xref: /openbmc/linux/fs/btrfs/ioctl.c (revision 272d7089)
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 "inode-map.h"
38 #include "backref.h"
39 #include "rcu-string.h"
40 #include "send.h"
41 #include "dev-replace.h"
42 #include "props.h"
43 #include "sysfs.h"
44 #include "qgroup.h"
45 #include "tree-log.h"
46 #include "compression.h"
47 #include "space-info.h"
48 #include "delalloc-space.h"
49 #include "block-group.h"
50 
51 #ifdef CONFIG_64BIT
52 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
53  * structures are incorrect, as the timespec structure from userspace
54  * is 4 bytes too small. We define these alternatives here to teach
55  * the kernel about the 32-bit struct packing.
56  */
57 struct btrfs_ioctl_timespec_32 {
58 	__u64 sec;
59 	__u32 nsec;
60 } __attribute__ ((__packed__));
61 
62 struct btrfs_ioctl_received_subvol_args_32 {
63 	char	uuid[BTRFS_UUID_SIZE];	/* in */
64 	__u64	stransid;		/* in */
65 	__u64	rtransid;		/* out */
66 	struct btrfs_ioctl_timespec_32 stime; /* in */
67 	struct btrfs_ioctl_timespec_32 rtime; /* out */
68 	__u64	flags;			/* in */
69 	__u64	reserved[16];		/* in */
70 } __attribute__ ((__packed__));
71 
72 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
73 				struct btrfs_ioctl_received_subvol_args_32)
74 #endif
75 
76 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
77 struct btrfs_ioctl_send_args_32 {
78 	__s64 send_fd;			/* in */
79 	__u64 clone_sources_count;	/* in */
80 	compat_uptr_t clone_sources;	/* in */
81 	__u64 parent_root;		/* in */
82 	__u64 flags;			/* in */
83 	__u64 reserved[4];		/* in */
84 } __attribute__ ((__packed__));
85 
86 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
87 			       struct btrfs_ioctl_send_args_32)
88 #endif
89 
90 /* Mask out flags that are inappropriate for the given type of inode. */
91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
92 		unsigned int flags)
93 {
94 	if (S_ISDIR(inode->i_mode))
95 		return flags;
96 	else if (S_ISREG(inode->i_mode))
97 		return flags & ~FS_DIRSYNC_FL;
98 	else
99 		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
100 }
101 
102 /*
103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
104  * ioctl.
105  */
106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
107 {
108 	unsigned int iflags = 0;
109 
110 	if (flags & BTRFS_INODE_SYNC)
111 		iflags |= FS_SYNC_FL;
112 	if (flags & BTRFS_INODE_IMMUTABLE)
113 		iflags |= FS_IMMUTABLE_FL;
114 	if (flags & BTRFS_INODE_APPEND)
115 		iflags |= FS_APPEND_FL;
116 	if (flags & BTRFS_INODE_NODUMP)
117 		iflags |= FS_NODUMP_FL;
118 	if (flags & BTRFS_INODE_NOATIME)
119 		iflags |= FS_NOATIME_FL;
120 	if (flags & BTRFS_INODE_DIRSYNC)
121 		iflags |= FS_DIRSYNC_FL;
122 	if (flags & BTRFS_INODE_NODATACOW)
123 		iflags |= FS_NOCOW_FL;
124 
125 	if (flags & BTRFS_INODE_NOCOMPRESS)
126 		iflags |= FS_NOCOMP_FL;
127 	else if (flags & BTRFS_INODE_COMPRESS)
128 		iflags |= FS_COMPR_FL;
129 
130 	return iflags;
131 }
132 
133 /*
134  * Update inode->i_flags based on the btrfs internal flags.
135  */
136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
137 {
138 	struct btrfs_inode *binode = BTRFS_I(inode);
139 	unsigned int new_fl = 0;
140 
141 	if (binode->flags & BTRFS_INODE_SYNC)
142 		new_fl |= S_SYNC;
143 	if (binode->flags & BTRFS_INODE_IMMUTABLE)
144 		new_fl |= S_IMMUTABLE;
145 	if (binode->flags & BTRFS_INODE_APPEND)
146 		new_fl |= S_APPEND;
147 	if (binode->flags & BTRFS_INODE_NOATIME)
148 		new_fl |= S_NOATIME;
149 	if (binode->flags & BTRFS_INODE_DIRSYNC)
150 		new_fl |= S_DIRSYNC;
151 
152 	set_mask_bits(&inode->i_flags,
153 		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
154 		      new_fl);
155 }
156 
157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
158 {
159 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
160 	unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
161 
162 	if (copy_to_user(arg, &flags, sizeof(flags)))
163 		return -EFAULT;
164 	return 0;
165 }
166 
167 /*
168  * Check if @flags are a supported and valid set of FS_*_FL flags and that
169  * the old and new flags are not conflicting
170  */
171 static int check_fsflags(unsigned int old_flags, unsigned int flags)
172 {
173 	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
174 		      FS_NOATIME_FL | FS_NODUMP_FL | \
175 		      FS_SYNC_FL | FS_DIRSYNC_FL | \
176 		      FS_NOCOMP_FL | FS_COMPR_FL |
177 		      FS_NOCOW_FL))
178 		return -EOPNOTSUPP;
179 
180 	/* COMPR and NOCOMP on new/old are valid */
181 	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
182 		return -EINVAL;
183 
184 	if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
185 		return -EINVAL;
186 
187 	/* NOCOW and compression options are mutually exclusive */
188 	if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
189 		return -EINVAL;
190 	if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
191 		return -EINVAL;
192 
193 	return 0;
194 }
195 
196 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
197 {
198 	struct inode *inode = file_inode(file);
199 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
200 	struct btrfs_inode *binode = BTRFS_I(inode);
201 	struct btrfs_root *root = binode->root;
202 	struct btrfs_trans_handle *trans;
203 	unsigned int fsflags, old_fsflags;
204 	int ret;
205 	const char *comp = NULL;
206 	u32 binode_flags;
207 
208 	if (!inode_owner_or_capable(inode))
209 		return -EPERM;
210 
211 	if (btrfs_root_readonly(root))
212 		return -EROFS;
213 
214 	if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
215 		return -EFAULT;
216 
217 	ret = mnt_want_write_file(file);
218 	if (ret)
219 		return ret;
220 
221 	inode_lock(inode);
222 	fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
223 	old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
224 
225 	ret = vfs_ioc_setflags_prepare(inode, old_fsflags, fsflags);
226 	if (ret)
227 		goto out_unlock;
228 
229 	ret = check_fsflags(old_fsflags, fsflags);
230 	if (ret)
231 		goto out_unlock;
232 
233 	binode_flags = binode->flags;
234 	if (fsflags & FS_SYNC_FL)
235 		binode_flags |= BTRFS_INODE_SYNC;
236 	else
237 		binode_flags &= ~BTRFS_INODE_SYNC;
238 	if (fsflags & FS_IMMUTABLE_FL)
239 		binode_flags |= BTRFS_INODE_IMMUTABLE;
240 	else
241 		binode_flags &= ~BTRFS_INODE_IMMUTABLE;
242 	if (fsflags & FS_APPEND_FL)
243 		binode_flags |= BTRFS_INODE_APPEND;
244 	else
245 		binode_flags &= ~BTRFS_INODE_APPEND;
246 	if (fsflags & FS_NODUMP_FL)
247 		binode_flags |= BTRFS_INODE_NODUMP;
248 	else
249 		binode_flags &= ~BTRFS_INODE_NODUMP;
250 	if (fsflags & FS_NOATIME_FL)
251 		binode_flags |= BTRFS_INODE_NOATIME;
252 	else
253 		binode_flags &= ~BTRFS_INODE_NOATIME;
254 	if (fsflags & FS_DIRSYNC_FL)
255 		binode_flags |= BTRFS_INODE_DIRSYNC;
256 	else
257 		binode_flags &= ~BTRFS_INODE_DIRSYNC;
258 	if (fsflags & FS_NOCOW_FL) {
259 		if (S_ISREG(inode->i_mode)) {
260 			/*
261 			 * It's safe to turn csums off here, no extents exist.
262 			 * Otherwise we want the flag to reflect the real COW
263 			 * status of the file and will not set it.
264 			 */
265 			if (inode->i_size == 0)
266 				binode_flags |= BTRFS_INODE_NODATACOW |
267 						BTRFS_INODE_NODATASUM;
268 		} else {
269 			binode_flags |= BTRFS_INODE_NODATACOW;
270 		}
271 	} else {
272 		/*
273 		 * Revert back under same assumptions as above
274 		 */
275 		if (S_ISREG(inode->i_mode)) {
276 			if (inode->i_size == 0)
277 				binode_flags &= ~(BTRFS_INODE_NODATACOW |
278 						  BTRFS_INODE_NODATASUM);
279 		} else {
280 			binode_flags &= ~BTRFS_INODE_NODATACOW;
281 		}
282 	}
283 
284 	/*
285 	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
286 	 * flag may be changed automatically if compression code won't make
287 	 * things smaller.
288 	 */
289 	if (fsflags & FS_NOCOMP_FL) {
290 		binode_flags &= ~BTRFS_INODE_COMPRESS;
291 		binode_flags |= BTRFS_INODE_NOCOMPRESS;
292 	} else if (fsflags & FS_COMPR_FL) {
293 
294 		if (IS_SWAPFILE(inode)) {
295 			ret = -ETXTBSY;
296 			goto out_unlock;
297 		}
298 
299 		binode_flags |= BTRFS_INODE_COMPRESS;
300 		binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
301 
302 		comp = btrfs_compress_type2str(fs_info->compress_type);
303 		if (!comp || comp[0] == 0)
304 			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
305 	} else {
306 		binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
307 	}
308 
309 	/*
310 	 * 1 for inode item
311 	 * 2 for properties
312 	 */
313 	trans = btrfs_start_transaction(root, 3);
314 	if (IS_ERR(trans)) {
315 		ret = PTR_ERR(trans);
316 		goto out_unlock;
317 	}
318 
319 	if (comp) {
320 		ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
321 				     strlen(comp), 0);
322 		if (ret) {
323 			btrfs_abort_transaction(trans, ret);
324 			goto out_end_trans;
325 		}
326 	} else {
327 		ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
328 				     0, 0);
329 		if (ret && ret != -ENODATA) {
330 			btrfs_abort_transaction(trans, ret);
331 			goto out_end_trans;
332 		}
333 	}
334 
335 	binode->flags = binode_flags;
336 	btrfs_sync_inode_flags_to_i_flags(inode);
337 	inode_inc_iversion(inode);
338 	inode->i_ctime = current_time(inode);
339 	ret = btrfs_update_inode(trans, root, inode);
340 
341  out_end_trans:
342 	btrfs_end_transaction(trans);
343  out_unlock:
344 	inode_unlock(inode);
345 	mnt_drop_write_file(file);
346 	return ret;
347 }
348 
349 /*
350  * Translate btrfs internal inode flags to xflags as expected by the
351  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
352  * silently dropped.
353  */
354 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
355 {
356 	unsigned int xflags = 0;
357 
358 	if (flags & BTRFS_INODE_APPEND)
359 		xflags |= FS_XFLAG_APPEND;
360 	if (flags & BTRFS_INODE_IMMUTABLE)
361 		xflags |= FS_XFLAG_IMMUTABLE;
362 	if (flags & BTRFS_INODE_NOATIME)
363 		xflags |= FS_XFLAG_NOATIME;
364 	if (flags & BTRFS_INODE_NODUMP)
365 		xflags |= FS_XFLAG_NODUMP;
366 	if (flags & BTRFS_INODE_SYNC)
367 		xflags |= FS_XFLAG_SYNC;
368 
369 	return xflags;
370 }
371 
372 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
373 static int check_xflags(unsigned int flags)
374 {
375 	if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
376 		      FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
377 		return -EOPNOTSUPP;
378 	return 0;
379 }
380 
381 /*
382  * Set the xflags from the internal inode flags. The remaining items of fsxattr
383  * are zeroed.
384  */
385 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
386 {
387 	struct btrfs_inode *binode = BTRFS_I(file_inode(file));
388 	struct fsxattr fa;
389 
390 	simple_fill_fsxattr(&fa, btrfs_inode_flags_to_xflags(binode->flags));
391 	if (copy_to_user(arg, &fa, sizeof(fa)))
392 		return -EFAULT;
393 
394 	return 0;
395 }
396 
397 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
398 {
399 	struct inode *inode = file_inode(file);
400 	struct btrfs_inode *binode = BTRFS_I(inode);
401 	struct btrfs_root *root = binode->root;
402 	struct btrfs_trans_handle *trans;
403 	struct fsxattr fa, old_fa;
404 	unsigned old_flags;
405 	unsigned old_i_flags;
406 	int ret = 0;
407 
408 	if (!inode_owner_or_capable(inode))
409 		return -EPERM;
410 
411 	if (btrfs_root_readonly(root))
412 		return -EROFS;
413 
414 	if (copy_from_user(&fa, arg, sizeof(fa)))
415 		return -EFAULT;
416 
417 	ret = check_xflags(fa.fsx_xflags);
418 	if (ret)
419 		return ret;
420 
421 	if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
422 		return -EOPNOTSUPP;
423 
424 	ret = mnt_want_write_file(file);
425 	if (ret)
426 		return ret;
427 
428 	inode_lock(inode);
429 
430 	old_flags = binode->flags;
431 	old_i_flags = inode->i_flags;
432 
433 	simple_fill_fsxattr(&old_fa,
434 			    btrfs_inode_flags_to_xflags(binode->flags));
435 	ret = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
436 	if (ret)
437 		goto out_unlock;
438 
439 	if (fa.fsx_xflags & FS_XFLAG_SYNC)
440 		binode->flags |= BTRFS_INODE_SYNC;
441 	else
442 		binode->flags &= ~BTRFS_INODE_SYNC;
443 	if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
444 		binode->flags |= BTRFS_INODE_IMMUTABLE;
445 	else
446 		binode->flags &= ~BTRFS_INODE_IMMUTABLE;
447 	if (fa.fsx_xflags & FS_XFLAG_APPEND)
448 		binode->flags |= BTRFS_INODE_APPEND;
449 	else
450 		binode->flags &= ~BTRFS_INODE_APPEND;
451 	if (fa.fsx_xflags & FS_XFLAG_NODUMP)
452 		binode->flags |= BTRFS_INODE_NODUMP;
453 	else
454 		binode->flags &= ~BTRFS_INODE_NODUMP;
455 	if (fa.fsx_xflags & FS_XFLAG_NOATIME)
456 		binode->flags |= BTRFS_INODE_NOATIME;
457 	else
458 		binode->flags &= ~BTRFS_INODE_NOATIME;
459 
460 	/* 1 item for the inode */
461 	trans = btrfs_start_transaction(root, 1);
462 	if (IS_ERR(trans)) {
463 		ret = PTR_ERR(trans);
464 		goto out_unlock;
465 	}
466 
467 	btrfs_sync_inode_flags_to_i_flags(inode);
468 	inode_inc_iversion(inode);
469 	inode->i_ctime = current_time(inode);
470 	ret = btrfs_update_inode(trans, root, inode);
471 
472 	btrfs_end_transaction(trans);
473 
474 out_unlock:
475 	if (ret) {
476 		binode->flags = old_flags;
477 		inode->i_flags = old_i_flags;
478 	}
479 
480 	inode_unlock(inode);
481 	mnt_drop_write_file(file);
482 
483 	return ret;
484 }
485 
486 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
487 {
488 	struct inode *inode = file_inode(file);
489 
490 	return put_user(inode->i_generation, arg);
491 }
492 
493 static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
494 					void __user *arg)
495 {
496 	struct btrfs_device *device;
497 	struct request_queue *q;
498 	struct fstrim_range range;
499 	u64 minlen = ULLONG_MAX;
500 	u64 num_devices = 0;
501 	int ret;
502 
503 	if (!capable(CAP_SYS_ADMIN))
504 		return -EPERM;
505 
506 	/*
507 	 * If the fs is mounted with nologreplay, which requires it to be
508 	 * mounted in RO mode as well, we can not allow discard on free space
509 	 * inside block groups, because log trees refer to extents that are not
510 	 * pinned in a block group's free space cache (pinning the extents is
511 	 * precisely the first phase of replaying a log tree).
512 	 */
513 	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
514 		return -EROFS;
515 
516 	rcu_read_lock();
517 	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
518 				dev_list) {
519 		if (!device->bdev)
520 			continue;
521 		q = bdev_get_queue(device->bdev);
522 		if (blk_queue_discard(q)) {
523 			num_devices++;
524 			minlen = min_t(u64, q->limits.discard_granularity,
525 				     minlen);
526 		}
527 	}
528 	rcu_read_unlock();
529 
530 	if (!num_devices)
531 		return -EOPNOTSUPP;
532 	if (copy_from_user(&range, arg, sizeof(range)))
533 		return -EFAULT;
534 
535 	/*
536 	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
537 	 * block group is in the logical address space, which can be any
538 	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
539 	 */
540 	if (range.len < fs_info->sb->s_blocksize)
541 		return -EINVAL;
542 
543 	range.minlen = max(range.minlen, minlen);
544 	ret = btrfs_trim_fs(fs_info, &range);
545 	if (ret < 0)
546 		return ret;
547 
548 	if (copy_to_user(arg, &range, sizeof(range)))
549 		return -EFAULT;
550 
551 	return 0;
552 }
553 
554 int __pure btrfs_is_empty_uuid(u8 *uuid)
555 {
556 	int i;
557 
558 	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
559 		if (uuid[i])
560 			return 0;
561 	}
562 	return 1;
563 }
564 
565 static noinline int create_subvol(struct inode *dir,
566 				  struct dentry *dentry,
567 				  const char *name, int namelen,
568 				  struct btrfs_qgroup_inherit *inherit)
569 {
570 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
571 	struct btrfs_trans_handle *trans;
572 	struct btrfs_key key;
573 	struct btrfs_root_item *root_item;
574 	struct btrfs_inode_item *inode_item;
575 	struct extent_buffer *leaf;
576 	struct btrfs_root *root = BTRFS_I(dir)->root;
577 	struct btrfs_root *new_root;
578 	struct btrfs_block_rsv block_rsv;
579 	struct timespec64 cur_time = current_time(dir);
580 	struct inode *inode;
581 	int ret;
582 	int err;
583 	dev_t anon_dev = 0;
584 	u64 objectid;
585 	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
586 	u64 index = 0;
587 
588 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
589 	if (!root_item)
590 		return -ENOMEM;
591 
592 	ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
593 	if (ret)
594 		goto fail_free;
595 
596 	ret = get_anon_bdev(&anon_dev);
597 	if (ret < 0)
598 		goto fail_free;
599 
600 	/*
601 	 * Don't create subvolume whose level is not zero. Or qgroup will be
602 	 * screwed up since it assumes subvolume qgroup's level to be 0.
603 	 */
604 	if (btrfs_qgroup_level(objectid)) {
605 		ret = -ENOSPC;
606 		goto fail_free;
607 	}
608 
609 	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
610 	/*
611 	 * The same as the snapshot creation, please see the comment
612 	 * of create_snapshot().
