xref: /linux/fs/btrfs/ioctl.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
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 	rcu_read_lock();
505 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
506 				dev_list) {
507 		if (!device->bdev)
508 			continue;
509 		q = bdev_get_queue(device->bdev);
510 		if (blk_queue_discard(q)) {
511 			num_devices++;
512 			minlen = min_t(u64, q->limits.discard_granularity,
513 				     minlen);
514 		}
515 	}
516 	rcu_read_unlock();
517 
518 	if (!num_devices)
519 		return -EOPNOTSUPP;
520 	if (copy_from_user(&range, arg, sizeof(range)))
521 		return -EFAULT;
522 
523 	/*
524 	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
525 	 * block group is in the logical address space, which can be any
526 	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
527 	 */
528 	if (range.len < fs_info->sb->s_blocksize)
529 		return -EINVAL;
530 
531 	range.minlen = max(range.minlen, minlen);
532 	ret = btrfs_trim_fs(fs_info, &range);
533 	if (ret < 0)
534 		return ret;
535 
536 	if (copy_to_user(arg, &range, sizeof(range)))
537 		return -EFAULT;
538 
539 	return 0;
540 }
541 
542 int btrfs_is_empty_uuid(u8 *uuid)
543 {
544 	int i;
545 
546 	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
547 		if (uuid[i])
548 			return 0;
549 	}
550 	return 1;
551 }
552 
553 static noinline int create_subvol(struct inode *dir,
554 				  struct dentry *dentry,
555 				  const char *name, int namelen,
556 				  u64 *async_transid,
557 				  struct btrfs_qgroup_inherit *inherit)
558 {
559 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
560 	struct btrfs_trans_handle *trans;
561 	struct btrfs_key key;
562 	struct btrfs_root_item *root_item;
563 	struct btrfs_inode_item *inode_item;
564 	struct extent_buffer *leaf;
565 	struct btrfs_root *root = BTRFS_I(dir)->root;
566 	struct btrfs_root *new_root;
567 	struct btrfs_block_rsv block_rsv;
568 	struct timespec64 cur_time = current_time(dir);
569 	struct inode *inode;
570 	int ret;
571 	int err;
572 	u64 objectid;
573 	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
574 	u64 index = 0;
575 	uuid_le new_uuid;
576 
577 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
578 	if (!root_item)
579 		return -ENOMEM;
580 
581 	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
582 	if (ret)
583 		goto fail_free;
584 
585 	/*
586 	 * Don't create subvolume whose level is not zero. Or qgroup will be
587 	 * screwed up since it assumes subvolume qgroup's level to be 0.
588 	 */
589 	if (btrfs_qgroup_level(objectid)) {
590 		ret = -ENOSPC;
591 		goto fail_free;
592 	}
593 
594 	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
595 	/*
596 	 * The same as the snapshot creation, please see the comment
597 	 * of create_snapshot().
598 	 */
599 	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
600 	if (ret)
601 		goto fail_free;
602 
603 	trans = btrfs_start_transaction(root, 0);
604 	if (IS_ERR(trans)) {
605 		ret = PTR_ERR(trans);
606 		btrfs_subvolume_release_metadata(fs_info, &block_rsv);
607 		goto fail_free;
608 	}
609 	trans->block_rsv = &block_rsv;
610 	trans->bytes_reserved = block_rsv.size;
611 
612 	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
613 	if (ret)
614 		goto fail;
615 
616 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
617 	if (IS_ERR(leaf)) {
618 		ret = PTR_ERR(leaf);
619 		goto fail;
620 	}
621 
622 	btrfs_mark_buffer_dirty(leaf);
623 
624 	inode_item = &root_item->inode;
625 	btrfs_set_stack_inode_generation(inode_item, 1);
626 	btrfs_set_stack_inode_size(inode_item, 3);
627 	btrfs_set_stack_inode_nlink(inode_item, 1);
628 	btrfs_set_stack_inode_nbytes(inode_item,
629 				     fs_info->nodesize);
630 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
631 
632 	btrfs_set_root_flags(root_item, 0);
633 	btrfs_set_root_limit(root_item, 0);
634 	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
635 
636 	btrfs_set_root_bytenr(root_item, leaf->start);
637 	btrfs_set_root_generation(root_item, trans->transid);
638 	btrfs_set_root_level(root_item, 0);
639 	btrfs_set_root_refs(root_item, 1);
640 	btrfs_set_root_used(root_item, leaf->len);
641 	btrfs_set_root_last_snapshot(root_item, 0);
642 
643 	btrfs_set_root_generation_v2(root_item,
644 			btrfs_root_generation(root_item));
645 	uuid_le_gen(&new_uuid);
646 	memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
647 	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
648 	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
649 	root_item->ctime = root_item->otime;
650 	btrfs_set_root_ctransid(root_item, trans->transid);
651 	btrfs_set_root_otransid(root_item, trans->transid);
652 
653 	btrfs_tree_unlock(leaf);
654 	free_extent_buffer(leaf);
655 	leaf = NULL;
656 
657 	btrfs_set_root_dirid(root_item, new_dirid);
658 
659 	key.objectid = objectid;
660 	key.offset = 0;
661 	key.type = BTRFS_ROOT_ITEM_KEY;
662 	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
663 				root_item);
664 	if (ret)
665 		goto fail;
666 
667 	key.offset = (u64)-1;
668 	new_root = btrfs_read_fs_root_no_name(fs_info, &key);
669 	if (IS_ERR(new_root)) {
670 		ret = PTR_ERR(new_root);
671 		btrfs_abort_transaction(trans, ret);
672 		goto fail;
673 	}
674 
675 	btrfs_record_root_in_trans(trans, new_root);
676 
677 	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
678 	if (ret) {
679 		/* We potentially lose an unused inode item here */
680 		btrfs_abort_transaction(trans, ret);
681 		goto fail;
682 	}
683 
684 	mutex_lock(&new_root->objectid_mutex);
685 	new_root->highest_objectid = new_dirid;
686 	mutex_unlock(&new_root->objectid_mutex);
687 
688 	/*
689 	 * insert the directory item
690 	 */
691 	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
692 	if (ret) {
693 		btrfs_abort_transaction(trans, ret);
694 		goto fail;
695 	}
696 
697 	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
698 				    BTRFS_FT_DIR, index);
699 	if (ret) {
700 		btrfs_abort_transaction(trans, ret);
701 		goto fail;
702 	}
703 
704 	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
705 	ret = btrfs_update_inode(trans, root, dir);
706 	BUG_ON(ret);
707 
708 	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
709 				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
710 	BUG_ON(ret);
711 
712 	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
713 				  BTRFS_UUID_KEY_SUBVOL, objectid);
714 	if (ret)
715 		btrfs_abort_transaction(trans, ret);
716 
717 fail:
718 	kfree(root_item);
719 	trans->block_rsv = NULL;
720 	trans->bytes_reserved = 0;
721 	btrfs_subvolume_release_metadata(fs_info, &block_rsv);
722 
723 	if (async_transid) {
724 		*async_transid = trans->transid;
725 		err = btrfs_commit_transaction_async(trans, 1);
726 		if (err)
727 			err = btrfs_commit_transaction(trans);
728 	} else {
729 		err = btrfs_commit_transaction(trans);
730 	}
731 	if (err && !ret)
732 		ret = err;
733 
734 	if (!ret) {
735 		inode = btrfs_lookup_dentry(dir, dentry);
736 		if (IS_ERR(inode))
737 			return PTR_ERR(inode);
738 		d_instantiate(dentry, inode);
739 	}
740 	return ret;
741 
742 fail_free:
743 	kfree(root_item);
744 	return ret;
745 }
746 
747 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
748 			   struct dentry *dentry,
749 			   u64 *async_transid, bool readonly,
750 			   struct btrfs_qgroup_inherit *inherit)
751 {
752 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
753 	struct inode *inode;
754 	struct btrfs_pending_snapshot *pending_snapshot;
755 	struct btrfs_trans_handle *trans;
756 	int ret;
757 	bool snapshot_force_cow = false;
758 
759 	if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
760 		return -EINVAL;
761 
762 	if (atomic_read(&root->nr_swapfiles)) {
763 		btrfs_warn(fs_info,
764 			   "cannot snapshot subvolume with active swapfile");
765 		return -ETXTBSY;
766 	}
767 
768 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
769 	if (!pending_snapshot)
770 		return -ENOMEM;
771 
772 	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
773 			GFP_KERNEL);
774 	pending_snapshot->path = btrfs_alloc_path();
775 	if (!pending_snapshot->root_item || !pending_snapshot->path) {
776 		ret = -ENOMEM;
777 		goto free_pending;
778 	}
779 
780 	/*
781 	 * Force new buffered writes to reserve space even when NOCOW is
782 	 * possible. This is to avoid later writeback (running dealloc) to
783 	 * fallback to COW mode and unexpectedly fail with ENOSPC.
784 	 */
785 	atomic_inc(&root->will_be_snapshotted);
786 	smp_mb__after_atomic();
787 	/* wait for no snapshot writes */
788 	wait_event(root->subv_writers->wait,
789 		   percpu_counter_sum(&root->subv_writers->counter) == 0);
790 
791 	ret = btrfs_start_delalloc_snapshot(root);
792 	if (ret)
793 		goto dec_and_free;
794 
795 	/*
796 	 * All previous writes have started writeback in NOCOW mode, so now
797 	 * we force future writes to fallback to COW mode during snapshot
798 	 * creation.
799 	 */
800 	atomic_inc(&root->snapshot_force_cow);
801 	snapshot_force_cow = true;
802 
803 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
804 
805 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
806 			     BTRFS_BLOCK_RSV_TEMP);
807 	/*
808 	 * 1 - parent dir inode
809 	 * 2 - dir entries
810 	 * 1 - root item
811 	 * 2 - root ref/backref
812 	 * 1 - root of snapshot
813 	 * 1 - UUID item
814 	 */
815 	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
816 					&pending_snapshot->block_rsv, 8,
817 					false);
818 	if (ret)
819 		goto dec_and_free;
820 
821 	pending_snapshot->dentry = dentry;
822 	pending_snapshot->root = root;
823 	pending_snapshot->readonly = readonly;
824 	pending_snapshot->dir = dir;
825 	pending_snapshot->inherit = inherit;
826 
827 	trans = btrfs_start_transaction(root, 0);
828 	if (IS_ERR(trans)) {
829 		ret = PTR_ERR(trans);
830 		goto fail;
831 	}
832 
833 	spin_lock(&fs_info->trans_lock);
834 	list_add(&pending_snapshot->list,
835 		 &trans->transaction->pending_snapshots);
836 	spin_unlock(&fs_info->trans_lock);
837 	if (async_transid) {
838 		*async_transid = trans->transid;
839 		ret = btrfs_commit_transaction_async(trans, 1);
840 		if (ret)
841 			ret = btrfs_commit_transaction(trans);
842 	} else {
843 		ret = btrfs_commit_transaction(trans);
844 	}
845 	if (ret)
846 		goto fail;
847 
848 	ret = pending_snapshot->error;
849 	if (ret)
850 		goto fail;
851 
852 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
853 	if (ret)
854 		goto fail;
855 
856 	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
857 	if (IS_ERR(inode)) {
858 		ret = PTR_ERR(inode);
859 		goto fail;
860 	}
861 
862 	d_instantiate(dentry, inode);
863 	ret = 0;
864 fail:
865 	btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
866 dec_and_free:
867 	if (snapshot_force_cow)
868 		atomic_dec(&root->snapshot_force_cow);
869 	if (atomic_dec_and_test(&root->will_be_snapshotted))
870 		wake_up_var(&root->will_be_snapshotted);
871 free_pending:
872 	kfree(pending_snapshot->root_item);
873 	btrfs_free_path(pending_snapshot->path);
874 	kfree(pending_snapshot);
875 
876 	return ret;
877 }
878 
879 /*  copy of may_delete in fs/namei.c()
880  *	Check whether we can remove a link victim from directory dir, check
881  *  whether the type of victim is right.
882  *  1. We can't do it if dir is read-only (done in permission())
883  *  2. We should have write and exec permissions on dir
884  *  3. We can't remove anything from append-only dir
885  *  4. We can't do anything with immutable dir (done in permission())
886  *  5. If the sticky bit on dir is set we should either
887  *	a. be owner of dir, or
888  *	b. be owner of victim, or
889  *	c. have CAP_FOWNER capability
890  *  6. If the victim is append-only or immutable we can't do anything with
891  *     links pointing to it.
892  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
893  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
894  *  9. We can't remove a root or mountpoint.
895  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
896  *     nfs_async_unlink().
897  */
898 
899 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
900 {
901 	int error;
902 
903 	if (d_really_is_negative(victim))
904 		return -ENOENT;
905 
906 	BUG_ON(d_inode(victim->d_parent) != dir);
907 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
908 
909 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
910 	if (error)
911 		return error;
912 	if (IS_APPEND(dir))
913 		return -EPERM;
914 	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
915 	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
916 		return -EPERM;
917 	if (isdir) {
918 		if (!d_is_dir(victim))
919 			return -ENOTDIR;
920 		if (IS_ROOT(victim))
921 			return -EBUSY;
922 	} else if (d_is_dir(victim))
923 		return -EISDIR;
924 	if (IS_DEADDIR(dir))
925 		return -ENOENT;
926 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
927 		return -EBUSY;
928 	return 0;
929 }
930 
931 /* copy of may_create in fs/namei.c() */
932 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
933 {
934 	if (d_really_is_positive(child))
935 		return -EEXIST;
936 	if (IS_DEADDIR(dir))
937 		return -ENOENT;
938 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
939 }
940 
941 /*
942  * Create a new subvolume below @parent.  This is largely modeled after
943  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
944  * inside this filesystem so it's quite a bit simpler.
945  */
946 static noinline int btrfs_mksubvol(const struct path *parent,
947 				   const char *name, int namelen,
948 				   struct btrfs_root *snap_src,
949 				   u64 *async_transid, bool readonly,
950 				   struct btrfs_qgroup_inherit *inherit)
951 {
952 	struct inode *dir = d_inode(parent->dentry);
953 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
954 	struct dentry *dentry;
955 	int error;
956 
957 	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
958 	if (error == -EINTR)
959 		return error;
960 
961 	dentry = lookup_one_len(name, parent->dentry, namelen);
962 	error = PTR_ERR(dentry);
963 	if (IS_ERR(dentry))
964 		goto out_unlock;
965 
966 	error = btrfs_may_create(dir, dentry);
967 	if (error)
968 		goto out_dput;
969 
970 	/*
971 	 * even if this name doesn't exist, we may get hash collisions.
972 	 * check for them now when we can safely fail
973 	 */
974 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
975 					       dir->i_ino, name,
976 					       namelen);
977 	if (error)
978 		goto out_dput;
979 
980 	down_read(&fs_info->subvol_sem);
981 
982 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
983 		goto out_up_read;
984 
985 	if (snap_src) {
986 		error = create_snapshot(snap_src, dir, dentry,
987 					async_transid, readonly, inherit);
988 	} else {
989 		error = create_subvol(dir, dentry, name, namelen,
990 				      async_transid, inherit);
991 	}
992 	if (!error)
993 		fsnotify_mkdir(dir, dentry);
994 out_up_read:
995 	up_read(&fs_info->subvol_sem);
996 out_dput:
997 	dput(dentry);
998 out_unlock:
999 	inode_unlock(dir);
1000 	return error;
1001 }
1002 
1003 /*
1004  * When we're defragging a range, we don't want to kick it off again
1005  * if it is really just waiting for delalloc to send it down.
1006  * If we find a nice big extent or delalloc range for the bytes in the
1007  * file you want to defrag, we return 0 to let you know to skip this
1008  * part of the file
1009  */
1010 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1011 {
1012 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1013 	struct extent_map *em = NULL;
1014 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1015 	u64 end;
1016 
1017 	read_lock(&em_tree->lock);
1018 	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1019 	read_unlock(&em_tree->lock);
1020 
1021 	if (em) {
1022 		end = extent_map_end(em);
1023 		free_extent_map(em);
1024 		if (end - offset > thresh)
1025 			return 0;
1026 	}
1027 	/* if we already have a nice delalloc here, just stop */
1028 	thresh /= 2;
1029 	end = count_range_bits(io_tree, &offset, offset + thresh,
1030 			       thresh, EXTENT_DELALLOC, 1);
1031 	if (end >= thresh)
1032 		return 0;
1033 	return 1;
1034 }
1035 
1036 /*
1037  * helper function to walk through a file and find extents
1038  * newer than a specific transid, and smaller than thresh.
1039  *
1040  * This is used by the defragging code to find new and small
1041  * extents
1042  */
1043 static int find_new_extents(struct btrfs_root *root,
1044 			    struct inode *inode, u64 newer_than,
1045 			    u64 *off, u32 thresh)
1046 {
1047 	struct btrfs_path *path;
1048 	struct btrfs_key min_key;
1049 	struct extent_buffer *leaf;
1050 	struct btrfs_file_extent_item *extent;
1051 	int type;
1052 	int ret;
1053 	u64 ino = btrfs_ino(BTRFS_I(inode));
1054 
1055 	path = btrfs_alloc_path();
1056 	if (!path)
1057 		return -ENOMEM;
1058 
1059 	min_key.objectid = ino;
1060 	min_key.type = BTRFS_EXTENT_DATA_KEY;
1061 	min_key.offset = *off;
1062 
1063 	while (1) {
1064 		ret = btrfs_search_forward(root, &min_key, path, newer_than);
1065 		if (ret != 0)
1066 			goto none;
1067 process_slot:
1068 		if (min_key.objectid != ino)
1069 			goto none;
1070 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1071 			goto none;
1072 
1073 		leaf = path->nodes[0];
1074 		extent = btrfs_item_ptr(leaf, path->slots[0],
1075 					struct btrfs_file_extent_item);
1076 
1077 		type = btrfs_file_extent_type(leaf, extent);
1078 		if (type == BTRFS_FILE_EXTENT_REG &&
1079 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1080 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
1081 			*off = min_key.offset;
1082 			btrfs_free_path(path);
1083 			return 0;
1084 		}
1085 
1086 		path->slots[0]++;
1087 		if (path->slots[0] < btrfs_header_nritems(leaf)) {
1088 			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1089 			goto process_slot;
1090 		}
1091 
1092 		if (min_key.offset == (u64)-1)
1093 			goto none;
1094 
1095 		min_key.offset++;
1096 		btrfs_release_path(path);
1097 	}
1098 none:
1099 	btrfs_free_path(path);
1100 	return -ENOENT;
1101 }
1102 
1103 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1104 {
1105 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1106 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1107 	struct extent_map *em;
1108 	u64 len = PAGE_SIZE;
1109 
1110 	/*
1111 	 * hopefully we have this extent in the tree already, try without
1112 	 * the full extent lock
1113 	 */
1114 	read_lock(&em_tree->lock);
1115 	em = lookup_extent_mapping(em_tree, start, len);
1116 	read_unlock(&em_tree->lock);
1117 
1118 	if (!em) {
1119 		struct extent_state *cached = NULL;
1120 		u64 end = start + len - 1;
1121 
1122 		/* get the big lock and read metadata off disk */
1123 		lock_extent_bits(io_tree, start, end, &cached);
1124 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1125 		unlock_extent_cached(io_tree, start, end, &cached);
1126 
1127 		if (IS_ERR(em))
1128 			return NULL;
1129 	}
1130 
1131 	return em;
1132 }
1133 
1134 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1135 {
1136 	struct extent_map *next;
1137 	bool ret = true;
1138 
1139 	/* this is the last extent */
1140 	if (em->start + em->len >= i_size_read(inode))
1141 		return false;
1142 
1143 	next = defrag_lookup_extent(inode, em->start + em->len);
1144 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1145 		ret = false;
1146 	else if ((em->block_start + em->block_len == next->block_start) &&
1147 		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1148 		ret = false;
1149 
1150 	free_extent_map(next);
1151 	return ret;
1152 }
1153 
1154 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1155 			       u64 *last_len, u64 *skip, u64 *defrag_end,
1156 			       int compress)
1157 {
1158 	struct extent_map *em;
1159 	int ret = 1;
1160 	bool next_mergeable = true;
1161 	bool prev_mergeable = true;
1162 
1163 	/*
1164 	 * make sure that once we start defragging an extent, we keep on
1165 	 * defragging it
1166 	 */
1167 	if (start < *defrag_end)
1168 		return 1;
1169 
1170 	*skip = 0;
1171 
1172 	em = defrag_lookup_extent(inode, start);
1173 	if (!em)
1174 		return 0;
1175 
1176 	/* this will cover holes, and inline extents */
1177 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1178 		ret = 0;
1179 		goto out;
1180 	}
1181 
1182 	if (!*defrag_end)
1183 		prev_mergeable = false;
1184 
1185 	next_mergeable = defrag_check_next_extent(inode, em);
1186 	/*
1187 	 * we hit a real extent, if it is big or the next extent is not a
1188 	 * real extent, don't bother defragging it
1189 	 */
1190 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1191 	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1192 		ret = 0;
1193 out:
1194 	/*
1195 	 * last_len ends up being a counter of how many bytes we've defragged.
