ioctl.c revision 6623d9a0
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 <linux/fileattr.h>
30#include <linux/fsverity.h>
31#include "ctree.h"
32#include "disk-io.h"
33#include "export.h"
34#include "transaction.h"
35#include "btrfs_inode.h"
36#include "print-tree.h"
37#include "volumes.h"
38#include "locking.h"
39#include "backref.h"
40#include "rcu-string.h"
41#include "send.h"
42#include "dev-replace.h"
43#include "props.h"
44#include "sysfs.h"
45#include "qgroup.h"
46#include "tree-log.h"
47#include "compression.h"
48#include "space-info.h"
49#include "delalloc-space.h"
50#include "block-group.h"
51
52#ifdef CONFIG_64BIT
53/* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
54 * structures are incorrect, as the timespec structure from userspace
55 * is 4 bytes too small. We define these alternatives here to teach
56 * the kernel about the 32-bit struct packing.
57 */
58struct btrfs_ioctl_timespec_32 {
59	__u64 sec;
60	__u32 nsec;
61} __attribute__ ((__packed__));
62
63struct btrfs_ioctl_received_subvol_args_32 {
64	char	uuid[BTRFS_UUID_SIZE];	/* in */
65	__u64	stransid;		/* in */
66	__u64	rtransid;		/* out */
67	struct btrfs_ioctl_timespec_32 stime; /* in */
68	struct btrfs_ioctl_timespec_32 rtime; /* out */
69	__u64	flags;			/* in */
70	__u64	reserved[16];		/* in */
71} __attribute__ ((__packed__));
72
73#define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
74				struct btrfs_ioctl_received_subvol_args_32)
75#endif
76
77#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
78struct btrfs_ioctl_send_args_32 {
79	__s64 send_fd;			/* in */
80	__u64 clone_sources_count;	/* in */
81	compat_uptr_t clone_sources;	/* in */
82	__u64 parent_root;		/* in */
83	__u64 flags;			/* in */
84	__u64 reserved[4];		/* in */
85} __attribute__ ((__packed__));
86
87#define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
88			       struct btrfs_ioctl_send_args_32)
89#endif
90
91/* Mask out flags that are inappropriate for the given type of inode. */
92static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
93		unsigned int flags)
94{
95	if (S_ISDIR(inode->i_mode))
96		return flags;
97	else if (S_ISREG(inode->i_mode))
98		return flags & ~FS_DIRSYNC_FL;
99	else
100		return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
101}
102
103/*
104 * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
105 * ioctl.
106 */
107static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode)
108{
109	unsigned int iflags = 0;
110	u32 flags = binode->flags;
111	u32 ro_flags = binode->ro_flags;
112
113	if (flags & BTRFS_INODE_SYNC)
114		iflags |= FS_SYNC_FL;
115	if (flags & BTRFS_INODE_IMMUTABLE)
116		iflags |= FS_IMMUTABLE_FL;
117	if (flags & BTRFS_INODE_APPEND)
118		iflags |= FS_APPEND_FL;
119	if (flags & BTRFS_INODE_NODUMP)
120		iflags |= FS_NODUMP_FL;
121	if (flags & BTRFS_INODE_NOATIME)
122		iflags |= FS_NOATIME_FL;
123	if (flags & BTRFS_INODE_DIRSYNC)
124		iflags |= FS_DIRSYNC_FL;
125	if (flags & BTRFS_INODE_NODATACOW)
126		iflags |= FS_NOCOW_FL;
127	if (ro_flags & BTRFS_INODE_RO_VERITY)
128		iflags |= FS_VERITY_FL;
129
130	if (flags & BTRFS_INODE_NOCOMPRESS)
131		iflags |= FS_NOCOMP_FL;
132	else if (flags & BTRFS_INODE_COMPRESS)
133		iflags |= FS_COMPR_FL;
134
135	return iflags;
136}
137
138/*
139 * Update inode->i_flags based on the btrfs internal flags.
140 */
141void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
142{
143	struct btrfs_inode *binode = BTRFS_I(inode);
144	unsigned int new_fl = 0;
145
146	if (binode->flags & BTRFS_INODE_SYNC)
147		new_fl |= S_SYNC;
148	if (binode->flags & BTRFS_INODE_IMMUTABLE)
149		new_fl |= S_IMMUTABLE;
150	if (binode->flags & BTRFS_INODE_APPEND)
151		new_fl |= S_APPEND;
152	if (binode->flags & BTRFS_INODE_NOATIME)
153		new_fl |= S_NOATIME;
154	if (binode->flags & BTRFS_INODE_DIRSYNC)
155		new_fl |= S_DIRSYNC;
156	if (binode->ro_flags & BTRFS_INODE_RO_VERITY)
157		new_fl |= S_VERITY;
158
159	set_mask_bits(&inode->i_flags,
160		      S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC |
161		      S_VERITY, new_fl);
162}
163
164/*
165 * Check if @flags are a supported and valid set of FS_*_FL flags and that
166 * the old and new flags are not conflicting
167 */
168static int check_fsflags(unsigned int old_flags, unsigned int flags)
169{
170	if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
171		      FS_NOATIME_FL | FS_NODUMP_FL | \
172		      FS_SYNC_FL | FS_DIRSYNC_FL | \
173		      FS_NOCOMP_FL | FS_COMPR_FL |
174		      FS_NOCOW_FL))
175		return -EOPNOTSUPP;
176
177	/* COMPR and NOCOMP on new/old are valid */
178	if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
179		return -EINVAL;
180
181	if ((flags & FS_COMPR_FL) && (flags & FS_NOCOW_FL))
182		return -EINVAL;
183
184	/* NOCOW and compression options are mutually exclusive */
185	if ((old_flags & FS_NOCOW_FL) && (flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
186		return -EINVAL;
187	if ((flags & FS_NOCOW_FL) && (old_flags & (FS_COMPR_FL | FS_NOCOMP_FL)))
188		return -EINVAL;
189
190	return 0;
191}
192
193static int check_fsflags_compatible(struct btrfs_fs_info *fs_info,
194				    unsigned int flags)
195{
196	if (btrfs_is_zoned(fs_info) && (flags & FS_NOCOW_FL))
197		return -EPERM;
198
199	return 0;
200}
201
202/*
203 * Set flags/xflags from the internal inode flags. The remaining items of
204 * fsxattr are zeroed.
205 */
206int btrfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
207{
208	struct btrfs_inode *binode = BTRFS_I(d_inode(dentry));
209
210	fileattr_fill_flags(fa, btrfs_inode_flags_to_fsflags(binode));
211	return 0;
212}
213
214int btrfs_fileattr_set(struct user_namespace *mnt_userns,
215		       struct dentry *dentry, struct fileattr *fa)
216{
217	struct inode *inode = d_inode(dentry);
218	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
219	struct btrfs_inode *binode = BTRFS_I(inode);
220	struct btrfs_root *root = binode->root;
221	struct btrfs_trans_handle *trans;
222	unsigned int fsflags, old_fsflags;
223	int ret;
224	const char *comp = NULL;
225	u32 binode_flags;
226
227	if (btrfs_root_readonly(root))
228		return -EROFS;
229
230	if (fileattr_has_fsx(fa))
231		return -EOPNOTSUPP;
232
233	fsflags = btrfs_mask_fsflags_for_type(inode, fa->flags);
234	old_fsflags = btrfs_inode_flags_to_fsflags(binode);
235	ret = check_fsflags(old_fsflags, fsflags);
236	if (ret)
237		return ret;
238
239	ret = check_fsflags_compatible(fs_info, fsflags);
240	if (ret)
241		return ret;
242
243	binode_flags = binode->flags;
244	if (fsflags & FS_SYNC_FL)
245		binode_flags |= BTRFS_INODE_SYNC;
246	else
247		binode_flags &= ~BTRFS_INODE_SYNC;
248	if (fsflags & FS_IMMUTABLE_FL)
249		binode_flags |= BTRFS_INODE_IMMUTABLE;
250	else
251		binode_flags &= ~BTRFS_INODE_IMMUTABLE;
252	if (fsflags & FS_APPEND_FL)
253		binode_flags |= BTRFS_INODE_APPEND;
254	else
255		binode_flags &= ~BTRFS_INODE_APPEND;
256	if (fsflags & FS_NODUMP_FL)
257		binode_flags |= BTRFS_INODE_NODUMP;
258	else
259		binode_flags &= ~BTRFS_INODE_NODUMP;
260	if (fsflags & FS_NOATIME_FL)
261		binode_flags |= BTRFS_INODE_NOATIME;
262	else
263		binode_flags &= ~BTRFS_INODE_NOATIME;
264
265	/* If coming from FS_IOC_FSSETXATTR then skip unconverted flags */
266	if (!fa->flags_valid) {
267		/* 1 item for the inode */
268		trans = btrfs_start_transaction(root, 1);
269		if (IS_ERR(trans))
270			return PTR_ERR(trans);
271		goto update_flags;
272	}
273
274	if (fsflags & FS_DIRSYNC_FL)
275		binode_flags |= BTRFS_INODE_DIRSYNC;
276	else
277		binode_flags &= ~BTRFS_INODE_DIRSYNC;
278	if (fsflags & FS_NOCOW_FL) {
279		if (S_ISREG(inode->i_mode)) {
280			/*
281			 * It's safe to turn csums off here, no extents exist.
282			 * Otherwise we want the flag to reflect the real COW
283			 * status of the file and will not set it.
284			 */
285			if (inode->i_size == 0)
286				binode_flags |= BTRFS_INODE_NODATACOW |
287						BTRFS_INODE_NODATASUM;
288		} else {
289			binode_flags |= BTRFS_INODE_NODATACOW;
290		}
291	} else {
292		/*
293		 * Revert back under same assumptions as above
294		 */
295		if (S_ISREG(inode->i_mode)) {
296			if (inode->i_size == 0)
297				binode_flags &= ~(BTRFS_INODE_NODATACOW |
298						  BTRFS_INODE_NODATASUM);
299		} else {
300			binode_flags &= ~BTRFS_INODE_NODATACOW;
301		}
302	}
303
304	/*
305	 * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
306	 * flag may be changed automatically if compression code won't make
307	 * things smaller.
308	 */
309	if (fsflags & FS_NOCOMP_FL) {
310		binode_flags &= ~BTRFS_INODE_COMPRESS;
311		binode_flags |= BTRFS_INODE_NOCOMPRESS;
312	} else if (fsflags & FS_COMPR_FL) {
313
314		if (IS_SWAPFILE(inode))
315			return -ETXTBSY;
316
317		binode_flags |= BTRFS_INODE_COMPRESS;
318		binode_flags &= ~BTRFS_INODE_NOCOMPRESS;
319
320		comp = btrfs_compress_type2str(fs_info->compress_type);
321		if (!comp || comp[0] == 0)
322			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
323	} else {
324		binode_flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
325	}
326
327	/*
328	 * 1 for inode item
329	 * 2 for properties
330	 */
331	trans = btrfs_start_transaction(root, 3);
332	if (IS_ERR(trans))
333		return PTR_ERR(trans);
334
335	if (comp) {
336		ret = btrfs_set_prop(trans, inode, "btrfs.compression", comp,
337				     strlen(comp), 0);
338		if (ret) {
339			btrfs_abort_transaction(trans, ret);
340			goto out_end_trans;
341		}
342	} else {
343		ret = btrfs_set_prop(trans, inode, "btrfs.compression", NULL,
344				     0, 0);
345		if (ret && ret != -ENODATA) {
346			btrfs_abort_transaction(trans, ret);
347			goto out_end_trans;
348		}
349	}
350
351update_flags:
352	binode->flags = binode_flags;
353	btrfs_sync_inode_flags_to_i_flags(inode);
354	inode_inc_iversion(inode);
355	inode->i_ctime = current_time(inode);
356	ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
357
358 out_end_trans:
359	btrfs_end_transaction(trans);
360	return ret;
361}
362
363/*
364 * Start exclusive operation @type, return true on success
365 */
366bool btrfs_exclop_start(struct btrfs_fs_info *fs_info,
367			enum btrfs_exclusive_operation type)
368{
369	bool ret = false;
370
371	spin_lock(&fs_info->super_lock);
372	if (fs_info->exclusive_operation == BTRFS_EXCLOP_NONE) {
373		fs_info->exclusive_operation = type;
374		ret = true;
375	}
376	spin_unlock(&fs_info->super_lock);
377
378	return ret;
379}
380
381/*
382 * Conditionally allow to enter the exclusive operation in case it's compatible
383 * with the running one.  This must be paired with btrfs_exclop_start_unlock and
384 * btrfs_exclop_finish.
385 *
386 * Compatibility:
387 * - the same type is already running
388 * - not BTRFS_EXCLOP_NONE - this is intentionally incompatible and the caller
389 *   must check the condition first that would allow none -> @type
390 */
391bool btrfs_exclop_start_try_lock(struct btrfs_fs_info *fs_info,
392				 enum btrfs_exclusive_operation type)
393{
394	spin_lock(&fs_info->super_lock);
395	if (fs_info->exclusive_operation == type)
396		return true;
397
398	spin_unlock(&fs_info->super_lock);
399	return false;
400}
401
402void btrfs_exclop_start_unlock(struct btrfs_fs_info *fs_info)
403{
404	spin_unlock(&fs_info->super_lock);
405}
406
407void btrfs_exclop_finish(struct btrfs_fs_info *fs_info)
408{
409	spin_lock(&fs_info->super_lock);
410	WRITE_ONCE(fs_info->exclusive_operation, BTRFS_EXCLOP_NONE);
411	spin_unlock(&fs_info->super_lock);
412	sysfs_notify(&fs_info->fs_devices->fsid_kobj, NULL, "exclusive_operation");
413}
414
415static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
416{
417	struct inode *inode = file_inode(file);
418
419	return put_user(inode->i_generation, arg);
420}
421
422static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
423					void __user *arg)
424{
425	struct btrfs_device *device;
426	struct request_queue *q;
427	struct fstrim_range range;
428	u64 minlen = ULLONG_MAX;
429	u64 num_devices = 0;
430	int ret;
431
432	if (!capable(CAP_SYS_ADMIN))
433		return -EPERM;
434
435	/*
436	 * btrfs_trim_block_group() depends on space cache, which is not
437	 * available in zoned filesystem. So, disallow fitrim on a zoned
438	 * filesystem for now.
439	 */
440	if (btrfs_is_zoned(fs_info))
441		return -EOPNOTSUPP;
442
443	/*
444	 * If the fs is mounted with nologreplay, which requires it to be
445	 * mounted in RO mode as well, we can not allow discard on free space
446	 * inside block groups, because log trees refer to extents that are not
447	 * pinned in a block group's free space cache (pinning the extents is
448	 * precisely the first phase of replaying a log tree).
449	 */
450	if (btrfs_test_opt(fs_info, NOLOGREPLAY))
451		return -EROFS;
452
453	rcu_read_lock();
454	list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
455				dev_list) {
456		if (!device->bdev)
457			continue;
458		q = bdev_get_queue(device->bdev);
459		if (blk_queue_discard(q)) {
460			num_devices++;
461			minlen = min_t(u64, q->limits.discard_granularity,
462				     minlen);
463		}
464	}
465	rcu_read_unlock();
466
467	if (!num_devices)
468		return -EOPNOTSUPP;
469	if (copy_from_user(&range, arg, sizeof(range)))
470		return -EFAULT;
471
472	/*
473	 * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
474	 * block group is in the logical address space, which can be any
475	 * sectorsize aligned bytenr in  the range [0, U64_MAX].
476	 */
477	if (range.len < fs_info->sb->s_blocksize)
478		return -EINVAL;
479
480	range.minlen = max(range.minlen, minlen);
481	ret = btrfs_trim_fs(fs_info, &range);
482	if (ret < 0)
483		return ret;
484
485	if (copy_to_user(arg, &range, sizeof(range)))
486		return -EFAULT;
487
488	return 0;
489}
490
491int __pure btrfs_is_empty_uuid(u8 *uuid)
492{
493	int i;
494
495	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
496		if (uuid[i])
497			return 0;
498	}
499	return 1;
500}
501
502static noinline int create_subvol(struct user_namespace *mnt_userns,
503				  struct inode *dir, struct dentry *dentry,
504				  const char *name, int namelen,
505				  struct btrfs_qgroup_inherit *inherit)
506{
507	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
508	struct btrfs_trans_handle *trans;
509	struct btrfs_key key;
510	struct btrfs_root_item *root_item;
511	struct btrfs_inode_item *inode_item;
512	struct extent_buffer *leaf;
513	struct btrfs_root *root = BTRFS_I(dir)->root;
514	struct btrfs_root *new_root;
515	struct btrfs_block_rsv block_rsv;
516	struct timespec64 cur_time = current_time(dir);
517	struct inode *inode;
518	int ret;
519	int err;
520	dev_t anon_dev = 0;
521	u64 objectid;
522	u64 index = 0;
523
524	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
525	if (!root_item)
526		return -ENOMEM;
527
528	ret = btrfs_get_free_objectid(fs_info->tree_root, &objectid);
529	if (ret)
530		goto fail_free;
531
532	ret = get_anon_bdev(&anon_dev);
533	if (ret < 0)
534		goto fail_free;
535
536	/*
537	 * Don't create subvolume whose level is not zero. Or qgroup will be
538	 * screwed up since it assumes subvolume qgroup's level to be 0.
539	 */
540	if (btrfs_qgroup_level(objectid)) {
541		ret = -ENOSPC;
542		goto fail_free;
543	}
544
545	btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
546	/*
547	 * The same as the snapshot creation, please see the comment
548	 * of create_snapshot().
549	 */
550	ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
551	if (ret)
552		goto fail_free;
553
554	trans = btrfs_start_transaction(root, 0);
555	if (IS_ERR(trans)) {
556		ret = PTR_ERR(trans);
557		btrfs_subvolume_release_metadata(root, &block_rsv);
558		goto fail_free;
559	}
560	trans->block_rsv = &block_rsv;
561	trans->bytes_reserved = block_rsv.size;
562
563	ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
564	if (ret)
565		goto fail;
566
567	leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0,
568				      BTRFS_NESTING_NORMAL);
569	if (IS_ERR(leaf)) {
570		ret = PTR_ERR(leaf);
571		goto fail;
572	}
573
574	btrfs_mark_buffer_dirty(leaf);
575
576	inode_item = &root_item->inode;
577	btrfs_set_stack_inode_generation(inode_item, 1);
578	btrfs_set_stack_inode_size(inode_item, 3);
579	btrfs_set_stack_inode_nlink(inode_item, 1);
580	btrfs_set_stack_inode_nbytes(inode_item,
581				     fs_info->nodesize);
582	btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
583
584	btrfs_set_root_flags(root_item, 0);
585	btrfs_set_root_limit(root_item, 0);
586	btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
587
588	btrfs_set_root_bytenr(root_item, leaf->start);
589	btrfs_set_root_generation(root_item, trans->transid);
590	btrfs_set_root_level(root_item, 0);
591	btrfs_set_root_refs(root_item, 1);
592	btrfs_set_root_used(root_item, leaf->len);
593	btrfs_set_root_last_snapshot(root_item, 0);
594
595	btrfs_set_root_generation_v2(root_item,
596			btrfs_root_generation(root_item));
597	generate_random_guid(root_item->uuid);
598	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
599	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
600	root_item->ctime = root_item->otime;
601	btrfs_set_root_ctransid(root_item, trans->transid);
602	btrfs_set_root_otransid(root_item, trans->transid);
603
604	btrfs_tree_unlock(leaf);
605
606	btrfs_set_root_dirid(root_item, BTRFS_FIRST_FREE_OBJECTID);
607
608	key.objectid = objectid;
609	key.offset = 0;
610	key.type = BTRFS_ROOT_ITEM_KEY;
611	ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
612				root_item);
613	if (ret) {
614		/*
615		 * Since we don't abort the transaction in this case, free the
616		 * tree block so that we don't leak space and leave the
617		 * filesystem in an inconsistent state (an extent item in the
618		 * extent tree without backreferences). Also no need to have
619		 * the tree block locked since it is not in any tree at this
620		 * point, so no other task can find it and use it.
