xref: /openbmc/linux/fs/btrfs/ioctl.c (revision b5f184fbdb03b4fcc1141de34dd5ec964ca5d99e)
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 "export.h"
32 #include "transaction.h"
33 #include "btrfs_inode.h"
34 #include "print-tree.h"
35 #include "volumes.h"
36 #include "locking.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 #include "space-info.h"
47 #include "delalloc-space.h"
48 #include "block-group.h"
49 
50 #ifdef CONFIG_64BIT
51 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
52  * structures are incorrect, as the timespec structure from userspace
53  * is 4 bytes too small. We define these alternatives here to teach
54  * the kernel about the 32-bit struct packing.
55  */
56 struct btrfs_ioctl_timespec_32 {
57 	__u64 sec;
58 	__u32 nsec;
59 } __attribute__ ((__packed__));
60 
61 struct btrfs_ioctl_received_subvol_args_32 {
62 	char	uuid[BTRFS_UUID_SIZE];	/* in */
63 	__u64	stransid;		/* in */
64 	__u64	rtransid;		/* out */
65 	struct btrfs_ioctl_timespec_32 stime; /* in */
66 	struct btrfs_ioctl_timespec_32 rtime; /* out */
67 	__u64	flags;			/* in */
68 	__u64	reserved[16];		/* in */
69 } __attribute__ ((__packed__));
70 
71 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
72 				struct btrfs_ioctl_received_subvol_args_32)
73 #endif
74 
75 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
76 struct btrfs_ioctl_send_args_32 {
77 	__s64 send_fd;			/* in */
78 	__u64 clone_sources_count;	/* in */
79 	compat_uptr_t clone_sources;	/* in */
80 	__u64 parent_root;		/* in */
81 	__u64 flags;			/* in */
82 	__u64 reserved[4];		/* in */
83 } __attribute__ ((__packed__));
84 
85 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
86 			       struct btrfs_ioctl_send_args_32)
87 #endif
88 
89 /* Mask out flags that are inappropriate for the given type of inode. */
90 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
91 		unsigned int flags)
92 {
93 	if (S_ISDIR(inode->i_mode))
94 		return flags;
95 	else if (S_ISREG(inode->i_mode))
96 		return flags & ~FS_DIRSYNC_FL;
97 	else
98 		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
99 }
100 
101 /*
102  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
103  * ioctl.
104  */
105 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
106 {
107 	unsigned int iflags = 0;
108 
109 	if (flags & BTRFS_INODE_SYNC)
110 		iflags |= FS_SYNC_FL;
111 	if (flags & BTRFS_INODE_IMMUTABLE)
112 		iflags |= FS_IMMUTABLE_FL;
113 	if (flags & BTRFS_INODE_APPEND)
114 		iflags |= FS_APPEND_FL;
115 	if (flags & BTRFS_INODE_NODUMP)
116 		iflags |= FS_NODUMP_FL;
117 	if (flags & BTRFS_INODE_NOATIME)
118 		iflags |= FS_NOATIME_FL;
119 	if (flags & BTRFS_INODE_DIRSYNC)
120 		iflags |= FS_DIRSYNC_FL;
121 	if (flags & BTRFS_INODE_NODATACOW)
122 		iflags |= FS_NOCOW_FL;
123 
124 	if (flags & BTRFS_INODE_NOCOMPRESS)
125 		iflags |= FS_NOCOMP_FL;
126 	else if (flags & BTRFS_INODE_COMPRESS)
127 		iflags |= FS_COMPR_FL;
128 
129 	return iflags;
130 }
131 
132 /*
133  * Update inode->i_flags based on the btrfs internal flags.
134  */
135 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
136 {
137 	struct btrfs_inode *binode = BTRFS_I(inode);
138 	unsigned int new_fl = 0;
139 
140 	if (binode->flags & BTRFS_INODE_SYNC)
141 		new_fl |= S_SYNC;
142 	if (binode->flags & BTRFS_INODE_IMMUTABLE)
143 		new_fl |= S_IMMUTABLE;
144 	if (binode->flags & BTRFS_INODE_APPEND)
145 		new_fl |= S_APPEND;
146 	if (binode->flags & BTRFS_INODE_NOATIME)
147 		new_fl |= S_NOATIME;
148 	if (binode->flags & BTRFS_INODE_DIRSYNC)
149 		new_fl |= S_DIRSYNC;
150 
151 	set_mask_bits(&inode->i_flags,
152 		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
153 		      new_fl);
154 }
155 
156 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
157 {
158 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
159 	unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
160 
161 	if (copy_to_user(arg, &flags, sizeof(flags)))
162 		return -EFAULT;
163 	return 0;
164 }
165 
166 /*
167  * Check if @flags are a supported and valid set of FS_*_FL flags and that
168  * the old and new flags are not conflicting
169  */
170 static int check_fsflags(unsigned int old_flags, unsigned int flags)
171 {
172 	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
173 		      FS_NOATIME_FL | FS_NODUMP_FL | \
174 		      FS_SYNC_FL | FS_DIRSYNC_FL | \
175 		      FS_NOCOMP_FL | FS_COMPR_FL |
176 		      FS_NOCOW_FL))
177 		return -EOPNOTSUPP;
178 
179 	/* COMPR and NOCOMP on new/old are valid */
180 	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
181 		return -EINVAL;
182 
183 	if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
184 		return -EINVAL;
185 
186 	/* NOCOW and compression options are mutually exclusive */
187 	if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
188 		return -EINVAL;
189 	if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
190 		return -EINVAL;
191 
192 	return 0;
193 }
194 
195 static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
196 				    unsigned int flags)
197 {
198 	if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
199 		return -EPERM;
200 
201 	return 0;
202 }
203 
204 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
205 {
206 	struct inode *inode = file_inode(file);
207 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
208 	struct btrfs_inode *binode = BTRFS_I(inode);
209 	struct btrfs_root *root = binode->root;
210 	struct btrfs_trans_handle *trans;
211 	unsigned int fsflags, old_fsflags;
212 	int ret;
213 	const char *comp = NULL;
214 	u32 binode_flags;
215 
216 	if (!inode_owner_or_capable(inode))
217 		return -EPERM;
218 
219 	if (btrfs_root_readonly(root))
220 		return -EROFS;
221 
222 	if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
223 		return -EFAULT;
224 
225 	ret = mnt_want_write_file(file);
226 	if (ret)
227 		return ret;
228 
229 	inode_lock(inode);
230 	fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
231 	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
232 
233 	ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags);
234 	if (ret)
235 		goto out_unlock;
236 
237 	ret = check_fsflags(old_fsflags, fsflags);
238 	if (ret)
239 		goto out_unlock;
240 
241 	ret = check_fsflags_compatible(fs_info, fsflags);
242 	if (ret)
243 		goto out_unlock;
244 
245 	binode_flags = binode->flags;
246 	if (fsflags & FS_SYNC_FL)
247 		binode_flags |= BTRFS_INODE_SYNC;
248 	else
249 		binode_flags &= ~BTRFS_INODE_SYNC;
250 	if (fsflags & FS_IMMUTABLE_FL)
251 		binode_flags |= BTRFS_INODE_IMMUTABLE;
252 	else
253 		binode_flags &= ~BTRFS_INODE_IMMUTABLE;
254 	if (fsflags & FS_APPEND_FL)
255 		binode_flags |= BTRFS_INODE_APPEND;
256 	else
257 		binode_flags &= ~BTRFS_INODE_APPEND;
258 	if (fsflags & FS_NODUMP_FL)
259 		binode_flags |= BTRFS_INODE_NODUMP;
260 	else
261 		binode_flags &= ~BTRFS_INODE_NODUMP;
262 	if (fsflags & FS_NOATIME_FL)
263 		binode_flags |= BTRFS_INODE_NOATIME;
264 	else
265 		binode_flags &= ~BTRFS_INODE_NOATIME;
266 	if (fsflags & FS_DIRSYNC_FL)
267 		binode_flags |= BTRFS_INODE_DIRSYNC;
268 	else
269 		binode_flags &= ~BTRFS_INODE_DIRSYNC;
270 	if (fsflags & FS_NOCOW_FL) {
271 		if (S_ISREG(inode->i_mode)) {
272 			/*
273 			 * It's safe to turn csums off here, no extents exist.
274 			 * Otherwise we want the flag to reflect the real COW
275 			 * status of the file and will not set it.
276 			 */
277 			if (inode->i_size == 0)
278 				binode_flags |= BTRFS_INODE_NODATACOW |
279 						BTRFS_INODE_NODATASUM;
280 		} else {
281 			binode_flags |= BTRFS_INODE_NODATACOW;
282 		}
283 	} else {
284 		/*
285 		 * Revert back under same assumptions as above
286 		 */
287 		if (S_ISREG(inode->i_mode)) {
288 			if (inode->i_size == 0)
289 				binode_flags &= ~(BTRFS_INODE_NODATACOW |
290 						  BTRFS_INODE_NODATASUM);
291 		} else {
292 			binode_flags &= ~BTRFS_INODE_NODATACOW;
293 		}
294 	}
295 
296 	/*
297 	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
298 	 * flag may be changed automatically if compression code won't make
299 	 * things smaller.
300 	 */
301 	if (fsflags & FS_NOCOMP_FL) {
302 		binode_flags &= ~BTRFS_INODE_COMPRESS;
303 		binode_flags |= BTRFS_INODE_NOCOMPRESS;
304 	} else if (fsflags & FS_COMPR_FL) {
305 
306 		if (IS_SWAPFILE(inode)) {
307 			ret = -ETXTBSY;
308 			goto out_unlock;
309 		}
310 
311 		binode_flags |= BTRFS_INODE_COMPRESS;
312 		binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
313 
314 		comp = btrfs_compress_type2str(fs_info->compress_type);
315 		if (!comp || comp[0] == 0)
316 			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
317 	} else {
318 		binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
319 	}
320 
321 	/*
322 	 * 1 for inode item
323 	 * 2 for properties
324 	 */
325 	trans = btrfs_start_transaction(root, 3);
326 	if (IS_ERR(trans)) {
327 		ret = PTR_ERR(trans);
328 		goto out_unlock;
329 	}
330 
331 	if (comp) {
332 		ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
333 				     strlen(comp), 0);
334 		if (ret) {
335 			btrfs_abort_transaction(trans, ret);
336 			goto out_end_trans;
337 		}
338 	} else {
339 		ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
340 				     0, 0);
341 		if (ret && ret != -ENODATA) {
342 			btrfs_abort_transaction(trans, ret);
343 			goto out_end_trans;
344 		}
345 	}
346 
347 	binode->flags = binode_flags;
348 	btrfs_sync_inode_flags_to_i_flags(inode);
349 	inode_inc_iversion(inode);
350 	inode->i_ctime = current_time(inode);
351 	ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
352 
353  out_end_trans:
354 	btrfs_end_transaction(trans);
355  out_unlock:
356 	inode_unlock(inode);
357 	mnt_drop_write_file(file);
358 	return ret;
359 }
360 
361 /*
362  * Translate btrfs internal inode flags to xflags as expected by the
363  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
364  * silently dropped.
365  */
366 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
367 {
368 	unsigned int xflags = 0;
369 
370 	if (flags & BTRFS_INODE_APPEND)
371 		xflags |= FS_XFLAG_APPEND;
372 	if (flags & BTRFS_INODE_IMMUTABLE)
373 		xflags |= FS_XFLAG_IMMUTABLE;
374 	if (flags & BTRFS_INODE_NOATIME)
375 		xflags |= FS_XFLAG_NOATIME;
376 	if (flags & BTRFS_INODE_NODUMP)
377 		xflags |= FS_XFLAG_NODUMP;
378 	if (flags & BTRFS_INODE_SYNC)
379 		xflags |= FS_XFLAG_SYNC;
380 
381 	return xflags;
382 }
383 
384 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
385 static int check_xflags(unsigned int flags)
386 {
387 	if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
388 		      FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
389 		return -EOPNOTSUPP;
390 	return 0;
391 }
392 
393 bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
394 			enum btrfs_exclusive_operation type)
395 {
396 	return !cmpxchg(&fs_info->exclusive_operation, BTRFS_EXCLOP_NONE, type);
397 }
398 
399 void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
400 {
401 	WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
402 	sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
403 }
404 
405 /*
406  * Set the xflags from the internal inode flags. The remaining items of fsxattr
407  * are zeroed.
408  */
409 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
410 {
411 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
412 	struct fsxattr fa;
413 
414 	simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags));
415 	if (copy_to_user(arg, &fa, sizeof(fa)))
416 		return -EFAULT;
417 
418 	return 0;
419 }
420 
421 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
422 {
423 	struct inode *inode = file_inode(file);
424 	struct btrfs_inode *binode = BTRFS_I(inode);
425 	struct btrfs_root *root = binode->root;
426 	struct btrfs_trans_handle *trans;
427 	struct fsxattr fa, old_fa;
428 	unsigned old_flags;
429 	unsigned old_i_flags;
430 	int ret = 0;
431 
432 	if (!inode_owner_or_capable(inode))
433 		return -EPERM;
434 
435 	if (btrfs_root_readonly(root))
436 		return -EROFS;
437 
438 	if (copy_from_user(&fa, arg, sizeof(fa)))
439 		return -EFAULT;
440 
441 	ret = check_xflags(fa.fsx_xflags);
442 	if (ret)
443 		return ret;
444 
445 	if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
446 		return -EOPNOTSUPP;
447 
448 	ret = mnt_want_write_file(file);
449 	if (ret)
450 		return ret;
451 
452 	inode_lock(inode);
453 
454 	old_flags = binode->flags;
455 	old_i_flags = inode->i_flags;
456 
457 	simple_fill_fsxattr(&old_fa,
458 			    btrfs_inode_flags_to_xflags(binode->flags));
459 	ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
460 	if (ret)
461 		goto out_unlock;
462 
463 	if (fa.fsx_xflags & FS_XFLAG_SYNC)
464 		binode->flags |= BTRFS_INODE_SYNC;
465 	else
466 		binode->flags &= ~BTRFS_INODE_SYNC;
467 	if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
468 		binode->flags |= BTRFS_INODE_IMMUTABLE;
469 	else
470 		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
471 	if (fa.fsx_xflags & FS_XFLAG_APPEND)
472 		binode->flags |= BTRFS_INODE_APPEND;
473 	else
474 		binode->flags &= ~BTRFS_INODE_APPEND;
475 	if (fa.fsx_xflags & FS_XFLAG_NODUMP)
476 		binode->flags |= BTRFS_INODE_NODUMP;
477 	else
478 		binode->flags &= ~BTRFS_INODE_NODUMP;
479 	if (fa.fsx_xflags & FS_XFLAG_NOATIME)
480 		binode->flags |= BTRFS_INODE_NOATIME;
481 	else
482 		binode->flags &= ~BTRFS_INODE_NOATIME;
483 
484 	/* 1 item for the inode */
485 	trans = btrfs_start_transaction(root, 1);
486 	if (IS_ERR(trans)) {
487 		ret = PTR_ERR(trans);
488 		goto out_unlock;
489 	}
490 
491 	btrfs_sync_inode_flags_to_i_flags(inode);
492 	inode_inc_iversion(inode);
493 	inode->i_ctime = current_time(inode);
494 	ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
495 
496 	btrfs_end_transaction(trans);
497 
498 out_unlock:
499 	if (ret) {
500 		binode->flags = old_flags;
501 		inode->i_flags = old_i_flags;
502 	}
503 
504 	inode_unlock(inode);
505 	mnt_drop_write_file(file);
506 
507 	return ret;
508 }
509 
510 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
511 {
512 	struct inode *inode = file_inode(file);
513 
514 	return put_user(inode->i_generation, arg);
515 }
516 
517 static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
518 					void __user *arg)
519 {
520 	struct btrfs_device *device;
521 	struct request_queue *q;
522 	struct fstrim_range range;
523 	u64 minlen = ULLONG_MAX;
524 	u64 num_devices = 0;
525 	int ret;
526 
527 	if (!capable(CAP_SYS_ADMIN))
528 		return -EPERM;
529 
530 	/*
531 	 * btrfs_trim_block_group() depends on space cache, which is not
532 	 * available in zoned filesystem. So, disallow fitrim on a zoned
533 	 * filesystem for now.
534 	 */
535 	if (btrfs_is_zoned(fs_info))
536 		return -EOPNOTSUPP;
537 
538 	/*
539 	 * If the fs is mounted with nologreplay, which requires it to be
540 	 * mounted in RO mode as well, we can not allow discard on free space
541 	 * inside block groups, because log trees refer to extents that are not
542 	 * pinned in a block group's free space cache (pinning the extents is
543 	 * precisely the first phase of replaying a log tree).
544 	 */
545 	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
546 		return -EROFS;
547 
548 	rcu_read_lock();
549 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
550 				dev_list) {
551 		if (!device->bdev)
552 			continue;
553 		q = bdev_get_queue(device->bdev);
554 		if (blk_queue_discard(q)) {
555 			num_devices++;
556 			minlen = min_t(u64, q->limits.discard_granularity,
557 				     minlen);
558 		}
559 	}
560 	rcu_read_unlock();
561 
562 	if (!num_devices)
563 		return -EOPNOTSUPP;
564 	if (copy_from_user(&range, arg, sizeof(range)))
565 		return -EFAULT;
566 
567 	/*
568 	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
569 	 * block group is in the logical address space, which can be any
570 	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
571 	 */
572 	if (range.len < fs_info->sb->s_blocksize)
573 		return -EINVAL;
574 
575 	range.minlen = max(range.minlen, minlen);
576 	ret = btrfs_trim_fs(fs_info, &range);
577 	if (ret < 0)
578 		return ret;
579 
580 	if (copy_to_user(arg, &range, sizeof(range)))
581 		return -EFAULT;
582 
583 	return 0;
584 }
585 
586 int __pure btrfs_is_empty_uuid(u8 *uuid)
587 {
588 	int i;
589 
590 	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
591 		if (uuid[i])
592 			return 0;
593 	}
594 	return 1;
595 }
596 
597 static noinline int create_subvol(struct inode *dir,
598 				  struct dentry *dentry,
599 				  const char *name, int namelen,
600 				  struct btrfs_qgroup_inherit *inherit)
601 {
602 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
603 	struct btrfs_trans_handle *trans;
604 	struct btrfs_key key;
605 	struct btrfs_root_item *root_item;
606 	struct btrfs_inode_item *inode_item;
607 	struct extent_buffer *leaf;
608 	struct btrfs_root *root = BTRFS_I(dir)->root;
609 	struct btrfs_root *new_root;
610 	struct btrfs_block_rsv block_rsv;
611 	struct timespec64 cur_time = current_time(dir);
612 	struct inode *inode;
613 	int ret;
614 	int err;
615 	dev_t anon_dev = 0;
616 	u64 objectid;
617 	u64 index = 0;
618 
619 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
620 	if (!root_item)
621 		return -ENOMEM;
622 
623 	ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
624 	if (ret)
625 		goto fail_free;
626 
627 	ret = get_anon_bdev(&anon_dev);
628 	if (ret < 0)
629 		goto fail_free;
630 
631 	/*
632 	 * Don't create subvolume whose level is not zero. Or qgroup will be
633 	 * screwed up since it assumes subvolume qgroup's level to be 0.
634 	 */
635 	if (btrfs_qgroup_level(objectid)) {
636 		ret = -ENOSPC;
637 		goto fail_free;
638 	}
639 
640 	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
641 	/*
642 	 * The same as the snapshot creation, please see the comment
643 	 * of create_snapshot().