1196 	 * every time we choose not to defrag an extent, we reset *last_len
1197 	 * so that the next tiny extent will force a defrag.
1198 	 *
1199 	 * The end result of this is that tiny extents before a single big
1200 	 * extent will force at least part of that big extent to be defragged.
1201 	 */
1202 	if (ret) {
1203 		*defrag_end = extent_map_end(em);
1204 	} else {
1205 		*last_len = 0;
1206 		*skip = extent_map_end(em);
1207 		*defrag_end = 0;
1208 	}
1209 
1210 	free_extent_map(em);
1211 	return ret;
1212 }
1213 
1214 /*
1215  * it doesn't do much good to defrag one or two pages
1216  * at a time.  This pulls in a nice chunk of pages
1217  * to COW and defrag.
1218  *
1219  * It also makes sure the delalloc code has enough
1220  * dirty data to avoid making new small extents as part
1221  * of the defrag
1222  *
1223  * It's a good idea to start RA on this range
1224  * before calling this.
1225  */
1226 static int cluster_pages_for_defrag(struct inode *inode,
1227 				    struct page **pages,
1228 				    unsigned long start_index,
1229 				    unsigned long num_pages)
1230 {
1231 	unsigned long file_end;
1232 	u64 isize = i_size_read(inode);
1233 	u64 page_start;
1234 	u64 page_end;
1235 	u64 page_cnt;
1236 	int ret;
1237 	int i;
1238 	int i_done;
1239 	struct btrfs_ordered_extent *ordered;
1240 	struct extent_state *cached_state = NULL;
1241 	struct extent_io_tree *tree;
1242 	struct extent_changeset *data_reserved = NULL;
1243 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1244 
1245 	file_end = (isize - 1) >> PAGE_SHIFT;
1246 	if (!isize || start_index > file_end)
1247 		return 0;
1248 
1249 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1250 
1251 	ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1252 			start_index << PAGE_SHIFT,
1253 			page_cnt << PAGE_SHIFT);
1254 	if (ret)
1255 		return ret;
1256 	i_done = 0;
1257 	tree = &BTRFS_I(inode)->io_tree;
1258 
1259 	/* step one, lock all the pages */
1260 	for (i = 0; i < page_cnt; i++) {
1261 		struct page *page;
1262 again:
1263 		page = find_or_create_page(inode->i_mapping,
1264 					   start_index + i, mask);
1265 		if (!page)
1266 			break;
1267 
1268 		page_start = page_offset(page);
1269 		page_end = page_start + PAGE_SIZE - 1;
1270 		while (1) {
1271 			lock_extent_bits(tree, page_start, page_end,
1272 					 &cached_state);
1273 			ordered = btrfs_lookup_ordered_extent(inode,
1274 							      page_start);
1275 			unlock_extent_cached(tree, page_start, page_end,
1276 					     &cached_state);
1277 			if (!ordered)
1278 				break;
1279 
1280 			unlock_page(page);
1281 			btrfs_start_ordered_extent(inode, ordered, 1);
1282 			btrfs_put_ordered_extent(ordered);
1283 			lock_page(page);
1284 			/*
1285 			 * we unlocked the page above, so we need check if
1286 			 * it was released or not.
1287 			 */
1288 			if (page->mapping != inode->i_mapping) {
1289 				unlock_page(page);
1290 				put_page(page);
1291 				goto again;
1292 			}
1293 		}
1294 
1295 		if (!PageUptodate(page)) {
1296 			btrfs_readpage(NULL, page);
1297 			lock_page(page);
1298 			if (!PageUptodate(page)) {
1299 				unlock_page(page);
1300 				put_page(page);
1301 				ret = -EIO;
1302 				break;
1303 			}
1304 		}
1305 
1306 		if (page->mapping != inode->i_mapping) {
1307 			unlock_page(page);
1308 			put_page(page);
1309 			goto again;
1310 		}
1311 
1312 		pages[i] = page;
1313 		i_done++;
1314 	}
1315 	if (!i_done || ret)
1316 		goto out;
1317 
1318 	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1319 		goto out;
1320 
1321 	/*
1322 	 * so now we have a nice long stream of locked
1323 	 * and up to date pages, lets wait on them
1324 	 */
1325 	for (i = 0; i < i_done; i++)
1326 		wait_on_page_writeback(pages[i]);
1327 
1328 	page_start = page_offset(pages[0]);
1329 	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1330 
1331 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1332 			 page_start, page_end - 1, &cached_state);
1333 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1334 			  page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1335 			  EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1336 			  &cached_state);
1337 
1338 	if (i_done != page_cnt) {
1339 		spin_lock(&BTRFS_I(inode)->lock);
1340 		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1341 		spin_unlock(&BTRFS_I(inode)->lock);
1342 		btrfs_delalloc_release_space(inode, data_reserved,
1343 				start_index << PAGE_SHIFT,
1344 				(page_cnt - i_done) << PAGE_SHIFT, true);
1345 	}
1346 
1347 
1348 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1349 			  &cached_state);
1350 
1351 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1352 			     page_start, page_end - 1, &cached_state);
1353 
1354 	for (i = 0; i < i_done; i++) {
1355 		clear_page_dirty_for_io(pages[i]);
1356 		ClearPageChecked(pages[i]);
1357 		set_page_extent_mapped(pages[i]);
1358 		set_page_dirty(pages[i]);
1359 		unlock_page(pages[i]);
1360 		put_page(pages[i]);
1361 	}
1362 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1363 				       false);
1364 	extent_changeset_free(data_reserved);
1365 	return i_done;
1366 out:
1367 	for (i = 0; i < i_done; i++) {
1368 		unlock_page(pages[i]);
1369 		put_page(pages[i]);
1370 	}
1371 	btrfs_delalloc_release_space(inode, data_reserved,
1372 			start_index << PAGE_SHIFT,
1373 			page_cnt << PAGE_SHIFT, true);
1374 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1375 				       true);
1376 	extent_changeset_free(data_reserved);
1377 	return ret;
1378 
1379 }
1380 
1381 int btrfs_defrag_file(struct inode *inode, struct file *file,
1382 		      struct btrfs_ioctl_defrag_range_args *range,
1383 		      u64 newer_than, unsigned long max_to_defrag)
1384 {
1385 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1386 	struct btrfs_root *root = BTRFS_I(inode)->root;
1387 	struct file_ra_state *ra = NULL;
1388 	unsigned long last_index;
1389 	u64 isize = i_size_read(inode);
1390 	u64 last_len = 0;
1391 	u64 skip = 0;
1392 	u64 defrag_end = 0;
1393 	u64 newer_off = range->start;
1394 	unsigned long i;
1395 	unsigned long ra_index = 0;
1396 	int ret;
1397 	int defrag_count = 0;
1398 	int compress_type = BTRFS_COMPRESS_ZLIB;
1399 	u32 extent_thresh = range->extent_thresh;
1400 	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1401 	unsigned long cluster = max_cluster;
1402 	u64 new_align = ~((u64)SZ_128K - 1);
1403 	struct page **pages = NULL;
1404 	bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1405 
1406 	if (isize == 0)
1407 		return 0;
1408 
1409 	if (range->start >= isize)
1410 		return -EINVAL;
1411 
1412 	if (do_compress) {
1413 		if (range->compress_type > BTRFS_COMPRESS_TYPES)
1414 			return -EINVAL;
1415 		if (range->compress_type)
1416 			compress_type = range->compress_type;
1417 	}
1418 
1419 	if (extent_thresh == 0)
1420 		extent_thresh = SZ_256K;
1421 
1422 	/*
1423 	 * If we were not given a file, allocate a readahead context. As
1424 	 * readahead is just an optimization, defrag will work without it so
1425 	 * we don't error out.
1426 	 */
1427 	if (!file) {
1428 		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1429 		if (ra)
1430 			file_ra_state_init(ra, inode->i_mapping);
1431 	} else {
1432 		ra = &file->f_ra;
1433 	}
1434 
1435 	pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1436 	if (!pages) {
1437 		ret = -ENOMEM;
1438 		goto out_ra;
1439 	}
1440 
1441 	/* find the last page to defrag */
1442 	if (range->start + range->len > range->start) {
1443 		last_index = min_t(u64, isize - 1,
1444 			 range->start + range->len - 1) >> PAGE_SHIFT;
1445 	} else {
1446 		last_index = (isize - 1) >> PAGE_SHIFT;
1447 	}
1448 
1449 	if (newer_than) {
1450 		ret = find_new_extents(root, inode, newer_than,
1451 				       &newer_off, SZ_64K);
1452 		if (!ret) {
1453 			range->start = newer_off;
1454 			/*
1455 			 * we always align our defrag to help keep
1456 			 * the extents in the file evenly spaced
1457 			 */
1458 			i = (newer_off & new_align) >> PAGE_SHIFT;
1459 		} else
1460 			goto out_ra;
1461 	} else {
1462 		i = range->start >> PAGE_SHIFT;
1463 	}
1464 	if (!max_to_defrag)
1465 		max_to_defrag = last_index - i + 1;
1466 
1467 	/*
1468 	 * make writeback starts from i, so the defrag range can be
1469 	 * written sequentially.
1470 	 */
1471 	if (i < inode->i_mapping->writeback_index)
1472 		inode->i_mapping->writeback_index = i;
1473 
1474 	while (i <= last_index && defrag_count < max_to_defrag &&
1475 	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1476 		/*
1477 		 * make sure we stop running if someone unmounts
1478 		 * the FS
1479 		 */
1480 		if (!(inode->i_sb->s_flags & SB_ACTIVE))
1481 			break;
1482 
1483 		if (btrfs_defrag_cancelled(fs_info)) {
1484 			btrfs_debug(fs_info, "defrag_file cancelled");
1485 			ret = -EAGAIN;
1486 			break;
1487 		}
1488 
1489 		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1490 					 extent_thresh, &last_len, &skip,
1491 					 &defrag_end, do_compress)){
1492 			unsigned long next;
1493 			/*
1494 			 * the should_defrag function tells us how much to skip
1495 			 * bump our counter by the suggested amount
1496 			 */
1497 			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1498 			i = max(i + 1, next);
1499 			continue;
1500 		}
1501 
1502 		if (!newer_than) {
1503 			cluster = (PAGE_ALIGN(defrag_end) >>
1504 				   PAGE_SHIFT) - i;
1505 			cluster = min(cluster, max_cluster);
1506 		} else {
1507 			cluster = max_cluster;
1508 		}
1509 
1510 		if (i + cluster > ra_index) {
1511 			ra_index = max(i, ra_index);
1512 			if (ra)
1513 				page_cache_sync_readahead(inode->i_mapping, ra,
1514 						file, ra_index, cluster);
1515 			ra_index += cluster;
1516 		}
1517 
1518 		inode_lock(inode);
1519 		if (IS_SWAPFILE(inode)) {
1520 			ret = -ETXTBSY;
1521 		} else {
1522 			if (do_compress)
1523 				BTRFS_I(inode)->defrag_compress = compress_type;
1524 			ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1525 		}
1526 		if (ret < 0) {
1527 			inode_unlock(inode);
1528 			goto out_ra;
1529 		}
1530 
1531 		defrag_count += ret;
1532 		balance_dirty_pages_ratelimited(inode->i_mapping);
1533 		inode_unlock(inode);
1534 
1535 		if (newer_than) {
1536 			if (newer_off == (u64)-1)
1537 				break;
1538 
1539 			if (ret > 0)
1540 				i += ret;
1541 
1542 			newer_off = max(newer_off + 1,
1543 					(u64)i << PAGE_SHIFT);
1544 
1545 			ret = find_new_extents(root, inode, newer_than,
1546 					       &newer_off, SZ_64K);
1547 			if (!ret) {
1548 				range->start = newer_off;
1549 				i = (newer_off & new_align) >> PAGE_SHIFT;
1550 			} else {
1551 				break;
1552 			}
1553 		} else {
1554 			if (ret > 0) {
1555 				i += ret;
1556 				last_len += ret << PAGE_SHIFT;
1557 			} else {
1558 				i++;
1559 				last_len = 0;
1560 			}
1561 		}
1562 	}
1563 
1564 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1565 		filemap_flush(inode->i_mapping);
1566 		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1567 			     &BTRFS_I(inode)->runtime_flags))
1568 			filemap_flush(inode->i_mapping);
1569 	}
1570 
1571 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1572 		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1573 	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1574 		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1575 	}
1576 
1577 	ret = defrag_count;
1578 
1579 out_ra:
1580 	if (do_compress) {
1581 		inode_lock(inode);
1582 		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1583 		inode_unlock(inode);
1584 	}
1585 	if (!file)
1586 		kfree(ra);
1587 	kfree(pages);
1588 	return ret;
1589 }
1590 
1591 static noinline int btrfs_ioctl_resize(struct file *file,
1592 					void __user *arg)
1593 {
1594 	struct inode *inode = file_inode(file);
1595 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1596 	u64 new_size;
1597 	u64 old_size;
1598 	u64 devid = 1;
1599 	struct btrfs_root *root = BTRFS_I(inode)->root;
1600 	struct btrfs_ioctl_vol_args *vol_args;
1601 	struct btrfs_trans_handle *trans;
1602 	struct btrfs_device *device = NULL;
1603 	char *sizestr;
1604 	char *retptr;
1605 	char *devstr = NULL;
1606 	int ret = 0;
1607 	int mod = 0;
1608 
1609 	if (!capable(CAP_SYS_ADMIN))
1610 		return -EPERM;
1611 
1612 	ret = mnt_want_write_file(file);
1613 	if (ret)
1614 		return ret;
1615 
1616 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1617 		mnt_drop_write_file(file);
1618 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1619 	}
1620 
1621 	vol_args = memdup_user(arg, sizeof(*vol_args));
1622 	if (IS_ERR(vol_args)) {
1623 		ret = PTR_ERR(vol_args);
1624 		goto out;
1625 	}
1626 
1627 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1628 
1629 	sizestr = vol_args->name;
1630 	devstr = strchr(sizestr, ':');
1631 	if (devstr) {
1632 		sizestr = devstr + 1;
1633 		*devstr = '\0';
1634 		devstr = vol_args->name;
1635 		ret = kstrtoull(devstr, 10, &devid);
1636 		if (ret)
1637 			goto out_free;
1638 		if (!devid) {
1639 			ret = -EINVAL;
1640 			goto out_free;
1641 		}
1642 		btrfs_info(fs_info, "resizing devid %llu", devid);
1643 	}
1644 
1645 	device = btrfs_find_device(fs_info, devid, NULL, NULL);
1646 	if (!device) {
1647 		btrfs_info(fs_info, "resizer unable to find device %llu",
1648 			   devid);
1649 		ret = -ENODEV;
1650 		goto out_free;
1651 	}
1652 
1653 	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1654 		btrfs_info(fs_info,
1655 			   "resizer unable to apply on readonly device %llu",
1656 		       devid);
1657 		ret = -EPERM;
1658 		goto out_free;
1659 	}
1660 
1661 	if (!strcmp(sizestr, "max"))
1662 		new_size = device->bdev->bd_inode->i_size;
1663 	else {
1664 		if (sizestr[0] == '-') {
1665 			mod = -1;
1666 			sizestr++;
1667 		} else if (sizestr[0] == '+') {
1668 			mod = 1;
1669 			sizestr++;
1670 		}
1671 		new_size = memparse(sizestr, &retptr);
1672 		if (*retptr != '\0' || new_size == 0) {
1673 			ret = -EINVAL;
1674 			goto out_free;
1675 		}
1676 	}
1677 
1678 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1679 		ret = -EPERM;
1680 		goto out_free;
1681 	}
1682 
1683 	old_size = btrfs_device_get_total_bytes(device);
1684 
1685 	if (mod < 0) {
1686 		if (new_size > old_size) {
1687 			ret = -EINVAL;
1688 			goto out_free;
1689 		}
1690 		new_size = old_size - new_size;
1691 	} else if (mod > 0) {
1692 		if (new_size > ULLONG_MAX - old_size) {
1693 			ret = -ERANGE;
1694 			goto out_free;
1695 		}
1696 		new_size = old_size + new_size;
1697 	}
1698 
1699 	if (new_size < SZ_256M) {
1700 		ret = -EINVAL;
1701 		goto out_free;
1702 	}
1703 	if (new_size > device->bdev->bd_inode->i_size) {
1704 		ret = -EFBIG;
1705 		goto out_free;
1706 	}
1707 
1708 	new_size = round_down(new_size, fs_info->sectorsize);
1709 
1710 	btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1711 			  rcu_str_deref(device->name), new_size);
1712 
1713 	if (new_size > old_size) {
1714 		trans = btrfs_start_transaction(root, 0);
1715 		if (IS_ERR(trans)) {
1716 			ret = PTR_ERR(trans);
1717 			goto out_free;
1718 		}
1719 		ret = btrfs_grow_device(trans, device, new_size);
1720 		btrfs_commit_transaction(trans);
1721 	} else if (new_size < old_size) {
1722 		ret = btrfs_shrink_device(device, new_size);
1723 	} /* equal, nothing need to do */
1724 
1725 out_free:
1726 	kfree(vol_args);
1727 out:
1728 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1729 	mnt_drop_write_file(file);
1730 	return ret;
1731 }
1732 
1733 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1734 				const char *name, unsigned long fd, int subvol,
1735 				u64 *transid, bool readonly,
1736 				struct btrfs_qgroup_inherit *inherit)
1737 {
1738 	int namelen;
1739 	int ret = 0;
1740 
1741 	if (!S_ISDIR(file_inode(file)->i_mode))
1742 		return -ENOTDIR;
1743 
1744 	ret = mnt_want_write_file(file);
1745 	if (ret)
1746 		goto out;
1747 
1748 	namelen = strlen(name);
1749 	if (strchr(name, '/')) {
1750 		ret = -EINVAL;
1751 		goto out_drop_write;
1752 	}
1753 
1754 	if (name[0] == '.' &&
1755 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1756 		ret = -EEXIST;
1757 		goto out_drop_write;
1758 	}
1759 
1760 	if (subvol) {
1761 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1762 				     NULL, transid, readonly, inherit);
1763 	} else {
1764 		struct fd src = fdget(fd);
1765 		struct inode *src_inode;
1766 		if (!src.file) {
1767 			ret = -EINVAL;
1768 			goto out_drop_write;
1769 		}
1770 
1771 		src_inode = file_inode(src.file);
1772 		if (src_inode->i_sb != file_inode(file)->i_sb) {
1773 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1774 				   "Snapshot src from another FS");
1775 			ret = -EXDEV;
1776 		} else if (!inode_owner_or_capable(src_inode)) {
1777 			/*
1778 			 * Subvolume creation is not restricted, but snapshots
1779 			 * are limited to own subvolumes only
1780 			 */
1781 			ret = -EPERM;
1782 		} else {
1783 			ret = btrfs_mksubvol(&file->f_path, name, namelen,
1784 					     BTRFS_I(src_inode)->root,
1785 					     transid, readonly, inherit);
1786 		}
1787 		fdput(src);
1788 	}
1789 out_drop_write:
1790 	mnt_drop_write_file(file);
1791 out:
1792 	return ret;
1793 }
1794 
1795 static noinline int btrfs_ioctl_snap_create(struct file *file,
1796 					    void __user *arg, int subvol)
1797 {
1798 	struct btrfs_ioctl_vol_args *vol_args;
1799 	int ret;
1800 
1801 	if (!S_ISDIR(file_inode(file)->i_mode))
1802 		return -ENOTDIR;
1803 
1804 	vol_args = memdup_user(arg, sizeof(*vol_args));
1805 	if (IS_ERR(vol_args))
1806 		return PTR_ERR(vol_args);
1807 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1808 
1809 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1810 					      vol_args->fd, subvol,
1811 					      NULL, false, NULL);
1812 
1813 	kfree(vol_args);
1814 	return ret;
1815 }
1816 
1817 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1818 					       void __user *arg, int subvol)
1819 {
1820 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1821 	int ret;
1822 	u64 transid = 0;
1823 	u64 *ptr = NULL;
1824 	bool readonly = false;
1825 	struct btrfs_qgroup_inherit *inherit = NULL;
1826 
1827 	if (!S_ISDIR(file_inode(file)->i_mode))
1828 		return -ENOTDIR;
1829 
1830 	vol_args = memdup_user(arg, sizeof(*vol_args));
1831 	if (IS_ERR(vol_args))
1832 		return PTR_ERR(vol_args);
1833 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1834 
1835 	if (vol_args->flags &
1836 	    ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1837 	      BTRFS_SUBVOL_QGROUP_INHERIT)) {
1838 		ret = -EOPNOTSUPP;
1839 		goto free_args;
1840 	}
1841 
1842 	if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1843 		ptr = &transid;
1844 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1845 		readonly = true;
1846 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1847 		if (vol_args->size > PAGE_SIZE) {
1848 			ret = -EINVAL;
1849 			goto free_args;
1850 		}
1851 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1852 		if (IS_ERR(inherit)) {
1853 			ret = PTR_ERR(inherit);
1854 			goto free_args;
1855 		}
1856 	}
1857 
1858 	ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1859 					      vol_args->fd, subvol, ptr,
1860 					      readonly, inherit);
1861 	if (ret)
1862 		goto free_inherit;
1863 
1864 	if (ptr && copy_to_user(arg +
1865 				offsetof(struct btrfs_ioctl_vol_args_v2,
1866 					transid),
1867 				ptr, sizeof(*ptr)))