621		 */
622		btrfs_free_tree_block(trans, root, leaf, 0, 1);
623		free_extent_buffer(leaf);
624		goto fail;
625	}
626
627	free_extent_buffer(leaf);
628	leaf = NULL;
629
630	key.offset = (u64)-1;
631	new_root = btrfs_get_new_fs_root(fs_info, objectid, anon_dev);
632	if (IS_ERR(new_root)) {
633		free_anon_bdev(anon_dev);
634		ret = PTR_ERR(new_root);
635		btrfs_abort_transaction(trans, ret);
636		goto fail;
637	}
638	/* Freeing will be done in btrfs_put_root() of new_root */
639	anon_dev = 0;
640
641	ret = btrfs_record_root_in_trans(trans, new_root);
642	if (ret) {
643		btrfs_put_root(new_root);
644		btrfs_abort_transaction(trans, ret);
645		goto fail;
646	}
647
648	ret = btrfs_create_subvol_root(trans, new_root, root, mnt_userns);
649	btrfs_put_root(new_root);
650	if (ret) {
651		/* We potentially lose an unused inode item here */
652		btrfs_abort_transaction(trans, ret);
653		goto fail;
654	}
655
656	/*
657	 * insert the directory item
658	 */
659	ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
660	if (ret) {
661		btrfs_abort_transaction(trans, ret);
662		goto fail;
663	}
664
665	ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
666				    BTRFS_FT_DIR, index);
667	if (ret) {
668		btrfs_abort_transaction(trans, ret);
669		goto fail;
670	}
671
672	btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
673	ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
674	if (ret) {
675		btrfs_abort_transaction(trans, ret);
676		goto fail;
677	}
678
679	ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
680				 btrfs_ino(BTRFS_I(dir)), index, name, namelen);
681	if (ret) {
682		btrfs_abort_transaction(trans, ret);
683		goto fail;
684	}
685
686	ret = btrfs_uuid_tree_add(trans, root_item->uuid,
687				  BTRFS_UUID_KEY_SUBVOL, objectid);
688	if (ret)
689		btrfs_abort_transaction(trans, ret);
690
691fail:
692	kfree(root_item);
693	trans->block_rsv = NULL;
694	trans->bytes_reserved = 0;
695	btrfs_subvolume_release_metadata(root, &block_rsv);
696
697	err = btrfs_commit_transaction(trans);
698	if (err && !ret)
699		ret = err;
700
701	if (!ret) {
702		inode = btrfs_lookup_dentry(dir, dentry);
703		if (IS_ERR(inode))
704			return PTR_ERR(inode);
705		d_instantiate(dentry, inode);
706	}
707	return ret;
708
709fail_free:
710	if (anon_dev)
711		free_anon_bdev(anon_dev);
712	kfree(root_item);
713	return ret;
714}
715
716static int create_snapshot(struct btrfs_root *root, struct inode *dir,
717			   struct dentry *dentry, bool readonly,
718			   struct btrfs_qgroup_inherit *inherit)
719{
720	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
721	struct inode *inode;
722	struct btrfs_pending_snapshot *pending_snapshot;
723	struct btrfs_trans_handle *trans;
724	int ret;
725
726	if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
727		return -EINVAL;
728
729	if (atomic_read(&root->nr_swapfiles)) {
730		btrfs_warn(fs_info,
731			   "cannot snapshot subvolume with active swapfile");
732		return -ETXTBSY;
733	}
734
735	pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
736	if (!pending_snapshot)
737		return -ENOMEM;
738
739	ret = get_anon_bdev(&pending_snapshot->anon_dev);
740	if (ret < 0)
741		goto free_pending;
742	pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
743			GFP_KERNEL);
744	pending_snapshot->path = btrfs_alloc_path();
745	if (!pending_snapshot->root_item || !pending_snapshot->path) {
746		ret = -ENOMEM;
747		goto free_pending;
748	}
749
750	btrfs_init_block_rsv(&pending_snapshot->block_rsv,
751			     BTRFS_BLOCK_RSV_TEMP);
752	/*
753	 * 1 - parent dir inode
754	 * 2 - dir entries
755	 * 1 - root item
756	 * 2 - root ref/backref
757	 * 1 - root of snapshot
758	 * 1 - UUID item
759	 */
760	ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
761					&pending_snapshot->block_rsv, 8,
762					false);
763	if (ret)
764		goto free_pending;
765
766	pending_snapshot->dentry = dentry;
767	pending_snapshot->root = root;
768	pending_snapshot->readonly = readonly;
769	pending_snapshot->dir = dir;
770	pending_snapshot->inherit = inherit;
771
772	trans = btrfs_start_transaction(root, 0);
773	if (IS_ERR(trans)) {
774		ret = PTR_ERR(trans);
775		goto fail;
776	}
777
778	spin_lock(&fs_info->trans_lock);
779	list_add(&pending_snapshot->list,
780		 &trans->transaction->pending_snapshots);
781	spin_unlock(&fs_info->trans_lock);
782
783	ret = btrfs_commit_transaction(trans);
784	if (ret)
785		goto fail;
786
787	ret = pending_snapshot->error;
788	if (ret)
789		goto fail;
790
791	ret = btrfs_orphan_cleanup(pending_snapshot->snap);
792	if (ret)
793		goto fail;
794
795	inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
796	if (IS_ERR(inode)) {
797		ret = PTR_ERR(inode);
798		goto fail;
799	}
800
801	d_instantiate(dentry, inode);
802	ret = 0;
803	pending_snapshot->anon_dev = 0;
804fail:
805	/* Prevent double freeing of anon_dev */
806	if (ret && pending_snapshot->snap)
807		pending_snapshot->snap->anon_dev = 0;
808	btrfs_put_root(pending_snapshot->snap);
809	btrfs_subvolume_release_metadata(root, &pending_snapshot->block_rsv);
810free_pending:
811	if (pending_snapshot->anon_dev)
812		free_anon_bdev(pending_snapshot->anon_dev);
813	kfree(pending_snapshot->root_item);
814	btrfs_free_path(pending_snapshot->path);
815	kfree(pending_snapshot);
816
817	return ret;
818}
819
820/*  copy of may_delete in fs/namei.c()
821 *	Check whether we can remove a link victim from directory dir, check
822 *  whether the type of victim is right.
823 *  1. We can't do it if dir is read-only (done in permission())
824 *  2. We should have write and exec permissions on dir
825 *  3. We can't remove anything from append-only dir
826 *  4. We can't do anything with immutable dir (done in permission())
827 *  5. If the sticky bit on dir is set we should either
828 *	a. be owner of dir, or
829 *	b. be owner of victim, or
830 *	c. have CAP_FOWNER capability
831 *  6. If the victim is append-only or immutable we can't do anything with
832 *     links pointing to it.
833 *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
834 *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
835 *  9. We can't remove a root or mountpoint.
836 * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
837 *     nfs_async_unlink().
838 */
839
840static int btrfs_may_delete(struct user_namespace *mnt_userns,
841			    struct inode *dir, struct dentry *victim, int isdir)
842{
843	int error;
844
845	if (d_really_is_negative(victim))
846		return -ENOENT;
847
848	BUG_ON(d_inode(victim->d_parent) != dir);
849	audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
850
851	error = inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
852	if (error)
853		return error;
854	if (IS_APPEND(dir))
855		return -EPERM;
856	if (check_sticky(mnt_userns, dir, d_inode(victim)) ||
857	    IS_APPEND(d_inode(victim)) || IS_IMMUTABLE(d_inode(victim)) ||
858	    IS_SWAPFILE(d_inode(victim)))
859		return -EPERM;
860	if (isdir) {
861		if (!d_is_dir(victim))
862			return -ENOTDIR;
863		if (IS_ROOT(victim))
864			return -EBUSY;
865	} else if (d_is_dir(victim))
866		return -EISDIR;
867	if (IS_DEADDIR(dir))
868		return -ENOENT;
869	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
870		return -EBUSY;
871	return 0;
872}
873
874/* copy of may_create in fs/namei.c() */
875static inline int btrfs_may_create(struct user_namespace *mnt_userns,
876				   struct inode *dir, struct dentry *child)
877{
878	if (d_really_is_positive(child))
879		return -EEXIST;
880	if (IS_DEADDIR(dir))
881		return -ENOENT;
882	if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns))
883		return -EOVERFLOW;
884	return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC);
885}
886
887/*
888 * Create a new subvolume below @parent.  This is largely modeled after
889 * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
890 * inside this filesystem so it's quite a bit simpler.
891 */
892static noinline int btrfs_mksubvol(const struct path *parent,
893				   struct user_namespace *mnt_userns,
894				   const char *name, int namelen,
895				   struct btrfs_root *snap_src,
896				   bool readonly,
897				   struct btrfs_qgroup_inherit *inherit)
898{
899	struct inode *dir = d_inode(parent->dentry);
900	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
901	struct dentry *dentry;
902	int error;
903
904	error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
905	if (error == -EINTR)
906		return error;
907
908	dentry = lookup_one(mnt_userns, name, parent->dentry, namelen);
909	error = PTR_ERR(dentry);
910	if (IS_ERR(dentry))
911		goto out_unlock;
912
913	error = btrfs_may_create(mnt_userns, dir, dentry);
914	if (error)
915		goto out_dput;
916
917	/*
918	 * even if this name doesn't exist, we may get hash collisions.
919	 * check for them now when we can safely fail
920	 */
921	error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
922					       dir->i_ino, name,
923					       namelen);
924	if (error)
925		goto out_dput;
926
927	down_read(&fs_info->subvol_sem);
928
929	if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
930		goto out_up_read;
931
932	if (snap_src)
933		error = create_snapshot(snap_src, dir, dentry, readonly, inherit);
934	else
935		error = create_subvol(mnt_userns, dir, dentry, name, namelen, inherit);
936
937	if (!error)
938		fsnotify_mkdir(dir, dentry);
939out_up_read:
940	up_read(&fs_info->subvol_sem);
941out_dput:
942	dput(dentry);
943out_unlock:
944	btrfs_inode_unlock(dir, 0);
945	return error;
946}
947
948static noinline int btrfs_mksnapshot(const struct path *parent,
949				   struct user_namespace *mnt_userns,
950				   const char *name, int namelen,
951				   struct btrfs_root *root,
952				   bool readonly,
953				   struct btrfs_qgroup_inherit *inherit)
954{
955	int ret;
956	bool snapshot_force_cow = false;
957
958	/*
959	 * Force new buffered writes to reserve space even when NOCOW is
960	 * possible. This is to avoid later writeback (running dealloc) to
961	 * fallback to COW mode and unexpectedly fail with ENOSPC.
962	 */
963	btrfs_drew_read_lock(&root->snapshot_lock);
964
965	ret = btrfs_start_delalloc_snapshot(root, false);
966	if (ret)
967		goto out;
968
969	/*
970	 * All previous writes have started writeback in NOCOW mode, so now
971	 * we force future writes to fallback to COW mode during snapshot
972	 * creation.
973	 */
974	atomic_inc(&root->snapshot_force_cow);
975	snapshot_force_cow = true;
976
977	btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
978
979	ret = btrfs_mksubvol(parent, mnt_userns, name, namelen,
980			     root, readonly, inherit);
981out:
982	if (snapshot_force_cow)
983		atomic_dec(&root->snapshot_force_cow);
984	btrfs_drew_read_unlock(&root->snapshot_lock);
985	return ret;
986}
987
988/*
989 * When we're defragging a range, we don't want to kick it off again
990 * if it is really just waiting for delalloc to send it down.
991 * If we find a nice big extent or delalloc range for the bytes in the
992 * file you want to defrag, we return 0 to let you know to skip this
993 * part of the file
994 */
995static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
996{
997	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
998	struct extent_map *em = NULL;
999	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1000	u64 end;
1001
1002	read_lock(&em_tree->lock);
1003	em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1004	read_unlock(&em_tree->lock);
1005
1006	if (em) {
1007		end = extent_map_end(em);
1008		free_extent_map(em);
1009		if (end - offset > thresh)
1010			return 0;
1011	}
1012	/* if we already have a nice delalloc here, just stop */
1013	thresh /= 2;
1014	end = count_range_bits(io_tree, &offset, offset + thresh,
1015			       thresh, EXTENT_DELALLOC, 1);
1016	if (end >= thresh)
1017		return 0;
1018	return 1;
1019}
1020
1021/*
1022 * helper function to walk through a file and find extents
1023 * newer than a specific transid, and smaller than thresh.
1024 *
1025 * This is used by the defragging code to find new and small
1026 * extents
1027 */
1028static int find_new_extents(struct btrfs_root *root,
1029			    struct inode *inode, u64 newer_than,
1030			    u64 *off, u32 thresh)
1031{
1032	struct btrfs_path *path;
1033	struct btrfs_key min_key;
1034	struct extent_buffer *leaf;
1035	struct btrfs_file_extent_item *extent;
1036	int type;
1037	int ret;
1038	u64 ino = btrfs_ino(BTRFS_I(inode));
1039
1040	path = btrfs_alloc_path();
1041	if (!path)
1042		return -ENOMEM;
1043
1044	min_key.objectid = ino;
1045	min_key.type = BTRFS_EXTENT_DATA_KEY;
1046	min_key.offset = *off;
1047
1048	while (1) {
1049		ret = btrfs_search_forward(root, &min_key, path, newer_than);
1050		if (ret != 0)
1051			goto none;
1052process_slot:
1053		if (min_key.objectid != ino)
1054			goto none;
1055		if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1056			goto none;
1057
1058		leaf = path->nodes[0];
1059		extent = btrfs_item_ptr(leaf, path->slots[0],
1060					struct btrfs_file_extent_item);
1061
1062		type = btrfs_file_extent_type(leaf, extent);
1063		if (type == BTRFS_FILE_EXTENT_REG &&
1064		    btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1065		    check_defrag_in_cache(inode, min_key.offset, thresh)) {
1066			*off = min_key.offset;
1067			btrfs_free_path(path);
1068			return 0;
1069		}
1070
1071		path->slots[0]++;
1072		if (path->slots[0] < btrfs_header_nritems(leaf)) {
1073			btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1074			goto process_slot;
1075		}
1076
1077		if (min_key.offset == (u64)-1)
1078			goto none;
1079
1080		min_key.offset++;
1081		btrfs_release_path(path);
1082	}
1083none:
1084	btrfs_free_path(path);
1085	return -ENOENT;
1086}
1087
1088static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1089{
1090	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1091	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1092	struct extent_map *em;
1093	u64 len = PAGE_SIZE;
1094
1095	/*
1096	 * hopefully we have this extent in the tree already, try without
1097	 * the full extent lock
1098	 */
1099	read_lock(&em_tree->lock);
1100	em = lookup_extent_mapping(em_tree, start, len);
1101	read_unlock(&em_tree->lock);
1102
1103	if (!em) {
1104		struct extent_state *cached = NULL;
1105		u64 end = start + len - 1;
1106
1107		/* get the big lock and read metadata off disk */
1108		lock_extent_bits(io_tree, start, end, &cached);
1109		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
1110		unlock_extent_cached(io_tree, start, end, &cached);
1111
1112		if (IS_ERR(em))
1113			return NULL;
1114	}
1115
1116	return em;
1117}
1118
1119static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1120{
1121	struct extent_map *next;
1122	bool ret = true;
1123
1124	/* this is the last extent */
1125	if (em->start + em->len >= i_size_read(inode))
1126		return false;
1127
1128	next = defrag_lookup_extent(inode, em->start + em->len);
1129	if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1130		ret = false;
1131	else if ((em->block_start + em->block_len == next->block_start) &&
1132		 (em->block_len > SZ_128K && next->block_len > SZ_128K))
1133		ret = false;
1134
1135	free_extent_map(next);
1136	return ret;
1137}
1138
1139static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1140			       u64 *last_len, u64 *skip, u64 *defrag_end,
1141			       int compress)
1142{
1143	struct extent_map *em;
1144	int ret = 1;
1145	bool next_mergeable = true;
1146	bool prev_mergeable = true;
1147
1148	/*
1149	 * make sure that once we start defragging an extent, we keep on
1150	 * defragging it
1151	 */
1152	if (start < *defrag_end)
1153		return 1;
1154
1155	*skip = 0;
1156
1157	em = defrag_lookup_extent(inode, start);
1158	if (!em)
1159		return 0;
1160
1161	/* this will cover holes, and inline extents */
1162	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1163		ret = 0;
1164		goto out;
1165	}
1166
1167	if (!*defrag_end)
1168		prev_mergeable = false;
1169
1170	next_mergeable = defrag_check_next_extent(inode, em);
1171	/*
1172	 * we hit a real extent, if it is big or the next extent is not a
1173	 * real extent, don't bother defragging it
1174	 */
1175	if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1176	    (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1177		ret = 0;
1178out:
1179	/*
1180	 * last_len ends up being a counter of how many bytes we've defragged.
1181	 * every time we choose not to defrag an extent, we reset *last_len
1182	 * so that the next tiny extent will force a defrag.
1183	 *
1184	 * The end result of this is that tiny extents before a single big
1185	 * extent will force at least part of that big extent to be defragged.
1186	 */
1187	if (ret) {
1188		*defrag_end = extent_map_end(em);
1189	} else {
1190		*last_len = 0;
1191		*skip = extent_map_end(em);
1192		*defrag_end = 0;
1193	}
1194
1195	free_extent_map(em);
1196	return ret;
1197}
1198
1199/*
1200 * it doesn't do much good to defrag one or two pages
1201 * at a time.  This pulls in a nice chunk of pages
1202 * to COW and defrag.
1203 *
1204 * It also makes sure the delalloc code has enough
1205 * dirty data to avoid making new small extents as part
1206 * of the defrag
1207 *
1208 * It's a good idea to start RA on this range
1209 * before calling this.
