2628 	struct btrfs_key key;
2629 	struct btrfs_root_item *root_item;
2630 	struct btrfs_root_ref *rref;
2631 	struct extent_buffer *leaf;
2632 	unsigned long item_off;
2633 	unsigned long item_len;
2634 	struct inode *inode;
2635 	int slot;
2636 	int ret = 0;
2637 
2638 	path = btrfs_alloc_path();
2639 	if (!path)
2640 		return -ENOMEM;
2641 
2642 	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2643 	if (!subvol_info) {
2644 		btrfs_free_path(path);
2645 		return -ENOMEM;
2646 	}
2647 
2648 	inode = file_inode(file);
2649 	fs_info = BTRFS_I(inode)->root->fs_info;
2650 
2651 	/* Get root_item of inode's subvolume */
2652 	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2653 	key.type = BTRFS_ROOT_ITEM_KEY;
2654 	key.offset = (u64)-1;
2655 	root = btrfs_read_fs_root_no_name(fs_info, &key);
2656 	if (IS_ERR(root)) {
2657 		ret = PTR_ERR(root);
2658 		goto out;
2659 	}
2660 	root_item = &root->root_item;
2661 
2662 	subvol_info->treeid = key.objectid;
2663 
2664 	subvol_info->generation = btrfs_root_generation(root_item);
2665 	subvol_info->flags = btrfs_root_flags(root_item);
2666 
2667 	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2668 	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2669 						    BTRFS_UUID_SIZE);
2670 	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2671 						    BTRFS_UUID_SIZE);
2672 
2673 	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2674 	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2675 	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2676 
2677 	subvol_info->otransid = btrfs_root_otransid(root_item);
2678 	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2679 	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2680 
2681 	subvol_info->stransid = btrfs_root_stransid(root_item);
2682 	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2683 	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2684 
2685 	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2686 	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2687 	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2688 
2689 	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2690 		/* Search root tree for ROOT_BACKREF of this subvolume */
2691 		root = fs_info->tree_root;
2692 
2693 		key.type = BTRFS_ROOT_BACKREF_KEY;
2694 		key.offset = 0;
2695 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2696 		if (ret < 0) {
2697 			goto out;
2698 		} else if (path->slots[0] >=
2699 			   btrfs_header_nritems(path->nodes[0])) {
2700 			ret = btrfs_next_leaf(root, path);
2701 			if (ret < 0) {
2702 				goto out;
2703 			} else if (ret > 0) {
2704 				ret = -EUCLEAN;
2705 				goto out;
2706 			}
2707 		}
2708 
2709 		leaf = path->nodes[0];
2710 		slot = path->slots[0];
2711 		btrfs_item_key_to_cpu(leaf, &key, slot);
2712 		if (key.objectid == subvol_info->treeid &&
2713 		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2714 			subvol_info->parent_id = key.offset;
2715 
2716 			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2717 			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2718 
2719 			item_off = btrfs_item_ptr_offset(leaf, slot)
2720 					+ sizeof(struct btrfs_root_ref);
2721 			item_len = btrfs_item_size_nr(leaf, slot)
2722 					- sizeof(struct btrfs_root_ref);
2723 			read_extent_buffer(leaf, subvol_info->name,
2724 					   item_off, item_len);
2725 		} else {
2726 			ret = -ENOENT;
2727 			goto out;
2728 		}
2729 	}
2730 
2731 	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2732 		ret = -EFAULT;
2733 
2734 out:
2735 	btrfs_free_path(path);
2736 	kzfree(subvol_info);
2737 	return ret;
2738 }
2739 
2740 /*
2741  * Return ROOT_REF information of the subvolume containing this inode
2742  * except the subvolume name.
2743  */
2744 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2745 {
2746 	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2747 	struct btrfs_root_ref *rref;
2748 	struct btrfs_root *root;
2749 	struct btrfs_path *path;
2750 	struct btrfs_key key;
2751 	struct extent_buffer *leaf;
2752 	struct inode *inode;
2753 	u64 objectid;
2754 	int slot;
2755 	int ret;
2756 	u8 found;
2757 
2758 	path = btrfs_alloc_path();
2759 	if (!path)
2760 		return -ENOMEM;
2761 
2762 	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2763 	if (IS_ERR(rootrefs)) {
2764 		btrfs_free_path(path);
2765 		return PTR_ERR(rootrefs);
2766 	}
2767 
2768 	inode = file_inode(file);
2769 	root = BTRFS_I(inode)->root->fs_info->tree_root;
2770 	objectid = BTRFS_I(inode)->root->root_key.objectid;
2771 
2772 	key.objectid = objectid;
2773 	key.type = BTRFS_ROOT_REF_KEY;
2774 	key.offset = rootrefs->min_treeid;
2775 	found = 0;
2776 
2777 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2778 	if (ret < 0) {
2779 		goto out;
2780 	} else if (path->slots[0] >=
2781 		   btrfs_header_nritems(path->nodes[0])) {
2782 		ret = btrfs_next_leaf(root, path);
2783 		if (ret < 0) {
2784 			goto out;
2785 		} else if (ret > 0) {
2786 			ret = -EUCLEAN;
2787 			goto out;
2788 		}
2789 	}
2790 	while (1) {
2791 		leaf = path->nodes[0];
2792 		slot = path->slots[0];
2793 
2794 		btrfs_item_key_to_cpu(leaf, &key, slot);
2795 		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2796 			ret = 0;
2797 			goto out;
2798 		}
2799 
2800 		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2801 			ret = -EOVERFLOW;
2802 			goto out;
2803 		}
2804 
2805 		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2806 		rootrefs->rootref[found].treeid = key.offset;
2807 		rootrefs->rootref[found].dirid =
2808 				  btrfs_root_ref_dirid(leaf, rref);
2809 		found++;
2810 
2811 		ret = btrfs_next_item(root, path);
2812 		if (ret < 0) {
2813 			goto out;
2814 		} else if (ret > 0) {
2815 			ret = -EUCLEAN;
2816 			goto out;
2817 		}
2818 	}
2819 
2820 out:
2821 	if (!ret || ret == -EOVERFLOW) {
2822 		rootrefs->num_items = found;
2823 		/* update min_treeid for next search */
2824 		if (found)
2825 			rootrefs->min_treeid =
2826 				rootrefs->rootref[found - 1].treeid + 1;
2827 		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2828 			ret = -EFAULT;
2829 	}
2830 
2831 	kfree(rootrefs);
2832 	btrfs_free_path(path);
2833 
2834 	return ret;
2835 }
2836 
2837 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2838 					     void __user *arg)
2839 {
2840 	struct dentry *parent = file->f_path.dentry;
2841 	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2842 	struct dentry *dentry;
2843 	struct inode *dir = d_inode(parent);
2844 	struct inode *inode;
2845 	struct btrfs_root *root = BTRFS_I(dir)->root;
2846 	struct btrfs_root *dest = NULL;
2847 	struct btrfs_ioctl_vol_args *vol_args;
2848 	int namelen;
2849 	int err = 0;
2850 
2851 	if (!S_ISDIR(dir->i_mode))
2852 		return -ENOTDIR;
2853 
2854 	vol_args = memdup_user(arg, sizeof(*vol_args));
2855 	if (IS_ERR(vol_args))
2856 		return PTR_ERR(vol_args);
2857 
2858 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2859 	namelen = strlen(vol_args->name);
2860 	if (strchr(vol_args->name, '/') ||
2861 	    strncmp(vol_args->name, "..", namelen) == 0) {
2862 		err = -EINVAL;
2863 		goto out;
2864 	}
2865 
2866 	err = mnt_want_write_file(file);
2867 	if (err)
2868 		goto out;
2869 
2870 
2871 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2872 	if (err == -EINTR)
2873 		goto out_drop_write;
2874 	dentry = lookup_one_len(vol_args->name, parent, namelen);
2875 	if (IS_ERR(dentry)) {
2876 		err = PTR_ERR(dentry);
2877 		goto out_unlock_dir;
2878 	}
2879 
2880 	if (d_really_is_negative(dentry)) {
2881 		err = -ENOENT;
2882 		goto out_dput;
2883 	}
2884 
2885 	inode = d_inode(dentry);
2886 	dest = BTRFS_I(inode)->root;
2887 	if (!capable(CAP_SYS_ADMIN)) {
2888 		/*
2889 		 * Regular user.  Only allow this with a special mount
2890 		 * option, when the user has write+exec access to the
2891 		 * subvol root, and when rmdir(2) would have been
2892 		 * allowed.
2893 		 *
2894 		 * Note that this is _not_ check that the subvol is
2895 		 * empty or doesn't contain data that we wouldn't
2896 		 * otherwise be able to delete.
2897 		 *
2898 		 * Users who want to delete empty subvols should try
2899 		 * rmdir(2).
2900 		 */
2901 		err = -EPERM;
2902 		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2903 			goto out_dput;
2904 
2905 		/*
2906 		 * Do not allow deletion if the parent dir is the same
2907 		 * as the dir to be deleted.  That means the ioctl
2908 		 * must be called on the dentry referencing the root
2909 		 * of the subvol, not a random directory contained
2910 		 * within it.
2911 		 */
2912 		err = -EINVAL;
2913 		if (root == dest)
2914 			goto out_dput;
2915 
2916 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2917 		if (err)
2918 			goto out_dput;
2919 	}
2920 
2921 	/* check if subvolume may be deleted by a user */
2922 	err = btrfs_may_delete(dir, dentry, 1);
2923 	if (err)
2924 		goto out_dput;
2925 
2926 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2927 		err = -EINVAL;
2928 		goto out_dput;
2929 	}
2930 
2931 	inode_lock(inode);
2932 	err = btrfs_delete_subvolume(dir, dentry);
2933 	inode_unlock(inode);
2934 	if (!err)
2935 		d_delete(dentry);
2936 
2937 out_dput:
2938 	dput(dentry);
2939 out_unlock_dir:
2940 	inode_unlock(dir);
2941 out_drop_write:
2942 	mnt_drop_write_file(file);
2943 out:
2944 	kfree(vol_args);
2945 	return err;
2946 }
2947 
2948 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2949 {
2950 	struct inode *inode = file_inode(file);
2951 	struct btrfs_root *root = BTRFS_I(inode)->root;
2952 	struct btrfs_ioctl_defrag_range_args *range;
2953 	int ret;
2954 
2955 	ret = mnt_want_write_file(file);
2956 	if (ret)
2957 		return ret;
2958 
2959 	if (btrfs_root_readonly(root)) {
2960 		ret = -EROFS;
2961 		goto out;
2962 	}
2963 
2964 	switch (inode->i_mode & S_IFMT) {
2965 	case S_IFDIR:
2966 		if (!capable(CAP_SYS_ADMIN)) {
2967 			ret = -EPERM;
2968 			goto out;
2969 		}
2970 		ret = btrfs_defrag_root(root);
2971 		break;
2972 	case S_IFREG:
2973 		/*
2974 		 * Note that this does not check the file descriptor for write
2975 		 * access. This prevents defragmenting executables that are
2976 		 * running and allows defrag on files open in read-only mode.