613 	 */
614 	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
615 	if (ret)
616 		goto fail_free;
617 
618 	trans = btrfs_start_transaction(root, 0);
619 	if (IS_ERR(trans)) {
620 		ret = PTR_ERR(trans);
621 		btrfs_subvolume_release_metadata(fs_info, &block_rsv);
622 		goto fail_free;
623 	}
624 	trans->block_rsv = &block_rsv;
625 	trans->bytes_reserved = block_rsv.size;
626 
627 	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
628 	if (ret)
629 		goto fail;
630 
631 	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
632 	if (IS_ERR(leaf)) {
633 		ret = PTR_ERR(leaf);
634 		goto fail;
635 	}
636 
637 	btrfs_mark_buffer_dirty(leaf);
638 
639 	inode_item = &root_item->inode;
640 	btrfs_set_stack_inode_generation(inode_item, 1);
641 	btrfs_set_stack_inode_size(inode_item, 3);
642 	btrfs_set_stack_inode_nlink(inode_item, 1);
643 	btrfs_set_stack_inode_nbytes(inode_item,
644 				     fs_info->nodesize);
645 	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
646 
647 	btrfs_set_root_flags(root_item, 0);
648 	btrfs_set_root_limit(root_item, 0);
649 	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
650 
651 	btrfs_set_root_bytenr(root_item, leaf->start);
652 	btrfs_set_root_generation(root_item, trans->transid);
653 	btrfs_set_root_level(root_item, 0);
654 	btrfs_set_root_refs(root_item, 1);
655 	btrfs_set_root_used(root_item, leaf->len);
656 	btrfs_set_root_last_snapshot(root_item, 0);
657 
658 	btrfs_set_root_generation_v2(root_item,
659 			btrfs_root_generation(root_item));
660 	generate_random_guid(root_item->uuid);
661 	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
662 	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
663 	root_item->ctime = root_item->otime;
664 	btrfs_set_root_ctransid(root_item, trans->transid);
665 	btrfs_set_root_otransid(root_item, trans->transid);
666 
667 	btrfs_tree_unlock(leaf);
668 	free_extent_buffer(leaf);
669 	leaf = NULL;
670 
671 	btrfs_set_root_dirid(root_item, new_dirid);
672 
673 	key.objectid = objectid;
674 	key.offset = 0;
675 	key.type = BTRFS_ROOT_ITEM_KEY;
676 	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
677 				root_item);
678 	if (ret)
679 		goto fail;
680 
681 	key.offset = (u64)-1;
682 	new_root = btrfs_get_new_fs_root(fs_info, objectid, anon_dev);
683 	if (IS_ERR(new_root)) {
684 		free_anon_bdev(anon_dev);
685 		ret = PTR_ERR(new_root);
686 		btrfs_abort_transaction(trans, ret);
687 		goto fail;
688 	}
689 	/* Freeing will be done in btrfs_put_root() of new_root */
690 	anon_dev = 0;
691 
692 	btrfs_record_root_in_trans(trans, new_root);
693 
694 	ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
695 	btrfs_put_root(new_root);
696 	if (ret) {
697 		/* We potentially lose an unused inode item here */
698 		btrfs_abort_transaction(trans, ret);
699 		goto fail;
700 	}
701 
702 	mutex_lock(&new_root->objectid_mutex);
703 	new_root->highest_objectid = new_dirid;
704 	mutex_unlock(&new_root->objectid_mutex);
705 
706 	/*
707 	 * insert the directory item
708 	 */
709 	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
710 	if (ret) {
711 		btrfs_abort_transaction(trans, ret);
712 		goto fail;
713 	}
714 
715 	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
716 				    BTRFS_FT_DIR, index);
717 	if (ret) {
718 		btrfs_abort_transaction(trans, ret);
719 		goto fail;
720 	}
721 
722 	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
723 	ret = btrfs_update_inode(trans, root, dir);
724 	if (ret) {
725 		btrfs_abort_transaction(trans, ret);
726 		goto fail;
727 	}
728 
729 	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
730 				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
731 	if (ret) {
732 		btrfs_abort_transaction(trans, ret);
733 		goto fail;
734 	}
735 
736 	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
737 				  BTRFS_UUID_KEY_SUBVOL, objectid);
738 	if (ret)
739 		btrfs_abort_transaction(trans, ret);
740 
741 fail:
742 	kfree(root_item);
743 	trans->block_rsv = NULL;
744 	trans->bytes_reserved = 0;
745 	btrfs_subvolume_release_metadata(fs_info, &block_rsv);
746 
747 	err = btrfs_commit_transaction(trans);
748 	if (err && !ret)
749 		ret = err;
750 
751 	if (!ret) {
752 		inode = btrfs_lookup_dentry(dir, dentry);
753 		if (IS_ERR(inode))
754 			return PTR_ERR(inode);
755 		d_instantiate(dentry, inode);
756 	}
757 	return ret;
758 
759 fail_free:
760 	if (anon_dev)
761 		free_anon_bdev(anon_dev);
762 	kfree(root_item);
763 	return ret;
764 }
765 
766 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
767 			   struct dentry *dentry, bool readonly,
768 			   struct btrfs_qgroup_inherit *inherit)
769 {
770 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
771 	struct inode *inode;
772 	struct btrfs_pending_snapshot *pending_snapshot;
773 	struct btrfs_trans_handle *trans;
774 	int ret;
775 
776 	if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
777 		return -EINVAL;
778 
779 	if (atomic_read(&root->nr_swapfiles)) {
780 		btrfs_warn(fs_info,
781 			   "cannot snapshot subvolume with active swapfile");
782 		return -ETXTBSY;
783 	}
784 
785 	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
786 	if (!pending_snapshot)
787 		return -ENOMEM;
788 
789 	ret = get_anon_bdev(&pending_snapshot->anon_dev);
790 	if (ret < 0)
791 		goto free_pending;
792 	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
793 			GFP_KERNEL);
794 	pending_snapshot->path = btrfs_alloc_path();
795 	if (!pending_snapshot->root_item || !pending_snapshot->path) {
796 		ret = -ENOMEM;
797 		goto free_pending;
798 	}
799 
800 	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
801 			     BTRFS_BLOCK_RSV_TEMP);
802 	/*
803 	 * 1 - parent dir inode
804 	 * 2 - dir entries
805 	 * 1 - root item
806 	 * 2 - root ref/backref
807 	 * 1 - root of snapshot
808 	 * 1 - UUID item
809 	 */
810 	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
811 					&pending_snapshot->block_rsv, 8,
812 					false);
813 	if (ret)
814 		goto free_pending;
815 
816 	pending_snapshot->dentry = dentry;
817 	pending_snapshot->root = root;
818 	pending_snapshot->readonly = readonly;
819 	pending_snapshot->dir = dir;
820 	pending_snapshot->inherit = inherit;
821 
822 	trans = btrfs_start_transaction(root, 0);
823 	if (IS_ERR(trans)) {
824 		ret = PTR_ERR(trans);
825 		goto fail;
826 	}
827 
828 	spin_lock(&fs_info->trans_lock);
829 	list_add(&pending_snapshot->list,
830 		 &trans->transaction->pending_snapshots);
831 	spin_unlock(&fs_info->trans_lock);
832 
833 	ret = btrfs_commit_transaction(trans);
834 	if (ret)
835 		goto fail;
836 
837 	ret = pending_snapshot->error;
838 	if (ret)
839 		goto fail;
840 
841 	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
842 	if (ret)
843 		goto fail;
844 
845 	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
846 	if (IS_ERR(inode)) {
847 		ret = PTR_ERR(inode);
848 		goto fail;
849 	}
850 
851 	d_instantiate(dentry, inode);
852 	ret = 0;
853 	pending_snapshot->anon_dev = 0;
854 fail:
855 	/* Prevent double freeing of anon_dev */
856 	if (ret && pending_snapshot->snap)
857 		pending_snapshot->snap->anon_dev = 0;
858 	btrfs_put_root(pending_snapshot->snap);
859 	btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
860 free_pending:
861 	if (pending_snapshot->anon_dev)
862 		free_anon_bdev(pending_snapshot->anon_dev);
863 	kfree(pending_snapshot->root_item);
864 	btrfs_free_path(pending_snapshot->path);
865 	kfree(pending_snapshot);
866 
867 	return ret;
868 }
869 
870 /*  copy of may_delete in fs/namei.c()
871  *	Check whether we can remove a link victim from directory dir, check
872  *  whether the type of victim is right.
873  *  1. We can't do it if dir is read-only (done in permission())
874  *  2. We should have write and exec permissions on dir
875  *  3. We can't remove anything from append-only dir
876  *  4. We can't do anything with immutable dir (done in permission())
877  *  5. If the sticky bit on dir is set we should either
878  *	a. be owner of dir, or
879  *	b. be owner of victim, or
880  *	c. have CAP_FOWNER capability
881  *  6. If the victim is append-only or immutable we can't do anything with
882  *     links pointing to it.
883  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
884  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
885  *  9. We can't remove a root or mountpoint.
886  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
887  *     nfs_async_unlink().
888  */
889 
890 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
891 {
892 	int error;
893 
894 	if (d_really_is_negative(victim))
895 		return -ENOENT;
896 
897 	BUG_ON(d_inode(victim->d_parent) != dir);
898 	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
899 
900 	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
901 	if (error)
902 		return error;
903 	if (IS_APPEND(dir))
904 		return -EPERM;
905 	if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
906 	    IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
907 		return -EPERM;
908 	if (isdir) {
909 		if (!d_is_dir(victim))
910 			return -ENOTDIR;
911 		if (IS_ROOT(victim))
912 			return -EBUSY;
913 	} else if (d_is_dir(victim))
914 		return -EISDIR;
915 	if (IS_DEADDIR(dir))
916 		return -ENOENT;
917 	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
918 		return -EBUSY;
919 	return 0;
920 }
921 
922 /* copy of may_create in fs/namei.c() */
923 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
924 {
925 	if (d_really_is_positive(child))
926 		return -EEXIST;
927 	if (IS_DEADDIR(dir))
928 		return -ENOENT;
929 	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
930 }
931 
932 /*
933  * Create a new subvolume below @parent.  This is largely modeled after
934  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
935  * inside this filesystem so it's quite a bit simpler.
936  */
937 static noinline int btrfs_mksubvol(const struct path *parent,
938 				   const char *name, int namelen,
939 				   struct btrfs_root *snap_src,
940 				   bool readonly,
941 				   struct btrfs_qgroup_inherit *inherit)
942 {
943 	struct inode *dir = d_inode(parent->dentry);
944 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
945 	struct dentry *dentry;
946 	int error;
947 
948 	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
949 	if (error == -EINTR)
950 		return error;
951 
952 	dentry = lookup_one_len(name, parent->dentry, namelen);
953 	error = PTR_ERR(dentry);
954 	if (IS_ERR(dentry))
955 		goto out_unlock;
956 
957 	error = btrfs_may_create(dir, dentry);
958 	if (error)
959 		goto out_dput;
960 
961 	/*
962 	 * even if this name doesn't exist, we may get hash collisions.
963 	 * check for them now when we can safely fail
964 	 */
965 	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
966 					       dir->i_ino, name,
967 					       namelen);
968 	if (error)
969 		goto out_dput;
970 
971 	down_read(&fs_info->subvol_sem);
972 
973 	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
974 		goto out_up_read;
975 
976 	if (snap_src)
977 		error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
978 	else
979 		error = create_subvol(dir, dentry, name, namelen, inherit);
980 
981 	if (!error)
982 		fsnotify_mkdir(dir, dentry);
983 out_up_read:
984 	up_read(&fs_info->subvol_sem);
985 out_dput:
986 	dput(dentry);
987 out_unlock:
988 	inode_unlock(dir);
989 	return error;
990 }
991 
992 static noinline int btrfs_mksnapshot(const struct path *parent,
993 				   const char *name, int namelen,
994 				   struct btrfs_root *root,
995 				   bool readonly,
996 				   struct btrfs_qgroup_inherit *inherit)
997 {
998 	int ret;
999 	bool snapshot_force_cow = false;
1000 
1001 	/*
1002 	 * Force new buffered writes to reserve space even when NOCOW is
1003 	 * possible. This is to avoid later writeback (running dealloc) to
1004 	 * fallback to COW mode and unexpectedly fail with ENOSPC.
1005 	 */
1006 	btrfs_drew_read_lock(&root->snapshot_lock);
1007 
1008 	ret = btrfs_start_delalloc_snapshot(root);
1009 	if (ret)
1010 		goto out;
1011 
1012 	/*
1013 	 * All previous writes have started writeback in NOCOW mode, so now
1014 	 * we force future writes to fallback to COW mode during snapshot
1015 	 * creation.
1016 	 */
1017 	atomic_inc(&root->snapshot_force_cow);
1018 	snapshot_force_cow = true;
1019 
1020 	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
1021 
1022 	ret = btrfs_mksubvol(parent, name, namelen,
1023 			     root, readonly, inherit);
1024 out:
1025 	if (snapshot_force_cow)
1026 		atomic_dec(&root->snapshot_force_cow);
1027 	btrfs_drew_read_unlock(&root->snapshot_lock);
1028 	return ret;
1029 }
1030 
1031 /*
1032  * When we're defragging a range, we don't want to kick it off again
1033  * if it is really just waiting for delalloc to send it down.
1034  * If we find a nice big extent or delalloc range for the bytes in the
1035  * file you want to defrag, we return 0 to let you know to skip this
1036  * part of the file
1037  */
1038 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1039 {
1040 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1041 	struct extent_map *em = NULL;
1042 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1043 	u64 end;
1044 
1045 	read_lock(&em_tree->lock);
1046 	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1047 	read_unlock(&em_tree->lock);
1048 
1049 	if (em) {
1050 		end = extent_map_end(em);
1051 		free_extent_map(em);
1052 		if (end - offset > thresh)
1053 			return 0;
1054 	}
1055 	/* if we already have a nice delalloc here, just stop */
1056 	thresh /= 2;
1057 	end = count_range_bits(io_tree, &offset, offset + thresh,
1058 			       thresh, EXTENT_DELALLOC, 1);
1059 	if (end >= thresh)
1060 		return 0;
1061 	return 1;
1062 }
1063 
1064 /*
1065  * helper function to walk through a file and find extents
1066  * newer than a specific transid, and smaller than thresh.
1067  *
1068  * This is used by the defragging code to find new and small
1069  * extents
1070  */
1071 static int find_new_extents(struct btrfs_root *root,
1072 			    struct inode *inode, u64 newer_than,
1073 			    u64 *off, u32 thresh)
1074 {
1075 	struct btrfs_path *path;
1076 	struct btrfs_key min_key;
1077 	struct extent_buffer *leaf;
1078 	struct btrfs_file_extent_item *extent;
1079 	int type;
1080 	int ret;
1081 	u64 ino = btrfs_ino(BTRFS_I(inode));
1082 
1083 	path = btrfs_alloc_path();
1084 	if (!path)
1085 		return -ENOMEM;
1086 
1087 	min_key.objectid = ino;
1088 	min_key.type = BTRFS_EXTENT_DATA_KEY;
1089 	min_key.offset = *off;
1090 
1091 	while (1) {
1092 		ret = btrfs_search_forward(root, &min_key, path, newer_than);
1093 		if (ret != 0)
1094 			goto none;
1095 process_slot:
1096 		if (min_key.objectid != ino)
1097 			goto none;
1098 		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1099 			goto none;
1100 
1101 		leaf = path->nodes[0];
1102 		extent = btrfs_item_ptr(leaf, path->slots[0],
1103 					struct btrfs_file_extent_item);
1104 
1105 		type = btrfs_file_extent_type(leaf, extent);
1106 		if (type == BTRFS_FILE_EXTENT_REG &&
1107 		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1108 		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
1109 			*off = min_key.offset;
1110 			btrfs_free_path(path);
1111 			return 0;
1112 		}
1113 
1114 		path->slots[0]++;
1115 		if (path->slots[0] < btrfs_header_nritems(leaf)) {
1116 			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1117 			goto process_slot;
1118 		}
1119 
1120 		if (min_key.offset == (u64)-1)
1121 			goto none;
1122 
1123 		min_key.offset++;
1124 		btrfs_release_path(path);
1125 	}
1126 none:
1127 	btrfs_free_path(path);
1128 	return -ENOENT;
1129 }
1130 
1131 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1132 {
1133 	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1134 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1135 	struct extent_map *em;
1136 	u64 len = PAGE_SIZE;
1137 
1138 	/*
1139 	 * hopefully we have this extent in the tree already, try without
1140 	 * the full extent lock
1141 	 */
1142 	read_lock(&em_tree->lock);
1143 	em = lookup_extent_mapping(em_tree, start, len);
1144 	read_unlock(&em_tree->lock);
1145 
1146 	if (!em) {
1147 		struct extent_state *cached = NULL;
1148 		u64 end = start + len - 1;
1149 
1150 		/* get the big lock and read metadata off disk */
1151 		lock_extent_bits(io_tree, start, end, &cached);
1152 		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
1153 		unlock_extent_cached(io_tree, start, end, &cached);
1154 
1155 		if (IS_ERR(em))
1156 			return NULL;
1157 	}
1158 
1159 	return em;
1160 }
1161 
1162 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1163 {
1164 	struct extent_map *next;
1165 	bool ret = true;
1166 
1167 	/* this is the last extent */
1168 	if (em->start + em->len >= i_size_read(inode))
1169 		return false;
1170 
1171 	next = defrag_lookup_extent(inode, em->start + em->len);
1172 	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1173 		ret = false;
1174 	else if ((em->block_start + em->block_len == next->block_start) &&
1175 		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1176 		ret = false;
1177 
1178 	free_extent_map(next);
1179 	return ret;
1180 }
1181 
1182 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1183 			       u64 *last_len, u64 *skip, u64 *defrag_end,
1184 			       int compress)
1185 {
1186 	struct extent_map *em;
1187 	int ret = 1;
1188 	bool next_mergeable = true;
1189 	bool prev_mergeable = true;
1190 
1191 	/*
1192 	 * make sure that once we start defragging an extent, we keep on
1193 	 * defragging it
1194 	 */
1195 	if (start < *defrag_end)
1196 		return 1;
1197 
1198 	*skip = 0;
1199 
1200 	em = defrag_lookup_extent(inode, start);
1201 	if (!em)
1202 		return 0;
1203 
1204 	/* this will cover holes, and inline extents */
1205 	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1206 		ret = 0;
1207 		goto out;
1208 	}
1209 
1210 	if (!*defrag_end)
1211 		prev_mergeable = false;
1212 
1213 	next_mergeable = defrag_check_next_extent(inode, em);
1214 	/*
1215 	 * we hit a real extent, if it is big or the next extent is not a
1216 	 * real extent, don't bother defragging it
1217 	 */
1218 	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1219 	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1220 		ret = 0;
1221 out:
1222 	/*
1223 	 * last_len ends up being a counter of how many bytes we've defragged.
1224 	 * every time we choose not to defrag an extent, we reset *last_len
1225 	 * so that the next tiny extent will force a defrag.
1226 	 *
1227 	 * The end result of this is that tiny extents before a single big
1228 	 * extent will force at least part of that big extent to be defragged.
1229 	 */
1230 	if (ret) {
1231 		*defrag_end = extent_map_end(em);
1232 	} else {
1233 		*last_len = 0;
1234 		*skip = extent_map_end(em);
1235 		*defrag_end = 0;
1236 	}
1237 
1238 	free_extent_map(em);
1239 	return ret;
1240 }
1241 
1242 /*
1243  * it doesn't do much good to defrag one or two pages
1244  * at a time.  This pulls in a nice chunk of pages
1245  * to COW and defrag.
1246  *
1247  * It also makes sure the delalloc code has enough
1248  * dirty data to avoid making new small extents as part
1249  * of the defrag
1250  *
1251  * It's a good idea to start RA on this range
1252  * before calling this.