644 	 */
645 	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
646 	if (ret)
647 		goto fail_free;
648 
649 	trans = btrfs_start_transaction(root, 0);
650 	if (IS_ERR(trans)) {
651 		ret = PTR_ERR(trans);
652 		btrfs_subvolume_release_metadata(root, &block_rsv);
653 		goto fail_free;
654 	}
655 	trans->block_rsv = &block_rsv;
656 	trans->bytes_reserved = block_rsv.size;
657 
658 	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
659 	if (ret)
660 		goto fail;
661 
662 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
663 				      BTRFS_NESTING_NORMAL);
664 	if (IS_ERR(leaf)) {
665 		ret = PTR_ERR(leaf);
666 		goto fail;
667 	}
668 
669 	btrfs_mark_buffer_dirty(leaf);
670 
671 	inode_item = &root_item->inode;
672 	btrfs_set_stack_inode_generation(inode_item, 1);
673 	btrfs_set_stack_inode_size(inode_item, 3);
674 	btrfs_set_stack_inode_nlink(inode_item, 1);
675 	btrfs_set_stack_inode_nbytes(inode_item,
676 				     fs_info->nodesize);
677 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
678 
679 	btrfs_set_root_flags(root_item, 0);
680 	btrfs_set_root_limit(root_item, 0);
681 	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
682 
683 	btrfs_set_root_bytenr(root_item, leaf->start);
684 	btrfs_set_root_generation(root_item, trans->transid);
685 	btrfs_set_root_level(root_item, 0);
686 	btrfs_set_root_refs(root_item, 1);
687 	btrfs_set_root_used(root_item, leaf->len);
688 	btrfs_set_root_last_snapshot(root_item, 0);
689 
690 	btrfs_set_root_generation_v2(root_item,
691 			btrfs_root_generation(root_item));
692 	generate_random_guid(root_item->uuid);
693 	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
694 	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
695 	root_item->ctime = root_item->otime;
696 	btrfs_set_root_ctransid(root_item, trans->transid);
697 	btrfs_set_root_otransid(root_item, trans->transid);
698 
699 	btrfs_tree_unlock(leaf);
700 	free_extent_buffer(leaf);
701 	leaf = NULL;
702 
703 	btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
704 
705 	key.objectid = objectid;
706 	key.offset = 0;
707 	key.type = BTRFS_ROOT_ITEM_KEY;
708 	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
709 				root_item);
710 	if (ret)
711 		goto fail;
712 
713 	key.offset = (u64)-1;
714 	new_root = btrfs_get_new_fs_root(fs_info, objectid, anon_dev);
715 	if (IS_ERR(new_root)) {
716 		free_anon_bdev(anon_dev);
717 		ret = PTR_ERR(new_root);
718 		btrfs_abort_transaction(trans, ret);
719 		goto fail;
720 	}
721 	/* Freeing will be done in btrfs_put_root() of new_root */
722 	anon_dev = 0;
723 
724 	btrfs_record_root_in_trans(trans, new_root);
725 
726 	ret = btrfs_create_subvol_root(trans, new_root, root);
727 	btrfs_put_root(new_root);
728 	if (ret) {
729 		/* We potentially lose an unused inode item here */
730 		btrfs_abort_transaction(trans, ret);
731 		goto fail;
732 	}
733 
734 	/*
735 	 * insert the directory item
736 	 */
737 	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
738 	if (ret) {
739 		btrfs_abort_transaction(trans, ret);
740 		goto fail;
741 	}
742 
743 	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
744 				    BTRFS_FT_DIR, index);
745 	if (ret) {
746 		btrfs_abort_transaction(trans, ret);
747 		goto fail;
748 	}
749 
750 	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
751 	ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
752 	if (ret) {
753 		btrfs_abort_transaction(trans, ret);
754 		goto fail;
755 	}
756 
757 	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
758 				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
759 	if (ret) {
760 		btrfs_abort_transaction(trans, ret);
761 		goto fail;
762 	}
763 
764 	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
765 				  BTRFS_UUID_KEY_SUBVOL, objectid);
766 	if (ret)
767 		btrfs_abort_transaction(trans, ret);
768 
769 fail:
770 	kfree(root_item);
771 	trans->block_rsv = NULL;
772 	trans->bytes_reserved = 0;
773 	btrfs_subvolume_release_metadata(root, &block_rsv);
774 
775 	err = btrfs_commit_transaction(trans);
776 	if (err && !ret)
777 		ret = err;
778 
779 	if (!ret) {
780 		inode = btrfs_lookup_dentry(dir, dentry);
781 		if (IS_ERR(inode))
782 			return PTR_ERR(inode);
783 		d_instantiate(dentry, inode);
784 	}
785 	return ret;
786 
787 fail_free:
788 	if (anon_dev)
789 		free_anon_bdev(anon_dev);
790 	kfree(root_item);
791 	return ret;
792 }
793 
794 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
795 			   struct dentry *dentry, bool readonly,
796 			   struct btrfs_qgroup_inherit *inherit)
797 {
798 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
799 	struct inode *inode;
800 	struct btrfs_pending_snapshot *pending_snapshot;
801 	struct btrfs_trans_handle *trans;
802 	int ret;
803 
804 	if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
805 		return -EINVAL;
806 
807 	if (atomic_read(&root->nr_swapfiles)) {
808 		btrfs_warn(fs_info,
809 			   "cannot snapshot subvolume with active swapfile");
810 		return -ETXTBSY;
811 	}
812 
813 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
814 	if (!pending_snapshot)
815 		return -ENOMEM;
816 
817 	ret = get_anon_bdev(&pending_snapshot->anon_dev);
818 	if (ret < 0)
819 		goto free_pending;
820 	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
821 			GFP_KERNEL);
822 	pending_snapshot->path = btrfs_alloc_path();
823 	if (!pending_snapshot->root_item || !pending_snapshot->path) {
824 		ret = -ENOMEM;
825 		goto free_pending;
826 	}
827 
828 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
829 			     BTRFS_BLOCK_RSV_TEMP);
830 	/*
831 	 * 1 - parent dir inode
832 	 * 2 - dir entries
833 	 * 1 - root item
834 	 * 2 - root ref/backref
835 	 * 1 - root of snapshot
836 	 * 1 - UUID item
837 	 */
838 	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
839 					&pending_snapshot->block_rsv, 8,
840 					false);
841 	if (ret)
842 		goto free_pending;
843 
844 	pending_snapshot->dentry = dentry;
845 	pending_snapshot->root = root;
846 	pending_snapshot->readonly = readonly;
847 	pending_snapshot->dir = dir;
848 	pending_snapshot->inherit = inherit;
849 
850 	trans = btrfs_start_transaction(root, 0);
851 	if (IS_ERR(trans)) {
852 		ret = PTR_ERR(trans);
853 		goto fail;
854 	}
855 
856 	spin_lock(&fs_info->trans_lock);
857 	list_add(&pending_snapshot->list,
858 		 &trans->transaction->pending_snapshots);
859 	spin_unlock(&fs_info->trans_lock);
860 
861 	ret = btrfs_commit_transaction(trans);
862 	if (ret)
863 		goto fail;
864 
865 	ret = pending_snapshot->error;
866 	if (ret)
867 		goto fail;
868 
869 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
870 	if (ret)
871 		goto fail;
872 
873 	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
874 	if (IS_ERR(inode)) {
875 		ret = PTR_ERR(inode);
876 		goto fail;
877 	}
878 
879 	d_instantiate(dentry, inode);
880 	ret = 0;
881 	pending_snapshot->anon_dev = 0;
882 fail:
883 	/* Prevent double freeing of anon_dev */
884 	if (ret && pending_snapshot->snap)
885 		pending_snapshot->snap->anon_dev = 0;
886 	btrfs_put_root(pending_snapshot->snap);
887 	btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv);
888 free_pending:
889 	if (pending_snapshot->anon_dev)
890 		free_anon_bdev(pending_snapshot->anon_dev);
891 	kfree(pending_snapshot->root_item);
892 	btrfs_free_path(pending_snapshot->path);
893 	kfree(pending_snapshot);
894 
895 	return ret;
896 }
897 
898 /*  copy of may_delete in fs/namei.c()
899  *	Check whether we can remove a link victim from directory dir, check
900  *  whether the type of victim is right.
901  *  1. We can't do it if dir is read-only (done in permission())
902  *  2. We should have write and exec permissions on dir
903  *  3. We can't remove anything from append-only dir
904  *  4. We can't do anything with immutable dir (done in permission())
905  *  5. If the sticky bit on dir is set we should either
906  *	a. be owner of dir, or
907  *	b. be owner of victim, or
908  *	c. have CAP_FOWNER capability
909  *  6. If the victim is append-only or immutable we can't do anything with
910  *     links pointing to it.
911  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
912  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
913  *  9. We can't remove a root or mountpoint.
914  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
915  *     nfs_async_unlink().
916  */
917 
918 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
919 {
920 	int error;
921 
922 	if (d_really_is_negative(victim))
923 		return -ENOENT;
924 
925 	BUG_ON(d_inode(victim->d_parent) != dir);
926 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
927 
928 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
929 	if (error)
930 		return error;
931 	if (IS_APPEND(dir))
932 		return -EPERM;
933 	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
934 	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
935 		return -EPERM;
936 	if (isdir) {
937 		if (!d_is_dir(victim))
938 			return -ENOTDIR;
939 		if (IS_ROOT(victim))
940 			return -EBUSY;
941 	} else if (d_is_dir(victim))
942 		return -EISDIR;
943 	if (IS_DEADDIR(dir))
944 		return -ENOENT;
945 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
946 		return -EBUSY;
947 	return 0;
948 }
949 
950 /* copy of may_create in fs/namei.c() */
951 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
952 {
953 	if (d_really_is_positive(child))
954 		return -EEXIST;
955 	if (IS_DEADDIR(dir))
956 		return -ENOENT;
957 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
958 }
959 
960 /*
961  * Create a new subvolume below @parent.  This is largely modeled after
962  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
963  * inside this filesystem so it's quite a bit simpler.
964  */
965 static noinline int btrfs_mksubvol(const struct path *parent,
966 				   const char *name, int namelen,
967 				   struct btrfs_root *snap_src,
968 				   bool readonly,
969 				   struct btrfs_qgroup_inherit *inherit)
970 {
971 	struct inode *dir = d_inode(parent->dentry);
972 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
973 	struct dentry *dentry;
974 	int error;
975 
976 	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
977 	if (error == -EINTR)
978 		return error;
979 
980 	dentry = lookup_one_len(name, parent->dentry, namelen);
981 	error = PTR_ERR(dentry);
982 	if (IS_ERR(dentry))
983 		goto out_unlock;
984 
985 	error = btrfs_may_create(dir, dentry);
986 	if (error)
987 		goto out_dput;
988 
989 	/*
990 	 * even if this name doesn't exist, we may get hash collisions.
991 	 * check for them now when we can safely fail
992 	 */
993 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
994 					       dir->i_ino, name,
995 					       namelen);
996 	if (error)
997 		goto out_dput;
998 
999 	down_read(&fs_info->subvol_sem);
1000 
1001 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
1002 		goto out_up_read;
1003 
1004 	if (snap_src)
1005 		error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
1006 	else
1007 		error = create_subvol(dir, dentry, name, namelen, inherit);
1008 
1009 	if (!error)
1010 		fsnotify_mkdir(dir, dentry);
1011 out_up_read:
1012 	up_read(&fs_info->subvol_sem);
1013 out_dput:
1014 	dput(dentry);
1015 out_unlock:
1016 	inode_unlock(dir);
1017 	return error;
1018 }
1019 
1020 static noinline int btrfs_mksnapshot(const struct path *parent,
1021 				   const char *name, int namelen,
1022 				   struct btrfs_root *root,
1023 				   bool readonly,
1024 				   struct btrfs_qgroup_inherit *inherit)
1025 {
1026 	int ret;
1027 	bool snapshot_force_cow = false;
1028 
1029 	/*
1030 	 * Force new buffered writes to reserve space even when NOCOW is
1031 	 * possible. This is to avoid later writeback (running dealloc) to
1032 	 * fallback to COW mode and unexpectedly fail with ENOSPC.
1033 	 */
1034 	btrfs_drew_read_lock(&root->snapshot_lock);
1035 
1036 	ret = btrfs_start_delalloc_snapshot(root);
1037 	if (ret)
1038 		goto out;
1039 
1040 	/*
1041 	 * All previous writes have started writeback in NOCOW mode, so now
1042 	 * we force future writes to fallback to COW mode during snapshot
1043 	 * creation.
1044 	 */
1045 	atomic_inc(&root->snapshot_force_cow);
1046 	snapshot_force_cow = true;
1047 
1048 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
1049 
1050 	ret = btrfs_mksubvol(parent, name, namelen,
1051 			     root, readonly, inherit);
1052 out:
1053 	if (snapshot_force_cow)
1054 		atomic_dec(&root->snapshot_force_cow);
1055 	btrfs_drew_read_unlock(&root->snapshot_lock);
1056 	return ret;
1057 }
1058 
1059 /*
1060  * When we're defragging a range, we don't want to kick it off again
1061  * if it is really just waiting for delalloc to send it down.
1062  * If we find a nice big extent or delalloc range for the bytes in the
1063  * file you want to defrag, we return 0 to let you know to skip this
1064  * part of the file
1065  */
1066 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1067 {
1068 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1069 	struct extent_map *em = NULL;
1070 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1071 	u64 end;
1072 
1073 	read_lock(&em_tree->lock);
1074 	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1075 	read_unlock(&em_tree->lock);
1076 
1077 	if (em) {
1078 		end = extent_map_end(em);
1079 		free_extent_map(em);
1080 		if (end - offset > thresh)
1081 			return 0;
1082 	}
1083 	/* if we already have a nice delalloc here, just stop */
1084 	thresh /= 2;
1085 	end = count_range_bits(io_tree, &offset, offset + thresh,
1086 			       thresh, EXTENT_DELALLOC, 1);
1087 	if (end >= thresh)
1088 		return 0;
1089 	return 1;
1090 }
1091 
1092 /*
1093  * helper function to walk through a file and find extents
1094  * newer than a specific transid, and smaller than thresh.
1095  *
1096  * This is used by the defragging code to find new and small
1097  * extents
1098  */
1099 static int find_new_extents(struct btrfs_root *root,
1100 			    struct inode *inode, u64 newer_than,
1101 			    u64 *off, u32 thresh)
1102 {
1103 	struct btrfs_path *path;
1104 	struct btrfs_key min_key;
1105 	struct extent_buffer *leaf;
1106 	struct btrfs_file_extent_item *extent;
1107 	int type;
1108 	int ret;
1109 	u64 ino = btrfs_ino(BTRFS_I(inode));
1110 
1111 	path = btrfs_alloc_path();
1112 	if (!path)
1113 		return -ENOMEM;
1114 
1115 	min_key.objectid = ino;
1116 	min_key.type = BTRFS_EXTENT_DATA_KEY;
1117 	min_key.offset = *off;
1118 
1119 	while (1) {
1120 		ret = btrfs_search_forward(root, &min_key, path, newer_than);
1121 		if (ret != 0)
1122 			goto none;
1123 process_slot:
1124 		if (min_key.objectid != ino)
1125 			goto none;
1126 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1127 			goto none;
1128 
1129 		leaf = path->nodes[0];
1130 		extent = btrfs_item_ptr(leaf, path->slots[0],
1131 					struct btrfs_file_extent_item);
1132 
1133 		type = btrfs_file_extent_type(leaf, extent);
1134 		if (type == BTRFS_FILE_EXTENT_REG &&
1135 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1136 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
1137 			*off = min_key.offset;
1138 			btrfs_free_path(path);
1139 			return 0;
1140 		}
1141 
1142 		path->slots[0]++;
1143 		if (path->slots[0] < btrfs_header_nritems(leaf)) {
1144 			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1145 			goto process_slot;
1146 		}
1147 
1148 		if (min_key.offset == (u64)-1)
1149 			goto none;
1150 
1151 		min_key.offset++;
1152 		btrfs_release_path(path);
1153 	}
1154 none:
1155 	btrfs_free_path(path);
1156 	return -ENOENT;
1157 }
1158 
1159 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1160 {
1161 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1162 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1163 	struct extent_map *em;
1164 	u64 len = PAGE_SIZE;
1165 
1166 	/*
1167 	 * hopefully we have this extent in the tree already, try without
1168 	 * the full extent lock
1169 	 */
1170 	read_lock(&em_tree->lock);
1171 	em = lookup_extent_mapping(em_tree, start, len);
1172 	read_unlock(&em_tree->lock);
1173 
1174 	if (!em) {
1175 		struct extent_state *cached = NULL;
1176 		u64 end = start + len - 1;
1177 
1178 		/* get the big lock and read metadata off disk */
1179 		lock_extent_bits(io_tree, start, end, &cached);
1180 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
1181 		unlock_extent_cached(io_tree, start, end, &cached);
1182 
1183 		if (IS_ERR(em))
1184 			return NULL;
1185 	}
1186 
1187 	return em;
1188 }
1189 
1190 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1191 {
1192 	struct extent_map *next;
1193 	bool ret = true;
1194 
1195 	/* this is the last extent */
1196 	if (em->start + em->len >= i_size_read(inode))
1197 		return false;
1198 
1199 	next = defrag_lookup_extent(inode, em->start + em->len);
1200 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1201 		ret = false;
1202 	else if ((em->block_start + em->block_len == next->block_start) &&
1203 		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1204 		ret = false;
1205 
1206 	free_extent_map(next);
1207 	return ret;
1208 }
1209 
1210 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1211 			       u64 *last_len, u64 *skip, u64 *defrag_end,
1212 			       int compress)
1213 {
1214 	struct extent_map *em;
1215 	int ret = 1;
1216 	bool next_mergeable = true;
1217 	bool prev_mergeable = true;
1218 
1219 	/*
1220 	 * make sure that once we start defragging an extent, we keep on
1221 	 * defragging it
1222 	 */
1223 	if (start < *defrag_end)
1224 		return 1;
1225 
1226 	*skip = 0;
1227 
1228 	em = defrag_lookup_extent(inode, start);
1229 	if (!em)
1230 		return 0;
1231 
1232 	/* this will cover holes, and inline extents */
1233 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1234 		ret = 0;
1235 		goto out;
1236 	}
1237 
1238 	if (!*defrag_end)
1239 		prev_mergeable = false;
1240 
1241 	next_mergeable = defrag_check_next_extent(inode, em);
1242 	/*
1243 	 * we hit a real extent, if it is big or the next extent is not a
1244 	 * real extent, don't bother defragging it
1245 	 */
1246 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1247 	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1248 		ret = 0;
1249 out:
1250 	/*
1251 	 * last_len ends up being a counter of how many bytes we've defragged.
1252 	 * every time we choose not to defrag an extent, we reset *last_len
1253 	 * so that the next tiny extent will force a defrag.
1254 	 *
1255 	 * The end result of this is that tiny extents before a single big
1256 	 * extent will force at least part of that big extent to be defragged.
1257 	 */
1258 	if (ret) {
1259 		*defrag_end = extent_map_end(em);
1260 	} else {
1261 		*last_len = 0;
1262 		*skip = extent_map_end(em);
1263 		*defrag_end = 0;
1264 	}
1265 
1266 	free_extent_map(em);
1267 	return ret;
1268 }
1269 
1270 /*
1271  * it doesn't do much good to defrag one or two pages
1272  * at a time.  This pulls in a nice chunk of pages
1273  * to COW and defrag.
1274  *
1275  * It also makes sure the delalloc code has enough
1276  * dirty data to avoid making new small extents as part
1277  * of the defrag
1278  *
1279  * It's a good idea to start RA on this range
1280  * before calling this.