1868 		ret = -EFAULT;
1869 
1870 free_inherit:
1871 	kfree(inherit);
1872 free_args:
1873 	kfree(vol_args);
1874 	return ret;
1875 }
1876 
1877 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1878 						void __user *arg)
1879 {
1880 	struct inode *inode = file_inode(file);
1881 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1882 	struct btrfs_root *root = BTRFS_I(inode)->root;
1883 	int ret = 0;
1884 	u64 flags = 0;
1885 
1886 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1887 		return -EINVAL;
1888 
1889 	down_read(&fs_info->subvol_sem);
1890 	if (btrfs_root_readonly(root))
1891 		flags |= BTRFS_SUBVOL_RDONLY;
1892 	up_read(&fs_info->subvol_sem);
1893 
1894 	if (copy_to_user(arg, &flags, sizeof(flags)))
1895 		ret = -EFAULT;
1896 
1897 	return ret;
1898 }
1899 
1900 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1901 					      void __user *arg)
1902 {
1903 	struct inode *inode = file_inode(file);
1904 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1905 	struct btrfs_root *root = BTRFS_I(inode)->root;
1906 	struct btrfs_trans_handle *trans;
1907 	u64 root_flags;
1908 	u64 flags;
1909 	int ret = 0;
1910 
1911 	if (!inode_owner_or_capable(inode))
1912 		return -EPERM;
1913 
1914 	ret = mnt_want_write_file(file);
1915 	if (ret)
1916 		goto out;
1917 
1918 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1919 		ret = -EINVAL;
1920 		goto out_drop_write;
1921 	}
1922 
1923 	if (copy_from_user(&flags, arg, sizeof(flags))) {
1924 		ret = -EFAULT;
1925 		goto out_drop_write;
1926 	}
1927 
1928 	if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1929 		ret = -EINVAL;
1930 		goto out_drop_write;
1931 	}
1932 
1933 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1934 		ret = -EOPNOTSUPP;
1935 		goto out_drop_write;
1936 	}
1937 
1938 	down_write(&fs_info->subvol_sem);
1939 
1940 	/* nothing to do */
1941 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1942 		goto out_drop_sem;
1943 
1944 	root_flags = btrfs_root_flags(&root->root_item);
1945 	if (flags & BTRFS_SUBVOL_RDONLY) {
1946 		btrfs_set_root_flags(&root->root_item,
1947 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1948 	} else {
1949 		/*
1950 		 * Block RO -> RW transition if this subvolume is involved in
1951 		 * send
1952 		 */
1953 		spin_lock(&root->root_item_lock);
1954 		if (root->send_in_progress == 0) {
1955 			btrfs_set_root_flags(&root->root_item,
1956 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1957 			spin_unlock(&root->root_item_lock);
1958 		} else {
1959 			spin_unlock(&root->root_item_lock);
1960 			btrfs_warn(fs_info,
1961 				   "Attempt to set subvolume %llu read-write during send",
1962 				   root->root_key.objectid);
1963 			ret = -EPERM;
1964 			goto out_drop_sem;
1965 		}
1966 	}
1967 
1968 	trans = btrfs_start_transaction(root, 1);
1969 	if (IS_ERR(trans)) {
1970 		ret = PTR_ERR(trans);
1971 		goto out_reset;
1972 	}
1973 
1974 	ret = btrfs_update_root(trans, fs_info->tree_root,
1975 				&root->root_key, &root->root_item);
1976 	if (ret < 0) {
1977 		btrfs_end_transaction(trans);
1978 		goto out_reset;
1979 	}
1980 
1981 	ret = btrfs_commit_transaction(trans);
1982 
1983 out_reset:
1984 	if (ret)
1985 		btrfs_set_root_flags(&root->root_item, root_flags);
1986 out_drop_sem:
1987 	up_write(&fs_info->subvol_sem);
1988 out_drop_write:
1989 	mnt_drop_write_file(file);
1990 out:
1991 	return ret;
1992 }
1993 
1994 static noinline int key_in_sk(struct btrfs_key *key,
1995 			      struct btrfs_ioctl_search_key *sk)
1996 {
1997 	struct btrfs_key test;
1998 	int ret;
1999 
2000 	test.objectid = sk->min_objectid;
2001 	test.type = sk->min_type;
2002 	test.offset = sk->min_offset;
2003 
2004 	ret = btrfs_comp_cpu_keys(key, &test);
2005 	if (ret < 0)
2006 		return 0;
2007 
2008 	test.objectid = sk->max_objectid;
2009 	test.type = sk->max_type;
2010 	test.offset = sk->max_offset;
2011 
2012 	ret = btrfs_comp_cpu_keys(key, &test);
2013 	if (ret > 0)
2014 		return 0;
2015 	return 1;
2016 }
2017 
2018 static noinline int copy_to_sk(struct btrfs_path *path,
2019 			       struct btrfs_key *key,
2020 			       struct btrfs_ioctl_search_key *sk,
2021 			       size_t *buf_size,
2022 			       char __user *ubuf,
2023 			       unsigned long *sk_offset,
2024 			       int *num_found)
2025 {
2026 	u64 found_transid;
2027 	struct extent_buffer *leaf;
2028 	struct btrfs_ioctl_search_header sh;
2029 	struct btrfs_key test;
2030 	unsigned long item_off;
2031 	unsigned long item_len;
2032 	int nritems;
2033 	int i;
2034 	int slot;
2035 	int ret = 0;
2036 
2037 	leaf = path->nodes[0];
2038 	slot = path->slots[0];
2039 	nritems = btrfs_header_nritems(leaf);
2040 
2041 	if (btrfs_header_generation(leaf) > sk->max_transid) {
2042 		i = nritems;
2043 		goto advance_key;
2044 	}
2045 	found_transid = btrfs_header_generation(leaf);
2046 
2047 	for (i = slot; i < nritems; i++) {
2048 		item_off = btrfs_item_ptr_offset(leaf, i);
2049 		item_len = btrfs_item_size_nr(leaf, i);
2050 
2051 		btrfs_item_key_to_cpu(leaf, key, i);
2052 		if (!key_in_sk(key, sk))
2053 			continue;
2054 
2055 		if (sizeof(sh) + item_len > *buf_size) {
2056 			if (*num_found) {
2057 				ret = 1;
2058 				goto out;
2059 			}
2060 
2061 			/*
2062 			 * return one empty item back for v1, which does not
2063 			 * handle -EOVERFLOW
2064 			 */
2065 
2066 			*buf_size = sizeof(sh) + item_len;
2067 			item_len = 0;
2068 			ret = -EOVERFLOW;
2069 		}
2070 
2071 		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2072 			ret = 1;
2073 			goto out;
2074 		}
2075 
2076 		sh.objectid = key->objectid;
2077 		sh.offset = key->offset;
2078 		sh.type = key->type;
2079 		sh.len = item_len;
2080 		sh.transid = found_transid;
2081 
2082 		/* copy search result header */
2083 		if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2084 			ret = -EFAULT;
2085 			goto out;
2086 		}
2087 
2088 		*sk_offset += sizeof(sh);
2089 
2090 		if (item_len) {
2091 			char __user *up = ubuf + *sk_offset;
2092 			/* copy the item */
2093 			if (read_extent_buffer_to_user(leaf, up,
2094 						       item_off, item_len)) {
2095 				ret = -EFAULT;
2096 				goto out;
2097 			}
2098 
2099 			*sk_offset += item_len;
2100 		}
2101 		(*num_found)++;
2102 
2103 		if (ret) /* -EOVERFLOW from above */
2104 			goto out;
2105 
2106 		if (*num_found >= sk->nr_items) {
2107 			ret = 1;
2108 			goto out;
2109 		}
2110 	}
2111 advance_key:
2112 	ret = 0;
2113 	test.objectid = sk->max_objectid;
2114 	test.type = sk->max_type;
2115 	test.offset = sk->max_offset;
2116 	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2117 		ret = 1;
2118 	else if (key->offset < (u64)-1)
2119 		key->offset++;
2120 	else if (key->type < (u8)-1) {
2121 		key->offset = 0;
2122 		key->type++;
2123 	} else if (key->objectid < (u64)-1) {
2124 		key->offset = 0;
2125 		key->type = 0;
2126 		key->objectid++;
2127 	} else
2128 		ret = 1;
2129 out:
2130 	/*
2131 	 *  0: all items from this leaf copied, continue with next
2132 	 *  1: * more items can be copied, but unused buffer is too small
2133 	 *     * all items were found
2134 	 *     Either way, it will stops the loop which iterates to the next
2135 	 *     leaf
2136 	 *  -EOVERFLOW: item was to large for buffer
2137 	 *  -EFAULT: could not copy extent buffer back to userspace
2138 	 */
2139 	return ret;
2140 }
2141 
2142 static noinline int search_ioctl(struct inode *inode,
2143 				 struct btrfs_ioctl_search_key *sk,
2144 				 size_t *buf_size,
2145 				 char __user *ubuf)
2146 {
2147 	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2148 	struct btrfs_root *root;
2149 	struct btrfs_key key;
2150 	struct btrfs_path *path;
2151 	int ret;
2152 	int num_found = 0;
2153 	unsigned long sk_offset = 0;
2154 
2155 	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2156 		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2157 		return -EOVERFLOW;
2158 	}
2159 
2160 	path = btrfs_alloc_path();
2161 	if (!path)
2162 		return -ENOMEM;
2163 
2164 	if (sk->tree_id == 0) {
2165 		/* search the root of the inode that was passed */
2166 		root = BTRFS_I(inode)->root;
2167 	} else {
2168 		key.objectid = sk->tree_id;
2169 		key.type = BTRFS_ROOT_ITEM_KEY;
2170 		key.offset = (u64)-1;
2171 		root = btrfs_read_fs_root_no_name(info, &key);
2172 		if (IS_ERR(root)) {
2173 			btrfs_free_path(path);
2174 			return PTR_ERR(root);
2175 		}
2176 	}
2177 
2178 	key.objectid = sk->min_objectid;
2179 	key.type = sk->min_type;
2180 	key.offset = sk->min_offset;
2181 
2182 	while (1) {
2183 		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2184 		if (ret != 0) {
2185 			if (ret > 0)
2186 				ret = 0;
2187 			goto err;
2188 		}
2189 		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2190 				 &sk_offset, &num_found);
2191 		btrfs_release_path(path);
2192 		if (ret)
2193 			break;
2194 
2195 	}
2196 	if (ret > 0)
2197 		ret = 0;
2198 err:
2199 	sk->nr_items = num_found;
2200 	btrfs_free_path(path);
2201 	return ret;
2202 }
2203 
2204 static noinline int btrfs_ioctl_tree_search(struct file *file,
2205 					   void __user *argp)
2206 {
2207 	struct btrfs_ioctl_search_args __user *uargs;
2208 	struct btrfs_ioctl_search_key sk;
2209 	struct inode *inode;
2210 	int ret;
2211 	size_t buf_size;
2212 
2213 	if (!capable(CAP_SYS_ADMIN))
2214 		return -EPERM;
2215 
2216 	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2217 
2218 	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2219 		return -EFAULT;
2220 
2221 	buf_size = sizeof(uargs->buf);
2222 
2223 	inode = file_inode(file);
2224 	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2225 
2226 	/*
2227 	 * In the origin implementation an overflow is handled by returning a
2228 	 * search header with a len of zero, so reset ret.
2229 	 */
2230 	if (ret == -EOVERFLOW)
2231 		ret = 0;
2232 
2233 	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2234 		ret = -EFAULT;
2235 	return ret;
2236 }
2237 
2238 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2239 					       void __user *argp)
2240 {
2241 	struct btrfs_ioctl_search_args_v2 __user *uarg;
2242 	struct btrfs_ioctl_search_args_v2 args;
2243 	struct inode *inode;
2244 	int ret;
2245 	size_t buf_size;
2246 	const size_t buf_limit = SZ_16M;
2247 
2248 	if (!capable(CAP_SYS_ADMIN))
2249 		return -EPERM;
2250 
2251 	/* copy search header and buffer size */
2252 	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2253 	if (copy_from_user(&args, uarg, sizeof(args)))
2254 		return -EFAULT;
2255 
2256 	buf_size = args.buf_size;
2257 
2258 	/* limit result size to 16MB */
2259 	if (buf_size > buf_limit)
2260 		buf_size = buf_limit;
2261 
2262 	inode = file_inode(file);
2263 	ret = search_ioctl(inode, &args.key, &buf_size,
2264 			   (char __user *)(&uarg->buf[0]));
2265 	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2266 		ret = -EFAULT;
2267 	else if (ret == -EOVERFLOW &&
2268 		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2269 		ret = -EFAULT;
2270 
2271 	return ret;
2272 }
2273 
2274 /*
2275  * Search INODE_REFs to identify path name of 'dirid' directory
2276  * in a 'tree_id' tree. and sets path name to 'name'.
2277  */
2278 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2279 				u64 tree_id, u64 dirid, char *name)
2280 {
2281 	struct btrfs_root *root;
2282 	struct btrfs_key key;
2283 	char *ptr;
2284 	int ret = -1;
2285 	int slot;
2286 	int len;
2287 	int total_len = 0;
2288 	struct btrfs_inode_ref *iref;
2289 	struct extent_buffer *l;
2290 	struct btrfs_path *path;
2291 
2292 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2293 		name[0]='\0';
2294 		return 0;
2295 	}
2296 
2297 	path = btrfs_alloc_path();
2298 	if (!path)
2299 		return -ENOMEM;
2300 
2301 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2302 
2303 	key.objectid = tree_id;
2304 	key.type = BTRFS_ROOT_ITEM_KEY;
2305 	key.offset = (u64)-1;
2306 	root = btrfs_read_fs_root_no_name(info, &key);
2307 	if (IS_ERR(root)) {
2308 		ret = PTR_ERR(root);
2309 		goto out;
2310 	}
2311 
2312 	key.objectid = dirid;
2313 	key.type = BTRFS_INODE_REF_KEY;
2314 	key.offset = (u64)-1;
2315 
2316 	while (1) {
2317 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2318 		if (ret < 0)
2319 			goto out;
2320 		else if (ret > 0) {
2321 			ret = btrfs_previous_item(root, path, dirid,
2322 						  BTRFS_INODE_REF_KEY);
2323 			if (ret < 0)
2324 				goto out;
2325 			else if (ret > 0) {
2326 				ret = -ENOENT;
2327 				goto out;
2328 			}
2329 		}
2330 
2331 		l = path->nodes[0];
2332 		slot = path->slots[0];
2333 		btrfs_item_key_to_cpu(l, &key, slot);
2334 
2335 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2336 		len = btrfs_inode_ref_name_len(l, iref);
2337 		ptr -= len + 1;
2338 		total_len += len + 1;
2339 		if (ptr < name) {
2340 			ret = -ENAMETOOLONG;
2341 			goto out;
2342 		}
2343 
2344 		*(ptr + len) = '/';
2345 		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2346 
2347 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2348 			break;
2349 
2350 		btrfs_release_path(path);
2351 		key.objectid = key.offset;
2352 		key.offset = (u64)-1;
2353 		dirid = key.objectid;
2354 	}
2355 	memmove(name, ptr, total_len);
2356 	name[total_len] = '\0';
2357 	ret = 0;
2358 out:
2359 	btrfs_free_path(path);
2360 	return ret;
2361 }
2362 
2363 static int btrfs_search_path_in_tree_user(struct inode *inode,
2364 				struct btrfs_ioctl_ino_lookup_user_args *args)
2365 {
2366 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2367 	struct super_block *sb = inode->i_sb;
2368 	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2369 	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2370 	u64 dirid = args->dirid;
2371 	unsigned long item_off;
2372 	unsigned long item_len;
2373 	struct btrfs_inode_ref *iref;
2374 	struct btrfs_root_ref *rref;
2375 	struct btrfs_root *root;
2376 	struct btrfs_path *path;
2377 	struct btrfs_key key, key2;
2378 	struct extent_buffer *leaf;
2379 	struct inode *temp_inode;
2380 	char *ptr;
2381 	int slot;
2382 	int len;
2383 	int total_len = 0;
2384 	int ret;
2385 
2386 	path = btrfs_alloc_path();
2387 	if (!path)
2388 		return -ENOMEM;
2389 
2390 	/*
2391 	 * If the bottom subvolume does not exist directly under upper_limit,
2392 	 * construct the path in from the bottom up.
2393 	 */
2394 	if (dirid != upper_limit.objectid) {
2395 		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2396 
2397 		key.objectid = treeid;
2398 		key.type = BTRFS_ROOT_ITEM_KEY;
2399 		key.offset = (u64)-1;
2400 		root = btrfs_read_fs_root_no_name(fs_info, &key);
2401 		if (IS_ERR(root)) {
2402 			ret = PTR_ERR(root);
2403 			goto out;
2404 		}
2405 
2406 		key.objectid = dirid;
2407 		key.type = BTRFS_INODE_REF_KEY;
2408 		key.offset = (u64)-1;
2409 		while (1) {
2410 			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2411 			if (ret < 0) {
2412 				goto out;
2413 			} else if (ret > 0) {
2414 				ret = btrfs_previous_item(root, path, dirid,
2415 							  BTRFS_INODE_REF_KEY);
2416 				if (ret < 0) {
2417 					goto out;
2418 				} else if (ret > 0) {
2419 					ret = -ENOENT;
2420 					goto out;
2421 				}
2422 			}
2423 
2424 			leaf = path->nodes[0];
2425 			slot = path->slots[0];
2426 			btrfs_item_key_to_cpu(leaf, &key, slot);
2427 
2428 			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2429 			len = btrfs_inode_ref_name_len(leaf, iref);
2430 			ptr -= len + 1;
2431 			total_len += len + 1;
2432 			if (ptr < args->path) {
2433 				ret = -ENAMETOOLONG;
2434 				goto out;
2435 			}
2436 
2437 			*(ptr + len) = '/';
2438 			read_extent_buffer(leaf, ptr,
2439 					(unsigned long)(iref + 1), len);
2440 
2441 			/* Check the read+exec permission of this directory */
2442 			ret = btrfs_previous_item(root, path, dirid,
2443 						  BTRFS_INODE_ITEM_KEY);
2444 			if (ret < 0) {
2445 				goto out;
2446 			} else if (ret > 0) {
2447 				ret = -ENOENT;
2448 				goto out;
2449 			}
2450 
2451 			leaf = path->nodes[0];
2452 			slot = path->slots[0];
2453 			btrfs_item_key_to_cpu(leaf, &key2, slot);
2454 			if (key2.objectid != dirid) {
2455 				ret = -ENOENT;
2456 				goto out;
2457 			}
2458 
2459 			temp_inode = btrfs_iget(sb, &key2, root, NULL);
2460 			if (IS_ERR(temp_inode)) {
2461 				ret = PTR_ERR(temp_inode);
2462 				goto out;
2463 			}
2464 			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2465 			iput(temp_inode);
2466 			if (ret) {
2467 				ret = -EACCES;
2468 				goto out;
2469 			}
2470 
2471 			if (key.offset == upper_limit.objectid)
2472 				break;
2473 			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2474 				ret = -EACCES;
2475 				goto out;
2476 			}
2477 
2478 			btrfs_release_path(path);
2479 			key.objectid = key.offset;
2480 			key.offset = (u64)-1;
2481 			dirid = key.objectid;
2482 		}
2483 
2484 		memmove(args->path, ptr, total_len);
2485 		args->path[total_len] = '\0';
2486 		btrfs_release_path(path);
2487 	}
2488 
2489 	/* Get the bottom subvolume's name from ROOT_REF */
2490 	root = fs_info->tree_root;
2491 	key.objectid = treeid;
2492 	key.type = BTRFS_ROOT_REF_KEY;
2493 	key.offset = args->treeid;
2494 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2495 	if (ret < 0) {
2496 		goto out;
2497 	} else if (ret > 0) {
2498 		ret = -ENOENT;
2499 		goto out;
2500 	}
2501 
2502 	leaf = path->nodes[0];
2503 	slot = path->slots[0];
2504 	btrfs_item_key_to_cpu(leaf, &key, slot);
2505 
2506 	item_off = btrfs_item_ptr_offset(leaf, slot);
2507 	item_len = btrfs_item_size_nr(leaf, slot);
2508 	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2509 	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2510 	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2511 		ret = -EINVAL;
2512 		goto out;
2513 	}
2514 
2515 	/* Copy subvolume's name */
2516 	item_off += sizeof(struct btrfs_root_ref);
2517 	item_len -= sizeof(struct btrfs_root_ref);
2518 	read_extent_buffer(leaf, args->name, item_off, item_len);
2519 	args->name[item_len] = 0;
2520 
2521 out:
2522 	btrfs_free_path(path);
2523 	return ret;
2524 }
2525 
2526 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2527 					   void __user *argp)
2528 {
2529 	struct btrfs_ioctl_ino_lookup_args *args;
2530 	struct inode *inode;
2531 	int ret = 0;
2532 
2533 	args = memdup_user(argp, sizeof(*args));
2534 	if (IS_ERR(args))
2535 		return PTR_ERR(args);
2536 
2537 	inode = file_inode(file);
2538 
2539 	/*
2540 	 * Unprivileged query to obtain the containing subvolume root id. The
2541 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2542 	 */
2543 	if (args->treeid == 0)
2544 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2545 
2546 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2547 		args->name[0] = 0;
2548 		goto out;
2549 	}
2550 
2551 	if (!capable(CAP_SYS_ADMIN)) {
2552 		ret = -EPERM;
2553 		goto out;
2554 	}
2555 
2556 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2557 					args->treeid, args->objectid,
2558 					args->name);
2559 
2560 out:
2561 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2562 		ret = -EFAULT;
2563 
2564 	kfree(args);
2565 	return ret;
2566 }
2567 
2568 /*
2569  * Version of ino_lookup ioctl (unprivileged)
2570  *
2571  * The main differences from ino_lookup ioctl are:
2572  *
2573  *   1. Read + Exec permission will be checked using inode_permission() during
2574  *      path construction. -EACCES will be returned in case of failure.