1253  */
1254 static int cluster_pages_for_defrag(struct inode *inode,
1255 				    struct page **pages,
1256 				    unsigned long start_index,
1257 				    unsigned long num_pages)
1258 {
1259 	unsigned long file_end;
1260 	u64 isize = i_size_read(inode);
1261 	u64 page_start;
1262 	u64 page_end;
1263 	u64 page_cnt;
1264 	int ret;
1265 	int i;
1266 	int i_done;
1267 	struct btrfs_ordered_extent *ordered;
1268 	struct extent_state *cached_state = NULL;
1269 	struct extent_io_tree *tree;
1270 	struct extent_changeset *data_reserved = NULL;
1271 	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1272 
1273 	file_end = (isize - 1) >> PAGE_SHIFT;
1274 	if (!isize || start_index > file_end)
1275 		return 0;
1276 
1277 	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1278 
1279 	ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
1280 			start_index << PAGE_SHIFT,
1281 			page_cnt << PAGE_SHIFT);
1282 	if (ret)
1283 		return ret;
1284 	i_done = 0;
1285 	tree = &BTRFS_I(inode)->io_tree;
1286 
1287 	/* step one, lock all the pages */
1288 	for (i = 0; i < page_cnt; i++) {
1289 		struct page *page;
1290 again:
1291 		page = find_or_create_page(inode->i_mapping,
1292 					   start_index + i, mask);
1293 		if (!page)
1294 			break;
1295 
1296 		page_start = page_offset(page);
1297 		page_end = page_start + PAGE_SIZE - 1;
1298 		while (1) {
1299 			lock_extent_bits(tree, page_start, page_end,
1300 					 &cached_state);
1301 			ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode),
1302 							      page_start);
1303 			unlock_extent_cached(tree, page_start, page_end,
1304 					     &cached_state);
1305 			if (!ordered)
1306 				break;
1307 
1308 			unlock_page(page);
1309 			btrfs_start_ordered_extent(inode, ordered, 1);
1310 			btrfs_put_ordered_extent(ordered);
1311 			lock_page(page);
1312 			/*
1313 			 * we unlocked the page above, so we need check if
1314 			 * it was released or not.
1315 			 */
1316 			if (page->mapping != inode->i_mapping) {
1317 				unlock_page(page);
1318 				put_page(page);
1319 				goto again;
1320 			}
1321 		}
1322 
1323 		if (!PageUptodate(page)) {
1324 			btrfs_readpage(NULL, page);
1325 			lock_page(page);
1326 			if (!PageUptodate(page)) {
1327 				unlock_page(page);
1328 				put_page(page);
1329 				ret = -EIO;
1330 				break;
1331 			}
1332 		}
1333 
1334 		if (page->mapping != inode->i_mapping) {
1335 			unlock_page(page);
1336 			put_page(page);
1337 			goto again;
1338 		}
1339 
1340 		pages[i] = page;
1341 		i_done++;
1342 	}
1343 	if (!i_done || ret)
1344 		goto out;
1345 
1346 	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1347 		goto out;
1348 
1349 	/*
1350 	 * so now we have a nice long stream of locked
1351 	 * and up to date pages, lets wait on them
1352 	 */
1353 	for (i = 0; i < i_done; i++)
1354 		wait_on_page_writeback(pages[i]);
1355 
1356 	page_start = page_offset(pages[0]);
1357 	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1358 
1359 	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1360 			 page_start, page_end - 1, &cached_state);
1361 	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1362 			  page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
1363 			  EXTENT_DEFRAG, 0, 0, &cached_state);
1364 
1365 	if (i_done != page_cnt) {
1366 		spin_lock(&BTRFS_I(inode)->lock);
1367 		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1368 		spin_unlock(&BTRFS_I(inode)->lock);
1369 		btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
1370 				start_index << PAGE_SHIFT,
1371 				(page_cnt - i_done) << PAGE_SHIFT, true);
1372 	}
1373 
1374 
1375 	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1376 			  &cached_state);
1377 
1378 	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1379 			     page_start, page_end - 1, &cached_state);
1380 
1381 	for (i = 0; i < i_done; i++) {
1382 		clear_page_dirty_for_io(pages[i]);
1383 		ClearPageChecked(pages[i]);
1384 		set_page_extent_mapped(pages[i]);
1385 		set_page_dirty(pages[i]);
1386 		unlock_page(pages[i]);
1387 		put_page(pages[i]);
1388 	}
1389 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1390 	extent_changeset_free(data_reserved);
1391 	return i_done;
1392 out:
1393 	for (i = 0; i < i_done; i++) {
1394 		unlock_page(pages[i]);
1395 		put_page(pages[i]);
1396 	}
1397 	btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
1398 			start_index << PAGE_SHIFT,
1399 			page_cnt << PAGE_SHIFT, true);
1400 	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1401 	extent_changeset_free(data_reserved);
1402 	return ret;
1403 
1404 }
1405 
1406 int btrfs_defrag_file(struct inode *inode, struct file *file,
1407 		      struct btrfs_ioctl_defrag_range_args *range,
1408 		      u64 newer_than, unsigned long max_to_defrag)
1409 {
1410 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1411 	struct btrfs_root *root = BTRFS_I(inode)->root;
1412 	struct file_ra_state *ra = NULL;
1413 	unsigned long last_index;
1414 	u64 isize = i_size_read(inode);
1415 	u64 last_len = 0;
1416 	u64 skip = 0;
1417 	u64 defrag_end = 0;
1418 	u64 newer_off = range->start;
1419 	unsigned long i;
1420 	unsigned long ra_index = 0;
1421 	int ret;
1422 	int defrag_count = 0;
1423 	int compress_type = BTRFS_COMPRESS_ZLIB;
1424 	u32 extent_thresh = range->extent_thresh;
1425 	unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1426 	unsigned long cluster = max_cluster;
1427 	u64 new_align = ~((u64)SZ_128K - 1);
1428 	struct page **pages = NULL;
1429 	bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1430 
1431 	if (isize == 0)
1432 		return 0;
1433 
1434 	if (range->start >= isize)
1435 		return -EINVAL;
1436 
1437 	if (do_compress) {
1438 		if (range->compress_type >= BTRFS_NR_COMPRESS_TYPES)
1439 			return -EINVAL;
1440 		if (range->compress_type)
1441 			compress_type = range->compress_type;
1442 	}
1443 
1444 	if (extent_thresh == 0)
1445 		extent_thresh = SZ_256K;
1446 
1447 	/*
1448 	 * If we were not given a file, allocate a readahead context. As
1449 	 * readahead is just an optimization, defrag will work without it so
1450 	 * we don't error out.
1451 	 */
1452 	if (!file) {
1453 		ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1454 		if (ra)
1455 			file_ra_state_init(ra, inode->i_mapping);
1456 	} else {
1457 		ra = &file->f_ra;
1458 	}
1459 
1460 	pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1461 	if (!pages) {
1462 		ret = -ENOMEM;
1463 		goto out_ra;
1464 	}
1465 
1466 	/* find the last page to defrag */
1467 	if (range->start + range->len > range->start) {
1468 		last_index = min_t(u64, isize - 1,
1469 			 range->start + range->len - 1) >> PAGE_SHIFT;
1470 	} else {
1471 		last_index = (isize - 1) >> PAGE_SHIFT;
1472 	}
1473 
1474 	if (newer_than) {
1475 		ret = find_new_extents(root, inode, newer_than,
1476 				       &newer_off, SZ_64K);
1477 		if (!ret) {
1478 			range->start = newer_off;
1479 			/*
1480 			 * we always align our defrag to help keep
1481 			 * the extents in the file evenly spaced
1482 			 */
1483 			i = (newer_off & new_align) >> PAGE_SHIFT;
1484 		} else
1485 			goto out_ra;
1486 	} else {
1487 		i = range->start >> PAGE_SHIFT;
1488 	}
1489 	if (!max_to_defrag)
1490 		max_to_defrag = last_index - i + 1;
1491 
1492 	/*
1493 	 * make writeback starts from i, so the defrag range can be
1494 	 * written sequentially.
1495 	 */
1496 	if (i < inode->i_mapping->writeback_index)
1497 		inode->i_mapping->writeback_index = i;
1498 
1499 	while (i <= last_index && defrag_count < max_to_defrag &&
1500 	       (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1501 		/*
1502 		 * make sure we stop running if someone unmounts
1503 		 * the FS
1504 		 */
1505 		if (!(inode->i_sb->s_flags & SB_ACTIVE))
1506 			break;
1507 
1508 		if (btrfs_defrag_cancelled(fs_info)) {
1509 			btrfs_debug(fs_info, "defrag_file cancelled");
1510 			ret = -EAGAIN;
1511 			break;
1512 		}
1513 
1514 		if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1515 					 extent_thresh, &last_len, &skip,
1516 					 &defrag_end, do_compress)){
1517 			unsigned long next;
1518 			/*
1519 			 * the should_defrag function tells us how much to skip
1520 			 * bump our counter by the suggested amount
1521 			 */
1522 			next = DIV_ROUND_UP(skip, PAGE_SIZE);
1523 			i = max(i + 1, next);
1524 			continue;
1525 		}
1526 
1527 		if (!newer_than) {
1528 			cluster = (PAGE_ALIGN(defrag_end) >>
1529 				   PAGE_SHIFT) - i;
1530 			cluster = min(cluster, max_cluster);
1531 		} else {
1532 			cluster = max_cluster;
1533 		}
1534 
1535 		if (i + cluster > ra_index) {
1536 			ra_index = max(i, ra_index);
1537 			if (ra)
1538 				page_cache_sync_readahead(inode->i_mapping, ra,
1539 						file, ra_index, cluster);
1540 			ra_index += cluster;
1541 		}
1542 
1543 		inode_lock(inode);
1544 		if (IS_SWAPFILE(inode)) {
1545 			ret = -ETXTBSY;
1546 		} else {
1547 			if (do_compress)
1548 				BTRFS_I(inode)->defrag_compress = compress_type;
1549 			ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1550 		}
1551 		if (ret < 0) {
1552 			inode_unlock(inode);
1553 			goto out_ra;
1554 		}
1555 
1556 		defrag_count += ret;
1557 		balance_dirty_pages_ratelimited(inode->i_mapping);
1558 		inode_unlock(inode);
1559 
1560 		if (newer_than) {
1561 			if (newer_off == (u64)-1)
1562 				break;
1563 
1564 			if (ret > 0)
1565 				i += ret;
1566 
1567 			newer_off = max(newer_off + 1,
1568 					(u64)i << PAGE_SHIFT);
1569 
1570 			ret = find_new_extents(root, inode, newer_than,
1571 					       &newer_off, SZ_64K);
1572 			if (!ret) {
1573 				range->start = newer_off;
1574 				i = (newer_off & new_align) >> PAGE_SHIFT;
1575 			} else {
1576 				break;
1577 			}
1578 		} else {
1579 			if (ret > 0) {
1580 				i += ret;
1581 				last_len += ret << PAGE_SHIFT;
1582 			} else {
1583 				i++;
1584 				last_len = 0;
1585 			}
1586 		}
1587 	}
1588 
1589 	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1590 		filemap_flush(inode->i_mapping);
1591 		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1592 			     &BTRFS_I(inode)->runtime_flags))
1593 			filemap_flush(inode->i_mapping);
1594 	}
1595 
1596 	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1597 		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1598 	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1599 		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1600 	}
1601 
1602 	ret = defrag_count;
1603 
1604 out_ra:
1605 	if (do_compress) {
1606 		inode_lock(inode);
1607 		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1608 		inode_unlock(inode);
1609 	}
1610 	if (!file)
1611 		kfree(ra);
1612 	kfree(pages);
1613 	return ret;
1614 }
1615 
1616 static noinline int btrfs_ioctl_resize(struct file *file,
1617 					void __user *arg)
1618 {
1619 	struct inode *inode = file_inode(file);
1620 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1621 	u64 new_size;
1622 	u64 old_size;
1623 	u64 devid = 1;
1624 	struct btrfs_root *root = BTRFS_I(inode)->root;
1625 	struct btrfs_ioctl_vol_args *vol_args;
1626 	struct btrfs_trans_handle *trans;
1627 	struct btrfs_device *device = NULL;
1628 	char *sizestr;
1629 	char *retptr;
1630 	char *devstr = NULL;
1631 	int ret = 0;
1632 	int mod = 0;
1633 
1634 	if (!capable(CAP_SYS_ADMIN))
1635 		return -EPERM;
1636 
1637 	ret = mnt_want_write_file(file);
1638 	if (ret)
1639 		return ret;
1640 
1641 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1642 		mnt_drop_write_file(file);
1643 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1644 	}
1645 
1646 	vol_args = memdup_user(arg, sizeof(*vol_args));
1647 	if (IS_ERR(vol_args)) {
1648 		ret = PTR_ERR(vol_args);
1649 		goto out;
1650 	}
1651 
1652 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1653 
1654 	sizestr = vol_args->name;
1655 	devstr = strchr(sizestr, ':');
1656 	if (devstr) {
1657 		sizestr = devstr + 1;
1658 		*devstr = '\0';
1659 		devstr = vol_args->name;
1660 		ret = kstrtoull(devstr, 10, &devid);
1661 		if (ret)
1662 			goto out_free;
1663 		if (!devid) {
1664 			ret = -EINVAL;
1665 			goto out_free;
1666 		}
1667 		btrfs_info(fs_info, "resizing devid %llu", devid);
1668 	}
1669 
1670 	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL, true);
1671 	if (!device) {
1672 		btrfs_info(fs_info, "resizer unable to find device %llu",
1673 			   devid);
1674 		ret = -ENODEV;
1675 		goto out_free;
1676 	}
1677 
1678 	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1679 		btrfs_info(fs_info,
1680 			   "resizer unable to apply on readonly device %llu",
1681 		       devid);
1682 		ret = -EPERM;
1683 		goto out_free;
1684 	}
1685 
1686 	if (!strcmp(sizestr, "max"))
1687 		new_size = device->bdev->bd_inode->i_size;
1688 	else {
1689 		if (sizestr[0] == '-') {
1690 			mod = -1;
1691 			sizestr++;
1692 		} else if (sizestr[0] == '+') {
1693 			mod = 1;
1694 			sizestr++;
1695 		}
1696 		new_size = memparse(sizestr, &retptr);
1697 		if (*retptr != '\0' || new_size == 0) {
1698 			ret = -EINVAL;
1699 			goto out_free;
1700 		}
1701 	}
1702 
1703 	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1704 		ret = -EPERM;
1705 		goto out_free;
1706 	}
1707 
1708 	old_size = btrfs_device_get_total_bytes(device);
1709 
1710 	if (mod < 0) {
1711 		if (new_size > old_size) {
1712 			ret = -EINVAL;
1713 			goto out_free;
1714 		}
1715 		new_size = old_size - new_size;
1716 	} else if (mod > 0) {
1717 		if (new_size > ULLONG_MAX - old_size) {
1718 			ret = -ERANGE;
1719 			goto out_free;
1720 		}
1721 		new_size = old_size + new_size;
1722 	}
1723 
1724 	if (new_size < SZ_256M) {
1725 		ret = -EINVAL;
1726 		goto out_free;
1727 	}
1728 	if (new_size > device->bdev->bd_inode->i_size) {
1729 		ret = -EFBIG;
1730 		goto out_free;
1731 	}
1732 
1733 	new_size = round_down(new_size, fs_info->sectorsize);
1734 
1735 	if (new_size > old_size) {
1736 		trans = btrfs_start_transaction(root, 0);
1737 		if (IS_ERR(trans)) {
1738 			ret = PTR_ERR(trans);
1739 			goto out_free;
1740 		}
1741 		ret = btrfs_grow_device(trans, device, new_size);
1742 		btrfs_commit_transaction(trans);
1743 	} else if (new_size < old_size) {
1744 		ret = btrfs_shrink_device(device, new_size);
1745 	} /* equal, nothing need to do */
1746 
1747 	if (ret == 0 && new_size != old_size)
1748 		btrfs_info_in_rcu(fs_info,
1749 			"resize device %s (devid %llu) from %llu to %llu",
1750 			rcu_str_deref(device->name), device->devid,
1751 			old_size, new_size);
1752 out_free:
1753 	kfree(vol_args);
1754 out:
1755 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1756 	mnt_drop_write_file(file);
1757 	return ret;
1758 }
1759 
1760 static noinline int __btrfs_ioctl_snap_create(struct file *file,
1761 				const char *name, unsigned long fd, int subvol,
1762 				bool readonly,
1763 				struct btrfs_qgroup_inherit *inherit)
1764 {
1765 	int namelen;
1766 	int ret = 0;
1767 
1768 	if (!S_ISDIR(file_inode(file)->i_mode))
1769 		return -ENOTDIR;
1770 
1771 	ret = mnt_want_write_file(file);
1772 	if (ret)
1773 		goto out;
1774 
1775 	namelen = strlen(name);
1776 	if (strchr(name, '/')) {
1777 		ret = -EINVAL;
1778 		goto out_drop_write;
1779 	}
1780 
1781 	if (name[0] == '.' &&
1782 	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1783 		ret = -EEXIST;
1784 		goto out_drop_write;
1785 	}
1786 
1787 	if (subvol) {
1788 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
1789 				     NULL, readonly, inherit);
1790 	} else {
1791 		struct fd src = fdget(fd);
1792 		struct inode *src_inode;
1793 		if (!src.file) {
1794 			ret = -EINVAL;
1795 			goto out_drop_write;
1796 		}
1797 
1798 		src_inode = file_inode(src.file);
1799 		if (src_inode->i_sb != file_inode(file)->i_sb) {
1800 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1801 				   "Snapshot src from another FS");
1802 			ret = -EXDEV;
1803 		} else if (!inode_owner_or_capable(src_inode)) {
1804 			/*
1805 			 * Subvolume creation is not restricted, but snapshots
1806 			 * are limited to own subvolumes only
1807 			 */
1808 			ret = -EPERM;
1809 		} else {
1810 			ret = btrfs_mksnapshot(&file->f_path, name, namelen,
1811 					     BTRFS_I(src_inode)->root,
1812 					     readonly, inherit);
1813 		}
1814 		fdput(src);
1815 	}
1816 out_drop_write:
1817 	mnt_drop_write_file(file);
1818 out:
1819 	return ret;
1820 }
1821 
1822 static noinline int btrfs_ioctl_snap_create(struct file *file,
1823 					    void __user *arg, int subvol)
1824 {
1825 	struct btrfs_ioctl_vol_args *vol_args;
1826 	int ret;
1827 
1828 	if (!S_ISDIR(file_inode(file)->i_mode))
1829 		return -ENOTDIR;
1830 
1831 	vol_args = memdup_user(arg, sizeof(*vol_args));
1832 	if (IS_ERR(vol_args))
1833 		return PTR_ERR(vol_args);
1834 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1835 
1836 	ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
1837 					subvol, false, NULL);
1838 
1839 	kfree(vol_args);
1840 	return ret;
1841 }
1842 
1843 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1844 					       void __user *arg, int subvol)
1845 {
1846 	struct btrfs_ioctl_vol_args_v2 *vol_args;
1847 	int ret;
1848 	bool readonly = false;
1849 	struct btrfs_qgroup_inherit *inherit = NULL;
1850 
1851 	if (!S_ISDIR(file_inode(file)->i_mode))
1852 		return -ENOTDIR;
1853 
1854 	vol_args = memdup_user(arg, sizeof(*vol_args));
1855 	if (IS_ERR(vol_args))
1856 		return PTR_ERR(vol_args);
1857 	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1858 
1859 	if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1860 		ret = -EOPNOTSUPP;
1861 		goto free_args;
1862 	}
1863 
1864 	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1865 		readonly = true;
1866 	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1867 		if (vol_args->size > PAGE_SIZE) {
1868 			ret = -EINVAL;
1869 			goto free_args;
1870 		}
1871 		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1872 		if (IS_ERR(inherit)) {
1873 			ret = PTR_ERR(inherit);
1874 			goto free_args;
1875 		}
1876 	}
1877 
1878 	ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,
1879 					subvol, readonly, inherit);
1880 	if (ret)
1881 		goto free_inherit;
1882 free_inherit:
1883 	kfree(inherit);
1884 free_args:
1885 	kfree(vol_args);
1886 	return ret;
1887 }
1888 
1889 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1890 						void __user *arg)
1891 {
1892 	struct inode *inode = file_inode(file);
1893 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1894 	struct btrfs_root *root = BTRFS_I(inode)->root;
1895 	int ret = 0;
1896 	u64 flags = 0;
1897 
1898 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1899 		return -EINVAL;
1900 
1901 	down_read(&fs_info->subvol_sem);
1902 	if (btrfs_root_readonly(root))
1903 		flags |= BTRFS_SUBVOL_RDONLY;
1904 	up_read(&fs_info->subvol_sem);
1905 
1906 	if (copy_to_user(arg, &flags, sizeof(flags)))
1907 		ret = -EFAULT;
1908 
1909 	return ret;
1910 }
1911 