1281  */
1282 static int cluster_pages_for_defrag(struct inode *inode,
1283 				    struct page **pages,
1284 				    unsigned long start_index,
1285 				    unsigned long num_pages)
1286 {
1287 	unsigned long file_end;
1288 	u64 isize = i_size_read(inode);
1289 	u64 page_start;
1290 	u64 page_end;
1291 	u64 page_cnt;
1292 	u64 start = (u64)start_index << PAGE_SHIFT;
1293 	u64 search_start;
1294 	int ret;
1295 	int i;
1296 	int i_done;
1297 	struct btrfs_ordered_extent *ordered;
1298 	struct extent_state *cached_state = NULL;
1299 	struct extent_io_tree *tree;
1300 	struct extent_changeset *data_reserved = NULL;
1301 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1302 
1303 	file_end = (isize - 1) >> PAGE_SHIFT;
1304 	if (!isize || start_index > file_end)
1305 		return 0;
1306 
1307 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1308 
1309 	ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
1310 			start, page_cnt << PAGE_SHIFT);
1311 	if (ret)
1312 		return ret;
1313 	i_done = 0;
1314 	tree = &BTRFS_I(inode)->io_tree;
1315 
1316 	/* step one, lock all the pages */
1317 	for (i = 0; i < page_cnt; i++) {
1318 		struct page *page;
1319 again:
1320 		page = find_or_create_page(inode->i_mapping,
1321 					   start_index + i, mask);
1322 		if (!page)
1323 			break;
1324 
1325 		ret = set_page_extent_mapped(page);
1326 		if (ret < 0) {
1327 			unlock_page(page);
1328 			put_page(page);
1329 			break;
1330 		}
1331 
1332 		page_start = page_offset(page);
1333 		page_end = page_start + PAGE_SIZE - 1;
1334 		while (1) {
1335 			lock_extent_bits(tree, page_start, page_end,
1336 					 &cached_state);
1337 			ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode),
1338 							      page_start);
1339 			unlock_extent_cached(tree, page_start, page_end,
1340 					     &cached_state);
1341 			if (!ordered)
1342 				break;
1343 
1344 			unlock_page(page);
1345 			btrfs_start_ordered_extent(ordered, 1);
1346 			btrfs_put_ordered_extent(ordered);
1347 			lock_page(page);
1348 			/*
1349 			 * we unlocked the page above, so we need check if
1350 			 * it was released or not.
1351 			 */
1352 			if (page->mapping != inode->i_mapping) {
1353 				unlock_page(page);
1354 				put_page(page);
1355 				goto again;
1356 			}
1357 		}
1358 
1359 		if (!PageUptodate(page)) {
1360 			btrfs_readpage(NULL, page);
1361 			lock_page(page);
1362 			if (!PageUptodate(page)) {
1363 				unlock_page(page);
1364 				put_page(page);
1365 				ret = -EIO;
1366 				break;
1367 			}
1368 		}
1369 
1370 		if (page->mapping != inode->i_mapping) {
1371 			unlock_page(page);
1372 			put_page(page);
1373 			goto again;
1374 		}
1375 
1376 		pages[i] = page;
1377 		i_done++;
1378 	}
1379 	if (!i_done || ret)
1380 		goto out;
1381 
1382 	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1383 		goto out;
1384 
1385 	/*
1386 	 * so now we have a nice long stream of locked
1387 	 * and up to date pages, lets wait on them
1388 	 */
1389 	for (i = 0; i < i_done; i++)
1390 		wait_on_page_writeback(pages[i]);
1391 
1392 	page_start = page_offset(pages[0]);
1393 	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1394 
1395 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1396 			 page_start, page_end - 1, &cached_state);
1397 
1398 	/*
1399 	 * When defragmenting we skip ranges that have holes or inline extents,
1400 	 * (check should_defrag_range()), to avoid unnecessary IO and wasting
1401 	 * space. At btrfs_defrag_file(), we check if a range should be defragged
1402 	 * before locking the inode and then, if it should, we trigger a sync
1403 	 * page cache readahead - we lock the inode only after that to avoid
1404 	 * blocking for too long other tasks that possibly want to operate on
1405 	 * other file ranges. But before we were able to get the inode lock,
1406 	 * some other task may have punched a hole in the range, or we may have
1407 	 * now an inline extent, in which case we should not defrag. So check
1408 	 * for that here, where we have the inode and the range locked, and bail
1409 	 * out if that happened.
1410 	 */
1411 	search_start = page_start;
1412 	while (search_start < page_end) {
1413 		struct extent_map *em;
1414 
1415 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, search_start,
1416 				      page_end - search_start);
1417 		if (IS_ERR(em)) {
1418 			ret = PTR_ERR(em);
1419 			goto out_unlock_range;
1420 		}
1421 		if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1422 			free_extent_map(em);
1423 			/* Ok, 0 means we did not defrag anything */
1424 			ret = 0;
1425 			goto out_unlock_range;
1426 		}
1427 		search_start = extent_map_end(em);
1428 		free_extent_map(em);
1429 	}
1430 
1431 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1432 			  page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
1433 			  EXTENT_DEFRAG, 0, 0, &cached_state);
1434 
1435 	if (i_done != page_cnt) {
1436 		spin_lock(&BTRFS_I(inode)->lock);
1437 		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1438 		spin_unlock(&BTRFS_I(inode)->lock);
1439 		btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
1440 				start, (page_cnt - i_done) << PAGE_SHIFT, true);
1441 	}
1442 
1443 
1444 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1445 			  &cached_state);
1446 
1447 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1448 			     page_start, page_end - 1, &cached_state);
1449 
1450 	for (i = 0; i < i_done; i++) {
1451 		clear_page_dirty_for_io(pages[i]);
1452 		ClearPageChecked(pages[i]);
1453 		set_page_dirty(pages[i]);
1454 		unlock_page(pages[i]);
1455 		put_page(pages[i]);
1456 	}
1457 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1458 	extent_changeset_free(data_reserved);
1459 	return i_done;
1460 
1461 out_unlock_range:
1462 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1463 			     page_start, page_end - 1, &cached_state);
1464 out:
1465 	for (i = 0; i < i_done; i++) {
1466 		unlock_page(pages[i]);
1467 		put_page(pages[i]);
1468 	}
1469 	btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
1470 			start, page_cnt << PAGE_SHIFT, true);
1471 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1472 	extent_changeset_free(data_reserved);
1473 	return ret;
1474 
1475 }
1476 
1477 int btrfs_defrag_file(struct inode *inode, struct file *file,
1478 		      struct btrfs_ioctl_defrag_range_args *range,
1479 		      u64 newer_than, unsigned long max_to_defrag)
1480 {
1481 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1482 	struct btrfs_root *root = BTRFS_I(inode)->root;
1483 	struct file_ra_state *ra = NULL;
1484 	unsigned long last_index;
1485 	u64 isize = i_size_read(inode);
1486 	u64 last_len = 0;
1487 	u64 skip = 0;
1488 	u64 defrag_end = 0;
1489 	u64 newer_off = range->start;
1490 	unsigned long i;
1491 	unsigned long ra_index = 0;
1492 	int ret;
1493 	int defrag_count = 0;
1494 	int compress_type = BTRFS_COMPRESS_ZLIB;
1495 	u32 extent_thresh = range->extent_thresh;
1496 	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1497 	unsigned long cluster = max_cluster;
1498 	u64 new_align = ~((u64)SZ_128K - 1);
1499 	struct page **pages = NULL;
1500 	bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1501 
1502 	if (isize == 0)
1503 		return 0;
1504 
1505 	if (range->start >= isize)
1506 		return -EINVAL;
1507 
1508 	if (do_compress) {
1509 		if (range->compress_type >= BTRFS_NR_COMPRESS_TYPES)
1510 			return -EINVAL;
1511 		if (range->compress_type)
1512 			compress_type = range->compress_type;
1513 	}
1514 
1515 	if (extent_thresh == 0)
1516 		extent_thresh = SZ_256K;
1517 
1518 	/*
1519 	 * If we were not given a file, allocate a readahead context. As
1520 	 * readahead is just an optimization, defrag will work without it so
1521 	 * we don't error out.
1522 	 */
1523 	if (!file) {
1524 		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1525 		if (ra)
1526 			file_ra_state_init(ra, inode->i_mapping);
1527 	} else {
1528 		ra = &file->f_ra;
1529 	}
1530 
1531 	pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1532 	if (!pages) {
1533 		ret = -ENOMEM;
1534 		goto out_ra;
1535 	}
1536 
1537 	/* find the last page to defrag */
1538 	if (range->start + range->len > range->start) {
1539 		last_index = min_t(u64, isize - 1,
1540 			 range->start + range->len - 1) >> PAGE_SHIFT;
1541 	} else {
1542 		last_index = (isize - 1) >> PAGE_SHIFT;
1543 	}
1544 
1545 	if (newer_than) {
1546 		ret = find_new_extents(root, inode, newer_than,
1547 				       &newer_off, SZ_64K);
1548 		if (!ret) {
1549 			range->start = newer_off;
1550 			/*
1551 			 * we always align our defrag to help keep
1552 			 * the extents in the file evenly spaced
1553 			 */
1554 			i = (newer_off & new_align) >> PAGE_SHIFT;
1555 		} else
1556 			goto out_ra;
1557 	} else {
1558 		i = range->start >> PAGE_SHIFT;
1559 	}
1560 	if (!max_to_defrag)
1561 		max_to_defrag = last_index - i + 1;
1562 
1563 	/*
1564 	 * make writeback starts from i, so the defrag range can be
1565 	 * written sequentially.
1566 	 */
1567 	if (i < inode->i_mapping->writeback_index)
1568 		inode->i_mapping->writeback_index = i;
1569 
1570 	while (i <= last_index && defrag_count < max_to_defrag &&
1571 	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1572 		/*
1573 		 * make sure we stop running if someone unmounts
1574 		 * the FS
1575 		 */
1576 		if (!(inode->i_sb->s_flags & SB_ACTIVE))
1577 			break;
1578 
1579 		if (btrfs_defrag_cancelled(fs_info)) {
1580 			btrfs_debug(fs_info, "defrag_file cancelled");
1581 			ret = -EAGAIN;
1582 			break;
1583 		}
1584 
1585 		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1586 					 extent_thresh, &last_len, &skip,
1587 					 &defrag_end, do_compress)){
1588 			unsigned long next;
1589 			/*
1590 			 * the should_defrag function tells us how much to skip
1591 			 * bump our counter by the suggested amount
1592 			 */
1593 			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1594 			i = max(i + 1, next);
1595 			continue;
1596 		}
1597 
1598 		if (!newer_than) {
1599 			cluster = (PAGE_ALIGN(defrag_end) >>
1600 				   PAGE_SHIFT) - i;
1601 			cluster = min(cluster, max_cluster);
1602 		} else {
1603 			cluster = max_cluster;
1604 		}
1605 
1606 		if (i + cluster > ra_index) {
1607 			ra_index = max(i, ra_index);
1608 			if (ra)
1609 				page_cache_sync_readahead(inode->i_mapping, ra,
1610 						file, ra_index, cluster);
1611 			ra_index += cluster;
1612 		}
1613 
1614 		inode_lock(inode);
1615 		if (IS_SWAPFILE(inode)) {
1616 			ret = -ETXTBSY;
1617 		} else {
1618 			if (do_compress)
1619 				BTRFS_I(inode)->defrag_compress = compress_type;
1620 			ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1621 		}
1622 		if (ret < 0) {
1623 			inode_unlock(inode);
1624 			goto out_ra;
1625 		}
1626 
1627 		defrag_count += ret;
1628 		balance_dirty_pages_ratelimited(inode->i_mapping);
1629 		inode_unlock(inode);
1630 
1631 		if (newer_than) {
1632 			if (newer_off == (u64)-1)
1633 				break;
1634 
1635 			if (ret > 0)
1636 				i += ret;
1637 
1638 			newer_off = max(newer_off + 1,
1639 					(u64)i << PAGE_SHIFT);
1640 
1641 			ret = find_new_extents(root, inode, newer_than,
1642 					       &newer_off, SZ_64K);
1643 			if (!ret) {
1644 				range->start = newer_off;
1645 				i = (newer_off & new_align) >> PAGE_SHIFT;
1646 			} else {
1647 				break;
1648 			}
1649 		} else {
1650 			if (ret > 0) {
1651 				i += ret;
1652 				last_len += ret << PAGE_SHIFT;
1653 			} else {
1654 				i++;
1655 				last_len = 0;
1656 			}
1657 		}
1658 	}
1659 
1660 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1661 		filemap_flush(inode->i_mapping);
1662 		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1663 			     &BTRFS_I(inode)->runtime_flags))
1664 			filemap_flush(inode->i_mapping);
1665 	}
1666 
1667 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1668 		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1669 	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1670 		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1671 	}
1672 
1673 	ret = defrag_count;
1674 
1675 out_ra:
1676 	if (do_compress) {
1677 		inode_lock(inode);
1678 		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1679 		inode_unlock(inode);
1680 	}
1681 	if (!file)
1682 		kfree(ra);
1683 	kfree(pages);
1684 	return ret;
1685 }
1686 
1687 static noinline int btrfs_ioctl_resize(struct file *file,
1688 					void __user *arg)
1689 {
1690 	struct inode *inode = file_inode(file);
1691 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1692 	u64 new_size;
1693 	u64 old_size;
1694 	u64 devid = 1;
1695 	struct btrfs_root *root = BTRFS_I(inode)->root;
1696 	struct btrfs_ioctl_vol_args *vol_args;
1697 	struct btrfs_trans_handle *trans;
1698 	struct btrfs_device *device = NULL;
1699 	char *sizestr;
1700 	char *retptr;
1701 	char *devstr = NULL;
1702 	int ret = 0;
1703 	int mod = 0;
1704 
1705 	if (!capable(CAP_SYS_ADMIN))
1706 		return -EPERM;
1707 
1708 	ret = mnt_want_write_file(file);
1709 	if (ret)
1710 		return ret;
1711 
1712 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_RESIZE)) {
1713 		mnt_drop_write_file(file);
1714 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1715 	}
1716 
1717 	vol_args = memdup_user(arg, sizeof(*vol_args));
1718 	if (IS_ERR(vol_args)) {
1719 		ret = PTR_ERR(vol_args);
1720 		goto out;
1721 	}
1722 
1723 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1724 
1725 	sizestr = vol_args->name;
1726 	devstr = strchr(sizestr, ':');
1727 	if (devstr) {
1728 		sizestr = devstr + 1;
1729 		*devstr = '\0';
1730 		devstr = vol_args->name;
1731 		ret = kstrtoull(devstr, 10, &devid);
1732 		if (ret)
1733 			goto out_free;
1734 		if (!devid) {
1735 			ret = -EINVAL;
1736 			goto out_free;
1737 		}
1738 		btrfs_info(fs_info, "resizing devid %llu", devid);
1739 	}
1740 
1741 	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
1742 	if (!device) {
1743 		btrfs_info(fs_info, "resizer unable to find device %llu",
1744 			   devid);
1745 		ret = -ENODEV;
1746 		goto out_free;
1747 	}
1748 
1749 	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1750 		btrfs_info(fs_info,
1751 			   "resizer unable to apply on readonly device %llu",
1752 		       devid);
1753 		ret = -EPERM;
1754 		goto out_free;
1755 	}
1756 
1757 	if (!strcmp(sizestr, "max"))
1758 		new_size = device->bdev->bd_inode->i_size;
1759 	else {
1760 		if (sizestr[0] == '-') {
1761 			mod = -1;
1762 			sizestr++;
1763 		} else if (sizestr[0] == '+') {
1764 			mod = 1;
1765 			sizestr++;
1766 		}
1767 		new_size = memparse(sizestr, &retptr);
1768 		if (*retptr != '\0' || new_size == 0) {
1769 			ret = -EINVAL;
1770 			goto out_free;
1771 		}
1772 	}
1773 
1774 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1775 		ret = -EPERM;
1776 		goto out_free;
1777 	}
1778 
1779 	old_size = btrfs_device_get_total_bytes(device);
1780 
1781 	if (mod < 0) {
1782 		if (new_size > old_size) {
1783 			ret = -EINVAL;
1784 			goto out_free;
1785 		}
1786 		new_size = old_size - new_size;
1787 	} else if (mod > 0) {
1788 		if (new_size > ULLONG_MAX - old_size) {
1789 			ret = -ERANGE;
1790 			goto out_free;
1791 		}
1792 		new_size = old_size + new_size;
1793 	}
1794 
1795 	if (new_size < SZ_256M) {
1796 		ret = -EINVAL;
1797 		goto out_free;
1798 	}
1799 	if (new_size > device->bdev->bd_inode->i_size) {
1800 		ret = -EFBIG;
1801 		goto out_free;
1802 	}
1803 
1804 	new_size = round_down(new_size, fs_info->sectorsize);
1805 
1806 	if (new_size > old_size) {
1807 		trans = btrfs_start_transaction(root, 0);
1808 		if (IS_ERR(trans)) {
1809 			ret = PTR_ERR(trans);
1810 			goto out_free;
1811 		}
1812 		ret = btrfs_grow_device(trans, device, new_size);
1813 		btrfs_commit_transaction(trans);
1814 	} else if (new_size < old_size) {
1815 		ret = btrfs_shrink_device(device, new_size);
1816 	} /* equal, nothing need to do */
1817 
1818 	if (ret == 0 && new_size != old_size)
1819 		btrfs_info_in_rcu(fs_info,
1820 			"resize device %s (devid %llu) from %llu to %llu",
1821 			rcu_str_deref(device->name), device->devid,
1822 			old_size, new_size);
1823 out_free:
1824 	kfree(vol_args);
1825 out:
1826 	btrfs_exclop_finish(fs_info);
1827 	mnt_drop_write_file(file);
1828 	return ret;
1829 }
1830 
1831 static noinline int __btrfs_ioctl_snap_create(struct file *file,
1832 				const char *name, unsigned long fd, int subvol,
1833 				bool readonly,
1834 				struct btrfs_qgroup_inherit *inherit)
1835 {
1836 	int namelen;
1837 	int ret = 0;
1838 
1839 	if (!S_ISDIR(file_inode(file)->i_mode))
1840 		return -ENOTDIR;
1841 
1842 	ret = mnt_want_write_file(file);
1843 	if (ret)
1844 		goto out;
1845 
1846 	namelen = strlen(name);
1847 	if (strchr(name, '/')) {
1848 		ret = -EINVAL;
1849 		goto out_drop_write;
1850 	}
1851 
1852 	if (name[0] == '.' &&
1853 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1854 		ret = -EEXIST;
1855 		goto out_drop_write;
1856 	}
1857 
1858 	if (subvol) {
1859 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1860 				     NULL, readonly, inherit);
1861 	} else {
1862 		struct fd src = fdget(fd);
1863 		struct inode *src_inode;
1864 		if (!src.file) {
1865 			ret = -EINVAL;
1866 			goto out_drop_write;
1867 		}
1868 
1869 		src_inode = file_inode(src.file);
1870 		if (src_inode->i_sb != file_inode(file)->i_sb) {
1871 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1872 				   "Snapshot src from another FS");
1873 			ret = -EXDEV;
1874 		} else if (!inode_owner_or_capable(src_inode)) {
1875 			/*
1876 			 * Subvolume creation is not restricted, but snapshots
1877 			 * are limited to own subvolumes only
1878 			 */
1879 			ret = -EPERM;
1880 		} else {
1881 			ret = btrfs_mksnapshot(&file->f_path, name, namelen,
1882 					     BTRFS_I(src_inode)->root,
1883 					     readonly, inherit);
1884 		}
1885 		fdput(src);
1886 	}
1887 out_drop_write:
1888 	mnt_drop_write_file(file);
1889 out:
1890 	return ret;
1891 }
1892 
1893 static noinline int btrfs_ioctl_snap_create(struct file *file,
1894 					    void __user *arg, int subvol)
1895 {
1896 	struct btrfs_ioctl_vol_args *vol_args;
1897 	int ret;
1898 
1899 	if (!S_ISDIR(file_inode(file)->i_mode))
1900 		return -ENOTDIR;
1901 
1902 	vol_args = memdup_user(arg, sizeof(*vol_args));
1903 	if (IS_ERR(vol_args))
1904 		return PTR_ERR(vol_args);
1905 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1906 
1907 	ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
1908 					subvol, false, NULL);
1909 
1910 	kfree(vol_args);
1911 	return ret;
1912 }
1913 
1914 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1915 					       void __user *arg, int subvol)
1916 {
1917 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1918 	int ret;
1919 	bool readonly = false;
1920 	struct btrfs_qgroup_inherit *inherit = NULL;
1921 
1922 	if (!S_ISDIR(file_inode(file)->i_mode))
1923 		return -ENOTDIR;
1924 
1925 	vol_args = memdup_user(arg, sizeof(*vol_args));
1926 	if (IS_ERR(vol_args))
1927 		return PTR_ERR(vol_args);
1928 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1929 
1930 	if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1931 		ret = -EOPNOTSUPP;
1932 		goto free_args;
1933 	}
1934 
1935 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1936 		readonly = true;
1937 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1938 		if (vol_args->size > PAGE_SIZE) {
1939 			ret = -EINVAL;
1940 			goto free_args;
1941 		}
1942 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1943 		if (IS_ERR(inherit)) {
1944 			ret = PTR_ERR(inherit);
1945 			goto free_args;
1946 		}
1947 	}
1948 
1949 	ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
1950 					subvol, readonly, inherit);