1210 */
1211static int cluster_pages_for_defrag(struct inode *inode,
1212				    struct page **pages,
1213				    unsigned long start_index,
1214				    unsigned long num_pages)
1215{
1216	unsigned long file_end;
1217	u64 isize = i_size_read(inode);
1218	u64 page_start;
1219	u64 page_end;
1220	u64 page_cnt;
1221	u64 start = (u64)start_index << PAGE_SHIFT;
1222	u64 search_start;
1223	int ret;
1224	int i;
1225	int i_done;
1226	struct btrfs_ordered_extent *ordered;
1227	struct extent_state *cached_state = NULL;
1228	struct extent_io_tree *tree;
1229	struct extent_changeset *data_reserved = NULL;
1230	gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1231
1232	file_end = (isize - 1) >> PAGE_SHIFT;
1233	if (!isize || start_index > file_end)
1234		return 0;
1235
1236	page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1237
1238	ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
1239			start, page_cnt << PAGE_SHIFT);
1240	if (ret)
1241		return ret;
1242	i_done = 0;
1243	tree = &BTRFS_I(inode)->io_tree;
1244
1245	/* step one, lock all the pages */
1246	for (i = 0; i < page_cnt; i++) {
1247		struct page *page;
1248again:
1249		page = find_or_create_page(inode->i_mapping,
1250					   start_index + i, mask);
1251		if (!page)
1252			break;
1253
1254		ret = set_page_extent_mapped(page);
1255		if (ret < 0) {
1256			unlock_page(page);
1257			put_page(page);
1258			break;
1259		}
1260
1261		page_start = page_offset(page);
1262		page_end = page_start + PAGE_SIZE - 1;
1263		while (1) {
1264			lock_extent_bits(tree, page_start, page_end,
1265					 &cached_state);
1266			ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode),
1267							      page_start);
1268			unlock_extent_cached(tree, page_start, page_end,
1269					     &cached_state);
1270			if (!ordered)
1271				break;
1272
1273			unlock_page(page);
1274			btrfs_start_ordered_extent(ordered, 1);
1275			btrfs_put_ordered_extent(ordered);
1276			lock_page(page);
1277			/*
1278			 * we unlocked the page above, so we need check if
1279			 * it was released or not.
1280			 */
1281			if (page->mapping != inode->i_mapping) {
1282				unlock_page(page);
1283				put_page(page);
1284				goto again;
1285			}
1286		}
1287
1288		if (!PageUptodate(page)) {
1289			btrfs_readpage(NULL, page);
1290			lock_page(page);
1291			if (!PageUptodate(page)) {
1292				unlock_page(page);
1293				put_page(page);
1294				ret = -EIO;
1295				break;
1296			}
1297		}
1298
1299		if (page->mapping != inode->i_mapping) {
1300			unlock_page(page);
1301			put_page(page);
1302			goto again;
1303		}
1304
1305		pages[i] = page;
1306		i_done++;
1307	}
1308	if (!i_done || ret)
1309		goto out;
1310
1311	if (!(inode->i_sb->s_flags & SB_ACTIVE))
1312		goto out;
1313
1314	/*
1315	 * so now we have a nice long stream of locked
1316	 * and up to date pages, lets wait on them
1317	 */
1318	for (i = 0; i < i_done; i++)
1319		wait_on_page_writeback(pages[i]);
1320
1321	page_start = page_offset(pages[0]);
1322	page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1323
1324	lock_extent_bits(&BTRFS_I(inode)->io_tree,
1325			 page_start, page_end - 1, &cached_state);
1326
1327	/*
1328	 * When defragmenting we skip ranges that have holes or inline extents,
1329	 * (check should_defrag_range()), to avoid unnecessary IO and wasting
1330	 * space. At btrfs_defrag_file(), we check if a range should be defragged
1331	 * before locking the inode and then, if it should, we trigger a sync
1332	 * page cache readahead - we lock the inode only after that to avoid
1333	 * blocking for too long other tasks that possibly want to operate on
1334	 * other file ranges. But before we were able to get the inode lock,
1335	 * some other task may have punched a hole in the range, or we may have
1336	 * now an inline extent, in which case we should not defrag. So check
1337	 * for that here, where we have the inode and the range locked, and bail
1338	 * out if that happened.
1339	 */
1340	search_start = page_start;
1341	while (search_start < page_end) {
1342		struct extent_map *em;
1343
1344		em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, search_start,
1345				      page_end - search_start);
1346		if (IS_ERR(em)) {
1347			ret = PTR_ERR(em);
1348			goto out_unlock_range;
1349		}
1350		if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1351			free_extent_map(em);
1352			/* Ok, 0 means we did not defrag anything */
1353			ret = 0;
1354			goto out_unlock_range;
1355		}
1356		search_start = extent_map_end(em);
1357		free_extent_map(em);
1358	}
1359
1360	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1361			  page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
1362			  EXTENT_DEFRAG, 0, 0, &cached_state);
1363
1364	if (i_done != page_cnt) {
1365		spin_lock(&BTRFS_I(inode)->lock);
1366		btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1367		spin_unlock(&BTRFS_I(inode)->lock);
1368		btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
1369				start, (page_cnt - i_done) << PAGE_SHIFT, true);
1370	}
1371
1372
1373	set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1374			  &cached_state);
1375
1376	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1377			     page_start, page_end - 1, &cached_state);
1378
1379	for (i = 0; i < i_done; i++) {
1380		clear_page_dirty_for_io(pages[i]);
1381		ClearPageChecked(pages[i]);
1382		set_page_dirty(pages[i]);
1383		unlock_page(pages[i]);
1384		put_page(pages[i]);
1385	}
1386	btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
1387	extent_changeset_free(data_reserved);
1388	return i_done;
1389
1390out_unlock_range:
1391	unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1392			     page_start, page_end - 1, &cached_state);
1393out:
1394	for (i = 0; i < i_done; i++) {
1395		unlock_page(pages[i]);
1396		put_page(pages[i]);
1397	}
1398	btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved,
1399			start, 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
1406int 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			goto error;
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		btrfs_inode_lock(inode, 0);
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			btrfs_inode_unlock(inode, 0);
1553			goto out_ra;
1554		}
1555
1556		defrag_count += ret;
1557		balance_dirty_pages_ratelimited(inode->i_mapping);
1558		btrfs_inode_unlock(inode, 0);
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	ret = defrag_count;
1590error:
1591	if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1592		filemap_flush(inode->i_mapping);
1593		if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1594			     &BTRFS_I(inode)->runtime_flags))
1595			filemap_flush(inode->i_mapping);
1596	}
1597
1598	if (range->compress_type == BTRFS_COMPRESS_LZO) {
1599		btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1600	} else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1601		btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1602	}
1603
1604out_ra:
1605	if (do_compress) {
1606		btrfs_inode_lock(inode, 0);
1607		BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1608		btrfs_inode_unlock(inode, 0);
1609	}
1610	if (!file)
1611		kfree(ra);
1612	kfree(pages);
1613	return ret;
1614}
1615
1616/*
1617 * Try to start exclusive operation @type or cancel it if it's running.
1618 *
1619 * Return:
1620 *   0        - normal mode, newly claimed op started
1621 *  >0        - normal mode, something else is running,
1622 *              return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS to user space
1623 * ECANCELED  - cancel mode, successful cancel
1624 * ENOTCONN   - cancel mode, operation not running anymore
1625 */
1626static int exclop_start_or_cancel_reloc(struct btrfs_fs_info *fs_info,
1627			enum btrfs_exclusive_operation type, bool cancel)
1628{
1629	if (!cancel) {
1630		/* Start normal op */
1631		if (!btrfs_exclop_start(fs_info, type))
1632			return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1633		/* Exclusive operation is now claimed */
1634		return 0;
1635	}
1636
1637	/* Cancel running op */
1638	if (btrfs_exclop_start_try_lock(fs_info, type)) {
1639		/*
1640		 * This blocks any exclop finish from setting it to NONE, so we
1641		 * request cancellation. Either it runs and we will wait for it,
1642		 * or it has finished and no waiting will happen.
1643		 */
1644		atomic_inc(&fs_info->reloc_cancel_req);
1645		btrfs_exclop_start_unlock(fs_info);
1646
1647		if (test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags))
1648			wait_on_bit(&fs_info->flags, BTRFS_FS_RELOC_RUNNING,
1649				    TASK_INTERRUPTIBLE);
1650
1651		return -ECANCELED;
1652	}
1653
1654	/* Something else is running or none */
1655	return -ENOTCONN;
1656}
1657
1658static noinline int btrfs_ioctl_resize(struct file *file,
1659					void __user *arg)
1660{
1661	struct inode *inode = file_inode(file);
1662	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1663	u64 new_size;
1664	u64 old_size;
1665	u64 devid = 1;
1666	struct btrfs_root *root = BTRFS_I(inode)->root;
1667	struct btrfs_ioctl_vol_args *vol_args;
1668	struct btrfs_trans_handle *trans;
1669	struct btrfs_device *device = NULL;
1670	char *sizestr;
1671	char *retptr;
1672	char *devstr = NULL;
1673	int ret = 0;
1674	int mod = 0;
1675	bool cancel;
1676
1677	if (!capable(CAP_SYS_ADMIN))
1678		return -EPERM;
1679
1680	ret = mnt_want_write_file(file);
1681	if (ret)
1682		return ret;
1683
1684	/*
1685	 * Read the arguments before checking exclusivity to be able to
1686	 * distinguish regular resize and cancel
1687	 */
1688	vol_args = memdup_user(arg, sizeof(*vol_args));
1689	if (IS_ERR(vol_args)) {
1690		ret = PTR_ERR(vol_args);
1691		goto out_drop;
1692	}
1693	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1694	sizestr = vol_args->name;
1695	cancel = (strcmp("cancel", sizestr) == 0);
1696	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_RESIZE, cancel);
1697	if (ret)
1698		goto out_free;
1699	/* Exclusive operation is now claimed */
1700
1701	devstr = strchr(sizestr, ':');
1702	if (devstr) {
1703		sizestr = devstr + 1;
1704		*devstr = '\0';
1705		devstr = vol_args->name;
1706		ret = kstrtoull(devstr, 10, &devid);
1707		if (ret)
1708			goto out_finish;
1709		if (!devid) {
1710			ret = -EINVAL;
1711			goto out_finish;
1712		}
1713		btrfs_info(fs_info, "resizing devid %llu", devid);
1714	}
1715
1716	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
1717	if (!device) {
1718		btrfs_info(fs_info, "resizer unable to find device %llu",
1719			   devid);
1720		ret = -ENODEV;
1721		goto out_finish;
1722	}
1723
1724	if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1725		btrfs_info(fs_info,
1726			   "resizer unable to apply on readonly device %llu",
1727		       devid);
1728		ret = -EPERM;
1729		goto out_finish;
1730	}
1731
1732	if (!strcmp(sizestr, "max"))
1733		new_size = device->bdev->bd_inode->i_size;
1734	else {
1735		if (sizestr[0] == '-') {
1736			mod = -1;
1737			sizestr++;
1738		} else if (sizestr[0] == '+') {
1739			mod = 1;
1740			sizestr++;
1741		}
1742		new_size = memparse(sizestr, &retptr);
1743		if (*retptr != '\0' || new_size == 0) {
1744			ret = -EINVAL;
1745			goto out_finish;
1746		}
1747	}
1748
1749	if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1750		ret = -EPERM;
1751		goto out_finish;
1752	}
1753
1754	old_size = btrfs_device_get_total_bytes(device);
1755
1756	if (mod < 0) {
1757		if (new_size > old_size) {
1758			ret = -EINVAL;
1759			goto out_finish;
1760		}
1761		new_size = old_size - new_size;
1762	} else if (mod > 0) {
1763		if (new_size > ULLONG_MAX - old_size) {
1764			ret = -ERANGE;
1765			goto out_finish;
1766		}
1767		new_size = old_size + new_size;
1768	}
1769
1770	if (new_size < SZ_256M) {
1771		ret = -EINVAL;
1772		goto out_finish;
1773	}
1774	if (new_size > device->bdev->bd_inode->i_size) {
1775		ret = -EFBIG;
1776		goto out_finish;
1777	}
1778
1779	new_size = round_down(new_size, fs_info->sectorsize);
1780
1781	if (new_size > old_size) {
1782		trans = btrfs_start_transaction(root, 0);
1783		if (IS_ERR(trans)) {
1784			ret = PTR_ERR(trans);
1785			goto out_finish;
1786		}
1787		ret = btrfs_grow_device(trans, device, new_size);
1788		btrfs_commit_transaction(trans);
1789	} else if (new_size < old_size) {
1790		ret = btrfs_shrink_device(device, new_size);
1791	} /* equal, nothing need to do */
1792
1793	if (ret == 0 && new_size != old_size)
1794		btrfs_info_in_rcu(fs_info,
1795			"resize device %s (devid %llu) from %llu to %llu",
1796			rcu_str_deref(device->name), device->devid,
1797			old_size, new_size);
1798out_finish:
1799	btrfs_exclop_finish(fs_info);
1800out_free:
1801	kfree(vol_args);
1802out_drop:
1803	mnt_drop_write_file(file);
1804	return ret;
1805}
1806
1807static noinline int __btrfs_ioctl_snap_create(struct file *file,
1808				struct user_namespace *mnt_userns,
1809				const char *name, unsigned long fd, int subvol,
1810				bool readonly,
1811				struct btrfs_qgroup_inherit *inherit)
1812{
1813	int namelen;
1814	int ret = 0;
1815
1816	if (!S_ISDIR(file_inode(file)->i_mode))
1817		return -ENOTDIR;
1818
1819	ret = mnt_want_write_file(file);
1820	if (ret)
1821		goto out;
1822
1823	namelen = strlen(name);
1824	if (strchr(name, '/')) {
1825		ret = -EINVAL;
1826		goto out_drop_write;
1827	}
1828
1829	if (name[0] == '.' &&
1830	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1831		ret = -EEXIST;
1832		goto out_drop_write;
1833	}
1834
1835	if (subvol) {
1836		ret = btrfs_mksubvol(&file->f_path, mnt_userns, name,
1837				     namelen, NULL, readonly, inherit);
1838	} else {
1839		struct fd src = fdget(fd);
1840		struct inode *src_inode;
1841		if (!src.file) {
1842			ret = -EINVAL;
1843			goto out_drop_write;
1844		}
1845
1846		src_inode = file_inode(src.file);
1847		if (src_inode->i_sb != file_inode(file)->i_sb) {
1848			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1849				   "Snapshot src from another FS");
1850			ret = -EXDEV;
1851		} else if (!inode_owner_or_capable(mnt_userns, src_inode)) {
1852			/*
1853			 * Subvolume creation is not restricted, but snapshots
1854			 * are limited to own subvolumes only
1855			 */
1856			ret = -EPERM;
1857		} else {
1858			ret = btrfs_mksnapshot(&file->f_path, mnt_userns,
1859					       name, namelen,
1860					       BTRFS_I(src_inode)->root,
1861					       readonly, inherit);
1862		}
1863		fdput(src);
1864	}
1865out_drop_write:
1866	mnt_drop_write_file(file);
1867out:
1868	return ret;
1869}
1870
1871static noinline int btrfs_ioctl_snap_create(struct file *file,
1872					    void __user *arg, int subvol)
1873{
1874	struct btrfs_ioctl_vol_args *vol_args;
1875	int ret;
1876
1877	if (!S_ISDIR(file_inode(file)->i_mode))
1878		return -ENOTDIR;
1879
1880	vol_args = memdup_user(arg, sizeof(*vol_args));
1881	if (IS_ERR(vol_args))
1882		return PTR_ERR(vol_args);
1883	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1884
1885	ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
1886					vol_args->name, vol_args->fd, subvol,
1887					false, NULL);
1888
1889	kfree(vol_args);
1890	return ret;
1891}
1892
1893static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1894					       void __user *arg, int subvol)
1895{
1896	struct btrfs_ioctl_vol_args_v2 *vol_args;
1897	int ret;
1898	bool readonly = false;
1899	struct btrfs_qgroup_inherit *inherit = NULL;
1900
1901	if (!S_ISDIR(file_inode(file)->i_mode))
1902		return -ENOTDIR;
1903
1904	vol_args = memdup_user(arg, sizeof(*vol_args));
1905	if (IS_ERR(vol_args))
1906		return PTR_ERR(vol_args);
1907	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1908
1909	if (vol_args->flags & ~BTRFS_SUBVOL_CREATE_ARGS_MASK) {
1910		ret = -EOPNOTSUPP;
1911		goto free_args;
1912	}
1913
1914	if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1915		readonly = true;
1916	if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1917		u64 nums;
1918
1919		if (vol_args->size < sizeof(*inherit) ||
1920		    vol_args->size > PAGE_SIZE) {
1921			ret = -EINVAL;
1922			goto free_args;
1923		}
1924		inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1925		if (IS_ERR(inherit)) {
1926			ret = PTR_ERR(inherit);
1927			goto free_args;
1928		}
1929
1930		if (inherit->num_qgroups > PAGE_SIZE ||
1931		    inherit->num_ref_copies > PAGE_SIZE ||
1932		    inherit->num_excl_copies > PAGE_SIZE) {
1933			ret = -EINVAL;
1934			goto free_inherit;
1935		}
1936
1937		nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
1938		       2 * inherit->num_excl_copies;
1939		if (vol_args->size != struct_size(inherit, qgroups, nums)) {
1940			ret = -EINVAL;
1941			goto free_inherit;
1942		}
1943	}
1944
1945	ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file),
1946					vol_args->name, vol_args->fd, subvol,
1947					readonly, inherit);
1948	if (ret)
1949		goto free_inherit;
1950free_inherit:
1951	kfree(inherit);
1952free_args:
1953	kfree(vol_args);
1954	return ret;
1955}
1956
1957static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1958						void __user *arg)
1959{
1960	struct inode *inode = file_inode(file);
1961	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1962	struct btrfs_root *root = BTRFS_I(inode)->root;
1963	int ret = 0;
1964	u64 flags = 0;
1965
1966	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1967		return -EINVAL;
1968
1969	down_read(&fs_info->subvol_sem);
1970	if (btrfs_root_readonly(root))
1971		flags |= BTRFS_SUBVOL_RDONLY;
1972	up_read(&fs_info->subvol_sem);
1973
1974	if (copy_to_user(arg, &flags, sizeof(flags)))
1975		ret = -EFAULT;
1976
1977	return ret;
1978}
1979
1980static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1981					      void __user *arg)
1982{
1983	struct inode *inode = file_inode(file);
1984	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1985	struct btrfs_root *root = BTRFS_I(inode)->root;
1986	struct btrfs_trans_handle *trans;
1987	u64 root_flags;
1988	u64 flags;
1989	int ret = 0;
1990
1991	if (!inode_owner_or_capable(file_mnt_user_ns(file), inode))
1992		return -EPERM;
1993
1994	ret = mnt_want_write_file(file);
1995	if (ret)
1996		goto out;
1997
1998	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1999		ret = -EINVAL;
2000		goto out_drop_write;
2001	}
2002
2003	if (copy_from_user(&flags, arg, sizeof(flags))) {
2004		ret = -EFAULT;
2005		goto out_drop_write;
2006	}
2007
2008	if (flags & ~BTRFS_SUBVOL_RDONLY) {
2009		ret = -EOPNOTSUPP;
2010		goto out_drop_write;
2011	}
2012
2013	down_write(&fs_info->subvol_sem);
2014
2015	/* nothing to do */
2016	if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
2017		goto out_drop_sem;
2018
2019	root_flags = btrfs_root_flags(&root->root_item);
2020	if (flags & BTRFS_SUBVOL_RDONLY) {
2021		btrfs_set_root_flags(&root->root_item,
2022				     root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
2023	} else {
2024		/*
2025		 * Block RO -> RW transition if this subvolume is involved in
2026		 * send
2027		 */
2028		spin_lock(&root->root_item_lock);
2029		if (root->send_in_progress == 0) {
2030			btrfs_set_root_flags(&root->root_item,
2031				     root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
2032			spin_unlock(&root->root_item_lock);
2033		} else {
2034			spin_unlock(&root->root_item_lock);
2035			btrfs_warn(fs_info,
2036				   "Attempt to set subvolume %llu read-write during send",
2037				   root->root_key.objectid);
2038			ret = -EPERM;
2039			goto out_drop_sem;
2040		}
2041	}
2042
2043	trans = btrfs_start_transaction(root, 1);
2044	if (IS_ERR(trans)) {
2045		ret = PTR_ERR(trans);
2046		goto out_reset;
2047	}
2048
2049	ret = btrfs_update_root(trans, fs_info->tree_root,
2050				&root->root_key, &root->root_item);
2051	if (ret < 0) {
2052		btrfs_end_transaction(trans);
2053		goto out_reset;
2054	}
2055
2056	ret = btrfs_commit_transaction(trans);
2057
2058out_reset:
2059	if (ret)
2060		btrfs_set_root_flags(&root->root_item, root_flags);
2061out_drop_sem:
2062	up_write(&fs_info->subvol_sem);
2063out_drop_write:
2064	mnt_drop_write_file(file);
2065out:
2066	return ret;
2067}
2068
2069static noinline int key_in_sk(struct btrfs_key *key,
2070			      struct btrfs_ioctl_search_key *sk)
2071{
2072	struct btrfs_key test;
2073	int ret;
2074
2075	test.objectid = sk->min_objectid;
2076	test.type = sk->min_type;
2077	test.offset = sk->min_offset;
2078
2079	ret = btrfs_comp_cpu_keys(key, &test);
2080	if (ret < 0)
2081		return 0;
2082
2083	test.objectid = sk->max_objectid;
2084	test.type = sk->max_type;
2085	test.offset = sk->max_offset;
2086
2087	ret = btrfs_comp_cpu_keys(key, &test);
2088	if (ret > 0)
2089		return 0;
2090	return 1;
2091}
2092
2093static noinline int copy_to_sk(struct btrfs_path *path,
2094			       struct btrfs_key *key,
2095			       struct btrfs_ioctl_search_key *sk,
2096			       size_t *buf_size,
2097			       char __user *ubuf,
2098			       unsigned long *sk_offset,
2099			       int *num_found)
2100{
2101	u64 found_transid;
2102	struct extent_buffer *leaf;
2103	struct btrfs_ioctl_search_header sh;
2104	struct btrfs_key test;
2105	unsigned long item_off;
2106	unsigned long item_len;
2107	int nritems;
2108	int i;
2109	int slot;
2110	int ret = 0;
2111
2112	leaf = path->nodes[0];
2113	slot = path->slots[0];
2114	nritems = btrfs_header_nritems(leaf);
2115
2116	if (btrfs_header_generation(leaf) > sk->max_transid) {
2117		i = nritems;
2118		goto advance_key;
2119	}
2120	found_transid = btrfs_header_generation(leaf);
2121
2122	for (i = slot; i < nritems; i++) {
2123		item_off = btrfs_item_ptr_offset(leaf, i);
2124		item_len = btrfs_item_size_nr(leaf, i);
2125
2126		btrfs_item_key_to_cpu(leaf, key, i);
2127		if (!key_in_sk(key, sk))
2128			continue;
2129
2130		if (sizeof(sh) + item_len > *buf_size) {
2131			if (*num_found) {
2132				ret = 1;
2133				goto out;
2134			}
2135
2136			/*
2137			 * return one empty item back for v1, which does not
2138			 * handle -EOVERFLOW
2139			 */
2140
2141			*buf_size = sizeof(sh) + item_len;
2142			item_len = 0;
2143			ret = -EOVERFLOW;
2144		}
2145
2146		if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2147			ret = 1;
2148			goto out;
2149		}
2150
2151		sh.objectid = key->objectid;
2152		sh.offset = key->offset;
2153		sh.type = key->type;
2154		sh.len = item_len;
2155		sh.transid = found_transid;
2156
2157		/*
2158		 * Copy search result header. If we fault then loop again so we
2159		 * can fault in the pages and -EFAULT there if there's a
2160		 * problem. Otherwise we'll fault and then copy the buffer in
2161		 * properly this next time through
2162		 */
2163		if (copy_to_user_nofault(ubuf + *sk_offset, &sh, sizeof(sh))) {
2164			ret = 0;
2165			goto out;
2166		}
2167
2168		*sk_offset += sizeof(sh);
2169
2170		if (item_len) {
2171			char __user *up = ubuf + *sk_offset;
2172			/*
2173			 * Copy the item, same behavior as above, but reset the
2174			 * * sk_offset so we copy the full thing again.