2575  *   2. Path construction will be stopped at the inode number which corresponds
2576  *      to the fd with which this ioctl is called. If constructed path does not
2577  *      exist under fd's inode, -EACCES will be returned.
2578  *   3. The name of bottom subvolume is also searched and filled.
2579  */
2580 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2581 {
2582 	struct btrfs_ioctl_ino_lookup_user_args *args;
2583 	struct inode *inode;
2584 	int ret;
2585 
2586 	args = memdup_user(argp, sizeof(*args));
2587 	if (IS_ERR(args))
2588 		return PTR_ERR(args);
2589 
2590 	inode = file_inode(file);
2591 
2592 	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2593 	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2594 		/*
2595 		 * The subvolume does not exist under fd with which this is
2596 		 * called
2597 		 */
2598 		kfree(args);
2599 		return -EACCES;
2600 	}
2601 
2602 	ret = btrfs_search_path_in_tree_user(inode, args);
2603 
2604 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2605 		ret = -EFAULT;
2606 
2607 	kfree(args);
2608 	return ret;
2609 }
2610 
2611 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2612 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2613 {
2614 	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2615 	struct btrfs_fs_info *fs_info;
2616 	struct btrfs_root *root;
2617 	struct btrfs_path *path;
2618 	struct btrfs_key key;
2619 	struct btrfs_root_item *root_item;
2620 	struct btrfs_root_ref *rref;
2621 	struct extent_buffer *leaf;
2622 	unsigned long item_off;
2623 	unsigned long item_len;
2624 	struct inode *inode;
2625 	int slot;
2626 	int ret = 0;
2627 
2628 	path = btrfs_alloc_path();
2629 	if (!path)
2630 		return -ENOMEM;
2631 
2632 	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2633 	if (!subvol_info) {
2634 		btrfs_free_path(path);
2635 		return -ENOMEM;
2636 	}
2637 
2638 	inode = file_inode(file);
2639 	fs_info = BTRFS_I(inode)->root->fs_info;
2640 
2641 	/* Get root_item of inode's subvolume */
2642 	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2643 	key.type = BTRFS_ROOT_ITEM_KEY;
2644 	key.offset = (u64)-1;
2645 	root = btrfs_read_fs_root_no_name(fs_info, &key);
2646 	if (IS_ERR(root)) {
2647 		ret = PTR_ERR(root);
2648 		goto out;
2649 	}
2650 	root_item = &root->root_item;
2651 
2652 	subvol_info->treeid = key.objectid;
2653 
2654 	subvol_info->generation = btrfs_root_generation(root_item);
2655 	subvol_info->flags = btrfs_root_flags(root_item);
2656 
2657 	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2658 	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2659 						    BTRFS_UUID_SIZE);
2660 	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2661 						    BTRFS_UUID_SIZE);
2662 
2663 	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2664 	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2665 	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2666 
2667 	subvol_info->otransid = btrfs_root_otransid(root_item);
2668 	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2669 	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2670 
2671 	subvol_info->stransid = btrfs_root_stransid(root_item);
2672 	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2673 	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2674 
2675 	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2676 	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2677 	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2678 
2679 	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2680 		/* Search root tree for ROOT_BACKREF of this subvolume */
2681 		root = fs_info->tree_root;
2682 
2683 		key.type = BTRFS_ROOT_BACKREF_KEY;
2684 		key.offset = 0;
2685 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2686 		if (ret < 0) {
2687 			goto out;
2688 		} else if (path->slots[0] >=
2689 			   btrfs_header_nritems(path->nodes[0])) {
2690 			ret = btrfs_next_leaf(root, path);
2691 			if (ret < 0) {
2692 				goto out;
2693 			} else if (ret > 0) {
2694 				ret = -EUCLEAN;
2695 				goto out;
2696 			}
2697 		}
2698 
2699 		leaf = path->nodes[0];
2700 		slot = path->slots[0];
2701 		btrfs_item_key_to_cpu(leaf, &key, slot);
2702 		if (key.objectid == subvol_info->treeid &&
2703 		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2704 			subvol_info->parent_id = key.offset;
2705 
2706 			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2707 			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2708 
2709 			item_off = btrfs_item_ptr_offset(leaf, slot)
2710 					+ sizeof(struct btrfs_root_ref);
2711 			item_len = btrfs_item_size_nr(leaf, slot)
2712 					- sizeof(struct btrfs_root_ref);
2713 			read_extent_buffer(leaf, subvol_info->name,
2714 					   item_off, item_len);
2715 		} else {
2716 			ret = -ENOENT;
2717 			goto out;
2718 		}
2719 	}
2720 
2721 	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2722 		ret = -EFAULT;
2723 
2724 out:
2725 	btrfs_free_path(path);
2726 	kzfree(subvol_info);
2727 	return ret;
2728 }
2729 
2730 /*
2731  * Return ROOT_REF information of the subvolume containing this inode
2732  * except the subvolume name.
2733  */
2734 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2735 {
2736 	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2737 	struct btrfs_root_ref *rref;
2738 	struct btrfs_root *root;
2739 	struct btrfs_path *path;
2740 	struct btrfs_key key;
2741 	struct extent_buffer *leaf;
2742 	struct inode *inode;
2743 	u64 objectid;
2744 	int slot;
2745 	int ret;
2746 	u8 found;
2747 
2748 	path = btrfs_alloc_path();
2749 	if (!path)
2750 		return -ENOMEM;
2751 
2752 	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2753 	if (IS_ERR(rootrefs)) {
2754 		btrfs_free_path(path);
2755 		return PTR_ERR(rootrefs);
2756 	}
2757 
2758 	inode = file_inode(file);
2759 	root = BTRFS_I(inode)->root->fs_info->tree_root;
2760 	objectid = BTRFS_I(inode)->root->root_key.objectid;
2761 
2762 	key.objectid = objectid;
2763 	key.type = BTRFS_ROOT_REF_KEY;
2764 	key.offset = rootrefs->min_treeid;
2765 	found = 0;
2766 
2767 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2768 	if (ret < 0) {
2769 		goto out;
2770 	} else if (path->slots[0] >=
2771 		   btrfs_header_nritems(path->nodes[0])) {
2772 		ret = btrfs_next_leaf(root, path);
2773 		if (ret < 0) {
2774 			goto out;
2775 		} else if (ret > 0) {
2776 			ret = -EUCLEAN;
2777 			goto out;
2778 		}
2779 	}
2780 	while (1) {
2781 		leaf = path->nodes[0];
2782 		slot = path->slots[0];
2783 
2784 		btrfs_item_key_to_cpu(leaf, &key, slot);
2785 		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2786 			ret = 0;
2787 			goto out;
2788 		}
2789 
2790 		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2791 			ret = -EOVERFLOW;
2792 			goto out;
2793 		}
2794 
2795 		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2796 		rootrefs->rootref[found].treeid = key.offset;
2797 		rootrefs->rootref[found].dirid =
2798 				  btrfs_root_ref_dirid(leaf, rref);
2799 		found++;
2800 
2801 		ret = btrfs_next_item(root, path);
2802 		if (ret < 0) {
2803 			goto out;
2804 		} else if (ret > 0) {
2805 			ret = -EUCLEAN;
2806 			goto out;
2807 		}
2808 	}
2809 
2810 out:
2811 	if (!ret || ret == -EOVERFLOW) {
2812 		rootrefs->num_items = found;
2813 		/* update min_treeid for next search */
2814 		if (found)
2815 			rootrefs->min_treeid =
2816 				rootrefs->rootref[found - 1].treeid + 1;
2817 		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2818 			ret = -EFAULT;
2819 	}
2820 
2821 	kfree(rootrefs);
2822 	btrfs_free_path(path);
2823 
2824 	return ret;
2825 }
2826 
2827 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2828 					     void __user *arg)
2829 {
2830 	struct dentry *parent = file->f_path.dentry;
2831 	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2832 	struct dentry *dentry;
2833 	struct inode *dir = d_inode(parent);
2834 	struct inode *inode;
2835 	struct btrfs_root *root = BTRFS_I(dir)->root;
2836 	struct btrfs_root *dest = NULL;
2837 	struct btrfs_ioctl_vol_args *vol_args;
2838 	int namelen;
2839 	int err = 0;
2840 
2841 	if (!S_ISDIR(dir->i_mode))
2842 		return -ENOTDIR;
2843 
2844 	vol_args = memdup_user(arg, sizeof(*vol_args));
2845 	if (IS_ERR(vol_args))
2846 		return PTR_ERR(vol_args);
2847 
2848 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2849 	namelen = strlen(vol_args->name);
2850 	if (strchr(vol_args->name, '/') ||
2851 	    strncmp(vol_args->name, "..", namelen) == 0) {
2852 		err = -EINVAL;
2853 		goto out;
2854 	}
2855 
2856 	err = mnt_want_write_file(file);
2857 	if (err)
2858 		goto out;
2859 
2860 
2861 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2862 	if (err == -EINTR)
2863 		goto out_drop_write;
2864 	dentry = lookup_one_len(vol_args->name, parent, namelen);
2865 	if (IS_ERR(dentry)) {
2866 		err = PTR_ERR(dentry);
2867 		goto out_unlock_dir;
2868 	}
2869 
2870 	if (d_really_is_negative(dentry)) {
2871 		err = -ENOENT;
2872 		goto out_dput;
2873 	}
2874 
2875 	inode = d_inode(dentry);
2876 	dest = BTRFS_I(inode)->root;
2877 	if (!capable(CAP_SYS_ADMIN)) {
2878 		/*
2879 		 * Regular user.  Only allow this with a special mount
2880 		 * option, when the user has write+exec access to the
2881 		 * subvol root, and when rmdir(2) would have been
2882 		 * allowed.
2883 		 *
2884 		 * Note that this is _not_ check that the subvol is
2885 		 * empty or doesn't contain data that we wouldn't
2886 		 * otherwise be able to delete.
2887 		 *
2888 		 * Users who want to delete empty subvols should try
2889 		 * rmdir(2).
2890 		 */
2891 		err = -EPERM;
2892 		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2893 			goto out_dput;
2894 
2895 		/*
2896 		 * Do not allow deletion if the parent dir is the same
2897 		 * as the dir to be deleted.  That means the ioctl
2898 		 * must be called on the dentry referencing the root
2899 		 * of the subvol, not a random directory contained
2900 		 * within it.
2901 		 */
2902 		err = -EINVAL;
2903 		if (root == dest)
2904 			goto out_dput;
2905 
2906 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2907 		if (err)
2908 			goto out_dput;
2909 	}
2910 
2911 	/* check if subvolume may be deleted by a user */
2912 	err = btrfs_may_delete(dir, dentry, 1);
2913 	if (err)
2914 		goto out_dput;
2915 
2916 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2917 		err = -EINVAL;
2918 		goto out_dput;
2919 	}
2920 
2921 	inode_lock(inode);
2922 	err = btrfs_delete_subvolume(dir, dentry);
2923 	inode_unlock(inode);
2924 	if (!err)
2925 		d_delete(dentry);
2926 
2927 out_dput:
2928 	dput(dentry);
2929 out_unlock_dir:
2930 	inode_unlock(dir);
2931 out_drop_write:
2932 	mnt_drop_write_file(file);
2933 out:
2934 	kfree(vol_args);
2935 	return err;
2936 }
2937 
2938 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2939 {
2940 	struct inode *inode = file_inode(file);
2941 	struct btrfs_root *root = BTRFS_I(inode)->root;
2942 	struct btrfs_ioctl_defrag_range_args *range;
2943 	int ret;
2944 
2945 	ret = mnt_want_write_file(file);
2946 	if (ret)
2947 		return ret;
2948 
2949 	if (btrfs_root_readonly(root)) {
2950 		ret = -EROFS;
2951 		goto out;
2952 	}
2953 
2954 	switch (inode->i_mode & S_IFMT) {
2955 	case S_IFDIR:
2956 		if (!capable(CAP_SYS_ADMIN)) {
2957 			ret = -EPERM;
2958 			goto out;
2959 		}
2960 		ret = btrfs_defrag_root(root);
2961 		break;
2962 	case S_IFREG:
2963 		/*
2964 		 * Note that this does not check the file descriptor for write
2965 		 * access. This prevents defragmenting executables that are
2966 		 * running and allows defrag on files open in read-only mode.
2967 		 */
2968 		if (!capable(CAP_SYS_ADMIN) &&
2969 		    inode_permission(inode, MAY_WRITE)) {
2970 			ret = -EPERM;
2971 			goto out;
2972 		}
2973 
2974 		range = kzalloc(sizeof(*range), GFP_KERNEL);
2975 		if (!range) {
2976 			ret = -ENOMEM;
2977 			goto out;
2978 		}
2979 
2980 		if (argp) {
2981 			if (copy_from_user(range, argp,
2982 					   sizeof(*range))) {
2983 				ret = -EFAULT;
2984 				kfree(range);
2985 				goto out;
2986 			}
2987 			/* compression requires us to start the IO */
2988 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2989 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2990 				range->extent_thresh = (u32)-1;
2991 			}
2992 		} else {
2993 			/* the rest are all set to zero by kzalloc */
2994 			range->len = (u64)-1;
2995 		}
2996 		ret = btrfs_defrag_file(file_inode(file), file,
2997 					range, BTRFS_OLDEST_GENERATION, 0);
2998 		if (ret > 0)
2999 			ret = 0;
3000 		kfree(range);
3001 		break;
3002 	default:
3003 		ret = -EINVAL;
3004 	}
3005 out:
3006 	mnt_drop_write_file(file);
3007 	return ret;
3008 }
3009 
3010 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3011 {
3012 	struct btrfs_ioctl_vol_args *vol_args;
3013 	int ret;
3014 
3015 	if (!capable(CAP_SYS_ADMIN))
3016 		return -EPERM;
3017 
3018 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3019 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3020 
3021 	vol_args = memdup_user(arg, sizeof(*vol_args));
3022 	if (IS_ERR(vol_args)) {
3023 		ret = PTR_ERR(vol_args);
3024 		goto out;
3025 	}
3026 
3027 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3028 	ret = btrfs_init_new_device(fs_info, vol_args->name);
3029 
3030 	if (!ret)
3031 		btrfs_info(fs_info, "disk added %s", vol_args->name);
3032 
3033 	kfree(vol_args);
3034 out:
3035 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3036 	return ret;
3037 }
3038 
3039 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3040 {
3041 	struct inode *inode = file_inode(file);
3042 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3043 	struct btrfs_ioctl_vol_args_v2 *vol_args;
3044 	int ret;
3045 
3046 	if (!capable(CAP_SYS_ADMIN))
3047 		return -EPERM;
3048 
3049 	ret = mnt_want_write_file(file);
3050 	if (ret)
3051 		return ret;
3052 
3053 	vol_args = memdup_user(arg, sizeof(*vol_args));
3054 	if (IS_ERR(vol_args)) {
3055 		ret = PTR_ERR(vol_args);
3056 		goto err_drop;
3057 	}
3058 
3059 	/* Check for compatibility reject unknown flags */
3060 	if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3061 		ret = -EOPNOTSUPP;
3062 		goto out;
3063 	}
3064 
3065 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3066 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3067 		goto out;
3068 	}
3069 
3070 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3071 		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3072 	} else {
3073 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3074 		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3075 	}
3076 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3077 
3078 	if (!ret) {
3079 		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3080 			btrfs_info(fs_info, "device deleted: id %llu",
3081 					vol_args->devid);
3082 		else
3083 			btrfs_info(fs_info, "device deleted: %s",
3084 					vol_args->name);
3085 	}
3086 out:
3087 	kfree(vol_args);
3088 err_drop:
3089 	mnt_drop_write_file(file);
3090 	return ret;
3091 }
3092 
3093 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3094 {
3095 	struct inode *inode = file_inode(file);
3096 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3097 	struct btrfs_ioctl_vol_args *vol_args;
3098 	int ret;
3099 
3100 	if (!capable(CAP_SYS_ADMIN))
3101 		return -EPERM;
3102 
3103 	ret = mnt_want_write_file(file);
3104 	if (ret)
3105 		return ret;
3106 
3107 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3108 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3109 		goto out_drop_write;
3110 	}
3111 
3112 	vol_args = memdup_user(arg, sizeof(*vol_args));
3113 	if (IS_ERR(vol_args)) {
3114 		ret = PTR_ERR(vol_args);
3115 		goto out;
3116 	}
3117 
3118 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3119 	ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3120 
3121 	if (!ret)
3122 		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3123 	kfree(vol_args);
3124 out:
3125 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3126 out_drop_write:
3127 	mnt_drop_write_file(file);
3128 
3129 	return ret;
3130 }
3131 
3132 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3133 				void __user *arg)
3134 {
3135 	struct btrfs_ioctl_fs_info_args *fi_args;
3136 	struct btrfs_device *device;
3137 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3138 	int ret = 0;
3139 
3140 	fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3141 	if (!fi_args)
3142 		return -ENOMEM;
3143 
3144 	rcu_read_lock();
3145 	fi_args->num_devices = fs_devices->num_devices;
3146 
3147 	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3148 		if (device->devid > fi_args->max_id)
3149 			fi_args->max_id = device->devid;
3150 	}
3151 	rcu_read_unlock();
3152 
3153 	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3154 	fi_args->nodesize = fs_info->nodesize;
3155 	fi_args->sectorsize = fs_info->sectorsize;
3156 	fi_args->clone_alignment = fs_info->sectorsize;
3157 
3158 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3159 		ret = -EFAULT;
3160 
3161 	kfree(fi_args);
3162 	return ret;
3163 }
3164 
3165 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3166 				 void __user *arg)
3167 {
3168 	struct btrfs_ioctl_dev_info_args *di_args;
3169 	struct btrfs_device *dev;
3170 	int ret = 0;
3171 	char *s_uuid = NULL;
3172 
3173 	di_args = memdup_user(arg, sizeof(*di_args));
3174 	if (IS_ERR(di_args))
3175 		return PTR_ERR(di_args);
3176 
3177 	if (!btrfs_is_empty_uuid(di_args->uuid))
3178 		s_uuid = di_args->uuid;
3179 
3180 	rcu_read_lock();
3181 	dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3182 
3183 	if (!dev) {
3184 		ret = -ENODEV;
3185 		goto out;
3186 	}
3187 
3188 	di_args->devid = dev->devid;
3189 	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3190 	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3191 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3192 	if (dev->name) {
3193 		strncpy(di_args->path, rcu_str_deref(dev->name),
3194 				sizeof(di_args->path) - 1);
3195 		di_args->path[sizeof(di_args->path) - 1] = 0;
3196 	} else {
3197 		di_args->path[0] = '\0';
3198 	}
3199 
3200 out:
3201 	rcu_read_unlock();
3202 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3203 		ret = -EFAULT;
3204 
3205 	kfree(di_args);
3206 	return ret;
3207 }
3208 
3209 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3210 {
3211 	inode_unlock(inode1);
3212 	inode_unlock(inode2);
3213 }
3214 
3215 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3216 {
3217 	if (inode1 < inode2)
3218 		swap(inode1, inode2);
3219 
3220 	inode_lock_nested(inode1, I_MUTEX_PARENT);
3221 	inode_lock_nested(inode2, I_MUTEX_CHILD);
3222 }
3223 
3224 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3225 				   struct inode *dst, u64 dst_loff)
3226 {
3227 	u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
3228 	int ret;
3229 	u64 len = olen;
3230 
3231 	if (loff + len == src->i_size)
3232 		len = ALIGN(src->i_size, bs) - loff;
3233 	/*
3234 	 * For same inode case we don't want our length pushed out past i_size
3235 	 * as comparing that data range makes no sense.