1951 	if (ret)
1952 		goto free_inherit;
1953 free_inherit:
1954 	kfree(inherit);
1955 free_args:
1956 	kfree(vol_args);
1957 	return ret;
1958 }
1959 
1960 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1961 						void __user *arg)
1962 {
1963 	struct inode *inode = file_inode(file);
1964 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1965 	struct btrfs_root *root = BTRFS_I(inode)->root;
1966 	int ret = 0;
1967 	u64 flags = 0;
1968 
1969 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1970 		return -EINVAL;
1971 
1972 	down_read(&fs_info->subvol_sem);
1973 	if (btrfs_root_readonly(root))
1974 		flags |= BTRFS_SUBVOL_RDONLY;
1975 	up_read(&fs_info->subvol_sem);
1976 
1977 	if (copy_to_user(arg, &flags, sizeof(flags)))
1978 		ret = -EFAULT;
1979 
1980 	return ret;
1981 }
1982 
1983 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1984 					      void __user *arg)
1985 {
1986 	struct inode *inode = file_inode(file);
1987 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1988 	struct btrfs_root *root = BTRFS_I(inode)->root;
1989 	struct btrfs_trans_handle *trans;
1990 	u64 root_flags;
1991 	u64 flags;
1992 	int ret = 0;
1993 
1994 	if (!inode_owner_or_capable(inode))
1995 		return -EPERM;
1996 
1997 	ret = mnt_want_write_file(file);
1998 	if (ret)
1999 		goto out;
2000 
2001 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2002 		ret = -EINVAL;
2003 		goto out_drop_write;
2004 	}
2005 
2006 	if (copy_from_user(&flags, arg, sizeof(flags))) {
2007 		ret = -EFAULT;
2008 		goto out_drop_write;
2009 	}
2010 
2011 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
2012 		ret = -EOPNOTSUPP;
2013 		goto out_drop_write;
2014 	}
2015 
2016 	down_write(&fs_info->subvol_sem);
2017 
2018 	/* nothing to do */
2019 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
2020 		goto out_drop_sem;
2021 
2022 	root_flags = btrfs_root_flags(&root->root_item);
2023 	if (flags & BTRFS_SUBVOL_RDONLY) {
2024 		btrfs_set_root_flags(&root->root_item,
2025 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
2026 	} else {
2027 		/*
2028 		 * Block RO -> RW transition if this subvolume is involved in
2029 		 * send
2030 		 */
2031 		spin_lock(&root->root_item_lock);
2032 		if (root->send_in_progress == 0) {
2033 			btrfs_set_root_flags(&root->root_item,
2034 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
2035 			spin_unlock(&root->root_item_lock);
2036 		} else {
2037 			spin_unlock(&root->root_item_lock);
2038 			btrfs_warn(fs_info,
2039 				   "Attempt to set subvolume %llu read-write during send",
2040 				   root->root_key.objectid);
2041 			ret = -EPERM;
2042 			goto out_drop_sem;
2043 		}
2044 	}
2045 
2046 	trans = btrfs_start_transaction(root, 1);
2047 	if (IS_ERR(trans)) {
2048 		ret = PTR_ERR(trans);
2049 		goto out_reset;
2050 	}
2051 
2052 	ret = btrfs_update_root(trans, fs_info->tree_root,
2053 				&root->root_key, &root->root_item);
2054 	if (ret < 0) {
2055 		btrfs_end_transaction(trans);
2056 		goto out_reset;
2057 	}
2058 
2059 	ret = btrfs_commit_transaction(trans);
2060 
2061 out_reset:
2062 	if (ret)
2063 		btrfs_set_root_flags(&root->root_item, root_flags);
2064 out_drop_sem:
2065 	up_write(&fs_info->subvol_sem);
2066 out_drop_write:
2067 	mnt_drop_write_file(file);
2068 out:
2069 	return ret;
2070 }
2071 
2072 static noinline int key_in_sk(struct btrfs_key *key,
2073 			      struct btrfs_ioctl_search_key *sk)
2074 {
2075 	struct btrfs_key test;
2076 	int ret;
2077 
2078 	test.objectid = sk->min_objectid;
2079 	test.type = sk->min_type;
2080 	test.offset = sk->min_offset;
2081 
2082 	ret = btrfs_comp_cpu_keys(key, &test);
2083 	if (ret < 0)
2084 		return 0;
2085 
2086 	test.objectid = sk->max_objectid;
2087 	test.type = sk->max_type;
2088 	test.offset = sk->max_offset;
2089 
2090 	ret = btrfs_comp_cpu_keys(key, &test);
2091 	if (ret > 0)
2092 		return 0;
2093 	return 1;
2094 }
2095 
2096 static noinline int copy_to_sk(struct btrfs_path *path,
2097 			       struct btrfs_key *key,
2098 			       struct btrfs_ioctl_search_key *sk,
2099 			       size_t *buf_size,
2100 			       char __user *ubuf,
2101 			       unsigned long *sk_offset,
2102 			       int *num_found)
2103 {
2104 	u64 found_transid;
2105 	struct extent_buffer *leaf;
2106 	struct btrfs_ioctl_search_header sh;
2107 	struct btrfs_key test;
2108 	unsigned long item_off;
2109 	unsigned long item_len;
2110 	int nritems;
2111 	int i;
2112 	int slot;
2113 	int ret = 0;
2114 
2115 	leaf = path->nodes[0];
2116 	slot = path->slots[0];
2117 	nritems = btrfs_header_nritems(leaf);
2118 
2119 	if (btrfs_header_generation(leaf) > sk->max_transid) {
2120 		i = nritems;
2121 		goto advance_key;
2122 	}
2123 	found_transid = btrfs_header_generation(leaf);
2124 
2125 	for (i = slot; i < nritems; i++) {
2126 		item_off = btrfs_item_ptr_offset(leaf, i);
2127 		item_len = btrfs_item_size_nr(leaf, i);
2128 
2129 		btrfs_item_key_to_cpu(leaf, key, i);
2130 		if (!key_in_sk(key, sk))
2131 			continue;
2132 
2133 		if (sizeof(sh) + item_len > *buf_size) {
2134 			if (*num_found) {
2135 				ret = 1;
2136 				goto out;
2137 			}
2138 
2139 			/*
2140 			 * return one empty item back for v1, which does not
2141 			 * handle -EOVERFLOW
2142 			 */
2143 
2144 			*buf_size = sizeof(sh) + item_len;
2145 			item_len = 0;
2146 			ret = -EOVERFLOW;
2147 		}
2148 
2149 		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2150 			ret = 1;
2151 			goto out;
2152 		}
2153 
2154 		sh.objectid = key->objectid;
2155 		sh.offset = key->offset;
2156 		sh.type = key->type;
2157 		sh.len = item_len;
2158 		sh.transid = found_transid;
2159 
2160 		/*
2161 		 * Copy search result header. If we fault then loop again so we
2162 		 * can fault in the pages and -EFAULT there if there's a
2163 		 * problem. Otherwise we'll fault and then copy the buffer in
2164 		 * properly this next time through
2165 		 */
2166 		if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
2167 			ret = 0;
2168 			goto out;
2169 		}
2170 
2171 		*sk_offset += sizeof(sh);
2172 
2173 		if (item_len) {
2174 			char __user *up = ubuf + *sk_offset;
2175 			/*
2176 			 * Copy the item, same behavior as above, but reset the
2177 			 * * sk_offset so we copy the full thing again.
2178 			 */
2179 			if (read_extent_buffer_to_user_nofault(leaf, up,
2180 						item_off, item_len)) {
2181 				ret = 0;
2182 				*sk_offset -= sizeof(sh);
2183 				goto out;
2184 			}
2185 
2186 			*sk_offset += item_len;
2187 		}
2188 		(*num_found)++;
2189 
2190 		if (ret) /* -EOVERFLOW from above */
2191 			goto out;
2192 
2193 		if (*num_found >= sk->nr_items) {
2194 			ret = 1;
2195 			goto out;
2196 		}
2197 	}
2198 advance_key:
2199 	ret = 0;
2200 	test.objectid = sk->max_objectid;
2201 	test.type = sk->max_type;
2202 	test.offset = sk->max_offset;
2203 	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2204 		ret = 1;
2205 	else if (key->offset < (u64)-1)
2206 		key->offset++;
2207 	else if (key->type < (u8)-1) {
2208 		key->offset = 0;
2209 		key->type++;
2210 	} else if (key->objectid < (u64)-1) {
2211 		key->offset = 0;
2212 		key->type = 0;
2213 		key->objectid++;
2214 	} else
2215 		ret = 1;
2216 out:
2217 	/*
2218 	 *  0: all items from this leaf copied, continue with next
2219 	 *  1: * more items can be copied, but unused buffer is too small
2220 	 *     * all items were found
2221 	 *     Either way, it will stops the loop which iterates to the next
2222 	 *     leaf
2223 	 *  -EOVERFLOW: item was to large for buffer
2224 	 *  -EFAULT: could not copy extent buffer back to userspace
2225 	 */
2226 	return ret;
2227 }
2228 
2229 static noinline int search_ioctl(struct inode *inode,
2230 				 struct btrfs_ioctl_search_key *sk,
2231 				 size_t *buf_size,
2232 				 char __user *ubuf)
2233 {
2234 	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2235 	struct btrfs_root *root;
2236 	struct btrfs_key key;
2237 	struct btrfs_path *path;
2238 	int ret;
2239 	int num_found = 0;
2240 	unsigned long sk_offset = 0;
2241 
2242 	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2243 		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2244 		return -EOVERFLOW;
2245 	}
2246 
2247 	path = btrfs_alloc_path();
2248 	if (!path)
2249 		return -ENOMEM;
2250 
2251 	if (sk->tree_id == 0) {
2252 		/* search the root of the inode that was passed */
2253 		root = btrfs_grab_root(BTRFS_I(inode)->root);
2254 	} else {
2255 		root = btrfs_get_fs_root(info, sk->tree_id, true);
2256 		if (IS_ERR(root)) {
2257 			btrfs_free_path(path);
2258 			return PTR_ERR(root);
2259 		}
2260 	}
2261 
2262 	key.objectid = sk->min_objectid;
2263 	key.type = sk->min_type;
2264 	key.offset = sk->min_offset;
2265 
2266 	while (1) {
2267 		ret = fault_in_pages_writeable(ubuf + sk_offset,
2268 					       *buf_size - sk_offset);
2269 		if (ret)
2270 			break;
2271 
2272 		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2273 		if (ret != 0) {
2274 			if (ret > 0)
2275 				ret = 0;
2276 			goto err;
2277 		}
2278 		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2279 				 &sk_offset, &num_found);
2280 		btrfs_release_path(path);
2281 		if (ret)
2282 			break;
2283 
2284 	}
2285 	if (ret > 0)
2286 		ret = 0;
2287 err:
2288 	sk->nr_items = num_found;
2289 	btrfs_put_root(root);
2290 	btrfs_free_path(path);
2291 	return ret;
2292 }
2293 
2294 static noinline int btrfs_ioctl_tree_search(struct file *file,
2295 					   void __user *argp)
2296 {
2297 	struct btrfs_ioctl_search_args __user *uargs;
2298 	struct btrfs_ioctl_search_key sk;
2299 	struct inode *inode;
2300 	int ret;
2301 	size_t buf_size;
2302 
2303 	if (!capable(CAP_SYS_ADMIN))
2304 		return -EPERM;
2305 
2306 	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2307 
2308 	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2309 		return -EFAULT;
2310 
2311 	buf_size = sizeof(uargs->buf);
2312 
2313 	inode = file_inode(file);
2314 	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2315 
2316 	/*
2317 	 * In the origin implementation an overflow is handled by returning a
2318 	 * search header with a len of zero, so reset ret.
2319 	 */
2320 	if (ret == -EOVERFLOW)
2321 		ret = 0;
2322 
2323 	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2324 		ret = -EFAULT;
2325 	return ret;
2326 }
2327 
2328 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2329 					       void __user *argp)
2330 {
2331 	struct btrfs_ioctl_search_args_v2 __user *uarg;
2332 	struct btrfs_ioctl_search_args_v2 args;
2333 	struct inode *inode;
2334 	int ret;
2335 	size_t buf_size;
2336 	const size_t buf_limit = SZ_16M;
2337 
2338 	if (!capable(CAP_SYS_ADMIN))
2339 		return -EPERM;
2340 
2341 	/* copy search header and buffer size */
2342 	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2343 	if (copy_from_user(&args, uarg, sizeof(args)))
2344 		return -EFAULT;
2345 
2346 	buf_size = args.buf_size;
2347 
2348 	/* limit result size to 16MB */
2349 	if (buf_size > buf_limit)
2350 		buf_size = buf_limit;
2351 
2352 	inode = file_inode(file);
2353 	ret = search_ioctl(inode, &args.key, &buf_size,
2354 			   (char __user *)(&uarg->buf[0]));
2355 	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2356 		ret = -EFAULT;
2357 	else if (ret == -EOVERFLOW &&
2358 		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2359 		ret = -EFAULT;
2360 
2361 	return ret;
2362 }
2363 
2364 /*
2365  * Search INODE_REFs to identify path name of 'dirid' directory
2366  * in a 'tree_id' tree. and sets path name to 'name'.
2367  */
2368 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2369 				u64 tree_id, u64 dirid, char *name)
2370 {
2371 	struct btrfs_root *root;
2372 	struct btrfs_key key;
2373 	char *ptr;
2374 	int ret = -1;
2375 	int slot;
2376 	int len;
2377 	int total_len = 0;
2378 	struct btrfs_inode_ref *iref;
2379 	struct extent_buffer *l;
2380 	struct btrfs_path *path;
2381 
2382 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2383 		name[0]='\0';
2384 		return 0;
2385 	}
2386 
2387 	path = btrfs_alloc_path();
2388 	if (!path)
2389 		return -ENOMEM;
2390 
2391 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2392 
2393 	root = btrfs_get_fs_root(info, tree_id, true);
2394 	if (IS_ERR(root)) {
2395 		ret = PTR_ERR(root);
2396 		root = NULL;
2397 		goto out;
2398 	}
2399 
2400 	key.objectid = dirid;
2401 	key.type = BTRFS_INODE_REF_KEY;
2402 	key.offset = (u64)-1;
2403 
2404 	while (1) {
2405 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2406 		if (ret < 0)
2407 			goto out;
2408 		else if (ret > 0) {
2409 			ret = btrfs_previous_item(root, path, dirid,
2410 						  BTRFS_INODE_REF_KEY);
2411 			if (ret < 0)
2412 				goto out;
2413 			else if (ret > 0) {
2414 				ret = -ENOENT;
2415 				goto out;
2416 			}
2417 		}
2418 
2419 		l = path->nodes[0];
2420 		slot = path->slots[0];
2421 		btrfs_item_key_to_cpu(l, &key, slot);
2422 
2423 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2424 		len = btrfs_inode_ref_name_len(l, iref);
2425 		ptr -= len + 1;
2426 		total_len += len + 1;
2427 		if (ptr < name) {
2428 			ret = -ENAMETOOLONG;
2429 			goto out;
2430 		}
2431 
2432 		*(ptr + len) = '/';
2433 		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2434 
2435 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2436 			break;
2437 
2438 		btrfs_release_path(path);
2439 		key.objectid = key.offset;
2440 		key.offset = (u64)-1;
2441 		dirid = key.objectid;
2442 	}
2443 	memmove(name, ptr, total_len);
2444 	name[total_len] = '\0';
2445 	ret = 0;
2446 out:
2447 	btrfs_put_root(root);
2448 	btrfs_free_path(path);
2449 	return ret;
2450 }
2451 
2452 static int btrfs_search_path_in_tree_user(struct inode *inode,
2453 				struct btrfs_ioctl_ino_lookup_user_args *args)
2454 {
2455 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2456 	struct super_block *sb = inode->i_sb;
2457 	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2458 	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2459 	u64 dirid = args->dirid;
2460 	unsigned long item_off;
2461 	unsigned long item_len;
2462 	struct btrfs_inode_ref *iref;
2463 	struct btrfs_root_ref *rref;
2464 	struct btrfs_root *root = NULL;
2465 	struct btrfs_path *path;
2466 	struct btrfs_key key, key2;
2467 	struct extent_buffer *leaf;
2468 	struct inode *temp_inode;
2469 	char *ptr;
2470 	int slot;
2471 	int len;
2472 	int total_len = 0;
2473 	int ret;
2474 
2475 	path = btrfs_alloc_path();
2476 	if (!path)
2477 		return -ENOMEM;
2478 
2479 	/*
2480 	 * If the bottom subvolume does not exist directly under upper_limit,
2481 	 * construct the path in from the bottom up.
2482 	 */
2483 	if (dirid != upper_limit.objectid) {
2484 		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2485 
2486 		root = btrfs_get_fs_root(fs_info, treeid, true);
2487 		if (IS_ERR(root)) {
2488 			ret = PTR_ERR(root);
2489 			goto out;
2490 		}
2491 
2492 		key.objectid = dirid;
2493 		key.type = BTRFS_INODE_REF_KEY;
2494 		key.offset = (u64)-1;
2495 		while (1) {
2496 			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2497 			if (ret < 0) {
2498 				goto out_put;
2499 			} else if (ret > 0) {
2500 				ret = btrfs_previous_item(root, path, dirid,
2501 							  BTRFS_INODE_REF_KEY);
2502 				if (ret < 0) {
2503 					goto out_put;
2504 				} else if (ret > 0) {
2505 					ret = -ENOENT;
2506 					goto out_put;
2507 				}
2508 			}
2509 
2510 			leaf = path->nodes[0];
2511 			slot = path->slots[0];
2512 			btrfs_item_key_to_cpu(leaf, &key, slot);
2513 
2514 			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2515 			len = btrfs_inode_ref_name_len(leaf, iref);
2516 			ptr -= len + 1;
2517 			total_len += len + 1;
2518 			if (ptr < args->path) {
2519 				ret = -ENAMETOOLONG;
2520 				goto out_put;
2521 			}
2522 
2523 			*(ptr + len) = '/';
2524 			read_extent_buffer(leaf, ptr,
2525 					(unsigned long)(iref + 1), len);
2526 
2527 			/* Check the read+exec permission of this directory */
2528 			ret = btrfs_previous_item(root, path, dirid,
2529 						  BTRFS_INODE_ITEM_KEY);
2530 			if (ret < 0) {
2531 				goto out_put;
2532 			} else if (ret > 0) {
2533 				ret = -ENOENT;
2534 				goto out_put;
2535 			}
2536 
2537 			leaf = path->nodes[0];
2538 			slot = path->slots[0];
2539 			btrfs_item_key_to_cpu(leaf, &key2, slot);
2540 			if (key2.objectid != dirid) {
2541 				ret = -ENOENT;
2542 				goto out_put;
2543 			}
2544 
2545 			temp_inode = btrfs_iget(sb, key2.objectid, root);
2546 			if (IS_ERR(temp_inode)) {
2547 				ret = PTR_ERR(temp_inode);
2548 				goto out_put;
2549 			}
2550 			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2551 			iput(temp_inode);
2552 			if (ret) {
2553 				ret = -EACCES;
2554 				goto out_put;
2555 			}
2556 
2557 			if (key.offset == upper_limit.objectid)
2558 				break;
2559 			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2560 				ret = -EACCES;
2561 				goto out_put;
2562 			}
2563 
2564 			btrfs_release_path(path);
2565 			key.objectid = key.offset;
2566 			key.offset = (u64)-1;
2567 			dirid = key.objectid;
2568 		}
2569 
2570 		memmove(args->path, ptr, total_len);
2571 		args->path[total_len] = '\0';
2572 		btrfs_put_root(root);
2573 		root = NULL;
2574 		btrfs_release_path(path);
2575 	}
2576 
2577 	/* Get the bottom subvolume's name from ROOT_REF */
2578 	key.objectid = treeid;
2579 	key.type = BTRFS_ROOT_REF_KEY;
2580 	key.offset = args->treeid;
2581 	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2582 	if (ret < 0) {
2583 		goto out;
2584 	} else if (ret > 0) {
2585 		ret = -ENOENT;
2586 		goto out;
2587 	}
2588 
2589 	leaf = path->nodes[0];
2590 	slot = path->slots[0];
2591 	btrfs_item_key_to_cpu(leaf, &key, slot);
2592 
2593 	item_off = btrfs_item_ptr_offset(leaf, slot);
2594 	item_len = btrfs_item_size_nr(leaf, slot);
2595 	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2596 	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2597 	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2598 		ret = -EINVAL;
2599 		goto out;
2600 	}
2601 
2602 	/* Copy subvolume's name */
2603 	item_off += sizeof(struct btrfs_root_ref);
2604 	item_len -= sizeof(struct btrfs_root_ref);
2605 	read_extent_buffer(leaf, args->name, item_off, item_len);
2606 	args->name[item_len] = 0;
2607 
2608 out_put:
2609 	btrfs_put_root(root);
2610 out:
2611 	btrfs_free_path(path);
2612 	return ret;
2613 }
2614 
2615 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2616 					   void __user *argp)
2617 {
2618 	struct btrfs_ioctl_ino_lookup_args *args;
2619 	struct inode *inode;
2620 	int ret = 0;
2621 
2622 	args = memdup_user(argp, sizeof(*args));
2623 	if (IS_ERR(args))
2624 		return PTR_ERR(args);
2625 
2626 	inode = file_inode(file);
2627 
2628 	/*
2629 	 * Unprivileged query to obtain the containing subvolume root id. The
2630 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2631 	 */
2632 	if (args->treeid == 0)
2633 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2634 
2635 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2636 		args->name[0] = 0;
2637 		goto out;
2638 	}
2639 
2640 	if (!capable(CAP_SYS_ADMIN)) {
2641 		ret = -EPERM;
2642 		goto out;
2643 	}
2644 
2645 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2646 					args->treeid, args->objectid,
2647 					args->name);
2648 
2649 out:
2650 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2651 		ret = -EFAULT;
2652 
2653 	kfree(args);
2654 	return ret;
2655 }
2656 
2657 /*
2658  * Version of ino_lookup ioctl (unprivileged)
2659  *
2660  * The main differences from ino_lookup ioctl are:
2661  *
2662  *   1. Read + Exec permission will be checked using inode_permission() during
2663  *      path construction. -EACCES will be returned in case of failure.