2175			 */
2176			if (read_extent_buffer_to_user_nofault(leaf, up,
2177						item_off, item_len)) {
2178				ret = 0;
2179				*sk_offset -= sizeof(sh);
2180				goto out;
2181			}
2182
2183			*sk_offset += item_len;
2184		}
2185		(*num_found)++;
2186
2187		if (ret) /* -EOVERFLOW from above */
2188			goto out;
2189
2190		if (*num_found >= sk->nr_items) {
2191			ret = 1;
2192			goto out;
2193		}
2194	}
2195advance_key:
2196	ret = 0;
2197	test.objectid = sk->max_objectid;
2198	test.type = sk->max_type;
2199	test.offset = sk->max_offset;
2200	if (btrfs_comp_cpu_keys(key, &test) >= 0)
2201		ret = 1;
2202	else if (key->offset < (u64)-1)
2203		key->offset++;
2204	else if (key->type < (u8)-1) {
2205		key->offset = 0;
2206		key->type++;
2207	} else if (key->objectid < (u64)-1) {
2208		key->offset = 0;
2209		key->type = 0;
2210		key->objectid++;
2211	} else
2212		ret = 1;
2213out:
2214	/*
2215	 *  0: all items from this leaf copied, continue with next
2216	 *  1: * more items can be copied, but unused buffer is too small
2217	 *     * all items were found
2218	 *     Either way, it will stops the loop which iterates to the next
2219	 *     leaf
2220	 *  -EOVERFLOW: item was to large for buffer
2221	 *  -EFAULT: could not copy extent buffer back to userspace
2222	 */
2223	return ret;
2224}
2225
2226static noinline int search_ioctl(struct inode *inode,
2227				 struct btrfs_ioctl_search_key *sk,
2228				 size_t *buf_size,
2229				 char __user *ubuf)
2230{
2231	struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2232	struct btrfs_root *root;
2233	struct btrfs_key key;
2234	struct btrfs_path *path;
2235	int ret;
2236	int num_found = 0;
2237	unsigned long sk_offset = 0;
2238
2239	if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2240		*buf_size = sizeof(struct btrfs_ioctl_search_header);
2241		return -EOVERFLOW;
2242	}
2243
2244	path = btrfs_alloc_path();
2245	if (!path)
2246		return -ENOMEM;
2247
2248	if (sk->tree_id == 0) {
2249		/* search the root of the inode that was passed */
2250		root = btrfs_grab_root(BTRFS_I(inode)->root);
2251	} else {
2252		root = btrfs_get_fs_root(info, sk->tree_id, true);
2253		if (IS_ERR(root)) {
2254			btrfs_free_path(path);
2255			return PTR_ERR(root);
2256		}
2257	}
2258
2259	key.objectid = sk->min_objectid;
2260	key.type = sk->min_type;
2261	key.offset = sk->min_offset;
2262
2263	while (1) {
2264		ret = fault_in_pages_writeable(ubuf + sk_offset,
2265					       *buf_size - sk_offset);
2266		if (ret)
2267			break;
2268
2269		ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2270		if (ret != 0) {
2271			if (ret > 0)
2272				ret = 0;
2273			goto err;
2274		}
2275		ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2276				 &sk_offset, &num_found);
2277		btrfs_release_path(path);
2278		if (ret)
2279			break;
2280
2281	}
2282	if (ret > 0)
2283		ret = 0;
2284err:
2285	sk->nr_items = num_found;
2286	btrfs_put_root(root);
2287	btrfs_free_path(path);
2288	return ret;
2289}
2290
2291static noinline int btrfs_ioctl_tree_search(struct file *file,
2292					   void __user *argp)
2293{
2294	struct btrfs_ioctl_search_args __user *uargs;
2295	struct btrfs_ioctl_search_key sk;
2296	struct inode *inode;
2297	int ret;
2298	size_t buf_size;
2299
2300	if (!capable(CAP_SYS_ADMIN))
2301		return -EPERM;
2302
2303	uargs = (struct btrfs_ioctl_search_args __user *)argp;
2304
2305	if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2306		return -EFAULT;
2307
2308	buf_size = sizeof(uargs->buf);
2309
2310	inode = file_inode(file);
2311	ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2312
2313	/*
2314	 * In the origin implementation an overflow is handled by returning a
2315	 * search header with a len of zero, so reset ret.
2316	 */
2317	if (ret == -EOVERFLOW)
2318		ret = 0;
2319
2320	if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2321		ret = -EFAULT;
2322	return ret;
2323}
2324
2325static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2326					       void __user *argp)
2327{
2328	struct btrfs_ioctl_search_args_v2 __user *uarg;
2329	struct btrfs_ioctl_search_args_v2 args;
2330	struct inode *inode;
2331	int ret;
2332	size_t buf_size;
2333	const size_t buf_limit = SZ_16M;
2334
2335	if (!capable(CAP_SYS_ADMIN))
2336		return -EPERM;
2337
2338	/* copy search header and buffer size */
2339	uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2340	if (copy_from_user(&args, uarg, sizeof(args)))
2341		return -EFAULT;
2342
2343	buf_size = args.buf_size;
2344
2345	/* limit result size to 16MB */
2346	if (buf_size > buf_limit)
2347		buf_size = buf_limit;
2348
2349	inode = file_inode(file);
2350	ret = search_ioctl(inode, &args.key, &buf_size,
2351			   (char __user *)(&uarg->buf[0]));
2352	if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2353		ret = -EFAULT;
2354	else if (ret == -EOVERFLOW &&
2355		copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2356		ret = -EFAULT;
2357
2358	return ret;
2359}
2360
2361/*
2362 * Search INODE_REFs to identify path name of 'dirid' directory
2363 * in a 'tree_id' tree. and sets path name to 'name'.
2364 */
2365static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2366				u64 tree_id, u64 dirid, char *name)
2367{
2368	struct btrfs_root *root;
2369	struct btrfs_key key;
2370	char *ptr;
2371	int ret = -1;
2372	int slot;
2373	int len;
2374	int total_len = 0;
2375	struct btrfs_inode_ref *iref;
2376	struct extent_buffer *l;
2377	struct btrfs_path *path;
2378
2379	if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2380		name[0]='\0';
2381		return 0;
2382	}
2383
2384	path = btrfs_alloc_path();
2385	if (!path)
2386		return -ENOMEM;
2387
2388	ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2389
2390	root = btrfs_get_fs_root(info, tree_id, true);
2391	if (IS_ERR(root)) {
2392		ret = PTR_ERR(root);
2393		root = NULL;
2394		goto out;
2395	}
2396
2397	key.objectid = dirid;
2398	key.type = BTRFS_INODE_REF_KEY;
2399	key.offset = (u64)-1;
2400
2401	while (1) {
2402		ret = btrfs_search_backwards(root, &key, path);
2403		if (ret < 0)
2404			goto out;
2405		else if (ret > 0) {
2406			ret = -ENOENT;
2407			goto out;
2408		}
2409
2410		l = path->nodes[0];
2411		slot = path->slots[0];
2412
2413		iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2414		len = btrfs_inode_ref_name_len(l, iref);
2415		ptr -= len + 1;
2416		total_len += len + 1;
2417		if (ptr < name) {
2418			ret = -ENAMETOOLONG;
2419			goto out;
2420		}
2421
2422		*(ptr + len) = '/';
2423		read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2424
2425		if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2426			break;
2427
2428		btrfs_release_path(path);
2429		key.objectid = key.offset;
2430		key.offset = (u64)-1;
2431		dirid = key.objectid;
2432	}
2433	memmove(name, ptr, total_len);
2434	name[total_len] = '\0';
2435	ret = 0;
2436out:
2437	btrfs_put_root(root);
2438	btrfs_free_path(path);
2439	return ret;
2440}
2441
2442static int btrfs_search_path_in_tree_user(struct user_namespace *mnt_userns,
2443				struct inode *inode,
2444				struct btrfs_ioctl_ino_lookup_user_args *args)
2445{
2446	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2447	struct super_block *sb = inode->i_sb;
2448	struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2449	u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2450	u64 dirid = args->dirid;
2451	unsigned long item_off;
2452	unsigned long item_len;
2453	struct btrfs_inode_ref *iref;
2454	struct btrfs_root_ref *rref;
2455	struct btrfs_root *root = NULL;
2456	struct btrfs_path *path;
2457	struct btrfs_key key, key2;
2458	struct extent_buffer *leaf;
2459	struct inode *temp_inode;
2460	char *ptr;
2461	int slot;
2462	int len;
2463	int total_len = 0;
2464	int ret;
2465
2466	path = btrfs_alloc_path();
2467	if (!path)
2468		return -ENOMEM;
2469
2470	/*
2471	 * If the bottom subvolume does not exist directly under upper_limit,
2472	 * construct the path in from the bottom up.
2473	 */
2474	if (dirid != upper_limit.objectid) {
2475		ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2476
2477		root = btrfs_get_fs_root(fs_info, treeid, true);
2478		if (IS_ERR(root)) {
2479			ret = PTR_ERR(root);
2480			goto out;
2481		}
2482
2483		key.objectid = dirid;
2484		key.type = BTRFS_INODE_REF_KEY;
2485		key.offset = (u64)-1;
2486		while (1) {
2487			ret = btrfs_search_backwards(root, &key, path);
2488			if (ret < 0)
2489				goto out_put;
2490			else if (ret > 0) {
2491				ret = -ENOENT;
2492				goto out_put;
2493			}
2494
2495			leaf = path->nodes[0];
2496			slot = path->slots[0];
2497
2498			iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2499			len = btrfs_inode_ref_name_len(leaf, iref);
2500			ptr -= len + 1;
2501			total_len += len + 1;
2502			if (ptr < args->path) {
2503				ret = -ENAMETOOLONG;
2504				goto out_put;
2505			}
2506
2507			*(ptr + len) = '/';
2508			read_extent_buffer(leaf, ptr,
2509					(unsigned long)(iref + 1), len);
2510
2511			/* Check the read+exec permission of this directory */
2512			ret = btrfs_previous_item(root, path, dirid,
2513						  BTRFS_INODE_ITEM_KEY);
2514			if (ret < 0) {
2515				goto out_put;
2516			} else if (ret > 0) {
2517				ret = -ENOENT;
2518				goto out_put;
2519			}
2520
2521			leaf = path->nodes[0];
2522			slot = path->slots[0];
2523			btrfs_item_key_to_cpu(leaf, &key2, slot);
2524			if (key2.objectid != dirid) {
2525				ret = -ENOENT;
2526				goto out_put;
2527			}
2528
2529			temp_inode = btrfs_iget(sb, key2.objectid, root);
2530			if (IS_ERR(temp_inode)) {
2531				ret = PTR_ERR(temp_inode);
2532				goto out_put;
2533			}
2534			ret = inode_permission(mnt_userns, temp_inode,
2535					       MAY_READ | MAY_EXEC);
2536			iput(temp_inode);
2537			if (ret) {
2538				ret = -EACCES;
2539				goto out_put;
2540			}
2541
2542			if (key.offset == upper_limit.objectid)
2543				break;
2544			if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2545				ret = -EACCES;
2546				goto out_put;
2547			}
2548
2549			btrfs_release_path(path);
2550			key.objectid = key.offset;
2551			key.offset = (u64)-1;
2552			dirid = key.objectid;
2553		}
2554
2555		memmove(args->path, ptr, total_len);
2556		args->path[total_len] = '\0';
2557		btrfs_put_root(root);
2558		root = NULL;
2559		btrfs_release_path(path);
2560	}
2561
2562	/* Get the bottom subvolume's name from ROOT_REF */
2563	key.objectid = treeid;
2564	key.type = BTRFS_ROOT_REF_KEY;
2565	key.offset = args->treeid;
2566	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2567	if (ret < 0) {
2568		goto out;
2569	} else if (ret > 0) {
2570		ret = -ENOENT;
2571		goto out;
2572	}
2573
2574	leaf = path->nodes[0];
2575	slot = path->slots[0];
2576	btrfs_item_key_to_cpu(leaf, &key, slot);
2577
2578	item_off = btrfs_item_ptr_offset(leaf, slot);
2579	item_len = btrfs_item_size_nr(leaf, slot);
2580	/* Check if dirid in ROOT_REF corresponds to passed dirid */
2581	rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2582	if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2583		ret = -EINVAL;
2584		goto out;
2585	}
2586
2587	/* Copy subvolume's name */
2588	item_off += sizeof(struct btrfs_root_ref);
2589	item_len -= sizeof(struct btrfs_root_ref);
2590	read_extent_buffer(leaf, args->name, item_off, item_len);
2591	args->name[item_len] = 0;
2592
2593out_put:
2594	btrfs_put_root(root);
2595out:
2596	btrfs_free_path(path);
2597	return ret;
2598}
2599
2600static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2601					   void __user *argp)
2602{
2603	struct btrfs_ioctl_ino_lookup_args *args;
2604	struct inode *inode;
2605	int ret = 0;
2606
2607	args = memdup_user(argp, sizeof(*args));
2608	if (IS_ERR(args))
2609		return PTR_ERR(args);
2610
2611	inode = file_inode(file);
2612
2613	/*
2614	 * Unprivileged query to obtain the containing subvolume root id. The
2615	 * path is reset so it's consistent with btrfs_search_path_in_tree.
2616	 */
2617	if (args->treeid == 0)
2618		args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2619
2620	if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2621		args->name[0] = 0;
2622		goto out;
2623	}
2624
2625	if (!capable(CAP_SYS_ADMIN)) {
2626		ret = -EPERM;
2627		goto out;
2628	}
2629
2630	ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2631					args->treeid, args->objectid,
2632					args->name);
2633
2634out:
2635	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2636		ret = -EFAULT;
2637
2638	kfree(args);
2639	return ret;
2640}
2641
2642/*
2643 * Version of ino_lookup ioctl (unprivileged)
2644 *
2645 * The main differences from ino_lookup ioctl are:
2646 *
2647 *   1. Read + Exec permission will be checked using inode_permission() during
2648 *      path construction. -EACCES will be returned in case of failure.
2649 *   2. Path construction will be stopped at the inode number which corresponds
2650 *      to the fd with which this ioctl is called. If constructed path does not
2651 *      exist under fd's inode, -EACCES will be returned.
2652 *   3. The name of bottom subvolume is also searched and filled.