3236 	 *
3237 	 * This effectively means we require aligned extents for the single
3238 	 * inode case, whereas the other cases allow an unaligned length so long
3239 	 * as it ends at i_size.
3240 	 */
3241 	if (dst == src && len != olen)
3242 		return -EINVAL;
3243 
3244 	/*
3245 	 * Lock destination range to serialize with concurrent readpages().
3246 	 */
3247 	lock_extent(&BTRFS_I(dst)->io_tree, dst_loff, dst_loff + len - 1);
3248 	ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3249 	unlock_extent(&BTRFS_I(dst)->io_tree, dst_loff, dst_loff + len - 1);
3250 
3251 	return ret;
3252 }
3253 
3254 #define BTRFS_MAX_DEDUPE_LEN	SZ_16M
3255 
3256 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3257 			     struct inode *dst, u64 dst_loff)
3258 {
3259 	int ret;
3260 	int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3261 	u64 i, tail_len, chunk_count;
3262 
3263 	/* don't make the dst file partly checksummed */
3264 	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3265 	    (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM))
3266 		return -EINVAL;
3267 
3268 	if (IS_SWAPFILE(src) || IS_SWAPFILE(dst))
3269 		return -ETXTBSY;
3270 
3271 	tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3272 	chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3273 	if (chunk_count == 0)
3274 		num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3275 
3276 	for (i = 0; i < chunk_count; i++) {
3277 		ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3278 					      dst, dst_loff);
3279 		if (ret)
3280 			return ret;
3281 
3282 		loff += BTRFS_MAX_DEDUPE_LEN;
3283 		dst_loff += BTRFS_MAX_DEDUPE_LEN;
3284 	}
3285 
3286 	if (tail_len > 0)
3287 		ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3288 					      dst_loff);
3289 
3290 	return ret;
3291 }
3292 
3293 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3294 				     struct inode *inode,
3295 				     u64 endoff,
3296 				     const u64 destoff,
3297 				     const u64 olen,
3298 				     int no_time_update)
3299 {
3300 	struct btrfs_root *root = BTRFS_I(inode)->root;
3301 	int ret;
3302 
3303 	inode_inc_iversion(inode);
3304 	if (!no_time_update)
3305 		inode->i_mtime = inode->i_ctime = current_time(inode);
3306 	/*
3307 	 * We round up to the block size at eof when determining which
3308 	 * extents to clone above, but shouldn't round up the file size.
3309 	 */
3310 	if (endoff > destoff + olen)
3311 		endoff = destoff + olen;
3312 	if (endoff > inode->i_size)
3313 		btrfs_i_size_write(BTRFS_I(inode), endoff);
3314 
3315 	ret = btrfs_update_inode(trans, root, inode);
3316 	if (ret) {
3317 		btrfs_abort_transaction(trans, ret);
3318 		btrfs_end_transaction(trans);
3319 		goto out;
3320 	}
3321 	ret = btrfs_end_transaction(trans);
3322 out:
3323 	return ret;
3324 }
3325 
3326 static void clone_update_extent_map(struct btrfs_inode *inode,
3327 				    const struct btrfs_trans_handle *trans,
3328 				    const struct btrfs_path *path,
3329 				    const u64 hole_offset,
3330 				    const u64 hole_len)
3331 {
3332 	struct extent_map_tree *em_tree = &inode->extent_tree;
3333 	struct extent_map *em;
3334 	int ret;
3335 
3336 	em = alloc_extent_map();
3337 	if (!em) {
3338 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3339 		return;
3340 	}
3341 
3342 	if (path) {
3343 		struct btrfs_file_extent_item *fi;
3344 
3345 		fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3346 				    struct btrfs_file_extent_item);
3347 		btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3348 		em->generation = -1;
3349 		if (btrfs_file_extent_type(path->nodes[0], fi) ==
3350 		    BTRFS_FILE_EXTENT_INLINE)
3351 			set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3352 					&inode->runtime_flags);
3353 	} else {
3354 		em->start = hole_offset;
3355 		em->len = hole_len;
3356 		em->ram_bytes = em->len;
3357 		em->orig_start = hole_offset;
3358 		em->block_start = EXTENT_MAP_HOLE;
3359 		em->block_len = 0;
3360 		em->orig_block_len = 0;
3361 		em->compress_type = BTRFS_COMPRESS_NONE;
3362 		em->generation = trans->transid;
3363 	}
3364 
3365 	while (1) {
3366 		write_lock(&em_tree->lock);
3367 		ret = add_extent_mapping(em_tree, em, 1);
3368 		write_unlock(&em_tree->lock);
3369 		if (ret != -EEXIST) {
3370 			free_extent_map(em);
3371 			break;
3372 		}
3373 		btrfs_drop_extent_cache(inode, em->start,
3374 					em->start + em->len - 1, 0);
3375 	}
3376 
3377 	if (ret)
3378 		set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3379 }
3380 
3381 /*
3382  * Make sure we do not end up inserting an inline extent into a file that has
3383  * already other (non-inline) extents. If a file has an inline extent it can
3384  * not have any other extents and the (single) inline extent must start at the
3385  * file offset 0. Failing to respect these rules will lead to file corruption,
3386  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3387  *
3388  * We can have extents that have been already written to disk or we can have
3389  * dirty ranges still in delalloc, in which case the extent maps and items are
3390  * created only when we run delalloc, and the delalloc ranges might fall outside
3391  * the range we are currently locking in the inode's io tree. So we check the
3392  * inode's i_size because of that (i_size updates are done while holding the
3393  * i_mutex, which we are holding here).
3394  * We also check to see if the inode has a size not greater than "datal" but has
3395  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3396  * protected against such concurrent fallocate calls by the i_mutex).
3397  *
3398  * If the file has no extents but a size greater than datal, do not allow the
3399  * copy because we would need turn the inline extent into a non-inline one (even
3400  * with NO_HOLES enabled). If we find our destination inode only has one inline
3401  * extent, just overwrite it with the source inline extent if its size is less
3402  * than the source extent's size, or we could copy the source inline extent's
3403  * data into the destination inode's inline extent if the later is greater then
3404  * the former.
3405  */
3406 static int clone_copy_inline_extent(struct inode *dst,
3407 				    struct btrfs_trans_handle *trans,
3408 				    struct btrfs_path *path,
3409 				    struct btrfs_key *new_key,
3410 				    const u64 drop_start,
3411 				    const u64 datal,
3412 				    const u64 skip,
3413 				    const u64 size,
3414 				    char *inline_data)
3415 {
3416 	struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3417 	struct btrfs_root *root = BTRFS_I(dst)->root;
3418 	const u64 aligned_end = ALIGN(new_key->offset + datal,
3419 				      fs_info->sectorsize);
3420 	int ret;
3421 	struct btrfs_key key;
3422 
3423 	if (new_key->offset > 0)
3424 		return -EOPNOTSUPP;
3425 
3426 	key.objectid = btrfs_ino(BTRFS_I(dst));
3427 	key.type = BTRFS_EXTENT_DATA_KEY;
3428 	key.offset = 0;
3429 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3430 	if (ret < 0) {
3431 		return ret;
3432 	} else if (ret > 0) {
3433 		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3434 			ret = btrfs_next_leaf(root, path);
3435 			if (ret < 0)
3436 				return ret;
3437 			else if (ret > 0)
3438 				goto copy_inline_extent;
3439 		}
3440 		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3441 		if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3442 		    key.type == BTRFS_EXTENT_DATA_KEY) {
3443 			ASSERT(key.offset > 0);
3444 			return -EOPNOTSUPP;
3445 		}
3446 	} else if (i_size_read(dst) <= datal) {
3447 		struct btrfs_file_extent_item *ei;
3448 		u64 ext_len;
3449 
3450 		/*
3451 		 * If the file size is <= datal, make sure there are no other
3452 		 * extents following (can happen do to an fallocate call with
3453 		 * the flag FALLOC_FL_KEEP_SIZE).
3454 		 */
3455 		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3456 				    struct btrfs_file_extent_item);
3457 		/*
3458 		 * If it's an inline extent, it can not have other extents
3459 		 * following it.
3460 		 */
3461 		if (btrfs_file_extent_type(path->nodes[0], ei) ==
3462 		    BTRFS_FILE_EXTENT_INLINE)
3463 			goto copy_inline_extent;
3464 
3465 		ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3466 		if (ext_len > aligned_end)
3467 			return -EOPNOTSUPP;
3468 
3469 		ret = btrfs_next_item(root, path);
3470 		if (ret < 0) {
3471 			return ret;
3472 		} else if (ret == 0) {
3473 			btrfs_item_key_to_cpu(path->nodes[0], &key,
3474 					      path->slots[0]);
3475 			if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3476 			    key.type == BTRFS_EXTENT_DATA_KEY)
3477 				return -EOPNOTSUPP;
3478 		}
3479 	}
3480 
3481 copy_inline_extent:
3482 	/*
3483 	 * We have no extent items, or we have an extent at offset 0 which may
3484 	 * or may not be inlined. All these cases are dealt the same way.
3485 	 */
3486 	if (i_size_read(dst) > datal) {
3487 		/*
3488 		 * If the destination inode has an inline extent...
3489 		 * This would require copying the data from the source inline
3490 		 * extent into the beginning of the destination's inline extent.
3491 		 * But this is really complex, both extents can be compressed
3492 		 * or just one of them, which would require decompressing and
3493 		 * re-compressing data (which could increase the new compressed
3494 		 * size, not allowing the compressed data to fit anymore in an
3495 		 * inline extent).
3496 		 * So just don't support this case for now (it should be rare,
3497 		 * we are not really saving space when cloning inline extents).
3498 		 */
3499 		return -EOPNOTSUPP;
3500 	}
3501 
3502 	btrfs_release_path(path);
3503 	ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3504 	if (ret)
3505 		return ret;
3506 	ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3507 	if (ret)
3508 		return ret;
3509 
3510 	if (skip) {
3511 		const u32 start = btrfs_file_extent_calc_inline_size(0);
3512 
3513 		memmove(inline_data + start, inline_data + start + skip, datal);
3514 	}
3515 
3516 	write_extent_buffer(path->nodes[0], inline_data,
3517 			    btrfs_item_ptr_offset(path->nodes[0],
3518 						  path->slots[0]),
3519 			    size);
3520 	inode_add_bytes(dst, datal);
3521 
3522 	return 0;
3523 }
3524 
3525 /**
3526  * btrfs_clone() - clone a range from inode file to another
3527  *
3528  * @src: Inode to clone from
3529  * @inode: Inode to clone to
3530  * @off: Offset within source to start clone from
3531  * @olen: Original length, passed by user, of range to clone
3532  * @olen_aligned: Block-aligned value of olen
3533  * @destoff: Offset within @inode to start clone
3534  * @no_time_update: Whether to update mtime/ctime on the target inode
3535  */
3536 static int btrfs_clone(struct inode *src, struct inode *inode,
3537 		       const u64 off, const u64 olen, const u64 olen_aligned,
3538 		       const u64 destoff, int no_time_update)
3539 {
3540 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3541 	struct btrfs_root *root = BTRFS_I(inode)->root;
3542 	struct btrfs_path *path = NULL;
3543 	struct extent_buffer *leaf;
3544 	struct btrfs_trans_handle *trans;
3545 	char *buf = NULL;
3546 	struct btrfs_key key;
3547 	u32 nritems;
3548 	int slot;
3549 	int ret;
3550 	const u64 len = olen_aligned;
3551 	u64 last_dest_end = destoff;
3552 
3553 	ret = -ENOMEM;
3554 	buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3555 	if (!buf)
3556 		return ret;
3557 
3558 	path = btrfs_alloc_path();
3559 	if (!path) {
3560 		kvfree(buf);
3561 		return ret;
3562 	}
3563 
3564 	path->reada = READA_FORWARD;
3565 	/* clone data */
3566 	key.objectid = btrfs_ino(BTRFS_I(src));
3567 	key.type = BTRFS_EXTENT_DATA_KEY;
3568 	key.offset = off;
3569 
3570 	while (1) {
3571 		u64 next_key_min_offset = key.offset + 1;
3572 
3573 		/*
3574 		 * note the key will change type as we walk through the
3575 		 * tree.
3576 		 */
3577 		path->leave_spinning = 1;
3578 		ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3579 				0, 0);
3580 		if (ret < 0)
3581 			goto out;
3582 		/*
3583 		 * First search, if no extent item that starts at offset off was
3584 		 * found but the previous item is an extent item, it's possible
3585 		 * it might overlap our target range, therefore process it.
3586 		 */
3587 		if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3588 			btrfs_item_key_to_cpu(path->nodes[0], &key,
3589 					      path->slots[0] - 1);
3590 			if (key.type == BTRFS_EXTENT_DATA_KEY)
3591 				path->slots[0]--;
3592 		}
3593 
3594 		nritems = btrfs_header_nritems(path->nodes[0]);
3595 process_slot:
3596 		if (path->slots[0] >= nritems) {
3597 			ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3598 			if (ret < 0)
3599 				goto out;
3600 			if (ret > 0)
3601 				break;
3602 			nritems = btrfs_header_nritems(path->nodes[0]);
3603 		}
3604 		leaf = path->nodes[0];
3605 		slot = path->slots[0];
3606 
3607 		btrfs_item_key_to_cpu(leaf, &key, slot);
3608 		if (key.type > BTRFS_EXTENT_DATA_KEY ||
3609 		    key.objectid != btrfs_ino(BTRFS_I(src)))
3610 			break;
3611 
3612 		if (key.type == BTRFS_EXTENT_DATA_KEY) {
3613 			struct btrfs_file_extent_item *extent;
3614 			int type;
3615 			u32 size;
3616 			struct btrfs_key new_key;
3617 			u64 disko = 0, diskl = 0;
3618 			u64 datao = 0, datal = 0;
3619 			u8 comp;
3620 			u64 drop_start;
3621 
3622 			extent = btrfs_item_ptr(leaf, slot,
3623 						struct btrfs_file_extent_item);
3624 			comp = btrfs_file_extent_compression(leaf, extent);
3625 			type = btrfs_file_extent_type(leaf, extent);
3626 			if (type == BTRFS_FILE_EXTENT_REG ||
3627 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3628 				disko = btrfs_file_extent_disk_bytenr(leaf,
3629 								      extent);
3630 				diskl = btrfs_file_extent_disk_num_bytes(leaf,
3631 								 extent);
3632 				datao = btrfs_file_extent_offset(leaf, extent);
3633 				datal = btrfs_file_extent_num_bytes(leaf,
3634 								    extent);
3635 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3636 				/* take upper bound, may be compressed */
3637 				datal = btrfs_file_extent_ram_bytes(leaf,
3638 								    extent);
3639 			}
3640 
3641 			/*
3642 			 * The first search might have left us at an extent
3643 			 * item that ends before our target range's start, can
3644 			 * happen if we have holes and NO_HOLES feature enabled.
3645 			 */
3646 			if (key.offset + datal <= off) {
3647 				path->slots[0]++;
3648 				goto process_slot;
3649 			} else if (key.offset >= off + len) {
3650 				break;
3651 			}
3652 			next_key_min_offset = key.offset + datal;
3653 			size = btrfs_item_size_nr(leaf, slot);
3654 			read_extent_buffer(leaf, buf,
3655 					   btrfs_item_ptr_offset(leaf, slot),
3656 					   size);
3657 
3658 			btrfs_release_path(path);
3659 			path->leave_spinning = 0;
3660 
3661 			memcpy(&new_key, &key, sizeof(new_key));
3662 			new_key.objectid = btrfs_ino(BTRFS_I(inode));
3663 			if (off <= key.offset)
3664 				new_key.offset = key.offset + destoff - off;
3665 			else
3666 				new_key.offset = destoff;
3667 
3668 			/*
3669 			 * Deal with a hole that doesn't have an extent item
3670 			 * that represents it (NO_HOLES feature enabled).
3671 			 * This hole is either in the middle of the cloning
3672 			 * range or at the beginning (fully overlaps it or
3673 			 * partially overlaps it).
3674 			 */
3675 			if (new_key.offset != last_dest_end)
3676 				drop_start = last_dest_end;
3677 			else
3678 				drop_start = new_key.offset;
3679 
3680 			/*
3681 			 * 1 - adjusting old extent (we may have to split it)
3682 			 * 1 - add new extent
3683 			 * 1 - inode update
3684 			 */
3685 			trans = btrfs_start_transaction(root, 3);
3686 			if (IS_ERR(trans)) {
3687 				ret = PTR_ERR(trans);
3688 				goto out;
3689 			}
3690 
3691 			if (type == BTRFS_FILE_EXTENT_REG ||
3692 			    type == BTRFS_FILE_EXTENT_PREALLOC) {
3693 				/*
3694 				 *    a  | --- range to clone ---|  b
3695 				 * | ------------- extent ------------- |
3696 				 */
3697 
3698 				/* subtract range b */
3699 				if (key.offset + datal > off + len)
3700 					datal = off + len - key.offset;
3701 
3702 				/* subtract range a */
3703 				if (off > key.offset) {
3704 					datao += off - key.offset;
3705 					datal -= off - key.offset;
3706 				}
3707 
3708 				ret = btrfs_drop_extents(trans, root, inode,
3709 							 drop_start,
3710 							 new_key.offset + datal,
3711 							 1);
3712 				if (ret) {
3713 					if (ret != -EOPNOTSUPP)
3714 						btrfs_abort_transaction(trans,
3715 									ret);
3716 					btrfs_end_transaction(trans);
3717 					goto out;
3718 				}
3719 
3720 				ret = btrfs_insert_empty_item(trans, root, path,
3721 							      &new_key, size);
3722 				if (ret) {
3723 					btrfs_abort_transaction(trans, ret);
3724 					btrfs_end_transaction(trans);
3725 					goto out;
3726 				}
3727 
3728 				leaf = path->nodes[0];
3729 				slot = path->slots[0];
3730 				write_extent_buffer(leaf, buf,
3731 					    btrfs_item_ptr_offset(leaf, slot),
3732 					    size);
3733 
3734 				extent = btrfs_item_ptr(leaf, slot,
3735 						struct btrfs_file_extent_item);
3736 
3737 				/* disko == 0 means it's a hole */
3738 				if (!disko)
3739 					datao = 0;
3740 
3741 				btrfs_set_file_extent_offset(leaf, extent,
3742 							     datao);
3743 				btrfs_set_file_extent_num_bytes(leaf, extent,
3744 								datal);
3745 
3746 				if (disko) {
3747 					inode_add_bytes(inode, datal);
3748 					ret = btrfs_inc_extent_ref(trans,
3749 							root,
3750 							disko, diskl, 0,
3751 							root->root_key.objectid,
3752 							btrfs_ino(BTRFS_I(inode)),
3753 							new_key.offset - datao);
3754 					if (ret) {
3755 						btrfs_abort_transaction(trans,
3756 									ret);
3757 						btrfs_end_transaction(trans);
3758 						goto out;
3759 
3760 					}
3761 				}
3762 			} else if (type == BTRFS_FILE_EXTENT_INLINE) {
3763 				u64 skip = 0;
3764 				u64 trim = 0;
3765 
3766 				if (off > key.offset) {
3767 					skip = off - key.offset;
3768 					new_key.offset += skip;
3769 				}
3770 
3771 				if (key.offset + datal > off + len)
3772 					trim = key.offset + datal - (off + len);
3773 
3774 				if (comp && (skip || trim)) {
3775 					ret = -EINVAL;
3776 					btrfs_end_transaction(trans);
3777 					goto out;
3778 				}
3779 				size -= skip + trim;
3780 				datal -= skip + trim;
3781 
3782 				ret = clone_copy_inline_extent(inode,
3783 							       trans, path,
3784 							       &new_key,
3785 							       drop_start,
3786 							       datal,
3787 							       skip, size, buf);
3788 				if (ret) {
3789 					if (ret != -EOPNOTSUPP)
3790 						btrfs_abort_transaction(trans,
3791 									ret);
3792 					btrfs_end_transaction(trans);
3793 					goto out;
3794 				}
3795 				leaf = path->nodes[0];
3796 				slot = path->slots[0];
3797 			}
3798 
3799 			/* If we have an implicit hole (NO_HOLES feature). */
3800 			if (drop_start < new_key.offset)
3801 				clone_update_extent_map(BTRFS_I(inode), trans,
3802 						NULL, drop_start,
3803 						new_key.offset - drop_start);
3804 
3805 			clone_update_extent_map(BTRFS_I(inode), trans,
3806 					path, 0, 0);
3807 
3808 			btrfs_mark_buffer_dirty(leaf);
3809 			btrfs_release_path(path);
3810 
3811 			last_dest_end = ALIGN(new_key.offset + datal,
3812 					      fs_info->sectorsize);
3813 			ret = clone_finish_inode_update(trans, inode,
3814 							last_dest_end,
3815 							destoff, olen,
3816 							no_time_update);
3817 			if (ret)
3818 				goto out;
3819 			if (new_key.offset + datal >= destoff + len)
3820 				break;
3821 		}
3822 		btrfs_release_path(path);
3823 		key.offset = next_key_min_offset;
3824 
3825 		if (fatal_signal_pending(current)) {
3826 			ret = -EINTR;
3827 			goto out;
3828 		}
3829 	}
3830 	ret = 0;
3831 
3832 	if (last_dest_end < destoff + len) {
3833 		/*
3834 		 * We have an implicit hole (NO_HOLES feature is enabled) that
3835 		 * fully or partially overlaps our cloning range at its end.