2664  *   2. Path construction will be stopped at the inode number which corresponds
2665  *      to the fd with which this ioctl is called. If constructed path does not
2666  *      exist under fd's inode, -EACCES will be returned.
2667  *   3. The name of bottom subvolume is also searched and filled.
2668  */
2669 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2670 {
2671 	struct btrfs_ioctl_ino_lookup_user_args *args;
2672 	struct inode *inode;
2673 	int ret;
2674 
2675 	args = memdup_user(argp, sizeof(*args));
2676 	if (IS_ERR(args))
2677 		return PTR_ERR(args);
2678 
2679 	inode = file_inode(file);
2680 
2681 	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2682 	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2683 		/*
2684 		 * The subvolume does not exist under fd with which this is
2685 		 * called
2686 		 */
2687 		kfree(args);
2688 		return -EACCES;
2689 	}
2690 
2691 	ret = btrfs_search_path_in_tree_user(inode, args);
2692 
2693 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2694 		ret = -EFAULT;
2695 
2696 	kfree(args);
2697 	return ret;
2698 }
2699 
2700 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2701 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2702 {
2703 	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2704 	struct btrfs_fs_info *fs_info;
2705 	struct btrfs_root *root;
2706 	struct btrfs_path *path;
2707 	struct btrfs_key key;
2708 	struct btrfs_root_item *root_item;
2709 	struct btrfs_root_ref *rref;
2710 	struct extent_buffer *leaf;
2711 	unsigned long item_off;
2712 	unsigned long item_len;
2713 	struct inode *inode;
2714 	int slot;
2715 	int ret = 0;
2716 
2717 	path = btrfs_alloc_path();
2718 	if (!path)
2719 		return -ENOMEM;
2720 
2721 	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2722 	if (!subvol_info) {
2723 		btrfs_free_path(path);
2724 		return -ENOMEM;
2725 	}
2726 
2727 	inode = file_inode(file);
2728 	fs_info = BTRFS_I(inode)->root->fs_info;
2729 
2730 	/* Get root_item of inode's subvolume */
2731 	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2732 	root = btrfs_get_fs_root(fs_info, key.objectid, true);
2733 	if (IS_ERR(root)) {
2734 		ret = PTR_ERR(root);
2735 		goto out_free;
2736 	}
2737 	root_item = &root->root_item;
2738 
2739 	subvol_info->treeid = key.objectid;
2740 
2741 	subvol_info->generation = btrfs_root_generation(root_item);
2742 	subvol_info->flags = btrfs_root_flags(root_item);
2743 
2744 	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2745 	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2746 						    BTRFS_UUID_SIZE);
2747 	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2748 						    BTRFS_UUID_SIZE);
2749 
2750 	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2751 	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2752 	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2753 
2754 	subvol_info->otransid = btrfs_root_otransid(root_item);
2755 	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2756 	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2757 
2758 	subvol_info->stransid = btrfs_root_stransid(root_item);
2759 	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2760 	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2761 
2762 	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2763 	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2764 	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2765 
2766 	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2767 		/* Search root tree for ROOT_BACKREF of this subvolume */
2768 		key.type = BTRFS_ROOT_BACKREF_KEY;
2769 		key.offset = 0;
2770 		ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2771 		if (ret < 0) {
2772 			goto out;
2773 		} else if (path->slots[0] >=
2774 			   btrfs_header_nritems(path->nodes[0])) {
2775 			ret = btrfs_next_leaf(fs_info->tree_root, path);
2776 			if (ret < 0) {
2777 				goto out;
2778 			} else if (ret > 0) {
2779 				ret = -EUCLEAN;
2780 				goto out;
2781 			}
2782 		}
2783 
2784 		leaf = path->nodes[0];
2785 		slot = path->slots[0];
2786 		btrfs_item_key_to_cpu(leaf, &key, slot);
2787 		if (key.objectid == subvol_info->treeid &&
2788 		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2789 			subvol_info->parent_id = key.offset;
2790 
2791 			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2792 			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2793 
2794 			item_off = btrfs_item_ptr_offset(leaf, slot)
2795 					+ sizeof(struct btrfs_root_ref);
2796 			item_len = btrfs_item_size_nr(leaf, slot)
2797 					- sizeof(struct btrfs_root_ref);
2798 			read_extent_buffer(leaf, subvol_info->name,
2799 					   item_off, item_len);
2800 		} else {
2801 			ret = -ENOENT;
2802 			goto out;
2803 		}
2804 	}
2805 
2806 	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2807 		ret = -EFAULT;
2808 
2809 out:
2810 	btrfs_put_root(root);
2811 out_free:
2812 	btrfs_free_path(path);
2813 	kfree(subvol_info);
2814 	return ret;
2815 }
2816 
2817 /*
2818  * Return ROOT_REF information of the subvolume containing this inode
2819  * except the subvolume name.
2820  */
2821 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2822 {
2823 	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2824 	struct btrfs_root_ref *rref;
2825 	struct btrfs_root *root;
2826 	struct btrfs_path *path;
2827 	struct btrfs_key key;
2828 	struct extent_buffer *leaf;
2829 	struct inode *inode;
2830 	u64 objectid;
2831 	int slot;
2832 	int ret;
2833 	u8 found;
2834 
2835 	path = btrfs_alloc_path();
2836 	if (!path)
2837 		return -ENOMEM;
2838 
2839 	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2840 	if (IS_ERR(rootrefs)) {
2841 		btrfs_free_path(path);
2842 		return PTR_ERR(rootrefs);
2843 	}
2844 
2845 	inode = file_inode(file);
2846 	root = BTRFS_I(inode)->root->fs_info->tree_root;
2847 	objectid = BTRFS_I(inode)->root->root_key.objectid;
2848 
2849 	key.objectid = objectid;
2850 	key.type = BTRFS_ROOT_REF_KEY;
2851 	key.offset = rootrefs->min_treeid;
2852 	found = 0;
2853 
2854 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2855 	if (ret < 0) {
2856 		goto out;
2857 	} else if (path->slots[0] >=
2858 		   btrfs_header_nritems(path->nodes[0])) {
2859 		ret = btrfs_next_leaf(root, path);
2860 		if (ret < 0) {
2861 			goto out;
2862 		} else if (ret > 0) {
2863 			ret = -EUCLEAN;
2864 			goto out;
2865 		}
2866 	}
2867 	while (1) {
2868 		leaf = path->nodes[0];
2869 		slot = path->slots[0];
2870 
2871 		btrfs_item_key_to_cpu(leaf, &key, slot);
2872 		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2873 			ret = 0;
2874 			goto out;
2875 		}
2876 
2877 		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2878 			ret = -EOVERFLOW;
2879 			goto out;
2880 		}
2881 
2882 		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2883 		rootrefs->rootref[found].treeid = key.offset;
2884 		rootrefs->rootref[found].dirid =
2885 				  btrfs_root_ref_dirid(leaf, rref);
2886 		found++;
2887 
2888 		ret = btrfs_next_item(root, path);
2889 		if (ret < 0) {
2890 			goto out;
2891 		} else if (ret > 0) {
2892 			ret = -EUCLEAN;
2893 			goto out;
2894 		}
2895 	}
2896 
2897 out:
2898 	if (!ret || ret == -EOVERFLOW) {
2899 		rootrefs->num_items = found;
2900 		/* update min_treeid for next search */
2901 		if (found)
2902 			rootrefs->min_treeid =
2903 				rootrefs->rootref[found - 1].treeid + 1;
2904 		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2905 			ret = -EFAULT;
2906 	}
2907 
2908 	kfree(rootrefs);
2909 	btrfs_free_path(path);
2910 
2911 	return ret;
2912 }
2913 
2914 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2915 					     void __user *arg,
2916 					     bool destroy_v2)
2917 {
2918 	struct dentry *parent = file->f_path.dentry;
2919 	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2920 	struct dentry *dentry;
2921 	struct inode *dir = d_inode(parent);
2922 	struct inode *inode;
2923 	struct btrfs_root *root = BTRFS_I(dir)->root;
2924 	struct btrfs_root *dest = NULL;
2925 	struct btrfs_ioctl_vol_args *vol_args = NULL;
2926 	struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2927 	char *subvol_name, *subvol_name_ptr = NULL;
2928 	int subvol_namelen;
2929 	int err = 0;
2930 	bool destroy_parent = false;
2931 
2932 	if (destroy_v2) {
2933 		vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2934 		if (IS_ERR(vol_args2))
2935 			return PTR_ERR(vol_args2);
2936 
2937 		if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2938 			err = -EOPNOTSUPP;
2939 			goto out;
2940 		}
2941 
2942 		/*
2943 		 * If SPEC_BY_ID is not set, we are looking for the subvolume by
2944 		 * name, same as v1 currently does.
2945 		 */
2946 		if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2947 			vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2948 			subvol_name = vol_args2->name;
2949 
2950 			err = mnt_want_write_file(file);
2951 			if (err)
2952 				goto out;
2953 		} else {
2954 			if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2955 				err = -EINVAL;
2956 				goto out;
2957 			}
2958 
2959 			err = mnt_want_write_file(file);
2960 			if (err)
2961 				goto out;
2962 
2963 			dentry = btrfs_get_dentry(fs_info->sb,
2964 					BTRFS_FIRST_FREE_OBJECTID,
2965 					vol_args2->subvolid, 0, 0);
2966 			if (IS_ERR(dentry)) {
2967 				err = PTR_ERR(dentry);
2968 				goto out_drop_write;
2969 			}
2970 
2971 			/*
2972 			 * Change the default parent since the subvolume being
2973 			 * deleted can be outside of the current mount point.
2974 			 */
2975 			parent = btrfs_get_parent(dentry);
2976 
2977 			/*
2978 			 * At this point dentry->d_name can point to '/' if the
2979 			 * subvolume we want to destroy is outsite of the
2980 			 * current mount point, so we need to release the
2981 			 * current dentry and execute the lookup to return a new
2982 			 * one with ->d_name pointing to the
2983 			 * <mount point>/subvol_name.
2984 			 */
2985 			dput(dentry);
2986 			if (IS_ERR(parent)) {
2987 				err = PTR_ERR(parent);
2988 				goto out_drop_write;
2989 			}
2990 			dir = d_inode(parent);
2991 
2992 			/*
2993 			 * If v2 was used with SPEC_BY_ID, a new parent was
2994 			 * allocated since the subvolume can be outside of the
2995 			 * current mount point. Later on we need to release this
2996 			 * new parent dentry.
2997 			 */
2998 			destroy_parent = true;
2999 
3000 			subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
3001 						fs_info, vol_args2->subvolid);
3002 			if (IS_ERR(subvol_name_ptr)) {
3003 				err = PTR_ERR(subvol_name_ptr);
3004 				goto free_parent;
3005 			}
3006 			/* subvol_name_ptr is already NULL termined */
3007 			subvol_name = (char *)kbasename(subvol_name_ptr);
3008 		}
3009 	} else {
3010 		vol_args = memdup_user(arg, sizeof(*vol_args));
3011 		if (IS_ERR(vol_args))
3012 			return PTR_ERR(vol_args);
3013 
3014 		vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
3015 		subvol_name = vol_args->name;
3016 
3017 		err = mnt_want_write_file(file);
3018 		if (err)
3019 			goto out;
3020 	}
3021 
3022 	subvol_namelen = strlen(subvol_name);
3023 
3024 	if (strchr(subvol_name, '/') ||
3025 	    strncmp(subvol_name, "..", subvol_namelen) == 0) {
3026 		err = -EINVAL;
3027 		goto free_subvol_name;
3028 	}
3029 
3030 	if (!S_ISDIR(dir->i_mode)) {
3031 		err = -ENOTDIR;
3032 		goto free_subvol_name;
3033 	}
3034 
3035 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
3036 	if (err == -EINTR)
3037 		goto free_subvol_name;
3038 	dentry = lookup_one_len(subvol_name, parent, subvol_namelen);
3039 	if (IS_ERR(dentry)) {
3040 		err = PTR_ERR(dentry);
3041 		goto out_unlock_dir;
3042 	}
3043 
3044 	if (d_really_is_negative(dentry)) {
3045 		err = -ENOENT;
3046 		goto out_dput;
3047 	}
3048 
3049 	inode = d_inode(dentry);
3050 	dest = BTRFS_I(inode)->root;
3051 	if (!capable(CAP_SYS_ADMIN)) {
3052 		/*
3053 		 * Regular user.  Only allow this with a special mount
3054 		 * option, when the user has write+exec access to the
3055 		 * subvol root, and when rmdir(2) would have been
3056 		 * allowed.
3057 		 *
3058 		 * Note that this is _not_ check that the subvol is
3059 		 * empty or doesn't contain data that we wouldn't
3060 		 * otherwise be able to delete.
3061 		 *
3062 		 * Users who want to delete empty subvols should try
3063 		 * rmdir(2).
3064 		 */
3065 		err = -EPERM;
3066 		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
3067 			goto out_dput;
3068 
3069 		/*
3070 		 * Do not allow deletion if the parent dir is the same
3071 		 * as the dir to be deleted.  That means the ioctl
3072 		 * must be called on the dentry referencing the root
3073 		 * of the subvol, not a random directory contained
3074 		 * within it.
3075 		 */
3076 		err = -EINVAL;
3077 		if (root == dest)
3078 			goto out_dput;
3079 
3080 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
3081 		if (err)
3082 			goto out_dput;
3083 	}
3084 
3085 	/* check if subvolume may be deleted by a user */
3086 	err = btrfs_may_delete(dir, dentry, 1);
3087 	if (err)
3088 		goto out_dput;
3089 
3090 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
3091 		err = -EINVAL;
3092 		goto out_dput;
3093 	}
3094 
3095 	inode_lock(inode);
3096 	err = btrfs_delete_subvolume(dir, dentry);
3097 	inode_unlock(inode);
3098 	if (!err) {
3099 		fsnotify_rmdir(dir, dentry);
3100 		d_delete(dentry);
3101 	}
3102 
3103 out_dput:
3104 	dput(dentry);
3105 out_unlock_dir:
3106 	inode_unlock(dir);
3107 free_subvol_name:
3108 	kfree(subvol_name_ptr);
3109 free_parent:
3110 	if (destroy_parent)
3111 		dput(parent);
3112 out_drop_write:
3113 	mnt_drop_write_file(file);
3114 out:
3115 	kfree(vol_args2);
3116 	kfree(vol_args);
3117 	return err;
3118 }
3119 
3120 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
3121 {
3122 	struct inode *inode = file_inode(file);
3123 	struct btrfs_root *root = BTRFS_I(inode)->root;
3124 	struct btrfs_ioctl_defrag_range_args *range;
3125 	int ret;
3126 
3127 	ret = mnt_want_write_file(file);
3128 	if (ret)
3129 		return ret;
3130 
3131 	if (btrfs_root_readonly(root)) {
3132 		ret = -EROFS;
3133 		goto out;
3134 	}
3135 
3136 	switch (inode->i_mode & S_IFMT) {
3137 	case S_IFDIR:
3138 		if (!capable(CAP_SYS_ADMIN)) {
3139 			ret = -EPERM;
3140 			goto out;
3141 		}
3142 		ret = btrfs_defrag_root(root);
3143 		break;
3144 	case S_IFREG:
3145 		/*
3146 		 * Note that this does not check the file descriptor for write
3147 		 * access. This prevents defragmenting executables that are
3148 		 * running and allows defrag on files open in read-only mode.