1912 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1913 					      void __user *arg)
1914 {
1915 	struct inode *inode = file_inode(file);
1916 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1917 	struct btrfs_root *root = BTRFS_I(inode)->root;
1918 	struct btrfs_trans_handle *trans;
1919 	u64 root_flags;
1920 	u64 flags;
1921 	int ret = 0;
1922 
1923 	if (!inode_owner_or_capable(inode))
1924 		return -EPERM;
1925 
1926 	ret = mnt_want_write_file(file);
1927 	if (ret)
1928 		goto out;
1929 
1930 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1931 		ret = -EINVAL;
1932 		goto out_drop_write;
1933 	}
1934 
1935 	if (copy_from_user(&flags, arg, sizeof(flags))) {
1936 		ret = -EFAULT;
1937 		goto out_drop_write;
1938 	}
1939 
1940 	if (flags & ~BTRFS_SUBVOL_RDONLY) {
1941 		ret = -EOPNOTSUPP;
1942 		goto out_drop_write;
1943 	}
1944 
1945 	down_write(&fs_info->subvol_sem);
1946 
1947 	/* nothing to do */
1948 	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1949 		goto out_drop_sem;
1950 
1951 	root_flags = btrfs_root_flags(&root->root_item);
1952 	if (flags & BTRFS_SUBVOL_RDONLY) {
1953 		btrfs_set_root_flags(&root->root_item,
1954 				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1955 	} else {
1956 		/*
1957 		 * Block RO -> RW transition if this subvolume is involved in
1958 		 * send
1959 		 */
1960 		spin_lock(&root->root_item_lock);
1961 		if (root->send_in_progress == 0) {
1962 			btrfs_set_root_flags(&root->root_item,
1963 				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1964 			spin_unlock(&root->root_item_lock);
1965 		} else {
1966 			spin_unlock(&root->root_item_lock);
1967 			btrfs_warn(fs_info,
1968 				   "Attempt to set subvolume %llu read-write during send",
1969 				   root->root_key.objectid);
1970 			ret = -EPERM;
1971 			goto out_drop_sem;
1972 		}
1973 	}
1974 
1975 	trans = btrfs_start_transaction(root, 1);
1976 	if (IS_ERR(trans)) {
1977 		ret = PTR_ERR(trans);
1978 		goto out_reset;
1979 	}
1980 
1981 	ret = btrfs_update_root(trans, fs_info->tree_root,
1982 				&root->root_key, &root->root_item);
1983 	if (ret < 0) {
1984 		btrfs_end_transaction(trans);
1985 		goto out_reset;
1986 	}
1987 
1988 	ret = btrfs_commit_transaction(trans);
1989 
1990 out_reset:
1991 	if (ret)
1992 		btrfs_set_root_flags(&root->root_item, root_flags);
1993 out_drop_sem:
1994 	up_write(&fs_info->subvol_sem);
1995 out_drop_write:
1996 	mnt_drop_write_file(file);
1997 out:
1998 	return ret;
1999 }
2000 
2001 static noinline int key_in_sk(struct btrfs_key *key,
2002 			      struct btrfs_ioctl_search_key *sk)
2003 {
2004 	struct btrfs_key test;
2005 	int ret;
2006 
2007 	test.objectid = sk->min_objectid;
2008 	test.type = sk->min_type;
2009 	test.offset = sk->min_offset;
2010 
2011 	ret = btrfs_comp_cpu_keys(key, &test);
2012 	if (ret < 0)
2013 		return 0;
2014 
2015 	test.objectid = sk->max_objectid;
2016 	test.type = sk->max_type;
2017 	test.offset = sk->max_offset;
2018 
2019 	ret = btrfs_comp_cpu_keys(key, &test);
2020 	if (ret > 0)
2021 		return 0;
2022 	return 1;
2023 }
2024 
2025 static noinline int copy_to_sk(struct btrfs_path *path,
2026 			       struct btrfs_key *key,
2027 			       struct btrfs_ioctl_search_key *sk,
2028 			       size_t *buf_size,
2029 			       char __user *ubuf,
2030 			       unsigned long *sk_offset,
2031 			       int *num_found)
2032 {
2033 	u64 found_transid;
2034 	struct extent_buffer *leaf;
2035 	struct btrfs_ioctl_search_header sh;
2036 	struct btrfs_key test;
2037 	unsigned long item_off;
2038 	unsigned long item_len;
2039 	int nritems;
2040 	int i;
2041 	int slot;
2042 	int ret = 0;
2043 
2044 	leaf = path->nodes[0];
2045 	slot = path->slots[0];
2046 	nritems = btrfs_header_nritems(leaf);
2047 
2048 	if (btrfs_header_generation(leaf) > sk->max_transid) {
2049 		i = nritems;
2050 		goto advance_key;
2051 	}
2052 	found_transid = btrfs_header_generation(leaf);
2053 
2054 	for (i = slot; i < nritems; i++) {
2055 		item_off = btrfs_item_ptr_offset(leaf, i);
2056 		item_len = btrfs_item_size_nr(leaf, i);
2057 
2058 		btrfs_item_key_to_cpu(leaf, key, i);
2059 		if (!key_in_sk(key, sk))
2060 			continue;
2061 
2062 		if (sizeof(sh) + item_len > *buf_size) {
2063 			if (*num_found) {
2064 				ret = 1;
2065 				goto out;
2066 			}
2067 
2068 			/*
2069 			 * return one empty item back for v1, which does not
2070 			 * handle -EOVERFLOW
2071 			 */
2072 
2073 			*buf_size = sizeof(sh) + item_len;
2074 			item_len = 0;
2075 			ret = -EOVERFLOW;
2076 		}
2077 
2078 		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2079 			ret = 1;
2080 			goto out;
2081 		}
2082 
2083 		sh.objectid = key->objectid;
2084 		sh.offset = key->offset;
2085 		sh.type = key->type;
2086 		sh.len = item_len;
2087 		sh.transid = found_transid;
2088 
2089 		/*
2090 		 * Copy search result header. If we fault then loop again so we
2091 		 * can fault in the pages and -EFAULT there if there's a
2092 		 * problem. Otherwise we'll fault and then copy the buffer in
2093 		 * properly this next time through
2094 		 */
2095 		if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
2096 			ret = 0;
2097 			goto out;
2098 		}
2099 
2100 		*sk_offset += sizeof(sh);
2101 
2102 		if (item_len) {
2103 			char __user *up = ubuf + *sk_offset;
2104 			/*
2105 			 * Copy the item, same behavior as above, but reset the
2106 			 * * sk_offset so we copy the full thing again.
2107 			 */
2108 			if (read_extent_buffer_to_user_nofault(leaf, up,
2109 						item_off, item_len)) {
2110 				ret = 0;
2111 				*sk_offset -= sizeof(sh);
2112 				goto out;
2113 			}
2114 
2115 			*sk_offset += item_len;
2116 		}
2117 		(*num_found)++;
2118 
2119 		if (ret) /* -EOVERFLOW from above */
2120 			goto out;
2121 
2122 		if (*num_found >= sk->nr_items) {
2123 			ret = 1;
2124 			goto out;
2125 		}
2126 	}
2127 advance_key:
2128 	ret = 0;
2129 	test.objectid = sk->max_objectid;
2130 	test.type = sk->max_type;
2131 	test.offset = sk->max_offset;
2132 	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2133 		ret = 1;
2134 	else if (key->offset < (u64)-1)
2135 		key->offset++;
2136 	else if (key->type < (u8)-1) {
2137 		key->offset = 0;
2138 		key->type++;
2139 	} else if (key->objectid < (u64)-1) {
2140 		key->offset = 0;
2141 		key->type = 0;
2142 		key->objectid++;
2143 	} else
2144 		ret = 1;
2145 out:
2146 	/*
2147 	 *  0: all items from this leaf copied, continue with next
2148 	 *  1: * more items can be copied, but unused buffer is too small
2149 	 *     * all items were found
2150 	 *     Either way, it will stops the loop which iterates to the next
2151 	 *     leaf
2152 	 *  -EOVERFLOW: item was to large for buffer
2153 	 *  -EFAULT: could not copy extent buffer back to userspace
2154 	 */
2155 	return ret;
2156 }
2157 
2158 static noinline int search_ioctl(struct inode *inode,
2159 				 struct btrfs_ioctl_search_key *sk,
2160 				 size_t *buf_size,
2161 				 char __user *ubuf)
2162 {
2163 	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2164 	struct btrfs_root *root;
2165 	struct btrfs_key key;
2166 	struct btrfs_path *path;
2167 	int ret;
2168 	int num_found = 0;
2169 	unsigned long sk_offset = 0;
2170 
2171 	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2172 		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2173 		return -EOVERFLOW;
2174 	}
2175 
2176 	path = btrfs_alloc_path();
2177 	if (!path)
2178 		return -ENOMEM;
2179 
2180 	if (sk->tree_id == 0) {
2181 		/* search the root of the inode that was passed */
2182 		root = btrfs_grab_root(BTRFS_I(inode)->root);
2183 	} else {
2184 		root = btrfs_get_fs_root(info, sk->tree_id, true);
2185 		if (IS_ERR(root)) {
2186 			btrfs_free_path(path);
2187 			return PTR_ERR(root);
2188 		}
2189 	}
2190 
2191 	key.objectid = sk->min_objectid;
2192 	key.type = sk->min_type;
2193 	key.offset = sk->min_offset;
2194 
2195 	while (1) {
2196 		ret = fault_in_pages_writeable(ubuf, *buf_size - sk_offset);
2197 		if (ret)
2198 			break;
2199 
2200 		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2201 		if (ret != 0) {
2202 			if (ret > 0)
2203 				ret = 0;
2204 			goto err;
2205 		}
2206 		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2207 				 &sk_offset, &num_found);
2208 		btrfs_release_path(path);
2209 		if (ret)
2210 			break;
2211 
2212 	}
2213 	if (ret > 0)
2214 		ret = 0;
2215 err:
2216 	sk->nr_items = num_found;
2217 	btrfs_put_root(root);
2218 	btrfs_free_path(path);
2219 	return ret;
2220 }
2221 
2222 static noinline int btrfs_ioctl_tree_search(struct file *file,
2223 					   void __user *argp)
2224 {
2225 	struct btrfs_ioctl_search_args __user *uargs;
2226 	struct btrfs_ioctl_search_key sk;
2227 	struct inode *inode;
2228 	int ret;
2229 	size_t buf_size;
2230 
2231 	if (!capable(CAP_SYS_ADMIN))
2232 		return -EPERM;
2233 
2234 	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2235 
2236 	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2237 		return -EFAULT;
2238 
2239 	buf_size = sizeof(uargs->buf);
2240 
2241 	inode = file_inode(file);
2242 	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2243 
2244 	/*
2245 	 * In the origin implementation an overflow is handled by returning a
2246 	 * search header with a len of zero, so reset ret.
2247 	 */
2248 	if (ret == -EOVERFLOW)
2249 		ret = 0;
2250 
2251 	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2252 		ret = -EFAULT;
2253 	return ret;
2254 }
2255 
2256 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2257 					       void __user *argp)
2258 {
2259 	struct btrfs_ioctl_search_args_v2 __user *uarg;
2260 	struct btrfs_ioctl_search_args_v2 args;
2261 	struct inode *inode;
2262 	int ret;
2263 	size_t buf_size;
2264 	const size_t buf_limit = SZ_16M;
2265 
2266 	if (!capable(CAP_SYS_ADMIN))
2267 		return -EPERM;
2268 
2269 	/* copy search header and buffer size */
2270 	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2271 	if (copy_from_user(&args, uarg, sizeof(args)))
2272 		return -EFAULT;
2273 
2274 	buf_size = args.buf_size;
2275 
2276 	/* limit result size to 16MB */
2277 	if (buf_size > buf_limit)
2278 		buf_size = buf_limit;
2279 
2280 	inode = file_inode(file);
2281 	ret = search_ioctl(inode, &args.key, &buf_size,
2282 			   (char __user *)(&uarg->buf[0]));
2283 	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2284 		ret = -EFAULT;
2285 	else if (ret == -EOVERFLOW &&
2286 		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2287 		ret = -EFAULT;
2288 
2289 	return ret;
2290 }
2291 
2292 /*
2293  * Search INODE_REFs to identify path name of 'dirid' directory
2294  * in a 'tree_id' tree. and sets path name to 'name'.
2295  */
2296 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2297 				u64 tree_id, u64 dirid, char *name)
2298 {
2299 	struct btrfs_root *root;
2300 	struct btrfs_key key;
2301 	char *ptr;
2302 	int ret = -1;
2303 	int slot;
2304 	int len;
2305 	int total_len = 0;
2306 	struct btrfs_inode_ref *iref;
2307 	struct extent_buffer *l;
2308 	struct btrfs_path *path;
2309 
2310 	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2311 		name[0]='\0';
2312 		return 0;
2313 	}
2314 
2315 	path = btrfs_alloc_path();
2316 	if (!path)
2317 		return -ENOMEM;
2318 
2319 	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2320 
2321 	root = btrfs_get_fs_root(info, tree_id, true);
2322 	if (IS_ERR(root)) {
2323 		ret = PTR_ERR(root);
2324 		root = NULL;
2325 		goto out;
2326 	}
2327 
2328 	key.objectid = dirid;
2329 	key.type = BTRFS_INODE_REF_KEY;
2330 	key.offset = (u64)-1;
2331 
2332 	while (1) {
2333 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2334 		if (ret < 0)
2335 			goto out;
2336 		else if (ret > 0) {
2337 			ret = btrfs_previous_item(root, path, dirid,
2338 						  BTRFS_INODE_REF_KEY);
2339 			if (ret < 0)
2340 				goto out;
2341 			else if (ret > 0) {
2342 				ret = -ENOENT;
2343 				goto out;
2344 			}
2345 		}
2346 
2347 		l = path->nodes[0];
2348 		slot = path->slots[0];
2349 		btrfs_item_key_to_cpu(l, &key, slot);
2350 
2351 		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2352 		len = btrfs_inode_ref_name_len(l, iref);
2353 		ptr -= len + 1;
2354 		total_len += len + 1;
2355 		if (ptr < name) {
2356 			ret = -ENAMETOOLONG;
2357 			goto out;
2358 		}
2359 
2360 		*(ptr + len) = '/';
2361 		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2362 
2363 		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2364 			break;
2365 
2366 		btrfs_release_path(path);
2367 		key.objectid = key.offset;
2368 		key.offset = (u64)-1;
2369 		dirid = key.objectid;
2370 	}
2371 	memmove(name, ptr, total_len);
2372 	name[total_len] = '\0';
2373 	ret = 0;
2374 out:
2375 	btrfs_put_root(root);
2376 	btrfs_free_path(path);
2377 	return ret;
2378 }
2379 
2380 static int btrfs_search_path_in_tree_user(struct inode *inode,
2381 				struct btrfs_ioctl_ino_lookup_user_args *args)
2382 {
2383 	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2384 	struct super_block *sb = inode->i_sb;
2385 	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2386 	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2387 	u64 dirid = args->dirid;
2388 	unsigned long item_off;
2389 	unsigned long item_len;
2390 	struct btrfs_inode_ref *iref;
2391 	struct btrfs_root_ref *rref;
2392 	struct btrfs_root *root = NULL;
2393 	struct btrfs_path *path;
2394 	struct btrfs_key key, key2;
2395 	struct extent_buffer *leaf;
2396 	struct inode *temp_inode;
2397 	char *ptr;
2398 	int slot;
2399 	int len;
2400 	int total_len = 0;
2401 	int ret;
2402 
2403 	path = btrfs_alloc_path();
2404 	if (!path)
2405 		return -ENOMEM;
2406 
2407 	/*
2408 	 * If the bottom subvolume does not exist directly under upper_limit,
2409 	 * construct the path in from the bottom up.
2410 	 */
2411 	if (dirid != upper_limit.objectid) {
2412 		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2413 
2414 		root = btrfs_get_fs_root(fs_info, treeid, true);
2415 		if (IS_ERR(root)) {
2416 			ret = PTR_ERR(root);
2417 			goto out;
2418 		}
2419 
2420 		key.objectid = dirid;
2421 		key.type = BTRFS_INODE_REF_KEY;
2422 		key.offset = (u64)-1;
2423 		while (1) {
2424 			ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2425 			if (ret < 0) {
2426 				goto out_put;
2427 			} else if (ret > 0) {
2428 				ret = btrfs_previous_item(root, path, dirid,
2429 							  BTRFS_INODE_REF_KEY);
2430 				if (ret < 0) {
2431 					goto out_put;
2432 				} else if (ret > 0) {
2433 					ret = -ENOENT;
2434 					goto out_put;
2435 				}
2436 			}
2437 
2438 			leaf = path->nodes[0];
2439 			slot = path->slots[0];
2440 			btrfs_item_key_to_cpu(leaf, &key, slot);
2441 
2442 			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2443 			len = btrfs_inode_ref_name_len(leaf, iref);
2444 			ptr -= len + 1;
2445 			total_len += len + 1;
2446 			if (ptr < args->path) {
2447 				ret = -ENAMETOOLONG;
2448 				goto out_put;
2449 			}
2450 
2451 			*(ptr + len) = '/';
2452 			read_extent_buffer(leaf, ptr,
2453 					(unsigned long)(iref + 1), len);
2454 
2455 			/* Check the read+exec permission of this directory */
2456 			ret = btrfs_previous_item(root, path, dirid,
2457 						  BTRFS_INODE_ITEM_KEY);
2458 			if (ret < 0) {
2459 				goto out_put;
2460 			} else if (ret > 0) {
2461 				ret = -ENOENT;
2462 				goto out_put;
2463 			}
2464 
2465 			leaf = path->nodes[0];
2466 			slot = path->slots[0];
2467 			btrfs_item_key_to_cpu(leaf, &key2, slot);
2468 			if (key2.objectid != dirid) {
2469 				ret = -ENOENT;
2470 				goto out_put;
2471 			}
2472 
2473 			temp_inode = btrfs_iget(sb, key2.objectid, root);
2474 			if (IS_ERR(temp_inode)) {
2475 				ret = PTR_ERR(temp_inode);
2476 				goto out_put;
2477 			}
2478 			ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2479 			iput(temp_inode);
2480 			if (ret) {
2481 				ret = -EACCES;
2482 				goto out_put;
2483 			}
2484 
2485 			if (key.offset == upper_limit.objectid)
2486 				break;
2487 			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2488 				ret = -EACCES;
2489 				goto out_put;
2490 			}
2491 
2492 			btrfs_release_path(path);
2493 			key.objectid = key.offset;
2494 			key.offset = (u64)-1;
2495 			dirid = key.objectid;
2496 		}
2497 
2498 		memmove(args->path, ptr, total_len);
2499 		args->path[total_len] = '\0';
2500 		btrfs_put_root(root);
2501 		root = NULL;
2502 		btrfs_release_path(path);
2503 	}
2504 
2505 	/* Get the bottom subvolume's name from ROOT_REF */
2506 	key.objectid = treeid;
2507 	key.type = BTRFS_ROOT_REF_KEY;
2508 	key.offset = args->treeid;
2509 	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2510 	if (ret < 0) {
2511 		goto out;
2512 	} else if (ret > 0) {
2513 		ret = -ENOENT;
2514 		goto out;
2515 	}
2516 
2517 	leaf = path->nodes[0];
2518 	slot = path->slots[0];
2519 	btrfs_item_key_to_cpu(leaf, &key, slot);
2520 
2521 	item_off = btrfs_item_ptr_offset(leaf, slot);
2522 	item_len = btrfs_item_size_nr(leaf, slot);
2523 	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2524 	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2525 	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2526 		ret = -EINVAL;
2527 		goto out;
2528 	}
2529 
2530 	/* Copy subvolume's name */
2531 	item_off += sizeof(struct btrfs_root_ref);
2532 	item_len -= sizeof(struct btrfs_root_ref);
2533 	read_extent_buffer(leaf, args->name, item_off, item_len);
2534 	args->name[item_len] = 0;
2535 
2536 out_put:
2537 	btrfs_put_root(root);
2538 out:
2539 	btrfs_free_path(path);
2540 	return ret;
2541 }
2542 
2543 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2544 					   void __user *argp)
2545 {
2546 	struct btrfs_ioctl_ino_lookup_args *args;
2547 	struct inode *inode;
2548 	int ret = 0;
2549 
2550 	args = memdup_user(argp, sizeof(*args));
2551 	if (IS_ERR(args))
2552 		return PTR_ERR(args);
2553 
2554 	inode = file_inode(file);
2555 
2556 	/*
2557 	 * Unprivileged query to obtain the containing subvolume root id. The
2558 	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2559 	 */
2560 	if (args->treeid == 0)
2561 		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2562 
2563 	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2564 		args->name[0] = 0;
2565 		goto out;
2566 	}
2567 
2568 	if (!capable(CAP_SYS_ADMIN)) {
2569 		ret = -EPERM;
2570 		goto out;
2571 	}
2572 
2573 	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2574 					args->treeid, args->objectid,
2575 					args->name);
2576 
2577 out:
2578 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2579 		ret = -EFAULT;
2580 
2581 	kfree(args);
2582 	return ret;
2583 }
2584 
2585 /*
2586  * Version of ino_lookup ioctl (unprivileged)
2587  *
2588  * The main differences from ino_lookup ioctl are:
2589  *
2590  *   1. Read + Exec permission will be checked using inode_permission() during
2591  *      path construction. -EACCES will be returned in case of failure.