2977 		 */
2978 		if (!capable(CAP_SYS_ADMIN) &&
2979 		    inode_permission(inode, MAY_WRITE)) {
2980 			ret = -EPERM;
2981 			goto out;
2982 		}
2983 
2984 		range = kzalloc(sizeof(*range), GFP_KERNEL);
2985 		if (!range) {
2986 			ret = -ENOMEM;
2987 			goto out;
2988 		}
2989 
2990 		if (argp) {
2991 			if (copy_from_user(range, argp,
2992 					   sizeof(*range))) {
2993 				ret = -EFAULT;
2994 				kfree(range);
2995 				goto out;
2996 			}
2997 			/* compression requires us to start the IO */
2998 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2999 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
3000 				range->extent_thresh = (u32)-1;
3001 			}
3002 		} else {
3003 			/* the rest are all set to zero by kzalloc */
3004 			range->len = (u64)-1;
3005 		}
3006 		ret = btrfs_defrag_file(file_inode(file), file,
3007 					range, BTRFS_OLDEST_GENERATION, 0);
3008 		if (ret > 0)
3009 			ret = 0;
3010 		kfree(range);
3011 		break;
3012 	default:
3013 		ret = -EINVAL;
3014 	}
3015 out:
3016 	mnt_drop_write_file(file);
3017 	return ret;
3018 }
3019 
3020 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3021 {
3022 	struct btrfs_ioctl_vol_args *vol_args;
3023 	int ret;
3024 
3025 	if (!capable(CAP_SYS_ADMIN))
3026 		return -EPERM;
3027 
3028 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3029 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3030 
3031 	vol_args = memdup_user(arg, sizeof(*vol_args));
3032 	if (IS_ERR(vol_args)) {
3033 		ret = PTR_ERR(vol_args);
3034 		goto out;
3035 	}
3036 
3037 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3038 	ret = btrfs_init_new_device(fs_info, vol_args->name);
3039 
3040 	if (!ret)
3041 		btrfs_info(fs_info, "disk added %s", vol_args->name);
3042 
3043 	kfree(vol_args);
3044 out:
3045 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3046 	return ret;
3047 }
3048 
3049 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3050 {
3051 	struct inode *inode = file_inode(file);
3052 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3053 	struct btrfs_ioctl_vol_args_v2 *vol_args;
3054 	int ret;
3055 
3056 	if (!capable(CAP_SYS_ADMIN))
3057 		return -EPERM;
3058 
3059 	ret = mnt_want_write_file(file);
3060 	if (ret)
3061 		return ret;
3062 
3063 	vol_args = memdup_user(arg, sizeof(*vol_args));
3064 	if (IS_ERR(vol_args)) {
3065 		ret = PTR_ERR(vol_args);
3066 		goto err_drop;
3067 	}
3068 
3069 	/* Check for compatibility reject unknown flags */
3070 	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3071 		ret = -EOPNOTSUPP;
3072 		goto out;
3073 	}
3074 
3075 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3076 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3077 		goto out;
3078 	}
3079 
3080 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3081 		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3082 	} else {
3083 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3084 		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3085 	}
3086 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3087 
3088 	if (!ret) {
3089 		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3090 			btrfs_info(fs_info, "device deleted: id %llu",
3091 					vol_args->devid);
3092 		else
3093 			btrfs_info(fs_info, "device deleted: %s",
3094 					vol_args->name);
3095 	}
3096 out:
3097 	kfree(vol_args);
3098 err_drop:
3099 	mnt_drop_write_file(file);
3100 	return ret;
3101 }
3102 
3103 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3104 {
3105 	struct inode *inode = file_inode(file);
3106 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3107 	struct btrfs_ioctl_vol_args *vol_args;
3108 	int ret;
3109 
3110 	if (!capable(CAP_SYS_ADMIN))
3111 		return -EPERM;
3112 
3113 	ret = mnt_want_write_file(file);
3114 	if (ret)
3115 		return ret;
3116 
3117 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3118 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3119 		goto out_drop_write;
3120 	}
3121 
3122 	vol_args = memdup_user(arg, sizeof(*vol_args));
3123 	if (IS_ERR(vol_args)) {
3124 		ret = PTR_ERR(vol_args);
3125 		goto out;
3126 	}
3127 
3128 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3129 	ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3130 
3131 	if (!ret)
3132 		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3133 	kfree(vol_args);
3134 out:
3135 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3136 out_drop_write:
3137 	mnt_drop_write_file(file);
3138 
3139 	return ret;
3140 }
3141 
3142 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3143 				void __user *arg)
3144 {
3145 	struct btrfs_ioctl_fs_info_args *fi_args;
3146 	struct btrfs_device *device;
3147 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3148 	int ret = 0;
3149 
3150 	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3151 	if (!fi_args)
3152 		return -ENOMEM;
3153 
3154 	rcu_read_lock();
3155 	fi_args->num_devices = fs_devices->num_devices;
3156 
3157 	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3158 		if (device->devid > fi_args->max_id)
3159 			fi_args->max_id = device->devid;
3160 	}
3161 	rcu_read_unlock();
3162 
3163 	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3164 	fi_args->nodesize = fs_info->nodesize;
3165 	fi_args->sectorsize = fs_info->sectorsize;
3166 	fi_args->clone_alignment = fs_info->sectorsize;
3167 
3168 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3169 		ret = -EFAULT;
3170 
3171 	kfree(fi_args);
3172 	return ret;
3173 }
3174 
3175 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3176 				 void __user *arg)
3177 {
3178 	struct btrfs_ioctl_dev_info_args *di_args;
3179 	struct btrfs_device *dev;
3180 	int ret = 0;
3181 	char *s_uuid = NULL;
3182 
3183 	di_args = memdup_user(arg, sizeof(*di_args));
3184 	if (IS_ERR(di_args))
3185 		return PTR_ERR(di_args);
3186 
3187 	if (!btrfs_is_empty_uuid(di_args->uuid))
3188 		s_uuid = di_args->uuid;
3189 
3190 	rcu_read_lock();
3191 	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3192 				NULL, true);
3193 
3194 	if (!dev) {
3195 		ret = -ENODEV;
3196 		goto out;
3197 	}
3198 
3199 	di_args->devid = dev->devid;
3200 	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3201 	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3202 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3203 	if (dev->name) {
3204 		strncpy(di_args->path, rcu_str_deref(dev->name),
3205 				sizeof(di_args->path) - 1);
3206 		di_args->path[sizeof(di_args->path) - 1] = 0;
3207 	} else {
3208 		di_args->path[0] = '\0';
3209 	}
3210 
3211 out:
3212 	rcu_read_unlock();
3213 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3214 		ret = -EFAULT;
3215 
3216 	kfree(di_args);
3217 	return ret;
3218 }
3219 
3220 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3221 				       struct inode *inode2, u64 loff2, u64 len)
3222 {
3223 	unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3224 	unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3225 }
3226 
3227 static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3228 				     struct inode *inode2, u64 loff2, u64 len)
3229 {
3230 	if (inode1 < inode2) {
3231 		swap(inode1, inode2);
3232 		swap(loff1, loff2);
3233 	} else if (inode1 == inode2 && loff2 < loff1) {
3234 		swap(loff1, loff2);
3235 	}
3236 	lock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3237 	lock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3238 }
3239 
3240 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
3241 				   struct inode *dst, u64 dst_loff)
3242 {
3243 	int ret;
3244 
3245 	/*
3246 	 * Lock destination range to serialize with concurrent readpages() and
3247 	 * source range to serialize with relocation.
3248 	 */
3249 	btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
3250 	ret = btrfs_clone(src, dst, loff, len, len, dst_loff, 1);
3251 	btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3252 
3253 	return ret;
3254 }
3255 
3256 #define BTRFS_MAX_DEDUPE_LEN	SZ_16M
3257 
3258 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3259 			     struct inode *dst, u64 dst_loff)
3260 {
3261 	int ret;
3262 	u64 i, tail_len, chunk_count;
3263 
3264 	tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3265 	chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3266 
3267 	for (i = 0; i < chunk_count; i++) {
3268 		ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3269 					      dst, dst_loff);
3270 		if (ret)
3271 			return ret;
3272 
3273 		loff += BTRFS_MAX_DEDUPE_LEN;
3274 		dst_loff += BTRFS_MAX_DEDUPE_LEN;
3275 	}
3276 
3277 	if (tail_len > 0)
3278 		ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3279 					      dst_loff);
3280 
3281 	return ret;
3282 }
3283 
3284 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3285 				     struct inode *inode,
3286 				     u64 endoff,
3287 				     const u64 destoff,
3288 				     const u64 olen,
3289 				     int no_time_update)
3290 {
3291 	struct btrfs_root *root = BTRFS_I(inode)->root;
3292 	int ret;
3293 
3294 	inode_inc_iversion(inode);
3295 	if (!no_time_update)
3296 		inode->i_mtime = inode->i_ctime = current_time(inode);
3297 	/*
3298 	 * We round up to the block size at eof when determining which
3299 	 * extents to clone above, but shouldn't round up the file size.
3300 	 */
3301 	if (endoff > destoff + olen)
3302 		endoff = destoff + olen;
3303 	if (endoff > inode->i_size)
3304 		btrfs_i_size_write(BTRFS_I(inode), endoff);
3305 
3306 	ret = btrfs_update_inode(trans, root, inode);
3307 	if (ret) {
3308 		btrfs_abort_transaction(trans, ret);
3309 		btrfs_end_transaction(trans);
3310 		goto out;
3311 	}
3312 	ret = btrfs_end_transaction(trans);
3313 out:
3314 	return ret;
3315 }
3316 
3317 static void clone_update_extent_map(struct btrfs_inode *inode,
3318 				    const struct btrfs_trans_handle *trans,
3319 				    const struct btrfs_path *path,
3320 				    const u64 hole_offset,
3321 				    const u64 hole_len)
3322 {
3323 	struct extent_map_tree *em_tree = &inode->extent_tree;
3324 	struct extent_map *em;
3325 	int ret;
3326 
3327 	em = alloc_extent_map();
3328 	if (!em) {
3329 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3330 		return;
3331 	}
3332 
3333 	if (path) {
3334 		struct btrfs_file_extent_item *fi;
3335 
3336 		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3337 				    struct btrfs_file_extent_item);
3338 		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3339 		em->generation = -1;
3340 		if (btrfs_file_extent_type(path->nodes[0], fi) ==
3341 		    BTRFS_FILE_EXTENT_INLINE)
3342 			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3343 					&inode->runtime_flags);
3344 	} else {
3345 		em->start = hole_offset;
3346 		em->len = hole_len;
3347 		em->ram_bytes = em->len;
3348 		em->orig_start = hole_offset;
3349 		em->block_start = EXTENT_MAP_HOLE;
3350 		em->block_len = 0;
3351 		em->orig_block_len = 0;
3352 		em->compress_type = BTRFS_COMPRESS_NONE;
3353 		em->generation = trans->transid;
3354 	}
3355 
3356 	while (1) {
3357 		write_lock(&em_tree->lock);
3358 		ret = add_extent_mapping(em_tree, em, 1);
3359 		write_unlock(&em_tree->lock);
3360 		if (ret != -EEXIST) {
3361 			free_extent_map(em);
3362 			break;
3363 		}
3364 		btrfs_drop_extent_cache(inode, em->start,
3365 					em->start + em->len - 1, 0);
3366 	}
3367 
3368 	if (ret)
3369 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3370 }
3371 
3372 /*
3373  * Make sure we do not end up inserting an inline extent into a file that has
3374  * already other (non-inline) extents. If a file has an inline extent it can
3375  * not have any other extents and the (single) inline extent must start at the
3376  * file offset 0. Failing to respect these rules will lead to file corruption,
3377  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3378  *
3379  * We can have extents that have been already written to disk or we can have
3380  * dirty ranges still in delalloc, in which case the extent maps and items are
3381  * created only when we run delalloc, and the delalloc ranges might fall outside
3382  * the range we are currently locking in the inode's io tree. So we check the
3383  * inode's i_size because of that (i_size updates are done while holding the
3384  * i_mutex, which we are holding here).
3385  * We also check to see if the inode has a size not greater than "datal" but has
3386  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3387  * protected against such concurrent fallocate calls by the i_mutex).
3388  *
3389  * If the file has no extents but a size greater than datal, do not allow the
3390  * copy because we would need turn the inline extent into a non-inline one (even
3391  * with NO_HOLES enabled). If we find our destination inode only has one inline
3392  * extent, just overwrite it with the source inline extent if its size is less
3393  * than the source extent's size, or we could copy the source inline extent's
3394  * data into the destination inode's inline extent if the later is greater then
3395  * the former.
3396  */
3397 static int clone_copy_inline_extent(struct inode *dst,
3398 				    struct btrfs_trans_handle *trans,
3399 				    struct btrfs_path *path,
3400 				    struct btrfs_key *new_key,
3401 				    const u64 drop_start,
3402 				    const u64 datal,
3403 				    const u64 skip,
3404 				    const u64 size,
3405 				    char *inline_data)
3406 {
3407 	struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3408 	struct btrfs_root *root = BTRFS_I(dst)->root;
3409 	const u64 aligned_end = ALIGN(new_key->offset + datal,
3410 				      fs_info->sectorsize);
3411 	int ret;
3412 	struct btrfs_key key;
3413 
3414 	if (new_key->offset > 0)
3415 		return -EOPNOTSUPP;
3416 
3417 	key.objectid = btrfs_ino(BTRFS_I(dst));
3418 	key.type = BTRFS_EXTENT_DATA_KEY;
3419 	key.offset = 0;
3420 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3421 	if (ret < 0) {
3422 		return ret;
3423 	} else if (ret > 0) {
3424 		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3425 			ret = btrfs_next_leaf(root, path);
3426 			if (ret < 0)
3427 				return ret;
3428 			else if (ret > 0)
3429 				goto copy_inline_extent;
3430 		}
3431 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3432 		if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3433 		    key.type == BTRFS_EXTENT_DATA_KEY) {
3434 			ASSERT(key.offset > 0);
3435 			return -EOPNOTSUPP;
3436 		}
3437 	} else if (i_size_read(dst) <= datal) {
3438 		struct btrfs_file_extent_item *ei;
3439 		u64 ext_len;
3440 
3441 		/*
3442 		 * If the file size is <= datal, make sure there are no other
3443 		 * extents following (can happen do to an fallocate call with
3444 		 * the flag FALLOC_FL_KEEP_SIZE).