3149 		 */
3150 		if (!capable(CAP_SYS_ADMIN) &&
3151 		    inode_permission(inode, MAY_WRITE)) {
3152 			ret = -EPERM;
3153 			goto out;
3154 		}
3155 
3156 		range = kzalloc(sizeof(*range), GFP_KERNEL);
3157 		if (!range) {
3158 			ret = -ENOMEM;
3159 			goto out;
3160 		}
3161 
3162 		if (argp) {
3163 			if (copy_from_user(range, argp,
3164 					   sizeof(*range))) {
3165 				ret = -EFAULT;
3166 				kfree(range);
3167 				goto out;
3168 			}
3169 			/* compression requires us to start the IO */
3170 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
3171 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
3172 				range->extent_thresh = (u32)-1;
3173 			}
3174 		} else {
3175 			/* the rest are all set to zero by kzalloc */
3176 			range->len = (u64)-1;
3177 		}
3178 		ret = btrfs_defrag_file(file_inode(file), file,
3179 					range, BTRFS_OLDEST_GENERATION, 0);
3180 		if (ret > 0)
3181 			ret = 0;
3182 		kfree(range);
3183 		break;
3184 	default:
3185 		ret = -EINVAL;
3186 	}
3187 out:
3188 	mnt_drop_write_file(file);
3189 	return ret;
3190 }
3191 
3192 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3193 {
3194 	struct btrfs_ioctl_vol_args *vol_args;
3195 	int ret;
3196 
3197 	if (!capable(CAP_SYS_ADMIN))
3198 		return -EPERM;
3199 
3200 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD))
3201 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3202 
3203 	vol_args = memdup_user(arg, sizeof(*vol_args));
3204 	if (IS_ERR(vol_args)) {
3205 		ret = PTR_ERR(vol_args);
3206 		goto out;
3207 	}
3208 
3209 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3210 	ret = btrfs_init_new_device(fs_info, vol_args->name);
3211 
3212 	if (!ret)
3213 		btrfs_info(fs_info, "disk added %s", vol_args->name);
3214 
3215 	kfree(vol_args);
3216 out:
3217 	btrfs_exclop_finish(fs_info);
3218 	return ret;
3219 }
3220 
3221 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3222 {
3223 	struct inode *inode = file_inode(file);
3224 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3225 	struct btrfs_ioctl_vol_args_v2 *vol_args;
3226 	int ret;
3227 
3228 	if (!capable(CAP_SYS_ADMIN))
3229 		return -EPERM;
3230 
3231 	ret = mnt_want_write_file(file);
3232 	if (ret)
3233 		return ret;
3234 
3235 	vol_args = memdup_user(arg, sizeof(*vol_args));
3236 	if (IS_ERR(vol_args)) {
3237 		ret = PTR_ERR(vol_args);
3238 		goto err_drop;
3239 	}
3240 
3241 	if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
3242 		ret = -EOPNOTSUPP;
3243 		goto out;
3244 	}
3245 
3246 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REMOVE)) {
3247 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3248 		goto out;
3249 	}
3250 
3251 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3252 		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3253 	} else {
3254 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3255 		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3256 	}
3257 	btrfs_exclop_finish(fs_info);
3258 
3259 	if (!ret) {
3260 		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3261 			btrfs_info(fs_info, "device deleted: id %llu",
3262 					vol_args->devid);
3263 		else
3264 			btrfs_info(fs_info, "device deleted: %s",
3265 					vol_args->name);
3266 	}
3267 out:
3268 	kfree(vol_args);
3269 err_drop:
3270 	mnt_drop_write_file(file);
3271 	return ret;
3272 }
3273 
3274 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3275 {
3276 	struct inode *inode = file_inode(file);
3277 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3278 	struct btrfs_ioctl_vol_args *vol_args;
3279 	int ret;
3280 
3281 	if (!capable(CAP_SYS_ADMIN))
3282 		return -EPERM;
3283 
3284 	ret = mnt_want_write_file(file);
3285 	if (ret)
3286 		return ret;
3287 
3288 	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REMOVE)) {
3289 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3290 		goto out_drop_write;
3291 	}
3292 
3293 	vol_args = memdup_user(arg, sizeof(*vol_args));
3294 	if (IS_ERR(vol_args)) {
3295 		ret = PTR_ERR(vol_args);
3296 		goto out;
3297 	}
3298 
3299 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3300 	ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3301 
3302 	if (!ret)
3303 		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3304 	kfree(vol_args);
3305 out:
3306 	btrfs_exclop_finish(fs_info);
3307 out_drop_write:
3308 	mnt_drop_write_file(file);
3309 
3310 	return ret;
3311 }
3312 
3313 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3314 				void __user *arg)
3315 {
3316 	struct btrfs_ioctl_fs_info_args *fi_args;
3317 	struct btrfs_device *device;
3318 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3319 	u64 flags_in;
3320 	int ret = 0;
3321 
3322 	fi_args = memdup_user(arg, sizeof(*fi_args));
3323 	if (IS_ERR(fi_args))
3324 		return PTR_ERR(fi_args);
3325 
3326 	flags_in = fi_args->flags;
3327 	memset(fi_args, 0, sizeof(*fi_args));
3328 
3329 	rcu_read_lock();
3330 	fi_args->num_devices = fs_devices->num_devices;
3331 
3332 	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3333 		if (device->devid > fi_args->max_id)
3334 			fi_args->max_id = device->devid;
3335 	}
3336 	rcu_read_unlock();
3337 
3338 	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3339 	fi_args->nodesize = fs_info->nodesize;
3340 	fi_args->sectorsize = fs_info->sectorsize;
3341 	fi_args->clone_alignment = fs_info->sectorsize;
3342 
3343 	if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
3344 		fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
3345 		fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
3346 		fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
3347 	}
3348 
3349 	if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
3350 		fi_args->generation = fs_info->generation;
3351 		fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
3352 	}
3353 
3354 	if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
3355 		memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
3356 		       sizeof(fi_args->metadata_uuid));
3357 		fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
3358 	}
3359 
3360 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3361 		ret = -EFAULT;
3362 
3363 	kfree(fi_args);
3364 	return ret;
3365 }
3366 
3367 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3368 				 void __user *arg)
3369 {
3370 	struct btrfs_ioctl_dev_info_args *di_args;
3371 	struct btrfs_device *dev;
3372 	int ret = 0;
3373 	char *s_uuid = NULL;
3374 
3375 	di_args = memdup_user(arg, sizeof(*di_args));
3376 	if (IS_ERR(di_args))
3377 		return PTR_ERR(di_args);
3378 
3379 	if (!btrfs_is_empty_uuid(di_args->uuid))
3380 		s_uuid = di_args->uuid;
3381 
3382 	rcu_read_lock();
3383 	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3384 				NULL);
3385 
3386 	if (!dev) {
3387 		ret = -ENODEV;
3388 		goto out;
3389 	}
3390 
3391 	di_args->devid = dev->devid;
3392 	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3393 	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3394 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3395 	if (dev->name) {
3396 		strncpy(di_args->path, rcu_str_deref(dev->name),
3397 				sizeof(di_args->path) - 1);
3398 		di_args->path[sizeof(di_args->path) - 1] = 0;
3399 	} else {
3400 		di_args->path[0] = '\0';
3401 	}
3402 
3403 out:
3404 	rcu_read_unlock();
3405 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3406 		ret = -EFAULT;
3407 
3408 	kfree(di_args);
3409 	return ret;
3410 }
3411 
3412 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3413 {
3414 	struct inode *inode = file_inode(file);
3415 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3416 	struct btrfs_root *root = BTRFS_I(inode)->root;
3417 	struct btrfs_root *new_root;
3418 	struct btrfs_dir_item *di;
3419 	struct btrfs_trans_handle *trans;
3420 	struct btrfs_path *path = NULL;
3421 	struct btrfs_disk_key disk_key;
3422 	u64 objectid = 0;
3423 	u64 dir_id;
3424 	int ret;
3425 
3426 	if (!capable(CAP_SYS_ADMIN))
3427 		return -EPERM;
3428 
3429 	ret = mnt_want_write_file(file);
3430 	if (ret)
3431 		return ret;
3432 
3433 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3434 		ret = -EFAULT;
3435 		goto out;
3436 	}
3437 
3438 	if (!objectid)
3439 		objectid = BTRFS_FS_TREE_OBJECTID;
3440 
3441 	new_root = btrfs_get_fs_root(fs_info, objectid, true);
3442 	if (IS_ERR(new_root)) {
3443 		ret = PTR_ERR(new_root);
3444 		goto out;
3445 	}
3446 	if (!is_fstree(new_root->root_key.objectid)) {
3447 		ret = -ENOENT;
3448 		goto out_free;
3449 	}
3450 
3451 	path = btrfs_alloc_path();
3452 	if (!path) {
3453 		ret = -ENOMEM;
3454 		goto out_free;
3455 	}
3456 
3457 	trans = btrfs_start_transaction(root, 1);
3458 	if (IS_ERR(trans)) {
3459 		ret = PTR_ERR(trans);
3460 		goto out_free;
3461 	}
3462 
3463 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
3464 	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3465 				   dir_id, "default", 7, 1);
3466 	if (IS_ERR_OR_NULL(di)) {
3467 		btrfs_release_path(path);
3468 		btrfs_end_transaction(trans);
3469 		btrfs_err(fs_info,
3470 			  "Umm, you don't have the default diritem, this isn't going to work");
3471 		ret = -ENOENT;
3472 		goto out_free;
3473 	}
3474 
3475 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3476 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3477 	btrfs_mark_buffer_dirty(path->nodes[0]);
3478 	btrfs_release_path(path);
3479 
3480 	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3481 	btrfs_end_transaction(trans);
3482 out_free:
3483 	btrfs_put_root(new_root);
3484 	btrfs_free_path(path);
3485 out:
3486 	mnt_drop_write_file(file);
3487 	return ret;
3488 }
3489 
3490 static void get_block_group_info(struct list_head *groups_list,
3491 				 struct btrfs_ioctl_space_info *space)
3492 {
3493 	struct btrfs_block_group *block_group;
3494 
3495 	space->total_bytes = 0;
3496 	space->used_bytes = 0;
3497 	space->flags = 0;
3498 	list_for_each_entry(block_group, groups_list, list) {
3499 		space->flags = block_group->flags;
3500 		space->total_bytes += block_group->length;
3501 		space->used_bytes += block_group->used;
3502 	}
3503 }
3504 
3505 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3506 				   void __user *arg)
3507 {
3508 	struct btrfs_ioctl_space_args space_args;
3509 	struct btrfs_ioctl_space_info space;
3510 	struct btrfs_ioctl_space_info *dest;
3511 	struct btrfs_ioctl_space_info *dest_orig;
3512 	struct btrfs_ioctl_space_info __user *user_dest;
3513 	struct btrfs_space_info *info;
3514 	static const u64 types[] = {
3515 		BTRFS_BLOCK_GROUP_DATA,
3516 		BTRFS_BLOCK_GROUP_SYSTEM,
3517 		BTRFS_BLOCK_GROUP_METADATA,
3518 		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3519 	};
3520 	int num_types = 4;
3521 	int alloc_size;
3522 	int ret = 0;
3523 	u64 slot_count = 0;
3524 	int i, c;
3525 
3526 	if (copy_from_user(&space_args,
3527 			   (struct btrfs_ioctl_space_args __user *)arg,
3528 			   sizeof(space_args)))
3529 		return -EFAULT;
3530 
3531 	for (i = 0; i < num_types; i++) {
3532 		struct btrfs_space_info *tmp;
3533 
3534 		info = NULL;
3535 		list_for_each_entry(tmp, &fs_info->space_info, list) {
3536 			if (tmp->flags == types[i]) {
3537 				info = tmp;
3538 				break;
3539 			}
3540 		}
3541 
3542 		if (!info)
3543 			continue;
3544 
3545 		down_read(&info->groups_sem);
3546 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3547 			if (!list_empty(&info->block_groups[c]))
3548 				slot_count++;
3549 		}
3550 		up_read(&info->groups_sem);
3551 	}
3552 
3553 	/*
3554 	 * Global block reserve, exported as a space_info
3555 	 */
3556 	slot_count++;
3557 
3558 	/* space_slots == 0 means they are asking for a count */
3559 	if (space_args.space_slots == 0) {
3560 		space_args.total_spaces = slot_count;
3561 		goto out;
3562 	}
3563 
3564 	slot_count = min_t(u64, space_args.space_slots, slot_count);
3565 
3566 	alloc_size = sizeof(*dest) * slot_count;
3567 
3568 	/* we generally have at most 6 or so space infos, one for each raid
3569 	 * level.  So, a whole page should be more than enough for everyone
3570 	 */
3571 	if (alloc_size > PAGE_SIZE)
3572 		return -ENOMEM;
3573 
3574 	space_args.total_spaces = 0;
3575 	dest = kmalloc(alloc_size, GFP_KERNEL);
3576 	if (!dest)
3577 		return -ENOMEM;
3578 	dest_orig = dest;
3579 
3580 	/* now we have a buffer to copy into */
3581 	for (i = 0; i < num_types; i++) {
3582 		struct btrfs_space_info *tmp;
3583 
3584 		if (!slot_count)
3585 			break;
3586 
3587 		info = NULL;
3588 		list_for_each_entry(tmp, &fs_info->space_info, list) {
3589 			if (tmp->flags == types[i]) {
3590 				info = tmp;
3591 				break;
3592 			}
3593 		}
3594 
3595 		if (!info)
3596 			continue;
3597 		down_read(&info->groups_sem);
3598 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3599 			if (!list_empty(&info->block_groups[c])) {
3600 				get_block_group_info(&info->block_groups[c],
3601 						     &space);
3602 				memcpy(dest, &space, sizeof(space));
3603 				dest++;
3604 				space_args.total_spaces++;
3605 				slot_count--;
3606 			}
3607 			if (!slot_count)
3608 				break;
3609 		}
3610 		up_read(&info->groups_sem);
3611 	}
3612 
3613 	/*
3614 	 * Add global block reserve
3615 	 */
3616 	if (slot_count) {
3617 		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3618 
3619 		spin_lock(&block_rsv->lock);
3620 		space.total_bytes = block_rsv->size;
3621 		space.used_bytes = block_rsv->size - block_rsv->reserved;
3622 		spin_unlock(&block_rsv->lock);
3623 		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3624 		memcpy(dest, &space, sizeof(space));
3625 		space_args.total_spaces++;
3626 	}
3627 
3628 	user_dest = (struct btrfs_ioctl_space_info __user *)
3629 		(arg + sizeof(struct btrfs_ioctl_space_args));
3630 
3631 	if (copy_to_user(user_dest, dest_orig, alloc_size))
3632 		ret = -EFAULT;
3633 
3634 	kfree(dest_orig);
3635 out:
3636 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3637 		ret = -EFAULT;
3638 
3639 	return ret;
3640 }
3641 
3642 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3643 					    void __user *argp)
3644 {
3645 	struct btrfs_trans_handle *trans;
3646 	u64 transid;
3647 	int ret;
3648 
3649 	trans = btrfs_attach_transaction_barrier(root);
3650 	if (IS_ERR(trans)) {
3651 		if (PTR_ERR(trans) != -ENOENT)
3652 			return PTR_ERR(trans);
3653 
3654 		/* No running transaction, don't bother */
3655 		transid = root->fs_info->last_trans_committed;
3656 		goto out;
3657 	}
3658 	transid = trans->transid;
3659 	ret = btrfs_commit_transaction_async(trans, 0);
3660 	if (ret) {
3661 		btrfs_end_transaction(trans);
3662 		return ret;
3663 	}
3664 out:
3665 	if (argp)
3666 		if (copy_to_user(argp, &transid, sizeof(transid)))
3667 			return -EFAULT;
3668 	return 0;
3669 }
3670 
3671 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3672 					   void __user *argp)
3673 {
3674 	u64 transid;
3675 
3676 	if (argp) {
3677 		if (copy_from_user(&transid, argp, sizeof(transid)))
3678 			return -EFAULT;
3679 	} else {
3680 		transid = 0;  /* current trans */
3681 	}
3682 	return btrfs_wait_for_commit(fs_info, transid);
3683 }
3684 
3685 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3686 {
3687 	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3688 	struct btrfs_ioctl_scrub_args *sa;
3689 	int ret;
3690 
3691 	if (!capable(CAP_SYS_ADMIN))
3692 		return -EPERM;
3693 
3694 	sa = memdup_user(arg, sizeof(*sa));
3695 	if (IS_ERR(sa))
3696 		return PTR_ERR(sa);
3697 
3698 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3699 		ret = mnt_want_write_file(file);
3700 		if (ret)
3701 			goto out;
3702 	}
3703 
3704 	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3705 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3706 			      0);
3707 
3708 	/*
3709 	 * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3710 	 * error. This is important as it allows user space to know how much
3711 	 * progress scrub has done. For example, if scrub is canceled we get
3712 	 * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3713 	 * space. Later user space can inspect the progress from the structure
3714 	 * btrfs_ioctl_scrub_args and resume scrub from where it left off
3715 	 * previously (btrfs-progs does this).
3716 	 * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3717 	 * then return -EFAULT to signal the structure was not copied or it may
3718 	 * be corrupt and unreliable due to a partial copy.
3719 	 */
3720 	if (copy_to_user(arg, sa, sizeof(*sa)))
3721 		ret = -EFAULT;
3722 
3723 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
3724 		mnt_drop_write_file(file);
3725 out:
3726 	kfree(sa);
3727 	return ret;
3728 }
3729 
3730 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3731 {
3732 	if (!capable(CAP_SYS_ADMIN))
3733 		return -EPERM;
3734 
3735 	return btrfs_scrub_cancel(fs_info);
3736 }
3737 
3738 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3739 				       void __user *arg)
3740 {
3741 	struct btrfs_ioctl_scrub_args *sa;
3742 	int ret;
3743 
3744 	if (!capable(CAP_SYS_ADMIN))
3745 		return -EPERM;
3746 
3747 	sa = memdup_user(arg, sizeof(*sa));
3748 	if (IS_ERR(sa))
3749 		return PTR_ERR(sa);
3750 
3751 	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3752 
3753 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3754 		ret = -EFAULT;
3755 
3756 	kfree(sa);
3757 	return ret;
3758 }
3759 
3760 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3761 				      void __user *arg)
3762 {
3763 	struct btrfs_ioctl_get_dev_stats *sa;
3764 	int ret;
3765 
3766 	sa = memdup_user(arg, sizeof(*sa));
3767 	if (IS_ERR(sa))
3768 		return PTR_ERR(sa);
3769 
3770 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3771 		kfree(sa);
3772 		return -EPERM;
3773 	}
3774 
3775 	ret = btrfs_get_dev_stats(fs_info, sa);
3776 
3777 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3778 		ret = -EFAULT;
3779 
3780 	kfree(sa);
3781 	return ret;
3782 }
3783 
3784 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3785 				    void __user *arg)
3786 {
3787 	struct btrfs_ioctl_dev_replace_args *p;
3788 	int ret;
3789 
3790 	if (!capable(CAP_SYS_ADMIN))
3791 		return -EPERM;
3792 
3793 	p = memdup_user(arg, sizeof(*p));
3794 	if (IS_ERR(p))
3795 		return PTR_ERR(p);
3796 
3797 	switch (p->cmd) {
3798 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3799 		if (sb_rdonly(fs_info->sb)) {
3800 			ret = -EROFS;
3801 			goto out;
3802 		}
3803 		if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
3804 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3805 		} else {
3806 			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3807 			btrfs_exclop_finish(fs_info);
3808 		}
3809 		break;
3810 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3811 		btrfs_dev_replace_status(fs_info, p);
3812 		ret = 0;
3813 		break;
3814 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3815 		p->result = btrfs_dev_replace_cancel(fs_info);
3816 		ret = 0;
3817 		break;
3818 	default:
3819 		ret = -EINVAL;
3820 		break;
3821 	}
3822 
3823 	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3824 		ret = -EFAULT;
3825 out:
3826 	kfree(p);
3827 	return ret;
3828 }
3829 
3830 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3831 {
3832 	int ret = 0;
3833 	int i;
3834 	u64 rel_ptr;
3835 	int size;
3836 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
3837 	struct inode_fs_paths *ipath = NULL;
3838 	struct btrfs_path *path;
3839 
3840 	if (!capable(CAP_DAC_READ_SEARCH))
3841 		return -EPERM;
3842 
3843 	path = btrfs_alloc_path();
3844 	if (!path) {
3845 		ret = -ENOMEM;
3846 		goto out;
3847 	}
3848 
3849 	ipa = memdup_user(arg, sizeof(*ipa));
3850 	if (IS_ERR(ipa)) {
3851 		ret = PTR_ERR(ipa);
3852 		ipa = NULL;
3853 		goto out;
3854 	}
3855 
3856 	size = min_t(u32, ipa->size, 4096);
3857 	ipath = init_ipath(size, root, path);
3858 	if (IS_ERR(ipath)) {
3859 		ret = PTR_ERR(ipath);
3860 		ipath = NULL;
3861 		goto out;
3862 	}
3863 
3864 	ret = paths_from_inode(ipa->inum, ipath);
3865 	if (ret < 0)
3866 		goto out;
3867 
3868 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3869 		rel_ptr = ipath->fspath->val[i] -
3870 			  (u64)(unsigned long)ipath->fspath->val;
3871 		ipath->fspath->val[i] = rel_ptr;
3872 	}
3873 
3874 	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3875 			   ipath->fspath, size);
3876 	if (ret) {
3877 		ret = -EFAULT;
3878 		goto out;
3879 	}
3880 
3881 out:
3882 	btrfs_free_path(path);
3883 	free_ipath(ipath);
3884 	kfree(ipa);
3885 
3886 	return ret;
3887 }
3888 
3889 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3890 {
3891 	struct btrfs_data_container *inodes = ctx;
3892 	const size_t c = 3 * sizeof(u64);
3893 
3894 	if (inodes->bytes_left >= c) {
3895 		inodes->bytes_left -= c;
3896 		inodes->val[inodes->elem_cnt] = inum;
3897 		inodes->val[inodes->elem_cnt + 1] = offset;
3898 		inodes->val[inodes->elem_cnt + 2] = root;
3899 		inodes->elem_cnt += 3;
3900 	} else {
3901 		inodes->bytes_missing += c - inodes->bytes_left;
3902 		inodes->bytes_left = 0;
3903 		inodes->elem_missed += 3;
3904 	}
3905 
3906 	return 0;
3907 }
3908 
3909 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3910 					void __user *arg, int version)
3911 {
3912 	int ret = 0;
3913 	int size;
3914 	struct btrfs_ioctl_logical_ino_args *loi;
3915 	struct btrfs_data_container *inodes = NULL;
3916 	struct btrfs_path *path = NULL;
3917 	bool ignore_offset;
3918 
3919 	if (!capable(CAP_SYS_ADMIN))
3920 		return -EPERM;
3921 
3922 	loi = memdup_user(arg, sizeof(*loi));
3923 	if (IS_ERR(loi))
3924 		return PTR_ERR(loi);
3925 
3926 	if (version == 1) {
3927 		ignore_offset = false;
3928 		size = min_t(u32, loi->size, SZ_64K);
3929 	} else {
3930 		/* All reserved bits must be 0 for now */
3931 		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3932 			ret = -EINVAL;
3933 			goto out_loi;
3934 		}
3935 		/* Only accept flags we have defined so far */
3936 		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3937 			ret = -EINVAL;
3938 			goto out_loi;
3939 		}
3940 		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3941 		size = min_t(u32, loi->size, SZ_16M);
3942 	}
3943 
3944 	path = btrfs_alloc_path();
3945 	if (!path) {
3946 		ret = -ENOMEM;
3947 		goto out;
3948 	}
3949 
3950 	inodes = init_data_container(size);
3951 	if (IS_ERR(inodes)) {
3952 		ret = PTR_ERR(inodes);
3953 		inodes = NULL;
3954 		goto out;
3955 	}
3956 
3957 	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3958 					  build_ino_list, inodes, ignore_offset);
3959 	if (ret == -EINVAL)
3960 		ret = -ENOENT;
3961 	if (ret < 0)
3962 		goto out;
3963 
3964 	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3965 			   size);
3966 	if (ret)
3967 		ret = -EFAULT;
3968 
3969 out:
3970 	btrfs_free_path(path);
3971 	kvfree(inodes);
3972 out_loi:
3973 	kfree(loi);
3974 
3975 	return ret;
3976 }
3977 
3978 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3979 			       struct btrfs_ioctl_balance_args *bargs)
3980 {
3981 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3982 
3983 	bargs->flags = bctl->flags;
3984 
3985 	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3986 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3987 	if (atomic_read(&fs_info->balance_pause_req))
3988 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3989 	if (atomic_read(&fs_info->balance_cancel_req))
3990 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3991 
3992 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3993 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3994 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3995 
3996 	spin_lock(&fs_info->balance_lock);
3997 	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3998 	spin_unlock(&fs_info->balance_lock);
3999 }
4000 
4001 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4002 {
4003 	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4004 	struct btrfs_fs_info *fs_info = root->fs_info;
4005 	struct btrfs_ioctl_balance_args *bargs;
4006 	struct btrfs_balance_control *bctl;
4007 	bool need_unlock; /* for mut. excl. ops lock */
4008 	int ret;
4009 
4010 	if (!capable(CAP_SYS_ADMIN))
4011 		return -EPERM;
4012 
4013 	ret = mnt_want_write_file(file);
4014 	if (ret)
4015 		return ret;
4016 
4017 again:
4018 	if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
4019 		mutex_lock(&fs_info->balance_mutex);
4020 		need_unlock = true;
4021 		goto locked;
4022 	}
4023 
4024 	/*
4025 	 * mut. excl. ops lock is locked.  Three possibilities:
4026 	 *   (1) some other op is running
4027 	 *   (2) balance is running
4028 	 *   (3) balance is paused -- special case (think resume)
4029 	 */
4030 	mutex_lock(&fs_info->balance_mutex);
4031 	if (fs_info->balance_ctl) {
4032 		/* this is either (2) or (3) */
4033 		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4034 			mutex_unlock(&fs_info->balance_mutex);
4035 			/*
4036 			 * Lock released to allow other waiters to continue,
4037 			 * we'll reexamine the status again.