2653 */
2654static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2655{
2656	struct btrfs_ioctl_ino_lookup_user_args *args;
2657	struct inode *inode;
2658	int ret;
2659
2660	args = memdup_user(argp, sizeof(*args));
2661	if (IS_ERR(args))
2662		return PTR_ERR(args);
2663
2664	inode = file_inode(file);
2665
2666	if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2667	    BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2668		/*
2669		 * The subvolume does not exist under fd with which this is
2670		 * called
2671		 */
2672		kfree(args);
2673		return -EACCES;
2674	}
2675
2676	ret = btrfs_search_path_in_tree_user(file_mnt_user_ns(file), inode, args);
2677
2678	if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2679		ret = -EFAULT;
2680
2681	kfree(args);
2682	return ret;
2683}
2684
2685/* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2686static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2687{
2688	struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2689	struct btrfs_fs_info *fs_info;
2690	struct btrfs_root *root;
2691	struct btrfs_path *path;
2692	struct btrfs_key key;
2693	struct btrfs_root_item *root_item;
2694	struct btrfs_root_ref *rref;
2695	struct extent_buffer *leaf;
2696	unsigned long item_off;
2697	unsigned long item_len;
2698	struct inode *inode;
2699	int slot;
2700	int ret = 0;
2701
2702	path = btrfs_alloc_path();
2703	if (!path)
2704		return -ENOMEM;
2705
2706	subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2707	if (!subvol_info) {
2708		btrfs_free_path(path);
2709		return -ENOMEM;
2710	}
2711
2712	inode = file_inode(file);
2713	fs_info = BTRFS_I(inode)->root->fs_info;
2714
2715	/* Get root_item of inode's subvolume */
2716	key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2717	root = btrfs_get_fs_root(fs_info, key.objectid, true);
2718	if (IS_ERR(root)) {
2719		ret = PTR_ERR(root);
2720		goto out_free;
2721	}
2722	root_item = &root->root_item;
2723
2724	subvol_info->treeid = key.objectid;
2725
2726	subvol_info->generation = btrfs_root_generation(root_item);
2727	subvol_info->flags = btrfs_root_flags(root_item);
2728
2729	memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2730	memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2731						    BTRFS_UUID_SIZE);
2732	memcpy(subvol_info->received_uuid, root_item->received_uuid,
2733						    BTRFS_UUID_SIZE);
2734
2735	subvol_info->ctransid = btrfs_root_ctransid(root_item);
2736	subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2737	subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2738
2739	subvol_info->otransid = btrfs_root_otransid(root_item);
2740	subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2741	subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2742
2743	subvol_info->stransid = btrfs_root_stransid(root_item);
2744	subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2745	subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2746
2747	subvol_info->rtransid = btrfs_root_rtransid(root_item);
2748	subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2749	subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2750
2751	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2752		/* Search root tree for ROOT_BACKREF of this subvolume */
2753		key.type = BTRFS_ROOT_BACKREF_KEY;
2754		key.offset = 0;
2755		ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2756		if (ret < 0) {
2757			goto out;
2758		} else if (path->slots[0] >=
2759			   btrfs_header_nritems(path->nodes[0])) {
2760			ret = btrfs_next_leaf(fs_info->tree_root, path);
2761			if (ret < 0) {
2762				goto out;
2763			} else if (ret > 0) {
2764				ret = -EUCLEAN;
2765				goto out;
2766			}
2767		}
2768
2769		leaf = path->nodes[0];
2770		slot = path->slots[0];
2771		btrfs_item_key_to_cpu(leaf, &key, slot);
2772		if (key.objectid == subvol_info->treeid &&
2773		    key.type == BTRFS_ROOT_BACKREF_KEY) {
2774			subvol_info->parent_id = key.offset;
2775
2776			rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2777			subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2778
2779			item_off = btrfs_item_ptr_offset(leaf, slot)
2780					+ sizeof(struct btrfs_root_ref);
2781			item_len = btrfs_item_size_nr(leaf, slot)
2782					- sizeof(struct btrfs_root_ref);
2783			read_extent_buffer(leaf, subvol_info->name,
2784					   item_off, item_len);
2785		} else {
2786			ret = -ENOENT;
2787			goto out;
2788		}
2789	}
2790
2791	if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2792		ret = -EFAULT;
2793
2794out:
2795	btrfs_put_root(root);
2796out_free:
2797	btrfs_free_path(path);
2798	kfree(subvol_info);
2799	return ret;
2800}
2801
2802/*
2803 * Return ROOT_REF information of the subvolume containing this inode
2804 * except the subvolume name.
2805 */
2806static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2807{
2808	struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2809	struct btrfs_root_ref *rref;
2810	struct btrfs_root *root;
2811	struct btrfs_path *path;
2812	struct btrfs_key key;
2813	struct extent_buffer *leaf;
2814	struct inode *inode;
2815	u64 objectid;
2816	int slot;
2817	int ret;
2818	u8 found;
2819
2820	path = btrfs_alloc_path();
2821	if (!path)
2822		return -ENOMEM;
2823
2824	rootrefs = memdup_user(argp, sizeof(*rootrefs));
2825	if (IS_ERR(rootrefs)) {
2826		btrfs_free_path(path);
2827		return PTR_ERR(rootrefs);
2828	}
2829
2830	inode = file_inode(file);
2831	root = BTRFS_I(inode)->root->fs_info->tree_root;
2832	objectid = BTRFS_I(inode)->root->root_key.objectid;
2833
2834	key.objectid = objectid;
2835	key.type = BTRFS_ROOT_REF_KEY;
2836	key.offset = rootrefs->min_treeid;
2837	found = 0;
2838
2839	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2840	if (ret < 0) {
2841		goto out;
2842	} else if (path->slots[0] >=
2843		   btrfs_header_nritems(path->nodes[0])) {
2844		ret = btrfs_next_leaf(root, path);
2845		if (ret < 0) {
2846			goto out;
2847		} else if (ret > 0) {
2848			ret = -EUCLEAN;
2849			goto out;
2850		}
2851	}
2852	while (1) {
2853		leaf = path->nodes[0];
2854		slot = path->slots[0];
2855
2856		btrfs_item_key_to_cpu(leaf, &key, slot);
2857		if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2858			ret = 0;
2859			goto out;
2860		}
2861
2862		if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2863			ret = -EOVERFLOW;
2864			goto out;
2865		}
2866
2867		rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2868		rootrefs->rootref[found].treeid = key.offset;
2869		rootrefs->rootref[found].dirid =
2870				  btrfs_root_ref_dirid(leaf, rref);
2871		found++;
2872
2873		ret = btrfs_next_item(root, path);
2874		if (ret < 0) {
2875			goto out;
2876		} else if (ret > 0) {
2877			ret = -EUCLEAN;
2878			goto out;
2879		}
2880	}
2881
2882out:
2883	if (!ret || ret == -EOVERFLOW) {
2884		rootrefs->num_items = found;
2885		/* update min_treeid for next search */
2886		if (found)
2887			rootrefs->min_treeid =
2888				rootrefs->rootref[found - 1].treeid + 1;
2889		if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2890			ret = -EFAULT;
2891	}
2892
2893	kfree(rootrefs);
2894	btrfs_free_path(path);
2895
2896	return ret;
2897}
2898
2899static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2900					     void __user *arg,
2901					     bool destroy_v2)
2902{
2903	struct dentry *parent = file->f_path.dentry;
2904	struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2905	struct dentry *dentry;
2906	struct inode *dir = d_inode(parent);
2907	struct inode *inode;
2908	struct btrfs_root *root = BTRFS_I(dir)->root;
2909	struct btrfs_root *dest = NULL;
2910	struct btrfs_ioctl_vol_args *vol_args = NULL;
2911	struct btrfs_ioctl_vol_args_v2 *vol_args2 = NULL;
2912	struct user_namespace *mnt_userns = file_mnt_user_ns(file);
2913	char *subvol_name, *subvol_name_ptr = NULL;
2914	int subvol_namelen;
2915	int err = 0;
2916	bool destroy_parent = false;
2917
2918	if (destroy_v2) {
2919		vol_args2 = memdup_user(arg, sizeof(*vol_args2));
2920		if (IS_ERR(vol_args2))
2921			return PTR_ERR(vol_args2);
2922
2923		if (vol_args2->flags & ~BTRFS_SUBVOL_DELETE_ARGS_MASK) {
2924			err = -EOPNOTSUPP;
2925			goto out;
2926		}
2927
2928		/*
2929		 * If SPEC_BY_ID is not set, we are looking for the subvolume by
2930		 * name, same as v1 currently does.
2931		 */
2932		if (!(vol_args2->flags & BTRFS_SUBVOL_SPEC_BY_ID)) {
2933			vol_args2->name[BTRFS_SUBVOL_NAME_MAX] = 0;
2934			subvol_name = vol_args2->name;
2935
2936			err = mnt_want_write_file(file);
2937			if (err)
2938				goto out;
2939		} else {
2940			struct inode *old_dir;
2941
2942			if (vol_args2->subvolid < BTRFS_FIRST_FREE_OBJECTID) {
2943				err = -EINVAL;
2944				goto out;
2945			}
2946
2947			err = mnt_want_write_file(file);
2948			if (err)
2949				goto out;
2950
2951			dentry = btrfs_get_dentry(fs_info->sb,
2952					BTRFS_FIRST_FREE_OBJECTID,
2953					vol_args2->subvolid, 0, 0);
2954			if (IS_ERR(dentry)) {
2955				err = PTR_ERR(dentry);
2956				goto out_drop_write;
2957			}
2958
2959			/*
2960			 * Change the default parent since the subvolume being
2961			 * deleted can be outside of the current mount point.
2962			 */
2963			parent = btrfs_get_parent(dentry);
2964
2965			/*
2966			 * At this point dentry->d_name can point to '/' if the
2967			 * subvolume we want to destroy is outsite of the
2968			 * current mount point, so we need to release the
2969			 * current dentry and execute the lookup to return a new
2970			 * one with ->d_name pointing to the
2971			 * <mount point>/subvol_name.
2972			 */
2973			dput(dentry);
2974			if (IS_ERR(parent)) {
2975				err = PTR_ERR(parent);
2976				goto out_drop_write;
2977			}
2978			old_dir = dir;
2979			dir = d_inode(parent);
2980
2981			/*
2982			 * If v2 was used with SPEC_BY_ID, a new parent was
2983			 * allocated since the subvolume can be outside of the
2984			 * current mount point. Later on we need to release this
2985			 * new parent dentry.
2986			 */
2987			destroy_parent = true;
2988
2989			/*
2990			 * On idmapped mounts, deletion via subvolid is
2991			 * restricted to subvolumes that are immediate
2992			 * ancestors of the inode referenced by the file
2993			 * descriptor in the ioctl. Otherwise the idmapping
2994			 * could potentially be abused to delete subvolumes
2995			 * anywhere in the filesystem the user wouldn't be able
2996			 * to delete without an idmapped mount.
2997			 */
2998			if (old_dir != dir && mnt_userns != &init_user_ns) {
2999				err = -EOPNOTSUPP;
3000				goto free_parent;
3001			}
3002
3003			subvol_name_ptr = btrfs_get_subvol_name_from_objectid(
3004						fs_info, vol_args2->subvolid);
3005			if (IS_ERR(subvol_name_ptr)) {
3006				err = PTR_ERR(subvol_name_ptr);
3007				goto free_parent;
3008			}
3009			/* subvol_name_ptr is already nul terminated */
3010			subvol_name = (char *)kbasename(subvol_name_ptr);
3011		}
3012	} else {
3013		vol_args = memdup_user(arg, sizeof(*vol_args));
3014		if (IS_ERR(vol_args))
3015			return PTR_ERR(vol_args);
3016
3017		vol_args->name[BTRFS_PATH_NAME_MAX] = 0;
3018		subvol_name = vol_args->name;
3019
3020		err = mnt_want_write_file(file);
3021		if (err)
3022			goto out;
3023	}
3024
3025	subvol_namelen = strlen(subvol_name);
3026
3027	if (strchr(subvol_name, '/') ||
3028	    strncmp(subvol_name, "..", subvol_namelen) == 0) {
3029		err = -EINVAL;
3030		goto free_subvol_name;
3031	}
3032
3033	if (!S_ISDIR(dir->i_mode)) {
3034		err = -ENOTDIR;
3035		goto free_subvol_name;
3036	}
3037
3038	err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
3039	if (err == -EINTR)
3040		goto free_subvol_name;
3041	dentry = lookup_one(mnt_userns, subvol_name, parent, subvol_namelen);
3042	if (IS_ERR(dentry)) {
3043		err = PTR_ERR(dentry);
3044		goto out_unlock_dir;
3045	}
3046
3047	if (d_really_is_negative(dentry)) {
3048		err = -ENOENT;
3049		goto out_dput;
3050	}
3051
3052	inode = d_inode(dentry);
3053	dest = BTRFS_I(inode)->root;
3054	if (!capable(CAP_SYS_ADMIN)) {
3055		/*
3056		 * Regular user.  Only allow this with a special mount
3057		 * option, when the user has write+exec access to the
3058		 * subvol root, and when rmdir(2) would have been
3059		 * allowed.
3060		 *
3061		 * Note that this is _not_ check that the subvol is
3062		 * empty or doesn't contain data that we wouldn't
3063		 * otherwise be able to delete.
3064		 *
3065		 * Users who want to delete empty subvols should try
3066		 * rmdir(2).
3067		 */
3068		err = -EPERM;
3069		if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
3070			goto out_dput;
3071
3072		/*
3073		 * Do not allow deletion if the parent dir is the same
3074		 * as the dir to be deleted.  That means the ioctl
3075		 * must be called on the dentry referencing the root
3076		 * of the subvol, not a random directory contained
3077		 * within it.
3078		 */
3079		err = -EINVAL;
3080		if (root == dest)
3081			goto out_dput;
3082
3083		err = inode_permission(mnt_userns, inode, MAY_WRITE | MAY_EXEC);
3084		if (err)
3085			goto out_dput;
3086	}
3087
3088	/* check if subvolume may be deleted by a user */
3089	err = btrfs_may_delete(mnt_userns, dir, dentry, 1);
3090	if (err)
3091		goto out_dput;
3092
3093	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
3094		err = -EINVAL;
3095		goto out_dput;
3096	}
3097
3098	btrfs_inode_lock(inode, 0);
3099	err = btrfs_delete_subvolume(dir, dentry);
3100	btrfs_inode_unlock(inode, 0);
3101	if (!err) {
3102		fsnotify_rmdir(dir, dentry);
3103		d_delete(dentry);
3104	}
3105
3106out_dput:
3107	dput(dentry);
3108out_unlock_dir:
3109	btrfs_inode_unlock(dir, 0);
3110free_subvol_name:
3111	kfree(subvol_name_ptr);
3112free_parent:
3113	if (destroy_parent)
3114		dput(parent);
3115out_drop_write:
3116	mnt_drop_write_file(file);
3117out:
3118	kfree(vol_args2);
3119	kfree(vol_args);
3120	return err;
3121}
3122
3123static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
3124{
3125	struct inode *inode = file_inode(file);
3126	struct btrfs_root *root = BTRFS_I(inode)->root;
3127	struct btrfs_ioctl_defrag_range_args range = {0};
3128	int ret;
3129
3130	ret = mnt_want_write_file(file);
3131	if (ret)
3132		return ret;
3133
3134	if (btrfs_root_readonly(root)) {
3135		ret = -EROFS;
3136		goto out;
3137	}
3138
3139	/* Subpage defrag will be supported in later commits */
3140	if (root->fs_info->sectorsize < PAGE_SIZE) {
3141		ret = -ENOTTY;
3142		goto out;
3143	}
3144
3145	switch (inode->i_mode & S_IFMT) {
3146	case S_IFDIR:
3147		if (!capable(CAP_SYS_ADMIN)) {
3148			ret = -EPERM;
3149			goto out;
3150		}
3151		ret = btrfs_defrag_root(root);
3152		break;
3153	case S_IFREG:
3154		/*
3155		 * Note that this does not check the file descriptor for write
3156		 * access. This prevents defragmenting executables that are
3157		 * running and allows defrag on files open in read-only mode.