2592  *   2. Path construction will be stopped at the inode number which corresponds
2593  *      to the fd with which this ioctl is called. If constructed path does not
2594  *      exist under fd's inode, -EACCES will be returned.
2595  *   3. The name of bottom subvolume is also searched and filled.
2596  */
2597 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2598 {
2599 	struct btrfs_ioctl_ino_lookup_user_args *args;
2600 	struct inode *inode;
2601 	int ret;
2602 
2603 	args = memdup_user(argp, sizeof(*args));
2604 	if (IS_ERR(args))
2605 		return PTR_ERR(args);
2606 
2607 	inode = file_inode(file);
2608 
2609 	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2610 	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2611 		/*
2612 		 * The subvolume does not exist under fd with which this is
2613 		 * called
2614 		 */
2615 		kfree(args);
2616 		return -EACCES;
2617 	}
2618 
2619 	ret = btrfs_search_path_in_tree_user(inode, args);
2620 
2621 	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2622 		ret = -EFAULT;
2623 
2624 	kfree(args);
2625 	return ret;
2626 }
2627 
2628 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2629 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2630 {
2631 	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2632 	struct btrfs_fs_info *fs_info;
2633 	struct btrfs_root *root;
2634 	struct btrfs_path *path;
2635 	struct btrfs_key key;
2636 	struct btrfs_root_item *root_item;
2637 	struct btrfs_root_ref *rref;
2638 	struct extent_buffer *leaf;
2639 	unsigned long item_off;
2640 	unsigned long item_len;
2641 	struct inode *inode;
2642 	int slot;
2643 	int ret = 0;
2644 
2645 	path = btrfs_alloc_path();
2646 	if (!path)
2647 		return -ENOMEM;
2648 
2649 	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2650 	if (!subvol_info) {
2651 		btrfs_free_path(path);
2652 		return -ENOMEM;
2653 	}
2654 
2655 	inode = file_inode(file);
2656 	fs_info = BTRFS_I(inode)->root->fs_info;
2657 
2658 	/* Get root_item of inode's subvolume */
2659 	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2660 	root = btrfs_get_fs_root(fs_info, key.objectid, true);
2661 	if (IS_ERR(root)) {
2662 		ret = PTR_ERR(root);
2663 		goto out_free;
2664 	}
2665 	root_item = &root->root_item;
2666 
2667 	subvol_info->treeid = key.objectid;
2668 
2669 	subvol_info->generation = btrfs_root_generation(root_item);
2670 	subvol_info->flags = btrfs_root_flags(root_item);
2671 
2672 	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2673 	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2674 						    BTRFS_UUID_SIZE);
2675 	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2676 						    BTRFS_UUID_SIZE);
2677 
2678 	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2679 	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2680 	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2681 
2682 	subvol_info->otransid = btrfs_root_otransid(root_item);
2683 	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2684 	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2685 
2686 	subvol_info->stransid = btrfs_root_stransid(root_item);
2687 	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2688 	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2689 
2690 	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2691 	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2692 	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2693 
2694 	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2695 		/* Search root tree for ROOT_BACKREF of this subvolume */
2696 		key.type = BTRFS_ROOT_BACKREF_KEY;
2697 		key.offset = 0;
2698 		ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2699 		if (ret < 0) {
2700 			goto out;
2701 		} else if (path->slots[0] >=
2702 			   btrfs_header_nritems(path->nodes[0])) {
2703 			ret = btrfs_next_leaf(fs_info->tree_root, path);
2704 			if (ret < 0) {
2705 				goto out;
2706 			} else if (ret > 0) {
2707 				ret = -EUCLEAN;
2708 				goto out;
2709 			}
2710 		}
2711 
2712 		leaf = path->nodes[0];
2713 		slot = path->slots[0];
2714 		btrfs_item_key_to_cpu(leaf, &key, slot);
2715 		if (key.objectid == subvol_info->treeid &&
2716 		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2717 			subvol_info->parent_id = key.offset;
2718 
2719 			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2720 			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2721 
2722 			item_off = btrfs_item_ptr_offset(leaf, slot)
2723 					+ sizeof(struct btrfs_root_ref);
2724 			item_len = btrfs_item_size_nr(leaf, slot)
2725 					- sizeof(struct btrfs_root_ref);
2726 			read_extent_buffer(leaf, subvol_info->name,
2727 					   item_off, item_len);
2728 		} else {
2729 			ret = -ENOENT;
2730 			goto out;
2731 		}
2732 	}
2733 
2734 	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2735 		ret = -EFAULT;
2736 
2737 out:
2738 	btrfs_put_root(root);
2739 out_free:
2740 	btrfs_free_path(path);
2741 	kfree(subvol_info);
2742 	return ret;
2743 }
2744 
2745 /*
2746  * Return ROOT_REF information of the subvolume containing this inode
2747  * except the subvolume name.
2748  */
2749 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2750 {
2751 	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2752 	struct btrfs_root_ref *rref;
2753 	struct btrfs_root *root;
2754 	struct btrfs_path *path;
2755 	struct btrfs_key key;
2756 	struct extent_buffer *leaf;
2757 	struct inode *inode;
2758 	u64 objectid;
2759 	int slot;
2760 	int ret;
2761 	u8 found;
2762 
2763 	path = btrfs_alloc_path();
2764 	if (!path)
2765 		return -ENOMEM;
2766 
2767 	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2768 	if (IS_ERR(rootrefs)) {
2769 		btrfs_free_path(path);
2770 		return PTR_ERR(rootrefs);
2771 	}
2772 
2773 	inode = file_inode(file);
2774 	root = BTRFS_I(inode)->root->fs_info->tree_root;
2775 	objectid = BTRFS_I(inode)->root->root_key.objectid;
2776 
2777 	key.objectid = objectid;
2778 	key.type = BTRFS_ROOT_REF_KEY;
2779 	key.offset = rootrefs->min_treeid;
2780 	found = 0;
2781 
2782 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2783 	if (ret < 0) {
2784 		goto out;
2785 	} else if (path->slots[0] >=
2786 		   btrfs_header_nritems(path->nodes[0])) {
2787 		ret = btrfs_next_leaf(root, path);
2788 		if (ret < 0) {
2789 			goto out;
2790 		} else if (ret > 0) {
2791 			ret = -EUCLEAN;
2792 			goto out;
2793 		}
2794 	}
2795 	while (1) {
2796 		leaf = path->nodes[0];
2797 		slot = path->slots[0];
2798 
2799 		btrfs_item_key_to_cpu(leaf, &key, slot);
2800 		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2801 			ret = 0;
2802 			goto out;
2803 		}
2804 
2805 		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2806 			ret = -EOVERFLOW;
2807 			goto out;
2808 		}
2809 
2810 		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2811 		rootrefs->rootref[found].treeid = key.offset;
2812 		rootrefs->rootref[found].dirid =
2813 				  btrfs_root_ref_dirid(leaf, rref);
2814 		found++;
2815 
2816 		ret = btrfs_next_item(root, path);
2817 		if (ret < 0) {
2818 			goto out;
2819 		} else if (ret > 0) {
2820 			ret = -EUCLEAN;
2821 			goto out;
2822 		}
2823 	}
2824 
2825 out:
2826 	if (!ret || ret == -EOVERFLOW) {
2827 		rootrefs->num_items = found;
2828 		/* update min_treeid for next search */
2829 		if (found)
2830 			rootrefs->min_treeid =
2831 				rootrefs->rootref[found - 1].treeid + 1;
2832 		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2833 			ret = -EFAULT;
2834 	}
2835 
2836 	kfree(rootrefs);
2837 	btrfs_free_path(path);
2838 
2839 	return ret;
2840 }
2841 
2842 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2843 					     void __user *arg,
2844 					     bool destroy_v2)
2845 {
2846 	struct dentry *parent = file->f_path.dentry;
2847 	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2848 	struct dentry *dentry;
2849 	struct inode *dir = d_inode(parent);
2850 	struct inode *inode;
2851 	struct btrfs_root *root = BTRFS_I(dir)->root;
2852 	struct btrfs_root *dest = NULL;
2853 	struct btrfs_ioctl_vol_args *vol_args = NULL;
2854 	struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2855 	char *subvol_name, *subvol_name_ptr = NULL;
2856 	int subvol_namelen;
2857 	int err = 0;
2858 	bool destroy_parent = false;
2859 
2860 	if (destroy_v2) {
2861 		vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2862 		if (IS_ERR(vol_args2))
2863 			return PTR_ERR(vol_args2);
2864 
2865 		if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2866 			err = -EOPNOTSUPP;
2867 			goto out;
2868 		}
2869 
2870 		/*
2871 		 * If SPEC_BY_ID is not set, we are looking for the subvolume by
2872 		 * name, same as v1 currently does.
2873 		 */
2874 		if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2875 			vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2876 			subvol_name = vol_args2->name;
2877 
2878 			err = mnt_want_write_file(file);
2879 			if (err)
2880 				goto out;
2881 		} else {
2882 			if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2883 				err = -EINVAL;
2884 				goto out;
2885 			}
2886 
2887 			err = mnt_want_write_file(file);
2888 			if (err)
2889 				goto out;
2890 
2891 			dentry = btrfs_get_dentry(fs_info->sb,
2892 					BTRFS_FIRST_FREE_OBJECTID,
2893 					vol_args2->subvolid, 0, 0);
2894 			if (IS_ERR(dentry)) {
2895 				err = PTR_ERR(dentry);
2896 				goto out_drop_write;
2897 			}
2898 
2899 			/*
2900 			 * Change the default parent since the subvolume being
2901 			 * deleted can be outside of the current mount point.
2902 			 */
2903 			parent = btrfs_get_parent(dentry);
2904 
2905 			/*
2906 			 * At this point dentry->d_name can point to '/' if the
2907 			 * subvolume we want to destroy is outsite of the
2908 			 * current mount point, so we need to release the
2909 			 * current dentry and execute the lookup to return a new
2910 			 * one with ->d_name pointing to the
2911 			 * <mount point>/subvol_name.
2912 			 */
2913 			dput(dentry);
2914 			if (IS_ERR(parent)) {
2915 				err = PTR_ERR(parent);
2916 				goto out_drop_write;
2917 			}
2918 			dir = d_inode(parent);
2919 
2920 			/*
2921 			 * If v2 was used with SPEC_BY_ID, a new parent was
2922 			 * allocated since the subvolume can be outside of the
2923 			 * current mount point. Later on we need to release this
2924 			 * new parent dentry.
2925 			 */
2926 			destroy_parent = true;
2927 
2928 			subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
2929 						fs_info, vol_args2->subvolid);
2930 			if (IS_ERR(subvol_name_ptr)) {
2931 				err = PTR_ERR(subvol_name_ptr);
2932 				goto free_parent;
2933 			}
2934 			/* subvol_name_ptr is already NULL termined */
2935 			subvol_name = (char *)kbasename(subvol_name_ptr);
2936 		}
2937 	} else {
2938 		vol_args = memdup_user(arg, sizeof(*vol_args));
2939 		if (IS_ERR(vol_args))
2940 			return PTR_ERR(vol_args);
2941 
2942 		vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
2943 		subvol_name = vol_args->name;
2944 
2945 		err = mnt_want_write_file(file);
2946 		if (err)
2947 			goto out;
2948 	}
2949 
2950 	subvol_namelen = strlen(subvol_name);
2951 
2952 	if (strchr(subvol_name, '/') ||
2953 	    strncmp(subvol_name, "..", subvol_namelen) == 0) {
2954 		err = -EINVAL;
2955 		goto free_subvol_name;
2956 	}
2957 
2958 	if (!S_ISDIR(dir->i_mode)) {
2959 		err = -ENOTDIR;
2960 		goto free_subvol_name;
2961 	}
2962 
2963 	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2964 	if (err == -EINTR)
2965 		goto free_subvol_name;
2966 	dentry = lookup_one_len(subvol_name, parent, subvol_namelen);
2967 	if (IS_ERR(dentry)) {
2968 		err = PTR_ERR(dentry);
2969 		goto out_unlock_dir;
2970 	}
2971 
2972 	if (d_really_is_negative(dentry)) {
2973 		err = -ENOENT;
2974 		goto out_dput;
2975 	}
2976 
2977 	inode = d_inode(dentry);
2978 	dest = BTRFS_I(inode)->root;
2979 	if (!capable(CAP_SYS_ADMIN)) {
2980 		/*
2981 		 * Regular user.  Only allow this with a special mount
2982 		 * option, when the user has write+exec access to the
2983 		 * subvol root, and when rmdir(2) would have been
2984 		 * allowed.
2985 		 *
2986 		 * Note that this is _not_ check that the subvol is
2987 		 * empty or doesn't contain data that we wouldn't
2988 		 * otherwise be able to delete.
2989 		 *
2990 		 * Users who want to delete empty subvols should try
2991 		 * rmdir(2).
2992 		 */
2993 		err = -EPERM;
2994 		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2995 			goto out_dput;
2996 
2997 		/*
2998 		 * Do not allow deletion if the parent dir is the same
2999 		 * as the dir to be deleted.  That means the ioctl
3000 		 * must be called on the dentry referencing the root
3001 		 * of the subvol, not a random directory contained
3002 		 * within it.
3003 		 */
3004 		err = -EINVAL;
3005 		if (root == dest)
3006 			goto out_dput;
3007 
3008 		err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
3009 		if (err)
3010 			goto out_dput;
3011 	}
3012 
3013 	/* check if subvolume may be deleted by a user */
3014 	err = btrfs_may_delete(dir, dentry, 1);
3015 	if (err)
3016 		goto out_dput;
3017 
3018 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
3019 		err = -EINVAL;
3020 		goto out_dput;
3021 	}
3022 
3023 	inode_lock(inode);
3024 	err = btrfs_delete_subvolume(dir, dentry);
3025 	inode_unlock(inode);
3026 	if (!err) {
3027 		fsnotify_rmdir(dir, dentry);
3028 		d_delete(dentry);
3029 	}
3030 
3031 out_dput:
3032 	dput(dentry);
3033 out_unlock_dir:
3034 	inode_unlock(dir);
3035 free_subvol_name:
3036 	kfree(subvol_name_ptr);
3037 free_parent:
3038 	if (destroy_parent)
3039 		dput(parent);
3040 out_drop_write:
3041 	mnt_drop_write_file(file);
3042 out:
3043 	kfree(vol_args2);
3044 	kfree(vol_args);
3045 	return err;
3046 }
3047 
3048 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
3049 {
3050 	struct inode *inode = file_inode(file);
3051 	struct btrfs_root *root = BTRFS_I(inode)->root;
3052 	struct btrfs_ioctl_defrag_range_args *range;
3053 	int ret;
3054 
3055 	ret = mnt_want_write_file(file);
3056 	if (ret)
3057 		return ret;
3058 
3059 	if (btrfs_root_readonly(root)) {
3060 		ret = -EROFS;
3061 		goto out;
3062 	}
3063 
3064 	switch (inode->i_mode & S_IFMT) {
3065 	case S_IFDIR:
3066 		if (!capable(CAP_SYS_ADMIN)) {
3067 			ret = -EPERM;
3068 			goto out;
3069 		}
3070 		ret = btrfs_defrag_root(root);
3071 		break;
3072 	case S_IFREG:
3073 		/*
3074 		 * Note that this does not check the file descriptor for write
3075 		 * access. This prevents defragmenting executables that are
3076 		 * running and allows defrag on files open in read-only mode.