4038 			 */
4039 			mutex_lock(&fs_info->balance_mutex);
4040 
4041 			if (fs_info->balance_ctl &&
4042 			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4043 				/* this is (3) */
4044 				need_unlock = false;
4045 				goto locked;
4046 			}
4047 
4048 			mutex_unlock(&fs_info->balance_mutex);
4049 			goto again;
4050 		} else {
4051 			/* this is (2) */
4052 			mutex_unlock(&fs_info->balance_mutex);
4053 			ret = -EINPROGRESS;
4054 			goto out;
4055 		}
4056 	} else {
4057 		/* this is (1) */
4058 		mutex_unlock(&fs_info->balance_mutex);
4059 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4060 		goto out;
4061 	}
4062 
4063 locked:
4064 
4065 	if (arg) {
4066 		bargs = memdup_user(arg, sizeof(*bargs));
4067 		if (IS_ERR(bargs)) {
4068 			ret = PTR_ERR(bargs);
4069 			goto out_unlock;
4070 		}
4071 
4072 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4073 			if (!fs_info->balance_ctl) {
4074 				ret = -ENOTCONN;
4075 				goto out_bargs;
4076 			}
4077 
4078 			bctl = fs_info->balance_ctl;
4079 			spin_lock(&fs_info->balance_lock);
4080 			bctl->flags |= BTRFS_BALANCE_RESUME;
4081 			spin_unlock(&fs_info->balance_lock);
4082 
4083 			goto do_balance;
4084 		}
4085 	} else {
4086 		bargs = NULL;
4087 	}
4088 
4089 	if (fs_info->balance_ctl) {
4090 		ret = -EINPROGRESS;
4091 		goto out_bargs;
4092 	}
4093 
4094 	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4095 	if (!bctl) {
4096 		ret = -ENOMEM;
4097 		goto out_bargs;
4098 	}
4099 
4100 	if (arg) {
4101 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4102 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4103 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4104 
4105 		bctl->flags = bargs->flags;
4106 	} else {
4107 		/* balance everything - no filters */
4108 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4109 	}
4110 
4111 	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4112 		ret = -EINVAL;
4113 		goto out_bctl;
4114 	}
4115 
4116 do_balance:
4117 	/*
4118 	 * Ownership of bctl and exclusive operation goes to btrfs_balance.
4119 	 * bctl is freed in reset_balance_state, or, if restriper was paused
4120 	 * all the way until unmount, in free_fs_info.  The flag should be
4121 	 * cleared after reset_balance_state.
4122 	 */
4123 	need_unlock = false;
4124 
4125 	ret = btrfs_balance(fs_info, bctl, bargs);
4126 	bctl = NULL;
4127 
4128 	if ((ret == 0 || ret == -ECANCELED) && arg) {
4129 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4130 			ret = -EFAULT;
4131 	}
4132 
4133 out_bctl:
4134 	kfree(bctl);
4135 out_bargs:
4136 	kfree(bargs);
4137 out_unlock:
4138 	mutex_unlock(&fs_info->balance_mutex);
4139 	if (need_unlock)
4140 		btrfs_exclop_finish(fs_info);
4141 out:
4142 	mnt_drop_write_file(file);
4143 	return ret;
4144 }
4145 
4146 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4147 {
4148 	if (!capable(CAP_SYS_ADMIN))
4149 		return -EPERM;
4150 
4151 	switch (cmd) {
4152 	case BTRFS_BALANCE_CTL_PAUSE:
4153 		return btrfs_pause_balance(fs_info);
4154 	case BTRFS_BALANCE_CTL_CANCEL:
4155 		return btrfs_cancel_balance(fs_info);
4156 	}
4157 
4158 	return -EINVAL;
4159 }
4160 
4161 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4162 					 void __user *arg)
4163 {
4164 	struct btrfs_ioctl_balance_args *bargs;
4165 	int ret = 0;
4166 
4167 	if (!capable(CAP_SYS_ADMIN))
4168 		return -EPERM;
4169 
4170 	mutex_lock(&fs_info->balance_mutex);
4171 	if (!fs_info->balance_ctl) {
4172 		ret = -ENOTCONN;
4173 		goto out;
4174 	}
4175 
4176 	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4177 	if (!bargs) {
4178 		ret = -ENOMEM;
4179 		goto out;
4180 	}
4181 
4182 	btrfs_update_ioctl_balance_args(fs_info, bargs);
4183 
4184 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4185 		ret = -EFAULT;
4186 
4187 	kfree(bargs);
4188 out:
4189 	mutex_unlock(&fs_info->balance_mutex);
4190 	return ret;
4191 }
4192 
4193 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4194 {
4195 	struct inode *inode = file_inode(file);
4196 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4197 	struct btrfs_ioctl_quota_ctl_args *sa;
4198 	int ret;
4199 
4200 	if (!capable(CAP_SYS_ADMIN))
4201 		return -EPERM;
4202 
4203 	ret = mnt_want_write_file(file);
4204 	if (ret)
4205 		return ret;
4206 
4207 	sa = memdup_user(arg, sizeof(*sa));
4208 	if (IS_ERR(sa)) {
4209 		ret = PTR_ERR(sa);
4210 		goto drop_write;
4211 	}
4212 
4213 	down_write(&fs_info->subvol_sem);
4214 
4215 	switch (sa->cmd) {
4216 	case BTRFS_QUOTA_CTL_ENABLE:
4217 		ret = btrfs_quota_enable(fs_info);
4218 		break;
4219 	case BTRFS_QUOTA_CTL_DISABLE:
4220 		ret = btrfs_quota_disable(fs_info);
4221 		break;
4222 	default:
4223 		ret = -EINVAL;
4224 		break;
4225 	}
4226 
4227 	kfree(sa);
4228 	up_write(&fs_info->subvol_sem);
4229 drop_write:
4230 	mnt_drop_write_file(file);
4231 	return ret;
4232 }
4233 
4234 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4235 {
4236 	struct inode *inode = file_inode(file);
4237 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4238 	struct btrfs_root *root = BTRFS_I(inode)->root;
4239 	struct btrfs_ioctl_qgroup_assign_args *sa;
4240 	struct btrfs_trans_handle *trans;
4241 	int ret;
4242 	int err;
4243 
4244 	if (!capable(CAP_SYS_ADMIN))
4245 		return -EPERM;
4246 
4247 	ret = mnt_want_write_file(file);
4248 	if (ret)
4249 		return ret;
4250 
4251 	sa = memdup_user(arg, sizeof(*sa));
4252 	if (IS_ERR(sa)) {
4253 		ret = PTR_ERR(sa);
4254 		goto drop_write;
4255 	}
4256 
4257 	trans = btrfs_join_transaction(root);
4258 	if (IS_ERR(trans)) {
4259 		ret = PTR_ERR(trans);
4260 		goto out;
4261 	}
4262 
4263 	if (sa->assign) {
4264 		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4265 	} else {
4266 		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4267 	}
4268 
4269 	/* update qgroup status and info */
4270 	err = btrfs_run_qgroups(trans);
4271 	if (err < 0)
4272 		btrfs_handle_fs_error(fs_info, err,
4273 				      "failed to update qgroup status and info");
4274 	err = btrfs_end_transaction(trans);
4275 	if (err && !ret)
4276 		ret = err;
4277 
4278 out:
4279 	kfree(sa);
4280 drop_write:
4281 	mnt_drop_write_file(file);
4282 	return ret;
4283 }
4284 
4285 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4286 {
4287 	struct inode *inode = file_inode(file);
4288 	struct btrfs_root *root = BTRFS_I(inode)->root;
4289 	struct btrfs_ioctl_qgroup_create_args *sa;
4290 	struct btrfs_trans_handle *trans;
4291 	int ret;
4292 	int err;
4293 
4294 	if (!capable(CAP_SYS_ADMIN))
4295 		return -EPERM;
4296 
4297 	ret = mnt_want_write_file(file);
4298 	if (ret)
4299 		return ret;
4300 
4301 	sa = memdup_user(arg, sizeof(*sa));
4302 	if (IS_ERR(sa)) {
4303 		ret = PTR_ERR(sa);
4304 		goto drop_write;
4305 	}
4306 
4307 	if (!sa->qgroupid) {
4308 		ret = -EINVAL;
4309 		goto out;
4310 	}
4311 
4312 	trans = btrfs_join_transaction(root);
4313 	if (IS_ERR(trans)) {
4314 		ret = PTR_ERR(trans);
4315 		goto out;
4316 	}
4317 
4318 	if (sa->create) {
4319 		ret = btrfs_create_qgroup(trans, sa->qgroupid);
4320 	} else {
4321 		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4322 	}
4323 
4324 	err = btrfs_end_transaction(trans);
4325 	if (err && !ret)
4326 		ret = err;
4327 
4328 out:
4329 	kfree(sa);
4330 drop_write:
4331 	mnt_drop_write_file(file);
4332 	return ret;
4333 }
4334 
4335 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4336 {
4337 	struct inode *inode = file_inode(file);
4338 	struct btrfs_root *root = BTRFS_I(inode)->root;
4339 	struct btrfs_ioctl_qgroup_limit_args *sa;
4340 	struct btrfs_trans_handle *trans;
4341 	int ret;
4342 	int err;
4343 	u64 qgroupid;
4344 
4345 	if (!capable(CAP_SYS_ADMIN))
4346 		return -EPERM;
4347 
4348 	ret = mnt_want_write_file(file);
4349 	if (ret)
4350 		return ret;
4351 
4352 	sa = memdup_user(arg, sizeof(*sa));
4353 	if (IS_ERR(sa)) {
4354 		ret = PTR_ERR(sa);
4355 		goto drop_write;
4356 	}
4357 
4358 	trans = btrfs_join_transaction(root);
4359 	if (IS_ERR(trans)) {
4360 		ret = PTR_ERR(trans);
4361 		goto out;
4362 	}
4363 
4364 	qgroupid = sa->qgroupid;
4365 	if (!qgroupid) {
4366 		/* take the current subvol as qgroup */
4367 		qgroupid = root->root_key.objectid;
4368 	}
4369 
4370 	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4371 
4372 	err = btrfs_end_transaction(trans);
4373 	if (err && !ret)
4374 		ret = err;
4375 
4376 out:
4377 	kfree(sa);
4378 drop_write:
4379 	mnt_drop_write_file(file);
4380 	return ret;
4381 }
4382 
4383 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4384 {
4385 	struct inode *inode = file_inode(file);
4386 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4387 	struct btrfs_ioctl_quota_rescan_args *qsa;
4388 	int ret;
4389 
4390 	if (!capable(CAP_SYS_ADMIN))
4391 		return -EPERM;
4392 
4393 	ret = mnt_want_write_file(file);
4394 	if (ret)
4395 		return ret;
4396 
4397 	qsa = memdup_user(arg, sizeof(*qsa));
4398 	if (IS_ERR(qsa)) {
4399 		ret = PTR_ERR(qsa);
4400 		goto drop_write;
4401 	}
4402 
4403 	if (qsa->flags) {
4404 		ret = -EINVAL;
4405 		goto out;
4406 	}
4407 
4408 	ret = btrfs_qgroup_rescan(fs_info);
4409 
4410 out:
4411 	kfree(qsa);
4412 drop_write:
4413 	mnt_drop_write_file(file);
4414 	return ret;
4415 }
4416 
4417 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
4418 						void __user *arg)
4419 {
4420 	struct btrfs_ioctl_quota_rescan_args *qsa;
4421 	int ret = 0;
4422 
4423 	if (!capable(CAP_SYS_ADMIN))
4424 		return -EPERM;
4425 
4426 	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
4427 	if (!qsa)
4428 		return -ENOMEM;
4429 
4430 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4431 		qsa->flags = 1;
4432 		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
4433 	}
4434 
4435 	if (copy_to_user(arg, qsa, sizeof(*qsa)))
4436 		ret = -EFAULT;
4437 
4438 	kfree(qsa);
4439 	return ret;
4440 }
4441 
4442 static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
4443 						void __user *arg)
4444 {
4445 	if (!capable(CAP_SYS_ADMIN))
4446 		return -EPERM;
4447 
4448 	return btrfs_qgroup_wait_for_completion(fs_info, true);
4449 }
4450 
4451 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4452 					    struct btrfs_ioctl_received_subvol_args *sa)
4453 {
4454 	struct inode *inode = file_inode(file);
4455 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4456 	struct btrfs_root *root = BTRFS_I(inode)->root;
4457 	struct btrfs_root_item *root_item = &root->root_item;
4458 	struct btrfs_trans_handle *trans;
4459 	struct timespec64 ct = current_time(inode);
4460 	int ret = 0;
4461 	int received_uuid_changed;
4462 
4463 	if (!inode_owner_or_capable(inode))
4464 		return -EPERM;
4465 
4466 	ret = mnt_want_write_file(file);
4467 	if (ret < 0)
4468 		return ret;
4469 
4470 	down_write(&fs_info->subvol_sem);
4471 
4472 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4473 		ret = -EINVAL;
4474 		goto out;
4475 	}
4476 
4477 	if (btrfs_root_readonly(root)) {
4478 		ret = -EROFS;
4479 		goto out;
4480 	}
4481 
4482 	/*
4483 	 * 1 - root item
4484 	 * 2 - uuid items (received uuid + subvol uuid)
4485 	 */
4486 	trans = btrfs_start_transaction(root, 3);
4487 	if (IS_ERR(trans)) {
4488 		ret = PTR_ERR(trans);
4489 		trans = NULL;
4490 		goto out;
4491 	}
4492 
4493 	sa->rtransid = trans->transid;
4494 	sa->rtime.sec = ct.tv_sec;
4495 	sa->rtime.nsec = ct.tv_nsec;
4496 
4497 	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4498 				       BTRFS_UUID_SIZE);
4499 	if (received_uuid_changed &&
4500 	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
4501 		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4502 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4503 					  root->root_key.objectid);
4504 		if (ret && ret != -ENOENT) {
4505 		        btrfs_abort_transaction(trans, ret);
4506 		        btrfs_end_transaction(trans);
4507 		        goto out;
4508 		}
4509 	}
4510 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4511 	btrfs_set_root_stransid(root_item, sa->stransid);
4512 	btrfs_set_root_rtransid(root_item, sa->rtransid);
4513 	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4514 	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4515 	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4516 	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4517 
4518 	ret = btrfs_update_root(trans, fs_info->tree_root,
4519 				&root->root_key, &root->root_item);
4520 	if (ret < 0) {
4521 		btrfs_end_transaction(trans);
4522 		goto out;
4523 	}
4524 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4525 		ret = btrfs_uuid_tree_add(trans, sa->uuid,
4526 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4527 					  root->root_key.objectid);
4528 		if (ret < 0 && ret != -EEXIST) {
4529 			btrfs_abort_transaction(trans, ret);
4530 			btrfs_end_transaction(trans);
4531 			goto out;
4532 		}
4533 	}
4534 	ret = btrfs_commit_transaction(trans);
4535 out:
4536 	up_write(&fs_info->subvol_sem);
4537 	mnt_drop_write_file(file);
4538 	return ret;
4539 }
4540 
4541 #ifdef CONFIG_64BIT
4542 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4543 						void __user *arg)
4544 {
4545 	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4546 	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4547 	int ret = 0;
4548 
4549 	args32 = memdup_user(arg, sizeof(*args32));
4550 	if (IS_ERR(args32))
4551 		return PTR_ERR(args32);
4552 
4553 	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4554 	if (!args64) {
4555 		ret = -ENOMEM;
4556 		goto out;
4557 	}
4558 
4559 	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4560 	args64->stransid = args32->stransid;
4561 	args64->rtransid = args32->rtransid;
4562 	args64->stime.sec = args32->stime.sec;
4563 	args64->stime.nsec = args32->stime.nsec;
4564 	args64->rtime.sec = args32->rtime.sec;
4565 	args64->rtime.nsec = args32->rtime.nsec;
4566 	args64->flags = args32->flags;
4567 
4568 	ret = _btrfs_ioctl_set_received_subvol(file, args64);
4569 	if (ret)
4570 		goto out;
4571 
4572 	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4573 	args32->stransid = args64->stransid;
4574 	args32->rtransid = args64->rtransid;
4575 	args32->stime.sec = args64->stime.sec;
4576 	args32->stime.nsec = args64->stime.nsec;
4577 	args32->rtime.sec = args64->rtime.sec;
4578 	args32->rtime.nsec = args64->rtime.nsec;
4579 	args32->flags = args64->flags;
4580 
4581 	ret = copy_to_user(arg, args32, sizeof(*args32));
4582 	if (ret)
4583 		ret = -EFAULT;
4584 
4585 out:
4586 	kfree(args32);
4587 	kfree(args64);
4588 	return ret;
4589 }
4590 #endif
4591 
4592 static long btrfs_ioctl_set_received_subvol(struct file *file,
4593 					    void __user *arg)
4594 {
4595 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
4596 	int ret = 0;
4597 
4598 	sa = memdup_user(arg, sizeof(*sa));
4599 	if (IS_ERR(sa))
4600 		return PTR_ERR(sa);
4601 
4602 	ret = _btrfs_ioctl_set_received_subvol(file, sa);
4603 
4604 	if (ret)
4605 		goto out;
4606 
4607 	ret = copy_to_user(arg, sa, sizeof(*sa));
4608 	if (ret)
4609 		ret = -EFAULT;
4610 
4611 out:
4612 	kfree(sa);
4613 	return ret;
4614 }
4615 
4616 static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4617 					void __user *arg)
4618 {
4619 	size_t len;
4620 	int ret;
4621 	char label[BTRFS_LABEL_SIZE];