3158		 */
3159		if (!capable(CAP_SYS_ADMIN) &&
3160		    inode_permission(&init_user_ns, inode, MAY_WRITE)) {
3161			ret = -EPERM;
3162			goto out;
3163		}
3164
3165		if (argp) {
3166			if (copy_from_user(&range, argp, sizeof(range))) {
3167				ret = -EFAULT;
3168				goto out;
3169			}
3170			/* compression requires us to start the IO */
3171			if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
3172				range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
3173				range.extent_thresh = (u32)-1;
3174			}
3175		} else {
3176			/* the rest are all set to zero by kzalloc */
3177			range.len = (u64)-1;
3178		}
3179		ret = btrfs_defrag_file(file_inode(file), file,
3180					&range, BTRFS_OLDEST_GENERATION, 0);
3181		if (ret > 0)
3182			ret = 0;
3183		break;
3184	default:
3185		ret = -EINVAL;
3186	}
3187out:
3188	mnt_drop_write_file(file);
3189	return ret;
3190}
3191
3192static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
3193{
3194	struct btrfs_ioctl_vol_args *vol_args;
3195	int ret;
3196
3197	if (!capable(CAP_SYS_ADMIN))
3198		return -EPERM;
3199
3200	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_ADD))
3201		return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3202
3203	vol_args = memdup_user(arg, sizeof(*vol_args));
3204	if (IS_ERR(vol_args)) {
3205		ret = PTR_ERR(vol_args);
3206		goto out;
3207	}
3208
3209	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3210	ret = btrfs_init_new_device(fs_info, vol_args->name);
3211
3212	if (!ret)
3213		btrfs_info(fs_info, "disk added %s", vol_args->name);
3214
3215	kfree(vol_args);
3216out:
3217	btrfs_exclop_finish(fs_info);
3218	return ret;
3219}
3220
3221static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3222{
3223	struct inode *inode = file_inode(file);
3224	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3225	struct btrfs_ioctl_vol_args_v2 *vol_args;
3226	int ret;
3227	bool cancel = false;
3228
3229	if (!capable(CAP_SYS_ADMIN))
3230		return -EPERM;
3231
3232	ret = mnt_want_write_file(file);
3233	if (ret)
3234		return ret;
3235
3236	vol_args = memdup_user(arg, sizeof(*vol_args));
3237	if (IS_ERR(vol_args)) {
3238		ret = PTR_ERR(vol_args);
3239		goto err_drop;
3240	}
3241
3242	if (vol_args->flags & ~BTRFS_DEVICE_REMOVE_ARGS_MASK) {
3243		ret = -EOPNOTSUPP;
3244		goto out;
3245	}
3246	vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3247	if (!(vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) &&
3248	    strcmp("cancel", vol_args->name) == 0)
3249		cancel = true;
3250
3251	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
3252					   cancel);
3253	if (ret)
3254		goto out;
3255	/* Exclusive operation is now claimed */
3256
3257	if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3258		ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3259	else
3260		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3261
3262	btrfs_exclop_finish(fs_info);
3263
3264	if (!ret) {
3265		if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3266			btrfs_info(fs_info, "device deleted: id %llu",
3267					vol_args->devid);
3268		else
3269			btrfs_info(fs_info, "device deleted: %s",
3270					vol_args->name);
3271	}
3272out:
3273	kfree(vol_args);
3274err_drop:
3275	mnt_drop_write_file(file);
3276	return ret;
3277}
3278
3279static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3280{
3281	struct inode *inode = file_inode(file);
3282	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3283	struct btrfs_ioctl_vol_args *vol_args;
3284	int ret;
3285	bool cancel;
3286
3287	if (!capable(CAP_SYS_ADMIN))
3288		return -EPERM;
3289
3290	ret = mnt_want_write_file(file);
3291	if (ret)
3292		return ret;
3293
3294	vol_args = memdup_user(arg, sizeof(*vol_args));
3295	if (IS_ERR(vol_args)) {
3296		ret = PTR_ERR(vol_args);
3297		goto out_drop_write;
3298	}
3299	vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3300	cancel = (strcmp("cancel", vol_args->name) == 0);
3301
3302	ret = exclop_start_or_cancel_reloc(fs_info, BTRFS_EXCLOP_DEV_REMOVE,
3303					   cancel);
3304	if (ret == 0) {
3305		ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3306		if (!ret)
3307			btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3308		btrfs_exclop_finish(fs_info);
3309	}
3310
3311	kfree(vol_args);
3312out_drop_write:
3313	mnt_drop_write_file(file);
3314
3315	return ret;
3316}
3317
3318static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3319				void __user *arg)
3320{
3321	struct btrfs_ioctl_fs_info_args *fi_args;
3322	struct btrfs_device *device;
3323	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3324	u64 flags_in;
3325	int ret = 0;
3326
3327	fi_args = memdup_user(arg, sizeof(*fi_args));
3328	if (IS_ERR(fi_args))
3329		return PTR_ERR(fi_args);
3330
3331	flags_in = fi_args->flags;
3332	memset(fi_args, 0, sizeof(*fi_args));
3333
3334	rcu_read_lock();
3335	fi_args->num_devices = fs_devices->num_devices;
3336
3337	list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3338		if (device->devid > fi_args->max_id)
3339			fi_args->max_id = device->devid;
3340	}
3341	rcu_read_unlock();
3342
3343	memcpy(&fi_args->fsid, fs_devices->fsid, sizeof(fi_args->fsid));
3344	fi_args->nodesize = fs_info->nodesize;
3345	fi_args->sectorsize = fs_info->sectorsize;
3346	fi_args->clone_alignment = fs_info->sectorsize;
3347
3348	if (flags_in & BTRFS_FS_INFO_FLAG_CSUM_INFO) {
3349		fi_args->csum_type = btrfs_super_csum_type(fs_info->super_copy);
3350		fi_args->csum_size = btrfs_super_csum_size(fs_info->super_copy);
3351		fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
3352	}
3353
3354	if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
3355		fi_args->generation = fs_info->generation;
3356		fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
3357	}
3358
3359	if (flags_in & BTRFS_FS_INFO_FLAG_METADATA_UUID) {
3360		memcpy(&fi_args->metadata_uuid, fs_devices->metadata_uuid,
3361		       sizeof(fi_args->metadata_uuid));
3362		fi_args->flags |= BTRFS_FS_INFO_FLAG_METADATA_UUID;
3363	}
3364
3365	if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3366		ret = -EFAULT;
3367
3368	kfree(fi_args);
3369	return ret;
3370}
3371
3372static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3373				 void __user *arg)
3374{
3375	struct btrfs_ioctl_dev_info_args *di_args;
3376	struct btrfs_device *dev;
3377	int ret = 0;
3378	char *s_uuid = NULL;
3379
3380	di_args = memdup_user(arg, sizeof(*di_args));
3381	if (IS_ERR(di_args))
3382		return PTR_ERR(di_args);
3383
3384	if (!btrfs_is_empty_uuid(di_args->uuid))
3385		s_uuid = di_args->uuid;
3386
3387	rcu_read_lock();
3388	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
3389				NULL);
3390
3391	if (!dev) {
3392		ret = -ENODEV;
3393		goto out;
3394	}
3395
3396	di_args->devid = dev->devid;
3397	di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3398	di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3399	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3400	if (dev->name) {
3401		strncpy(di_args->path, rcu_str_deref(dev->name),
3402				sizeof(di_args->path) - 1);
3403		di_args->path[sizeof(di_args->path) - 1] = 0;
3404	} else {
3405		di_args->path[0] = '\0';
3406	}
3407
3408out:
3409	rcu_read_unlock();
3410	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3411		ret = -EFAULT;
3412
3413	kfree(di_args);
3414	return ret;
3415}
3416
3417static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
3418{
3419	struct inode *inode = file_inode(file);
3420	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3421	struct btrfs_root *root = BTRFS_I(inode)->root;
3422	struct btrfs_root *new_root;
3423	struct btrfs_dir_item *di;
3424	struct btrfs_trans_handle *trans;
3425	struct btrfs_path *path = NULL;
3426	struct btrfs_disk_key disk_key;
3427	u64 objectid = 0;
3428	u64 dir_id;
3429	int ret;
3430
3431	if (!capable(CAP_SYS_ADMIN))
3432		return -EPERM;
3433
3434	ret = mnt_want_write_file(file);
3435	if (ret)
3436		return ret;
3437
3438	if (copy_from_user(&objectid, argp, sizeof(objectid))) {
3439		ret = -EFAULT;
3440		goto out;
3441	}
3442
3443	if (!objectid)
3444		objectid = BTRFS_FS_TREE_OBJECTID;
3445
3446	new_root = btrfs_get_fs_root(fs_info, objectid, true);
3447	if (IS_ERR(new_root)) {
3448		ret = PTR_ERR(new_root);
3449		goto out;
3450	}
3451	if (!is_fstree(new_root->root_key.objectid)) {
3452		ret = -ENOENT;
3453		goto out_free;
3454	}
3455
3456	path = btrfs_alloc_path();
3457	if (!path) {
3458		ret = -ENOMEM;
3459		goto out_free;
3460	}
3461
3462	trans = btrfs_start_transaction(root, 1);
3463	if (IS_ERR(trans)) {
3464		ret = PTR_ERR(trans);
3465		goto out_free;
3466	}
3467
3468	dir_id = btrfs_super_root_dir(fs_info->super_copy);
3469	di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
3470				   dir_id, "default", 7, 1);
3471	if (IS_ERR_OR_NULL(di)) {
3472		btrfs_release_path(path);
3473		btrfs_end_transaction(trans);
3474		btrfs_err(fs_info,
3475			  "Umm, you don't have the default diritem, this isn't going to work");
3476		ret = -ENOENT;
3477		goto out_free;
3478	}
3479
3480	btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
3481	btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
3482	btrfs_mark_buffer_dirty(path->nodes[0]);
3483	btrfs_release_path(path);
3484
3485	btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
3486	btrfs_end_transaction(trans);
3487out_free:
3488	btrfs_put_root(new_root);
3489	btrfs_free_path(path);
3490out:
3491	mnt_drop_write_file(file);
3492	return ret;
3493}
3494
3495static void get_block_group_info(struct list_head *groups_list,
3496				 struct btrfs_ioctl_space_info *space)
3497{
3498	struct btrfs_block_group *block_group;
3499
3500	space->total_bytes = 0;
3501	space->used_bytes = 0;
3502	space->flags = 0;
3503	list_for_each_entry(block_group, groups_list, list) {
3504		space->flags = block_group->flags;
3505		space->total_bytes += block_group->length;
3506		space->used_bytes += block_group->used;
3507	}
3508}
3509
3510static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
3511				   void __user *arg)
3512{
3513	struct btrfs_ioctl_space_args space_args;
3514	struct btrfs_ioctl_space_info space;
3515	struct btrfs_ioctl_space_info *dest;
3516	struct btrfs_ioctl_space_info *dest_orig;
3517	struct btrfs_ioctl_space_info __user *user_dest;
3518	struct btrfs_space_info *info;
3519	static const u64 types[] = {
3520		BTRFS_BLOCK_GROUP_DATA,
3521		BTRFS_BLOCK_GROUP_SYSTEM,
3522		BTRFS_BLOCK_GROUP_METADATA,
3523		BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
3524	};
3525	int num_types = 4;
3526	int alloc_size;
3527	int ret = 0;
3528	u64 slot_count = 0;
3529	int i, c;
3530
3531	if (copy_from_user(&space_args,
3532			   (struct btrfs_ioctl_space_args __user *)arg,
3533			   sizeof(space_args)))
3534		return -EFAULT;
3535
3536	for (i = 0; i < num_types; i++) {
3537		struct btrfs_space_info *tmp;
3538
3539		info = NULL;
3540		list_for_each_entry(tmp, &fs_info->space_info, list) {
3541			if (tmp->flags == types[i]) {
3542				info = tmp;
3543				break;
3544			}
3545		}
3546
3547		if (!info)
3548			continue;
3549
3550		down_read(&info->groups_sem);
3551		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3552			if (!list_empty(&info->block_groups[c]))
3553				slot_count++;
3554		}
3555		up_read(&info->groups_sem);
3556	}
3557
3558	/*
3559	 * Global block reserve, exported as a space_info
3560	 */
3561	slot_count++;
3562
3563	/* space_slots == 0 means they are asking for a count */
3564	if (space_args.space_slots == 0) {
3565		space_args.total_spaces = slot_count;
3566		goto out;
3567	}
3568
3569	slot_count = min_t(u64, space_args.space_slots, slot_count);
3570
3571	alloc_size = sizeof(*dest) * slot_count;
3572
3573	/* we generally have at most 6 or so space infos, one for each raid
3574	 * level.  So, a whole page should be more than enough for everyone
3575	 */
3576	if (alloc_size > PAGE_SIZE)
3577		return -ENOMEM;
3578
3579	space_args.total_spaces = 0;
3580	dest = kmalloc(alloc_size, GFP_KERNEL);
3581	if (!dest)
3582		return -ENOMEM;
3583	dest_orig = dest;
3584
3585	/* now we have a buffer to copy into */
3586	for (i = 0; i < num_types; i++) {
3587		struct btrfs_space_info *tmp;
3588
3589		if (!slot_count)
3590			break;
3591
3592		info = NULL;
3593		list_for_each_entry(tmp, &fs_info->space_info, list) {
3594			if (tmp->flags == types[i]) {
3595				info = tmp;
3596				break;
3597			}
3598		}
3599
3600		if (!info)
3601			continue;
3602		down_read(&info->groups_sem);
3603		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
3604			if (!list_empty(&info->block_groups[c])) {
3605				get_block_group_info(&info->block_groups[c],
3606						     &space);
3607				memcpy(dest, &space, sizeof(space));
3608				dest++;
3609				space_args.total_spaces++;
3610				slot_count--;
3611			}
3612			if (!slot_count)
3613				break;
3614		}
3615		up_read(&info->groups_sem);
3616	}
3617
3618	/*
3619	 * Add global block reserve
3620	 */
3621	if (slot_count) {
3622		struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
3623
3624		spin_lock(&block_rsv->lock);
3625		space.total_bytes = block_rsv->size;
3626		space.used_bytes = block_rsv->size - block_rsv->reserved;
3627		spin_unlock(&block_rsv->lock);
3628		space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
3629		memcpy(dest, &space, sizeof(space));
3630		space_args.total_spaces++;
3631	}
3632
3633	user_dest = (struct btrfs_ioctl_space_info __user *)
3634		(arg + sizeof(struct btrfs_ioctl_space_args));
3635
3636	if (copy_to_user(user_dest, dest_orig, alloc_size))
3637		ret = -EFAULT;
3638
3639	kfree(dest_orig);
3640out:
3641	if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
3642		ret = -EFAULT;
3643
3644	return ret;
3645}
3646
3647static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
3648					    void __user *argp)
3649{
3650	struct btrfs_trans_handle *trans;
3651	u64 transid;
3652	int ret;
3653
3654	trans = btrfs_attach_transaction_barrier(root);
3655	if (IS_ERR(trans)) {
3656		if (PTR_ERR(trans) != -ENOENT)
3657			return PTR_ERR(trans);
3658
3659		/* No running transaction, don't bother */
3660		transid = root->fs_info->last_trans_committed;
3661		goto out;
3662	}
3663	transid = trans->transid;
3664	ret = btrfs_commit_transaction_async(trans);
3665	if (ret) {
3666		btrfs_end_transaction(trans);
3667		return ret;
3668	}
3669out:
3670	if (argp)
3671		if (copy_to_user(argp, &transid, sizeof(transid)))
3672			return -EFAULT;
3673	return 0;
3674}
3675
3676static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
3677					   void __user *argp)
3678{
3679	u64 transid;
3680
3681	if (argp) {
3682		if (copy_from_user(&transid, argp, sizeof(transid)))
3683			return -EFAULT;
3684	} else {
3685		transid = 0;  /* current trans */
3686	}
3687	return btrfs_wait_for_commit(fs_info, transid);
3688}
3689
3690static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
3691{
3692	struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
3693	struct btrfs_ioctl_scrub_args *sa;
3694	int ret;
3695
3696	if (!capable(CAP_SYS_ADMIN))
3697		return -EPERM;
3698
3699	sa = memdup_user(arg, sizeof(*sa));
3700	if (IS_ERR(sa))
3701		return PTR_ERR(sa);
3702
3703	if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
3704		ret = mnt_want_write_file(file);
3705		if (ret)
3706			goto out;
3707	}
3708
3709	ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
3710			      &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
3711			      0);
3712
3713	/*
3714	 * Copy scrub args to user space even if btrfs_scrub_dev() returned an
3715	 * error. This is important as it allows user space to know how much
3716	 * progress scrub has done. For example, if scrub is canceled we get
3717	 * -ECANCELED from btrfs_scrub_dev() and return that error back to user
3718	 * space. Later user space can inspect the progress from the structure
3719	 * btrfs_ioctl_scrub_args and resume scrub from where it left off
3720	 * previously (btrfs-progs does this).
3721	 * If we fail to copy the btrfs_ioctl_scrub_args structure to user space
3722	 * then return -EFAULT to signal the structure was not copied or it may
3723	 * be corrupt and unreliable due to a partial copy.
3724	 */
3725	if (copy_to_user(arg, sa, sizeof(*sa)))
3726		ret = -EFAULT;
3727
3728	if (!(sa->flags & BTRFS_SCRUB_READONLY))
3729		mnt_drop_write_file(file);
3730out:
3731	kfree(sa);
3732	return ret;
3733}
3734
3735static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
3736{
3737	if (!capable(CAP_SYS_ADMIN))
3738		return -EPERM;
3739
3740	return btrfs_scrub_cancel(fs_info);
3741}
3742
3743static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
3744				       void __user *arg)
3745{
3746	struct btrfs_ioctl_scrub_args *sa;
3747	int ret;
3748
3749	if (!capable(CAP_SYS_ADMIN))
3750		return -EPERM;
3751
3752	sa = memdup_user(arg, sizeof(*sa));
3753	if (IS_ERR(sa))
3754		return PTR_ERR(sa);
3755
3756	ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
3757
3758	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3759		ret = -EFAULT;
3760
3761	kfree(sa);
3762	return ret;
3763}
3764
3765static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
3766				      void __user *arg)
3767{
3768	struct btrfs_ioctl_get_dev_stats *sa;
3769	int ret;
3770
3771	sa = memdup_user(arg, sizeof(*sa));
3772	if (IS_ERR(sa))
3773		return PTR_ERR(sa);
3774
3775	if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
3776		kfree(sa);
3777		return -EPERM;
3778	}
3779
3780	ret = btrfs_get_dev_stats(fs_info, sa);
3781
3782	if (ret == 0 && copy_to_user(arg, sa, sizeof(*sa)))
3783		ret = -EFAULT;
3784
3785	kfree(sa);
3786	return ret;
3787}
3788
3789static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
3790				    void __user *arg)
3791{
3792	struct btrfs_ioctl_dev_replace_args *p;
3793	int ret;
3794
3795	if (!capable(CAP_SYS_ADMIN))
3796		return -EPERM;
3797
3798	p = memdup_user(arg, sizeof(*p));
3799	if (IS_ERR(p))
3800		return PTR_ERR(p);
3801
3802	switch (p->cmd) {
3803	case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
3804		if (sb_rdonly(fs_info->sb)) {
3805			ret = -EROFS;
3806			goto out;
3807		}
3808		if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_DEV_REPLACE)) {
3809			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3810		} else {
3811			ret = btrfs_dev_replace_by_ioctl(fs_info, p);
3812			btrfs_exclop_finish(fs_info);
3813		}
3814		break;
3815	case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
3816		btrfs_dev_replace_status(fs_info, p);
3817		ret = 0;
3818		break;
3819	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
3820		p->result = btrfs_dev_replace_cancel(fs_info);
3821		ret = 0;
3822		break;
3823	default:
3824		ret = -EINVAL;
3825		break;
3826	}
3827
3828	if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p)))
3829		ret = -EFAULT;
3830out:
3831	kfree(p);
3832	return ret;
3833}
3834
3835static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
3836{
3837	int ret = 0;
3838	int i;
3839	u64 rel_ptr;
3840	int size;
3841	struct btrfs_ioctl_ino_path_args *ipa = NULL;
3842	struct inode_fs_paths *ipath = NULL;
3843	struct btrfs_path *path;
3844
3845	if (!capable(CAP_DAC_READ_SEARCH))
3846		return -EPERM;
3847
3848	path = btrfs_alloc_path();
3849	if (!path) {
3850		ret = -ENOMEM;
3851		goto out;
3852	}
3853
3854	ipa = memdup_user(arg, sizeof(*ipa));
3855	if (IS_ERR(ipa)) {
3856		ret = PTR_ERR(ipa);
3857		ipa = NULL;
3858		goto out;
3859	}
3860
3861	size = min_t(u32, ipa->size, 4096);
3862	ipath = init_ipath(size, root, path);
3863	if (IS_ERR(ipath)) {
3864		ret = PTR_ERR(ipath);
3865		ipath = NULL;
3866		goto out;
3867	}
3868
3869	ret = paths_from_inode(ipa->inum, ipath);
3870	if (ret < 0)
3871		goto out;
3872
3873	for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
3874		rel_ptr = ipath->fspath->val[i] -
3875			  (u64)(unsigned long)ipath->fspath->val;
3876		ipath->fspath->val[i] = rel_ptr;
3877	}
3878
3879	ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
3880			   ipath->fspath, size);
3881	if (ret) {
3882		ret = -EFAULT;
3883		goto out;
3884	}
3885
3886out:
3887	btrfs_free_path(path);
3888	free_ipath(ipath);
3889	kfree(ipa);
3890
3891	return ret;
3892}
3893
3894static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
3895{
3896	struct btrfs_data_container *inodes = ctx;
3897	const size_t c = 3 * sizeof(u64);
3898
3899	if (inodes->bytes_left >= c) {
3900		inodes->bytes_left -= c;
3901		inodes->val[inodes->elem_cnt] = inum;
3902		inodes->val[inodes->elem_cnt + 1] = offset;
3903		inodes->val[inodes->elem_cnt + 2] = root;
3904		inodes->elem_cnt += 3;
3905	} else {
3906		inodes->bytes_missing += c - inodes->bytes_left;
3907		inodes->bytes_left = 0;
3908		inodes->elem_missed += 3;
3909	}
3910
3911	return 0;
3912}
3913
3914static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
3915					void __user *arg, int version)
3916{
3917	int ret = 0;
3918	int size;
3919	struct btrfs_ioctl_logical_ino_args *loi;
3920	struct btrfs_data_container *inodes = NULL;
3921	struct btrfs_path *path = NULL;
3922	bool ignore_offset;
3923
3924	if (!capable(CAP_SYS_ADMIN))
3925		return -EPERM;
3926
3927	loi = memdup_user(arg, sizeof(*loi));
3928	if (IS_ERR(loi))
3929		return PTR_ERR(loi);
3930
3931	if (version == 1) {
3932		ignore_offset = false;
3933		size = min_t(u32, loi->size, SZ_64K);
3934	} else {
3935		/* All reserved bits must be 0 for now */
3936		if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
3937			ret = -EINVAL;
3938			goto out_loi;
3939		}
3940		/* Only accept flags we have defined so far */
3941		if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
3942			ret = -EINVAL;
3943			goto out_loi;
3944		}
3945		ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
3946		size = min_t(u32, loi->size, SZ_16M);
3947	}
3948
3949	path = btrfs_alloc_path();
3950	if (!path) {
3951		ret = -ENOMEM;
3952		goto out;
3953	}
3954
3955	inodes = init_data_container(size);
3956	if (IS_ERR(inodes)) {
3957		ret = PTR_ERR(inodes);
3958		inodes = NULL;
3959		goto out;
3960	}
3961
3962	ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
3963					  build_ino_list, inodes, ignore_offset);
3964	if (ret == -EINVAL)
3965		ret = -ENOENT;
3966	if (ret < 0)
3967		goto out;
3968
3969	ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
3970			   size);
3971	if (ret)
3972		ret = -EFAULT;
3973
3974out:
3975	btrfs_free_path(path);
3976	kvfree(inodes);
3977out_loi:
3978	kfree(loi);
3979
3980	return ret;
3981}
3982
3983void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
3984			       struct btrfs_ioctl_balance_args *bargs)
3985{
3986	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3987
3988	bargs->flags = bctl->flags;
3989
3990	if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
3991		bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
3992	if (atomic_read(&fs_info->balance_pause_req))
3993		bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
3994	if (atomic_read(&fs_info->balance_cancel_req))
3995		bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
3996
3997	memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
3998	memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
3999	memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4000
4001	spin_lock(&fs_info->balance_lock);
4002	memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4003	spin_unlock(&fs_info->balance_lock);
4004}
4005
4006static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4007{
4008	struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4009	struct btrfs_fs_info *fs_info = root->fs_info;
4010	struct btrfs_ioctl_balance_args *bargs;
4011	struct btrfs_balance_control *bctl;
4012	bool need_unlock; /* for mut. excl. ops lock */
4013	int ret;
4014
4015	if (!capable(CAP_SYS_ADMIN))
4016		return -EPERM;
4017
4018	ret = mnt_want_write_file(file);
4019	if (ret)
4020		return ret;
4021
4022again:
4023	if (btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
4024		mutex_lock(&fs_info->balance_mutex);
4025		need_unlock = true;
4026		goto locked;
4027	}
4028
4029	/*
4030	 * mut. excl. ops lock is locked.  Three possibilities:
4031	 *   (1) some other op is running
4032	 *   (2) balance is running
4033	 *   (3) balance is paused -- special case (think resume)
4034	 */
4035	mutex_lock(&fs_info->balance_mutex);
4036	if (fs_info->balance_ctl) {
4037		/* this is either (2) or (3) */
4038		if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4039			mutex_unlock(&fs_info->balance_mutex);
4040			/*
4041			 * Lock released to allow other waiters to continue,
4042			 * we'll reexamine the status again.