3445 		 */
3446 		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3447 				    struct btrfs_file_extent_item);
3448 		/*
3449 		 * If it's an inline extent, it can not have other extents
3450 		 * following it.
3451 		 */
3452 		if (btrfs_file_extent_type(path->nodes[0], ei) ==
3453 		    BTRFS_FILE_EXTENT_INLINE)
3454 			goto copy_inline_extent;
3455 
3456 		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3457 		if (ext_len > aligned_end)
3458 			return -EOPNOTSUPP;
3459 
3460 		ret = btrfs_next_item(root, path);
3461 		if (ret < 0) {
3462 			return ret;
3463 		} else if (ret == 0) {
3464 			btrfs_item_key_to_cpu(path->nodes[0], &key,
3465 					      path->slots[0]);
3466 			if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3467 			    key.type == BTRFS_EXTENT_DATA_KEY)
3468 				return -EOPNOTSUPP;
3469 		}
3470 	}
3471 
3472 copy_inline_extent:
3473 	/*
3474 	 * We have no extent items, or we have an extent at offset 0 which may
3475 	 * or may not be inlined. All these cases are dealt the same way.
3476 	 */
3477 	if (i_size_read(dst) > datal) {
3478 		/*
3479 		 * If the destination inode has an inline extent...
3480 		 * This would require copying the data from the source inline
3481 		 * extent into the beginning of the destination's inline extent.
3482 		 * But this is really complex, both extents can be compressed
3483 		 * or just one of them, which would require decompressing and
3484 		 * re-compressing data (which could increase the new compressed
3485 		 * size, not allowing the compressed data to fit anymore in an
3486 		 * inline extent).
3487 		 * So just don't support this case for now (it should be rare,
3488 		 * we are not really saving space when cloning inline extents).
3489 		 */
3490 		return -EOPNOTSUPP;
3491 	}
3492 
3493 	btrfs_release_path(path);
3494 	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3495 	if (ret)
3496 		return ret;
3497 	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3498 	if (ret)
3499 		return ret;
3500 
3501 	if (skip) {
3502 		const u32 start = btrfs_file_extent_calc_inline_size(0);
3503 
3504 		memmove(inline_data + start, inline_data + start + skip, datal);
3505 	}
3506 
3507 	write_extent_buffer(path->nodes[0], inline_data,
3508 			    btrfs_item_ptr_offset(path->nodes[0],
3509 						  path->slots[0]),
3510 			    size);
3511 	inode_add_bytes(dst, datal);
3512 
3513 	return 0;
3514 }
3515 
3516 /**
3517  * btrfs_clone() - clone a range from inode file to another
3518  *
3519  * @src: Inode to clone from
3520  * @inode: Inode to clone to
3521  * @off: Offset within source to start clone from
3522  * @olen: Original length, passed by user, of range to clone
3523  * @olen_aligned: Block-aligned value of olen
3524  * @destoff: Offset within @inode to start clone
3525  * @no_time_update: Whether to update mtime/ctime on the target inode
3526  */
3527 static int btrfs_clone(struct inode *src, struct inode *inode,
3528 		       const u64 off, const u64 olen, const u64 olen_aligned,
3529 		       const u64 destoff, int no_time_update)
3530 {
3531 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3532 	struct btrfs_root *root = BTRFS_I(inode)->root;
3533 	struct btrfs_path *path = NULL;
3534 	struct extent_buffer *leaf;
3535 	struct btrfs_trans_handle *trans;
3536 	char *buf = NULL;
3537 	struct btrfs_key key;
3538 	u32 nritems;
3539 	int slot;
3540 	int ret;
3541 	const u64 len = olen_aligned;
3542 	u64 last_dest_end = destoff;
3543 
3544 	ret = -ENOMEM;
3545 	buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3546 	if (!buf)
3547 		return ret;
3548 
3549 	path = btrfs_alloc_path();
3550 	if (!path) {
3551 		kvfree(buf);
3552 		return ret;
3553 	}
3554 
3555 	path->reada = READA_FORWARD;
3556 	/* clone data */
3557 	key.objectid = btrfs_ino(BTRFS_I(src));
3558 	key.type = BTRFS_EXTENT_DATA_KEY;
3559 	key.offset = off;
3560 
3561 	while (1) {
3562 		u64 next_key_min_offset = key.offset + 1;
3563 
3564 		/*
3565 		 * note the key will change type as we walk through the
3566 		 * tree.
3567 		 */
3568 		path->leave_spinning = 1;
3569 		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3570 				0, 0);
3571 		if (ret < 0)
3572 			goto out;
3573 		/*
3574 		 * First search, if no extent item that starts at offset off was
3575 		 * found but the previous item is an extent item, it's possible
3576 		 * it might overlap our target range, therefore process it.
3577 		 */
3578 		if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3579 			btrfs_item_key_to_cpu(path->nodes[0], &key,
3580 					      path->slots[0] - 1);
3581 			if (key.type == BTRFS_EXTENT_DATA_KEY)
3582 				path->slots[0]--;
3583 		}
3584 
3585 		nritems = btrfs_header_nritems(path->nodes[0]);
3586 process_slot:
3587 		if (path->slots[0] >= nritems) {
3588 			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3589 			if (ret < 0)
3590 				goto out;
3591 			if (ret > 0)
3592 				break;
3593 			nritems = btrfs_header_nritems(path->nodes[0]);
3594 		}
3595 		leaf = path->nodes[0];
3596 		slot = path->slots[0];
3597 
3598 		btrfs_item_key_to_cpu(leaf, &key, slot);
3599 		if (key.type > BTRFS_EXTENT_DATA_KEY ||
3600 		    key.objectid != btrfs_ino(BTRFS_I(src)))
3601 			break;
3602 
3603 		if (key.type == BTRFS_EXTENT_DATA_KEY) {
3604 			struct btrfs_file_extent_item *extent;
3605 			int type;
3606 			u32 size;
3607 			struct btrfs_key new_key;
3608 			u64 disko = 0, diskl = 0;
3609 			u64 datao = 0, datal = 0;
3610 			u8 comp;
3611 			u64 drop_start;
3612 
3613 			extent = btrfs_item_ptr(leaf, slot,
3614 						struct btrfs_file_extent_item);
3615 			comp = btrfs_file_extent_compression(leaf, extent);
3616 			type = btrfs_file_extent_type(leaf, extent);
3617 			if (type == BTRFS_FILE_EXTENT_REG ||
3618 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3619 				disko = btrfs_file_extent_disk_bytenr(leaf,
3620 								      extent);
3621 				diskl = btrfs_file_extent_disk_num_bytes(leaf,
3622 								 extent);
3623 				datao = btrfs_file_extent_offset(leaf, extent);
3624 				datal = btrfs_file_extent_num_bytes(leaf,
3625 								    extent);
3626 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3627 				/* take upper bound, may be compressed */
3628 				datal = btrfs_file_extent_ram_bytes(leaf,
3629 								    extent);
3630 			}
3631 
3632 			/*
3633 			 * The first search might have left us at an extent
3634 			 * item that ends before our target range's start, can
3635 			 * happen if we have holes and NO_HOLES feature enabled.
3636 			 */
3637 			if (key.offset + datal <= off) {
3638 				path->slots[0]++;
3639 				goto process_slot;
3640 			} else if (key.offset >= off + len) {
3641 				break;
3642 			}
3643 			next_key_min_offset = key.offset + datal;
3644 			size = btrfs_item_size_nr(leaf, slot);
3645 			read_extent_buffer(leaf, buf,
3646 					   btrfs_item_ptr_offset(leaf, slot),
3647 					   size);
3648 
3649 			btrfs_release_path(path);
3650 			path->leave_spinning = 0;
3651 
3652 			memcpy(&new_key, &key, sizeof(new_key));
3653 			new_key.objectid = btrfs_ino(BTRFS_I(inode));
3654 			if (off <= key.offset)
3655 				new_key.offset = key.offset + destoff - off;
3656 			else
3657 				new_key.offset = destoff;
3658 
3659 			/*
3660 			 * Deal with a hole that doesn't have an extent item
3661 			 * that represents it (NO_HOLES feature enabled).
3662 			 * This hole is either in the middle of the cloning
3663 			 * range or at the beginning (fully overlaps it or
3664 			 * partially overlaps it).
3665 			 */
3666 			if (new_key.offset != last_dest_end)
3667 				drop_start = last_dest_end;
3668 			else
3669 				drop_start = new_key.offset;
3670 
3671 			/*
3672 			 * 1 - adjusting old extent (we may have to split it)
3673 			 * 1 - add new extent
3674 			 * 1 - inode update
3675 			 */
3676 			trans = btrfs_start_transaction(root, 3);
3677 			if (IS_ERR(trans)) {
3678 				ret = PTR_ERR(trans);
3679 				goto out;
3680 			}
3681 
3682 			if (type == BTRFS_FILE_EXTENT_REG ||
3683 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3684 				/*
3685 				 *    a  | --- range to clone ---|  b
3686 				 * | ------------- extent ------------- |
3687 				 */
3688 
3689 				/* subtract range b */
3690 				if (key.offset + datal > off + len)
3691 					datal = off + len - key.offset;
3692 
3693 				/* subtract range a */
3694 				if (off > key.offset) {
3695 					datao += off - key.offset;
3696 					datal -= off - key.offset;
3697 				}
3698 
3699 				ret = btrfs_drop_extents(trans, root, inode,
3700 							 drop_start,
3701 							 new_key.offset + datal,
3702 							 1);
3703 				if (ret) {
3704 					if (ret != -EOPNOTSUPP)
3705 						btrfs_abort_transaction(trans,
3706 									ret);
3707 					btrfs_end_transaction(trans);
3708 					goto out;
3709 				}
3710 
3711 				ret = btrfs_insert_empty_item(trans, root, path,
3712 							      &new_key, size);
3713 				if (ret) {
3714 					btrfs_abort_transaction(trans, ret);
3715 					btrfs_end_transaction(trans);
3716 					goto out;
3717 				}
3718 
3719 				leaf = path->nodes[0];
3720 				slot = path->slots[0];
3721 				write_extent_buffer(leaf, buf,
3722 					    btrfs_item_ptr_offset(leaf, slot),
3723 					    size);
3724 
3725 				extent = btrfs_item_ptr(leaf, slot,
3726 						struct btrfs_file_extent_item);
3727 
3728 				/* disko == 0 means it's a hole */
3729 				if (!disko)
3730 					datao = 0;
3731 
3732 				btrfs_set_file_extent_offset(leaf, extent,
3733 							     datao);
3734 				btrfs_set_file_extent_num_bytes(leaf, extent,
3735 								datal);
3736 
3737 				if (disko) {
3738 					inode_add_bytes(inode, datal);
3739 					ret = btrfs_inc_extent_ref(trans,
3740 							root,
3741 							disko, diskl, 0,
3742 							root->root_key.objectid,
3743 							btrfs_ino(BTRFS_I(inode)),
3744 							new_key.offset - datao);
3745 					if (ret) {
3746 						btrfs_abort_transaction(trans,
3747 									ret);
3748 						btrfs_end_transaction(trans);
3749 						goto out;
3750 
3751 					}
3752 				}
3753 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3754 				u64 skip = 0;
3755 				u64 trim = 0;
3756 
3757 				if (off > key.offset) {
3758 					skip = off - key.offset;
3759 					new_key.offset += skip;
3760 				}
3761 
3762 				if (key.offset + datal > off + len)
3763 					trim = key.offset + datal - (off + len);
3764 
3765 				if (comp && (skip || trim)) {
3766 					ret = -EINVAL;
3767 					btrfs_end_transaction(trans);
3768 					goto out;
3769 				}
3770 				size -= skip + trim;
3771 				datal -= skip + trim;
3772 
3773 				ret = clone_copy_inline_extent(inode,
3774 							       trans, path,
3775 							       &new_key,
3776 							       drop_start,
3777 							       datal,
3778 							       skip, size, buf);
3779 				if (ret) {
3780 					if (ret != -EOPNOTSUPP)
3781 						btrfs_abort_transaction(trans,
3782 									ret);
3783 					btrfs_end_transaction(trans);
3784 					goto out;
3785 				}
3786 				leaf = path->nodes[0];
3787 				slot = path->slots[0];
3788 			}
3789 
3790 			/* If we have an implicit hole (NO_HOLES feature). */
3791 			if (drop_start < new_key.offset)
3792 				clone_update_extent_map(BTRFS_I(inode), trans,
3793 						NULL, drop_start,
3794 						new_key.offset - drop_start);
3795 
3796 			clone_update_extent_map(BTRFS_I(inode), trans,
3797 					path, 0, 0);
3798 
3799 			btrfs_mark_buffer_dirty(leaf);
3800 			btrfs_release_path(path);
3801 
3802 			last_dest_end = ALIGN(new_key.offset + datal,
3803 					      fs_info->sectorsize);
3804 			ret = clone_finish_inode_update(trans, inode,
3805 							last_dest_end,
3806 							destoff, olen,
3807 							no_time_update);
3808 			if (ret)
3809 				goto out;
3810 			if (new_key.offset + datal >= destoff + len)
3811 				break;
3812 		}
3813 		btrfs_release_path(path);
3814 		key.offset = next_key_min_offset;
3815 
3816 		if (fatal_signal_pending(current)) {
3817 			ret = -EINTR;
3818 			goto out;
3819 		}
3820 	}
3821 	ret = 0;
3822 
3823 	if (last_dest_end < destoff + len) {
3824 		/*
3825 		 * We have an implicit hole (NO_HOLES feature is enabled) that
3826 		 * fully or partially overlaps our cloning range at its end.