4622 
4623 	spin_lock(&fs_info->super_lock);
4624 	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4625 	spin_unlock(&fs_info->super_lock);
4626 
4627 	len = strnlen(label, BTRFS_LABEL_SIZE);
4628 
4629 	if (len == BTRFS_LABEL_SIZE) {
4630 		btrfs_warn(fs_info,
4631 			   "label is too long, return the first %zu bytes",
4632 			   --len);
4633 	}
4634 
4635 	ret = copy_to_user(arg, label, len);
4636 
4637 	return ret ? -EFAULT : 0;
4638 }
4639 
4640 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4641 {
4642 	struct inode *inode = file_inode(file);
4643 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4644 	struct btrfs_root *root = BTRFS_I(inode)->root;
4645 	struct btrfs_super_block *super_block = fs_info->super_copy;
4646 	struct btrfs_trans_handle *trans;
4647 	char label[BTRFS_LABEL_SIZE];
4648 	int ret;
4649 
4650 	if (!capable(CAP_SYS_ADMIN))
4651 		return -EPERM;
4652 
4653 	if (copy_from_user(label, arg, sizeof(label)))
4654 		return -EFAULT;
4655 
4656 	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4657 		btrfs_err(fs_info,
4658 			  "unable to set label with more than %d bytes",
4659 			  BTRFS_LABEL_SIZE - 1);
4660 		return -EINVAL;
4661 	}
4662 
4663 	ret = mnt_want_write_file(file);
4664 	if (ret)
4665 		return ret;
4666 
4667 	trans = btrfs_start_transaction(root, 0);
4668 	if (IS_ERR(trans)) {
4669 		ret = PTR_ERR(trans);
4670 		goto out_unlock;
4671 	}
4672 
4673 	spin_lock(&fs_info->super_lock);
4674 	strcpy(super_block->label, label);
4675 	spin_unlock(&fs_info->super_lock);
4676 	ret = btrfs_commit_transaction(trans);
4677 
4678 out_unlock:
4679 	mnt_drop_write_file(file);
4680 	return ret;
4681 }
4682 
4683 #define INIT_FEATURE_FLAGS(suffix) \
4684 	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4685 	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4686 	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4687 
4688 int btrfs_ioctl_get_supported_features(void __user *arg)
4689 {
4690 	static const struct btrfs_ioctl_feature_flags features[3] = {
4691 		INIT_FEATURE_FLAGS(SUPP),
4692 		INIT_FEATURE_FLAGS(SAFE_SET),
4693 		INIT_FEATURE_FLAGS(SAFE_CLEAR)
4694 	};
4695 
4696 	if (copy_to_user(arg, &features, sizeof(features)))
4697 		return -EFAULT;
4698 
4699 	return 0;
4700 }
4701 
4702 static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4703 					void __user *arg)
4704 {
4705 	struct btrfs_super_block *super_block = fs_info->super_copy;
4706 	struct btrfs_ioctl_feature_flags features;
4707 
4708 	features.compat_flags = btrfs_super_compat_flags(super_block);
4709 	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4710 	features.incompat_flags = btrfs_super_incompat_flags(super_block);
4711 
4712 	if (copy_to_user(arg, &features, sizeof(features)))
4713 		return -EFAULT;
4714 
4715 	return 0;
4716 }
4717 
4718 static int check_feature_bits(struct btrfs_fs_info *fs_info,
4719 			      enum btrfs_feature_set set,
4720 			      u64 change_mask, u64 flags, u64 supported_flags,
4721 			      u64 safe_set, u64 safe_clear)
4722 {
4723 	const char *type = btrfs_feature_set_name(set);
4724 	char *names;
4725 	u64 disallowed, unsupported;
4726 	u64 set_mask = flags & change_mask;
4727 	u64 clear_mask = ~flags & change_mask;
4728 
4729 	unsupported = set_mask & ~supported_flags;
4730 	if (unsupported) {
4731 		names = btrfs_printable_features(set, unsupported);
4732 		if (names) {
4733 			btrfs_warn(fs_info,
4734 				   "this kernel does not support the %s feature bit%s",
4735 				   names, strchr(names, ',') ? "s" : "");
4736 			kfree(names);
4737 		} else
4738 			btrfs_warn(fs_info,
4739 				   "this kernel does not support %s bits 0x%llx",
4740 				   type, unsupported);
4741 		return -EOPNOTSUPP;
4742 	}
4743 
4744 	disallowed = set_mask & ~safe_set;
4745 	if (disallowed) {
4746 		names = btrfs_printable_features(set, disallowed);
4747 		if (names) {
4748 			btrfs_warn(fs_info,
4749 				   "can't set the %s feature bit%s while mounted",
4750 				   names, strchr(names, ',') ? "s" : "");
4751 			kfree(names);
4752 		} else
4753 			btrfs_warn(fs_info,
4754 				   "can't set %s bits 0x%llx while mounted",
4755 				   type, disallowed);
4756 		return -EPERM;
4757 	}
4758 
4759 	disallowed = clear_mask & ~safe_clear;
4760 	if (disallowed) {
4761 		names = btrfs_printable_features(set, disallowed);
4762 		if (names) {
4763 			btrfs_warn(fs_info,
4764 				   "can't clear the %s feature bit%s while mounted",
4765 				   names, strchr(names, ',') ? "s" : "");
4766 			kfree(names);
4767 		} else
4768 			btrfs_warn(fs_info,
4769 				   "can't clear %s bits 0x%llx while mounted",
4770 				   type, disallowed);
4771 		return -EPERM;
4772 	}
4773 
4774 	return 0;
4775 }
4776 
4777 #define check_feature(fs_info, change_mask, flags, mask_base)	\
4778 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
4779 		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
4780 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
4781 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4782 
4783 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4784 {
4785 	struct inode *inode = file_inode(file);
4786 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4787 	struct btrfs_root *root = BTRFS_I(inode)->root;
4788 	struct btrfs_super_block *super_block = fs_info->super_copy;
4789 	struct btrfs_ioctl_feature_flags flags[2];
4790 	struct btrfs_trans_handle *trans;
4791 	u64 newflags;
4792 	int ret;
4793 
4794 	if (!capable(CAP_SYS_ADMIN))
4795 		return -EPERM;
4796 
4797 	if (copy_from_user(flags, arg, sizeof(flags)))
4798 		return -EFAULT;
4799 
4800 	/* Nothing to do */
4801 	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4802 	    !flags[0].incompat_flags)
4803 		return 0;
4804 
4805 	ret = check_feature(fs_info, flags[0].compat_flags,
4806 			    flags[1].compat_flags, COMPAT);
4807 	if (ret)
4808 		return ret;
4809 
4810 	ret = check_feature(fs_info, flags[0].compat_ro_flags,
4811 			    flags[1].compat_ro_flags, COMPAT_RO);
4812 	if (ret)
4813 		return ret;
4814 
4815 	ret = check_feature(fs_info, flags[0].incompat_flags,
4816 			    flags[1].incompat_flags, INCOMPAT);
4817 	if (ret)
4818 		return ret;
4819 
4820 	ret = mnt_want_write_file(file);
4821 	if (ret)
4822 		return ret;
4823 
4824 	trans = btrfs_start_transaction(root, 0);
4825 	if (IS_ERR(trans)) {
4826 		ret = PTR_ERR(trans);
4827 		goto out_drop_write;
4828 	}
4829 
4830 	spin_lock(&fs_info->super_lock);
4831 	newflags = btrfs_super_compat_flags(super_block);
4832 	newflags |= flags[0].compat_flags & flags[1].compat_flags;
4833 	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4834 	btrfs_set_super_compat_flags(super_block, newflags);
4835 
4836 	newflags = btrfs_super_compat_ro_flags(super_block);
4837 	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4838 	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4839 	btrfs_set_super_compat_ro_flags(super_block, newflags);
4840 
4841 	newflags = btrfs_super_incompat_flags(super_block);
4842 	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4843 	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4844 	btrfs_set_super_incompat_flags(super_block, newflags);
4845 	spin_unlock(&fs_info->super_lock);
4846 
4847 	ret = btrfs_commit_transaction(trans);
4848 out_drop_write:
4849 	mnt_drop_write_file(file);
4850 
4851 	return ret;
4852 }
4853 
4854 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
4855 {
4856 	struct btrfs_ioctl_send_args *arg;
4857 	int ret;
4858 
4859 	if (compat) {
4860 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4861 		struct btrfs_ioctl_send_args_32 args32;
4862 
4863 		ret = copy_from_user(&args32, argp, sizeof(args32));
4864 		if (ret)
4865 			return -EFAULT;
4866 		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4867 		if (!arg)
4868 			return -ENOMEM;
4869 		arg->send_fd = args32.send_fd;
4870 		arg->clone_sources_count = args32.clone_sources_count;
4871 		arg->clone_sources = compat_ptr(args32.clone_sources);
4872 		arg->parent_root = args32.parent_root;
4873 		arg->flags = args32.flags;
4874 		memcpy(arg->reserved, args32.reserved,
4875 		       sizeof(args32.reserved));
4876 #else
4877 		return -ENOTTY;
4878 #endif
4879 	} else {
4880 		arg = memdup_user(argp, sizeof(*arg));
4881 		if (IS_ERR(arg))
4882 			return PTR_ERR(arg);
4883 	}
4884 	ret = btrfs_ioctl_send(file, arg);
4885 	kfree(arg);
4886 	return ret;
4887 }
4888 
4889 long btrfs_ioctl(struct file *file, unsigned int
4890 		cmd, unsigned long arg)
4891 {
4892 	struct inode *inode = file_inode(file);
4893 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4894 	struct btrfs_root *root = BTRFS_I(inode)->root;
4895 	void __user *argp = (void __user *)arg;
4896 
4897 	switch (cmd) {
4898 	case FS_IOC_GETFLAGS:
4899 		return btrfs_ioctl_getflags(file, argp);
4900 	case FS_IOC_SETFLAGS:
4901 		return btrfs_ioctl_setflags(file, argp);
4902 	case FS_IOC_GETVERSION:
4903 		return btrfs_ioctl_getversion(file, argp);
4904 	case FS_IOC_GETFSLABEL:
4905 		return btrfs_ioctl_get_fslabel(fs_info, argp);
4906 	case FS_IOC_SETFSLABEL:
4907 		return btrfs_ioctl_set_fslabel(file, argp);
4908 	case FITRIM:
4909 		return btrfs_ioctl_fitrim(fs_info, argp);
4910 	case BTRFS_IOC_SNAP_CREATE:
4911 		return btrfs_ioctl_snap_create(file, argp, 0);
4912 	case BTRFS_IOC_SNAP_CREATE_V2:
4913 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
4914 	case BTRFS_IOC_SUBVOL_CREATE:
4915 		return btrfs_ioctl_snap_create(file, argp, 1);
4916 	case BTRFS_IOC_SUBVOL_CREATE_V2:
4917 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
4918 	case BTRFS_IOC_SNAP_DESTROY:
4919 		return btrfs_ioctl_snap_destroy(file, argp, false);
4920 	case BTRFS_IOC_SNAP_DESTROY_V2:
4921 		return btrfs_ioctl_snap_destroy(file, argp, true);
4922 	case BTRFS_IOC_SUBVOL_GETFLAGS:
4923 		return btrfs_ioctl_subvol_getflags(file, argp);
4924 	case BTRFS_IOC_SUBVOL_SETFLAGS:
4925 		return btrfs_ioctl_subvol_setflags(file, argp);
4926 	case BTRFS_IOC_DEFAULT_SUBVOL:
4927 		return btrfs_ioctl_default_subvol(file, argp);
4928 	case BTRFS_IOC_DEFRAG:
4929 		return btrfs_ioctl_defrag(file, NULL);
4930 	case BTRFS_IOC_DEFRAG_RANGE:
4931 		return btrfs_ioctl_defrag(file, argp);
4932 	case BTRFS_IOC_RESIZE:
4933 		return btrfs_ioctl_resize(file, argp);
4934 	case BTRFS_IOC_ADD_DEV:
4935 		return btrfs_ioctl_add_dev(fs_info, argp);
4936 	case BTRFS_IOC_RM_DEV:
4937 		return btrfs_ioctl_rm_dev(file, argp);
4938 	case BTRFS_IOC_RM_DEV_V2:
4939 		return btrfs_ioctl_rm_dev_v2(file, argp);
4940 	case BTRFS_IOC_FS_INFO:
4941 		return btrfs_ioctl_fs_info(fs_info, argp);
4942 	case BTRFS_IOC_DEV_INFO:
4943 		return btrfs_ioctl_dev_info(fs_info, argp);
4944 	case BTRFS_IOC_BALANCE:
4945 		return btrfs_ioctl_balance(file, NULL);
4946 	case BTRFS_IOC_TREE_SEARCH:
4947 		return btrfs_ioctl_tree_search(file, argp);
4948 	case BTRFS_IOC_TREE_SEARCH_V2:
4949 		return btrfs_ioctl_tree_search_v2(file, argp);
4950 	case BTRFS_IOC_INO_LOOKUP:
4951 		return btrfs_ioctl_ino_lookup(file, argp);
4952 	case BTRFS_IOC_INO_PATHS:
4953 		return btrfs_ioctl_ino_to_path(root, argp);
4954 	case BTRFS_IOC_LOGICAL_INO:
4955 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
4956 	case BTRFS_IOC_LOGICAL_INO_V2:
4957 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
4958 	case BTRFS_IOC_SPACE_INFO:
4959 		return btrfs_ioctl_space_info(fs_info, argp);
4960 	case BTRFS_IOC_SYNC: {
4961 		int ret;
4962 
4963 		ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
4964 		if (ret)
4965 			return ret;
4966 		ret = btrfs_sync_fs(inode->i_sb, 1);
4967 		/*
4968 		 * The transaction thread may want to do more work,
4969 		 * namely it pokes the cleaner kthread that will start
4970 		 * processing uncleaned subvols.
4971 		 */
4972 		wake_up_process(fs_info->transaction_kthread);
4973 		return ret;
4974 	}
4975 	case BTRFS_IOC_START_SYNC:
4976 		return btrfs_ioctl_start_sync(root, argp);
4977 	case BTRFS_IOC_WAIT_SYNC:
4978 		return btrfs_ioctl_wait_sync(fs_info, argp);
4979 	case BTRFS_IOC_SCRUB:
4980 		return btrfs_ioctl_scrub(file, argp);
4981 	case BTRFS_IOC_SCRUB_CANCEL:
4982 		return btrfs_ioctl_scrub_cancel(fs_info);
4983 	case BTRFS_IOC_SCRUB_PROGRESS:
4984 		return btrfs_ioctl_scrub_progress(fs_info, argp);
4985 	case BTRFS_IOC_BALANCE_V2:
4986 		return btrfs_ioctl_balance(file, argp);
4987 	case BTRFS_IOC_BALANCE_CTL:
4988 		return btrfs_ioctl_balance_ctl(fs_info, arg);
4989 	case BTRFS_IOC_BALANCE_PROGRESS:
4990 		return btrfs_ioctl_balance_progress(fs_info, argp);
4991 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4992 		return btrfs_ioctl_set_received_subvol(file, argp);
4993 #ifdef CONFIG_64BIT
4994 	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
4995 		return btrfs_ioctl_set_received_subvol_32(file, argp);
4996 #endif
4997 	case BTRFS_IOC_SEND:
4998 		return _btrfs_ioctl_send(file, argp, false);
4999 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5000 	case BTRFS_IOC_SEND_32:
5001 		return _btrfs_ioctl_send(file, argp, true);
5002 #endif
5003 	case BTRFS_IOC_GET_DEV_STATS:
5004 		return btrfs_ioctl_get_dev_stats(fs_info, argp);
5005 	case BTRFS_IOC_QUOTA_CTL:
5006 		return btrfs_ioctl_quota_ctl(file, argp);
5007 	case BTRFS_IOC_QGROUP_ASSIGN:
5008 		return btrfs_ioctl_qgroup_assign(file, argp);
5009 	case BTRFS_IOC_QGROUP_CREATE:
5010 		return btrfs_ioctl_qgroup_create(file, argp);
5011 	case BTRFS_IOC_QGROUP_LIMIT:
5012 		return btrfs_ioctl_qgroup_limit(file, argp);
5013 	case BTRFS_IOC_QUOTA_RESCAN:
5014 		return btrfs_ioctl_quota_rescan(file, argp);
5015 	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5016 		return btrfs_ioctl_quota_rescan_status(fs_info, argp);
5017 	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5018 		return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
5019 	case BTRFS_IOC_DEV_REPLACE:
5020 		return btrfs_ioctl_dev_replace(fs_info, argp);
5021 	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5022 		return btrfs_ioctl_get_supported_features(argp);
5023 	case BTRFS_IOC_GET_FEATURES:
5024 		return btrfs_ioctl_get_features(fs_info, argp);
5025 	case BTRFS_IOC_SET_FEATURES:
5026 		return btrfs_ioctl_set_features(file, argp);
5027 	case FS_IOC_FSGETXATTR:
5028 		return btrfs_ioctl_fsgetxattr(file, argp);
5029 	case FS_IOC_FSSETXATTR:
5030 		return btrfs_ioctl_fssetxattr(file, argp);
5031 	case BTRFS_IOC_GET_SUBVOL_INFO:
5032 		return btrfs_ioctl_get_subvol_info(file, argp);
5033 	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5034 		return btrfs_ioctl_get_subvol_rootref(file, argp);
5035 	case BTRFS_IOC_INO_LOOKUP_USER:
5036 		return btrfs_ioctl_ino_lookup_user(file, argp);
5037 	}
5038 
5039 	return -ENOTTY;
5040 }
5041 
5042 #ifdef CONFIG_COMPAT
5043 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5044 {
5045 	/*
5046 	 * These all access 32-bit values anyway so no further
5047 	 * handling is necessary.
5048 	 */
5049 	switch (cmd) {
5050 	case FS_IOC32_GETFLAGS:
5051 		cmd = FS_IOC_GETFLAGS;
5052 		break;
5053 	case FS_IOC32_SETFLAGS:
5054 		cmd = FS_IOC_SETFLAGS;
5055 		break;
5056 	case FS_IOC32_GETVERSION:
5057 		cmd = FS_IOC_GETVERSION;
5058 		break;
5059 	}
5060 
5061 	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5062 }
5063 #endif
5064