4043			 */
4044			mutex_lock(&fs_info->balance_mutex);
4045
4046			if (fs_info->balance_ctl &&
4047			    !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4048				/* this is (3) */
4049				need_unlock = false;
4050				goto locked;
4051			}
4052
4053			mutex_unlock(&fs_info->balance_mutex);
4054			goto again;
4055		} else {
4056			/* this is (2) */
4057			mutex_unlock(&fs_info->balance_mutex);
4058			ret = -EINPROGRESS;
4059			goto out;
4060		}
4061	} else {
4062		/* this is (1) */
4063		mutex_unlock(&fs_info->balance_mutex);
4064		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4065		goto out;
4066	}
4067
4068locked:
4069
4070	if (arg) {
4071		bargs = memdup_user(arg, sizeof(*bargs));
4072		if (IS_ERR(bargs)) {
4073			ret = PTR_ERR(bargs);
4074			goto out_unlock;
4075		}
4076
4077		if (bargs->flags & BTRFS_BALANCE_RESUME) {
4078			if (!fs_info->balance_ctl) {
4079				ret = -ENOTCONN;
4080				goto out_bargs;
4081			}
4082
4083			bctl = fs_info->balance_ctl;
4084			spin_lock(&fs_info->balance_lock);
4085			bctl->flags |= BTRFS_BALANCE_RESUME;
4086			spin_unlock(&fs_info->balance_lock);
4087
4088			goto do_balance;
4089		}
4090	} else {
4091		bargs = NULL;
4092	}
4093
4094	if (fs_info->balance_ctl) {
4095		ret = -EINPROGRESS;
4096		goto out_bargs;
4097	}
4098
4099	bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
4100	if (!bctl) {
4101		ret = -ENOMEM;
4102		goto out_bargs;
4103	}
4104
4105	if (arg) {
4106		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
4107		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
4108		memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
4109
4110		bctl->flags = bargs->flags;
4111	} else {
4112		/* balance everything - no filters */
4113		bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
4114	}
4115
4116	if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
4117		ret = -EINVAL;
4118		goto out_bctl;
4119	}
4120
4121do_balance:
4122	/*
4123	 * Ownership of bctl and exclusive operation goes to btrfs_balance.
4124	 * bctl is freed in reset_balance_state, or, if restriper was paused
4125	 * all the way until unmount, in free_fs_info.  The flag should be
4126	 * cleared after reset_balance_state.
4127	 */
4128	need_unlock = false;
4129
4130	ret = btrfs_balance(fs_info, bctl, bargs);
4131	bctl = NULL;
4132
4133	if ((ret == 0 || ret == -ECANCELED) && arg) {
4134		if (copy_to_user(arg, bargs, sizeof(*bargs)))
4135			ret = -EFAULT;
4136	}
4137
4138out_bctl:
4139	kfree(bctl);
4140out_bargs:
4141	kfree(bargs);
4142out_unlock:
4143	mutex_unlock(&fs_info->balance_mutex);
4144	if (need_unlock)
4145		btrfs_exclop_finish(fs_info);
4146out:
4147	mnt_drop_write_file(file);
4148	return ret;
4149}
4150
4151static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
4152{
4153	if (!capable(CAP_SYS_ADMIN))
4154		return -EPERM;
4155
4156	switch (cmd) {
4157	case BTRFS_BALANCE_CTL_PAUSE:
4158		return btrfs_pause_balance(fs_info);
4159	case BTRFS_BALANCE_CTL_CANCEL:
4160		return btrfs_cancel_balance(fs_info);
4161	}
4162
4163	return -EINVAL;
4164}
4165
4166static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
4167					 void __user *arg)
4168{
4169	struct btrfs_ioctl_balance_args *bargs;
4170	int ret = 0;
4171
4172	if (!capable(CAP_SYS_ADMIN))
4173		return -EPERM;
4174
4175	mutex_lock(&fs_info->balance_mutex);
4176	if (!fs_info->balance_ctl) {
4177		ret = -ENOTCONN;
4178		goto out;
4179	}
4180
4181	bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
4182	if (!bargs) {
4183		ret = -ENOMEM;
4184		goto out;
4185	}
4186
4187	btrfs_update_ioctl_balance_args(fs_info, bargs);
4188
4189	if (copy_to_user(arg, bargs, sizeof(*bargs)))
4190		ret = -EFAULT;
4191
4192	kfree(bargs);
4193out:
4194	mutex_unlock(&fs_info->balance_mutex);
4195	return ret;
4196}
4197
4198static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
4199{
4200	struct inode *inode = file_inode(file);
4201	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4202	struct btrfs_ioctl_quota_ctl_args *sa;
4203	int ret;
4204
4205	if (!capable(CAP_SYS_ADMIN))
4206		return -EPERM;
4207
4208	ret = mnt_want_write_file(file);
4209	if (ret)
4210		return ret;
4211
4212	sa = memdup_user(arg, sizeof(*sa));
4213	if (IS_ERR(sa)) {
4214		ret = PTR_ERR(sa);
4215		goto drop_write;
4216	}
4217
4218	down_write(&fs_info->subvol_sem);
4219
4220	switch (sa->cmd) {
4221	case BTRFS_QUOTA_CTL_ENABLE:
4222		ret = btrfs_quota_enable(fs_info);
4223		break;
4224	case BTRFS_QUOTA_CTL_DISABLE:
4225		ret = btrfs_quota_disable(fs_info);
4226		break;
4227	default:
4228		ret = -EINVAL;
4229		break;
4230	}
4231
4232	kfree(sa);
4233	up_write(&fs_info->subvol_sem);
4234drop_write:
4235	mnt_drop_write_file(file);
4236	return ret;
4237}
4238
4239static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
4240{
4241	struct inode *inode = file_inode(file);
4242	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4243	struct btrfs_root *root = BTRFS_I(inode)->root;
4244	struct btrfs_ioctl_qgroup_assign_args *sa;
4245	struct btrfs_trans_handle *trans;
4246	int ret;
4247	int err;
4248
4249	if (!capable(CAP_SYS_ADMIN))
4250		return -EPERM;
4251
4252	ret = mnt_want_write_file(file);
4253	if (ret)
4254		return ret;
4255
4256	sa = memdup_user(arg, sizeof(*sa));
4257	if (IS_ERR(sa)) {
4258		ret = PTR_ERR(sa);
4259		goto drop_write;
4260	}
4261
4262	trans = btrfs_join_transaction(root);
4263	if (IS_ERR(trans)) {
4264		ret = PTR_ERR(trans);
4265		goto out;
4266	}
4267
4268	if (sa->assign) {
4269		ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
4270	} else {
4271		ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
4272	}
4273
4274	/* update qgroup status and info */
4275	err = btrfs_run_qgroups(trans);
4276	if (err < 0)
4277		btrfs_handle_fs_error(fs_info, err,
4278				      "failed to update qgroup status and info");
4279	err = btrfs_end_transaction(trans);
4280	if (err && !ret)
4281		ret = err;
4282
4283out:
4284	kfree(sa);
4285drop_write:
4286	mnt_drop_write_file(file);
4287	return ret;
4288}
4289
4290static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
4291{
4292	struct inode *inode = file_inode(file);
4293	struct btrfs_root *root = BTRFS_I(inode)->root;
4294	struct btrfs_ioctl_qgroup_create_args *sa;
4295	struct btrfs_trans_handle *trans;
4296	int ret;
4297	int err;
4298
4299	if (!capable(CAP_SYS_ADMIN))
4300		return -EPERM;
4301
4302	ret = mnt_want_write_file(file);
4303	if (ret)
4304		return ret;
4305
4306	sa = memdup_user(arg, sizeof(*sa));
4307	if (IS_ERR(sa)) {
4308		ret = PTR_ERR(sa);
4309		goto drop_write;
4310	}
4311
4312	if (!sa->qgroupid) {
4313		ret = -EINVAL;
4314		goto out;
4315	}
4316
4317	trans = btrfs_join_transaction(root);
4318	if (IS_ERR(trans)) {
4319		ret = PTR_ERR(trans);
4320		goto out;
4321	}
4322
4323	if (sa->create) {
4324		ret = btrfs_create_qgroup(trans, sa->qgroupid);
4325	} else {
4326		ret = btrfs_remove_qgroup(trans, sa->qgroupid);
4327	}
4328
4329	err = btrfs_end_transaction(trans);
4330	if (err && !ret)
4331		ret = err;
4332
4333out:
4334	kfree(sa);
4335drop_write:
4336	mnt_drop_write_file(file);
4337	return ret;
4338}
4339
4340static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
4341{
4342	struct inode *inode = file_inode(file);
4343	struct btrfs_root *root = BTRFS_I(inode)->root;
4344	struct btrfs_ioctl_qgroup_limit_args *sa;
4345	struct btrfs_trans_handle *trans;
4346	int ret;
4347	int err;
4348	u64 qgroupid;
4349
4350	if (!capable(CAP_SYS_ADMIN))
4351		return -EPERM;
4352
4353	ret = mnt_want_write_file(file);
4354	if (ret)
4355		return ret;
4356
4357	sa = memdup_user(arg, sizeof(*sa));
4358	if (IS_ERR(sa)) {
4359		ret = PTR_ERR(sa);
4360		goto drop_write;
4361	}
4362
4363	trans = btrfs_join_transaction(root);
4364	if (IS_ERR(trans)) {
4365		ret = PTR_ERR(trans);
4366		goto out;
4367	}
4368
4369	qgroupid = sa->qgroupid;
4370	if (!qgroupid) {
4371		/* take the current subvol as qgroup */
4372		qgroupid = root->root_key.objectid;
4373	}
4374
4375	ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
4376
4377	err = btrfs_end_transaction(trans);
4378	if (err && !ret)
4379		ret = err;
4380
4381out:
4382	kfree(sa);
4383drop_write:
4384	mnt_drop_write_file(file);
4385	return ret;
4386}
4387
4388static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
4389{
4390	struct inode *inode = file_inode(file);
4391	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4392	struct btrfs_ioctl_quota_rescan_args *qsa;
4393	int ret;
4394
4395	if (!capable(CAP_SYS_ADMIN))
4396		return -EPERM;
4397
4398	ret = mnt_want_write_file(file);
4399	if (ret)
4400		return ret;
4401
4402	qsa = memdup_user(arg, sizeof(*qsa));
4403	if (IS_ERR(qsa)) {
4404		ret = PTR_ERR(qsa);
4405		goto drop_write;
4406	}
4407
4408	if (qsa->flags) {
4409		ret = -EINVAL;
4410		goto out;
4411	}
4412
4413	ret = btrfs_qgroup_rescan(fs_info);
4414
4415out:
4416	kfree(qsa);
4417drop_write:
4418	mnt_drop_write_file(file);
4419	return ret;
4420}
4421
4422static long btrfs_ioctl_quota_rescan_status(struct btrfs_fs_info *fs_info,
4423						void __user *arg)
4424{
4425	struct btrfs_ioctl_quota_rescan_args qsa = {0};
4426	int ret = 0;
4427
4428	if (!capable(CAP_SYS_ADMIN))
4429		return -EPERM;
4430
4431	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
4432		qsa.flags = 1;
4433		qsa.progress = fs_info->qgroup_rescan_progress.objectid;
4434	}
4435
4436	if (copy_to_user(arg, &qsa, sizeof(qsa)))
4437		ret = -EFAULT;
4438
4439	return ret;
4440}
4441
4442static long btrfs_ioctl_quota_rescan_wait(struct btrfs_fs_info *fs_info,
4443						void __user *arg)
4444{
4445	if (!capable(CAP_SYS_ADMIN))
4446		return -EPERM;
4447
4448	return btrfs_qgroup_wait_for_completion(fs_info, true);
4449}
4450
4451static long _btrfs_ioctl_set_received_subvol(struct file *file,
4452					    struct user_namespace *mnt_userns,
4453					    struct btrfs_ioctl_received_subvol_args *sa)
4454{
4455	struct inode *inode = file_inode(file);
4456	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4457	struct btrfs_root *root = BTRFS_I(inode)->root;
4458	struct btrfs_root_item *root_item = &root->root_item;
4459	struct btrfs_trans_handle *trans;
4460	struct timespec64 ct = current_time(inode);
4461	int ret = 0;
4462	int received_uuid_changed;
4463
4464	if (!inode_owner_or_capable(mnt_userns, inode))
4465		return -EPERM;
4466
4467	ret = mnt_want_write_file(file);
4468	if (ret < 0)
4469		return ret;
4470
4471	down_write(&fs_info->subvol_sem);
4472
4473	if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
4474		ret = -EINVAL;
4475		goto out;
4476	}
4477
4478	if (btrfs_root_readonly(root)) {
4479		ret = -EROFS;
4480		goto out;
4481	}
4482
4483	/*
4484	 * 1 - root item
4485	 * 2 - uuid items (received uuid + subvol uuid)
4486	 */
4487	trans = btrfs_start_transaction(root, 3);
4488	if (IS_ERR(trans)) {
4489		ret = PTR_ERR(trans);
4490		trans = NULL;
4491		goto out;
4492	}
4493
4494	sa->rtransid = trans->transid;
4495	sa->rtime.sec = ct.tv_sec;
4496	sa->rtime.nsec = ct.tv_nsec;
4497
4498	received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
4499				       BTRFS_UUID_SIZE);
4500	if (received_uuid_changed &&
4501	    !btrfs_is_empty_uuid(root_item->received_uuid)) {
4502		ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
4503					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4504					  root->root_key.objectid);
4505		if (ret && ret != -ENOENT) {
4506		        btrfs_abort_transaction(trans, ret);
4507		        btrfs_end_transaction(trans);
4508		        goto out;
4509		}
4510	}
4511	memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
4512	btrfs_set_root_stransid(root_item, sa->stransid);
4513	btrfs_set_root_rtransid(root_item, sa->rtransid);
4514	btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
4515	btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
4516	btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
4517	btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
4518
4519	ret = btrfs_update_root(trans, fs_info->tree_root,
4520				&root->root_key, &root->root_item);
4521	if (ret < 0) {
4522		btrfs_end_transaction(trans);
4523		goto out;
4524	}
4525	if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
4526		ret = btrfs_uuid_tree_add(trans, sa->uuid,
4527					  BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4528					  root->root_key.objectid);
4529		if (ret < 0 && ret != -EEXIST) {
4530			btrfs_abort_transaction(trans, ret);
4531			btrfs_end_transaction(trans);
4532			goto out;
4533		}
4534	}
4535	ret = btrfs_commit_transaction(trans);
4536out:
4537	up_write(&fs_info->subvol_sem);
4538	mnt_drop_write_file(file);
4539	return ret;
4540}
4541
4542#ifdef CONFIG_64BIT
4543static long btrfs_ioctl_set_received_subvol_32(struct file *file,
4544						void __user *arg)
4545{
4546	struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
4547	struct btrfs_ioctl_received_subvol_args *args64 = NULL;
4548	int ret = 0;
4549
4550	args32 = memdup_user(arg, sizeof(*args32));
4551	if (IS_ERR(args32))
4552		return PTR_ERR(args32);
4553
4554	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
4555	if (!args64) {
4556		ret = -ENOMEM;
4557		goto out;
4558	}
4559
4560	memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
4561	args64->stransid = args32->stransid;
4562	args64->rtransid = args32->rtransid;
4563	args64->stime.sec = args32->stime.sec;
4564	args64->stime.nsec = args32->stime.nsec;
4565	args64->rtime.sec = args32->rtime.sec;
4566	args64->rtime.nsec = args32->rtime.nsec;
4567	args64->flags = args32->flags;
4568
4569	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), args64);
4570	if (ret)
4571		goto out;
4572
4573	memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
4574	args32->stransid = args64->stransid;
4575	args32->rtransid = args64->rtransid;
4576	args32->stime.sec = args64->stime.sec;
4577	args32->stime.nsec = args64->stime.nsec;
4578	args32->rtime.sec = args64->rtime.sec;
4579	args32->rtime.nsec = args64->rtime.nsec;
4580	args32->flags = args64->flags;
4581
4582	ret = copy_to_user(arg, args32, sizeof(*args32));
4583	if (ret)
4584		ret = -EFAULT;
4585
4586out:
4587	kfree(args32);
4588	kfree(args64);
4589	return ret;
4590}
4591#endif
4592
4593static long btrfs_ioctl_set_received_subvol(struct file *file,
4594					    void __user *arg)
4595{
4596	struct btrfs_ioctl_received_subvol_args *sa = NULL;
4597	int ret = 0;
4598
4599	sa = memdup_user(arg, sizeof(*sa));
4600	if (IS_ERR(sa))
4601		return PTR_ERR(sa);
4602
4603	ret = _btrfs_ioctl_set_received_subvol(file, file_mnt_user_ns(file), sa);
4604
4605	if (ret)
4606		goto out;
4607
4608	ret = copy_to_user(arg, sa, sizeof(*sa));
4609	if (ret)
4610		ret = -EFAULT;
4611
4612out:
4613	kfree(sa);
4614	return ret;
4615}
4616
4617static int btrfs_ioctl_get_fslabel(struct btrfs_fs_info *fs_info,