3827 		 */
3828 		btrfs_release_path(path);
3829 
3830 		/*
3831 		 * 1 - remove extent(s)
3832 		 * 1 - inode update
3833 		 */
3834 		trans = btrfs_start_transaction(root, 2);
3835 		if (IS_ERR(trans)) {
3836 			ret = PTR_ERR(trans);
3837 			goto out;
3838 		}
3839 		ret = btrfs_drop_extents(trans, root, inode,
3840 					 last_dest_end, destoff + len, 1);
3841 		if (ret) {
3842 			if (ret != -EOPNOTSUPP)
3843 				btrfs_abort_transaction(trans, ret);
3844 			btrfs_end_transaction(trans);
3845 			goto out;
3846 		}
3847 		clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3848 				last_dest_end,
3849 				destoff + len - last_dest_end);
3850 		ret = clone_finish_inode_update(trans, inode, destoff + len,
3851 						destoff, olen, no_time_update);
3852 	}
3853 
3854 out:
3855 	btrfs_free_path(path);
3856 	kvfree(buf);
3857 	return ret;
3858 }
3859 
3860 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3861 					u64 off, u64 olen, u64 destoff)
3862 {
3863 	struct inode *inode = file_inode(file);
3864 	struct inode *src = file_inode(file_src);
3865 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3866 	int ret;
3867 	u64 len = olen;
3868 	u64 bs = fs_info->sb->s_blocksize;
3869 
3870 	/*
3871 	 * TODO:
3872 	 * - split compressed inline extents.  annoying: we need to
3873 	 *   decompress into destination's address_space (the file offset
3874 	 *   may change, so source mapping won't do), then recompress (or
3875 	 *   otherwise reinsert) a subrange.
3876 	 *
3877 	 * - split destination inode's inline extents.  The inline extents can
3878 	 *   be either compressed or non-compressed.
3879 	 */
3880 
3881 	/*
3882 	 * VFS's generic_remap_file_range_prep() protects us from cloning the
3883 	 * eof block into the middle of a file, which would result in corruption
3884 	 * if the file size is not blocksize aligned. So we don't need to check
3885 	 * for that case here.
3886 	 */
3887 	if (off + len == src->i_size)
3888 		len = ALIGN(src->i_size, bs) - off;
3889 
3890 	if (destoff > inode->i_size) {
3891 		const u64 wb_start = ALIGN_DOWN(inode->i_size, bs);
3892 
3893 		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3894 		if (ret)
3895 			return ret;
3896 		/*
3897 		 * We may have truncated the last block if the inode's size is
3898 		 * not sector size aligned, so we need to wait for writeback to
3899 		 * complete before proceeding further, otherwise we can race
3900 		 * with cloning and attempt to increment a reference to an
3901 		 * extent that no longer exists (writeback completed right after
3902 		 * we found the previous extent covering eof and before we
3903 		 * attempted to increment its reference count).
3904 		 */
3905 		ret = btrfs_wait_ordered_range(inode, wb_start,
3906 					       destoff - wb_start);
3907 		if (ret)
3908 			return ret;
3909 	}
3910 
3911 	/*
3912 	 * Lock destination range to serialize with concurrent readpages() and
3913 	 * source range to serialize with relocation.
3914 	 */
3915 	btrfs_double_extent_lock(src, off, inode, destoff, len);
3916 	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3917 	btrfs_double_extent_unlock(src, off, inode, destoff, len);
3918 	/*
3919 	 * Truncate page cache pages so that future reads will see the cloned
3920 	 * data immediately and not the previous data.
3921 	 */
3922 	truncate_inode_pages_range(&inode->i_data,
3923 				round_down(destoff, PAGE_SIZE),
3924 				round_up(destoff + len, PAGE_SIZE) - 1);
3925 
3926 	return ret;
3927 }
3928 
3929 static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
3930 				       struct file *file_out, loff_t pos_out,
3931 				       loff_t *len, unsigned int remap_flags)
3932 {
3933 	struct inode *inode_in = file_inode(file_in);
3934 	struct inode *inode_out = file_inode(file_out);
3935 	u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
3936 	bool same_inode = inode_out == inode_in;
3937 	u64 wb_len;
3938 	int ret;
3939 
3940 	if (!(remap_flags & REMAP_FILE_DEDUP)) {
3941 		struct btrfs_root *root_out = BTRFS_I(inode_out)->root;
3942 
3943 		if (btrfs_root_readonly(root_out))
3944 			return -EROFS;
3945 
3946 		if (file_in->f_path.mnt != file_out->f_path.mnt ||
3947 		    inode_in->i_sb != inode_out->i_sb)
3948 			return -EXDEV;
3949 	}
3950 
3951 	if (same_inode)
3952 		inode_lock(inode_in);
3953 	else
3954 		lock_two_nondirectories(inode_in, inode_out);
3955 
3956 	/* don't make the dst file partly checksummed */
3957 	if ((BTRFS_I(inode_in)->flags & BTRFS_INODE_NODATASUM) !=
3958 	    (BTRFS_I(inode_out)->flags & BTRFS_INODE_NODATASUM)) {
3959 		ret = -EINVAL;
3960 		goto out_unlock;
3961 	}
3962 
3963 	/*
3964 	 * Now that the inodes are locked, we need to start writeback ourselves
3965 	 * and can not rely on the writeback from the VFS's generic helper
3966 	 * generic_remap_file_range_prep() because:
3967 	 *
3968 	 * 1) For compression we must call filemap_fdatawrite_range() range
3969 	 *    twice (btrfs_fdatawrite_range() does it for us), and the generic
3970 	 *    helper only calls it once;
3971 	 *
3972 	 * 2) filemap_fdatawrite_range(), called by the generic helper only
3973 	 *    waits for the writeback to complete, i.e. for IO to be done, and
3974 	 *    not for the ordered extents to complete. We need to wait for them
3975 	 *    to complete so that new file extent items are in the fs tree.
3976 	 */
3977 	if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP))
3978 		wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs);
3979 	else
3980 		wb_len = ALIGN(*len, bs);
3981 
3982 	/*
3983 	 * Since we don't lock ranges, wait for ongoing lockless dio writes (as
3984 	 * any in progress could create its ordered extents after we wait for
3985 	 * existing ordered extents below).
3986 	 */
3987 	inode_dio_wait(inode_in);
3988 	if (!same_inode)
3989 		inode_dio_wait(inode_out);
3990 
3991 	ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
3992 				       wb_len);
3993 	if (ret < 0)
3994 		goto out_unlock;
3995 	ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs),
3996 				       wb_len);
3997 	if (ret < 0)
3998 		goto out_unlock;
3999 
4000 	ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
4001 					    len, remap_flags);
4002 	if (ret < 0 || *len == 0)
4003 		goto out_unlock;
4004 
4005 	return 0;
4006 
4007  out_unlock:
4008 	if (same_inode)
4009 		inode_unlock(inode_in);
4010 	else
4011 		unlock_two_nondirectories(inode_in, inode_out);
4012 
4013 	return ret;
4014 }
4015 
4016 loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
4017 		struct file *dst_file, loff_t destoff, loff_t len,
4018 		unsigned int remap_flags)
4019 {
4020 	struct inode *src_inode = file_inode(src_file);
4021 	struct inode *dst_inode = file_inode(dst_file);
4022 	bool same_inode = dst_inode == src_inode;
4023 	int ret;
4024 
4025 	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
4026 		return -EINVAL;
4027 
4028 	ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
4029 					  &len, remap_flags);
4030 	if (ret < 0 || len == 0)
4031 		return ret;
4032 
4033 	if (remap_flags & REMAP_FILE_DEDUP)
4034 		ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
4035 	else
4036 		ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
4037 
4038 	if (same_inode)
4039 		inode_unlock(src_inode);
4040 	else
4041 		unlock_two_nondirectories(src_inode, dst_inode);
4042 
4043 	return ret < 0 ? ret : len;
4044 }
4045 
4046 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4047 {
4048 	struct inode *inode = file_inode(file);
4049 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4050 	struct btrfs_root *root = BTRFS_I(inode)->root;
4051 	struct btrfs_root *new_root;
4052 	struct btrfs_dir_item *di;
4053 	struct btrfs_trans_handle *trans;
4054 	struct btrfs_path *path;
4055 	struct btrfs_key location;
4056 	struct btrfs_disk_key disk_key;
4057 	u64 objectid = 0;
4058 	u64 dir_id;
4059 	int ret;
4060 
4061 	if (!capable(CAP_SYS_ADMIN))
4062 		return -EPERM;
4063 
4064 	ret = mnt_want_write_file(file);
4065 	if (ret)
4066 		return ret;
4067 
4068 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4069 		ret = -EFAULT;
4070 		goto out;
4071 	}
4072 
4073 	if (!objectid)
4074 		objectid = BTRFS_FS_TREE_OBJECTID;
4075 
4076 	location.objectid = objectid;
4077 	location.type = BTRFS_ROOT_ITEM_KEY;
4078 	location.offset = (u64)-1;
4079 
4080 	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4081 	if (IS_ERR(new_root)) {
4082 		ret = PTR_ERR(new_root);
4083 		goto out;
4084 	}
4085 	if (!is_fstree(new_root->root_key.objectid)) {
4086 		ret = -ENOENT;
4087 		goto out;
4088 	}
4089 
4090 	path = btrfs_alloc_path();
4091 	if (!path) {
4092 		ret = -ENOMEM;
4093 		goto out;
4094 	}
4095 	path->leave_spinning = 1;
4096 
4097 	trans = btrfs_start_transaction(root, 1);
4098 	if (IS_ERR(trans)) {
4099 		btrfs_free_path(path);
4100 		ret = PTR_ERR(trans);
4101 		goto out;
4102 	}
4103 
4104 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
4105 	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4106 				   dir_id, "default", 7, 1);
4107 	if (IS_ERR_OR_NULL(di)) {
4108 		btrfs_free_path(path);
4109 		btrfs_end_transaction(trans);
4110 		btrfs_err(fs_info,
4111 			  "Umm, you don't have the default diritem, this isn't going to work");
4112 		ret = -ENOENT;
4113 		goto out;
4114 	}
4115 
4116 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4117 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4118 	btrfs_mark_buffer_dirty(path->nodes[0]);
4119 	btrfs_free_path(path);
4120 
4121 	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4122 	btrfs_end_transaction(trans);
4123 out:
4124 	mnt_drop_write_file(file);
4125 	return ret;
4126 }
4127 
4128 static void get_block_group_info(struct list_head *groups_list,
4129 				 struct btrfs_ioctl_space_info *space)
4130 {
4131 	struct btrfs_block_group_cache *block_group;
4132 
4133 	space->total_bytes = 0;
4134 	space->used_bytes = 0;
4135 	space->flags = 0;
4136 	list_for_each_entry(block_group, groups_list, list) {
4137 		space->flags = block_group->flags;
4138 		space->total_bytes += block_group->key.offset;
4139 		space->used_bytes +=
4140 			btrfs_block_group_used(&block_group->item);
4141 	}
4142 }
4143 
4144 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4145 				   void __user *arg)
4146 {
4147 	struct btrfs_ioctl_space_args space_args;
4148 	struct btrfs_ioctl_space_info space;
4149 	struct btrfs_ioctl_space_info *dest;
4150 	struct btrfs_ioctl_space_info *dest_orig;
4151 	struct btrfs_ioctl_space_info __user *user_dest;
4152 	struct btrfs_space_info *info;
4153 	static const u64 types[] = {
4154 		BTRFS_BLOCK_GROUP_DATA,
4155 		BTRFS_BLOCK_GROUP_SYSTEM,
4156 		BTRFS_BLOCK_GROUP_METADATA,
4157 		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4158 	};
4159 	int num_types = 4;
4160 	int alloc_size;
4161 	int ret = 0;
4162 	u64 slot_count = 0;
4163 	int i, c;
4164 
4165 	if (copy_from_user(&space_args,
4166 			   (struct btrfs_ioctl_space_args __user *)arg,
4167 			   sizeof(space_args)))
4168 		return -EFAULT;
4169 
4170 	for (i = 0; i < num_types; i++) {
4171 		struct btrfs_space_info *tmp;
4172 
4173 		info = NULL;
4174 		rcu_read_lock();
4175 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4176 					list) {
4177 			if (tmp->flags == types[i]) {
4178 				info = tmp;
4179 				break;
4180 			}
4181 		}
4182 		rcu_read_unlock();
4183 
4184 		if (!info)
4185 			continue;
4186 
4187 		down_read(&info->groups_sem);
4188 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4189 			if (!list_empty(&info->block_groups[c]))
4190 				slot_count++;
4191 		}
4192 		up_read(&info->groups_sem);
4193 	}
4194 
4195 	/*
4196 	 * Global block reserve, exported as a space_info
4197 	 */
4198 	slot_count++;
4199 
4200 	/* space_slots == 0 means they are asking for a count */
4201 	if (space_args.space_slots == 0) {
4202 		space_args.total_spaces = slot_count;
4203 		goto out;
4204 	}
4205 
4206 	slot_count = min_t(u64, space_args.space_slots, slot_count);
4207 
4208 	alloc_size = sizeof(*dest) * slot_count;
4209 
4210 	/* we generally have at most 6 or so space infos, one for each raid
4211 	 * level.  So, a whole page should be more than enough for everyone
4212 	 */
4213 	if (alloc_size > PAGE_SIZE)
4214 		return -ENOMEM;