3077 		 */
3078 		if (!capable(CAP_SYS_ADMIN) &&
3079 		    inode_permission(inode, MAY_WRITE)) {
3080 			ret = -EPERM;
3081 			goto out;
3082 		}
3083 
3084 		range = kzalloc(sizeof(*range), GFP_KERNEL);
3085 		if (!range) {
3086 			ret = -ENOMEM;
3087 			goto out;
3088 		}
3089 
3090 		if (argp) {
3091 			if (copy_from_user(range, argp,
3092 					   sizeof(*range))) {
3093 				ret = -EFAULT;
3094 				kfree(range);
3095 				goto out;
3096 			}
3097 			/* compression requires us to start the IO */
3098 			if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
3099 				range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
3100 				range->extent_thresh = (u32)-1;
3101 			}
3102 		} else {
3103 			/* the rest are all set to zero by kzalloc */
3104 			range->len = (u64)-1;
3105 		}
3106 		ret = btrfs_defrag_file(file_inode(file), file,
3107 					range, BTRFS_OLDEST_GENERATION, 0);
3108 		if (ret > 0)
3109 			ret = 0;
3110 		kfree(range);
3111 		break;
3112 	default:
3113 		ret = -EINVAL;
3114 	}
3115 out:
3116 	mnt_drop_write_file(file);
3117 	return ret;
3118 }
3119 
3120 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3121 {
3122 	struct btrfs_ioctl_vol_args *vol_args;
3123 	int ret;
3124 
3125 	if (!capable(CAP_SYS_ADMIN))
3126 		return -EPERM;
3127 
3128 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3129 		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3130 
3131 	vol_args = memdup_user(arg, sizeof(*vol_args));
3132 	if (IS_ERR(vol_args)) {
3133 		ret = PTR_ERR(vol_args);
3134 		goto out;
3135 	}
3136 
3137 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3138 	ret = btrfs_init_new_device(fs_info, vol_args->name);
3139 
3140 	if (!ret)
3141 		btrfs_info(fs_info, "disk added %s", vol_args->name);
3142 
3143 	kfree(vol_args);
3144 out:
3145 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3146 	return ret;
3147 }
3148 
3149 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3150 {
3151 	struct inode *inode = file_inode(file);
3152 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3153 	struct btrfs_ioctl_vol_args_v2 *vol_args;
3154 	int ret;
3155 
3156 	if (!capable(CAP_SYS_ADMIN))
3157 		return -EPERM;
3158 
3159 	ret = mnt_want_write_file(file);
3160 	if (ret)
3161 		return ret;
3162 
3163 	vol_args = memdup_user(arg, sizeof(*vol_args));
3164 	if (IS_ERR(vol_args)) {
3165 		ret = PTR_ERR(vol_args);
3166 		goto err_drop;
3167 	}
3168 
3169 	if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
3170 		ret = -EOPNOTSUPP;
3171 		goto out;
3172 	}
3173 
3174 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3175 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3176 		goto out;
3177 	}
3178 
3179 	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3180 		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3181 	} else {
3182 		vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3183 		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3184 	}
3185 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3186 
3187 	if (!ret) {
3188 		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3189 			btrfs_info(fs_info, "device deleted: id %llu",
3190 					vol_args->devid);
3191 		else
3192 			btrfs_info(fs_info, "device deleted: %s",
3193 					vol_args->name);
3194 	}
3195 out:
3196 	kfree(vol_args);
3197 err_drop:
3198 	mnt_drop_write_file(file);
3199 	return ret;
3200 }
3201 
3202 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3203 {
3204 	struct inode *inode = file_inode(file);
3205 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3206 	struct btrfs_ioctl_vol_args *vol_args;
3207 	int ret;
3208 
3209 	if (!capable(CAP_SYS_ADMIN))
3210 		return -EPERM;
3211 
3212 	ret = mnt_want_write_file(file);
3213 	if (ret)
3214 		return ret;
3215 
3216 	if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3217 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3218 		goto out_drop_write;
3219 	}
3220 
3221 	vol_args = memdup_user(arg, sizeof(*vol_args));
3222 	if (IS_ERR(vol_args)) {
3223 		ret = PTR_ERR(vol_args);
3224 		goto out;
3225 	}
3226 
3227 	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3228 	ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3229 
3230 	if (!ret)
3231 		btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3232 	kfree(vol_args);
3233 out:
3234 	clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3235 out_drop_write:
3236 	mnt_drop_write_file(file);
3237 
3238 	return ret;
3239 }
3240 
3241 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3242 				void __user *arg)
3243 {
3244 	struct btrfs_ioctl_fs_info_args *fi_args;
3245 	struct btrfs_device *device;
3246 	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3247 	u64 flags_in;
3248 	int ret = 0;
3249 
3250 	fi_args = memdup_user(arg, sizeof(*fi_args));
3251 	if (IS_ERR(fi_args))
3252 		return PTR_ERR(fi_args);
3253 
3254 	flags_in = fi_args->flags;
3255 	memset(fi_args, 0, sizeof(*fi_args));
3256 
3257 	rcu_read_lock();
3258 	fi_args->num_devices = fs_devices->num_devices;
3259 
3260 	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3261 		if (device->devid > fi_args->max_id)
3262 			fi_args->max_id = device->devid;
3263 	}
3264 	rcu_read_unlock();
3265 
3266 	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3267 	fi_args->nodesize = fs_info->nodesize;
3268 	fi_args->sectorsize = fs_info->sectorsize;
3269 	fi_args->clone_alignment = fs_info->sectorsize;
3270 
3271 	if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
3272 		fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
3273 		fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
3274 		fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
3275 	}
3276 
3277 	if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
3278 		fi_args->generation = fs_info->generation;
3279 		fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
3280 	}
3281 
3282 	if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
3283 		memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
3284 		       sizeof(fi_args->metadata_uuid));
3285 		fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
3286 	}
3287 
3288 	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3289 		ret = -EFAULT;
3290 
3291 	kfree(fi_args);
3292 	return ret;
3293 }
3294 
3295 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3296 				 void __user *arg)
3297 {
3298 	struct btrfs_ioctl_dev_info_args *di_args;
3299 	struct btrfs_device *dev;
3300 	int ret = 0;
3301 	char *s_uuid = NULL;
3302 
3303 	di_args = memdup_user(arg, sizeof(*di_args));
3304 	if (IS_ERR(di_args))
3305 		return PTR_ERR(di_args);
3306 
3307 	if (!btrfs_is_empty_uuid(di_args->uuid))
3308 		s_uuid = di_args->uuid;
3309 
3310 	rcu_read_lock();
3311 	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3312 				NULL, true);
3313 
3314 	if (!dev) {
3315 		ret = -ENODEV;
3316 		goto out;
3317 	}
3318 
3319 	di_args->devid = dev->devid;
3320 	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3321 	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3322 	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3323 	if (dev->name) {
3324 		strncpy(di_args->path, rcu_str_deref(dev->name),
3325 				sizeof(di_args->path) - 1);
3326 		di_args->path[sizeof(di_args->path) - 1] = 0;
3327 	} else {
3328 		di_args->path[0] = '\0';
3329 	}
3330 
3331 out:
3332 	rcu_read_unlock();
3333 	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3334 		ret = -EFAULT;
3335 
3336 	kfree(di_args);
3337 	return ret;
3338 }
3339 
3340 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3341 {
3342 	struct inode *inode = file_inode(file);
3343 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3344 	struct btrfs_root *root = BTRFS_I(inode)->root;
3345 	struct btrfs_root *new_root;
3346 	struct btrfs_dir_item *di;
3347 	struct btrfs_trans_handle *trans;
3348 	struct btrfs_path *path = NULL;
3349 	struct btrfs_disk_key disk_key;
3350 	u64 objectid = 0;
3351 	u64 dir_id;
3352 	int ret;
3353 
3354 	if (!capable(CAP_SYS_ADMIN))
3355 		return -EPERM;
3356 
3357 	ret = mnt_want_write_file(file);
3358 	if (ret)
3359 		return ret;
3360 
3361 	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3362 		ret = -EFAULT;
3363 		goto out;
3364 	}
3365 
3366 	if (!objectid)
3367 		objectid = BTRFS_FS_TREE_OBJECTID;
3368 
3369 	new_root = btrfs_get_fs_root(fs_info, objectid, true);
3370 	if (IS_ERR(new_root)) {
3371 		ret = PTR_ERR(new_root);
3372 		goto out;
3373 	}
3374 	if (!is_fstree(new_root->root_key.objectid)) {
3375 		ret = -ENOENT;
3376 		goto out_free;
3377 	}
3378 
3379 	path = btrfs_alloc_path();
3380 	if (!path) {
3381 		ret = -ENOMEM;
3382 		goto out_free;
3383 	}
3384 	path->leave_spinning = 1;
3385 
3386 	trans = btrfs_start_transaction(root, 1);
3387 	if (IS_ERR(trans)) {
3388 		ret = PTR_ERR(trans);
3389 		goto out_free;
3390 	}
3391 
3392 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
3393 	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3394 				   dir_id, "default", 7, 1);
3395 	if (IS_ERR_OR_NULL(di)) {
3396 		btrfs_release_path(path);
3397 		btrfs_end_transaction(trans);
3398 		btrfs_err(fs_info,
3399 			  "Umm, you don't have the default diritem, this isn't going to work");
3400 		ret = -ENOENT;
3401 		goto out_free;
3402 	}
3403 
3404 	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3405 	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3406 	btrfs_mark_buffer_dirty(path->nodes[0]);
3407 	btrfs_release_path(path);
3408 
3409 	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3410 	btrfs_end_transaction(trans);
3411 out_free:
3412 	btrfs_put_root(new_root);
3413 	btrfs_free_path(path);
3414 out:
3415 	mnt_drop_write_file(file);
3416 	return ret;
3417 }
3418 
3419 static void get_block_group_info(struct list_head *groups_list,
3420 				 struct btrfs_ioctl_space_info *space)
3421 {
3422 	struct btrfs_block_group *block_group;
3423 
3424 	space->total_bytes = 0;
3425 	space->used_bytes = 0;
3426 	space->flags = 0;
3427 	list_for_each_entry(block_group, groups_list, list) {
3428 		space->flags = block_group->flags;
3429 		space->total_bytes += block_group->length;
3430 		space->used_bytes += block_group->used;
3431 	}
3432 }
3433 
3434 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3435 				   void __user *arg)
3436 {
3437 	struct btrfs_ioctl_space_args space_args;
3438 	struct btrfs_ioctl_space_info space;
3439 	struct btrfs_ioctl_space_info *dest;
3440 	struct btrfs_ioctl_space_info *dest_orig;
3441 	struct btrfs_ioctl_space_info __user *user_dest;
3442 	struct btrfs_space_info *info;
3443 	static const u64 types[] = {
3444 		BTRFS_BLOCK_GROUP_DATA,
3445 		BTRFS_BLOCK_GROUP_SYSTEM,
3446 		BTRFS_BLOCK_GROUP_METADATA,
3447 		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3448 	};
3449 	int num_types = 4;
3450 	int alloc_size;
3451 	int ret = 0;
3452 	u64 slot_count = 0;
3453 	int i, c;
3454 
3455 	if (copy_from_user(&space_args,
3456 			   (struct btrfs_ioctl_space_args __user *)arg,
3457 			   sizeof(space_args)))
3458 		return -EFAULT;
3459 
3460 	for (i = 0; i < num_types; i++) {
3461 		struct btrfs_space_info *tmp;
3462 
3463 		info = NULL;
3464 		rcu_read_lock();
3465 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
3466 					list) {
3467 			if (tmp->flags == types[i]) {
3468 				info = tmp;
3469 				break;
3470 			}
3471 		}
3472 		rcu_read_unlock();
3473 
3474 		if (!info)
3475 			continue;
3476 
3477 		down_read(&info->groups_sem);
3478 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3479 			if (!list_empty(&info->block_groups[c]))
3480 				slot_count++;
3481 		}
3482 		up_read(&info->groups_sem);
3483 	}
3484 
3485 	/*
3486 	 * Global block reserve, exported as a space_info
3487 	 */
3488 	slot_count++;
3489 
3490 	/* space_slots == 0 means they are asking for a count */
3491 	if (space_args.space_slots == 0) {
3492 		space_args.total_spaces = slot_count;
3493 		goto out;
3494 	}
3495 
3496 	slot_count = min_t(u64, space_args.space_slots, slot_count);
3497 
3498 	alloc_size = sizeof(*dest) * slot_count;
3499 
3500 	/* we generally have at most 6 or so space infos, one for each raid
3501 	 * level.  So, a whole page should be more than enough for everyone
3502 	 */
3503 	if (alloc_size > PAGE_SIZE)
3504 		return -ENOMEM;
3505 
3506 	space_args.total_spaces = 0;
3507 	dest = kmalloc(alloc_size, GFP_KERNEL);
3508 	if (!dest)
3509 		return -ENOMEM;
3510 	dest_orig = dest;
3511 
3512 	/* now we have a buffer to copy into */
3513 	for (i = 0; i < num_types; i++) {
3514 		struct btrfs_space_info *tmp;
3515 
3516 		if (!slot_count)
3517 			break;
3518 
3519 		info = NULL;
3520 		rcu_read_lock();
3521 		list_for_each_entry_rcu(tmp, &fs_info->space_info,
3522 					list) {
3523 			if (tmp->flags == types[i]) {
3524 				info = tmp;
3525 				break;
3526 			}
3527 		}
3528 		rcu_read_unlock();
3529 
3530 		if (!info)
3531 			continue;
3532 		down_read(&info->groups_sem);
3533 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3534 			if (!list_empty(&info->block_groups[c])) {
3535 				get_block_group_info(&info->block_groups[c],
3536 						     &space);
3537 				memcpy(dest, &space, sizeof(space));
3538 				dest++;
3539 				space_args.total_spaces++;
3540 				slot_count--;
3541 			}
3542 			if (!slot_count)
3543 				break;
3544 		}
3545 		up_read(&info->groups_sem);
3546 	}
3547 
3548 	/*
3549 	 * Add global block reserve
3550 	 */
3551 	if (slot_count) {
3552 		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3553 
3554 		spin_lock(&block_rsv->lock);
3555 		space.total_bytes = block_rsv->size;
3556 		space.used_bytes = block_rsv->size - block_rsv->reserved;
3557 		spin_unlock(&block_rsv->lock);
3558 		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3559 		memcpy(dest, &space, sizeof(space));
3560 		space_args.total_spaces++;
3561 	}
3562 
3563 	user_dest = (struct btrfs_ioctl_space_info __user *)
3564 		(arg + sizeof(struct btrfs_ioctl_space_args));
3565 
3566 	if (copy_to_user(user_dest, dest_orig, alloc_size))
3567 		ret = -EFAULT;
3568 
3569 	kfree(dest_orig);
3570 out:
3571 	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3572 		ret = -EFAULT;
3573 
3574 	return ret;
3575 }
3576 
3577 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3578 					    void __user *argp)
3579 {
3580 	struct btrfs_trans_handle *trans;
3581 	u64 transid;
3582 	int ret;
3583 
3584 	trans = btrfs_attach_transaction_barrier(root);
3585 	if (IS_ERR(trans)) {
3586 		if (PTR_ERR(trans) != -ENOENT)
3587 			return PTR_ERR(trans);
3588 
3589 		/* No running transaction, don't bother */
3590 		transid = root->fs_info->last_trans_committed;
3591 		goto out;
3592 	}
3593 	transid = trans->transid;
3594 	ret = btrfs_commit_transaction_async(trans, 0);
3595 	if (ret) {
3596 		btrfs_end_transaction(trans);
3597 		return ret;
3598 	}
3599 out:
3600 	if (argp)
3601 		if (copy_to_user(argp, &transid, sizeof(transid)))
3602 			return -EFAULT;
3603 	return 0;
3604 }
3605 
3606 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3607 					   void __user *argp)
3608 {
3609 	u64 transid;
3610 
3611 	if (argp) {
3612 		if (copy_from_user(&transid, argp, sizeof(transid)))
3613 			return -EFAULT;
3614 	} else {
3615 		transid = 0;  /* current trans */
3616 	}
3617 	return btrfs_wait_for_commit(fs_info, transid);
3618 }
3619 
3620 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3621 {
3622 	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3623 	struct btrfs_ioctl_scrub_args *sa;
3624 	int ret;
3625 
3626 	if (!capable(CAP_SYS_ADMIN))
3627 		return -EPERM;
3628 
3629 	sa = memdup_user(arg, sizeof(*sa));
3630 	if (IS_ERR(sa))
3631 		return PTR_ERR(sa);
3632 
3633 	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3634 		ret = mnt_want_write_file(file);
3635 		if (ret)
3636 			goto out;
3637 	}
3638 
3639 	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3640 			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3641 			      0);
3642 
3643 	/*
3644 	 * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3645 	 * error. This is important as it allows user space to know how much
3646 	 * progress scrub has done. For example, if scrub is canceled we get
3647 	 * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3648 	 * space. Later user space can inspect the progress from the structure
3649 	 * btrfs_ioctl_scrub_args and resume scrub from where it left off
3650 	 * previously (btrfs-progs does this).
3651 	 * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3652 	 * then return -EFAULT to signal the structure was not copied or it may
3653 	 * be corrupt and unreliable due to a partial copy.
3654 	 */
3655 	if (copy_to_user(arg, sa, sizeof(*sa)))
3656 		ret = -EFAULT;
3657 
3658 	if (!(sa->flags & BTRFS_SCRUB_READONLY))
3659 		mnt_drop_write_file(file);
3660 out:
3661 	kfree(sa);
3662 	return ret;
3663 }
3664 
3665 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3666 {
3667 	if (!capable(CAP_SYS_ADMIN))
3668 		return -EPERM;
3669 
3670 	return btrfs_scrub_cancel(fs_info);
3671 }
3672 
3673 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3674 				       void __user *arg)
3675 {
3676 	struct btrfs_ioctl_scrub_args *sa;
3677 	int ret;
3678 
3679 	if (!capable(CAP_SYS_ADMIN))
3680 		return -EPERM;
3681 
3682 	sa = memdup_user(arg, sizeof(*sa));
3683 	if (IS_ERR(sa))
3684 		return PTR_ERR(sa);
3685 
3686 	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3687 
3688 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3689 		ret = -EFAULT;
3690 
3691 	kfree(sa);
3692 	return ret;
3693 }
3694 
3695 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3696 				      void __user *arg)
3697 {
3698 	struct btrfs_ioctl_get_dev_stats *sa;
3699 	int ret;
3700 
3701 	sa = memdup_user(arg, sizeof(*sa));
3702 	if (IS_ERR(sa))
3703 		return PTR_ERR(sa);
3704 
3705 	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3706 		kfree(sa);
3707 		return -EPERM;
3708 	}
3709 
3710 	ret = btrfs_get_dev_stats(fs_info, sa);
3711 
3712 	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3713 		ret = -EFAULT;
3714 
3715 	kfree(sa);
3716 	return ret;
3717 }
3718 
3719 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3720 				    void __user *arg)
3721 {
3722 	struct btrfs_ioctl_dev_replace_args *p;
3723 	int ret;
3724 
3725 	if (!capable(CAP_SYS_ADMIN))
3726 		return -EPERM;
3727 
3728 	p = memdup_user(arg, sizeof(*p));
3729 	if (IS_ERR(p))
3730 		return PTR_ERR(p);
3731 
3732 	switch (p->cmd) {
3733 	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3734 		if (sb_rdonly(fs_info->sb)) {
3735 			ret = -EROFS;
3736 			goto out;
3737 		}
3738 		if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3739 			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3740 		} else {
3741 			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3742 			clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3743 		}
3744 		break;
3745 	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3746 		btrfs_dev_replace_status(fs_info, p);
3747 		ret = 0;
3748 		break;
3749 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3750 		p->result = btrfs_dev_replace_cancel(fs_info);
3751 		ret = 0;
3752 		break;
3753 	default:
3754 		ret = -EINVAL;
3755 		break;
3756 	}
3757 
3758 	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3759 		ret = -EFAULT;
3760 out:
3761 	kfree(p);
3762 	return ret;
3763 }
3764 
3765 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3766 {
3767 	int ret = 0;
3768 	int i;
3769 	u64 rel_ptr;
3770 	int size;
3771 	struct btrfs_ioctl_ino_path_args *ipa = NULL;
3772 	struct inode_fs_paths *ipath = NULL;
3773 	struct btrfs_path *path;
3774 
3775 	if (!capable(CAP_DAC_READ_SEARCH))
3776 		return -EPERM;
3777 
3778 	path = btrfs_alloc_path();
3779 	if (!path) {
3780 		ret = -ENOMEM;
3781 		goto out;
3782 	}
3783 
3784 	ipa = memdup_user(arg, sizeof(*ipa));
3785 	if (IS_ERR(ipa)) {
3786 		ret = PTR_ERR(ipa);
3787 		ipa = NULL;
3788 		goto out;
3789 	}
3790 
3791 	size = min_t(u32, ipa->size, 4096);
3792 	ipath = init_ipath(size, root, path);
3793 	if (IS_ERR(ipath)) {
3794 		ret = PTR_ERR(ipath);
3795 		ipath = NULL;
3796 		goto out;
3797 	}
3798 
3799 	ret = paths_from_inode(ipa->inum, ipath);
3800 	if (ret < 0)
3801 		goto out;
3802 
3803 	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3804 		rel_ptr = ipath->fspath->val[i] -
3805 			  (u64)(unsigned long)ipath->fspath->val;
3806 		ipath->fspath->val[i] = rel_ptr;
3807 	}
3808 
3809 	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3810 			   ipath->fspath, size);
3811 	if (ret) {
3812 		ret = -EFAULT;
3813 		goto out;
3814 	}
3815 
3816 out:
3817 	btrfs_free_path(path);
3818 	free_ipath(ipath);
3819 	kfree(ipa);
3820 
3821 	return ret;
3822 }
3823 
3824 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3825 {
3826 	struct btrfs_data_container *inodes = ctx;
3827 	const size_t c = 3 * sizeof(u64);
3828 
3829 	if (inodes->bytes_left >= c) {
3830 		inodes->bytes_left -= c;
3831 		inodes->val[inodes->elem_cnt] = inum;
3832 		inodes->val[inodes->elem_cnt + 1] = offset;
3833 		inodes->val[inodes->elem_cnt + 2] = root;
3834 		inodes->elem_cnt += 3;
3835 	} else {
3836 		inodes->bytes_missing += c - inodes->bytes_left;
3837 		inodes->bytes_left = 0;
3838 		inodes->elem_missed += 3;
3839 	}
3840 
3841 	return 0;
3842 }
3843 
3844 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3845 					void __user *arg, int version)
3846 {
3847 	int ret = 0;
3848 	int size;
3849 	struct btrfs_ioctl_logical_ino_args *loi;
3850 	struct btrfs_data_container *inodes = NULL;
3851 	struct btrfs_path *path = NULL;
3852 	bool ignore_offset;
3853 
3854 	if (!capable(CAP_SYS_ADMIN))
3855 		return -EPERM;
3856 
3857 	loi = memdup_user(arg, sizeof(*loi));
3858 	if (IS_ERR(loi))
3859 		return PTR_ERR(loi);
3860 
3861 	if (version == 1) {
3862 		ignore_offset = false;
3863 		size = min_t(u32, loi->size, SZ_64K);
3864 	} else {
3865 		/* All reserved bits must be 0 for now */
3866 		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3867 			ret = -EINVAL;
3868 			goto out_loi;
3869 		}
3870 		/* Only accept flags we have defined so far */
3871 		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3872 			ret = -EINVAL;
3873 			goto out_loi;
3874 		}
3875 		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3876 		size = min_t(u32, loi->size, SZ_16M);
3877 	}
3878 
3879 	path = btrfs_alloc_path();
3880 	if (!path) {
3881 		ret = -ENOMEM;
3882 		goto out;
3883 	}
3884 
3885 	inodes = init_data_container(size);
3886 	if (IS_ERR(inodes)) {
3887 		ret = PTR_ERR(inodes);
3888 		inodes = NULL;
3889 		goto out;
3890 	}
3891 
3892 	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3893 					  build_ino_list, inodes, ignore_offset);
3894 	if (ret == -EINVAL)
3895 		ret = -ENOENT;
3896 	if (ret < 0)
3897 		goto out;
3898 
3899 	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3900 			   size);
3901 	if (ret)
3902 		ret = -EFAULT;
3903 
3904 out:
3905 	btrfs_free_path(path);
3906 	kvfree(inodes);
3907 out_loi:
3908 	kfree(loi);
3909 
3910 	return ret;
3911 }
3912 
3913 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3914 			       struct btrfs_ioctl_balance_args *bargs)
3915 {
3916 	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3917 
3918 	bargs->flags = bctl->flags;
3919 
3920 	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3921 		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3922 	if (atomic_read(&fs_info->balance_pause_req))
3923 		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3924 	if (atomic_read(&fs_info->balance_cancel_req))
3925 		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3926 
3927 	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3928 	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3929 	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
3930 
3931 	spin_lock(&fs_info->balance_lock);
3932 	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
3933 	spin_unlock(&fs_info->balance_lock);
3934 }
3935 
3936 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
3937 {
3938 	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
3939 	struct btrfs_fs_info *fs_info = root->fs_info;
3940 	struct btrfs_ioctl_balance_args *bargs;
3941 	struct btrfs_balance_control *bctl;
3942 	bool need_unlock; /* for mut. excl. ops lock */
3943 	int ret;
3944 
3945 	if (!capable(CAP_SYS_ADMIN))
3946 		return -EPERM;
3947 
3948 	ret = mnt_want_write_file(file);
3949 	if (ret)
3950 		return ret;
3951 
3952 again:
3953 	if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3954 		mutex_lock(&fs_info->balance_mutex);
3955 		need_unlock = true;
3956 		goto locked;
3957 	}
3958 
3959 	/*
3960 	 * mut. excl. ops lock is locked.  Three possibilities:
3961 	 *   (1) some other op is running
3962 	 *   (2) balance is running
3963 	 *   (3) balance is paused -- special case (think resume)
3964 	 */
3965 	mutex_lock(&fs_info->balance_mutex);
3966 	if (fs_info->balance_ctl) {
3967 		/* this is either (2) or (3) */
3968 		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3969 			mutex_unlock(&fs_info->balance_mutex);
3970 			/*
3971 			 * Lock released to allow other waiters to continue,
3972 			 * we'll reexamine the status again.