3836 		 */
3837 		btrfs_release_path(path);
3838 
3839 		/*
3840 		 * 1 - remove extent(s)
3841 		 * 1 - inode update
3842 		 */
3843 		trans = btrfs_start_transaction(root, 2);
3844 		if (IS_ERR(trans)) {
3845 			ret = PTR_ERR(trans);
3846 			goto out;
3847 		}
3848 		ret = btrfs_drop_extents(trans, root, inode,
3849 					 last_dest_end, destoff + len, 1);
3850 		if (ret) {
3851 			if (ret != -EOPNOTSUPP)
3852 				btrfs_abort_transaction(trans, ret);
3853 			btrfs_end_transaction(trans);
3854 			goto out;
3855 		}
3856 		clone_update_extent_map(BTRFS_I(inode), trans, NULL,
3857 				last_dest_end,
3858 				destoff + len - last_dest_end);
3859 		ret = clone_finish_inode_update(trans, inode, destoff + len,
3860 						destoff, olen, no_time_update);
3861 	}
3862 
3863 out:
3864 	btrfs_free_path(path);
3865 	kvfree(buf);
3866 	return ret;
3867 }
3868 
3869 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
3870 					u64 off, u64 olen, u64 destoff)
3871 {
3872 	struct inode *inode = file_inode(file);
3873 	struct inode *src = file_inode(file_src);
3874 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3875 	int ret;
3876 	u64 len = olen;
3877 	u64 bs = fs_info->sb->s_blocksize;
3878 
3879 	/*
3880 	 * TODO:
3881 	 * - split compressed inline extents.  annoying: we need to
3882 	 *   decompress into destination's address_space (the file offset
3883 	 *   may change, so source mapping won't do), then recompress (or
3884 	 *   otherwise reinsert) a subrange.
3885 	 *
3886 	 * - split destination inode's inline extents.  The inline extents can
3887 	 *   be either compressed or non-compressed.
3888 	 */
3889 
3890 	/* don't make the dst file partly checksummed */
3891 	if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3892 	    (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM))
3893 		return -EINVAL;
3894 
3895 	if (IS_SWAPFILE(src) || IS_SWAPFILE(inode))
3896 		return -ETXTBSY;
3897 
3898 	/*
3899 	 * VFS's generic_remap_file_range_prep() protects us from cloning the
3900 	 * eof block into the middle of a file, which would result in corruption
3901 	 * if the file size is not blocksize aligned. So we don't need to check
3902 	 * for that case here.
3903 	 */
3904 	if (off + len == src->i_size)
3905 		len = ALIGN(src->i_size, bs) - off;
3906 
3907 	if (destoff > inode->i_size) {
3908 		ret = btrfs_cont_expand(inode, inode->i_size, destoff);
3909 		if (ret)
3910 			return ret;
3911 	}
3912 
3913 	/*
3914 	 * Lock destination range to serialize with concurrent readpages().
3915 	 */
3916 	lock_extent(&BTRFS_I(inode)->io_tree, destoff, destoff + len - 1);
3917 	ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
3918 	unlock_extent(&BTRFS_I(inode)->io_tree, destoff, destoff + len - 1);
3919 	/*
3920 	 * Truncate page cache pages so that future reads will see the cloned
3921 	 * data immediately and not the previous data.
3922 	 */
3923 	truncate_inode_pages_range(&inode->i_data,
3924 				round_down(destoff, PAGE_SIZE),
3925 				round_up(destoff + len, PAGE_SIZE) - 1);
3926 
3927 	return ret;
3928 }
3929 
3930 static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
3931 				       struct file *file_out, loff_t pos_out,
3932 				       loff_t *len, unsigned int remap_flags)
3933 {
3934 	struct inode *inode_in = file_inode(file_in);
3935 	struct inode *inode_out = file_inode(file_out);
3936 	u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
3937 	bool same_inode = inode_out == inode_in;
3938 	u64 wb_len;
3939 	int ret;
3940 
3941 	if (!(remap_flags & REMAP_FILE_DEDUP)) {
3942 		struct btrfs_root *root_out = BTRFS_I(inode_out)->root;
3943 
3944 		if (btrfs_root_readonly(root_out))
3945 			return -EROFS;
3946 
3947 		if (file_in->f_path.mnt != file_out->f_path.mnt ||
3948 		    inode_in->i_sb != inode_out->i_sb)
3949 			return -EXDEV;
3950 	}
3951 
3952 	if (same_inode)
3953 		inode_lock(inode_in);
3954 	else
3955 		btrfs_double_inode_lock(inode_in, inode_out);
3956 
3957 	/*
3958 	 * Now that the inodes are locked, we need to start writeback ourselves
3959 	 * and can not rely on the writeback from the VFS's generic helper
3960 	 * generic_remap_file_range_prep() because:
3961 	 *
3962 	 * 1) For compression we must call filemap_fdatawrite_range() range
3963 	 *    twice (btrfs_fdatawrite_range() does it for us), and the generic
3964 	 *    helper only calls it once;
3965 	 *
3966 	 * 2) filemap_fdatawrite_range(), called by the generic helper only
3967 	 *    waits for the writeback to complete, i.e. for IO to be done, and
3968 	 *    not for the ordered extents to complete. We need to wait for them
3969 	 *    to complete so that new file extent items are in the fs tree.
3970 	 */
3971 	if (*len == 0 && !(remap_flags & REMAP_FILE_DEDUP))
3972 		wb_len = ALIGN(inode_in->i_size, bs) - ALIGN_DOWN(pos_in, bs);
3973 	else
3974 		wb_len = ALIGN(*len, bs);
3975 
3976 	/*
3977 	 * Since we don't lock ranges, wait for ongoing lockless dio writes (as
3978 	 * any in progress could create its ordered extents after we wait for
3979 	 * existing ordered extents below).
3980 	 */
3981 	inode_dio_wait(inode_in);
3982 	if (!same_inode)
3983 		inode_dio_wait(inode_out);
3984 
3985 	ret = btrfs_wait_ordered_range(inode_in, ALIGN_DOWN(pos_in, bs),
3986 				       wb_len);
3987 	if (ret < 0)
3988 		goto out_unlock;
3989 	ret = btrfs_wait_ordered_range(inode_out, ALIGN_DOWN(pos_out, bs),
3990 				       wb_len);
3991 	if (ret < 0)
3992 		goto out_unlock;
3993 
3994 	ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out,
3995 					    len, remap_flags);
3996 	if (ret < 0 || *len == 0)
3997 		goto out_unlock;
3998 
3999 	return 0;
4000 
4001  out_unlock:
4002 	if (same_inode)
4003 		inode_unlock(inode_in);
4004 	else
4005 		btrfs_double_inode_unlock(inode_in, inode_out);
4006 
4007 	return ret;
4008 }
4009 
4010 loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
4011 		struct file *dst_file, loff_t destoff, loff_t len,
4012 		unsigned int remap_flags)
4013 {
4014 	struct inode *src_inode = file_inode(src_file);
4015 	struct inode *dst_inode = file_inode(dst_file);
4016 	bool same_inode = dst_inode == src_inode;
4017 	int ret;
4018 
4019 	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
4020 		return -EINVAL;
4021 
4022 	ret = btrfs_remap_file_range_prep(src_file, off, dst_file, destoff,
4023 					  &len, remap_flags);
4024 	if (ret < 0 || len == 0)
4025 		return ret;
4026 
4027 	if (remap_flags & REMAP_FILE_DEDUP)
4028 		ret = btrfs_extent_same(src_inode, off, len, dst_inode, destoff);
4029 	else
4030 		ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
4031 
4032 	if (same_inode)
4033 		inode_unlock(src_inode);
4034 	else
4035 		btrfs_double_inode_unlock(src_inode, dst_inode);
4036 
4037 	return ret < 0 ? ret : len;
4038 }
4039 
4040 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4041 {
4042 	struct inode *inode = file_inode(file);
4043 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4044 	struct btrfs_root *root = BTRFS_I(inode)->root;
4045 	struct btrfs_root *new_root;
4046 	struct btrfs_dir_item *di;
4047 	struct btrfs_trans_handle *trans;
4048 	struct btrfs_path *path;
4049 	struct btrfs_key location;
4050 	struct btrfs_disk_key disk_key;
4051 	u64 objectid = 0;
4052 	u64 dir_id;
4053 	int ret;
4054 
4055 	if (!capable(CAP_SYS_ADMIN))
4056 		return -EPERM;
4057 
4058 	ret = mnt_want_write_file(file);
4059 	if (ret)
4060 		return ret;
4061 
4062 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4063 		ret = -EFAULT;
4064 		goto out;
4065 	}
4066 
4067 	if (!objectid)
4068 		objectid = BTRFS_FS_TREE_OBJECTID;
4069 
4070 	location.objectid = objectid;
4071 	location.type = BTRFS_ROOT_ITEM_KEY;
4072 	location.offset = (u64)-1;
4073 
4074 	new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4075 	if (IS_ERR(new_root)) {
4076 		ret = PTR_ERR(new_root);
4077 		goto out;
4078 	}
4079 	if (!is_fstree(new_root->root_key.objectid)) {
4080 		ret = -ENOENT;
4081 		goto out;
4082 	}
4083 
4084 	path = btrfs_alloc_path();
4085 	if (!path) {
4086 		ret = -ENOMEM;
4087 		goto out;
4088 	}
4089 	path->leave_spinning = 1;
4090 
4091 	trans = btrfs_start_transaction(root, 1);
4092 	if (IS_ERR(trans)) {
4093 		btrfs_free_path(path);
4094 		ret = PTR_ERR(trans);
4095 		goto out;
4096 	}
4097 
4098 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
4099 	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4100 				   dir_id, "default", 7, 1);
4101 	if (IS_ERR_OR_NULL(di)) {
4102 		btrfs_free_path(path);
4103 		btrfs_end_transaction(trans);
4104 		btrfs_err(fs_info,
4105 			  "Umm, you don't have the default diritem, this isn't going to work");
4106 		ret = -ENOENT;
4107 		goto out;
4108 	}
4109 
4110 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4111 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4112 	btrfs_mark_buffer_dirty(path->nodes[0]);
4113 	btrfs_free_path(path);
4114 
4115 	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4116 	btrfs_end_transaction(trans);
4117 out:
4118 	mnt_drop_write_file(file);
4119 	return ret;
4120 }
4121 
4122 static void get_block_group_info(struct list_head *groups_list,
4123 				 struct btrfs_ioctl_space_info *space)
4124 {
4125 	struct btrfs_block_group_cache *block_group;
4126 
4127 	space->total_bytes = 0;
4128 	space->used_bytes = 0;
4129 	space->flags = 0;
4130 	list_for_each_entry(block_group, groups_list, list) {
4131 		space->flags = block_group->flags;
4132 		space->total_bytes += block_group->key.offset;
4133 		space->used_bytes +=
4134 			btrfs_block_group_used(&block_group->item);
4135 	}
4136 }
4137 
4138 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4139 				   void __user *arg)
4140 {
4141 	struct btrfs_ioctl_space_args space_args;
4142 	struct btrfs_ioctl_space_info space;
4143 	struct btrfs_ioctl_space_info *dest;
4144 	struct btrfs_ioctl_space_info *dest_orig;
4145 	struct btrfs_ioctl_space_info __user *user_dest;
4146 	struct btrfs_space_info *info;
4147 	static const u64 types[] = {
4148 		BTRFS_BLOCK_GROUP_DATA,
4149 		BTRFS_BLOCK_GROUP_SYSTEM,
4150 		BTRFS_BLOCK_GROUP_METADATA,
4151 		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4152 	};
4153 	int num_types = 4;
4154 	int alloc_size;
4155 	int ret = 0;
4156 	u64 slot_count = 0;
4157 	int i, c;
4158 
4159 	if (copy_from_user(&space_args,
4160 			   (struct btrfs_ioctl_space_args __user *)arg,
4161 			   sizeof(space_args)))
4162 		return -EFAULT;
4163 
4164 	for (i = 0; i < num_types; i++) {
4165 		struct btrfs_space_info *tmp;
4166 
4167 		info = NULL;
4168 		rcu_read_lock();
4169 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4170 					list) {
4171 			if (tmp->flags == types[i]) {
4172 				info = tmp;
4173 				break;
4174 			}
4175 		}
4176 		rcu_read_unlock();
4177 
4178 		if (!info)
4179 			continue;
4180 
4181 		down_read(&info->groups_sem);
4182 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4183 			if (!list_empty(&info->block_groups[c]))
4184 				slot_count++;
4185 		}
4186 		up_read(&info->groups_sem);
4187 	}
4188 
4189 	/*
4190 	 * Global block reserve, exported as a space_info
4191 	 */
4192 	slot_count++;
4193 
4194 	/* space_slots == 0 means they are asking for a count */
4195 	if (space_args.space_slots == 0) {
4196 		space_args.total_spaces = slot_count;
4197 		goto out;
4198 	}
4199 
4200 	slot_count = min_t(u64, space_args.space_slots, slot_count);
4201 
4202 	alloc_size = sizeof(*dest) * slot_count;
4203 
4204 	/* we generally have at most 6 or so space infos, one for each raid
4205 	 * level.  So, a whole page should be more than enough for everyone
4206 	 */
4207 	if (alloc_size > PAGE_SIZE)
4208 		return -ENOMEM;
4209 
4210 	space_args.total_spaces = 0;
4211 	dest = kmalloc(alloc_size, GFP_KERNEL);
4212 	if (!dest)
4213 		return -ENOMEM;
4214 	dest_orig = dest;
4215 
4216 	/* now we have a buffer to copy into */
4217 	for (i = 0; i < num_types; i++) {
4218 		struct btrfs_space_info *tmp;
4219 
4220 		if (!slot_count)
4221 			break;
4222 
4223 		info = NULL;
4224 		rcu_read_lock();
4225 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
4226 					list) {
4227 			if (tmp->flags == types[i]) {
4228 				info = tmp;
4229 				break;
4230 			}
4231 		}
4232 		rcu_read_unlock();
4233 
4234 		if (!info)
4235 			continue;
4236 		down_read(&info->groups_sem);
4237 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4238 			if (!list_empty(&info->block_groups[c])) {
4239 				get_block_group_info(&info->block_groups[c],
4240 						     &space);
4241 				memcpy(dest, &space, sizeof(space));
4242 				dest++;
4243 				space_args.total_spaces++;
4244 				slot_count--;
4245 			}
4246 			if (!slot_count)
4247 				break;
4248 		}
4249 		up_read(&info->groups_sem);
4250 	}
4251 
4252 	/*
4253 	 * Add global block reserve
4254 	 */
4255 	if (slot_count) {
4256 		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4257 
4258 		spin_lock(&block_rsv->lock);
4259 		space.total_bytes = block_rsv->size;
4260 		space.used_bytes = block_rsv->size - block_rsv->reserved;
4261 		spin_unlock(&block_rsv->lock);
4262 		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4263 		memcpy(dest, &space, sizeof(space));
4264 		space_args.total_spaces++;
4265 	}
4266 
4267 	user_dest = (struct btrfs_ioctl_space_info __user *)
4268 		(arg + sizeof(struct btrfs_ioctl_space_args));
4269 
4270 	if (copy_to_user(user_dest, dest_orig, alloc_size))
4271 		ret = -EFAULT;
4272 
4273 	kfree(dest_orig);
4274 out:
4275 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4276 		ret = -EFAULT;
4277 
4278 	return ret;
4279 }
4280 
4281 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4282 					    void __user *argp)
4283 {
4284 	struct btrfs_trans_handle *trans;
4285 	u64 transid;
4286 	int ret;
4287 
4288 	trans = btrfs_attach_transaction_barrier(root);
4289 	if (IS_ERR(trans)) {
4290 		if (PTR_ERR(trans) != -ENOENT)
4291 			return PTR_ERR(trans);
4292 
4293 		/* No running transaction, don't bother */
4294 		transid = root->fs_info->last_trans_committed;
4295 		goto out;
4296 	}
4297 	transid = trans->transid;
4298 	ret = btrfs_commit_transaction_async(trans, 0);
4299 	if (ret) {
4300 		btrfs_end_transaction(trans);
4301 		return ret;
4302 	}
4303 out:
4304 	if (argp)
4305 		if (copy_to_user(argp, &transid, sizeof(transid)))
4306 			return -EFAULT;
4307 	return 0;
4308 }
4309 
4310 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4311 					   void __user *argp)
4312 {
4313 	u64 transid;
4314 
4315 	if (argp) {
4316 		if (copy_from_user(&transid, argp, sizeof(transid)))
4317 			return -EFAULT;
4318 	} else {
4319 		transid = 0;  /* current trans */
4320 	}
4321 	return btrfs_wait_for_commit(fs_info, transid);
4322 }
4323 
4324 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4325 {
4326 	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4327 	struct btrfs_ioctl_scrub_args *sa;
4328 	int ret;
4329 
4330 	if (!capable(CAP_SYS_ADMIN))
4331 		return -EPERM;
4332 
4333 	sa = memdup_user(arg, sizeof(*sa));
4334 	if (IS_ERR(sa))
4335 		return PTR_ERR(sa);
4336 
4337 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4338 		ret = mnt_want_write_file(file);
4339 		if (ret)
4340 			goto out;
4341 	}
4342 
4343 	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4344 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4345 			      0);
4346 
4347 	if (copy_to_user(arg, sa, sizeof(*sa)))
4348 		ret = -EFAULT;
4349 
4350 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
4351 		mnt_drop_write_file(file);
4352 out:
4353 	kfree(sa);
4354 	return ret;
4355 }
4356 
4357 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4358 {
4359 	if (!capable(CAP_SYS_ADMIN))
4360 		return -EPERM;
4361 
4362 	return btrfs_scrub_cancel(fs_info);
4363 }
4364 
4365 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4366 				       void __user *arg)
4367 {
4368 	struct btrfs_ioctl_scrub_args *sa;
4369 	int ret;
4370 
4371 	if (!capable(CAP_SYS_ADMIN))
4372 		return -EPERM;
4373 
4374 	sa = memdup_user(arg, sizeof(*sa));
4375 	if (IS_ERR(sa))
4376 		return PTR_ERR(sa);
4377 
4378 	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4379 
4380 	if (copy_to_user(arg, sa, sizeof(*sa)))
4381 		ret = -EFAULT;
4382 
4383 	kfree(sa);
4384 	return ret;
4385 }
4386 
4387 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4388 				      void __user *arg)
4389 {
4390 	struct btrfs_ioctl_get_dev_stats *sa;
4391 	int ret;
4392 
4393 	sa = memdup_user(arg, sizeof(*sa));
4394 	if (IS_ERR(sa))
4395 		return PTR_ERR(sa);
4396 
4397 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4398 		kfree(sa);
4399 		return -EPERM;
4400 	}
4401 
4402 	ret = btrfs_get_dev_stats(fs_info, sa);
4403 
4404 	if (copy_to_user(arg, sa, sizeof(*sa)))
4405 		ret = -EFAULT;
4406 
4407 	kfree(sa);
4408 	return ret;
4409 }
4410 
4411 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4412 				    void __user *arg)
4413 {
4414 	struct btrfs_ioctl_dev_replace_args *p;
4415 	int ret;
4416 
4417 	if (!capable(CAP_SYS_ADMIN))
4418 		return -EPERM;
4419 
4420 	p = memdup_user(arg, sizeof(*p));
4421 	if (IS_ERR(p))
4422 		return PTR_ERR(p);
4423 
4424 	switch (p->cmd) {
4425 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4426 		if (sb_rdonly(fs_info->sb)) {
4427 			ret = -EROFS;
4428 			goto out;
4429 		}
4430 		if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4431 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4432 		} else {
4433 			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4434 			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4435 		}
4436 		break;
4437 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4438 		btrfs_dev_replace_status(fs_info, p);
4439 		ret = 0;
4440 		break;
4441 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4442 		p->result = btrfs_dev_replace_cancel(fs_info);
4443 		ret = 0;
4444 		break;
4445 	default:
4446 		ret = -EINVAL;
4447 		break;
4448 	}
4449 
4450 	if (copy_to_user(arg, p, sizeof(*p)))
4451 		ret = -EFAULT;
4452 out:
4453 	kfree(p);
4454 	return ret;
4455 }
4456 
4457 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4458 {
4459 	int ret = 0;
4460 	int i;
4461 	u64 rel_ptr;
4462 	int size;
4463 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
4464 	struct inode_fs_paths *ipath = NULL;
4465 	struct btrfs_path *path;
4466 
4467 	if (!capable(CAP_DAC_READ_SEARCH))
4468 		return -EPERM;
4469 
4470 	path = btrfs_alloc_path();
4471 	if (!path) {
4472 		ret = -ENOMEM;
4473 		goto out;
4474 	}
4475 
4476 	ipa = memdup_user(arg, sizeof(*ipa));
4477 	if (IS_ERR(ipa)) {
4478 		ret = PTR_ERR(ipa);
4479 		ipa = NULL;
4480 		goto out;
4481 	}
4482 
4483 	size = min_t(u32, ipa->size, 4096);
4484 	ipath = init_ipath(size, root, path);
4485 	if (IS_ERR(ipath)) {
4486 		ret = PTR_ERR(ipath);
4487 		ipath = NULL;
4488 		goto out;
4489 	}
4490 
4491 	ret = paths_from_inode(ipa->inum, ipath);
4492 	if (ret < 0)
4493 		goto out;
4494 
4495 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4496 		rel_ptr = ipath->fspath->val[i] -
4497 			  (u64)(unsigned long)ipath->fspath->val;
4498 		ipath->fspath->val[i] = rel_ptr;
4499 	}
4500 
4501 	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4502 			   ipath->fspath, size);
4503 	if (ret) {
4504 		ret = -EFAULT;
4505 		goto out;
4506 	}
4507 
4508 out:
4509 	btrfs_free_path(path);
4510 	free_ipath(ipath);
4511 	kfree(ipa);
4512 
4513 	return ret;
4514 }
4515 
4516 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4517 {
4518 	struct btrfs_data_container *inodes = ctx;
4519 	const size_t c = 3 * sizeof(u64);
4520 
4521 	if (inodes->bytes_left >= c) {
4522 		inodes->bytes_left -= c;
4523 		inodes->val[inodes->elem_cnt] = inum;
4524 		inodes->val[inodes->elem_cnt + 1] = offset;
4525 		inodes->val[inodes->elem_cnt + 2] = root;
4526 		inodes->elem_cnt += 3;
4527 	} else {
4528 		inodes->bytes_missing += c - inodes->bytes_left;
4529 		inodes->bytes_left = 0;
4530 		inodes->elem_missed += 3;
4531 	}
4532 
4533 	return 0;
4534 }
4535 
4536 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4537 					void __user *arg, int version)
4538 {
4539 	int ret = 0;
4540 	int size;
4541 	struct btrfs_ioctl_logical_ino_args *loi;
4542 	struct btrfs_data_container *inodes = NULL;
4543 	struct btrfs_path *path = NULL;
4544 	bool ignore_offset;
4545 
4546 	if (!capable(CAP_SYS_ADMIN))
4547 		return -EPERM;
4548 
4549 	loi = memdup_user(arg, sizeof(*loi));
4550 	if (IS_ERR(loi))
4551 		return PTR_ERR(loi);
4552 
4553 	if (version == 1) {
4554 		ignore_offset = false;
4555 		size = min_t(u32, loi->size, SZ_64K);
4556 	} else {
4557 		/* All reserved bits must be 0 for now */
4558 		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4559 			ret = -EINVAL;
4560 			goto out_loi;
4561 		}
4562 		/* Only accept flags we have defined so far */
4563 		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4564 			ret = -EINVAL;
4565 			goto out_loi;
4566 		}
4567 		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4568 		size = min_t(u32, loi->size, SZ_16M);
4569 	}
4570 
4571 	path = btrfs_alloc_path();
4572 	if (!path) {
4573 		ret = -ENOMEM;
4574 		goto out;
4575 	}
4576 
4577 	inodes = init_data_container(size);
4578 	if (IS_ERR(inodes)) {
4579 		ret = PTR_ERR(inodes);
4580 		inodes = NULL;
4581 		goto out;
4582 	}
4583 
4584 	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4585 					  build_ino_list, inodes, ignore_offset);
4586 	if (ret == -EINVAL)
4587 		ret = -ENOENT;
4588 	if (ret < 0)
4589 		goto out;
4590 
4591 	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4592 			   size);
4593 	if (ret)
4594 		ret = -EFAULT;
4595 
4596 out:
4597 	btrfs_free_path(path);
4598 	kvfree(inodes);
4599 out_loi:
4600 	kfree(loi);
4601 
4602 	return ret;
4603 }
4604 
4605 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4606 			       struct btrfs_ioctl_balance_args *bargs)
4607 {
4608 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4609 
4610 	bargs->flags = bctl->flags;
4611 
4612 	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4613 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4614 	if (atomic_read(&fs_info->balance_pause_req))
4615 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4616 	if (atomic_read(&fs_info->balance_cancel_req))
4617 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4618 
4619 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4620 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4621 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4622 
4623 	spin_lock(&fs_info->balance_lock);
4624 	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4625 	spin_unlock(&fs_info->balance_lock);
4626 }
4627 
4628 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4629 {
4630 	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4631 	struct btrfs_fs_info *fs_info = root->fs_info;
4632 	struct btrfs_ioctl_balance_args *bargs;
4633 	struct btrfs_balance_control *bctl;
4634 	bool need_unlock; /* for mut. excl. ops lock */
4635 	int ret;
4636 
4637 	if (!capable(CAP_SYS_ADMIN))
4638 		return -EPERM;
4639 
4640 	ret = mnt_want_write_file(file);
4641 	if (ret)
4642 		return ret;
4643 
4644 again:
4645 	if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4646 		mutex_lock(&fs_info->balance_mutex);
4647 		need_unlock = true;
4648 		goto locked;
4649 	}
4650 
4651 	/*
4652 	 * mut. excl. ops lock is locked.  Three possibilities:
4653 	 *   (1) some other op is running
4654 	 *   (2) balance is running
4655 	 *   (3) balance is paused -- special case (think resume)
4656 	 */
4657 	mutex_lock(&fs_info->balance_mutex);
4658 	if (fs_info->balance_ctl) {
4659 		/* this is either (2) or (3) */
4660 		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4661 			mutex_unlock(&fs_info->balance_mutex);
4662 			/*
4663 			 * Lock released to allow other waiters to continue,
4664 			 * we'll reexamine the status again.