4215 
4216 	space_args.total_spaces = 0;
4217 	dest = kmalloc(alloc_size, GFP_KERNEL);
4218 	if (!dest)
4219 		return -ENOMEM;
4220 	dest_orig = dest;
4221 
4222 	/* now we have a buffer to copy into */
4223 	for (i = 0; i < num_types; i++) {
4224 		struct btrfs_space_info *tmp;
4225 
4226 		if (!slot_count)
4227 			break;
4228 
4229 		info = NULL;
4230 		rcu_read_lock();
4231 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4232 					list) {
4233 			if (tmp->flags == types[i]) {
4234 				info = tmp;
4235 				break;
4236 			}
4237 		}
4238 		rcu_read_unlock();
4239 
4240 		if (!info)
4241 			continue;
4242 		down_read(&info->groups_sem);
4243 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4244 			if (!list_empty(&info->block_groups[c])) {
4245 				get_block_group_info(&info->block_groups[c],
4246 						     &space);
4247 				memcpy(dest, &space, sizeof(space));
4248 				dest++;
4249 				space_args.total_spaces++;
4250 				slot_count--;
4251 			}
4252 			if (!slot_count)
4253 				break;
4254 		}
4255 		up_read(&info->groups_sem);
4256 	}
4257 
4258 	/*
4259 	 * Add global block reserve
4260 	 */
4261 	if (slot_count) {
4262 		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4263 
4264 		spin_lock(&block_rsv->lock);
4265 		space.total_bytes = block_rsv->size;
4266 		space.used_bytes = block_rsv->size - block_rsv->reserved;
4267 		spin_unlock(&block_rsv->lock);
4268 		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4269 		memcpy(dest, &space, sizeof(space));
4270 		space_args.total_spaces++;
4271 	}
4272 
4273 	user_dest = (struct btrfs_ioctl_space_info __user *)
4274 		(arg + sizeof(struct btrfs_ioctl_space_args));
4275 
4276 	if (copy_to_user(user_dest, dest_orig, alloc_size))
4277 		ret = -EFAULT;
4278 
4279 	kfree(dest_orig);
4280 out:
4281 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4282 		ret = -EFAULT;
4283 
4284 	return ret;
4285 }
4286 
4287 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4288 					    void __user *argp)
4289 {
4290 	struct btrfs_trans_handle *trans;
4291 	u64 transid;
4292 	int ret;
4293 
4294 	trans = btrfs_attach_transaction_barrier(root);
4295 	if (IS_ERR(trans)) {
4296 		if (PTR_ERR(trans) != -ENOENT)
4297 			return PTR_ERR(trans);
4298 
4299 		/* No running transaction, don't bother */
4300 		transid = root->fs_info->last_trans_committed;
4301 		goto out;
4302 	}
4303 	transid = trans->transid;
4304 	ret = btrfs_commit_transaction_async(trans, 0);
4305 	if (ret) {
4306 		btrfs_end_transaction(trans);
4307 		return ret;
4308 	}
4309 out:
4310 	if (argp)
4311 		if (copy_to_user(argp, &transid, sizeof(transid)))
4312 			return -EFAULT;
4313 	return 0;
4314 }
4315 
4316 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4317 					   void __user *argp)
4318 {
4319 	u64 transid;
4320 
4321 	if (argp) {
4322 		if (copy_from_user(&transid, argp, sizeof(transid)))
4323 			return -EFAULT;
4324 	} else {
4325 		transid = 0;  /* current trans */
4326 	}
4327 	return btrfs_wait_for_commit(fs_info, transid);
4328 }
4329 
4330 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4331 {
4332 	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4333 	struct btrfs_ioctl_scrub_args *sa;
4334 	int ret;
4335 
4336 	if (!capable(CAP_SYS_ADMIN))
4337 		return -EPERM;
4338 
4339 	sa = memdup_user(arg, sizeof(*sa));
4340 	if (IS_ERR(sa))
4341 		return PTR_ERR(sa);
4342 
4343 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4344 		ret = mnt_want_write_file(file);
4345 		if (ret)
4346 			goto out;
4347 	}
4348 
4349 	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4350 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4351 			      0);
4352 
4353 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4354 		ret = -EFAULT;
4355 
4356 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
4357 		mnt_drop_write_file(file);
4358 out:
4359 	kfree(sa);
4360 	return ret;
4361 }
4362 
4363 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4364 {
4365 	if (!capable(CAP_SYS_ADMIN))
4366 		return -EPERM;
4367 
4368 	return btrfs_scrub_cancel(fs_info);
4369 }
4370 
4371 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4372 				       void __user *arg)
4373 {
4374 	struct btrfs_ioctl_scrub_args *sa;
4375 	int ret;
4376 
4377 	if (!capable(CAP_SYS_ADMIN))
4378 		return -EPERM;
4379 
4380 	sa = memdup_user(arg, sizeof(*sa));
4381 	if (IS_ERR(sa))
4382 		return PTR_ERR(sa);
4383 
4384 	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4385 
4386 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4387 		ret = -EFAULT;
4388 
4389 	kfree(sa);
4390 	return ret;
4391 }
4392 
4393 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4394 				      void __user *arg)
4395 {
4396 	struct btrfs_ioctl_get_dev_stats *sa;
4397 	int ret;
4398 
4399 	sa = memdup_user(arg, sizeof(*sa));
4400 	if (IS_ERR(sa))
4401 		return PTR_ERR(sa);
4402 
4403 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4404 		kfree(sa);
4405 		return -EPERM;
4406 	}
4407 
4408 	ret = btrfs_get_dev_stats(fs_info, sa);
4409 
4410 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
4411 		ret = -EFAULT;
4412 
4413 	kfree(sa);
4414 	return ret;
4415 }
4416 
4417 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4418 				    void __user *arg)
4419 {
4420 	struct btrfs_ioctl_dev_replace_args *p;
4421 	int ret;
4422 
4423 	if (!capable(CAP_SYS_ADMIN))
4424 		return -EPERM;
4425 
4426 	p = memdup_user(arg, sizeof(*p));
4427 	if (IS_ERR(p))
4428 		return PTR_ERR(p);
4429 
4430 	switch (p->cmd) {
4431 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4432 		if (sb_rdonly(fs_info->sb)) {
4433 			ret = -EROFS;
4434 			goto out;
4435 		}
4436 		if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4437 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4438 		} else {
4439 			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4440 			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4441 		}
4442 		break;
4443 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4444 		btrfs_dev_replace_status(fs_info, p);
4445 		ret = 0;
4446 		break;
4447 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4448 		p->result = btrfs_dev_replace_cancel(fs_info);
4449 		ret = 0;
4450 		break;
4451 	default:
4452 		ret = -EINVAL;
4453 		break;
4454 	}
4455 
4456 	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
4457 		ret = -EFAULT;
4458 out:
4459 	kfree(p);
4460 	return ret;
4461 }
4462 
4463 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4464 {
4465 	int ret = 0;
4466 	int i;
4467 	u64 rel_ptr;
4468 	int size;
4469 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
4470 	struct inode_fs_paths *ipath = NULL;
4471 	struct btrfs_path *path;
4472 
4473 	if (!capable(CAP_DAC_READ_SEARCH))
4474 		return -EPERM;
4475 
4476 	path = btrfs_alloc_path();
4477 	if (!path) {
4478 		ret = -ENOMEM;
4479 		goto out;
4480 	}
4481 
4482 	ipa = memdup_user(arg, sizeof(*ipa));
4483 	if (IS_ERR(ipa)) {
4484 		ret = PTR_ERR(ipa);
4485 		ipa = NULL;
4486 		goto out;
4487 	}
4488 
4489 	size = min_t(u32, ipa->size, 4096);
4490 	ipath = init_ipath(size, root, path);
4491 	if (IS_ERR(ipath)) {
4492 		ret = PTR_ERR(ipath);
4493 		ipath = NULL;
4494 		goto out;
4495 	}
4496 
4497 	ret = paths_from_inode(ipa->inum, ipath);
4498 	if (ret < 0)
4499 		goto out;
4500 
4501 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4502 		rel_ptr = ipath->fspath->val[i] -
4503 			  (u64)(unsigned long)ipath->fspath->val;
4504 		ipath->fspath->val[i] = rel_ptr;
4505 	}
4506 
4507 	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4508 			   ipath->fspath, size);
4509 	if (ret) {
4510 		ret = -EFAULT;
4511 		goto out;
4512 	}
4513 
4514 out:
4515 	btrfs_free_path(path);
4516 	free_ipath(ipath);
4517 	kfree(ipa);
4518 
4519 	return ret;
4520 }
4521 
4522 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4523 {
4524 	struct btrfs_data_container *inodes = ctx;
4525 	const size_t c = 3 * sizeof(u64);
4526 
4527 	if (inodes->bytes_left >= c) {
4528 		inodes->bytes_left -= c;
4529 		inodes->val[inodes->elem_cnt] = inum;
4530 		inodes->val[inodes->elem_cnt + 1] = offset;
4531 		inodes->val[inodes->elem_cnt + 2] = root;
4532 		inodes->elem_cnt += 3;
4533 	} else {
4534 		inodes->bytes_missing += c - inodes->bytes_left;
4535 		inodes->bytes_left = 0;
4536 		inodes->elem_missed += 3;
4537 	}
4538 
4539 	return 0;
4540 }
4541 
4542 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4543 					void __user *arg, int version)
4544 {
4545 	int ret = 0;
4546 	int size;
4547 	struct btrfs_ioctl_logical_ino_args *loi;
4548 	struct btrfs_data_container *inodes = NULL;
4549 	struct btrfs_path *path = NULL;
4550 	bool ignore_offset;
4551 
4552 	if (!capable(CAP_SYS_ADMIN))
4553 		return -EPERM;
4554 
4555 	loi = memdup_user(arg, sizeof(*loi));
4556 	if (IS_ERR(loi))
4557 		return PTR_ERR(loi);
4558 
4559 	if (version == 1) {
4560 		ignore_offset = false;
4561 		size = min_t(u32, loi->size, SZ_64K);
4562 	} else {
4563 		/* All reserved bits must be 0 for now */
4564 		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4565 			ret = -EINVAL;
4566 			goto out_loi;
4567 		}
4568 		/* Only accept flags we have defined so far */
4569 		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4570 			ret = -EINVAL;
4571 			goto out_loi;
4572 		}
4573 		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4574 		size = min_t(u32, loi->size, SZ_16M);
4575 	}
4576 
4577 	path = btrfs_alloc_path();
4578 	if (!path) {
4579 		ret = -ENOMEM;
4580 		goto out;
4581 	}
4582 
4583 	inodes = init_data_container(size);
4584 	if (IS_ERR(inodes)) {
4585 		ret = PTR_ERR(inodes);
4586 		inodes = NULL;
4587 		goto out;
4588 	}
4589 
4590 	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4591 					  build_ino_list, inodes, ignore_offset);
4592 	if (ret == -EINVAL)
4593 		ret = -ENOENT;
4594 	if (ret < 0)
4595 		goto out;
4596 
4597 	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4598 			   size);
4599 	if (ret)
4600 		ret = -EFAULT;
4601 
4602 out:
4603 	btrfs_free_path(path);
4604 	kvfree(inodes);
4605 out_loi:
4606 	kfree(loi);
4607 
4608 	return ret;
4609 }
4610 
4611 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4612 			       struct btrfs_ioctl_balance_args *bargs)
4613 {
4614 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4615 
4616 	bargs->flags = bctl->flags;
4617 
4618 	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4619 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4620 	if (atomic_read(&fs_info->balance_pause_req))
4621 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4622 	if (atomic_read(&fs_info->balance_cancel_req))
4623 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4624 
4625 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4626 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4627 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4628 
4629 	spin_lock(&fs_info->balance_lock);
4630 	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4631 	spin_unlock(&fs_info->balance_lock);
4632 }
4633 
4634 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4635 {
4636 	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4637 	struct btrfs_fs_info *fs_info = root->fs_info;
4638 	struct btrfs_ioctl_balance_args *bargs;
4639 	struct btrfs_balance_control *bctl;
4640 	bool need_unlock; /* for mut. excl. ops lock */
4641 	int ret;
4642 
4643 	if (!capable(CAP_SYS_ADMIN))
4644 		return -EPERM;
4645 
4646 	ret = mnt_want_write_file(file);
4647 	if (ret)
4648 		return ret;
4649 
4650 again:
4651 	if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4652 		mutex_lock(&fs_info->balance_mutex);
4653 		need_unlock = true;
4654 		goto locked;
4655 	}
4656 
4657 	/*
4658 	 * mut. excl. ops lock is locked.  Three possibilities:
4659 	 *   (1) some other op is running
4660 	 *   (2) balance is running
4661 	 *   (3) balance is paused -- special case (think resume)
4662 	 */
4663 	mutex_lock(&fs_info->balance_mutex);
4664 	if (fs_info->balance_ctl) {
4665 		/* this is either (2) or (3) */
4666 		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4667 			mutex_unlock(&fs_info->balance_mutex);
4668 			/*
4669 			 * Lock released to allow other waiters to continue,
4670 			 * we'll reexamine the status again.