3973 			 */
3974 			mutex_lock(&fs_info->balance_mutex);
3975 
3976 			if (fs_info->balance_ctl &&
3977 			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
3978 				/* this is (3) */
3979 				need_unlock = false;
3980 				goto locked;
3981 			}
3982 
3983 			mutex_unlock(&fs_info->balance_mutex);
3984 			goto again;
3985 		} else {
3986 			/* this is (2) */
3987 			mutex_unlock(&fs_info->balance_mutex);
3988 			ret = -EINPROGRESS;
3989 			goto out;
3990 		}
3991 	} else {
3992 		/* this is (1) */
3993 		mutex_unlock(&fs_info->balance_mutex);
3994 		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3995 		goto out;
3996 	}
3997 
3998 locked:
3999 	BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
4000 
4001 	if (arg) {
4002 		bargs = memdup_user(arg, sizeof(*bargs));
4003 		if (IS_ERR(bargs)) {
4004 			ret = PTR_ERR(bargs);
4005 			goto out_unlock;
4006 		}
4007 
4008 		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4009 			if (!fs_info->balance_ctl) {
4010 				ret = -ENOTCONN;
4011 				goto out_bargs;
4012 			}
4013 
4014 			bctl = fs_info->balance_ctl;
4015 			spin_lock(&fs_info->balance_lock);
4016 			bctl->flags |= BTRFS_BALANCE_RESUME;
4017 			spin_unlock(&fs_info->balance_lock);
4018 
4019 			goto do_balance;
4020 		}
4021 	} else {
4022 		bargs = NULL;
4023 	}
4024 
4025 	if (fs_info->balance_ctl) {
4026 		ret = -EINPROGRESS;
4027 		goto out_bargs;
4028 	}
4029 
4030 	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4031 	if (!bctl) {
4032 		ret = -ENOMEM;
4033 		goto out_bargs;
4034 	}
4035 
4036 	if (arg) {
4037 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4038 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4039 		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4040 
4041 		bctl->flags = bargs->flags;
4042 	} else {
4043 		/* balance everything - no filters */
4044 		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4045 	}
4046 
4047 	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4048 		ret = -EINVAL;
4049 		goto out_bctl;
4050 	}
4051 
4052 do_balance:
4053 	/*
4054 	 * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
4055 	 * btrfs_balance.  bctl is freed in reset_balance_state, or, if
4056 	 * restriper was paused all the way until unmount, in free_fs_info.
4057 	 * The flag should be cleared after reset_balance_state.
4058 	 */
4059 	need_unlock = false;
4060 
4061 	ret = btrfs_balance(fs_info, bctl, bargs);
4062 	bctl = NULL;
4063 
4064 	if ((ret == 0 || ret == -ECANCELED) && arg) {
4065 		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4066 			ret = -EFAULT;
4067 	}
4068 
4069 out_bctl:
4070 	kfree(bctl);
4071 out_bargs:
4072 	kfree(bargs);
4073 out_unlock:
4074 	mutex_unlock(&fs_info->balance_mutex);
4075 	if (need_unlock)
4076 		clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4077 out:
4078 	mnt_drop_write_file(file);
4079 	return ret;
4080 }
4081 
4082 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4083 {
4084 	if (!capable(CAP_SYS_ADMIN))
4085 		return -EPERM;
4086 
4087 	switch (cmd) {
4088 	case BTRFS_BALANCE_CTL_PAUSE:
4089 		return btrfs_pause_balance(fs_info);
4090 	case BTRFS_BALANCE_CTL_CANCEL:
4091 		return btrfs_cancel_balance(fs_info);
4092 	}
4093 
4094 	return -EINVAL;
4095 }
4096 
4097 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4098 					 void __user *arg)
4099 {
4100 	struct btrfs_ioctl_balance_args *bargs;
4101 	int ret = 0;
4102 
4103 	if (!capable(CAP_SYS_ADMIN))
4104 		return -EPERM;
4105 
4106 	mutex_lock(&fs_info->balance_mutex);
4107 	if (!fs_info->balance_ctl) {
4108 		ret = -ENOTCONN;
4109 		goto out;
4110 	}
4111 
4112 	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4113 	if (!bargs) {
4114 		ret = -ENOMEM;
4115 		goto out;
4116 	}
4117 
4118 	btrfs_update_ioctl_balance_args(fs_info, bargs);
4119 
4120 	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4121 		ret = -EFAULT;
4122 
4123 	kfree(bargs);
4124 out:
4125 	mutex_unlock(&fs_info->balance_mutex);
4126 	return ret;
4127 }
4128 
4129 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4130 {
4131 	struct inode *inode = file_inode(file);
4132 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4133 	struct btrfs_ioctl_quota_ctl_args *sa;
4134 	int ret;
4135 
4136 	if (!capable(CAP_SYS_ADMIN))
4137 		return -EPERM;
4138 
4139 	ret = mnt_want_write_file(file);
4140 	if (ret)
4141 		return ret;
4142 
4143 	sa = memdup_user(arg, sizeof(*sa));
4144 	if (IS_ERR(sa)) {
4145 		ret = PTR_ERR(sa);
4146 		goto drop_write;
4147 	}
4148 
4149 	down_write(&fs_info->subvol_sem);
4150 
4151 	switch (sa->cmd) {
4152 	case BTRFS_QUOTA_CTL_ENABLE:
4153 		ret = btrfs_quota_enable(fs_info);
4154 		break;
4155 	case BTRFS_QUOTA_CTL_DISABLE:
4156 		ret = btrfs_quota_disable(fs_info);
4157 		break;
4158 	default:
4159 		ret = -EINVAL;
4160 		break;
4161 	}
4162 
4163 	kfree(sa);
4164 	up_write(&fs_info->subvol_sem);
4165 drop_write:
4166 	mnt_drop_write_file(file);
4167 	return ret;
4168 }
4169 
4170 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4171 {
4172 	struct inode *inode = file_inode(file);
4173 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4174 	struct btrfs_root *root = BTRFS_I(inode)->root;
4175 	struct btrfs_ioctl_qgroup_assign_args *sa;
4176 	struct btrfs_trans_handle *trans;
4177 	int ret;
4178 	int err;
4179 
4180 	if (!capable(CAP_SYS_ADMIN))
4181 		return -EPERM;
4182 
4183 	ret = mnt_want_write_file(file);
4184 	if (ret)
4185 		return ret;
4186 
4187 	sa = memdup_user(arg, sizeof(*sa));
4188 	if (IS_ERR(sa)) {
4189 		ret = PTR_ERR(sa);
4190 		goto drop_write;
4191 	}
4192 
4193 	trans = btrfs_join_transaction(root);
4194 	if (IS_ERR(trans)) {
4195 		ret = PTR_ERR(trans);
4196 		goto out;
4197 	}
4198 
4199 	if (sa->assign) {
4200 		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4201 	} else {
4202 		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4203 	}
4204 
4205 	/* update qgroup status and info */
4206 	err = btrfs_run_qgroups(trans);
4207 	if (err < 0)
4208 		btrfs_handle_fs_error(fs_info, err,
4209 				      "failed to update qgroup status and info");
4210 	err = btrfs_end_transaction(trans);
4211 	if (err && !ret)
4212 		ret = err;
4213 
4214 out:
4215 	kfree(sa);
4216 drop_write:
4217 	mnt_drop_write_file(file);
4218 	return ret;
4219 }
4220 
4221 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4222 {
4223 	struct inode *inode = file_inode(file);
4224 	struct btrfs_root *root = BTRFS_I(inode)->root;
4225 	struct btrfs_ioctl_qgroup_create_args *sa;
4226 	struct btrfs_trans_handle *trans;
4227 	int ret;
4228 	int err;
4229 
4230 	if (!capable(CAP_SYS_ADMIN))
4231 		return -EPERM;
4232 
4233 	ret = mnt_want_write_file(file);
4234 	if (ret)
4235 		return ret;
4236 
4237 	sa = memdup_user(arg, sizeof(*sa));
4238 	if (IS_ERR(sa)) {
4239 		ret = PTR_ERR(sa);
4240 		goto drop_write;
4241 	}
4242 
4243 	if (!sa->qgroupid) {
4244 		ret = -EINVAL;
4245 		goto out;
4246 	}
4247 
4248 	trans = btrfs_join_transaction(root);
4249 	if (IS_ERR(trans)) {
4250 		ret = PTR_ERR(trans);
4251 		goto out;
4252 	}
4253 
4254 	if (sa->create) {
4255 		ret = btrfs_create_qgroup(trans, sa->qgroupid);
4256 	} else {
4257 		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4258 	}
4259 
4260 	err = btrfs_end_transaction(trans);
4261 	if (err && !ret)
4262 		ret = err;
4263 
4264 out:
4265 	kfree(sa);
4266 drop_write:
4267 	mnt_drop_write_file(file);
4268 	return ret;
4269 }
4270 
4271 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4272 {
4273 	struct inode *inode = file_inode(file);
4274 	struct btrfs_root *root = BTRFS_I(inode)->root;
4275 	struct btrfs_ioctl_qgroup_limit_args *sa;
4276 	struct btrfs_trans_handle *trans;
4277 	int ret;
4278 	int err;
4279 	u64 qgroupid;
4280 
4281 	if (!capable(CAP_SYS_ADMIN))
4282 		return -EPERM;
4283 
4284 	ret = mnt_want_write_file(file);
4285 	if (ret)
4286 		return ret;
4287 
4288 	sa = memdup_user(arg, sizeof(*sa));
4289 	if (IS_ERR(sa)) {
4290 		ret = PTR_ERR(sa);
4291 		goto drop_write;
4292 	}
4293 
4294 	trans = btrfs_join_transaction(root);
4295 	if (IS_ERR(trans)) {
4296 		ret = PTR_ERR(trans);
4297 		goto out;
4298 	}
4299 
4300 	qgroupid = sa->qgroupid;
4301 	if (!qgroupid) {
4302 		/* take the current subvol as qgroup */
4303 		qgroupid = root->root_key.objectid;
4304 	}
4305 
4306 	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4307 
4308 	err = btrfs_end_transaction(trans);
4309 	if (err && !ret)
4310 		ret = err;
4311 
4312 out:
4313 	kfree(sa);
4314 drop_write:
4315 	mnt_drop_write_file(file);
4316 	return ret;
4317 }
4318 
4319 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4320 {
4321 	struct inode *inode = file_inode(file);
4322 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4323 	struct btrfs_ioctl_quota_rescan_args *qsa;
4324 	int ret;
4325 
4326 	if (!capable(CAP_SYS_ADMIN))
4327 		return -EPERM;
4328 
4329 	ret = mnt_want_write_file(file);
4330 	if (ret)
4331 		return ret;
4332 
4333 	qsa = memdup_user(arg, sizeof(*qsa));
4334 	if (IS_ERR(qsa)) {
4335 		ret = PTR_ERR(qsa);
4336 		goto drop_write;
4337 	}
4338 
4339 	if (qsa->flags) {
4340 		ret = -EINVAL;
4341 		goto out;
4342 	}
4343 
4344 	ret = btrfs_qgroup_rescan(fs_info);
4345 
4346 out:
4347 	kfree(qsa);
4348 drop_write:
4349 	mnt_drop_write_file(file);
4350 	return ret;
4351 }
4352 
4353 static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
4354 						void __user *arg)
4355 {
4356 	struct btrfs_ioctl_quota_rescan_args *qsa;
4357 	int ret = 0;
4358 
4359 	if (!capable(CAP_SYS_ADMIN))
4360 		return -EPERM;
4361 
4362 	qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
4363 	if (!qsa)
4364 		return -ENOMEM;
4365 
4366 	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4367 		qsa->flags = 1;
4368 		qsa->progress = fs_info->qgroup_rescan_progress.objectid;
4369 	}
4370 
4371 	if (copy_to_user(arg, qsa, sizeof(*qsa)))
4372 		ret = -EFAULT;
4373 
4374 	kfree(qsa);
4375 	return ret;
4376 }
4377 
4378 static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
4379 						void __user *arg)
4380 {
4381 	if (!capable(CAP_SYS_ADMIN))
4382 		return -EPERM;
4383 
4384 	return btrfs_qgroup_wait_for_completion(fs_info, true);
4385 }
4386 
4387 static long _btrfs_ioctl_set_received_subvol(struct file *file,
4388 					    struct btrfs_ioctl_received_subvol_args *sa)
4389 {
4390 	struct inode *inode = file_inode(file);
4391 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4392 	struct btrfs_root *root = BTRFS_I(inode)->root;
4393 	struct btrfs_root_item *root_item = &root->root_item;
4394 	struct btrfs_trans_handle *trans;
4395 	struct timespec64 ct = current_time(inode);
4396 	int ret = 0;
4397 	int received_uuid_changed;
4398 
4399 	if (!inode_owner_or_capable(inode))
4400 		return -EPERM;
4401 
4402 	ret = mnt_want_write_file(file);
4403 	if (ret < 0)
4404 		return ret;
4405 
4406 	down_write(&fs_info->subvol_sem);
4407 
4408 	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4409 		ret = -EINVAL;
4410 		goto out;
4411 	}
4412 
4413 	if (btrfs_root_readonly(root)) {
4414 		ret = -EROFS;
4415 		goto out;
4416 	}
4417 
4418 	/*
4419 	 * 1 - root item
4420 	 * 2 - uuid items (received uuid + subvol uuid)
4421 	 */
4422 	trans = btrfs_start_transaction(root, 3);
4423 	if (IS_ERR(trans)) {
4424 		ret = PTR_ERR(trans);
4425 		trans = NULL;
4426 		goto out;
4427 	}
4428 
4429 	sa->rtransid = trans->transid;
4430 	sa->rtime.sec = ct.tv_sec;
4431 	sa->rtime.nsec = ct.tv_nsec;
4432 
4433 	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4434 				       BTRFS_UUID_SIZE);
4435 	if (received_uuid_changed &&
4436 	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
4437 		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4438 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4439 					  root->root_key.objectid);
4440 		if (ret && ret != -ENOENT) {
4441 		        btrfs_abort_transaction(trans, ret);
4442 		        btrfs_end_transaction(trans);
4443 		        goto out;
4444 		}
4445 	}
4446 	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4447 	btrfs_set_root_stransid(root_item, sa->stransid);
4448 	btrfs_set_root_rtransid(root_item, sa->rtransid);
4449 	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4450 	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4451 	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4452 	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4453 
4454 	ret = btrfs_update_root(trans, fs_info->tree_root,
4455 				&root->root_key, &root->root_item);
4456 	if (ret < 0) {
4457 		btrfs_end_transaction(trans);
4458 		goto out;
4459 	}
4460 	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4461 		ret = btrfs_uuid_tree_add(trans, sa->uuid,
4462 					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4463 					  root->root_key.objectid);
4464 		if (ret < 0 && ret != -EEXIST) {
4465 			btrfs_abort_transaction(trans, ret);
4466 			btrfs_end_transaction(trans);
4467 			goto out;
4468 		}
4469 	}
4470 	ret = btrfs_commit_transaction(trans);
4471 out:
4472 	up_write(&fs_info->subvol_sem);
4473 	mnt_drop_write_file(file);
4474 	return ret;
4475 }
4476 
4477 #ifdef CONFIG_64BIT
4478 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4479 						void __user *arg)
4480 {
4481 	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4482 	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4483 	int ret = 0;
4484 
4485 	args32 = memdup_user(arg, sizeof(*args32));
4486 	if (IS_ERR(args32))
4487 		return PTR_ERR(args32);
4488 
4489 	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4490 	if (!args64) {
4491 		ret = -ENOMEM;
4492 		goto out;
4493 	}
4494 
4495 	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4496 	args64->stransid = args32->stransid;
4497 	args64->rtransid = args32->rtransid;
4498 	args64->stime.sec = args32->stime.sec;
4499 	args64->stime.nsec = args32->stime.nsec;
4500 	args64->rtime.sec = args32->rtime.sec;
4501 	args64->rtime.nsec = args32->rtime.nsec;
4502 	args64->flags = args32->flags;
4503 
4504 	ret = _btrfs_ioctl_set_received_subvol(file, args64);
4505 	if (ret)
4506 		goto out;
4507 
4508 	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4509 	args32->stransid = args64->stransid;
4510 	args32->rtransid = args64->rtransid;
4511 	args32->stime.sec = args64->stime.sec;
4512 	args32->stime.nsec = args64->stime.nsec;
4513 	args32->rtime.sec = args64->rtime.sec;
4514 	args32->rtime.nsec = args64->rtime.nsec;
4515 	args32->flags = args64->flags;
4516 
4517 	ret = copy_to_user(arg, args32, sizeof(*args32));
4518 	if (ret)
4519 		ret = -EFAULT;
4520 
4521 out:
4522 	kfree(args32);
4523 	kfree(args64);
4524 	return ret;
4525 }
4526 #endif
4527 
4528 static long btrfs_ioctl_set_received_subvol(struct file *file,
4529 					    void __user *arg)
4530 {
4531 	struct btrfs_ioctl_received_subvol_args *sa = NULL;
4532 	int ret = 0;
4533 
4534 	sa = memdup_user(arg, sizeof(*sa));
4535 	if (IS_ERR(sa))
4536 		return PTR_ERR(sa);
4537 
4538 	ret = _btrfs_ioctl_set_received_subvol(file, sa);
4539 
4540 	if (ret)
4541 		goto out;
4542 
4543 	ret = copy_to_user(arg, sa, sizeof(*sa));
4544 	if (ret)
4545 		ret = -EFAULT;
4546 
4547 out:
4548 	kfree(sa);
4549 	return ret;
4550 }
4551 
4552 static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4553 					void __user *arg)
4554 {