4665 			 */
4666 			mutex_lock(&fs_info->balance_mutex);
4667 
4668 			if (fs_info->balance_ctl &&
4669 			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4670 				/* this is (3) */
4671 				need_unlock = false;
4672 				goto locked;
4673 			}
4674 
4675 			mutex_unlock(&fs_info->balance_mutex);
4676 			goto again;
4677 		} else {
4678 			/* this is (2) */
4679 			mutex_unlock(&fs_info->balance_mutex);
4680 			ret = -EINPROGRESS;
4681 			goto out;
4682 		}
4683 	} else {
4684 		/* this is (1) */
4685 		mutex_unlock(&fs_info->balance_mutex);
4686 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4687 		goto out;
4688 	}
4689 
4690 locked:
4691 	BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4692 
4693 	if (arg) {
4694 		bargs = memdup_user(arg, sizeof(*bargs));
4695 		if (IS_ERR(bargs)) {
4696 			ret = PTR_ERR(bargs);
4697 			goto out_unlock;
4698 		}
4699 
4700 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4701 			if (!fs_info->balance_ctl) {
4702 				ret = -ENOTCONN;
4703 				goto out_bargs;
4704 			}
4705 
4706 			bctl = fs_info->balance_ctl;
4707 			spin_lock(&fs_info->balance_lock);
4708 			bctl->flags |= BTRFS_BALANCE_RESUME;
4709 			spin_unlock(&fs_info->balance_lock);
4710 
4711 			goto do_balance;
4712 		}
4713 	} else {
4714 		bargs = NULL;
4715 	}
4716 
4717 	if (fs_info->balance_ctl) {
4718 		ret = -EINPROGRESS;
4719 		goto out_bargs;
4720 	}
4721 
4722 	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4723 	if (!bctl) {
4724 		ret = -ENOMEM;
4725 		goto out_bargs;
4726 	}
4727 
4728 	if (arg) {
4729 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4730 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4731 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4732 
4733 		bctl->flags = bargs->flags;
4734 	} else {
4735 		/* balance everything - no filters */
4736 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4737 	}
4738 
4739 	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4740 		ret = -EINVAL;
4741 		goto out_bctl;
4742 	}
4743 
4744 do_balance:
4745 	/*
4746 	 * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
4747 	 * btrfs_balance.  bctl is freed in reset_balance_state, or, if
4748 	 * restriper was paused all the way until unmount, in free_fs_info.
4749 	 * The flag should be cleared after reset_balance_state.
4750 	 */
4751 	need_unlock = false;
4752 
4753 	ret = btrfs_balance(fs_info, bctl, bargs);
4754 	bctl = NULL;
4755 
4756 	if (arg) {
4757 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4758 			ret = -EFAULT;
4759 	}
4760 
4761 out_bctl:
4762 	kfree(bctl);
4763 out_bargs:
4764 	kfree(bargs);
4765 out_unlock:
4766 	mutex_unlock(&fs_info->balance_mutex);
4767 	if (need_unlock)
4768 		clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4769 out:
4770 	mnt_drop_write_file(file);
4771 	return ret;
4772 }
4773 
4774 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4775 {
4776 	if (!capable(CAP_SYS_ADMIN))
4777 		return -EPERM;
4778 
4779 	switch (cmd) {
4780 	case BTRFS_BALANCE_CTL_PAUSE:
4781 		return btrfs_pause_balance(fs_info);
4782 	case BTRFS_BALANCE_CTL_CANCEL:
4783 		return btrfs_cancel_balance(fs_info);
4784 	}
4785 
4786 	return -EINVAL;
4787 }
4788 
4789 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4790 					 void __user *arg)
4791 {
4792 	struct btrfs_ioctl_balance_args *bargs;
4793 	int ret = 0;
4794 
4795 	if (!capable(CAP_SYS_ADMIN))
4796 		return -EPERM;
4797 
4798 	mutex_lock(&fs_info->balance_mutex);
4799 	if (!fs_info->balance_ctl) {
4800 		ret = -ENOTCONN;
4801 		goto out;
4802 	}
4803 
4804 	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4805 	if (!bargs) {
4806 		ret = -ENOMEM;
4807 		goto out;
4808 	}
4809 
4810 	btrfs_update_ioctl_balance_args(fs_info, bargs);
4811 
4812 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4813 		ret = -EFAULT;
4814 
4815 	kfree(bargs);
4816 out:
4817 	mutex_unlock(&fs_info->balance_mutex);
4818 	return ret;
4819 }
4820 
4821 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4822 {
4823 	struct inode *inode = file_inode(file);
4824 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4825 	struct btrfs_ioctl_quota_ctl_args *sa;
4826 	int ret;
4827 
4828 	if (!capable(CAP_SYS_ADMIN))
4829 		return -EPERM;
4830 
4831 	ret = mnt_want_write_file(file);
4832 	if (ret)
4833 		return ret;
4834 
4835 	sa = memdup_user(arg, sizeof(*sa));
4836 	if (IS_ERR(sa)) {
4837 		ret = PTR_ERR(sa);
4838 		goto drop_write;
4839 	}
4840 
4841 	down_write(&fs_info->subvol_sem);
4842 
4843 	switch (sa->cmd) {
4844 	case BTRFS_QUOTA_CTL_ENABLE:
4845 		ret = btrfs_quota_enable(fs_info);
4846 		break;
4847 	case BTRFS_QUOTA_CTL_DISABLE:
4848 		ret = btrfs_quota_disable(fs_info);
4849 		break;
4850 	default:
4851 		ret = -EINVAL;
4852 		break;
4853 	}
4854 
4855 	kfree(sa);
4856 	up_write(&fs_info->subvol_sem);
4857 drop_write:
4858 	mnt_drop_write_file(file);
4859 	return ret;
4860 }
4861 
4862 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4863 {
4864 	struct inode *inode = file_inode(file);
4865 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4866 	struct btrfs_root *root = BTRFS_I(inode)->root;
4867 	struct btrfs_ioctl_qgroup_assign_args *sa;
4868 	struct btrfs_trans_handle *trans;
4869 	int ret;
4870 	int err;
4871 
4872 	if (!capable(CAP_SYS_ADMIN))
4873 		return -EPERM;
4874 
4875 	ret = mnt_want_write_file(file);
4876 	if (ret)
4877 		return ret;
4878 
4879 	sa = memdup_user(arg, sizeof(*sa));
4880 	if (IS_ERR(sa)) {
4881 		ret = PTR_ERR(sa);
4882 		goto drop_write;
4883 	}
4884 
4885 	trans = btrfs_join_transaction(root);
4886 	if (IS_ERR(trans)) {
4887 		ret = PTR_ERR(trans);
4888 		goto out;
4889 	}
4890 
4891 	if (sa->assign) {
4892 		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4893 	} else {
4894 		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4895 	}
4896 
4897 	/* update qgroup status and info */
4898 	err = btrfs_run_qgroups(trans);
4899 	if (err < 0)
4900 		btrfs_handle_fs_error(fs_info, err,
4901 				      "failed to update qgroup status and info");
4902 	err = btrfs_end_transaction(trans);
4903 	if (err && !ret)
4904 		ret = err;
4905 
4906 out:
4907 	kfree(sa);
4908 drop_write:
4909 	mnt_drop_write_file(file);
4910 	return ret;
4911 }
4912 
4913 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4914 {
4915 	struct inode *inode = file_inode(file);
4916 	struct btrfs_root *root = BTRFS_I(inode)->root;
4917 	struct btrfs_ioctl_qgroup_create_args *sa;
4918 	struct btrfs_trans_handle *trans;
4919 	int ret;
4920 	int err;
4921 
4922 	if (!capable(CAP_SYS_ADMIN))
4923 		return -EPERM;
4924 
4925 	ret = mnt_want_write_file(file);
4926 	if (ret)
4927 		return ret;
4928 
4929 	sa = memdup_user(arg, sizeof(*sa));
4930 	if (IS_ERR(sa)) {
4931 		ret = PTR_ERR(sa);
4932 		goto drop_write;
4933 	}
4934 
4935 	if (!sa->qgroupid) {
4936 		ret = -EINVAL;
4937 		goto out;
4938 	}
4939 
4940 	trans = btrfs_join_transaction(root);
4941 	if (IS_ERR(trans)) {
4942 		ret = PTR_ERR(trans);
4943 		goto out;
4944 	}
4945 
4946 	if (sa->create) {
4947 		ret = btrfs_create_qgroup(trans, sa->qgroupid);
4948 	} else {
4949 		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4950 	}
4951 
4952 	err = btrfs_end_transaction(trans);
4953 	if (err && !ret)
4954 		ret = err;
4955 
4956 out:
4957 	kfree(sa);
4958 drop_write:
4959 	mnt_drop_write_file(file);
4960 	return ret;
4961 }
4962 
4963 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4964 {
4965 	struct inode *inode = file_inode(file);
4966 	struct btrfs_root *root = BTRFS_I(inode)->root;
4967 	struct btrfs_ioctl_qgroup_limit_args *sa;
4968 	struct btrfs_trans_handle *trans;
4969 	int ret;
4970 	int err;
4971 	u64 qgroupid;
4972 
4973 	if (!capable(CAP_SYS_ADMIN))
4974 		return -EPERM;
4975 
4976 	ret = mnt_want_write_file(file);
4977 	if (ret)
4978 		return ret;
4979 
4980 	sa = memdup_user(arg, sizeof(*sa));
4981 	if (IS_ERR(sa)) {
4982 		ret = PTR_ERR(sa);
4983 		goto drop_write;
4984 	}
4985 
4986 	trans = btrfs_join_transaction(root);
4987 	if (IS_ERR(trans)) {
4988 		ret = PTR_ERR(trans);
4989 		goto out;
4990 	}
4991 
4992 	qgroupid = sa->qgroupid;
4993 	if (!qgroupid) {
4994 		/* take the current subvol as qgroup */
4995 		qgroupid = root->root_key.objectid;
4996 	}
4997 
4998 	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4999 
5000 	err = btrfs_end_transaction(trans);
5001 	if (err && !ret)
5002 		ret = err;
5003 
5004 out:
5005 	kfree(sa);
5006 drop_write:
5007 	mnt_drop_write_file(file);
5008 	return ret;
5009 }
5010 
5011 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5012 {
5013 	struct inode *inode = file_inode(file);
5014 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5015 	struct btrfs_ioctl_quota_rescan_args *qsa;
5016 	int ret;
5017 
5018 	if (!capable(CAP_SYS_ADMIN))
5019 		return -EPERM;
5020 
5021 	ret = mnt_want_write_file(file);
5022 	if (ret)
5023 		return ret;
5024 
5025 	qsa = memdup_user(arg, sizeof(*qsa));
5026 	if (IS_ERR(qsa)) {
5027 		ret = PTR_ERR(qsa);
5028 		goto drop_write;
5029 	}
5030 
5031 	if (qsa->flags) {
5032 		ret = -EINVAL;
5033 		goto out;
5034 	}
5035 
5036 	ret = btrfs_qgroup_rescan(fs_info);
5037 
5038 out:
5039 	kfree(qsa);
5040 drop_write:
5041 	mnt_drop_write_file(file);
5042 	return ret;
5043 }
5044 
5045 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5046 {
5047 	struct inode *inode = file_inode(file);
5048 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5049 	struct btrfs_ioctl_quota_rescan_args *qsa;
5050 	int ret = 0;
5051 
5052 	if (!capable(CAP_SYS_ADMIN))
5053 		return -EPERM;
5054 
5055 	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5056 	if (!qsa)
5057 		return -ENOMEM;
5058 
5059 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5060 		qsa->flags = 1;
5061 		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5062 	}
5063 
5064 	if (copy_to_user(arg, qsa, sizeof(*qsa)))
5065 		ret = -EFAULT;
5066 
5067 	kfree(qsa);
5068 	return ret;
5069 }
5070 
5071 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5072 {
5073 	struct inode *inode = file_inode(file);
5074 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5075 
5076 	if (!capable(CAP_SYS_ADMIN))
5077 		return -EPERM;
5078 
5079 	return btrfs_qgroup_wait_for_completion(fs_info, true);
5080 }
5081 
5082 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5083 					    struct btrfs_ioctl_received_subvol_args *sa)
5084 {
5085 	struct inode *inode = file_inode(file);
5086 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5087 	struct btrfs_root *root = BTRFS_I(inode)->root;
5088 	struct btrfs_root_item *root_item = &root->root_item;
5089 	struct btrfs_trans_handle *trans;
5090 	struct timespec64 ct = current_time(inode);
5091 	int ret = 0;
5092 	int received_uuid_changed;
5093 
5094 	if (!inode_owner_or_capable(inode))
5095 		return -EPERM;
5096 
5097 	ret = mnt_want_write_file(file);
5098 	if (ret < 0)
5099 		return ret;
5100 
5101 	down_write(&fs_info->subvol_sem);
5102 
5103 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5104 		ret = -EINVAL;
5105 		goto out;
5106 	}
5107 
5108 	if (btrfs_root_readonly(root)) {
5109 		ret = -EROFS;
5110 		goto out;
5111 	}
5112 
5113 	/*
5114 	 * 1 - root item
5115 	 * 2 - uuid items (received uuid + subvol uuid)
5116 	 */
5117 	trans = btrfs_start_transaction(root, 3);
5118 	if (IS_ERR(trans)) {
5119 		ret = PTR_ERR(trans);
5120 		trans = NULL;
5121 		goto out;
5122 	}
5123 
5124 	sa->rtransid = trans->transid;
5125 	sa->rtime.sec = ct.tv_sec;
5126 	sa->rtime.nsec = ct.tv_nsec;
5127 
5128 	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5129 				       BTRFS_UUID_SIZE);
5130 	if (received_uuid_changed &&
5131 	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
5132 		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5133 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5134 					  root->root_key.objectid);
5135 		if (ret && ret != -ENOENT) {
5136 		        btrfs_abort_transaction(trans, ret);
5137 		        btrfs_end_transaction(trans);
5138 		        goto out;
5139 		}
5140 	}
5141 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5142 	btrfs_set_root_stransid(root_item, sa->stransid);
5143 	btrfs_set_root_rtransid(root_item, sa->rtransid);
5144 	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5145 	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5146 	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5147 	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5148 
5149 	ret = btrfs_update_root(trans, fs_info->tree_root,
5150 				&root->root_key, &root->root_item);
5151 	if (ret < 0) {
5152 		btrfs_end_transaction(trans);
5153 		goto out;
5154 	}
5155 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5156 		ret = btrfs_uuid_tree_add(trans, sa->uuid,
5157 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5158 					  root->root_key.objectid);
5159 		if (ret < 0 && ret != -EEXIST) {
5160 			btrfs_abort_transaction(trans, ret);
5161 			btrfs_end_transaction(trans);
5162 			goto out;
5163 		}
5164 	}
5165 	ret = btrfs_commit_transaction(trans);
5166 out:
5167 	up_write(&fs_info->subvol_sem);
5168 	mnt_drop_write_file(file);
5169 	return ret;
5170 }
5171 
5172 #ifdef CONFIG_64BIT
5173 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5174 						void __user *arg)
5175 {
5176 	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5177 	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5178 	int ret = 0;
5179 
5180 	args32 = memdup_user(arg, sizeof(*args32));
5181 	if (IS_ERR(args32))
5182 		return PTR_ERR(args32);
5183 
5184 	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5185 	if (!args64) {
5186 		ret = -ENOMEM;
5187 		goto out;
5188 	}
5189 
5190 	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5191 	args64->stransid = args32->stransid;
5192 	args64->rtransid = args32->rtransid;
5193 	args64->stime.sec = args32->stime.sec;
5194 	args64->stime.nsec = args32->stime.nsec;
5195 	args64->rtime.sec = args32->rtime.sec;
5196 	args64->rtime.nsec = args32->rtime.nsec;
5197 	args64->flags = args32->flags;
5198 
5199 	ret = _btrfs_ioctl_set_received_subvol(file, args64);
5200 	if (ret)
5201 		goto out;
5202 
5203 	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5204 	args32->stransid = args64->stransid;
5205 	args32->rtransid = args64->rtransid;
5206 	args32->stime.sec = args64->stime.sec;
5207 	args32->stime.nsec = args64->stime.nsec;
5208 	args32->rtime.sec = args64->rtime.sec;
5209 	args32->rtime.nsec = args64->rtime.nsec;
5210 	args32->flags = args64->flags;
5211 
5212 	ret = copy_to_user(arg, args32, sizeof(*args32));
5213 	if (ret)
5214 		ret = -EFAULT;
5215 
5216 out:
5217 	kfree(args32);
5218 	kfree(args64);
5219 	return ret;
5220 }
5221 #endif
5222 
5223 static long btrfs_ioctl_set_received_subvol(struct file *file,
5224 					    void __user *arg)
5225 {
5226 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
5227 	int ret = 0;
5228 
5229 	sa = memdup_user(arg, sizeof(*sa));
5230 	if (IS_ERR(sa))
5231 		return PTR_ERR(sa);
5232 
5233 	ret = _btrfs_ioctl_set_received_subvol(file, sa);
5234 
5235 	if (ret)
5236 		goto out;
5237 
5238 	ret = copy_to_user(arg, sa, sizeof(*sa));
5239 	if (ret)
5240 		ret = -EFAULT;
5241 
5242 out:
5243 	kfree(sa);
5244 	return ret;
5245 }
5246 
5247 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5248 {