4618					void __user *arg)
4619{
4620	size_t len;
4621	int ret;
4622	char label[BTRFS_LABEL_SIZE];
4623
4624	spin_lock(&fs_info->super_lock);
4625	memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
4626	spin_unlock(&fs_info->super_lock);
4627
4628	len = strnlen(label, BTRFS_LABEL_SIZE);
4629
4630	if (len == BTRFS_LABEL_SIZE) {
4631		btrfs_warn(fs_info,
4632			   "label is too long, return the first %zu bytes",
4633			   --len);
4634	}
4635
4636	ret = copy_to_user(arg, label, len);
4637
4638	return ret ? -EFAULT : 0;
4639}
4640
4641static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
4642{
4643	struct inode *inode = file_inode(file);
4644	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4645	struct btrfs_root *root = BTRFS_I(inode)->root;
4646	struct btrfs_super_block *super_block = fs_info->super_copy;
4647	struct btrfs_trans_handle *trans;
4648	char label[BTRFS_LABEL_SIZE];
4649	int ret;
4650
4651	if (!capable(CAP_SYS_ADMIN))
4652		return -EPERM;
4653
4654	if (copy_from_user(label, arg, sizeof(label)))
4655		return -EFAULT;
4656
4657	if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
4658		btrfs_err(fs_info,
4659			  "unable to set label with more than %d bytes",
4660			  BTRFS_LABEL_SIZE - 1);
4661		return -EINVAL;
4662	}
4663
4664	ret = mnt_want_write_file(file);
4665	if (ret)
4666		return ret;
4667
4668	trans = btrfs_start_transaction(root, 0);
4669	if (IS_ERR(trans)) {
4670		ret = PTR_ERR(trans);
4671		goto out_unlock;
4672	}
4673
4674	spin_lock(&fs_info->super_lock);
4675	strcpy(super_block->label, label);
4676	spin_unlock(&fs_info->super_lock);
4677	ret = btrfs_commit_transaction(trans);
4678
4679out_unlock:
4680	mnt_drop_write_file(file);
4681	return ret;
4682}
4683
4684#define INIT_FEATURE_FLAGS(suffix) \
4685	{ .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
4686	  .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
4687	  .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
4688
4689int btrfs_ioctl_get_supported_features(void __user *arg)
4690{
4691	static const struct btrfs_ioctl_feature_flags features[3] = {
4692		INIT_FEATURE_FLAGS(SUPP),
4693		INIT_FEATURE_FLAGS(SAFE_SET),
4694		INIT_FEATURE_FLAGS(SAFE_CLEAR)
4695	};
4696
4697	if (copy_to_user(arg, &features, sizeof(features)))
4698		return -EFAULT;
4699
4700	return 0;
4701}
4702
4703static int btrfs_ioctl_get_features(struct btrfs_fs_info *fs_info,
4704					void __user *arg)
4705{
4706	struct btrfs_super_block *super_block = fs_info->super_copy;
4707	struct btrfs_ioctl_feature_flags features;
4708
4709	features.compat_flags = btrfs_super_compat_flags(super_block);
4710	features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
4711	features.incompat_flags = btrfs_super_incompat_flags(super_block);
4712
4713	if (copy_to_user(arg, &features, sizeof(features)))
4714		return -EFAULT;
4715
4716	return 0;
4717}
4718
4719static int check_feature_bits(struct btrfs_fs_info *fs_info,
4720			      enum btrfs_feature_set set,
4721			      u64 change_mask, u64 flags, u64 supported_flags,
4722			      u64 safe_set, u64 safe_clear)
4723{
4724	const char *type = btrfs_feature_set_name(set);
4725	char *names;
4726	u64 disallowed, unsupported;
4727	u64 set_mask = flags & change_mask;
4728	u64 clear_mask = ~flags & change_mask;
4729
4730	unsupported = set_mask & ~supported_flags;
4731	if (unsupported) {
4732		names = btrfs_printable_features(set, unsupported);
4733		if (names) {
4734			btrfs_warn(fs_info,
4735				   "this kernel does not support the %s feature bit%s",
4736				   names, strchr(names, ',') ? "s" : "");
4737			kfree(names);
4738		} else
4739			btrfs_warn(fs_info,
4740				   "this kernel does not support %s bits 0x%llx",
4741				   type, unsupported);
4742		return -EOPNOTSUPP;
4743	}
4744
4745	disallowed = set_mask & ~safe_set;
4746	if (disallowed) {
4747		names = btrfs_printable_features(set, disallowed);
4748		if (names) {
4749			btrfs_warn(fs_info,
4750				   "can't set the %s feature bit%s while mounted",
4751				   names, strchr(names, ',') ? "s" : "");
4752			kfree(names);
4753		} else
4754			btrfs_warn(fs_info,
4755				   "can't set %s bits 0x%llx while mounted",
4756				   type, disallowed);
4757		return -EPERM;
4758	}
4759
4760	disallowed = clear_mask & ~safe_clear;
4761	if (disallowed) {
4762		names = btrfs_printable_features(set, disallowed);
4763		if (names) {
4764			btrfs_warn(fs_info,
4765				   "can't clear the %s feature bit%s while mounted",
4766				   names, strchr(names, ',') ? "s" : "");
4767			kfree(names);
4768		} else
4769			btrfs_warn(fs_info,
4770				   "can't clear %s bits 0x%llx while mounted",
4771				   type, disallowed);
4772		return -EPERM;
4773	}
4774
4775	return 0;
4776}
4777
4778#define check_feature(fs_info, change_mask, flags, mask_base)	\
4779check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,	\
4780		   BTRFS_FEATURE_ ## mask_base ## _SUPP,	\
4781		   BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,	\
4782		   BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
4783
4784static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
4785{
4786	struct inode *inode = file_inode(file);
4787	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4788	struct btrfs_root *root = BTRFS_I(inode)->root;
4789	struct btrfs_super_block *super_block = fs_info->super_copy;
4790	struct btrfs_ioctl_feature_flags flags[2];
4791	struct btrfs_trans_handle *trans;
4792	u64 newflags;
4793	int ret;
4794
4795	if (!capable(CAP_SYS_ADMIN))
4796		return -EPERM;
4797
4798	if (copy_from_user(flags, arg, sizeof(flags)))
4799		return -EFAULT;
4800
4801	/* Nothing to do */
4802	if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
4803	    !flags[0].incompat_flags)
4804		return 0;
4805
4806	ret = check_feature(fs_info, flags[0].compat_flags,
4807			    flags[1].compat_flags, COMPAT);
4808	if (ret)
4809		return ret;
4810
4811	ret = check_feature(fs_info, flags[0].compat_ro_flags,
4812			    flags[1].compat_ro_flags, COMPAT_RO);
4813	if (ret)
4814		return ret;
4815
4816	ret = check_feature(fs_info, flags[0].incompat_flags,
4817			    flags[1].incompat_flags, INCOMPAT);
4818	if (ret)
4819		return ret;
4820
4821	ret = mnt_want_write_file(file);
4822	if (ret)
4823		return ret;
4824
4825	trans = btrfs_start_transaction(root, 0);
4826	if (IS_ERR(trans)) {
4827		ret = PTR_ERR(trans);
4828		goto out_drop_write;
4829	}
4830
4831	spin_lock(&fs_info->super_lock);
4832	newflags = btrfs_super_compat_flags(super_block);
4833	newflags |= flags[0].compat_flags & flags[1].compat_flags;
4834	newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
4835	btrfs_set_super_compat_flags(super_block, newflags);
4836
4837	newflags = btrfs_super_compat_ro_flags(super_block);
4838	newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
4839	newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
4840	btrfs_set_super_compat_ro_flags(super_block, newflags);
4841
4842	newflags = btrfs_super_incompat_flags(super_block);
4843	newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
4844	newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
4845	btrfs_set_super_incompat_flags(super_block, newflags);
4846	spin_unlock(&fs_info->super_lock);
4847
4848	ret = btrfs_commit_transaction(trans);
4849out_drop_write:
4850	mnt_drop_write_file(file);
4851
4852	return ret;
4853}
4854
4855static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
4856{
4857	struct btrfs_ioctl_send_args *arg;
4858	int ret;
4859
4860	if (compat) {
4861#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4862		struct btrfs_ioctl_send_args_32 args32;
4863
4864		ret = copy_from_user(&args32, argp, sizeof(args32));
4865		if (ret)
4866			return -EFAULT;
4867		arg = kzalloc(sizeof(*arg), GFP_KERNEL);
4868		if (!arg)
4869			return -ENOMEM;
4870		arg->send_fd = args32.send_fd;
4871		arg->clone_sources_count = args32.clone_sources_count;
4872		arg->clone_sources = compat_ptr(args32.clone_sources);
4873		arg->parent_root = args32.parent_root;
4874		arg->flags = args32.flags;
4875		memcpy(arg->reserved, args32.reserved,
4876		       sizeof(args32.reserved));
4877#else
4878		return -ENOTTY;
4879#endif
4880	} else {
4881		arg = memdup_user(argp, sizeof(*arg));
4882		if (IS_ERR(arg))
4883			return PTR_ERR(arg);
4884	}
4885	ret = btrfs_ioctl_send(file, arg);
4886	kfree(arg);
4887	return ret;
4888}
4889
4890long btrfs_ioctl(struct file *file, unsigned int
4891		cmd, unsigned long arg)
4892{
4893	struct inode *inode = file_inode(file);
4894	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4895	struct btrfs_root *root = BTRFS_I(inode)->root;
4896	void __user *argp = (void __user *)arg;
4897
4898	switch (cmd) {
4899	case FS_IOC_GETVERSION:
4900		return btrfs_ioctl_getversion(file, argp);
4901	case FS_IOC_GETFSLABEL:
4902		return btrfs_ioctl_get_fslabel(fs_info, argp);
4903	case FS_IOC_SETFSLABEL:
4904		return btrfs_ioctl_set_fslabel(file, argp);
4905	case FITRIM:
4906		return btrfs_ioctl_fitrim(fs_info, argp);
4907	case BTRFS_IOC_SNAP_CREATE:
4908		return btrfs_ioctl_snap_create(file, argp, 0);
4909	case BTRFS_IOC_SNAP_CREATE_V2:
4910		return btrfs_ioctl_snap_create_v2(file, argp, 0);
4911	case BTRFS_IOC_SUBVOL_CREATE:
4912		return btrfs_ioctl_snap_create(file, argp, 1);
4913	case BTRFS_IOC_SUBVOL_CREATE_V2:
4914		return btrfs_ioctl_snap_create_v2(file, argp, 1);
4915	case BTRFS_IOC_SNAP_DESTROY:
4916		return btrfs_ioctl_snap_destroy(file, argp, false);
4917	case BTRFS_IOC_SNAP_DESTROY_V2:
4918		return btrfs_ioctl_snap_destroy(file, argp, true);
4919	case BTRFS_IOC_SUBVOL_GETFLAGS:
4920		return btrfs_ioctl_subvol_getflags(file, argp);
4921	case BTRFS_IOC_SUBVOL_SETFLAGS:
4922		return btrfs_ioctl_subvol_setflags(file, argp);
4923	case BTRFS_IOC_DEFAULT_SUBVOL:
4924		return btrfs_ioctl_default_subvol(file, argp);
4925	case BTRFS_IOC_DEFRAG:
4926		return btrfs_ioctl_defrag(file, NULL);
4927	case BTRFS_IOC_DEFRAG_RANGE:
4928		return btrfs_ioctl_defrag(file, argp);
4929	case BTRFS_IOC_RESIZE:
4930		return btrfs_ioctl_resize(file, argp);
4931	case BTRFS_IOC_ADD_DEV:
4932		return btrfs_ioctl_add_dev(fs_info, argp);
4933	case BTRFS_IOC_RM_DEV:
4934		return btrfs_ioctl_rm_dev(file, argp);
4935	case BTRFS_IOC_RM_DEV_V2:
4936		return btrfs_ioctl_rm_dev_v2(file, argp);
4937	case BTRFS_IOC_FS_INFO:
4938		return btrfs_ioctl_fs_info(fs_info, argp);
4939	case BTRFS_IOC_DEV_INFO:
4940		return btrfs_ioctl_dev_info(fs_info, argp);
4941	case BTRFS_IOC_BALANCE:
4942		return btrfs_ioctl_balance(file, NULL);
4943	case BTRFS_IOC_TREE_SEARCH:
4944		return btrfs_ioctl_tree_search(file, argp);
4945	case BTRFS_IOC_TREE_SEARCH_V2:
4946		return btrfs_ioctl_tree_search_v2(file, argp);
4947	case BTRFS_IOC_INO_LOOKUP:
4948		return btrfs_ioctl_ino_lookup(file, argp);
4949	case BTRFS_IOC_INO_PATHS:
4950		return btrfs_ioctl_ino_to_path(root, argp);
4951	case BTRFS_IOC_LOGICAL_INO:
4952		return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
4953	case BTRFS_IOC_LOGICAL_INO_V2:
4954		return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
4955	case BTRFS_IOC_SPACE_INFO:
4956		return btrfs_ioctl_space_info(fs_info, argp);
4957	case BTRFS_IOC_SYNC: {
4958		int ret;
4959
4960		ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false);
4961		if (ret)
4962			return ret;
4963		ret = btrfs_sync_fs(inode->i_sb, 1);
4964		/*
4965		 * The transaction thread may want to do more work,
4966		 * namely it pokes the cleaner kthread that will start
4967		 * processing uncleaned subvols.
4968		 */
4969		wake_up_process(fs_info->transaction_kthread);
4970		return ret;
4971	}
4972	case BTRFS_IOC_START_SYNC:
4973		return btrfs_ioctl_start_sync(root, argp);
4974	case BTRFS_IOC_WAIT_SYNC:
4975		return btrfs_ioctl_wait_sync(fs_info, argp);
4976	case BTRFS_IOC_SCRUB:
4977		return btrfs_ioctl_scrub(file, argp);
4978	case BTRFS_IOC_SCRUB_CANCEL:
4979		return btrfs_ioctl_scrub_cancel(fs_info);
4980	case BTRFS_IOC_SCRUB_PROGRESS:
4981		return btrfs_ioctl_scrub_progress(fs_info, argp);
4982	case BTRFS_IOC_BALANCE_V2:
4983		return btrfs_ioctl_balance(file, argp);
4984	case BTRFS_IOC_BALANCE_CTL:
4985		return btrfs_ioctl_balance_ctl(fs_info, arg);
4986	case BTRFS_IOC_BALANCE_PROGRESS:
4987		return btrfs_ioctl_balance_progress(fs_info, argp);
4988	case BTRFS_IOC_SET_RECEIVED_SUBVOL:
4989		return btrfs_ioctl_set_received_subvol(file, argp);
4990#ifdef CONFIG_64BIT
4991	case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
4992		return btrfs_ioctl_set_received_subvol_32(file, argp);
4993#endif
4994	case BTRFS_IOC_SEND:
4995		return _btrfs_ioctl_send(file, argp, false);
4996#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
4997	case BTRFS_IOC_SEND_32:
4998		return _btrfs_ioctl_send(file, argp, true);
4999#endif
5000	case BTRFS_IOC_GET_DEV_STATS:
5001		return btrfs_ioctl_get_dev_stats(fs_info, argp);
5002	case BTRFS_IOC_QUOTA_CTL:
5003		return btrfs_ioctl_quota_ctl(file, argp);
5004	case BTRFS_IOC_QGROUP_ASSIGN:
5005		return btrfs_ioctl_qgroup_assign(file, argp);
5006	case BTRFS_IOC_QGROUP_CREATE:
5007		return btrfs_ioctl_qgroup_create(file, argp);
5008	case BTRFS_IOC_QGROUP_LIMIT:
5009		return btrfs_ioctl_qgroup_limit(file, argp);
5010	case BTRFS_IOC_QUOTA_RESCAN:
5011		return btrfs_ioctl_quota_rescan(file, argp);
5012	case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5013		return btrfs_ioctl_quota_rescan_status(fs_info, argp);
5014	case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5015		return btrfs_ioctl_quota_rescan_wait(fs_info, argp);
5016	case BTRFS_IOC_DEV_REPLACE:
5017		return btrfs_ioctl_dev_replace(fs_info, argp);
5018	case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5019		return btrfs_ioctl_get_supported_features(argp);
5020	case BTRFS_IOC_GET_FEATURES:
5021		return btrfs_ioctl_get_features(fs_info, argp);
5022	case BTRFS_IOC_SET_FEATURES:
5023		return btrfs_ioctl_set_features(file, argp);
5024	case BTRFS_IOC_GET_SUBVOL_INFO:
5025		return btrfs_ioctl_get_subvol_info(file, argp);
5026	case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5027		return btrfs_ioctl_get_subvol_rootref(file, argp);
5028	case BTRFS_IOC_INO_LOOKUP_USER:
5029		return btrfs_ioctl_ino_lookup_user(file, argp);
5030	case FS_IOC_ENABLE_VERITY:
5031		return fsverity_ioctl_enable(file, (const void __user *)argp);
5032	case FS_IOC_MEASURE_VERITY:
5033		return fsverity_ioctl_measure(file, argp);
5034	}
5035
5036	return -ENOTTY;
5037}
5038
5039#ifdef CONFIG_COMPAT
5040long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
5041{
5042	/*
5043	 * These all access 32-bit values anyway so no further
5044	 * handling is necessary.
5045	 */
5046	switch (cmd) {
5047	case FS_IOC32_GETVERSION:
5048		cmd = FS_IOC_GETVERSION;
5049		break;
5050	}
5051
5052	return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
5053}
5054#endif
5055