4555 	size_t len;
4556 	int ret;
4557 	char label[BTRFS_LABEL_SIZE];
4558 
4559 	spin_lock(&fs_info->super_lock);
4560 	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4561 	spin_unlock(&fs_info->super_lock);
4562 
4563 	len = strnlen(label, BTRFS_LABEL_SIZE);
4564 
4565 	if (len == BTRFS_LABEL_SIZE) {
4566 		btrfs_warn(fs_info,
4567 			   "label is too long, return the first %zu bytes",
4568 			   --len);
4569 	}
4570 
4571 	ret = copy_to_user(arg, label, len);
4572 
4573 	return ret ? -EFAULT : 0;
4574 }
4575 
4576 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4577 {
4578 	struct inode *inode = file_inode(file);
4579 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4580 	struct btrfs_root *root = BTRFS_I(inode)->root;
4581 	struct btrfs_super_block *super_block = fs_info->super_copy;
4582 	struct btrfs_trans_handle *trans;
4583 	char label[BTRFS_LABEL_SIZE];
4584 	int ret;
4585 
4586 	if (!capable(CAP_SYS_ADMIN))
4587 		return -EPERM;
4588 
4589 	if (copy_from_user(label, arg, sizeof(label)))
4590 		return -EFAULT;
4591 
4592 	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4593 		btrfs_err(fs_info,
4594 			  "unable to set label with more than %d bytes",
4595 			  BTRFS_LABEL_SIZE - 1);
4596 		return -EINVAL;
4597 	}
4598 
4599 	ret = mnt_want_write_file(file);
4600 	if (ret)
4601 		return ret;
4602 
4603 	trans = btrfs_start_transaction(root, 0);
4604 	if (IS_ERR(trans)) {
4605 		ret = PTR_ERR(trans);
4606 		goto out_unlock;
4607 	}
4608 
4609 	spin_lock(&fs_info->super_lock);
4610 	strcpy(super_block->label, label);
4611 	spin_unlock(&fs_info->super_lock);
4612 	ret = btrfs_commit_transaction(trans);
4613 
4614 out_unlock:
4615 	mnt_drop_write_file(file);
4616 	return ret;
4617 }
4618 
4619 #define INIT_FEATURE_FLAGS(suffix) \
4620 	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4621 	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4622 	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4623 
4624 int btrfs_ioctl_get_supported_features(void __user *arg)
4625 {
4626 	static const struct btrfs_ioctl_feature_flags features[3] = {
4627 		INIT_FEATURE_FLAGS(SUPP),
4628 		INIT_FEATURE_FLAGS(SAFE_SET),
4629 		INIT_FEATURE_FLAGS(SAFE_CLEAR)
4630 	};
4631 
4632 	if (copy_to_user(arg, &features, sizeof(features)))
4633 		return -EFAULT;
4634 
4635 	return 0;
4636 }
4637 
4638 static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4639 					void __user *arg)
4640 {
4641 	struct btrfs_super_block *super_block = fs_info->super_copy;
4642 	struct btrfs_ioctl_feature_flags features;
4643 
4644 	features.compat_flags = btrfs_super_compat_flags(super_block);
4645 	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4646 	features.incompat_flags = btrfs_super_incompat_flags(super_block);
4647 
4648 	if (copy_to_user(arg, &features, sizeof(features)))
4649 		return -EFAULT;
4650 
4651 	return 0;
4652 }
4653 
4654 static int check_feature_bits(struct btrfs_fs_info *fs_info,
4655 			      enum btrfs_feature_set set,
4656 			      u64 change_mask, u64 flags, u64 supported_flags,
4657 			      u64 safe_set, u64 safe_clear)
4658 {
4659 	const char *type = btrfs_feature_set_name(set);
4660 	char *names;
4661 	u64 disallowed, unsupported;
4662 	u64 set_mask = flags & change_mask;
4663 	u64 clear_mask = ~flags & change_mask;
4664 
4665 	unsupported = set_mask & ~supported_flags;
4666 	if (unsupported) {
4667 		names = btrfs_printable_features(set, unsupported);
4668 		if (names) {
4669 			btrfs_warn(fs_info,
4670 				   "this kernel does not support the %s feature bit%s",
4671 				   names, strchr(names, ',') ? "s" : "");
4672 			kfree(names);
4673 		} else
4674 			btrfs_warn(fs_info,
4675 				   "this kernel does not support %s bits 0x%llx",
4676 				   type, unsupported);
4677 		return -EOPNOTSUPP;
4678 	}
4679 
4680 	disallowed = set_mask & ~safe_set;
4681 	if (disallowed) {
4682 		names = btrfs_printable_features(set, disallowed);
4683 		if (names) {
4684 			btrfs_warn(fs_info,
4685 				   "can't set the %s feature bit%s while mounted",
4686 				   names, strchr(names, ',') ? "s" : "");
4687 			kfree(names);
4688 		} else
4689 			btrfs_warn(fs_info,
4690 				   "can't set %s bits 0x%llx while mounted",
4691 				   type, disallowed);
4692 		return -EPERM;
4693 	}
4694 
4695 	disallowed = clear_mask & ~safe_clear;
4696 	if (disallowed) {
4697 		names = btrfs_printable_features(set, disallowed);
4698 		if (names) {
4699 			btrfs_warn(fs_info,
4700 				   "can't clear the %s feature bit%s while mounted",
4701 				   names, strchr(names, ',') ? "s" : "");
4702 			kfree(names);
4703 		} else
4704 			btrfs_warn(fs_info,
4705 				   "can't clear %s bits 0x%llx while mounted",
4706 				   type, disallowed);
4707 		return -EPERM;
4708 	}
4709 
4710 	return 0;
4711 }
4712 
4713 #define check_feature(fs_info, change_mask, flags, mask_base)	\
4714 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
4715 		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
4716 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
4717 		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4718 
4719 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4720 {
4721 	struct inode *inode = file_inode(file);
4722 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4723 	struct btrfs_root *root = BTRFS_I(inode)->root;
4724 	struct btrfs_super_block *super_block = fs_info->super_copy;
4725 	struct btrfs_ioctl_feature_flags flags[2];
4726 	struct btrfs_trans_handle *trans;
4727 	u64 newflags;
4728 	int ret;
4729 
4730 	if (!capable(CAP_SYS_ADMIN))
4731 		return -EPERM;
4732 
4733 	if (copy_from_user(flags, arg, sizeof(flags)))
4734 		return -EFAULT;
4735 
4736 	/* Nothing to do */
4737 	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4738 	    !flags[0].incompat_flags)
4739 		return 0;
4740 
4741 	ret = check_feature(fs_info, flags[0].compat_flags,
4742 			    flags[1].compat_flags, COMPAT);
4743 	if (ret)
4744 		return ret;
4745 
4746 	ret = check_feature(fs_info, flags[0].compat_ro_flags,
4747 			    flags[1].compat_ro_flags, COMPAT_RO);
4748 	if (ret)
4749 		return ret;
4750 
4751 	ret = check_feature(fs_info, flags[0].incompat_flags,
4752 			    flags[1].incompat_flags, INCOMPAT);
4753 	if (ret)
4754 		return ret;
4755 
4756 	ret = mnt_want_write_file(file);
4757 	if (ret)
4758 		return ret;
4759 
4760 	trans = btrfs_start_transaction(root, 0);
4761 	if (IS_ERR(trans)) {
4762 		ret = PTR_ERR(trans);
4763 		goto out_drop_write;
4764 	}
4765 
4766 	spin_lock(&fs_info->super_lock);
4767 	newflags = btrfs_super_compat_flags(super_block);
4768 	newflags |= flags[0].compat_flags & flags[1].compat_flags;
4769 	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4770 	btrfs_set_super_compat_flags(super_block, newflags);
4771 
4772 	newflags = btrfs_super_compat_ro_flags(super_block);
4773 	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4774 	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4775 	btrfs_set_super_compat_ro_flags(super_block, newflags);
4776 
4777 	newflags = btrfs_super_incompat_flags(super_block);
4778 	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4779 	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4780 	btrfs_set_super_incompat_flags(super_block, newflags);
4781 	spin_unlock(&fs_info->super_lock);
4782 
4783 	ret = btrfs_commit_transaction(trans);
4784 out_drop_write:
4785 	mnt_drop_write_file(file);
4786 
4787 	return ret;
4788 }
4789 
4790 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
4791 {
4792 	struct btrfs_ioctl_send_args *arg;
4793 	int ret;
4794 
4795 	if (compat) {
4796 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4797 		struct btrfs_ioctl_send_args_32 args32;
4798 
4799 		ret = copy_from_user(&args32, argp, sizeof(args32));
4800 		if (ret)
4801 			return -EFAULT;
4802 		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4803 		if (!arg)
4804 			return -ENOMEM;
4805 		arg->send_fd = args32.send_fd;
4806 		arg->clone_sources_count = args32.clone_sources_count;
4807 		arg->clone_sources = compat_ptr(args32.clone_sources);
4808 		arg->parent_root = args32.parent_root;
4809 		arg->flags = args32.flags;
4810 		memcpy(arg->reserved, args32.reserved,
4811 		       sizeof(args32.reserved));
4812 #else
4813 		return -ENOTTY;
4814 #endif
4815 	} else {
4816 		arg = memdup_user(argp, sizeof(*arg));
4817 		if (IS_ERR(arg))
4818 			return PTR_ERR(arg);
4819 	}
4820 	ret = btrfs_ioctl_send(file, arg);
4821 	kfree(arg);
4822 	return ret;
4823 }
4824 
4825 long btrfs_ioctl(struct file *file, unsigned int
4826 		cmd, unsigned long arg)
4827 {
4828 	struct inode *inode = file_inode(file);
4829 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4830 	struct btrfs_root *root = BTRFS_I(inode)->root;
4831 	void __user *argp = (void __user *)arg;
4832 
4833 	switch (cmd) {
4834 	case FS_IOC_GETFLAGS:
4835 		return btrfs_ioctl_getflags(file, argp);
4836 	case FS_IOC_SETFLAGS:
4837 		return btrfs_ioctl_setflags(file, argp);
4838 	case FS_IOC_GETVERSION:
4839 		return btrfs_ioctl_getversion(file, argp);
4840 	case FS_IOC_GETFSLABEL:
4841 		return btrfs_ioctl_get_fslabel(fs_info, argp);
4842 	case FS_IOC_SETFSLABEL:
4843 		return btrfs_ioctl_set_fslabel(file, argp);
4844 	case FITRIM:
4845 		return btrfs_ioctl_fitrim(fs_info, argp);
4846 	case BTRFS_IOC_SNAP_CREATE:
4847 		return btrfs_ioctl_snap_create(file, argp, 0);
4848 	case BTRFS_IOC_SNAP_CREATE_V2:
4849 		return btrfs_ioctl_snap_create_v2(file, argp, 0);
4850 	case BTRFS_IOC_SUBVOL_CREATE:
4851 		return btrfs_ioctl_snap_create(file, argp, 1);
4852 	case BTRFS_IOC_SUBVOL_CREATE_V2:
4853 		return btrfs_ioctl_snap_create_v2(file, argp, 1);
4854 	case BTRFS_IOC_SNAP_DESTROY:
4855 		return btrfs_ioctl_snap_destroy(file, argp, false);
4856 	case BTRFS_IOC_SNAP_DESTROY_V2:
4857 		return btrfs_ioctl_snap_destroy(file, argp, true);
4858 	case BTRFS_IOC_SUBVOL_GETFLAGS:
4859 		return btrfs_ioctl_subvol_getflags(file, argp);
4860 	case BTRFS_IOC_SUBVOL_SETFLAGS:
4861 		return btrfs_ioctl_subvol_setflags(file, argp);
4862 	case BTRFS_IOC_DEFAULT_SUBVOL:
4863 		return btrfs_ioctl_default_subvol(file, argp);
4864 	case BTRFS_IOC_DEFRAG:
4865 		return btrfs_ioctl_defrag(file, NULL);
4866 	case BTRFS_IOC_DEFRAG_RANGE:
4867 		return btrfs_ioctl_defrag(file, argp);
4868 	case BTRFS_IOC_RESIZE:
4869 		return btrfs_ioctl_resize(file, argp);
4870 	case BTRFS_IOC_ADD_DEV:
4871 		return btrfs_ioctl_add_dev(fs_info, argp);
4872 	case BTRFS_IOC_RM_DEV:
4873 		return btrfs_ioctl_rm_dev(file, argp);
4874 	case BTRFS_IOC_RM_DEV_V2:
4875 		return btrfs_ioctl_rm_dev_v2(file, argp);
4876 	case BTRFS_IOC_FS_INFO:
4877 		return btrfs_ioctl_fs_info(fs_info, argp);
4878 	case BTRFS_IOC_DEV_INFO:
4879 		return btrfs_ioctl_dev_info(fs_info, argp);
4880 	case BTRFS_IOC_BALANCE:
4881 		return btrfs_ioctl_balance(file, NULL);
4882 	case BTRFS_IOC_TREE_SEARCH:
4883 		return btrfs_ioctl_tree_search(file, argp);
4884 	case BTRFS_IOC_TREE_SEARCH_V2:
4885 		return btrfs_ioctl_tree_search_v2(file, argp);
4886 	case BTRFS_IOC_INO_LOOKUP:
4887 		return btrfs_ioctl_ino_lookup(file, argp);
4888 	case BTRFS_IOC_INO_PATHS:
4889 		return btrfs_ioctl_ino_to_path(root, argp);
4890 	case BTRFS_IOC_LOGICAL_INO:
4891 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
4892 	case BTRFS_IOC_LOGICAL_INO_V2:
4893 		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
4894 	case BTRFS_IOC_SPACE_INFO:
4895 		return btrfs_ioctl_space_info(fs_info, argp);
4896 	case BTRFS_IOC_SYNC: {
4897 		int ret;
4898 
4899 		ret = btrfs_start_delalloc_roots(fs_info, -1);
4900 		if (ret)
4901 			return ret;
4902 		ret = btrfs_sync_fs(inode->i_sb, 1);
4903 		/*
4904 		 * The transaction thread may want to do more work,
4905 		 * namely it pokes the cleaner kthread that will start
4906 		 * processing uncleaned subvols.
4907 		 */
4908 		wake_up_process(fs_info->transaction_kthread);
4909 		return ret;
4910 	}
4911 	case BTRFS_IOC_START_SYNC:
4912 		return btrfs_ioctl_start_sync(root, argp);
4913 	case BTRFS_IOC_WAIT_SYNC:
4914 		return btrfs_ioctl_wait_sync(fs_info, argp);
4915 	case BTRFS_IOC_SCRUB:
4916 		return btrfs_ioctl_scrub(file, argp);
4917 	case BTRFS_IOC_SCRUB_CANCEL:
4918 		return btrfs_ioctl_scrub_cancel(fs_info);
4919 	case BTRFS_IOC_SCRUB_PROGRESS:
4920 		return btrfs_ioctl_scrub_progress(fs_info, argp);
4921 	case BTRFS_IOC_BALANCE_V2:
4922 		return btrfs_ioctl_balance(file, argp);
4923 	case BTRFS_IOC_BALANCE_CTL:
4924 		return btrfs_ioctl_balance_ctl(fs_info, arg);
4925 	case BTRFS_IOC_BALANCE_PROGRESS:
4926 		return btrfs_ioctl_balance_progress(fs_info, argp);
4927 	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4928 		return btrfs_ioctl_set_received_subvol(file, argp);
4929 #ifdef CONFIG_64BIT
4930 	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
4931 		return btrfs_ioctl_set_received_subvol_32(file, argp);
4932 #endif
4933 	case BTRFS_IOC_SEND:
4934 		return _btrfs_ioctl_send(file, argp, false);
4935 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4936 	case BTRFS_IOC_SEND_32:
4937 		return _btrfs_ioctl_send(file, argp, true);
4938 #endif
4939 	case BTRFS_IOC_GET_DEV_STATS:
4940 		return btrfs_ioctl_get_dev_stats(fs_info, argp);
4941 	case BTRFS_IOC_QUOTA_CTL:
4942 		return btrfs_ioctl_quota_ctl(file, argp);
4943 	case BTRFS_IOC_QGROUP_ASSIGN:
4944 		return btrfs_ioctl_qgroup_assign(file, argp);
4945 	case BTRFS_IOC_QGROUP_CREATE:
4946 		return btrfs_ioctl_qgroup_create(file, argp);
4947 	case BTRFS_IOC_QGROUP_LIMIT:
4948 		return btrfs_ioctl_qgroup_limit(file, argp);
4949 	case BTRFS_IOC_QUOTA_RESCAN:
4950 		return btrfs_ioctl_quota_rescan(file, argp);
4951 	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
4952 		return btrfs_ioctl_quota_rescan_status(fs_info, argp);
4953 	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
4954 		return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
4955 	case BTRFS_IOC_DEV_REPLACE:
4956 		return btrfs_ioctl_dev_replace(fs_info, argp);
4957 	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
4958 		return btrfs_ioctl_get_supported_features(argp);
4959 	case BTRFS_IOC_GET_FEATURES:
4960 		return btrfs_ioctl_get_features(fs_info, argp);
4961 	case BTRFS_IOC_SET_FEATURES:
4962 		return btrfs_ioctl_set_features(file, argp);
4963 	case FS_IOC_FSGETXATTR:
4964 		return btrfs_ioctl_fsgetxattr(file, argp);
4965 	case FS_IOC_FSSETXATTR:
4966 		return btrfs_ioctl_fssetxattr(file, argp);
4967 	case BTRFS_IOC_GET_SUBVOL_INFO:
4968 		return btrfs_ioctl_get_subvol_info(file, argp);
4969 	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
4970 		return btrfs_ioctl_get_subvol_rootref(file, argp);
4971 	case BTRFS_IOC_INO_LOOKUP_USER:
4972 		return btrfs_ioctl_ino_lookup_user(file, argp);
4973 	}
4974 
4975 	return -ENOTTY;
4976 }
4977 
4978 #ifdef CONFIG_COMPAT
4979 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4980 {
4981 	/*
4982 	 * These all access 32-bit values anyway so no further
4983 	 * handling is necessary.
4984 	 */
4985 	switch (cmd) {
4986 	case FS_IOC32_GETFLAGS:
4987 		cmd = FS_IOC_GETFLAGS;
4988 		break;
4989 	case FS_IOC32_SETFLAGS:
4990 		cmd = FS_IOC_SETFLAGS;
4991 		break;
4992 	case FS_IOC32_GETVERSION:
4993 		cmd = FS_IOC_GETVERSION;
4994 		break;
4995 	}
4996 
4997 	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
4998 }
4999 #endif
5000