4671 			 */
4672 			mutex_lock(&fs_info->balance_mutex);
4673 
4674 			if (fs_info->balance_ctl &&
4675 			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4676 				/* this is (3) */
4677 				need_unlock = false;
4678 				goto locked;
4679 			}
4680 
4681 			mutex_unlock(&fs_info->balance_mutex);
4682 			goto again;
4683 		} else {
4684 			/* this is (2) */
4685 			mutex_unlock(&fs_info->balance_mutex);
4686 			ret = -EINPROGRESS;
4687 			goto out;
4688 		}
4689 	} else {
4690 		/* this is (1) */
4691 		mutex_unlock(&fs_info->balance_mutex);
4692 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4693 		goto out;
4694 	}
4695 
4696 locked:
4697 	BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4698 
4699 	if (arg) {
4700 		bargs = memdup_user(arg, sizeof(*bargs));
4701 		if (IS_ERR(bargs)) {
4702 			ret = PTR_ERR(bargs);
4703 			goto out_unlock;
4704 		}
4705 
4706 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4707 			if (!fs_info->balance_ctl) {
4708 				ret = -ENOTCONN;
4709 				goto out_bargs;
4710 			}
4711 
4712 			bctl = fs_info->balance_ctl;
4713 			spin_lock(&fs_info->balance_lock);
4714 			bctl->flags |= BTRFS_BALANCE_RESUME;
4715 			spin_unlock(&fs_info->balance_lock);
4716 
4717 			goto do_balance;
4718 		}
4719 	} else {
4720 		bargs = NULL;
4721 	}
4722 
4723 	if (fs_info->balance_ctl) {
4724 		ret = -EINPROGRESS;
4725 		goto out_bargs;
4726 	}
4727 
4728 	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4729 	if (!bctl) {
4730 		ret = -ENOMEM;
4731 		goto out_bargs;
4732 	}
4733 
4734 	if (arg) {
4735 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4736 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4737 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4738 
4739 		bctl->flags = bargs->flags;
4740 	} else {
4741 		/* balance everything - no filters */
4742 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4743 	}
4744 
4745 	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4746 		ret = -EINVAL;
4747 		goto out_bctl;
4748 	}
4749 
4750 do_balance:
4751 	/*
4752 	 * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
4753 	 * btrfs_balance.  bctl is freed in reset_balance_state, or, if
4754 	 * restriper was paused all the way until unmount, in free_fs_info.
4755 	 * The flag should be cleared after reset_balance_state.
4756 	 */
4757 	need_unlock = false;
4758 
4759 	ret = btrfs_balance(fs_info, bctl, bargs);
4760 	bctl = NULL;
4761 
4762 	if ((ret == 0 || ret == -ECANCELED) && arg) {
4763 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4764 			ret = -EFAULT;
4765 	}
4766 
4767 out_bctl:
4768 	kfree(bctl);
4769 out_bargs:
4770 	kfree(bargs);
4771 out_unlock:
4772 	mutex_unlock(&fs_info->balance_mutex);
4773 	if (need_unlock)
4774 		clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4775 out:
4776 	mnt_drop_write_file(file);
4777 	return ret;
4778 }
4779 
4780 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4781 {
4782 	if (!capable(CAP_SYS_ADMIN))
4783 		return -EPERM;
4784 
4785 	switch (cmd) {
4786 	case BTRFS_BALANCE_CTL_PAUSE:
4787 		return btrfs_pause_balance(fs_info);
4788 	case BTRFS_BALANCE_CTL_CANCEL:
4789 		return btrfs_cancel_balance(fs_info);
4790 	}
4791 
4792 	return -EINVAL;
4793 }
4794 
4795 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4796 					 void __user *arg)
4797 {
4798 	struct btrfs_ioctl_balance_args *bargs;
4799 	int ret = 0;
4800 
4801 	if (!capable(CAP_SYS_ADMIN))
4802 		return -EPERM;
4803 
4804 	mutex_lock(&fs_info->balance_mutex);
4805 	if (!fs_info->balance_ctl) {
4806 		ret = -ENOTCONN;
4807 		goto out;
4808 	}
4809 
4810 	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4811 	if (!bargs) {
4812 		ret = -ENOMEM;
4813 		goto out;
4814 	}
4815 
4816 	btrfs_update_ioctl_balance_args(fs_info, bargs);
4817 
4818 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4819 		ret = -EFAULT;
4820 
4821 	kfree(bargs);
4822 out:
4823 	mutex_unlock(&fs_info->balance_mutex);
4824 	return ret;
4825 }
4826 
4827 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4828 {
4829 	struct inode *inode = file_inode(file);
4830 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4831 	struct btrfs_ioctl_quota_ctl_args *sa;
4832 	int ret;
4833 
4834 	if (!capable(CAP_SYS_ADMIN))
4835 		return -EPERM;
4836 
4837 	ret = mnt_want_write_file(file);
4838 	if (ret)
4839 		return ret;
4840 
4841 	sa = memdup_user(arg, sizeof(*sa));
4842 	if (IS_ERR(sa)) {
4843 		ret = PTR_ERR(sa);
4844 		goto drop_write;
4845 	}
4846 
4847 	down_write(&fs_info->subvol_sem);
4848 
4849 	switch (sa->cmd) {
4850 	case BTRFS_QUOTA_CTL_ENABLE:
4851 		ret = btrfs_quota_enable(fs_info);
4852 		break;
4853 	case BTRFS_QUOTA_CTL_DISABLE:
4854 		ret = btrfs_quota_disable(fs_info);
4855 		break;
4856 	default:
4857 		ret = -EINVAL;
4858 		break;
4859 	}
4860 
4861 	kfree(sa);
4862 	up_write(&fs_info->subvol_sem);
4863 drop_write:
4864 	mnt_drop_write_file(file);
4865 	return ret;
4866 }
4867 
4868 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4869 {
4870 	struct inode *inode = file_inode(file);
4871 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4872 	struct btrfs_root *root = BTRFS_I(inode)->root;
4873 	struct btrfs_ioctl_qgroup_assign_args *sa;
4874 	struct btrfs_trans_handle *trans;
4875 	int ret;
4876 	int err;
4877 
4878 	if (!capable(CAP_SYS_ADMIN))
4879 		return -EPERM;
4880 
4881 	ret = mnt_want_write_file(file);
4882 	if (ret)
4883 		return ret;
4884 
4885 	sa = memdup_user(arg, sizeof(*sa));
4886 	if (IS_ERR(sa)) {
4887 		ret = PTR_ERR(sa);
4888 		goto drop_write;
4889 	}
4890 
4891 	trans = btrfs_join_transaction(root);
4892 	if (IS_ERR(trans)) {
4893 		ret = PTR_ERR(trans);
4894 		goto out;
4895 	}
4896 
4897 	if (sa->assign) {
4898 		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4899 	} else {
4900 		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4901 	}
4902 
4903 	/* update qgroup status and info */
4904 	err = btrfs_run_qgroups(trans);
4905 	if (err < 0)
4906 		btrfs_handle_fs_error(fs_info, err,
4907 				      "failed to update qgroup status and info");
4908 	err = btrfs_end_transaction(trans);
4909 	if (err && !ret)
4910 		ret = err;
4911 
4912 out:
4913 	kfree(sa);
4914 drop_write:
4915 	mnt_drop_write_file(file);
4916 	return ret;
4917 }
4918 
4919 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4920 {
4921 	struct inode *inode = file_inode(file);
4922 	struct btrfs_root *root = BTRFS_I(inode)->root;
4923 	struct btrfs_ioctl_qgroup_create_args *sa;
4924 	struct btrfs_trans_handle *trans;
4925 	int ret;
4926 	int err;
4927 
4928 	if (!capable(CAP_SYS_ADMIN))
4929 		return -EPERM;
4930 
4931 	ret = mnt_want_write_file(file);
4932 	if (ret)
4933 		return ret;
4934 
4935 	sa = memdup_user(arg, sizeof(*sa));
4936 	if (IS_ERR(sa)) {
4937 		ret = PTR_ERR(sa);
4938 		goto drop_write;
4939 	}
4940 
4941 	if (!sa->qgroupid) {
4942 		ret = -EINVAL;
4943 		goto out;
4944 	}
4945 
4946 	trans = btrfs_join_transaction(root);
4947 	if (IS_ERR(trans)) {
4948 		ret = PTR_ERR(trans);
4949 		goto out;
4950 	}
4951 
4952 	if (sa->create) {
4953 		ret = btrfs_create_qgroup(trans, sa->qgroupid);
4954 	} else {
4955 		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4956 	}
4957 
4958 	err = btrfs_end_transaction(trans);
4959 	if (err && !ret)
4960 		ret = err;
4961 
4962 out:
4963 	kfree(sa);
4964 drop_write:
4965 	mnt_drop_write_file(file);
4966 	return ret;
4967 }
4968 
4969 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4970 {
4971 	struct inode *inode = file_inode(file);
4972 	struct btrfs_root *root = BTRFS_I(inode)->root;
4973 	struct btrfs_ioctl_qgroup_limit_args *sa;
4974 	struct btrfs_trans_handle *trans;
4975 	int ret;
4976 	int err;
4977 	u64 qgroupid;
4978 
4979 	if (!capable(CAP_SYS_ADMIN))
4980 		return -EPERM;
4981 
4982 	ret = mnt_want_write_file(file);
4983 	if (ret)
4984 		return ret;
4985 
4986 	sa = memdup_user(arg, sizeof(*sa));
4987 	if (IS_ERR(sa)) {
4988 		ret = PTR_ERR(sa);
4989 		goto drop_write;
4990 	}
4991 
4992 	trans = btrfs_join_transaction(root);
4993 	if (IS_ERR(trans)) {
4994 		ret = PTR_ERR(trans);
4995 		goto out;
4996 	}
4997 
4998 	qgroupid = sa->qgroupid;
4999 	if (!qgroupid) {
5000 		/* take the current subvol as qgroup */
5001 		qgroupid = root->root_key.objectid;
5002 	}
5003 
5004 	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
5005 
5006 	err = btrfs_end_transaction(trans);
5007 	if (err && !ret)
5008 		ret = err;
5009 
5010 out:
5011 	kfree(sa);
5012 drop_write:
5013 	mnt_drop_write_file(file);
5014 	return ret;
5015 }
5016 
5017 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5018 {
5019 	struct inode *inode = file_inode(file);
5020 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5021 	struct btrfs_ioctl_quota_rescan_args *qsa;
5022 	int ret;
5023 
5024 	if (!capable(CAP_SYS_ADMIN))
5025 		return -EPERM;
5026 
5027 	ret = mnt_want_write_file(file);
5028 	if (ret)
5029 		return ret;
5030 
5031 	qsa = memdup_user(arg, sizeof(*qsa));
5032 	if (IS_ERR(qsa)) {
5033 		ret = PTR_ERR(qsa);
5034 		goto drop_write;
5035 	}
5036 
5037 	if (qsa->flags) {
5038 		ret = -EINVAL;
5039 		goto out;
5040 	}
5041 
5042 	ret = btrfs_qgroup_rescan(fs_info);
5043 
5044 out:
5045 	kfree(qsa);
5046 drop_write:
5047 	mnt_drop_write_file(file);
5048 	return ret;
5049 }
5050 
5051 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5052 {
5053 	struct inode *inode = file_inode(file);
5054 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5055 	struct btrfs_ioctl_quota_rescan_args *qsa;
5056 	int ret = 0;
5057 
5058 	if (!capable(CAP_SYS_ADMIN))
5059 		return -EPERM;
5060 
5061 	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5062 	if (!qsa)
5063 		return -ENOMEM;
5064 
5065 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5066 		qsa->flags = 1;
5067 		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5068 	}
5069 
5070 	if (copy_to_user(arg, qsa, sizeof(*qsa)))
5071 		ret = -EFAULT;
5072 
5073 	kfree(qsa);
5074 	return ret;
5075 }
5076 
5077 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5078 {
5079 	struct inode *inode = file_inode(file);
5080 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5081 
5082 	if (!capable(CAP_SYS_ADMIN))
5083 		return -EPERM;