5249 	struct inode *inode = file_inode(file);
5250 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5251 	size_t len;
5252 	int ret;
5253 	char label[BTRFS_LABEL_SIZE];
5254 
5255 	spin_lock(&fs_info->super_lock);
5256 	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5257 	spin_unlock(&fs_info->super_lock);
5258 
5259 	len = strnlen(label, BTRFS_LABEL_SIZE);
5260 
5261 	if (len == BTRFS_LABEL_SIZE) {
5262 		btrfs_warn(fs_info,
5263 			   "label is too long, return the first %zu bytes",
5264 			   --len);
5265 	}
5266 
5267 	ret = copy_to_user(arg, label, len);
5268 
5269 	return ret ? -EFAULT : 0;
5270 }
5271 
5272 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5273 {
5274 	struct inode *inode = file_inode(file);
5275 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5276 	struct btrfs_root *root = BTRFS_I(inode)->root;
5277 	struct btrfs_super_block *super_block = fs_info->super_copy;
5278 	struct btrfs_trans_handle *trans;
5279 	char label[BTRFS_LABEL_SIZE];
5280 	int ret;
5281 
5282 	if (!capable(CAP_SYS_ADMIN))
5283 		return -EPERM;
5284 
5285 	if (copy_from_user(label, arg, sizeof(label)))
5286 		return -EFAULT;
5287 
5288 	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5289 		btrfs_err(fs_info,
5290 			  "unable to set label with more than %d bytes",
5291 			  BTRFS_LABEL_SIZE - 1);
5292 		return -EINVAL;
5293 	}
5294 
5295 	ret = mnt_want_write_file(file);
5296 	if (ret)
5297 		return ret;
5298 
5299 	trans = btrfs_start_transaction(root, 0);
5300 	if (IS_ERR(trans)) {
5301 		ret = PTR_ERR(trans);
5302 		goto out_unlock;
5303 	}
5304 
5305 	spin_lock(&fs_info->super_lock);
5306 	strcpy(super_block->label, label);
5307 	spin_unlock(&fs_info->super_lock);
5308 	ret = btrfs_commit_transaction(trans);
5309 
5310 out_unlock:
5311 	mnt_drop_write_file(file);
5312 	return ret;
5313 }
5314 
5315 #define INIT_FEATURE_FLAGS(suffix) \
5316 	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5317 	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5318 	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5319 
5320 int btrfs_ioctl_get_supported_features(void __user *arg)
5321 {
5322 	static const struct btrfs_ioctl_feature_flags features[3] = {
5323 		INIT_FEATURE_FLAGS(SUPP),
5324 		INIT_FEATURE_FLAGS(SAFE_SET),
5325 		INIT_FEATURE_FLAGS(SAFE_CLEAR)
5326 	};
5327 
5328 	if (copy_to_user(arg, &features, sizeof(features)))
5329 		return -EFAULT;
5330 
5331 	return 0;
5332 }
5333 
5334 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5335 {
5336 	struct inode *inode = file_inode(file);
5337 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5338 	struct btrfs_super_block *super_block = fs_info->super_copy;
5339 	struct btrfs_ioctl_feature_flags features;
5340 
5341 	features.compat_flags = btrfs_super_compat_flags(super_block);
5342 	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5343 	features.incompat_flags = btrfs_super_incompat_flags(super_block);
5344 
5345 	if (copy_to_user(arg, &features, sizeof(features)))
5346 		return -EFAULT;
5347 
5348 	return 0;
5349 }
5350 
5351 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5352 			      enum btrfs_feature_set set,
5353 			      u64 change_mask, u64 flags, u64 supported_flags,
5354 			      u64 safe_set, u64 safe_clear)
5355 {
5356 	const char *type = btrfs_feature_set_names[set];
5357 	char *names;
5358 	u64 disallowed, unsupported;
5359 	u64 set_mask = flags & change_mask;
5360 	u64 clear_mask = ~flags & change_mask;
5361 
5362 	unsupported = set_mask & ~supported_flags;
5363 	if (unsupported) {
5364 		names = btrfs_printable_features(set, unsupported);
5365 		if (names) {
5366 			btrfs_warn(fs_info,
5367 				   "this kernel does not support the %s feature bit%s",
5368 				   names, strchr(names, ',') ? "s" : "");
5369 			kfree(names);
5370 		} else
5371 			btrfs_warn(fs_info,
5372 				   "this kernel does not support %s bits 0x%llx",
5373 				   type, unsupported);
5374 		return -EOPNOTSUPP;
5375 	}
5376 
5377 	disallowed = set_mask & ~safe_set;
5378 	if (disallowed) {
5379 		names = btrfs_printable_features(set, disallowed);
5380 		if (names) {
5381 			btrfs_warn(fs_info,
5382 				   "can't set the %s feature bit%s while mounted",
5383 				   names, strchr(names, ',') ? "s" : "");
5384 			kfree(names);
5385 		} else
5386 			btrfs_warn(fs_info,
5387 				   "can't set %s bits 0x%llx while mounted",
5388 				   type, disallowed);
5389 		return -EPERM;
5390 	}
5391 
5392 	disallowed = clear_mask & ~safe_clear;
5393 	if (disallowed) {
5394 		names = btrfs_printable_features(set, disallowed);
5395 		if (names) {
5396 			btrfs_warn(fs_info,
5397 				   "can't clear the %s feature bit%s while mounted",
5398 				   names, strchr(names, ',') ? "s" : "");
5399 			kfree(names);
5400 		} else
5401 			btrfs_warn(fs_info,
5402 				   "can't clear %s bits 0x%llx while mounted",
5403 				   type, disallowed);
5404 		return -EPERM;
5405 	}
5406 
5407 	return 0;
5408 }
5409 
5410 #define check_feature(fs_info, change_mask, flags, mask_base)	\
5411 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
5412 		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
5413 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
5414 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5415 
5416 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5417 {
5418 	struct inode *inode = file_inode(file);
5419 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5420 	struct btrfs_root *root = BTRFS_I(inode)->root;
5421 	struct btrfs_super_block *super_block = fs_info->super_copy;
5422 	struct btrfs_ioctl_feature_flags flags[2];
5423 	struct btrfs_trans_handle *trans;
5424 	u64 newflags;
5425 	int ret;
5426 
5427 	if (!capable(CAP_SYS_ADMIN))
5428 		return -EPERM;
5429 
5430 	if (copy_from_user(flags, arg, sizeof(flags)))
5431 		return -EFAULT;
5432 
5433 	/* Nothing to do */
5434 	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5435 	    !flags[0].incompat_flags)
5436 		return 0;
5437 
5438 	ret = check_feature(fs_info, flags[0].compat_flags,
5439 			    flags[1].compat_flags, COMPAT);
5440 	if (ret)
5441 		return ret;
5442 
5443 	ret = check_feature(fs_info, flags[0].compat_ro_flags,
5444 			    flags[1].compat_ro_flags, COMPAT_RO);
5445 	if (ret)
5446 		return ret;
5447 
5448 	ret = check_feature(fs_info, flags[0].incompat_flags,
5449 			    flags[1].incompat_flags, INCOMPAT);
5450 	if (ret)
5451 		return ret;
5452 
5453 	ret = mnt_want_write_file(file);
5454 	if (ret)
5455 		return ret;
5456 
5457 	trans = btrfs_start_transaction(root, 0);
5458 	if (IS_ERR(trans)) {
5459 		ret = PTR_ERR(trans);
5460 		goto out_drop_write;
5461 	}
5462 
5463 	spin_lock(&fs_info->super_lock);
5464 	newflags = btrfs_super_compat_flags(super_block);
5465 	newflags |= flags[0].compat_flags & flags[1].compat_flags;
5466 	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5467 	btrfs_set_super_compat_flags(super_block, newflags);
5468 
5469 	newflags = btrfs_super_compat_ro_flags(super_block);
5470 	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5471 	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5472 	btrfs_set_super_compat_ro_flags(super_block, newflags);
5473 
5474 	newflags = btrfs_super_incompat_flags(super_block);
5475 	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5476 	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5477 	btrfs_set_super_incompat_flags(super_block, newflags);
5478 	spin_unlock(&fs_info->super_lock);
5479 
5480 	ret = btrfs_commit_transaction(trans);
5481 out_drop_write:
5482 	mnt_drop_write_file(file);
5483 
5484 	return ret;
5485 }
5486 
5487 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5488 {
5489 	struct btrfs_ioctl_send_args *arg;
5490 	int ret;
5491 
5492 	if (compat) {
5493 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5494 		struct btrfs_ioctl_send_args_32 args32;
5495 
5496 		ret = copy_from_user(&args32, argp, sizeof(args32));
5497 		if (ret)
5498 			return -EFAULT;
5499 		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5500 		if (!arg)
5501 			return -ENOMEM;
5502 		arg->send_fd = args32.send_fd;
5503 		arg->clone_sources_count = args32.clone_sources_count;
5504 		arg->clone_sources = compat_ptr(args32.clone_sources);
5505 		arg->parent_root = args32.parent_root;
5506 		arg->flags = args32.flags;
5507 		memcpy(arg->reserved, args32.reserved,
5508 		       sizeof(args32.reserved));
5509 #else
5510 		return -ENOTTY;
5511 #endif
5512 	} else {
5513 		arg = memdup_user(argp, sizeof(*arg));
5514 		if (IS_ERR(arg))
5515 			return PTR_ERR(arg);
5516 	}
5517 	ret = btrfs_ioctl_send(file, arg);
5518 	kfree(arg);
5519 	return ret;
5520 }
5521 
5522 long btrfs_ioctl(struct file *file, unsigned int
5523 		cmd, unsigned long arg)
5524 {
5525 	struct inode *inode = file_inode(file);
5526 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5527 	struct btrfs_root *root = BTRFS_I(inode)->root;
5528 	void __user *argp = (void __user *)arg;
5529 
5530 	switch (cmd) {
5531 	case FS_IOC_GETFLAGS:
5532 		return btrfs_ioctl_getflags(file, argp);
5533 	case FS_IOC_SETFLAGS:
5534 		return btrfs_ioctl_setflags(file, argp);
5535 	case FS_IOC_GETVERSION:
5536 		return btrfs_ioctl_getversion(file, argp);
5537 	case FITRIM:
5538 		return btrfs_ioctl_fitrim(file, argp);
5539 	case BTRFS_IOC_SNAP_CREATE:
5540 		return btrfs_ioctl_snap_create(file, argp, 0);
5541 	case BTRFS_IOC_SNAP_CREATE_V2:
5542 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
5543 	case BTRFS_IOC_SUBVOL_CREATE:
5544 		return btrfs_ioctl_snap_create(file, argp, 1);
5545 	case BTRFS_IOC_SUBVOL_CREATE_V2:
5546 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
5547 	case BTRFS_IOC_SNAP_DESTROY:
5548 		return btrfs_ioctl_snap_destroy(file, argp);
5549 	case BTRFS_IOC_SUBVOL_GETFLAGS:
5550 		return btrfs_ioctl_subvol_getflags(file, argp);
5551 	case BTRFS_IOC_SUBVOL_SETFLAGS:
5552 		return btrfs_ioctl_subvol_setflags(file, argp);
5553 	case BTRFS_IOC_DEFAULT_SUBVOL:
5554 		return btrfs_ioctl_default_subvol(file, argp);
5555 	case BTRFS_IOC_DEFRAG:
5556 		return btrfs_ioctl_defrag(file, NULL);
5557 	case BTRFS_IOC_DEFRAG_RANGE:
5558 		return btrfs_ioctl_defrag(file, argp);
5559 	case BTRFS_IOC_RESIZE:
5560 		return btrfs_ioctl_resize(file, argp);
5561 	case BTRFS_IOC_ADD_DEV:
5562 		return btrfs_ioctl_add_dev(fs_info, argp);
5563 	case BTRFS_IOC_RM_DEV:
5564 		return btrfs_ioctl_rm_dev(file, argp);
5565 	case BTRFS_IOC_RM_DEV_V2:
5566 		return btrfs_ioctl_rm_dev_v2(file, argp);
5567 	case BTRFS_IOC_FS_INFO:
5568 		return btrfs_ioctl_fs_info(fs_info, argp);
5569 	case BTRFS_IOC_DEV_INFO:
5570 		return btrfs_ioctl_dev_info(fs_info, argp);
5571 	case BTRFS_IOC_BALANCE:
5572 		return btrfs_ioctl_balance(file, NULL);
5573 	case BTRFS_IOC_TREE_SEARCH:
5574 		return btrfs_ioctl_tree_search(file, argp);
5575 	case BTRFS_IOC_TREE_SEARCH_V2:
5576 		return btrfs_ioctl_tree_search_v2(file, argp);
5577 	case BTRFS_IOC_INO_LOOKUP:
5578 		return btrfs_ioctl_ino_lookup(file, argp);
5579 	case BTRFS_IOC_INO_PATHS:
5580 		return btrfs_ioctl_ino_to_path(root, argp);
5581 	case BTRFS_IOC_LOGICAL_INO:
5582 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5583 	case BTRFS_IOC_LOGICAL_INO_V2:
5584 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5585 	case BTRFS_IOC_SPACE_INFO:
5586 		return btrfs_ioctl_space_info(fs_info, argp);
5587 	case BTRFS_IOC_SYNC: {
5588 		int ret;
5589 
5590 		ret = btrfs_start_delalloc_roots(fs_info, -1);
5591 		if (ret)
5592 			return ret;
5593 		ret = btrfs_sync_fs(inode->i_sb, 1);
5594 		/*
5595 		 * The transaction thread may want to do more work,
5596 		 * namely it pokes the cleaner kthread that will start
5597 		 * processing uncleaned subvols.
5598 		 */
5599 		wake_up_process(fs_info->transaction_kthread);
5600 		return ret;
5601 	}
5602 	case BTRFS_IOC_START_SYNC:
5603 		return btrfs_ioctl_start_sync(root, argp);
5604 	case BTRFS_IOC_WAIT_SYNC:
5605 		return btrfs_ioctl_wait_sync(fs_info, argp);
5606 	case BTRFS_IOC_SCRUB:
5607 		return btrfs_ioctl_scrub(file, argp);
5608 	case BTRFS_IOC_SCRUB_CANCEL:
5609 		return btrfs_ioctl_scrub_cancel(fs_info);
5610 	case BTRFS_IOC_SCRUB_PROGRESS:
5611 		return btrfs_ioctl_scrub_progress(fs_info, argp);
5612 	case BTRFS_IOC_BALANCE_V2:
5613 		return btrfs_ioctl_balance(file, argp);
5614 	case BTRFS_IOC_BALANCE_CTL:
5615 		return btrfs_ioctl_balance_ctl(fs_info, arg);
5616 	case BTRFS_IOC_BALANCE_PROGRESS:
5617 		return btrfs_ioctl_balance_progress(fs_info, argp);
5618 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5619 		return btrfs_ioctl_set_received_subvol(file, argp);
5620 #ifdef CONFIG_64BIT
5621 	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5622 		return btrfs_ioctl_set_received_subvol_32(file, argp);
5623 #endif
5624 	case BTRFS_IOC_SEND:
5625 		return _btrfs_ioctl_send(file, argp, false);
5626 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5627 	case BTRFS_IOC_SEND_32:
5628 		return _btrfs_ioctl_send(file, argp, true);
5629 #endif
5630 	case BTRFS_IOC_GET_DEV_STATS:
5631 		return btrfs_ioctl_get_dev_stats(fs_info, argp);
5632 	case BTRFS_IOC_QUOTA_CTL:
5633 		return btrfs_ioctl_quota_ctl(file, argp);
5634 	case BTRFS_IOC_QGROUP_ASSIGN:
5635 		return btrfs_ioctl_qgroup_assign(file, argp);
5636 	case BTRFS_IOC_QGROUP_CREATE:
5637 		return btrfs_ioctl_qgroup_create(file, argp);
5638 	case BTRFS_IOC_QGROUP_LIMIT:
5639 		return btrfs_ioctl_qgroup_limit(file, argp);
5640 	case BTRFS_IOC_QUOTA_RESCAN:
5641 		return btrfs_ioctl_quota_rescan(file, argp);
5642 	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5643 		return btrfs_ioctl_quota_rescan_status(file, argp);
5644 	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5645 		return btrfs_ioctl_quota_rescan_wait(file, argp);
5646 	case BTRFS_IOC_DEV_REPLACE:
5647 		return btrfs_ioctl_dev_replace(fs_info, argp);
5648 	case BTRFS_IOC_GET_FSLABEL:
5649 		return btrfs_ioctl_get_fslabel(file, argp);
5650 	case BTRFS_IOC_SET_FSLABEL:
5651 		return btrfs_ioctl_set_fslabel(file, argp);
5652 	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5653 		return btrfs_ioctl_get_supported_features(argp);
5654 	case BTRFS_IOC_GET_FEATURES:
5655 		return btrfs_ioctl_get_features(file, argp);
5656 	case BTRFS_IOC_SET_FEATURES:
5657 		return btrfs_ioctl_set_features(file, argp);
5658 	case FS_IOC_FSGETXATTR:
5659 		return btrfs_ioctl_fsgetxattr(file, argp);
5660 	case FS_IOC_FSSETXATTR:
5661 		return btrfs_ioctl_fssetxattr(file, argp);
5662 	case BTRFS_IOC_GET_SUBVOL_INFO:
5663 		return btrfs_ioctl_get_subvol_info(file, argp);
5664 	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5665 		return btrfs_ioctl_get_subvol_rootref(file, argp);
5666 	case BTRFS_IOC_INO_LOOKUP_USER:
5667 		return btrfs_ioctl_ino_lookup_user(file, argp);
5668 	}
5669 
5670 	return -ENOTTY;
5671 }
5672 
5673 #ifdef CONFIG_COMPAT
5674 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5675 {
5676 	/*
5677 	 * These all access 32-bit values anyway so no further
5678 	 * handling is necessary.
5679 	 */
5680 	switch (cmd) {
5681 	case FS_IOC32_GETFLAGS:
5682 		cmd = FS_IOC_GETFLAGS;
5683 		break;
5684 	case FS_IOC32_SETFLAGS:
5685 		cmd = FS_IOC_SETFLAGS;
5686 		break;
5687 	case FS_IOC32_GETVERSION:
5688 		cmd = FS_IOC_GETVERSION;
5689 		break;
5690 	}
5691 
5692 	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5693 }
5694 #endif
5695