5084 
5085 	return btrfs_qgroup_wait_for_completion(fs_info, true);
5086 }
5087 
5088 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5089 					    struct btrfs_ioctl_received_subvol_args *sa)
5090 {
5091 	struct inode *inode = file_inode(file);
5092 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5093 	struct btrfs_root *root = BTRFS_I(inode)->root;
5094 	struct btrfs_root_item *root_item = &root->root_item;
5095 	struct btrfs_trans_handle *trans;
5096 	struct timespec64 ct = current_time(inode);
5097 	int ret = 0;
5098 	int received_uuid_changed;
5099 
5100 	if (!inode_owner_or_capable(inode))
5101 		return -EPERM;
5102 
5103 	ret = mnt_want_write_file(file);
5104 	if (ret < 0)
5105 		return ret;
5106 
5107 	down_write(&fs_info->subvol_sem);
5108 
5109 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5110 		ret = -EINVAL;
5111 		goto out;
5112 	}
5113 
5114 	if (btrfs_root_readonly(root)) {
5115 		ret = -EROFS;
5116 		goto out;
5117 	}
5118 
5119 	/*
5120 	 * 1 - root item
5121 	 * 2 - uuid items (received uuid + subvol uuid)
5122 	 */
5123 	trans = btrfs_start_transaction(root, 3);
5124 	if (IS_ERR(trans)) {
5125 		ret = PTR_ERR(trans);
5126 		trans = NULL;
5127 		goto out;
5128 	}
5129 
5130 	sa->rtransid = trans->transid;
5131 	sa->rtime.sec = ct.tv_sec;
5132 	sa->rtime.nsec = ct.tv_nsec;
5133 
5134 	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5135 				       BTRFS_UUID_SIZE);
5136 	if (received_uuid_changed &&
5137 	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
5138 		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5139 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5140 					  root->root_key.objectid);
5141 		if (ret && ret != -ENOENT) {
5142 		        btrfs_abort_transaction(trans, ret);
5143 		        btrfs_end_transaction(trans);
5144 		        goto out;
5145 		}
5146 	}
5147 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5148 	btrfs_set_root_stransid(root_item, sa->stransid);
5149 	btrfs_set_root_rtransid(root_item, sa->rtransid);
5150 	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5151 	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5152 	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5153 	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5154 
5155 	ret = btrfs_update_root(trans, fs_info->tree_root,
5156 				&root->root_key, &root->root_item);
5157 	if (ret < 0) {
5158 		btrfs_end_transaction(trans);
5159 		goto out;
5160 	}
5161 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5162 		ret = btrfs_uuid_tree_add(trans, sa->uuid,
5163 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5164 					  root->root_key.objectid);
5165 		if (ret < 0 && ret != -EEXIST) {
5166 			btrfs_abort_transaction(trans, ret);
5167 			btrfs_end_transaction(trans);
5168 			goto out;
5169 		}
5170 	}
5171 	ret = btrfs_commit_transaction(trans);
5172 out:
5173 	up_write(&fs_info->subvol_sem);
5174 	mnt_drop_write_file(file);
5175 	return ret;
5176 }
5177 
5178 #ifdef CONFIG_64BIT
5179 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5180 						void __user *arg)
5181 {
5182 	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5183 	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5184 	int ret = 0;
5185 
5186 	args32 = memdup_user(arg, sizeof(*args32));
5187 	if (IS_ERR(args32))
5188 		return PTR_ERR(args32);
5189 
5190 	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5191 	if (!args64) {
5192 		ret = -ENOMEM;
5193 		goto out;
5194 	}
5195 
5196 	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5197 	args64->stransid = args32->stransid;
5198 	args64->rtransid = args32->rtransid;
5199 	args64->stime.sec = args32->stime.sec;
5200 	args64->stime.nsec = args32->stime.nsec;
5201 	args64->rtime.sec = args32->rtime.sec;
5202 	args64->rtime.nsec = args32->rtime.nsec;
5203 	args64->flags = args32->flags;
5204 
5205 	ret = _btrfs_ioctl_set_received_subvol(file, args64);
5206 	if (ret)
5207 		goto out;
5208 
5209 	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5210 	args32->stransid = args64->stransid;
5211 	args32->rtransid = args64->rtransid;
5212 	args32->stime.sec = args64->stime.sec;
5213 	args32->stime.nsec = args64->stime.nsec;
5214 	args32->rtime.sec = args64->rtime.sec;
5215 	args32->rtime.nsec = args64->rtime.nsec;
5216 	args32->flags = args64->flags;
5217 
5218 	ret = copy_to_user(arg, args32, sizeof(*args32));
5219 	if (ret)
5220 		ret = -EFAULT;
5221 
5222 out:
5223 	kfree(args32);
5224 	kfree(args64);
5225 	return ret;
5226 }
5227 #endif
5228 
5229 static long btrfs_ioctl_set_received_subvol(struct file *file,
5230 					    void __user *arg)
5231 {
5232 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
5233 	int ret = 0;
5234 
5235 	sa = memdup_user(arg, sizeof(*sa));
5236 	if (IS_ERR(sa))
5237 		return PTR_ERR(sa);
5238 
5239 	ret = _btrfs_ioctl_set_received_subvol(file, sa);
5240 
5241 	if (ret)
5242 		goto out;
5243 
5244 	ret = copy_to_user(arg, sa, sizeof(*sa));
5245 	if (ret)
5246 		ret = -EFAULT;
5247 
5248 out:
5249 	kfree(sa);
5250 	return ret;
5251 }
5252 
5253 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5254 {
5255 	struct inode *inode = file_inode(file);
5256 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5257 	size_t len;
5258 	int ret;
5259 	char label[BTRFS_LABEL_SIZE];
5260 
5261 	spin_lock(&fs_info->super_lock);
5262 	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5263 	spin_unlock(&fs_info->super_lock);
5264 
5265 	len = strnlen(label, BTRFS_LABEL_SIZE);
5266 
5267 	if (len == BTRFS_LABEL_SIZE) {
5268 		btrfs_warn(fs_info,
5269 			   "label is too long, return the first %zu bytes",
5270 			   --len);
5271 	}
5272 
5273 	ret = copy_to_user(arg, label, len);
5274 
5275 	return ret ? -EFAULT : 0;
5276 }
5277 
5278 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5279 {
5280 	struct inode *inode = file_inode(file);
5281 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5282 	struct btrfs_root *root = BTRFS_I(inode)->root;
5283 	struct btrfs_super_block *super_block = fs_info->super_copy;
5284 	struct btrfs_trans_handle *trans;
5285 	char label[BTRFS_LABEL_SIZE];
5286 	int ret;
5287 
5288 	if (!capable(CAP_SYS_ADMIN))
5289 		return -EPERM;
5290 
5291 	if (copy_from_user(label, arg, sizeof(label)))
5292 		return -EFAULT;
5293 
5294 	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5295 		btrfs_err(fs_info,
5296 			  "unable to set label with more than %d bytes",
5297 			  BTRFS_LABEL_SIZE - 1);
5298 		return -EINVAL;
5299 	}
5300 
5301 	ret = mnt_want_write_file(file);
5302 	if (ret)
5303 		return ret;
5304 
5305 	trans = btrfs_start_transaction(root, 0);
5306 	if (IS_ERR(trans)) {
5307 		ret = PTR_ERR(trans);
5308 		goto out_unlock;
5309 	}
5310 
5311 	spin_lock(&fs_info->super_lock);
5312 	strcpy(super_block->label, label);
5313 	spin_unlock(&fs_info->super_lock);
5314 	ret = btrfs_commit_transaction(trans);
5315 
5316 out_unlock:
5317 	mnt_drop_write_file(file);
5318 	return ret;
5319 }
5320 
5321 #define INIT_FEATURE_FLAGS(suffix) \
5322 	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5323 	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5324 	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5325 
5326 int btrfs_ioctl_get_supported_features(void __user *arg)
5327 {
5328 	static const struct btrfs_ioctl_feature_flags features[3] = {
5329 		INIT_FEATURE_FLAGS(SUPP),
5330 		INIT_FEATURE_FLAGS(SAFE_SET),
5331 		INIT_FEATURE_FLAGS(SAFE_CLEAR)
5332 	};
5333 
5334 	if (copy_to_user(arg, &features, sizeof(features)))
5335 		return -EFAULT;
5336 
5337 	return 0;
5338 }
5339 
5340 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5341 {
5342 	struct inode *inode = file_inode(file);
5343 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5344 	struct btrfs_super_block *super_block = fs_info->super_copy;
5345 	struct btrfs_ioctl_feature_flags features;
5346 
5347 	features.compat_flags = btrfs_super_compat_flags(super_block);
5348 	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5349 	features.incompat_flags = btrfs_super_incompat_flags(super_block);
5350 
5351 	if (copy_to_user(arg, &features, sizeof(features)))
5352 		return -EFAULT;
5353 
5354 	return 0;
5355 }
5356 
5357 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5358 			      enum btrfs_feature_set set,
5359 			      u64 change_mask, u64 flags, u64 supported_flags,
5360 			      u64 safe_set, u64 safe_clear)
5361 {
5362 	const char *type = btrfs_feature_set_names[set];
5363 	char *names;
5364 	u64 disallowed, unsupported;
5365 	u64 set_mask = flags & change_mask;
5366 	u64 clear_mask = ~flags & change_mask;
5367 
5368 	unsupported = set_mask & ~supported_flags;
5369 	if (unsupported) {
5370 		names = btrfs_printable_features(set, unsupported);
5371 		if (names) {
5372 			btrfs_warn(fs_info,
5373 				   "this kernel does not support the %s feature bit%s",
5374 				   names, strchr(names, ',') ? "s" : "");
5375 			kfree(names);
5376 		} else
5377 			btrfs_warn(fs_info,
5378 				   "this kernel does not support %s bits 0x%llx",
5379 				   type, unsupported);
5380 		return -EOPNOTSUPP;
5381 	}
5382 
5383 	disallowed = set_mask & ~safe_set;
5384 	if (disallowed) {
5385 		names = btrfs_printable_features(set, disallowed);
5386 		if (names) {
5387 			btrfs_warn(fs_info,
5388 				   "can't set the %s feature bit%s while mounted",
5389 				   names, strchr(names, ',') ? "s" : "");
5390 			kfree(names);
5391 		} else
5392 			btrfs_warn(fs_info,
5393 				   "can't set %s bits 0x%llx while mounted",
5394 				   type, disallowed);
5395 		return -EPERM;
5396 	}
5397 
5398 	disallowed = clear_mask & ~safe_clear;
5399 	if (disallowed) {
5400 		names = btrfs_printable_features(set, disallowed);
5401 		if (names) {
5402 			btrfs_warn(fs_info,
5403 				   "can't clear the %s feature bit%s while mounted",
5404 				   names, strchr(names, ',') ? "s" : "");
5405 			kfree(names);
5406 		} else
5407 			btrfs_warn(fs_info,
5408 				   "can't clear %s bits 0x%llx while mounted",
5409 				   type, disallowed);
5410 		return -EPERM;
5411 	}
5412 
5413 	return 0;
5414 }
5415 
5416 #define check_feature(fs_info, change_mask, flags, mask_base)	\
5417 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
5418 		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
5419 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
5420 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5421 
5422 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5423 {
5424 	struct inode *inode = file_inode(file);
5425 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5426 	struct btrfs_root *root = BTRFS_I(inode)->root;
5427 	struct btrfs_super_block *super_block = fs_info->super_copy;
5428 	struct btrfs_ioctl_feature_flags flags[2];
5429 	struct btrfs_trans_handle *trans;
5430 	u64 newflags;
5431 	int ret;
5432 
5433 	if (!capable(CAP_SYS_ADMIN))
5434 		return -EPERM;
5435 
5436 	if (copy_from_user(flags, arg, sizeof(flags)))
5437 		return -EFAULT;
5438 
5439 	/* Nothing to do */
5440 	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5441 	    !flags[0].incompat_flags)
5442 		return 0;
5443 
5444 	ret = check_feature(fs_info, flags[0].compat_flags,
5445 			    flags[1].compat_flags, COMPAT);
5446 	if (ret)
5447 		return ret;
5448 
5449 	ret = check_feature(fs_info, flags[0].compat_ro_flags,
5450 			    flags[1].compat_ro_flags, COMPAT_RO);
5451 	if (ret)
5452 		return ret;
5453 
5454 	ret = check_feature(fs_info, flags[0].incompat_flags,
5455 			    flags[1].incompat_flags, INCOMPAT);
5456 	if (ret)
5457 		return ret;
5458 
5459 	ret = mnt_want_write_file(file);
5460 	if (ret)
5461 		return ret;
5462 
5463 	trans = btrfs_start_transaction(root, 0);
5464 	if (IS_ERR(trans)) {
5465 		ret = PTR_ERR(trans);
5466 		goto out_drop_write;
5467 	}
5468 
5469 	spin_lock(&fs_info->super_lock);
5470 	newflags = btrfs_super_compat_flags(super_block);
5471 	newflags |= flags[0].compat_flags & flags[1].compat_flags;
5472 	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5473 	btrfs_set_super_compat_flags(super_block, newflags);
5474 
5475 	newflags = btrfs_super_compat_ro_flags(super_block);
5476 	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5477 	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5478 	btrfs_set_super_compat_ro_flags(super_block, newflags);
5479 
5480 	newflags = btrfs_super_incompat_flags(super_block);
5481 	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5482 	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5483 	btrfs_set_super_incompat_flags(super_block, newflags);
5484 	spin_unlock(&fs_info->super_lock);
5485 
5486 	ret = btrfs_commit_transaction(trans);
5487 out_drop_write:
5488 	mnt_drop_write_file(file);
5489 
5490 	return ret;
5491 }
5492 
5493 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5494 {
5495 	struct btrfs_ioctl_send_args *arg;
5496 	int ret;
5497 
5498 	if (compat) {
5499 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5500 		struct btrfs_ioctl_send_args_32 args32;
5501 
5502 		ret = copy_from_user(&args32, argp, sizeof(args32));
5503 		if (ret)
5504 			return -EFAULT;
5505 		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5506 		if (!arg)
5507 			return -ENOMEM;
5508 		arg->send_fd = args32.send_fd;
5509 		arg->clone_sources_count = args32.clone_sources_count;
5510 		arg->clone_sources = compat_ptr(args32.clone_sources);
5511 		arg->parent_root = args32.parent_root;
5512 		arg->flags = args32.flags;
5513 		memcpy(arg->reserved, args32.reserved,
5514 		       sizeof(args32.reserved));
5515 #else
5516 		return -ENOTTY;
5517 #endif
5518 	} else {
5519 		arg = memdup_user(argp, sizeof(*arg));
5520 		if (IS_ERR(arg))
5521 			return PTR_ERR(arg);
5522 	}
5523 	ret = btrfs_ioctl_send(file, arg);
5524 	kfree(arg);
5525 	return ret;
5526 }
5527 
5528 long btrfs_ioctl(struct file *file, unsigned int
5529 		cmd, unsigned long arg)
5530 {
5531 	struct inode *inode = file_inode(file);
5532 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5533 	struct btrfs_root *root = BTRFS_I(inode)->root;
5534 	void __user *argp = (void __user *)arg;
5535 
5536 	switch (cmd) {
5537 	case FS_IOC_GETFLAGS:
5538 		return btrfs_ioctl_getflags(file, argp);
5539 	case FS_IOC_SETFLAGS:
5540 		return btrfs_ioctl_setflags(file, argp);
5541 	case FS_IOC_GETVERSION:
5542 		return btrfs_ioctl_getversion(file, argp);
5543 	case FITRIM:
5544 		return btrfs_ioctl_fitrim(file, argp);
5545 	case BTRFS_IOC_SNAP_CREATE:
5546 		return btrfs_ioctl_snap_create(file, argp, 0);
5547 	case BTRFS_IOC_SNAP_CREATE_V2:
5548 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
5549 	case BTRFS_IOC_SUBVOL_CREATE:
5550 		return btrfs_ioctl_snap_create(file, argp, 1);
5551 	case BTRFS_IOC_SUBVOL_CREATE_V2:
5552 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
5553 	case BTRFS_IOC_SNAP_DESTROY:
5554 		return btrfs_ioctl_snap_destroy(file, argp);
5555 	case BTRFS_IOC_SUBVOL_GETFLAGS:
5556 		return btrfs_ioctl_subvol_getflags(file, argp);
5557 	case BTRFS_IOC_SUBVOL_SETFLAGS:
5558 		return btrfs_ioctl_subvol_setflags(file, argp);
5559 	case BTRFS_IOC_DEFAULT_SUBVOL:
5560 		return btrfs_ioctl_default_subvol(file, argp);
5561 	case BTRFS_IOC_DEFRAG:
5562 		return btrfs_ioctl_defrag(file, NULL);
5563 	case BTRFS_IOC_DEFRAG_RANGE:
5564 		return btrfs_ioctl_defrag(file, argp);
5565 	case BTRFS_IOC_RESIZE:
5566 		return btrfs_ioctl_resize(file, argp);
5567 	case BTRFS_IOC_ADD_DEV:
5568 		return btrfs_ioctl_add_dev(fs_info, argp);
5569 	case BTRFS_IOC_RM_DEV:
5570 		return btrfs_ioctl_rm_dev(file, argp);
5571 	case BTRFS_IOC_RM_DEV_V2:
5572 		return btrfs_ioctl_rm_dev_v2(file, argp);
5573 	case BTRFS_IOC_FS_INFO:
5574 		return btrfs_ioctl_fs_info(fs_info, argp);
5575 	case BTRFS_IOC_DEV_INFO:
5576 		return btrfs_ioctl_dev_info(fs_info, argp);
5577 	case BTRFS_IOC_BALANCE:
5578 		return btrfs_ioctl_balance(file, NULL);
5579 	case BTRFS_IOC_TREE_SEARCH:
5580 		return btrfs_ioctl_tree_search(file, argp);
5581 	case BTRFS_IOC_TREE_SEARCH_V2:
5582 		return btrfs_ioctl_tree_search_v2(file, argp);
5583 	case BTRFS_IOC_INO_LOOKUP:
5584 		return btrfs_ioctl_ino_lookup(file, argp);
5585 	case BTRFS_IOC_INO_PATHS:
5586 		return btrfs_ioctl_ino_to_path(root, argp);
5587 	case BTRFS_IOC_LOGICAL_INO:
5588 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5589 	case BTRFS_IOC_LOGICAL_INO_V2:
5590 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5591 	case BTRFS_IOC_SPACE_INFO:
5592 		return btrfs_ioctl_space_info(fs_info, argp);
5593 	case BTRFS_IOC_SYNC: {
5594 		int ret;
5595 
5596 		ret = btrfs_start_delalloc_roots(fs_info, -1);
5597 		if (ret)
5598 			return ret;
5599 		ret = btrfs_sync_fs(inode->i_sb, 1);
5600 		/*
5601 		 * The transaction thread may want to do more work,
5602 		 * namely it pokes the cleaner kthread that will start
5603 		 * processing uncleaned subvols.
5604 		 */
5605 		wake_up_process(fs_info->transaction_kthread);
5606 		return ret;
5607 	}
5608 	case BTRFS_IOC_START_SYNC:
5609 		return btrfs_ioctl_start_sync(root, argp);
5610 	case BTRFS_IOC_WAIT_SYNC:
5611 		return btrfs_ioctl_wait_sync(fs_info, argp);
5612 	case BTRFS_IOC_SCRUB:
5613 		return btrfs_ioctl_scrub(file, argp);
5614 	case BTRFS_IOC_SCRUB_CANCEL:
5615 		return btrfs_ioctl_scrub_cancel(fs_info);
5616 	case BTRFS_IOC_SCRUB_PROGRESS:
5617 		return btrfs_ioctl_scrub_progress(fs_info, argp);
5618 	case BTRFS_IOC_BALANCE_V2:
5619 		return btrfs_ioctl_balance(file, argp);
5620 	case BTRFS_IOC_BALANCE_CTL:
5621 		return btrfs_ioctl_balance_ctl(fs_info, arg);
5622 	case BTRFS_IOC_BALANCE_PROGRESS:
5623 		return btrfs_ioctl_balance_progress(fs_info, argp);
5624 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5625 		return btrfs_ioctl_set_received_subvol(file, argp);
5626 #ifdef CONFIG_64BIT
5627 	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5628 		return btrfs_ioctl_set_received_subvol_32(file, argp);
5629 #endif
5630 	case BTRFS_IOC_SEND:
5631 		return _btrfs_ioctl_send(file, argp, false);
5632 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5633 	case BTRFS_IOC_SEND_32:
5634 		return _btrfs_ioctl_send(file, argp, true);
5635 #endif
5636 	case BTRFS_IOC_GET_DEV_STATS:
5637 		return btrfs_ioctl_get_dev_stats(fs_info, argp);
5638 	case BTRFS_IOC_QUOTA_CTL:
5639 		return btrfs_ioctl_quota_ctl(file, argp);
5640 	case BTRFS_IOC_QGROUP_ASSIGN:
5641 		return btrfs_ioctl_qgroup_assign(file, argp);
5642 	case BTRFS_IOC_QGROUP_CREATE:
5643 		return btrfs_ioctl_qgroup_create(file, argp);
5644 	case BTRFS_IOC_QGROUP_LIMIT:
5645 		return btrfs_ioctl_qgroup_limit(file, argp);
5646 	case BTRFS_IOC_QUOTA_RESCAN:
5647 		return btrfs_ioctl_quota_rescan(file, argp);
5648 	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5649 		return btrfs_ioctl_quota_rescan_status(file, argp);
5650 	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5651 		return btrfs_ioctl_quota_rescan_wait(file, argp);
5652 	case BTRFS_IOC_DEV_REPLACE:
5653 		return btrfs_ioctl_dev_replace(fs_info, argp);
5654 	case BTRFS_IOC_GET_FSLABEL:
5655 		return btrfs_ioctl_get_fslabel(file, argp);
5656 	case BTRFS_IOC_SET_FSLABEL:
5657 		return btrfs_ioctl_set_fslabel(file, argp);
5658 	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5659 		return btrfs_ioctl_get_supported_features(argp);
5660 	case BTRFS_IOC_GET_FEATURES:
5661 		return btrfs_ioctl_get_features(file, argp);
5662 	case BTRFS_IOC_SET_FEATURES:
5663 		return btrfs_ioctl_set_features(file, argp);
5664 	case FS_IOC_FSGETXATTR:
5665 		return btrfs_ioctl_fsgetxattr(file, argp);
5666 	case FS_IOC_FSSETXATTR:
5667 		return btrfs_ioctl_fssetxattr(file, argp);
5668 	case BTRFS_IOC_GET_SUBVOL_INFO:
5669 		return btrfs_ioctl_get_subvol_info(file, argp);
5670 	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5671 		return btrfs_ioctl_get_subvol_rootref(file, argp);
5672 	case BTRFS_IOC_INO_LOOKUP_USER:
5673 		return btrfs_ioctl_ino_lookup_user(file, argp);
5674 	}
5675 
5676 	return -ENOTTY;
5677 }
5678 
5679 #ifdef CONFIG_COMPAT
5680 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5681 {
5682 	/*
5683 	 * These all access 32-bit values anyway so no further
5684 	 * handling is necessary.
5685 	 */
5686 	switch (cmd) {
5687 	case FS_IOC32_GETFLAGS:
5688 		cmd = FS_IOC_GETFLAGS;
5689 		break;
5690 	case FS_IOC32_SETFLAGS:
5691 		cmd = FS_IOC_SETFLAGS;
5692 		break;
5693 	case FS_IOC32_GETVERSION:
5694 		cmd = FS_IOC_GETVERSION;
5695 		break;
5696 	}
5697 
5698 	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5699 }
5700 #endif
5701